JP2010047042A - Bearing device for driving wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a driving wheel capable of making a contact state of a tooth surface good, improving an assembling property, suppressing looseness in a circumferential direction or axial misalignment, reducing a manufacturing cost, and enabling practical use. <P>SOLUTION: A rolling bearing 20 and a constant velocity universal joint 30 are unitized. The rolling bearing 20 is equipped with an external member 11, an internal member 8, and balls 13a, 13b. An outside joint member 32 is coupled to the internal member 8. An internal member corresponding surface 62 of a mouse potion 32a of the outside joint member 32 and an end portion of the internal member 8 are integrated. A projecting portion 41 having higher hardness than the end portion of the internal member 8 is formed on the internal member corresponding surface 62, and a recessed portion 42 extending in a diametrical direction by pressing of the projecting portion 41 is formed at the end portion of the internal member 8, thereby configuring a recessed/projecting fitting structure M. The outside joint member 32 and the internal member 8 are coupled through a fixing bolt 51 so as to separate from each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive wheel bearing device for rotatably supporting a wheel with respect to a vehicle body in a vehicle such as an automobile.

  To facilitate the assembly and disassembly of the hub wheel and the constant velocity universal joint in the wheel bearing device (drive wheel bearing device) in which the hub wheel, the double row rolling bearing and the constant velocity universal joint are unitized. In some cases, a hub wheel and a constant velocity universal joint are bolted together (Patent Document 1 and Patent Document 2).

  As shown in FIG. 7, the wheel bearing device in this case includes a hub wheel 102 having a flange 101 extending in the outer diameter direction, a constant velocity universal joint 104 to which an outer joint member 103 is fixed to the hub wheel 102, And a rolling bearing 100 disposed on the outer peripheral side of the hub wheel 102.

  The constant velocity universal joint 104 includes the outer joint member 103, an inner joint member 108 disposed in a hooked portion (mouse portion) 107 of the outer joint member 103, and the inner joint member 108 and the outer joint member 103. And a retainer 110 that holds the ball 109. Further, a spline portion 111 is formed on the inner peripheral surface of the center hole of the inner joint member 108, and an end spline portion of a shaft (not shown) is inserted into the center hole, and the spline portion 111 on the inner joint member 108 side The spline portion on the shaft side is engaged.

  The hub wheel 102 has a cylindrical portion 113 and the flange 101, and a short cylindrical shape in which a wheel and a brake rotor (not shown) are mounted on the outer end surface 114 (end surface on the opposite joint side) of the flange 101. A pilot part 115 is provided in a protruding manner.

  A notch 116 is provided on the outer peripheral surface of the end portion of the cylindrical portion 113 on the flange 107 side, and an inner ring 117 constituting the inner member of the rolling bearing 100 is fitted into the notch 116. A first inner raceway surface 118 is provided in the vicinity of the flange on the outer peripheral surface of the cylindrical portion 113 of the hub wheel 102, and a second inner raceway surface 119 is provided on the outer peripheral surface of the inner ring 117. A bolt mounting hole 112 is provided in the flange 101 of the hub wheel 102, and a hub bolt for fixing the wheel and the brake rotor to the flange 101 is mounted in the bolt mounting hole 112.

  The outer member 105 of the rolling bearing 100 is provided with two rows of outer raceway surfaces 120 and 121 on the inner periphery thereof. The first outer raceway surface 120 of the outer member 105 and the first inner raceway surface 118 of the hub wheel 102 face each other, and the second outer raceway surface 121 of the outer member 105 and the raceway surface 119 of the inner ring 117 face each other. The rolling element 122 is interposed between them.

  A partition wall 124 is provided in the tube portion 113 of the hub wheel 102, and a connecting bolt member 125 is inserted into the through hole 124 a of the partition wall 124. Further, a screw hole 127 is provided in the bottom wall 126 of the bowl-shaped portion 107, and the bolt member 125 is screwed into the screw hole 127.

  Then, face splines 128 and 129 are respectively provided on the hub wheel facing surface of the bottom wall 126 of the hook-shaped portion 107 and the hook-shaped portion facing surface of the cylindrical portion 113 of the hub wheel 102, and these are fitted. Here, the face splines 128 and 129 are formed by alternately arranging a plurality of ridges extending in the radial direction and a plurality of ridges extending in the radial direction along the circumferential direction.

The face splines 128 and 129 eliminate the circumferential shift between the hub wheel 102 side and the constant velocity universal joint side.
DE3219747 DE 3604630

  However, since the face spline as described above has teeth arranged radially, the tooth thickness also changes radially. It is difficult to improve the tooth forming accuracy (tooth thickness, pitch, etc.) and to improve the contact state of the tooth surface when it is fitted to the mating spline. If there is a variation in spline accuracy, there are teeth that are in strong contact and those that are hardly in contact, and the radial inner diameter side or outer diameter side is in strong contact with one another, so-called single contact, etc. Cannot be fully utilized.

  Further, the face spline 128 on the constant velocity universal joint side and the face spline 129 on the hub wheel side are separately formed by machining. For this reason, it is necessary to match the unevenness of both splines, which tends to cause circumferential play and axial misalignment. As described above, when there is a backlash in the circumferential direction, the transmission performance of the rotational torque is inferior and abnormal noise may occur. In addition, in order to keep the circumferential play and coaxiality (axial misalignment between the hub wheel and the constant velocity universal joint) within a predetermined range (small range), it is required to finish each face spline 128, 129 with high accuracy. Is done. For this reason, the cost is high and practical application is difficult.

  In view of the above problems, the present invention can improve the contact state of the tooth surface, can improve the assemblability, and can suppress circumferential play and misalignment. In addition, a drive wheel bearing device that can reduce the manufacturing cost and can be put to practical use is provided.

  In the drive wheel bearing device of the present invention, a double-row rolling bearing and a constant velocity universal joint are unitized, and the double-row rolling bearing is an outer member in which a double-row outer raceway surface is formed on the inner periphery. And an inner member in which an inner race surface facing the outer race surface of the double row is formed on the outer periphery, and a double row accommodated in a freely rollable manner between both raceway surfaces of the inner member and the outer member. In the drive wheel bearing device in which the outer joint member of the constant velocity universal joint is connected to the inner member, the outer joint member includes a mouth portion in which the inner joint member is accommodated. The inner member-corresponding surface of the inner part and the inboard side end of the inner member are integrated into a concave-convex fitting structure, and the inboard side end of the inner member or the inner part of the mouth part of the outer joint member One of the member-corresponding surfaces extends in the radial direction with a hardness higher than the other hardness. The concave-convex fitting structure in which a convex portion is formed, a concave portion extending in a radial direction to be fitted to the convex portion by pressing of the convex portion is formed on the other side, and the entire fitting contact portion between the convex portion and the concave portion is in close contact. The outer joint member and the inner member are configured to be separably connected via a fixing bolt for preventing an axial disconnection.

  According to the drive wheel bearing device of the present invention, the concave / convex fitting structure is configured such that either the convex portion of the mouth portion of the inner member or the outer joint member is fitted to the concave portion of the mating member fitted to the convex portion. Since the entire contact portion is in close contact, the fitting structure does not form a gap in which play occurs in the circumferential direction. In addition, by pressing the convex portion against the mating member, it is possible to form a radially extending concave portion that fits into the convex portion, and it is not necessary to separately form a concave portion in the mating member. . Furthermore, the rolling bearing and the constant velocity universal joint can be integrated in the axial direction via a fixing bolt that is brought into contact with the hub wheel and fastened to the outer joint member. Thereby, the axial disconnection between the outer joint member and the inner member can be prevented.

  A face spline in which a plurality of radially extending ridges and a plurality of radially extending ridges are alternately arranged along the circumferential direction is formed on the inner member corresponding surface of the mouth portion of the outer joint member. The convex line extending in the radial direction of the face spline can be used as the convex part of the concave-convex fitting structure.

  Further, on the inboard side end portion of the inner member, a face spline is formed in which a plurality of ridges extending in the radial direction and a plurality of ridges extending in the radial direction are alternately arranged along the circumferential direction, The convex line extending in the radial direction of the face spline can be used as the convex part of the concave-convex fitting structure.

  The inner member integrally has a wheel mounting flange at one end, and has a hub ring having one inner raceway surface facing the outer raceway of the double row on the outer periphery, and an outer periphery fitted to the hub ring. And an inner ring having the other inner raceway surface facing the outer raceway surface of the double row, and forming a crimped portion by plastically deforming an inboard side end portion of the hub wheel radially outward. In this caulking portion, the inboard side end portion of the inner member integrated with the inner member corresponding surface of the mouse portion can be configured. As a result, the preload is applied to the inner ring of the rolling bearing that is fitted on the end of the hub ring by crimping the end of the hub ring.

  The inner member integrally has a wheel mounting flange at one end, and has a hub wheel having one inner raceway surface facing the outer raceway of the double row on the outer periphery, and is fitted into the hub wheel and is fitted on the outer periphery. And a cylindrical member having the other inner raceway surface facing the outer raceway surface of the double row, and a hardened uneven portion is formed on the inner periphery of the hub wheel, and the fitting portion of the cylindrical member is expanded in diameter. The hub ring and the cylindrical member are integrally plastically joined, and integrated with the inner member corresponding surface of the mouse portion at the end of the cylindrical member on the mouse portion side. The inboard side end of the side member can be configured. Thereby, the hub wheel and the cylindrical member can be integrally plastically bonded in a state where a preload is applied.

  It is preferable that the hardness of the convex portion is 30 points or more higher in HRC than the hardness of the counterpart member.

  According to the drive wheel bearing device of the present invention, in the concave-convex fitting structure, there is no gap in which play occurs in the circumferential direction, so that the rotational torque transmission is excellent and no abnormal noise is generated. Further, it is possible to keep the circumferential play and the coaxiality (the axial deviation between the inner member and the constant velocity universal joint) within a predetermined range (small range), so that torque transmission can be improved. Stable rotation transmission. Moreover, instead of meshing the face splines separately formed as in the prior art, a convex portion is formed on the mouse portion side, and this convex portion may be pressed against the inboard side end portion of the inner member. Therefore, it is not required to finish the convex portion with high accuracy. For this reason, cost reduction can be achieved and practical use can be achieved. Furthermore, since the uneven contact structure is in close contact with the entire contact area of the fitting, the strength of the torque transmission area is improved. Further, since the rolling bearing and the constant velocity universal joint can be integrated in the axial direction via the fixing bolt, the axial disconnection between the outer joint member and the inner member can be prevented. The function of the apparatus can be stably maintained over a long period of time. Since the outer joint member and the inner member can be connected to each other in a separable manner, there is an advantage that the detachment at the time of assembly or repair can be simplified.

  If the convex line extending in the radial direction of the face spline is used as the convex portion of the concave-convex fitting structure, the range of the concave-convex fitting structure is disposed over the entire circumference, and the rotational torque transmission performance can be improved. Moreover, it is easy to form a face spline, which contributes to cost reduction.

  When the inner ring is fixed in the axial direction with a crimping portion formed at the inboard side end of the hub ring, or when the inner ring is expanded in diameter and the hub ring and the inner ring are integrally plastically bonded, a fixing bolt, etc. It is no longer necessary to apply a preload at, and the ease of incorporation into the vehicle can be simplified. In addition, the preload amount can be maintained for a long time, and adjustment of the preload at the shipping destination becomes unnecessary. Furthermore, the weight and size can be reduced, and the strength and durability of the hub wheel can be improved.

  By making the hardness of the convex part of the concave-convex fitting structure 30 or more points higher by HRC than the hardness of the mating member, the concave part that fits into the convex part can be more reliably formed.

  Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 shows a bearing device for a drive wheel. In this drive wheel bearing device, a double row rolling bearing 20 and a constant velocity universal joint 30 are unitized.

  The constant velocity universal joint 30 is interposed between the outer joint member 32, the inner joint member 31 disposed inside the outer joint member 32, and the outer joint member 32 and the inner joint member 31. The ball 33 and the cage 34 that is interposed between the outer joint member 32 and the inner joint member 31 and holds the ball 33 are configured as main members.

  The outer joint member 32 is integrally extended in the axial direction from the cup-like mouth portion 32a that houses the inner joint member 31, the cage 34, and the torque transmission ball 33, and the bottom wall 27 of the mouth portion 32a, and has an outer diameter surface 26a. A disc-shaped axial alignment projection 26 is provided with a cylindrical surface.

  The inner joint member 31 has a plurality of track grooves 36 formed on its outer peripheral surface (convex spherical outer peripheral surface). A shaft 38 is inserted into the center hole (inner diameter hole) 35 of the inner joint member 31 and is spline-fitted, so that torque can be transmitted between the two by the spline fitting. Note that a retaining ring 40 for preventing the shaft from coming off is fitted to the end of the shaft 38.

  The same number of track grooves 37 as the track grooves 36 of the inner joint member 31 are formed on the inner peripheral surface (cylindrical inner peripheral surface) of the outer joint member 32. A plurality of balls 33 for transmitting torque are incorporated between the track groove 37 of the outer joint member 32 and the track groove 36 of the inner joint member 31. A cage 34 is disposed between the inner joint member 31 and the outer joint member 32, and the ball 33 is held in a pocket 39 of the cage 34. The large diameter portion of the boot 64 is fixed to the outer peripheral surface on the opening side of the mouth portion 32 a via the boot band 48, and the small diameter portion of the boot 64 is fixed to the outer peripheral surface of the shaft 38. The constant velocity universal joint in this case is a Zepper type constant velocity universal joint that does not have a straight straight portion at the bottom of each track groove 36, 37. Other constant velocity universal joints such as an undercut free type having a straight portion at the groove bottom may be used.

  The rolling bearing 20 includes an outer member (outer ring) 11 having a double row outer raceway surfaces 21 and 22 formed on the inner periphery, and inner raceway surfaces 23 and 24 facing the double row outer raceway surfaces 21 and 22 on the outer periphery. And the double-row balls 13a and 13b accommodated between the raceway surfaces of the inner member 8 and the outer member 11 so as to roll freely.

  The outer member (outer ring) 11 is provided with two rows of outer raceway surfaces (outer races) 21 and 22 on the inner circumference thereof, and the first inner side provided on the outer circumference of the first outer raceway surface 21 and the cylindrical portion of the hub wheel 10. The raceway surface (inner race) 23 faces, the second outer raceway surface 22 and the second inner raceway surface (inner race) 24 provided on the outer peripheral surface of the inner ring 12 face each other, and the rolling element 13a is interposed therebetween. , 13b is interposed. Seal members 19 a and 19 b are attached to both openings of the outer ring 11.

  The inner member 8 has a hub wheel 10 having one inner raceway surface 23 facing the outer raceway surface 21 on the outer periphery, and the other inner raceway that is fitted on the hub wheel 10 and faces the outer raceway surface 22 on the outer periphery. And an inner ring 12 having a surface 24. The hub wheel 10 includes a tube portion 16 and a wheel mounting flange 17 that protrudes from the tube portion 16 and mounts a wheel (not shown) on the outer diameter surface thereof. Further, a circular hole portion 47 into which the axial alignment projection portion 26 of the bottom wall 27 is fitted is provided on the inner diameter surface of the cylindrical portion 16. A step portion 28 is provided on the joint side of the tube portion 16 of the hub wheel 10, and the inner ring 12 is fitted to the step portion 28.

  Bolt mounting holes 18 are provided in the wheel mounting flange 17 along the circumferential direction, and hub bolts 25 are mounted in the bolt mounting holes 18. That is, the brake rotor and the wheel are overlapped with the end face of the wheel mounting flange 17 and fixed by the hub bolt 25. On the flange-side end face 63 of the hub wheel 10, a short tubular pilot portion 66 to which a wheel and a brake rotor (not shown) are attached is projected.

  In this case, the end of the hub wheel 10 on the joint side is swaged, and a preload is applied to the inner member (inner ring) 12 by the swaged portion 15. As a result, the inner ring 12 can be fastened to the hub wheel 10. Further, a screw hole 50 is provided in the axis alignment protrusion 26 of the mouse portion 32a. The fixing bolt 51 inserted from the hole 29 on the opposite constant velocity universal joint side into the circular hole 47 has its screw shaft portion 70 a screwed into the screw hole 50. At this time, the head 70 b of the fixing bolt 51 is in contact with the end surface 56 on the side opposite to the joint of the presser plate 54, and the end surface 52 on the joint side of the presser plate 54 is in contact with the end surface 53 on the hole 29 side.

  In this drive wheel bearing device, a concave-convex fitting structure in which the inner member corresponding surface 62 of the bottom wall 27 of the mouth portion 32a of the outer joint member 32 and the inboard side end portion 15a of the crimping portion 15 are integrated. M is provided. The concave / convex fitting structure M includes a convex portion 41 extending in the radial direction provided on the inner member corresponding surface 62, and a concave portion 42 provided on the inboard side end portion 15 a of the crimping portion 15 and fitted to the convex portion 41. The fitting contact part whole area of the convex part 41 and the recessed part 42 fitted to the convex part 41 is closely_contact | adhered. That is, as shown in FIG. 3, a large number of convex portions 41 are arranged on the inner member corresponding surface (hub wheel corresponding surface) 62 of the bottom wall 27 as shown in FIG. The recess 42 is tightly fitted.

  Next, the fitting method of the uneven fitting structure M will be described. Before connecting the hub wheel 10 and the outer joint member 32 of the constant velocity universal joint 30, as described above, the end portion on the side opposite to the flange of the cylindrical portion 16 of the hub wheel 10 is crimped. The inner ring 12 is fastened to the cylindrical portion 16 at the portion 15. As a result, a preload (preliminary preload) is applied to the inner ring 12.

  On the inner member corresponding surface 62 of the mouse portion 32a, a convex portion 41 is formed that extends in the radial direction and has a hardness that is higher than the hardness of the inboard side end portion 15a of the crimped portion 15. That is, a face spline 45 in which a plurality of ridges 43 extending in the radial direction and a plurality of ridges 44 extending in the radial direction are alternately arranged along the circumferential direction is formed, and the face spline 45 is subjected to thermosetting treatment. Apply. In this case, the convex portion 41 is formed of a triangular section having a top 41a having a sharp edge. The caulking portion 15 of the hub wheel 10 is made of raw material that is not subjected to thermosetting. The face spline 45 can be formed by various processing methods such as rolling, cutting, pressing, drawing, etc., which are known publicly known means.

  As this thermosetting treatment, various heat treatments such as induction hardening and carburizing and quenching can be employed. Here, induction hardening is a hardening method that applies the principle of heating a conductive object by placing Joule heat in a coil through which high-frequency current flows, and generating Joule heat by electromagnetic induction. is there. In addition, carburizing and quenching is a method in which carbon is infiltrated / diffused from the surface of a low carbon material and then quenched. In this case, it is preferable that the hardness of the convex portion 41 is 30 points or more larger than the hardness of the caulking portion 15.

  As shown in FIG. 2, the axial center of the outer joint member 32 and the hub wheel 10 are aligned, and the shaft alignment protrusion 26 of the outer joint member 32 is fitted into the circular hole 47 of the hole 29 of the hub wheel 10. . At this time, it is preferable to use an axis alignment jig (for example, a cylindrical body inserted through the hub wheel 10) so as not to cause an axis deviation.

  Then, as shown in FIG. 1, the face spline 45 of the mouse part 32 a, that is, the convex part 41 on the mouse part side of the concave-convex fitting structure M is pressed against the inboard side end part 15 a of the crimping part 15. At this time, since the hardness of the convex portion 41 is 30 points or more larger than the hardness of the inboard side end portion 15a of the crimping portion 15, the convex portion 41 becomes the inboard side end of the crimping portion 15 if pressed. The convex portion 41 bites into the portion 15a, and the concave portion 42 into which the convex portion 41 is fitted is formed along the entire circumference in the circumferential direction. In addition, although it will press by giving an axial load to the opening end surface of the mouse | mouth part 32a, this axial load is given to various axial reciprocation mechanisms, such as a cylinder mechanism and a ball screw mechanism, for example. Can be used.

  Thereby, the whole fitting contact part of the convex part 41 by the side of the mouse | mouth part 32a and the recessed part 42 fitted to this is closely_contact | adhered. That is, the shape of the convex portion 41 is transferred to the inboard side end portion 15 a of the crimping portion 15.

  Then, the fixing bolt 51 is screwed onto the threaded portion 50 of the shaft alignment protrusion 26 to fix the outer joint member 32 side and the hub wheel 10 side. In this case, the inner end surface (back surface) 52 of the presser plate 54 and the outer end surface 53 of the cylindrical portion 16 are in contact with each other. As a result, the hub wheel 10 and the outer joint member 32 are coupled to each other through the presser plate 54 so as to be separable in the axial direction. The board side end 15a comes into contact. That is, by tightening the fixing bolt 51, the hub wheel 10 is sandwiched between the fixing bolt 51 and the mouth portion 32a via the inner ring 12, and the inboard side end portion 15a of the crimping portion 15 and the bottom wall of the mouth portion 32a. The concave-convex fitting structure M provided between the inner member-corresponding surface 27 of the inner member 27 is fixed in the axial direction.

  In the present invention, in the concave-convex fitting structure M, the entire fitting contact site between the convex portion 41 on the mouse portion side and the concave portion 42 of the caulking portion 15 of the hub wheel 10 fitted to the convex portion 41 is in close contact. Therefore, in this fitting structure, there is no gap in which play occurs in the circumferential direction. For this reason, it is excellent in the transmission property of rotational torque, and an abnormal noise is not produced. In addition, it is possible to keep the backlash and coaxiality in the circumferential direction (axial misalignment between the hub wheel and the constant velocity universal joint) within a predetermined range (small range), so that torque transmission can be improved. Stable rotation transmission is possible. Furthermore, since the rolling bearing 20 and the constant velocity universal joint 30 can be integrated in the axial direction via the fixing bolt 51, it is possible to prevent the outer joint member 32 and the inner member 8 from coming off in the axial direction. Thus, the function of this device can be stably maintained over a long period of time. Since the outer joint member 32 and the inner member 8 can be connected to each other in a separable manner, there is an advantage that the detachment at the time of assembly or repair can be simplified.

  Further, by pressing the convex portion 41 on the mouse portion side against the caulking portion 15 of the hub wheel 10, a radially extending concave portion 42 fitted to the convex portion 41 can be formed. It is not necessary to form a separate recess in the caulking portion 15. That is, instead of meshing face splines that are separately formed as in the prior art, if the convex portion 41 is formed on the mouth portion side and the convex portion 42 is pressed against the crimping portion 15 of the hub wheel 10, Therefore, it is not required to finish the convex portion 42 with high accuracy. For this reason, cost reduction can be achieved and practical use can be achieved. Furthermore, since the entire fitting contact portion of the concave / convex fitting structure M is in close contact with the gap, the strength of the torque transmission portion is improved.

  Since the ridges 43 extending in the radial direction of the face spline 45 are used as the convex portions 41 of the concave-convex fitting structure M, the range of the concave-convex fitting structure M is arranged over the entire circumference, thereby improving rotational torque transmission. it can. In addition, the face spline 45 can be easily formed, which contributes to cost reduction.

  The inboard side end of the hub wheel 10 is plastically deformed radially outward to form a crimped portion 15, and the inner ring 12 is fixed in the axial direction by the crimped portion 15, and the inboard of the hub wheel 10 is also fixed. The side end portion and the hub wheel corresponding surface 62 of the mouth portion 32a of the outer joint member 32 can be integrated. For this reason, it is not necessary to apply a preload with a fixing bolt or the like, and the incorporation into the vehicle can be simplified. In addition, the preload amount can be maintained for a long time, and adjustment of the preload at the shipping destination becomes unnecessary. Furthermore, the weight and size can be reduced, and the strength and durability of the hub wheel 10 can be improved.

  Before forming the uneven fitting structure M, as shown in FIG. 4, the uneven portion (spline) 60 can be roughly formed on the crimping portion 15 side. That is, the caulking part 15 side spline 60 fitted to the mouse part side spline may be roughly processed, and then the above-described transfer (finish transfer) may be performed. Thereby, since the amount of molding at the time of press-fitting can be reduced, the pressing force at the time of spline processing on the crimping portion 15 side by the spline on the mouse portion side can be reduced, and the assemblability (workability) can be improved. it can.

  Next, FIG. 5 and FIG. 6 show a second embodiment, and the inner member 8 in this case is constituted by a hub wheel 10 and a cylindrical member 14 fitted inside the hub wheel 10. The cylindrical member 14 has a shaft portion 9 extending in the axial direction on the outboard side, and has a large diameter portion 7 larger in diameter than the shaft portion 9 on the inboard side. For this reason, a support step portion 49 for fixing the hub wheel 10 to the shaft portion 9 is provided.

  Here, an uneven portion 55 is formed on the inner periphery of the hub wheel 10, and the uneven portion 55 is heat-treated. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable.

  The uneven portion 55 is formed, for example, in the form of an iris knurl, and is formed by orthogonally crossing a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like. It consists of a crossing groove or a crossing groove composed of spiral grooves inclined to each other. Further, in order to ensure good biting properties, the tip of the concavo-convex portion 55 is formed in a spire shape such as a triangular shape.

  The hub wheel 10 and the cylindrical member 14 are coupled to each other by first contacting the end surface of the cylindrical portion 16 of the hub wheel 10 with the support step portion 49 of the cylindrical member 14 until the hub wheel 10 is abutted. The shaft portion 9 is fitted inside. Then, a diameter expanding jig such as a punch is pushed into the inner diameter of the fitting portion 5 in the shaft portion 9 to increase the diameter of the fitting portion 5, and the fitting portion 5 is bitten into the uneven portion 55 of the hub wheel 10. By caulking, the hub wheel 10 and the cylindrical member 14 are integrally plastically joined.

  On the inboard side end of the cylindrical member 14, a convex portion 41 is formed that extends in the radial direction and has a hardness that is higher than the hardness of the inner member corresponding surface 62 of the mouse portion 32a. That is, a face spline 45 in which a plurality of ridges 43 extending in the radial direction and a plurality of ridges 44 extending in the radial direction are alternately arranged along the circumferential direction is formed, and the face spline 45 is subjected to thermosetting treatment. Apply. In this case, the convex portion 41 is formed of a triangular section having a top 41a having a sharp edge. Further, the inner member corresponding surface 62 of the bottom wall 27 is a raw material that is not subjected to thermosetting.

  Then, as shown in FIG. 6, the face spline 45 of the end portion 14 a of the cylindrical member 14, that is, the convex portion 41 on the side of the projection portion for alignment of the concave-convex fitting structure M is pressed against the mouse portion 32 a. At this time, since the hardness of the convex portion 41 is 30 points or more larger than the hardness of the end portion 14a of the cylindrical member 14, if the pressure is pressed, the convex portion 41 will bite into the mouse portion 32a. The concave portion 42 into which the convex portion 41 is fitted is formed along the entire circumference in the circumferential direction.

  Thereby, the whole fitting contact part of the convex part 41 by the side of the cylindrical member 14 and the recessed part 42 fitted to this is closely_contact | adhered. That is, the shape of the convex portion 41 is transferred to the mouse portion 32a.

  Then, the fixing bolt 51 is screwed onto the threaded portion 50 of the shaft alignment protrusion 26 to fix the outer joint member 32 side and the hub wheel 10 side.

  For this reason, the drive wheel bearing device of the second embodiment also has the same effects as the first embodiment. In particular, after forming the hardened concave and convex portion 55 on the inner periphery of the hub wheel 10, the diameter of the fitting portion 5 of the cylindrical member 14 is expanded to bite into the concave and convex portion 55. Can be fixed in the axial direction, so there is no need to control the preload by tightening firmly with a nut or the like as in the prior art, so that the weight and size of the hub wheel 10 can be reduced. The durability can be improved and the preload amount can be maintained for a long time.

  In the drive wheel bearing device shown in FIGS. 5 and 6, the same components as those of the drive wheel bearing device shown in FIGS. Omitted.

  As another embodiment, contrary to the first embodiment, an uneven portion (spline) is formed on the outer surface of the inboard side end portion 15a of the crimping portion 15, and the uneven portion is hardened by quenching. The concave-convex fitting structure M can be formed by biting the spline on the crimping portion 15 side into the outer surface of the mouse portion 32a without forming the spline on the outer surface of the mouse portion 32a. Thereby, the hub wheel 10 and the mouse | mouth part 32a can be couple | bonded.

  Furthermore, as another embodiment, contrary to the second embodiment, an uneven portion (spline) is formed on the inner member corresponding surface 62 of the mouse portion 32a, and the uneven portion is hardened by quenching, It is possible to form the concave-convex fitting structure M by causing the spline on the mouse part 32a side to bite into the inboard side end surface of the cylindrical member 14 without forming a spline on the inboard side end part 14a of the cylindrical member 14. it can. Thereby, the cylindrical member 14 and the mouse | mouth part 32a can be couple | bonded.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, the number of the convex portions 41 of the concave-convex fitting structure M, the circumferential arrangement The installation pitch can be arbitrarily changed. That is, in the said embodiment, although the convex part 41 of the uneven | corrugated fitting structure M was comprised with the convex line 43 of the face spline 45, without forming such a convex line 43, the convex part extended in radial direction 41 may be arranged at a predetermined pitch along the circumferential direction. As described above, the hardness difference between the convex portion 41 side and the end crimped portion 32 formed by the convex portion 41 is preferably 30 points or more in HRC, but the convex portion 41 is press-fitted. If possible, it may be less than 30 points. The face spline 45 can also be formed by using the method described in JP-T-2001-514969.

It is sectional drawing of the bearing apparatus for drive wheels which shows 1st Embodiment of this invention. It is sectional drawing of the decomposition | disassembly state of the bearing apparatus for drive wheels of the said FIG. It is a side view of the constant velocity universal joint of the said wheel bearing apparatus. It is sectional drawing of the rolling bearing used for the bearing apparatus for drive wheels. It is sectional drawing of the bearing apparatus for drive wheels which shows 2nd Embodiment of this invention. It is sectional drawing of the decomposition | disassembly state of the bearing apparatus for drive wheels of the said FIG. It is sectional drawing of the conventional bearing unit for drive wheels.

Explanation of symbols

5 Fitting part 8 Inner member 10 Hub ring 11 Outer member 12 Inner ring 13a, 13b Ball 14 Cylindrical member 14a End part 15 Clamping part 15a End part 17 Wheel mounting flange 20 Rolling bearings 21, 22, 23, 24 Track surface 30 constant velocity universal joint 31 inner joint member 32 outer joint member 32a mouse part 41 convex part 42 concave part 43 convex part 44 concave part 51 fixing bolt 55 uneven part 62 inner member corresponding surface M uneven part fitting structure

Claims (6)

Double row rolling bearings and constant velocity universal joints are unitized,
The double-row rolling bearing is an outer member in which a double-row outer raceway surface is formed on the inner periphery, and an inner member in which an inner raceway surface is formed on the outer periphery to face the double-row outer raceway surface, A drive wheel comprising the inner member and a double row of balls accommodated between the raceway surfaces of the outer member so as to roll freely, and an outer joint member of a constant velocity universal joint connected to the inner member. In the bearing device,
The outer joint member includes a mouth portion in which the inner joint member is accommodated, and includes an uneven fitting structure in which an inner member corresponding surface of the mouse portion and an inboard side end portion of the inner member are integrated. A convex portion extending in the radial direction is formed on either the inboard side end of the inner member or the inner member corresponding surface of the mouth portion of the outer joint member, and the convex portion on the other. Forming a concave portion extending in the radial direction to be fitted to the convex portion by pressing, and forming the concave-convex fitting structure in which the entire fitting contact portion between the convex portion and the concave portion is in close contact,
A bearing device for a drive wheel, wherein the outer joint member and the inner member are detachably connected to each other via a fixing bolt for preventing an axial disconnection.   A face spline in which a plurality of radially extending ridges and a plurality of radially extending ridges are alternately arranged along the circumferential direction is formed on the inner member corresponding surface of the mouth portion of the outer joint member. The drive wheel bearing device according to claim 1, wherein a ridge extending in a radial direction of the face spline is used as a protrusion of the uneven fitting structure.   A face spline in which a plurality of ridges extending in the radial direction and a plurality of recesses extending in the radial direction are alternately arranged along the circumferential direction is formed at the inboard side end of the inner member. The drive wheel bearing device according to claim 1, wherein a protrusion extending in a radial direction of the spline is a protrusion of the uneven fitting structure. The inner member integrally has a wheel mounting flange at one end, and has a hub ring having one inner raceway surface facing the outer raceway of the double row on the outer periphery, and an outer periphery fitted to the hub ring. And an inner ring having the other inner raceway surface opposite to the double row outer raceway surface,
An inner member integrated with the inner member corresponding surface of the mouth portion is formed by plastically deforming the end portion on the inboard side of the hub wheel radially outward to form a crimp portion. The drive wheel bearing device according to any one of claims 1 to 3, wherein an inboard side end portion is configured. The inner member integrally has a wheel mounting flange at one end, and has a hub wheel having one inner raceway surface facing the outer raceway of the double row on the outer periphery, and is fitted into the hub wheel and is fitted on the outer periphery. And a cylindrical member having the other inner raceway surface facing the outer raceway surface of the double row,
A hardened uneven portion is formed on the inner periphery of the hub wheel, the fitting portion of the cylindrical member is expanded to bite into the uneven portion, and the hub wheel and the cylindrical member are integrally plastically bonded,
The inboard side end portion of the inner member integrated with the inner member corresponding surface of the mouse portion is configured at the end portion of the cylindrical member on the mouse portion side. The drive wheel bearing device according to any one of the preceding claims.   The drive wheel bearing device according to any one of claims 1 to 5, wherein the hardness of the convex portion is 30 points or more higher in HRC than the hardness of the counterpart member.

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