JP2012025259A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain stable connection between a hub ring and an outer coupling member by surely securing fixing force by a bolt member in a bearing device for a wheel configured such that separation of the hub ring and an outer coupling ring from each other is allowed.SOLUTION: In this bearing device, protrusions axially extending are provided on a shaft part 11 of the outer coupling ring 4, and the shaft part 11 is press-fitted into a hole 20 of the hub ring 1. Through this press-fitting operation, recesses to be closely fitted on the protrusions are formed on the inside diameter surface of the hub ring 1 by means of the protrusions, and as a result, there is formed with recess-protrusion-fitting structure M wherein the protrusions are in close contact with the recesses over the whole fitting area. The hub ring 1 and the shaft part 11 of the outer coupling ring 4 are fixed to each other by a bolt member 37 in a state where it is allowed to separate the recess-protrusion-fitting structure M by providing an axial pull-out force. Furthermore, a bolt receiving surface 20e1 of the hub ring 1, on which a seat surface 37a1 of a head part 37a provided in the bolt member 37 abuts, is formed with a hardening layer H2 by heat treatment, and surface hardness thereof is made a subject of control, and an allowable value equal to or more than 50 HRC is given.

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.

  The wheel bearing device has evolved from a structure called the first generation, which uses a combination of double row rolling bearings, to a second generation in which the body mounting flange is integrally provided on the outer member. One of the two inner raceways of the rolling bearing is formed on the outer circumference of the hub ring, and one of the two inner raceways of the double row rolling bearing is formed on the outer circumference of the hub ring. At the same time, a fourth-generation one having the other formed on the outer periphery of the outer joint member of the constant velocity universal joint has been developed.

  For example, Patent Document 1 describes what is called a third generation. As shown in FIG. 11, the wheel bearing device called the third generation includes a hub wheel 152 having a flange 151 extending in the outer diameter direction, and a constant velocity universal joint 154 in which an outer joint member 153 is fixed to the hub wheel 152. And an outer member 155 disposed on the outer peripheral side of the hub wheel 152.

  The constant velocity universal joint 154 is disposed between the outer joint member 153, the inner joint member 158 disposed in the mouth portion 157 of the outer joint member 153, and the inner joint member 158 and the outer joint member 153. And a cage 160 for holding the ball 159. A female spline 161 is formed on the inner peripheral surface of the center hole of the inner joint member 158, and a male spline formed at the end of the shaft (not shown) is inserted into the center hole. By fitting the female spline 161 on the inner joint member 158 side and the male spline on the shaft side, the inner joint member 158 and the shaft are coupled so that torque can be transmitted.

  The hub wheel 152 has a cylindrical portion 163 and a flange 151, and a short cylindrical shape for mounting a wheel and a brake rotor (not shown) on the outer end surface 164 (end surface on the outboard side) of the flange 151. A pilot part 165 is provided so as to protrude. The pilot portion 165 includes a large diameter portion 165a and a small diameter portion 165b, and a brake rotor is externally fitted to the large diameter portion 165a, and a wheel is externally fitted to the small diameter portion 165b.

  A fitting portion 166 is provided on the outer peripheral surface of the end portion on the inboard side of the cylindrical portion 163, and the inner ring 167 is fitted to the fitting portion 166. A first inner raceway surface 168 is provided in the vicinity of the flange 151 on the outer peripheral surface of the cylindrical portion 163, and a second inner raceway surface 169 is provided on the outer peripheral surface of the inner ring 167. The flange 151 of the hub wheel 152 is provided with a bolt mounting hole 162, and a hub bolt for fixing the wheel and the brake rotor to the flange 151 is mounted in the bolt mounting hole 162.

  The outer member 155 of the rolling bearing is provided with two rows of outer raceways 170 and 171 on the inner periphery thereof, and a flange (vehicle body mounting flange) 182 on the outer periphery thereof. The first outer raceway surface 170 of the outer member 155 and the first inner raceway surface 168 of the hub wheel 152 face each other, and the second outer raceway surface 171 of the outer member 155 and the raceway surface 169 of the inner ring 167 face each other. The rolling elements 172 are interposed between these.

  The shaft portion 173 of the outer joint member 153 is inserted into the tube portion 163 of the hub wheel 152. A screw portion 174 is formed at the shaft end portion of the shaft portion 173, and a male spline 175 is formed at the outer diameter portion on the inboard side of the screw portion 174. In addition, a female spline 176 is formed on the inner diameter surface of the cylindrical portion 163 of the hub wheel 152, and the shaft portion 173 is press-fitted into the cylindrical portion 163 of the hub wheel 152, so that the male spline 175 on the shaft portion 173 side and the hub wheel 152 side. The female spline 176 is fitted.

  Then, the nut member 177 is screwed to the screw portion 174 of the shaft portion 173, and the hub wheel 152 and the outer joint member 153 are fixed. At this time, the seat surface 178 of the nut member 177 and the outer end surface 179 of the cylindrical portion 163 come into contact with each other, and the end surface 180 on the outboard side of the mouse portion 157 and the end surface 181 of the inner ring 167 come into contact with each other. As a result, the hub wheel 152 is sandwiched between the nut member 177 and the mouth portion 157 via the inner ring 167.

  However, when such a configuration is adopted, the outer joint member 153 and the hub wheel 152 press-fit the male spline 175 provided on the shaft portion 173 of the outer joint member 153 into the female spline 176 provided on the hub wheel 152. Therefore, both the shaft portion 173 and the hub wheel 152 need to be splined, which increases costs. In addition, it is necessary to match the unevenness of the male spline 175 of the shaft portion 173 and the female spline 176 of the hub wheel 152 at the time of press-fitting, but if the press-fitting is performed by tooth surface alignment, the tooth surface may be damaged due to peeling or the like. If it is press-fitted by diameter matching, play in the circumferential direction is likely to occur. If there is a backlash in the circumferential direction, the torque transmission is inferior and abnormal noise may occur. In this way, when the outer joint member 153 and the hub wheel 152 are coupled by spline fitting, there are problems of tooth surface damage during press-fitting and generation of play during use, and both problems can be avoided at the same time. It was difficult.

  Further, when repairing the wheel bearing device or the like, it may be difficult to repair in a state where the hub wheel and the outer joint member remain coupled. Therefore, in order to be able to repair the bearing part and the joint part individually, it is desirable to be able to separate the hub wheel and the outer joint member, and after separation of both, they are recombined (reassembled). It needs to be possible.

  Therefore, the present applicant has proposed a wheel bearing device disclosed in Patent Document 2 in order to deal with these problems. Specifically, by pressing a convex portion extending in the axial direction provided in one of the shaft portion of the outer joint member and the hole of the hub wheel into the other, and forming the concave portion by the convex portion on the other side. The concave-convex fitting structure in which the entire fitting portion between the convex portion and the concave portion is in close contact is configured. When the concave / convex fitting structure is configured, it is not necessary to previously form the spline portion on the member in which the concave portion is formed, so that productivity can be improved. Moreover, since the damage of the tooth surface at the time of press fit can be avoided, the stable fitting state can be maintained. Further, in the above-described concave / convex fitting structure, no gap is formed in which the play occurs in the radial direction and the circumferential direction, so that stable torque transmission is possible and the generation of abnormal noise is prevented. In addition, since the shaft portion is in close contact with the hole portion and the strength of the torque transmitting portion is improved, the length of the fitting portion can be shortened to make the bearing device compact in the axial direction.

  Furthermore, since the above-described concave-convex fitting structure is separable by applying an axial pull-out force with the bolt member removed from the bolt hole provided in the shaft portion, it has good repair workability (maintenance) Gender) is secured. In addition, after the repair, the concave-convex fitting structure can be reconfigured by press-fitting the shaft portion of the outer joint member into the hole portion of the hub wheel. Reconstruction of the concave-convex fitting structure (recombination of the hub wheel and the outer joint member) can be performed by screwing the bolt member into the bolt hole provided in the shaft portion. Therefore, it is not necessary to use a large-scale facility such as a press-fitting press machine when reconstructing the concave-convex fitting structure. Therefore, it is possible to easily inspect and repair the wheel bearing device even at a site such as an automobile maintenance factory.

JP 2004340403 A JP 2009-56869 A

  Incidentally, in the wheel bearing device disclosed in Patent Document 2, the hub wheel and the outer joint member are fastened in a state where the bolt member is screwed into the bolt hole. Only when the seating surface is properly brought into contact with the bolt receiving surface provided on the hub wheel, the desired force is exhibited.

  However, if the surface hardness of the bolt receiving surface of the hub wheel is insufficient, there is a risk that the contact state between the head seating surface of the bolt member and the bolt receiving surface of the hub wheel may be defective. That is, in this case, there is a possibility that wear or indentation may occur on the bolt receiving surface of the hub wheel due to contact with the head seat surface of the bolt member. If wear or indentation occurs on the bolt receiving surface of the hub wheel, the bolt receiving surface may be scraped or depressed, so that there is a subsequent gap between the bolt receiving surface of the hub wheel and the head seating surface of the bolt member. As a result, the fixing force by the bolt member is reduced.

  Therefore, from the viewpoint of maintaining the fixing force by the bolt member, it is necessary to manage the surface hardness of the bolt receiving surface of the hub wheel from the relationship with the head seating surface of the bolt member. There was no mention of and there were still problems to be improved.

  In view of the above circumstances, the present invention reliably secures the fixing force by the bolt member by preventing a situation in which the bolt receiving surface of the hub wheel is worn or indented due to contact with the head seating surface of the bolt member. Therefore, it is a technical object to maintain a stable fastening state between the hub wheel and the outer joint member.

  A wheel bearing device according to the present invention, which was created to solve the above-mentioned problems, includes an outer member having a double-row raceway surface on the inner periphery and a hub wheel attached to the wheel, and the outer member raceway. A wheel bearing having an inner member having a double-row raceway surface facing the surface on the outer periphery, a double-row rolling element interposed between the outer member and the raceway surface of the inner member, and an outer joint member A convex portion extending in the axial direction provided in one of the shaft portion of the outer joint member and the hole portion of the hub wheel is press-fitted into the other, and the other is By forming the concave portion with the convex portion, a concave-convex fitting structure is formed in which the entire fitting portion between the convex portion and the concave portion is in close contact, and a bolt hole is provided in the shaft portion of the outer joint member. With the bolt member screwed into the hole, the hub wheel and the outer joint member are And a bearing device for a wheel that allows separation of the concave-convex fitting structure by applying an axial pull-out force in a state where the bolt member is removed, wherein a head seat surface of the bolt member is provided on the hub wheel. It is characterized in that a bolt receiving surface that is in contact with and subjected to a curing process is provided, the surface hardness of the bolt receiving surface is set as a management target, and an allowable value of 50 HRC or more is given as the surface hardness.

  In addition, as described above, the “concave / concave fitting structure” here is one in which the entire fitting part of the convex part and the concave part are in close contact, but there may be a gap in a very small region of the fitting part. . Since such a gap is inevitably generated in the formation process of the concave portion by the convex portion, even if there is such a gap, the concept that “the entire fitting part of the convex portion and the concave portion is in close contact” is used. It shall be included (hereinafter the same).

  As described above, according to the present invention, the bolt receiving surface of the hub wheel with which the head seat surface of the bolt member abuts is subjected to hardening treatment, and the surface hardness of the bolt receiving surface of the hub wheel subjected to the hardening treatment is set. Since it is set as a management target, if this surface hardness is managed within a predetermined range, the surface hardness of the bolt receiving surface may be optimized from the relationship with the head seating surface of the bolt member. it can. In other words, it is possible to prevent subsequent occurrence of wear or indentation on the bolt receiving surface of the hub wheel due to contact with the head seat surface of the bolt member. Therefore, a stable fastening state between the outer joint member and the hub wheel can be maintained by the bolt member, and stable torque transmission can be performed over a long period of time. In addition, by stabilizing the fastening state between the outer joint member and the hub wheel, it is possible to prevent muddy water from the outboard side through the bolt hole by preventing a subsequent gap from being formed between them. It is possible to reliably prevent the intrusion of foreign matters such as the above. On the other hand, the surface hardness of the bolt receiving surface as a management target can contribute to the prevention of bolt receiving surface wear and indentation as the value increases, but if this is controlled too strictly, the hardening treatment Since special considerations are required, the production cost of the hub wheel may be unduly increased. Therefore, an allowable value of 50 HRC or more is given to the surface hardness of the bolt receiving surface subjected to the hardening treatment. As a result, wear and indentation are prevented from occurring on the bolt receiving surface of the hub wheel, and the hub ring manufacturing cost increases while maintaining a stable fastening state between the hub wheel and the outer joint member by the bolt member. Can be reliably suppressed.

  Said structure WHEREIN: It is preferable that the said hardening process is induction hardening.

  In this way, there is an advantage that the heating efficiency is good and the work time required for the curing process is short. Further, partial quenching is possible, and there is an advantage that quenching distortion is small.

  In the above configuration, the hardness of at least the axial end portion on the press-fitting start side of the convex portion provided on one of the shaft portion of the outer joint member and the hole of the hub wheel is determined by press-fitting the convex portion. It is preferable that the hardness of the other recessed portion forming portion where the recessed portion is formed is higher.

  In this way, when the convex portion is press-fitted into the counterpart, it becomes easy to cut out or push out a part of the counterpart, so that a concave portion that follows the shape of the convex portion is formed on the counterpart. It becomes easy to form accurately. That is, the fitting state between the convex portion and the concave portion becomes denser, and the close contact state between the convex portion and the concave portion can be made better.

  In the configuration described above, a pocket portion is provided in the one of the shaft portion of the outer joint member and the hole portion of the hub wheel in which the convex portion is provided to accommodate the other protruding portion generated by the formation of the concave portion. May be. Here, the “extrusion portion” is the amount of material corresponding to the volume of the concave portion formed by the convex portion, and is extruded from the concave portion to be formed, or cut to form the concave portion. It is comprised from what was extruded, what was extruded, and what was cut.

  In this way, since the protruding portion can be held in the pocket portion, the protruding portion does not enter the vehicle outside the apparatus. Therefore, since it is not necessary to perform the removal process of the protruding portion, the removal process can be omitted to reduce the number of assembling work, and the assembling workability can be improved and the cost can be reduced.

  Said structure WHEREIN: The tooth bottom part between the said convex part provided in one among the axial part of the said outer joint member, and the hole part of the said hub ring | wheel, and the said other said recessed part facing this tooth bottom part in radial direction A gap may be formed between the forming portion and the forming portion.

  By doing so, the frictional force is reduced by the amount of the gap at the time of press-fitting, so that the pressure input at the time of press-fitting can be reduced. In addition, even if the press fitting is performed with the shaft center of the outer joint member and the shaft center of the hub wheel slightly deviated from each other, both can be assembled with the gap absorbed, so that the assembly action Time work management becomes easy.

  In the above configuration, the convex portions are provided at a plurality of locations in the circumferential direction, and the sum of the circumferential thicknesses of the convex portions is determined between the adjacent convex portions at an intermediate portion in the height direction of the convex portions. It is preferable to make it smaller than the total sum of the groove widths.

  In this way, since the mating meat that has entered the groove between the adjacent convex portions has a large thickness in the circumferential direction, the shear area of the meat can be increased, and the torsional strength can be improved. Can do. And since the tooth thickness of a convex part is small, a press-fit load can be made small and a press-fit property can be aimed at.

  In the above configuration, the inner member includes the hub wheel and an inner ring that is press-fitted into the outer periphery of the end portion on the inboard side of the hub wheel, and the inner member is disposed on the outer periphery of the hub wheel and the outer periphery of the inner ring, respectively. A raceway surface is preferably formed.

  In this way, the raceway surfaces can be formed on the outer periphery of the hub wheel and the outer periphery of the inner ring, respectively. As a result, the wheel bearing device can be reduced in weight and size.

  Said structure WHEREIN: It is preferable that the back surface of the mouth part of the said outer joint member and the end surface of the said hub ring are non-contact, or are contacting with the contact surface pressure of 100 Mpa or less.

  If the outer joint member and the hub wheel are not in contact with each other as in the former case, it is possible to prevent the generation of noise due to contact between the two. In addition, when both are brought into contact as in the latter case, when the contact surface pressure increases, torque is transmitted even at the contact portion to which the pressure is applied, and a larger torque is loaded, and the contact portion becomes torque. When it becomes impossible to withstand transmission, there is a risk that sudden slip occurs at the contact portion and abnormal noise is generated. Therefore, the occurrence of abnormal noise can be prevented by setting the contact surface pressure to a low surface pressure of 100 MPa or less.

  Said structure WHEREIN: It is preferable to seal at least one between the back surface of the mouth part of the said outer joint member, and the said inward member, or between the head seat surface of the said bolt member, and the said bolt receiving surface. .

  In this way, since the intrusion of rainwater and foreign matter into the concave-convex fitting structure is suppressed, it is possible to maintain good product quality over a long period of time.

  Said structure WHEREIN: It is preferable that the axial direction position of the said uneven | corrugated fitting structure exists in the position which avoided the direct under of the said track surface of the said wheel bearing.

  That is, when the shaft portion of the outer joint member is press-fitted into the hole portion of the hub wheel, the hub wheel expands. By this expansion, a force for expanding the diameter in the outer diameter direction, that is, a hoop stress is generated on the raceway surface of the wheel bearing. Therefore, when a hoop stress is generated on the raceway surface, there is a risk of causing a reduction in rolling fatigue life and occurrence of cracks. Therefore, the occurrence of hoop stress on the raceway surface can be suppressed by arranging the concave-convex fitting structure at a position that avoids a position directly below the raceway surface of the rolling bearing.

  In the above configuration, after separating the outer joint member and the hub wheel, the convex portion formed on the one of the shaft portion of the outer joint member and the hole portion of the hub wheel is formed on the other side. A guide recess for matching the phase of the projection formed on one side with the phase of the recess formed on the other side when re-pressing into the formed recess and recombining them. You may provide in the press injection start side of the said recessed part formed in the other.

  In this way, when the shaft portion of the outer joint member is press-fitted into the hole of the hub wheel again, the convex portion is accurately fitted into the concave portion formed at the previous press-fitting, and the concave portion can be damaged. Absent. For this reason, it is possible to form a concave / convex fitting structure with high accuracy, in which there is no gap between the radial direction and the circumferential direction.

  According to the present invention as described above, the surface of the bolt receiving surface is subjected to the hardening treatment, and the surface hardness of the bolt receiving surface subjected to the hardening treatment is set as a management target. The hardness is optimized, and it is possible to prevent a situation in which wear or indentation occurs on the bolt receiving surface of the hub wheel due to contact with the head seat surface of the bolt member. Therefore, a stable fastening state of the hub wheel and the outer joint member by the bolt member can be maintained.

It is sectional drawing which shows embodiment of the wheel bearing apparatus. (A) is sectional drawing of the uneven | corrugated fitting structure of the said wheel bearing apparatus, (b) is an enlarged view of the X section shown to (a). It is a principal part expanded sectional view of the said wheel bearing apparatus. It is sectional drawing which shows the assembly method of the said bearing apparatus for wheels. It is sectional drawing which shows the isolation | separation process of the uneven | corrugated fitting structure in the said wheel bearing apparatus. The re-pressing method of the said wheel bearing apparatus is shown, Comprising: (a) is sectional drawing which shows a state immediately before press-fitting, (b) is sectional drawing which shows in the middle of press-fitting, (c) is sectional drawing which shows a press-fit completion state It is. It is sectional drawing which shows the re-pressing method of the said bearing apparatus for wheels. (A) is sectional drawing which shows the other example of the convex part of an uneven | corrugated fitting structure, (b) is sectional drawing which shows the other example of the convex part of an uneven | corrugated fitting structure. (A) is sectional drawing which shows the other example of an uneven | corrugated fitting structure, (b) is an enlarged view of the Y section shown to (a). (A) is an expanded sectional view when an O-ring is used as a sealing member, and (b) is an enlarged sectional view when a gasket is used as a sealing member. It is sectional drawing of the conventional wheel bearing apparatus.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a cross-sectional view showing a wheel bearing device according to an embodiment of the present invention. As shown in the figure, this wheel bearing device is formed by integrating a double row rolling bearing 2 including a hub wheel 1 and a constant velocity universal joint 3. In the following description, the inboard side means the side that is inside the vehicle width direction of the vehicle when attached to the vehicle, and the outboard side means the vehicle width direction of the vehicle when attached to the vehicle. This means the outside side.

  The constant velocity universal joint 3 is interposed between a joint outer ring 4 as an outer joint member, a joint inner ring 5 as an inner joint member arranged inside the joint outer ring 4, and the joint outer ring 4 and the joint inner ring 5. A plurality of balls 6 that transmit torque and a cage 7 that is interposed between the joint outer ring 4 and the joint inner ring 5 and holds the balls 6 are configured as main members. The joint inner ring 5 is spline-fitted by press-fitting the end 8a of the shaft 8 into the hole inner diameter 5a, and is coupled to the shaft 8 so that torque can be transmitted. Note that a retaining ring 9 for preventing the shaft from coming off is fitted to the end portion 8 a of the shaft 8.

  The joint outer ring 4 includes a mouth portion 10 and a shaft portion (also referred to as a stem portion) 11. The mouth portion 10 has a bowl shape opened at one end, and a plurality of track grooves 13 extending in the axial direction on the inner spherical surface 12 thereof. Are formed at equal intervals in the circumferential direction. The track groove 13 extends to the open end of the mouse portion 10. In the joint inner ring 5, a plurality of track grooves 15 extending in the axial direction are formed on the outer spherical surface 14 at equal intervals in the circumferential direction.

  The track groove 13 of the joint outer ring 4 and the track groove 15 of the joint inner ring 5 form a pair, and one ball 6 as a torque transmission element rolls on each ball track constituted by the pair of track grooves 13 and 15. Incorporated as possible. The ball 6 is interposed between the track groove 13 of the joint outer ring 4 and the track groove 15 of the joint inner ring 5 to transmit torque. The cage 7 is slidably interposed between the joint outer ring 4 and the joint inner ring 5, and is fitted to the inner spherical surface 12 of the joint outer ring 4 by the outer spherical surface 7a, and the outer spherical surface 14 of the joint inner ring 5 by the inner spherical surface 7b. Mates with. The constant velocity universal joint 3 in this case is a Rzeppa type. However, the track groove 13 of the joint outer ring 4 is linear on the opening side of the mouth portion 10 and the joint inner ring 5 on the back side of the mouth portion 10. Other constant velocity universal joints such as an undercut free type in which the track grooves 15 are straight may be used.

  Further, the opening of the mouse portion 10 is closed by a boot 16. The boot 16 includes a large diameter portion 16a, a small diameter portion 16b, and a bellows portion 16c that connects the large diameter portion 16a and the small diameter portion 16b. The large-diameter portion 16a is fitted on the opening of the mouse portion 10, and is fastened with the boot band 17a in this state. Moreover, the small diameter part 16b is externally fitted by the boot mounting part 8b of the shaft 8, and is fastened by the boot band 17b in this state.

  The hub wheel 1 includes a cylindrical portion 18 and a wheel mounting flange 19 provided at an end portion on the outboard side of the cylindrical portion 18. The hole portion 20 of the cylindrical portion 18 includes a shaft portion fitting hole 20a, a tapered hole 20b on the outboard side, and a large diameter hole 20c provided on the inboard side. In the shaft portion fitting hole 20a, the shaft portion 11 of the joint outer ring 4 and the hub wheel 1 are detachably coupled via the uneven fitting structure M. A tapered portion (tapered hole) 20d is provided between the shaft portion fitting hole 20a and the large diameter hole 20c, and protrudes in the inner diameter direction between the shaft portion fitting hole 20a and the tapered hole 20b. An inner wall 20e is provided.

  A small-diameter step portion 21 is formed on the outer peripheral surface of the hub wheel 1 on the inboard side. By fitting the inner ring 22 to the stepped portion 21, an inner member having double row inner raceways (inner races) 23, 24 is formed. Among the double-row inner raceway surfaces, the outboard side inner raceway surface 23 is formed on the outer peripheral surface of the hub wheel 1, and the inboard side inner raceway surface 24 is formed on the outer peripheral surface of the inner ring 22. The wheel bearing 2 is disposed on the inner member, the outer diameter side of the inner member, an outer member 27 having double-row outer raceways (outer races) 25 and 26 on the inner periphery, and the outer member 27. Between the outer raceway surface 25 on the outboard side and the inner raceway surface 23 of the hub wheel 1, and between the outer raceway surface 26 on the inboard side of the outer member 27 and the inner raceway surface 24 of the inner ring 22. The ball 28 functions as a rolling element. Since the hub ring 1 and the inner ring 22 press-fitted into the outer periphery of the hub ring 1 constitute an inner member having the inner raceways 23 and 24, the wheel bearing device can be reduced in weight and size. Seal members S1 and S2 are attached to both openings of the outer member 27.

  The wheel bearing 2 has a structure in which a cylindrical end portion on the inboard side of the hub wheel 1 is swaged, and an inner ring 22 is pressed by a swaged portion 29 formed by swaging to apply a preload to the inside of the bearing. is there. Thereby, the inner ring 22 can be fixed to the hub ring 1. When preload is applied to the bearing 2 by the crimping portion 29 formed at the end of the hub wheel 1, it is not necessary to apply preload at the mouth portion 10 of the joint outer ring 4. Therefore, the shaft portion 11 of the joint outer ring 4 can be press-fitted without considering the amount of preload, and the connectivity (assembleability) between the hub wheel 1 and the joint outer ring 4 can be improved.

  The caulking portion 29 of the hub wheel 1 and the back surface 10a of the mouse portion 10 are in contact with each other. In this case, since the shaft portion 11 of the joint outer ring 4 is positioned, the dimensional accuracy of the wheel bearing device is stabilized, and the axial length of the concave-convex fitting structure M is stabilized to improve torque transmission. Can be planned. Thus, when the crimping part 29 of the hub wheel 1 and the back surface 10a of the mouse | mouth part 10 are contact | abutted, it is desirable that both contact surface pressure shall be 100 Mpa or less. When the contact surface pressure increases, torque is transmitted even in the contact area to which pressure is applied, and when the larger torque is applied and the contact area cannot withstand torque transmission, a sudden slip occurs in the contact area. This is because abnormal noise may be generated. Therefore, by setting the contact surface pressure to 100 MPa or less, it is possible to provide a quiet wheel bearing device that prevents the generation of abnormal noise.

  A bolt mounting hole 30 is provided in the flange 19 of the hub wheel 1, and a hub bolt 31 for fixing the wheel and the brake rotor to the flange 19 is mounted in the bolt mounting hole 30.

  As shown in FIGS. 2 (a) and 2 (b), the concave / convex fitting structure M includes, for example, a protruding portion 32 provided in an end portion of the shaft portion 11 on the outboard side and extending in the axial direction, and It is comprised by the recessed part 33 formed in the internal-diameter surface of the hole part 20. As shown in FIG. In the present embodiment, the recess 33 is formed in the inner diameter surface 34 of the shaft portion fitting hole 20a. The whole fitting part of the convex part 32 and the concave part 33 of the hub wheel 1 fitted to the convex part 32 is in close contact. A plurality of convex portions 32 extending in the axial direction are arranged at a predetermined pitch along the circumferential direction on the outer peripheral surface of the end portion on the outboard side of the shaft portion 11, and the shaft portion fitting hole of the hole portion 20 of the hub wheel 1. A plurality of axial recesses 33 into which the protrusions 32 are fitted are formed in the inner diameter surface 34 of 20a along the circumferential direction. The convex portion 32 and the concave portion 33 are tight-fitted over the entire circumference.

  In this case, as shown in FIG. 2B, each convex portion 32 has a triangular shape (mountain shape) having a convex round-shaped top, and a fitting portion of each convex portion 32 with the concave portion 33. Is the range A shown in FIG. Each convex part 32 and the recessed part 33 are fitted in the range from the middle part on both sides in the circumferential direction of the convex part 32 in the cross section to the top part. And in this fitting state, the clearance gap 35 is formed in the inner diameter side rather than the inner diameter surface 34 of the hub wheel 1 used as a recessed part formation part between the adjacent convex parts 32 of the circumferential direction.

  Moreover, as shown in FIG. 1, the bolt member 37 is screwed by the bolt hole 36 of the axial part 11 from the outboard side. The bolt member 37 includes a head portion 37a with a flange and a shaft portion 37b having a screw portion 37b1 around the distal end side. A through hole 38 is provided in the inner wall 20 e, and the shaft portion 37 b of the bolt member 37 is inserted into the through hole 38, and the screw portion 37 b 1 is screwed into the bolt hole 36 of the shaft portion 11. The seat surface 37a1 of the head portion 37a is in contact with the bolt receiving surface 20e1 provided on the end surface of the inner wall 20e on the outboard side with the screw portion 37b1 screwed in this way. The entire end surface of the inner wall 20e on the outboard side may be a flat surface, and the bolt receiving surface 20e1 may be formed by a part of the end surface. However, in this embodiment, a part of the end surface of the inner wall 20e on the outboard side is used. A recess is formed by recessing on the board side, and the bottom surface of the recess constitutes a bolt receiving surface 20e1. The seat surface 37a1 of the head portion 37a of the bolt member 37 is a flat surface on which no spline or the like is formed.

  In this wheel bearing device, the inboard side and the outboard side are sealed from the concave / convex fitting structure M in order to prevent rainwater and foreign matter from entering the concave / convex fitting structure M, respectively.

That is, as shown in FIG. 1, the inboard side forms a seal structure by bringing the caulking portion 29 of the hub wheel 1 into contact with the back surface 10 a of the mouth portion 10 of the joint outer ring 4. Therefore, this seal structure can prevent a situation in which rainwater and foreign matter enter the concave-convex fitting structure M from the inboard side. A sealing material such as a resin material may be separately applied to at least one of the caulking portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10 of the joint outer ring 4.

  On the other hand, on the outboard side, a seal material (not shown) is interposed between the seating surface 37a1 of the bolt member 37 and the inner wall 20e to constitute a seal structure. In this case, the sealing structure can be configured by applying a sealing material such as a resin to at least one of the seat surface 37a1 of the bolt member 37 and the bolt receiving surface 20e1 of the inner wall 20e. When the bolt member 37 is screwed, such a sealing material can be omitted if the seat surface 37a1 of the bolt member 37 and the bolt receiving surface 20e1 of the inner wall 20e are excellent in adhesion. It is. For example, if the bolt receiving surface 20e1 is ground, adhesion with the seating surface 37a1 of the bolt member 37 is improved, so that it is possible to omit application of the sealing material. As long as the adhesion is ensured, the grinding process to the bolt receiving surface 20e1 can be omitted, and the forged skin and the turning finished state can be left as they are.

  Further, a sealing material may be interposed between the convex portion 32 and the concave portion 33. In this case, for example, sealing materials made of various resins that can be cured after application and exhibit sealing properties at the fitting portion may be applied to the surface of the convex portion 32.

  The uneven fitting structure M can be obtained by the following procedure.

  First, a male spline 39 having a large number of teeth extending in the axial direction is formed on the shaft portion 11 of the joint outer ring 4 using a known processing method (rolling, cutting, pressing, drawing, etc.). . Then, as shown in FIG. 2B, a region surrounded by the circle passing through the root 39 a, the tooth tip 39 b, and both side surfaces connected to the tooth tip 39 b of the male spline 39 becomes the convex portion 32.

  The male spline 39 preferably has a module of 0.5 or less, and has a smaller tooth than a commonly used spline module. As a result, the moldability of the male spline 39 can be improved, and the press-fitting load when the male spline 39 is press-fitted into the shaft portion fitting hole 20a of the hub wheel 1 can be reduced. By forming the convex part 32 of the shaft part 11 with the male spline 39, it is possible to utilize the processing equipment for forming the spline on this kind of shaft, and it is possible to form the convex part 32 at a low cost. is there.

  Next, as shown by cross hatching in FIGS. 1 and 3, the outer diameter surface of the shaft portion 11 is subjected to a thermosetting treatment to form a hardened layer H <b> 1. The hardened layer H1 is continuously formed in the circumferential direction including the entire convex portion 32 and the tooth bottom 39a. In addition, the axial formation range of the hardened layer H1 includes a range including at least a continuous region from the end edge on the outboard side of the male spline 39 to the inner diameter portion of the bottom wall of the mouth portion 10 of the joint outer ring 4. To do. As the thermosetting treatment, various heat treatments such as carburizing and quenching can be adopted. However, in this embodiment, induction hardening is adopted because partial quenching is easy. 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.

  On the other hand, the inner diameter side of the hub wheel 1 is maintained in an unburned state. That is, the inner diameter surface 34 of the hole portion 20 of the hub wheel 1 is an uncured portion (unburned state) that is not subjected to thermosetting. The hardness difference between the hardened layer H1 of the shaft portion 11 of the joint outer ring 4 and the uncured portion of the hub wheel 1 is 20 points or more in HRC. For example, the hardness of the hardened layer H1 is about 50 HRC to 65 HRC, and the hardness of the uncured portion is about 10 HRC to about 30 HRC. Of the inner diameter surface 34 of the hub wheel 1, it is sufficient that at least the inner diameter surface 34 of the shaft portion fitting hole 20 a is an uncured portion, and the other inner diameter surface may be subjected to thermosetting treatment. Further, if the hardness difference is ensured, the region to be the “uncured portion” may be subjected to a heat curing treatment.

  At this time, the intermediate portion in the height direction of the convex portion 32 is made to correspond to the position of the inner diameter surface 34 of the shaft portion fitting hole 20a of the hub wheel 1 before the concave portion is formed. That is, as shown in FIG. 2A, the inner diameter D1 of the inner diameter surface 34 of the shaft portion fitting hole 20a is set to the maximum outer diameter of the convex portion 32 of the male spline 39 (the tooth tip 39b of the male spline 39). It is set to be smaller than the circumscribed circle diameter dimension D2 and larger than the diameter dimension D3 of the circle connecting the roots of the male spline 39 (D3 <D1 <D2).

  Next, the shaft portion 11 of the joint outer ring 4 is press-fitted into the hole 20 of the hub wheel 1 in a state where the shaft center of the hub wheel 1 and the shaft center of the joint outer ring 4 of the constant velocity universal joint 3 are aligned. At this time, since the tapered portion 20d having a diameter reduced along the press-fitting direction is formed in the hole portion 20 of the hub wheel 1, the tapered portion 20d is connected to the hole portion 20 of the hub wheel 1 at the start of press-fitting and the joint outer ring 4. Centering with the shaft portion 11 is performed. Further, since the inner diameter dimension D1 of the shaft fitting hole 20a, the maximum outer diameter dimension D2 of the convex portion 32, and the minimum outer diameter dimension D3 of the tooth bottom of the male spline 39 are as described above, the shaft section 11 is press-fitted into the shaft fitting hole 20a of the hub wheel 1, so that the convex portion 32 bites into the inner diameter portion of the end surface on the inboard side of the hub wheel 1 and cuts the meat of the hub wheel 1. By pushing forward the shaft portion 11, the inner diameter surface 34 of the shaft portion fitting hole 20 a of the hub wheel 1 is cut out or extruded by the convex portion 32, and the shape corresponding to the convex portion 32 of the shaft portion 11 is formed on the inner diameter surface 34. A recess 33 is formed. In addition, since the hardness of the convex portion 32 of the shaft portion 11 is 20 points or more higher than the inner diameter surface 34 of the shaft portion fitting hole 20a of the hub wheel 1, it is easy to form a recess in the inner diameter surface 34 of the hub wheel 1. It becomes. Moreover, the torsional strength of the shaft portion 11 can be improved by increasing the hardness of the shaft portion side.

  By passing through this press-fitting process, as shown in FIGS. 2A and 2B, a concave portion 33 that fits into the convex portion 32 of the shaft portion 11 is formed. When the convex portion 32 bites into the inner diameter surface 34 of the hub wheel 1, the hole portion 20 is slightly expanded in diameter, and the convex portion 32 is allowed to move in the axial direction. On the other hand, if the movement in the axial direction stops, the inner diameter surface 34 is reduced in diameter to return to the original diameter. In other words, when the convex portion 32 is press-fitted, the hub wheel 1 is elastically deformed in the outer diameter direction, and a preload corresponding to the elastic deformation is applied to the surface of a portion of the convex portion 32 that fits into the concave portion 33. For this reason, the recessed part 33 closely_contact | adheres to the surface of the convex part 32 over the whole axial direction. Thereby, the concave-convex fitting structure M is configured.

  Further, as the shaft portion 11 is press-fitted, plastic deformation occurs on the hub wheel 1 side, so that work hardening occurs on the surface of the recess 33. For this reason, the inner diameter surface 34 of the hub wheel 1 on the concave portion 33 side is hardened, and the rotational torque transmission can be improved.

  The tapered portion 20d can function as a guide when starting press-fitting of the shaft portion 11. Therefore, the shaft portion 11 of the joint outer ring 4 can be pressed into the hole portion 20 of the hub wheel 1 without causing misalignment.

  On the outboard side of the tapered portion 20d, as shown in FIGS. 3 and 6, guide concave portions 40 are provided at a predetermined pitch along the circumferential direction. By fitting the convex portion 32 of the shaft portion 11 into the guide concave portion 40, the convex portion 32 can be positioned at the start of press-fitting. In addition, with the convex portion 32 fitted in the guide concave portion 40, a slight amount is allowed between the guide concave portion 40 and the convex portion 32 to allow the circumferential movement and radial movement of the convex portion 32. Gaps are formed. As will be described later, the guide recess 40 is used when the joint outer ring 4 and the hub wheel 1 are once separated and then the shaft portion 11 of the joint outer ring 4 is re-fitted into the hub wheel 1 to recombine them. Is also used. In this case, the guide recess 40 is used to make the phase of the projection 32 and the phase of the recess 33 coincide with each other at the time of re-pressing.

  The concave / convex fitting structure M is required to be arranged so as to avoid the inner diameter side of the raceway surfaces 23, 24, 25, and 26 of the bearing 2 as much as possible. In particular, it is desirable to avoid the inner diameter side of the intersection with the line through which the contact angle passes on the inner races 23 and 24, and to form the concave / convex fitting structure M in a partial region in the axial direction between these intersections. Thereby, generation | occurrence | production of the hoop stress in a bearing raceway surface can be suppressed. Accordingly, it is possible to prevent bearing failures such as a decrease in rolling fatigue life, occurrence of cracks, and stress corrosion cracking, and a high-quality bearing can be provided.

  When the shaft portion 11 of the joint outer ring 4 is press-fitted into the hole portion 20 of the hub wheel 1, as shown in FIG. 4, the press-fitting is performed on the stepped surface 41 provided on the outer diameter surface of the mouth portion 10 of the joint outer ring 4. A press-fit load (axial load) may be applied to the stepped surface 41 from the press-fit jig K by engaging the work jig K. In addition, as the level | step difference surface 41, you may provide in the circumferential direction whole periphery, or may provide with a predetermined pitch along the circumferential direction. The press-fitting jig to be used only needs to be able to apply an axial load corresponding to the shape of these stepped surfaces 41.

  Then, after the shaft portion 11 of the joint outer ring 4 is press-fitted into the hole portion 20 of the hub wheel 1 to form the uneven fitting structure M, a bolt member is inserted into the bolt hole 36 of the shaft portion 11 as shown in FIG. 37 is screwed. In this state, the seating surface 37a1 of the head portion 37a of the bolt member 37 abuts on the bolt receiving surface 20e1 provided on the end surface of the inner wall 20e on the outboard side, and the fixing force by the bolt member 37 is the shaft portion of the joint outer ring 4. 11 acts. At this time, if the surface hardness of the inner wall 20e with which the seat surface 37a1 of the head portion 37a of the bolt member 37 abuts is inappropriate, contact between the seat surface 37a1 of the head portion 37a of the bolt member 37 and the bolt receiving surface 20e1 occurs. As a result, wear and indentation occur on the bolt receiving surface 20e1. When the bolt receiving surface 20e1 is thus worn, a gap is formed between the seating surface 37a1 of the head portion 37a and the bolt receiving surface 20e1, and the fixing force of the bolt member 37 is significantly reduced. Arise. Therefore, in order to prevent the occurrence of such a problem, the bolt receiving surface 20e1 is subjected to thermosetting treatment to form a hardened layer H2, and the surface hardness of the hardened layer H2 is set as a management target. As the hardness, an allowable value of 50 HRC or more was given. The formation range of the hardened layer H2 includes at least a region where the bearing surface 37a1 of the bolt member 37 directly abuts. In this embodiment, the formation region of the hardened layer H2 is a continuous region from the opening edge of the through hole 38 on the outboard side to the connecting portion of the bolt receiving surface 20e1 and the tapered hole 20b. Thereby, the surface hardness of the bolt receiving surface 20e1 of the inner wall 20e becomes optimal from the relationship with the seating surface 37a1 of the head portion 37a, and the rate at which wear and indentation are generated on the bolt receiving surface 20e1 is reduced as much as possible. be able to. Therefore, it is possible to reliably suppress a situation in which a gap is formed afterward from the seat surface 37a1 of the head portion 37a of the bolt member 37 by cutting the inner wall 20e of the hub wheel 1, particularly the bolt receiving surface 20e1. can do. Therefore, the bolt member 37 can maintain a stable fastening state between the joint outer ring 4 and the hub wheel 1, and stable torque transmission can be performed over a long period of time. In addition, by stabilizing the fastening state between the joint outer ring 4 and the hub wheel 1, it is possible to prevent a gap from being formed later between the two, so that muddy water or the like is generated from the outboard side through the bolt hole 36. It is also possible to suppress a situation where foreign matter enters.

  In addition, although various hardening, such as carburizing hardening, can be employ | adopted as a thermosetting process for forming the hardened layer H2 in the volt | bolt receiving surface 20e1, in this embodiment, reasons for partial hardening being easy, etc. Induction hardening is adopted.

  In the concave / convex fitting structure M described above, since the entire fitting portion between the convex portion 32 and the concave portion 33 is in close contact, there is no gap in which play occurs in the radial direction and the circumferential direction. For this reason, all the fitting parts contribute to rotational torque transmission, stable torque transmission is possible, and no abnormal noise is generated.

  Further, it is not necessary to previously form a female spline or the like on the member in which the recess 33 is formed (in this case, the hub wheel 1). Therefore, the productivity is excellent and the phase alignment between the splines is not required, so that the assemblability can be improved. Furthermore, damage to the tooth surface during press-fitting can be avoided, and a stable fitting state can be maintained. Moreover, since the inner diameter side of the hub wheel 1 is relatively soft, the concave portion of the hub wheel 1 is fitted with the convex portion 32 of the shaft portion 11 with high adhesion. Therefore, it becomes more effective by preventing play in the radial direction and the circumferential direction.

  Further, in the wheel bearing device described above, since the inboard side and the outboard side of the concave / convex fitting structure M are sealed, rainwater and foreign matter from both ends in the axial direction to the concave / convex fitting structure M are prevented. Intrusion is prevented, and the adhesion between the convex portion 32 and the concave portion 33 can be stably maintained for a long period of time.

  When the shaft portion 11 of the joint outer ring 4 is press-fitted into the hub wheel 1, as shown in FIG. 3, the material protrudes from the concave portion 33 by cutting out or pushing out the convex portion 32, and the protruding portion 42 is formed. . The protruding portion 42 has an amount corresponding to the volume of the portion of the convex portion 32 that fits into the concave portion 33. If the protruding portion 42 is left unattended, it may fall off and enter the vehicle. Therefore, as shown in the figure, a pocket portion 43 for accommodating the protruding portion 42 is formed on the outer diameter surface of the shaft portion 11, and the protruding portion 42 is accommodated in the pocket portion 43. Specifically, the pocket portion 43 can be formed, for example, by providing a circumferential groove 44 on the outer diameter surface on the outboard side of the male spline 39 of the shaft portion 11. Thus, by providing the pocket part 43 which accommodates the protrusion part 42, the protrusion part 42 can be hold | maintained in this pocket part 43, and the protrusion part 42 may enter into the vehicle etc. outside an apparatus. Absent. As a result, the protruding portion 42 can be kept stored in the pocket portion 43, and there is no need to perform the removal processing of the protruding portion 42, and the assembly workability is improved and the cost is reduced by reducing the number of assembling operations. be able to.

  Next, a procedure for separating the joint outer ring 4 and the hub wheel 1 connected by the concave-convex fitting structure M as described above, and a procedure for reconnecting the separated joint outer ring 4 and the hub wheel 1 will be described in order.

  First, when the joint outer ring 4 and the hub wheel 1 are separated, the bolt member 37 is removed from the state shown in FIG. 1 and then the fitting force of the concave-convex fitting structure M between the hub wheel 1 and the joint outer ring 4 is exceeded. The joint outer ring 4 is pulled out from the hub wheel 1 by applying a pulling force of. This extraction can be performed using a jig 45 as shown in FIG. The jig 45 includes a base 46, a pressing bolt member 48 that is screwed into the bolt hole 47 of the base 46, and a screw shaft 49 that is screwed into the bolt hole 36 of the shaft portion 11. A through hole 50 is provided in the base 46, and the hub bolt 31 of the hub wheel 1 is inserted into the through hole 50, and the nut member 51 is screwed into the hub bolt 31. At this time, the base 46 and the flange 19 of the hub wheel 1 are overlapped, and the base 46 is attached to the hub wheel 1.

  Thus, after attaching the base 46 to the hub wheel 1, the screw shaft 49 is screwed into the bolt hole 36 of the shaft portion 11 so that the screw shaft 49 protrudes from the inner wall 20e to the outboard side. The protruding amount of the screw shaft 49 is set to be longer than the axial length of the concave-convex fitting structure M. The screw shaft 49 and the pressing bolt member 48 are disposed on the same axis.

  Thereafter, the pressing bolt member 48 is screwed into the bolt hole 47 of the base 46 from the outboard side, and in this state, the bolt member 48 is screwed in the direction of the arrow. At this time, since the screw shaft 49 and the pressing bolt member 48 are disposed on the same axis, the bolt member 48 presses the screw shaft 49 toward the inboard side. As a result, the joint outer ring 4 moves toward the inboard side with respect to the hub wheel 1, and the joint outer ring 4 is detached from the hub wheel 1.

  Further, from the state where the joint outer ring 4 is detached from the hub wheel 1, for example, the hub wheel 1 and the joint outer ring 4 can be connected again using the bolt member 37. That is, the base 46 is removed from the hub wheel 1 and the screw shaft 49 is removed from the shaft 11, and the projection 32 of the shaft 11 is fitted into the guide recess 40 as shown in FIG. Let Thereby, the phase of the convex part 32 by the side of the axial part 11 and the recessed part 33 of the hub ring 1 formed by the last press-fitting suits.

  In this state, as shown in FIG. 7, the bolt member 37 is screwed into the bolt hole 36 of the shaft portion 11 through the through hole 38 of the hub wheel 1, and the bolt member 37 is screwed into the bolt hole 36. . As a result, as shown in FIG. 6B, the shaft portion 11 is fitted into the hub wheel 1. At this time, the hole portion 20 is slightly expanded in diameter, allowing the shaft portion 11 to enter in the axial direction, and the back surface 10a of the mouth portion 10 of the joint outer ring 4 contacts the end surface 29a of the crimping portion 29. Enter until touching. In this case, at the same time, as shown in FIG. 6C, the end surface of the convex portion 32 comes into contact with the end surface of the concave portion 33. And if the movement of an axial direction stops in this way, the hole 20 will reduce in diameter so that it may return to the original diameter. As a result, as in the previous press-fitting, the concave / convex fitting structure M in which the entire fitting portion of the convex portion 32 is in close contact with the corresponding concave portion 33 is formed again, and the joint outer ring 4 and the hub ring 1 are reconnected. Separation and re-coupling of the hub wheel 1 and the joint outer ring 4 described above should be performed with the outer member 27 of the bearing 2 attached to the knuckle 52 of the vehicle as shown in FIGS. Can do.

  In the first press-fitting (press-fitting to form the recess 33 in the inner diameter surface 34 of the hole 20), the press-fitting load is relatively large. Therefore, when the shaft part 11 is press-fitted, it is necessary to use a press machine or the like. On the other hand, in such re-pressing, since the press-fitting load is smaller than the first press-fitting load, the shaft portion 11 can be stably and accurately inserted into the hole of the hub wheel 1 without using a press machine or the like. 20 can be press-fitted. For this reason, the joint outer ring 4 and the hub wheel 1 can be separated and connected in the field.

  In the male spline 39 shown in FIGS. 2A and 2B, as an example, the pitch of the convex portions 32 and the pitch of the concave portions 33 are set to the same value. For this reason, as shown in FIG. 2B, the circumferential thickness L of the convex portion 32 and the groove width L0 between the adjacent convex portions are substantially the same in the intermediate portion in the height direction of the convex portion 32. It has become.

  On the other hand, as shown in FIG. 8A, in the intermediate portion in the height direction of the convex portion 32, the circumferential thickness L2 of the convex portion 32 is smaller than the groove width L1 between the adjacent convex portions. May be. In other words, at the intermediate portion in the height direction of the convex portion 32, the circumferential thickness (tooth thickness) L2 of the convex portion 32 on the shaft portion 11 side is set to the circumferential thickness of the protruding portion 53 on the hub wheel 1 side ( Tooth thickness) is smaller than L1.

  By satisfying the above relationship in each convex portion 32, the total sum Σ (B1 + B2 + B3 +...) Of the circumferential thickness L2 of the convex portion 32 on the shaft portion 11 side is set to the circumferential thickness of the protruding portion 53 on the hub wheel 1 side. Can be set smaller than the total sum Σ (A1 + A2 + A3 +...). As a result, the shear area of the protruding portion 53 on the hub wheel 1 side can be increased, and the torsional strength can be ensured. And since the tooth thickness of the convex part 32 is small, a press-fit load can be made small and a press-fit property can be aimed at.

  In this case, it is not necessary to satisfy the relationship of L2 <L1 for all the convex portions 32 and the protruding portions 53, and the total thickness in the circumferential direction is larger than the total thickness in the circumferential direction in the protruding portion 53 on the hub wheel 1 side. As long as it becomes smaller, some of the convex portions 32 and the protruding portions 53 can be set to L2 = L1 or L2> L1.

  In FIG. 8A, the convex portion 32 is formed in a trapezoidal cross section, but as shown in FIG. 8B, it can also be formed in an involute-shaped cross section.

  In the above embodiment, the case where the convex part 32 is formed on the shaft part side by forming the male spline 39 on the shaft part 11 is illustrated, but conversely, FIG. As shown in b), a convex portion 32 may be formed on the hub wheel 1 side by forming a female spline 54 on the inner diameter surface of the hole 20 of the hub wheel 1. In this case, as in the case where the male spline 39 is formed on the shaft portion 11, for example, a means for subjecting the hub wheel 1 to thermosetting treatment on the female spline 54 and making the outer diameter surface of the shaft portion 11 unburned, etc. Thus, the hardness of the convex portion 32 of the hub wheel 1 is made 20 points or more harder than the outer diameter surface of the shaft portion by HRC. The female spline 54 can be formed by various processing methods such as known broaching, cutting, pressing, and drawing. As the thermosetting treatment, various heat treatments such as induction hardening and carburizing and quenching can be employed.

  Then, when the shaft portion 11 is press-fitted into the hole portion 20 of the hub wheel 1, the convex portion 32 on the hub wheel 1 side forms a concave portion 33 that fits the convex portion 32 on the outer peripheral surface of the shaft portion 11, thereby A concave-convex fitting structure M is formed in which the entire fitting portion of the convex portion 32 and the concave portion 33 is in close contact. The fitting part of the convex part 32 and the recessed part 33 is the range B shown in FIG.9 (b). A gap 55 is formed between the convex portions 32 that are on the outer diameter side of the outer peripheral surface of the shaft portion 11 and adjacent in the circumferential direction.

  An intermediate portion in the height direction of the convex portion 32 corresponds to the position of the outer diameter surface of the shaft portion 11 before the concave portion is formed. That is, the outer diameter dimension D4 of the shaft portion 11 is larger than the minimum inner diameter dimension D5 of the convex portion 32 of the female spline 54 (diameter dimension of a circumscribed circle passing through the tooth tip 54a of the female spline 54), and the maximum inner diameter of the female spline 54 It is set smaller than the dimension D6 (diameter dimension of a circle connecting the tooth bottom 54b of the female spline 54) (D5 <D4 <D6).

  Even in this case, since the protruding portion 42 is formed by press-fitting, it is preferable to provide a pocket portion 43 for storing the protruding portion 42. Since the protruding portion 42 is formed on the inboard side of the shaft portion 11, the pocket portion is provided on the inboard side with respect to the concave-convex fitting structure M and on the hub wheel 1 side.

  As described above, when the convex portion 32 of the concave-convex fitting structure M is provided on the inner diameter surface of the hole portion 20 of the hub wheel 1, it is not necessary to perform the thermosetting treatment on the shaft portion 11 side. The advantage that the productivity of the outer ring 4 is excellent is obtained.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be variously modified. For example, in the above embodiment, the case where the bolt receiving surface 20e1 is directly provided on the hub wheel 1 has been described. However, another member such as a ring body is mounted on the hub wheel 1, and the end surface on the outboard side of this mounted member. A bolt receiving surface may be formed. In this case, at least a hardening process is performed on the bolt receiving surface formed by the separate member, but the entire separate member may be subjected to a hardening process to give a surface hardness of 50 HRC or more.

  In the above embodiment, the case where the back surface 10a of the mouse portion 10 is brought into contact with the end portion of the hub wheel 1 (in the above embodiment, the end surface 29a of the crimping portion 29) has been described. It is good. That is, as shown in FIGS. 10A and 10B, a gap may be provided between the end surface 29 a of the caulking portion 29 of the hub wheel 1 and the back surface 10 a of the mouth portion 10. In this way, it is possible to reliably prevent the generation of abnormal noise that occurs when the contact between the mouse unit 10 and the hub wheel 1 is in an inappropriate state. Further, in this case, as shown in FIG. 5A, a seal member S3 is fitted into the gap between the crimped portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10, and the seal member S3 You may make it prevent the penetration | invasion of rain water and a foreign material from the inboard side. As the seal member S3, for example, a commercially available O-ring as shown in FIG. 10A can be used, but can be interposed between the end of the hub wheel 1 and the bottom of the mouse portion 10. As far as the O-ring is concerned, a gasket or the like as shown in FIG.

  Moreover, the cross-sectional shape of the convex part 32 of the uneven | corrugated fitting structure M is not specifically limited to the shape mentioned above, Various cross-sectional shapes, such as a semicircle shape, a semi-elliptical shape, and a rectangular shape, can be employ | adopted. Also, the area and number of the convex portions 32, the circumferential arrangement pitch, and the like can be arbitrarily changed.

  Further, the hole portion 20 of the hub wheel 1 may be a deformed hole such as a polygonal hole other than a circular hole, and the cross-sectional shape of the end portion of the shaft portion 11 to be inserted into the hole portion 20 may be other than a circular cross section. An irregular cross section such as a square may be used. Furthermore, when the shaft portion 11 is press-fitted into the hub wheel 1, it is sufficient that the hardness of the end region including at least the end surface on the press-fitting start side of the convex portion 32 is higher than the hardness of the press-fitted side. There is no need to increase the overall hardness of 32. In FIG. 2B and FIG. 9B, gaps 35 and 55 are formed between the spline root and the member in which the concave portion 33 is formed. You may make it satisfy with the member of the side.

  Moreover, you may provide the small recessed part arrange | positioned by the predetermined pitch along the circumferential direction previously in the recessed part formation surface of the member in which a recessed part is formed. The small recess needs to be smaller than the volume of the recess 33. By providing such a small concave portion, the capacity of the protruding portion 42 formed when the convex portion 32 is press-fitted can be reduced, so that the press-fit resistance can be reduced. Moreover, since the protrusion part 42 can be decreased, the volume of the pocket part 43 can be made small and the workability of the pocket part 43 and the improvement of the intensity | strength of the axial part 11 can be aimed at. In addition, the shape of a small recessed part can employ | adopt various things, such as a triangle shape, semi-ellipse shape, and a rectangle, and can also set the number arbitrarily.

  In the above-described embodiment, the case where the bottom of the guide recess 40 forms a flat surface whose radial depth is constant along the press-fitting direction has been described. An inclined surface that is inclined while being reduced in diameter along the traveling direction) may be formed. In addition, the cross-sectional shape of the guide concave portion 40 is not particularly limited as long as the convex portion 32 can be fitted therein, and can be variously changed according to the cross-sectional shape of the convex portion 32 and the like.

  In addition to the balls 28, rollers can be used as the rolling elements of the bearing 2. Furthermore, in the above-described embodiment, the present invention is applied to the third generation wheel bearing device. However, the present invention can be similarly applied to the first generation, second generation, and further fourth generation wheel bearing devices. it can. In addition, when press-fitting the convex portion 32, even if the side where the concave portion 33 is formed is fixed and the side where the convex portion 32 is formed is moved, the side where the convex portion 32 is formed is reversed. You may fix and move the side in which the recessed part 33 is formed. Alternatively, both may be moved. In the constant velocity universal joint 3, the inner ring 5 and the shaft 8 may be integrated via the concave-convex fitting structure M described in each of the above embodiments.

DESCRIPTION OF SYMBOLS 1 Hub wheel 2 Wheel bearing 3 Constant velocity universal joint 4 Joint outer ring 5 Joint inner ring 6 Ball 7 Cage 8 Shaft 10 Mouse part 10a Back surface 11 Shaft part 20 Hole part 20a Shaft part fitting hole 20b Taper hole 20c Large diameter hole 20d Tapered portion 20e Inner wall 20e1 Bolt receiving surface 22 Inner rings 23, 24 Inner raceway surface (inner race)
25, 26 Outer raceway (outer race)
27 Outer member 28 Ball 29 Caulking portion 32 Protruding portion 33 Recessing portion 34 Inner diameter surface 36 Bolt hole 37 Bolt member 37a Head portion 37a1 Seating surface 37b Shaft portion 37b1 Screw portion 38 Through hole 40 Guide recessed portion 42 Protruding portion 43 Pocket portion H1 Hardened layer H2 Hardened layer M Concave and convex fitting structure

Claims (11)

An outer member having a double-row raceway surface on the inner periphery, a hub ring attached to a wheel, and an inner member having a double-row raceway surface facing the raceway surface of the outer member on the outer periphery; And a hub for a wheel having a double row rolling element interposed between raceways of the inner member and a constant velocity universal joint having an outer joint member, and a shaft portion of the outer joint member and the hub By fitting a convex portion extending in the axial direction provided in one of the hole portions of the ring into the other, and forming a concave portion with the convex portion on the other, the convex portion and the concave portion are fitted to each other. The concave and convex fitting structure in which the entire region is in close contact is formed, and a bolt hole is provided in the shaft portion of the outer joint member, and the hub wheel and the outer joint member are connected with the bolt member screwed into the bolt hole. Applying axial pull-out force with the bolt member removed A wheel bearing device that allows more separation of the recess-projection fitting structure,
A bolt receiving surface in which the head seating surface of the bolt member abuts on the hub wheel and is subjected to a hardening process is provided, and the surface hardness of the bolt receiving surface is set as a management target, and the surface hardness is set to 50 HRC. A bearing device for a wheel, characterized in that the above allowable values are given.   The wheel bearing device according to claim 1, wherein the hardening treatment is induction hardening.   Of the shaft portion of the outer joint member and the hole of the hub wheel, the concave portion is formed by press-fitting the convex portion so that the hardness of at least the axial end portion on the press-fitting start side of the convex portion provided on one side is formed. 3. The wheel bearing device according to claim 1, wherein the hardness of the other concave portion forming portion is higher than that of the second concave portion forming portion.   Of the shaft portion of the outer joint member and the hole of the hub wheel, the one provided with a convex portion is provided with a pocket portion that accommodates the other protruding portion generated by the formation of the concave portion. The wheel bearing device according to any one of claims 1 to 3.   Between the shaft portion of the outer joint member and the hole of the hub wheel, the tooth bottom portion between the convex portions provided on one side and the other concave portion forming portion facing the tooth bottom portion in the radial direction. The wheel bearing device according to claim 1, wherein a gap is formed in the wheel bearing device.   The convex portions are provided at a plurality of locations in the circumferential direction, and the sum of the circumferential thicknesses of the convex portions in the intermediate portion in the height direction of the convex portions is the sum of the groove widths between the adjacent convex portions. The wheel bearing device according to any one of claims 1 to 5, wherein the wheel bearing device is smaller.   The inner member is composed of the hub wheel and an inner ring that is press-fitted into the outer periphery of the inboard side end of the hub wheel, and the raceway surfaces are formed on the outer periphery of the hub wheel and the outer periphery of the inner ring, respectively. The wheel bearing device according to any one of claims 1 to 6, wherein the wheel bearing device is provided.   The back surface of the mouth portion of the outer joint member and the end surface of the hub wheel are not in contact with each other or are in contact with each other at a contact surface pressure of 100 MPa or less. Wheel bearing device.   2. The seal between at least one of a back surface of the mouth portion of the outer joint member and the inward member, or between a head seat surface of the bolt member and the bolt receiving surface. The wheel bearing apparatus of any one of -8.   The wheel bearing device according to any one of claims 1 to 9, wherein an axial position of the concave-convex fitting structure is at a position avoiding a position directly below the raceway surface of the wheel bearing.   After separating the outer joint member and the hub wheel, the convex portion formed on the one of the shaft portion of the outer joint member and the hole portion of the hub wheel is changed to the concave portion formed on the other side. When re-pressing and recombining them, a guide recess that matches the phase of the projection formed on the one with the phase of the recess formed on the other is started to be pressed into the other recess. The wheel bearing device according to claim 1, wherein the wheel bearing device is provided on a side.

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