JP2009085363A - Wheel support device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel support device in which creep is hardly generated in a bearing.
SOLUTION: A shoulder portion 17 of an inner ring 9 is extended in an axial direction from an end surface 9b on the inner side of the inner ring 9 on the inner side of the vehicle to form an extending portion 18, and an inner peripheral surface of the extending portion 18 is formed. Is fitted to the outer peripheral surface of the tip of the retainer ring 6 through a slight gap. When the axle shaft 1 is rotating, even if a large load acts on the inner ring raceway surface 14 of the inner ring 9 to cause the inner ring 9 to bend, the inner circumferential surface of the extending portion 18 contacts the outer circumferential surface of the retainer ring 6. Therefore, the inner ring 9 is restrained from being bent further. As a result, the degree of movement of the retainer ring 6 in the axial direction is reduced, and creep is less likely to occur between the inner ring 9 and the axle shaft 1.
[Selection] Figure 1

Description

  The present invention relates to a vehicle wheel support device.

  As an axle structure used on the drive wheel side of a vehicle (for example, an automobile), there is one called a “half-floating type wheel support device” (see Patent Document 1). Since this type of wheel support device is lightweight, it is often used for small vehicles such as passenger cars. In the semi-floating type wheel support device, an axle shaft having a wheel attachment portion at an end is accommodated in an axle housing via a bearing. The power is transmitted to the wheel by the axle shaft.

  The bearings of the semi-floating wheel support device are pressed against the outer peripheral surface of the axle shaft to prevent rotation. However, since the bearing of the semi-floating type wheel support device is only press-fitted into the axle shaft, if an unexpected excessive moment load is applied to the bearing, creep occurs between the axle shaft and the bearing. May be easier. Here, the creep in the bearing is “in the case of rotational load, when a clearance is generated in the fitting surface between the raceway surface of the inner ring and the outer peripheral surface of the axle shaft, the inner surface of the fitting surface is relative to the outer surface. In particular, it means a phenomenon that shifts in the direction opposite to the rotation direction of the inner ring rotational load (in a broad sense, including a case where the driving side slips in the driving direction relative to the other side on the fitting surface regardless of the rotation direction). As a result, the raceway surface of the bearing may be peeled off, or abnormal noise or vibration may occur.

In recent vehicles, the anti-lock brake is used to detect the rotational speed of the wheel by a sensor (for example, an encoder) attached to the inner ring of the bearing. If creep occurs in the bearing, the detection accuracy of the rotational speed of the wheel may be reduced.
JP-A-4-113902

  In view of the above-described problems, an object of the present invention is to provide a wheel support device in which creep is unlikely to occur in a bearing.

Means for Solving the Problems and Effects of the Invention

The present invention for achieving the above-mentioned problems
In order to support the axle shaft for transmitting the driving force to the wheel attached to the front end portion of the vehicle outer side with the axle housing, the mounting flange portion fixed to the axle housing, the mounting flange portion, A semi-floating wheel support device comprising a bearing unit including a bearing interposed between an axle shaft and
The axle shaft is fitted with an inner peripheral surface of a cylindrical retainer ring,
A shoulder portion of the inner ring of the bearing extends toward the retainer ring, and at least the inner peripheral surface of the extended portion of the shoulder portion and the outer peripheral surface of the retainer ring are in contact with each other when the axle shaft rotates. , They are characterized by rotating together.

  Since the wheel support device according to the present invention is configured as described above, even if a large load acts on the raceway surface of the inner ring to bend the inner ring, the inner peripheral surface of the extending portion of the inner ring is the retainer ring. Since it contacts the outer peripheral surface of the inner ring, the inner ring is prevented from further bending. As a result, the degree of movement of the retainer ring in the axial direction is reduced, and the inner ring, the retainer ring, and the axle shaft are more reliably integrated. As a result, the reduction of the axial force on the inner ring is prevented, and the occurrence of creep between the inner ring and the axle shaft to prevent the trouble that the raceway surface peels off or abnormal noise or vibration occurs. Can do.

  The fit between the inner peripheral surface of the extending portion of the shoulder portion of the inner ring and the outer peripheral surface of the retainer ring is preferably an interference fit.

  Thereby, since the inner peripheral surface of the extension part of the shoulder part of an inner ring | wheel and the outer peripheral surface of a retainer ring will always be in a contact state, an inner ring | wheel, a retainer ring, and an axle shaft can be integrated more reliably.

  Examples of the present invention will be described. FIG. 1 is a front sectional view of a wheel support device 100 according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is a sectional view taken along line X1-X1 of FIG.

  A wheel support device 100 according to an embodiment of the present invention will be described. As shown in FIG. 1, the wheel support device 100 according to the present embodiment includes an axle housing 2 that transmits an axle shaft 1 for transmitting a driving force to a wheel (not shown) attached to a front end portion of the vehicle outer side. In order to support, a bearing unit 200 including a mounting flange portion 3 fixed to the axle housing 2 and a double row bearing 4 interposed between the mounting flange portion 3 and the axle shaft 1 is provided. ing. The front end portion of the axle shaft 1 on the vehicle outer side extends toward the outside in the radial direction, and a wheel mounting portion is provided in the extended portion. In the wheel support device 100 of this embodiment, the conical washer 5, the retainer ring 6, and the snap ring 7 are fitted in this order on the vehicle inner side of the bearing 4 attached to the axle shaft 1. The retainer ring 7 is press-fitted into the axle shaft 1 in a state where the conical washer 5 is crushed in the axial direction to be compressed and deformed. Further, the snap ring 7 prevents the retainer ring 6 press-fitted into the axle shaft 1 from moving in the axial direction.

  The bearing 4 will be described. As shown in FIG. 1, the bearing 4 of the wheel support device 100 of this embodiment is a double-row angular contact ball bearing, and is rotated integrally with the axle shaft 1 by being press-fitted into the outer peripheral surface of the axle shaft 1. A pair of inner rings (an inner ring 8 on the vehicle outer side and an inner ring 9 on the vehicle inner side), an outer ring 11 fixed to the axle housing 2 via the mounting flange 3, and a pair of inner rings 8, 9 and the outer ring 11 And a plurality of rolling elements (balls 12) interposed therebetween. Each inner ring 8, 9 is composed of a large diameter portion and a small diameter portion that are joined in a continuous state, and inner ring raceway surfaces 13, 14 for rolling the balls 12 are provided at the joint portions of both. An end surface 8 a (end surface on the vehicle outer side) of the inner ring 8 on the large diameter portion side is in contact with a lower end portion of the wheel mounting portion of the axle shaft 1. Further, the end faces 8b, 9a on the small diameter side of the inner rings 8, 9 are opposed to each other in a state of being abutted. Similarly, an outer ring raceway surface 15 is formed on the inner peripheral surface of the outer ring 11. The plurality of balls 11 are held by a cage 16.

  As shown in FIGS. 1 to 3, in the inner ring 9 on the vehicle inner side, the outer peripheral edge portion (the portion including the shoulder portion 17 of the inner ring 9) of the end surface 9b on the vehicle inner side is extended in the axial direction. An installation portion 18 is formed. The distal end edge of the extending portion 18 is disposed closer to the vehicle inner side than the distal end edge of the retainer ring 6 on the vehicle outer side. The inner diameter D of the extending portion 18 is slightly larger than the outer diameter d of the distal end portion of the retainer ring 6. In other words, the fit between the inner peripheral surface of the extending portion 18 of the inner ring 9 and the outer peripheral surface of the distal end portion of the retainer ring 6 is, for example, a clearance fit or an intermediate fit. When the axle shaft 1 is rotating around the axis 1a, the inner shaft 9 and the inner ring 9 of the extending portion 18 of the inner ring 9 and the retainer ring 6 are deformed due to bending, thermal expansion or the like of the axle shaft 1 or the inner ring 9 accompanying the rotation. Contact with the outer peripheral surface of the tip. Thereby, the inner ring 9 and the retainer ring 6 are rotated integrally with the axle shaft 1.

  The effect | action of the wheel support apparatus 100 of a present Example is demonstrated. As shown in FIG. 2, when an unexpected excessive moment load is applied to the bearing 4 of the bearing unit 200 while the vehicle is traveling, the inner ring raceway surface 14 of the inner ring 9 on the vehicle inner side rather than the inner ring 8 on the vehicle outer side. A large load F acts on the.

  In the wheel support device 100 of the present embodiment, the shoulder portion 17 of the inner ring 9 extends in the axial direction, and the inner peripheral surface of the extended portion 18 is slightly between the outer peripheral surface of the retainer ring 6. It arrange | positions in the overlapping state at the front-end | tip part of the retainer ring 6 through the clearance gap. In addition, the inner peripheral surface of the extending portion 18 of the inner ring 9 and the outer peripheral surface of the distal end portion of the retainer ring 6 are in contact with each other in the rotating state of the axle shaft 1 (the traveling state of the vehicle). As a result, the degree of movement of the retainer ring 6 in the axial direction is reduced as compared with the case of the conventional wheel support device in which the extending portion 18 is not provided, and the inner ring 9 and the retainer ring 6 and the axle shaft 1 are not moved. Integration is more reliably achieved. As a result, a decrease in the axial force on the inner ring 9 is prevented, and it is possible to prevent a problem that creep occurs in the inner ring 9 and the inner ring raceway surface 14 is peeled off or abnormal noise or vibration is generated. .

  In the wheel support device 100 of the embodiment described in the present specification, at least when the axle shaft 1 rotates, the inner peripheral surface of the extending portion 18 of the inner ring 9 and the outer peripheral surface of the distal end portion of the retainer ring 6 are in contact with each other. It is the structure which both rotate integrally. That is, the inner peripheral surface of the inner ring 9 and the extending portion 18 and the outer peripheral surface of the distal end portion of the retainer ring 6 are assembled by clearance fit or intermediate fit. Thereby, the assembly | attachment of the retainer ring 6 becomes easy. However, the inner peripheral surface of the extending portion 18 of the inner ring 9 and the outer peripheral surface of the distal end portion of the retainer ring 6 may be assembled by an interference fit so that they are always in contact with each other. In this case, the occurrence of creep between the inner ring 9 and the axle shaft 1 can be more reliably prevented.

It is front sectional drawing of the wheel support apparatus 100 of 1st Example of this invention. It is an enlarged view of the principal part of FIG. It is the X1-X1 sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Wheel support apparatus 200 Bearing unit 1 Axle shaft 2 Axle housing 3 Mounting flange part 4 Bearing 6 Retainer ring 8, 9 Inner ring 17 Shoulder part 18 Extension part

Claims (2)

In order to support the axle shaft for transmitting the driving force to the wheel attached to the front end portion of the vehicle outer side with the axle housing, the mounting flange portion fixed to the axle housing, the mounting flange portion, A semi-floating wheel support device comprising a bearing unit including a bearing interposed between an axle shaft and
The axle shaft is fitted with an inner peripheral surface of a cylindrical retainer ring,
A shoulder portion of the inner ring of the bearing extends toward the retainer ring, and at least the inner peripheral surface of the extended portion of the shoulder portion and the outer peripheral surface of the retainer ring are in contact with each other when the axle shaft rotates. The wheel support device is characterized in that they rotate integrally.   The wheel support device according to claim 1, wherein the fit between the inner peripheral surface of the extending portion of the shoulder portion of the inner ring and the outer peripheral surface of the retainer ring is an interference fit.

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