JP2007303651A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel, securing durability of a bearing and further increasing rigidity, while restraining a weight increase. <P>SOLUTION: This bearing device for the wheel is fitted to the outer periphery of a hub wheel 10 adjacent to a wheel installing flange 9, by forming a large collar composed of a conical roller bearing of double rows and arranged on the large diameter side of an inside rollingly traveling surface 10a of the hub wheel 10, as a collar wheel 16 separate from the hub wheel 10. Since a pitch circle diameter PCDo of an outer side conical roller 5 row is set in a larger diameter than a pitch circle diameter PCDi of an inner side conical roller 6 row and a diameter of an outer side conical roller 5 is formed in a smaller diameter than a diameter of an inner side conical roller 6, the number of outer side conical rollers 5 can be stored in larger number than the number of inner side conical rollers 6, and the bearing device for the wheel for securing durability of the bearing and increasing the rigidity while restraining the weight increase, can be provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, and more particularly, to a wheel bearing device that includes a double-row tapered roller bearing and rotatably supports a wheel of a large truck or a wagon car. Is.

  In vehicles such as trucks, in recent years, the horsepower and loading capacity of vehicles have increased, and accordingly, wheel bearing devices are required to withstand the temperature rise during high loads and high speeds. A double row tapered roller bearing suitable for receiving a radial load, a thrust load, and a combined load thereof is generally used for a bearing portion of a wheel bearing device in such a vehicle.

  An example of a wheel bearing device using such a double-row tapered roller bearing is shown in FIG. This wheel bearing device is mounted on an axle for a driven wheel such as a truck and rotatably supports a wheel (not shown). 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).

  The wheel bearing device includes an outer member 51 formed with tapered double-row outer rolling surfaces 51a, 51a that are adjacent to each other on the inner circumference on the small-diameter side, and an outer rolling surface 51a of these double rows on the outer circumference. An inner member 52 formed with double-row inner rolling surfaces 58a and 59a facing 51a, and a double-row tapered roller 54 accommodated between the rolling surfaces via a retainer 53 so as to be freely rollable; 54. The seals 55 and 56 include seal members 55a and 56a fitted to both ends of the outer member 51, and slinger 55b and 56b slidably contacting the seal members 55a and 56a. Leakage and rainwater and dust are prevented from entering the bearing from the outside.

  The inner member 52 integrally has a wheel mounting flange 57 for attaching a wheel to the outer end portion, and has an outer side inner rolling surface 58a on the outer periphery and an axial direction extending from the inner rolling surface 58a. The hub wheel 58 is formed with a cylindrical small-diameter stepped portion 58b, and the inner ring 59 is press-fitted into the small-diameter stepped portion 58b of the hub wheel 58 to form an inner side rolling surface 59a. The inner ring 59 is fixed in the axial direction by a caulking portion 60 formed by plastic deformation of the end portion of the small-diameter stepped portion 58b of the hub wheel 58.

  Bolt holes 57a are formed in the wheel mounting flange 57 of the hub wheel 58 at equal intervals in the circumferential direction, and the wheel is fixed via a fastening bolt (not shown). In addition, a flange ring 61 that is in contact with the large end face of the outer tapered roller 54 is fitted to the outer periphery of the hub ring 58 that is the base of the wheel mounting flange 57.

  The inner ring 59 is provided with a large flange 59b on the larger diameter side of the inner rolling surface 59a thereof, and the large end surface of the tapered roller 54 on the inner side is in contact with and guided by the large flange 59b. Further, a small flange 59c is provided on the small diameter side of the inner rolling surface 59a to prevent the tapered roller 54 from falling off. A slinger 56b constituting an inner side seal 56 is fitted to the outer periphery of the large collar 59b of the inner ring 59.

  A cylindrical saddle wheel fitting surface 62 is formed on the outer periphery of the hub wheel 58 adjacent to the wheel mounting flange 57, and an arcuate cross-sectional portion 63 that connects the saddle wheel fitting surface 62 to the side surface of the wheel mounting flange 57 is formed. Has been. The saddle wheel 61 is fitted to the saddle wheel fitting surface 62 and comes into contact with and guides the large end surface of the outer tapered roller 54, a cylindrical inner peripheral surface 61 b, and a wheel mounting flange 57. An end surface 61c that comes into contact with the side surface and an arc-shaped portion 61d that engages with the arc-shaped cross-section 63 of the hub wheel 58 in a non-contact state from the end surface 61c to the inner peripheral surface 61b. Further, the outer peripheral surface of the saddle wheel 61 is formed in a stepped cylindrical surface having a large diameter on the wheel mounting flange 57 side, and a slinger 55b constituting the outer seal 55 is fitted to a small diameter portion 61e on the outer peripheral surface. Has been.

In this wheel bearing device, a large flange provided on the large-diameter side of the inner raceway surface 58 a of the hub wheel 58 is formed as a flange wheel 61 separate from the hub wheel 58, and the hub adjacent to the wheel mounting flange 57 is formed. Since the ring 58 is fitted to the outer periphery, stress concentration caused by contact with the tapered roller 54 near the boundary between the inner rolling surface 58a and the flange surface 61a of the flange ring 61 is alleviated. Therefore, even when applied to a vehicle type with a heavy vehicle weight, fatigue near the boundary portion hardly occurs and the bearing device has excellent durability. Further, since the saddle wheel 61 is provided with an arc-shaped portion 61d that is not in contact with the arc-shaped cross-sectional portion 63 having a large curvature radius connected to the side surface of the wheel mounting flange 57, the tapered roller 54 to the saddle wheel 61 are provided in this portion. It is possible to further reduce stress concentration due to the load applied via the.
JP 2004-340242 A

  In such a conventional wheel bearing device, a large collar that contacts the large end face of the outer tapered roller 54 and guides the tapered roller 54 is constituted by a separate collar 61, which is a wheel mounting flange 57. Since the hub wheel 58 is fitted on the outer periphery of the hub wheel 58, stress concentration on the hub wheel 58 is alleviated and the durability is excellent. However, in this type of wheel bearing device, it has been a big challenge to realize further increase in rigidity while suppressing an increase in weight.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a wheel bearing device that ensures durability of the bearing and further increases rigidity while suppressing an increase in weight. .

  In order to achieve such an object, the invention according to claim 1 of the present invention attaches an outer member having a tapered double-row outer rolling surface formed on the inner circumference and adjacent to each other on the small diameter side, and a wheel. And a tapered inner rolling surface facing one of the double-row outer rolling surfaces and a small-diameter step portion extending in the axial direction from the inner rolling surface. Hub ring, and an inner ring that is press-fitted into a small-diameter step portion of the hub ring through a predetermined shimiro and has a tapered inner rolling surface facing the other of the outer rolling surfaces of the double row on the outer periphery. An inner member, a double-row tapered roller housed between the rolling surfaces of the inner member and the outer member via a cage, and the outer member and the inner member. And a seal mounted in an opening of an annular space formed between the inner ring and the inner ring. A large flange for guiding the tapered roller is formed on the large-diameter side of the surface, and in contact with the large end surface of the outer tapered roller at a location adjacent to the wheel mounting flange on the outer periphery of the hub wheel. In a wheel bearing device in which a saddle wheel for guiding a tapered roller is fitted, a pitch circle diameter of the outer tapered roller row is set larger than a pitch circle diameter of the inner tapered roller row. .

  As described above, the large collar provided on the large diameter side of the inner raceway surface of the hub wheel is formed as a separate collar from the hub wheel, and is formed of a double row tapered roller bearing. In the wheel bearing device fitted to the outer periphery of the hub wheel adjacent to the mounting flange, the pitch circle diameter of the outer tapered roller row is set larger than the pitch circle diameter of the inner tapered roller row. Therefore, the number of outer side tapered rollers can be accommodated more than the number of inner side tapered rollers, the rigidity is improved not only when the vehicle is stationary but also when turning, and the service life of the wheel bearing device is extended. Can be achieved.

  Preferably, if the diameter of the outer tapered roller is smaller than the diameter of the inner tapered roller, the rigidity is increased while suppressing an increase in weight. A wheel bearing device can be provided.

  Further, as in the third aspect of the present invention, if the outer cage is formed by injection molding synthetic resin and is held so that the tapered rollers do not fall off to the inner diameter side, the inner side of the hub wheel A small punch for holding the tapered roller on the small diameter side of the rolling surface is not required, so that the workability of the hub wheel is improved and the weight increase can be further suppressed.

  According to a fourth aspect of the present invention, the outer peripheral surface of the saddle wheel is formed into a stepped cylindrical surface having a large diameter on the wheel mounting flange side, and the small diameter portion and the outer member on the outer peripheral surface. The outer side seal is mounted in the annular space formed between the outer peripheral surface and a slight radial clearance is formed between the large-diameter portion on the outer peripheral surface and the outer member, thereby forming a labyrinth seal. If so, the sealing performance of the seal can be further improved.

  Further, as in the invention according to claim 5, in the state in which the bearing preload is applied by the crimping portion formed by plastically deforming the end portion of the small-diameter step portion of the hub wheel radially outward. If the inner ring is fixed in the axial direction with respect to the ring, the weight can be reduced and the size can be reduced, and the initially set preload can be maintained over a long period of time.

  The wheel bearing device according to the present invention integrally includes an outer member having a tapered double row outer raceway formed on the inner circumference and adjacent to each other on the small diameter side, and a wheel mounting flange for mounting the wheel. A hub ring having a tapered inner rolling surface facing one of the double row outer rolling surfaces on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and An inner member formed of an inner ring that is press-fitted into a small-diameter step portion through a predetermined scissors and has a tapered inner rolling surface facing the other of the outer circumferential rolling surfaces of the double row on the outer periphery; An annular space formed between the outer member and the inner member; and a double row tapered roller housed between the rolling surfaces of the member and the outer member via a cage. And the tapered roller on the large diameter side of the inner raceway surface of the inner ring. A guide collar is formed, and a guide ring that contacts the outer end of the tapered roller on the outer side and guides the tapered roller is fitted at a location adjacent to the wheel mounting flange on the outer periphery of the hub wheel. In the above wheel bearing device, since the pitch circle diameter of the outer tapered roller row is set larger than the pitch circle diameter of the inner tapered roller row, the number of outer tapered rollers is More than the number of tapered rollers on the inner side can be accommodated, the rigidity is improved not only when the vehicle is stationary but also when turning, and the life of the wheel bearing device can be extended.

  An outer member formed with a tapered double-row outer rolling surface adjacent to each other on the inner circumference on the small diameter side, and a wheel mounting flange for attaching a wheel to one end are integrally provided, and the double-row on the outer circumference. A tapered inner rolling surface facing one of the outer rolling surfaces, a hub wheel formed with a small-diameter step portion extending in the axial direction from the inner rolling surface, and a predetermined shimoshiro on the small-diameter step portion of the hub ring An inner member formed of an inner ring having a tapered inner rolling surface formed on the outer periphery and facing the other of the double row outer rolling surfaces, and the inner member and the outer member. A double-row tapered roller housed in a rollable manner between both rolling surfaces via a cage, and a seal attached to an opening in an annular space formed between the outer member and the inner member And a large flange is formed on the inner diameter rolling surface of the inner ring for guiding the tapered roller. And a wheel bearing device in which a saddle wheel that contacts the large end surface of the outer tapered roller and guides the tapered roller is fitted at a location adjacent to the wheel mounting flange on the outer periphery of the hub wheel. The pitch circle diameter of the outer side tapered roller row is set larger than the pitch circle diameter of the inner side tapered roller row, and the diameter of the outer side tapered roller is set to be smaller than that of the inner side tapered roller. The diameter is smaller than the diameter.

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. This wheel bearing device is mounted on an axle (not shown) for a driven wheel, and has an outer member 1 formed with tapered double-row outer rolling surfaces 1a, 1b adjacent to each other on the inner circumference. The inner member 2 having a tapered double-row inner rolling surface 10a, 11a formed on the outer periphery and facing the double-row outer rolling surfaces 1a, 1b, and a cage 3 between both rolling surfaces, 4, seals 7 and 8 attached to the openings of the annular space formed between the double-row tapered rollers 5 and 6 and the outer member 1 and the inner member 2, which are rotatably accommodated via 4. And. These seals 7 and 8 are composed of seal members 7a and 8a fitted to both ends of the outer member 1, and slinger 7b and 8b slidably in contact with the seal members 7a and 8a. It prevents grease leakage and rainwater and dust from entering the bearing.

  The outer member 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 1a and 1b are hardened in a range of 58 to 64 HRC by induction hardening. Has been processed.

  The inner member 2 includes a hub ring 10 and an inner ring 11 fixed to the hub ring 10. The hub wheel 10 integrally has a wheel mounting flange 9 for mounting a wheel (not shown) at an end portion on the outer side, and bolt holes 9a are formed at equal intervals in the circumferential direction so that a bolt for fastening (FIG. A wheel is fixed via a not-shown), and an outer side inner rolling surface 10a and a cylindrical small-diameter step portion 10b extending in the axial direction from the inner rolling surface 10a are formed on the outer periphery. The hub wheel 10 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the shoulder portion 14 serving as the base portion of the wheel mounting flange 9 to the inner rolling surface 10a and the small diameter step portion 10b. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. In addition, the crimping part 12 mentioned later is made into the raw material hardness after a forge process. A large collar for guiding the tapered roller 5 is not formed on the large diameter side of the inner raceway surface 10a of the hub wheel 10, and a separate collar 16 described later is fitted. Further, a small collar for holding rollers is not formed on the small diameter side, and synthetic resin is held by a retainer 3 formed by injection molding so that the tapered roller 5 does not fall off to the inner diameter side. Thereby, the workability of the hub wheel can be improved and the weight increase can be further suppressed.

  On the other hand, the inner ring 11 is press-fitted into the small-diameter step portion 10b of the hub wheel 10, and an inner side inner rolling surface 11a is formed on the outer periphery. And the inner ring | wheel 11 is being fixed to the axial direction in the state to which the predetermined bearing preload was provided by the crimping part 12 formed by plastically deforming the edge part of the small diameter step part 10b of the hub wheel 10. FIG. As a result, the apparatus can be reduced in weight and size, and the initially set preload can be maintained over a long period of time. In addition, a large flange 11b is provided on the large diameter side of the inner raceway surface 11a of the inner ring 11, and the large end surface of the tapered roller 6 on the inner side is in contact with and guided by the large flange 11b. A gavel 11c is provided to prevent the tapered roller 6 from falling off. A slinger 8b constituting the inner seal 8 is fitted to the outer periphery of the large collar 11b of the inner ring 11. The inner ring 11 and the tapered rollers 5 and 6 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core portion by quenching.

  A cylindrical saddle wheel fitting surface 13 is formed on the outer periphery adjacent to the wheel mounting flange 9 of the hub wheel 10, and between the saddle wheel fitting surface 13 and a shoulder 14 connected to the side surface of the wheel mounting flange 9. Is formed with a corner 15 having a circular cross section. And the collar 16 is fitted to this collar fitting surface 13, and comprises the separate large collar.

  This saddle wheel 16 is made of high carbon chrome bearing steel such as SUJ2, and is provided with a flange surface 16 a that contacts the large end surface of the tapered roller 5 on the outer side and guides the tapered roller 5, and a flange ring fitting surface 13 of the hub wheel 10. The cylindrical inner peripheral surface 16b fitted to the end portion 16b, the end surface 16c that abuts the shoulder portion 14, and the end surface 16c and the inner peripheral surface 16b are connected to each other and engaged with the corner portion 15 of the hub wheel 10 in a non-contact state. And a chamfered portion 16d having a predetermined radius of curvature. Further, the outer peripheral surface of the saddle wheel 16 is formed in a stepped cylindrical surface having a large diameter on the wheel mounting flange 9 side, and a slinger 7b constituting the outer-side seal 7 is fitted to the small-diameter portion 16e on the outer peripheral surface. Has been. Furthermore, a slight radial clearance is formed between the large-diameter portion 16 f and the outer end portion of the outer member 1, thereby forming a labyrinth seal 17. Thereby, the sealing performance of the seal 7 can be further improved. The eaves 16 is hardened in the range of 58 to 64 HRC up to the core part by quenching.

  In this way, the large hook provided on the large diameter side of the inner raceway surface 10 a of the hub wheel 10 is formed as a separate ring 16 from the hub wheel 10, and the hub wheel 10 adjacent to the wheel mounting flange 9 is formed. Since the outer periphery is fitted, the stress concentration caused by the contact with the tapered roller 5 near the boundary between the inner rolling surface 10a and the flange surface 16a of the flange 16 is reduced. Therefore, even if it is applied to a vehicle type with a heavy vehicle weight, fatigue near the boundary portion hardly occurs. Further, since the chamfer 16 is provided with a chamfered portion 16 d that is not in contact with the corner 15 of the shoulder 14, stress concentration due to a load applied from the tapered roller 5 through the girdle 16 is concentrated on this portion. It can be further relaxed.

  Here, in this embodiment, the pitch circle diameter PCDo of the outer side tapered rollers 5 rows is set larger than the pitch circle diameter PCDi of the inner side tapered rollers 6 rows, and the outer side tapered rollers 5 The diameter is smaller than the diameter of the tapered roller 6 on the inner side. Accordingly, the inner raceway surface 10a of the hub wheel 10 is expanded in diameter compared to the inner raceway surface 11a of the inner race 11, and the outer raceway surface 1a on the outer side of the outer member 1 is also outer raceway on the inner side. The diameter is larger than that of the surface 1b. And the number of the outer side tapered rollers 5 is accommodated more than the number of the inner side tapered rollers 6. Thus, by setting the pitch circle diameters PCDo and PCDi to PCDo> PCDi, the rigidity is improved not only when the vehicle is stationary but also when turning, and the life of the wheel bearing device can be extended. . Further, since the diameter of the outer tapered roller 5 is smaller than the diameter of the inner tapered cone 6, it is possible to provide a wheel bearing device that further increases rigidity while suppressing an increase in weight.

  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 for a driven wheel or a driving wheel for rotatably supporting a wheel by a double row tapered roller bearing.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Outer member 1a, 1b ... Outer rolling surface 2 ... Inner member 3, 4, ... Retainer 5, 6, ... Tapered rollers 7, 8 ... Seals 7a, 8a ... Seal members 7b, 8b ... Slinger 9 ... Wheel mounting flange 9a ... .... Bolt hole 10 ... Hub wheels 10a, 11a ... Inner rolling surface 10b ... Small diameter step 11 ... Inner ring 11b ...・ Large collar 11c ・ ・ ・ ・ ・ ・ Small 12 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping section 13 ・ ・ ・ ・ Rose ring fitting surface 14 ・ ・ ・ ・ ・ ・ Shoulder 15 ··· Corner 16 ··············· 16n ···················································· Chamfered part 16e ... Small diameter part 16f ... Large diameter portion 17 ... Labyrinth seal 51 ... Outer member 51a ... Outer rolling surface 52 ... Inner member 53 ... .... Retainer 54 ... Tapered rollers 55, 56 ... Seals 55a, 56a ... Seal members 55b, 56b ... Slinger 57 ... Wheel mounting flange 57a ... ..... Bolt hole 58 ..... Hub wheel 58a, 59a ... Inner rolling surface 58b ... Small diameter step 59 ... Inner ring 59b ...・ ・ Large 59c ・ ・ ・ ・ ・ ・ Small 60 ・ ・ ・ ・ ・ ・ Clamping part 61 ・ ・ ・ ・ Riddle 61 a ・ ・ ・ ・ ・ ・ Rid 61b ・ ・ ・ ・ ・ ・Inner circumferential surface 61c .... End face 61d .... Arc portion 61e .... Small diameter portion 62 ..... Ring ring fitting surface 63 ..... Pitch circle diameter of the arcuate cross section PCDi · · · · · of the inner side of the tapered roller row pitch circle diameter PCDo · · · · · outer side of the tapered roller rows

Claims (5)

An outer member having a tapered double row outer rolling surface formed on the inner circumference and adjacent to each other on the small diameter side;
A wheel mounting flange for mounting the wheel integrally, a tapered inner rolling surface facing one of the double row outer rolling surfaces on the outer periphery, and a small diameter step extending in the axial direction from the inner rolling surface And a tapered inner rolling surface facing the other of the outer rolling surfaces of the double row is formed on the outer periphery by press-fitting into a small diameter step portion of the hub wheel through a predetermined shimeiro. An inner member made of an inner ring,
A double row tapered roller accommodated between the rolling surfaces of the inner member and the outer member so as to roll freely through a cage;
A seal attached to an opening of an annular space formed between the outer member and the inner member;
A large flange for guiding the tapered roller is formed on the large diameter side of the inner raceway surface of the inner ring, and the outer tapered roller is large at a location adjacent to the wheel mounting flange on the outer periphery of the hub ring. In a wheel bearing device in which a saddle wheel that contacts the end surface and guides the tapered roller is fitted,
A wheel bearing device, wherein a pitch circle diameter of the outer tapered roller row is set to be larger than a pitch circle diameter of the inner tapered roller row.   The wheel bearing device according to claim 1, wherein a diameter of the outer side tapered roller is smaller than a diameter of the inner side tapered roller.   The wheel bearing device according to claim 1 or 2, wherein the outer cage is formed by injection molding synthetic resin, and the tapered rollers are held so as not to fall off to the inner diameter side.   The outer peripheral surface of the saddle wheel is formed in a stepped cylindrical surface having a large diameter on the wheel mounting flange side, and the outer side is formed in an annular space formed between the small diameter portion on the outer peripheral surface and the outer member. The labyrinth seal is formed by forming a slight radial clearance between the large-diameter portion on the outer peripheral surface and the outer member. Wheel bearing device.   The inner ring is fixed to the hub ring in the axial direction with a bearing preload applied by a crimping portion formed by plastically deforming the end of the small-diameter step portion of the hub ring radially outward. The wheel bearing device according to any one of claims 1 to 4.

Images