JP2004360777A

JP2004360777A - Transmission

Info

Publication number: JP2004360777A
Application number: JP2003158911A
Authority: JP
Inventors: Kazunori Sato; 和範佐藤; Tadahiko Miyazawa; 忠彦宮澤; Mutsuo Nishimoto; 睦男西本; Masanori Ishihara; 正紀石原; Toshifumi Yamakawa; 敏文山川; Yuichi Kimura; 勇一木村
Original assignee: Isuzu Motors Ltd
Current assignee: Isuzu Motors Ltd
Priority date: 2003-06-04
Filing date: 2003-06-04
Publication date: 2004-12-24

Abstract

【課題】遊星歯車機構を構成する回転要素の一つに非接触で制動力を与えることができかつ駆動力の伝達性能を向上させること。
【解決手段】入力軸２と出力軸３との間に配設された第１〜第３の遊星歯車機構４１〜４３を備えている変速装置。該装置は、各遊星歯車機構の回転要素の一つに連結された第１〜第３の制動ドラム４１Ｄ〜４３Ｄと、各制動ドラムの外周側に軸方向のみに移動可能に配設された磁石手段５００と、磁石手段５００を軸方向に移動させて、制動ドラムの外周面と対向する第１〜第４の制動位置と制動ドラムの外周面と対向しない制動解除位置に位置付ける磁石作動手段６とを備えている。磁石手段５００は複数個の永久磁石５５０を備え、永久磁石５５０の各々は第１及び第２の磁極部５５０ａ及び５５０ｂと、第１及び第２の磁極部５５０ａ及び５５０ｂを接続するよう配設された橋絡部５５０ｃとからなる。
【選択図】図１An object of the present invention is to provide a non-contact braking force to one of the rotating elements constituting a planetary gear mechanism, and to improve the driving force transmission performance.
A transmission device includes first to third planetary gear mechanisms (41 to 43) disposed between an input shaft (2) and an output shaft (3). The apparatus includes first to third brake drums 41D to 43D connected to one of the rotating elements of each planetary gear mechanism, and a magnet arranged on the outer peripheral side of each brake drum so as to be movable only in the axial direction. Means 500 and magnet actuating means 6 for moving magnet means 500 in the axial direction so as to be positioned at first to fourth braking positions facing the outer peripheral surface of the braking drum and at a braking release position not facing the outer peripheral surface of the braking drum. It has. The magnet means 500 includes a plurality of permanent magnets 550, each of which is arranged to connect the first and second magnetic pole portions 550a and 550b with the first and second magnetic pole portions 550a and 550b. 550c.
[Selection diagram] Fig. 1

Description

【０００１】
【発明の属する技術分野】
本発明は、車両等に搭載する変速装置、更に詳しくは遊星歯車機構を備えた変速装置に関する。
【０００２】
【従来の技術】
遊星歯車機構は、サンギヤと、サンギヤと同心に配設されたリングギヤと、リングギヤとサンギヤとに噛み合うプラネタリギヤ、及びプラネタリギヤを支持するプラネタリキャリア等の回転要素からなっている。このような遊星歯車機構は、サンギヤとリングギヤ及びプラネタリキャリアの何れか一つを固定し、残りの一方を入力側に他方を出力側にそれぞれ伝動連結することにより、入力側に伝達された動力を遊星歯車機構を介して出力側に伝達することができる。このような遊星歯車機構を備えた動力伝達装置、例えば変速装置において、遊星歯車機構を構成するサンギヤとリングギヤ及びプラネタリキャリアの何れか一つを固定する手段として、従来はブレーキバンドまたは多板ディスクブレーキが一般に用いられている。而して、ブレーキバンド及び多板ディスクブレーキは回転力を摩擦力によって制動するため、磨耗が発生し耐久性の面で問題がある。
【０００３】
上記事実に基づいて、遊星歯車機構を構成する回転要素の一つに非接触で制動力を与えることができる変速装置が、本出願人であるいすゞ自動車株式会社によって既に提案されている（特許文献１参照）。特許文献１に開示された変速装置は、原動機の動力によって駆動させられる入力軸と、入力軸と同一軸上に配設された出力軸と、入力軸と出力軸との間に配設された第１、第２、第３及び第４の遊星歯車機構を備えている。この変速装置は更に、第１、第２、第３及び第４の遊星歯車機構をそれぞれ構成する回転要素の一つに連結された制動ドラムと、各制動ドラムの外周側に回転が規制され軸方向に移動可能に配設された磁石手段と、磁石手段を軸方向に移動させ、各制動ドラムの外周面とそれぞれ対向する制動位置と各制動ドラムの外周面と対向しない制動解除位置に位置付ける磁石作動手段とを備えている。以上の構成により、４段変速が可能な変速装置が得られる。
【０００４】
上記変速装置によれば、磁石手段を制動ドラムの外周面と対向する制動位置に位置付けることにより、磁石手段と制動ドラムとの相対速度差によって制動ドラムの外周面に渦電流を生じさせ、制動ドラムすなわち回転要素の一つに制動力を与えることができる。この結果、機械的な接触をすることなく遊星歯車機構を機能させ動力伝達を行うことができるので、磨耗が無く耐久性に優れた変速装置を得ることができる。また、上記変速装置を車両に搭載した場合には、入力軸を原動機に直接連結しても車両を発進駆動させることができ、車両を発進するために用いられている摩擦クラッチやトルクコンバータ等の流体継手を除去することが可能となる。
【０００５】
【特許文献１】
特開２００１−１５３１９１号公報（第４−第５頁、図７）
【０００６】
【発明が解決しようとする課題】
しかしながら上記変速装置には次のような問題が存在することが判明した。
（１）第１、第２、第３及び第４の遊星歯車機構を配列することにより、４段変速が可能な変速装置を得るよう構成されているので、部品点数が多く、全体の構成が複雑となり、重量が重く、コストアップとなる。
（２）変速装置を高速段側で作動させる場合には、比較的多数のギヤを駆動しなければ出力軸に動力を伝達できないので、駆動効率が低下し、実用的には好ましくない。更に具体的には変速装置を３速で作動させる場合には、第１、第２及び第３の遊星歯車機構を駆動する必要があり、また変速装置を４速で作動させる場合には、第１、第２、第３及び第４の遊星歯車機構を駆動する必要がある。その結果、駆動効率が大きく低下するので、該装置を実用化するためには、駆動効率を改善する必要がある。
（３）他方、変速装置を低速段側で作動させる場合には、更に具体的には変速装置を１速又は２速で作動させる場合には、３速及び４速用の遊星歯車機構である第３及び第４の遊星歯車機構の回転要素の一つである制動ドラムが高速で空転させられる。その結果、駆動エネルギーのロスが増加し、駆動効率が大きく低下するので、該装置を実用化するためには、駆動エネルギーのロスを少なくする必要がある。
【０００７】
上記事実に基づいて本発明者は鋭意研究を行った結果、次に記載する変速装置によれば、上記技術的課題を解決することができると考えた。この変速装置は、入力軸と出力軸との間に配設された第１、第２及び第３の遊星歯車機構と、導電性材料からなる第１、第２及び第３の制動ドラムと、各制動ドラムの外周側に軸方向のみに移動可能に配設された磁石手段と、磁石手段を移動させて、制動ドラムの外周面と対向する第１、第２、第３及び第４の制動位置と制動ドラムの外周面と対向しない制動解除位置に位置付ける磁石作動手段とを備えている。入力軸には、各遊星歯車機構のサンギヤを備えたサンギヤユニットがワンウエイクラッチを介して連結されかつ第３の遊星歯車機構のプラネタリキャリアが連結され、第３の遊星歯車機構のリングギヤには第３の制動ドラムが、第２の遊星歯車機構のリングギヤには第２の制動ドラムが連結され、第１の遊星歯車機構のリングギヤには第１の制動ドラム及び第２の遊星歯車機構のプラネタリキャリアが連結され、第１の遊星歯車機構のプラネタリキャリアは出力軸に連結されている。磁石手段が、第１の制動位置に位置付けられると第１の制動ドラムの外周面に対向し、第２の制動位置に位置付けられると第２の制動ドラムの外周面に対向し、第３の制動位置に位置付けられると第３の制動ドラム及び第１の制動ドラムの外周面に対向し、第４の制動位置に位置付けられると第３の制動ドラム及び第２の制動ドラムの外周面に対向する。
【０００８】
第１、第２及び第３の遊星歯車機構を配列することにより、４段変速が可能な上記変速装置によれば、先に述べた（１）〜（３）の技術的課題を解決することが可能になった。しかしながら、上記変速装置には更に別の問題が存在することが判明した。すなわち、各変速段において、制動ドラムに作用する制動力を増大するほど入力軸から出力軸への駆動力の伝達性能が向上するが、制動ドラムに作用する制動力を増大するためには、磁石の磁力を強化する必要がある。磁石が永久磁石からなる場合には、永久磁石の各々における磁極面間の距離を増加させる必要がある。しかしながら、永久磁石の各々における磁極面は半径方向に向けられているため、磁極面間の距離を増加させた場合には、永久磁石の各々の半径方向寸法が増加するので変速装置全体の半径方向寸法が増加し、変速装置をコンパクト化できなくなると共に重量が増加し、車両への搭載上不利となる。
【０００９】
本発明の目的は、永久磁石の半径方向寸法を増加させることなく、永久磁石の磁力を強化することを可能にし、その結果、駆動力の伝達性能を向上させることを可能にする、新規な変速装置を提供することである。
【００１０】
本発明の他の目的は、永久磁石の半径方向寸法を増加させることなく、しかも半径方向内側に向けられた、永久磁石の磁極面の面積を増加させることなく、永久磁石の磁力を強化することを可能にし、その結果、駆動力の伝達性能を向上させることを可能にする、新規な変速装置を提供することである。
【００１１】
【課題を解決するための手段】
本発明によれば、入力軸と出力軸との間に配設された第１、第２及び第３の遊星歯車機構を備えている変速装置において、
導電性材料からなる第１、第２及び第３の制動ドラムと、各制動ドラムの外周側に軸方向のみに移動可能に配設された磁石手段と、磁石手段を移動させて、制動ドラムの外周面と対向する第１、第２、第３及び第４の制動位置と制動ドラムの外周面と対向しない制動解除位置に位置付ける磁石作動手段とを備え、
入力軸には、各遊星歯車機構のサンギヤを備えたサンギヤユニットがワンウエイクラッチを介して連結されかつ第３の遊星歯車機構のプラネタリキャリアが連結され、第３の遊星歯車機構のリングギヤには第３の制動ドラムが、第２の遊星歯車機構のリングギヤには第２の制動ドラムが連結され、第１の遊星歯車機構のリングギヤには第１の制動ドラム及び第２の遊星歯車機構のプラネタリキャリアが連結され、第１の遊星歯車機構のプラネタリキャリアは出力軸に連結され、
磁石手段は、磁石支持手段と、相互に周方向に間隔をおいて磁石支持手段に配設された複数個の永久磁石とを備え、永久磁石の各々は、軸方向に延在する本体部と、本体部の軸方向両端からそれぞれ半径方向内側に延び出す第１及び第２の磁極部からなり、永久磁石の各々において、第１及び第２の磁極部は、半径方向内側に向けられた、相互に異極をなす異極面を有し、周方向に相互に隣り合う永久磁石の各々における、第１の磁極部の磁極面同士及び第２の磁極部の磁極面同士は相互に異極をなし、
磁石手段が、第１の制動位置に位置付けられると永久磁石の各々の第１の磁極部の磁極面が第１の制動ドラムの外周面に対向し、第２の制動位置に位置付けられると第１の磁極部の磁極面が第２の制動ドラムの外周面に対向し、第３の制動位置に位置付けられると第１の磁極部の磁極面が第３の制動ドラムに対向しかつ第２の磁極部の磁極面が第１の制動ドラムの外周面に対向し、第４の制動位置に位置付けられると第１の磁極部の磁極面が第３の制動ドラムに対向しかつ第２の磁極部の磁極面が第２の制動ドラムの外周面に対向する、
ことを特徴とする変速装置、が提供される。
【００１２】
第１の制動ドラムに隣接して中立ドラムが配設され、磁石手段が制動解除位置に位置付けられると、永久磁石の各々の第１の磁極部の磁極面及び第２の磁極部の磁極面が中立ドラムの外周面に対向する、ことが好ましい。
入力軸の回転を逆転して出力軸に伝達する第４の遊星歯車機構が備えられ、第４の遊星歯車機構は、リングギヤと、該リングギヤ及び第１の遊星歯車機構のプラネタリギヤに噛み合わされたプラネタリギヤと、第１の遊星歯車機構のプラネタリキャリアに連結されたプラネタリキャリアと、該リングギヤに連結された導電性材料からなる第４の制動ドラムとを備え、磁石作動手段は、磁石手段を移動させて、第４の制動ドラムの外周面と対向する第５の制動位置に位置付けるよう構成され、磁石手段が、第５の制動位置に位置付けられると永久磁石の各々の第２の磁極部の磁極面が第５の制動ドラムの外周面に対向する、ことが好ましい。
第１の制動ドラムと第４の制動ドラムとの間には磁性材からなる中立ドラムが配設され、磁石手段が第５の制動位置に位置付けられると第２の磁極部の磁極面が第５の制動ドラムに対向しかつ第１の磁極部の磁極面が中立ドラムの外周面に対向する、ことが好ましい。
【００１３】
【発明の実施の形態】
以下、本発明による変速装置の好適実施形態を図示している添付図面を参照して、更に詳細に説明する。図１には、本発明による変速装置の実施形態の概略構成図が示されている。図１に示す変速装置は、図示しない車両に搭載されており、原動機の動力によって駆動される入力軸２と、入力軸２と同一軸上に配設された出力軸３と、入力軸２と出力軸３との間に配設された第１の遊星歯車機構４１、第２の遊星歯車機構４２、第３の遊星歯車機構４３及び第４の遊星歯車機構４４とを備えている。第１、第２及び第３の遊星歯車機構４１、４２及び４３は、出力軸３側から入力軸２側に向かってこの順に配列され、第４の遊星歯車機構４４は、第１の遊星歯車機構４１の、出力軸３側に配置されている。入力軸２には、ワンウエイクラッチ２１を介してサンギヤユニット２２が連結されている。入力軸２には、入力軸２よりも大径のボス部２ａが設けられている。ボス部２ａには入力軸２と共通の軸線を有する嵌合孔が形成され、該嵌合孔にワンウエイクラッチ２１の外輪が嵌合されて一体に連結されている。ボス部２ａの一部は、第３の遊星歯車機構４３のプラネタリキャリア４３ｄを構成している。サンギヤユニット２２は、中心軸部２２Ａと、中心軸部２２Ａの外周部に軸方向に間隔をおいて一体に配設されたサンギヤ４１ａ、４２ａ及び４３ａとを備えている。サンギヤユニット２２の中心軸部２２Ａは、ワンウエイクラッチ２１の内輪又は中心軸に一体に連結されている。
【００１４】
第１の遊星歯車機構４１は、上記サンギヤ４１ａ、サンギヤ４１ａと同心に配設されたリングギヤ４１ｂ、サンギヤ４１ａとリングギヤ４１ｂとに噛み合わされたプラネタリギヤ４１ｃ、及びプラネタリキャリア４１ｄの各回転要素を備えている。プラネタリギヤ４１ｃはプラネタリキャリア４１ｄに回転自在に支持されている。第２の遊星歯車機構４２は、上記サンギヤ４２ａ、サンギヤ４２ａと同心に配設されたリングギヤ４２ｂ、サンギヤ４２ａとリングギヤ４２ｂとに噛み合わされたプラネタリギヤ４２ｃ、及びプラネタリキャリア４２ｄの各回転要素を備えている。プラネタリギヤ４２ｃはプラネタリキャリア４２ｄに回転自在に支持されている。第３の遊星歯車機構４３は、上記サンギヤ４３ａ、サンギヤ４３ａと同心に配設されたリングギヤ４３ｂ、サンギヤ４３ａとリングギヤ４３ｂとに噛み合わされたプラネタリギヤ４３ｃ、及びプラネタリキャリア４３ｄの各回転要素を備えている。プラネタリギヤ４３ｃはプラネタリキャリア４３ｄに回転自在に支持されている。第４の遊星歯車機構４４は、入力軸２及び出力軸３と共通の軸線上に配置されたリングギヤ４４ｂ、リングギヤ４４ｂと第１の遊星歯車機構４１のプラネタリギヤ４１ｃとに噛み合わされたプラネタリギヤ４４ｃ、及び第１の遊星歯車機構４１のプラネタリキャリア４１ｄに一体に連結されたプラネタリキャリア４４ｄの各回転要素を備えている。プラネタリギヤ４４ｃはプラネタリキャリア４４ｄに回転自在に支持されている。
【００１５】
第１の遊星歯車機構４１のプラネタリキャリア４１ｄは出力軸３に一体に連結され、プラネタリギヤ４１ｃは、図示の実施形態においては歯幅が比較的広く形成されている。第１の遊星歯車機構４１のリングギヤ４１ｂには第１の制動ドラム４１Ｄと第２の遊星歯車機構４２のプラネタリキャリア４２ｄとが一体に連結されている。第２の遊星歯車機構４２のリングギヤ４２ｂには第２の制動ドラム４２Ｄが一体に連結されている。第３の遊星歯車機構４３のリングギヤ４３ｂには第３の制動ドラム４３Ｄが一体に連結されている。第３の遊星歯車機構４３のプラネタリキャリア４３ｄは、先に述べたとおりにして入力軸２に一体に連結されている。第４の遊星歯車機構４４のリングギヤ４４ｂには第４の制動ドラム４４Ｄが一体に連結されている。入力軸２及び出力軸３と共通の軸線を有する第１、第２、第３及び第４の制動ドラム４１Ｄ、４２Ｄ、４３Ｄ及び４４Ｄは、それぞれ、リングギヤ４１ｂ、４２ｂ及び４３ｂの外周側、すなわち半径方向外側位置に配置されている。第１、第２及び第３の制動ドラム４１Ｄ、４２Ｄ及び４３Ｄは、出力軸３側から入力軸２側に向かってこの順に、軸方向に相互に比較的小さな一定の間隔をおいて配列され、第４の制動ドラム４４Ｄは、第１の制動ドラム４１Ｄの、出力軸３側に比較的大きな軸方向間隔をおいて配置されている。第１、第２、第３及び第４の制動ドラム４１Ｄ、４２Ｄ、４３Ｄ及び４４Ｄは、それぞれ導電性材料（例えば、銅、アルミニウム、鉄、鋼など）から形成され、それぞれ実質的に同じ外径寸法を有するよう形成されている。これらの制動ドラムを、磁性材である鉄や鋼よりも優れた導電性を有する銅、アルミニウムなどにより形成することは、後述する磁石手段５０００との間に相対回転が生じた場合、表面に発生する渦電流が鉄や鋼に較べて大きくなって上記ドラムの制動効率が向上するので好ましいといえる。
【００１６】
第１の制動ドラム４１Ｄに対し軸方向に隣接した位置（第１の制動ドラム４１Ｄの、第２の制動ドラム４２Ｄと軸方向反対側に隣接した位置）には、中立ドラム４５Ｄが配設されている。中立ドラム４５Ｄは磁性材から形成されている。図示の実施形態において、第４の遊星歯車機構４４のリングギヤ４４ｂは、比較的広い軸方向幅を有する円筒部を備えている。中立ドラム４５Ｄは、該円筒部の外周面の幅方向のほぼ全域を覆うよう、該円筒部の外周面に、相対回転を許容する周知の部材、例えば、コロあるいは軸受部材を介して相対回転可能に支持されている（実施形態においてはコロが図示されている）。リングギヤ４４ｂの軸方向幅が比較的広いことに起因して、第１の制動ドラム４１Ｄと第４の制動ドラム４４Ｄとの間には、所定の軸方向間隔（比較的大きな間隔）が設けられ、該間隔内に中立ドラム４５Ｄが配設されている。中立ドラム４５Ｄの外径寸法も他の制動ドラムと実質的に同じに規定されている。第４の制動ドラム４４Ｄ、中立ドラム４５Ｄ、第１、第２及び第３の制動ドラム４１Ｄ、４２Ｄ及び４３Ｄは、相互に軸方向に一定の間隔をおいて配置されている。第４の制動ドラム４４Ｄ、第１及び第２の制動ドラム４１Ｄ及び４２Ｄの軸方向幅は相互に実質的に同じに形成されているが、第３の制動ドラム４３Ｄは、第４の制動ドラム４４Ｄ、第１及び第２の制動ドラム４１Ｄ及び４２Ｄよりも軸方向幅が広く形成されている（第４の制動ドラム４４Ｄ、第１及び第２の制動ドラム４１Ｄ及び４２Ｄの軸方向幅の少なくとも２倍）。また、中立ドラム４５Ｄは、第３の制動ドラム４３Ｄよりも軸方向幅が広く形成されている（第４の制動ドラム４４Ｄ、第１及び第２の制動ドラム４１Ｄ及び４２Ｄの軸方向幅の少なくとも３倍）。なお、第３の制動ドラム４３Ｄは、図示の実施形態においては一体に形成されているが、相互にリンギギヤ４３ｂに一体に連結された二つの部材から構成してもよい。また、中立ドラム４５Ｄも、軸方向に間隔をおいて配列された三つの部材から構成してもよい。
【００１７】
図示の変速装置は、上記第１〜第４の制動ドラム４１Ｄ〜４４Ｄと中立ドラム４５Ｄ、の外周側に回転が規制されかつ軸方向に移動可能に配設された磁石手段５００（換言すれば、軸方向のみに移動可能に配設された磁石手段５００）と、磁石手段５００を軸方向に移動させて、制動ドラム４１Ｄ〜４４Ｄの外周面と対向する第１〜第５の制動位置と、制動ドラム４１Ｄ〜４４Ｄの外周面と対向しない制動解除位置に位置付ける磁石作動手段６とを備えている。これら第１〜第４の制動ドラム４１Ｄ〜４４Ｄと中立ドラム４５Ｄ、磁石手段５００及び磁石作動手段６は、各遊星歯車機構４１〜４４を構成する回転要素の一つに制動力を与える回転要素制動手段を構成する。
【００１８】
図７〜図１０を参照して、磁石手段５００は、磁石支持手段５００Ａと、磁石支持手段５００Ａに配設された複数個の永久磁石５５０とを備えている。永久磁石５５０の各々は相互に実質的に同じ形状及び大きさを有している。永久磁石５５０は、図９に明示されているように、軸方向に間隔をおいて相互に対向するよう配置された第１の磁極部５５０ａ及び第２の磁極部５５０ｂと、第１及び第２の磁極部５５０ａ及び５５０ｂを接続するよう配設された橋絡部５５０ｃとからなる。第１及び第２の磁極部５５０ａ及び５５０ｂは橋絡部５５０ｃの両端から相互に平行にかつ橋絡部５５０ｃに対して直角に同じ長さだけ延び出すよう構成されている。第１及び第２の磁極部５５０ａ及び５５０ｂと橋絡部５５０ｃは横断面がほぼ矩形状をなしている。したがって、第１及び第２の磁極部５５０ａ及び５５０ｂは、橋絡部５５０ｃの長手方向両端において、橋絡部５５０ｃの片面から相互に平行にかつ該片面に対して直角に同じ長さだけ延び出すよう構成されている。この実施形態において、第１の磁極部５５０ａ及び第２の磁極部５５０ｂと橋絡部５５０ｃとは一体に形成されている。図９から明らかなように、上記の如く構成された永久磁石５５０は、全体としてほぼチャンネル形状ないしＵ形状をなしている。第１及び第２の磁極部５５０ａ及び５５０ｂは、各々の先端に、相互に異極（Ｎ−Ｓ）をなす磁極面を有している。磁極面の各々は矩形状をなしている。後述するとおりにして磁石作動手段６のねじロッド部材６０に配設された状態、広義には変速装置に配設された状態において、永久磁石５５０の各々は、入力軸２及び出力軸３の軸方向に間隔をおいて相互に対向するよう配置された第１及び第２の磁極部５５０ａ及び５５０ｂと、第１及び第２の磁極部５５０ａ及び５５０ｂを接続するよう配設された橋絡部５５０ｃとからなり、第１及び第２の磁極部５５０ａ及び５５０ｂは橋絡部５５０ｃの両端から半径方向内側に延び出すよう構成され、永久磁石５５０の各々において、第１及び第２の磁極部５５０ａ及び５５０ｂは、半径方向内側に向けられた、相互に異極をなす磁極面（Ｎ又はＳ）を有している。
【００１９】
磁石支持手段５００Ａは、第１の磁石支持環５５１と、第２の磁石支持環５５２と、第１の磁石押さえ環５５３と、第２の磁石押さえ環５５４とを備えている。図１０にその一部が明示されているように、第１の磁石支持環５５１は、一定の軸方向幅及び半径方向厚さを有する円筒状の本体部５５１ａと、本体部５５１ａの外周面の全周にわたって相互に等間隔をおいて半径方向外方に延び出す複数個（偶数個）の突起部５５１ｂとを備えている。第１の磁石支持環５５１は、例えばアルミニウム合金などの非磁性材から形成されている。突起部５５１ｂの半径方向外側面は、本体部５５１ａと共通の軸心を有する共通の円周面上に位置付けられた円弧面からなる。
【００２０】
例えばアルミニウム合金などの非磁性材から形成することができる第２の磁石支持環５５２は、一定の軸方向幅及び半径方向厚さを有する円筒状の本体部５５５と、本体部５５５の外周面から半径方向外方に延び出すボス部５５６と、ボス部５５６に対し軸心を挟んだ反対側の位置における外周面から半径方向外方に延び出す他のボス部５５７（図１参照）とを備えている。本体部５５５には、周方向に間隔おいて複数個の取付孔５５５ａが軸方向に延在するよう形成されている。ボス部５５６には雌ねじ５５６ａが軸方向に延在するよう形成され、他のボス部５５７には被ガイド孔５５７ａが軸方向に延在するよう形成されている。雌ねじ５５６ａは、鋼材など耐久性に優れた他の円筒部材の内側に形成し、この円筒部材をボス部５５６に埋め込むことが好ましい。また、被ガイド孔５５７ａは、摩擦係数が低く耐久性に優れた他の円筒部材の内側に形成し、この円筒部材を他のボス部５５７に埋め込むことが好ましい。
【００２１】
第１の磁石支持環５５１の軸方向幅は、永久磁石５５０の第１及び第２の磁極部５５０ａ及び５５０ｂの、相互に対向する面間の間隔にほぼ等しく、第１の磁石支持環５５１の内径は、第１〜第４の制動ドラム４１Ｄ〜４４Ｄの外径よりも若干大きい。また、第１の磁石支持環５５１の本体部５５１ａの半径方向厚さは、永久磁石５５０の第１及び第２の磁極部５５０ａ及び５５０ｂの、橋絡部５５０ｃからの延び出し長さとほぼ等しい。更にはまた、第１の磁石支持環５５１の突起部５５１ｂ間の間隔は、永久磁石５５０の幅とほぼ等しい。第２の磁石支持環５５２の軸方向幅は、永久磁石５５０の長手方向両端面（第１及び第２の磁極部５５０ａ及び５５０ｂの、相互に対向する面と反対側の端面）間の距離にほぼ等しい。また、第２の磁石支持環５５２の本体部５５５ａの内周面は、第１の磁石支持環５５１の突起部５５１ｂにおける半径方向外側面の外径（該外側面と共通の円周面の外径）とほぼ同じ内径を有している。
【００２２】
相互に実質的に共通部品からなる第１及び第２の磁石押さえ環５５３及び５５４は、一定の軸方向厚さ及び半径方向幅を有する環状円板からなり、例えばアルミニウム合金などの非磁性材から形成されている。第１及び第２の磁石押さえ環５５３及び５５４には、それぞれ周方向に間隔おいて複数個の取付孔５５３ａ及び５４ａが軸方向に延在するよう形成されている。取付孔５５３ａ及び５５４ａの各々は、第２の磁石支持環５５２の本体部５５５に形成された上記取付孔５５５ａの各々と整合する。第１及び第２の磁石押さえ環５５３及び５５４の内径は、第１〜第４の制動ドラム４１Ｄ〜４４Ｄの外径よりも若干大きく、また第１及び第２の磁石押さえ環５３及び５４の外径は、第２の磁石支持環５５２の本体部５５５の外径とほぼ等しい。
【００２３】
永久磁石５５０は、第１の磁石支持環５５１の本体部５５１ａにおける半径方向外側面であって、突起部５５１ｂの各々の間に装着される。永久磁石５５０の各々の第１及び第２の磁極部５５０ａ及び５５０ｂの相互の対向面は、第１の磁石支持環５５１の本体部５５１ａの両側面にほぼ密着し、第１及び第２の磁極部５５０ａ及び５５０ｂの磁極面は、第１の磁石支持環５５１の本体部５５１ａの幅方向両側において、本体部５５１ａの内周面と一致する円周面に対し、半径方向外側からほぼ接するよう位置付けられる。また、永久磁石５５０の各々の橋絡部５５０ｃの両側面は、第１の磁石支持環５５１の突起部５５１ｂの各々の、相互に対向する周方向面にほぼ密着させられる（該周方向面の間隔は半径方向外方に向かってわずかずつ拡大するよう形成されている）。更にはまた、永久磁石５５０の各々の半径方向外側面であって、最大外径部は、第１の磁石支持環５５１の突起部５５１ｂの半径方向外側面と共通の円周面に対し、半径方向内側からほぼ接するよう位置付けられる。なお、第１の磁石支持環５５１に装着された状態において、永久磁石５５０の各々の半径方向外側面を、第１の磁石支持環５５１の突起部５５１ｂの半径方向外側面と共通の円周面にほぼ整合する円弧面に形成してもよい。
【００２４】
上記した如く、複数の永久磁石５５０が第１の磁石支持環５５１に装着された状態で、第１の磁石支持環５５１は第２の磁石支持環５５２の本体部５５５の内周面に嵌合される。第１の磁石支持環５５１の突起部５５１ｂの各々の半径方向外側面は、第２の磁石支持環５５２の本体部５５５の内周面にほぼ密着ないし圧接される。永久磁石５５０の各々の長手方向両端面は、それぞれ第２の磁石支持環５５２の幅方向両側面とほぼ共通の面上に位置付けられる。第１及び第２の磁石押さえ環５５３及び５５４は、それぞれ第２の磁石支持環５５２の本体部５５５の幅方向両側面に当接され、第１及び第２の磁石押さえ環５５３及び５５４の取付孔５５３ａ及び５５４ａと、第２の磁石支持環５５２の本体部５５５の取付孔５５５ａを整合した状態で複数のボルト５５８及び５５９により、軸方向に締結する。第１及び第２の磁石押さえ環５５３及び５５４の内周面は、第１の磁石支持環５５１の本体部５５１ａの内周面と共通の円周面にほぼ整合するよう位置付けられる。
【００２５】
磁石作動手段６は、図示の実施形態においては、外周面に雄ねじが形成された１本のねじロッド部材６０と、ねじロッド部材６０を回転駆動する駆動源であるステッピングモータＭとを備えている。ねじロッド部材６０の一端部はステッピングモータＭの図示しない駆動軸に駆動連結され、他端部は、変速装置のハウジング１に回転自在に支持されている。磁石作動手段６はまた、変速装置のハウジング１に配設された少なくとも１本（実施形態においては１本）のガイドロッド６１を備えている。ねじロッド部材６０及びガイドロッド６１は、入力軸２及び出力軸３と共通の軸線に平行に延在する。第２の磁石支持環５５２のボス部５５６に形成された雌ねじ５５６ａがねじロッド部材６０にねじ係合され、かつ、第２の磁石支持環５５２の他のボス部５５７に形成された被ガイド孔５５７ａがガイドロッド６１にスライド自在に嵌合されることにより、第２の磁石支持環５５２は、ねじロッド部材６０及びガイドロッド６１に沿って軸方向に往復移動自在に支持される。
【００２６】
上記したとおりにして、永久磁石５５０の各々が磁石支持手段５００Ａに支持された状態において、周方向に相互に隣り合う永久磁石５５０の各々における、第１の磁極部５５０ａは、第１の磁石支持環５５１の軸方向一側に周方向に等間隔をおいて配列され、周方向に相互に隣合う第１の磁極部５５０ａの各々の磁極面同士は相互に異極をなす。また、第２の磁極部５５０ｂは、第１の磁石支持環５５１の軸方向他側に周方向に等間隔をおいて配列され、周方向に相互に隣合う第２の磁極部５５０ｂの各々の磁極面同士は相互に異極をなす。図１１及び図１２を参照して、周方向に相互に隣り合う永久磁石５５０の各々における、第１の磁極部５５０ａの磁極面間には、それぞれＮからＳに向かう磁力線で示すことができる磁界が形成され、また、周方向に相互に隣り合う永久磁石５５０の各々における、第２の磁極部５５０ｂの磁極面間には、それぞれＮからＳに向かう磁力線で示すことができる磁界が形成される。更に、永久磁石５５０の各々における橋絡部５５０ｃには、第１の磁極部５５０ａの磁極面から第２の磁極部５５０ｂの磁極面に向かう磁力線で示すことができる磁路が形成される（第１の磁極部５５０ａの磁極面がＳ、第２の磁極部５５０ｂの磁極面がＮの場合）か、又は、第２の磁極部５５０ｂの磁極面から第１の磁極部５５０ａの磁極面に向かう磁力線で示すことができる磁路が形成される（第２の磁極部５５０ｂの磁極面がＳ、第１の磁極部５５０ａの磁極面がＮの場合）。このようにして、環状に配列された永久磁石５５０の各々間には、全周にわたって、周方向及び軸方向に連続した磁気回路が形成される。
【００２７】
図１を参照して、磁石作動手段６のステッピングモータＭを回転駆動制御することにより、磁石手段５００、更に具体的には、永久磁石５５０の各々における第１の磁極部５５０ａの磁極面及び／又は第２の磁極部５５０ｂの磁極面は、第１〜第４の制動ドラム４１Ｄ〜４４Ｄの少なくとも１個の制動ドラムの外周面と所定の隙間をおいて対向する第１、第２、第３、第４又は第５の制動位置と、第１〜第４の制動ドラム４１Ｄ〜４４Ｄのいずれの外周面とも対向しない制動解除位置に位置付けられる。
【００２８】
更に具体的に説明すると、磁石手段５００が、図１に示す制動解除位置〔中立位置（Ｎ）〕に位置付けられた状態においては、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面及び第２の磁極部５５０ｂの磁極面が、それぞれ中立ドラム４５Ｄの外周面の軸方向両端部に所定の隙間をおいて対向する。磁石手段５００が、図２に示す第１の制動位置〔１速位置（Ｉ）〕に位置付けられると、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第１の制動ドラム４１Ｄの外周面に対向し、かつ第２の磁極部５５０ｂの磁極面は中立ドラム４５Ｄの外周面の軸方向中央部に対向する。磁石手段５００が、図３に示す第２の制動位置〔２速位置（ＩＩ）〕に位置付けられると、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第２の制動ドラム４２Ｄの外周面に対向し、かつ第２の磁極部５５０ｂの磁極面は中立ドラム４５Ｄの外周面の軸方向一端部（第１の制動ドラム４１Ｄ側の一端部）に対向する。磁石手段５００が、図４に示す第３の制動位置〔３速位置（ＩＩＩ）〕に位置付けられると、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第３の制動ドラム４３Ｄの外周面の軸方向一端部（第２の制動ドラム４２Ｄ側の一端部）に対向し、かつ第２の磁極部５５０ｂの磁極面は第１の制動ドラム４１Ｄの外周面に対向する。磁石手段５００が、図５に示す第４の制動位置〔４速位置（ＩＶ）〕に位置付けられると、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第３の制動ドラム４３Ｄの外周面の他端部に対向し、かつ第２の磁極部５５０ｂの磁極面は第２の制動ドラム４２Ｄの外周面に対向する。また、磁石手段５００が、図６に示す第５の制動位置〔後進位置（Ｒ）〕に位置付けられると、永久磁石５５０の各々の第２の磁極部５５０ｂの磁極面が第４の制動ドラム４４Ｄの外周面に対向し、かつ第１の磁極部５５０ａの磁極面は中立ドラム４５Ｄの外周面の中間部に対向する。
【００２９】
磁石作動手段６のステッピングモータＭの回転駆動制御は、例えば、次のとおりにして容易に行なうことができる。すなわち、磁石手段５００における第２の磁石支持環５５２の、図１に示す制動解除位置〔中立位置（Ｎ）〕を基準位置として予め定め、該基準位置である制動解除位置〔中立位置（Ｎ）〕から上記第１〜第５の制動位置までの移動ストロークに対応した回転数を予め算定して図示しないコントローラに記憶しておく。そして、運転者による変速指示信号に基づく制動位置と現在の制動位置との間の移動ストロークに対応した回転数をコントローラにより演算し、ステッピングモータＭを該回転数だけ正転又は逆転させることにより、第２の磁石支持環５５２を現在の制動位置から変速指示信号に基づく制動位置へ、ねじロッド部材６０及びガイドロッド６１に沿って、回転が規制された状態で軸方向に移動させることができる。
【００３０】
図１に示す変速装置は以上のように構成されており、以下その作動について説明する。磁石手段５００が図１、図７及び図８に示すように中立位置（Ｎ）に位置付けられている場合には、先に述べたように、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面及び第２の磁極部５５０ｂの磁極面が中立ドラム４５Ｄの外周面と対向するので、第１の磁極部５５０ａの各々の磁極面と磁性材からなる中立ドラム４５Ｄとの間、第２の磁極部５５０ｂの各々の磁極面と中立ドラム４５Ｄとの間及び永久磁石５５０の各々における第１の磁極部５５０ａの磁極面と第２の磁極部５５０ｂの磁極面との間に磁気回路が形成される。このため、永久磁石５５０の各々の磁気が、第１〜第４の制動ドラム４１Ｄ〜４４Ｄに作用することはない。上記したように、中立ドラム４５Ｄは、リングギヤ４４ｂの円筒部の外周面を覆うよう該円筒部に相対回転自在に配置されているので、永久磁石５５０の各々が中立ドラム４５Ｄの外周面に対向しても、その磁気は実質的に中立ドラム４５Ｄに吸収され、その内側に位置するリングギヤ４４ｂに磁気が及ぶことはなく、したがってリングギヤ４４ｂに制動が作用することはないので動力は実質的に伝達されない。すなわち、磁石手段５００が中立位置（Ｎ）にある状態では、中立ドラム４５Ｄは、磁石手段５００が動力を伝達するための制動力を発揮しないよう機能する。出力軸３は、一般的には、車両の制動装置の作動などにより固定された状態にある。このため、第１の遊星歯車機構４１及び第４の遊星歯車機構４４のプラネタリキャリア４１ｄ及び４４ｄは固定される。他方、第１〜第４の制動ドラム４１Ｄ〜４４Ｄ、すなわち第１の遊星歯車機構４１のリングギヤ４１ｂ及び第２の遊星歯車機構４２のプラネタリキャリア４２ｄ、第２の遊星歯車機構４２及び第３の遊星歯車機構４３のリングギヤ４２ｂ及び４３ｂ、及び第４の遊星歯車機構４４のリングギヤ４４ｂはいずれも固定されない。その結果、入力軸２から出力軸３へ動力は実質的に伝達されない。なお、第１〜第４の制動ドラム４１Ｄ〜４４Ｄは空転させられる。
【００３１】
図２を参照して、変速装置を１速で作動させるため、磁石手段５００を１速位置（Ｉ）に位置付けると、先に述べたように、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第１の制動ドラム４１Ｄの外周面に対向し、第２の磁極部５５０ｂの磁極面は中立ドラム４５Ｄの外周面に対向する。なお、図１１及び図１２には、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第１の制動ドラム４１Ｄの外周面に対向した状態が示されている。永久磁石５５０の各々の第１の磁極部５５０ａの磁極面間に磁界が形成され、第２の磁極部５５０ｂの磁極面と中立ドラム４５Ｄとの間に磁気回路が形成される。第１の制動ドラム４１Ｄは、第１の磁極部５５０ａの各々の磁極面間に形成される磁界内に位置付けられるので、第１の磁極部５５０ａの各々の磁極面間の磁気作用を受ける。第１の制動ドラム４１Ｄは空転させられるので、第１の磁極部５５０ａの各々と第１の制動ドラム４１Ｄとの間に相対速度差が生ずる。この相対速度差によって第１の制動ドラム４１Ｄの外周面に渦電流が生ずるので、第１の制動ドラム４１Ｄ、すなわち第１の遊星歯車機構４１のリングギヤ４１ｂ及び第２の遊星歯車機構４２のプラネタリキャリア４２ｄが制動トルクを受ける。その結果、入力軸２に伝達された回転トルクは、ワンウエイクラッチ２１、サンギヤユニット２２に配設された、第１の遊星歯車機構４１のサンギヤ４１ａを介して第１の遊星歯車機構４１のプラネタリギヤ４１ｃに伝達される。プラネタリギヤ４１ｃはリングギヤ４１ｂに沿って自転しつつ公転し、この公転がプラネタリキャリア４１ｄを介して出力軸３に伝達される。この場合、入力軸２の回転速度は減速されて出力軸３に伝達される。なお、第１の制動ドラム４１Ｄ、すなわちリングギヤ４１ｂ及びプラネタリキャリア４２ｄは、渦電流に基づく制動トルクを受けて回転速度が低下するが、この回転速度が小さくなると上記渦電流に基づく制動トルクが発生しなくなるため停止することはない。このため、リングギヤ４１ｂ及びプラネタリキャリア４２ｄは、トルク伝達時においても低い所定の回転速度付近で回転している。なお上記したような第１の制動ドラム４１Ｄに作用する制動力発生の原理は、他の制動ドラムにおいても同じであるので、以降の説明においては説明を省略する。
【００３２】
図３を参照して、変速装置を２速で作動させるため、磁石手段５００を２速位置（ＩＩ）に位置付けると、先に述べたように、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第２の制動ドラム４２Ｄの外周面に対向し、第２の磁極部５５０ｂの磁極面は中立ドラム４５Ｄの外周面に対向する。第２の制動ドラム４２Ｄは、第１の磁極部５５０ａの各々の磁極面間に形成される磁界内に位置付けられるので、第１の磁極部５５０ａの各々の磁極面間の磁気作用を受ける。第２の制動ドラム４２Ｄは空転させられるので、第２の制動ドラム４２Ｄ、すなわち第２の遊星歯車機構４２のリングギヤ４２ｂが制動トルクを受ける。その結果、入力軸２に伝達された回転トルクは、ワンウエイクラッチ２１、サンギヤユニット２２に配設された、第２の遊星歯車機構４２のサンギヤ４２ａを介して第２の遊星歯車機構４２のプラネタリギヤ４２ｃに伝達されると共に、第１の遊星歯車機構４１のサンギヤ４１ａを介して第１の遊星歯車機構４１のプラネタリギヤ４１ｃに伝達される。プラネタリギヤ４２ｃはリングギヤ４２ｂに沿って自転しつつ公転し、この公転は、プラネタリキャリア４２ｄ、第１の遊星歯車機構４１のリングギヤ４１ｂ、プラネタリギヤ４１ｃ、プラネタリキャリア４１ｄを介して出力軸３に伝達される。この２速の場合、入力軸２の回転速度は１速の場合よりも増速されて出力軸３に伝達される。
【００３３】
上記したように変速装置が低速段である１速又は２速で作動しているとき、高速段側の回転要素である第３の制動ドラム４３Ｄも空転させられるが、その回転数は入力軸２の回転数を越えることはない。その結果、変速装置の低速段での作動時に高速段側の回転要素、すなわち第３の制動ドラム４３Ｄが高速で空転することが防止され、駆動エネルギーのロスが少なくなるので、駆動効率が、先に述べた従来の変速装置よりも向上する。なお、変速装置が低速段である１速又は２速で作動しているとき、第４の制動ドラム４４Ｄも空転させられるが、その回転数は入力軸２の回転数を越えることはない。
【００３４】
図４を参照して、変速装置を３速で作動させるため、磁石手段５００を３速位置（ＩＩＩ）に位置付けると、先に述べたように、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第３の制動ドラム４３Ｄの外周面に対向し、第２の磁極部５５０ｂの磁極面は第１の制動ドラム４１Ｄの外周面に対向する。第３の制動ドラム４３Ｄは、第１の磁極部５５０ａの各々の磁極面間に形成される磁界内に位置付けられるので、第１の磁極部５５０ａの各々の磁極面間の磁気作用を受ける。また、第１の制動ドラム４１Ｄは、第２の磁極部５５０ｂの各々の磁極面間に形成される磁界内に位置付けられるので、第２の磁極部５５０ｂの各々の磁極面間の磁気作用を受ける。第３の制動ドラム４３Ｄ及び第１の制動ドラム４１Ｄは空転させられるので、第３の制動ドラム４３Ｄ、すなわち第３の遊星歯車機構４３のリングギヤ４３ｂと、第１の制動ドラム４１Ｄ、すなわち第１の遊星歯車機構４１のリングギヤ４１ｂ及び第２の遊星歯車機構４２のプラネタリキャリア４２ｄが制動トルクを受ける。その結果、入力軸２に伝達された回転トルクは、第３の遊星歯車機構４３のプラネタリキャリア４３ｄを介してプラネタリギヤ４３ｃに伝達される。プラネタリギヤ４３ｃはリングギヤ４３ｂに沿って自転しつつ公転し、この自転及び公転は、サンギヤユニット２２に配設された、第３の遊星歯車機構４３のサンギヤ４３ａを介してサンギヤユニット２２に伝達される。サンギヤ４３ａ、したがってサンギヤユニット２２は、入力軸２よりも増速されるので、ワンウエイクラッチ２１の締結状態が解除される。以上のようにしてサンギヤユニット２２に伝達された回転トルクは、第１の遊星歯車機構４１のサンギヤ４１ａを介してプラネタリギヤ４１ｃに伝達される。プラネタリギヤ４１ｃはリングギヤ４１ｂに沿って自転しつつ公転し、この公転がプラネタリキャリア４１ｄを介して出力軸３に伝達される。この３速の場合、入力軸２の回転速度は２速の場合よりも増速されて出力軸３に伝達される。また、第３の遊星歯車機構４３と第１の遊星歯車機構４１のギヤ比を同一に設定した場合には、出力軸３の回転数は入力軸２の回転数と同じとなり、１：１の速度比を得ることができる。
【００３５】
図５を参照して、変速装置を４速で作動させるため、磁石手段５００を４速位置（ＩＶ）に位置付けると、先に述べたように、永久磁石５５０の各々の第１の磁極部５５０ａの磁極面が第３の制動ドラム４３Ｄの外周面の他端部に対向し、第２の磁極部５５０ｂの磁極面は第２の制動ドラム４２Ｄの外周面に対向する。第３の制動ドラム４３Ｄは、第１の磁極部５５０ａの各々の磁極面間に形成される磁界内に位置付けられるので、第１の磁極部５５０ａの各々の磁極面間の磁気作用を受ける。また、第２の制動ドラム４２Ｄは、第２の磁極部５５０ｂの各々の磁極面間に形成される磁界内に位置付けられるので、第２の磁極部５５０ｂの各々の磁極面間の磁気作用を受ける。第３の制動ドラム４３Ｄ及び第２の制動ドラム４２Ｄは空転させられるので、第３の制動ドラム４３Ｄ、すなわち第３の遊星歯車機構４３のリングギヤ４３ｂと、第２の制動ドラム４２Ｄ、すなわち第２の遊星歯車機構４２のリングギヤ４２ｂが制動トルクを受ける。その結果、上記した３速の場合と同じく、入力軸２に伝達された回転トルクは、第３の遊星歯車機構４３のプラネタリキャリア４３ｄを介してプラネタリギヤ４３ｃに伝達される。プラネタリギヤ４３ｃはリングギヤ４３ｂに沿って自転しつつ公転し、この自転及び公転は、サンギヤユニット２２の本体部２２ａに配設された、第３の遊星歯車機構４３のサンギヤ４３ａを介してサンギヤユニット２２に伝達される。サンギヤ４３ａ、したがってサンギヤユニット２２は、入力軸２よりも増速されるので、ワンウエイクラッチ２１は締結解除状態に維持される。以上のようにしてサンギヤユニット２２に伝達された回転トルクは、第２の遊星歯車機構４２のサンギヤ４２ａを介してプラネタリギヤ４２ｃに伝達されると共に、第１の遊星歯車機構４１のサンギヤ４１ａを介して第１の遊星歯車機構４１のプラネタリギヤ４１ｃに伝達される。プラネタリギヤ４２ｃはリングギヤ４２ｂに沿って自転しつつ公転し、この公転が第１の遊星歯車機構４１のリングギヤ４１ｂに伝達される。リングギヤ４１ｂに伝達された回転トルクは、プラネタリギヤ４１ｃ及びプラネタリキャリア４１ｄを介して出力軸３に伝達される。この４速の場合、入力軸２の回転速度は３速の場合よりも増速されて出力軸３に伝達される。
【００３６】
上記変速装置において、３速で作動させられる場合（図４参照）、上記したように、入力軸２に伝達された回転トルクは、第３の遊星歯車機構４３のプラネタリキャリア４３ｄ、プラネタリギヤ４３ｃ及びサンギヤユニット２２に配設されたサンギヤ４３ａ、及び第１の遊星歯車機構４１の、サンギヤユニット２２に配設されたサンギヤ４１ａ、プラネタリギヤ４１ｃ及びプラネタリキャリア４１ｄを介して出力軸３に伝達されるよう構成されているので、先に述べた従来の変速装置における如く、３個の遊星歯車機構を駆動する必要がなく、比較的少ないギヤを駆動することによって出力軸３に動力を伝達することができる。その結果、変速装置の駆動効率を向上させることができ、実用上有用である。
【００３７】
また、変速装置が４速で作動させられる場合（図５参照）、上記したように、入力軸２に伝達された回転トルクは、第３の遊星歯車機構４３のプラネタリキャリア４３ｄ、プラネタリギヤ４３ｃ及びサンギヤユニット２２に配設されたサンギヤ４３ａ、第２の遊星歯車機構４２の、サンギヤユニット２２に配設されたサンギヤ４２ａ、プラネタリギヤ４２ｃ及びプラネタリキャリア４２ｄ、第１の遊星歯車機構４１のリングギヤ４１ｂ（プラネタリキャリア４２ｄに連結されている）、プラネタリギヤ４１ｃ及びプラネタリキャリア４１ｄを介して出力軸３に伝達されるよう構成されている。この４速の場合においても、先に述べた従来の変速装置における如く、４個の遊星歯車機構を駆動する必要がなく、比較的少ないギヤを駆動することによって出力軸３に動力を伝達することができる。また先に述べた従来の変速装置においては、３個の制動ドラムを駆動する必要があるが、上記変速装置においては１個の制動ドラム（第１の制動ドラム４１Ｄのみ）を駆動すればよく、この点においても、有利である。以上の結果、変速装置の駆動効率を向上させることができ、実用上有用である。
【００３８】
次に、図６を参照して、変速装置を後進で作動させるため、磁石手段５００を後進位置（Ｒ）に位置付けると、先に述べたように、永久磁石５５０の各々の第２の磁極部５５０ｂの磁極面が第４の制動ドラム４４Ｄの外周面に対向し、かつ第１の磁極部５５０ａの磁極面は中立ドラム４５Ｄの外周面に対向する。第４の制動ドラム４４Ｄは、第２の磁極部５５０ｂの各々の磁極面間に形成される磁界内に位置付けられるので、第２の磁極部５５０ｂの各々の磁極面間の磁気作用を受ける。第４の制動ドラム４４Ｄは空転させられるので、第４の制動ドラム４４Ｄ、すなわち第４の遊星歯車機構４４のリングギヤ４４ｂが制動トルクを受ける。その結果、入力軸２に伝達された回転トルクは、ワンウエイクラッチ２１、サンギヤユニット２２に配設された、第１の遊星歯車機構４１のサンギヤ４１ａを介して第１の遊星歯車機構４１のプラネタリギヤ４１ｃに伝達される。プラネタリギヤ４１ｃが駆動されると、第４の遊星歯車機構４４のプラネタリギヤ４４ｃがリングギヤ４４ｂに沿って自転しつつ公転する。このプラネタリギヤ４４ｃは、第１の遊星歯車機構４１のサンギヤ４１ａにより、プラネタリギヤ４１ｃを介して駆動されるため、サンギヤ４１ａと回転方向が同じとなるので、公転方向が逆方向となる。つまりプラネタリキャリア４４ｄの回転方向はサンギヤ４１ａとは逆方向となる。その結果、プラネタリギヤ４４ｃに伝達された動力は、プラネタリキャリア４４ｄを介して出力軸３を入力軸２とは逆方向に回転させるように伝達される。出力軸３は車両を後進させる方向に回転駆動されることになる。上記した後進の作動において、中立ドラム４５Ｄが第１の永久磁石５１による制動作用を受けても、変速の作動に影響することはない。
【００３９】
以上のように、上記変速装置においては、磁石手段５００を、１速位置（Ｉ）、２速位置（ＩＩ）、３速位置（ＩＩＩ）、４速位置（ＩＶ）及び後進位置（Ｒ）に選択的に位置付けることにより、それぞれ所定の変速比の出力を得ることができる。上記各リングギヤ、プラネタリキャリアなどに制動力を与える回転要素制動手段は渦電流による制動機構であるため、機械的な接触部がなく、非接触で制動力を与えることができる。その結果、制動における摩耗がなく、耐久性を向上することができる。また、渦電流による制動機構は制動ドラムと磁石手段との間に滑りが発生することで制動力が作用し、遊星歯車機構を機能させることができるので、入力軸２を車両の原動機である内燃機関に直接連結しても車両を停止状態から発進駆動することができる。すなわち、本発明に従って構成された変速装置を車両の変速装置に適用した場合には、車両を発進するために用いられている摩擦クラッチやトルクコンバータ等の流体継手を除去することが可能となる。
【００４０】
また上記変速装置においては、第１、第２及び第３の遊星歯車機構を配列することにより、４段変速が可能な変速装置を得ることができるので、先に述べた従来の変速装置に較べて、部品点数が少なく、全体の構成がコンパクトとなり、軽量化及びコストダウンを可能にした。
【００４１】
更にはまた、上記変速装置において、周方向に間隔をおいて配列された永久磁石５５０の各々は、軸方向に間隔をおいて相互に対向するよう配置された第１及び第２の磁極部５５０ａ及び５５０ｂと、第１及び第２の磁極部５５０ａ及び５５０ｂを接続するよう配設された橋絡部５５０ｃとからなる。第１及び第２の磁極部５５０ａ及び５５０ｂは橋絡部５５０ｃの両端から半径方向内側に延び出すよう構成されている。永久磁石５５０の各々において、第１及び第２の磁極部５５０ａ及び５５０ｂは、半径方向内側に向けられた、相互に異極をなす磁極面を有し、周方向に相互に隣り合う永久磁石５５０の各々における、第１の磁極部５５０ａの磁極面同士及び第２の磁極部５５０ｂの磁極面同士は相互に異極をなしている。つまり、本発明における永久磁石５５０の各々においては、周方向に配列された第１の磁極部５５０ａの磁極面間に磁界が連続して形成され、かつ、周方向に配列された第２の磁極部５５０ｂの磁極面間に磁界が連続して形成されると共に、第１の磁極部５５０ａと第２の磁極部５５０ｂとの間は、それぞれ、軸方向に延在する橋絡部５５０ｃにより形成される磁束流路を介して連通されているので、第１の磁極部５５０ａと第２の磁極部５５０ｂとが分離されている形態の従来の永久磁石の構成及び配列と比較して、永久磁石５５０の各々の半径方向寸法を増加させることなく、永久磁石５５０の各々の磁力を一層強化することができる。また、半径方向内側に向けられた、永久磁石５５０の各々の磁極面の面積を増加させることなく、永久磁石５５０の各々の磁力を強化することができる。その結果、駆動力の伝達性能を一層向上させることができる。先に述べたように、各変速段において、制動ドラムに作用する制動力を増大するほど入力軸２から出力軸３への駆動力の伝達性能が向上するが、本発明による変速装置においては、永久磁石５５０の各々の半径方向寸法を増加させることなく、また永久磁石５５０の各々の磁極面の面積を増加させることなく、制動ドラムに作用する制動力を増大させることが可能となるので、変速装置のコンパクト化及び軽量化を達成しながら、駆動性能を向上させることができる。したがって、本発明による変速装置は、車両への搭載上、きわめて有利となる。
【００４２】
なお、本発明における変速装置において、第４の遊星歯車機構４４のプラネタリギヤ４４ｃが、第１の遊星歯車機構４１のプラネタリギヤ４１ｃに対し、ほぼ周方向に隣接しかつ若干半径方向外側寄りの位置に配置されて噛み合わされるよう構成する他の実施形態もある。この変速装置によれば、第１の遊星歯車機構４１のプラネタリギヤ４１ｃの歯幅及び第４の遊星歯車機構４４のリングギヤ４４ｂの直径をそれぞれ短縮することができる。リングギヤ４４ｂの直径が短縮されると、第４の制動ドラム４４Ｄと共に、それぞれ外径が同じである中立ドラム４５Ｄ、及び第１〜第３の制動ドラム４１Ｄ〜４３Ｄの直径もそれに合わせて短縮される。その結果、変速装置全体の構成がコンパクト化され、軽量化及びコストダウンが可能となり、実用上有利である。また上記実施形態において、磁石作動手段６は、ねじロッド部材６０及びステッピングモータＭから構成されているが、これに代えて、他の磁石作動手段、例えば、流体圧シリンダ機構から構成する他の実施形態も可能である。
【００４３】
以上、本発明を車両に搭載された変速装置の実施形態により説明したが、本発明による変速装置の用途が車両に限定される理由はなく、産業上使用される変速装置として広く適用することが可能である。本発明による変速装置において、入力軸２の回転方向を出力軸３に逆転して伝達する必要がない場合には、逆転機構である第４の遊星歯車機構４４及び第４の制動ドラム４４Ｄが不要となることはいうまでもない。上記実施形態において、中立ドラム４５Ｄは鉄あるいは鋼などの磁性材から形成されているので、永久磁石５５０の各々の第１の磁極部５５０ａ及び及び／又は第２の磁極部５５０ｂが中立ドラム４５Ｄの外周面に対向させられたとき（中立位置、１速位置、２速位置及び後進位置のいずれか）、中立ドラム４５Ｄと、第１の磁極部５５０ａ及び／又は第２の磁極部５５０ｂとの間に磁気回路が形成されるので、第４の遊星歯車機構４４のリングギヤ４４ｂに磁気が及ぼされることが回避され、リングギヤ４４ｂが制動作用を受けることはない。なお、永久磁石５５０の各々の第１及び第２の磁極部部５０ａ及び第２の磁極部５５０ｂと、リングギヤ４４ｂの円筒部の外周面との間に、渦電流に起因する制動力が実質的に作用することのない十分なエアギャップを設定できるスペースを確保できる場合には、中立ドラム４５Ｄを省略する他の実施形態が可能となる。
【００４４】
【発明の効果】
本発明による変速装置によれば、永久磁石の半径方向寸法を増加させることなく、永久磁石の磁力を強化することを可能にし、その結果、駆動力の伝達性能を向上させることを可能にする。また、永久磁石の半径方向寸法を増加させることなく、しかも半径方向内側に向けられた、永久磁石の磁極面の面積を増加させることなく、永久磁石の磁力を強化することを可能にし、その結果、駆動力の伝達性能を向上させることを可能にする。
【図面の簡単な説明】
【図１】本発明による変速装置の実施形態の概略構成図であって、中立状態を示す概略構成図。
【図２】図１に示す変速装置の、１速作動状態を示す概略構成図。
【図３】図１に示す変速装置の、２速作動状態を示す概略構成図。
【図４】図１に示す変速装置の、３速作動状態を示す概略構成図。
【図５】図１に示す変速装置の、４速作動状態を示す概略構成図。
【図６】図１に示す変速装置の、後進作動状態を示す概略構成図。
【図７】本発明による磁石手段の他の実施形態の要部を示す断面概略図であって、磁石手段が中立位置に位置付けられた状態を示す断面概略図。
【図８】図７のＡ−Ａ矢視断面図であって、一部を破断して示す断面図。
【図９】図７に示す磁石手段に備えられている永久磁石を拡大して示す斜視図。
【図１０】図７に示す磁石手段に備えられている第１の磁石支持環の一部を拡大して示す斜視図。
【図１１】図７に示す磁石手段に備えられている永久磁石間に形成される磁界の状態を磁力線で示す模式図。
【図１２】図１１に示す永久磁石列を軸方向から見た模式図。
【符号の説明】
２入力軸
３出力軸
６磁石作動手段
２１ワンウエイクラッチ
２２サンギヤユニット
２２Ａ中心軸部
４１第１の遊星歯車機構
４１Ｄ第１の制動ドラム
４２第２の遊星歯車機構
４２Ｄ第２の制動ドラム
４３第３の遊星歯車機構
４３Ｄ第３の制動ドラム
４４第４の遊星歯車機構
４４Ｄ第４の制動ドラム
４５Ｄ中立ドラム
４１ａ、４２ａ、４３ａサンギヤ
４１ｂ、４２ｂ、４３ｂ４４ｂ
リングギヤ
４１ｃ、４２ｃ、４３ｃ、４４ｃプラネタリギヤ
４１ｄ、４２ｄ、４３ｄ、４４ｄプラネタリキャリア
５００磁石手段
５５０永久磁石
５５０ａ第１の磁極部
５５０ｂ第２の磁極部
５５０ｃ橋絡部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a transmission mounted on a vehicle or the like, and more particularly, to a transmission including a planetary gear mechanism.
[0002]
[Prior art]
The planetary gear mechanism includes a sun gear, a ring gear disposed concentrically with the sun gear, a planetary gear that meshes with the ring gear and the sun gear, and a rotating element such as a planetary carrier that supports the planetary gear. In such a planetary gear mechanism, one of the sun gear, the ring gear, and the planetary carrier is fixed, and the other is transmission-coupled to the input side and the other is output-coupled, so that the power transmitted to the input side is transmitted. It can be transmitted to the output side via a planetary gear mechanism. Conventionally, in a power transmission device having such a planetary gear mechanism, for example, a transmission, as a means for fixing any one of a sun gear, a ring gear, and a planetary carrier constituting a planetary gear mechanism, a brake band or a multi-plate disc brake is conventionally used. Is generally used. However, since the brake band and the multi-disc disc brake brake the rotational force by a frictional force, they are worn and have a problem in durability.
[0003]
Based on the above fact, a transmission capable of applying a braking force to one of the rotating elements constituting the planetary gear mechanism in a non-contact manner has already been proposed by the present applicant, Isuzu Motors Limited (Patent Document 1). 1). The transmission disclosed in Patent Document 1 is provided with an input shaft driven by the power of a prime mover, an output shaft disposed on the same shaft as the input shaft, and disposed between the input shaft and the output shaft. First, second, third, and fourth planetary gear mechanisms are provided. The transmission further includes a braking drum connected to one of the rotating elements constituting each of the first, second, third and fourth planetary gear mechanisms, and a shaft whose rotation is regulated on the outer peripheral side of each braking drum. Magnet means arranged so as to be movable in the direction, and a magnet which moves the magnet means in the axial direction and is positioned at a braking position opposing the outer peripheral surface of each brake drum and a braking release position not opposing the outer peripheral surface of each brake drum. Operating means. With the above configuration, a transmission that can perform four-speed shifting is obtained.
[0004]
According to the above transmission, by positioning the magnet means at the braking position facing the outer peripheral surface of the braking drum, an eddy current is generated on the outer peripheral surface of the braking drum by a relative speed difference between the magnet means and the braking drum, and That is, a braking force can be applied to one of the rotating elements. As a result, since the planetary gear mechanism can function and transmit power without making mechanical contact, it is possible to obtain a transmission that has no wear and is excellent in durability. In addition, when the transmission is mounted on a vehicle, the vehicle can be driven to start even when the input shaft is directly connected to the prime mover, such as a friction clutch or a torque converter used for starting the vehicle. The fluid coupling can be eliminated.
[0005]
[Patent Document 1]
JP 2001-153191 A (pages 4 to 5, FIG. 7)
[0006]
[Problems to be solved by the invention]
However, it has been found that the transmission has the following problems.
(1) Since the first, second, third, and fourth planetary gear mechanisms are arranged to obtain a transmission capable of four-speed shifting, the number of parts is large, and the overall configuration is large. It becomes complicated, heavy, and costly.
(2) When the transmission is operated on the high-speed side, since power cannot be transmitted to the output shaft unless a relatively large number of gears are driven, the driving efficiency is reduced, which is not practically preferable. More specifically, when operating the transmission at the third speed, it is necessary to drive the first, second, and third planetary gear mechanisms. When operating the transmission at the fourth speed, the first, second, and third planetary gear mechanisms are required. It is necessary to drive the first, second, third and fourth planetary gear mechanisms. As a result, the driving efficiency is greatly reduced. Therefore, it is necessary to improve the driving efficiency in order to put the device into practical use.
(3) On the other hand, when the transmission is operated on the low speed side, more specifically, when the transmission is operated at the first speed or the second speed, the planetary gear mechanism is for the third and fourth speeds. The braking drum, which is one of the rotating elements of the third and fourth planetary gear mechanisms, is caused to idle at high speed. As a result, the driving energy loss increases, and the driving efficiency greatly decreases. Therefore, it is necessary to reduce the driving energy loss in order to put the device into practical use.
[0007]
Based on the above facts, the inventor has conducted intensive studies, and as a result, thought that the following technical problem can be solved by the transmission described below. The transmission includes first, second, and third planetary gear mechanisms disposed between an input shaft and an output shaft; first, second, and third brake drums made of a conductive material; Magnet means arranged on the outer peripheral side of each brake drum so as to be movable only in the axial direction, and first, second, third and fourth braking opposing the outer peripheral surface of the brake drum by moving the magnet means And a magnet actuating means positioned at a braking release position that does not oppose the position and the outer peripheral surface of the braking drum. A sun gear unit having a sun gear of each planetary gear mechanism is connected to the input shaft via a one-way clutch, and a planetary carrier of a third planetary gear mechanism is connected to the input shaft. The ring gear of the third planetary gear mechanism has a third gear. The second braking drum is connected to the ring gear of the second planetary gear mechanism, and the first braking drum and the planetary carrier of the second planetary gear mechanism are connected to the ring gear of the first planetary gear mechanism. The planetary carrier of the first planetary gear mechanism is connected to the output shaft. When the magnet means is located at the first braking position, it faces the outer peripheral surface of the first braking drum, and when it is located at the second braking position, it faces the outer peripheral surface of the second braking drum. When it is located at the position, it faces the outer peripheral surface of the third braking drum and the first braking drum, and when it is located at the fourth braking position, it faces the outer peripheral surface of the third braking drum and the second braking drum.
[0008]
By arranging the first, second, and third planetary gear mechanisms, according to the above-described transmission capable of performing four-speed shifting, the above-described technical problems (1) to (3) are solved. Is now possible. However, it has been found that there is still another problem with the transmission. That is, at each speed, the transmission performance of the driving force from the input shaft to the output shaft is improved as the braking force acting on the braking drum increases, but in order to increase the braking force acting on the braking drum, Needs to be strengthened. If the magnets are made of permanent magnets, it is necessary to increase the distance between the pole faces in each of the permanent magnets. However, because the pole faces in each of the permanent magnets are oriented radially, increasing the distance between the pole faces increases the radial dimensions of each of the permanent magnets, thus increasing the radial The size increases, the transmission cannot be made compact, and the weight increases, which is disadvantageous for mounting on a vehicle.
[0009]
It is an object of the present invention to provide a new transmission which allows to increase the magnetic force of the permanent magnet without increasing the radial dimension of the permanent magnet, and consequently to improve the driving force transmission performance. It is to provide a device.
[0010]
It is another object of the present invention to enhance the magnetic force of a permanent magnet without increasing the radial dimension of the permanent magnet and without increasing the area of the pole face of the permanent magnet that is oriented radially inward. And, consequently, to provide a novel transmission capable of improving the transmission performance of the driving force.
[0011]
[Means for Solving the Problems]
According to the present invention, there is provided a transmission having first, second, and third planetary gear mechanisms disposed between an input shaft and an output shaft.
First, second, and third brake drums made of a conductive material, magnet means disposed on the outer peripheral side of each brake drum so as to be movable only in the axial direction, and moving the magnet means to form the brake drum. Magnet operating means positioned at first, second, third, and fourth braking positions facing the outer peripheral surface and at a braking release position not facing the outer peripheral surface of the braking drum;
A sun gear unit having a sun gear of each planetary gear mechanism is connected to the input shaft via a one-way clutch, and a planetary carrier of a third planetary gear mechanism is connected to the input shaft. The ring gear of the third planetary gear mechanism has a third gear. The second braking drum is connected to the ring gear of the second planetary gear mechanism, and the first braking drum and the planetary carrier of the second planetary gear mechanism are connected to the ring gear of the first planetary gear mechanism. Connected, the planetary carrier of the first planetary gear mechanism is connected to the output shaft,
The magnet means includes a magnet support means and a plurality of permanent magnets disposed on the magnet support means at circumferentially spaced intervals from each other, each of the permanent magnets having a body extending in the axial direction. A first and a second magnetic pole portion extending radially inward from both ends in the axial direction of the main body portion. In each of the permanent magnets, the first and second magnetic pole portions are directed radially inward. The magnetic pole surfaces of the first magnetic pole portion and the magnetic pole surfaces of the second magnetic pole portion of the permanent magnets having mutually different polar surfaces and mutually adjacent in the circumferential direction have mutually different polarities. Without
When the magnet means is positioned at the first braking position, the magnetic pole surface of each first magnetic pole portion of the permanent magnet faces the outer peripheral surface of the first braking drum, and the first magnetic pole portion is positioned at the second braking position. The magnetic pole surface of the magnetic pole portion faces the outer peripheral surface of the second braking drum, and when positioned at the third braking position, the magnetic pole surface of the first magnetic pole portion faces the third braking drum and the second magnetic pole The magnetic pole surface of the first magnetic pole portion faces the outer circumferential surface of the first braking drum, and when positioned at the fourth braking position, the magnetic pole surface of the first magnetic pole portion faces the third braking drum and the second magnetic pole portion The magnetic pole surface faces the outer peripheral surface of the second braking drum,
A transmission is provided.
[0012]
When a neutral drum is disposed adjacent to the first braking drum and the magnet means is positioned in the braking release position, the pole faces of the first and second pole portions of each of the permanent magnets are It is preferable to face the outer peripheral surface of the neutral drum.
A fourth planetary gear mechanism for transmitting the rotation of the input shaft to the output shaft by reversing the rotation of the input shaft is provided. The fourth planetary gear mechanism includes a ring gear, and a planetary gear meshed with the ring gear and the planetary gears of the first planetary gear mechanism. A planetary carrier connected to the planetary carrier of the first planetary gear mechanism, and a fourth braking drum made of a conductive material connected to the ring gear, wherein the magnet operating means moves the magnet means. , Configured to be positioned at a fifth braking position facing the outer peripheral surface of the fourth braking drum, and when the magnet means is positioned at the fifth braking position, the magnetic pole surface of each of the second magnetic pole portions of the permanent magnets It is preferable to face the outer peripheral surface of the fifth braking drum.
A neutral drum made of a magnetic material is disposed between the first braking drum and the fourth braking drum, and when the magnet means is positioned at the fifth braking position, the magnetic pole surface of the second magnetic pole portion is moved to the fifth braking position. And the magnetic pole surface of the first magnetic pole portion preferably faces the outer peripheral surface of the neutral drum.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a transmission according to the present invention will be described in more detail with reference to the accompanying drawings illustrating a preferred embodiment thereof. FIG. 1 shows a schematic configuration diagram of an embodiment of a transmission according to the present invention. The transmission shown in FIG. 1 is mounted on a vehicle (not shown), and has an input shaft 2 driven by the power of a prime mover, an output shaft 3 arranged on the same axis as the input shaft 2, and an input shaft 2. A first planetary gear mechanism 41, a second planetary gear mechanism 42, a third planetary gear mechanism 43, and a fourth planetary gear mechanism 44 are disposed between the output shaft 3. The first, second, and third planetary gear mechanisms 41, 42, and 43 are arranged in this order from the output shaft 3 side to the input shaft 2 side, and the fourth planetary gear mechanism 44 includes a first planetary gear mechanism. The mechanism 41 is arranged on the output shaft 3 side. A sun gear unit 22 is connected to the input shaft 2 via a one-way clutch 21. The input shaft 2 is provided with a boss 2a having a larger diameter than the input shaft 2. The boss 2a is formed with a fitting hole having a common axis with the input shaft 2, and the outer ring of the one-way clutch 21 is fitted into the fitting hole and integrally connected. Part of the boss 2a constitutes a planetary carrier 43d of the third planetary gear mechanism 43. The sun gear unit 22 includes a central shaft portion 22A, and sun gears 41a, 42a, and 43a that are integrally provided on an outer peripheral portion of the central shaft portion 22A with an axial interval therebetween. The central shaft portion 22A of the sun gear unit 22 is integrally connected to the inner ring or central shaft of the one-way clutch 21.
[0014]
The first planetary gear mechanism 41 includes the sun gear 41a, a ring gear 41b concentrically disposed with the sun gear 41a, a planetary gear 41c meshed with the sun gear 41a and the ring gear 41b, and a planetary carrier 41d. . The planetary gear 41c is rotatably supported by the planetary carrier 41d. The second planetary gear mechanism 42 includes the sun gear 42a, a ring gear 42b disposed concentrically with the sun gear 42a, a planetary gear 42c meshed with the sun gear 42a and the ring gear 42b, and a planetary carrier 42d. . The planetary gear 42c is rotatably supported by the planetary carrier 42d. The third planetary gear mechanism 43 includes the sun gear 43a, a ring gear 43b arranged concentrically with the sun gear 43a, a planetary gear 43c meshed with the sun gear 43a and the ring gear 43b, and a planetary carrier 43d. . The planetary gear 43c is rotatably supported by the planetary carrier 43d. The fourth planetary gear mechanism 44 includes a ring gear 44b disposed on a common axis with the input shaft 2 and the output shaft 3, a planetary gear 44c meshed with the ring gear 44b and the planetary gear 41c of the first planetary gear mechanism 41, and The first planetary gear mechanism 41 includes respective rotating elements of a planetary carrier 44d integrally connected to a planetary carrier 41d of the planetary gear mechanism 41. The planetary gear 44c is rotatably supported by the planetary carrier 44d.
[0015]
The planetary carrier 41d of the first planetary gear mechanism 41 is integrally connected to the output shaft 3, and the planetary gear 41c has a relatively large tooth width in the illustrated embodiment. The first braking drum 41D and the planetary carrier 42d of the second planetary gear mechanism 42 are integrally connected to the ring gear 41b of the first planetary gear mechanism 41. A second braking drum 42D is integrally connected to a ring gear 42b of the second planetary gear mechanism 42. A third braking drum 43D is integrally connected to the ring gear 43b of the third planetary gear mechanism 43. The planetary carrier 43d of the third planetary gear mechanism 43 is integrally connected to the input shaft 2 as described above. A fourth braking drum 44D is integrally connected to the ring gear 44b of the fourth planetary gear mechanism 44. The first, second, third, and fourth brake drums 41D, 42D, 43D, and 44D having a common axis with the input shaft 2 and the output shaft 3 are provided on the outer peripheral sides of the ring gears 41b, 42b, and 43b, respectively, It is arranged at a position outside the direction. The first, second, and third braking drums 41D, 42D, and 43D are arranged in this order from the output shaft 3 side to the input shaft 2 side at relatively small constant intervals in the axial direction, The fourth brake drum 44D is disposed on the output shaft 3 side of the first brake drum 41D with a relatively large axial interval. The first, second, third, and fourth braking drums 41D, 42D, 43D, and 44D are each formed from a conductive material (eg, copper, aluminum, iron, steel, etc.) and each have substantially the same outer diameter. It is formed to have dimensions. Forming these braking drums from copper, aluminum, or the like, which has a higher conductivity than magnetic materials, such as iron and steel, can be generated on the surface when relative rotation occurs with magnet means 5000 described later. This is preferable because the eddy current that occurs is larger than that of iron or steel, and the braking efficiency of the drum is improved.
[0016]
A neutral drum 45D is provided at a position axially adjacent to the first braking drum 41D (a position adjacent to the second braking drum 42D on the opposite side in the axial direction of the first braking drum 41D). I have. The neutral drum 45D is formed from a magnetic material. In the illustrated embodiment, the ring gear 44b of the fourth planetary gear mechanism 44 includes a cylindrical portion having a relatively large axial width. The neutral drum 45D is rotatable relative to the outer peripheral surface of the cylindrical portion via a well-known member that allows relative rotation, for example, a roller or a bearing member, so as to cover substantially the entire area in the width direction of the outer peripheral surface of the cylindrical portion. (In the embodiment, rollers are shown). Due to the relatively large axial width of the ring gear 44b, a predetermined axial interval (relatively large interval) is provided between the first braking drum 41D and the fourth braking drum 44D. A neutral drum 45D is provided within the interval. The outer diameter of the neutral drum 45D is also substantially the same as the other brake drums. The fourth brake drum 44D, the neutral drum 45D, the first, second, and third brake drums 41D, 42D, and 43D are arranged at a certain interval in the axial direction. Although the fourth brake drum 44D and the first and second brake drums 41D and 42D have substantially the same axial width as each other, the third brake drum 43D is different from the fourth brake drum 44D. , The axial width is formed wider than the first and second brake drums 41D and 42D (at least twice the axial width of the fourth brake drum 44D, the first and second brake drums 41D and 42D). ). Further, the neutral drum 45D is formed to be wider in the axial direction than the third braking drum 43D (at least three axial widths of the fourth braking drum 44D, the first and second braking drums 41D and 42D). Times). Although the third braking drum 43D is formed integrally in the illustrated embodiment, it may be constituted by two members integrally connected to the ring gear 43b. Further, the neutral drum 45D may also be constituted by three members arranged at intervals in the axial direction.
[0017]
The illustrated transmission includes magnet means 500 (in other words, the rotation is restricted and axially movable on the outer peripheral sides of the first to fourth brake drums 41D to 44D and the neutral drum 45D). Magnet means 500 movably arranged only in the axial direction) and the first to fifth braking positions facing the outer peripheral surfaces of the braking drums 41D to 44D by moving the magnet means 500 in the axial direction; And magnet actuating means 6 positioned at a braking release position that does not face the outer peripheral surfaces of the drums 41D to 44D. The first to fourth braking drums 41D to 44D, the neutral drum 45D, the magnet means 500, and the magnet operating means 6 provide a rotary element brake for applying a braking force to one of the rotary elements constituting each of the planetary gear mechanisms 41 to 44. Configure means.
[0018]
Referring to FIGS. 7 to 10, magnet means 500 includes magnet support means 500A and a plurality of permanent magnets 550 arranged on magnet support means 500A. Each of the permanent magnets 550 has substantially the same shape and size as one another. As shown in FIG. 9, the permanent magnet 550 includes a first magnetic pole portion 550a and a second magnetic pole portion 550b that are arranged to face each other at an interval in the axial direction, and the first and second magnetic pole portions 550b. And a bridging portion 550c arranged to connect the magnetic pole portions 550a and 550b. The first and second magnetic pole portions 550a and 550b are configured to extend from both ends of the bridging portion 550c in parallel with each other and at the same length at right angles to the bridging portion 550c. The first and second magnetic pole portions 550a and 550b and the bridging portion 550c have a substantially rectangular cross section. Therefore, the first and second magnetic pole portions 550a and 550b extend from one surface of the bridging portion 550c at the two ends in the longitudinal direction of the bridging portion 550c by the same length in parallel with each other and at right angles to the one surface. It is configured as follows. In this embodiment, the first magnetic pole part 550a, the second magnetic pole part 550b, and the bridging part 550c are formed integrally. As is clear from FIG. 9, the permanent magnet 550 configured as described above has a substantially channel shape or a U shape as a whole. Each of the first and second magnetic pole portions 550a and 550b has a magnetic pole surface that forms mutually different poles (N-S) at the respective tips. Each of the pole faces has a rectangular shape. As described later, in a state where the permanent magnet 550 is disposed on the screw rod member 60 of the magnet operating means 6, and in a broader sense, a state where the permanent magnet 550 is disposed on the transmission, each of the permanent magnets 550 First and second magnetic pole portions 550a and 550b arranged so as to face each other at intervals in the direction, and a bridging portion 550c arranged to connect the first and second magnetic pole portions 550a and 550b. The first and second magnetic pole portions 550a and 550b are configured to extend radially inward from both ends of the bridging portion 550c, and in each of the permanent magnets 550, the first and second magnetic pole portions 550a and 550b 550b has magnetic pole faces (N or S) oriented inward in the radial direction and having mutually opposite polarities.
[0019]
The magnet support means 500A includes a first magnet support ring 551, a second magnet support ring 552, a first magnet press ring 553, and a second magnet press ring 554. As partially shown in FIG. 10, the first magnet support ring 551 has a cylindrical main body 551a having a constant axial width and a radial thickness, and an outer peripheral surface of the main body 551a. A plurality (even number) of protrusions 551b extending radially outward at equal intervals from each other over the entire circumference. The first magnet support ring 551 is formed from a non-magnetic material such as an aluminum alloy, for example. The radially outer surface of the protrusion 551b is formed of an arc surface positioned on a common circumferential surface having a common axis with the main body 551a.
[0020]
For example, the second magnet support ring 552, which can be formed from a non-magnetic material such as an aluminum alloy, has a cylindrical main body 555 having a certain axial width and a constant radial thickness, and an outer peripheral surface of the main body 555. A boss portion 556 extending radially outward and another boss portion 557 (see FIG. 1) extending radially outward from the outer peripheral surface at a position opposite to the boss portion 556 across the axis. ing. A plurality of mounting holes 555a are formed in the main body 555 so as to extend in the axial direction at intervals in the circumferential direction. A female screw 556a is formed on the boss 556 so as to extend in the axial direction, and a guided hole 557a is formed on the other boss 557 so as to extend in the axial direction. It is preferable that the female screw 556a is formed inside another cylindrical member having excellent durability such as a steel material, and this cylindrical member is embedded in the boss portion 556. The guided hole 557a is preferably formed inside another cylindrical member having a low coefficient of friction and excellent in durability, and this cylindrical member is preferably embedded in another boss 557.
[0021]
The axial width of the first magnet support ring 551 is substantially equal to the distance between the opposing surfaces of the first and second magnetic pole portions 550a and 550b of the permanent magnet 550. The inner diameter is slightly larger than the outer diameter of the first to fourth brake drums 41D to 44D. The radial thickness of the main body portion 551a of the first magnet support ring 551 is substantially equal to the length of the first and second magnetic pole portions 550a and 550b of the permanent magnet 550 extending from the bridge portion 550c. Furthermore, the interval between the protrusions 551b of the first magnet support ring 551 is substantially equal to the width of the permanent magnet 550. The axial width of the second magnet support ring 552 is determined by the distance between both end surfaces in the longitudinal direction of the permanent magnet 550 (end surfaces of the first and second magnetic pole portions 550a and 550b opposite to the surfaces facing each other). Almost equal. The inner peripheral surface of the main body 555a of the second magnet support ring 552 has the outer diameter of the radially outer surface of the protrusion 551b of the first magnet support ring 551 (the outer diameter of the outer peripheral surface common to the outer surface). Diameter).
[0022]
The first and second magnet retaining rings 553 and 554, which are substantially common to each other, are formed of annular disks having a constant axial thickness and radial width, and are made of a non-magnetic material such as an aluminum alloy. Is formed. A plurality of mounting holes 553a and 54a are formed in the first and second magnet holding rings 553 and 554 so as to extend in the axial direction at intervals in the circumferential direction, respectively. Each of the mounting holes 553a and 554a is aligned with each of the mounting holes 555a formed in the main body 555 of the second magnet support ring 552. The inner diameters of the first and second magnet holding rings 553 and 554 are slightly larger than the outer diameters of the first to fourth brake drums 41D to 44D, and the outer diameters of the first and second magnet holding rings 53 and 54 are different. The diameter is substantially equal to the outer diameter of the main body 555 of the second magnet support ring 552.
[0023]
The permanent magnet 550 is a radially outer surface of the main body 551a of the first magnet support ring 551, and is mounted between each of the protrusions 551b. The mutually opposing surfaces of the first and second magnetic pole portions 550a and 550b of the permanent magnet 550 are substantially in contact with both side surfaces of the main body portion 551a of the first magnet support ring 551, and the first and second magnetic poles are provided. The magnetic pole surfaces of the portions 550a and 550b are positioned so as to be almost in contact with the circumferential surface coinciding with the inner circumferential surface of the main body portion 551a from the outside in the radial direction on both sides in the width direction of the main body portion 551a of the first magnet support ring 551. Can be Further, both side surfaces of each bridging portion 550c of the permanent magnet 550 are substantially brought into close contact with the mutually facing circumferential surfaces of the projections 551b of the first magnet support ring 551 (the circumferential surfaces of the projecting portions 551b). The spacing is formed so as to gradually increase radially outward). Still further, the maximum outer diameter portion of each of the permanent magnets 550 in the radial outer surface has a radius relative to a common circumferential surface with the radial outer surface of the projection 551b of the first magnet support ring 551. It is positioned so as to be almost in contact from the inside in the direction. In a state where the permanent magnet 550 is mounted on the first magnet support ring 551, each radial outer surface of the permanent magnet 550 is formed into a common circumferential surface with the radial outer surface of the protrusion 551 b of the first magnet support ring 551. May be formed on an arc surface that substantially matches with the angle.
[0024]
As described above, with the plurality of permanent magnets 550 mounted on the first magnet support ring 551, the first magnet support ring 551 fits on the inner peripheral surface of the main body 555 of the second magnet support ring 552. Is done. The radially outer surface of each of the projections 551b of the first magnet support ring 551 is substantially in close contact or pressure contact with the inner peripheral surface of the main body 555 of the second magnet support ring 552. Both end surfaces in the longitudinal direction of the permanent magnet 550 are located on substantially the same plane as both side surfaces in the width direction of the second magnet support ring 552, respectively. The first and second magnet holding rings 553 and 554 are respectively abutted on both side surfaces in the width direction of the main body 555 of the second magnet supporting ring 552, and the first and second magnet holding rings 553 and 554 are attached. The holes 553a and 554a and the mounting holes 555a of the main body portion 555 of the second magnet support ring 552 are aligned in an axial direction with a plurality of bolts 558 and 559 in alignment. The inner peripheral surfaces of the first and second magnet holding rings 553 and 554 are positioned so as to be substantially aligned with the inner peripheral surface of the main body 551a of the first magnet support ring 551.
[0025]
In the illustrated embodiment, the magnet actuating means 6 includes one screw rod member 60 having an external thread formed on the outer peripheral surface, and a stepping motor M as a drive source for driving the screw rod member 60 to rotate. . One end of the screw rod member 60 is drivingly connected to a drive shaft (not shown) of the stepping motor M, and the other end is rotatably supported by the housing 1 of the transmission. The magnet actuating means 6 also includes at least one (in the embodiment, one) guide rod 61 disposed on the housing 1 of the transmission. The screw rod member 60 and the guide rod 61 extend in parallel with an axis common to the input shaft 2 and the output shaft 3. A female screw 556a formed in the boss portion 556 of the second magnet support ring 552 is screw-engaged with the screw rod member 60, and a guided hole formed in another boss portion 557 of the second magnet support ring 552. By the 557a being slidably fitted to the guide rod 61, the second magnet support ring 552 is supported along the screw rod member 60 and the guide rod 61 so as to be reciprocally movable in the axial direction.
[0026]
As described above, in a state where each of the permanent magnets 550 is supported by the magnet supporting means 500A, the first magnetic pole portion 550a of each of the permanent magnets 550 adjacent to each other in the circumferential direction is connected to the first magnet support 550. The magnetic pole surfaces of the first magnetic pole portions 550a which are arranged at equal intervals in the circumferential direction on one side in the axial direction of the ring 551, and which are adjacent to each other in the circumferential direction, have mutually different polarities. Further, the second magnetic pole portions 550b are arranged at equal intervals in the circumferential direction on the other axial side of the first magnet support ring 551, and each of the second magnetic pole portions 550b adjacent to each other in the circumferential direction. The magnetic pole faces have mutually different polarities. Referring to FIG. 11 and FIG. 12, a magnetic field which can be represented by magnetic force lines from N to S between magnetic pole surfaces of first magnetic pole portion 550 a in each of permanent magnets 550 circumferentially adjacent to each other. Is formed between the magnetic pole surfaces of the second magnetic pole portion 550b in each of the permanent magnets 550 adjacent to each other in the circumferential direction. . Further, a magnetic path which can be indicated by a magnetic force line extending from the magnetic pole surface of the first magnetic pole portion 550a to the magnetic pole surface of the second magnetic pole portion 550b is formed in the bridging portion 550c of each of the permanent magnets 550 (the (When the magnetic pole surface of the first magnetic pole portion 550a is S and the magnetic pole surface of the second magnetic pole portion 550b is N), or from the magnetic pole surface of the second magnetic pole portion 550b to the magnetic pole surface of the first magnetic pole portion 550a. A magnetic path that can be represented by lines of magnetic force is formed (when the magnetic pole surface of the second magnetic pole portion 550b is S and the magnetic pole surface of the first magnetic pole portion 550a is N). In this way, a magnetic circuit that is continuous in the circumferential and axial directions is formed between the permanent magnets 550 arranged in an annular shape over the entire circumference.
[0027]
Referring to FIG. 1, by controlling the rotation of the stepping motor M of the magnet operating means 6, the magnet unit 500, more specifically, the magnetic pole surface of the first magnetic pole part 550 a in each of the permanent magnets 550 and / or Alternatively, the magnetic pole surface of the second magnetic pole portion 550b is opposed to the outer peripheral surface of at least one of the first to fourth brake drums 41D to 44D with a predetermined gap therebetween, and the first, second, and third magnetic pole portions 550b. , The fourth or fifth braking position, and the braking release position that does not face any of the outer peripheral surfaces of the first to fourth braking drums 41D to 44D.
[0028]
More specifically, in a state where the magnet means 500 is positioned at the braking release position [neutral position (N)] shown in FIG. 1, the magnetic pole surfaces of the first magnetic pole portions 550a of the permanent magnets 550 and The magnetic pole surfaces of the second magnetic pole portion 550b are opposed to both axial ends of the outer peripheral surface of the neutral drum 45D with a predetermined gap. When the magnet means 500 is positioned at the first braking position [first speed position (I)] shown in FIG. 2, the magnetic pole surfaces of the first magnetic pole portions 550a of the permanent magnets 550 correspond to the first braking drum 41D. The magnetic pole surface of the second magnetic pole portion 550b faces the outer peripheral surface, and faces the axial center of the outer peripheral surface of the neutral drum 45D. When the magnet means 500 is positioned at the second braking position [second speed position (II)] shown in FIG. 3, the magnetic pole surfaces of the first magnetic pole portions 550a of the permanent magnets 550 correspond to the second braking drum 42D. The magnetic pole surface of the second magnetic pole portion 550b faces the outer circumferential surface, and faces one axial end (one end portion on the first braking drum 41D side) of the outer circumferential surface of the neutral drum 45D. When the magnet means 500 is positioned at the third braking position [third speed position (III)] shown in FIG. 4, the magnetic pole surfaces of the first magnetic pole portions 550a of the permanent magnets 550 correspond to the third braking drum 43D. The outer peripheral surface faces one axial end (one end on the second braking drum 42D side), and the magnetic pole surface of the second magnetic pole portion 550b faces the outer peripheral surface of the first braking drum 41D. When the magnet means 500 is positioned at the fourth braking position [fourth speed position (IV)] shown in FIG. 5, the magnetic pole surface of each first magnetic pole portion 550a of the permanent magnet 550 is positioned on the third braking drum 43D. Opposite the other end of the outer peripheral surface, and the magnetic pole surface of the second magnetic pole portion 550b opposes the outer peripheral surface of the second braking drum 42D. When the magnet means 500 is positioned at the fifth braking position [reverse position (R)] shown in FIG. 6, the magnetic pole surface of each second magnetic pole portion 550b of the permanent magnet 550 is connected to the fourth braking drum 44D. And the magnetic pole surface of the first magnetic pole portion 550a faces an intermediate portion of the outer peripheral surface of the neutral drum 45D.
[0029]
The rotational drive control of the stepping motor M of the magnet operating means 6 can be easily performed, for example, as follows. That is, the braking release position [neutral position (N)] shown in FIG. 1 of the second magnet support ring 552 in the magnet means 500 is determined in advance as a reference position, and the braking release position [neutral position (N)] which is the reference position ] Is calculated in advance and stored in a controller (not shown) corresponding to the movement stroke from the first to fifth braking positions. Then, the controller calculates the rotation speed corresponding to the movement stroke between the braking position based on the shift instruction signal from the driver and the current braking position, and causes the stepping motor M to rotate forward or reverse by the rotation speed. The second magnet support ring 552 can be axially moved from the current braking position to the braking position based on the shift instruction signal along the screw rod member 60 and the guide rod 61 while rotation is restricted.
[0030]
The transmission shown in FIG. 1 is configured as described above, and its operation will be described below. When the magnet means 500 is positioned in the neutral position (N) as shown in FIGS. 1, 7 and 8, as described above, the first magnetic pole portion 550a of each of the permanent magnets 550 Since the magnetic pole surface and the magnetic pole surface of the second magnetic pole portion 550b are opposed to the outer peripheral surface of the neutral drum 45D, the second magnetic pole between the magnetic pole surface of the first magnetic pole portion 550a and the neutral drum 45D made of a magnetic material, A magnetic circuit is formed between each magnetic pole surface of the magnetic pole portion 550b and the neutral drum 45D and between each magnetic pole surface of the first magnetic pole portion 550a and the magnetic pole surface of the second magnetic pole portion 550b in each of the permanent magnets 550. You. For this reason, each magnetism of the permanent magnet 550 does not act on the first to fourth brake drums 41D to 44D. As described above, since the neutral drum 45D is relatively rotatably disposed on the cylindrical portion of the ring gear 44b so as to cover the outer peripheral surface thereof, each of the permanent magnets 550 faces the outer peripheral surface of the neutral drum 45D. However, the magnetism is substantially absorbed by the neutral drum 45D, and the magnetism does not reach the ring gear 44b located inside the neutral drum 45D. Therefore, the braking does not act on the ring gear 44b, so that the power is not substantially transmitted. . That is, when the magnet unit 500 is in the neutral position (N), the neutral drum 45D functions so that the magnet unit 500 does not exert a braking force for transmitting power. The output shaft 3 is generally in a state of being fixed by the operation of a braking device of the vehicle or the like. Therefore, the planetary carriers 41d and 44d of the first planetary gear mechanism 41 and the fourth planetary gear mechanism 44 are fixed. On the other hand, the first to fourth brake drums 41D to 44D, that is, the ring gear 41b of the first planetary gear mechanism 41 and the planetary carrier 42d of the second planetary gear mechanism 42, the second planetary gear mechanism 42, and the third planetary gear None of the ring gears 42b and 43b of the gear mechanism 43 and the ring gear 44b of the fourth planetary gear mechanism 44 are fixed. As a result, power is not substantially transmitted from the input shaft 2 to the output shaft 3. The first to fourth brake drums 41D to 44D are caused to idle.
[0031]
Referring to FIG. 2, to operate the transmission at the first speed, if the magnet means 500 is positioned at the first speed position (I), as described above, each first magnetic pole portion 550a of each of the permanent magnets 550 will be described. Is opposed to the outer peripheral surface of the first braking drum 41D, and the magnetic pole surface of the second magnetic pole portion 550b is opposed to the outer peripheral surface of the neutral drum 45D. FIGS. 11 and 12 show a state in which the magnetic pole surface of each first magnetic pole portion 550a of the permanent magnet 550 faces the outer peripheral surface of the first brake drum 41D. A magnetic field is formed between the magnetic pole surfaces of the first magnetic pole portions 550a of the permanent magnet 550, and a magnetic circuit is formed between the magnetic pole surfaces of the second magnetic pole portions 550b and the neutral drum 45D. The first braking drum 41D is located in the magnetic field formed between the magnetic pole surfaces of the first magnetic pole portion 550a, and thus receives the magnetic action between the magnetic pole surfaces of the first magnetic pole portion 550a. Since the first brake drum 41D is caused to idle, a relative speed difference occurs between each of the first magnetic pole portions 550a and the first brake drum 41D. Since the eddy current is generated on the outer peripheral surface of the first braking drum 41D due to the relative speed difference, the planetary carriers of the first braking drum 41D, ie, the ring gear 41b of the first planetary gear mechanism 41 and the second planetary gear mechanism 42. 42d receives the braking torque. As a result, the rotational torque transmitted to the input shaft 2 is transmitted to the planetary gear 41c of the first planetary gear mechanism 41 via the sun gear 41a of the first planetary gear mechanism 41 provided in the one-way clutch 21 and the sun gear unit 22. Is transmitted to. The planetary gear 41c revolves while rotating along the ring gear 41b, and this revolution is transmitted to the output shaft 3 via the planetary carrier 41d. In this case, the rotation speed of the input shaft 2 is reduced and transmitted to the output shaft 3. The first braking drum 41D, that is, the ring gear 41b and the planetary carrier 42d receive a braking torque based on the eddy current, and the rotation speed decreases. However, when the rotation speed decreases, a braking torque based on the eddy current is generated. There is no stop because it is gone. Therefore, the ring gear 41b and the planetary carrier 42d rotate around a low predetermined rotation speed even during torque transmission. Note that the principle of the generation of the braking force acting on the first braking drum 41D as described above is the same for the other braking drums, and therefore, description thereof will be omitted in the following description.
[0032]
Referring to FIG. 3, to operate the transmission at the second speed, if the magnet means 500 is positioned at the second speed position (II), as described above, the first magnetic pole portion 550a of each of the permanent magnets 550 will be described. Is opposed to the outer peripheral surface of the second braking drum 42D, and the magnetic pole surface of the second magnetic pole portion 550b is opposed to the outer peripheral surface of the neutral drum 45D. Since the second braking drum 42D is positioned in the magnetic field formed between the magnetic pole surfaces of the first magnetic pole portion 550a, it receives the magnetic action between the magnetic pole surfaces of the first magnetic pole portion 550a. Since the second brake drum 42D is idled, the second brake drum 42D, that is, the ring gear 42b of the second planetary gear mechanism 42 receives the braking torque. As a result, the rotational torque transmitted to the input shaft 2 is transmitted to the planetary gear 42 c of the second planetary gear mechanism 42 via the sun gear 42 a of the second planetary gear mechanism 42 provided in the one-way clutch 21 and the sun gear unit 22. Is transmitted to the planetary gear 41c of the first planetary gear mechanism 41 via the sun gear 41a of the first planetary gear mechanism 41. The planetary gear 42c revolves while rotating along the ring gear 42b, and the revolution is transmitted to the output shaft 3 via the planetary carrier 42d, the ring gear 41b of the first planetary gear mechanism 41, the planetary gear 41c, and the planetary carrier 41d. In the case of the second speed, the rotation speed of the input shaft 2 is increased to be higher than that in the case of the first speed and transmitted to the output shaft 3.
[0033]
As described above, when the transmission is operating at the first speed or the second speed, which is the lower speed, the third braking drum 43D, which is the rotating element on the higher speed side, is also idled, but its rotation speed is the input shaft 2. Will not exceed the number of revolutions. As a result, when the transmission is operated at a low gear, the rotating element on the high gear, that is, the third braking drum 43D is prevented from idling at high speed, and the loss of driving energy is reduced, so that the driving efficiency is improved. This is improved over the conventional transmission described above. When the transmission is operating at the first speed or the second speed, which is the low speed, the fourth brake drum 44D is also idled, but its rotation speed does not exceed the rotation speed of the input shaft 2.
[0034]
Referring to FIG. 4, in order to operate the transmission at the third speed, if the magnet means 500 is positioned at the third speed position (III), as described above, each first magnetic pole portion 550a of each of the permanent magnets 550 will be described. Is opposed to the outer peripheral surface of the third braking drum 43D, and the magnetic pole surface of the second magnetic pole portion 550b is opposed to the outer peripheral surface of the first braking drum 41D. The third braking drum 43D is positioned in the magnetic field formed between the magnetic pole surfaces of the first magnetic pole portion 550a, and thus receives the magnetic action between the magnetic pole surfaces of the first magnetic pole portion 550a. In addition, since the first braking drum 41D is positioned in the magnetic field formed between the magnetic pole surfaces of the second magnetic pole portion 550b, the first braking drum 41D receives the magnetic action between the magnetic pole surfaces of the second magnetic pole portion 550b. . Since the third brake drum 43D and the first brake drum 41D are idled, the third brake drum 43D, ie, the ring gear 43b of the third planetary gear mechanism 43, and the first brake drum 41D, ie, the first The ring gear 41b of the planetary gear mechanism 41 and the planetary carrier 42d of the second planetary gear mechanism 42 receive the braking torque. As a result, the rotation torque transmitted to the input shaft 2 is transmitted to the planetary gear 43c via the planetary carrier 43d of the third planetary gear mechanism 43. The planetary gear 43c revolves while rotating along the ring gear 43b, and the rotation and the revolution are transmitted to the sun gear unit 22 via the sun gear 43a of the third planetary gear mechanism 43 provided in the sun gear unit 22. Since the speed of the sun gear 43a, that is, the sun gear unit 22, is higher than that of the input shaft 2, the engaged state of the one-way clutch 21 is released. The rotational torque transmitted to the sun gear unit 22 as described above is transmitted to the planetary gear 41c via the sun gear 41a of the first planetary gear mechanism 41. The planetary gear 41c revolves while rotating along the ring gear 41b, and this revolution is transmitted to the output shaft 3 via the planetary carrier 41d. In the case of the third speed, the rotation speed of the input shaft 2 is increased to be higher than that in the case of the second speed and transmitted to the output shaft 3. When the gear ratios of the third planetary gear mechanism 43 and the first planetary gear mechanism 41 are set to be the same, the rotation speed of the output shaft 3 becomes the same as the rotation speed of the input shaft 2 and becomes 1: 1. Speed ratio can be obtained.
[0035]
Referring to FIG. 5, in order to operate the transmission at the fourth speed, if the magnet means 500 is positioned at the fourth speed position (IV), as described above, each first magnetic pole portion 550a of each of the permanent magnets 550 will be described. Is opposed to the other end of the outer peripheral surface of the third braking drum 43D, and the magnetic pole surface of the second magnetic pole portion 550b is opposed to the outer peripheral surface of the second braking drum 42D. The third braking drum 43D is positioned in the magnetic field formed between the magnetic pole surfaces of the first magnetic pole portion 550a, and thus receives the magnetic action between the magnetic pole surfaces of the first magnetic pole portion 550a. In addition, since the second braking drum 42D is positioned in the magnetic field formed between the magnetic pole surfaces of the second magnetic pole portion 550b, it receives the magnetic action between the magnetic pole surfaces of the second magnetic pole portion 550b. . Since the third brake drum 43D and the second brake drum 42D are idled, the third brake drum 43D, ie, the ring gear 43b of the third planetary gear mechanism 43, and the second brake drum 42D, ie, the second The ring gear 42b of the planetary gear mechanism 42 receives the braking torque. As a result, as in the case of the third speed, the rotational torque transmitted to the input shaft 2 is transmitted to the planetary gear 43c via the planetary carrier 43d of the third planetary gear mechanism 43. The planetary gear 43c revolves while rotating along the ring gear 43b, and the rotation and the rotation are transmitted to the sun gear unit 22 via the sun gear 43a of the third planetary gear mechanism 43 disposed on the main body 22a of the sun gear unit 22. Is transmitted. The speed of the sun gear 43a, that is, the sun gear unit 22, is higher than that of the input shaft 2, so that the one-way clutch 21 is maintained in the disengaged state. The rotational torque transmitted to the sun gear unit 22 as described above is transmitted to the planetary gear 42c via the sun gear 42a of the second planetary gear mechanism 42, and is also transmitted via the sun gear 41a of the first planetary gear mechanism 41. The power is transmitted to the planetary gear 41 c of the first planetary gear mechanism 41. The planetary gear 42c revolves while rotating along the ring gear 42b, and this revolution is transmitted to the ring gear 41b of the first planetary gear mechanism 41. The rotation torque transmitted to the ring gear 41b is transmitted to the output shaft 3 via the planetary gear 41c and the planetary carrier 41d. In the case of the fourth speed, the rotation speed of the input shaft 2 is increased and transmitted to the output shaft 3 as compared with the case of the third speed.
[0036]
When the transmission is operated at the third speed (see FIG. 4), as described above, the rotational torque transmitted to the input shaft 2 is applied to the planetary carrier 43d, the planetary gear 43c, and the sun gear of the third planetary gear mechanism 43. It is configured to be transmitted to the output shaft 3 via the sun gear 43a provided in the unit 22 and the sun gear 41a, the planetary gear 41c and the planetary carrier 41d provided in the sun gear unit 22 of the first planetary gear mechanism 41. Therefore, unlike the conventional transmission described above, it is not necessary to drive three planetary gear mechanisms, and power can be transmitted to the output shaft 3 by driving relatively few gears. As a result, the drive efficiency of the transmission can be improved, which is practically useful.
[0037]
When the transmission is operated at the fourth speed (see FIG. 5), as described above, the rotational torque transmitted to the input shaft 2 is applied to the planetary carrier 43d, the planetary gear 43c and the sun gear of the third planetary gear mechanism 43. The sun gear 43a provided in the unit 22, the sun gear 42a of the second planetary gear mechanism 42, the planetary gear 42c and the planetary carrier 42d provided in the sun gear unit 22, the ring gear 41b of the first planetary gear mechanism 41 (the planetary carrier 42d) and is transmitted to the output shaft 3 via a planetary gear 41c and a planetary carrier 41d. Even in the case of the fourth speed, it is not necessary to drive the four planetary gear mechanisms as in the conventional transmission described above, and power is transmitted to the output shaft 3 by driving relatively few gears. Can be. Further, in the conventional transmission described above, it is necessary to drive three brake drums. However, in the above-described transmission, it is sufficient to drive one brake drum (only the first brake drum 41D). This point is also advantageous. As a result, the drive efficiency of the transmission can be improved, which is practically useful.
[0038]
Next, referring to FIG. 6, in order to operate the transmission in reverse, when the magnet means 500 is positioned at the reverse position (R), the second magnetic pole portion of each of the permanent magnets 550 is set as described above. The magnetic pole surface of 550b faces the outer peripheral surface of the fourth braking drum 44D, and the magnetic pole surface of the first magnetic pole portion 550a faces the outer peripheral surface of the neutral drum 45D. The fourth braking drum 44D is positioned in a magnetic field formed between the magnetic pole surfaces of the second magnetic pole portion 550b, and thus receives the magnetic action between the magnetic pole surfaces of the second magnetic pole portion 550b. Since the fourth braking drum 44D is caused to idle, the fourth braking drum 44D, that is, the ring gear 44b of the fourth planetary gear mechanism 44 receives the braking torque. As a result, the rotational torque transmitted to the input shaft 2 is transmitted to the planetary gear 41c of the first planetary gear mechanism 41 via the sun gear 41a of the first planetary gear mechanism 41 provided in the one-way clutch 21 and the sun gear unit 22. Is transmitted to. When the planetary gear 41c is driven, the planetary gear 44c of the fourth planetary gear mechanism 44 revolves while rotating along the ring gear 44b. Since the planetary gear 44c is driven by the sun gear 41a of the first planetary gear mechanism 41 via the planetary gear 41c, the rotation direction is the same as that of the sun gear 41a, so that the revolving direction is opposite. That is, the rotation direction of the planetary carrier 44d is opposite to that of the sun gear 41a. As a result, the power transmitted to the planetary gear 44c is transmitted via the planetary carrier 44d so as to rotate the output shaft 3 in the opposite direction to the input shaft 2. The output shaft 3 is rotationally driven in a direction for moving the vehicle backward. In the reverse operation described above, even if the neutral drum 45D is subjected to the braking action by the first permanent magnet 51, it does not affect the shifting operation.
[0039]
As described above, in the above transmission, the magnet unit 500 is moved to the first speed position (I), the second speed position (II), the third speed position (III), the fourth speed position (IV), and the reverse position (R). By selectively positioning, it is possible to obtain an output of a predetermined gear ratio. Since the rotary element braking means for applying a braking force to each of the ring gears, the planetary carrier, and the like is a braking mechanism using an eddy current, there is no mechanical contact portion, and the braking force can be applied in a non-contact manner. As a result, there is no wear during braking, and the durability can be improved. In addition, the braking mechanism by the eddy current generates a slipping force between the braking drum and the magnet means to apply a braking force, thereby allowing the planetary gear mechanism to function. Even if the vehicle is directly connected to the engine, the vehicle can be driven to start from a stopped state. That is, when the transmission configured according to the present invention is applied to a transmission of a vehicle, it is possible to eliminate a fluid coupling such as a friction clutch and a torque converter used for starting the vehicle.
[0040]
Further, in the transmission, by arranging the first, second and third planetary gear mechanisms, it is possible to obtain a transmission capable of performing four-speed shifting. As a result, the number of parts is small, the overall configuration is compact, and the weight and cost have been reduced.
[0041]
Still further, in the above-described transmission, each of the permanent magnets 550 arranged at intervals in the circumferential direction has the first and second magnetic pole portions 550a arranged to face each other at intervals in the axial direction. And 550b, and a bridging portion 550c arranged to connect the first and second magnetic pole portions 550a and 550b. The first and second magnetic pole portions 550a and 550b are configured to extend radially inward from both ends of the bridging portion 550c. In each of the permanent magnets 550, the first and second magnetic pole portions 550a and 550b have magnetic pole faces that are radially inwardly oriented and have mutually different polarities, and are adjacent to each other in the circumferential direction. , The magnetic pole surfaces of the first magnetic pole portion 550a and the magnetic pole surfaces of the second magnetic pole portion 550b have mutually different polarities. That is, in each of the permanent magnets 550 of the present invention, a magnetic field is continuously formed between the magnetic pole surfaces of the first magnetic pole portions 550a arranged in the circumferential direction, and the second magnetic poles arranged in the circumferential direction. A magnetic field is continuously formed between the magnetic pole surfaces of the portion 550b, and a bridging portion 550c extending in the axial direction is formed between the first magnetic pole portion 550a and the second magnetic pole portion 550b. Since the first magnetic pole portion 550a and the second magnetic pole portion 550b are separated from each other, the permanent magnet 550 is compared with a conventional permanent magnet having a configuration in which the first magnetic pole portion 550a and the second magnetic pole portion 550b are separated from each other. Can be further enhanced without increasing the radial dimension of each of the permanent magnets. Further, the magnetic force of each of the permanent magnets 550 can be strengthened without increasing the area of each of the magnetic pole faces of the permanent magnets 550 that are directed radially inward. As a result, the transmission performance of the driving force can be further improved. As described above, the transmission performance of the driving force from the input shaft 2 to the output shaft 3 is improved as the braking force acting on the braking drum is increased in each gear, but in the transmission according to the present invention, Since the braking force acting on the braking drum can be increased without increasing the radial dimension of each of the permanent magnets 550 and without increasing the area of the pole faces of each of the permanent magnets 550, the speed change can be performed. The drive performance can be improved while achieving a compact and lightweight device. Therefore, the transmission according to the present invention is extremely advantageous in mounting on a vehicle.
[0042]
In the transmission according to the present invention, the planetary gear 44c of the fourth planetary gear mechanism 44 is disposed substantially adjacent to the planetary gear 41c of the first planetary gear mechanism 41 in the circumferential direction and slightly outward in the radial direction. There are other embodiments that are configured to be engaged and engaged. According to this transmission, the tooth width of the planetary gear 41c of the first planetary gear mechanism 41 and the diameter of the ring gear 44b of the fourth planetary gear mechanism 44 can be reduced. When the diameter of the ring gear 44b is reduced, the diameters of the fourth brake drum 44D, the neutral drum 45D having the same outer diameter, and the first to third brake drums 41D to 43D are reduced accordingly. . As a result, the configuration of the entire transmission is reduced in size, weight and cost can be reduced, which is practically advantageous. In the above embodiment, the magnet actuating means 6 is constituted by the screw rod member 60 and the stepping motor M. However, instead of this, another embodiment constituted by another magnet actuating means, for example, a fluid pressure cylinder mechanism. Forms are also possible.
[0043]
Although the present invention has been described with reference to the embodiment of the transmission mounted on the vehicle, there is no reason why the use of the transmission according to the present invention is not limited to the vehicle, and the transmission can be widely applied as an industrially used transmission. It is possible. In the transmission according to the present invention, when it is not necessary to reversely transmit the rotation direction of the input shaft 2 to the output shaft 3, the fourth planetary gear mechanism 44 and the fourth braking drum 44D, which are reverse rotation mechanisms, are unnecessary. Needless to say, In the above embodiment, since the neutral drum 45D is formed of a magnetic material such as iron or steel, each of the first magnetic pole 550a and / or the second magnetic pole 550b of the permanent magnet 550 is formed of the neutral drum 45D. When opposed to the outer peripheral surface (one of the neutral position, the first speed position, the second speed position, and the reverse position), between the neutral drum 45D and the first magnetic pole part 550a and / or the second magnetic pole part 550b Since the magnetic circuit is formed in the first planetary gear mechanism 44, the magnetic field is prevented from being applied to the ring gear 44b of the fourth planetary gear mechanism 44, and the ring gear 44b is not subjected to the braking action. The braking force caused by the eddy current is substantially between the first and second magnetic pole portions 50a and 550b of the permanent magnet 550 and the outer peripheral surface of the cylindrical portion of the ring gear 44b. In the case where a space for setting a sufficient air gap without acting on the neutral drum 45D can be secured, another embodiment in which the neutral drum 45D is omitted can be realized.
[0044]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the transmission by this invention, it becomes possible to strengthen the magnetic force of a permanent magnet, without increasing the radial dimension of a permanent magnet, As a result, it becomes possible to improve the transmission performance of a driving force. Also, it is possible to enhance the magnetic force of the permanent magnet without increasing the radial dimension of the permanent magnet, and without increasing the area of the magnetic pole face of the permanent magnet, which is directed radially inward. Thus, it is possible to improve the transmission performance of the driving force.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of a transmission according to the present invention, and is a schematic configuration diagram showing a neutral state.
FIG. 2 is a schematic configuration diagram showing a first-speed operation state of the transmission shown in FIG. 1;
FIG. 3 is a schematic configuration diagram showing a second speed operating state of the transmission shown in FIG. 1;
FIG. 4 is a schematic configuration diagram showing a third-speed operating state of the transmission shown in FIG. 1;
FIG. 5 is a schematic configuration diagram showing a fourth-speed operating state of the transmission shown in FIG. 1;
FIG. 6 is a schematic configuration diagram showing a reverse operation state of the transmission shown in FIG. 1;
FIG. 7 is a schematic cross-sectional view showing a main part of another embodiment of the magnet means according to the present invention, showing a state where the magnet means is positioned at a neutral position.
FIG. 8 is a cross-sectional view taken along the line AA of FIG.
FIG. 9 is an enlarged perspective view showing a permanent magnet provided in the magnet means shown in FIG. 7;
FIG. 10 is an enlarged perspective view showing a part of a first magnet support ring provided in the magnet unit shown in FIG. 7;
FIG. 11 is a schematic diagram showing a state of a magnetic field formed between permanent magnets provided in the magnet unit shown in FIG. 7 by magnetic lines of force.
FIG. 12 is a schematic diagram of the permanent magnet array shown in FIG. 11 as viewed from the axial direction.
[Explanation of symbols]
2 Input shaft
3 Output shaft
6. Magnet operating means
21 One Way Clutch
22 Sun gear unit
22A center shaft
41 First Planetary Gear Mechanism
41D first braking drum
42 Second planetary gear mechanism
42D second braking drum
43 Third planetary gear mechanism
43D third braking drum
44 Fourth planetary gear mechanism
44D fourth braking drum
45D neutral drum
41a, 42a, 43a Sun gear
41b, 42b, 43b 44b
Ring gear
41c, 42c, 43c, 44c Planetary gear
41d, 42d, 43d, 44d planetary carrier
500 magnet means
550 permanent magnet
550a First magnetic pole part
550b Second magnetic pole part
550c Bridge

Claims

In a transmission having first, second, and third planetary gear mechanisms disposed between an input shaft and an output shaft,
First, second, and third brake drums made of a conductive material, magnet means disposed on the outer peripheral side of each brake drum so as to be movable only in the axial direction, and moving the magnet means to form the brake drum. Magnet operating means positioned at first, second, third, and fourth braking positions facing the outer peripheral surface and at a braking release position not facing the outer peripheral surface of the braking drum;
A sun gear unit having a sun gear of each planetary gear mechanism is connected to the input shaft via a one-way clutch, and a planetary carrier of a third planetary gear mechanism is connected to the input shaft. The ring gear of the third planetary gear mechanism has a third gear. The second braking drum is connected to the ring gear of the second planetary gear mechanism, and the first braking drum and the planetary carrier of the second planetary gear mechanism are connected to the ring gear of the first planetary gear mechanism. Connected, the planetary carrier of the first planetary gear mechanism is connected to the output shaft,
The magnet means includes a magnet support means and a plurality of permanent magnets disposed on the magnet support means at a circumferential distance from each other, and each of the permanent magnets is mutually spaced at an axial direction. The first and second magnetic pole parts are arranged so as to face each other, and the bridging part is arranged so as to connect the first and second magnetic pole parts. Wherein each of the permanent magnets has a first and second pole portion having a radially inwardly directed, mutually opposite pole face, and configured to extend radially inward from both ends of the portion. In each of the permanent magnets adjacent to each other in the circumferential direction, the magnetic pole surfaces of the first magnetic pole portion and the magnetic pole surfaces of the second magnetic pole portion form mutually different polarities,
When the magnet means is positioned at the first braking position, the magnetic pole surface of each first magnetic pole portion of the permanent magnet faces the outer peripheral surface of the first braking drum, and the first magnetic pole portion is positioned at the second braking position. The magnetic pole surface of the magnetic pole portion faces the outer peripheral surface of the second braking drum, and when positioned at the third braking position, the magnetic pole surface of the first magnetic pole portion faces the third braking drum and the second magnetic pole The magnetic pole surface of the first magnetic pole portion faces the outer circumferential surface of the first braking drum, and when positioned at the fourth braking position, the magnetic pole surface of the first magnetic pole portion faces the third braking drum and the second magnetic pole portion The magnetic pole surface faces the outer peripheral surface of the second braking drum,
A transmission, comprising:

When a neutral drum is disposed adjacent to the first braking drum and the magnet means is positioned in the braking release position, the pole faces of the first and second pole portions of each of the permanent magnets are The transmission according to claim 1, wherein the transmission faces the outer peripheral surface of the neutral drum.

A fourth planetary gear mechanism is provided for transmitting the rotation of the input shaft to the output shaft by reversing the rotation of the input shaft. The fourth planetary gear mechanism includes a ring gear, a planetary gear meshed with the ring gear and a planetary gear of the first planetary gear mechanism. And a planetary carrier connected to the planetary carrier of the first planetary gear mechanism, and a fourth braking drum made of a conductive material connected to the ring gear, wherein the magnet operating means moves the magnet means. , Configured to be positioned at a fifth braking position facing the outer peripheral surface of the fourth braking drum, and when the magnet means is positioned at the fifth braking position, the magnetic pole surface of each of the second magnetic pole portions of the permanent magnets The transmission according to claim 1, wherein the transmission is opposed to an outer peripheral surface of the fifth braking drum.

A neutral drum made of a magnetic material is disposed between the first braking drum and the fourth braking drum, and when the magnet means is positioned at the fifth braking position, the magnetic pole surface of the second magnetic pole portion is moved to the fifth braking position. 4. The transmission according to claim 3, wherein the magnetic pole surface of the first magnetic pole portion faces the outer peripheral surface of the neutral drum.