WO2011132706A1

WO2011132706A1 - Bearing device for wheel

Info

Publication number: WO2011132706A1
Application number: PCT/JP2011/059728
Authority: WO
Inventors: 梅木田　光; 清武柴田; 小澤　仁博; 祐一淺野
Original assignee: Ntn株式会社
Priority date: 2010-04-21
Filing date: 2011-04-20
Publication date: 2011-10-27

Abstract

Disclosed is a bearing device for a wheel such that separation of a hub ring and an outer coupling ring from each other is allowed, and that the abutting state between a bolt receiving surface, and a head section bearing surface of a bolt member, is made appropriate, resulting in the prevention of a reduction in a fixing force acting between an outer coupling member and the hub ring. In this bearing device, protrusions (32) which extend axially are provided on a shaft section (11) of the outer coupling ring (4), and the shaft section (11) is press-fitted into a hole (20) of the hub ring (1). Through this press-fitting operation, recesses (33) which are closely fitted over the protrusions (32) are formed on the inside diameter surface of the hub ring (1) by means of the protrusions (32), with the result that there is formed a recess-protrusion-fitting structure (M) wherein the protrusions (32) are in close contact with the recesses (33) in the whole fitting area. The hub ring (1), and the shaft section (11) of the outer coupling ring (4), are fixed to each other with 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, the squareness of a bolt receiving surface (20e1) of the hub ring (1) with respect to the inside diameter surface (34) of a shaft section fitting hole (20a) is made a subject of control, said bolt receiving surface (20e1) being abutted by a head bearing surface (37a1) of the bolt member (37). A value of 0.1 mm or less is assigned as the squareness.

Description

Wheel bearing device

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. 17, 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 to which an outer joint member 153 is fixed. 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.

The fitting part 166 is provided in the outer peripheral surface of the inboard side edge part of the cylinder part 163, and the inner ring 167 is fitted to this fitting part 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. 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.

Also, when repairing the wheel bearing device, etc., it may be difficult to repair if the hub wheel and the outer joint member remain connected. 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 applicant of the present application has proposed the 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.

In other words, if the abutting state between the head seat surface of the bolt member and the bolt receiving surface of the hub wheel is in an inappropriate state, the tightening by the bolt member is easy to loosen, and the fixing acts between the outer joint member and the hub wheel. There is a risk of power loss. At this time, if the head seat surface of the bolt member comes into contact with the bolt receiving surface, stress concentration occurs at the piece receiving portion, and wear or indentation may occur on the bolt receiving surface. If wear or the like occurs in this way, a gap is formed between the head seating surface of the bolt member and the bolt receiving surface, and a reduction in fixing force appears more remarkably.

When the fixing force acting between the outer joint member and the hub wheel is reduced, there is a risk that an axial backlash may occur between the two and the bolt member head seat surface and the bolt receiving surface. This causes a problem because foreign matter such as muddy water may enter from the outboard side through the bolt hole.

Therefore, as described above, it is important to properly maintain the contact state between the head seating surface of the bolt member and the bolt receiving surface, but Patent Document 2 does not mention this point and should be improved. The problem remained.

In view of the above circumstances, the present invention reduces the fixing force acting between the outer joint member and the hub wheel by optimizing the contact state between the head seat surface of the bolt member and the bolt receiving surface. It is a technical problem to prevent this.

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 a concave portion with the convex portion, a concave-convex fitting structure in which the entire fitting portion between the convex portion and the concave portion is in close contact is formed, and a bolt hole is provided in the shaft portion of the outer joint member. The hub wheel and the outer joint member are tightened with the bolt member screwed to the 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 ring. A bolt receiving surface that abuts is provided directly or via another member, and the perpendicularity of the bolt receiving surface with respect to the hole inner diameter surface of the hub wheel corresponding to the formation region of the uneven fitting structure is set as a management target. It is characterized in that an allowable value of 0.1 mm or less is given as the squareness.

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, in the present invention, the perpendicularity of the bolt receiving surface of the hub wheel with respect to the bore inner surface of the hub wheel corresponding to the formation region of the uneven fitting structure is set as a management target. This is due to the following reason.

That is, since the shaft portion of the outer joint member is press-fitted along the inner diameter surface of the hole portion of the hub wheel, if the perpendicularity is not sufficiently secured, the perpendicularity of the bolt receiving surface with respect to the bolt hole of the shaft portion However, it is inevitably difficult to secure within an appropriate range. Therefore, in this case, even if the bolt member is screwed into the bolt hole and the head seating surface of the bolt member is brought into contact with the bolt receiving surface, the head seating surface of the bolt member is not parallel to the bolt receiving surface. Instead, a part of the seating surface comes into contact with the bolt receiving surface, and the contact state between the head seating surface of the bolt member and the bolt receiving surface becomes inappropriate. Therefore, in order to eliminate the problem of the contact state between the head seat surface of the bolt member and the bolt receiving surface, as described above, with respect to the hole inner diameter surface of the hub ring corresponding to the formation region of the uneven fitting structure, The perpendicularity of the bolt receiving surface of the hub wheel was set as a management target.

Therefore, if the perpendicularity is managed within a predetermined range, the contact state between the head seating surface of the bolt member and the bolt receiving surface can be properly maintained, and the fixing force is reduced by the bolt member. Can be prevented. As a result, it is possible to reliably prevent foreign matters such as muddy water from entering from the outboard side through the bolt holes and the axial play between the outer joint member and the hub wheel caused by a decrease in the fixing force by the bolt member. It becomes. And, as the squareness as the management object is smaller, the contact state between the head seating surface of the bolt member and the bolt receiving surface of the hub wheel can be kept better, but this is too strict. If it is controlled too much, special considerations are required when processing the hub wheel, which may unduly increase the manufacturing cost of the hub wheel. Therefore, an allowable value of 0.1 mm or less is given to the perpendicularity of the bolt receiving surface of the hub wheel with respect to the hole inner diameter surface of the hub wheel. Thereby, it is possible to reliably suppress an unreasonable increase in the manufacturing cost of the hub wheel while preventing a decrease in the fixing force due to the bolt member.

In the above configuration, it is preferable that the flatness of the bolt receiving surface is set as a management target and an allowable value of 0.1 mm or less is given as the flatness.

As described above, in addition to the squareness, if the flatness of the bolt receiving surface is further set as a management target, the entire head seating surface of the bolt member is bolted by managing the flatness within a predetermined range. It becomes possible to make it contact uniformly by a receiving surface. That is, the contact state between the head seating surface of the bolt member and the bolt receiving surface is a more preferable aspect. The flatness as the management target is such that the smaller the value is, the closer the bolt receiving surface is to an ideal plane, so that the contact state between the head seating surface of the bolt member and the bolt receiving surface can be favorably maintained. However, if this is controlled too strictly, the processing cost of the bolt receiving surface may be unreasonably increased. Therefore, an allowable value of 0.1 mm or less is given to the flatness of the bolt receiving surface. As a result, an unreasonable increase in processing cost can be suppressed while maintaining a better contact state between the head seating surface of the bolt member and the bolt receiving surface.

In the above configuration, it is preferable that the bolt receiving surface is subjected to a hardening process, 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.

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.

In the above configuration, it is preferable that the curing treatment is induction hardening.

In this way, there are advantages that the heating efficiency is high 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 configuration described above, 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.

In this way, since the frictional force is reduced by the amount of the gap at the time of press-fitting, it is possible to reduce the pressure input at the time of press-fitting. 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.

In the above configuration, it is preferable that the back surface of the mouth portion of the outer joint member and the end surface of the hub ring are not in contact with each other or in contact with a 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, if the contact surface pressure increases, torque is transmitted even on the contact surface to which pressure is applied, and a larger torque is loaded, and the contact surface is When it becomes impossible to endure torque transmission, a sudden slip may occur at the contact portion, which may cause abnormal noise. 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. .

This makes it possible to maintain good product quality over a long period of time because rainwater and foreign matter can be prevented from entering the uneven fitting structure.

In the above configuration, it is preferable that an axial position of the concave-convex fitting structure is in a position avoiding a position directly below the raceway surface of the wheel bearing.

That is, if 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. When re-pressing into the recessed portion and reassembling both, a guide portion that matches the phase of the convex portion formed on the one with the phase of the concave portion formed on the other is provided on the other side. You may provide in the press injection start side of a recessed part.

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.

In the above configuration, the convex portion is provided in the shaft portion of the outer joint member, the concave portion is formed in the hole portion of the hub wheel, and the bolt member is used to fasten the hub wheel and the outer joint member. It is configured so as to be performed between the receiving surface and the bolt hole, and the coaxiality of the bolt hole with respect to the convex portion is defined as a dimension management target for fastening the bolt member, and the coaxiality is 0. It is preferable to give a tolerance of 1 mm or less.

The coaxiality of the bolt hole with respect to the convex portion referred to in the present invention means a deviation amount of the virtual center of the bolt hole with respect to the virtual center of the circular orbit passing through a predetermined portion in the height direction of the convex portion.

As described above, in the present invention, since the coaxiality of the bolt hole with respect to the convex portion is defined as the object of dimension management for fastening the bolt member, if this coaxiality is managed within a predetermined range, The bolt member can be fastened smoothly and with high accuracy. The smaller the value of the coaxiality as the object of dimension management, the smoother and more accurate the bolt member can be fastened. However, if this is specified too severely, special consideration is required for the processing of the bolt hole. Thus, the manufacturing cost of the outer joint member may be unduly increased. Therefore, an allowable value of 0.1 mm or less is given to the coaxiality of the bolt hole with respect to the convex portion. Thereby, it is possible to suppress an increase in the manufacturing cost of the outer joint member while enabling the bolt member to be fastened smoothly and with high accuracy.

In order to define the coaxiality of the bolt hole with respect to the convex part, it is first necessary to define the virtual center of the convex part. This virtual center may be a circular orbit passing through any position in the height direction of the convex part, but it is assumed that the virtual center of the circular orbit passing through the top of the convex part (the circumscribed circle of the convex part) desirable. This is because the relative position (posture) accuracy of the hub wheel and the outer joint member, that is, the accuracy of the concave-convex fitting structure depends on the top portion of the convex portion. Further, the position in the axial direction of the convex portion that defines the coaxiality (imaginary center) may be the end portion on the press-fitting start side for convenience.

According to the present invention as described above, since the perpendicularity of the bolt receiving surface of the hub wheel with respect to the hole inner diameter surface of the hub wheel corresponding to the formation region of the concave-convex fitting structure is set as a management target, The contact state between the head seat surface of the member and the bolt receiving surface can be optimized. Therefore, it is possible to prevent a situation in which the bolt member is loosened or the bolt receiving surface is worn or indented due to contact with the bolt member, so that the fixing force acting between the outer joint member and the hub wheel can be prevented. It can be maintained well.

It is sectional drawing which shows the wheel bearing apparatus which concerns on 1st Embodiment of this invention. It is an axial orthogonal cross section of the uneven | corrugated fitting structure provided in the said wheel bearing apparatus. It is the X section enlarged view of Drawing 2a. It is a front view of the convex part shown in FIG. 2b. It is a front view which shows the other example of a convex part. It is a front view which shows the other example of a convex part. It is a figure which expands and shows the periphery of an uneven | corrugated fitting structure. It is a principal part expanded sectional view which shows the other example of FIG. 4a. It is sectional drawing which shows the state before the assembly of the said wheel bearing apparatus. It is an axial orthogonal cross section which shows notionally the state which has arrange | positioned the axial part of the joint outer ring | wheel to the hole internal diameter of a hub ring. It is an axial orthogonal cross section which shows the other example of the guide part shown to FIG. 6a. It is an axial orthogonal cross section which shows the other example of the guide part shown to FIG. 6a. It is an enlarged view in an axial orthogonal sectional view of an uneven fitting structure. 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. It is a sectional view showing a re-pressing method of the wheel bearing device and showing a state immediately before press-fitting. It is a sectional view showing the re-pressing method of the wheel bearing device, and showing the way of press-fitting. It is a sectional view showing a re-pressing method of the wheel bearing device, and showing a press-fitting completion state. It is sectional drawing which shows the re-pressing method of the said bearing apparatus for wheels. It is sectional drawing which shows the other example of the convex part of an uneven | corrugated fitting structure. It is sectional drawing which shows the other example of the convex part of an uneven | corrugated fitting structure. It is sectional drawing which shows the other example of an uneven | corrugated fitting structure. It is an enlarged view of the Y section shown in FIG. 13a. It is sectional drawing which shows the vehicle bearing apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the wheel bearing apparatus which concerns on 3rd Embodiment of this invention. It is an expanded sectional view when using an O-ring as a seal member. It is an expanded sectional view when using a gasket as a sealing member. It is sectional drawing of the conventional wheel bearing apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view showing a wheel bearing device according to a first embodiment of the present invention. As shown in the figure, the wheel bearing device according to the first embodiment 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.

In addition, the opening of the mouse part 10 is closed by the 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.

A bolt hole 36 opened on the end face on the outboard side is provided on the axial center of the distal end portion of the shaft portion 11. The bolt hole 36 is provided with a female screw portion, and a screw portion 37b1 of a bolt member 37 through which the hub wheel 1 is inserted is screwed into the female screw portion. As a result, the shaft portion 11 of the joint outer ring 4 is bolted to the hub wheel 1 and the removal of the shaft portion 11 of the joint outer ring 4 from the hub wheel 1 is restricted. The bolt member 37 includes a head portion 37a integrally having a flange (washer) and a shaft portion 37b. The shaft portion 37 b has a columnar base portion 37 b 2 and a screw portion 37 b 1 screwed into the female screw portion of the bolt hole 36.

The hub wheel 1 has a cylindrical portion 18 and a flange 19 provided at an end portion on the outboard side of the cylindrical portion 18. The flange 19 functions as an attachment portion for attaching the hub wheel 1 to the wheel, and has a bolt attachment hole 30. A hub bolt 31 is mounted in the bolt mounting hole 30, and the wheel and the brake rotor are fixed to the flange 19 with the hub bolt 31. The hub wheel 1 of the present embodiment is not provided with the pilot portion 165 provided in the conventional hub wheel 152 shown in FIG.

A hole 20 is provided in the tube portion 18 of the hub wheel 1. 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. Between the shaft portion fitting hole 20a and the large diameter hole 20c, a tapered portion (tapered hole) 20d having a diameter gradually reduced toward the outboard side is provided. The taper angle (inclination angle with respect to the axis) of the taper portion 20d is, for example, 15 ° to 75 °. In the shaft portion fitting hole 20a, the shaft portion 11 of the joint outer ring 4 and the hub wheel 1 are coupled to each other through an uneven fitting structure M described later.

A cylindrical inner wall 20e protruding in the inner diameter direction is provided on the outboard side of the shaft portion 18 with respect to the shaft portion fitting hole 20a. The shaft portion 37b of the bolt member 37 is inserted through the inner periphery of the inner wall 20e. When the screw portion 37b1 of the shaft portion 37b is screwed into the female screw portion of the bolt hole 36, the inner peripheral surface of the inner wall 20e faces the cylindrical outer peripheral surface of the base portion 37b2 of the shaft portion 37b. The inner diameter d1 of the inner wall 20e is set slightly larger than the outer diameter (shaft diameter) d of the base portion 37b2 of the shaft portion 37b (see FIG. 4a). Specifically, it is about 0.05 mm <d1-d <0.5 mm.

Further, as shown in FIG. 1, in a state where the bolt member 37 is screwed into the bolt hole 36 of the shaft portion 11 from the outboard side, the seat surface 37a1 of the head portion 37a is on the end surface of the inner wall 20e on the outboard side. It abuts against the provided bolt receiving surface 20e1. 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.

A small-diameter stepped portion 21 is formed on the outer peripheral surface of the hub wheel 1 on the inboard side, and an inner ring 22 is fitted into the stepped portion 21 to thereby have

inner raceways

23 and 24 in double rows. A direction member is configured. 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 includes the inner member, a cylindrical outer member 27 that is disposed on the outer diameter side of the inner member, and has double-row outer raceways (outer races) 25 and 26 on the inner periphery. Between the outer raceway surface 25 on the outboard side of the side member 27 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 main part is composed of the balls 28 as rolling elements arranged in the above. The outer member 27 is attached to a knuckle 52 extending from a vehicle suspension system (not shown). Seal members S1 and S2 are provided at both end openings of the wheel bearing 2 (outer member 27), so that external leakage of a lubricant such as grease sealed in the bearing 2 or the inside of the bearing Foreign matter can be prevented from entering. As described above, the hub wheel 1 and the inner ring 22 fitted to the stepped portion 21 of the hub wheel 1 constitute the inner member having the inner raceway surfaces 23 and 24, so that the weight of the wheel bearing device is reduced.・ Compactness is achieved.

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. Thus, if the end surface 29a 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 are brought into contact with each other, the bending rigidity in the axial direction of the wheel bearing device is improved and durability is increased. It becomes a high-quality product rich in nature. 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. You can plan. 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 at the contact portion to which pressure is applied, and when the larger torque is applied and the contact portion cannot withstand torque transmission, a sudden slip occurs at the contact portion. This is because abnormal noise may occur. 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.

As shown in FIGS. 2 a and 2 b, the concave-convex fitting structure M includes, for example, an axially protruding portion 32 provided at an end portion on the outboard side of the shaft portion 11, and the hole portion 20 of the hub wheel 1. It is comprised with the recessed part 33 formed in an internal-diameter surface. 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. 2 b, each convex portion 32 has a triangular shape (mountain shape) having a convex round-shaped cross section, and a fitting portion of each convex portion 32 with the concave portion 33 is illustrated in FIG. It is the range A shown in 2b. 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. Therefore, the side surface 32 a of each convex portion 32 has a portion C that does not fit into the concave portion 33.

In the concavo-convex fitting structure M, as shown in FIG. 3b, when the angle formed by the radial line (radius line) R and the side surface 32a of the convex portion 32 is θ1 on the pitch circle of the convex portion 32, It is set to 0 ° ≦ θ1 ≦ 45 ° (in the same figure, θ1 is about 30 °). Here, the pitch circle of the convex portion 32 refers to a circle C1 passing through a boundary portion between a region fitted into the concave portion 33 and a region not fitted into the concave portion 33 in the side surface 32a of the convex portion 32. It is a circle C2 that passes through the midpoint of the distance to the tooth tip 39b. When the diameter of the pitch circle C2 of the convex portion 32 is PCD and the number of the convex portions 32 is Z, the ratio P of Z to PCD (P = PCD / Z) is 0.3 ≦ P ≦ 1.0. .

2A, 2B, and 3A show the convex portion 32 having a triangular cross-section with a rounded tooth tip 39b, the convex portion 32 having another shape as shown in FIGS. 3B and 3C. Can also be adopted. FIG. 3b shows a convex part 32 having a rectangular cross section with θ1 of about 0 °, and FIG. 3c shows a convex part 32 having a triangular cross section with a tooth tip of about 90 ° and θ1 of about 45 °. Each is shown.

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, as shown in FIG. 4B, a seal material S is interposed between the seat surface 37a1 of the bolt member 37 and the inner wall 20e to form a seal structure. In this case, the seal structure can be configured by applying a sealing material S such as 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 S may 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. Is possible. 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 the application of the sealing material S can be omitted. 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 hub wheel 1 and the joint outer ring 4 are joined by the concave and convex fitting structure M formed between the hole 20 of the hub wheel 1 and the shaft part 11 of the joint outer ring 4. The uneven fitting structure M is obtained, for example, through 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. 2 b, in the male spline 39, a circle surrounded by the tooth bottom 39 a, the tooth tip 39 b, and a region surrounded by both side surfaces connected to the tooth tip 39 b becomes the convex portion 32.

The male spline 39 has a module of 0.5 or less, and preferably has a smaller tooth than that of a normally 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.

In addition, a bolt hole 36 is formed on the shaft center of the end portion on the outboard side of the shaft portion 11. As will be described later, a bolt member 37 is fastened to the bolt hole 36 after the concave-convex fitting structure M is configured (and also when the concave-convex fitting structure M is reconfigured). And the coaxiality of the bolt hole 36 with respect to the convex part 32 is prescribed | regulated as the object of the dimension management for enabling fastening of the bolt member 37 to the bolt hole 36 easily and with high precision. As the coaxiality, an allowable value of 0.1 mm or less is given. That is, the bolt hole 36 is formed so that the coaxiality with the convex portion 32 is 0.1 mm or less. More specifically, here, a radial separation distance (displacement) between a virtual center of a circular orbit (a circumscribed circle of the male spline 39) passing through the tooth tip 39b of the convex portion 32 and a virtual center of the bolt hole 36. The amount) is 0.1 mm or less.

Next, as shown by cross-hatching in FIGS. 1 and 4a, the outer diameter surface of the shaft portion 11 is subjected to thermosetting treatment to form a hardened layer H1. The hardened layer H1 is continuously formed in the circumferential direction including the entire convex portion 32 and the tooth bottom 39a. Note that the axial formation range of the hardened layer H1 includes a range including at least a continuous region from the edge of the male spline 39 on the outboard side 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.

As described above, if the male spline 39 and the bolt hole 36 are formed before the thermosetting process, the processing cost can be reduced as compared with the case where the bolt hole 36 is formed after the thermosetting process. There is a merit. Such a processing procedure has a large difference in diameter between the outer diameter of the male spline 39 to be formed (the outer diameter of the shaft portion 11) and the hole diameter of the bolt hole 36 (the inner diameter of the shaft portion 11). It is mainly used when the wall thickness can be increased.

The bolt hole 36 is formed in a state in which, for example, a male spline 39 (convex portion 32) is formed on the shaft portion 11, and then the thermosetting treatment is performed on the shaft portion 11, and then the male spline 39 of the shaft portion 11 is constrained. It can also be formed by turning or the like on the axial center of the end portion on the outboard side of the shaft portion 11. In this manner, if the bolt hole 36 is formed after the thermosetting process is performed on the shaft portion 11 on which the spline 39 is formed, the spline (convex portion 32) after the deformation caused by the thermosetting process occurs. Since the bolt hole 36 is formed with reference to the tooth tip 39b), there is an advantage that a higher coaxial accuracy can be secured between the bolt hole 36 and the convex portion 32. Further, it also serves as a measure for preventing the cracks in the bolt holes 36, and there is an advantage that a high quality shaft portion 11 and eventually the joint outer ring 4 can be obtained.

On the other hand, the inner diameter side of the hub wheel 1 is maintained in an unbaked 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 forming the concave portion. That is, as shown in FIG. 5, the inner diameter dimension D of the inner diameter surface 34 of the shaft fitting hole 20a is set to the maximum outer diameter dimension of the convex portion 32 of the male spline 39 (the circumscribed circle passing through the tooth tip 39b of the male spline 39). It is set to be smaller than the diameter dimension (D1) and larger than the minimum outer diameter dimension (diameter dimension of a circle connecting the roots of the male spline 39) D2 of the male spline 39 (D2 <D <D1).

As shown in FIG. 5, in the hole portion 20 of the hub wheel 1, the inboard side end portion of the shaft portion fitting hole 20 a, that is, the end portion on the press-fitting start side of the convex portion 32 (shaft portion 11) is protruded. A guide part M1 is provided for performing a guide at the start of press-fitting of the part 32 (when re-pressing the convex part 32, the phase of the convex part 32 and the concave part 33 formed by the convex part 32 is matched). As shown in FIG. 6a, the guide portion M1 is a plurality of guide grooves 40 provided at a predetermined interval in the circumferential direction (here, the same pitch as the formation pitch of the convex portions 32) at the inboard side end portion of the shaft portion fitting hole 20a. Composed. The bottom diameter dimension of the guide groove 40 (the diameter dimension of the circular orbit connecting the groove bottoms of the guide groove 40) D3 is set to be slightly larger than the maximum outer diameter dimension D1 of the male spline 39 (D3> D1). Thereby, in the state which has arrange | positioned the front-end | tip part of the convex part 32 provided in the axial part 11 in the inboard side edge part of the axial part fitting hole 20a of the hub wheel 1, the tooth tip 39b and the guide groove 40 of the convex part 32 are provided. A radial gap E1 is formed between the bottom of the groove.

And after arrange | positioning the front-end | tip of the axial part 11 of the joint outer ring | wheel 4 to the inboard side edge part of the hole 20 of the hub wheel 1 as shown in FIG. Press fit into 20a. When the shaft portion 11 is press-fitted, each convex portion 32 of the shaft portion 11 is fitted into the guide groove 40 provided at the end portion on the inboard side of the shaft portion fitting hole 20a. At this time, as described above, since the radial gap E1 is formed between the convex portion 32 and the guide groove 40, the phase alignment of the convex portion 32 and the guide groove 40 can be easily performed. In addition, the guide groove 40 does not hinder the press-fitting of the convex portion 32. Prior to press-fitting the shaft portion 11, a sealing material is applied in advance to the outer diameter surface on the distal end side including the male spline 39 in the shaft portion 11. Although there is no special limitation in the seal material which can be used, the seal material which consists of various resin can be selected and used, for example.

Next, the shaft portion 11 of the joint outer ring 4 is press-fitted into the hole 20 of the hub wheel 1 with 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 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 D of the shaft fitting hole 20a, the maximum outer diameter dimension D1 of the convex portion 32, and the minimum outer diameter dimension D2 of the tooth bottom of the male spline 39 are as described above, 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.

Through this press-fitting step, 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. Since the sealing material is applied in advance to the outer diameter surface on the distal end side of the shaft portion 11, the sealing material is applied to the fitting portion between the convex portion 32 and the concave portion 33 as the shaft portion 11 is press-fitted. Go around. Therefore, entry of foreign matter into the fitting portion is effectively prevented.

Also, as the shaft portion 11 is press-fitted, plastic deformation occurs on the hub wheel 1 side, so 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.

As described above, the tapered portion 20d can function as a guide when starting the press-fitting of the shaft portion 11, so that the press-fitting accuracy of the shaft portion 11 can be improved. In addition, since the guide groove 40 (guide portion M1) is provided at the inboard side end of the shaft portion fitting hole 20a, which is the front side in the press-fitting direction of the shaft portion 11 with respect to the taper portion 20d, The shaft portion 11 can be press-fitted in a state where the convex portion 32 is aligned. As a result, the press-fitting accuracy is further improved, so that it is possible to more effectively prevent misalignment and a situation where the convex portion 32 is press-fitted in a tilted state, thereby obtaining a highly accurate uneven fitting structure M. Can do. Further, when the shaft portion 11 is press-fitted, the seal material applied to the outer diameter surface of the shaft portion 11 functions as a lubricant, so that the shaft portion 11 can be smoothly press-fitted.

In this embodiment, as shown in FIG. 6a, a radial groove E1 is formed between the tooth tip 39b of the convex portion 32, and a guide groove is formed at the inboard side end of the shaft portion fitting hole 20a. Although 40 is formed, the formation mode of the guide groove 40 is not limited to this. For example, as shown in FIG. 6 b, the guide groove 40 may be formed so that a circumferential gap E <b> 2 is formed between the side surface 32 a of the convex portion 32. Further, as shown in FIG. 6c, the guide groove 40 is formed so that a radial gap E1 is formed between the tooth tip 39b of the convex portion 32 and a circumferential gap E2 is formed between the side surface 32a of the convex portion 32. It may be formed.

The concave / convex fitting structure M is required to be arranged avoiding 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 raceway surfaces 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. Therefore, 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.

Further, as shown in FIG. 7, when the concave-convex fitting structure M is configured, Δd / when the press-fitting allowance of the convex portion 32 to the hub wheel 1 is Δd and the height of the convex portion 32 is h. It is desirable to set 2h in a range of 0.3 <Δd / 2h <0.86. Here, the press-fit allowance Δd is expressed by a difference in diameter (D1−D) between the maximum outer diameter D1 of the male spline 39 provided in the shaft portion 11 and the inner diameter D of the shaft portion fitting hole 20a of the hub wheel 1. The As a result, the vicinity of the intermediate portion in the height direction of the convex portion 32 bites into the inner diameter surface of the hub wheel 1, so that the press-fitting allowance of the convex portion 32 can be sufficiently ensured, and the concave portion 33 is reliably formed. Is possible.

When Δd / 2h is 0.3 or less, the torsional strength is low, and when Δd / 2h is 0.86 or more, the entire convex portion 32 is caused by a slight misalignment or a press-fitting inclination. May bite into the other side and the press-fitting load increases rapidly, and the moldability of the concave-convex fitting structure M may be deteriorated. When the formability of the concave-convex fitting structure M is deteriorated, not only the torsional strength is reduced, but also the expansion amount of the outer diameter of the hub wheel 1 is increased, and thus the function of the wheel bearing 2 having the hub wheel 1 as a component is adversely affected. However, problems such as a decrease in rotational life occur. On the other hand, by setting Δd / 2h within the above range, the formability of the concave-convex fitting structure M is stabilized, there is no variation in press-fit load, and a stable torsional strength can be obtained.

In the concave / convex fitting structure M described above, since the entire fitting portion of the convex portion 32 and the concave portion 33 is in close contact with each other without gaps, play in the radial direction and the circumferential direction can be suppressed. Therefore, even if the connecting portion (concave fitting structure M) between the hub wheel 1 and the joint outer ring 4 is made compact, a high load capacity can be secured, and the wheel bearing device can be reduced in size and weight. Moreover, since the play in the concave-convex fitting structure M can be suppressed, it is possible to effectively prevent the generation of abnormal noise during torque transmission.

Further, since it is not necessary to previously form a female spline or the like in the hole 20 of the hub wheel 1, the processing cost of the hub wheel 1 can be reduced and the productivity can be increased. Further, when the hub wheel 1 and the shaft portion 11 of the joint outer ring 4 are assembled, the phase alignment between the splines can be omitted, 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. Further, as described above, since the inner diameter side of the hub wheel 1 has low hardness, the concave portion 33 formed in 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, as shown in FIGS. 3a to 3c, on the pitch circle C2 of each convex portion 32, the angle θ1 formed by the radial line (radial line) and the convex side surface 32a is in the range of 0 ° ≦ θ1 ≦ 45 °. Therefore, the diameter of the hub wheel 1 after press-fitting can be reduced and the press-fitting property can be improved. This is because when the shaft portion 11 is press-fitted, the hole portion 20 of the hub wheel 1 is expanded in diameter. However, if θ1 is too large, the diameter expansion force at the time of press-fitting is likely to work. Because the tensile stress (hoop stress) of the outer diameter portion of the hub wheel 1 and the inner ring 22 of the bearing 2 is increased, and the component force in the radial direction is increased during torque transmission. This is because the outer diameter of the hub wheel 1 is increased, and the tensile stress (hoop stress) of the outer diameter portion of the hub wheel 1 and the outer diameter portion of the inner ring 22 is increased. These increases in tensile stress (hoop stress) lead to a decrease in bearing life.

Further, assuming that the pitch circle diameter of the convex portions 32 is PCD and the number of the convex portions 32 is Z, 0.30 ≦ PCD / Z ≦ 1.0. When PCD / Z is too small (when PCD / Z is smaller than 0.30), the application range of the press-fitting allowance of the convex portion 32 with respect to the hub wheel 1 is very narrow, and the dimensional tolerance is also narrowed. Because it becomes.

In particular, by setting 20 ° ≦ θ1 ≦ 35 ° and 0.33 ≦ PCD / Z ≦ 0.7, a special steel is used as a material for forming the shaft portion 11 (joint outer ring 4). Without taking measures such as surface treatment or making the convex portion 32 sharp, the concave portion 33 is formed by the convex portion 32 by press-fitting the shaft portion 11 formed of general mechanical structural steel. It becomes possible. Moreover, the amount of expansion of the outer diameter of the hub wheel 1 after the shaft portion 11 is press-fitted can be kept small. In addition, by setting θ1 ≧ 20 °, when the convex portion 32 is provided on the shaft portion 11 side, the convex portion 32 is formed by rolling processing that has the most balanced cost and processing accuracy among the above-described processing methods. can do.

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. 8, 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.

When the press-fitting of the shaft portion 11 is completed and the concave-convex fitting structure M is configured, the screw portion 37b1 of the bolt member 37 is fastened (screwed) to the bolt hole 36 of the shaft portion 11 via the inner wall 20e of the hub wheel 1. . As a result, the shaft portion 11 of the joint outer ring 4 is bolted to the hub wheel 1, and separation of the hub wheel 1 and the joint outer ring 4 is restricted. The bolt member 37 is fastened by bringing the seating surface 37a1 of the bolt member 37 into contact with the bolt receiving surface 20e1 of the hub wheel 1. When the fastening of the bolt member 37 is completed, the hub wheel 1 is sandwiched between the head portion 37a of the bolt member 37 and the mouth portion 10 (the back surface 10a thereof) of the joint outer ring 4. In this way, by holding the hub wheel 1 in the axial direction between the bolt member 37 and the mouse portion 10, the bending rigidity in the axial direction of the apparatus can be further improved, and further durability can be improved.

When the hub wheel 1 is sandwiched between the head portion 37a of the bolt member 37 and the mouth portion 10 (the back surface 10a) of the joint outer ring 4, the surface of the inner wall 20e with which the seat surface 37a1 of the head portion 37a of the bolt member 37 abuts. If the hardness is inappropriate, the bolt receiving surface 20e1 is worn or indented due to the contact between the bearing surface 37a1 of the head portion 37a of the bolt member 37 and 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.

Further, if the contact state between the seat surface 37a1 of the head portion 37a of the bolt member 37 and the bolt receiving surface 20e1 of the hub wheel 1 is inappropriate, a part of the seat surface 37a1 of the bolt member 37 becomes a bolt receiving surface. 20e1 is locally press-contacted, and indentation and wear are likely to occur on the bolt receiving surface 20e1. Such indentation or the like causes a decrease in the fixing force of the bolt member 37. Accordingly, the perpendicularity of the bolt receiving surface 20e1 with respect to the inner diameter surface 34 of the shaft portion fitting hole 20a is set as a management target, and an allowable value of 0.1 mm or less is given as this perpendicularity. In this embodiment, in addition to this squareness, the flatness of the bolt receiving surface 20e1 is set as a management target, and an allowable value of 0.1 mm or less is given as this flatness.

This prevents the bolt member 37 from being unduly inclined with respect to the bolt receiving surface 20e1 in a state where the bolt member 37 is screwed into the bolt hole 36 of the shaft portion 11. That is, the seat surface 37a1 of the bolt member 37 is not parallel to the bolt receiving surface 20e1, and a part of the seat surface 37a1 comes into contact with the bolt receiving surface 20e1. A situation in which the contact state with the surface 20e1 becomes inappropriate can be prevented. Therefore, the contact state between the seat surface 37a1 of the head portion 37a of the bolt member 37 and the bolt receiving surface 20e1 of the hub wheel 1 is optimized, and the joint member 4 and the hub wheel 1 are stably coupled by the bolt member 37. It becomes possible to maintain the state. As a result, stable torque transmission can be performed over a long period of time. In addition, since the bolt member 37 is less likely to loosen, the relative positional relationship between the hub wheel 1 and the joint outer ring 4 does not unduly change. Therefore, since the sealing performance on the inboard side and the outboard side of the concavo-convex fitting structure M can be maintained over a long period of time, it becomes possible to continue to prevent intrusion of foreign matters such as muddy water, and practically. Is also extremely preferable.

In addition, when the bolt member 37 is fastened, if the predetermined coaxial accuracy is not secured between the bolt hole 36 provided in the shaft portion 11 and the convex portion 32, the bolt hole 36 is positioned with respect to the central axis of the hub wheel 1. The central axis is in an eccentric or inclined state. Therefore, the bolt member 37 interferes with the inner wall 20e of the hub wheel 1, and it is difficult to fasten the bolt member 37 smoothly. Even if the predetermined coaxiality is not ensured, the bolt member 37 can be forcibly fastened, but the hub wheel 1 or the bolt member 37 may be deformed. On the other hand, in the present invention, since the coaxiality of the bolt hole 36 with respect to the convex portion 32 is defined as a dimension management target for fastening the bolt member 37, the coaxiality should be managed within a predetermined range. The bolt member 37 can be fastened smoothly and with high accuracy. The smaller the value of the coaxiality as a dimension management target, the smoother the bolt member 37 can be fastened. However, if the allowable value (upper limit value) is set too severe, the bolt hole 36 can be processed. Special considerations are necessary, and the manufacturing cost of the joint outer ring 4 may be unduly increased. In this respect, since the allowable value of 0.1 mm or less is given as the coaxiality, it is possible to fasten the bolt member 37 smoothly and with high accuracy, and to suppress an increase in manufacturing cost of the joint outer ring 4. Can do.

In particular, when the coaxiality is defined, the virtual center on the convex portion 32 side is set as the virtual center of a circular orbit (a circumscribed circle of the convex portion 32) passing through the tooth tip 39b of the convex portion 32. Get the maximum. This is because the relative positional accuracy between the hub wheel 1 and the shaft portion 11 of the joint outer ring 4 depends on the forming accuracy of the uneven fitting structure M formed prior to the fastening of the bolt member 37. This is because the formation accuracy of the combined structure M depends on the tooth top 39b of the convex portion 32 in particular. Of course, in defining the coaxiality, the virtual center on the convex portion 32 side does not necessarily have to be the virtual center of the circular orbit passing through the tooth tip 39b. For example, the virtual center of a circular orbit passing through the intermediate portion in the height direction of the convex portion 32 may be used as the reference on the convex portion 32 side.

In the concave / convex fitting structure M described above, since the entire fitting portion of the convex portion 32 and the concave portion 33 is in close contact, a gap in which play occurs in the radial direction and the circumferential direction is not formed. 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 concave portion 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. 4A, the material protrudes from the recessed portion 33 by the cutting or pushing action of the protruding 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.

The wheel bearing device described above is capable of repairing the bearing portion (wheel bearing 2) and the joint portion (constant universal joint 3) individually when it is necessary to repair the wheel bearing device. Separation of the joint outer ring 4 and the hub ring 1 is allowed. The joint outer ring 4 and the hub wheel 1 are separated from each other by removing the bolt member 37 from the finished product state shown in FIG. 1 and then fitting the concave and convex portions between the hub wheel 1 and the shaft portion 11 of the joint outer ring 4. This is performed by pulling out the shaft portion 11 of the joint outer ring 4 from the hub wheel 1 by applying a pulling force greater than the fitting force of the structure M. Here, taking the case where the hub wheel 1 and the joint outer ring 4 are separated and then the separated hub ring 1 and the joint outer ring 4 are re-coupled as they are as an example, the separation and re-coupling methods of both will be described in detail below.

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 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 in which 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 convex portion 32 of the shaft 11 is fitted into the guide groove 40 as shown in FIG. 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. 11, 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. . Thereby, as shown in FIG. 10 b, 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. 10 c, 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 recombination 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. Therefore, the maintainability on site is particularly good.

In the first press-fitting (press-fitting to form the concave portion 33 in the inner diameter surface 34 of the hole 20), the press-fitting load is relatively large. Therefore, a press machine or the like needs to be used for press-fitting the shaft portion 11. 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.

Here, as described above, the bolt member 37 also has a function as a coupling means used for rejoining the joint outer ring 4 and the hub ring 1. At this time, if a predetermined coaxial accuracy is not ensured between the bolt hole 36 and the convex portion 32, the bolt member 37 is screwed into the bolt hole 36 in an inclined state, and as a result, reconfigured. The accuracy of the uneven fitting structure M is reduced. On the other hand, as described above, if the coaxiality of the bolt hole 36 with respect to the convex portion 32 is defined and an allowable value of 0.1 mm or less is given as this coaxiality, the hub wheel 1 and the joint outer ring 4 can be re-established. It is also possible to effectively prevent a decrease in accuracy of the concave-convex fitting structure M reconfigured with the coupling. Thereby, even after the hub wheel 1 and the joint outer ring 4 are recombined, good torque transmission performance is ensured.

As described with reference to FIG. 4a, the inner diameter d1 of the inner wall 20e of the hub wheel 1 is set slightly larger than the shaft diameter d of the bolt member 37 (specifically, 0.05 mm <d1− d <about 0.5 mm), the outer diameter of the shaft portion 37b of the bolt member 37 and the inner diameter of the inner wall 20e can constitute a guide when the bolt member 37 is screwed through the bolt hole 36. . Therefore, the bolt member 37 can be prevented from being misaligned, and the shaft portion 11 of the joint outer ring 4 can be press-fitted with high accuracy into the hole portion 20 of the hub wheel 1. If the axial dimension (thickness) of the inner wall 20e is too small, there is a possibility that a stable guide function cannot be exhibited. On the other hand, when the axial dimension of the inner wall 20e is increased, the axial length of the concave-convex fitting structure M cannot be secured, and the weight of the hub wheel 1 is increased. Therefore, the axial dimension of the inner wall 20e to be provided on the hub wheel 1 is determined in consideration of the above circumstances.

Although the case where the separated hub wheel 1 and the joint outer ring 4 are re-coupled as described above has been described above, for example, even when the hub wheel 1 is damaged and the like needs to be replaced, The hub wheel 1 and the joint outer ring 4 can be coupled by the procedure.

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, in the intermediate portion in the height direction of the convex portion 32, the circumferential thickness L of the convex portion 32 and the groove width L0 between the adjacent convex portions are substantially the same. .

On the other hand, as shown in FIG. 12a, even if the circumferential thickness L2 of the convex portion 32 is smaller than the groove width L1 between the adjacent convex portions in the intermediate portion in the height direction of the convex portion 32. Good. 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. 12a, the convex part 32 is formed in a trapezoidal cross section, but it can also be formed in an involute cross section as shown in FIG. 12b.

In the first embodiment described above, the male spline 39 is formed on the shaft portion 11 to illustrate the case where the convex portion 32 is formed on the shaft portion side, but conversely, FIGS. 13a and 13b. As shown in FIG. 2, the convex portion 32 may be formed on the hub wheel 1 side by forming the 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.

When the shaft portion 11 is press-fitted into the hole 20 of the hub wheel 1, the convex portion 32 on the hub wheel 1 side forms a concave portion 33 that fits with the convex portion 32 on the outer peripheral surface of the shaft portion 11. 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. 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.

The 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 (the diameter dimension of the inscribed circle passing through the tooth tip 54a of the female spline 54). It is set smaller than the inner diameter 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.

FIG. 14 is a cross-sectional view showing a wheel bearing device according to a second embodiment of the present invention. As shown in the figure, the wheel bearing device according to the second embodiment differs from the wheel bearing device according to the first embodiment in that the inner wall 20e is not integrally provided on the hub wheel 1, The ring body 56 is attached to the hole 20 of the hub wheel 1 instead of the inner wall 20e. That is, a ring fitting notch 57 is provided in the hole 20 of the hub wheel 1, and the ring body 56 is fitted to the ring fitting notch 57. At this time, the ring body 56 is engaged with the notch end surface 57a of the ring fitting notch 57. A bolt insertion hole 58 through which the bolt member 37 is inserted is formed in the ring body 56.

In this way, since the bolt insertion hole 58 is formed by the ring body 56 which is a separate member from the hub wheel 1, the bolt insertion hole 58 can be stably formed with high accuracy. Further, when the ring body 56 is damaged or the like, it can be replaced, and it is not necessary to replace the hub wheel 1 as a whole, and the cost can be reduced.

In this case, the end surface 56a on the outboard side of the ring body 56 functions as a bolt receiving surface against which the seat surface 37a1 of the head portion 37a of the bolt member 37 abuts. That is, in the wheel bearing device according to the first embodiment, the bolt receiving surface is formed directly on the hub wheel 1, whereas in the wheel bearing device according to the second embodiment, the ring body 56 as a separate member. A bolt receiving surface is formed on the hub wheel 1 via Therefore, the perpendicularity of the end surface 56a on the outboard side of the ring body 56 with respect to the inner diameter surface 34 of the shaft portion fitting hole 20a corresponding to the formation region of the concave-convex fitting structure M is set as a management target. A tolerance of 1 mm or less is given. In this embodiment, in addition to this perpendicularity, the flatness of the end surface 56a on the outboard side of the ring body 56 is set as a management target, and an allowable value of 0.1 mm or less is given as this flatness. Alternatively, a part of the end surface 56a on the outboard side of the ring body 56 may be recessed toward the inboard side to form a recess, and the bolt receiving surface may be configured by the bottom surface of the recess.

In this case, at least a hardening process is applied to the bolt receiving surface of the ring body 56, but the entire ring body 56 may be subjected to a hardening process to give a surface hardness of 50 HRC or more.

Since the configuration other than the above is substantially the same as the bearing device shown in FIG. 1, a common reference number is assigned and a duplicate description is omitted.

FIG. 15 is a sectional view showing a wheel bearing device according to a third embodiment of the present invention. The main difference between the wheel bearing device shown in FIG. 1 and the wheel bearing device shown in FIG. 1 is that the end surface 29a of the caulking portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10 are not in contact with each other. At the same time, the axial dimension of the shaft portion 11 is lengthened, and the end surface (end surface on the outboard side) 11a of the shaft portion 11 is brought into contact with the inboard side end surface of the inner wall 20e of the hub wheel 1. In this case, the inner wall 20e of the hub wheel 1 is sandwiched in the axial direction by the head portion 37a of the bolt member 37 and the end surface 11a on the outboard side of the shaft portion 11, so that the axial direction of the hub wheel 1 and the joint outer ring 4 is increased. Positioning is performed.

In this case, a gap 80 is provided between the end surface 29a of the crimping portion 29 and the back surface 10a of the mouse portion 10 as shown in FIG. 16a. The gap 80 is formed from between the caulking portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10 to between the large-diameter hole 20c of the hub wheel 1 and the shaft portion 11. Thus, by making the mouse part 10 and the hub wheel 1 non-contact, generation | occurrence | production of the abnormal noise resulting from both contact can be prevented more effectively.

As described above, when the end surface 29a of the hub wheel 1 and the back surface 10a of the mouse portion 10 are not in contact with each other, the foreign matter intrusion preventing means to the concave / convex fitting structure M is closer to the inboard side than the concave / convex fitting structure M. Provided. Specifically, as shown in FIG. 16a, the foreign matter intrusion prevention means is configured by a seal member S3 fitted in a gap 80 between the crimping portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10. . In this way, the sealing member S3 closes the gap 80 between the caulking portion 29 of the hub wheel 1 and the back surface 10a of the mouth portion 10, so that rainwater or Intrusion of foreign matter can be prevented. As the seal member S3, a commercially available O-ring or the like as shown in FIG. 16a can be used, and for example, a gasket or the like as shown in FIG. 16b can be used.

Further, in the wheel bearing device according to the third embodiment, a tapered portion 11b having a diameter increasing toward the opening side (outboard side) is provided in the opening portion of the bolt hole 36 of the shaft portion 11. If the tapered portion 11b is formed, a bolt member 37 used when the hub wheel 1 and the shaft portion 11 of the joint outer ring 4 are fastened, and a screw shaft 49 used when the hub wheel 1 and the joint outer ring 4 are separated. There is an advantage that it is easy to be screwed into the bolt hole 36. Such a configuration is also applicable to the wheel bearing device 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. The convex portion 32 can also be formed of a key separate from the shaft portion 11 and the hub wheel 1.

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. 2b and 13b,

gaps

35 and 55 are formed between the spline root and the member in which the recess 33 is formed, but the entire groove between the protrusions 32 is formed by the mating member. It may be satisfied.

Small recesses arranged at a predetermined pitch along the circumferential direction may be provided in advance on the recess forming surface of the member where the recess 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, a semi-ellipse shape, and a rectangle, and can also set the number arbitrarily.

In the above-described embodiment, the case where the bottom portion of the guide groove 40 forms a flat surface whose radial depth is constant along the press-fitting direction has been described. A slanting surface that is slanted while reducing the diameter along the direction) may be formed. In addition, the cross-sectional shape of the guide groove 40 is not particularly limited as long as the convex portion 32 can be fitted therein, and various changes can be made according to the cross-sectional shape of the convex portion 32 and the like.

Also, as the rolling element of the bearing 2, rollers other than the balls 28 can be used. 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 joint inner ring 5 and the shaft 8 may be integrated through 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 part 32 Convex part 33 Concave part 34 Inner diameter surface 36 Bolt hole 37 Bolt member 37a Head part 37a1 Seat surface 37b Shaft part 37b1 Screw part 38 Through hole 40 Guide groove 42 Projecting part 43 Pocket part H1, H2 Hardened layer M Concave / concave fitting structure M1 Guide part

Claims

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. Constructs a concave-convex fitting structure in which the entire region is in close contact, 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 fastened with the bolt member screwed into the bolt hole. By applying an axial pulling force with the bolt member removed. A wheel bearing device that allows the separation of the recess-projection fitting structure,
The hub ring is provided with a bolt receiving surface with which the head seat surface of the bolt member abuts directly or via another member, and with respect to the hole inner diameter surface of the hub ring corresponding to the formation region of the uneven fitting structure. A right angle of the bolt receiving surface is set as a management target, and a tolerance of 0.1 mm or less is given as the right angle.
2. The wheel bearing device according to claim 1, wherein the flatness of the bolt receiving surface is set as a management target, and an allowable value of 0.1 mm or less is given as the flatness.
3. The bolt receiving surface is subjected to a curing process, 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. Wheel bearing device.
The wheel bearing device according to claim 3, 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. The wheel bearing device according to any one of claims 1 to 4, characterized in that the hardness is higher than that of the other recess 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 5.
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 any one of claims 1 to 6, wherein a gap is formed in the wheel.
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 7, 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 8, 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 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. 11. The wheel bearing device according to any one of 1 to 10.
The wheel bearing device according to any one of claims 1 to 11, 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 reassembling both, the guide portion that matches the phase of the convex portion formed on one side with the phase of the concave portion formed on the other side is the press-fitting start side of the other concave portion. The wheel bearing device according to any one of claims 1 to 12, wherein the wheel bearing device is provided.
Providing the convex portion on the shaft portion of the outer joint member, forming the concave portion in the hole of the hub wheel,
The bolt member is configured to fasten the hub wheel and the outer joint member between the bolt receiving surface and the bolt hole, and as a dimension management target for fastening the bolt member, The wheel bearing device according to any one of claims 1 to 13, wherein a coaxiality of the bolt hole with respect to a convex portion is defined, and an allowable value of 0.1 mm or less is given as the coaxiality.