Hub assembly

Abstract

The present invention provides a hub assembly for a wheel bearing device and a constant velocity universal joint that can suppress slippage such as stick-slip and can be easily manufactured. [Solution] This hub assembly 41 connects a wheel bearing device 1 and a constant velocity universal joint 21 in a way that enables power transmission. An inner ring 4 is press-fitted onto the outer circumference of a hub ring 3 from the inboard side, and an annular connecting member 14 is fitted onto the outer circumference of the hub ring 3 with the inner ring 4 in axial contact with its inboard side. The inner ring 4 and the connecting member 14 are clamped and fixed to the hub ring 3 by the radially outward plastic deformation of the inboard end of the hub ring 3, and the outer joint member 22 of the constant velocity universal joint 21 and the connecting member 14 are connected to each other by serration fitting.

Description

Technical Field

[0001] The present invention relates to a hub assembly, and particularly to a hub assembly of a wheel bearing device and a constant velocity joint.

Background Art

[0002] For example, a power transmission device that transmits engine power to wheels in an automobile or the like transmits power from the engine to the wheels, and in addition to angular displacement and axial displacement due to vehicle bounce during driving, allows angular displacement for vehicle turning. Therefore, generally, a drive shaft of an automobile or the like has a sliding constant velocity joint that can cope with angular displacement and axial displacement on the differential side (inboard side), and a fixed constant velocity joint that can take a large operating angle on the drive wheel side (outboard side), and has a structure in which both constant velocity joints are connected by a shaft. Further, the constant velocity joint (fixed constant velocity joint) on the drive wheel side is connected to a wheel bearing device that rotatably supports the drive wheel.

[0003] As the power transmission structure between the above-described wheel bearing device and the constant velocity joint, a serration fitting structure between the outer ring stem portion of the constant velocity joint and the hub ring of the wheel bearing device is common (for example, refer to Patent Document 1). Recently, in a wheel bearing device in which an outer joint member is connected to an inner ring member plastically bonded to a hub ring via a serration and is axially separably fastened by screw means, a connecting portion protrudes from the inner ring member, a female serration is formed thereon, and a male serration is formed on the shoulder portion of the outer joint member. A structure for achieving power transmission between the wheel bearing device and the constant velocity joint through a portion where these serrations are fitted to each other has also been proposed. In this case, the hub ring and the inner ring member are integrally plastically bonded, the outer joint member is connected to the inner ring member via a serration, and the outer joint member is axially separably fastened to the inner ring member by screw means (for example, refer to Patent Document 2).

[0004] In conventional power transmission structures (serrated fitting structure between the outer ring stem and the hub ring), when high torque is input from the vehicle, deformation such as twisting can cause the axial end face of the hub ring to slip against the axial end face of the outer ring of the constant velocity universal joint, which are butted against each other in the axial direction (a stick-slip phenomenon occurs), potentially leading to the generation of abnormal noise and vibration. In contrast, when a structure is adopted in which serrations are provided on the outer circumference of the shoulder portion of the outer joint member of the constant velocity universal joint and on the inner circumference of the connecting portion protruding from the inboard side of the inner ring member, and power is transmitted by the fitting of these serrations, the torsional rigidity of the torque transmission section (serrated fitting section) is improved, and the amount of slippage at the axial contact surface between the inner ring member and the outer joint member is reduced, thereby suppressing the generation of abnormal noise and vibration. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-129698 [Patent Document 2] Japanese Patent Publication No. 2007-69704 [Overview of the project] [Problems that the invention aims to solve]

[0006] On the other hand, the serrated fitting structure between the inner ring member and the outer joint member, described later, is expected to be more difficult to implement in the vehicle assembly process compared to the conventional serrated fitting structure between the outer ring stem and the hub ring. In other words, the serrated fitting structure between the inner ring member and the outer joint member is characterized by plastic bonding between the inner circumference of the hub ring and the outer circumference of the inner ring member as a structural feature of the wheel bearing device components. Therefore, in order to maintain the accuracy of the wheel bearing device after plastic bonding in the manufacturing process, high-precision machining, such as the coaxiality of the hub ring and the inner ring member, is required, which inevitably increases costs. In addition, since a predetermined load must be applied to the inner ring member during plastic bonding, preload control of the bearing section becomes difficult. This makes practical production difficult.

[0007] In view of the above circumstances, this specification aims to provide a hub assembly for a wheel bearing device and a constant velocity universal joint that can suppress slippage such as stick-slip and can be easily manufactured. [Means for solving the problem]

[0008] The aforementioned problems are solved by the hub assembly according to the present invention. Specifically, this hub assembly is a hub assembly of a wheel bearing device and a constant velocity universal joint, wherein the wheel bearing device comprises an outer member, a hub ring and an inner ring disposed radially inward of the outer member, and rolling elements disposed between the outer member and the hub ring, and between the outer member and the inner ring, wherein the inner ring is press-fitted onto the outer circumference of the hub ring from the inboard side, an annular connecting member is fitted onto the outer circumference of the hub ring with the inner ring and its inboard side in axial contact, the inner ring and the connecting member are clamped and fixed to the hub ring by the radially outward plastic deformation of the inboard end of the hub ring, and the outer joint member and the connecting member of the constant velocity universal joint are connected to each other by serration fitting.

[0009] As described above, the hub assembly according to the present invention is provided with a structure in which the connecting member fitted to the outer circumference of the hub ring and the outer joint member of the constant velocity universal joint are interconnected by serration fitting, thereby improving the torsional rigidity of the torque transmission section (serration fitting section). Therefore, when high torque is input, the amount of slippage at the axial contact portion between the inner member (hub ring) and the outer joint member is reduced, making it possible to suppress slippage such as stick-slip, and consequently the generation of abnormal noise and vibration caused by such slippage.

[0010] Furthermore, in the hub assembly according to the present invention, a connecting member, which is a separate component from both the hub ring and the inner ring that constitute the wheel bearing device, is newly provided, and the connecting member is clamped and fixed to the hub ring together with the inner ring by plastic deformation of the radially outward end of the inboard side of the hub ring. With this configuration, the wheel bearing device can be assembled in the same way as before. In addition, the machining and assembly accuracy of the hub ring and inner ring can be substantially at the same level as before. The preload of the bearing part can also be controlled by the same means (crimping) as before. As described above, with the hub assembly according to the present invention, it is possible to produce (mass produce) this hub assembly with the same productivity and production cost as before.

[0011] Furthermore, in the hub assembly according to the present invention, the connecting member integrally comprises a ring portion fitted onto the outer circumference of the hub ring and a cylindrical portion extending from the outer diameter side of the ring portion to the inboard side, and the portion of the cylindrical portion facing the outer joint member in the radial direction may be connected to the outer joint member by serration fitting.

[0012] By configuring the connecting member in this way, power transmission can be achieved in the largest diameter region of the outer joint member, such as the outer circumferential surface of the shoulder. Therefore, even if the axial dimension cannot be made very long, it is possible to obtain sufficient torsional rigidity to suppress slippage such as stick-slip.

[0013] Furthermore, in the hub assembly according to the present invention, the portion of the ring that faces the hub ring in the radial direction may be connected to the hub ring by a serration fitting.

[0014] By using this structure, in which the hub ring and the ring portion are connected by a serrated fitting, power transmission between the hub ring and the connecting member can be performed reliably and without slippage. Therefore, power transmission between the wheel bearing device and the constant velocity universal joint via the connecting member can be performed smoothly and without loss.

[0015] Furthermore, in the hub assembly according to the present invention, a relatively hard uneven portion may be formed on either the ring portion or the hub ring that are facing each other in the radial direction, and the other portion that is facing each other in the radial direction may bite into the uneven portion and be joined together.

[0016] By using this structure in which the hub ring and the ring portion are joined, the hub ring and the connecting member can be engaged in the circumferential direction, thereby enabling smooth power transmission between the hub ring and the connecting member. Furthermore, by using a structure in which the joining is achieved by biting into the relatively hard uneven surface, when the connecting member is clamped and fixed to the hub ring by plastic deformation such as crimping, it is possible to simultaneously bite into the uneven surface. Therefore, it becomes possible to easily connect the connecting member and the hub ring in a power-transmitting manner without having to perform circumferential alignment as in serration fitting.

[0017] Furthermore, in the hub assembly according to the present invention, a relatively hard uneven portion may be formed on either the ring portion or the hub ring that face each other in the axial direction, and the other portion that faces each other in the axial direction may bite into the uneven portion and be joined together.

[0018] By using this structure to connect the hub ring and the ring portion, the hub ring and the connecting member can be engaged in the circumferential direction, thereby enabling smooth power transmission between the hub ring and the connecting member. Furthermore, by using a structure in which the connection is made by biting into the relatively hard uneven portion, when the connecting member is clamped and fixed to the hub ring by plastic deformation such as crimping, it is possible to simultaneously bite into the uneven portion. Therefore, it is possible to easily connect the connecting member and the hub ring in a power-transmitting manner without having to perform circumferential alignment as in serration fitting. In particular, by providing uneven portions on the parts facing each other in the axial direction, it is possible to bite into the uneven portion more easily by the plastic deformation (plastic deformation) described above.

[0019] Furthermore, the aforementioned problems can also be solved by the hub assembly assembly method according to the present invention. Specifically, this assembly method is a method for assembling a hub assembly of a wheel bearing device and a constant velocity universal joint, characterized in that an inner ring is press-fitted onto the outer circumference of a hub ring, which together constitutes the wheel bearing device, and an annular connecting member is fitted onto the outer circumference of the hub ring, causing the connecting member to abut against the inner ring from the inboard side, and then the inboard end of the hub ring is plastically deformed radially outward to clamp and fix the inner ring and the connecting member to the hub ring, and then the outer joint member and the connecting member of the constant velocity universal joint are connected to each other by serration fitting.

[0020] According to the assembly method of the present invention, similar to the hub assembly according to the present invention, a structure can be provided in which the connecting member fitted to the outer circumference of the hub wheel and the outer joint member of the constant velocity universal joint are interconnected by serration fitting, thereby improving the torsional rigidity of the torque transmission section (serration fitting section). Therefore, when high torque is input, the amount of slippage at the axial contact portion between the hub wheel and the outer joint member can be reduced, making it possible to suppress slippage such as stick-slip, and consequently the generation of abnormal noise and vibration caused by such slippage.

[0021] Furthermore, in the hub assembly assembly method according to the present invention, a connecting member, which is a separate component from both the hub ring and the inner ring constituting the wheel bearing device, is newly provided, and the connecting member is clamped and fixed to the hub ring together with the inner ring by plastic deformation of the radially outward end of the inboard side of the hub ring. By adopting this configuration, the wheel bearing device can be assembled in the same way as conventional methods. In addition, the machining and assembly accuracy of the hub ring and the inner ring can be substantially at the same level as conventional methods. The preload of the bearing part can also be controlled by the same means (crimping) as conventional methods. As described above, the hub assembly assembly method according to the present invention makes it possible to produce this hub assembly with the same productivity and production cost as conventional methods. [Effects of the Invention]

[0022] As described above, according to the present invention, it is possible to provide a hub assembly of a wheel bearing device and a constant velocity joint that can suppress slipping such as stick-slip and can be easily produced.

Brief Description of the Drawings

[0023] [Figure 1] It is a cross-sectional view of a hub assembly of a wheel bearing device and a constant velocity joint according to a first embodiment of the present invention. [Figure 2] It is an enlarged cross-sectional view of a main part of the hub assembly shown in FIG. 1. [Figure 3] It is an enlarged cross-sectional view of a main part of a hub assembly of a wheel bearing device and a constant velocity joint according to a second embodiment of the present invention. [Figure 4] It is an enlarged cross-sectional view of a main part of a hub assembly of a wheel bearing device and a constant velocity joint according to a third embodiment of the present invention.

Modes for Carrying Out the Invention

[0024] Hereinafter, a first embodiment of the present invention will be described based on the drawings. First, after explaining the basic configurations of the wheel bearing device and the constant velocity joint, details of the power transmission structure and the connection and fixing structure between the wheel bearing device and the constant velocity joint will be described.

[0025] Figure 1 shows a hub assembly 41 of a wheel bearing device 1 and a constant velocity universal joint 21. In this embodiment, the wheel bearing device 1 is unitized and is configured to be detachably attached to the unitized constant velocity universal joint 21. Here, the wheel bearing device 1 mainly comprises an outer member 2, a hub ring 3, an inner ring 4, balls 5 as rolling elements, and a cage 6. Double rows of outer raceway surfaces 7, 7 are formed on the inner circumference of the outer member 2, and a vehicle body mounting flange 8 for attachment to a vehicle body knuckle (not shown) is integrally formed on the outer circumference of the outer member 2. A wheel mounting flange 9 for attaching a wheel (not shown) is integrally formed on the outboard side of the hub ring 3, and an inner raceway surface 10 facing one of the double rows of outer raceway surfaces 7, 7 of the outer member 2 and a cylindrical small-diameter stepped portion 11 extending axially from this inner raceway surface 10 are formed on the outer circumference. An inner ring 4 is press-fitted into this small-diameter stepped portion 11, and an inner raceway surface 10 is formed on the outer circumference of the inner ring 4, opposite to the other of the double-row outer raceway surfaces 7, 7 of the outer member 2. In this case, the inner member 12 is composed of the hub ring 3, the inner ring 4, and a connecting member 14, which will be described later. Multiple balls 5, 5 are rotatably incorporated between the double-row outer raceway surfaces 7, 7 of the outer member 2 and the double-row inner raceway surfaces 10, 10 of the inner member 12, and each ball 5 is housed in a retainer 6. The inner ring 4 is fixed axially by a crimping portion 13 formed by plastically deforming the inboard end of the small-diameter stepped portion 11 of the hub ring 3 radially outward.

[0026] Furthermore, the wheel bearing device 1 further includes a connecting member 14. This connecting member 14 is formed separately from the outer member 2, the hub ring 3, and the inner ring 4, and is connectable to the constant velocity universal joint 21 by serration fitting. In other words, the connecting member 14 is interposed between the wheel bearing device 1 and the constant velocity universal joint 21 and functions as an element for power transmission.

[0027] The connecting member 14 as a whole is annular in shape and, as shown in Figure 2, integrally has a ring portion 15 that fits onto the outer circumference of the hub wheel 3 and a cylindrical portion 16 that extends from the outer diameter side of the ring portion 15 to the inboard side.

[0028] Of these, the ring portion 15 is fitted onto the outer circumference of the hub wheel 3 while in axial contact with the inner ring 4 on its inboard side (see Figure 1). Then, due to the radial outward plastic deformation of the axial end of the small-diameter stepped portion 11 of the hub wheel 3, a crimp portion 13 is formed on the inboard side of the ring portion 15, and the inner ring 4 and the ring portion 15 are clamped and fixed to the hub wheel 3 by this crimp portion 13 and the hub wheel 3 body located on the outboard side of the inner ring 4 (see Figure 1).

[0029] In this embodiment, the radial dimension of the connecting member 14 (ring portion 15) is set to a predetermined size so that the end face of the inner ring 4 abuts against the end face of the connecting member 14 (ring portion 15) over its entire length. Also in this embodiment, the inner diameter of the cylindrical portion 16 (or the outer diameter of the crimping portion 13) is set to a predetermined size so that a predetermined space (radial gap) is formed between it and the crimping portion 13 (see Figure 2 for both).

[0030] Furthermore, a structure is provided between the connecting member 14 and the hub wheel 3 to enable power (especially torque) transmission between the connecting member 14 and the hub wheel 3. In this embodiment, the portion of the ring portion 15 that faces the hub wheel 3 in the radial direction (here, the inner diameter end portion 15a) is connected to the hub wheel 3 by serration fitting. In this case, a first serration portion 17 is formed on the inner diameter end portion 15a of the ring portion 15. In addition, a second serration portion 18 is formed on the portion of the hub wheel 3 that faces the ring portion 15 in the radial direction (here, the region of the small diameter stepped portion 11 that is axially close to the crimping portion 13).

[0031] The serrated portion 18 engages with the first serrated portion 17 by fitting the ring portion 15 onto the outer circumference of the small-diameter stepped portion 11 of the hub wheel 3, accompanied by circumferential alignment. This enables bidirectional power (torque) transmission between the hub wheel 3 and the connecting member 14.

[0032] Here, the first serrated portion 17 is made up of multiple teeth 19 arranged in the circumferential direction as convex portions. In this embodiment, each tooth 19 extends along the axial direction of the ring portion 15 on which the first serrated portion 17 is provided, and its cross-sectional shape is the same at any axial position. The inner diameter dimensions of each tooth 19 and the spaces between each tooth 19 (tooth roots) are the same at any axial position. The second serrated portion 18 is made up of multiple teeth 20 arranged in the circumferential direction as convex portions, similar to the first serrated portion 17. In this embodiment, each tooth 20 extends along the axial direction of the small-diameter stepped portion 11 on which the second serrated portion 18 is provided, and its cross-sectional shape is the same at any axial position. The outer diameter dimensions of each tooth 20 and the spaces between each tooth 20 (tooth roots) are the same at any axial position.

[0033] In this embodiment, with the crimping portion 13 formed and the inner ring 4 and connecting member 14 clamped and fixed to the hub ring 3, the axial position and axial dimensions of the second serration portion 18 are set such that a part of the outboard side of the second serration portion 18 does not fit with the first serration portion 17, or in other words, the outboard end of the first serration portion 17 fits securely with the second serration portion 18 (see Figure 2). Furthermore, in order to minimize deformation of the second serration portion 18 provided on the outer circumference of the small-diameter step portion 11 during the forming of the crimping portion 13, a relatively small diameter relief portion 13a is provided at the outboard end of the second serration portion 18 (see Figure 2).

[0034] Of course, the forms of the serrated sections 17 and 18 described above are merely examples. The configuration is arbitrary, as long as the serration fitting connects the hub wheel 3 and the connecting member 14 in a way that enables power transmission.

[0035] These serrated portions 17 and 18 can be formed by various known methods (such as cutting and plastic deformation). The first serrated portion 17 may be formed simultaneously with the molding of the ring portion 15, or it may be formed by a separate process after the ring portion 15 has been molded. Similarly, the second serrated portion 18 may be formed simultaneously with the molding of the hub ring 3 (small diameter stepped portion 11), or it may be formed by a separate process after the small diameter stepped portion 11 has been molded.

[0036] On the other hand, the constant velocity universal joint 21 mainly comprises an outer joint member 22, an inner joint member 23, a retainer 24, and a torque transmission ball 25. The outer joint member 22 consists of a cup portion 26 and a bottom portion 27 formed integrally with the cup portion 26 (see Figure 1). In this case, a third serration portion 29 is formed on the outer circumference of a shoulder portion 28 corresponding to the radially outer region of the bottom portion 27. On the other hand, a fourth serration portion 30 is formed in the cylindrical portion 16 of the connecting member 14, in the portion that faces the third serration portion 29 in the radial direction. Therefore, power transmission between the outer joint member 22 and the connecting member 14 is possible by fitting these third serration portion 29 and fourth serration portion 30 together (see Figure 2). For example, if rotational torque is input from a shaft (not shown) connected to the inner joint member 23 of the constant velocity universal joint 21, this rotational torque can be transmitted to the wheel mounting flange 9 via the constant velocity universal joint 21, the connecting member 14 of the wheel bearing device 1, and the hub wheel 3.

[0037] Here, the third serration portion 29 is made up of multiple teeth 31 arranged in the circumferential direction as convex portions. In this embodiment, each tooth 31 extends along the axial direction of the outer joint member 22 on which the third serration portion 29 is provided, and its cross-sectional shape is the same at any axial position. The inner diameter dimensions of each tooth 31 and the spaces between each tooth 31 (tooth roots) are the same at any axial position. The fourth serration portion 30 is made up of multiple teeth 32 arranged in the circumferential direction as convex portions, similar to the third serration portion 29. In this embodiment, each tooth 32 extends along the axial direction of the cylindrical portion 16 on which the fourth serration portion 30 is provided, and its cross-sectional shape is the same at any axial position. The outer diameter dimensions of each tooth 32 and the spaces between each tooth 32 (tooth roots) are the same at any axial position.

[0038] In this embodiment, the axial position and axial dimensions of each serration portion 29, 30 are set such that, when the crimping portion 13 and the outer joint member 22 are in axial contact, the third serration portion 29 fits with the fourth serration portion 30 over its entire axial area (see Figure 2).

[0039] Of course, the forms of the serrated portions 29 and 30 described above are merely examples. The configuration is arbitrary, as long as the connecting member 14 and the outer joint member 22 are connected in a way that enables power transmission through serration fitting.

[0040] These serrated portions 29 and 30 can be formed by various known methods (such as cutting and plastic deformation). The third serrated portion 29 may be formed simultaneously with the molding of the outer joint member 22, or it may be formed by a separate process after the outer joint member 22 has been molded. Similarly, the fourth serrated portion 30 may be formed simultaneously with the molding of the connecting member 14 (cylindrical portion 16), or it may be formed by a separate process after the connecting member 14 has been molded.

[0041] The wheel bearing device 1 and the constant velocity universal joint 21 in the above configuration are fastened together by bolts 33 so as to be separable in the axial direction. Specifically, a female screw hole 34 is provided in the bottom 27 of the outer joint member 22, and with the wheel bearing device 1 and the constant velocity universal joint 21 butted together in the axial direction, the bolts 33 are inserted through the through hole 35 of the hub wheel 3 from the outboard side and screwed into the female screw hole 34 to connect them to each other.

[0042] The hub assembly 41 with the above configuration can be assembled, for example, by the following procedure.

[0043] First, the assembled (unitized) wheel bearing device 1 and constant velocity universal joint 21 are prepared. Of these, the wheel bearing device 1 is assembled with all elements except the inner ring 4 and the connecting member 14 assembled, and the inner ring 4 is pressed onto the outer circumference of the hub ring 3 before the crimping portion 13 is formed. Then, the ring portion 15 of the connecting member 14 is fitted onto the outer circumference of the hub ring 3 from the inboard side. At this time, by fitting the ring portion 15 onto the outer circumference of the hub ring 3 with circumferential alignment, the first serration portion 17 provided on the inner diameter end 15a of the ring portion 15 is fitted into the second serration portion 18 provided on the outer circumference of the hub ring 3. Furthermore, the fitting of the ring portion 15 is continued until the ring portion 15 abuts the inner ring 4 in the axial direction.

[0044] After fitting the inner ring 4 and the ring portion 15 (connecting member 14) onto the outer circumference of the hub wheel 3 as described above, a crimping portion 13 with the shape shown in Figure 1 is formed by performing plastic deformation on the inboard end of the small-diameter stepped portion 11, which involves plastic deformation radially outward. The inner ring 4 and the connecting member 14 are then clamped and fixed in the axial direction between the outboard side of the hub wheel 3 (hub wheel 3 body) and the crimping portion 13. Furthermore, a predetermined preload is applied to the bearing portion when clamping and fixing the connecting member 14 by crimping. This completes the assembly (unitization) of the wheel bearing device 1.

[0045] Subsequently, the wheel bearing device 1 and the constant velocity universal joint 21 are butted together in the axial direction to integrate them. Specifically, the outer joint member 22 is brought into contact with the crimped portion 13 of the hub wheel 3 in the axial direction, and the fourth serration portion 30 provided on the inner circumferential surface 16a of the cylindrical portion 16 and the third serration portion 29 provided on the outer circumferential surface 28a of the shoulder portion 28 of the outer joint member 22 are fitted together with their circumferential positions aligned. Finally, the bolt 33 is screwed into the female threaded hole 34 of the outer joint member 22 until its flange portion 36 contacts the hub wheel 3 in the axial direction. As a result, the wheel bearing device 1 and the constant velocity universal joint 21 are connected and fixed, and rotational power between the wheel bearing device 1 and the constant velocity universal joint 21 can be transmitted bidirectionally due to the serration fitting of the third serration portion 29 and the fourth serration portion 30.

[0046] As described above, in the hub assembly 41 according to this embodiment, the connecting member 14 fitted to the outer circumference of the hub wheel 3 and the outer joint member 22 of the constant velocity universal joint 21 are connected to each other by serration fitting, thereby improving the torsional rigidity of the torque transmission section (serration fitting section). Therefore, for example, when high torque is input, the amount of slippage at the axial contact portion between the inner member 12 (the crimped portion 13 of the hub wheel 3 in this embodiment) and the outer joint member 22 can be reduced, making it possible to suppress slippage such as stick-slip, and consequently the generation of abnormal noise and vibration caused by such slippage.

[0047] Furthermore, in the hub assembly 41 according to this embodiment, a connecting member 14 is newly provided, which is a separate component from both the hub ring 3 and the inner ring 4 that constitute the wheel bearing device 1. A crimping portion 13 is formed by the radially outward plastic deformation of the inboard end of the hub ring 3, and the connecting member 14 and the inner ring 4 are clamped and fixed to the hub ring 3 by this crimping portion 13 and the outboard side of the hub ring 3. By adopting this configuration, the wheel bearing device 1 can be assembled in the same way as before. In addition, the machining and assembly accuracy of the hub ring 3 and the inner ring 4 can be substantially at the same level as before. The preload of the bearing portion can also be controlled by the same means (crimping) as before. As described above, the hub assembly 41 according to this embodiment makes it possible to produce this hub assembly 41 with the same productivity and production cost as before.

[0048] Furthermore, in this embodiment, the hub wheel 3 and the ring portion 15 of the connecting member 14 are connected by a serrated fitting, so that power transmission between the hub wheel 3 and the connecting member 14 can be performed reliably and without slippage. Therefore, power transmission between the wheel bearing device 1 and the constant velocity universal joint 21 via the connecting member 14 can be performed smoothly and without loss.

[0049] Although the first embodiment of the present invention has been described above, the hub assembly of the wheel bearing device and constant velocity universal joint and the method of assembling the same can take other forms as long as they remain within the scope of the present invention.

[0050] For example, in the above embodiment, the case in which the hub wheel 3 and the ring portion 15 of the connecting member 14 are connected by serration fitting was illustrated, but of course, the hub wheel 3 and the connecting member 14 can also be connected by means other than those described above. Figure 3 shows an enlarged cross-sectional view of the main part of a hub assembly 41 according to one example (second embodiment of the present invention). As shown in Figure 3, in the hub assembly 41 according to this embodiment, a relatively hard first uneven portion 37 is formed on the inner diameter side end 15a of the ring portion 15 that faces the hub wheel 3 in the radial direction, and the portion of the hub wheel 3 that faces the first uneven portion 37 in the radial direction bites into the first uneven portion 37, thereby forming a first plastic joint portion 38. The first uneven portion 37 is formed by arranging, for example, a plurality of convex portions extending in the axial direction of the ring portion 15 and groove portions between the convex portions alternately in the circumferential direction. At least the portion of the hub wheel 3 that faces the first uneven portion 37 in the radial direction is formed to be relatively soft. As a result, a portion of the hub ring 3 enters the relatively recessed portion of the first uneven portion 37 through plastic flow, and is coupled to it. In this case, for example, the hardness difference described above can be created by applying a predetermined hardening treatment to the first uneven portion 37 of the ring portion 15. Of course, if conditions such as cost and processing surface allow, the ring portion 15 (connecting member 14) may be formed from a material that is harder than the hub ring 3.

[0051] By forming a structure in which the hub wheel 3 and the ring portion 15 are joined in this manner, the hub wheel 3 and the connecting member 14 can be engaged in the circumferential direction. Therefore, smooth power transmission can be achieved between the hub wheel 3 and the connecting member 14. Furthermore, by forming a structure in which the connection is made by biting into the relatively hard first uneven portion 37, when the connecting member 14 is clamped and fixed to the hub wheel 3 by plastic deformation such as crimping, it is possible to simultaneously bite into the first uneven portion 37. Therefore, it is possible to easily connect the connecting member 14 and the hub wheel 3 in a power-transmitting manner without having to perform circumferential alignment as in serration fitting.

[0052] The shape of the first uneven portion 37 is, in principle, arbitrary. For example, although not shown in the illustration, multiple convex portions may be formed to extend in a direction that forms a predetermined angle with respect to the axial direction of the ring portion 15. Alternatively, the first uneven portion 37 may have multiple intersecting grooves in a diagonal pattern, similar to the shape obtained by knurling. In short, the first uneven portion 37 can take any shape as long as the ring portion 15 and the hub wheel 3 engage in the circumferential direction by biting from the hub wheel 3 side, and rotational power can be transmitted to each other through the engaging portion.

[0053] Figure 4 shows an enlarged cross-sectional view of the main part of a hub assembly 41 according to yet another embodiment (third embodiment) of the present invention. In the hub assembly 41 according to this embodiment, a relatively hard second uneven portion 39 is formed on the outboard side end of the ring portion 15 that faces the crimping portion 13 of the hub ring 3 in the axial direction, and a plastic joint portion 40 is formed when the portion of the crimping portion 13 that faces the second uneven portion 39 in the axial direction bites into the second uneven portion 39. The second uneven portion 39 is formed by arranging, for example, a plurality of convex portions extending radially of the ring portion 15 and groove portions between the convex portions alternately in the circumferential direction. At least the portion of the crimping portion 13 that faces the second uneven portion 39 in the axial direction is formed to be relatively soft. As a result, a part of the crimping portion 13 enters into the relatively recessed portion of the second uneven portion 39 by plastic flow and is coupled to each other. In this case, for example, the hardness difference described above can be created by applying a predetermined hardening treatment to the second uneven portion 39 of the ring portion 15. Of course, if conditions such as cost and processing surface allow, the ring portion 15 (connecting member 14) may be formed from a material that is harder than the crimped portion 13.

[0054] By forming a structure in which the hub wheel 3 and the ring portion 15 are joined in this manner, the hub wheel 3 and the connecting member 14 can be engaged in the circumferential direction. Therefore, smooth power transmission can be achieved between the hub wheel 3 and the connecting member 14. Furthermore, by forming a structure in which the connection is made by biting into the relatively hard second protrusions 39, when the connecting member 14 is clamped and fixed to the hub wheel 3 by plastic deformation such as crimping, it is possible to simultaneously bite into the second protrusions 39. Therefore, it is possible to easily connect the connecting member 14 and the hub wheel 3 in a power-transmitting manner without having to perform circumferential alignment as in serration fitting. In particular, by providing the second protrusions 39 on opposing portions in the axial direction, it is possible to more easily bite into the second protrusions 39 by the plastic deformation (plastic deformation to form the crimping portion 13) as described above.

[0055] The shape of each of the protrusions 37 and 39 is, in principle, arbitrary. For example, although not shown in the illustration, the first protrusion 37 may have multiple convex portions extending in a direction that forms a predetermined angle with respect to the axial direction of the ring portion 15. The second protrusion 39 may have multiple convex portions extending in a direction that forms a predetermined angle with respect to the radial direction of the ring portion 15. Alternatively, each of the protrusions 37 and 39 may have a shape in which multiple intersecting grooves are provided in a diagonal pattern, similar to the shape obtained by knurling. In short, each of the protrusions 37 and 39 can take any shape as long as the ring portion 15 and the hub ring 3 engage in the circumferential direction by biting from the hub ring 3 side and rotational power can be transmitted to each other through the engaged portion.

[0056] Furthermore, although the above embodiment illustrates the case where each of the protrusions 37 and 39 is provided on the side of the ring portion 15, it is of course possible to provide each of the protrusions 37 and 39 on the side of the opposing hub wheel 3.

[0057] Furthermore, in the above embodiment, an example was given in which one of the first recessed portion 37 and the second recessed portion 39 is provided on the side of the ring portion 15, but of course, both recessed portions 37 and 39 may be provided. In this case, one of the recessed portions 37 and 39 may be provided on the side of the ring portion 15 and the other of the recessed portions 37 and 39 may be provided on the side of the hub wheel 3, or both recessed portions 37 and 39 may be provided on only one side of either the ring portion 15 or the hub wheel 3.

[0058] Furthermore, the above description illustrates a case where a third serration portion 29 is provided on the outer peripheral surface 28a of the shoulder portion 28 of the outer joint member 22 so as to fit with the fourth serration portion 30 provided on the connecting member 14 (cylindrical portion 16), but of course, it is not limited to this. For example, although not shown in the illustration, a third serration portion 29 may be provided on the outer peripheral surface of a cup portion 26 located radially outward from the shoulder portion 28.

[0059] Furthermore, the above description illustrates the case in which the outer joint member 22 and the connecting member 14 (cylindrical portion 16) have third and fourth serration portions 29 and 30 on the radially facing portions of each other. However, other configurations are also possible. For example, although not shown in the illustration, the end face of the outer joint member 22 that abuts the crimping portion 13 in the axial direction may be extended radially, and a third serration portion may be provided on this extended portion, while a fourth serration portion may be provided on the portion of the connecting member 14 (cylindrical portion 16) that faces the third serration portion in the axial direction. In this case, the convex portions forming each serration shape will have a radially extended form. [Explanation of symbols]

[0060] 1. Wheel bearing device 2 Outer member 3 Hub wheels 4. Inner Ring 5 balls 6 Cage 7 Outer raceway surface 8. Body mounting flange 9 Wheel mounting flange 10 Inner raceway surface 11 Small diameter stepped section 12 Inner member 13 Crimping section 13a Escape Club 14 Connecting members 15 Ring section 15a Inner diameter end 16. Cylindrical part 16a Inner surface 17 First serration section 18 Second serration section 19,20 teeth 21. Constant velocity universal joint 22 Outer joint member 23. Inner joint member 24 Cage 25 Torque transmission ball 26 cup section 27 Bottom 28 Shoulder 28a Outer surface 29 Third serration section 30 Fourth serration section 31, 32 teeth 33 volts 34 Female threaded holes 35 Through holes 36. Guard section 37,39 Uneven part 38,40 Plastic joint 41 Hub Assembly

Claims

1. A hub assembly comprising a wheel bearing device and a constant velocity universal joint, The wheel bearing device comprises an outer member, a hub ring and an inner ring disposed radially inward of the outer member, and rolling elements disposed between the outer member and the hub ring, and between the outer member and the inner ring. The inner ring is press-fitted onto the outer circumference of the hub ring from the inboard side, and the annular connecting member is fitted onto the outer circumference of the hub ring while the inner ring and its inboard side are in axial contact. Due to the radially outward plastic deformation of the inboard end of the hub ring, the inner ring and the connecting member are clamped and fixed to the hub ring, A hub assembly of a wheel bearing device and a constant velocity universal joint, wherein the outer joint member and the connecting member of the constant velocity universal joint are connected to each other by serration fitting.

2. The connecting member integrally comprises a ring portion fitted onto the outer circumference of the hub wheel and a cylindrical portion extending from the outer diameter side of the ring portion toward the inboard side. The hub assembly of a wheel bearing device and a constant velocity universal joint according to claim 1, wherein the portion of the cylindrical part that faces the outer joint member in the radial direction is connected to the outer joint member by a serrated fitting.

3. The hub assembly of a wheel bearing device and a constant velocity universal joint according to claim 2, wherein the portion of the ring portion that faces the hub ring in the radial direction is connected to the hub ring by a serrated fitting.

4. A hub assembly of a wheel bearing device and a constant velocity universal joint according to claim 2, wherein a relatively hard uneven portion is formed on either the ring portion or the hub ring that are radially opposite to each other, and the other radially opposite portion bites into the uneven portion and is coupled to it.

5. The assembly of a wheel bearing device and a constant velocity universal joint according to claim 2, wherein a relatively hard uneven portion is formed on either the ring portion or the hub ring that faces each other in the axial direction, and the other portion that faces each other in the axial direction bites into the uneven portion and is coupled.

6. A method for assembling a hub assembly of a wheel bearing device and a constant velocity universal joint, The inner ring is press-fitted onto the outer circumference of the hub ring constituting the wheel bearing device, and an annular connecting member is fitted onto the outer circumference of the hub ring, so that the connecting member abuts against the inner ring from the inboard side, and thereafter, The inboard end of the hub ring is plastically deformed radially outward, thereby clamping and fixing the inner ring and the connecting member to the hub ring, and thereafter, A method for assembling a hub assembly of a wheel bearing device and a constant velocity universal joint, wherein the outer joint member of the constant velocity universal joint and the connecting member are connected to each other by serration fitting.

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