JP2007315508A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of solving a contradictory problem requiring the reduction of the weight and size of the device and an increase in rigidity simultaneously. <P>SOLUTION: In this bearing device for the wheel of a self-retaining type having a third generation structure constituted of a double row tapered roller bearing, a diameter PCDi of a pitch circle of a tapered roller 4 on an inner side among the double row tapered rollers 3, 4 is set to be smaller than a diameter PCDo of a pitch circle of the tapered roller 3 on an outer side, a conical recessed part 15 is formed in an end part on an outer side of a hub wheel 5 and has such a depth that exceeds the depth of the groove bottom of the inner side rolling face 5a of the hub wheel 5 and reaches a part in the vicinity of a shaft-like part 8, the wall thickness t1 on a large diameter side on the inner side rolling face 5a is set to be larger than the wall thickness t2 of a central part, and the relation between the wall thickness t1 and the diameter d1 in this section is set to be in a range of 0.2≤t1/d1≤0.3 to solve the contradictory problem requiring the reduction of the weight and size of the device and an increase in rigidity simultaneously. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that achieves higher rigidity and longer bearing life.

  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 an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Further, the 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. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. 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 speed universal joint.

  In such a wheel bearing device, conventionally, both rows of bearings have the same specification, so that they have sufficient rigidity when stationary, but the optimum rigidity is not always obtained when the vehicle turns. That is, the position of the vehicle weight when stationary is determined so that it acts on the approximate center of the double row rolling bearing, but when turning, the opposite side of the turning direction (when turning right, the vehicle A large radial load or axial load is applied to the left axle. Therefore, at the time of turning, it is effective to increase the rigidity of the outer bearing row rather than the inner bearing row. Therefore, a wheel bearing device shown in FIG. 3 is known as a wheel bearing device having improved turning rigidity without increasing the size of the device.

  The wheel bearing device 50 integrally has a vehicle body mounting flange 51c to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and double row outer rolling surfaces 51a and 51b are provided on the inner periphery. The outer member 51 formed and a wheel mounting flange 53 for attaching a wheel (not shown) at one end are integrally formed, and one inner side facing the double row outer rolling surfaces 51a and 51b on the outer periphery. A rolling wheel 52a, a hub wheel 52 formed with a small-diameter step portion 52b extending in the axial direction from the inner rolling surface 52a, and a small-diameter step portion 52b of the hub wheel 52 are externally fitted and double-row outer rolling. An inner member 55 comprising an inner ring 54 formed with the other inner rolling surface 54a opposite to the surfaces 51a, 51b, double rows of balls 56, 57 accommodated between the two rolling surfaces, and these double rows Balls 56 and 57 are kept free to roll Is composed of a double row angular contact ball bearing having a cage 58, 59.

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

Here, the pitch circle diameter D1 of the outer side ball 56 is set to be larger than the pitch circle diameter D2 of the inner side ball 57. Along with this, the inner rolling surface 52a of the hub wheel 52 is expanded in diameter than the inner rolling surface 54a of the inner ring 54, and the outer rolling surface 51a on the outer side of the outer member 51 is also rolled on the inner side. The diameter is larger than that of the surface 51b. Accordingly, more outer side balls 56 are accommodated than inner side balls 57. As described above, by setting the pitch circle diameters D1 and D2 to D1> D2, the rigidity increases not only when the vehicle is stationary but also when turning, and the life of the wheel bearing device 50 can be extended. it can.
JP 2004-108449 A

  In such a conventional wheel bearing device 50, the pitch circle diameter D1 of the outer ball 56 is set to be larger than the pitch circle diameter D2 of the inner ball 57, and accordingly, the inner rolling of the hub wheel 52 is performed. The surface 52a is larger in diameter than the inner rolling surface 54a of the inner ring 54. As a result, the rigidity of the outer bearing row is increased, and the life of the wheel bearing device 50 can be extended. However, the rigidity of the inner side bearing row is insufficient with respect to the rigidity of the outer side bearing row, and the outer side of the hub wheel 52 is formed to have a larger diameter. It was impossible to reduce the weight of the device.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device that solves the conflicting problems of light weight, compactness, and high rigidity of the device.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the suspension on the outer periphery, and a double row outer rolling surface is formed on the inner periphery. An outer member and a wheel mounting flange for attaching a wheel to one end of the outer member, and one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and from this inner rolling surface A hub wheel formed with a small-diameter step portion extending in the axial direction through the shaft-shaped portion, and a small-diameter step portion of the hub wheel is press-fitted through a predetermined shimiro to face the outer rolling surface of the double row on the outer periphery. An inner member formed of an inner ring formed with the other inner rolling surface, and a double row tapered roller that is rotatably accommodated between the inner member and both rolling surfaces of the outer member. In the above-described wheel bearing device, the pipes of the inner side tapered rollers of the double row tapered rollers are provided. The circular diameter is set to be smaller than the pitch circular diameter of the outer tapered roller, and a mortar-shaped recess is formed at the outer end of the hub ring, and the depth of the recess is the hub ring. The inner raceway surface of the inner raceway surface is made near the shaft-like portion, the inner raceway surface thickness is set within a predetermined range, and the outer side of the hub wheel is substantially uniform corresponding to the recess. It is formed to be a thick wall.

  Thus, an outer member having a vehicle body mounting flange on the outer periphery, a hub wheel having a wheel mounting flange at one end, an inner member made of an inner ring press-fitted into the hub wheel, and the inner member and the outer member. In a third-generation wheel bearing device having a double row tapered roller housed between members, the pitch circle diameter of the inner side tapered roller in the double row tapered roller is the pitch circle of the outer side tapered roller. The diameter is set smaller than the diameter, and a mortar-shaped recess is formed at the outer end of the hub wheel, and the depth of this recess exceeds the groove bottom of the inner raceway surface of the hub wheel. The thickness of the inner rolling surface is set within a predetermined range, and the outer side of the hub wheel is formed to have a substantially uniform thickness corresponding to the recess.・ Concurrently conflicting issues of compactness and high rigidity The resolved wheel bearing device can be provided.

  Preferably, as in the invention described in claim 2, the wall thickness t1 on the inner diameter side of the inner raceway surface of the hub wheel is set to be thicker than the wall thickness t2 of the central portion, and the wall thickness t1 If the relationship with the diameter d1 of this part is set to be in the range of 0.2 ≦ t1 / d1 ≦ 0.3, the hub wheel strength and rigidity corresponding to the use conditions can be secured while being lightweight. Can be achieved.

  More preferably, as in the invention according to claim 3, the relationship between the thickness t2 of the central portion on the inner raceway surface of the hub wheel and the diameter d2 of this portion is 0.2 ≦ t2 / d2 ≦ 0. If it is set to be in the range of .3, further weight reduction can be achieved while ensuring the strength and rigidity of the hub wheel.

  Further, as in the invention described in claim 4, a large collar for guiding the tapered roller is not formed on the large diameter side of the inner raceway surface of the hub wheel, and the large collar is formed on the outer member. If it is provided on the large-diameter side of the outer raceway, stress concentration on the hub wheel will be relaxed with respect to the load applied via the tapered roller, and the hub will be able to be loaded even if a large moment load is applied to the wheel mounting flange. Fatigue does not easily occur on the wheel, and strength and durability can be secured. In addition, the seal land that forms the base of the wheel mounting flange and the inner rolling surface can be ground and smoothed simultaneously with the entire grinding wheel, improving the workability of the hub wheel and further increasing the weight. Can be suppressed.

  Further, as in the invention according to claim 5, the inner ring is in a state in which a predetermined bearing preload is applied by a caulking portion formed by plastically deforming an end portion of the small diameter step portion radially outward. If it is fixed to the hub wheel in the axial direction, it is possible to further reduce the weight and size, and to maintain the initially set preload for a long period of time.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a suspension device on an outer periphery, an outer member having a double row outer rolling surface formed on an inner periphery, and one end portion. A wheel mounting flange for mounting a wheel is integrally formed, one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axial direction from the inner rolling surface via an axial portion. A hub wheel formed with an extending small-diameter step portion, and the other inner rolling surface that is press-fitted into the small-diameter step portion of the hub wheel via a predetermined shimiro and faces the outer rolling surface of the double row on the outer periphery. In the wheel bearing device, comprising: an inner member formed of an inner ring, and a double-row tapered roller that is rotatably accommodated between both rolling surfaces of the inner member and the outer member. The pitch circle diameter of the inner side tapered roller in the tapered roller of the row is the outer side The diameter is set smaller than the pitch circle diameter of the tapered roller, and a mortar-shaped recess is formed at the outer end of the hub ring, and the depth of the recess is a groove on the inner raceway surface of the hub ring. Being near the shaft-like portion beyond the bottom, the thickness of the inner rolling surface is set within a predetermined range, and the outer side of the hub wheel has a substantially uniform thickness corresponding to the recess. Since it is formed, it is possible to provide a wheel bearing device that simultaneously solves the conflicting problems of light weight, compactness, and high rigidity of the device.

  A body mounting flange for mounting to the suspension device on the outer periphery is integrated, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end And a hub wheel formed on the outer periphery with one inner rolling surface facing the outer rolling surface of the double row and a small-diameter step portion extending axially from the inner rolling surface via the shaft-shaped portion. And an inner member formed of an inner ring that is press-fitted into a small-diameter step portion of the hub wheel via a predetermined squeezing and has an inner ring surface on the outer periphery that is opposed to the outer rolling surface of the double row, The inner member and a double-row tapered roller accommodated in a freely rolling manner between both rolling surfaces of the outer member, and formed by plastically deforming the end portion of the small diameter step portion radially outward. The inner ring is in the axial direction with respect to the hub ring in a state where a predetermined bearing preload is applied by the crimped portion. In the fixed wheel bearing device, the pitch circle diameter of the inner side tapered rollers of the double row tapered rollers is set to be smaller than the pitch circle diameter of the outer side tapered rollers, and the outer diameter of the hub wheel is set. A mortar-shaped recess is formed at the end on the side, and the depth of this recess is near the shaft-like portion beyond the groove bottom of the inner rolling surface of the hub wheel, and the large diameter on the inner rolling surface The thickness t1 on the side is set to be thicker than the thickness t2 at the center, and the relationship between the thickness t1 and the diameter d1 of this part is in the range of 0.2 ≦ t1 / d1 ≦ 0.3. Is set to

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, and FIG. 2 is a longitudinal sectional view showing a single hub wheel 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 for a driven wheel called the third generation, and is a double row tapered roller housed in a freely rollable manner between the inner member 1, the outer member 2, and both members 1,2. 3 and 4. The inner member 1 includes a hub ring 5 and an inner ring 6 press-fitted into the hub ring 5.

  The hub wheel 5 integrally has a wheel mounting flange 7 for mounting a wheel (not shown) at one end portion, one (outer side) tapered inner rolling surface 5a on the outer periphery, and this inner rolling. A small-diameter step portion 5b is formed through an axial portion 8 extending in the axial direction from the surface 5a. A large collar for guiding the tapered roller 3 is not formed on the large diameter side of the inner raceway surface 5a of the hub wheel 5, and a large collar 14 is provided on the outer member 2 described later. Further, a roller holding small scissors is not formed on the small diameter side of the inner rolling surface 5a, and a shaft-like portion 8 extending straight in the axial direction from the small diameter side of the inner rolling surface 5a is formed. As a result, the seal land portion 7c serving as the base portion of the wheel mounting flange 7 and the inner rolling surface 5a can be simultaneously ground and smoothly connected by the total-type grindstone, and the workability of the hub wheel 5 is improved. , Weight increase can be further suppressed. Further, hub bolts 7a are planted on the wheel mounting flange 7 in a circumferentially equidistant manner, and circular holes 7b are formed between the hub bolts 7a. The circular hole 7b not only contributes to weight reduction, but also a fastening jig such as a wrench can be inserted from the circular hole 7b in the assembly / disassembly process of the apparatus, and the work can be simplified.

  The inner ring 6 is formed with the other (inner side) tapered inner rolling surface 6a on the outer periphery, a large collar 6b for guiding the tapered roller 4 to the large diameter side of the inner rolling surface 6a, and a small diameter side In addition, a small scissors 6c for preventing the tapered roller 4 from falling off is formed. The inner ring 6 is press-fitted into the small-diameter step portion 5b of the hub wheel 5 through a predetermined shimiro, and a predetermined bearing preload is applied by a crimping portion 9 formed by plastically deforming the end of the small-diameter step portion 5b. Is fixed in the axial direction. As a result, it is possible to provide a self-retaining structure that achieves light weight and compactness and that maintains the initially set preload for a long period of time.

  The hub wheel 5 is formed of medium-high carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 5a and an inner side of a wheel mounting flange 7 with which an outer seal 12 described later is in sliding contact. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening from the base portion 7c to the inner rolling surface 5a, the shaft portion 8 and the small diameter step portion 5b. The caulking portion 9 is kept in the surface hardness after forging. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 7, and the fretting resistance of the small-diameter step portion 5 b serving as the fitting portion of the inner ring 6 is improved, and caulking is performed. There is no generation of minute cracks or the like during processing, and the plastic processing of the crimped portion 9 can be performed smoothly. The inner ring 6 and the tapered rollers 3 and 4 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core portion by quenching.

  The outer member 2 integrally has a vehicle body mounting flange 2c to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and an outer member facing the inner rolling surface 5a of the hub wheel 5 on the inner periphery. A tapered outer rolling surface 2a on the side and an inner tapered outer rolling surface 2b facing the inner rolling surface 6a of the inner ring 6 are integrally formed. In the present embodiment, the outer member 2 is provided with a large collar 14 that guides the tapered roller 3 on the outer side. That is, a large collar 14 that abuts on the large end surface of the tapered roller 3 and guides the tapered roller 3 is integrally provided on the outer diameter side of the outer side outer rolling surface 2 a of the outer member 2. As a result, the stress concentration on the hub wheel 5 with respect to the load applied via the tapered roller 3 is alleviated, and even if a large moment load is applied to the wheel mounting flange 7, the hub ring 5 is not easily fatigued. -Durability can be ensured.

  This outer member 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the double row outer rolling surfaces 2a and 2b have a surface hardness in the range of 58 to 64HRC by induction hardening. Has been cured. And the double-row bo-conical rollers 3 and 4 are accommodated so that rolling is possible via the holder | retainer 10 and 11 between both rolling surface 2a, 4a and 2b, 6a. In addition, a seal 12 and a magnetic encoder 13 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, the pitch circle diameter PCDi of the inner side tapered roller 4 is set to be smaller than the pitch circle diameter PCDo of the outer side tapered roller 3. Thereby, the outer diameter D on the inner side of the outer member 2 can be set to a small diameter, and the rigidity is increased by using the double-row tapered rollers 3 and 4 as rolling elements, and the basic of each rolling element row The load life can be extended by increasing the rated load.

  In the present embodiment, a chamfered portion 8b is formed at a step portion between the shaft-like portion 8 of the hub wheel 5 and the shoulder portion 8a with which the inner ring 6 is abutted. Further, a mortar-shaped recess 15 is formed at the outer side end of the hub wheel 5 by forging. And the depth of this recess 15 is made from the groove bottom part of the inner side rolling surface 5a to the chamfering part 8b vicinity beyond the shaft-shaped part 8. FIG. That is, when a moment load is applied to the wheel mounting flange 7, it is considered that the hub wheel 5 is deformed starting from the inner rolling surface 5 a on the outer side. Focused on the side wall thickness.

  As shown in FIG. 2, the seal land portion 7c serving as the base portion of the wheel mounting flange 7 is formed in an arc surface having a predetermined radius of curvature, and a large inner rolling surface 5a smoothly connected to the seal land portion 7c. The radial thickness t1 is formed to be thicker than the thickness t2 at the center of the inner rolling surface 5a. Moreover, as a result of obtaining the rigidity of the hub wheel 5 from the relationship with the diameters d1 and d2 of the respective parts by FEM analysis, the thicknesses t1 and t2 are 0.2 ≦ t1 / d1 ≦ 0.3 and 0.2. It is set to be in the range of ≦ t2 / d2 ≦ 0.3. Thereby, weight reduction can be achieved, ensuring the intensity | strength and rigidity of the hub ring 5 corresponding to use conditions. Note that when the large-diameter side wall thickness t1 and the central wall thickness t2 of the inner raceway surface 5a are less than 20% of the diameters d1 and d2 of the respective portions, the deformation becomes large and the desired rigidity cannot be obtained. On the other hand, even if it exceeds 30%, the increase in rigidity is not recognized so much, which is undesirable because it causes an increase in weight.

  In the wheel bearing device having such a configuration, the pitch circle diameter PCDo of the outer tapered roller 3 is set to be larger than the pitch circle diameter PCDi of the inner tapered roller 4. Since a large number is accommodated, the bearing rigidity of the outer side portion increases. Further, a recess 15 is formed at the outer side end of the hub wheel 5, and the thicknesses t1 and t2 of the inner raceway surface 5a portion of the hub wheel 5 are set within a predetermined range corresponding to the recess 15. Therefore, it is possible to provide a wheel bearing device that can simultaneously solve the conflicting problems of light weight, compactness, and high rigidity of the device.

  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 third-generation wheel bearing device for a driven wheel.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a longitudinal cross-sectional view which shows the hub ring single-piece | unit of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1 ... Inner member 2 ... Outer member 2a ...・ ・ ・ ・ ・ ・ Outer side outer raceway 2b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner side outer raceway 2c ・ ・ ・ ・ ・ ・ ・ ・・ ・ Body mounting flange 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer side tapered roller 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner side tapered roller 5・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 5a, 6a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 5b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ Small diameter step 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 6b, 14 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Large 6c ・ ・ ・ ・ ・ ・ ・ ・··························· 7 ...... Hub bolt 7b ......... Circular hole 7c ......... Seal land 8 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft-shaped part 8a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder part 8b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Chamfered part 9 ··········································································································· ··· Seal 13 ············ Magnetic encoder 15 ······································ ... Wheel bearing device 51 ... Outer member 51a ... Outer rolling surface on the outer side 51b ... Outer rolling surface 51c on the inner side ...・ Vehicle mounting flange 52 ..... Hub wheels 52a, 54a ..... Inner rolling surface 52b ...・ ・ ・ ・ Small diameter stepped part 52c ・ ・ ・ ・ ・ ・ ・ ・ Clamping part 53 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 54 ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner members 56, 57 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Balls 58, 59 ・····················································· Seal D Outer diameter D1 on the inner side ............ Pitch circle diameter D2 of the outer side ball ..................... Pitch circle diameter PCDo ... Outer -Pitch circle diameter of the tapered roller on the side PCDi ......... Pitch circle diameter of the tapered roller on the inner side

Claims (5)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and having a double row outer rolling surface formed on the inner periphery;
It has a wheel mounting flange for mounting a wheel at one end, and has one inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a shaft-shaped portion from the inner rolling surface via the shaft-shaped portion. A hub wheel formed with a small-diameter step portion extending in the axial direction, and the other inner rolling member that is press-fitted into the small-diameter step portion of the hub wheel via a predetermined shimiro and faces the outer rolling surface of the double row on the outer periphery. An inner member comprising an inner ring having a surface formed thereon;
In the wheel bearing device comprising the inner member and a double row tapered roller accommodated so as to roll between both rolling surfaces of the outer member,
The pitch circle diameter of the inner side tapered rollers in the double row tapered rollers is set to be smaller than the pitch circle diameter of the outer side tapered rollers, and a mortar-shaped recess is formed at the outer side end of the hub ring. And the depth of the recess exceeds the groove bottom portion of the inner raceway surface of the hub wheel and is near the shaft-like portion, and the thickness of the inner raceway surface is set within a predetermined range, A wheel bearing device, wherein the outer side of the hub wheel is formed to have a substantially uniform thickness corresponding to the recess.   The thickness t1 on the large diameter side of the inner raceway surface of the hub wheel is set to be thicker than the thickness t2 at the center, and the relationship between the thickness t1 and the diameter d1 of this portion is 0.2 ≦ The wheel bearing device according to claim 1, wherein the wheel bearing device is set to be in a range of t1 / d1 ≦ 0.3.   2. The relationship between the thickness t2 of the central portion on the inner raceway surface of the hub wheel and the diameter d2 of this portion is set to be in a range of 0.2 ≦ t2 / d2 ≦ 0.3. Or the wheel bearing apparatus of 2.   A large flange for guiding the tapered roller is not formed on the large diameter side of the inner rolling surface of the hub wheel, and this large flange is provided on the large diameter side of the outer rolling surface of the outer member. The wheel bearing device according to any one of claims 1 to 3.   The inner ring is fixed to the hub ring in the axial direction in a state where a predetermined bearing preload is applied by a caulking portion formed by plastically deforming an end portion of the small-diameter stepped portion radially outward. Item 5. A wheel bearing device according to any one of Items 1 to 4.

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