WO2008056445A1

WO2008056445A1 - Bearing device for wheel

Info

Publication number: WO2008056445A1
Application number: PCT/JP2007/001214
Authority: WO
Inventors: Isao Hirai; Takayasu Takubo; Kiyotake Shibata; Syougo Suzuki
Original assignee: Ntn Corporation
Priority date: 2006-11-06
Filing date: 2007-11-06
Publication date: 2008-05-15

Abstract

[PROBLEMS] A bearing device for a wheel, reduced in weight and size, having increased bearing rigidity, and reduced in cost by a reduction in material losses. [MEANS FOR SOLVING PROBLEMS] The bearing device is of a third generation structure and has a hub ring (4) and an inner ring (5). The hub ring (4) integrally has at one end a wheel installation flange (6), has on its outer periphery one inner rolling surface (4a) of double-row inner rolling surfaces, and further has a small-diameter step section (4b) with a shaft-like section (7) in between, the shaft-like section (7) axially extending from the inner rolling surface (4a). The inner ring (5) is press-fitted on the small-diameter section (4b) of the hub ring (4) and has the other inner rolling surface (5a) formed on the outer periphery of the inner ring (5). The pitch circle diameter PCDo of outer-side rolling bodies (3) of double-row rolling bodies (3) is set greater than the pitch circle diameter PCDi of the inner-side rolling bodies (3). The shaft-like section (7) of the hub ring (4) is left as molded, and the surface of the shaft-like section (7) is shot-blasted.

Description

Specification

Wheel bearing device

Technical field

[0001] The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, in particular, while increasing the rigidity of the bearing while reducing the weight and reducing the cost by reducing the material size. The present invention relates to a wheel bearing device. Background art

[0002] Conventionally, wheel bearing devices for supporting wheels of automobiles and the like support a hub wheel for mounting a wheel rotatably via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, the inner ring rotation method is generally used for driving wheels, and both the inner ring rotation method and outer ring rotation method are used for driven wheels. In this wheel bearing device, a double-row angular contact ball bearing that has a desired bearing rigidity, exhibits durability against misalignment, and has a low rotational torque from the viewpoint of improving fuel efficiency is often used. . In this double-row anguilla ball bearing, a plurality of poles are interposed between the fixed ring and the rotating ring, and a predetermined contact angle is given to the pole to contact the fixed and rotating rings.

[0003] In addition, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double-row anguilla ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. Second generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the outer member, or third generation structure with one inner raceway formed directly on the outer periphery of the hub wheel, or hub It is roughly divided into the 4th generation structure in which the inner rolling surface is directly formed on the outer circumference of the outer joint member of the wheel and constant velocity universal joint. In the following description, the side closer to the outer side of the vehicle in the 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).

[0004] In a wheel bearing device composed of such double-row rolling bearings, the left and right rows of bearings have the same specifications, so that they have sufficient rigidity when stationary. The optimal rigidity is not always obtained when turning. In other words, the position of the vehicle at rest is determined so that it acts on the approximate center of the double-row rolling bearings, but when turning, the opposite side of the turning direction (when turning right, the vehicle Larger radial load or axial load is applied to the left axle. Therefore, during turning, it is effective to increase the rigidity of the outer bearing row rather than the inner one. Therefore, a wheel bearing device shown in FIG. 10 is known as a wheel bearing device that is highly rigid without increasing the size of the device.

[0005] This wheel bearing device 50 has a vehicle body mounting flange 5 1 c integrally attached to a knuckle (not shown) on the outer periphery, and a double row outer rolling surface 5 1 on the inner periphery. The outer member 5 1 formed with a and 5 1 b and the wheel mounting flange 5 3 for attaching a wheel (not shown) at one end are integrally formed, and the outer rolling surface 5 1 is provided on the outer periphery. a hub wheel 5 2 formed with one inner rolling surface 5 2 a opposite to a, a small-diameter step portion 5 2 b extending in the axial direction from the inner rolling surface 5 2 a, and the hub wheel 52 An inner member 5 5 composed of an inner ring 5 4 that is externally fitted to the small diameter step portion 5 2 b and has the other inner rolling surface 5 4 a opposite to the outer rolling surface 5 1 b, and both of these rolling Double-row annulus ball bearings with double-row poles 5 6 and 5 7 accommodated between the surfaces, and cages 5 8 and 5 9 that hold these double-row poles 5 6 and 5 7 in a rotatable manner Consists of That.

[0006] The inner ring 54 is fixed in the axial direction by a caulking portion 52c formed by plastically deforming the small-diameter stepped portion 52b of the hub wheel 52 in the radially outward direction. Seals 60 and 61 are attached to the opening of the annular space formed between the outer member 51 and the inner member 55, and leakage of the lubricating grease sealed inside the bearing Prevents rainwater and dust from entering the bearing.

Here, the pitch circle diameter D 1 of the poles 56 on the one side of the counter is set to be larger than the pitch circle diameter D 2 of the poles 57 on the one side. Accordingly, the inner raceway surface 5 2 a of the hub wheel 52 is expanded in diameter than the inner raceway surface 5 4 a of the inner race 54, and the outer raceway surface 5 on the outer side of the outer member 51 is also added. 1 a is larger in diameter than the outer rolling surface 5 1 b on the inner side. And the outer pole 5 6 is accommodated more than the pole 5 7 on the inner side. Thus, by setting the pitch circle diameters D 1 and D 2 to D 1> D 2, the rigidity is improved not only when the vehicle is stationary but also when turning, and the wheel bearing device 50 Long service life can be achieved.

Patent Document 1: Japanese Patent Laid-Open No. 2 0 0 4 _ 1 0 8 4 4 9

Disclosure of the invention

Problems to be solved by the invention

[0008] In such a conventional wheel bearing device 50, the outer member 51 and the hub wheel 52 are manufactured from a bar material as a raw material through forging, turning, heat treatment, grinding, superfinishing process, and the like. . For example, as shown in FIG. 11, the outer member 51 includes a side wall on the inner side of the vehicle body mounting flange 51 that contacts the knuckle, an outer peripheral surface on the inner side, and an inner peripheral surface from both end surfaces. As a result, the outer shape is formed with a predetermined turning allowance left by forging (indicated by a two-dot chain line in the figure).

[0009] Further, in the outer member 5 1 having different groove diameters of the double row outer rolling surfaces 5 1 a and 5 1 b, the groove shoulder 6 2 when a moment load is applied. In order to prevent the so-called shoulder climbing in which the contact ellipse of the poles 5 6 and 5 7 rides up and disengages from the outer rolling surfaces 5 1 a and 5 1 b, It is formed in a predetermined dimension. In particular, the corner (boundary) between the outer rolling surface 5 1 b on the inner side and the shoulder 6 3 of the groove is smaller than the outer rolling surface 5 1 a on the outer side. The size of the groove shoulder 63 is strictly regulated because it has a large impact and may cause an edge load when riding on the shoulder. Here, edge load is an excessive stress concentration that occurs at corners, etc., and is an event that is one of the factors of early delamination.

[0010] However, the turning of the groove shoulders 6 2 and 6 3 etc. in the outer member 5 1 not only causes material loss but also increases the number of processing steps, which is an impediment to cost reduction. It was. As described above, the problem is how to reduce the material loss of materials by reducing the number of turning processes as well as the forging shapes of the outer member 51 and the hub wheel 52 in the wheel bearing device. Has become It was.

[001 1] The present invention has been made in view of such circumstances, and is a lightweight and compact wheel bearing that increases the rigidity of the bearing while achieving compactness and reduces the cost by reducing material loss. The object is to provide a device.

[0012] Another object of the present invention is to reduce the number of processing steps and reduce the cost, and to improve the lubricity and prolong the life of the bearing.

Means for solving the problem

[0013] In order to achieve such an object, the present invention is an outer member that integrally has a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and has a double row outer rolling surface formed on the inner periphery. And a wheel mounting flange for mounting the wheel at one end, and one inner rolling surface facing the outer rolling surface of the double row on the outer circumference, and from the inner rolling surface in the axial direction. A hub wheel having a small-diameter step portion formed through an extending shaft-like portion, and a small-diameter step portion of the hub wheel that is press-fitted through a predetermined squeeze opening, and faces the outer rolling surface of the double row on the outer periphery. An inner member formed of an inner ring on which the other inner rolling surface is formed, and a double row rolling element that is rotatably accommodated between the inner member and both rolling surfaces of the outer member, At least the shaft-like portion of the hub wheel is left as forged skin. ■ ■ ■ Claim 1

As described above, the wheel mounting flange is integrally formed at one end portion, one inner rolling surface of the double row inner rolling surfaces on the outer periphery, and an axial shape extending in the axial direction from the inner rolling surface. Hub wheel with a small-diameter stepped portion formed through the part, and a third-generation wheel equipped with an inner ring that is press-fitted into the small-diameter stepped portion of this hub ring and has the other inner rolling surface formed on the outer periphery In the bearing device, at least the shaft part of the hub ring is left as the forging surface, so the parts to be deleted by turning can be reduced as much as possible to reduce material loss and to reduce costs. Can do.

[0015] Preferably, as in the present invention, if the surface of the shaft-shaped portion is shot blasted, the scale attached to the surface of the shaft-shaped portion is removed and the burrs at the respective corner portions are removed. Etc. are also removed at the same time and are smoothly rounded to reliably prevent abnormal noise during operation, abnormal vibration, and rotation failure due to scale loss. Improvements can be made. In addition, a compressive residual stress is formed on the surface of the shaft-like portion, and it is possible to improve the strength and durability against the moment load applied to the hub wheel. ■ ■ ■ Claim 2

[001 6] Further, as in the present invention, shoulder portions adjacent to the outer rolling surfaces of the double rows of the outer members are respectively formed, and these shoulder portions are formed at a predetermined groove depth by turning. In addition, if the inner diameter between the shoulders is not turned and the forged skin is left as it is, the groove depth of the outer rolling surface is severely restricted, and the edge load is prevented from occurring due to the shoulder ride. It is possible to reduce material loss by reducing the number of parts to be deleted by turning as much as possible. ■ ■ ■ Claim 3

[001 7] Also, as in the present invention, the pitch circle diameter of the outer rolling element group of the double row rolling elements is set to be larger than the pitch circle diameter of the inner rolling element group. If the shaft-shaped portion of the hub wheel is formed in a taper shape having a predetermined inclination angle between the force counter portion formed on the groove bottom portion of the inner rolling surface and the small-diameter step portion, the strength and rigidity It is possible to reduce the material loss without reducing the material loss and reduce material loss by reducing the number of parts to be deleted by turning as much as possible. ■ ■ ■ Claim 4

[0018] Further, as in the present invention, a mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of the recess is at least a groove bottom of the inner rolling surface of the hub wheel. If the outer shape of the hub ring is formed to have a substantially uniform thickness corresponding to the recess, the material loss of the hub ring is reduced without reducing the rigidity and rigidity. In addition, the plastic fluidity of the material in the forging process can be increased, and the machining accuracy can be improved. ■ ■ ■ Claim 5

[001 9] Also, as in the present invention, if annular notch portions are formed by cutting at both ends of the shoulder portion, the number of processing steps can be reduced and the cost can be reduced, and lubricity can be improved. It is possible to provide a wheel bearing device that has been improved to extend the life of the bearing. ■ ■ ■ Claim 6

[0020] Further, as in the present invention, the notch portion may be formed on a tapered surface having a predetermined inclination angle from the shoulder portion, and the notch portion may be the shoulder portion. To a predetermined step, the cross section may be formed in a substantially rectangular shape. ■ ■ ■ Claims 7 and 8

[0021] Further, as in the present invention, if the inclination angle is set in the range of 20 to 45 °, the crossing angle with the outer rolling surface becomes large, so the edge of the outer rolling surface Edge loading occurs at the edge, and the contact ellipse of the rolling element can be prevented from climbing over the shoulder, which is disengaged from the outer rolling surface. ■ ■ ■ Claim 9

The invention's effect

[0022] A wheel bearing device according to the present invention has an outer member integrally including a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and a double row outer rolling surface formed on the inner periphery. A wheel mounting flange for attaching the wheel to the unit, and an inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axial shape extending in an axial direction from the inner rolling surface A hub wheel having a small-diameter step portion formed through the portion, and the other inner side that is press-fitted into the small-diameter step portion of the hub wheel through a predetermined shim opening and faces the outer surface of the double row on the outer periphery. An inner member formed of an inner ring formed with a rolling surface, and a double row rolling element that is slidably accommodated between the inner member and the outer member, and at least the hub. Since the shaft part of the ring is left as the forged skin, the part to be deleted by turning Can help reduce the Materia Rurosu and brought as much as possible reduced, it is possible to reduce the cost.

BEST MODE FOR CARRYING OUT THE INVENTION

[0023] An outer member integrally having a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, a double row outer rolling surface formed on the inner periphery, and a wheel attachment for attaching a wheel to one end A flange is integrated, and one outer rolling surface facing the outer rolling surface of the double row on the outer periphery, and a te / -shaped shaft portion extending in the axial direction from the inner rolling surface A hub ring having a small-diameter step portion, and an inner ring that is press-fitted into the small-diameter step portion of the hub ring and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery. An inner member; and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member, and one side of the double row rolling element is on the outer side. The pitch circle diameter of the rolling element group is the pitch circle diameter of the inner rolling element group. In addition to being set to a large diameter, the shaft portion of the hub wheel is left forged and the surface is shot blasted.

Example 1

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is a longitudinal sectional view showing a single outer member of FIG. 1, and FIG. Fig. 3 (a) is an explanatory diagram showing shot blasting of the outer member in Fig. 1, and (b) is shot blasting of the hub wheel in Fig. 1. FIG.

[0025] The wheel bearing device is for a driven wheel called a third generation, and is an inner member.

1 and an outer member 2, and double row rolling elements (poles) 3, 3 accommodated between the members 1, 2 so as to roll freely. The inner member 1 includes a hub ring 4 and an inner ring 5 press-fitted into the hub ring 4 through a predetermined shim opening.

[0026] The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and an inner rolling surface 4a on one (outer side) on the outer periphery. A small-diameter step portion 4b is formed through a shaft-like portion 7 extending in the axial direction from the inner rolling surface 4a. In addition, hub ports 6 a for fixing the wheels in the circumferential direction of the wheel mounting flange 6 are planted.

[0027] The inner ring 5 is formed with the other (inner one side) inner rolling surface 5a on the outer periphery, and is press-fitted into the small-diameter stepped portion 4b of the hub ring 4 to form a back-to-back type double-row angular bearing. At the same time, the end of the small-diameter step 4b is fixed in the axial direction by a caulking portion 8 formed by plastic deformation. The inner ring 5 and the rolling element 3 are made of high carbon chrome steel such as S U J 2 and hardened in the range of 58 to 64 HRC up to the core part by quenching.

[0028] The hub wheel 4 is formed of medium and high carbon steel containing 0.44 to 0.80 wt% of carbon such as S53C, and the inner ring surface 4a and the inner ring of the wheel mounting flange 6 are formed. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening from the base 6b on the side to the small diameter step 4b. The caulking part 8 is the table after forging. It is said that the surface hardness remains. This provides sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6, improves the fretting resistance of the small-diameter stepped portion 4b that becomes the fitting portion of the inner ring 5, and makes it minute. The plastic working of the caulking portion 8 can be performed smoothly without generating any cracks.

[0029] The outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) on the outer periphery, and faces the inner rolling surface 4a of the hub wheel 4 on the inner periphery. An outer rolling surface 2 a on one side of the outer ring and an outer rolling surface 2 b on the inner side facing the inner rolling surface 5 a of the inner ring 5 are formed in a body. Double-row rolling elements 3 and 3 are accommodated between these rolling surfaces and are held by the cages 9 and 10 so as to be freely rollable.

[0030] This outer member 2 is formed of medium and high carbon steel containing carbon 0.40 to 0.80 wt% such as S 53 C, and the double row outer rolling surfaces 2a and 2b have high frequency. The surface hardness is hardened to a range of 58 to 64 HRC by quenching. Seals 11 and 12 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1, and leakage of grease sealed inside the bearing to the outside Prevents rainwater and dust from entering the bearing. Here, a double-row angular ball bearing using a pole as the rolling element 3 is illustrated, but the present invention is not limited to this, and a double-row tapered roller bearing using a tapered roller as the rolling element 3 may be used.

[0031] In this embodiment, the pitch circle diameter P CDo of the three rolling elements on the one side is set larger than the pitch circle diameter P CD i of the three rolling elements on the inner side. The size of the rolling elements 3 and 3 in the double row is the same, but due to the difference in the pitch circle diameters PCD o and PCD i, the number of rolling elements in the outer rolling element 3 group is the rolling element 3 in the inner side. More than the number of rolling elements in the group.

[0032] The outer shape of the hub wheel 4 is that the counter part 13 from the groove bottom part of the inner rolling surface 4a, the tapered shaft part 7 extending in the axial direction from the counter part 13 and the inner ring 5 project. It continues to the small diameter step 4b via the mated shoulder 7a. A mortar-shaped recess 14 is formed at the outer end of the hub wheel 4. The depth of this recess 14 is the depth to the groove bottom of the inner rolling surface 4 a. Uta one side is formed in a substantially uniform thickness. The inner raceway surface 4 a of the hub ring 4 is formed with a diameter larger than that of the inner raceway surface 5 a of the inner ring 5 with the difference between the pitch circle diameters PCDο and PCD i.

[0033] On the other hand, in the outer member 2, the outer rolling surface 2a on one side of the outer side is wider than the outer rolling surface 2b on the inner side due to the difference in pitch circle diameters PCDo and PCDi. The outer rolling surface 2a on the outer side is connected to the cylindrical shoulder portion 16 via the taper-shaped shoulder portion 15 and the inner diameter portion 15a. It is formed in an inner peripheral shape that reaches the outer rolling surface 2b.

[0034] In the wheel bearing device configured as described above, the pitch circle diameter PCD o of the outer side rolling elements 3 group is formed larger than the pitch circle diameter PCD i of the inner side rolling elements 3 group. The number of rolling elements 3 is also set so that the number of rolling elements in the outer rolling element group 3 is larger than the number of rolling elements in the inner one rolling element group. The bearing rigidity of the outer side can be increased compared to the side, and the life of the bearing can be extended. In addition, the recess 14 is formed in the outer end of the hub ring 4 along the outer shape, and the outer side of the hub ring 4 is set to a uniform thickness, so that the weight of the device can be reduced. The conflicting problem of high rigidity can be solved.

Here, the outer member 2 is formed into a predetermined forging shape as shown in FIG. 2 (a) by forging from the raw material bar (shown by a two-dot chain line in the figure). ) Specifically, the inner side surface 17 of the vehicle body mounting flange 2 c with which a knuckle (not shown) abuts, the inner side outer peripheral surface 18 on which the knuckle is fitted, and both end surfaces 19, 2 0, seal fitting surface 2 1 and 2 2 to which seals 1 and 1 2 are mounted, double row outer rolling surface 2 a and 2 b, large diameter shoulder 15 and small diameter side The forging process is performed in a state where the shoulder portion 16 is left with a predetermined turning allowance.

[0036] In this way, the shoulder portion 15 on the large diameter side and the shoulder portion 16 on the small diameter side are formed to a predetermined groove depth by turning, and the inner diameter between the shoulder portions 15 and 16 is The part 15 a is formed by a taper surface having a predetermined inclination angle. That is, the inner diameter portion 15 a is left as a forged surface without being turned. As a result, the outer rolling surface 2 The groove depths of a and 2b are strictly regulated, preventing edge load from being raised on the shoulder, and reducing material loss by reducing the number of parts removed by turning as much as possible. Cost reduction can be achieved

[0037] Further, in this embodiment, the outer member 2 is hardened by induction hardening after turning, and the inner diameter portion 15a is removed by shot blasting before grinding. Is done. That is, as shown in FIG. 3 (a), steel is directed from the nozzle 27 disposed radially inward of the outer member 2 toward the inner peripheral surface of the outer member 2 that is rotatably set. This is done by jetting media such as beads. Here, the particle size of the steel beads is 20 to 10 0; U m, the injection time is about 90 seconds, the injection pressure is 1 to 3 kg / cm ² , and the nozzle 27 is indicated by the arrow Shot blasting is performed while moving in the axial direction. As a result, the scale attached to the surface of the inner diameter portion 15 a is removed, and burrs and the like at the respective corner portions are removed at the same time and are smoothly rounded. Therefore, it is possible to reliably prevent abnormal noise during operation, abnormal vibration, and rotation failure due to scale dropout and improve product quality. Further, compressive residual stress is formed on the surface of the inner diameter portion 15a, and the strength and durability can be improved.

On the other hand, the hub wheel 4 is formed into a predetermined forging shape as shown in FIG. 2 (b) by forging from a bar material as a material, like the outer member 2 described above (FIG. 2). (Indicated by a chain double-dashed line). Specifically, the outer side surface 2 5 of the wheel mounting flange 6 with which the brake rotor (not shown) abuts, including the end surfaces 2 3 and 2 4, the pilot portion 2 6, and the base portion of the wheel mounting flange 6 6 b, the inner rolling surface 4 a, the counter part 13 and the small diameter step part 4 b are forged while leaving a predetermined turning allowance.

[0039] In this embodiment, the base portion 6b, which is the land portion of the seal 11 on the outer side, and the inner rolling surface 4a, the counter portion 13 and the small diameter step portion 4b are turned by turning. The shaft-shaped portion 7 is formed with a taper surface having a predetermined inclination angle. That is, the shaft 7 is forged without turning. It is considered to be skin. As a result, the groove depth of the inner rolling surface 4a is strictly regulated, and it is possible to prevent the occurrence of edge stagnation by riding on the shoulder, and to reduce the number of parts to be deleted by turning as much as possible. Material loss can be reduced and costs can be reduced.

[0040] Further, the hub wheel 4 is hardened by induction hardening after turning, as with the outer member 2 described above, and the shaft 7 is scaled by shot blasting before grinding. Removed. That is, as shown in FIG. 3 (b), the medium is ejected from the nozzle 28 disposed radially outward of the hub wheel 4 toward the outer peripheral surface of the hub wheel 4 that is rotatably set. Done. As a result, the scale attached to the surface of the shaft-like portion 7 is removed, and burrs and the like at the respective corner portions are simultaneously removed and smoothly rounded. Therefore, it is possible to reliably prevent abnormal noise during operation, abnormal vibration, and rotation failure due to the drop of the scale, and improve product quality. Further, a compressive residual stress is formed on the surface of the shaft-like portion 7, and the strength and durability against the moment load applied to the hub wheel 4 can be improved. The shot blasting may also be continuously performed on the inner rolling surface 4a and other parts to be ground.

Example 1

FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, and FIG. 5 is a longitudinal sectional view showing a single hub wheel of FIG. Note that the same parts and portions having the same functions as those of the first embodiment described above are denoted by the same reference numerals and detailed description thereof is omitted.

[0042] This wheel bearing device is for a driven wheel called the third generation, and is housed in a freely rollable manner between the inner member 29, the outer member 30, and both members 29, 30. Double-row rolling elements (poles) 3 and 3 are provided. The inner member 29 includes a hub ring 3 1 and an inner ring 5 press-fitted into the hub ring 31 through a predetermined shim opening.

[0043] The hub wheel 31 is integrally provided with a wheel mounting flange 6 at an end portion on the outer side, and one (outer side) inner rolling surface 4a and an inner rolling surface 4a on the outer periphery. A small-diameter step portion 4 b is formed via a shaft-like portion 3 2 extending straight in the axial direction. . The hub wheel 3 1 is formed of medium and high carbon steel containing carbon 0.40 to 0.80 wt% such as S 53 C, and includes the inner rolling surface 4 a and the base 6 b of the wheel mounting flange 6. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening over the small diameter step 4b.

[0044] The outer member 30 is integrally formed with a vehicle body mounting flange 2c on the outer periphery, and a double-row inner rolling surface 4a, 5a of the inner member 29 on the inner periphery. The outer rolling surfaces 2 a and 2 a are integrally formed. Double-row rolling elements 3 and 3 are accommodated between these rolling surfaces, and are held by the cages 9 and 9 so that they can roll freely. This outer member 30 is formed of medium and high carbon steel containing carbon 0.40 to 0.8 O wt% such as S 53 C, and double row outer rolling surfaces 2 a and 2 a are induction hardened. The surface hardness is hardened in the range of 58 to 64 HRC.

Here, the hub ring 31 is formed into a predetermined forging shape as shown in FIG. 5 by forging from a bar material as a raw material (indicated by a two-dot chain line in the figure). Specifically, including the end faces 2 3 and 2 4, at least the side face 2 5 on the outer side of the wheel mounting flange 6 with which the brake rotor (not shown) abuts, the pi opening part 2 6, and the wheel mounting flange 6 The base 6b, the inner rolling surface 4a, the counter 13 and the small diameter step 4b are forged with a predetermined turning allowance remaining. That is, the base portion 6 b that becomes the land portion of the seal 11 on the outer side, the inner rolling surface 4 a, the counter portion 13, and the small diameter step portion 4 b are formed to predetermined dimensions by turning, and The shaft-like part 3 2 is left as a forged surface without being turned. As a result, the groove depth of the inner rolling surface 4a is strictly regulated, and it is possible to prevent edge load from being generated by climbing the shoulder, and to reduce the material loss by reducing the number of parts to be deleted by turning as much as possible. It can be reduced and the cost can be reduced.

[0046] Further, as in the above-described embodiment, the hub wheel 31 is subjected to a hardening process by induction hardening after the turning process, and before the grinding process, the scale of the shaft-like part 3 2 is removed by the shot blasting process. Is done. As a result, the scale adhering to the surface of the shaft-shaped part 32 is removed, and burrs at each corner part are simultaneously removed. Removed and rounded smoothly. Therefore, abnormal noise during operation, abnormal vibration, and rotation failure due to scale dropout are reliably prevented, and compressive residual stress is formed on the surface of the shaft 3 2 and is applied to the hub ring 31. It can improve the strength against the moment load.

Example 3

FIG. 6 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention, FIG. 7 (a) is an enlarged sectional view showing a single outer member of FIG. 6, and (b). Fig. 6 is an enlarged view of the main part of Fig. 6. It should be noted that parts having the same parts or the same functions as those of the above-described embodiment are given the same reference numerals and detailed description thereof is omitted.

[0048] This wheel bearing device is called the third generation on the driven wheel side, and is composed of a plurality of inner members 33, outer members 34, and a plurality of rolling members accommodated between both members 33, 34. The rolling elements (poles) 3 and 3 are provided. The inner member 33 includes a hub ring 35 and an inner ring 36 that is press-fitted into the hub ring 35 through a predetermined shim opening.

[0049] The hub wheel 3 5 has a wheel mounting flange 6 integrally at the outer end, and a hub port 6 a for fixing the wheel at a circumferentially equidistant position of the wheel mounting flange 6 is implanted. Has been. Further, one (outer side) inner rolling surface 35a is directly formed on the outer periphery of the hub wheel 35, and a small-diameter step portion 35b extending in the axial direction from the inner rolling surface 35a is formed. Has been. Then, the inner ring 36 having the outer (inner one) inner raceway surface 36a formed on the outer periphery is press-fitted into the small-diameter step portion 35b, and the end of the small-diameter step portion 35b The inner ring 36 is fixed in the axial direction by a caulking portion 8 formed by plastically deforming the portion radially outward to constitute a back-to-back type double-row anguillar ball bearing.

[0050] The hub wheel 3 5 is formed of medium and high carbon steel containing carbon of 0.45 to 0.80% by weight, such as S 53 C, and includes an inner side rolling surface 3 5 a on the outer side and an outer side. The base 6b, which is the seal land where the seal 11 contacts, and the small-diameter step 35b are wound with induction hardening to a surface hardness of 58-64 HRC. . On the other hand, the inner ring 3 6 is made of high carbon chrome bearing steel such as SUJ 2 and hardened in the range of 58 to 64 HRC to the core part by quenching. . As a result, not only the wear resistance of the seal land portion is improved, but also the strength of the hub ring 35 is improved, and fretting wear on the fitting surface of the inner ring 36 is suppressed, thereby improving durability.

[0051] The outer member 3 4 integrally has a vehicle body mounting flange 2c on the outer periphery, and faces the double row inner rolling surfaces 3 5a, 3 6a of the inner member 3 3 on the inner periphery. Double row outer rolling surfaces 3 4 a and 3 4 a are integrally formed. This outer member 3 4 is formed of medium and high carbon steel containing carbon 0.40 to 0.80 wt% such as 3 5 30 as in the case of the hub wheel 3 5, and at least a double row outer rolling surface. 3 4 a and 3 4 a are hardened by induction hardening to a surface hardness range of 58 to 64 HRC. Then, double-row rolling elements 3 and 3 are accommodated between the respective rolling surfaces 3 4 a and 3 5 a and 3 4 a and 3 6 a. The moving bodies 3 and 3 are held so as to freely roll.

[0052] Here, a double-row anguilla ball bearing using the rolling elements 3 and 3 as poles is shown as an example, but the present invention is not limited to this, and is a double-row tapered roller bearing using a tapered roller for the rolling element 3. Also good.

[0053] Here, the outer member 3 4 has a cylindrical shoulder 3 7 between the double-row outer rolling surfaces 3 4 a and 3 4 a as shown in an enlarged view in FIG. 7 (a). Formed by forging, annular notches 3 8 and 3 8 are formed at both ends of the shoulder 37, that is, at the edge of the double row outer rolling surface 34 a. The notch portion 38 is formed on a taper surface having a predetermined inclination angle from the shoulder portion 37 by cutting. The inclination angle is set in the range of 20 to 45 ° in consideration of the yield of the material and the shoulder climbing described later.

Thus, in the present embodiment, the shoulder 3 7 is formed by forging, and only the notches 3 8 and 3 8 at the edges of the double row outer rolling surfaces 3 4 a and 3 4 a Since the cutting process is performed, the cutting range of the shoulder 37 is narrowed, and the cost can be reduced by reducing the number of processing steps.

[0055] Further, since the notch portion 3 8 increases the crossing angle with the outer rolling surface 3 4 a, an edge is generated at the edge of the outer rolling surface 3 4 a, and the rolling element 3, contact It is possible to prevent the ellipse from climbing over the shoulder 3 4 a.

[0056] Further, as shown in FIG. 7 (b), the notch 3 8 functions as a grease pocket, and the grease enclosed in the bearing is applied to the notch 3 8 by gravity and centrifugal force. It moves along and smoothly flows into the double row outer rolling surfaces 3 4 a and 3 4 a, so grease can effectively contribute to lubrication with a minimum amount of filling, and the lubrication environment is in good condition. Can be maintained. Furthermore, since the notches 3 8 and 3 8 are formed at the edges of the double row outer rolling surfaces 3 4 a and 3 4 a, interference with the cage 9 can be prevented, and Design flexibility is expanded.

Example 4

[0057] Fig. 8 is a longitudinal sectional view showing a fourth embodiment of the wheel bearing device according to the present invention, Fig. 9 (a) is an enlarged sectional view showing the outer member alone of Fig. 8, (b) Fig. 9 is an enlarged view of the main part of Fig. 8. Note that this embodiment is basically different from the third embodiment (FIG. 6) described above except that the configuration of the outer member is different, and other parts and parts having the same function or the same function are used. Are denoted by the same reference numerals and detailed description thereof is omitted.

The wheel bearing device includes an inner member 3 3, an outer member 39, and double row rolling elements 3, 3 accommodated between the members 3 3, 39 so as to be freely rollable. Yes. Here, as shown in the enlarged view of FIG. 9 (a), the outer member 3 9 has a cylindrical shoulder portion 3 7 formed by forging between the double row outer rolling surfaces 3 4a and 3 4a. The annular notches 40, 40 are formed by cutting at both ends of the shoulder 37. This notch 40 is formed to have a predetermined step from shoulder portion 37 (a substantially rectangular cross section consisting of 5. This step (5 is 0.5 in consideration of the yield of the material and the shoulder climbing, etc.). It is set in the range of 5 to 1. O mm.

[0059] Thus, in the present embodiment, as in the above-described embodiment, the shoulder portion 3 7 is formed by forging, and the outer row rolling surfaces 3 4 a and 3 4 a of the double row are notched at the edges. Since only parts 40 and 40 are cut, the number of machining steps can be reduced to reduce costs, and the notch 40 can function as a grease pocket to improve lubricity. it can. [0060] The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment in any way and is merely an example and does not depart from the gist of the present invention. Of course, the present invention can be implemented in various forms, and 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, Includes all changes.

Industrial applicability

The wheel bearing device according to the present invention can be applied to a third-generation wheel bearing device regardless of whether it is for a driving wheel or a driven wheel.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention.

FIG. 2 (a) is a longitudinal sectional view showing a single outer member in FIG. (B) is a longitudinal sectional view showing a single hub wheel of FIG.

FIG. 3 (a) is an explanatory view showing shot blasting of the outer member in FIG. (B) is an explanatory view showing shot blasting of the hub wheel of FIG.

FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention.

5 is a longitudinal sectional view showing a single hub wheel of FIG.

FIG. 6 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention.

FIG. 7 (a) is an enlarged cross-sectional view showing a single outer member in FIG. (B) is an enlarged view of the main part of FIG.

FIG. 8 is a longitudinal sectional view showing a fourth embodiment of a wheel bearing device according to the present invention.

FIG. 9 (a) is an enlarged cross-sectional view showing a single outer member in FIG. (B) is an enlarged view of the main part of FIG.

FIG. 10 is a longitudinal sectional view showing a conventional wheel bearing device.

FIG. 11 is an explanatory view showing the forged shape of the outer member.

Explanation of symbols

[0063] 1, 29, 33 Inner member

2, 30, 34, 39 Outer member Outer rolling surface

Body mounting flange

Rolling element

Hub wheel

Inner rolling surface

Small diameter step

Inner ring

Wheel mounting flange

Have Porto

Base

Shaft

Shoulder

Caulking section

Cage

sticker

Counter section

Recess

Large diameter shoulder

Inner diameter

Small diameter shoulder

Side surface on the inner side of the vehicle mounting flange Outer surface of the outer member on the inner side End surface of the outer member

Seal mating surface

End face of hub ring

Side surface of wheel mounting flange on one side of pilot

nozzle Notch

Wheel bearing device

Outer member

Outer rolling surface on the outer side

Outer rolling surface on the inner side

Body mounting flange

Hub wheel

Inner rolling surface

Small diameter step

Caulking section

Wheel mounting flange

Inner ring

Inner member

Pole

Cage

sticker

Groove shoulder

Pitch circle diameter of the pole group on the one side Pitch circle diameter of the pole group on the inner side Pitch circle diameter of the rolling element group on the inner side Pitch circle diameter of the rolling element group on the one side The inclination angle of the notch

Notch level difference

Claims

The scope of the claims

[1] An outer member integrally having a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and having a double row outer rolling surface formed on the inner periphery;

-A wheel mounting flange for mounting the wheel at the end is integrally formed, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axis extending in the axial direction from the inner rolling surface A hub wheel having a small-diameter step portion formed through the ring-shaped portion, and the other diameter of the hub wheel that is press-fitted into the small-diameter step portion of the hub ring through a predetermined squeeze port and that faces the outer rolling surface of the double row on the outer periphery. An inner member formed of an inner ring formed with an inner rolling surface, and a double row rolling element that is slidably accommodated between the inner member and both rolling surfaces of the outer member,

A wheel bearing device, characterized in that at least the shaft portion of the hub wheel is left as a forged surface.

[2] The wheel bearing device according to claim 1, wherein the surface of the shaft-shaped portion is shot blasted.

[3] Shoulders that are adjacent to the double row outer rolling surfaces of the outer member are formed, and the shoulders are formed to a predetermined groove depth by turning, and an inner diameter between the shoulders. The wheel bearing device according to claim 1 or 2, wherein the portion is not turned and remains forged.

[4] The pitch circle diameter of the outer side rolling element group of the double row rolling elements is set to be larger than the pitch circle diameter of the inner side rolling element group, and the shaft portion of the hub wheel is 4. The wheel bearing device according to claim 1, wherein the wheel bearing device is formed in a tapered shape having a predetermined inclination angle between a force counter portion formed at a groove bottom portion of the inner rolling surface and the small diameter step portion. .

[5] A mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of the recess is at least near the groove bottom of the inner raceway surface of the hub wheel. The wheel bearing device according to any one of claims 1 to 4, wherein the wheel bearing device is formed so as to have a substantially uniform thickness corresponding to the recess.

[6] The annular notch is formed by cutting at both ends of the shoulder. Item 4. The wheel bearing device according to Item 3.

7. The wheel bearing device according to claim 6, wherein the notch is formed in a tapered surface having a predetermined inclination angle from the shoulder.

8. The wheel bearing device according to claim 6, wherein the notch is formed in a substantially rectangular cross section having a predetermined step from the shoulder.

9. The wheel bearing device according to claim 7, wherein the inclination angle is set in a range of 20 to 45 °.