JP2009083698A - Wheel support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel support device in which creep is hardly generated on a bearing. <P>SOLUTION: A pressing part 6a of a nut member 6 is arranged between an inner ring 9 at a vehicle inner side on the bearing 4 and a retainer ring 7, and a female screw part 19 formed on an inner peripheral surface of a body part of the nut member 6 is thread-engaged with a male screw part 7a formed on an outer peripheral surface of the retainer ring 7. The pressing part 6a of the nut member 6 screw-rotates the nut member 6 so as to press an end surface 9b of the inner ring 9 through a conical washer 5 to advance it. To the inner ring 9, strong fastening force by the nut member 6 and the retainer ring 7 is applied. <P>COPYRIGHT: (C)2009,JPO&INPIT

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
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
A retainer ring that is formed in a cylindrical shape and is fitted and mounted to the axle shaft on the inner peripheral surface, and a male thread portion is formed on the outer peripheral surface;
The pressing shaft is fitted to the axle shaft so as to be movable between the inner ring of the bearing and the retainer ring, and has a pressing portion that presses the inner ring in the axial direction when contacting the inner ring. A ring-shaped nut member extending in the axial direction from the peripheral part of the part, and having an internal thread part formed on the inner peripheral surface thereof to be screwed with the external thread part of the retainer ring,
While holding the state where the pressing portion of the nut member is in contact with the inner ring, by rotating the female screw portion with respect to the male screw portion of the retainer ring, both the fitting force between the retainer ring and the axle shaft can be reduced. By applying a tightening force due to screwing of the threaded portion to the inner ring through the pressing portion of the nut member, occurrence of creep between the inner ring and the axle shaft is prevented.

  The wheel support device according to the present invention is configured as described above. The inner ring has not only a fitting force between the retainer ring and the axle shaft, but also a screw between the male thread portion of the retainer ring and the female thread portion of the nut member. A tightening force can be applied. For this reason, compared with the conventional wheel support apparatus, an inner ring | wheel can be pressed with bigger force. As a result, it is difficult for creep to occur between the inner ring and the axle shaft, and it is possible to prevent problems such as separation of the raceway surface of the inner ring and occurrence of abnormal noise or vibration.

  The male thread portion of the retainer ring is formed so that the nut member is tightened in a direction in which the inner ring is pressed in the axial direction when the axle shaft rotates in a direction to advance the vehicle. be able to.

  As a result, the inner ring is tightened more firmly by the nut member at the time of normal wheel rotation and forward movement when a large load acts on the inner ring. That is, when a large load is applied to the inner ring, a larger force can be applied to the inner ring without power, and the occurrence of creep can be reliably prevented.

  Examples of the present invention will be described. FIG. 1 is a front sectional view of a wheel support device 101 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 XX of FIG.

  A wheel support device 101 according to a first embodiment of the present invention will be described. As shown in FIG. 1, the wheel support device 101 of the present embodiment uses an axle housing 2 to transmit an axle shaft 1 for transmitting a driving force to a wheel (not shown) attached to a vehicle outer side tip. 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 101 of this embodiment, the conical washer 5, the pressing portion 6a (described later) of the nut member 6, and the retainer ring 7 are fitted in this order on the vehicle inner side of the bearing 4 attached to the axle shaft 1. Has been. The main body of the nut member 6 is screwed into the retainer ring 7.

  The bearing 4 will be described. As shown in FIG. 1, the bearing 4 of the wheel support device 101 of this embodiment is a double row angular 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 12 are held by a cage 16.

  The retainer ring 7 will be described. As shown in FIGS. 1 and 2, 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. The axle shaft 1 is formed with an annular groove 17 at an end edge of the retainer ring fitted and attached to the axle shaft 1 on the vehicle inner side, and a snap ring is attached to the groove 17. Thereby, it is suppressed that the retainer ring 7 moves to an axial direction. A male screw portion 7 a is formed on the outer peripheral surface of the retainer ring 7.

  The nut member 6 will be described. The nut member 6 has a bottomed cylindrical shape, and a disc-shaped bottom portion is disposed between the inner ring 9 and the retainer ring 7, and a cylindrical main body portion is disposed outside the outer peripheral surface of the retainer ring 7. ing. On the inner peripheral surface of the main body portion of the nut member 6, a female screw portion 19 that is screwed into a male screw portion 7 a formed on the outer peripheral surface of the retainer ring 7 is formed. Further, the bottom portion of the nut member 6 serves as a pressing portion 6 a that presses the end surface 9 b of the inner ring 9 via the conical washer 5. By rotating the main body of the nut member 6 with respect to the retainer ring 7 in a predetermined direction, the pressing portion 6a of the nut member 6 can be moved closer to and away from the end surface 9b of the inner ring 9.

  The operation of the wheel support device 101 of this embodiment will be described. As shown in FIG. 1, inner rings 8 and 9 are press-fitted into the axle shaft 1. Subsequently, the conical washer 5 is fitted. The retainer ring 7 is press-fitted into the axle shaft 1 in a state where the nut member 6 is screwed into the retainer ring 7 and the pressing portion 6 a of the nut member 6 is brought close to the retainer ring 7. A retainer ring 7 is fitted and attached to a predetermined position of the axle shaft 1. By fitting the snap ring into the groove portion 17 of the axle shaft 1, the retainer ring 7 is prevented from moving toward the vehicle inner side in the axial direction.

  The nut member 6 is screw-rotated in a predetermined direction around the axis 1a of the axle shaft 1 with respect to the retainer ring 7, and the nut member 6 is advanced. The nut member 6 moves to the vehicle outer side, and the pressing portion 6 a presses the inner ring 9 while crushing the conical washer 5. In the case of a conventional wheel support device, the inner ring 9 is only subjected to the axial force of the conical washer 5 that maintains the compressed state by the fitting force between the axle shaft 1 and the retainer ring 7. However, in the wheel support device 101 of this embodiment, a tightening force is applied to the inner ring 9 by screwing between the male threaded portion 7 a of the retainer ring 7 and the female threaded portion 19 of the nut member 6. Thereby, it is possible to make it difficult for creep to occur between the axle shaft 1 and the inner ring 9. As a result, the raceway surface of the inner ring 9 is prevented from being peeled off, and abnormal noise and vibration are prevented from being generated.

  In the case of the wheel support device 101 of the first embodiment described above, the pressing portion 6a of the nut member 6 is formed in a disc shape with the end surface of the main body portion extending in a skirt shape in the radial direction. Thereby, the contact area with the end surface 9b of the inner ring 9 in the pressing portion 6a is increased, and the tightening force is increased. However, the nut member 21 which consists only of a cylindrical main-body part may be sufficient like the wheel support apparatus 102 of 2nd Example shown by (a) of FIG. In the case of this nut member 21, since the retainer ring 7 can be screwed into the male thread portion 7a of the retainer ring 7 even after the retainer ring 7 is fitted to the axle shaft 1, the retainer ring 7 can be easily assembled. There is an advantage of becoming.

  Further, like the wheel support device 103 of the third embodiment shown in FIG. 4B, the nut member 22 may be configured to press the inner ring 9 through the conical washer 5. Even in this case, similarly to the wheel support device 102 of the second embodiment. There is an advantage that the nut member 22 can be screwed later.

It is front sectional drawing of the wheel support apparatus 101 of 1st Example of this invention. It is an enlarged view of the principal part of FIG. It is the XX sectional view taken on the line of FIG. (A) is an enlarged view of the principal part of the wheel support apparatus 102 of 2nd Example, (b) is an enlarged view of the principal part of the wheel support apparatus 103 of 3rd Example.

Explanation of symbols

101-103 Wheel support device 200 Bearing unit 1 Axle shaft 2 Axle housing 3 Mounting flange 4 Bearing 5 Conical washer 6, 21, 22 Nut member 6a Pressing part 7 Retainer ring 7a Male thread part 8, 9 Inner ring 18 Snap ring (holding) means)
19 Female thread

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
A retainer ring that is formed in a cylindrical shape and is fitted and mounted to the axle shaft on the inner peripheral surface, and a male thread portion is formed on the outer peripheral surface;
The pressing shaft is fitted to the axle shaft so as to be movable between the inner ring of the bearing and the retainer ring, and has a pressing portion that presses the inner ring in the axial direction when contacting the inner ring. A ring-shaped nut member extending in the axial direction from the peripheral part of the part, and having an internal thread part formed on the inner peripheral surface thereof to be screwed with the external thread part of the retainer ring,
While holding the state where the pressing portion of the nut member is in contact with the inner ring, by rotating the female screw portion with respect to the male screw portion of the retainer ring, both the fitting force between the retainer ring and the axle shaft can be reduced. A wheel that prevents the occurrence of creep between the inner ring and the axle shaft by exerting a tightening force due to screwing of the threaded portion on the inner ring via the pressing portion of the nut member. Support device.   The male thread portion of the retainer ring is formed so that the nut member is tightened in a direction of pressing the inner ring in the axial direction when the axle shaft rotates in a direction to advance the vehicle. The wheel support apparatus according to claim 1.

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