JP2000185507A - Constant velocity joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To damp a brake judder and a stick-slip noise by forming a shoulder portion, against which an end face of an inner race of an axle bearing abuts, and a stem connected to a wheel-mounting hub on an outer race of a constant velocity joint for drive wheels, thereby restricting squareness and runout of a side face of the shoulder portion with respect to the center of the stem axis within a specified range. SOLUTION: An axle bearing unit for drive wheels in automobiles is equipped with an axle bearing 4 that supports a wheel-mounting hub 3, on which a wheel 2 is mounted together with a brake rotor 1. A constant velocity joint 7, which transmits drive from a drive shaft 6 to the hub 3, is connected to the hub 3. The constant velocity joint 7 comprises an inner race 15, a ball 16, a cage 17 that supports the ball 16, and an outer race 18. A shoulder portion 19 that abuts to an end face of the axle bearing 4 and a stem 20 that extended axially are formed integrally on one end of the outer race 18. The stem 20 is fitted via splines 21 to a shaft portion 9 of the hub 3, thereby limiting squareness and runout of a side face of the shoulder portion with respect to the center of stem axis to the specification value, i.e., 30 μm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant velocity joint incorporated in a wheel bearing unit for driving wheels to transmit engine power of a vehicle such as an automobile to wheels.

[0002]

2. Description of the Related Art In recent years, with the speeding up of automobiles, brake judder, vibration and sound tend to be more severely restricted in wheel bearing units for driving wheels.

Conventionally, various measures have been taken for the brake judder to reduce axial runout of the brake rotor assembly, and various noises have been taken to prevent stick-slip noise from being generated by twisting of the shaft due to engine torque. Measures are being taken, but not enough.

[0004]

SUMMARY OF THE INVENTION Therefore, the present invention
An object of the present invention is to improve the reliability of a constant velocity joint incorporated in a wheel bearing unit for a drive wheel, thereby reducing the runout of a brake rotor and preventing stick-slip noise.

[0005]

According to the present invention, there is provided a constant velocity joint for a drive wheel in which a shoulder portion to which an inner ring end surface of an axle bearing contacts and a stem connected to a wheel mounting hub are formed on an outer ring. The right angle and the runout width of the side surface of the shoulder with which the inner ring end surface of the axle bearing abuts with respect to the stem axis are regulated within standard values.

When the side surface of the shoulder of the outer race of the constant velocity joint is regulated as described above, the runout of the wheel and the brake rotor via the wheel mounting hub is suppressed, so that the occurrence of brake judder and stick-slip noise is reduced. This can be prevented.

The above-mentioned standard value effective for preventing the brake rotor from swinging and preventing stick-slip noise is 30 μm.
Or less, more preferably 8 μm or less.

Further, in order to further reduce the contact surface pressure between the side surface of the shoulder of the constant velocity joint and the end surface of the inner ring of the wheel bearing, the side surface of the shoulder is subjected to a surface treatment for reducing frictional resistance. Is preferred.

As the surface treatment, a circumferential grease groove is formed on the side surface of the shoulder, a streak is formed concentrically with respect to the stem axis, or a slip agent is coated. Or means for doing so.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wheel bearing unit for driving wheels incorporating a constant velocity joint according to the present invention will be described below.

A wheel bearing unit for driving wheels shown in FIG. 1 is a first embodiment of the present invention, and a wheel mounting hub 3 on which wheels 2 are mounted together with a brake rotor 1.
And the wheel mounting hub 3 is connected to a double row of rolling elements 5a, 5b.
And a constant velocity joint 7 connected to the wheel mounting hub 3 so as to rotatably support the same via a shaft and transmitting the power of the drive shaft 6 to the wheel mounting hub 3.

The wheel mounting hub 3 includes a flange 8
And a shaft portion 9 extending from the flange portion 8 to the inner side along the axial direction. A shaft hole communicating with the closed portion of the flange portion 8 is formed through the shaft portion 9 to penetrate the shaft portion. A spline is formed on the inner surface of the hole. The wheel mounting hub 3 is inserted through the inner diameter surface of the brake rotor 1, and the wheel 2 is mounted on the flange 8 together with the brake rotor 1 by hub bolts 10.

The axle bearing 4 is mounted on a knuckle 11 extending from the vehicle body, and is disposed on an outer ring 12 having a double-row outer raceway surface and on the outer periphery of a shaft portion 9 of the wheel mounting hub 3. The inner races 13a, 13b of the axially split type having the inner raceways formed therein, and the double rows of rolling elements 5a, 5b interposed between the inner raceways of the inner races 13a, 13b and the outer raceway of the outer race 12. The seals 14a and 14b are provided outside the double row rolling elements 5a and 5b.

The constant velocity joint 7 includes an inner race 15 provided at one end of the drive shaft 6, a ball 16 for transmitting torque, a cage 17 for holding the ball 16, and an outer race 18.

The outer race 18 of the constant velocity joint 7
As shown in FIG. 2, a shoulder 19 with which the end surface of the inner ring 13b of the axle bearing 4 abuts and a stem 20 extending in the axial direction are integrally formed at one end of the stem 20.
Spline 21 that fits with shaft 9 of wheel mounting hub 3
Are formed.

The constant velocity joint 7 and the wheel mounting hub 3 are connected to each other by inserting the stem 20 of the constant velocity joint 7 into the shaft portion 9 of the wheel mounting hub 3 and spline-connecting the two. 7 to wheel mounting hub 3
Is mounted so that the rotational torque is transmitted to the motor. The tip of the stem 20 of the constant velocity joint 7 is
2 prevents the constant-velocity joint 7 from slipping off and prevents the axle bearing 4
Is provided with a predetermined set preload.

In the first embodiment, the run-out width of the side surface of the shoulder 19 of the constant velocity joint 7 with which the end surface of the inner ring 13b of the axle bearing 4 abuts and the perpendicularity to the axis of the stem 20 are within the standard values. Is managed.

This standard value is 30 μm or less, more preferably 8 μm or less.

The side surface of the shoulder 19 of the constant velocity joint 7 is preferably subjected to a surface treatment for reducing frictional resistance. By this surface treatment, smooth sliding can be obtained between the shoulder portion 19 of the constant velocity joint 7 and the inner ring 13b of the axle bearing 4, and the stick-slip noise can be more effectively suppressed.

As a specific example of the surface treatment, as shown in FIG. 3, a grease groove 23 is engraved on the side surface of the shoulder portion 19 of the constant velocity joint 7 in the circumferential direction, or as shown in FIG. When grinding the outer surface of the stem 2 and the side surface of the shoulder 19,
On the side surface of the shoulder portion 19, a streak 24 is formed concentrically with respect to the axis of the stem 20, or as shown in FIG.
There is a means for coating a side surface of the shoulder portion 19 with a slip agent 25 such as a bond or grease.

Next, a wheel bearing unit for driving wheels shown in FIG. 6 is a second embodiment of the present invention.

The second embodiment is a type in which the shaft 9 of the wheel mounting hub 3 in the first embodiment is not provided, and as shown in FIGS. 6 and 7, the stem 20 of the constant velocity joint 7 is formed. An axle bearing 4 is disposed on the outer periphery. The shapes of the wheel mounting hub 3 and the constant velocity joint 7 are different from those of the first embodiment, but corresponding portions are denoted by common reference numerals.

The constant velocity joint 7 of the second embodiment
Also, the deflection width of the side surface of the shoulder portion 19 of the outer ring 18 and the perpendicularity to the axis of the stem 20 are managed within a standard value, and the standard value is 30 μm or less, more preferably 8 μm or less.

Also, in the case of the second embodiment, the frictional resistance is applied to the side surface of the shoulder portion 19 of the constant velocity joint 7 as in the case of the first embodiment shown in FIGS. 3, 4 and 5. It is preferable to perform a surface treatment for reducing the size.

[0025]

According to the present invention, since the right angle and the swing width of the side surface of the shoulder of the constant velocity joint with respect to the stem are regulated within the standard values, high quality with reduced brake judder and stick-slip noise is achieved. Can be provided.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a first embodiment of a wheel bearing unit for a drive wheel incorporating a constant velocity joint according to the present invention.

FIG. 2 is a partial external view of a constant velocity joint used in the embodiment of FIG.

FIG. 3 is a perspective view showing an example of a surface treatment performed on a shoulder of the constant velocity joint according to the first embodiment.

FIG. 4 is a perspective view showing another example of the surface treatment applied to the shoulder of the constant velocity joint according to the first embodiment;

FIG. 5 is a perspective view showing another example of the surface treatment applied to the shoulder of the constant velocity joint of the above.

FIG. 6 is a partial cross-sectional view showing a second embodiment of a wheel bearing unit for a drive wheel incorporating a constant velocity joint according to the present invention.

FIG. 7 is a partial external view of a constant velocity joint used in the embodiment of FIG. 6;

[Explanation of symbols]

 Reference Signs List 1 brake rotor 2 wheel 3 wheel mounting hub 4 axle bearing 5a, 5b rolling element 6 drive shaft 7 constant velocity joint 8 flange portion 9 shaft portion 10 hub bolt 11 knuckle 12 outer ring 13a, 13b inner ring 14a, 14b seal 15 inner ring 16 ball 17 Cage 18 Outer ring 19 Shoulder 20 Stem 21 Spline 22 Nut 23 Grease groove 24 Streak 25 Slip agent

Claims (8)

[Claims] 1. A shoulder portion against which an inner ring end surface of an axle bearing abuts;
In a constant velocity joint for a drive wheel formed on an outer ring, a stem connected to a wheel mounting hub and a right angle and a runout width with respect to the stem axis of the shoulder side surface with which the inner ring end surface of the axle bearing contacts. A constant velocity joint characterized by being restricted to a value. 2. The constant velocity joint according to claim 1, wherein the standard value is 30 μm or less. 3. The constant velocity joint according to claim 1, wherein a side surface of the shoulder is subjected to a surface treatment for reducing frictional resistance. 4. The constant velocity joint according to claim 3, wherein the surface treatment is a circumferential grease groove formed in a side surface of the shoulder. 5. The constant velocity joint according to claim 3, wherein the surface treatment is a streak formed by grinding the side surface of the shoulder portion and concentric with the axis of the stem. 6. The constant velocity joint according to claim 3, wherein the surface treatment is a coating of a slip agent. 7. The wheel mounting hub according to claim 1, wherein the wheel mounting hub has a shaft portion protruding toward the inner side, and an inner ring of an axle bearing is arranged on an outer periphery of the shaft portion. Constant velocity joint. 8. The method according to claim 1, wherein the inner ring of the axle bearing is fitted around the outer periphery of the stem, and a spline is formed at the tip of the stem to engage with a wheel mounting hub. Speed joint.