JP5166757B2 - Wheel bearing and wheel bearing device provided with the same - Google Patents

Description

  The present invention relates to a wheel bearing for rotatably supporting a wheel of a vehicle such as an automobile, and more particularly, to a wheel bearing for reducing the weight, size and cost, and improving the durability of the bearing. The present invention relates to a wheel bearing device provided.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and both an inner ring rotation method and an outer member rotation method are generally used for driven wheels. This wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double-row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device, and an outer member. 2nd generation structure with body mounting flange or wheel mounting flange formed directly on the outer periphery of the wheel, 3rd generation structure with one inner rolling surface formed directly on the outer periphery of the hub wheel, or constant speed with the hub wheel It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the universal joint.

  Conventionally, an angular ball bearing having a structure in which an inner ring and an outer ring (outer member) are formed by pressing from a steel plate is known. For example, the angular ball bearing 50 shown in FIG. 4 is used in a magnetic hard disk drive or the like, but the outer ring 51 and the pair of inner rings 52 and 53 are formed from a stainless steel plate by pressing or rolling.

  The outer ring 51 is formed with an annular convex portion 51a protruding radially inward at a substantially middle portion of the inner peripheral surface, and outer rolling surfaces 51b and 51c are formed on inner peripheral surfaces on both sides of the annular convex portion 51a. Yes. The outer ring 51 has an outer peripheral surface fitted into a hole in the housing 54, and a flange 51 d formed at one end is brought into contact with the end surface of the housing 54 to perform axial positioning. An annular recess 51e is formed on the outer peripheral surface of the outer ring 51 by the annular protrusion 51a. The annular recess 51e is filled with an adhesive, and the outer ring 51 is fixed to the hole of the housing 54.

  On the other hand, the inner rings 52 and 53 are respectively fitted inside the double row outer raceway surfaces 51b and 51c of the outer ring 51 from both sides in the axial direction. Curved shoulder portions 52a and 53a are formed on the outer circumferences of the outer ends in the axial direction of the inner rings 52 and 53, and inner rolling surfaces 52b and 53b are formed on the curved shoulder portions 52a and 53a. The double rows of balls 56, 56 are arranged between the inner rolling surfaces 52b, 53b and the outer rolling surfaces 51b, 51c of the outer ring 51, and are retained by the cages 57, 57 for each row. Is retained.

  On the inner peripheral surfaces of the inner rings 52 and 53, fitting portions 52c and 53c that are fitted into the shaft member 55 with clearance are formed. After the inner rings 52, 53 are fitted into the shaft member 55 in the axial direction, a cylindrical weight 59 having a constant weight is placed on the curved shoulder 52 a of one inner ring 52, and the weight of the weight 59 The other inner ring 53 is pressed via the inner ring 52, the ball 56, the outer ring 51, and the ball 56, and the curved shoulder portion 53 a is fitted until it comes into contact with the flange portion 55 a of the shaft member 55. Thereby, an appropriate preload is set for the angular ball bearing 50.

When this gap fitting is completed, the adhesive 60 is filled in the gap between the curved shoulder portion 52a of the one inner ring 52 and the shaft member 55, and this adhesive 60 prevents the one inner ring 52 from being fitted off. The flange portion 55a of the shaft member 55 prevents the other inner ring 53 from being fitted off.
Japanese Utility Model Publication No. 6-1835

  When this type of angular contact ball bearing made of press is used as a wheel bearing, the size of the ball 56 and the PCD (pitch circle diameter) of the ball 56 depend on the radial load and moment load applied during vehicle axle load and turning. ) Etc. are set, and the optimum shape is determined. However, since the outer ring 51 or the inner rings 52 and 53 are formed from a steel plate by pressing or rolling, the thickness is substantially uniform. However, depending on the shape of the outer ring 51 or the inner rings 52 and 53, there may be a portion where the thickness is reduced.

  In particular, in the outer ring 51, when a moment load is applied, the contact ellipse of the ball 56 rides up and comes off the outer rolling surface 51 b, so-called shoulder riding occurs, and edge load may occur in the shoulder A. At the time of rolling processing, the center part of the outer ring 51 is recessed to fill the shoulder A with the material, and the shoulder height from the groove bottom of the outer rolling surface 51b to the annular convex part 51a is ensured to an appropriate shoulder height. However, in this case, depending on the size of the radius of curvature R of the connecting portion B from the outer diameter to the annular recess 51e, not only the wall thickness is reduced, but there is a possibility that the shoulder A may crack. It was. As a result, the rigidity of the outer ring 51 may be reduced and durability may be impaired. Here, the edge load is an excessive stress concentration generated at a corner or the like, and refers to an event that becomes one of the factors of early peeling.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a wheel bearing and a wheel bearing device including the wheel bearing that are designed to be lighter, more compact and lower in cost and to improve the durability of the bearing. It is intended to provide.

In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double-row arc-shaped outer rolling surface is integrally formed on the inner periphery, and the double-row on the outer periphery. A pair of inner rings formed with an arcuate inner rolling surface facing the outer rolling surface, and a double row of balls accommodated between the inner ring and both rolling surfaces of the outer member, the inner ring In the wheel bearing constituting the back-to-back type double-row angular contact ball bearing by abutting the end surfaces on the small diameter side in a butted state, the outer member and the inner ring are formed from a pipe material by plastic working, and the outer member An annular recess is formed by denting the central portion of the outer diameter of the outer ring, and the annular protrusion is formed in a flat shape on the inner periphery, and the connecting portion of the outer diameter and the annular recess has an arc shape having a predetermined radius of curvature. is formed, this portion is set to be substantially uniform thickness, both end surfaces of the outer member and the front The large-diameter side end surface of the inner ring is turned after plastic working, and after heat treatment, the outer diameters of both the rolling surfaces and the outer member, and the inner diameter and small-diameter side end surfaces of the inner ring are formed with predetermined dimensions and accuracy by grinding. Has been. Here, “substantially equal” means that the thickness of the pipe material before molding is uniform, and the thickness of the shape obtained as a result of molding without any plastic flow other than the purpose of forming the arc also in the connecting portion. It means a state, and it means that a state where the material is slightly thinned or thickened due to the displacement of the flesh of the material when forming the arc of the connecting portion is included.

In this way, in the wheel bearing constituted by the back-to-back type double row angular contact ball bearings, the outer member and the inner ring are formed by plastic processing from the pipe material, and the central portion of the outer diameter of the outer member is recessed. An annular recess is formed, an annular projection is formed in a flat shape on the inner periphery, and a connecting portion between the outer diameter and the annular recess is formed in an arc shape having a predetermined radius of curvature. Thickness is set , both end surfaces of the outer member and the large-diameter side end surface of the inner ring are turned after plastic working, and after heat treatment, both the rolling surface and the outer diameter of the outer member, the inner diameter of the inner ring, and the inner and small-diameter end surfaces are ground Since it is formed to a predetermined size and accuracy by machining, it prevents the shoulder from cracking, and prevents the ball contact ellipse from climbing over the shoulder and causing an edge load when a turning moment is applied. The durability of the bearing can It is possible to provide a wheel bearing with improved. Further, productivity is improved, yield is good, cost can be reduced, and bearing accuracy equivalent to conventional forged and machined bearings can be ensured.

  Preferably, as in the invention described in claim 2, the radius of curvature R of the joint portion is set to be in a range of R = 1.5 to 1.8 Rw when the radius of the ball is Rw. In this case, the thickness is not reduced and the rigidity is not lowered, and the thickness is increased and the workability of the plastic working is not lowered.

Further, as in the invention according to claim 3 , if the outer member and the inner ring are formed by cold rolling from the pipe material, the thickness can be made substantially uniform, and the shape, The dimensions can be ensured with a predetermined accuracy.

According to a fourth aspect of the present invention, the wheel according to claim 4 has a wheel mounting flange integrally formed at one end, and a hub wheel formed with a small-diameter stepped portion extending in the axial direction from the wheel mounting flange via the shoulder. And a wheel bearing according to any one of claims 1 to 3 that is press-fitted into the small-diameter step portion of the hub wheel through a predetermined shimiro, and the outer joint member of the constant velocity universal joint is serrated on the hub wheel. And the pair of inner rings are sandwiched between a shoulder portion of the hub wheel and a shoulder portion of the outer joint member, and a predetermined bearing preload is applied.

Thus, in the wheel bearing device of the first generation structure, a hub wheel having a wheel mounting flange integrally formed at one end and a small-diameter step portion extending in the axial direction from the wheel mounting flange via the shoulder is formed. And a wheel bearing according to any one of claims 1 to 3 that is press-fitted into the small-diameter step portion of the hub wheel through a predetermined shimiro, and the outer joint member of the constant velocity universal joint is serrated on the hub wheel. And the pair of inner rings are sandwiched between the shoulder part of the hub wheel and the shoulder part of the outer joint member, and a predetermined bearing preload is applied. Rolling fatigue life is improved.

The wheel bearing according to the present invention includes an outer member in which a double-row arc-shaped outer rolling surface is integrally formed on the inner periphery, and an arc-shaped inner surface facing the outer-rolling surface of the double-row on the outer periphery. A pair of inner rings formed with rolling surfaces, and a double row of balls accommodated between the inner rings and both rolling surfaces of the outer member, the end surfaces on the small diameter side of the inner ring abut each other in a butted state. In a wheel bearing constituting a back-to-back type double row angular contact ball bearing, the outer member and the inner ring are formed by plastic processing from a pipe material, and the outer member has an annular shape with a central portion of the outer diameter recessed. A concave portion is formed, an annular convex portion is formed in a flat shape on the inner periphery, and a connecting portion between the outer diameter and the annular concave portion is formed in an arc shape having a predetermined radius of curvature, and this portion has a substantially uniform thickness. It is set to both end faces and the large diameter side end face of the inner ring of the outer member after plastic processing Are cutting machining, after heat treatment, since the outer diameter and the inner ring inner diameter and the small diameter side end surface of the outer member and the two rolling surfaces are formed into a predetermined size, accuracy by grinding, cracks in the shoulder portion Provided is a wheel bearing that can prevent the occurrence of an edge load by preventing a contact ellipse of a ball from climbing over a shoulder when a turning moment is applied, and improving the durability of the bearing. be able to. Further, productivity is improved, yield is good, cost can be reduced, and bearing accuracy equivalent to conventional forged and machined bearings can be ensured.

  A pair of outer members in which a double-row arc-shaped outer rolling surface is integrally formed on the inner periphery, and an arc-shaped inner rolling surface facing the outer-rolling surface of the double-row is formed on the outer periphery. A back-to-back type double row angular contact comprising an inner ring and a double row of balls accommodated between both rolling surfaces of the inner ring and the outer member, wherein the end faces on the small diameter side of the inner ring abut each other in a butted state. In the wheel bearing constituting the ball bearing, the outer member and the inner ring are formed by cold rolling from a pipe material, and an annular recess is formed by recessing a central portion of the outer diameter of the outer member. An annular convex portion is formed in a flat shape on the circumference, and an outer diameter of the outer member and a radius of curvature R of the connecting portion of the annular concave portion are set such that R = 1.5 to It is formed in an arc shape with a range of 1.8 Rw, and this part is set to a substantially uniform thickness. There.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view showing the wheel bearing of FIG. 1, and FIG. 3 (a) is a single outer member of FIG. (B) is a longitudinal cross-sectional view which shows the inner ring single-piece | unit of FIG. 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 has a first generation structure, and includes a hub wheel 1 and a wheel bearing 2 attached to the hub wheel 1. A constant velocity universal joint 3 is fitted into the hub wheel 1 so as to be able to transmit torque, and the hub wheel 1 and the constant velocity universal joint 3 are detachably integrated via a fixing nut 4.

  The hub wheel 1 has a wheel mounting flange 5 for mounting a wheel (not shown) at one end portion on the outer side, and a cylindrical shape extending from the wheel mounting flange 5 to the outer periphery in the axial direction via a shoulder portion 1a. A small-diameter step portion 1b is formed, and a serration (or spline) 1c for torque transmission is formed on the inner periphery. The hub wheel 1 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and remains as forged. In addition, a method of performing a tempering treatment after forging in order to increase the fatigue strength with respect to the bending strength, or by subjecting the surface hardness to a range of 58 to 64 HRC by induction hardening from the shoulder portion 1a to the small diameter step portion 1b. May be.

  The wheel bearing 2 is fitted into a knuckle 6, and as shown in an enlarged view in FIG. 2, an outer member (outer ring) 7 in which double-row arc-shaped outer rolling surfaces 7a and 7a are formed on the inner periphery. A pair of inner rings 8 and 8 having arcuate inner rolling surfaces 8a and 8a formed on the outer periphery and facing these double-row outer rolling surfaces 7a and 7a, and cages 9 and 9 between both rolling surfaces. And the double-row balls 10 and 10 accommodated so as to be freely rollable via each other, and the seals 11 attached to both ends of the outer member 7. The small diameter (front) side end faces 8b, 8b of the inner rings 8, 8 are abutted in a butted state to constitute a so-called back-to-back type double row angular ball bearing.

  The seal 11 is composed of a core metal 11a fitted to the cylindrical portion 13 of the outer member 7, and a seal member 11b integrally joined to the core metal 11a by vulcanization adhesion or the like, and made of an elastomer such as nitrile rubber, It has a pair of radial lips. In addition, leakage of grease sealed in the bearing and foreign matter such as rainwater and dust from the outside are prevented from entering the bearing. Although not shown, a slinger is press-fitted into the outer diameter of the inner ring, and a seal is mounted on the cylindrical portion 13 of the outer member 7 so as to face the slinger. A pack seal may be used.

  As shown in FIG. 1, the constant velocity universal joint 3 includes an outer joint member 15, a joint inner ring 16, a cage 17, and a torque transmission ball 18. The outer joint member 15 integrally includes a cup-shaped mouth portion 19, a shoulder portion 20 that is a bottom portion of the mouth portion 19, and a shaft portion 21 that extends from the shoulder portion 20 in the axial direction. A serration 21a that engages with the serration 1c of the hub wheel 1 is formed on the outer periphery of the shaft portion 21, and a male screw 21b is formed at the end of the serration 21a. The outer joint member 15 is fitted into the hub wheel 1 via the serrations 1c and 21a until the shoulder 20 abuts the large end surface of the inner ring 8, and the pair of inner rings 8 and 8 is the shoulder 1a of the hub ring 1. The outer joint member 15 is press-fitted into the small-diameter step portion 1b of the hub wheel 1 through a predetermined squeeze while being sandwiched between the shoulder portions 20 of the outer joint member 15. Further, a predetermined bearing preload is applied to the male screw 21b by tightening the fixing nut 4 with a predetermined tightening torque. As a result, the bearing rigidity is increased and the rolling fatigue life of the bearing is improved.

  Here, the outer member 7 and the inner ring 8 are formed by pressing or cold rolling (hereinafter referred to as plastic working) a pipe material made of bearing steel such as SUJ2 or carburized steel such as SCr420 or SCM415. . Then, SUJ2 is hardened to a surface hardness of 50 to 64 HRC by submerged or induction hardening, and carburized steel is carburized and quenched. Other examples of the material of the outer member 7 and the inner ring 8 include carbon steel such as SCM440 and cold rolled steel plates (JIS standard SPCC system, etc.).

  On the other hand, in the case of cold rolled steel or carbon steel, at least the outer member 7 has double row outer rolling surfaces 7a and 7a, and the inner ring 8 has inner rolling surface 8a having a surface hardness by induction hardening. Is hardened in the range of 50 to 64 HRC to improve the rolling fatigue life. These rolling surfaces 7a and 8a are formed with predetermined dimensions and accuracy by grinding. After that, superfinishing is performed as necessary.

Next, the configuration of the outer member 7 and the inner ring 8 will be described in detail with reference to FIG.
As shown in (a), the outer member 7 is formed by forming a circular protrusion 12 projecting radially inward from the pipe material, which is a raw material, and a double row on both sides of the annular protrusion 12. Arc-shaped outer rolling surfaces 7a and 7a are formed, and cylindrical portions 13 and 13 which are fitting portions of the seal 11 are formed at both ends. And this cylindrical part 13 including the double row outer side rolling surfaces 7a and 7a mentioned later is formed with a predetermined | prescribed dimension and precision by grinding after plastic processing. Note that both end surfaces where burrs are generated by plastic working are turned after machining. Moreover, a grinding process is given as needed.

  Here, in order to appropriately secure the shoulder height of the annular convex portion 12 from the outer rolling surface 7a, the inner diameter of the annular convex portion 12 is formed in a flat shape during plastic processing of the outer member 7, and the outer side The center portion of the member 7 is recessed to form an annular recess 23 so that the shoulder 22 is filled with the material.

  On the other hand, as shown in (b), the inner ring 8 has an arcuate inner raceway surface 8a on the outer periphery and a shoulder portion 14 extending in the axial direction from the inner raceway surface 8a by plastic working from a pipe material as a material. Is formed. Here, the shoulder portion 14 becomes a seal land portion of the seal 11 and is ground at the same time as the inner rolling surface 8a after plastic working, and is formed with a predetermined size and accuracy. As with the outer member 7, both end surfaces where burrs are generated by plastic working are turned after machining. Moreover, a grinding process is given as needed.

  In the present embodiment, the outer member 7 and the inner ring 8 are formed from a pipe material by plastic working, and the cylindrical portion 13 of the outer member 7 serving as a fitting surface between the rolling surfaces 7a and 8a and the seal 11, and Since the shoulder portion 14 of the inner ring 8 that becomes the land portion of the seal 11 is formed by grinding, the productivity is improved, the yield is improved, the cost can be reduced, and the accuracy equivalent to that of the conventional bearing is achieved. And sealability can be secured.

  Here, in this embodiment, the radius of curvature R of the connecting portion 24 between the outer diameter 7b of the outer member 7 and the annular recess 23 is set within a predetermined range. Specifically, when the radius of the ball 10 is Rw, the radius of curvature R is set to be in the range of 1.5 to 1.8 Rw. As a result, the thickness of this portion can be formed substantially evenly, and cracks can be prevented from occurring in the shoulder portion 22, and the contact ellipse of the ball 10 rides on the shoulder portion 22 when a turning moment is applied, thereby causing edge loading. It is possible to provide the wheel bearing 2 that can prevent the occurrence and improve the durability of the bearing.

  When the radius of curvature R of the connecting portion 24 is smaller than 1.5 times the radius Rw of the ball 10, the thickness is reduced and the rigidity is lowered, so that it cannot withstand the stress at the time of turning moment load. If it exceeds 1.8 times, not only will the wall thickness increase and the workability of plastic working will decrease, but the shape will not greatly differ from conventional forged products, and it will not contribute to light weight and compactness in general. is there.

  Here, the outer diameter 7b of the outer member 7 that becomes the fitting surface of the knuckle 6 and the hub wheel 1, the inner diameter 8c of the inner ring 8, and the small-diameter side end surface 8b of the inner ring 8 that becomes the butting surface are formed by grinding. You may do it. Thereby, the bearing accuracy equivalent to the conventional forged and machined bearing can be ensured.

  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 having a first generation structure including a hub wheel integrally having a wheel mounting flange at one end and a pair of inner rings press-fitted into the hub wheel. .

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is an enlarged view which shows the wheel bearing of FIG. (A) is a longitudinal cross-sectional view which shows the outer member ring single-piece | unit of FIG. (B) is the longitudinal cross-sectional view which shows an inner ring single-piece | unit as above. It is a longitudinal cross-sectional view which shows the angular contact ball bearing of the structure where the conventional inner and outer ring | wheel was formed by press work.

Explanation of symbols

1 ················ Hub wheel 1a, 14, 20, 22 ··· shoulder 1b ········ Small diameter step 1c, 21a ... Serration 2 ... Wheel bearing 3 ...・ ・ ・ ・ ・ Constant velocity universal joint 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fixing nut 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 6 ・... knuckle 7 ... outer member 7a ... .... Outer rolling surface 7b ... Outer diameter 8 ... Inner ring 8a ...・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 8b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small-diameter side end surface 8c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ Inner diameter 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 10 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ball 11 ··················································································· Sealing member 12・ ・ ・ ・ ・ ・ ・ ・ Annular convex part 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cylindrical part 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 16 ・・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting inner ring 17 ・ ・ ・ ・ ・ ・ Cage 18 ・ ・ ・ ・ ・ ・ Torque Transmission ball 19 ............ Mouse part 21 ............ Shaft part 21 b ... ... Male thread 23 ............... annular recess 24 ... ··································································· Outer ring 51a ... Ring-shaped convex portions 51b, 51c ... Outer rolling surface 51d ... Flange 51e ... ························· 52 ... Inner rolling surfaces 52c, 53c ... Fitting part 54 ... Housing 55 ...・ ・ ・ ・ ・ ・ Shaft member 55a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hook 56 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ball 57 ・ ・ ・ ・ ・ ・... Cage 59 ...・ Weight 60 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Adhesive A ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder B ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・..... Joint R ...

Claims (4)

An outer member in which a double-row arc-shaped outer rolling surface is integrally formed on the inner periphery;
A pair of inner rings each having an arcuate inner rolling surface facing the double row outer rolling surface on the outer periphery;
The inner ring and a double row ball accommodated between both rolling surfaces of the outer member, and a small diameter side end face of the inner ring abuts in a butted state to form a back-to-back type double row angular ball bearing. In the wheel bearing that constitutes,
The outer member and the inner ring are formed from a pipe material by plastic working, the central portion of the outer diameter of the outer member is recessed to form an annular recess, and the annular protrusion is formed in a flat shape on the inner periphery. The connecting portion between the outer diameter and the annular recess is formed in an arc shape having a predetermined radius of curvature, and this portion is set to have a substantially uniform thickness, and both end surfaces of the outer member and the large-diameter side end surface of the inner ring Is subjected to turning after plastic working, and after heat treatment, the outer diameters of both the rolling surfaces and the outer member, the inner diameter of the inner ring and the end face on the small diameter side are formed with predetermined dimensions and accuracy by grinding. Wheel bearing.   2. The wheel bearing according to claim 1, wherein a radius of curvature R of the joint portion is set to be in a range of R = 1.5 to 1.8 Rw, where Rw is a radius of the ball. The wheel bearing according to claim 1 or 2 , wherein the outer member and the inner ring are formed by cold rolling from a pipe material. A hub wheel integrally having a wheel mounting flange at one end and having a small-diameter step portion extending in the axial direction from the wheel mounting flange via a shoulder portion, and a predetermined squeeze through a small-diameter step portion of the hub wheel The wheel bearing according to any one of claims 1 to 3 , wherein the outer joint member of the constant velocity universal joint is fitted into the hub wheel via a serration, and the pair of inner rings are the hub. A wheel bearing device characterized by being sandwiched between a shoulder portion of a ring and a shoulder portion of the outer joint member and given a predetermined bearing preload.

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