JPH06193644A - Constant speed universal joint - Google Patents

Abstract

PURPOSE:To facilitate the forming work of the shape of an outer race by casting process in a constant speed universal joint wherein a tripod member is slidably inserted into the inside of the outer race. CONSTITUTION:Guide blocks 10 are attached to leg shafts 7 of a tripod member 3 inserted into an outer race 1 so as to swing freely, and ball circulating passages 15 for rolling many balls 14 outward in the radial direction are provided on both sides of the guide block 10. Raceway grooves 19 for guiding the balls in the axial direction are provided on the inner peripheral surface of the outer race 1, and the balls can be guided and prevented from dropping out by a roll surface and a guide surface provided on both sides of each raceway groove 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slide type constant velocity universal joint mainly incorporated in a front wheel drive type automobile or the like.

[0002]

2. Description of the Related Art As a constant velocity universal joint of this type, there has already been proposed by the present applicant in Japanese Patent Laid-Open No. 3-113123.

In the proposed joint, as shown in FIG. 7, three axial projections 31 are provided on the inner surface of the outer ring 30 and a track groove 32 is provided between the projections 31 so that the inner ring of the outer ring 30 is provided. On the outer periphery of the inserted tripod member 33, three leg shafts 3
4 is provided, and a guide block 35 supported in the track groove 32 is swingably supported around a leg shaft 34 and slidable in the axial direction. Further, a ball circulation path 36 having a straight track path 39 is provided on each of both side surfaces of each guide block 35, and a plurality of balls 37 are rotatably accommodated in the ball circulation path 36. A track groove 38 for guiding the ball 37 is provided parallel to the groove center line of the track groove.

In the above structure, the ball 3 between the straight track 39 of the ball circulation path 36 and the track groove 38 of the track groove 32.
Since the guide block 35 is always kept horizontal by the guide block 35, the guide block 35 horizontally moves in the length direction of the track groove 32 during the transmission of the torque at which the constant velocity universal joint makes an operating angle. The ball rolls. Therefore, there is an advantage that the slide resistance when the joint has an operating angle can be greatly reduced.

[0005]

By the way, in the joint proposed above, the inversion portion of the ball circulation path 36 for circulating the balls 37 in the straight track path 39 is provided toward both side surfaces of the track groove 32. In order to prevent the ball 37 returning from the raceway groove 38 of the outer ring 30 from slipping out, a curved inclined portion 40 is provided at the tip of the projection 31 forming the track groove 32. I try to hold it down.

However, the inclined portion 40 as described above has a problem that it is difficult to form the outer ring by forging since the tip portion of the protrusion 31 has a sharply pointed edge shape.

[0007] Therefore, an object of the present invention is to provide a constant velocity universal joint in which the outer ring can be easily forged while taking advantage of the features of the above-proposed constant velocity universal joint.

[0008]

In order to solve the above problems, the present invention provides three leg shafts on the outer periphery of a tripod member inserted inside an outer ring, and the leg shafts are centered around the leg shafts. A guide block is supported so that it can be swung freely and slidably in the axial direction, and ball circulation paths are formed on both sides of this guide block that expose and roll a plurality of balls outward in the radial direction. In this structure, a linear track path in the direction is provided, and a raceway groove is provided on the inner peripheral surface of the outer ring for guiding balls rolling in the straight track path parallel to the central axis of the outer ring.

[0009]

In the above structure, since the balls in the ball circulation path roll radially outward, the raceway groove of the outer ring can be formed radially inward. For this reason,
It is not necessary to provide a protrusion that forms a track groove on the inner side of the outer ring or an inclined portion for preventing the balls from coming off on the protrusion, and a sharp edge shape can be eliminated from the inner side of the outer ring.

[0010]

1 and 2 show a constant velocity universal joint of an embodiment, and FIG. 3 shows a side view of an outer ring with an inner member removed from the joint.

As shown in the figure, the outer ring 1 is formed in a cylindrical shape with one end closed, and a first shaft 2 is provided at the closed end.

The tripod member 3 inserted inside the outer ring 1 is fitted on the outside of the second shaft 4 so as to rotate together through the serrations 5, and the stop shaft 6 attached to the second shaft 4 is attached.
Axial movement is stopped by.

The tripod member 3 has three leg shafts 7, and a spherical roller 9 is attached to the outside of the leg shafts 7 via needles 8 so as to be axially movable and rotatable. There is. A guide block 10 is fitted to the outside of the spherical roller 9, and a spherical inner surface 11 formed on the guide block 10 has a spherical outer surface 12 provided on the spherical roller 9.
Is contacted and guided.

Flat surfaces 13, 13 facing the inner peripheral surface of the outer ring 1 are formed on both sides of the guide block 10, and a large number of balls 14 are exposed to the outside in the radial direction on the respective flat surfaces 13, 13. Ball circulation paths 15, 15 for rolling are formed. On the other hand, raceway grooves 19, 19 extending parallel to the central axis of the outer ring are formed on the inner peripheral surface of the outer ring 1 facing the ball circulation paths 15, 15, and the raceway grooves 19 are formed.
The ball 14 fitted between the outer ring 1 and the ball circulation path 15.
It is designed to roll on a substantially cylindrical surface around the central axis of.

As shown in FIG. 5, the ball circulation path 15 has two linear track paths 1 on the torque load side and the torque return side.
6 and 17, and both ends of the linear track paths 16 and 17 are connected by arc-shaped inversion paths 18 to form an elliptical shape.

Further, the bottom surface 20 of the raceway groove 19 of the outer ring 1 is
As shown in FIG. 6, the flat surface 13 of the guide block 10
It is formed of a flat surface that is slightly inclined with respect to the bottom surface 20.
An arc-shaped ball rolling surface 21 that guides the linear movement of the load-side ball 14 is formed on one side. Also,
A ball guide surface 22 is formed on the other side of the bottom surface 20 to prevent the returning ball 14 from falling. The distance between the ball guide surface 22 and the return-side linear track 17 is
It is formed wider than the space between the ball rolling surface 21 and the load-side linear track 16, so that when the torque is transmitted between the outer ring 1 and the tripod member 3, no load is applied to the return-side ball 14. Is set to.

In FIG. 2, numeral 23 is a groove for preventing the outer ring 1 and the leg shaft 7 from interfering with each other.

The constant velocity universal joint of this embodiment has the structure as described above, and as shown in FIG. 4, when the first shaft 2 and the second shaft 4 are relatively inclined and the joint has an operating angle. , The leg shaft 7 inclines in the axial direction of the outer ring 1, but in this state, the guide block 10 is prevented from rotating by the ball 14 fitted between the linear trackway 16 on the load side and the raceway groove 19 of the outer ring 1, and its guide Since the block 10 and the spherical roller 9 are in spherical contact with each other, the spherical roller 9 does not move in the axial direction of the leg shaft 7.

Therefore, when the leg shaft 7 is tilted, the spherical roller 9 is tilted together with the leg shaft 7, and slippage occurs between the contact surfaces of the spherical roller 9 and the guide block 10, and the leg shaft 7
When A moves in the axial direction, slip occurs between the leg shaft 7 and the spherical roller 9.

Therefore, when the joint takes an operating angle and transmits torque, the leg shaft 7 and the spherical roller 9 perform a swinging motion inside the guide block 10, and the guide block 10 maintains a horizontal state and the outer ring 1 The ball 14 rolls by the movement of the guide block 10 and circulates along the ball circulation path 15.

In the joint of the embodiment having the above structure, as shown in FIG. 3, a raceway groove 19 is formed on the inner peripheral surface of the outer ring 1 so as to face inward in the radial direction, and balls on both sides of the raceway groove 19 are formed. Since the balls 14 are guided and prevented from coming off by the rolling surface 21 and the guide surface 22, a protrusion 31 for forming a track groove is formed inside the outer ring 1 as in the conventional structure shown in FIG. It is not necessary to provide the inclined portion 40. That is, since the inner peripheral surface of the outer ring 1 can be formed in a shape having a small step and the sharp edge shape can be eliminated from the outer ring, the outer ring 1 can be accurately formed by forging.

In the above embodiment, the guide block 1 is formed by the spherical roller 9 fitted on the outside of the leg shaft 7.
However, instead of this, the leg shaft 7 is provided with a spherical outer surface, and the guide block 10 is formed with a cylindrical inner surface.
The cylindrical inner surface and the spherical outer surface may be contact-guided.

[0023]

As described above, according to the structure of the present invention, since the guide block, the ball circulation groove provided in the outer ring, and the raceway groove are formed to face each other in the radial direction, the projection and the sharp edge for forming the track groove are formed from the outer ring. The edge shape can be eliminated, and the outer ring can be easily formed by forging.

Further, since the projection for forming the track groove can be omitted from the outer ring, the material of the outer ring can be reduced, and there is an advantage that the cost and the weight can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing a constant velocity universal joint according to an embodiment.

FIG. 2 is a vertical sectional side view of the above.

FIG. 3 is a side view showing the outer ring of the same.

FIG. 4 is a vertical sectional front view showing an operating state of the joint.

FIG. 5 is a plan view showing a ball circulation path.

FIG. 6 is a sectional view of a ball circulation path.

FIG. 7 is a vertical sectional side view showing a conventional example.

[Explanation of symbols]

 1 outer ring 3 tripod member 7 leg shaft 10 guide block 14 ball 15 ball circulation path 16, 17 straight track path 19 track groove 21 ball rolling surface 22 ball guide surface

Claims (1)

[Claims] 1. A tripod member inserted inside an outer ring is provided with three leg shafts on the outer periphery thereof, and a guide block is supported on the leg shafts so as to be swingable about the leg shafts and slidable in the axial direction, On both sides of this guide block, a ball circulation path that exposes a plurality of balls to the outside in the radial direction and rolls is formed, and a linear track path in the axial direction is provided in the ball circulation path, and on the inner peripheral surface of the outer ring, A constant velocity universal joint provided with a raceway groove for guiding a ball rolling in the straight raceway path in parallel to the central axis of the outer ring.