JP2008169899A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device having reduced creeps while avoiding the axial movement of an outer ring. <P>SOLUTION: The outer ring 5 is externally fitted to inner rings 3, 3 via rolling elements 4, 4. At the end of the outer ring 5 on the outer side, a cylindrical portion 5b is formed in a cylindrical shape extending to the axial direction. A housing 6 has a protruded portion 6a having the end on the inner side protruded inward to the radial direction. The protruded portion 6a abuts on the side face of the outer ring 5 on the inner side. On the inner side of a hub 9, a cylindrical portion 9b is formed in a cylindrical shape extending to the axial direction. The side face of the cylindrical portion 9b abuts on the side face of the outer ring 5 on the outer side. The side face of the outer ring 5 is held between the cylindrical portion 9b and the protruded portion 6a of the housing 6 and fixed with a bolt 7, thus reducing creeps while avoiding the axial movement of the outer ring 5. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and more particularly to a wheel bearing device for a large vehicle.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

An example of a wheel bearing device for a large vehicle is disclosed in Patent Document 1. In this example, the housing is attached to the knuckle by the bearing unit, and the inner peripheral surface of the disc rotor in the disc brake is in contact with the outer peripheral surface of the housing, and the outer peripheral surface of the hub is in contact with the inner peripheral surface of the housing. Is fixed to the outer end surface of the housing by bolts. The bearing unit includes a pair of inner rings and an outer ring that is externally fitted via double-row tapered rollers.
Japanese Patent Laid-Open No. 2003-312205

  In the wheel bearing device shown in Patent Document 1, the outer ring and the housing are fitted together with a tightening margin, but when a high load is applied, the outer ring may creep and come off in the axial direction. Therefore, it is conceivable to install a retaining ring, but at least the clearance between the outer ring and the retaining ring may cause the outer ring to move in the axial direction, and if the outer ring moves in the axial direction, the air gap between the encoder and sensor will increase. Therefore, the ABS (anti-lock brake system) may not operate correctly.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device capable of reducing creep without the outer ring moving in the axial direction.

  In order to achieve such an object, the present invention includes a pair of inner rings that are externally fitted to an axle, a rotatable outer ring that is externally fitted to the inner ring via a rolling element, and a press-fit fit to the outer periphery of the outer ring. A wheel bearing device including a housing, a brake member fastened to the housing by fastening means, and a hub, wherein both side surfaces of the outer ring are fixed by the housing and the hub is adopted.

  Thus, by fixing the both side surfaces of the outer ring, the outer ring does not creep and come off in the axial direction even when a high load is applied. Moreover, since creep usually involves axial movement, creep can be reduced by preventing the outer ring from moving in the axial direction. Moreover, since it is not necessary to use a retaining ring, the number of parts can be reduced. Furthermore, since the outer ring does not move in the axial direction, the air gap between the encoder and sensor does not increase, and the ABS can be operated accurately.

  Further, according to the present invention, the housing is formed with a protruding portion in which an end on the inner side protrudes radially inward, the protruding portion abuts on an inner side surface of the outer ring, and the hub is connected to the inner side. A cylindrical portion extending in the axial direction of the outer ring is formed, the cylindrical portion abuts on the outer side surface of the outer ring, and the housing and the hub can be fixed by a fastening means. As a result, the outer ring can be fixed so as to be sandwiched between the housing and the hub, so that the axial movement of the outer ring can be prevented.

  In the present invention, the outer ring may be formed with a cylindrical portion extending in the axial direction on the outer side. Thereby, it can prevent suitably that the nut etc. which fasten a hub and an axle shaft interfere.

  In the present invention, an encoder may be provided on a side surface of the housing. If the outer ring does not move in the axial direction, the housing fitted to the outer ring does not move in the axial direction, and stable controllability can be maintained by providing an encoder in the housing.

  In the present invention, the inner peripheral surface of the brake member may be positioned on the outer peripheral surface of the housing, and the outer peripheral surface of the hub may be positioned on the inner peripheral surface of the housing. Since the brake member and the hub can be positioned, the assembling property is improved, and stable performance can be exhibited even during use.

  A wheel bearing device according to the present invention includes a pair of inner rings that are externally fitted to an axle, a rotatable outer ring that is externally fitted to the inner ring via a rolling element, and a housing that is press-fitted to the outer periphery of the outer ring. And a bearing device for a wheel comprising a brake member and a hub that are fastened to the housing by fastening means, and both side surfaces of the outer ring are fixed by the housing and the hub, so that the outer ring moves in the axial direction. Thus, it is possible to provide a wheel bearing device that can reduce creep.

  A pair of inner rings that are externally fitted to the axle, a rotatable outer ring that is externally fitted to the inner ring via a rolling element, a housing that is press-fitted to the outer periphery of the outer ring, and a fastening means fastened to the housing A wheel bearing device comprising a brake member and a hub, wherein both side surfaces of the outer ring are fixed by the housing and the hub.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  This wheel bearing device 1 is for a driven wheel referred to as a first generation, and includes a pair of inner rings 3 and 3 fitted on the axle 2 and rolling elements (conical rollers) 4 and 4 on the inner rings 3 and 3. A brake member 8 and a hub 9 which are composed of a rotatable outer ring 5 which is externally fitted via a shaft, a disk rotor which is fastened by a fastening means (bolt) 7 to a side surface of a housing 6 which is press-fitted to the outer periphery of the outer ring 5 And consist of

  A stepped portion 2 a of the axle 2 is fitted to the inner peripheral surface of the inner ring 3. The shoulder portion 2 b of the axle 2 is in contact with the side surface of the inner ring 3. A small diameter portion 2c having a smaller diameter than the stepped portion 2a is formed on the outer side of the stepped portion 2a. A male screw portion 2d is formed on the outer side of the small diameter portion 2c. An annular washer 10 is inserted into the small diameter portion 2c. A nut 11 is screwed into the male screw portion 2d. The washer 10 is pressed against the side surface of the inner ring 3 by screwing the nut 11. In this way, the inner ring 3 is sandwiched between the shoulder 2 b of the axle 2 and the washer 10, and the inner ring 3 is fixed to the axle 2.

  A tapered inner rolling surface 3 a is formed on the outer periphery of the inner ring 3. The inner ring 3 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  An outer ring 5 is externally fitted to the inner rings 3 and 3 via rolling elements 4 and 4. The outer ring 5 is integrally formed with taper-shaped double-row outer rolling surfaces 5a and 5a that are opened outward on the inner circumference. A cylindrical portion 5 b having a cylindrical shape extending in the axial direction is formed at the outer end of the outer ring 5. The outer ring 5 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  The rolling elements 4 and 4 are held between the rolling surfaces of the inner ring 3 and the outer ring 5 by a cage so as to roll freely. The rolling element 4 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core by quenching. The bearing of the wheel bearing device 1 is a so-called back-to-back double row tapered roller bearing.

  In addition, seals 12 and 13 are attached to an opening of an annular space formed between the inner ring 3 and the outer ring 5. The seals 12 and 13 constitute a so-called pack seal, which is a composite seal composed of an annular seal plate and a slinger that have a substantially L-shaped cross section and are opposed to each other. These seals 12 and 13 prevent leakage of grease encapsulated inside the bearing, and intrusion of rainwater, dust, and the like from the outside into the bearing.

  The housing 6 has a substantially cylindrical shape as a whole, and the outer diameter surface thereof has a tapered shape in which the outer diameter decreases toward the inner side. The housing 6 is formed with a protruding portion 6 a having an inner end protruding radially inward, and the protruding portion 6 a is in contact with the inner side surface of the outer ring 5. The protruding height of the protruding portion 6 a is substantially equal to the thickness of the end portion of the outer ring 5. At the outer end of the housing 6, several female screw portions 6 b to which the bolts 7 are screwed are formed at equal positions. A metal core 14 having an L-shaped cross section is press-fitted and fixed to an end surface on the inner side of the housing 6. An encoder 15 is disposed on the peripheral surface of the cored bar 14. The encoder 15 is composed of a rubber magnet having magnetic poles N and S alternately formed in the circumferential direction, and constitutes a rotary encoder for detecting wheel rotation speed. The housing 6 is formed of a casting.

  The side surface of the brake member 8 is in contact with the side surface on the outer side of the housing 6. On the side surface of the brake member 8, several through holes 8 a are formed at equal positions, and the brake member 8 can be fixed to the housing 6 by inserting a bolt 7. The position of the inner end surface of the brake member 8 is substantially equal to the inner peripheral surface of the housing 6. The inner peripheral surface 8b of the brake member 8 is in contact with the outer peripheral surface of the housing 6, and positioning is performed.

  The hub 9 is disposed on the outer side of the brake member 8. On the side surface of the hub 9, several through holes 9 a are equally drilled at positions corresponding to the female screw portions 6 b and the through holes 8 a. Bolts 7 are inserted into the through holes 9 a so that the hub 9 and the brake member 8 can be fixed to the housing 6. On the inner side of the hub 9, a cylindrical portion 9b having a cylindrical shape extending in the axial direction is formed. The side surface of the cylindrical portion 9 b is in contact with the outer side surface of the outer ring 5. To provide a wheel bearing device that can reduce creep without moving the outer ring 5 in the axial direction by sandwiching the side surface of the outer ring 5 between the cylindrical part 9b and the projecting part 6a of the housing 6 and fixing with the bolt 7. Can do.

  An arc portion 9c having an arc shape that swells toward the outer side is formed at the base portion of the cylindrical portion 9b. The presence of the arc portion 9c prevents the hub 9 and the axle 2 from interfering with each other. A wheel mounting flange 9 d for mounting a wheel (not shown) is formed at the outer end of the hub 9. Hub bolts 16 are implanted in the wheel mounting flange 9d at equal intervals in the circumferential direction.

  In addition, although the bearing apparatus by the side of a driven wheel was illustrated here, this invention is not restricted to this, The drive wheel side may be sufficient. Moreover, in this embodiment, the double row tapered roller bearing which used the tapered roller for the rolling element 4 was illustrated, but of course, it is not restricted to this, The double row angular contact ball bearing which uses the ball for the rolling element 4 may be sufficient. .

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device in which an outer ring is used as a bearing regardless of whether it is for driving wheels or driven wheels.

It is a longitudinal section showing an embodiment of a wheel bearing device concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ...... Wheel bearing device 2 ... Axle 2a ... Stepped part 2b ... Shoulder 2c ······· Small diameter portion 2d ····················································· Inner ring 3a ... ... Rolling element 5 ... Outer ring 5a ... Outer rolling surface 5b ... Cylindrical part 6 ... ..Housing 6a... Projection 6b... Internal thread 7... Fastening means 8. 8a ... Through hole 8b ... Inner peripheral surface 9 ... Hub 9a ... Through hole 9b ... .... Cylindrical part 9c ......... Arc part 9d ......... Wheel mounting flange 10 ... ... Washer 11 ... Nuts 12, 13 ... Seal 14 ... Core 15 ... Encoder 16 ... ... Hub bolts

Claims (5)

A pair of inner rings that are externally fitted to the axle, a rotatable outer ring that is externally fitted to the inner ring via a rolling element, a housing that is press-fitted to the outer periphery of the outer ring, and fastening to the housing by fastening means A wheel bearing device comprising a brake member and a hub,
A bearing device for a wheel, wherein both side surfaces of the outer ring are fixed by the housing and the hub.   The housing is formed with a projecting portion having an inner end projecting radially inward, the projecting portion abutting on the inner side surface of the outer ring, and a cylinder extending in the inner axial direction on the hub The wheel bearing device according to claim 1, wherein a portion is formed, the cylindrical portion abuts against a side surface on the outer side of the outer ring, and the housing and the hub are fixed by fastening means.   The wheel bearing device according to claim 1 or 2, wherein a cylindrical portion extending in the axial direction on the outer side is formed on the outer ring.   The wheel bearing device according to any one of claims 1 to 3, wherein an encoder is provided on a side surface of the housing.   The wheel bearing device according to any one of claims 1 to 4, wherein an inner peripheral surface of the brake member is positioned on an outer peripheral surface of the housing, and an outer peripheral surface of the hub is positioned on an inner peripheral surface of the housing.

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