JP2000310308A - Toroidal type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce distribution of stresses applied to a lubricating oil passage of a retainer, to thereby improve durability and reliability. SOLUTION: This transmission has a thrust rolling bearing for bearing a thrust direction-wise load added to a power roller. The thrust rolling bearing which is constituted of a plurality of rolling elements 23 and a retainer 21 for rollably retaining a plurality of the rolling elements 23. The retainer 21 has a ring-like main body 22, a plurality of pockets 22 at a diameter direction- wise intermediate portion of the main body 22 for rollably retaining the rolling elements 23, and lubricating oil passages 25 each having a single circular arc-like section between an inner periphery edge and an outer periphery edge of the main body 22 in the condition transversing across the pocket 24.

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 having an improved cage for rotatably holding a plurality of rolling elements.

[0002]

2. Description of the Related Art In recent years, toroidal-type continuously variable transmissions have been used as transmissions for automobiles or transmissions for various industrial machines. This toroidal type continuously variable transmission is
For example, it is known from Japanese Utility Model Laid-Open Publication No. 7-35847 and the like, and the thrust rolling bearing and the lubricating device thereof are configured as shown in FIG.

[0003] In other words, an input disk 2 and an output disk 3 whose inner peripheral surfaces are opposed to each other are rotatably supported around the rotating shaft 1. A trunnion 4 is provided between the input disk 2 and the output disk 3 so as to swing about a pivot (not shown) which is twisted with respect to the central axes of the disks 2 and 3. The trunnion 4 is provided with a displacement shaft 5. Around the displacement shaft 5, a power roller 6 rotatably supported while being sandwiched between the input disk 2 and the output disk 3 is provided. Further, between the power roller 6 and the trunnion 4, there is provided a thrust rolling bearing 7 for supporting a load in the thrust direction applied to the power roller 6.

The inner peripheral surfaces 2a, 3a of the input disk 2 and the output disk 3 are concave surfaces each having a circular cross section.
The peripheral surface 6a of the power roller 6 is a spherical convex surface,
The peripheral surface 6a and the inner peripheral surfaces 2a, 3a are in contact with each other. The thrust rolling bearing 7 includes a plurality of rolling elements 8.
And a cage 9 for rotatably holding the plurality of rolling elements 8.
It has.

The retainer 9 has a ring-shaped main body 10, each of which is provided at a radially intermediate portion of the main body 10 and a rolling element 8.
And a plurality of pockets 11 that hold the roller in a freely rolling manner. Further, a lubricating oil flow path 12 composed of a concave groove is provided between the inner peripheral edge and the outer peripheral edge of the main body 10 so as to cross the pockets 11.

Therefore, according to the toroidal-type continuously variable transmission configured as described above, the cage 9 constituting the thrust rolling bearing 7 is displaced in the axial direction, and one side of the cage 9 and one side thereof are Even when the opposing surfaces are in close contact with each other, a sufficient amount of lubricating oil flows through the lubricating oil passage 12 into the pocket 11 holding each rolling element 8. As a result, there is no possibility that a part of the thrust rolling bearing 7 is significantly worn or seized.

[0007]

However, the thrust rolling bearing 7 as the power roller bearing of the toroidal type continuously variable transmission has a traction contact structure as shown in FIG.
As shown in the figure, the thrust rolling bearing 7 and the input disk 2
And the contact point (load point) of the output disk 3 is indicated by an arrow 2
And has a contact angle α. For this reason, the inner ring 7a of the thrust rolling bearing 7 receives a force in the thrust direction, and at the same time, a radial component force is generated at a position facing 180 ° on the circumference, so that the annular thrust rolling bearing 7 is compressed in the radial direction. I do.

As a result of this compression, the inner ring 7a is deformed into an elliptical shape as shown in FIG. Further, due to the power transmission, a tangential force 2Ft is generated at the traction contact portion as shown in FIG. This force is the force P that tends to knock down the thrust rolling bearing 7.
, Causing an imbalance in power.

The revolution speed of the rolling element 8 of the thrust rolling bearing 7 used in such a state has a distribution as shown in FIG. That is, the revolution speed of the rolling element 8 in the 2Ft direction is lower than the revolution speed of the rolling element 8 in the anti-2Ft direction (the length of the arrow indicates the revolution speed). Therefore, as shown in FIG. 7, the contact load between the rolling element 8 and the cage 9 is such that the rolling element 8 moves the cage 9 as shown by an arrow (the length indicates the size of the contact load) in the anti-2Ft direction. In the 2Ft direction, the retainer 9 is pushed in the direction opposite to the rotational direction. Therefore, compressive stress is applied to the pocket 11a and tensile stress is applied to the pocket 11b.
During one rotation, one pocket 11 is subjected to one cycle of stress load from both compression and tension swings.

Conventionally, as shown in FIG. 8, the lubricating oil flow passage 12 of the cage 9 used under such a use condition has a concave groove (both corners of a substantially U-shaped groove are formed as arcs R). Therefore, when the pocket 11 is pulled, the stress distribution around the concave groove is as shown in FIG. 9, and the maximum stress X is applied around the joint from the corner R to the groove bottom. There was a case where it was damaged from this part.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the distribution of stress applied to a lubricating oil flow path of a cage and improve the durability. It is to provide a continuously variable transmission.

[0012]

According to the present invention, in order to achieve the above-mentioned object, a first aspect of the present invention provides a rotating shaft and a rotatable support around the rotating shaft. A first and a second disk facing each other, a trunnion swinging about a pivot at a position twisted with respect to a center axis of the first and the second disk, and a displacement shaft provided on the trunnion. A power roller sandwiched between the first and second disks while being rotatably supported around the displacement axis; and a power roller provided between the power roller and the trunnion. A thrust rolling bearing for supporting a load in a thrust direction applied to the first and second disks, wherein the inner peripheral surfaces of the first and second disks are each concave in cross section, and the peripheral surface of the power roller is spherical. Convex The peripheral surface and the inner peripheral surface are in contact with each other, and the thrust rolling bearing is provided with a plurality of rolling elements and a toroidal stepless step including a retainer that holds the plurality of rolling elements in a freely rolling manner. In the transmission, the retainer has a ring-shaped main body, a plurality of pockets each provided at an intermediate portion of the main body with respect to the main body in the diametrical direction and rotatably holding the rolling element, and in a state crossing these pockets, It is provided between the inner peripheral edge and the outer peripheral edge of the main body, and is characterized by comprising a single arc-shaped lubricating oil flow path in cross section.

According to the above construction, the forcibly fed lubricating oil can lubricate the thrust rolling bearing through the lubricating oil flow path provided in the retainer, and the lubricating oil flow path has a cross section. The single arc shape reduces the stress generated in the lubricating oil flow path.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a first embodiment, in which the same components as those of the prior art are denoted by the same reference numerals and description thereof is omitted.
1A is a plan view of the cage, and FIG. 1B is an arrow A of FIG.
FIG. 2 is a side view seen from the direction, and FIG.

The retainer 21 shown in FIG. 1 is provided on the thrust rolling bearing 7 provided between the power roller 6 and the trunnion 4 in the toroidal type continuously variable transmission, as described in the prior art. . The retainer 21 includes a ring-shaped main body 22 and a plurality of pockets 24 each provided at an intermediate portion of the main body 22 in the diametrical direction and rotatably holding a rolling element 23. Further, a lubricating oil flow path 25 is provided between the inner peripheral edge and the outer peripheral edge of the main body 22 so as to cross the pockets 24.

The lubricating oil passage 25 provided on the inner peripheral edge and the outer peripheral edge of the main body 22 has a single arc-shaped cross section.
That is, the main body 22 of the retainer 21 has the same thickness T as the conventional one.
The distance t between the groove bottoms of the lubricating oil flow path 25 is the same as the conventional one, but the cross section of the lubricating oil flow path 25 has a single arc R dimension R3 mm to R10 mm, and the distance t between the groove bottoms is at least 3 mm. It is formed as described above, and preferably has a single arc R dimension R5 mm.

According to the experiment conducted by the inventor, it has been found that when the cross section of the lubricating oil flow path 25 is set to a single arc R dimension R5 mm, the stress generated in the lubricating oil flow path 25 is reduced to about 60%. Further, the cross-sectional area of the lubricating oil passage 25 can be made equal to that of the conventional groove, and the flow rate of the lubricating oil flowing through the lubricating oil passage 25 does not change.

Further, by changing the dimension of the single arc R of the lubricating oil flow passage 25, the distance t between the groove bottoms can be made equal to or larger than the conventional one. Since the retainer 21 is installed in a form sandwiched between the outer ring and the power roller 6,
Although it must be kept within the limited dimensions, as described above, the cross section of the lubricating oil flow path 25 has a single arc R dimension R3 mm.
It is desirable that the distance t between R10 mm and the groove bottom is at least 3 mm or more.

With this configuration, the lubricating oil flow path 25 of the retainer 21 used under the same operating conditions as the conventional one has a single arc, so that the stress distribution generated in the lubricating oil flow path 25 can be improved. Is as shown in FIG. 2, and the maximum stress X
Can be reduced, breakage from the lubricating oil flow path 25 can be prevented, and durability can be improved.

[0021]

As described above, according to the first aspect of the present invention, the retainer in the toroidal type continuously variable transmission is provided with a ring-shaped main body and a rolling element provided at an intermediate portion of the main body and the main body in the diameter direction. It consists of multiple pockets that hold freely rolling,
A stress distribution applied to the lubricating oil flow path of the retainer is reduced by providing a single arc-shaped lubricating oil flow path between the inner peripheral edge and the outer peripheral edge of the main body in a state crossing these pockets. Therefore, there is an effect that durability and reliability can be improved.

[Brief description of the drawings]

FIGS. 1A and 1B show a first embodiment of the present invention, in which FIG. 1A is a plan view of a retainer, and FIG. 1B is a side view as seen from the direction of arrow A in FIG.

FIG. 2 is a view showing a distribution of stress generated in a lubricating oil flow channel of the embodiment.

FIG. 3 is a longitudinal sectional side view showing a thrust rolling bearing and a lubrication device of a conventional toroidal type continuously variable transmission.

FIG. 4 is an explanatory diagram showing a deformed state of the inner ring due to the pressing force.

FIG. 5 is an explanatory diagram showing a tangential force generated in the traction contact portion.

FIG. 6 is an explanatory diagram showing a revolution speed of a rolling element of the thrust rolling bearing.

FIG. 7 is an explanatory view showing a contact load between a rolling element of a thrust rolling bearing and a retainer.

8A is a plan view of the retainer, and FIG. 8B is a side view of the retainer as seen from the direction of arrow B in FIG.

FIG. 9 is a diagram showing the distribution of stress generated in the lubricating oil flow path.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotary shaft 2 ... Input disk 3 ... Output disk 4 ... Trunnion 5 ... Displacement shaft 6 ... Power roller 7 ... Thrust rolling bearing 21 ... Cage 22 ... Main body 23 ... Rolling element 24 ... Pocket 25 ... Lubricating oil flow path

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masayoshi Shimizuya 1-5-150 Kugenuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3J051 AA03 BA03 BB01 BE09 CB04 DA04 ED08 FA02 3J063 AA02 AB33 AC04 BA11 BB11 BB23 CA01 CB36 CD03 XD46 XD73 XE15

Claims (1)

[Claims] 1. A rotating shaft, first and second disks rotatably supported around the rotating shaft and having respective inner peripheral surfaces opposed to each other, and the first and second disks A trunnion that swings about a pivot axis that is twisted with respect to the center axis of the trunnion, a displacement shaft provided on the trunnion, and the first and second trunnions supported rotatably around the displacement axis. And a thrust rolling bearing provided between the power roller and the trunnion and supporting a load in the thrust direction applied to the power roller.
And the inner peripheral surface of the second disk is a concave surface having an arc-shaped cross section, and the peripheral surface of the power roller is a spherical convex surface, and this peripheral surface and the inner peripheral surface are in contact with each other. ,
The thrust rolling bearing is a toroidal-type continuously variable transmission that includes a plurality of rolling elements and a retainer that rotatably holds the plurality of rolling elements. A plurality of pockets provided at the intermediate portion in the diametrical direction of the main body and rotatably holding the rolling element, and provided between the inner peripheral edge and the outer peripheral edge of the main body in a state of crossing these pockets, and having a single cross section. A toroidal-type continuously variable transmission comprising a circular arc-shaped lubricating oil flow path.