JP2011027130A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel with reduced weight and size, and with improved assembling workability. <P>SOLUTION: In the bearing device for a wheel, an inner diameter Do of an inner ring 7 on an outer side is set smaller than an inner diameter Di of an inner ring 8 on an inner side, an outer diameter So on the outer side of a shaft part 1a of an axle pipe 1 is set smaller than an outer diameter Si on the inner side, and a pair of inner rings 7, 8 is loosely fitted through a radial clearance equal in an axial direction. A connection ring 9 is constituted of an ended ring with approximately U-shaped cross-section, and is provided with a cylindrical part 9a, collar parts 9b extended from both ends of the cylindrical part 9a to the radially outside, and a cutout part 9c at a predetermined cut angle in a natural state. Inner peripheries of front side end parts of inner rings 7, 8 are provided with annular locking grooves 21, cylindrical mounting parts 22 extending from the locking grooves 21 to front side end faces 7c, and an inner diameter d of the cylindrical part 9a of the connection ring 9 is set to be larger than an inner diameter D of the mounting part 22 by sheet thickness t. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, and more particularly to a full floating type wheel bearing device for supporting a driving wheel with a wheel bearing.

  Many automobiles having a frame-structured body such as a truck adopt a conventional full floating type as an axle structure of a drive wheel. Also, recent drive wheel support structures are often adopted as a structure in which double row rolling bearings are unitized for the purpose of improving assemblability and reducing weight and size. As an example of the conventional structure, a wheel bearing device as shown in FIG. 7 is known.

  In this wheel bearing device, a drive shaft 52 connected to a differential (not shown) is inserted into an axle tube 51, and a double row tapered roller bearing 53 is mounted on the outer diameter surface of the axle tube 51. . A hub wheel 54 rotatably supported by the double row tapered roller bearing 53 is connected to a flange 56 of the drive shaft 52 via a hub bolt 55. A pair of left and right inner rings 57 of the double-row tapered roller bearing 53 are coupled by a connecting ring 58, are fitted on the shaft portion of the axle tube 51, and are fastened and fixed by a fixing nut 59. The outer ring 60 of the double-row tapered roller bearing 53 is fitted into the hub ring 54 and is fixed in the axial direction with both ends thereof being sandwiched between the flange 56 and the brake rotor 61. In the annular space between the inner and outer rings 57 and 60, double-row tapered rollers 62 are rotatably accommodated by a cage 63, and seals 64 are mounted at both ends to seal the bearing interior.

  An annular step 65 is formed at the inner end of the inner ring 57, and a seal ring 66 made of an elastic member is attached. An annular recess 67 is formed on the outer peripheral surface of the butted portion of the pair of inner rings 57, 57, and a seal ring 68 made of an elastic member is attached to the annular recess 67. This prevents intrusion of muddy water from the outside into the axle tube 51 and leakage of the diff oil to the outside, and also prevents the infiltration of the diff oil into the bearing (see, for example, Patent Document 1).

JP 2001-99172 A

  In such a conventional wheel bearing device, a double row tapered roller bearing 53 is mounted between the hub wheel 54 and the axle tube 51, and a drive shaft 52 is inserted into the axle tube 51. 56 and the hub ring 54 are connected by a hub bolt 55, and the outer ring 60 of the tapered roller bearing 53 is press-fitted and fixed to the hub ring 54, so that the pair of inner rings 57 and 57 are loosely connected to the axle tube 51. Is fitted.

  In this type of wheel bearing device, since the tapered roller bearing 53 is press-fitted into the hub ring 54 and the internal clearance of the bearing is reduced, the internal clearance of the bearing before assembly is set to a positive clearance. . However, this type of wheel bearing device is applied to large commercial vehicles such as trucks, and is relatively large bearings having a bearing inner diameter of φ60 or more and has a large bearing mass and a positive internal clearance. There is a problem that the inner rings 57, 57 are misaligned and the assembly workability is deteriorated in the vehicle assembly process.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a wheel bearing device that achieves light weight and compactness and improves assembly workability.

  In order to achieve such an object, the invention described in claim 1 of the present invention integrally has an axle tube through which a drive shaft connected to a differential is inserted, and a wheel mounting flange for mounting a wheel on the outer periphery, A wheel bearing device comprising: a hub wheel connected to the drive shaft; and a wheel bearing mounted between the hub wheel and a shaft portion of the axle tube and rotatably supporting the wheel. The wheel bearing is press-fitted into the inner diameter of the hub wheel, and an outer ring in which a double row outer rolling surface is integrally formed on the inner circumference, and an inner rolling that faces the outer rolling surface of the double row on the outer circumference. A running surface is formed and a pair of inner rings integrally joined by a connecting ring attached to the inner periphery of the front side end, and a plurality of inner rings and a plurality of rolling rings accommodated between the inner race and the outer race. A wheel bearing device comprising: a row of rolling elements; The inner diameter of the inner ring on the inner side is set to be smaller than the inner diameter of the inner ring on the inner side, and the outer diameter on the outer side of the shaft portion of the axle tube is set to be smaller than the outer diameter on the inner side. The pair of inner rings are loosely fitted through a uniform radial clearance.

  Thus, in the full floating type wheel bearing device that supports the driving wheel with the wheel bearing, the inner diameter of the inner ring on the outer side of the pair of inner rings is set smaller than the inner diameter of the inner ring on the inner side, The outer diameter of the outer side of the shaft part of the axle tube is set to be smaller than the outer diameter of the inner side, and the pair of inner rings are loosely fitted through a uniform radial clearance in the axial direction. In the process, even if a center misalignment occurs between the pair of inner rings, the wheel bearing can be easily fitted into the axle tube, and a wheel bearing device that improves assembly workability can be provided.

  According to a second aspect of the present invention, the inner diameter of the pair of inner rings is formed in a tapered shape that gradually decreases toward the outer side, and the maximum inner diameter of the inner ring on the outer side is the inner ring on the inner side. The outer diameter of the shaft portion of the axle tube may be formed in a tapered shape that gradually decreases toward the outer side.

  According to a third aspect of the present invention, the connecting ring includes a cylindrical portion and a flange portion extending radially outward from both ends of the cylindrical portion, and is cut at a predetermined notch angle in a natural state. If the cross section having the notch portion is formed of a substantially U-shaped end ring, and the inner diameter of the cylindrical portion is set to be larger than the inner diameter of the inner ring, the cores are connected to the pair of inner rings by the elasticity of the connecting ring. Even if there is a gap, it can be corrected.

  Preferably, as in the invention described in claim 4, an annular locking groove is formed on the inner periphery of the front side end portion of the inner ring, and a cylindrical mounting portion extends from the locking groove to the front side end surface. If the inner diameter of the mounting portion is set to be larger than the inner ring inner diameter by the thickness of the connecting ring, the connecting ring protrudes from the inner ring inner diameter after mounting and interferes with the axle tube during assembly. Can be prevented and assembly workability can be improved.

  Further, as in the invention according to claim 5, when the height of the flange portion of the connecting ring is h, the inner diameter of the cylindrical portion is d, and the inner diameter of the inner ring is D, the outer peripheral length of the connecting ring. If the notch angle α of the connecting ring is set so that π (d + 2h) (360−α) / 360 is smaller than the inner circumferential length πD of the inner diameter of the inner ring, the outer diameter of the connecting ring is The inner ring can be assembled by penetrating the inner diameter of the inner ring in a state where the diameter is reduced to be smaller than the inner diameter of the inner ring.

  Further, as in the invention described in claim 6, if the width of the connecting ring is set larger than the groove width of the locking groove of the inner ring, the locking groove is assembled when the connecting ring is assembled to the pair of inner rings. Can prevent you from falling in.

  Moreover, if the height of the collar part of the said connection ring is set smaller than the depth of the locking groove of the said inner ring like invention of Claim 7, the cylindrical part of a connection ring will be after assembly | attachment. Since the inner ring is in close contact with the mounting portion of the inner ring while being elastically contacted, it is possible to easily assemble the wheel bearing without correcting the misalignment of the pair of inner rings by the connection ring and without the connection ring interfering with the axle tube.

  Further, as in the invention according to claim 8, a chamfered portion having a predetermined inclination angle is formed at a corner portion between the inner diameter of the inner ring and the locking groove, and a predetermined inclination is provided at an end portion of the axle tube. If chamfered portions having corners are formed and the inclination angles of these chamfered portions are set in the range of 25 to 35 °, the end portion of the axle tube can be used even if a misalignment occurs between the pair of inner rings during assembly. Since the radial component of the contact force becomes larger than the axial component due to the contact with, the misalignment can be automatically corrected, and the assemblability can be further improved.

  Further, as in the invention described in claim 9, if the connecting ring is formed by pressing from a steel plate and the surface is subjected to hardening treatment in the range of 40 to 55 HRC by tempering or quenching, the desired ring is obtained. Strength can be secured.

  According to a tenth aspect of the present invention, the wheel bearing comprises a double-row tapered roller bearing, the hub wheel is connected to a flange of the drive shaft via a hub bolt, and the wheel bearing If the outer ring is fixed in the axial direction while being sandwiched between the flange and the brake rotor, it is possible to reduce the weight and size.

  A wheel bearing device according to the present invention includes an axle tube through which a drive shaft connected to a differential is inserted, a wheel mounting flange for mounting a wheel on the outer periphery, and a hub wheel connected to the drive shaft. A wheel bearing device comprising a wheel bearing mounted between the hub wheel and a shaft portion of the axle tube and rotatably supporting the wheel, wherein the wheel bearing comprises the hub wheel. An outer ring in which a double row outer rolling surface is integrally formed on the inner periphery and an inner rolling surface facing the double row outer rolling surface is formed on the outer periphery. A pair of inner rings integrally connected by a connecting ring mounted on the inner periphery of the inner ring, and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner ring and the outer ring. In the bearing device, the inner diameter of the inner ring on the outer side of the pair of inner rings has an inner diameter. Is set to be smaller than the inner diameter of the inner ring on the side, and the outer diameter on the outer side of the shaft portion of the axle tube is set to be smaller than the outer diameter on the inner side, through a uniform radial clearance in the axial direction. Since the pair of inner rings are loosely fitted, the wheel bearing can be easily fitted into the axle tube even if the pair of inner rings is misaligned in the vehicle assembly process. An improved wheel bearing device can be provided.

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 wheel bearing of FIG. 1, (b) is a principal part enlarged view which shows an axle tube. (A) is a longitudinal cross-sectional view which shows the connection ring which concerns on this invention, (b) is a front view of (a). (A) is an expanded sectional view of Fig.3 (a), (b) is a principal part enlarged view of the inner ring | wheel of Fig.2 (a). It is explanatory drawing which shows the relationship between an inner ring | wheel and an axle tube. (A) is a principal part enlarged view which shows the modification of FIG. 2, (b) is a principal part enlarged view which shows an axle tube same as the above. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

  An axle tube through which a drive shaft connected to the differential is inserted, a wheel mounting flange for mounting a wheel on the outer periphery, and a hub wheel connected to the drive shaft, and the hub wheel and the shaft of the axle tube A wheel bearing device that is mounted between the hub wheel and a wheel bearing that rotatably supports the wheel, wherein the wheel bearing is press-fitted into an inner diameter of the hub wheel and is An outer ring in which the outer rolling surface of the row is formed integrally, and an inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a connecting ring attached to the inner circumference of the front side end portion A wheel bearing device comprising a pair of integrally connected inner rings, and a double row rolling element that is rotatably accommodated between the rolling surfaces of the inner ring and the outer ring. The inner diameter of the inner ring on the outer side is set smaller than the inner diameter of the inner ring on the inner side. And the outer diameter of the outer side of the shaft portion of the axle tube is set smaller than the outer diameter of the inner side, and the pair of inner rings are loosely fitted through a uniform radial clearance in the axial direction. In addition, the connection ring includes a cylindrical portion and a flange portion extending radially outward from both ends of the cylindrical portion, and a cross-section having a notch portion having a predetermined notch angle in a natural state is substantially U-shaped. A ring-shaped locking groove on the inner periphery of the front side end of the inner ring, and a cylindrical mounting portion extending from the locking groove to the front side end surface. The inner diameter of the inner ring is set larger than the inner diameter of the inner ring by the thickness of the connecting ring.

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 (a) is a longitudinal sectional view showing the wheel bearing, and FIG. 1 (b) is a main portion showing an axle tube. 3A is a longitudinal sectional view showing a connecting ring according to the present invention, FIG. 3B is a front view of FIG. 4A, and FIG. 4A is an enlarged sectional view of FIG. FIGS. 5A and 5B are enlarged views of the main part of the inner ring in FIG. 2A, FIG. 5 is an explanatory view showing the relationship between the inner ring and the axle tube, and FIG. (B) is a principal part enlarged view which shows an axle tube same as the above. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  In this wheel bearing device, a drive shaft 2 connected to a differential (not shown) is inserted into an axle tube 1, and a wheel bearing 3 comprising a double row tapered roller bearing on the outer diameter surface of the axle tube 1. Is installed. A hub wheel 4 rotatably supported by the wheel bearing 3 is connected to a flange 6 of the drive shaft 2 via a hub bolt 5. A pair of inner rings 7, 8 of the wheel bearing 3 are coupled by a connecting ring 9, are fitted on the shaft portion of the axle tube 1, and are fastened and fixed by a fixing nut 10. Further, the outer ring 11 of the wheel bearing 3 is fitted in the hub ring 4 and is fixed in the axial direction with both ends sandwiched between the flange 6 and the brake rotor 12.

  An annular step 13 is formed on the inner periphery of the inner ring 8 on the inner side of the pair of inner rings 7, 8, and a seal ring 14 made of an elastic member is attached. An annular recess 15 is formed on the outer peripheral surface of the butted portion of the pair of inner rings 7 and 8, and a seal ring 16 made of an elastic member is attached to the annular recess 15. This prevents muddy water from entering the axle tube 1 from the outside and leakage of the differential oil to the outside, and prevents the differential oil from entering the bearing.

  On the other hand, the wheel bearing 3 has an outer ring 11 formed with double-row tapered outer rolling surfaces 11a and 11a that are opened outward on the inner periphery, as shown in FIG. A pair of inner races 7 and 8 that are inserted into the outer race 11 and formed with tapered inner raceway surfaces 7a and 7a facing the double row outer raceway surfaces 11a and 11a on the outer periphery, and both raceway surfaces It has double row rolling elements (conical rollers) 17, 17 accommodated between them, and a retainer 18 that holds these double row rolling elements 17, 17 in a rollable manner. A pair of inner rings 7, 8 is formed with a large collar 7 b at the large diameter side (back side) end portion to guide the rolling elements 17. The pair of inner rings 7 and 8 are set in a state where the front side (small diameter side) end faces thereof are abutted with each other, thereby forming a so-called back-to-back type double row tapered roller bearing. Seals 19 and 19 are attached to the opening of the annular space formed between the outer ring 11 and the pair of inner rings 7 and 8, and leakage of lubricating grease sealed inside the bearing to the outside, rainwater and Dust and the like are prevented from entering the bearing.

  The outer ring 11, the inner rings 7 and 8, and the rolling element 17 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. In addition, although the wheel bearing 3 which consists of the double row tapered roller bearing which used the rolling element 17 as the tapered roller was illustrated here, it is comprised not only in this but the double row angular ball bearing which uses the ball for the rolling element. Also good.

  Here, in this embodiment, the inner diameter Do of the inner ring 7 on the outer side of the wheel bearing 3 is set to be smaller than the inner diameter Di of the inner ring 8 on the inner side (Do <Di). On the other hand, as shown in (b), an annular groove 20 is formed with a slight depth at a substantially central portion in the axial direction of the shaft portion 1 a of the axle tube 1, and the inner rings 7, 8 are sandwiched between the annular grooves 20. The outer diameter So on the outer side of the shaft portion 1a to be inserted is set smaller than the outer diameter Si on the inner side (So <Si) and loosely fitted through a uniform radial clearance in the axial direction. . As a result, in the vehicle assembly process, even if a misalignment occurs in the pair of inner rings 7, 8, the wheel bearing 3 can be easily fitted into the axle tube 1, thereby improving the assembly workability. A bearing device can be provided.

  The connecting ring 9 that integrally couples the pair of inner rings 7 and 8 is a steel plate having rust prevention ability, such as an austenitic stainless steel plate (JIS standard SUS304), a ferritic stainless steel plate (JIS standard SUS430). Etc.), or steel plates such as tool steel and spring steel, which are formed by press working, and are composed of a ring with a substantially U-shaped cross section, and the surface is hardened in the range of 40 to 55 HRC by tempering or quenching. Processing has been applied. Thereby, desired intensity | strength (shearing force) is securable. And as shown in FIG. 3, it has the cylindrical part 9a and the collar parts 9b and 9b extended radially outward from both ends of this cylindrical part 9a, and has the notch part 9c of the predetermined notch angle (alpha) in a natural state. The inner diameter d of the cylindrical portion 9a is set to be larger than the inner diameters Do and Di of the inner rings 7 and 8 (d> Di> Do). Thereby, even if the misalignment occurs in the pair of inner rings 7 and 8 due to the elasticity of the connecting ring 9 at the time of assembly, it can be corrected.

  Here, since the connecting ring 9 is assembled through the inner diameters Do and Di of the inner rings 7 and 8, it is necessary to reduce the diameter so as to be smaller than the inner diameters Do and Di of the inner rings 7 and 8. Therefore, when the height of the flange 9b of the connecting ring 9 is h, the outer peripheral length of the connecting ring 9 is set smaller than the inner peripheral lengths of the inner diameters Do and Di of the inner rings 7 and 8. That is, the notch angle α is set so as to satisfy the relationship of πDi> πDo> π (d + 2h) (360−α) / 360.

  4 (a) and 4 (b), annular locking grooves 21 and 21 to which the connecting ring 9 is attached are formed on the inner periphery of the front side end portions of the inner rings 7 and 8, and these are formed. A cylindrical mounting portion 22 is formed from the locking grooves 21 and 21 to the front side end surfaces 7c and 7c. The inner diameter D0 of the mounting portion 22 is set larger than the inner diameters Do and Di of the inner rings 7 and 8 so that the connecting ring 9 protrudes from the inner diameters of the inner rings 7 and 8 after mounting and does not interfere with the axle tube 1 during assembly. ing. Specifically, D0> Di + 2t> Do + 2t, where t is the thickness of the connecting ring 9.

  Further, the width W of the connecting ring 9 is set to be larger than the groove width Wg of the locking groove 21 (W> Wg), and the heights h of the flange portions 9 b and 9 b of the connecting ring 9 are It is set smaller than the depth Gd (h <Gd). This prevents the connecting ring 9 from falling into the locking groove 21 when assembled to the pair of inner rings 7, 8, and after assembly, the cylindrical portion 9 a is in elastic contact with the mounting portion 22 of the inner rings 7, 8. Since they are in close contact with each other, the wheel bearing 3 can be easily assembled without correcting the misalignment of the pair of inner rings 7 and 8 with the connecting ring 9 and without the connecting ring 9 interfering with the axle tube 1.

  Further, as shown in FIG. 5, a chamfered portion 23 having a predetermined inclination angle β1 is formed at a corner portion between the inner diameter of the inner rings 7 and 8 and the locking groove 21, and a predetermined portion is provided at the end portion 1c of the axle tube 1. A chamfer 24 having an inclination angle β2 is formed. And inclination angle (beta) 1, (beta) 2 of these chamfering parts 23 and 24 is set to the range of 25-35 degrees. As a result, even if a misalignment occurs between the pair of inner rings 7 and 8 during assembly, the radial component of the contact force is greater than the axial component due to contact with the end 1c of the axle tube 1. Therefore, the misalignment can be corrected and the assemblability can be further improved. Note that when the inclination angles β1 and β2 of the chamfered portions 23 and 24 are less than 25 °, the fitting width of the inner rings 7 and 8 decreases, and when it exceeds 35 °, the radial component of the contact force becomes small and the insertion is reduced. It is not preferable because the properties deteriorate.

  FIG. 6 is an enlarged view of a main part showing a modification of FIG. As shown to (a), the internal diameter of a pair of inner ring | wheels 7 'and 8' is formed in the taper shape which diameter-reduces gradually toward an outer side. On the other hand, as shown in (b), the outer diameter of the shaft portion 1a ′ of the axle tube 1 ′ is also formed in a tapered shape having an inclination angle γ that gradually decreases toward the outer side, and has a uniform diameter in the axial direction. Loose fit through the directional clearance. Here, the inclination angles γo and γi of the inner diameters of the pair of inner rings 7 ′ and 8 ′ and the inclination angle γ of the outer diameter of the shaft portion 1a ′ are set to be substantially equal (γo≈γi≈γ), and the inner ring on the outer side is set. 7 ′ maximum inner diameter Domax. Is the minimum inner diameter Dimin. Of the inner ring 8 'on the inner side. Is set to be approximately equal to (Domax.≈Dimin.). As a result, in the vehicle assembly process, even if the pair of inner rings 7 ′ and 8 ′ are misaligned, they can be easily fitted into the axle tube 1 ′, and the assembly workability can be improved. The inclination angle γ (≈γi≈γo) is set in a range of 1 to 3 °.

  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. 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 full floating type wheel bearing device on the side of a driving wheel in which wheel bearings are mounted in openings of a driving shaft and an axle tube.

DESCRIPTION OF SYMBOLS 1, 1 'Axle tube 1a, 1a' Shaft part 1b Shoulder part 1c End part 2 Drive shaft 3 Wheel bearing 4 Hub wheel 5 Hub bolt 6 Drive shaft flange 7, 7 'Outer side inner ring 7a Inner rolling surface 7b Large鍔 7 c Front side end faces 8, 8 ′ Inner side inner ring 9 Connecting ring 10 Fixing nut 11 Outer ring 11 a Outer rolling surface 12 Brake rotor 13 Annular steps 14, 16 Seal ring 15 Annular recess 17 Rolling body 18 Cage 19 Seal 20 Annular groove 21 Locking groove 22 Mounting portion 23 Chamfered portion of inner ring inner diameter 24 Chamfered portion of shoulder of axle tube 51 Axle tube 52 Drive shaft 53 Double row tapered roller bearing 54 Hub wheel 55 Hub bolt 56 Flange 57 Inner ring 58 Connecting ring 59 Fixing nut 60 Outer ring 61 Brake rotor 62 Tapered roller 63 Cage 64 Seal 65 Annular step 66, 68 Seal ring D Inner ring inner diameter D0 Inner ring mounting portion Inner diameter Di Inner inner diameter of inner ring Do Outer inner diameter of inner ring Dimin. The minimum inner diameter Domax. Maximum inner diameter Gd of inner ring on the outer side Depth of locking groove h Height of flange of connecting ring Si Outer diameter of shaft inner side So Outer diameter of shaft outer side t Thickness W of connecting ring Ring width Wg Groove width of locking groove α Notch angles β1, β2 Chamfered portion inclination angle γ Shaft outer diameter inclination angle γo, γi Inner ring inner diameter inclination angle

Claims (10)

An axle tube through which a drive shaft connected to the differential is inserted;
A hub wheel integrally having a wheel mounting flange for mounting a wheel on the outer periphery, and connected to the drive shaft;
A wheel bearing device comprising a wheel bearing mounted between the hub wheel and a shaft portion of the axle tube and rotatably supporting the wheel,
This wheel bearing is press-fitted into the inner diameter of the hub wheel, and an outer ring in which a double row outer rolling surface is integrally formed on the inner periphery,
A pair of inner rings integrally formed by a connecting ring attached to the inner periphery of the front side end portion is formed with an inner rolling surface facing the outer rolling surface of the double row on the outer periphery,
In a wheel bearing device comprising a double-row rolling element housed in a freely rolling manner between both rolling surfaces of the inner ring and the outer ring,
Of the pair of inner rings, the inner diameter of the inner ring on the outer side is set smaller than the inner diameter of the inner ring on the inner side, and the outer diameter on the outer side of the shaft portion of the axle tube is smaller than the outer diameter on the inner side. A wheel bearing device, wherein the pair of inner rings are loosely fitted through a set radial gap that is uniform in the axial direction.   The inner diameter of the pair of inner rings is formed in a tapered shape that gradually decreases toward the outer side, and the maximum inner diameter of the inner ring on the outer side is set to be approximately equal to the minimum inner diameter of the inner ring on the inner side. The wheel bearing device according to claim 1, wherein an outer diameter of a shaft portion of the axle tube is formed in a tapered shape that gradually decreases toward the outer side.   The connecting ring includes a cylindrical portion and a flange portion extending radially outward from both ends of the cylindrical portion, and has a substantially U-shaped cross section having a notch portion having a predetermined notch angle in a natural state. The wheel bearing device according to claim 1 or 2, comprising an end ring, wherein an inner diameter of the cylindrical portion is set larger than an inner diameter of the inner ring.   An annular locking groove is formed on the inner periphery of the front end portion of the inner ring, and a cylindrical mounting portion is formed from the locking groove to the front end surface. The inner diameter of the mounting portion is the inner diameter of the inner ring. 4. The wheel bearing device according to claim 3, wherein the diameter of the connecting ring is set to be larger by the thickness of the connecting ring.   When the height of the flange portion of the connecting ring is h, the inner diameter of the cylindrical portion is d, and the inner diameter of the inner ring is D, the outer peripheral length π (d + 2h) (360−α) / 360 of the connecting ring is The wheel bearing device according to claim 3 or 4, wherein a notch angle α of the connecting ring is set so as to be smaller than an inner peripheral length πD of an inner diameter of the inner ring.   The wheel bearing device according to claim 4 or 5, wherein a width of the connecting ring is set larger than a groove width of the locking groove of the inner ring.   The wheel bearing device according to any one of claims 4 to 6, wherein a height of the flange portion of the connection ring is set to be smaller than a depth of the locking groove of the inner ring.   A chamfered portion having a predetermined inclination angle is formed at a corner portion between the inner diameter of the inner ring and the locking groove, and a chamfered portion having a predetermined inclination angle is formed at an end portion of the axle tube. The wheel bearing device according to any one of claims 4 to 7, wherein the inclination angle is set in a range of 25 to 35 °.   The wheel bearing device according to any one of claims 1 to 8, wherein the connection ring is formed by pressing from a steel plate, and the surface is subjected to hardening treatment in a range of 40 to 55 HRC by tempering or quenching.   The wheel bearing comprises a double-row tapered roller bearing, the hub wheel is connected to a flange of the drive shaft via a hub bolt, and an outer ring of the wheel bearing is sandwiched between the flange and a brake rotor. The wheel bearing device according to claim 1, wherein the wheel bearing device is fixed in an axial direction in a state.

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