JP2007186109A - Bearing device for wheel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel reduced in weight and size and improved in strength and durability, and its manufacturing method. <P>SOLUTION: In this method, a hardened rugged part 12 is formed on an inner periphery of a hub wheel 1, a fitting part 20b of a shaft part 20 is enlarged in diameter and is bitten into the rugged part 12, and the hub wheel 1 and an outside joint member 14 are integrally and plastically bonded. A coil 24 for heating is interposed into a small diameter step part 1b, a prescribed hardening layer 22 is formed on the inner peripheral surface by high frequency quenching, and a prescribed hardening layer 21 is formed on an outer peripheral surface from an inside rolling face 1a of the hub wheel 1 to the small diameter step part 1b by high frequency quenching in a state for cooling the inner peripheral surface by introducing cooling water into the small diameter step part 1b from a lower side and refluxing the cooling water. As a result, the hardening layer can be easily and exactly controlled to a prescribed hardening layer depth, and the hardening layers 21 and 22 can effectively prevent the small diameter step part 1b from getting out of quenching. <P>COPYRIGHT: (C)2007,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 is reduced in weight and size and improved in strength and durability, and a manufacturing method thereof.

  The wheel bearing device for rotatably supporting the wheel of an automobile or the like is a second generation having a body mounting flange integrally with an outer member from a structure in which a double row rolling bearing called a first generation is used independently. In addition, the third generation in which one inner rolling surface of the double row rolling bearing is integrally formed on the outer periphery of the hub ring integrally having the wheel mounting flange, and further, the constant velocity universal joint is provided on the hub ring. Have been developed to the fourth generation in which the other inner rolling surface of the double row rolling bearing is integrally formed on the outer periphery of the outer joint member constituting the constant velocity universal joint.

The wheel bearing device shown in FIG. 4 is a typical example of a fourth generation structure. 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 constituted by unitizing a hub wheel 51, a double row rolling bearing 52 and a constant velocity universal joint 53. The hub wheel 51 integrally has a wheel mounting flange 54 for mounting a wheel (not shown) at an end portion on the outer side, and hub bolts 56 are implanted at circumferentially equidistant positions. Further, an uneven portion 55 is formed on the inner peripheral surface of the hub wheel 51, and a hardened layer is formed in a surface hardness range of 54 to 64 HRC by induction hardening.

  The double-row rolling bearing 52 includes an outer member 57, an inner member 58, and double-row balls 59, 59. The outer member 57 integrally has a vehicle body mounting flange 57b for mounting to a suspension device (not shown) on the outer periphery, and double row outer rolling surfaces 57a and 57a are formed on the inner periphery. On the other hand, the inner member 58 includes a hub wheel 51 and an outer joint member 63 that is fitted into the small-diameter step portion 51b of the hub wheel 51 in a butted state.

  Inner rolling surfaces 51 a and 63 a facing the double-row outer rolling surfaces 57 a and 57 a formed on the outer member 57 are formed on the outer circumferences of the hub wheel 51 and the outer joint member 63, respectively. The double-row balls 59 and 59 are accommodated between the rolling surfaces 57a and 51a and 57a and 63a, respectively, and are held by the cages 60 and 60 so as to be freely rollable. In addition, seals 61 and 62 are attached to the ends of the double row rolling bearing 52 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing. ing.

The constant velocity universal joint 53 includes an outer joint member 63, a joint inner ring 64, a cage 65, and a torque transmission ball 66. The outer joint member 63 has a cup-shaped mouth portion 67, a shoulder portion 68 that forms the bottom portion of the mouth portion 67, and a hollow shaft portion 69 that extends from the shoulder portion 68 in the axial direction. On the outer periphery of the shaft portion 69, an in-row portion 69a that is fitted into the small-diameter step portion 51b of the hub wheel 51 and a fitting portion 69b that further extends in the axial direction from the in-row portion 69a are formed. Then, the shaft portion 69 of the outer joint member 63 is fitted into the hub wheel 51, and a fitting tool 69 b is expanded by pushing a diameter expanding jig such as a mandrel into the inner diameter of the shaft portion 69. The hub wheel 51 and the outer joint member 63 are integrally plastically joined by biting into the concavo-convex portion 55 of the hub wheel 51 and caulking. With such a configuration, it is possible to provide a wheel bearing device that achieves light weight and compactness and that does not loosen the coupling portion over a long period of time.
Japanese Patent Laid-Open No. 2001-18605

  In such a conventional wheel bearing device, since the hub wheel 51 and the outer joint member 63 are integrated by plastic bonding, loosening of the coupling portion is prevented over a long period of time, and the preload amount is maintained at a predetermined value. Features that can be done. However, in recent years, further weight reduction has been demanded in order to improve the vehicle fuel efficiency and the motion performance by reducing the unsprung weight. Further, it is desired to exhibit sufficient strength and durability even when a large moment load or the like is applied, and to increase bearing rigidity for stable running. Therefore, in such a conventional wheel bearing device, the wheel bearing is designed to be lighter and more compact in order to improve the vehicle fuel efficiency and the motion performance by reducing the unsprung weight and weight, while further improving the strength and durability. An apparatus is desired.

  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 and a method for manufacturing the same that are reduced in weight and size and improved in strength and durability.

  In order to achieve such an object, the invention according to claim 1 of the present invention is a wheel bearing device in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and the double row rolling device. The bearing has a body mounting flange integrally on the outer periphery, an outer member having a double row outer raceway formed on the inner periphery, a wheel mounting flange on one end, and the double row on the outer periphery. One inner rolling surface facing the outer rolling surface of the inner ring, a hub wheel formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and the outer circumferential rolling surface of the double row on the outer periphery The other inner rolling surface opposite to the inner rolling surface, and the outer joint member constituting the constant velocity universal joint integrally formed with the shaft portion extending in an axial direction from the inner rolling surface and fitted into the hub wheel. An inner member, and a plurality of the inner member and the outer member. A wheel bearing device in which the hub ring and the outer joint member are integrally plastically coupled by plastically deforming the shaft portion and crimping on the hub ring. A predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the rolling surface to the small diameter step portion and the inner peripheral surface of the small diameter step portion, and the depth of these hardened layers is the thickness of the small diameter step portion. Is set smaller than.

  Thus, in the wheel bearing device of the fourth generation structure in which the hub wheel and the outer joint member constituting the constant velocity universal joint are unitized by plastic coupling, the hub wheel extends from the inner rolling surface of the hub wheel to the small diameter step portion. A predetermined hardened layer is formed by induction hardening on the outer peripheral surface and the inner peripheral surface of the small diameter step portion, and the depth of these hardened layers is set to be smaller than the thickness of the small diameter step portion. The layer does not burn through the small diameter step. As a result, the weight and size of the hub wheel are reduced, and not only the wear resistance of the small diameter step portion but also the strength and durability of the hub wheel are improved.

  Preferably, as in the invention described in claim 2, an uneven portion hardened by induction hardening is formed on the inner periphery of the hub wheel, and the fitting portion of the shaft portion is expanded in diameter so as to bite into the uneven portion. As a result, if the hub wheel and the outer joint member are integrally plastically coupled, it is possible to reduce the weight and size, and it is not necessary to control the preload by tightening firmly with a nut or the like. The preload amount can be maintained over a long period of time.

  A method invention according to claim 3 of the present invention is a method of manufacturing a wheel bearing device in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and the double row rolling device. The bearing has a body mounting flange integrally on the outer periphery, an outer member having a double row outer raceway formed on the inner periphery, a wheel mounting flange on one end, and the double row on the outer periphery. One inner rolling surface facing the outer rolling surface of the inner ring, a hub wheel formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and the outer circumferential rolling surface of the double row on the outer periphery The other inner rolling surface opposite to the inner rolling surface, and the outer joint member constituting the constant velocity universal joint integrally formed with the shaft portion extending in an axial direction from the inner rolling surface and fitted into the hub wheel. An inner member, and a plurality of the inner member and the outer member. In the manufacturing method of a wheel bearing device, wherein the hub ring and the outer joint member are integrally plastically coupled by plastically deforming the shaft portion and crimping on the hub ring. A heating coil is inserted into the stepped portion, and a predetermined hardened layer is formed on the inner peripheral surface thereof by induction hardening, and cooling water is circulated to the small diameter stepped portion to cool the inner peripheral surface. A predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small diameter step portion.

  Thus, the heating coil is inserted into the small-diameter step portion of the hub wheel, a predetermined hardened layer is formed on the inner peripheral surface thereof by induction hardening, and the cooling water is circulated to the small-diameter step portion to return to the inside. In a state where the peripheral surface is cooled, a predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small-diameter stepped portion, so that it can be controlled to a predetermined hardened layer depth, It can prevent effectively that a hardened layer burns out a small diameter step part.

  According to a fourth aspect of the present invention, the hub wheel is placed in the vertical direction while being positioned on the rotating jig via the wheel mounting flange, and a lid member is provided on the end surface of the small diameter step portion. When a closing jig is installed and the cooling water is introduced from below the hub wheel, the cooling water can control the passage speed of the cooling water rather than following the flow path from the top to the bottom. And the inner peripheral surface can be effectively cooled.

  Further, as in the invention according to claim 5, if the tempering is performed by inserting the heating coil into the hub wheel after the quenching step, the brittleness due to quenching is improved and the hardened layer is obtained. Can be adjusted to a predetermined surface hardness.

  A wheel bearing device according to the present invention is a wheel bearing device in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and the double row rolling bearing has a vehicle body mounting flange on an outer periphery. An outer member integrally formed with a double row outer rolling surface formed on the inner periphery, and a wheel mounting flange integrally formed at one end and facing the double row outer rolling surface on the outer periphery. An inner rolling surface, a hub wheel formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and the other inner rolling surface opposite to the double-row outer rolling surface on the outer periphery. An inner member made of an outer joint member that extends in the axial direction from the inner rolling surface and forms the constant velocity universal joint integrally formed with a shaft portion fitted into the hub wheel, A double row rolling element housed in a freely rollable manner between both rolling surfaces of the member and the outer member, and the shaft In the wheel bearing device in which the hub wheel and the outer joint member are integrally plastically joined by plastic deformation of the hub wheel and the outer ring member extends from the inner rolling surface of the hub wheel to the small diameter step portion. A predetermined hardened layer is formed by induction hardening on the surface and the inner peripheral surface of the small diameter step portion, and the depth of the hardened layer is set smaller than the thickness of the small diameter step portion. Does not burn through the small diameter step. As a result, the weight and size of the hub wheel are reduced, and not only the wear resistance of the small diameter step portion but also the strength and durability of the hub wheel are improved.

  The wheel bearing device manufacturing method according to the present invention is a wheel bearing device manufacturing method in which a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and the double row rolling bearing. Has a body mounting flange integrally on the outer periphery, an outer member having a double row outer raceway formed on the inner periphery, a wheel mounting flange integrally on one end, and the double row on the outer periphery. One inner rolling surface facing the outer rolling surface, a hub wheel formed with a cylindrical small-diameter step extending in the axial direction from the inner rolling surface, and the outer circumferential surface of the double row on the outer periphery The other inner rolling surface which opposes, and the outer joint member which comprises the said constant velocity universal joint which extended in the axial direction from this inner rolling surface, and was integrally formed by the shaft part fitted in the said hub ring. An inner member, and a plurality of the inner member and the outer member that are accommodated so as to roll between the rolling surfaces of the inner member and the outer member. In the manufacturing method of a wheel bearing device, wherein the hub ring and the outer joint member are integrally plastically coupled by plastically deforming the shaft portion and crimping on the hub ring. A heating coil is inserted into the stepped portion, and a predetermined hardened layer is formed on the inner peripheral surface thereof by induction hardening, and cooling water is circulated to the small diameter stepped portion to cool the inner peripheral surface. Since the predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small diameter stepped portion, the predetermined hardened layer depth can be controlled, and the hardened layer is reduced to the small diameter stepped portion. Can be effectively prevented from being burned out.

  A manufacturing method of a wheel bearing device in which a hub wheel, a double row rolling bearing and a constant velocity universal joint are unitized, wherein the double row rolling bearing has a vehicle body mounting flange integrally on an outer periphery, An outer member on which a double row outer rolling surface is formed, a wheel mounting flange integrally formed at one end, and one inner rolling surface facing the outer rolling surface of the double row on the outer periphery; A hub wheel formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, the other inner rolling surface facing the double-row outer rolling surface on the outer periphery, and the inner rolling surface An inner member made of an outer joint member that constitutes the constant velocity universal joint that extends in the axial direction from and is integrally formed with a shaft portion that is fitted into the hub wheel, and the inner member and the outer member. And a double row of balls accommodated between the rolling surfaces so as to roll freely, and hardened on the inner periphery of the hub wheel. A wheel bearing in which a convex portion is formed and the hub wheel and the outer joint member are integrally plastically bonded by expanding the diameter of the fitting portion of the shaft portion and biting into the uneven portion. In the method for manufacturing the apparatus, a heating coil is inserted into the small diameter step portion, a predetermined hardened layer is formed on the inner peripheral surface thereof by induction hardening, and cooling water is introduced into the small diameter step portion from below. In a state where the inner peripheral surface is cooled by being refluxed, a predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small diameter step portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 (a) is a longitudinal sectional view showing a hub wheel of FIG. 1, and FIG. 1 (b) is another hub wheel. FIG. 3 is an explanatory view showing a heat treatment method for the hub wheel.

  In this wheel bearing device, a hub wheel 1, a double row rolling bearing 2 and a constant velocity universal joint 3 are configured as a unit. The double-row rolling bearing 2 includes an outer member 4, an inner member 5, and double-row rolling elements (balls) 6 and 6. The inner member 5 includes a hub wheel 1 and an outer joint member 14 fitted in the hub wheel 1.

  The outer member 4 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 4b for mounting to a vehicle body (not shown) on the outer periphery. Double row outer rolling surfaces 4a, 4a are formed. The double row outer rolling surfaces 4a, 4a are hardened by induction hardening to a surface hardness of 58 to 64 HRC.

  On the other hand, the hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a wheel mounting flange 7 for mounting a wheel to an end portion on the outer side. A plurality of hub bolts 8 are planted at equal intervals in the circumferential direction of the flange 7. Further, on the outer periphery of the hub wheel 1, one (outer side) inner rolling surface 1 a facing the double row outer rolling surfaces 4 a and 4 a formed on the inner periphery of the outer member 4 and the inner rolling surface are provided. A cylindrical small-diameter step portion 1b extending in the axial direction from the running surface 1a is formed.

  Concave and convex portions 12 are formed on the inner periphery of the hub wheel 1, and a hardened layer is formed with a surface hardness in the range of 54 to 64 HRC by heat treatment. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. The concave and convex portion 12 is formed in the shape of an iris knurl, and is a cross groove formed by a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like substantially orthogonal to each other. Alternatively, it consists of a cross groove composed of spiral grooves inclined with respect to each other. Further, in order to ensure good biting property, the tip of the concavo-convex portion 12 is formed in a spire shape such as a triangular shape.

  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 is made of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and has a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom portion of the mouth portion 18, and the shoulder portion. A cylindrical shaft portion 20 extending in the axial direction from 19 is integrally formed. The shaft portion 20 is formed with an in-row portion 20a that is cylindrically fitted to the small-diameter step portion 1b of the hub wheel 1 through a predetermined radial clearance, and a fitting portion 20b is formed at the end of the in-row portion 20a. Yes.

  A curved track groove 18 a extending in the axial direction is formed on the inner periphery of the mouse portion 18, and a track groove 15 a corresponding to the track groove 18 a is formed on the outer periphery of the joint inner ring 15. Further, on the outer periphery of the shoulder portion 19, the other (inner side) inner rolling surface 14 a facing the double row outer rolling surfaces 4 a, 4 a is formed. Then, a hardened layer is formed with a surface hardness of 58 to 64 HRC by induction quenching from the outer peripheral surface on which the inner seal 11 is mounted including the track groove 18a to the inner rolling surface 14a and the shaft portion 20. Has been. Here, the fitting part 20b is left raw after forging.

  Double-row rolling elements 6 and 6 are accommodated between the double-row outer rolling surfaces 4a and 4a of the outer member 4 and the double-row inner rolling surfaces 1a and 14a of the inner member 5 opposed thereto. The holders 9 and 9 are held so as to freely roll. In addition, seals 10 and 11 are attached to an opening of an annular space formed between the outer member 4 and the inner member 5, leakage of lubricating grease sealed inside the bearing, and rainwater entering the bearing from the outside. And dust are prevented from entering. In addition, although the double row angular contact ball bearing which used the ball for the rolling element 6 was illustrated as the double row rolling bearing 2 here, it is not restricted to this, For example, it is a double row tapered roller bearing using a tapered roller. There may be.

  The hub wheel 1 and the outer joint member 14 are coupled to each other by first engaging the shoulder 19 of the outer joint member 14 with the end surface of the small-diameter stepped portion 1b of the hub wheel 1 until the hub wheel 1 is brought into a butted state. 20 is fitted. Then, a diameter expanding jig such as a mandrel is pushed into the inner diameter of the fitting portion 20b in the shaft portion 20 to increase the diameter of the fitting portion 20b, and the fitting portion 20b is bitten into the uneven portion 12 of the hub wheel 1. The hub wheel 1 and the outer joint member 14 are integrally plastically joined by caulking. As a result, it is not necessary to control the preload by tightening firmly with a nut or the like as in the prior art, so that the weight and size can be reduced and the strength and durability of the hub wheel 1 can be improved, The amount of preload can be maintained for a long period of time. An end cap 13a is attached to the hollow shaft portion 20 to prevent the grease enclosed in the mouth portion 18 from leaking to the outside. An end cap 13b is also attached to the opening end portion of the hub wheel 1 to prevent rainwater or the like from entering the plastic coupling portion and rusting the portion.

  In addition to the configuration exemplified as means for plastically coupling the hub wheel 1 and the outer joint member 14, for example, although not shown, the shaft portion of the outer joint member is fitted into the hub wheel, and the shaft portion The ends may be plastically deformed outward in the radial direction to form a swaged portion, and the two members may be fixed in the axial direction by the swaged portion.

  In the present embodiment, as shown in FIG. 2A, the hub wheel 1 has a high frequency from the seal land portion 7a with which the outer seal 10 is in sliding contact to the inner rolling surface 1a and the end surface of the small diameter step portion 1b. The predetermined hardened layer 21 is formed in the surface hardness of 58 to 64 HRC by quenching. As a result, the seal land portion 7a serving as the base portion of the wheel mounting flange 7 not only has improved wear resistance, but also has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 7. The durability of the wheel 1 is further improved. Here, in the small-diameter step portion 1b of the hub wheel 1, when the thickness T1 is 5 mm or more, the hardened layer depth D1 of the groove bottom portion of the inner rolling surface 1a is preferably smaller than the thickness T1 (D1). <T1) That is, the strength and durability of the hub wheel 1 can be improved by preventing the hardened layer 21 at the bottom of the groove from being burned out to the inner peripheral surface of the small-diameter stepped portion 1b. When the thickness T2 of the small-diameter step portion 1b is 8 mm or more, as shown in FIG. 2B, a predetermined hardened layer 22 is formed not only on the outer peripheral surface of the hub wheel 1 but also on the inner peripheral surface by induction hardening. In addition, the depth D1 of the hardened layer 21 on the outer peripheral surface and the depth D2 of the hardened layer 22 on the inner peripheral surface are preferably smaller than the thickness T2 of the small diameter step portion 1b ((D1 + D2) <T2), It is preferable to prevent the hardened layers 21 and 22 from burning through the small diameter step 1b. Thereby, not only the wear resistance of the small diameter step portion 1b but also the strength and durability of the hub wheel 1 are further improved.

  3A and 3B are explanatory views showing a heat treatment method for the hub wheel 1 according to the present embodiment, in which FIG. 3A shows a heat treatment method for the inner peripheral surface of the hub wheel 1 and FIG. 3B shows a heat treatment method for the outer peripheral surface. As shown in FIG. 3A, the hub wheel 1 is placed on the rotating jig 23 in a vertically positioned state and is driven to rotate through the wheel mounting flange 7. Then, the heating coil 24 is inserted into the hub wheel 1 through a predetermined radial gap, and cooling water is introduced from below, cooling the inner peripheral surface of the hub wheel 1 heated by the coil 24, Thereafter, water is drained from above (the opening on the inner side of the hub wheel 1) (indicated by a white arrow). By adopting such a flow path of cooling water, the cooling water can control the passage speed of the cooling water rather than following the flow path from top to bottom, effectively cooling the inner peripheral surface. can do. Therefore, the predetermined hardened layer 22 can be easily and accurately formed corresponding to the thickness of the small diameter step portion 1b. Although not shown, after such a quenching process, the same coil 24 is inserted into the hub wheel 1 and tempering is performed. Thereby, the brittleness due to quenching is improved and the surface hardness can be adjusted to a predetermined level.

  After quenching the inner peripheral surface of the hub wheel 1, as shown in FIG. 3 (b), the hub wheel 1 is placed vertically while being positioned on the rotating jig 25. And is driven to rotate. A heating coil 26 is externally inserted into the hub wheel 1 through a predetermined radial clearance, and quenching cooling water is injected toward the outer peripheral surface of the hub wheel 1 (indicated by a black arrow in the figure). . In this step, quenching is performed on the outer peripheral surface of the hub wheel 1 extending from the seal land portion 7a to the inner rolling surface 1a and the small diameter step portion 1b while cooling the inner peripheral portion of the hub wheel 1. That is, a closing jig 27 that forms a lid member is attached to the end face of the small-diameter stepped portion 1 b, and cooling water introduced from below is stopped by this closing jig 27 to be refluxed, and then formed on the rotating jig 25. Cooling water is drained from the drainage holes 25a (shown by white arrows). Thereby, the outer peripheral hardened layer 21 can be easily and accurately controlled to a predetermined hardened layer depth, and the hardened layers 21 and 22 are effectively prevented from burning through the small diameter step portion 1b. Can do. In addition, tempering is performed after such a quenching process similarly to the process mentioned above.

  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 fourth generation wheel bearing device in which a hub wheel integrally having a wheel mounting flange and an outer joint member of a constant velocity universal joint are integrally plastically coupled. .

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. (A) is a longitudinal cross-sectional view which shows the hub wheel of FIG. (B) is a longitudinal cross-sectional view showing another hub wheel. (A) is explanatory drawing which shows the hardening process of the internal peripheral surface of a hub ring. (B) is explanatory drawing which shows the hardening process of an outer peripheral surface same as the above. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

Explanation of symbols

1 ... hub wheel 1a, 14a ... inner rolling surface 1b ... small diameter step 2 ... ····································································································· Member 4a ... Outer rolling surface 4b ... Body mounting flange 5 ... Inside Member 6 ... Rolling element 7 ... Wheel mounting flange 7a ... Seal land 8: Hub bolt 9: Retainer 10, 11: Seal 12 .... Uneven parts 13a, 13b ... End cap 14 ... · · · Outer joint member 15 ·········· Joint inner ring 16 ················ 17 Transmission ball 18 ········· Mouse portion 19 ········ Shoulder portion 20 ········· Shaft portion 20a ··· ···················································································································································· .. Rotating jigs 24, 26 ... Heating coil 25a ... Drain hole 27 ... Occlusion treatment Tool 51 ..... Hub wheel 51a, 63a .... Inner rolling surface 51b .... Small diameter step 52 .... ... Double-row rolling bearings 53・ Constant velocity universal joint 54 ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Uneven portion 56 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolt 57 · · · · · · · · Outer member 57a · · · Outer rolling surface 57b ······ Body mounting flange 58 ···・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Ball 60 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 61, 62 ・ ・ ・ ・ ・・ ・ ・ ・ Seal 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 64 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner joint ring 65 66 ············ Torque transmission ball 67 ············································· Shoulder 69. .... Shaft 69a ...・ In-row part 69b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting part

Claims (5)

A wheel bearing device in which a hub wheel and a double row rolling bearing and a constant velocity universal joint are unitized,
The double row rolling bearing has an outer member integrally formed with a vehicle body mounting flange on the outer periphery, and an outer rolling surface of the double row formed on the inner periphery;
One end has a wheel mounting flange integrally, and on the outer periphery is one inner rolling surface facing the double row outer rolling surface, and a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface. The formed hub wheel, the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a shaft portion extending in the axial direction from the inner rolling surface and fitted into the hub wheel. An inner member composed of an outer joint member constituting the constant velocity universal joint formed integrally;
A double row rolling element housed in a freely rolling manner between the rolling surfaces of the inner member and the outer member;
In the wheel bearing device in which the hub ring and the outer joint member are integrally plastically coupled by plastically deforming the shaft portion and tightening the hub ring,
A predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small-diameter step portion and the inner peripheral surface of the small-diameter step portion, and the depth of the hardened layer is the small-diameter portion. A wheel bearing device, wherein the wheel bearing device is set smaller than the thickness of the stepped portion.   An uneven portion hardened by induction hardening is formed on the inner periphery of the hub wheel, and the hub wheel and the outer joint member are integrated with each other by expanding the fitting portion of the shaft portion and biting into the uneven portion. The wheel bearing device according to claim 1, wherein the wheel bearing device is plastically coupled. A manufacturing method of a wheel bearing device in which a hub wheel and a double row rolling bearing and a constant velocity universal joint are unitized,
The double row rolling bearing has an outer member integrally formed with a vehicle body mounting flange on the outer periphery, and an outer rolling surface of the double row formed on the inner periphery;
One end has a wheel mounting flange integrally, and on the outer periphery is one inner rolling surface facing the double row outer rolling surface, and a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface. The formed hub wheel, the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a shaft portion extending in the axial direction from the inner rolling surface and fitted into the hub wheel. An inner member composed of an outer joint member constituting the constant velocity universal joint formed integrally;
A double row rolling element housed in a freely rolling manner between the rolling surfaces of the inner member and the outer member;
In the method of manufacturing a wheel bearing device in which the hub ring and the outer joint member are integrally plastically coupled by plastically deforming the shaft portion and crimping the hub ring,
A coil for heating is inserted in the small diameter step portion, and a predetermined hardened layer is formed on the inner peripheral surface thereof by induction hardening, and cooling water is refluxed to the small diameter step portion to cool the inner peripheral surface. In the state, a predetermined hardened layer is formed by induction hardening on the outer peripheral surface extending from the inner rolling surface of the hub wheel to the small diameter step portion.   The hub wheel is placed in a vertical direction in a state where the hub wheel is positioned on the rotating jig through the wheel mounting flange, and a closing jig that forms a lid member is attached to an end surface of the small diameter step part, The method for manufacturing a wheel bearing device according to claim 3, wherein cooling water is introduced from below the hub wheel.   The method for manufacturing a wheel bearing device according to claim 3 or 4, wherein after the quenching step, the heating coil is fitted into the hub wheel and tempering is performed.

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