JPS59133825A - Bar field type uniform universal coupling - Google Patents

Abstract

PURPOSE:To improve durable life by rendering coefficient of friction of a ball rolling surface on an outer race side smaller than that of a ball rolling surface on an inner race side. CONSTITUTION:Coefficient of friction of a ball rolling surface on an outer race 1 side relative to a ball 3 is rendered smaller than that of a ball rolling surface on an inner race 2 side, so that the ball 3 may be rolled on the ball rolling surface on the inner race 2 side under a torque transmitted condition. In the case that the ball rolling surface on the inner race 2 side is not treated, ''film forming simultaneous with heat treatment'', ''manganese phosphate treatment'', ''molybdenum disulfide treatment'', and ''resin lubricant coating and drying'', etc. are suitable as a surface treatment for the ball rolling surface on the outer race side. In the case that the ball rolling surface on the inner race 2 side is treated by molybdenum flame spraying, ''film forming simultaneous with heat treatment'', ''manganese phosphate treatment'', ''molybdenum disulfide treatment'', ''resin lubricant coating and drying'', and ''galvanizing'', etc. are suitable as surface treatment for the ball rolling surface on the outer race side.

Description

[Detailed description of the invention] The present invention is a barfield type constant velocity mortar 71f etc.

In particular, it relates to technology for improving the durability of Barfield type constant velocity universal joints.

Fig. 1 shows a longitudinal cross-sectional view of a half-yield type constant velocity universal joint. Side hole rolling n7) 2a+'J zo 1 no 5,
The ball rolling groove la on the outer race side is transmitted to the outer race 1.

Further, the cage 4 is held by the outer race inner spherical surface 1b and the inner race outer spherical surface 2b to position the rK-rule 3. Furthermore, this joint has a joint angle centered on point O.

FIG. 2 is a sectional view taken along the line AA in FIG. 1. Figure 3 shows inner lace 2. 2 is a partially enlarged view of FIG. 2 when a transmission torque is applied to the outer race 1 in the direction indicated by the % mark in the figure.

The ball rolling groove 2a of the inner race 2 and the ball 3 contact each other at the contact point a inside the inner race 2, and the contact force F is applied to the inner race rolling groove 2a.
The ball transfer groove la of the outer race 1 and the hole 3 contact each other at the outer contact point, and the contact force F1 acts on the outer race rolling groove 1a.

Section 4 is a partially enlarged view of FIG. 1 in the case of joint angle U. A characteristic of the Burfield type universal joint is that when the joint angle θ is attached, the hole 3 should be fixed, and the inner race 2. The outer race 1 is tilted in opposite directions, and the nail 3 and the inner race ball rolling groove 2a are in contact with each other at an inner contact point a', and with the outer race ball rolling groove 1a at an outer contact point b'.

If the torque T is now being transmitted at the shimmy angle 0 and the two wires are rotating by hand, the movement distance of the FJ contact a on the inner race 2 side is 2xaa', and the movement distance of the outer contact 1) on the outer race 1 side is becomes 2xbb', thereby.

Since hole 3 rolls around point O5 in Fig. 3 during one rotation of the joint, the difference in travel distance between the external contact point and the internal contact point is 2.
A slip of X (bb'-aa') occurs between the hole transfer groove 1a on the outer race 1 side or the ball rolling groove 2a on the inner race 2 pair.

Also, from FIG. 3, the nail 3 and the ball rolling groove la.

, and F',=F.

The contact surface pressure between the ball 3 and the Hall rolling grooves 1a and 2a is determined by the shape of the rolled UL in which the ball and the inner race are in circumscribed contact, and the ball and the outer race are inscribed in the contact surface pressure on the U inner race side, J>r on the outer race side. "Contact surface pressure".

As mentioned above, in a Barfield type constant velocity universal joint, torque is applied at a certain joint angle and the joint is rotating.The outer race side and the inner race Due to the difference between the sides, there is a difference between the hole and the hole transfer surface.
Slippage occurs on the outer race side, the inner race side, or both.

Also, as stated above, the contact pressure between the ball and the ball transfer surface is considerably greater on the inner race side than on the outer race side.

Despite this situation, the hole had zero ball rolling on the inner race and the ball on the outer race. Traditionally, little attention has been paid to the relationship between friction coefficients.
It was.

For this reason, the ball transfer groove on the outer race side.

In some cases, such as when the hole is removed by plastic working or the like, the l1lJ coefficient for the hole on the transfer surface on the outer race side becomes significantly larger than on the inner race side.

Due to this force, the pole slips between the surface pressure and the cartwheeling tendency of the inner race, and the surface of the ball transfer surface on the inner race side quickly peels off in scales due to rolling and sliding fatigue.

It has the disadvantage of causing so-called flaking.

The present invention provides a Barfield type constant velocity universal joint having a hole rolling groove on the outer race side with a plastic working finish and a rolling groove on the inner race side with a polishing finish, and the coefficient of friction of the ball rolling surface on the outer race side with respect to the ball on the inner race In the situation where the torque is transmitted by making the side ball transfer surface smaller than that.

There is always high contact pressure between the hall and the hall transfer surface.

On the inner race side, between the ball ψm side and the hole.

The object of the present invention is to provide a Barfield type constant velocity universal joint whose surface life is improved by rubbing it so that it rolls.

10.) The purpose of this is to improve the inner race side and outer race side of a Barfield type constant velocity universal joint that has a plastic processed ball rolling groove on the outer race side and a polished ball rolling groove on the inner race side. , -le ψ moving surface; Here, in a state where torque is transmitted, the N of the ball transfer surface on the outer race side relative to the ball is such that the inner race 01 reball rolling movement and the hole are rolling.
This is achieved by a Barfield type constant velocity universal joint characterized in that the m coefficient is smaller than that of the ball rolling surface on the inner race side.

Examples of the present invention will be described below.

The following table shows various surface treatments. The results of measuring the coefficient of friction when balls are used as the mating materials for the ball transfer groove on the outer race side and the ball rolling groove on the inner race side are shown.

As is clear from the table, for the untreated inner race side ball rolling surface, "heat treatment simultaneous film formation", "phosphoric acid mankan treatment", "molybdenum disulfide treatment", "resin lubricant application drying" ” etc. are suitable as surface treatments for the hole transfer surface on the outer race side.

In addition, when molybdenum thermal spraying is applied to the inner race side ball transfer surface, "heat treatment simultaneous film formation", "manganese phosphate treatment J", "molybdenum disulfide treatment", "resin lubricant application drying", ] - Normal lead plating" is suitable as a surface treatment for the hole transfer surface on the outer race side.

Note that when both the ball rolling surface on the outer race side and the hole transfer surface on the inner race side are left untreated, the coefficient of friction of the ball rolling surface on the outer race side with respect to the ball is:
@ Shift is larger than that of the hole transfer surface on the inner race side, which can be seen to be undesirable from the viewpoint of durability.

Among the above surface treatment combinations, the hole transfer surface on the inner race side was left untreated, and the ball transfer surface on the outer race side was subjected to a "lubricating film formation simultaneously with heat treatment" treatment. Barfield type constant velocity universal joint.

Compared to the untreated combination, the joint angle 2
~10°, torque 10-50 kt, vehicle speed 1 at 1-m
Results of high-speed durability tests equivalent to 40 to 200 km/'H.

The evaluated 2-
1! All of the throats have an equivalent mileage of less than 10,000 km,
Flaking occurs on the ball rolling surface on the inner race side.
On the other hand, it was not possible to continue the test, but one test case in which the ball transfer surface on the outer race side was treated with "simultaneous heat treatment film formation" showed no damage even after an equivalent mileage of 30,000 miles. .

In addition, in this example, the inner race side hole transfer surface,
This shows some of the combinations of surface treatments for the ball transfer surface on the outer race side.If the friction coefficient of the hole transfer surface on the outer race side with respect to the hole is smaller than that of the ball transfer surface on the inner race side, then this It is clear that the present invention can be widely applied without being limited to the embodiments.

As is clear from the above, the Barfield type constant velocity universal joint according to the present invention has a coefficient of friction of the ball rolling surface on the outer race side with respect to the ball.

It can be made smaller than that of the inner race side pole transfer surface, and in a state where torque is transmitted, the contact pressure between the ball and the ball transfer surface fights, and the inner race side ball transfer surface and the hole are in a rolling state.

As a result, there is an advantage that durability is significantly improved.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a Barfield type constant velocity universal joint, Figure 2 is a cross-sectional view taken along line A-A in Figure 1, and the third section shows the transmission torque applied to the inner race and outer race in the direction of the arrow in the figure. FIG. 4 is a partially enlarged view of FIG. 2 when the joint angle is θ, and FIG. 4 is a partially enlarged view of FIG. 1 when the joint angle is θ. 1 Outer race, 1a... ball transfer groove of outer race? J, 1b outer lace inner spherical surface, 2-inner lace, 2a inner lace ball k. 2b Inner race outer spherical surface, 3.Hole, 4.Cage, 5.Intermediate shaft, 6.Spline, 0.Joint angle, 1゛torqueApplicant Toyota Motor Corporation

Claims (2)

[Claims] (1) Ball rolling grooves finished by plastic processing are applied to the outer race, and small rolling grooves processed by the new calendar are applied to the inner race Il.
l! The barfield type constant velocity universal joint having i.
In the hole rolling movement of the inner race and the outer race l1flf, the torque is transmitted at the j seat. A Barfield type constant velocity universal joint characterized in that the thick edge coefficient of the rolling motion is smaller than that of the Interesle 1J hole rolling motion. (2) The friction coefficient balance between the ball transfer surface on the outer race side and the ball transfer surface on the inner race side with respect to the transfer hole is calculated as follows: Adjustments can be made by surface-treating the hole transfer surface on the inner race side or the hole transfer surfaces on both sides.
A Barfield type constant velocity universal joint according to claim 1.