JPH04296220A - Tripod universal joint - Google Patents

Abstract

PURPOSE:To reduce thrust force in a tripod universal joint. CONSTITUTION:In the case where a universal joint secures a joint angle for transmitting torque, an inside roller 32 and an outside roller 34 which compose a roller member 3 severally make relative movement toward a tripod shaft through the first and the second needle bearings 31, 33, and relatively rotate. The moving and rotating quantities as the whole of the roller member 3 are thereby broken up into both the rollers 32, 34 and the first and the second needle bearings 31, 33. Thus the possibility of the occurrence of the skew in the first and the second needle bearings 31, 33 can be reduced, and even if the skew occurs, its extent is small. Frictional resistance following after the occurrence of the skew therefore decreases to reduce thrust force.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a constant velocity joint used in the driving force transmission shaft of an automobile, and more specifically, the present invention relates to a constant velocity joint used in a driving force transmission shaft portion of an automobile. The present invention relates to a tripod type constant velocity joint that allows relative displacement in directions.

0002

2. Description of the Related Art Conventionally, a tripod type constant velocity joint (hereinafter simply referred to as constant velocity joint) having a general structure as shown in FIG. 3 has been known. This constant velocity joint has an outer joint member 1a which has a cylindrical shape with one end open, the bottom side of which is connected to a drive shaft (not shown), and has three spherical guide grooves 12a extending in the axial direction on the inner circumference; A spherical guide groove 12 is coaxially arranged inside the outer joint member 1a.
an inner joint member 2a having three tripod shafts 23a protruding inside a; and a spherical guide groove 2 rotatably provided on each tripod shaft 23a via a needle bearing 31a.
3a and a roller member 3a that rolls on the roller member 3a.

In this constant velocity joint, when the drive shaft rotates, the rotational torque is transmitted from the outer joint member 1a to the inner joint member 2a via each roller member 3a, and the driven shaft 5a
rotates at the same speed as the drive shaft. When an external force in the axial direction or an external force that changes the joint angle acts between the two shafts, the roller member 3a rolls in the spherical guide groove 12a, allowing the relative displacement and change in the joint angle. Ru.

0004

[Problems to be Solved by the Invention] By the way, when the above-mentioned constant velocity joint transmits rotational torque by adjusting the joint angle, the force in the shaft axial direction ( It is known that rotational tertiary thrust force is generated. This thrust force causes the tripod shaft 23a to swing in the direction along the spherical guide groove 12a, causing the roller member 3a to roll obliquely to the spherical guide groove 12a, causing slippage. Occurs due to That is, the frictional resistance force between the roller member 3a and the spherical guide groove 12a that occurs as the roller member 3a rotates, the frictional resistance force between the roller member 3a, the needle bearing 31a, and the tripod shaft 23a, and the tripod axial direction of the roller member 3a. The thrust force is the resultant force of the frictional resistance force between the roller member 3a, needle bearing 31a, and tripod shaft 23a that occurs as the roller member 3a slides. This thrust force tends to increase as the joint angle increases, but as the movement of the roller member 3a in the tripod axial direction increases, the needle bearing 3a
It is thought that skew (a phenomenon in which the needle bearing falls sideways) is likely to occur in 1a, which increases the frictional resistance.

The present invention was devised in view of the above circumstances, and an object to be solved is to provide a tripod type constant velocity joint that can reduce thrust force.

[0006]

[Means for Solving the Problems] The tripod type constant velocity joint of the present invention includes an outer joint member which is cylindrical with one end open and has a plurality of spherical guide grooves extending in the axial direction on the inner circumference; an inner joint member having a plurality of tripod shafts disposed coaxially inside the joint member and protruding into the spherical guide groove; and an inner joint member having a plurality of tripod shafts that are arranged coaxially inside the joint member and protrude into the spherical guide groove, and the spherical guide groove is rotatably provided on each of the tripod shafts via a needle bearing. In the tripod type constant velocity joint, the roller member includes an inner roller rotatably provided on the tripod shaft via a first needle bearing, and a second needle on the inner roller. It is characterized by being comprised of an outer roller rotatably provided via a bearing.

[0007]

[Operation] When the constant velocity joint transmits rotational torque by adjusting the joint angle, the roller member rolls in the spherical guide groove by rotating as it moves relative to the tripod axis in the tripod axis direction. . At this time, in the present invention, the inner roller and the outer roller constituting the roller member move relative to each other in the tripod axis direction via the first and second needle bearings and rotate relative to each other, so that the roller member as a whole The amount of movement and amount of rotation are distributed between both rollers and the first and second needle bearings. This reduces the possibility that skew will occur in the first and second needle bearings, and even if it does occur, the skew will remain to a small extent. Therefore, the frictional resistance associated with the occurrence of skew is reduced, and the thrust force is reduced.

[0008]

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings. A cross-sectional view of the constant velocity joint according to this embodiment is shown in FIG. 1, and a cross-sectional view of the main parts thereof is shown in FIG. The constant velocity joint of this embodiment includes an outer joint member 1 having three spherical guide grooves 12, an inner joint member 2 having three tripod shafts 23, and a first needle bearing 31 on each tripod shaft 23. The roller member 3 is mainly composed of an inner roller 32 disposed through the inner roller 32 and an outer roller 34 disposed on the inner roller 32 via a second needle bearing 33.

The outer joint member 1 has a cylindrical shape with one end open, and three spherical guide grooves 12 extending in the axial direction are formed at equal angular intervals on the inner periphery. The spherical guide groove 12 has concave spherical guide surfaces 14 on both sides thereof, on which the outer rollers 34 roll. The bottom side of the outer joint member 1 is connected and fixed to one end of a drive shaft (not shown). The inner joint member 2 includes a short cylindrical base 21 and three tripod shafts 23 that protrude radially from the outer periphery of the base 21 at equal angular intervals. This inner joint member 2 has a base 2
A driven shaft 5 is connected and fixed to the inner circumference of each tripod shaft 2.
3 are coaxially disposed inside the outer joint member 1 in a state in which the spherical guide grooves 12 are entered into the respective spherical guide grooves 12.

The roller member 3 includes an inner roller 32 rotatably provided on a tripod shaft 23 via a plurality of first needle bearings 31, and a plurality of second needle bearings on the inner roller 32.
It is comprised of an outer roller 34 rotatably provided via a needle bearing 33. The inner roller 32 includes a cylindrical roller base 321 and a ring-shaped flange 323 that projects radially outward from the lower end of the roller base 321, and has an L-shaped cross section. The first needle bearing 31 interposed between the inner roller 32 and the tripod shaft 23
Its lower end is supported by a first ring-shaped retainer 36 attached to the base, and a second ring-shaped retainer 37 attached and fixed to the tip of the tripod shaft 23 prevents it from coming off upward. has been done. The second needle bearing 33 interposed between the inner roller 32 and the outer roller 34 has its lower end supported by the flange portion 323 of the inner roller 32 and is attached and fixed to the tip of the inner roller 32. ring-shaped third
The retainer 38 prevents it from coming out upwards. The outer roller 34 is cylindrical and slightly shorter than the inner roller 32, and its outer peripheral surface is formed into a convex spherical shape that matches the guide surface 14 of the spherical guide groove 12.

A boot 6 is attached to the opening of the outer joint member 1, and the boot 6 has both ends fastened to the outer periphery of the opening of the outer joint member 1 and the outer periphery of the driven shaft 5 with a fastening band 61. This allows the inside of the joint to be sealed. In the constant velocity joint configured as described above, when the drive shaft rotates, the rotational torque is transmitted from the outer joint member 1 to the inner joint member 2 via each roller member 3, and the driven shaft 5
rotates at the same speed as the drive shaft. Furthermore, when an external force acts in the axial direction between the two shafts, the inner roller 32 and the outer roller 34 rotate relative to each other via the first and second needle bearings 31 and 33, and the outer roller 34 moves toward the spherical guide groove 12. Relative displacement between both shafts is allowed by rolling on the guide surface.

When the constant velocity joint transmits rotational torque by adjusting the joint angle, the tripod shaft 23
As the roller member 3 moves into a state where it performs an oscillating motion, the roller member 3
rotates while moving relative to the tripod shaft 23 in the tripod axial direction, and rolls on the guide surface 14 of the spherical guide groove 12. At this time, since each of the inner roller 32 and the outer roller 34 rotates while sliding relatively in the tripod axial direction via the first and second needle bearings 31 and 33, the entire roller member 3 rotates in the tripod axial direction. The amount of movement and rotation of is dispersed. This reduces the possibility that skew (a phenomenon in which the needle bearings fall sideways) will occur in the first and second needle bearings 31 and 33, and even if it occurs, the skew will remain small and will not become large. Therefore, the frictional resistance associated with the occurrence of skew is reduced, and the thrust force is reduced.

As described above, according to the constant velocity joint of this embodiment, when transmitting rotational torque by adjusting the joint angle, the amount of movement and rotation of the entire roller member 3 in the tripod axial direction is dispersed. As a result, the frictional resistance associated with the occurrence of skew is reduced, so that the thrust force can be reduced. In addition, since the amount of movement and rotation of the entire roller member 3 is distributed to the inner roller 32 and outer roller 34, and the first and second needle bearings 31 and 33, fatigue of each member is reduced, so the roller member 3 This makes it possible to extend the lifespan of the

[0014]

According to the present invention, the roller member includes an inner roller rotatably provided on the tripod shaft via a first needle bearing, and an inner roller rotatably provided on the inner roller via a second needle bearing. Since the joint angle is configured with the outer roller, it is possible to reduce the thrust force generated when rotating torque is transmitted by adjusting the joint angle.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a tripod type constant velocity joint according to an embodiment.

FIG. 2 is a cross-sectional view showing an enlarged main part of FIG. 1;

FIG. 3 is a sectional view of a conventional tripod constant velocity joint.

[Explanation of symbols]

1... Inner joint member 2... Outer joint member 3... Roller member 12... Spherical guide groove 23... Tripod shaft 31... First needle bearing 32... Inner roller 33... Second needle bearing 34... Outer roller

Claims (1)

[Claims] Claims: 1. An outer joint member having a cylindrical shape with one end open and having a plurality of spherical guide grooves extending in the axial direction on the inner circumference, and the spherical guide disposed coaxially inside the outer joint member. A tripod type constant velocity comprising: an inner joint member having a plurality of tripod shafts protruding into the groove; and a roller member rotatably provided on each of the tripod shafts via a needle bearing and rolling in the spherical guide groove. In the joint, the roller member includes an inner roller rotatably provided on the tripod shaft via a first needle bearing, and an outer roller rotatably provided on the inner roller via a second needle bearing. A tripod type constant velocity joint characterized by consisting of.