JP2013141861A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel capable of obtaining reliability and steering stability, and reducing cost while eliminating any circumferential wobbling of a coupling part.SOLUTION: A through-hole 12 formed of a fitting part 12a and a telescopic part 12b of a large diameter is formed in the inner circumference of a hub wheel 1. A shaft 20 of an outer joint member 14 is fitted to the through-hole 12. A plurality of key grooves 22 extending in the axial direction are formed in the inside diameter of the end of the hub wheel 1 at equal spaces in the circumferential direction. A key groove 23 corresponding to each key groove 22 is formed at the outer circumference at a fore end of the shaft 20 of the outer joint member. The key groove 23 is formed in an inclined manner so as to be gradually enlarged toward the inner side, and a plurality of wedge spaces are formed between the key grooves 22 and the key grooves. Pins 24 are inserted into these wedge spaces. A washer 29 is attached to an anchor bolt 30 and abutted on the pins 24. A male screw 30a of the anchor bolt 30 is screwed to a female screw 21 of the shaft 20, and the hub wheel 1 and the outer joint member 14 are coupled with each other in a torque transmitting manner.

Description

  The present invention relates to a wheel bearing device for rotatably supporting wheels of a vehicle such as an automobile, and more particularly to a wheel bearing device in which a bearing portion and a constant velocity universal joint are detachably unitized.

  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. Because it is necessary to allow moment displacement, one end of the drive shaft interposed between the engine side and the wheel side is connected to the differential via a sliding type constant velocity universal joint, and the other end is fixed. The wheel is connected to a wheel via a wheel bearing device including a constant velocity universal joint.

  As such a wheel bearing device, one as shown in FIG. 16 is known. This wheel bearing device is configured by detachably unitizing a hub wheel 50, a double row rolling bearing 51, and a constant velocity universal joint 52.

  The hub wheel 50 integrally has a wheel mounting flange 53 for mounting a wheel (not shown) at one end thereof, one inner rolling surface 50a of the double row rolling bearing 51 on the outer periphery, and this inner rolling. A cylindrical small-diameter step portion 50b extending in the axial direction from the surface 50a is formed, and a serration 54 is formed on the inner periphery to the vicinity of the small-diameter step portion 50b, and a cylindrical surface 55 is formed to the remaining end portion. . And from the inner rolling surface 50a to the outer peripheral surface of the small diameter step portion 50b, and from the serration 54 to the inner peripheral surface of the cylindrical surface 55, the surface hardness is set in the range of 54 to 64HRC by induction hardening. A hardened layer is formed.

  An inner ring 56 is press-fitted into the small-diameter step portion 50b of the hub wheel 50, and the inner ring 56 is fixed in the axial direction by a crimping portion 57 formed by plastically deforming an end portion of the small-diameter step portion 50b radially outward. . The other inner rolling surface 56a of the double row rolling bearing 51 is formed on the outer periphery of the inner ring 56, and the inner rolling surface 50a directly formed on the hub wheel 50 is double row inner rolling surfaces 50a, 56a. Is configured.

  The double row rolling bearing 51 includes an outer member 58, an inner member 59 composed of a hub ring 50 and an inner ring 56 fixed integrally to the hub ring 50, and a double row ball 60. The outer member 58 integrally has a vehicle body mounting flange 58b for mounting to the vehicle body (not shown) on the outer periphery, and double row outer rolling surfaces 58a, 58a are integrally formed on the inner periphery.

  Double rows of balls 60 and 60 are accommodated between the rolling surfaces of the outer member 58 and the inner member 59 and are held by a retainer 61 so as to be freely rollable. In addition, seals 62 and 63 are attached to both ends of the double row rolling bearing 51 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing. Yes.

  The constant velocity universal joint 52 includes an outer joint member 64, a joint inner ring 69, a cage 70, and a torque transmission ball 71. The outer joint member 64 integrally includes a cup-shaped mouth portion 65, a shoulder portion 66 that forms the bottom portion of the mouth portion 65, and a shaft portion 67 that extends from the shoulder portion 66 in the axial direction. The shaft portion 67 is formed with a small-diameter step portion 67a, a serration 67b, and a male screw 67c.

  Here, the shaft portion 67 is fitted into the hub wheel 50 so that a predetermined axial clearance δ1 remains between the inner end surface of the crimping portion 57 and the shoulder portion 66. A fixing nut 68 is screwed onto the male screw 67c, and the hub wheel 50 and the outer joint member 64 are coupled so as to be separable in the axial direction. Thereby, even if the shaft portion 67 is twisted by a large torque, a stick-slip sound is not generated between the caulking portion 57 and the shoulder portion 66. Further, the small-diameter step portion 67a of the shaft portion 67 is cylindrically fitted to the small-diameter step portion 50b of the hub wheel 50 via a predetermined radial clearance δ2, so that deformation of the hub wheel 50 is suppressed even when a large driving force is generated. Further, the durability is improved by increasing the rigidity against repeated bending moment loads (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2004-299643

  In this type of wheel bearing device, the hub wheel 50 having the serration 54 formed on the inner periphery and the shaft portion 67 of the outer joint member 64 having the serration 67b formed on the outer periphery are tightly fitted, and the shaft portion 67 is also fitted. The fixing nut 68 is screwed onto the male screw 67c formed at the tip of the shaft, so that the hub wheel 50 and the outer joint member 64 are detachably coupled in the axial direction, and the driving force from the engine is transmitted to the hub wheel 50. ing.

  However, these serrations 54 and 67b are fitted with BPDs (Between Pins Diameter) and OPDs (Over Pins Diameter) of Serrations 54 and 67b in order to prevent tooth wear and noise. Since the diameter is tightly controlled and tightly fitted, there is a problem that the management cost increases in addition to the manufacturing cost due to the formation of the serrations 54 and 67b, and the cost of the product increases.

  In order to prevent abrasion, it is effective to provide a hardened layer on the serrations 54 and 67b by heat treatment. In particular, the serration 54 of the hub wheel 50 is not hardened due to thermal deformation due to heat treatment. Currently.

  The present invention has been made in view of such circumstances, and it is intended to provide a wheel bearing device that achieves reliability and steering stability by eliminating the backlash in the circumferential direction of the coupling portion, and at a lower cost. It is aimed.

  In order to achieve such an object, the invention described in claim 1 of the present invention has a vehicle body mounting flange integrally attached to the vehicle body on the outer periphery, and a double row outer rolling surface is integrally formed on the inner periphery. A hub wheel having a wheel mounting flange integrally formed at one end and a cylindrical small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub wheel. An inner member formed of at least one inner ring and formed with a double-row inner rolling surface facing the double-row outer rolling surface, and a double row accommodated in a freely rolling manner between the both rolling surfaces An outer joint member integrally forming a cup-shaped mouth portion, a shoulder portion forming the bottom portion of the mouth portion, and a shaft portion extending in the axial direction from the shoulder portion. The shaft portion is fitted into the hub wheel until the shoulder portion abuts on the inner member. In the wheel bearing device in which the hub wheel and the outer joint member are detachably coupled to each other in the axial direction by a screw fastened to the distal end portion of the shaft portion, the fitting portion and the fitting are provided on the inner periphery of the hub wheel. A through-hole having an in-row portion formed with a larger diameter than the joint portion is formed, and the shaft portion of the outer joint member is fitted into the through-hole, and the inner diameter of the outer end portion of the hub wheel is axially A plurality of key grooves extending in the circumferential direction are formed in the circumferential direction, and a plurality of key grooves corresponding to these key grooves are formed in the circumferential direction at the outer periphery of the tip end of the shaft of the outer joint member. Is formed so as to be gradually expanded toward the inner side, and a plurality of wedge spaces are formed between the hub wheel and the key groove of the hub wheel, and a pin is inserted into the wedge space, and the hub wheel And the outer joint member are coupled so as to transmit torque.

  As described above, the outer member, the inner member, the double row rolling elements, and the constant velocity universal joint are configured, and the cup-shaped mouth portion, the shoulder portion that forms the bottom portion of the mouth portion, and the shaft from the shoulder portion. An outer joint member integrally having a shaft portion extending in the direction, and a screw that is fitted into the hub wheel until the shoulder portion abuts on the inner member, and is fastened to the tip portion of the shaft portion. Thus, in the wheel bearing device in which the hub wheel and the outer joint member are detachably coupled in the axial direction, the inner periphery of the hub wheel includes a fitting portion and an inrow portion having a larger diameter than the fitting portion. A through hole is formed, and the shaft portion of the outer joint member is fitted into the through hole, and a plurality of key grooves extending in the axial direction are formed in the outer peripheral end inner diameter of the hub wheel in the circumferential direction. A plurality of key grooves corresponding to the key groove of the outer joint member are formed on the outer periphery of the end of the shaft of the outer joint member in a circumferentially uniform manner At the same time, these key grooves are formed so as to be gradually enlarged toward the inner side, and a plurality of wedge spaces are formed between the key grooves of the hub wheel, and pins are fitted into these wedge spaces. Since the hub wheel and the outer joint member are connected so as to be able to transmit torque, there is no backlash in the circumferential direction between the hub wheel and the outer joint member, so that reliability and steering stability are achieved and serrations are not formed. However, it is possible to provide a wheel bearing device capable of reliably transmitting torque and reducing costs.

  Further, as in the invention described in claim 2, a female screw is formed at the tip of the shaft portion of the outer joint member, a washer is attached to the fixing bolt, and the washer is brought into contact with the pin. If the male screw of the fixing bolt is screwed into the female screw of the shaft portion, the pin bites into the key groove, and the hub wheel and the outer joint member are coupled so as to be separable in the axial direction.

  Further, as in the invention described in claim 3, the pin may be formed in a conical shape with a circular cross section.

  Further, as in the invention described in claim 4, the pin may be formed in a pyramid shape with a rectangular cross section.

  Further, as in the fifth aspect of the invention, a predetermined curing process is performed on the surface of the pin and the key groove, and the surface hardness of the key groove is higher than the surface hardness of the pin, If the difference is set to 20 HRC or more, it will have the desired strength and rigidity even when large surface pressure and shear force occur, and the pin will effectively bite into the key groove to suppress circumferential play and reduce fretting wear. It can suppress and improve durability.

  According to a sixth aspect of the present invention, the pin is integrated with a washer, and a disc-shaped base portion and a pin portion formed in a conical shape protruding in the axial direction from a side surface of the base portion are integrated. If the engagement member is provided, both the hub wheel and the outer joint member can be integrated by eliminating the backlash in the circumferential direction, the number of parts can be reduced, and the number of assembly steps can be reduced. Cost can be reduced.

  According to a seventh aspect of the present invention, the shaft portion includes a fitting portion that fits into the through-hole of the hub wheel, and an inrow portion that has a larger diameter than the fitting portion. The hub wheel fitting portion is press-fitted into the fitting portion of the shaft portion via a predetermined radial nip, and the in-row portion of the hub wheel is inserted into the in-row portion of the shaft portion with a predetermined radial clearance. If the fitting surface is subjected to a predetermined hardening treatment, the fitting surface is prevented from being worn and has sufficient mechanical strength against the rotational bending load applied. Durability is further improved.

  Further, as in the invention described in claim 8, the inner ring is given a predetermined bearing preload by a crimped portion formed by plastically deforming an end portion of the small diameter step portion of the hub wheel radially outward. In this state, if it is fixed in the axial direction with respect to the hub wheel, it is not necessary to firmly fasten the fixing bolt to the shaft portion, so that the assembling work is simplified and the cost can be further reduced.

  The wheel bearing device according to the present invention has an outer member integrally formed with a vehicle body mounting flange for mounting to the vehicle body on the outer periphery, and an outer member formed integrally with a double row outer rolling surface on the inner periphery, and one end portion. And a hub ring having a cylindrical small-diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring. An inner member in which a double row inner rolling surface facing the outer rolling surface of the row is formed, a double row rolling element housed so as to roll between the both rolling surfaces, and a constant velocity universal joint An outer joint member that integrally 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. The shaft portion is fitted into the hub wheel until the shoulder portion abuts, and is fastened to the tip portion of the shaft portion. In the wheel bearing device in which the hub wheel and the outer joint member are detachably coupled to each other in the axial direction by a threaded screw, a fitting portion and a larger diameter than the fitting portion are formed on the inner periphery of the hub wheel. A through-hole made of an in-row portion is formed, and the shaft portion of the outer joint member is fitted into the through-hole, and a key groove extending in the axial direction on the outer end inner diameter of the hub wheel is arranged in the circumferential direction. A plurality of key grooves corresponding to these key grooves are formed on the outer periphery of the distal end portion of the shaft of the outer joint member in a uniform manner in the circumferential direction, and these key grooves gradually increase in diameter toward the inner side. A plurality of wedge spaces are formed between the hub wheel and the key groove of the hub wheel, and pins are inserted into the wedge spaces so that the hub wheel and the outer joint member can transmit torque. Since it is connected, the hub wheel and the outer joint member It is possible to provide a wheel bearing device that can reduce the cost by reducing the circumferential play and improving the reliability and the handling stability, as well as reliably transmitting torque without forming serrations. .

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. (A) is the cross-sectional view along IIa-IIa of FIG. 1, (b) is the cross-sectional view along IIb-IIb of FIG. (A) is a perspective view which shows the pin single-piece | unit based on this invention, (b) is a longitudinal cross-sectional view same as the above. It is principal part sectional drawing which shows the keyway by which the pin which concerns on this invention is fitted. It is explanatory drawing which shows the assembly method of the wheel bearing apparatus of FIG. (A) is a cross-sectional view showing a modification of FIG. 2 (a), and (b) is a cross-sectional view showing a modification of FIG. 2 (b). (A) is a cross-sectional view showing another modification of FIG. 2 (a), and (b) is a cross-sectional view showing another modification of FIG. 2 (b). It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the wheel bearing apparatus which concerns on this invention. (A) is a front view which shows the engaging member based on this invention, (b) is explanatory drawing which shows the assembly method of the wheel bearing apparatus of FIG. It is a longitudinal cross-sectional view which shows 4th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 5th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 6th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 7th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 8th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

  A body mounting flange for mounting to the vehicle body is integrally provided on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange is integrally formed on one end. A hub wheel 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 a small diameter step of the hub wheel And an inner member formed of an inner ring formed with the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and accommodated in a freely rollable manner between the both rolling surfaces. An outer joint that forms a double row rolling element, a constant velocity universal joint, and integrally 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. A member, and the shaft portion is fitted into the hub wheel until the shoulder portion abuts on the inner ring. In the wheel bearing device in which the hub wheel and the outer joint member are detachably coupled to each other in the axial direction by a fixing bolt that is screwed into a female screw formed at the front end of the wheel, the hub wheel is fitted to the inner periphery of the hub wheel. And a through hole made of an in-row portion having a diameter larger than that of the fitting portion, the shaft portion of the outer joint member is fitted into the through hole, and the outer end portion of the hub wheel A plurality of key grooves extending in the axial direction on the inner diameter are formed in the circumferential direction, and a plurality of key grooves corresponding to these key grooves are formed in the circumferential direction at the outer periphery of the distal end portion of the shaft portion of the outer joint member. The key groove is formed so as to be gradually increased in diameter toward the inner side, and a plurality of wedge spaces are formed between the key grooves of the hub wheel, and pins are inserted into the wedge spaces. The pin is fitted with a washer on the fixing bolt. Brought into contact, the hub wheel and the outer joint member by screwing the external thread of the fixing bolt into the internal thread of the shaft portion is coupled to a torque transmittable.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 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 transverse sectional view taken along line IIa-IIa in FIG. 1, and FIG. FIG. 3A is a perspective view showing a single pin according to the present invention, FIG. 3B is a longitudinal sectional view thereof, and FIG. 4 is a pin according to the present invention. FIG. 5 is an explanatory view showing a method of assembling the wheel bearing device of FIG. 1, and FIG. 6 (a) shows a modification of FIG. 2 (a). FIG. 7B is a cross-sectional view showing a modification of FIG. 2B, FIG. 7A is a cross-sectional view showing another modification of FIG. 2A, and FIG. FIG. 5 is a cross-sectional view showing another modification of 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 6, an inner member 7, and double-row rolling elements (balls) 8 and 8.

  The outer member 6 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 6b for mounting to a vehicle body (not shown) on the outer periphery. Double row outer rolling surfaces 6a, 6a are integrally formed. The double row outer rolling surfaces 6a, 6a are subjected to a hardening process in a surface hardness range of 58 to 64 HRC by induction hardening.

  On the other hand, the inner member 7 is formed with double-row inner rolling surfaces 1 a and 5 a that face the double-row outer rolling surfaces 6 a and 6 a of the outer member 6. 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 7 refers to the hub wheel 1 and the inner ring 5. And the double-row rolling elements 8 and 8 are each accommodated between these rolling surfaces, and are hold | maintained so that rolling is possible by the holder | retainers 9 and 9. FIG. Seals 10 and 11 are attached to both ends of the outer member 6 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust, and the like into the bearing from the outside.

  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. A through hole 12 is formed on the inner periphery of the key groove 22, which will be described later, and a fitting portion 12a and an in-row portion 12b having a larger diameter than the fitting portion 12a. The inner ring 5 is press-fitted into the small-diameter step portion 1b via a predetermined shimiro, and a shaft portion 20 of an outer joint member 14 described later is fitted into the through hole 12. In addition, hub bolts 4 a for fixing the wheels to the circumferential direction of the wheel mounting flange 4 are planted.

  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 the like, and the wheel mounting flange 4 that serves as a seal land portion with which the outer side seal 11 starts sliding contact with the inner rolling surface 1a. From the inner side base portion 4b to the small-diameter step portion 1b, the surface hardness is set in the range of 58 to 64 HRC by induction hardening. Thereby, not only the wear resistance of the base portion 4b of the wheel mounting flange 4 is improved, but also the mechanical strength is sufficient with respect to the rotational bending load applied to the wheel mounting flange 4, and the durability of the hub wheel 1 is improved. Can be further improved, and fretting wear occurring on the fitting surface between the small-diameter step portion 1b and the inner ring 5 can be minimized. Further, a predetermined hardened layer 13 (indicated by cross-hatching in the figure) is formed on the inner peripheral surface of the through hole 12 of the hub wheel 1 by induction hardening in a surface hardness range of 50 to 64 HRC.

  Further, the inner ring 5 and the rolling element 8 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 apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 8 was illustrated here, it comprised by the double row tapered roller bearing which used the tapered roller for the rolling element 8. It may be.

  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.

  The shaft portion 20 includes a fitting portion 20a that fits into the above-described hub wheel through-hole 12 and an in-row portion 20b that has a larger diameter than the fitting portion 20a. A female screw 21 is formed at the tip of the shaft portion 20, and a key groove 23 described later is formed on the outer periphery. Then, the fitting portion 12a of the hub wheel 1 is press-fitted into the fitting portion 20a of the shaft portion 20 via a predetermined radial squeeze, and the in-row portion 12b of the hub wheel 1 is inserted into the in-row portion 20b of the shaft portion 20. It is inserted through a predetermined radial clearance.

  The outer joint member 14 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 50 to 64 HRC by induction hardening on the outer peripheral surface of the shaft portion 20 including the track grooves 18a and 15a. A predetermined hardened layer 28 (indicated by cross hatching in the figure) is formed in the range of. As a result, the wear of the fitting surface with the through-hole 12 of the hub wheel 1 is suppressed, and the mechanical strength against the rotational bending load applied to the shaft portion 20 is sufficient, and the durability of the outer joint member 14 is improved. The property is further improved.

  Here, in this embodiment, a plurality (four in this case) of key grooves 22 extending in the axial direction are formed in the inner diameter of the outer end of the hub wheel 1 in the circumferential direction. In addition, a plurality of key grooves 23 corresponding to the key grooves 22 of the hub wheel 1 are formed on the outer periphery of the distal end portion of the shaft 20 of the outer joint member 14 in the circumferential direction. The key groove 23 is formed so as to be gradually increased in diameter toward the inner side, and a plurality of wedge spaces are formed between the key groove 23 and the key groove 22 of the hub wheel 1.

  As shown in FIG. 2, these key grooves 22 and 23 are formed in a circular arc surface having a substantially semicircular cross section, and the key groove 22 of the hub wheel 1 is formed in a cylindrical shape and the key 20 of the shaft portion 20. The groove 23 is formed in a conical shape that gradually becomes smaller in diameter toward the tip. A pin 24 is inserted into a wedge space formed by these key grooves 22 and 23.

  The pin 24 is made of carbon steel such as S45C, and is formed in a conical shape having a circular cross section and a conical end surface on the large diameter side, as shown in FIG. A predetermined hardened layer 25 (indicated by cross-hatching in FIG. 3B) is formed in the range of 30 to 40 HRC by induction hardening. On the other hand, as shown in FIG. 4, predetermined hardened layers 26 and 27 (indicated by cross-hatching in the figure) are formed on the surfaces of the key grooves 22 and 23 by induction hardening in the range of 50 to 60 HRC. . Here, it is preferable that the difference in surface hardness between the pin 24 and the key grooves 22 and 23 is set to 20 HRC or more. As a result, it has the desired strength and rigidity even when a large surface pressure or shear force is generated, and the key grooves 22 and 23 effectively bite into the pins 24 to suppress circumferential backlash, thereby suppressing fretting wear and durability. Can be improved.

  In addition, as a material of the pin 24, it is not limited to the exemplified material, for example, it may be formed of a high carbon chrome bearing steel such as SUJ2, and may be hardened in a range of 30 to 40 HRC to the core portion by quenching. Further, it may be formed of carburized steel such as SCr420 or SCM415, and the surface may be hardened in a range of 30 to 40 HRC by carburizing and quenching.

Next, a method for assembling the wheel bearing device according to the present invention will be described with reference to FIG.
After the shaft portion 20 of the outer joint member 14 is fitted to the hub wheel 1 until the shoulder portion 19 of the outer joint member 14 abuts with the inner ring 5 (not shown), the key groove 22 of the hub wheel 1 and the shaft portion 20 are A pin 24 is inserted into a wedge space formed between the key groove 23. Thereafter, the washer 29 is brought into contact with each pin 24 and the male screw 30a of the fixing bolt 30 is screwed into the female screw 21 of the shaft portion 20, whereby the pin 24 bites into the key grooves 22, 23, and the hub wheel 1 and The outer joint member 14 is coupled in an axially separable manner. This eliminates the play in the circumferential direction between the hub wheel 1 and the outer joint member 14 to improve reliability and steering stability, and can reliably transmit torque without forming serrations, thereby reducing costs. It is possible to provide a wheel bearing device that achieves the above.

  Further, the special joint jig such as a conventional power press is not required, and the outer joint member 14 can be easily attached to the hub wheel 1 only by screwing the male screw 30a of the shaft portion 20 with the female screw 21 of the shaft portion 20. It can be pulled in and the workability at the time of disassembling / assembling can be improved, and the shaft portion 20 including the fixing bolt 30 can be accommodated in the inner peripheral region on the inner side of the pilot portion 31 of the hub wheel 1. Can be made lighter and more compact.

  FIG. 6 is a modification of the above-described embodiment (FIG. 2). A plurality (four in this case) of key grooves 33 extending in the axial direction are formed in the inner diameter of the outer end of the hub wheel 1 in the circumferential direction. In addition, a plurality of key grooves 35 corresponding to the key grooves 33 of the hub wheel 1 are formed on the outer periphery of the distal end portion of the shaft portion 34 of the outer joint member (not shown) at equal intervals in the circumferential direction. Like the key groove 23 described above, the key groove 35 is formed so as to be gradually increased in diameter toward the inner side, and a plurality of wedge spaces are formed between the key groove 35 and the key groove 33 of the hub wheel 1. Yes.

  These key grooves 33 and 35 are formed in a rectangular (semi-hexagonal) cross section, and the key groove 35 of the shaft portion 34 is formed so as to be gradually reduced toward the tip. A pin 24 is inserted into a wedge space formed by these key grooves 33 and 35. Thereby, even if the dimensional accuracy of the key grooves 33 and 35 is not strictly regulated, the play between the pin 24 and the key grooves 33 and 35 can be reliably suppressed.

  FIG. 7 shows another modification of the above-described embodiment (FIG. 2). A plurality (four in this case) of key grooves 37 extending in the axial direction are formed on the inner diameter of the outer end of the hub wheel 36 in the circumferential direction. In addition, a plurality of key grooves 39 corresponding to the key grooves 37 of the hub wheel 36 are formed on the outer periphery of the distal end portion of the shaft portion 38 of the outer joint member (not shown) at equal intervals in the circumferential direction. Like the key groove 23 described above, the key groove 39 is inclined so as to gradually increase in diameter toward the inner side, and a plurality of wedge spaces are formed between the key groove 37 of the hub wheel 36. Yes.

  The key grooves 37 and 39 are formed to have a rectangular (half-square) cross section, and the key groove 39 of the shaft portion 38 is formed so as to be gradually reduced toward the tip. A pin 40 is inserted into a wedge space formed by these key grooves 37 and 39.

  The pin 40 is made of carbon steel such as S45C and has a rectangular (semi-rectangular) cross section and is formed in a quadrangular pyramid shape. And the predetermined hardening process is performed in the range of 30-40 HRC by induction hardening.

  FIG. 8 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention. Note that this embodiment basically differs from the above-described embodiment (FIG. 1) only in part in the configuration of the hub wheel, and the same reference numerals are given to the same parts or parts having the same function. Detailed description will be omitted.

  This wheel bearing device has a configuration called a third generation in which the hub wheel 41, the double row rolling bearing 42, and the constant velocity universal joint 3 are detachably unitized. The double-row rolling bearing 42 includes an outer member 6, an inner member 43, and double-row rolling elements 8 and 8.

  The inner member 43 refers to the hub wheel 41 and the inner ring 5, and the hub wheel 41 is integrally formed with a wheel mounting flange 4 at an end portion on the outer side, and has a cylindrical shape that extends in the axial direction from the inner rolling surface 1a on the outer periphery. A small-diameter step portion 1b is formed, and a key groove 22 and a through hole 12 are formed on the inner periphery. An inner ring 5 is press-fitted into the small-diameter step portion 1b via a predetermined scissors, and is fixed in the axial direction by a crimping portion 41a formed by plastically deforming an end portion of the small-diameter step portion 1b radially outward. The shaft portion 20 of the outer joint member 14 is fitted into the through hole 12.

  The hub wheel 41 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the inner rolling surface 1a to the small diameter step portion 1b from the base portion 4b on the inner side of the wheel mounting flange 4. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. The caulking portion 41a is unquenched after forging.

  In this embodiment, since the inner ring 5 is fixed to the hub ring 41 with a predetermined bearing preload applied by the crimping portion 41a, the fixing bolt 30 is firmly attached to the shaft portion 20 as compared with the above-described embodiment. Since it is not necessary to fasten, the assembling work is simplified and the cost can be further reduced.

  FIG. 9 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention. Note that this embodiment is basically different from the above-described embodiment (FIG. 1) only in the key configuration, and other parts and parts having the same parts or parts having the same functions are denoted by the same reference numerals. Detailed description is omitted.

  This wheel bearing device has a configuration called a third generation in which the hub wheel 1, the double row rolling bearing 42, and the constant velocity universal joint 3 are detachably unitized.

  In the present embodiment, a plurality of key grooves 22 extending in the axial direction are formed on the outer diameter of the outer end of the hub wheel 1 at equal intervals in the circumferential direction. In addition, a plurality of key grooves 23 corresponding to the key grooves 22 of the hub wheel 1 are formed on the outer periphery of the distal end portion of the shaft 20 of the outer joint member 14 at equal intervals in the circumferential direction. The key groove 23 is formed so as to be gradually increased in diameter toward the inner side, and a plurality of wedge spaces are formed between the key groove 23 and the key groove 22 of the hub wheel 1.

  The key grooves 22 and 23 are formed in a circular arc surface having a substantially semicircular cross section, the key groove 22 of the hub wheel 1 is formed in a cylindrical shape, and the key groove 23 of the shaft portion 20 faces the tip. Thus, it is formed in a conical shape with a gradually decreasing diameter. And the pin part 44b of the engaging member 44 is inserted in the wedge space formed by these key grooves 22 and 23.

  The engagement member 44 is made of carbon steel such as S45C, and as shown in FIG. 10 (a), the washer and the pin described above are integrated, and a disc-shaped base portion 44a and an axial direction from the side surface of the base portion 44a. A pin portion 44a that protrudes and has a conical shape is integrally provided. A plurality (four in this case) of these pin portions 44b are formed at equal intervals in the circumferential direction. And the predetermined hardening process is performed in the range of 30-40 HRC by induction hardening.

  In addition, as a material of the engaging member 44, it does not restrict to what was illustrated, For example, it forms with high carbon chromium bearing steel, such as SUJ2, and it may harden in the range of 30-40HRC to a core part by quenching. Further, it may be formed of carburized steel such as SCr420 or SCM415, and the surface may be hardened in a range of 30 to 40 HRC by carburizing and quenching.

Next, the assembly method of the wheel bearing device according to the present invention will be described with reference to FIG.
Similarly to the above-described embodiment (FIG. 5), after the shaft portion 20 of the outer joint member 14 is fitted to the hub wheel 1 until the shoulder portion 19 of the outer joint member 14 abuts on the inner ring 5 (not shown), The fixing bolt 30 is attached to the joint member 44 via a washer 45 with an end. Then, by engaging the male screw 30a of the fixing bolt 30 with the female screw 21 of the shaft portion 20, it engages with a wedge space formed between the key groove 22 of the hub wheel 1 and the key groove 23 of the shaft portion 20. The pin portion 44b of the member 44 is inserted and the pin portion 44b bites into the key grooves 22 and 23, and the hub wheel 1 and the outer joint member 14 are coupled to be separable in the axial direction. By adopting such an engaging member 44, both the hub wheel 1 and the outer joint member 14 can be integrated by eliminating the circumferential play, and the number of parts can be reduced to reduce the number of assembly steps. Cost reduction can be achieved.

  FIG. 11 is a longitudinal sectional view showing a fourth embodiment of the wheel bearing device according to the present invention. This embodiment basically differs from the above-described embodiment (FIG. 9) only in part in the configuration of the hub wheel, and the same reference numerals are given to other parts and parts having the same function or the same function. Detailed description will be omitted.

  This wheel bearing device has a configuration called a third generation in which the hub wheel 41, the double row rolling bearing 42, and the constant velocity universal joint 3 are detachably unitized. The double-row rolling bearing 42 includes an outer member 6, an inner member 43, and double-row rolling elements 8 and 8.

  The inner member 43 refers to the hub wheel 41 and the inner ring 5, and the hub wheel 41 is integrally formed with a wheel mounting flange 4 at an end portion on the outer side, and has a cylindrical shape that extends in the axial direction from the inner rolling surface 1a on the outer periphery. A small-diameter step portion 1b is formed, and a key groove 22 and a through hole 12 are formed on the inner periphery. An inner ring 5 is press-fitted into the small-diameter step portion 1b via a predetermined scissors, and is fixed in the axial direction by a crimping portion 41a formed by plastically deforming an end portion of the small-diameter step portion 1b radially outward. The shaft portion 20 of the outer joint member 14 is fitted into the through hole 12.

  In this embodiment, since the inner ring 5 is fixed to the hub ring 41 with a predetermined bearing preload applied by the crimping portion 41a, the fixing bolt 30 is firmly attached to the shaft portion 20 as compared with the above-described embodiment. Since it is not necessary to fasten, the assembling work is simplified and the cost can be further reduced.

  FIG. 12 is a longitudinal sectional view showing a fifth embodiment of the wheel bearing device according to the present invention. This embodiment is basically different from the above-described embodiment (FIG. 1) only in the bearing structure, and other parts and parts having the same parts or parts having the same functions are denoted by the same reference numerals. The detailed explanation is omitted.

  The wheel bearing device has a so-called second generation configuration in which the hub wheel 46, the double row rolling bearing 47, and the constant velocity universal joint 3 are detachably unitized. The double row rolling bearing 47 includes an outer member 6, a pair of inner rings 5 and 5, and double row rolling elements 8 and 8.

  The hub wheel 46 integrally has a wheel mounting flange 4 at an end portion on the outer side, and a cylindrical small-diameter step portion 46b extending in the axial direction from the wheel mounting flange 4 to the outer periphery via a shoulder portion 46a is formed. Yes. The inner ring 5 is press-fitted into the small-diameter step portion 46 b via a predetermined shimiro, and the shaft portion 20 of the outer joint member 14 is fitted into the through hole 12.

  The hub wheel 46 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is hardened by induction hardening from the inner rolling surface 5a to the small diameter step portion 46b from the shoulder portion 46a. The hardening process is given to the range of 50-64HRC.

  Here, a plurality of key grooves 22 extending in the axial direction are formed in the outer end inner diameter of the hub wheel 46 in the circumferential direction, and the outer periphery of the end of the shaft 20 of the outer joint member 14 is formed on the outer periphery of the hub ring 46. A plurality of key grooves 23 corresponding to the key grooves 22 are formed at equal intervals in the circumferential direction.

  The key grooves 22 and 23 are formed in a circular arc surface having a substantially semicircular cross section, the key groove 22 of the hub wheel 46 is formed in a cylindrical shape, and the key groove 23 of the shaft portion 20 faces the tip. It is formed in a conical shape that gradually becomes smaller in diameter. A pin 24 is inserted into a wedge space formed by these key grooves 22 and 23.

  FIG. 13: is a longitudinal cross-sectional view which shows 6th Embodiment of the wheel bearing apparatus which concerns on this invention. Note that this embodiment basically differs from the above-described embodiment (FIG. 12) only in part in the configuration of the hub wheel, and the same reference numerals are given to other parts and parts having the same function or the same function. Detailed description will be omitted.

  This wheel bearing device has a configuration called a second generation in which the hub wheel 48, the double row rolling bearing 47, and the constant velocity universal joint 3 are detachably unitized. The double row rolling bearing 47 includes an outer member 6, a pair of inner rings 5 and 5, and double row rolling elements 8 and 8.

  The hub wheel 48 integrally has a wheel mounting flange 4 at an end portion on the outer side, and a cylindrical small diameter step portion 46b extending in an axial direction from the wheel mounting flange 4 via a shoulder portion 46a is formed on the outer periphery. A key groove 22 and a through hole 12 are formed on the inner periphery. A pair of inner rings 5 and 5 are press-fitted into the small-diameter step portion 46b through a predetermined scissors, and are fixed in the axial direction by a caulking portion 41a formed by plastically deforming an end portion of the small-diameter step portion 46b radially outward. Has been. The shaft portion 20 of the outer joint member 14 is fitted into the through hole 12.

  In the present embodiment, since the inner ring 5 is fixed to the hub ring 48 with a predetermined bearing preload applied by the caulking portion 41a, the fixing bolt 30 is firmly attached to the shaft portion 20 as compared with the above-described embodiment. Since it is not necessary to fasten, the assembling work is simplified and the cost can be further reduced.

  FIG. 14 is a longitudinal sectional view showing a seventh embodiment of the wheel bearing device according to the present invention. Note that this embodiment basically differs from the above-described embodiment (FIG. 12) only in the configuration of the keys, and the same reference numerals are given to the same parts or parts having the same functions or parts having the same functions. Detailed description is omitted.

  This wheel bearing device has a configuration called a second generation in which the hub wheel 46, the double row rolling bearing 47, and the constant velocity universal joint 3 are detachably unitized.

  In the present embodiment, a plurality of key grooves 22 extending in the axial direction are formed on the outer diameter of the outer end of the hub wheel 46 in the circumferential direction, and the hub wheel is formed on the outer periphery of the distal end of the shaft 20 of the outer joint member 14. A plurality of key grooves 23 corresponding to 46 key grooves 22 are formed at equal intervals in the circumferential direction. The key groove 23 is formed so as to be gradually increased in diameter toward the inner side, and a plurality of wedge spaces are formed between the key groove 23 and the key groove 22 of the hub wheel 46.

  The key grooves 22 and 23 are formed in a circular arc surface having a substantially semicircular cross section, the key groove 22 of the hub wheel 46 is formed in a cylindrical shape, and the key groove 23 of the shaft portion 20 faces the tip. Thus, it is formed in a conical shape with a gradually decreasing diameter. And the pin part 44b of the engaging member 44 is inserted in the wedge space formed by these key grooves 22 and 23.

  FIG. 15: is a longitudinal cross-sectional view which shows 8th Embodiment of the wheel bearing apparatus which concerns on this invention. Note that this embodiment basically differs from the above-described embodiment (FIG. 14) only in part in the configuration of the hub wheel, and other parts and parts having the same function or similar functions are denoted by the same reference numerals. Detailed description will be omitted.

  This wheel bearing device has a configuration called a second generation in which the hub wheel 48, the double row rolling bearing 47, and the constant velocity universal joint 3 are detachably unitized. The double row rolling bearing 47 includes an outer member 6, a pair of inner rings 5 and 5, and double row rolling elements 8 and 8.

  The hub wheel 48 integrally has a wheel mounting flange 4 at an end portion on the outer side, and a cylindrical small diameter step portion 46b extending in an axial direction from the wheel mounting flange 4 via a shoulder portion 46a is formed on the outer periphery. A key groove 22 and a through hole 12 are formed on the inner periphery. A pair of inner rings 5 and 5 are press-fitted into the small-diameter step portion 46b through a predetermined scissors, and are fixed in the axial direction by a caulking portion 41a formed by plastically deforming an end portion of the small-diameter step portion 46b radially outward. Has been. The shaft portion 20 of the outer joint member 14 is fitted into the through hole 12.

  In this embodiment, since the inner ring 5 is fixed to the hub ring 48 in a state where a predetermined bearing preload is applied by the caulking portion 41a as in the above-described embodiment, the fixing bolt 30 is compared with the above-described embodiment. Since it is not necessary to securely fasten to the shaft portion 20, the assembling work is simplified and the cost can be further reduced.

  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 is a wheel bearing device in which a bearing portion having a hub wheel and a constant velocity universal joint are connected via a pin so that torque can be transmitted, and both are detachably unitized by screw means. Can be applied.

1, 36, 41, 46, 48 Hub wheel 1a, 5a Inner rolling surface 1b Small diameter step 2, 42, 47 Double row rolling bearing 3 Constant velocity universal joint 4 Wheel mounting flange 4a Hub bolt 4b Inner side of wheel mounting flange Base part 5 Inner ring 6 Outer member 6a Outer rolling surface 6b Car body mounting flange 7, 43 Inner member 8 Rolling body 9 Cage 10, 11 Seal 12 Through hole 12a, 20a Fitting part 12b, 20b Inner part 13, 25 , 26, 27, 28 Hardened layer 14 Outer joint member 15 Joint inner ring 15a, 18a Track groove 16 Cage 17 Torque transmission ball 18 Mouse part 19, 46a Shoulder part 20, 34, 38 Shaft part 21 Female thread 22, 23, 33, 35 , 37, 39 Key groove 24, 40 Pin 29, 45 Washer 30 Fixing bolt 30a Male thread 31 Pilot part 41a Caulking part 44 Engaging member 44a Base 44b Pin 50 Hub wheels 50a, 56a Inner rolling surfaces 46b, 50b, 67a Small diameter step 51 Double row rolling bearing 52 Constant velocity universal joint 53 Wheel mounting flange 54, 67b Serration 55 Cylindrical surface 56 Inner ring 57 Caulking Portion 58 Outer member 58a Outer rolling surface 58b Car body mounting flange 59 Inner member 60 Ball 61 Cage 62, 63 Seal 64 Outer joint member 65 Mouse part 66 Shoulder part 67 Shaft part 67c Male thread 68 Fixed nut 69 Joint inner ring 70 Cage 71 Torque transmission ball δ1 Axial clearance δ2 Radial clearance

Claims (8)

An outer member integrally having a vehicle body mounting flange for being attached to the vehicle body on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
It has a wheel mounting flange integrally at one end, a hub wheel formed with a cylindrical small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub wheel, An inner member in which a double row inner rolling surface facing the double row outer rolling surface is formed;
A double row rolling element accommodated between the rolling surfaces so as to roll freely;
Constructing a constant velocity universal joint, comprising a cup-shaped mouth part, a shoulder part forming the bottom part of the mouth part, and an outer joint member integrally having a shaft part extending in the axial direction from the shoulder part,
The hub portion and the outer joint member are separated in the axial direction by a screw that is fitted into the hub wheel until the shoulder portion abuts on the inner member, and is fastened to a tip portion of the shaft portion. In a possible coupled wheel bearing device,
A through hole is formed in the inner periphery of the hub wheel, which includes a fitting portion and an inrow portion formed larger in diameter than the fitting portion, and the shaft portion of the outer joint member is fitted into the through hole. ,
A plurality of key grooves extending in the axial direction are formed on the outer diameter of the outer end of the hub wheel in the circumferential direction, and the key grooves corresponding to these key grooves are circumferentially arranged on the outer periphery of the distal end portion of the shaft of the outer joint member. A plurality of them are formed equally,
A plurality of wedge spaces are formed between the key grooves and the key grooves of the hub wheel so that the diameter gradually increases toward the inner side, and pins are inserted into the wedge spaces. The wheel bearing device is characterized in that the hub wheel and the outer joint member are coupled so as to be able to transmit torque.   A female screw is formed at the tip of the shaft portion of the outer joint member, and a washer is attached to the fixing bolt. The washer is brought into contact with the pin, and the male screw of the fixing bolt is screwed into the female screw of the shaft portion. The wheel bearing device according to claim 1, wherein   The wheel bearing device according to claim 1, wherein the pin has a circular cross section and is formed in a conical shape.   The wheel bearing device according to claim 1, wherein the pin has a rectangular cross section and is formed in a pyramid shape.   The surface of the pin and the key groove is subjected to a predetermined curing process, the surface hardness of the key groove is higher than the surface hardness of the pin, and the difference in surface hardness is set to 20 HRC or more. The wheel bearing device described.   The said pin is integrated with a washer, and is comprised by the engaging member which integrally provided the disk-shaped base part and the pin part formed in the conical shape which protruded from the side surface of this base part to the axial direction. The wheel bearing apparatus in any one of thru | or 4.   The shaft portion includes a fitting portion that fits into the through-hole of the hub wheel, and an inrow portion that has a larger diameter than the fitting portion, and the fitting portion of the hub wheel is the shaft portion. The hub wheel in-row part is inserted into the in-row part of the shaft part through a predetermined radial clearance, and is inserted into the fitting surface. The wheel bearing device according to claim 1, wherein the hardening treatment is performed.   The inner ring is fixed to the hub ring in the axial direction in a state where a predetermined bearing preload is applied by a caulking portion formed by plastically deforming an end portion of the small-diameter step portion of the hub ring radially outward. The wheel bearing device according to claim 1, wherein

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