JP5331385B2 - Drive wheel bearing device - Google Patents

Description

  The present invention relates to a drive wheel bearing device that rotatably supports a drive wheel of a vehicle such as an automobile, and more particularly to a drive wheel bearing device in which a bearing portion and a constant velocity universal joint are detachably unitized. .

  A power transmission device that transmits engine power of a vehicle such as an automobile to a wheel transmits power from the engine to the wheel, and also causes radial or axial displacement from the wheel that occurs when the vehicle bounces or turns when traveling on a rough road. In addition, one end of the drive shaft that is interposed between the engine side and the drive wheel side is connected to the differential via a sliding type constant velocity universal joint, and the other end is It is connected to the wheel via a drive wheel bearing device including a fixed type constant velocity universal joint.

  In recent years, demands for improving fuel efficiency have been severe from the viewpoint of resource saving or pollution. In automobile parts, weight reduction of a wheel bearing device has been noticed as a factor to meet such a demand and has been strongly desired for a long time. There are various proposals related to wheel bearing devices that have been reduced in weight, but it is also important to simplify the assembly and disassembly work and reduce the cost at the assembly site of automobiles and the repair market. It is a factor.

  The drive wheel bearing device shown in FIG. 7 is a typical example that satisfies these requirements. This drive wheel bearing device has double-row inner rolling surfaces 51a and 52a for a double-row ball row (not shown). One inner rolling surface 51a is formed on the outer periphery of a hub wheel 51 integrally having a wheel mounting flange 53 for mounting a wheel (not shown) at one end, and the other inner rolling surface 52a is a hub wheel. The inner ring 52 is press-fitted into a cylindrical small-diameter step portion 51 b formed on the outer periphery of the outer periphery 51. The inner ring 52 is fixed to the hub wheel 51 in the axial direction by a caulking portion 54 formed by plastically deforming an end portion of the small diameter step portion 51b. A face spline 54 a is formed on the end surface of the caulking portion 54.

  The outer joint member 55 constituting the constant velocity universal joint has a cup-shaped mouth portion 56 and a shoulder portion 57 which becomes the bottom portion of the mouth portion 56. The shoulder 57 is formed with a face spline 57 a that engages with the face spline 54 a of the caulking portion 54. A connecting portion 58 projects from the inner diameter of the shoulder portion 57, and a female screw 58a is formed on the inner periphery thereof.

  The connecting portion 58 has a contour 59 formed with a tapered outer diameter, and is inclined at an acute angle α with respect to the axis 60. On the other hand, the connecting member 62 is formed in a cylindrical shape, and has a support flange 61 integrally at one end, and a male screw 62a that is screwed into the female screw 58a of the connecting portion 58 at the other end. The hub wheel 51 and the outer joint member 55 are coupled by the connecting member 62 so as to be separable in the axial direction.

A seal ring 63 is mounted in an annular space formed between the hub wheel 51 and the connecting member 62 to prevent moisture and dust from entering from the outside. Further, the engaging portion 64 between the caulking portion 54 of the hub wheel 51 and the shoulder portion 57 of the outer joint member 55 is covered with a cover member 65. The cover member 65 is made of plastic, and an elastic sealing means such as a seal paste is applied during assembly to prevent moisture and dust from entering the engaging portion 64.
WO2006 / 111146A2 publication

  In such a drive wheel bearing device, since the engaging portion 64 between the caulking portion 54 and the shoulder portion 57 is sealed by the plastic cover member 65, a large moment load is applied to deform the hub wheel 51 and the like. In this case, the followability of the cover member 65 is low, and it is difficult to obtain high sealing performance. Further, when the ambient temperature rises, the linear expansion coefficient of the cover member 65 is higher than that of the outer joint member 55. Therefore, there is a possibility that a gap is formed between the fitting portions and the sealing performance is impaired.

  Further, when an elastic sealing means such as a seal paste is applied to the cover member 65 at the time of assembly, the sealing performance can be ensured. However, at the time of repair, the hub wheel 51 and the outer joint member 55 In addition to the deterioration in workability at the time of separation, even if separation is possible, the sealing means must be removed and the workability of disassembly / assembly must be improved.

  The present invention has been made in view of such circumstances, and provides a drive wheel bearing device that improves the sealing performance of the engaging portion of the face spline and improves the workability during disassembly and assembly. It is aimed.

In order to achieve such an object, the invention according to claim 1 of the present invention is a drive wheel bearing device in which a double row rolling bearing and a constant velocity universal joint are detachably unitized, The rolling bearing has a body mounting flange integrally attached to the vehicle body on the outer periphery, an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel for mounting a wheel on one end. A wheel mounting flange is integrally formed, and one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cylindrical small-diameter step portion extending in the axial direction from the inner rolling surface is formed. A hub ring, and an inner member formed of an inner ring or a cylindrical inner ring member that is fitted to the hub ring and has an inner ring surface that is formed on the outer periphery and that is opposed to the double-row outer roll surface. Double row accommodated in a freely rollable manner between the rolling surfaces of the inner member and the outer member A cylindrical joint having a rolling element, the constant velocity universal joint having a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, an axial direction extending from the shoulder portion, and an internal thread formed And an outer joint member integrally formed with the outer joint member, and face splines are respectively formed on a shoulder portion of the outer joint member and an end surface of the inner member, and abutting against an outer end surface of the inner member, The both face splines are pressed against and supported by fastening bolts screwed to the female thread of the connecting portion, and the double row rolling bearings and the constant velocity universal joint are coupled to be able to transmit torque and to be separated in the axial direction. In the drive wheel bearing device, a seal is attached to the outer diameter of the inner ring or inner ring member, and the seal is press-fitted into the outer diameter of the inner ring or inner ring member, and vulcanized adhesion or the like is applied to the core metal. Togetherness Are joined, and a synthetic rubber seal member having an axial lip, the engaging portion of the both face spline the axial lip is elastically in contact with the step portion formed in the shoulder portion of the outer joint member is sealed ing.

In this way, face splines are formed on the shoulder portion and the inner member of the outer joint member, respectively, and both the fastening bolts that are in contact with the outer end surface of the inner member and screwed to the female screw of the shaft portion are used. In a bearing device for a drive wheel in which a face spline is supported by pressure contact, and a double row rolling bearing and a constant velocity universal joint are coupled to be able to transmit torque and to be separated in the axial direction, the outer ring of the inner ring or inner ring member is sealed The core is pressed into the outer diameter of the inner ring or inner ring member, and a synthetic rubber sealing member integrally bonded to the core by vulcanization bonding or the like and having an axial lip. with Aki because lip is engaged portion of the resilient contact with both the face spline step portion formed in the shoulder portion of the outer joint member is sealed, the foreign matters such as rainwater or dust from the outside both In addition to preventing entry into the engaging portion of the Ace spline, the axial lip has adequate elasticity even if there are dimensional variations due to manufacturing errors or assembly errors of the inner and outer joint members. Therefore, it is possible to provide a drive wheel bearing device that can obtain high sealing performance over a long period of time and that has improved workability during disassembly and assembly.

Preferably, as in the invention of claim 2, wherein the axial lip is formed by a side lip extending obliquely radially outward, if the contact elastic on the stepped portion, Ya inner member Even if there is a dimensional variation due to a manufacturing error or an assembly error of the outer joint member, high sealing performance can be obtained by following the deformation of the side lip.

  Further, if the tip of the axial lip is formed in an arc shape as in the invention described in claim 3, the followability is good even if a large moment load is applied and the hub wheel or the outer joint member is deformed. High sealing performance can be obtained.

  Further, as in the invention described in claim 4, if the seal member has a grease lip and the engaging portion of both the face splines is filled with grease, the grease lip leaks to the outside. Can be reliably prevented, and wear of both face splines can be suppressed.

  According to a fifth aspect of the present invention, a predetermined bearing is formed by a caulking portion formed by press-fitting the inner ring into the small diameter step portion and plastically deforming an end portion of the small diameter step portion radially outward. The inner ring is fixed in the axial direction with a preload applied, the face spline is formed on the end surface of the caulking portion, and the fastening bolt is inserted into the inner diameter of the hub ring via a predetermined guide clearance. If the small diameter part to be inserted is formed, the centering of the outer joint member and the inner member can be easily performed, the disassembly / assembly work of the apparatus is simplified, and both face splines are free from play in the circumferential direction and the axial direction. Can be engaged.

According to a sixth aspect of the present invention, the face spline is formed on the end surface of the inner ring member, and a hardened uneven portion is formed on the inner periphery of the hub wheel, and the inner ring member is formed on the uneven portion. A cylindrical portion of the inner ring member may be internally fitted, and the hub portion and the inner ring member may be plastically coupled together in a state in which a predetermined bearing preload is applied by expanding the diameter of the cylindrical portion and biting into the uneven portion. Further, as in the invention according to claim 7, the face spline is formed on an end face of the inner ring member, and a cylindrical portion of the inner ring member is fitted into the hub ring, and an end portion of the cylindrical portion The hub ring and the inner ring member may be integrally plastically joined in a state where a predetermined bearing preload is applied by a caulking portion formed by plastically deforming the outer ring in a radially outward direction. This eliminates the need to control the preload by tightening firmly with a nut or the like as in the prior art, so that the weight and size can be reduced, the strength and durability of the hub wheel can be improved, and long-term operation can be achieved. The preload amount can be maintained.

  Further, as in the invention described in claim 8, the fastening bolt is screwed onto the female screw of the connecting portion via a spacer, and the spacer is formed in a substantially L-shaped cross section. If there is a flange portion that abuts on the outer end surface of the member and a cylindrical portion that is guided by the fastening bolt, the outer joint member and the inner member can be easily centered by the spacer. The disassembly / assembly operation of the apparatus is simplified, and both face splines can be engaged with each other without play in the circumferential direction and the axial direction.

A drive wheel bearing device according to the present invention is a drive wheel bearing device in which a double-row rolling bearing and a constant velocity universal joint are detachably unitized, and the double-row rolling bearing is attached to the vehicle body on the outer periphery. A body mounting flange for mounting is integrally formed, an outer member in which a double row outer raceway surface is integrally formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end are integrated. A hub wheel formed on the outer periphery with one inner rolling surface facing the outer rolling surface of the double row, a cylindrical small diameter step portion extending in an axial direction from the inner rolling surface, and the hub wheel An inner member made of an inner ring or a cylindrical inner ring member that is fitted and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and the inner member and the outer member And a double row rolling element accommodated in a freely rolling manner between both rolling surfaces. The constant velocity universal joint integrally includes a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and a cylindrical coupling portion that extends in the axial direction from the shoulder portion and has a female screw formed therein. An outer joint member is provided, and face splines are formed on the shoulder portion of the outer joint member and the end surface of the inner member, respectively, and abutted against the outer end surface of the inner member and screwed into the female screw of the connecting portion. In the bearing device for a drive wheel in which the both face splines are pressed and supported by attached fastening bolts, and the double row rolling bearing and the constant velocity universal joint are coupled to be able to transmit torque and to be separated in the axial direction. A seal is attached to the outer diameter of the inner ring or the inner ring member, and the seal is integrally joined to the outer diameter of the inner ring or the inner ring member, and the core metal is integrally joined to the core ring by vulcanization adhesion or the like. And a synthetic rubber seal member having-up, the axial since lip engaging portion of the resilient contact with the both face spline step portion formed in the shoulder portion of the outer joint member is sealed In addition, foreign matter such as rainwater and dust can be prevented from entering the engaging portions of both face splines from the outside, and there are dimensional variations due to manufacturing and assembly errors of the inner and outer joint members. However, since the axial lip has an appropriate elasticity, it is possible to provide a bearing device for a drive wheel that can obtain high sealing performance over a long period of time and has improved workability during disassembly and assembly. it can.

  A drive wheel bearing device in which a double-row rolling bearing and a constant velocity universal joint are detachably unitized, and the double-row rolling bearing has an integrally mounted vehicle body mounting flange on the outer periphery. And an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for attaching a wheel to one end, and the outer rolling surface of the double row on the outer periphery. And a hub wheel formed with a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, and fitted inside the hub wheel, the outer periphery of the double row on the outer periphery An inner member formed of an inner ring formed with the other inner rolling surface facing the rolling surface, and a double row of the inner member and the outer member accommodated in a freely rolling manner between the rolling surfaces of the inner member and the outer member. A caulking portion that includes a rolling element and is formed by plastically deforming an end portion of the small diameter step portion radially outward. Further, the inner ring is fixed in the axial direction, and the constant velocity universal joint includes a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and extends from the shoulder portion in the axial direction to form a female screw. An outer joint member integrally formed with the cylindrical connecting portion, and a face spline is formed on each end surface of the shoulder portion of the outer joint member and the caulking portion, and the end surface of the hub wheel is contacted. Both face splines are pressed against and supported by fastening bolts that are in contact with and screwed into the female thread of the connecting portion, so that the double row rolling bearings and the constant velocity universal joint can transmit torque and can be separated in the axial direction. In the coupled drive wheel bearing device, a seal is attached to the outer diameter of the inner ring, and the seal is integrally joined to the core metal by press-fitting to the outer diameter of the inner ring by vulcanization adhesion or the like. Is radially outward A synthetic rubber sealing member having a side lip extending in an inclined manner, and the side lip is elastically contacted with a stepped portion formed on a shoulder portion of the outer joint member, and the engaging portions of the both face splines are sealed. Has been.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a bearing device for a drive wheel according to the present invention, FIG. 2 is a longitudinal sectional view showing a bearing portion of FIG. 1, and FIG. 3 is a seal portion of FIG. FIG. 4 is an enlarged view of an essential part showing a modification of the seal of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This drive wheel bearing device has a so-called third generation configuration in which the hub wheel 1, the double row rolling bearing 2 and the constant velocity universal joint 3 are detachably unitized.

  The double-row rolling bearing 2 includes an outer member 7, an inner member 8, and double-row rolling elements (balls) 9 and 9. The outer member 7 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and integrally has a vehicle body mounting flange 7b for mounting to a vehicle body (not shown) on the outer periphery. The double row outer rolling surfaces 7a, 7a are integrally formed. Then, at least the double row outer raceway surfaces 7a and 7a are subjected to a hardening process in a range of 58 to 64 HRC by induction hardening.

  On the other hand, the inner member 8 is formed with double-row inner rolling surfaces 1a and 5a facing the outer rolling surfaces 7a and 7a of the outer member 7 described above. Of these double-row inner rolling surfaces 1a, 5a, one (outer side) inner rolling surface 1a is on the outer periphery of the hub wheel 1, and the other (inner side) inner rolling surface 5a is on the outer periphery of the inner ring 5, respectively. It is integrally formed. In this case, the inner member 8 refers to the hub wheel 1 and the inner ring 5. And the double row rolling elements 9 and 9 are accommodated between these both rolling surfaces, respectively, and are hold | maintained by the holder | retainers 10 and 10 so that rolling is possible. Further, seals 11 and 12 are attached to the opening portion of the annular space formed between the outer member 7 and the inner member 8, and leakage of the lubricating grease sealed inside the bearing and the inside of the bearing from the outside. Prevents intrusion of rainwater and dust.

  The hub wheel 1 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end portion on the outer side, and a cylindrical small diameter step portion 1b extending in the axial direction from the inner rolling surface 1a on the outer periphery. Is formed. This hub wheel 1 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 1a and the seal land portion where the outer seal 11 is in sliding contact to the small diameter step portion 1b. The outer peripheral surface is subjected to a hardening treatment within a range of 58 to 64 HRC by induction hardening. As a result, the seal land that is the base of the wheel mounting flange 4 not only has improved wear resistance, but also has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 4. The durability of 1 is further improved. The inner ring 5 and the rolling elements 9 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core portion by quenching.

  The inner ring 5 is press-fitted into the small-diameter step portion 1b of the hub wheel 1 through a predetermined shimiro, and a desired bearing preload is applied by a crimping portion 13 formed by plastic deformation of the end portion of the small-diameter step portion 1b. It is fixed in the axial direction. A face spline 13a is formed on the end face of the caulking portion 13 by plastic working during swing caulking (see FIG. 2). In addition, although the double row angular contact ball bearing which used the ball for the rolling element 9 was illustrated here, not only this but the double row tapered roller bearing which used the tapered roller for the rolling element 9 may be sufficient.

  The constant velocity universal joint 3 includes an outer joint member 14, a joint inner ring 15, a cage 16 and a torque transmission ball 17. The outer joint member 14 includes a cup-shaped mouth portion 18, a shoulder portion 19 that forms the bottom of the mouth portion 18, and a cylindrical connecting portion 20 that extends in the axial direction from the shoulder portion 19. Curved track grooves 18a and 15a extending in the axial direction are formed on the inner periphery of the inner ring 15 and the outer periphery of the joint inner ring 15, respectively. A face spline 19 a that engages with the face spline 13 a of the caulking portion 13 is formed on the end surface of the shoulder portion 19, and a female screw 20 a is formed on the connecting portion 20. The outer joint member 14 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the surface hardness of the track groove 18a is set to a range of 58 to 64 HRC by induction hardening.

  A fastening bolt 21 is screwed onto the female screw 20 a of the connecting portion 20, and both the face splines 19 a and 13 a facing the shoulder portion 19 of the outer joint member 14 and the caulking portion 13 of the hub wheel 1 are secured by the fastening bolt 21. The double row rolling bearing 2 and the constant velocity universal joint 3 are detachably unitized by pressure contact. In the present embodiment, since the small-diameter portion 1c into which the fastening bolt 21 is inserted through a predetermined guide clearance is formed on the inner diameter of the hub wheel 1, the outer joint member 14 and the inner member 8 can be easily centered. The disassembling / assembling work of the apparatus is simplified, and both face splines 19a, 13a can be engaged with each other without play in the circumferential direction and the axial direction.

  As described above, since the play of the engaging portions of both the face splines 19a and 13a is suppressed, there is little wear due to repeated contact, and the face spline 13a of the crimping portion 13 and the face spline 19a of the shoulder portion 19 are reduced. In order to prevent toughness deterioration due to high hardness, hardening treatment such as induction hardening is not performed, and the material hardness after forging is kept. And the grease is filled in the engaging part of both face splines 13a and 19a. Here, in order to improve the yield, the face spline 13a is formed by cold plastic working at the same time when the caulking portion 13 is swung, but the present invention is not limited to this. After forming by dynamic caulking, it may be formed by machining such as cutting.

  Here, in this embodiment, the step part 22 is formed in the shoulder part 19 of the outer joint member 14. Further, a seal 23 for sealing the engaging portion of both the face splines 19a and 13a described above is attached to the outer diameter of the inner ring 5. As shown in an enlarged view in FIG. 3, the seal 23 includes a cylindrical portion 24a that is press-fitted into the outer diameter of the inner ring 5, and a cored bar 24 that includes an inner diameter portion 24b that extends radially inward from the cylindrical portion 24a. The seal member 25 is integrally joined to the metal core 24 by vulcanization adhesion or the like.

  The core metal 24 is composed of an austenitic stainless steel plate (JIS standard SUS304, etc.), a ferritic stainless steel plate (JIS standard SUS430, etc.), and a rust-proof cold rolled steel plate (JIS standard SPCC, etc.). It is formed in a substantially L-shaped cross section by press working from a steel plate having a rust preventive ability. On the other hand, the seal member 25 is made of a synthetic rubber such as nitrile rubber, and has a pair of side lips (axial lips) 25a and 25b extending obliquely outward in the radial direction, and a grease lip 25c. The seal lips 25a, 25b, and 25c are in elastic contact with the step portion 22 of the shoulder portion 19. As a result, it is possible to prevent foreign matters such as rainwater and dust from entering the engaging portions of both face splines 19a and 13a from outside, and to ensure that the grease filled in the engaging portions leaks to the outside. It is possible to prevent the corrosion and wear of both face splines 19a and 13a. Further, the side lips 25a and 25b and the grease lip 25c have appropriate elasticity even if there are dimensional variations due to manufacturing errors and assembly errors of the inner member 8 and the outer joint member 14, and therefore, for a long period of time. A high sealing performance can be obtained.

  FIG. 4 is an enlarged view of a main part showing a modified example of the seal 23 described above. The same parts, the same parts, or parts or parts having the same function as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The seal 26 includes a cylindrical part 24a that is press-fitted into the outer diameter of the inner ring 5 and an inner diameter part 24b that extends radially inward from the cylindrical part 24a. The seal member 27 is integrally joined. The seal member 27 is made of a synthetic rubber such as nitrile rubber, and has an axial lip 27a having a tip formed in an arc shape. As a result, it is possible to prevent foreign matters such as rainwater and dust from entering the engaging portions of both face splines 19a and 13a from outside, and to ensure that the grease filled in the engaging portions leaks to the outside. Can be prevented. Further, the seal 26 can be simplified and made compact, and the contact portion of the axial lip 27a is formed in an arc shape, so that a large moment load is applied and the hub wheel 1 and the outer joint member 14 are deformed. However, the followability is good and high sealing performance can be obtained.

  FIG. 5 is a longitudinal sectional view showing a second embodiment of the drive wheel bearing device according to the present invention. This embodiment basically differs from the above-described first embodiment (FIG. 1) only in the configuration of the double-row rolling bearing, and has the same parts, the same parts, and the same functions as the other embodiments described above. The parts and parts that have the same reference numerals are assigned with the same reference numerals, and detailed description thereof is omitted.

  The double-row rolling bearing 28 includes an outer member 7, an inner member 29, and double-row rolling elements 9 and 9. The inner member 29 includes a hub ring 30 and an inner ring member 31 fitted into the hub ring 30. The hub wheel 30 integrally has a wheel mounting flange 4 at an end portion on the outer side, and an inner raceway surface 1a and a small-diameter step portion 30a extending in the axial direction from the inner raceway surface 1a are formed on the outer periphery. The concavo-convex portion 32 having a surface hardness of 54 to 64 HRC by a heat treatment is formed around the periphery. The concave and convex portion 32 is formed in the shape of an iris knurl, and is a cross groove formed by orthogonally crossing a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like. Alternatively, it consists of a cross groove composed of spiral grooves inclined with respect to each other. Further, in order to ensure good biting properties, the tip of the concavo-convex portion 32 is formed in a spire shape such as a triangular shape.

  The hub wheel 30 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and extends from the inner land surface 1a to the small diameter step portion 30a from the seal land portion where the outer seal 11 is in sliding contact. The outer peripheral surface is hardened by induction hardening to a surface hardness of 58 to 64 HRC.

  The inner ring member 31 is integrally formed with a cylindrical portion 33 extending in the axial direction from the inner rolling surface 5a. The cylindrical portion 33 is formed at an end portion of the in-row portion 33 a that is fitted into the small-diameter step portion 30 a of the hub wheel 30 through a predetermined shimiro, and is opposed to the uneven portion 32 of the hub wheel 30. And a fitting portion 33b. Further, a face spline 34 is formed on the inner end surface of the inner ring member 31. The inner ring member 31 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and is formed by cold forging or hot forging. In the case of cold forging, the face spline 34 is formed simultaneously with forging, or after cold forging, the face spline 34 is formed by cold plastic working such as rocking or machining such as cutting. In the case of hot forging, after turning, the face spline 34 is formed by cold plastic working such as rocking or machining such as cutting. The inner ring member 31 is hardened to a surface hardness of 58 to 64 HRC by induction hardening from the inner rolling surface 5a to the in-row portion 33a. In addition, the fitting part 33b is made into the raw material hardness after forging. The face spline 34 may be formed after induction hardening.

  Here, the cylindrical portion 33 of the inner ring member 31 is fitted into the hub wheel 30, and a diameter expanding jig such as a mandrel is pushed into the fitting portion 33 b to expand the diameter of the fitting portion 33 b. The hub wheel 30 and the inner ring member 31 are plastically coupled together in a state where a desired bearing preload is applied by so-called diameter-enlarging caulking, which bites into the uneven portion 32 of the hub wheel 30. As a result, it is not necessary to control the preload by tightening firmly with a nut or the like as in the prior art, so that the weight and size can be reduced, and the strength and durability of the hub wheel 30 can be improved and long. The amount of preload can be maintained for a period.

  Further, the fastening bolt 21 is screwed onto the female screw 20a of the connecting portion 20, and both the faces of the shoulder portion 19 of the outer joint member 14 and the inner side end face of the inner ring member 31 facing each other by the fastening bolt 21 via the spacer 35. The splines 19a and 34 are pressed and supported, and the double-row rolling bearing 28 and the constant velocity universal joint 3 are detachably unitized. The spacer 35 is formed in a substantially L-shaped cross section, and has a flange portion 35 a that abuts on the outer end surface of the hub wheel 30, and a cylindrical portion 35 b that is externally attached to the fastening bolt 21. Thereby, the centering of the outer joint member 14 and the inner member 29 can be facilitated by the spacer 35, the disassembling / assembling work of the apparatus is simplified, and both the face splines 19a, 34 are free of play in the circumferential direction and the axial direction. Can be engaged.

  FIG. 6 is a longitudinal sectional view showing a third embodiment of the drive wheel bearing device according to the present invention. This embodiment is basically the same as the second embodiment (FIG. 5) described above except for the configuration of the double-row rolling bearing, and other parts / parts similar to those of the above-described embodiment or similar. Parts / parts having functions are denoted by the same reference numerals, and detailed description thereof is omitted.

  The double-row rolling bearing 36 includes an outer member 7, an inner member 37, and double-row rolling elements 9 and 9. The inner member 37 includes a hub ring 38 and an inner ring member 39 that is press-fitted and fixed to the hub ring 38 through a predetermined shimiro. The hub wheel 38 integrally has a wheel mounting flange 4 at an end portion on the outer side, and a cylindrical small-diameter step portion 30a extending in the axial direction from the inner rolling surface 1a is formed on the outer periphery. The hub wheel 38 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and from the inner rolling surface 1a to the small diameter step portion 30a from the seal land portion where the outer seal 11 is in sliding contact. The outer peripheral surface and the inner peripheral surface are hardened by induction hardening to a surface hardness of 58 to 64 HRC.

  The inner ring member 39 is integrally formed with a cylindrical portion 40 extending in the axial direction from the inner rolling surface 5a. The inner ring member 39 and the hub ring 38 are integrally plastically coupled with a predetermined bearing preload by a crimping portion 40a formed by plastically deforming the end portion of the cylindrical portion 40 radially outward. ing. The inner ring member 39 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the surface hardness is set to a range of 58 to 64 HRC by induction hardening over the cylindrical portion 40 from the inner rolling surface 5a. A curing process is applied. In addition, the edge part of the cylindrical part 40 plastically processed is made into the raw material hardness after forging, and the crimping part 40a is set to the range of 15-35 HRC including plastic hardening. As a result, plastic working can be facilitated, generation of microcracks associated with the plastic working can be suppressed, and the strength of the crimped portion 40a can be secured to maintain a strong bond over a long period of time.

  The inner ring member 39 including the face spline 34 is formed by cold forging or hot forging as in the above-described embodiment, but may be subjected to tempering (after quenching, high temperature tempering) after forging. This tempering treatment can ensure low hardness and high toughness.

  Here, the fastening bolt 21 is screwed onto the female screw 20a of the connecting portion 20, and both the face splines 19a, 34 facing the outer joint member 14 and the inner ring member 39 are pressed against each other by the fastening bolt 21 via the spacer 41. The double row rolling bearing 36 and the constant velocity universal joint 3 are detachably unitized. The spacer 41 has a substantially L-shaped cross section, and has a flange portion 41 a that abuts on the end surface of the crimping portion 40 a and a cylindrical portion 41 b that is extrapolated to the fastening bolt 21. Thereby, the centering of the outer joint member 14 and the inner member 37 can be easily performed by the spacer 41, and the disassembling / assembling work of the apparatus is simplified.

  In the present embodiment, the configuration in which the inner ring member 39 is press-fitted and fixed to the small-diameter step portion 30a of the hub ring 38 is illustrated, but this is not limiting, and although not shown, serrations are formed on the inner circumference of the hub ring. A serration that engages with this serration may be formed in the cylindrical portion of the inner ring member, and both members may be fixed via these serrations.

  Further, although not shown, a spacer having a substantially L-shaped cross section used with the fastening bolt shown in the second and third embodiments may be used in the first embodiment. That is, the small-diameter portion of the inner diameter of the hub wheel in which the fastening bolt is inserted is eliminated, the inner diameter portion of the hub wheel is made cylindrical, and the flange portion of the spacer is brought into contact with the outer end surface of the hub wheel, thereby fastening the bolt. By guiding the cylindrical portion of the spacer that is externally mounted on the cylindrical inner diameter portion of the hub wheel, the centering of the outer joint member and the inner member can be facilitated, and the disassembly and assembly work of the device is simplified. Both face splines can be engaged without play in the circumferential direction and axial direction. Moreover, weight reduction of a product can be achieved by eliminating a small diameter part.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The drive wheel bearing device according to the present invention can be applied to a drive wheel bearing device in which a double row rolling bearing having a hub wheel and a constant velocity universal joint are detachably unitized.

It is a longitudinal section showing a 1st embodiment of a bearing device for drive wheels concerning the present invention. It is a longitudinal cross-sectional view which shows the bearing part of FIG. It is a principal part enlarged view which shows the seal part of FIG. It is a principal part enlarged view which shows the modification of the seal | sticker of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the bearing apparatus for drive wheels which concerns on this invention. It is a longitudinal cross-sectional view which shows 3rd Embodiment of the bearing apparatus for drive wheels which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional bearing apparatus for drive wheels.

Explanation of symbols

1, 30, 38 ···································· Hub wheel 1a, 5a ...・ ・ ・ ・ ・ ・ Small diameter step 1c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter 2, 28, 36 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double row rolling Bearing 3 ... Constant velocity universal joint 4 ... Wheel mounting flange 5 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer member 7a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ Outside rolling surface 7b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 8, 29, 37 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inward Member 9 ... rolling element 10 ... cage 1 , 12 ... Seals 13 and 40a ... Caulking parts 13a, 19a and 34 ... Face spline 14 ... Outer joint member 15 ... Inner joint ring 15a, 18a・ ・ ・ ・ ・ ・ ・ ・ Track groove 16 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cage 17 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 18 ················· Mouse portion 19 ············· Shoulder 20 ········ ·········· 20a ························ Female screw 21・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Step parts 23, 26 ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 24 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cores 24a, 33, 35b, 40, 41b ・ ・ Cylindrical portion 24b・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner diameter part 25,27 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal member 25a, 25b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Side lip 25c ············· Grease lip 27a ···············································・ ・ ・ ・ ・ Inner ring member 32 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Uneven portion 33a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ In-row portion 33b ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Fitting part 35, 41 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Spacer 35a, 41a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Flange 51 ... ... Hub wheels 51a, 52a ... Inside rolling surface 51b ... Small diameter step 52 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 53 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 54 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Fastening parts 54a, 57a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Face spline 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer joint member 56 ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 57 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 58 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Connecting part 58a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Female thread 59 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Contour 60 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Axis 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Support flange 62・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Connecting member 62a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Male thread 63 ・ ・ ・ ・ ・ ・ ・ ・·································································. ················acute angle

Claims (8)

A drive wheel bearing device in which a double-row rolling bearing and a constant velocity universal joint are detachably unitized,
The double-row rolling bearing integrally has a vehicle body mounting flange to be attached to the vehicle body on the outer periphery, and an outer member in which the double-row outer rolling surface is integrally formed on the inner periphery;
A wheel mounting flange for mounting the wheel at one end is integrally formed, one outer side rolling surface facing the outer side rolling surface of the double row on the outer periphery, and a cylindrical shape extending in the axial direction from the inner side rolling surface Hub ring formed with a small-diameter step portion, and an inner ring or a cylindrical inner ring member that is fitted to the hub ring and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery. An inner member comprising:
With the inner member and a double row rolling element accommodated between the rolling surfaces of the outer member so as to roll freely,
The constant velocity universal joint has an outer portion integrally including a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and a cylindrical connecting portion that extends in the axial direction from the shoulder portion and has a female screw formed therein. A joint member,
Face splines are formed on the shoulder of the outer joint member and the end surface of the inner member, respectively.
The both face splines are pressed against and supported by fastening bolts that are in contact with the outer end face of the inner member and screwed into the female thread of the connecting portion, and the double row rolling bearing and the constant velocity universal joint are torqued. In a drive wheel bearing device coupled so as to be able to transmit and to be separated in the axial direction,
A seal is attached to the outer diameter of the inner ring or the inner ring member, and the seal is integrally joined to the core bar by press-fitting into the outer diameter of the inner ring or the inner ring member by vulcanization adhesion or the like, and an axial lip A sealing member made of synthetic rubber, and the axial lip is elastically brought into contact with a stepped portion formed on a shoulder portion of the outer joint member so that the engaging portions of the both face splines are sealed. Drive wheel bearing device. 2. The drive wheel bearing device according to claim 1, wherein the axial lip is configured by a side lip that is inclined and extended radially outward, and is in elastic contact with the stepped portion .   The drive wheel bearing device according to claim 1, wherein a tip end of the axial lip is formed in an arc shape.   The drive wheel bearing device according to any one of claims 1 to 3, wherein the seal member has a grease lip, and the engaging portions of the both face splines are filled with grease.   The inner ring is axially inserted in a state in which the inner ring is press-fitted into the small-diameter stepped portion and a predetermined bearing preload is applied by a crimping portion formed by plastically deforming an end portion of the small-diameter stepped portion radially outward. The face spline is formed on the end face of the crimped portion, and a small-diameter portion into which the fastening bolt is inserted through a predetermined guide clearance is formed in the inner diameter of the hub wheel. 4. The drive wheel bearing device according to any one of 4 above.   The face spline is formed on the end face of the inner ring member, and a hardened uneven portion is formed on the inner periphery of the hub wheel. The cylindrical portion of the inner ring member is fitted into the uneven portion, and the cylindrical portion is expanded. The drive wheel bearing device according to any one of claims 1 to 4, wherein the hub wheel and the inner ring member are integrally plastically joined in a state in which a predetermined bearing preload is applied by causing a diameter to penetrate into the uneven portion. .   The face spline is formed on the end surface of the inner ring member, and the cylindrical portion of the inner ring member is fitted in the hub ring, and the end portion of the cylindrical portion is plastically deformed radially outward. 5. The drive wheel bearing device according to claim 1, wherein the hub wheel and the inner ring member are integrally plastically coupled to each other while a predetermined bearing preload is applied.   The fastening bolt is screwed to the female screw of the connecting portion via a spacer, the spacer is formed in a substantially L-shaped cross section, and a flange portion that abuts on the outer side end surface of the inner member; A bearing device for a drive wheel according to any one of claims 5 to 7, further comprising a cylindrical portion that is guided by being inserted by the fastening bolt.

Images