JP4959514B2 - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a vehicular wheel capable of suppressing rattle in the circumferential direction and misalignment of axes, of reducing the manufacturing cost, and assuring practical applicability. <P>SOLUTION: The bearing device for vehicular wheel includes a hub wheel 1, double-row rolling bearing 2, and a constant speed universal joint 3 which are unitized, wherein an outer joint member of the universal joint 3 is furnished with a mouth part 11 to admit fitting-in of an inner joint member, and is structured so that the end of the hub wheel 1 is pressurized so as to give a preload to the inner ring 1 of the rolling bearing 2 to be fitted externally on the hub wheel 1 and that a hub wheel mating surface 40 of the mouth part 11 bottom wall 12 and the at-end pressurized portion 31 of the hub wheel 1 are integrated through a recessed-protruding fitting structure M. A protruding part 41 having a higher hardness than the at-end pressurized portion 31 and stretching in the radial direction is formed on the hub wheel mating surface 40 of the mouth part 11 while a recessed part 42 is formed in the at-end pressurized portion 31 owing to a pressure application thereto 31 of the protruding part 41 on the mouth part side so that the recess-protrusion fitting structure M is formed where the whole area of the fit-in contacting part between the protruding 41 and the recessed 42 is in tight contacting. The pressure angle of the protruding part 41 on the mouth part side is not larger than 20&deg;. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a 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).

  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 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, respectively, 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 recesses extending in the radial direction along the circumferential direction.

The face splines 128 and 129 eliminate the circumferential displacement between the hub wheel 102 side and the constant velocity universal joint side.
US Pat. No. 4,893,960

  However, 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. Further, in order 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), it is necessary 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-described problems, the present invention provides a wheel bearing device that can suppress circumferential backlash and axial misalignment, and that can reduce the manufacturing cost and can be put to practical use. To do.

In the wheel bearing device of the present invention, a hub wheel, a double row rolling bearing, and a constant velocity universal joint are unitized, and an outer joint member of the constant velocity universal joint includes a mouth portion in which an inner joint member is housed. A preload is applied to the inner ring of the rolling bearing fitted on the hub ring by crimping the end of the hub ring, and the hub ring corresponding surface of the bottom wall of the mouth portion of the outer joint member and the hub ring A bearing device for a wheel in which an end caulking portion is integrated via a concave-convex fitting structure, and a plurality of ridges and diameters extending in a radial direction on a hub wheel corresponding surface of a mouth portion of the outer joint member A plurality of concave stripes extending in the direction form a face spline on the outer joint member side that is alternately arranged along the circumferential direction, and the hardness of each convex stripe of the face spline is determined by the end caulking portion of the hub wheel. Set to be higher than the hardness of the outer ring. By transferring the shape by pressing the face spline on the member side, a face spline on the hub wheel side to which the face spline on the outer joint member side is fitted is formed on this end caulked portion, The concave- convex fitting structure in which the entire fitting contact portion with the concave portion which is a concave stripe is in close contact is configured, and the pressure angle of the convex portion on the mouse portion side is set to 20 ° or less. Here, the pressure angle is an angle formed by a height direction line and a tangent to the tooth profile at one point (pitch point) of the tooth surface (side surface) of the convex portion.

  According to the wheel bearing device of the present invention, the concave / convex fitting structure is such that the entire contact area of the fitting between the convex portion on the mouse portion side and the concave portion of the end caulking portion of the hub wheel fitted to the convex portion is in close contact. Therefore, in this fitting structure, no gap is formed in which play occurs in the circumferential direction. Also, by pressing the convex portion on the mouth portion side against the end caulking portion of the hub wheel, a radially extending concave portion that fits into the convex portion can be formed. It is not necessary to form a separate recess in the fastening portion. Moreover, since the pressure angle of the convex part on the mouse part side is set to 20 ° or less, it is possible to improve workability (biting property) and set the thickness of the convex part (tooth part) to be relatively thick. The strength of the convex portion can be improved, and the separation force during torque transmission can be reduced. On the other hand, when the pressure angle exceeds 20 °, the tooth surface (side surface) is inclined too much with respect to the pressing direction, and the biting property is inferior.

  The hardness of the end caulking portion of the hub wheel is preferably 25 HRC to 35 HRC. Thus, by setting the hardness on the end caulking portion side of the hub wheel, the end caulking portion of the hub wheel becomes relatively soft.

  It is preferable to apply a metal surface treatment such as a WPC treatment or a shot peening treatment to the end crimping portion of the hub wheel in which the concave portion is formed at the convex portion on the mouse portion side. Here, the WPC treatment is a process in which a special shot of 40 to 200 microns is sprayed on a metal surface at a high speed and locally raised to the recrystallization temperature, so that the heat treatment effect and the forging effect are strengthened instantaneously. In this process, the retained austenite in the metal surface layer is converted into martensite, recrystallized, and the structure is refined. As a result, a fine structure with high hardness and toughness is formed on the metal surface, and the internal compressive residual stress can be increased. The shot peening process is a process for increasing the compressive residual stress by hitting a shot, similar to the WPC process. In shot peening, the compressive residual stress can be increased, but the structure cannot be refined. Moreover, the surface becomes rough in shot peening, and the slidability cannot be improved. On the other hand, in the WPC process, a change in structure, that is, a heat treatment effect can be obtained by hitting a shot finer than a shot used in shot peening at a high speed. WPC is formally an abbreviation for Wide Peering and Cleaning, and is also called Wonder Process Craft or Wonder Peering Craft.

  The surface of the WPC-treated surface has gentle and fine irregularities, and the irregularities have a high hardness and do not lose the surface pressure. For this reason, lubricating oil can be held in the concave portion, and by reducing the contact area, oil leakage can be eliminated, and at the same time, wear can be reduced and slidability can be improved. As described above, in the WPC treatment, the surface hardness can be increased and at the same time fine irregularities can be formed to improve the slidability.

  Moreover, since the WPC process strikes the shot, the compressive residual stress can be increased. The WPC-treated metal surface has a very fine carbide structure, and its surface area is large and strong. In this way, if the connection is strong, cracks are difficult to enter, and even if they enter, they are difficult to spread. For this reason, if WPC processing is performed, it will become strong to fatigue and a crease and a chip will reduce sharply. That is, by applying the WPC process, it is possible to improve fatigue strength and friction resistance.

  Moreover, you may heat-process by the laser hardening with respect to the edge part crimping part of the hub ring in which the recessed part was formed in the convex part by the side of a mouse | mouth part. Here, the laser quenching is to quench the surface by irradiating the metal surface with laser light.

  Heat treatment by laser quenching is applied to the end caulking portion of the hub wheel in which the concave portion is formed at the convex portion on the mouse side, and marking of product data by laser is applied to at least one of the outer joint member and the hub wheel. It is preferable to apply. Here, the product data includes the manufacturing date and time, the manufacturing location (factory, line), the product name, and the like of this product. The marking type includes a serial number, a barcode, and the like. Further, a laser processing machine (laser irradiation machine) or the like that marks product data can be used at the time of laser quenching, thereby reducing costs and working time.

  According to the present invention, in the concave-convex fitting structure, no gap is generated in which the play is generated in the circumferential direction, so that the rotational torque transmission is excellent and no abnormal noise is generated. 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. Moreover, it is only necessary to form a convex part on the mouth part side and press the convex part against the end caulking part of the hub wheel, instead of meshing the face splines formed separately as in the prior art. 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.

  By setting the pressure angle of the convex part on the mouse side to 20 ° or less, it is possible to improve the workability (biting property) and set the convex part (tooth part) to be relatively thick. The strength of the portion can be improved, and the separation force during torque transmission can be reduced. This enables stable torque transmission over a long period.

  If the ridges extending in the radial direction of the face spline are used as the convex portions 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 can be improved. In addition, face splines can be easily formed, contributing to cost reduction.

  By setting the hardness of the end caulking portion of the hub wheel from 25 HRC to 35 HRC, the end caulking portion of the hub wheel becomes relatively soft, and the hub wheel end caulking by the pressing of the convex portion on the outer joint member side becomes relatively soft. Formation of the concave portion on the tightening portion side is facilitated, and productivity can be improved.

  By applying a metal surface treatment such as WPC treatment or shot peening, the compressive residual stress of the convex portion for constituting the concave-convex fitting structure can be increased. Thereby, the concentration of tensile stress can be relaxed and the fatigue limit can be increased. In particular, if WPC treatment is performed, it is possible to improve fatigue strength and friction resistance, and to provide a high-quality product.

  The heat treatment by laser quenching can improve the strength and wear resistance of the protrusions, and provide a reliable wheel bearing device.

  By marking the product data with a laser on at least one of the outer joint member and the hub wheel, the traceability of the product can be improved. Traceability refers to a state in which the product distribution channel can be traced from the production stage to the final consumption stage or the disposal stage. In addition, a laser processing machine (laser irradiation machine) or the like for marking product data can be the same as that used for laser quenching, thereby reducing costs and working time.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. FIG. 1 shows a wheel bearing device, in which a hub wheel 1, a double row rolling bearing 2, and a constant velocity universal joint 3 are integrated.

  The constant velocity universal joint 3 includes a plurality of outer rings 5 serving as outer joint members, an inner ring 6 serving as an inner joint member disposed on the inner side of the outer ring 5, and a plurality of torque transmissions interposed between the outer ring 5 and the inner ring 6. The ball 7 and the cage 8 that is interposed between the outer ring 5 and the inner ring 6 and holds the ball 7 are configured as main members. The inner ring 6 is spline-fitted by press-fitting an end of a shaft (not shown) into the shaft hole inner diameter 6a and is coupled to the shaft so that torque can be transmitted.

  The outer ring 5 includes a mouth portion 11 having a bottom wall 12, and a plurality of track grooves 14 extending in the axial direction are formed on the inner spherical surface 13 at equal intervals in the circumferential direction. In the inner ring 6, a plurality of track grooves 16 extending in the axial direction are formed on the outer spherical surface 15 at equal intervals in the circumferential direction. The bottom wall 12 is provided with a disk-shaped axial alignment projection 17 whose outer diameter surface 17a is a cylindrical surface.

The track groove 14 of the outer ring 5 and the track groove 16 of the inner ring 6 make a pair, and one ball 7 as a torque transmitting element can roll on each ball track constituted by the pair of track grooves 14 and 16. It is incorporated. The ball 7 is interposed between the track groove 14 of the outer ring 5 and the track groove 16 of the inner ring 6 to transmit torque. The cage 8 is slidably interposed between the outer ring 5 and the inner ring 6, is in contact with the inner spherical surface 13 of the outer ring 5 at the outer spherical surface 8a, and is in contact with the outer spherical surface 15 of the inner ring 6 at the inner spherical surface 8b. 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 groove bottom of each track groove 14, 16.
Other constant velocity universal joints such as an undercut free type having a straight portion at the groove bottom may be used.

  The hub wheel 1 includes a cylindrical portion 20 having a partition wall 19 and a flange 21 provided at an end of the cylindrical portion 20 on the opposite joint side. The hole 20 a on the constant velocity universal joint side of the partition wall 19 of the cylindrical portion 20 includes a circular hole portion 47 into which the shaft alignment protrusion 17 of the bottom wall 12 is fitted, and an anti-constant velocity from the circular hole portion 47. A first taper portion 48 that decreases in diameter toward the universal joint side, a second taper portion 49 that decreases in diameter from the first taper portion 48 toward the anti-constant velocity universal joint, and an anti-constant velocity from the second taper portion 49. A third taper portion 50 having a diameter reduced toward the universal joint side is provided. As shown in FIG. 5, the inner diameter dimension D of the circular hole portion 47 is set to be slightly larger than the outer diameter dimension D <b> 1 of the axis alignment projection portion 17.

  Further, a short cylindrical pilot portion 35 to which a wheel and a brake rotor (not shown) are mounted is projected from the outer end surface (the end surface on the anti-joint side) of the flange 21 of the hub wheel 1. The flange 21 is provided with a bolt mounting hole 32, and a hub bolt 33 for fixing the wheel and the brake rotor to the flange 21 is mounted in the bolt mounting hole 32.

  The rolling bearing 2 includes an inner member 24 that fits into a stepped portion 23 provided on the joint side of the tubular portion 20 of the hub wheel 1, and an outer member 25 that is fitted onto the tubular portion 20 of the hub wheel 1. Prepare. The outer member 25 is provided with two rows of outer raceways (outer races) 26, 27 on its inner circumference, and a first inner raceway (provided on the outer circumference of the first outer raceway 26 and the cylindrical portion of the hub wheel 1). The inner race) 28 is opposed to the second outer raceway surface 27 and the second inner raceway surface (inner race) 29 provided on the outer peripheral surface of the inner ring 24 is opposed to the ball as the rolling element 30 therebetween. Is installed. Note that seal members S are attached to both openings of the outer member 25.

  In this case, the end of the hub wheel 1 on the joint side is swaged, and a preload is applied to the inner member (inner ring) 24 by the end swaged portion 31. As a result, the inner ring 24 can be fastened to the hub wheel 1. The partition wall 19 is provided with a through hole 36 and the bottom wall 12 of the mouse part 11 is provided with a screw hole 37. The bolt member 38 inserted into the through hole 36 from the hole 20 b on the opposite constant velocity universal joint side is screwed into the screw hole 37. At this time, the head portion 38b of the bolt member 38 contacts the end surface 39 of the partition wall 19 on the hole 20b side.

  The hub wheel corresponding surface 40 of the bottom wall 12 of the mouse part 11 of the outer ring 5 and the end caulking part 31 of the hub wheel 1 are integrated via the concave / convex fitting structure M. The concave / convex fitting structure M includes a radially extending convex portion 41 provided on the hub wheel corresponding surface 40, and a concave portion 42 provided on the outer end surface 31 a of the end caulking portion 31 and fitted to the convex portion 41. The entire fitting contact portion between the convex portion 41 and the concave portion 42 fitted into the convex portion 41 is in close contact. That is, as shown in FIG. 3 on the hub wheel corresponding surface 40 of the bottom wall 12, a large number of convex portions 41 are arranged over the entire circumference, and the total convex portions 41 and all the concave portions 42 fitted thereto are tight-fitted. Yes.

  By the way, as shown in FIG. 4, each convex part 41 is made into the substantially triangular shape which the cross-sectional shape bulged in the center part in the side surface height direction, and the pressure angle (alpha) is set to 20 degrees or less. Here, the pressure angle α is an angle formed by the height direction line L and the tangent line L1 to the tooth profile at one point (pitch point) P of the tooth surface (side surface) of the convex portion 41. The angle α ′ formed between the tangent line L2 of the reference circle (pitch circle) and the normal line L3 of the tooth surface can also be called a pressure angle. That is, 90 ° −α = 90 ° −α ′, and α = α ′.

  Next, the fitting method of the uneven fitting structure M will be described. In this case, 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 in the circumferential direction on the hub wheel corresponding surface 40 of the bottom wall 12. Form. The face spline 45 is subjected to a thermosetting process. The convex line 43 of the face spline 45 that has been subjected to the curing process is used as the convex part 41 of the concave-convex fitting structure M. Further, the end caulking portion 31 of the hub wheel 1 is a raw material that is not subjected to thermosetting. Specifically, the hardness of the end caulking portion 31 of the hub wheel 1 is set to about 25 HRC to 35 HRC.

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 larger by 20 points or more in HRC than the hardness of the end caulking portion 31. The hardness of the face spline 45 is about 50 HRC to 65 HRC.

  Then, as shown in FIG. 5, the axial centers of the outer ring 5 and the hub wheel 1 are aligned, and the shaft alignment protrusion 17 of the outer ring 5 is fitted into the circular hole 47 of the hole 20 a of the hub wheel 1. At this time, since the inner diameter dimension D of the circular hole portion 47 is set slightly larger than the outer diameter dimension D1 of the shaft alignment projection portion 17, the outer diameter surface 17a of the shaft alignment projection portion 17 becomes the pilot portion (adjustment). The shaft alignment protrusion 17 can be fitted into the circular hole portion 47 in a state where the outer ring 5 and the hub wheel 1 are aligned with each other.

  Then, the face spline 45 of the mouse part 11, that is, the convex part 41 on the stem side of the concave-convex fitting structure M is pressed against the outer end surface 31 a of the end caulking part 31. At this time, the hardness of the convex portion 41 is 20 points or more higher in HRC than the hardness of the end caulking portion 31, so if the pressure is applied, the convex portion 41 bites into the outer end surface 31 a of the end caulking portion 31. Thus, the convex portion 41 forms the concave portion 42 into which the convex portion 41 is fitted along the entire circumference in the circumferential direction. That is, a face spline 46 that fits the face spline 45 of the mouth portion 11 is formed on the outer end surface 31 a of the end caulking portion 31 of the hub wheel 1. In addition, although it will press by giving an axial load to the opening end surface of the mouse | mouth part 11, 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. The face spline 45 can be formed by various processing methods such as rolling, cutting, pressing, drawing, etc., which are known publicly known means.

  Thereby, the whole fitting contact site | part of the convex part 41 by the side of the mouse | mouth part 11 and the recessed part 42 fitted to this closely_contact | adheres. That is, the shape of the convex portion 41 is transferred to the outer end surface 31a of the end caulking portion 31. In this way, after the transfer, the bolt member 38 is inserted into the through hole 36 of the partition wall 19 from the hole portion 20b on the opposite constant velocity universal joint side, and the screw shaft portion 38a is inserted into the screw hole 37 of the outer ring 5. Screw it on. Thereby, the hub wheel 1 and the outer ring 5 are integrated.

  By the way, after forming the face spline 46 on the hub wheel 1 side and before screwing with the bolt member 38, the face spline 46 (the end portion of the hub wheel 1 in which the concave portion is formed at the convex portion on the mouse portion side). It is preferable to perform metal surface treatment such as WPC treatment or shot peening treatment on the crimping portion 31). In this case, the metal surface treatment is performed in the range H in FIG.

  Here, the WPC treatment is a process in which a special shot of 40 to 200 microns is sprayed on a metal surface at a high speed and locally raised to the recrystallization temperature, so that the heat treatment effect and the forging effect are strengthened instantaneously. In this process, the retained austenite in the metal surface layer is converted into martensite, recrystallized, and the structure is refined. As a result, a fine structure with high hardness and toughness is formed on the metal surface, and the internal compressive residual stress can be increased. The shot peening process is a process for increasing the compressive residual stress by hitting a shot, similar to the WPC process. In shot peening, the compressive residual stress can be increased, but the structure cannot be refined. Moreover, the surface becomes rough in shot peening, and the slidability cannot be improved. On the other hand, in the WPC process, a change in structure, that is, a heat treatment effect can be obtained by hitting a shot finer than a shot used in shot peening at a high speed.

  The surface of the WPC-treated surface has gentle and fine irregularities, and the irregularities have a high hardness and do not lose the surface pressure. For this reason, lubricating oil can be held in the concave portion, and by reducing the contact area, oil leakage can be eliminated, and at the same time, wear can be reduced and slidability can be improved. As described above, in the WPC treatment, the surface hardness can be increased and at the same time fine irregularities can be formed to improve the slidability.

  Moreover, since the WPC process strikes the shot, the compressive residual stress can be increased. The WPC-treated metal surface has a very fine carbide structure, and its surface area is large and strong. In this way, if the connection is strong, cracks are difficult to enter, and even if they enter, they are difficult to spread. For this reason, if WPC processing is performed, it will become strong to fatigue and a crease and a chip will reduce sharply.

  In the present invention, the concave-convex fitting structure M is in close contact with the entire fitting contact site between the convex portion 41 on the mouse portion side and the concave portion 42 of the end crimping portion 31 of the hub wheel 1 fitted to the convex portion 41. 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.

  Further, by pressing the convex portion 41 on the mouse portion side against the end caulking portion 31 of the hub wheel, it is possible to form a radially extending concave portion 42 that fits into the convex portion 41. It is not necessary to form a separate recess in the one end caulking portion 31. That is, instead of meshing the face splines that are separately formed as in the prior art, the convex portion 41 is formed on the mouth portion side, and the convex portion 42 is pressed against the end caulking portion 31 of the hub wheel 1. 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.

  Since the pressure angle of the convex part on the mouse side is set to 20 ° or less, the workability (biting property) can be improved and the thickness of the convex part (tooth part) can be set relatively thick. Strength can be improved, and the separation force during torque transmission can be reduced. This enables stable torque transmission over a long period. On the other hand, when the pressure angle exceeds 20 °, the tooth surface (side surface) is inclined too much with respect to the pressing direction, and the biting property is inferior.

  Since the convex line extending in the radial direction of the face spline 45 is the convex portion 41 of the concave-convex fitting structure M, the range of the concave-convex fitting structure M is arranged over the entire circumference, and the rotational torque transmission performance can be improved. . In addition, the face spline 45 can be easily formed, which contributes to cost reduction.

  By setting the hardness of the end caulking portion 31 of the hub wheel 1 to 25 HRC to 35 HRC, the end caulking portion 31 of the hub wheel 1 becomes relatively soft, and the hub is pressed by the convex portion 41 on the outer joint member side. Formation of the recess on the end caulking portion side of the wheel 1 is facilitated, and productivity can be improved.

  Since the axial alignment protrusion 17 is provided, the mouse portion 11 and the hub wheel 1 can be pressed while maintaining the coaxiality. For this reason, stable pressing is possible, and the concave-convex fitting structure M can be formed with high accuracy.

  By applying a metal surface treatment such as WPC treatment or shot peening, the compressive residual stress of the convex portion 41 for forming the concave-convex fitting structure M can be increased. Thereby, the concentration of tensile stress can be relaxed and the fatigue limit can be increased. In particular, if WPC treatment is performed, it is possible to improve fatigue strength and friction resistance, and to provide a high-quality product.

  By the way, instead of metal surface treatment such as WPC treatment or shot peening, heat treatment by laser quenching may be performed. Here, the laser quenching is to quench the surface by irradiating the metal surface with laser light. For example, the laser beam is spread and the surface is irradiated with high energy. As a result, the surface is rapidly cooled by the thermal diffusion of the material itself. At this time, it is preferable to flow helium, argon gas, or the like for preventing oxidation or sputtering from the nozzle.

  The heat treatment by laser quenching can improve the strength and wear resistance of the protrusions, and provide a reliable wheel bearing device. At the time of laser quenching, product data can be marked with laser on at least one of the outer ring 5 and the hub ring 1. That is, as marking, only the outer ring 5, only the hub ring 1, the outer ring 5 and the hub ring 1 may be provided. Here, the product data includes the manufacturing date and time, the manufacturing location (factory, line), the product name, and the like of this product. The marking type includes a serial number, a barcode, and the like. In this way, the product traceability can be improved by marking the product data. Traceability refers to a state in which the product distribution channel can be traced from the production stage to the final consumption stage or the disposal stage. In addition, a laser processing machine (laser irradiation machine) or the like for marking product data can be the same as that used for laser quenching, thereby reducing costs and working time.

  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 by the convex strip 43 of the face spline 45, it is a convex part extended in radial direction, without comprising such a convex strip 43. 41 may be arranged at a predetermined pitch along the circumferential direction. In the case of performing the metal surface treatment or the laser quenching treatment, the entire face spline 45 is applied in the embodiment, but only the range on the inner diameter side of the radial center position having a high contribution at the time of torque transmission may be applied. Good.

  The hardness difference between the convex portion 41 side and the end crimped portion 31 formed by the convex portion 41 is preferably 20 points or more in HRC as described above, but the convex portion 41 is press-fitted. If possible, it may be less than 20 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 wheel bearing apparatus which shows embodiment of this invention. It is sectional drawing of the constant velocity universal joint of the said wheel bearing apparatus. It is a side view of the constant velocity universal joint of the said wheel bearing apparatus. It is an expanded sectional view of the convex part of uneven | corrugated fitting structure M. FIG. It is sectional drawing of the decomposition | disassembly state of the said wheel bearing apparatus. It is sectional drawing of the hub wheel of the state which shape | molded the face spline. It is sectional drawing of the conventional wheel bearing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub wheel 2 Bearing 3 Constant velocity universal joint 11 Mouse | mouth part 12 Bottom wall 13 Inner spherical surface 31 End crimping part 31a Outer end surface 40 Hub wheel corresponding surface 41 Convex part 42 Concave part 45 Face spline

Claims (5)

A hub wheel, a double row rolling bearing and a constant velocity universal joint are unitized, and the outer joint member of the constant velocity universal joint has a mouth portion in which the inner joint member is housed, and the end of the hub wheel is crimped. Preload is applied to the inner ring of the rolling bearing that is fitted on the hub ring, and the hub ring corresponding surface of the bottom wall of the mouth portion of the outer joint member and the end caulking part of the hub ring are unevenly fitted. A wheel bearing device integrated through a joint structure,
A face on the outer joint member side 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 on the hub wheel corresponding surface of the mouth portion of the outer joint member The spline is formed, and the hardness of each protrusion of the face spline is set higher than the hardness of the end caulking portion of the hub ring, and the face spline on the outer joint member side to the end caulking portion of the hub ring is formed. By forming the shape by pressing, a face spline on the hub wheel side to which the face spline on the outer joint member side is fitted is formed on this end caulking portion, and a convex portion that is a convex strip and a concave portion that is a concave strip The wheel bearing device is characterized in that the concave-convex fitting structure in which the entire fitting contact part is closely contacted with each other and the pressure angle of the convex part on the mouse part side is 20 ° or less. The wheel bearing device according to claim 1, wherein the hardness of the end caulking portion of the hub wheel is 25 HRC to 35 HRC . To claim 1 or claim 2, characterized in that it has facilities for metal surface treatment of WPC treatment and shot peening relative to the end crimped portion of the hub wheel having a recess formed in the convex portion of the mouth portion side The wheel bearing device described. Wheel bearing according to claim 1 or claim 2, characterized in that it has facilities to heat treatment by laser quenching to the end crimped portion of the hub wheel having a recess formed in the convex portion of the mouth portion side apparatus. Heat treatment by laser quenching is applied to the end caulking portion of the hub wheel in which the concave portion is formed at the convex portion on the mouse side, and marking of product data by laser is applied to at least one of the outer joint member and the hub wheel. a bearing device for a wheel according to claim 1 or claim 2, characterized in that the facilities.

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