JP3871455B2 - Constant velocity joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a constant velocity joint incorporated in a wheel bearing unit for a drive wheel in order to transmit engine power of a vehicle such as an automobile to wheels.
[0002]
[Prior art]
In recent years, with the increase in speed of automobiles, brake judder, vibration, and noise tend to be more severely limited in wheel bearing units for driving wheels.
[0003]
Conventionally, measures have been taken for brake judder to reduce axial runout of the brake rotor assembly, and various measures have been taken to prevent stick-slip noise due to shaft twisting due to engine torque. Although it is being developed, it is still not enough.
[0004]
[Problems to be solved by the invention]
In view of this, the present invention aims to reduce the vibration of the brake rotor and prevent stick-slip noise by increasing the reliability of the constant velocity joint incorporated in the wheel bearing unit for the drive wheel.
[0005]
[Means for Solving the Problems]
According to the present invention, in the constant velocity joint for the drive wheel formed on the outer ring, the shoulder portion with which the inner ring end surface of the axle bearing abuts and the stem connected to the wheel mounting hub are configured to contact the inner ring end surface of the axle bearing. The perpendicularity to the stem axis on the side of the shoulder and the swing width are regulated within the standard values.
[0006]
In this way, restricting the side surface of the shoulder of the outer ring of the constant velocity joint suppresses the vibration of the wheel and brake rotor through the wheel mounting hub, thus preventing the occurrence of brake judder and stick-slip noise. Is possible.
[0007]
The standard value effective for preventing the brake rotor from shaking and stick-slip noise is 30 μm or less, more preferably 8 μm or less.
[0008]
Further, in order to reduce the contact surface pressure between the side surface of the shoulder portion of the constant velocity joint and the inner ring end surface of the wheel bearing, it is preferable to subject the side surface of the shoulder portion to a surface treatment for reducing frictional resistance.
[0009]
As this surface treatment, a circumferential grease groove is formed on the side surface of the shoulder portion, a concentric line is formed by grinding on the stem axis, or a slip agent is coated. Means can be employed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a wheel bearing unit for a drive wheel incorporating a constant velocity joint according to the present invention will be described.
[0011]
A wheel bearing unit for a drive wheel shown in FIG. 1 is a first embodiment of the present invention. A wheel mounting hub 3 on which a wheel 2 is mounted together with a brake rotor 1 and a wheel mounting hub 3 are combined. An axle bearing 4 rotatably supported via row rolling elements 5a and 5b, and a constant velocity joint 7 connected to the wheel mounting hub 3 and transmitting the power of the drive shaft 6 to the wheel mounting hub 3 are configured. Has been.
[0012]
The wheel mounting hub 3 has a flange portion 8 and a shaft portion 9 extending from the flange portion 8 to the inner side along the axial direction. The shaft portion 9 communicates with a closing portion of the flange portion 8. A shaft hole is formed therethrough, and a spline is formed on the inner diameter surface of the shaft hole. The wheel mounting hub 3 is inserted into the inner diameter surface of the brake rotor 1, and the wheel 2 is mounted on the flange portion 8 together with the brake rotor 1 by a hub bolt 10.
[0013]
The axle bearing 4 is attached to a knuckle 11 extending from the vehicle body, and is disposed on the outer periphery of the outer ring 12 having a double row outer raceway surface and the shaft portion 9 of the wheel mounting hub 3. The inner ring 13a, 13b of the axially divided type formed with a surface, and the double row rolling elements 5a, 5b interposed between the inner raceway surface of the inner ring 13a, 13b and the outer raceway surface of the outer ring 12, Seals 14a and 14b are provided outside the double-row rolling elements 5a and 5b.
[0014]
The constant velocity joint 7 includes an inner ring 15 provided at one end of the drive shaft 6, a torque transmission ball 16, a cage 17 that holds the ball 16, and an outer ring 18.
[0015]
Then, as shown in FIG. 2, a shoulder portion 19 with which the end face of the inner ring 13b of the axle bearing 4 abuts and an axially extending stem 20 are integrally formed at one end of the outer ring 18 of the constant velocity joint 7. A spline 21 that fits with the shaft portion 9 of the wheel mounting hub 3 is formed on the outer diameter surface of the stem 20.
[0016]
The constant velocity joint 7 and the wheel mounting hub 3 are formed by inserting the stem 20 of the constant velocity joint 7 into the shaft portion 9 of the wheel mounting hub 3 and connecting them together by spline connection. The mounting hub 3 is assembled so that rotational torque is transmitted. Further, the tip of the stem 20 of the constant velocity joint 7 is fastened to the wheel mounting hub 3 by a nut 22, thereby preventing the constant velocity joint 7 from coming off and applying a predetermined set preload to the axle bearing 4. It is supposed to be.
[0017]
In this first embodiment, the deflection width of the side surface of the shoulder portion 19 of the constant velocity joint 7 and the perpendicularity with respect to the axis of the stem 20 with which the end surface of the inner ring 13b of the axle bearing 4 abuts are managed within the standard value. ing.
[0018]
This standard value is 30 μm or less, more preferably 8 μm or less.
[0019]
Further, it is preferable that the side surface of the shoulder portion 19 of the constant velocity joint 7 is subjected to a surface treatment for reducing the frictional resistance. By this surface treatment, smooth slip is obtained between the shoulder portion 19 of the constant velocity joint 7 and the inner ring 13b of the axle bearing 4, and the suppression of stick-slip noise becomes more effective.
[0020]
As a specific example of the surface treatment, as shown in FIG. 3, a grease groove 23 is formed in the circumferential direction on the side surface of the shoulder portion 19 of the constant velocity joint 7, or as shown in FIG. When the outer surface and the side surface of the shoulder portion 19 are ground, a streak 24 that is concentric with the axis of the stem 20 is formed on the side surface of the shoulder portion 19 or, as shown in FIG. There is means for coating the side surface of the portion 19 with a slip agent 25 such as a bonder or grease.
[0021]
Next, the wheel bearing unit for driving wheels shown in FIG. 6 is a second embodiment of the present invention.
[0022]
This second embodiment is a type in which the shaft portion 9 of the wheel mounting hub 3 in the first embodiment is not provided. As shown in FIGS. 6 and 7, an axle is provided on the outer periphery of the stem 20 of the constant velocity joint 7. The bearing 4 is arranged, and 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.
[0023]
In the constant velocity joint 7 of the second embodiment, the swing width of the side surface of the shoulder portion 19 of the outer ring 18 and the perpendicularity with respect to the axis of the stem 20 are managed within the standard value, and the standard value is preferably 30 μm or less. Is 8 μm or less.
[0024]
Also in the case of the second embodiment, a surface on the side surface of the shoulder portion 19 of the constant velocity joint 7 reduces the frictional resistance as in the case of the first embodiment shown in FIGS. It is preferable to perform the treatment.
[0025]
【The invention's effect】
According to the present invention, since the perpendicularity and the swing width with respect to the stem of the side surface of the shoulder portion of the constant velocity joint are regulated within the standard value, the brake judder and the stick slip noise are suppressed for high quality drive wheels. A wheel bearing unit can be provided.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing a first form 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 the constant velocity joint used in the form of FIG. 3 is a perspective view showing an example of surface treatment applied to the shoulder of the constant velocity joint. FIG. 4 is a perspective view showing another example of surface treatment applied to the shoulder of the constant velocity joint. FIG. 5 is a perspective view showing another example of the surface treatment applied to the shoulder portion of the constant velocity joint. FIG. 6 is a second view of the wheel bearing unit for driving wheels incorporating the constant velocity joint according to the present invention. FIG. 7 is a partial sectional view showing the configuration. FIG. 7 is a partial external view of the constant velocity joint used in the configuration of FIG.
DESCRIPTION OF SYMBOLS 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 part 9 Shaft part 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 Streaks 25 Slip agent

Claims (3)

In a constant velocity joint for a drive wheel formed on an outer ring, a shoulder part that abuts the inner ring end face of the axle bearing and a stem that is connected to a wheel mounting hub. A constant velocity joint in which the perpendicularity and the swing width with respect to the stem axis are regulated to 30 μm or less, the shoulder side surface is ground, and concentric lines are ground by grinding with respect to the stem axis.   2. The constant velocity joint according to claim 1, wherein the wheel mounting hub has a shaft portion protruding toward an inner side, and an inner ring of an axle bearing is disposed on an outer periphery of the shaft portion.   3. The constant velocity joint according to claim 1, wherein an inner ring of the axle bearing is fitted on an outer periphery of the stem, and a spline that engages with a wheel mounting hub is formed at a tip of the stem.

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