JP2000304117A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of a disk and roller and the damage of a track surface and to always acheive the transmission of a power surely, even under a low temperature condition and high speed rotation. SOLUTION: In this toroidal type continuously variable transmission, disks 2, 3, 5 are made of an iron-based metal material and rollers 12, 13 are made of ceramic. Therefore, in this transmission, as the ceramic-made rollers 12, 13 are frictionally contacted with the metal-made disks 2, 3, 5, the seizure and damage become hard to occur compared with a case of the metal contacting mutually. In this transmission, as the rollers 12, 13 are made of ceramic against the heat generation caused by the high contact surface pressure between the disks 2, 3, 5 and rollers 12, 13, the heat resistance of the roller is improved and it is possible to use with higher contact bearing and higher rotation speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toroidal-type continuously variable transmission used for an automatic transmission of an automobile, for example.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional toroidal type continuously variable transmission. In this toroidal-type continuously variable transmission, a first input disk 81, an output disk 82, and a second input disk 83 are sequentially arranged on a concentric shaft.
The second input disks 81 and 83 and the output disk 82 rotate independently. Further, this transmission is sandwiched between a first input disk 81 and an output disk 82 so that
And a second roller 86 sandwiched between the second input disk 83 and the output disk 82 and transmitting power from the second input disk 83 to the output disk 82.

[0003] The first roller 85 is brought into frictional contact with the circumferential orbits 81A, 82A formed of concave curved surfaces of the first input disk 81 and the output disk 82, while the two disks 81, 82A are in contact with each other.
By rotating around a rotation axis 84 that intersects with the rotation axis of 82, power is transmitted from the first input disk 81 to the output disk 82. Further, the second roller 86 is connected to the second input disk 83.
And a circular orbit 8 composed of a concave curved surface of the output disk 82
3A and 82B while frictionally contacting both discs 83 and 82.
, And transmits power from the second input disk 83 to the output disk 82.

[0004] As shown by a solid line (dashed line) in FIG.
Rotation shafts 84 and 89 of roller 85 and second roller 86
However, the greater the angle of inclination of the disks 81, 82, 83 from the axis perpendicular to the rotation axis, the greater the speed increase ratio from the first and second input disks 81, 83 to the output disk 82.
(Reduction ratio) increases.

[0005]

In the above-mentioned conventional toroidal type continuously variable transmission, the disk and the roller are made of bearing steel or the like.

However, in a toroidal type continuously variable transmission,
The contact surface pressure between the disk and the roller is, for example, 4 GPa
(Gigapascal). For this reason, especially at a low temperature (for example, −40 ° C.), the viscosity of the lubricating oil increases, and a sufficient amount of oil is not supplied between the disk and the roller.
There is a problem that it becomes difficult to form an oil film, and adhesion between the disk and the roller and damage to the disk raceway surface occur.

Accordingly, an object of the present invention is to provide a toroidal-type continuously variable transmission which can prevent adhesion of a disk and a roller and damage to a raceway surface even under low-temperature conditions and high-speed rotation, and can always achieve reliable power transmission. Is to do.

[0008]

In order to achieve the above object, a toroidal type continuously variable transmission according to the present invention has a disk having a circular orbit having a concave curved surface opposed to each other, and has both circumferential surfaces of the opposed disk. A toroidal-type continuously variable transmission equipped with a roller that rotates while frictionally contacting a track to transmit power between the two disks, wherein the disk is made of a metal material, and the roller is made of ceramic. I have.

In the toroidal type continuously variable transmission according to the present invention,
Since the ceramic roller and the metal disk are in frictional contact, seizure and damage are less likely to occur than in the conventional example in which the metals are in contact with each other. Conventionally, the input / output disk has a large surface area and easily radiates heat in response to heat generated due to a high contact surface pressure between the disk and the roller, but the roller has a small surface area and tends to be heated to a high temperature. Since the roller is made of ceramic, the heat resistance of the roller is improved, and the roller can be used at a higher contact surface pressure and a higher rotation speed. Therefore,
ADVANTAGE OF THE INVENTION According to this invention, the adhesion of a disk and a roller and the damage of a raceway surface can be prevented even in low-temperature conditions and high-speed rotation, and reliable power transmission can always be achieved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of a toroidal type continuously variable transmission according to the present invention. In this embodiment, first and second input disks 2, 3 fixed to an input shaft 1 are disposed between the first and second input disks 2, 3, and the first and second input disks 2, 3, 3 and an output disk 5 which can be rotated coaxially and independently. The output disk 5 is rotatably supported by a bearing (not shown) with respect to the input shaft 1, and power is taken out to the output side by a belt 6 wound around a gear 5A.

The first input disk 2 has a concave curved surface circular orbit 8 facing the concave curved surface circular orbit 7 of the output disk 5, and the second input disk 3 has a concave curved circular orbit of the output disk 5. A concave curved surface-shaped circumferential orbit 11 facing the surface-assisted circumferential orbit 10 is provided. The first roller 12 is located between the track 8 of the first input disk 2 and the track 7 of the output disk 5.
Are arranged, and a second roller 13 is arranged between the track 11 of the second input disk 3 and the track 10 of the output disk 5. The first roller 12 rotates while frictionally contacting the tracks 8, 7 of the disks 2, 5, transmitting torque from the input disk 2 to the output disk 5, and the second roller 13 rotating the tracks 3, 5 It rotates while making frictional contact with 11,10,
The torque is transmitted from the input disk 3 to the output disk 5.

The first and second rollers 12 and 13 have rotating shafts 15 and 16 intersecting with the input shaft 1. The rotating shafts 15 and 16 are arranged such that the rollers 12 and 13 sandwich the output disk 5. Control is performed so that the inclination angles are symmetrical θ1 and θ2.
As the inclination angle θ1 increases, the reduction ratio increases, and the inclination angle θ
The larger the value of 2, the larger the speed increase ratio.

In this embodiment, the input disks 2, 3 and the output disk 5 are made of bearing steel, and the first and second rollers 12, 13 are made of a ceramic material.

When the input shaft 1 rotates, the first and second input disks 2 and 3 rotate together, and the toroidal-type continuously variable transmission having the above-described structure causes friction between the tracks 8 and 11 of the input disks 2 and 3. The rollers 12 and 13 that rotate in contact make frictional contact with both the tracks 7 and 10 of the output disk 5 to rotate the output disk 5 and transmit the rotational force.

Here, in this toroidal type continuously variable transmission, the rollers 12, 13 made of ceramic and the disks 2, 3, and 5 made of metal come into frictional contact with each other. Seizure and damage are less likely to occur. Further, in this embodiment, the heat resistance is improved by using the ceramic rollers 12 and 13 against the heat generated by the high contact surface pressure between the disks 2, 3, and 5 and the rollers 12, 13. Higher contact pressure and
It can be used at a higher rotation speed. Therefore, according to this embodiment, adhesion between the disks 2, 3, 5 and the rollers 12, 13 and damage to the raceway surfaces 8, 11, 7, 10 can be prevented even under low-temperature conditions and high-speed rotation. Power transmission can be achieved. Further, since the amount of oil at the time of high-speed rotation is small and seizure hardly occurs on the roller even when the temperature is high, the oil amount can be suppressed, the resistance to stirring of the oil can be suppressed, and the efficiency can be improved.

[0017]

As is clear from the above, in the toroidal type continuously variable transmission according to the present invention, the disk is made of a metal material, and the rollers are made of ceramic. Therefore, in the present invention, since the ceramic roller and the metal disk are in frictional contact, seizure and damage are less likely to occur as compared with the conventional example in which the metals are in contact with each other. Further, in the present invention, since a ceramic roller having better heat resistance is used for heat generated due to a high contact surface pressure between the disc and the roller, the roller is used at a higher contact surface pressure and a higher rotation speed. It becomes possible. Therefore, according to the present invention, even under low-temperature conditions and high-speed rotation, adhesion between the disk and the rollers and damage to the raceway surface can be prevented, and reliable power transmission can always be achieved.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of a toroidal type continuously variable transmission according to the present invention.

FIG. 2 is a partial sectional view showing a conventional toroidal type continuously variable transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Input shaft, 2, 3 ... Input disk, 5 ... Output disk, 5A ... Gear part, 6 ... Belt, 7, 8, 10, 11 ... Concave curved surface circular orbit, 12 ... First roller, 13 ... Second rollers, 15, 16,..., Rotation axes, θ1, θ2,.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuo Hekaku 3-5-8 Minamisenba, Chuo-ku, Osaka-shi, Osaka Inside Koyo Seiko Co., Ltd. (72) Inventor Shoji Eguchi 3-5-2 Minamisenba, Chuo-ku, Osaka-shi, Osaka No. 8 F-term in Koyo Seiko Co., Ltd. (reference) 3J051 AA03 BA03 BB01 BD02 BE09 CB04 EC03 EC08 FA02

Claims (1)

[Claims] 1. A disk having a circumferential orbit having a concave curved surface is opposed to a roller which rotates while frictionally contacting both circumferential orbits of the opposed disk to transmit power between the disks. A toroidal continuously variable transmission, wherein the disk is made of a metal material and the rollers are made of ceramic.