JP3321611B2 - Commutator assembly for micro motor and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable device, for example, a card type pager, a wristwatch, a portable telephone, or an information transmitting device such as a blind signal receiver, which generates vibration by rotating an eccentric vibrator. The present invention relates to a commutator assembly for a micro motor and a method for manufacturing the same. Further, the present invention relates to a commutator assembly of a micro-motor with low current consumption used for a portable electronic device using a dry battery, for example, a video camera or a small audio device, and a method of manufacturing the same.

[0002] Ultra-small motors used for the above purpose are required to be miniaturized year by year, and a motor having a diameter of about 5 mm is currently being developed. Furthermore, in recent years, those having a diameter of 3 mm to 4 mm including the housing have been demanded. However, it is difficult to continuously assemble a micro motor having a diameter of several millimeters including the housing by machining. Especially 3m including housing
The diameter of a shaft used for a micro motor having a diameter of m to 4 mm is about 1.0 mm. The ultra-small motor is required to have 10,000 rotations per minute. It has been difficult to continuously manufacture a commutator assembly including a shaft used for such a micro motor, which has no rotational runout. TECHNICAL FIELD The present invention relates to a commutator assembly for a micro motor, which has to rely on a manual operation in the current technology, and a method for manufacturing the same.

[0003]

2. Description of the Related Art FIG. 5 is a cross-sectional view for explaining a commutator assembly of a conventional microminiature motor. FIG. 6 is a plan view for explaining a commutator assembly of a conventional micro motor. 5 and 6, a commutator assembly 51 includes a shaft 52 serving as a rotating shaft of a micro motor.
, A molded resin member 53 and a commutator piece 54. One end of the shaft 52 is connected to the molding resin member 53.
Inside, a retaining ring 521 from which a knurl for rotation is cut is press-fitted.

The molding resin member 53 is made of, for example, an epoxy-based thermoplastic resin, and has a flange 531 serving as a base of the commutator assembly 51, a plurality of openings 532 formed in the flange 531, and a plurality of openings 532. A concave portion 533 connected to the opening 532 and a shaft fixing portion 534 for attaching the shaft 52 formed below the flange portion 531.
And a commutator piece support shaft 535 formed on the upper portion of the flange portion 531 to which the plurality of commutator pieces 54 are attached. The shaft 52 and the commutator piece 54 described above are
The molding resin is inserted into a mold (not shown).
At this time, the commutator pieces 54 adjacent to each other are arranged around the commutator piece support shaft 535 so as to be insulated. The commutator assembly 51 is assembled as described above.

[0005]

SUMMARY OF THE INVENTION An ultra-small motor to which the present invention is directed is for responding to a demand that the diameter of the shaft including the housing is 3 mm to 4 mm and the diameter of the shaft is 1.0 mm or less. is there. However, in order to reduce the diameter of the shaft of the ultra-small motor to 1.0 mm or less, it has become difficult to form a commutator piece support shaft with an insulating member at the end of the shaft. That is, in order to simply attach a commutator piece support shaft made of an insulating member to a metal shaft and rotate it 10,000 times per minute,
Unless the shaft is precisely machined, the commutator assembly has a problem that rotational runout occurs. There is also a demand for attaching a rotating object to both ends of a shaft of a micro motor. In this case, the commutator segments must be mounted around the shaft in an insulated state. If the insulating member interposed between the shaft and the commutator piece is not concentric with the center of the shaft, it may cause damage to the commutator piece and brushes, or cause abnormal rotation when the micro motor rotates. Becomes Furthermore, in a micro motor, the diameter of the shaft is often determined by the specifications of the user. But,
Since the diameter of the commutator segment assembly is often determined in advance, there is a problem that the thickness of the shaft selected by the user and the commutator assembly do not match.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is easy to assemble or manufacture and has no run-out even though it is an ultra-small motor which must rely on manual work. An object of the present invention is to provide a commutator assembly for a micro motor and a method for manufacturing the same.

[0007]

(First Invention) To achieve the above object, a commutator assembly for a micro motor according to the present invention comprises an insulating member (11 in FIG. 1) formed at a predetermined position on a wire.
1) and a detent boss (12 in FIG. 1) attached to the shaft (11).
A molded resin member (13 in FIG. 1) formed to include a detent boss (12) attached to the shaft (11) and a part of the insulating member (111); and the shaft (11). And a commutator piece (14 in FIG. 1) attached to the periphery of the insulating member (111).

(Second Invention) A commutator assembly for a micro motor according to the present invention is a shaft made of a wire (11 'in FIG. 3).
A detent boss (12 in FIG. 3) attached to the shaft (11 '), and a detent formed to cover the detent boss (12) attached to the shaft (11') and the wire. A resin member (13 'in FIG. 3) and a molded resin member (1) formed on the shaft (11').
Commutator piece attached around 3 ′) (14 in FIG. 3)
It is composed of

(Third Invention) A method of manufacturing a commutator assembly for a micro motor according to the present invention comprises the steps of: coating a predetermined position of one shaft (11) with an insulating member (111); Cutting the insulating member (111) concentrically with the shaft (11) while rotating the shaft; and rotating the boss (1) on the shaft (11).
2) attaching the shaft, a detent boss (12) attached to the shaft (11), and the insulating member (11).
Forming a molded resin member (13) so as to include 1); and commutator pieces (14) around the insulating member (111).
And a step of attaching

(Fourth Invention) The method for manufacturing a commutator assembly for a micro motor according to the present invention uses a single shaft (11 ').
Attaching the detent boss (12) to the shaft, and forming the molded resin member (1) so as to cover the detent boss (12) and the shaft (11 ') attached to the shaft (11').
3 '), and forming the molded resin member (13')
And attaching a commutator piece (14) around the periphery of the body.

[0011]

[Work] (First and Third Inventions) For example, an insulating member is applied or electrostatically coated at a predetermined position on a shaft of a micro motor. Since the insulating member applied or electrostatically coated on the shaft often does not have a perfect perfect circle, the insulating member is cut while rotating and formed concentrically with the shaft. A detent boss between the shaft and the commutator piece is attached to the shaft of the micro motor. Thereafter, a molded resin member is formed, for example, by being inserted into a part of the detent boss attached to the shaft and the insulating member. Further, a plurality of commutator pieces are attached around the insulating member of the shaft while being insulated from each other. The commutator assembly of a micro motor made in this way, even if the diameter of the shaft is extremely small,
It is easy to assemble and manufacture, and does not swing even at high speed rotation.

(Second and Fourth Inventions) A non-rotating boss such that the commutator piece does not rotate is press-fitted into the shaft of the micro motor, for example. Thereafter, the detent boss and the shaft attached to the shaft are formed by, for example, inserting a molded resin member. A plurality of commutator pieces are attached around the molding resin member of the shaft while being insulated from each other. The commutator assembly of the micro motor thus made is easy to assemble and manufacture even when the diameter of the shaft is extremely small, and does not swing even at high speed rotation.

[0013]

FIG. 1 is a sectional view for explaining a commutator assembly of a micro motor according to an embodiment of the present invention. FIG. 2 is a plan view illustrating a commutator assembly of a micro motor according to an embodiment of the present invention. 1 and 2, a commutator assembly 1 includes a metal shaft 11 serving as a rotating shaft of a micro motor, a molded resin member 13, a commutator piece 14, and a commutator piece 14 attached to the molded resin member 13. And a washer 15 for attaching the

A detent boss 12 having a detent knurl cut therein is press-fitted into the shaft 11 within the molded resin member 13. Further, an insulating member 111 such as Teflon (trade name) is applied or electrostatically applied to a predetermined position of the shaft 11, for example. After drying the insulating member 111, the insulating member 111 and the shaft 11
The insulating member 111 is cut while rotating the shaft 11 in order to make the shaft concentric.

Next, for example, a molding resin member 13 made of an epoxy-based thermoplastic resin includes a flange 131 serving as a base of the commutator assembly 1 and a plurality of openings 132 formed in the flange 131. And a shaft fixing portion 133 for attaching the shaft 11 formed below the flange portion 131, and a commutator piece support shaft 134 formed above the flange portion 131. The molding resin member 13 is inserted into the shaft 11 into which the detent boss 12 is press-fitted as described above using a mold (not shown). Next, the plurality of adjacent commutator pieces 14 are arranged around the insulating member 111 so as to form a gap 142 so as to be insulated from each other, and then fixed by the washer 15.

Thereafter, the coil (not shown) is attached to the flange portion 131, and its lead wire is arranged on the lead wire connection portion 141. Then, a current flows in a state in which a spot welding electrode (not shown) sandwiches the lead wire of the coil and the commutator piece 14 from the opening 132 and from above. The two are connected by Joule heat due to the contact resistance between the lead wire and the commutator piece 14.

In this embodiment, since the insulating member 111 is formed so as to be concentric with the shaft 11 after forming the insulating member 111 on a part of one metal shaft 11, high-speed rotation is performed. No swing. A metal shaft 11 is provided with an insulating member 111, and a commutator piece 14 is attached to this portion, so that a two-axis ultra-small motor can be obtained. Further, by using a wire having a diameter of 1 mm or less, a micro motor having a thin specification of the shaft 11 can be realized.

FIG. 3 is a sectional view for explaining a commutator assembly of a micro motor according to another embodiment of the present invention. FIG. 4 is a plan view illustrating a commutator assembly of a micro motor according to another embodiment of the present invention. The commutator assembly 1 'in FIGS. 3 and 4 and the commutator assembly 1 in FIGS.
3 'only. Shaft 1 in the present embodiment
As for 1 ', the shaft distal end 114 protrudes in order to use both axes. Further, the molded resin member 13 ′ is molded so as to cover the detent boss 12 and the shaft 11.

Commutator piece 14 in molded resin member 13 '
Is cut while rotating as necessary. Compared with the embodiment shown in FIGS. 1 and 2, this embodiment is more expensive in the mold for the molded resin member 13 '. However, the commutator piece 14 in the molded resin member 13 '
Is relatively easily concentric with the shaft 11 ', so that it is not necessary to use a high-speed rotation, and in particular, it is not necessary to perform a cutting process in order to make it concentric.

Although this embodiment has been described in detail, it is not limited to this embodiment. Various design changes can be made without departing from the present invention described in the appended claims. It goes without saying that the material of the shaft, the insulating member, the molded resin member and the like in this embodiment is not particularly limited as long as it is a commonly used material. The shape of the commutator assembly is
Even if this embodiment is modified, it is not particularly limited as long as it is within the range of design items.

[0021]

According to the present invention, the commutator assembly of the micro motor has a simple structure and does not swing even when rotating at high speed. According to the present invention, since the shaft passes through the center of the commutator assembly,
Easy for both axes. ADVANTAGE OF THE INVENTION According to this invention, a shaft and a commutator assembly can be made into a desired diameter only by forming an insulating member or a molding resin member on a shaft, without providing a step part in a shaft.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a commutator assembly of a micro motor according to an embodiment of the present invention.

FIG. 2 is a plan view illustrating a commutator assembly of a micro motor according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a commutator assembly of a micro motor according to another embodiment of the present invention.

FIG. 4 is a plan view illustrating a commutator assembly of a micro motor according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining a commutator of a micro motor in a conventional example.

FIG. 6 is a plan view for explaining a commutator of a micro motor in a conventional example.

[Explanation of symbols]

 1, 1 '... commutator assembly 11, 11' ... shaft 111 ... insulating member 114 ... shaft tip 12 ... detent boss 13, 13 '... molded resin member 131・ ・ ・ Flange part 132 ・ ・ ・ Opening part 133 ・ ・ ・ Shaft fixing part 134 ・ ・ ・ Commutator piece support shaft 14 ・ ・ ・ Commutator piece 141 ・ ・ ・ Lead wire connection part 142 ・ ・ ・ Void 15 ・ ・・ Washer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H02K 13/00-13/14 H02K 15/00-15/02 H02K 15/04-15/16 H02K 23 / 00-23/68

Claims (4)

(57) [Claims] 1. A shaft made of an insulating member formed at a predetermined position of a wire, a detent boss attached to the shaft, a detent boss attached to the shaft, and a part of the insulating member. A commutator assembly for a micro motor, comprising: a molded resin member formed on the shaft; and a commutator piece mounted around an insulating member formed on the shaft. 2. A shaft made of a wire, a detent boss attached to the shaft, a detent boss attached to the shaft and a molded resin member formed to cover the wire, and formed on the shaft. And a commutator piece attached to the periphery of the formed molded resin member. 3. A step of coating a predetermined position of one shaft with an insulating member; a step of cutting the insulating member concentrically with the shaft while rotating the shaft; and attaching a detent boss to the shaft. A step of forming a molded resin member so as to include the detent boss attached to the shaft and the insulating member; and a step of mounting a commutator piece around the insulating member. A method for manufacturing a commutator assembly for a small motor. 4. A step of attaching a detent boss to one shaft, a step of forming a molded resin member so as to cover the detent boss attached to the shaft and the shaft, and a commutator around the molded resin member. A method of manufacturing a commutator assembly for a micro motor, comprising: attaching a piece.