JP2000027880A - Constant velocity universal joint - Google Patents

Abstract

(57) [Problem] To provide a constant velocity universal joint capable of suppressing a moment acting on a roller assembly due to a load acting on the roller assembly from a trunnion. SOLUTION: A plurality of grooves 11 having a cylindrical outer race 10 and a shaft arranged inside the outer race 10 are formed at predetermined intervals in a circumferential direction on an inner periphery of the outer race 10. A plurality of trunnions 15 formed on the outer periphery of the shaft so as to protrude in the radial direction, and a roller assembly 17 attached to the outer periphery of each trunnion 15 and capable of rolling along each groove 11. In a tripod joint in which a curved surface 24 that is curved so as to protrude outward is formed on the outer peripheral surface of the solid 17, the inner peripheral surface 22 of the roller assembly 17 is located within a plane including the axis F <b> 2 of the roller assembly 17. Are curved so as to protrude inward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity universal joint arranged on a torque transmission path of a vehicle.

[0002]

2. Description of the Related Art Generally, when two members are arranged in a torque transmission path of a vehicle, and the two members are connected with a predetermined operating angle, the two members are connected by a constant velocity universal joint. Sometimes. This constant velocity universal joint includes a Zeppa type joint, a tripod type joint, a cross groove type joint, and a double offset type joint. A tripod joint is used for a portion where the amount of movement in the axial direction between the two members is large, such as the differential side of the front drive shaft of the vehicle, the wheel side of the rear drive shaft, or the differential side of the rear drive shaft. Is used. One example of such a tripod type joint is disclosed in Japanese Utility Model Laid-Open No. 3-100624 and Japanese Utility Model Laid-Open No. 3-1.
No. 05727.

The tripod joints described in the above publications are shown in FIGS. FIG. 5 is a half sectional view showing a partial configuration of the tripod joint 100, and FIG. 6 is a sectional view of the tripod joint 100 in the axial direction. Tripod joint 10
0 has a cylindrical outer ring 101 and a shaft member 102 disposed inside the outer ring 101. Also, the outer ring 101
Are provided with three grooves 103 at equal intervals in the circumferential direction.
Are formed. These three grooves 103 are provided on the outer race 10.
1 in the axial direction.

[0004] An annular tripod member 104 is attached to the outer periphery of the shaft member 102. On the outer periphery of the tripod member 104, three trunnions 105 protruding in the radial direction are formed at equal intervals in the circumferential direction. Each trunnion 105 is arranged to face each groove 103. Further, on the outer periphery of each trunnion 105,
An annular inner roller 10 through a plurality of needles 106
7 is attached. The trunnion 105 and the inner roller 107 constitute a protrusion. Then, in a plane including the axis of the inner roller 107, the shape of the outer peripheral surface 108 of the inner roller 107 is
It is curved so as to protrude outward.

[0005] An annular outer roller (torque transmitting member) 109 is attached to the outer periphery of the inner roller 107. The shape of the inner peripheral surface 110 of the outer roller 109 is substantially linear in a plane including the axis of the outer roller 109. Further, the inner diameter of the outer roller 109 is set slightly larger than the maximum outer diameter of the inner roller 107.

Therefore, the inner roller 107 and the outer roller 109 can move relative to each other in the axial direction by sliding between the outer peripheral surface 108 and the inner peripheral surface 110. Further, since the outer peripheral surface 108 of the inner roller 107 is a curved surface, the outer roller 109 can be turned and turned with respect to the inner roller 107. Since the outer roller 109 moves along the groove 103, the outer roller 109 actually moves with respect to the trunnion 105 along the axis B 1.
Swing in a plane including. Further, a curved surface 111 is formed on the outer periphery of the outer roller 109. This curved surface 111 is set based on a predetermined center of curvature,
And it is curved so as to protrude outward.

On the other hand, a pair of inner wall surfaces 112 is formed on both sides of each groove 103 in the width direction. The inner wall surface 112 is curved so as to protrude outward. The inner wall surface 112 and the curved surface 111 are in contact.

The tripod type joint 100 having the above structure
In a state in which is attached to the vehicle, the axis A1 of the outer ring 101 and the axis B1
, A predetermined operating angle (connection angle) θ1 is set. When the shaft member 102 rotates in a predetermined direction, the inner roller 107 moves from the inner roller 107 to the inner peripheral surface 11 of the outer roller 109.
A load acts at right angles to zero. Also, the shaft member 102
As the outer roller 109 rotates, the outer roller 109 moves in the length direction of the groove 103, and the outer roller 109 swings. By the above operation, the torque of the shaft member 102 is reduced by the trunnion 105, the inner roller 107, and the outer roller
And transmitted to the outer ring 101 via

[0009]

In the tripod joint 100 shown in FIGS. 5 and 6, the outer roller 109 moves along the groove 103, and the outer roller 109 moves the neck relative to the inner roller 107. With the swinging motion, the inner roller 107 and the outer roller 109 relatively move in the axial direction of the outer roller 109. That is, the inner roller 107 and the outer roller 109 reciprocate within a predetermined range with a change in the rotation phase of the shaft member 102 and the outer ring 101.

[0010] For example, referring to FIG.
In a case where the torque is transmitted by rotating clockwise in FIG. 4, a load acts on the inner peripheral surface of the outer roller 109 from the outer peripheral surface of the inner roller 107 on the right side of FIG. In addition, on the left side of FIG.
No load is generated between the inner peripheral surface of the inner roller 107 and the outer peripheral surface 108 of the inner roller 107.

When the inner roller 107 and the outer roller 109 move relative to each other in the axial direction of the outer roller 109, a line of action (not shown) of a load acting on the outer roller 109 from the inner roller 107 becomes
The curved surface 111 may deviate from the center of curvature. As a result, the distance from the center of curvature to the line of action of the load, in other words, the moment corresponding to the product of the arm length of the moment and the load acts around the center of curvature. This moment may cause the outer roller 109 to rotate in a plane including the axis.

Specifically, in FIG. 5, when the line of action of the load is set below the center of curvature, a moment is generated in the direction of rotating the outer roller 109 counterclockwise. As a result, the contact force between the outer roller 109 and the left inner wall surface 112 at the point C1 increases.

On the other hand, when the line of action of the load is set above the center of curvature, a moment is generated in the direction of rotating the outer roller 109 clockwise. As a result, the contact force between the outer roller 109 and the outer ring 101 at the point C2 increases.

The shaft member 102 and the outer ring 101
With the change in the rotation phase of
It is reciprocating in the axial direction along 03. For this reason,
As the outer roller 109 moves in the axial direction, an axial frictional force acts on the outer ring 101 at the points C1 and C2.

In the tripod type joint 100, since the torque is transmitted by the three outer rollers 109, the shaft member 102 and the outer ring 1 are formed.
During one rotation of 01, three cycles of forcing, that is, the third-order forcing (in other words, the fluctuation component of the induced thrust force)
Acts on the outer ring 101. As a result, this force is applied to the differential, transmission, engine,
There is a problem that noise is generated due to vibration of components that are transmitted to the body via the mount portion supporting the engine and are disposed on the transmission path of the forcing force.

In addition, as the frictional force between the outer roller 109 and the outer ring 101 increases, a part of the torque transmitted between the outer ring, 101 and the shaft member 102 is converted into frictional heat. As a result, the power transmission efficiency of the tripod type joint 100 is reduced, and the heat generation at the contact portion between the outer roller 109 and the outer ring 103 is increased, so that the durability of the tripod type joint 100 may be reduced.

The present invention has been made in view of the above circumstances, and provides a constant velocity universal joint capable of suppressing a moment acting on a torque transmitting member due to a load acting on the torque transmitting member from a projection. It is intended to provide.

[0018]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention has a cylindrical outer ring and a shaft member disposed inside the outer ring, and has a circle formed on the inner periphery of the outer ring. A plurality of grooves formed at predetermined intervals in a circumferential direction and extending in the axial direction of the outer ring; a plurality of protrusions formed on an outer periphery of the shaft member so as to protrude in a radial direction; and an outer periphery of each protrusion And a ring-shaped torque transmitting member which is attached to each of the grooves and is movable in the longitudinal direction of the groove by contacting each of the grooves. In a direction including the axis of the projecting portion, and swingable in a plane including the axis of the projecting portion. Where the axis of this torque transmitting member In a constant velocity universal joint having a curved surface that is curved so as to protrude toward the groove in a plane, a portion of the inner peripheral surface of the torque transmitting member that abuts on the outer peripheral surface of the protruding portion is formed. The torque transmission member is curved so as to protrude inward in a plane including the axis of the torque transmission member.

In the present invention, the ring-shaped torque transmitting member means that the shape of the portion that comes into contact with the outer peripheral surface of the projection is ring-shaped. Therefore, in the torque transmitting member according to the present invention, a portion of the torque transmitting member that abuts on the outer peripheral surface of the protruding portion is formed of an annular member, and a portion of the torque transmitting member that does not contact the protruding portion is a plate Closed with
A configuration having a bottomed cylindrical shape as a whole is also included.

According to this invention, the outer peripheral surface of the projecting portion abuts on the inner peripheral surface of the torque transmitting member, the curved surface of the torque transmitting member abuts on the inner surface of the outer race, and the torque is transmitted through each abutting portion. Is transmitted, and thus torque is transmitted between the shaft member and the outer ring. In addition, the torque transmitting member moves along the groove in the axial direction of the outer ring with a change in the rotational phase of the shaft member and the outer ring. Further, the torque transmitting member and the protruding portion move in the axial direction of the protruding portion, and the torque transmitting member swings with respect to the protruding portion in a plane including the axis of the protruding portion.

In the present invention, the inner peripheral surface of the torque transmitting member is curved so as to project inward in a plane including the axis of the torque transmitting member. For this reason, the line of action of the load applied from the outer peripheral surface of the protrusion to the inner peripheral surface of the torque transmitting member is set at right angles to a tangent including the contact portion (contact point) between the projecting portion and the torque transmitting member. .
That is, the line of action of the load is set in a direction as close as possible to the center of curvature. As a result, the distance from the center of curvature of the curved surface of the torque transmitting member to the line of action of the load, in other words, the length of the arm of the moment becomes as short as possible. Therefore, the moment generated around the center of curvature of the curved surface of the torque transmitting member due to the load acting on the torque transmitting member from the projecting portion is reduced.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a constant velocity universal joint according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 is a conceptual plan view of the front wheel drive vehicle 1 to which the present invention is applied. That is, at the front of the front wheel drive vehicle 1,
An engine 2, a transmission 3 for converting torque output from the engine 2, and a differential 4 connected to an output side of the transmission 3 are mounted. A pair of front drive shafts 5 are connected to the output side of the differential 4, and the pair of front drive shafts 5 are connected to the front wheels 6 respectively. That is, the pair of front drive shafts 5 are arranged to extend in the width direction of the front wheel drive vehicle 1.

The pair of front drive shafts 5 includes a tripod joint 7, which is a constant velocity universal joint, a shaft 8, and another constant velocity universal joint 9. That is, the tripod joint 7 is provided at one end of the shaft 8, and the constant velocity universal joint 9 is provided at the other end of the shaft 8. And one tripod joint 7
Are connected to the differential 4 side, and the other constant velocity universal joint 9 is connected to the front wheel 6 side. The tripod type joint 7 is called a so-called AAR (Angular Adjusted Roller) type. The constant velocity universal joint 9 is exemplified by a bar field type joint.

FIG. 3 shows the structure of the tripod joint 7 connected to the wheel 6 on the right side of FIG. FIG. 3 is a side end view of the tripod joint 7, and in FIG. 3, the shaft 8 is omitted for convenience. FIG. 4 is a front sectional view taken along line IV-IV in FIG.
FIG. 1 is a partially enlarged view of FIG. The tripod joint 7 connected to the wheel 6 on the left side of FIG. 2 is configured symmetrically to the tripod joint 7 shown in FIGS. 3 and 4, and a description thereof will be omitted.

The tripod type joint 7 has an outer race 10 having a bottomed cylindrical shape, and a shaft 8 having one end arranged inside the outer race 10. At the bottom of the outer race 10, a spline shaft (not shown) centered on the axis D1 is integrally formed. The differential 4 has a side gear (not shown), and the spline shaft and the side gear are connected. Further, three grooves 11 extending in the axial direction are formed on the inner periphery of the outer race 10. The grooves 11 are spaced at equal intervals in the circumferential direction,
They are arranged at intervals of 20 degrees.

Each groove 11 has a bottom surface 12 and an inner wall surface 13. The bottom surface 12 is substantially parallel to the axis D1, and a pair of inner wall surfaces 13 are connected to both sides of the bottom surface 12 in the width direction. In a plane orthogonal to the axis D <b> 1, the shape of the pair of inner wall surfaces 13 is curved so as to protrude outside the outer race 10. That is, the pair of inner wall surfaces 13 are configured to be mutually plane-symmetric.

When the tripod joint 7 is attached to the front wheel drive vehicle 1, a predetermined operating angle (connection angle) θ2 is set between the axis E1 of the shaft 8 and the axis D1 of the outer race 10. I have. Further, one end of the shaft 8 is disposed inside the outer race 10, and an annular tripod member 14 is spline-fitted to the outer periphery of the end of the shaft 8 on the outer race 10 side. The shaft 8 is provided with two snap rings 15A.
By A, the shaft 8 and the tripod member 14 are positioned in the axial direction of the shaft 8.

Then, on the outer periphery of the tripod member 14,
Three trunnions 15 projecting outward are formed. The trunnions 15 are arranged at equal intervals in the circumferential direction, specifically, at 120 ° intervals. Each trunnion 1
Reference numeral 5 has a substantially cylindrical shape. Tripod member 1
The protrusion amount of each trunnion 15 in the radial direction of 4 is set to a value such that the outer peripheral surface of each trunnion 15 reaches between the pair of inner wall surfaces 13. In addition, trunnion 15
Of the outer peripheral surface 16 is curved so as to protrude outward on a plane including the axis F <b> 1 of the trunnion 15.
That is, the shape of the outer peripheral surface 16 is set to a drum shape.

Further, an annular roller assembly 17 is attached to the outer periphery of each trunnion 15. The roller assembly 17 has an axis F2 (in FIG. 1,
(For convenience, it is common with the axis F1 of the trunnion 15)
Are formed in a ring around the center. The roller assembly 17 includes an inner ring 18, a needle 19, an outer roller 20, and a snap ring 21. The inner ring 18 is fitted on the outer periphery of the trunnion 15. The inner ring 18 is formed in a cylindrical shape, and the length of the inner ring 18 in the axial direction is set substantially equal to the amount of protrusion of the trunnion 15.

The shape of the inner peripheral surface 22 of the inner ring 18 is curved in a direction including the axis F2 of the inner ring 18 so as to protrude inward. That is, the inner peripheral surface 22 is formed in an arc shape that passes through the center in the axial direction of the roller assembly 17 and is based on a center of curvature (not shown) on a center line G1 orthogonal to the axis F2. I have. The minimum inner diameter of the inner peripheral surface 2 is the trunnion 1
5 is set slightly larger than the maximum outer diameter. For this reason, the inner ring 18 and the trunnion 15 can rotate relative to each other, and the inner ring 18
5 can be turned around.

The outer roller 20 is arranged outside the inner ring 18, and the outer roller 20 and the inner ring 18 are arranged concentrically. Further, a plurality of needle-shaped rolling elements 19 are arranged between the inner ring 18 and the outer roller 20. The inner ring 18 and the outer roller 20 are configured to be relatively rotatable via a plurality of rolling elements 19.

Further, two annular grooves 23 are formed on the inner peripheral surface of the outer roller 20. The snap ring 21 is attached to each annular groove 23,
The inner diameter of the snap ring 21 is set to a value smaller than the outer diameter of the inner ring 18 and larger than the inner diameter of the inner ring 18. The inner ring 18 and the plurality of rolling elements 19 are arranged between the two snap rings 21. In this manner, the inner ring 18 and the outer roller 20 are
The inner ring 18 and the outer roller 2
It is positioned and fixed in the 0 axis direction.

The outer roller 20 is formed in a ring shape, and a curved surface 24 is formed on the outer periphery of the outer roller 20. The curved surface 24 is curved so as to project outward of the outer roller 20 on a plane including the axis F2 of the outer roller 20. That is,
The curved surface 24 is set in a drum shape. In particular,
The curved surface 24 of the outer roller 20 in the plane
Is set on the center line G1 of the roller assembly 17 in the width direction.

The curved surface 24 and the inner wall surface 1 of the groove 11
The shape and dimensions of the curved surface 24 and the inner surface 13 are set so that the inner surface 3 and the inner surface 3 abut at two points in the width direction of the inner wall surface 13 and the outer roller 20 can move in the longitudinal direction of the groove 11. I have.

The trunnion 15 and the roller assembly 17
Is configured as described above, and the roller assembly 17 moves in the longitudinal direction of the groove 11.
Is capable of swinging (swinging) with respect to the trunnion 15 in a plane including the axis F1. Roller assembly 1
The trunnion 7 and the trunnion 15 are relatively movable in the axial direction of the trunnion 15.

Further, one end of a bellows-shaped boot 25 is fixed to the outer periphery on the open end side of the outer race 10, and the other end of the boot 25 is fixed to the shaft 8. Thus, the inside of the outer race 10 is sealed in a liquid-tight manner by the boot 25, and grease (not shown) is sealed in the sealed space L1.

The outer race 10 is made of a material such as carbon steel or chrome steel, the shaft 8 is made of a material such as carbon steel or boron steel, and the tripod member 14 is made of a material such as chrome steel. . The outer roller 20 and the inner ring 18 are made of a material such as bearing steel or chrome steel, and the needle 19 is made of a material such as bearing steel.

Here, the correspondence between the configuration of the embodiment and the configuration of the present invention will be described. That is, outer race 1
0 corresponds to the outer ring of the present invention, the shaft 8 corresponds to the shaft member of the present invention, the trunnion 15 corresponds to the protrusion of the present invention, and the roller assembly 17 corresponds to the torque transmitting member of the present invention.

Next, the running operation of the front wheel drive vehicle 1 shown in FIG. 2 will be described. The torque output from the engine 2 is transmitted to each front drive shaft 5 via a transmission 3 and a differential 4. Specifically, the torque output from the differential 4 causes the outer race 10 to rotate in a predetermined direction. The torque of the outer race 10 is transmitted to the shaft 8 via the roller assembly 17 and the tripod member 14.

Here, since the predetermined operating angle θ2 is set between the axis D1 and the axis E1, the roller assembly 17 moves in the longitudinal direction of the groove 11 with the rotation of the outer race 10, and Roller assembly 17 and trunnion 15
Are relatively moved in the axial direction, and the roller assembly 17 swings with respect to the trunnion 15. By these operations, the rotation of the outer race 10 and the shaft 8
The constant speed with the rotation of is maintained. Then, the torque of the shaft 8 is transmitted to the front wheels 6, and the front wheel drive vehicle 1 runs.

When torque is transmitted between the outer race 10 and the shaft 8, the trunnion 15
When the entire roller assembly 17 rolls in the groove 11 integrally based on conditions such as the frictional force between the outer roller 20 and the inner ring 1,
8 may move relative to each other via the rolling element 19, and only the outer roller 20 may roll in the groove 11. And
In this embodiment, any of the above cases is included in the rolling of the roller assembly 17.

Further, while the front wheel drive vehicle 1 is traveling, the operating angle θ2 varies depending on conditions such as the vertical movement of the front wheels 6. Furthermore, the grease sealed in the space L1 cools and lubricates a friction portion and a heat generation portion of the components arranged in the space L1.

By the way, when the roller assembly 17 is moving in the longitudinal direction of the groove 11, the outer race 10 is in contact with the curved surface 24 of the outer roller 20 and the inner wall surface 13 of the groove 11. An axial friction force is acting. In the tripod-type joint 7, the torque is transmitted by the three roller assemblies 17, so that the forcible force of three cycles during one rotation of the shaft 8 and the outer race 10, that is, the rotation tertiary Force (in other words, the fluctuation component of the induced thrust force)
Acts on the outer race 10.

Next, the mechanism for suppressing the third-order rotational forcing in the tripod-type joint 7 of this embodiment will be specifically described. In the following description,
For convenience, a case where torque is transmitted from the shaft 8 to the outer race 10 will be described as an example.

First, from the shaft 8 to the outer race 10
, The trunnion 15 and the inner ring 18 relatively move in the direction of the axis F1 as described above. That is, the shaft 8 and the outer race 1
With the change of the rotation phase of 0, the trunnion 15 and the inner ring 18 reciprocate within a predetermined range in the axial direction of the trunnion 15. Here, the relative movement range between the trunnion 15 and the inner ring 18 is determined by the axis D1 and the axis E1.
Is determined based on the operating angle θ2.

The outer peripheral surface 16 of the trunnion 15 and the inner peripheral surface 22 of the inner ring 18 are in contact with each other, and a load acts on the contact on the inner peripheral surface 22 side. Due to this load, the roller assembly 17 may generate a moment around the center of curvature Q2. This moment is determined by the product of the distance from the center of curvature Q2 to the line of action of the load and the load. And the curved surface 2 of the outer race 10
Since the inner wall 4 and the inner wall surface 13 of the groove 11 are in contact with each other, the above-mentioned moment is a force for rotating the roller assembly 17 in a predetermined direction about the center of curvature Q2.

In this embodiment, since the inner peripheral surface 22 is curved so as to protrude inward, the tangent line M1 including the contact point between the outer peripheral surface 16 and the inner peripheral surface 22 is formed.
, A load action line F3 is generated orthogonally. That is, the line of action F3 of the load is set in a direction as close as possible to the center of curvature Q. The direction of the line of action F3 of the load changes according to the relative movement of the roller assembly 17 and the trunnion 15 in the axial direction.

Specifically, in FIG. 1, when the contact point between the outer peripheral surface 16 and the inner peripheral surface 22 is set above the center line G1, the line of action F3 of the load is shifted from the center of curvature Q2. Also works on the upper side. When the contact point between the outer peripheral surface 16 and the inner peripheral surface 22 is set below the center line G1, the line of action F3 of the load acts below the center of curvature Q2. Further, when the contact point between the outer peripheral surface 16 and the inner peripheral surface 22 is set on the center line G1, the load acting line F3
Is set at a position passing through the center of curvature Q2.

As described above, in this embodiment, since the inner peripheral surface 22 of the inner ring 18 is curved in a direction protruding inward, the distance from the center of curvature Q2 to the line of action F3 of the load, that is, the moment The length L2 of the arm is as short as possible as compared with the case where the inner peripheral surface is formed parallel to the axis F2. As a result, the moment corresponding to the product of the load and the arm length L2 of the moment is suppressed, and the roller assembly 17 rotates about the center of curvature D1 in a plane including the axis F2 of the roller assembly 17. Is suppressed. When the load acting line F3 passes through the center of curvature Q2, no moment is generated on the roller assembly 17 because the arm length L2 of the moment becomes zero.

When the roller assembly 17 is rotated by the above mechanism, when the roller assembly 17 moves within the groove 11 in the direction of the axis D1, the outer roller 2
The frictional resistance between 0 and the inner wall surface 13 or the bottom surface 12 is reduced, and the forcing force of the third order of rotation is suppressed. Therefore,
The outer race 10 is less likely to vibrate in the axial direction, so that the forcing force is suppressed from being transmitted to the body via the differential 4, the transmission 3, the engine 2, and the mount supporting the engine 2, and the forcing force is suppressed. The noise caused by the vibration of the components arranged in the transmission path can be prevented, and the riding comfort is improved. That is, so-called NV (noise vibration) performance is improved.

In this embodiment, since the frictional force at the contact surface between the outer roller 20 and the outer race 10 is suppressed, a part of the torque transmitted between the outer roller 20 and the outer race 10 is reduced. Can be suppressed from being converted into frictional heat. Accordingly, a decrease in the power transmission efficiency of the tripod joint 7 can be suppressed, and heat generation at the contact portion between the outer roller 20 and the outer race 10 is suppressed, so that the durability of the tripod joint 7 is improved. Further, the deterioration and seizure of the grease due to the heat generated in the contact portion are suppressed.

Although FIG. 4 shows the case where the shaft 8 rotates clockwise, the same operation and effect can be obtained when the shaft 8 rotates counterclockwise. Also, when the torque of the outer race 10 is transmitted to the shaft 8 via the roller assembly 17, the third-order forcing force is suppressed by the same operation as described above.

[0053]

As described above, according to the present invention, the outer peripheral surface of the projection contacts the inner peripheral surface of the torque transmitting member, and the curved surface of the torque transmitting member contacts the inner surface of the outer race.
Torque is transmitted through each contact portion, and thus torque is transmitted between the shaft member and the outer ring. Further, the torque transmitting member moves in the longitudinal direction of the groove with a change in the rotational phase of the shaft member and the outer ring. Further, the torque transmitting member and the protruding portion move in the axial direction of the protruding portion, and the torque transmitting member swings with respect to the protruding portion in a plane including the axis of the protruding portion.

In the present invention, the inner peripheral surface of the torque transmitting member is curved so as to project inward in a plane including the axis of the torque transmitting member. For this reason, the line of action of the load acting on the inner peripheral surface of the torque transmitting member from the outer peripheral surface of the projecting portion is set at right angles to a tangent line including the contact portion (contact point) between the projecting portion and the torque transmitting member. .
That is, the distance from the center of curvature of the curved surface of the torque transmitting member to the line of action of the load, in other words, the length of the arm of the moment is suppressed as much as possible. As a result, the moment generated around the center of curvature of the curved surface of the torque transmitting member due to the load acting on the torque transmitting member from the protrusion is reduced, and the torque transmitting member rotates around the center of curvature. Is suppressed.

Therefore, when the torque transmitting member moves in the groove in the longitudinal direction, the axial load acting on the outer ring,
That is, the third-order forcing force is suppressed, and the vibration of the outer race in the axial direction and the noise caused by the vibration are reduced.

Further, since the frictional force at the contact surface between the torque transmitting member and the groove of the outer ring is suppressed, a part of the torque transmitted between the torque transmitting member and the outer ring is converted into frictional heat. Can be suppressed. Accordingly, a decrease in the power transmission efficiency of the tripod joint is suppressed, and heat generation at a contact portion between the torque transmission member and the outer ring is suppressed, thereby improving the durability of the tripod joint.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view of a tripod joint according to an embodiment of the present invention.

FIG. 2 is a plan view showing a schematic configuration of a front wheel drive vehicle equipped with a tripod joint according to an embodiment of the present invention.

FIG. 3 is a side end view of the tripod joint shown in FIG. 2;

FIG. 4 shows the IV of the tripod joint shown in FIG.
FIG. 4 is a front sectional view taken along line -IV.

FIG. 5 is a side sectional view showing a configuration example of a conventional tripod joint.

FIG. 6 is a sectional view of the tripod joint shown in FIG. 5 in the axial direction.

[Explanation of symbols]

8 ... shaft, 11 ... groove, 10 ... outer race,
15: trunnion, 16: outer peripheral surface, 17: roller assembly, 22: inner peripheral surface, 24: curved surface, F2, F2
... axis.

Claims (1)

[Claims] 1. An outer ring having a cylindrical shape, and a shaft member disposed inside the outer ring. The outer ring is formed on the inner periphery of the outer ring at predetermined intervals in a circumferential direction. A plurality of grooves extending in the radial direction on the outer periphery of the shaft member, a plurality of protrusions, respectively attached to the outer periphery of each protrusion, and abutting on each groove, the groove of the An annular torque transmitting member movable in the longitudinal direction, the plurality of torque transmitting members are configured to be relatively movable in the axial direction of the projecting portion with respect to each projecting portion, and The projecting portion is configured to be capable of swinging movement in a plane including the axis, and a portion of the outer periphery of the torque transmitting member that abuts on the groove is provided in a plane including the axis of the torque transmitting member. A curved surface is formed that protrudes toward In the constant velocity universal joint, a portion of the inner peripheral surface of the torque transmitting member that contacts the outer peripheral surface of the protruding portion projects inward in a plane including the axis of the torque transmitting member. A constant velocity universal joint characterized by being curved.