JP2008100632A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of reducing the weight while reducing material losses, and enhancing the strength and durability under the condition of the rotating bending load. <P>SOLUTION: In the bearing device for the wheel provided with a hub ring 2 having a wheel mounting flange 4 with a hub bolt 5 implanted thereon on one end thereof, pedal-shaped ribs 13, 14 in which portion for press-fitting the hub bolt 5 forms a thick-walled portion, and recesses 15, 17 between the ribs 13, 14 are forged on both sides 11, 12 of the wheel mounting flange 4. The side of the rib 13 on the outer side in the wheel mounting flange 4 is cut and regulated to the predetermined face deflection accuracy, and the strength/rigidity is ensured while reducing the weight. The contact area with a brake rotor is reduced, and the heat conduction is suppressed. Since a large space is formed between the brake rotor and a recess 15 having the predetermined step &delta;, the heat radiation effect can be expected, and the temperature rise of a bearing part can be suppressed. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a wheel bearing device that supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that reduces material loss to reduce weight and improves durability.

  In recent years, demands for improving fuel efficiency have been severe from the viewpoint of resource saving or pollution. In automobile parts, weight reduction of a wheel bearing device has been noticed as a factor to meet such a demand and has been strongly desired for a long time. In particular, among vehicles such as automobiles, light vehicles such as light four-wheel vehicles or small cars are not only cost-reduced, but demands for this weight reduction are increasing. There are various proposals related to wheel bearing devices that have been made lighter in the past. However, in the wheel bearing device that supports the wheel in a freely rotatable manner, reliability and durability contradicting this weight reduction in one aspect. Improving the performance is also an important factor.

  FIG. 6 shows an example of a wheel bearing device that is used in an automobile and is reduced in weight. This wheel bearing device has a typical structure used on the drive wheel side, and includes a hub wheel 51 and a double row rolling bearing 52 formed as a unit.

  The hub wheel 51 of the wheel bearing device is formed by forging to form a hollow structure, and integrally has a wheel mounting flange 53 for mounting a wheel (not shown), and one inward rolling of the double row rolling bearing 52 on the outer periphery thereof. A running surface 51a and a cylindrical small diameter step portion 51b extending in the axial direction from the inner rolling surface 51a are formed, and a torque transmission spline 54 is formed on the inner periphery.

  A separate inner ring 55 in which the other inner rolling surface 55a of the double row rolling bearing 52 is formed on the outer periphery is press-fitted into the small diameter step portion 51b. The end portion of the small diameter step portion 51 b is plastically deformed radially outward to form a crimped portion 56, and the inner ring 55 is fixed to the hub wheel 51 in the axial direction by the crimped portion 56.

  On the other hand, the outer member 57 constituting the wheel bearing device integrally has a vehicle body mounting flange 57b for fixing to the knuckle 58 constituting the suspension device, and is opposed to the inner rolling surfaces 51a and 55a on the inner periphery. Double row outer rolling surfaces 57a and 57a are formed. As described above, the wheel bearing device includes the hub wheel 51, the inner ring 55, the outer member 57, and the double row balls 59, 59 accommodated so as to roll between the rolling surfaces 51a, 57a, 55a, 57a. And.

  In the hub wheel 51, hub bolts 53a are implanted at four equal locations around the wheel mounting flange 53, and the brake rotor 60 and the wheel are fastened. As shown in FIG. 7, the hub wheel 51 is formed with a bolt insertion hole 61 in which the hub bolt 53 a is fixed to the wheel mounting flange 53, and avoids the periphery of the bolt insertion hole 61. , An R-shaped notch 62 is formed on the outer periphery of the wheel mounting flange 53.

The notch 62 is formed so that the deepest portion 62 a is close to the string B connecting the center of the adjacent bolt insertion hole 61 on the inner diameter side of the pitch circle diameter A of the bolt insertion hole 61. Further, the wheel mounting flange 53 is formed with a thin portion 63 in which the thickness in the vicinity of the outer periphery of each bolt insertion hole 61 is reduced, and the inner peripheral side including the bolt insertion holes 61 is not reduced in thickness. The normal thick portion 64 is used so that sufficient bending rigidity can be obtained. This prevents a reduction in the bending rigidity of the wheel mounting flange 53 while reducing the weight.
JP 2003-94905 A

  However, in the hub wheel 51 of such a conventional wheel bearing device, the outer peripheral part between the hub bolts 53a of the wheel mounting flange 53 is eliminated to reduce the weight, and the hub wheel 51 is slim. However, since the wheel mounting flange 53 has a petal shape, the turning process of the side surface 65 of the wheel mounting flange 53 becomes an intermittent process. The manufacturing time may be increased due to the longer time, and the surface runout accuracy of the side surface 65 may deteriorate due to insufficient rigidity during processing. Further, since the wheel mounting flange 53 has a petal shape, the tilt of the vicinity of each bolt insertion hole 61 of the wheel mounting flange 53 due to induction hardening of the flange base may not be uniform.

  If the surface runout accuracy of the side surface 65 of the wheel mounting flange 53 deteriorates, the surface runout accuracy of the brake rotor 60 fixed in close contact with the side surface 65 may deteriorate, and brake judder may occur. Here, the brake judder is a phenomenon in which vibration is generated during braking, particularly when the vehicle is traveling at a low speed, and low frequency unpleasant noise is induced.

  One factor of brake judder is the runout accuracy of the pad sliding contact surface of the brake rotor. This runout accuracy is not only the runout accuracy of the brake rotor alone, but also the runout accuracy of the wheel mounting flange to which the brake rotor is attached, The axial runout of the rolling bearing, the accuracy of the rolling surface, the assembly accuracy of the rolling bearing, and the like are accumulated, and finally appear as the runout accuracy of the side surface of the brake rotor.

  Also, in recent years, not only cost reduction, but also pursuit of weight reduction to improve fuel consumption, eliminate the surplus and make the wheel bearing device slim, and for wheel drive stability. The rigidity of the bearing device has been increased. Various measures for the above-mentioned surface runout accuracy of the side surface of the brake rotor are taken while satisfying the requirements that contradict each other.

  The present invention was made in view of such circumstances, and reduced the material loss to reduce the weight, while ensuring the surface runout accuracy of the wheel mounting flange and suppressing the occurrence of brake judder. Is intended to provide

  The present invention has been made in view of such conventional problems, and is intended to reduce the weight of the material by reducing material loss, and to improve the strength and durability under the condition of rotating bending load. An object is to provide an apparatus.

  In order to achieve such an object, the invention according to claim 1 of the present invention is such that an outer member having a double row outer raceway formed on the inner periphery and a bolt to which a hub bolt for attaching a wheel is fixed. A hub wheel having a wheel mounting flange with holes formed at equal intervals in the circumferential direction at one end and a small diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery, and a small diameter step portion of the hub wheel. An inner member formed of an outer joint member of at least one inner ring or a constant velocity universal joint fitted, and formed with an inner rolling surface of a double row opposite to the outer rolling surface of the double row on the outer periphery; and In a wheel bearing device comprising an inner member and a double row rolling element that is rotatably accommodated between both rolling surfaces of the outer member, the bolt holes are formed on both side surfaces of the wheel mounting flange. A petal-shaped rib with a thick part, and a recess between the ribs It is.

  In this way, on both sides of the wheel mounting flange, the petal-like ribs where the bolt hole portions are thick parts and the recesses are formed by forging between the ribs, so that weight reduction and rotation It is possible to provide a wheel bearing device that is improved in strength and durability under a bending load condition. In addition, the contact area with the brake rotor, which becomes hot during braking, is reduced and heat conduction is suppressed, and a large space is formed between the brake rotor and the wheel mounting flange by the recess, so a heat dissipation effect can be expected. The temperature rise of the bearing portion can be suppressed.

  Preferably, if the recess is formed by forging as in the invention described in claim 2, the material loss can be reduced and the cost can be reduced.

  Further, as in the invention according to claim 3, if the side surface of the outer rib in the wheel mounting flange is cut and regulated to a predetermined surface runout accuracy, the brake rotor mounted on the wheel mounting flange It is possible to suppress the surface runout accuracy of the side surfaces with high accuracy and to suppress the occurrence of brake judder.

  Further, as in the invention described in claim 4, if the recess is formed at a predetermined step so that the thickness of the wheel mounting flange gradually becomes thinner from the annular base toward the outer side in the radial direction. The predetermined durability can be ensured even when a large bending moment is applied to the wheel mounting flange while reducing the weight.

  Further, as in the invention described in claim 5, the inner member has a wheel mounting flange at one end, one inner rolling surface on the outer periphery, and a small diameter extending in the axial direction from the inner rolling surface. A hub ring formed with a step portion, and an inner ring press-fitted into a small-diameter step portion of the hub ring via a predetermined shimiro, and the other inner rolling surface is formed on the outer periphery. If it is fixed in the axial direction by a caulking portion formed by plastically deforming the end portion of the wheel in the radially outward direction, a wheel bearing device that is lightweight and compact can be provided.

  In the wheel bearing device according to the present invention, an outer member having a double row outer raceway formed on the inner periphery, and bolt holes in which hub bolts for attaching the wheel are fixed are formed in a circumferentially uniform manner. A hub wheel having a wheel mounting flange at one end and a small-diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery, and at least one inner ring or the like fitted in the small-diameter step portion of the hub wheel An inner member comprising an outer joint member of a speed universal joint and having a double row inner rolling surface facing the double row outer rolling surface on the outer periphery, and both the inner member and the outer member In a bearing device for a wheel provided with a double row rolling element that is rotatably accommodated between rolling surfaces, a petal-like shape in which the bolt hole portions are thick portions on both side surfaces of the wheel mounting flange. Since a recess is formed between the rib and this rib, weight reduction is achieved. With the intensity under the conditions of rotating bending load, it is possible to provide a wheel bearing apparatus with improved durability. In addition, the contact area with the brake rotor, which becomes hot during braking, is reduced and heat conduction is suppressed, and a large space is formed between the brake rotor and the wheel mounting flange by the recess, so a heat dissipation effect can be expected. Since the temperature rise of the bearing portion can be suppressed, the deterioration of grease can be prevented and the life of the bearing can be extended.

  An outer member that has a body mounting flange that can be attached to the vehicle body on the outer periphery, a double-row outer rolling surface is formed on the inner periphery, and hub bolts for mounting the wheels are planted in a uniform circumferential direction. The wheel mounting flange is formed at one end, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface is formed. An inner member comprising a hub ring and an inner ring press-fitted into a small-diameter step portion of the hub ring and having the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and the inner member And a double row rolling element accommodated between the outer members so as to be freely rollable, a portion where the hub bolt is press-fitted on both side surfaces of the wheel mounting flange is a thick portion. The petal-shaped ribs and the recesses between these ribs are formed by forging. , The rib side of the outer side of the wheel mounting flange is restricted to be machined predetermined surface runout accuracy.

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, FIG. 2 is a single hub wheel of FIG. 1, (a) is a longitudinal sectional view, and (b) is (a ) Is a left side view, and FIG. 7C is a right side view of FIG. 3 shows a forged shape of the single hub wheel of FIG. 1, (a) is a longitudinal sectional view, (b) is a left side view of (a), and (c) is a right side surface of (a). FIG. 4D is a sectional view taken along line dd in FIG. 4C, FIG. 4 is a longitudinal sectional view showing a state where the brake rotor is mounted on the wheel bearing device according to the present invention, and FIG. It is a longitudinal cross-sectional view which shows the modification 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 is called the third generation on the driven wheel side, and includes an inner member 1, an outer member 10, and double-row rolling elements (balls) 6 and 6. The inner member 1 includes a hub ring 2 and a separate inner ring 3 fixed to the hub ring 2.

  The hub wheel 2 integrally has a wheel mounting flange 4 for attaching a wheel (not shown) to an end portion on the outer side, one (outer side) inner rolling surface 2a on the outer periphery, and this inner rolling. A small diameter step 2b extending in the axial direction from the surface 2a is formed. Hub bolts 5 for fixing the wheels are planted at equal circumferential positions of the wheel mounting flanges 4. On the other hand, the inner ring 3 is formed with the other (inner side) inner rolling surface 3a on the outer periphery, and is press-fitted into the small-diameter step portion 2b of the hub ring 2 through a predetermined squeeze. The end of the small-diameter step 2b is fixed in the axial direction by a caulking portion 2c formed by plastic deformation (rocking caulking) radially outward.

  The outer member 10 integrally has a vehicle body mounting flange 10b for mounting to a vehicle body (not shown) on the outer periphery, and a double row facing the inner rolling surfaces 2a, 3a of the inner member 1 on the inner periphery. The outer rolling surfaces 10a and 10a are integrally formed. And between these both rolling surfaces 2a, 10a and 3a, 10a, the double row rolling elements 6 and 6 equally distributed by the holder | retainers 7 and 7 are each accommodated so that rolling is possible. Seals 8 and 9 are attached to the opening of the annular space formed between the outer member 10 and the inner member 1, and leakage of lubricating grease sealed inside the bearing, rainwater, dust, etc. from the outside. It prevents entry into the bearing.

  The hub wheel 2 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon such as S53C, and the small diameter step portion 2b from the flange base portion 4a to which the outer seal 8 comes into sliding contact, including the inner rolling surface 2a. Accordingly, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. The caulking portion 2c is kept in the surface hardness after forging. Such induction hardening improves the strength of the hub wheel 2, prevents fretting wear on the fitting surface of the inner ring 3, improves durability, facilitates plastic deformation, and causes cracks during swing caulking. It can be prevented from occurring.

  On the other hand, the inner ring 3 and the rolling element 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 by quenching. The outer member 10 is formed of medium and high carbon steel containing 0.40 to 0.80% by weight of carbon, such as S53C, similarly to the hub wheel 2, and the double row outer raceway surfaces 10a and 10a are formed by induction hardening. The surface hardness is set in the range of 58 to 64 HRC. In addition, although the double row angular contact ball bearing which used the ball for the rolling element 6 was illustrated here, not only this but the double row tapered roller bearing which used the tapered roller for the rolling element 6 may be sufficient.

  Here, in this embodiment, as shown in FIG. 2, petal-like ribs 13 and 14 are formed on both side surfaces 11 and 12 of the wheel mounting flange 4. That is, radially extending ribs 13 are formed on the outer side surface 11 of the side surfaces 11 and 12, and the bolt hole 4b portion into which the hub bolt 5 is press-fitted is formed in the thick portion. An R-shaped recess 15 is formed between the bolt holes 4b, avoiding the periphery of the bolt holes 4b. This recess 15 is formed at a predetermined step δ, and the thickness of the wheel mounting flange 4 gradually becomes thinner from the annular base portion 16a around the pilot portion 16 toward the outer side in the radial direction.

  On the other hand, similarly to the outer side surface 11, ribs 14 extending radially from the flange base portion 4 a are formed on the inner side surface 12, and the bolt hole 4 b is formed in a thick portion. A recess 17 having a predetermined step is formed between the bolt holes 4b, avoiding the periphery of the bolt holes 4b.

  The hub wheel 2 is forged from a round bar material, and is formed into a predetermined shape and size through a turning process, a heat treatment process, and a grinding process. The ribs 13 and 14 are formed in this forging process. ing. That is, as shown in FIG. 3, in the forging process, the hub wheel 2 (shown by a two-dot chain line in the drawing) is formed in a predetermined forging shape while leaving a turning allowance.

  In this embodiment, the ribs 13 and 14 in the both side surfaces 11 and 12 of the wheel mounting flange 4 are formed on a predetermined flat surface by cutting such as a lathe. In particular, the rib 13 and the pilot portion 16 on the outer side surface 11 to which a brake rotor (not shown) is attached in contact are formed by turning, and the side surface of the rib 13 is regulated to a predetermined surface runout accuracy. Here, since the annular base portion 16a is formed on the rib 13 with which the brake rotor abuts, and the recess 15 is formed between the ribs 13, the rigidity of the wheel mounting flange 4 is ensured while reducing the weight. In addition, the side surface of the rib 13 can be restricted to a predetermined surface deflection accuracy. Therefore, the surface runout accuracy of the side surface of the brake rotor mounted on the wheel mounting flange 4 can be suppressed with high accuracy, and the occurrence of brake judder can be suppressed. The ribs 13 are not limited to cutting with a lathe, and may be cutting with a milling machine or a grinding machine.

  As described above in detail, in the present embodiment, while reducing the material loss and reducing the weight, it is possible to prevent the bending rigidity of the wheel mounting flange 4 from being lowered, and the surface runout of the wheel mounting flange 4 can be prevented. It is possible to provide a wheel bearing device that ensures accuracy and suppresses the generation of brake judder.

  Further, since the petal-like ribs 13 are formed on the outer side surface 11, as shown in FIG. 4, the contact area with the brake rotor 18 that becomes a high temperature during braking is reduced and heat conduction is suppressed, Since a large space is formed between the brake rotor 18 and the wheel mounting flange 4 by the recess 15 having the predetermined step δ, a heat dissipation effect can be expected, and the temperature rise of the bearing portion can be suppressed. Therefore, it is possible to prevent the grease from deteriorating and extend the life of the bearing.

  In this example, ribs 13 and 14 are formed on both side surfaces 11 and 12 of the wheel mounting flange 4 and the ribs 13 and 14 are cut. However, only the ribs 13 on the outer side surface 11 are shown. You may make it form in a predetermined flat surface by cutting. Moreover, although the thing with which the outer periphery of the wheel mounting flange 4 was circularly illustrated was illustrated, it is not restricted to this, For example, although not shown in figure, a wheel mounting flange is a polygon which makes the site | part into which the hub bolt 5 is press-fitted as an apex angle. You may make it form in a shape and form the rib 13 mentioned above in this wheel mounting flange. As a result, the hub wheel can be further reduced in weight and size, and the heat dissipation effect during operation can be enhanced to further suppress the temperature rise of the bearing portion.

  Here, the hub bolt 5 for fixing the wheel to the wheel mounting flange 4 is illustrated as being press-fitted. However, the present invention is not limited to this, and for example, as shown in FIG. A bolt hole 19 with a female thread is formed on the wheel, and a wheel may be screwed into the bolt hole 19 via a fastening bolt (not shown).

  Although the embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and is merely an example. For example, an outer ring rotation having a wheel mounting flange on an outer member. Of course, it may be of a type and can be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is defined by the terms of the claims, and includes the equivalent meanings of the claims and all modifications within the scope.

  A wheel bearing device according to the present invention includes a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end via a brake rotor, and a double-row rolling bearing that rotatably supports the wheel. The present invention can be applied to all structures from the first generation to the fourth generation.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is a longitudinal cross-sectional view which shows the hub ring single-piece | unit of FIG. (B) is a left side view of (a). (C) is a right side view of (a). (A) is a longitudinal cross-sectional view which shows the forge shape of the hub ring single-piece | unit of FIG. (B) is a left side view of (a). (C) is a right side view of (a). (D) is sectional drawing along the dd line of (c). It is a longitudinal cross-sectional view which shows the state with which the brake rotor was mounted | worn with the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the modification of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a front view which shows the conventional hub wheel.

Explanation of symbols

1 .... inner member 2 .... hub wheels 2a, 3a ... inward rolling surface 2b ...・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 2c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Clamping portion 3 ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 4 ... Wheel mounting flange 4a ... Flange base 4b ... Bolt hole 5 ... Hub bolt 6・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling element 7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 8, 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 10 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・··· Outer member 10a ··· Outer rolling surface 10b ··· Body mounting flange 11 ··· Wheel mounting Flange outer side surface 12 ... Inner wheel mounting flange Side surfaces 13 and 14 ... ribs 15 and 17 ... recess 16 ... pilot part 16a ... ... Band base 18 ... Brake rotor 19 ... Bolt hole 51 ... Hub wheels 51a, 55a・ ・ ・ ・ ・ ・ Inner rolling surface 51b ・ ・ ・ ・ ・ ・ ・ ・ Small diameter stepped part 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel bearing device 53 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Wheel mounting flange 53a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolt 54 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Spline 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 56 ・ ・ ・ ・ ・ ・························································ Outer member 57a ······ Outer rolling surface 57b Mounting part 58 Knuckle 59 ... Rolling element 60 ... Brake rotor 61 ... Bolt insertion hole 62 ...・ ・ ・ ・ ・ ・ Notch 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Thin wall 64 ・ ・ ・ ・ ・ ・ Thick wall 65 ・ ・ ・ ・ ・ ・Side δ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recess step δ ′ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recess step during forging

Claims (5)

An outer member having a double row outer raceway formed on the inner periphery;
A hub having a wheel mounting flange with a bolt hole to which a hub bolt for mounting a wheel is fixed formed in an equal circumferential direction at one end, and a small-diameter step portion extending in the axial direction from the wheel mounting flange on the outer periphery. A double-row inner race that includes an outer joint member of at least one inner ring or a constant velocity universal joint fitted to a small-diameter step portion of the wheel and the hub wheel, and that faces the outer race surface of the double-row on the outer periphery. An inner member having a surface formed thereon;
In the wheel bearing device including the inner member and a double-row rolling element that is accommodated in a freely rolling manner between both rolling surfaces of the outer member,
A bearing device for a wheel, characterized in that petal-like ribs in which the bolt hole portions are thick portions on both side surfaces of the wheel mounting flange, and recesses are formed between the ribs.   The wheel bearing device according to claim 1, wherein the recess is formed by forging.   The wheel bearing device according to claim 1 or 2, wherein a side surface of an outer rib in the wheel mounting flange is cut to be regulated to a predetermined surface runout accuracy.   4. The wheel bearing device according to claim 1, wherein the recess is formed at a predetermined step so that the wall thickness of the wheel mounting flange gradually becomes thinner from the annular base toward the radially outer side. 5. .   A hub ring in which the inner member has a wheel mounting flange at one end, one inner rolling surface on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub ring The inner ring is press-fitted into the small-diameter step portion through a predetermined squeezing and the other inner rolling surface is formed on the outer periphery, and this inner ring plastically deforms the end portion of the small-diameter step portion radially outward. The wheel bearing device according to any one of claims 1 to 4, wherein the wheel bearing device is fixed in an axial direction by a formed crimping portion.

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