JP2012206641A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and compact bearing device for a wheel, which reduces machining man-hour to simplify assembly and disassembly, thereby reducing cost.SOLUTION: The bearing device for a wheel includes: face splines 19a and 13 formed at a shoulder part 19 of an outer joint member 14 and an inner member 8 respectively; both face splines 19a and 13 pressed and supported by a fixing nut 22 which abuts on an end face of a hub wheel 1 and is screwed in a male screw 20a of a shaft part 20. In the bearing device, the face spline 13 is formed in an end face of an inner ring 5, the inner ring 5 is pressed into a small-diameter step part 1b of the hub wheel 1 with a predetermined interference, and a serration 21 which is hardened by induction hardening is formed in the small-diameter step part 1b, while an inner peripheral face of the inner ring 5 is not hardened and forms a flat face, and the inner face is cut and densely fit by the serration 21 for integrally press-cut fitting the hub wheel 1 and the inner ring 5.

Description

  The present invention relates to a wheel bearing device for supporting a wheel of a vehicle such as an automobile, and more specifically, a drive wheel (a front wheel of an FF vehicle, FR) provided with a wheel bearing and a constant velocity universal joint and mounted on an independent suspension type suspension. The present invention relates to a wheel bearing device that rotatably supports a rear wheel of a car or an RR car and all wheels of a 4WD car) with respect to a suspension device.

  A power transmission device that transmits engine power of a vehicle such as an automobile to a wheel transmits power from the engine to the wheel, and also causes radial or axial displacement from the wheel that occurs when the vehicle bounces or turns when traveling on a rough road. For example, one end of the drive shaft interposed between the engine side and the drive wheel side is connected to the differential through a sliding type constant velocity universal joint, and the like. The end is connected to the drive wheel via a wheel bearing device including a fixed type constant velocity universal joint.

  Various types of wheel bearing devices have been proposed in the past, and for example, those shown in FIG. 5 are known. The wheel bearing device 50 is connected to a hub wheel 51 for mounting a wheel (not shown) at one end, a double row rolling bearing 52 for rotatably supporting the hub wheel 51, and the hub wheel 51. A fixed type constant velocity universal joint 53 that transmits power of a drive shaft (not shown) to the hub wheel 51 is provided.

  The hub wheel 51 integrally has a wheel mounting flange 54 for mounting a wheel at one end, an inner rolling surface 51a on the outer periphery, and a cylindrical small-diameter step portion 51b extending in the axial direction from the inner rolling surface 51a. Is formed. The double-row rolling bearing 52 has a vehicle body mounting flange 55b integrally fixed to a suspension device (not shown) on the outer periphery, and an outer side in which double-row outer rolling surfaces 55a and 55a are formed on the inner periphery. It comprises a member 55 and an inner member 57 inserted into the outer member 55 via double rows of balls 56.

  The inner member 57 includes a hub wheel 51 and a separate inner ring 58 that is press-fitted into the small-diameter step portion 51b of the hub wheel 51 and has an inner rolling surface 58a formed on the outer periphery. The inner ring 58 is fixed to the hub wheel 51 in the axial direction by a caulking portion 51 c formed by plastically deforming the end portion of the small-diameter stepped portion 51 b of the hub wheel 51 radially outward.

  The constant velocity universal joint 53 includes an outer joint member 62 integrally including a cup-shaped mouth portion 59, a shoulder portion 60 that forms the bottom of the mouth portion 59, and a shaft portion 61 that extends from the shoulder portion 60 in the axial direction. The outer joint member 62 is fitted into the hub wheel 51 so that torque can be transmitted. That is, the female serration 63 is formed on the inner periphery of the hub wheel 51, and the male serration 64 is formed on the outer periphery of the shaft portion 61 of the outer joint member 62, and both the serrations 63 and 64 are engaged with each other. The shaft portion 61 of the outer joint member 62 is fitted into the hub wheel 51 until the shoulder portion 60 is abutted against the caulking portion 51 c of the hub wheel 51, and the male screw 65 formed at the end of the shaft portion 61. The fixing nut 66 is fastened with a predetermined tightening torque, and the hub wheel 51 and the outer joint member 62 are detachably coupled in the axial direction.

  It is known that a large torque is applied to the wheels of the vehicle from the engine via a sliding type constant velocity universal joint (not shown) when the engine rotates at a low speed, for example, when the vehicle starts, and the drive shaft is twisted. It has been. As a result, the inner member 57 of the double row rolling bearing 52 that supports the drive shaft is also twisted. Thus, when a large twist occurs in the drive shaft, a stick-slip sound due to a sudden slip is generated on the contact surface between the outer joint member 62 and the inner member 57.

  As a countermeasure, in the conventional wheel bearing device 50, a portion that contacts the shoulder portion 60 of the outer joint member 62, that is, a caulking portion 51c of the hub wheel 51 is formed on a flat surface, as shown in FIG. As described above, the concave groove 67 is formed in the central portion in the radial direction of the flat surface of the caulking portion 51c. Then, grease is filled in the concave groove 67. Since the friction coefficient of the contact surface can be lowered by this grease, the friction energy of the contact surface is reduced, and a stick-slip sound due to a sudden slip is generated on the contact surface between the shoulder portion 60 and the caulking portion 51c. Can be prevented (see, for example, Patent Document 1).

JP 2003-136908 A

  However, in such a conventional wheel bearing device 50, since the driving force is transmitted by the female serration 63 formed on the inner periphery of the hub wheel 51, the fitting distance of the female serration 63 is increased, and the assembly workability is increased. There was a problem that the man-hour of broaching for forming the female serration 63 was increased and the manufacturing cost was increased as well as decreasing.

  The present invention has been made in view of such circumstances, and provides a wheel bearing device that is light and compact, reduces the number of processing steps, simplifies assembly and disassembly, and reduces costs. The purpose is to do.

  In order to achieve the object, the invention according to claim 1 of the present invention is a wheel bearing device in which a double row rolling bearing and a constant velocity universal joint are detachably unitized, and the double row rolling device is provided. An outer member in which a bearing integrally has a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and a double row outer rolling surface is integrally formed on the inner periphery, and a wheel for mounting the wheel on one end. A hub having a mounting flange integrally and having an inner rolling surface facing the outer rolling surface of the double row on the outer periphery and a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface. An inner member comprising a ring and a cylindrical inner ring member which is fitted to the hub wheel and has an outer periphery formed with the other inner rolling surface opposed to the outer rolling surface of the double row, and the inner member And a double row rolling element housed between the rolling surfaces of the outer member so as to freely roll. The constant velocity universal joint includes a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and a shaft portion that extends in the axial direction from the shoulder portion and has an external thread formed at the end portion. The outer joint member has a face spline formed on the shoulder portion of the outer joint member and the inner member, and the shaft portion is press-fitted into the inner peripheral surface of the inner member through a predetermined shimiro. The face splines are pressed against and supported by a fixing nut that is in contact with the end face of the hub wheel and screwed to the male screw of the shaft portion, so that torque can be transmitted between the double row rolling bearing and the constant velocity universal joint. In the wheel bearing device coupled in an axially separable manner, a face spline is formed on an end surface of the inner ring member, and the inner ring member is press-fitted into the hub ring via a predetermined shimoshiro. A serration that is hardened by induction hardening is formed on the mating surface of one member of the surfaces, and the mating surface of the other member is unquenched to be a flat surface, and the serration is processed by the serration. The hub ring and the inner ring member are integrally press-cut joined while closely fitting with each other.

  In this way, face splines are formed on the shoulder portion and the inner member of the outer joint member, respectively, and the shaft portion is press-fitted into the inner peripheral surface of the inner member via a predetermined shimoshiro to contact the end surface of the hub wheel. Both face splines are pressed against and supported by a fixed nut screwed to the male screw of the shaft, and the double row rolling bearing and the constant velocity universal joint are coupled to be able to transmit torque and to be separated in the axial direction. In the wheel bearing device, a face spline is formed on the end surface of the inner ring member, the inner ring member is press-fitted into the hub ring via a predetermined shimoshiro, and one of these fitting surfaces is induction-quenched into the fitting surface of one member. A hardened serration is formed, and the mating surface of the other member is unquenched to be a flat surface. The wheel ring and inner ring member are press-cut joined together, providing a wheel bearing device that is lighter and more compact, reduces processing steps, simplifies assembly and disassembly, and reduces costs. can do.

  Preferably, as in the invention according to claim 2, if the serration is formed on a fitting surface of a member located radially inward among the fitting surfaces of the hub wheel and the inner ring member, press cut The cut residue generated at the time of joining can be discharged without accumulating between the fitting surfaces.

  Further, as in the invention according to claim 3, the inner ring member is externally fitted to the small-diameter step portion of the hub wheel, and the inner ring member is made of medium to high carbon steel containing carbon 0.40 to 0.80 wt%, At least the inner rolling surface and the face spline are hardened by induction hardening to a surface hardness in the range of 58 to 64 HRC, and the inner peripheral surface of the inner ring member is left with the material hardness after forging. May be.

  According to a fourth aspect of the present invention, the inner ring member is integrally formed with a cylindrical portion extending in the axial direction from the inner rolling surface, and the cylindrical portion is fitted into the inner peripheral surface of the hub wheel. May be.

  Further, as in the invention described in claim 5, the inner ring member is made of medium-high carbon steel containing carbon of 0.40 to 0.80 wt%, and is surfaced by induction hardening over the cylindrical portion from the inner rolling surface. Hardening may be performed in the range of 58 to 64 HRC hardness.

  Further, as in the invention described in claim 6, the inner ring member may be formed of high carbon chrome bearing steel, and may be hardened in a range of 60 to 64 HRC up to the core part by quenching.

  Moreover, if the face spline of the said inner ring member is formed simultaneously by the cold forging of the said inner ring member like invention of Claim 7, the yield of a raw material can be improved.

  Moreover, if the said inner ring member is tempered after forging like invention of Claim 8, low hardness and high toughness are securable.

  In addition, as in the ninth aspect of the present invention, if the tip of the serration is formed at the edge, the serration can be closely fitted to the other fitting surface while cutting.

  A wheel bearing device according to the present invention is a wheel bearing device in which a double-row rolling bearing and a constant velocity universal joint are detachably unitized, and the double-row rolling bearing is attached to a vehicle body on the outer periphery. A body mounting flange for integrally mounting, an outer member in which a double row outer rolling surface is formed integrally on the inner periphery, and a wheel mounting flange for mounting a wheel on one end of the body. A hub ring formed with one inner rolling surface facing the outer rolling surface of the double row, a cylindrical small diameter step portion extending in the axial direction from the inner rolling surface, and fitted to the hub wheel An inner member formed of a cylindrical inner ring member formed on the outer periphery with the other inner rolling surface facing the double row outer rolling surface, and both rolling of the inner member and the outer member. And a double row rolling element housed between the faces so as to be freely rollable. Is provided with an outer joint member integrally having a cup-shaped mouse part, a shoulder part forming the bottom part of the mouse part, and a shaft part extending in an axial direction from the shoulder part and having an external thread formed at an end part thereof, Face splines are formed on the shoulder portion of the outer joint member and the inner member, respectively, and the shaft portion is press-fitted into the inner peripheral surface of the inner member via a predetermined shimoshiro, and the end surface of the hub wheel is Both face splines are pressed against and supported by a fixing nut that is abutted and screwed onto the male screw of the shaft, so that the double row rolling bearing and the constant velocity universal joint can transmit torque and can be separated in the axial direction. In the combined wheel bearing device, a face spline is formed on an end surface of the inner ring member, the inner ring member is press-fitted into the hub ring through a predetermined shimiro, and one of the fitting surfaces is fitted. Together A serration that has been hardened by induction hardening is formed, and the fitting surface of the other member is unquenched to be a flat surface, and this fitting surface is closely fitted while the serration is being cut to form the hub wheel. Since the inner ring member and the inner ring member are press-cut joined together, it is possible to provide a wheel bearing device that is lighter and more compact, reduces the number of processing steps, simplifies assembly and disassembly, and reduces costs. Can do.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. (A) is a longitudinal cross-sectional view which shows the bearing part of FIG. 1, (b) is a side view of (a). It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. (A) is a longitudinal cross-sectional view which shows the bearing part of FIG. 3, (b) is a side view of (a). It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is an AA arrow line view of FIG.

  A wheel bearing device in which a double-row rolling bearing and a constant velocity universal joint are detachably unitized, and the double-row rolling bearing integrally has a vehicle body mounting flange for mounting to a vehicle body on the outer periphery. The outer member integrally formed with the outer circumferential surface of the double row on the inner periphery, and the wheel mounting flange for attaching the wheel to one end of the outer member, and the outer rolling surface of the double row on the outer periphery. One opposite inner rolling surface, a hub wheel formed with a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface, and a small-diameter step portion of the hub wheel are externally fitted to the outer periphery of the hub wheel. An inner member formed of an inner ring formed with the other inner rolling surface facing the outer rolling surface of the row, and is accommodated in a freely rollable manner between both rolling surfaces of the inner member and the outer member. A double row rolling element, and the constant velocity universal joint includes a cup-shaped mouth portion, An outer joint member integrally including a shoulder portion forming a bottom portion of the usus portion and a shaft portion extending in an axial direction from the shoulder portion and having an external thread formed at the end portion; and the shoulder portion of the outer joint member and the inner portion Each side member has a face spline, and the shaft portion is press-fitted into the inner peripheral surface of the inner member through a predetermined squeeze, abutting against the end surface of the hub wheel, and screwed into the male screw of the shaft portion. In the wheel bearing device in which both the face splines are pressed and supported by a fixed nut attached, and the double row rolling bearing and the constant velocity universal joint are coupled to be able to transmit torque and to be separated in the axial direction. A face spline is formed on the end face of the inner ring, and a serration with an edge at the tip is formed on the small-diameter step portion of the hub ring, and the inner peripheral surface of the inner ring is not hardened. In a flat plane, the hub wheel and the inner ring of this fitting face the serrations are contact-fitted with cutting is pressed cut bonded together.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is a longitudinal sectional view showing a bearing portion of FIG. 1, and (b) is (a). FIG. 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).

  This wheel bearing device has a so-called third generation configuration in which the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 are detachably unitized.

  The double-row rolling bearing 2 includes an outer member 7, an inner member 8, and double-row rolling elements (balls) 9 and 9. This outer member 7 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 7b for mounting to a vehicle body (not shown) on the outer periphery. Double row outer rolling surfaces 7a, 7a are formed. Then, at least the double row outer raceway surfaces 7a and 7a are subjected to a hardening process in a range of 58 to 64 HRC by induction hardening.

  On the other hand, the inner member 8 is formed with double-row inner rolling surfaces 1a and 5a facing the outer rolling surfaces 7a and 7a of the outer member 7 described above. Of these double-row inner rolling surfaces 1a, 5a, one (outer side) inner rolling surface 1a is on the outer periphery of the hub wheel 1, and the other (inner side) inner rolling surface 5a is on the outer periphery of the inner ring 5, respectively. It is integrally formed. In this case, the inner member 8 refers to the hub wheel 1 and the inner ring 5. And the double row rolling elements 9 and 9 are accommodated between these both rolling surfaces, respectively, and are hold | maintained by the holder | retainers 10 and 10 so that rolling is possible. Further, seals 11 and 12 are attached to the opening portion of the annular space formed between the outer member 7 and the inner member 8, and leakage of the lubricating grease sealed inside the bearing and the inside of the bearing from the outside. Prevents intrusion of rainwater and dust.

  The hub wheel 1 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end portion on the outer side, and a cylindrical small diameter step portion 1b extending in the axial direction from the inner rolling surface 1a on the outer periphery. And the inner ring 5 is fixed to the small diameter step portion 1b. Hub bolts 6 for fastening the wheels are arranged in the circumferential direction of the wheel mounting flange 4 at equal intervals.

  The hub wheel 1 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes an inner rolling surface 1a and an inner side of a wheel mounting flange 4 serving as a seal land portion of an outer seal 11. The outer peripheral surface extending from the base 4a to the small-diameter step 1b is hardened by induction hardening to a surface hardness of 58 to 64 HRC. Moreover, the rolling element 9 consists of high carbon chromium bearing steels, such as SUJ2, and is hardened in the range of 60-64 HRC to the core part by submerged hardening. In addition, although the double row angular contact ball bearing which used the ball for the rolling element 9 was illustrated here, not only this but the double row tapered roller bearing which used the tapered roller for the rolling element 9 may be sufficient.

  The constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring 15, a cage 16 and a torque transmission ball 17. The outer joint member 14 has a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom of the mouth portion 18, and a shaft portion 20 that extends in the axial direction from the shoulder portion 19. Curved track grooves 18a and 15a extending in the axial direction are formed on the outer periphery of the joint inner ring 15, respectively. A male screw 20 a is formed on the shaft portion 20, and a face spline 19 a is formed on the end surface of the shoulder portion 19. This outer joint member 14 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and has a surface hardness by induction hardening on the outer peripheral surface extending from the shoulder portion 19 to the shaft portion 20 including the track groove 18a. Is cured in the range of 58 to 64 HRC.

  In this embodiment, as shown in FIG. 2A, the face spline 13 that meshes with the face spline 19a formed on the shoulder portion 19 of the outer joint member 14 is formed on the end surface of the inner ring 5 by plastic working. Yes. The inner ring 5 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the inner rolling surface 5a and the face spline 13 are hardened to a surface hardness of 58 to 64 HRC by induction hardening. It has been subjected. Note that the inner peripheral surface 5b is kept in the material hardness after forging.

  Here, serrations (or splines) 21 hardened by induction hardening are formed on the outer periphery of the small-diameter step portion 1b of the hub wheel 1 to which the inner ring 5 is fitted. Then, the inner ring 5 is fitted into the small-diameter step portion 1b of the hub wheel 1 through a predetermined shimiro, and the serration 21 is closely fitted to the inner peripheral surface 5b of the unquenched inner ring 5 so that the hub ring 1 and the inner ring 5 are fitted. Are joined together, so-called press cut joining.

  Here, by forming the tip of the serration 21 of the small-diameter step portion 1b of the hub wheel 1 at the edge, the serration 21 can be closely fitted to the inner peripheral surface 5b of the inner ring 5 while being easily cut, Cut waste generated during press-cut joining can be discharged to the inner side without accumulating between the small-diameter step portion 1b and the inner ring 5. By adopting such press-cut joining, it is possible to transmit a desired driving force and to prevent loosening of the coupling portion between the hub wheel 1 and the inner ring 5 over a long period of time.

  As shown in FIG. 1, the double-row rolling bearing 2 and the constant velocity universal joint 3 have a shaft portion 20 of the outer joint member 14 fitted into the inner periphery of the hub wheel 1 through a predetermined shimiro. When the fixing nut 22 is screwed onto the male screw 20a of the shaft portion 20, both face splines 19a, 13 facing the shoulder portion 19 of the outer joint member 14 and the inner ring 5 are supported by pressure contact, and are detachably unitized. Has been.

  In the present embodiment, the face spline 13 is formed directly on the end surface of the inner ring 5, and further, the inner ring 5 and the hub wheel 1 are press-cut joined so that driving force can be transmitted. As a result, it is possible to provide a wheel bearing device that can be remarkably simplified, reduced in weight and size, and reduced in processing man-hours to reduce costs.

  FIG. 3 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 4A is a longitudinal sectional view showing the bearing portion of FIG. 3, and FIG. FIG. This embodiment basically differs from the above-described embodiment only in the configuration of the double-row rolling bearing, and in addition, the same parts, the same parts, or parts or parts having the same functions as the above-described embodiments. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the wheel bearing device has a configuration called a third generation in which a hub wheel 23, a double row rolling bearing 24, and a constant velocity universal joint 3 are detachably unitized.

  The double-row rolling bearing 24 includes an outer member 7, an inner member 25, and double-row rolling elements 9 and 9. The inner member 25 includes a hub wheel 23 and an inner ring member 26 fitted in the hub wheel 23, and the double-row inner rolling surface 1 a facing the outer rolling surfaces 7 a and 7 a of the outer member 7. 5a is formed.

  The hub wheel 23 integrally has a wheel mounting flange 4 at an end portion on the outer side, and a cylindrical small-diameter step portion 23a extending in the axial direction from the inner rolling surface 1a is formed on the outer periphery. The hub wheel 23 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes a base portion on the inner side of the wheel mounting flange 4 slidably in contact with the inner side rolling surface 1 a and the outer side seal 11. The outer peripheral surface extending from 4a to the small-diameter step portion 23a is subjected to a hardening treatment in a range of 58 to 64 HRC by induction hardening.

  The inner ring member 26 is integrally formed with a cylindrical portion 27 extending in the axial direction from the inner rolling surface 5a. The inner ring member 26 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the surface hardness is set to a range of 58 to 64 HRC by induction hardening over the cylindrical portion 27 from the inner rolling surface 5a. A curing process is applied. The inner ring member 26 may be formed of high carbon chrome bearing steel such as SUJ2, and may be hardened in the range of 60 to 64 HRC up to the core portion by quenching.

  Here, as shown in FIGS. 4A and 4B, a face spline 28 is formed on the end face of the inner ring member 26, and meshes with a face spline 19 a formed on the shoulder 19 of the outer joint member 14. . The inner ring member 26 including the face spline 28 is formed by cold forging, but may be tempered (after quenching and then tempered at high temperature) after forging. This tempering treatment can ensure low hardness and high toughness.

  In this embodiment, after the inner ring member 26 is formed by cold forging including the face spline 28, it is turned to a predetermined shape and size, and a predetermined part is heat treated, and then at least inwardly rolled. The running surface 5a is ground.

  Here, a serration (or spline) 29 hardened by induction hardening is formed on the outer periphery of the cylindrical portion 27 of the inner ring member 26. Then, the inner ring member 26 is fitted into the hub ring 23 through a predetermined shimiro, and the serration 29 is closely fitted to the inner peripheral surface 23b of the unquenched hub ring 23 so that the hub ring 23 and the inner ring member 26 are integrated. Is press-cut bonded.

  Here, by forming the tip of the serration 29 in the cylindrical portion 27 of the inner ring member 26 at the edge, the serration 29 can be closely fitted to the inner peripheral surface 23b of the hub ring 23 while being easily cut, Cut residue generated during press-cut joining can be discharged to the outer side without accumulating between the hub wheel 23 and the inner ring member 26. By adopting such press-cut joining, a desired driving force can be transmitted, and loosening of the joint between the hub wheel 23 and the inner ring member 26 can be prevented over a long period of time.

  As shown in FIG. 3, the double row rolling bearing 24 and the constant velocity universal joint 3 are configured such that the shaft portion 20 of the outer joint member 14 is fitted on the inner periphery of the hub wheel 23 via a predetermined shimiro. When the fixing nut 22 is screwed onto the male screw 20a of the shaft portion 20, both the face splines 19a, 28 facing the shoulder portion 19 of the outer joint member 14 and the inner ring member 26 are supported by pressure contact, and are detachably attached. It has become.

  In the present embodiment, the face spline 28 is formed directly on the end face of the inner ring member 26, and further, the inner ring member 26 and the hub ring 23 are press-cut joined so that driving force can be transmitted. In the same manner as above, the assembly with the constant velocity universal joint 3 can be remarkably simplified, and the wheel bearing device can be provided which is reduced in weight and cost while reducing the number of processing steps and reducing the cost.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device in which a double-row rolling bearing having a hub wheel and a constant velocity universal joint are detachably unitized.

1, 23 Hub wheel 1a, 5a Inner rolling surface 1b, 23a Small diameter stepped portion 2, 24 Double row rolling bearing 3 Constant velocity universal joint 4 Wheel mounting flange 4a Inner side base 5 of wheel mounting flange Inner ring 5b Inside of inner ring Peripheral surface 6 Hub bolt 7 Outer member 7a Outer rolling surface 7b Car body mounting flanges 8, 25 Inner member 9 Rolling body 10 Cage 11, 12 Seals 13, 19a, 28 Face spline 14 Outer joint member 15 Joint inner rings 15a, 18a Track groove 16 Cage 17 Torque transmission ball 18 Mouse part 19 Shoulder part 20 Shaft part 21, 29 Serration 20a Male screw 22 Fixing nut 26 Inner ring member 27 Cylindrical part 50 Wheel bearing device 51 Hub wheel 51a, 58a Inner rolling surface 51b Small diameter step Portion 51c Clamping portion 52 Double row rolling bearing 53 Constant velocity universal joint 54 Wheel mounting flange 55 Outer member 5 5a Outer rolling surface 55b Car body mounting flange 56 Ball 57 Inner member 58 Inner ring 59 Mouse part 60 Shoulder part 61 Shaft part 62 Outer joint member 63 Female serration 64 Male serration 65 Male screw 66 Fixed nut 67 Concave groove

Claims (9)

A wheel bearing device in which a double row rolling bearing and a constant velocity universal joint are detachably unitized,
The double-row rolling bearing integrally has a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, and an outer member in which the double-row outer rolling surface is integrally formed on the inner periphery;
A wheel mounting flange for mounting the wheel at one end is integrally formed, one outer side rolling surface facing the outer side rolling surface of the double row on the outer periphery, and a cylindrical shape extending in the axial direction from the inner side rolling surface And a cylindrical inner ring member that is fitted to the hub ring and that has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery. An inner member;
With the inner member and a double row rolling element accommodated between the rolling surfaces of the outer member so as to roll freely,
The constant velocity universal joint includes a cup-shaped mouse part and a shoulder part that forms the bottom of the mouse part,
An outer joint member that extends in an axial direction from the shoulder portion and integrally has a shaft portion having an external thread formed at the end portion,
Face splines are formed on the shoulder of the outer joint member and the inner member, respectively.
The both face splines are pressed against each other by a fixing nut that is press-fitted into the inner peripheral surface of the inner member via a predetermined squeeze and abutted against the end surface of the hub wheel and screwed to the male screw of the shaft portion. In the wheel bearing device that is supported and coupled to the double row rolling bearing and the constant velocity universal joint so that torque can be transmitted and can be separated in the axial direction,
A face spline is formed on the end surface of the inner ring member, the inner ring member is press-fitted into the hub ring via a predetermined shimoshiro, and the fitting surface of one of these fitting surfaces is hardened by induction hardening. The serration is formed and the mating surface of the other member is unquenched to be a flat surface. The serration is closely fitted while the serration is cut, and the hub ring and inner ring member are pressed together. A wheel bearing device characterized by being cut and joined.   The wheel bearing device according to claim 1, wherein the serration is formed on a fitting surface of a member located radially inward of the fitting surfaces of the hub wheel and the inner ring member.   The inner ring member is externally fitted to the small-diameter step portion of the hub wheel, and the inner ring member is made of medium-high carbon steel containing carbon of 0.40 to 0.80 wt%, and at least the inner rolling surface and the face spline are formed by induction hardening. The wheel bearing device according to claim 1 or 2, wherein the surface hardness is set in a range of 58 to 64 HRC, and the inner peripheral surface of the inner ring member is kept in the material hardness after forging. .   3. The wheel according to claim 1, wherein the inner ring member is integrally formed with a cylindrical portion extending in an axial direction from the inner rolling surface, and the cylindrical portion is fitted into an inner peripheral surface of the hub wheel. Bearing device.   The inner ring member is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt%, and the surface hardness is set to a range of 58 to 64 HRC by induction hardening from the inner rolling surface to the cylindrical portion. The wheel bearing device according to claim 4.   The wheel bearing device according to claim 4, wherein the inner ring member is made of high carbon chrome bearing steel and is hardened in a range of 60 to 64 HRC to the core portion by quenching.   The wheel bearing device according to any one of claims 1 to 6, wherein face splines of the inner ring member are simultaneously formed by cold forging of the inner ring member.   The wheel bearing device according to claim 7, wherein the inner ring member is tempered after forging.   The wheel bearing device according to claim 1 or 2, wherein a tip of the serration is formed at an edge.

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