JP4271015B2 - Drive wheel bearing device - Google Patents

Description

  The present invention relates to a drive wheel bearing device that supports a drive wheel of a vehicle such as an automobile, and more specifically, a drive wheel (front wheel of an FF vehicle, rear wheel of an FR vehicle or RR vehicle, and 4WD mounted on an independent suspension type suspension). The present invention relates to a drive wheel bearing device in which a wheel bearing and a constant velocity universal joint are unitized as one unit in order to rotatably support a vehicle (all wheels) with respect to a suspension device. .

  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. For example, as shown in FIG. 8, one end of a drive shaft 100 interposed between the engine side and the drive wheel side is connected to a sliding type constant velocity universal joint 101 as shown in FIG. The other end is connected to a drive wheel 105 via a drive wheel bearing device 104 including a fixed type constant velocity universal joint 103.

  Various types of drive wheel bearing devices have been proposed in the past. For example, the drive wheel bearing device shown in FIG. 7 is known. This drive wheel bearing device is connected to a hub wheel 106 that mounts the drive wheel at one end, a double row rolling bearing 107 that rotatably supports the hub wheel 106, and a hub wheel 106, and A fixed type constant velocity universal joint 103 that transmits power to the hub wheel 106 is provided.

  It is known that a large torque is applied to the drive wheel of such a vehicle from the engine via the sliding type constant velocity universal joint 101 when the engine rotates at a low speed, for example, when the vehicle starts, and the drive shaft 100 is twisted. . As a result, the inner ring 109 of the double row rolling bearing 107 that supports the drive shaft 100 is also twisted. When the twisting amount of the drive shaft 100 is large, a stick-slip sound due to a sudden slip is generated on the contact surface between the outer joint member 108 and the inner ring 109 constituting the constant velocity universal joint 103.

  A drive wheel bearing device as shown in FIG. 6 is known as a countermeasure for this. This drive wheel bearing device 104 fixes the inner ring 109 in the axial direction by a caulking portion 111 formed by fitting an inner ring 109 to the hub ring 110 and plastically deforming the inner end of the hub ring 110 in the radial direction. The outer joint member 108 is internally fitted via the serration 112, and the hub wheel 110 and the outer joint member 108 are tightened by the nut 113 in a state where the inner end surface of the crimping portion 111 and the shoulder portion of the outer joint member 108 are in contact with each other. And tighten.

Here, the average value of the surface pressure between the inner end surface of the caulking portion 111 and the shoulder portion of the outer joint member 108 is set to 1.5 × 10 ⁸ Pa or less (preferably 1.0 × 10 ⁸ Pa or less). Keep it low. As a result, the preload of the double row rolling bearing 107 is managed and maintained by the caulking portion 111 without tightening the nut 113 firmly as in the prior art and without strictly managing the tightening torque. In addition, the hub wheel 110 and the outer joint member 108 can be coupled by lightly tightening the nut 113, and even if the outer joint member 108 is twisted, the energy with which the inner end face and the shoulder are rubbed can be kept small. It is possible to prevent the occurrence of stick-slip noise over a long period of time.
JP 2002-106557 A

  However, in such a drive wheel bearing device, if the backlash in the circumferential direction of the fitting portion of the serrations 112 and 114 is large, abnormal noise occurs in the fitting portion of the serrations 112 and 114 during sudden acceleration or deceleration. There was a risk of the nut 113 becoming loose. Furthermore, when torque fluctuations repeatedly act on the threaded portion, the threaded portion may extend and the axial force may decrease. For this reason, a torsion angle is usually provided in the serration 112 of the outer joint member 108 and press-fitted into the serration 114 of the hub wheel 110 to kill the play in the circumferential direction of the fitting portion. In this case, of course, there is a problem that, when assembling, equipment such as a press is required to pull out the outer joint member 108 from the hub wheel 110 at the time of disassembly, and workability is poor.

  Further, while the preload of the double row rolling bearing 107 can be maintained by light tightening of the nut 113, a slight clearance is generated at the contact portion between the hub wheel 110 and the outer joint member 108 as the axial force decreases. The problem that the sealing performance is lowered is also inherent. If rainwater or the like enters from this abutting portion, the serration fitting portion may rust and adhere, and further deteriorate the workability at the time of disassembly.

  The present invention has been made in view of such circumstances, and provides a bearing device for a drive wheel that is excellent in repairability by preventing occurrence of abnormal noise in each part and improving workability at the time of disassembly. It is an object.

In order to achieve such an object, the invention according to claim 1 of the present invention has a double row rolling bearing and a wheel mounting flange integrally formed at one end portion, and one inner side of the double row rolling bearing on the outer periphery. A rolling surface, a cylindrical small-diameter stepped portion extending in the axial direction from the inner rolling surface, a hub ring formed with serrations on the inner periphery, and externally fitted on the small-diameter stepped portion, and A separate inner ring formed with the other inner rolling surface of the rolling bearing of the row, a cup-shaped mouse part fitted into the hub ring via serrations, and a shoulder part forming the bottom of the mouse part; And an outer joint constituting a constant velocity universal joint integrally having a shaft portion extending in the axial direction from the shoulder portion, and formed by plastically deforming the end portion of the small-diameter step portion of the hub wheel radially outward. The inner ring is fixed to the hub ring in the axial direction at the crimped portion, and In the drive wheel bearing device in which the hub wheel and the outer joint member are detachably coupled in a state where the inner end face of the crimping portion and the shoulder portion of the outer joint member are in contact with each other, the shaft portion and A preload is applied to the serration fitting portion with the hub wheel, and it is detachably fixed to the outer end surface of the hub wheel, and a female screw formed on the shaft portion through a plate having a female screw in the center. the fixing bolt is screwed, the hub wheel and Rutotomoni the outer joint member is attached at a predetermined axial force, upon degradation, screwed the fixing bolt into the internal thread of the plate, is fitted into the internal thread of the shaft portion The outer joint member is separated from the hub wheel by contacting the bolt .

Thus, in the drive wheel bearing device having the third-generation structure of the self-retain type, preload is applied to the serration fitting portion between the shaft portion of the outer joint member and the hub wheel, and the outer end surface of the hub wheel is applied. detachably fixed, the central internal thread is screwed a female screw in a fixing bolt that is formed in the shaft portion through the plate, which is formed in, to bind the hub wheel and the outer joint member at a predetermined axial force Rutotomoni, When disassembling, the fixing bolt is screwed into the female screw of the plate and brought into contact with the bolt fitted to the female screw of the shaft portion, so that the outer joint member is separated from the hub wheel, so that the serration fitting portion The occurrence of abnormal noise at the fitting portion can be prevented by eliminating the play in the circumferential direction, and the occurrence of stick-slip noise at the contact surface between the caulking portion of the hub wheel and the shoulder portion of the outer joint member can be prevented. . Moreover, even if a preload is applied to the serration fitting portion, assembly and disassembly can be easily performed, and workability can be improved.

  According to a second aspect of the present invention, the serration of the shaft portion of the outer joint member is provided with a torsion angle inclined by a predetermined angle with respect to the axis line, so that the shaft portion and the hub wheel are serrated. Since the preload is applied to the part, it is possible to provide a highly reliable preload means to the serration fitting part, and to prevent the generation of noise during sudden acceleration / deceleration of the vehicle. Can be prevented. Accordingly, it is possible to further prevent the occurrence of stick-slip noise and fretting wear on the contact surface between the caulking portion of the hub wheel and the shoulder portion of the outer joint member.

  According to a third aspect of the present invention, the plate has a disk shape, and a circular hole corresponding to a screw hole formed in the outer end surface of the hub wheel is formed in the outer peripheral portion. The plate can be detachably fixed to the outer end surface of the hub wheel simply by passing a bolt through the hole and fastening it to the screw hole.

  In the invention according to claim 4, since the locking means is provided between the fixing bolt and the plate, it is possible to reliably prevent the coupling portion of the fixing bolt from loosening.

  Preferably, as in the invention described in claim 5, the loosening-preventing means has a hat shape in which a central portion is formed into a convex shape by pressing a steel plate, and is fitted to the head of the fixing bolt in the center. And a bolt that fastens the locking cap to the plate via the long hole, so that it can be reliably configured with a simple configuration. The loosening of the fixing bolt can be prevented, and the reliability can be improved.

  In the invention according to claim 6, since the elastic ring is mounted in the annular space formed between the end face of the inner ring and the shoulder portion of the outer joint member, the end face of the inner ring and the outer joint member The sealing performance between the shoulder and the shoulder can be remarkably improved, and it is possible to reliably prevent the serration fitting portion from rusting due to the intrusion of rainwater and the like, thereby improving the durability of the apparatus. .

  Preferably, as in the invention described in claim 7, if the pulsar ring is attached to the shoulder portion of the outer joint member and one end of the pulsar ring is engaged with the elastic ring, the elastic ring can be securely removed. Can be prevented.

The bearing device for a drive wheel according to the present invention has a double row rolling bearing, a wheel mounting flange integrally formed at one end, one inner rolling surface of the double row rolling bearing on the outer periphery, and the inner rolling surface. A cylindrical small-diameter stepped portion extending in the axial direction from the running surface is formed, a hub ring having serrations formed on the inner periphery, and an outer fit on the small-diameter stepped portion, and the inner side of the other side of the double row rolling bearing on the outer periphery A separate inner ring on which a rolling surface is formed, a cup-shaped mouse part fitted into the hub ring via serrations, a shoulder part that forms the bottom part of the mouse part, and an axial direction from the shoulder part A caulking portion that is formed by plastically deforming an end portion of a small-diameter step portion of the hub wheel in a radially outward direction, and an outer joint that constitutes a constant velocity universal joint. The inner ring is fixed to the hub ring in the axial direction, and the inner end face of the caulking portion and the front In the drive wheel bearing device in which the hub wheel and the outer joint member are detachably coupled with the shoulder portion of the outer joint member being in contact with each other, the serration fitting portion between the shaft portion and the hub wheel is provided. A pre-load is applied, and a fixing bolt is screwed onto a female screw formed on the shaft portion through a plate that is detachably fixed to the outer end surface of the hub wheel and has a female screw formed in the center, and the hub Rutotomoni to bind the wheel and the outer joint member at a predetermined axial force, upon degradation, screwed the fixing bolt into the internal thread of the plate, by abutting the internal thread in the loading by a bolt of the shaft portion, Since the outer joint member is separated from the hub wheel, the circumferential play of the serration fitting portion is eliminated to prevent the fitting portion from generating abnormal noise, and the hub wheel crimping portion and the outer joint member At the contact surface with the shoulder It is possible to prevent the occurrence of ticks slip sound. Moreover, even if a preload is applied to the serration fitting portion, assembly and disassembly can be easily performed, and workability can be improved.

A double-row rolling bearing and a wheel mounting flange at one end are integrally formed, one inner rolling surface of the double-row rolling bearing on the outer periphery, and a cylindrical small diameter extending in the axial direction from the inner rolling surface A hub ring having a stepped portion and serrations formed on the inner periphery, and a separate inner ring fitted on the small-diameter stepped portion and formed on the outer periphery with the other inner rolling surface of the double row rolling bearing. And a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and a shaft portion that extends in the axial direction from the shoulder portion, and is integrally fitted to the hub wheel via serrations, etc. An outer joint that constitutes a speed universal joint, and the inner ring extends in the axial direction with respect to the hub ring by a crimped portion formed by plastically deforming the end of the small-diameter stepped portion of the hub ring radially outward. In addition to being fixed, the inner end surface of the caulking portion and the shoulder portion of the outer joint member are brought into contact with each other In the driving wheel bearing device in which the hub wheel and the outer joint member are detachably coupled, the serration of the shaft portion is provided with a torsion angle inclined by a predetermined angle with respect to the axis thereof. A preload is applied to the serration fitting portion between the hub ring and the internal thread formed on the shaft portion via a plate that is detachably fixed to the outer end surface of the hub ring and has a female thread in the center. the fixing bolts screwed, the hub wheel and Rutotomoni the outer joint member is attached at a predetermined axial force, upon degradation, screwed the fixing bolt into the internal thread of the plate, fitting into the internal thread of the shaft portion The outer joint member is separated from the hub wheel by contacting the bolt .

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a bearing device for a drive wheel according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of a bearing device for a drive wheel according to the present invention, and FIG. 2 is a side view of a main part of FIG.

  This drive wheel bearing device comprises a hub wheel 1, a double row rolling bearing 2 and a constant velocity universal joint 3 as a unit. In the following description, the side closer to the outside of the vehicle in the state assembled to the vehicle is referred to as the outboard side (left side in the drawing), and the side closer to the center is referred to as the inboard side (right side in the drawing).

  The hub wheel 1 integrally has a wheel mounting flange 4 for mounting a wheel (not shown) at an end portion on the outboard side, and an outer rolling surface on the outboard side of the double row rolling bearing 2 on the outer periphery. 1a and a cylindrical small diameter step portion 1b extending in the axial direction from the inner rolling surface 1a are formed. A serration (or spline) 5 is formed on the inner periphery. The hub wheel 1 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the outer peripheral surface thereof is inwardly rolled from the base on the inboard side of the wheel mounting flange 4 serving as a seal land. A hardened layer having a surface hardness in the range of 54 to 64 HRC is formed over the surface 1a and the small diameter step 1b. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. Here, the end portion of the small-diameter step portion 1b is unquenched with a surface hardness of 25 HRC or less, and is plastically deformed radially outward to form the crimped portion 6.

  And the separate inner ring | wheel 7 is press-fit in the small diameter step part 1b of the hub wheel 1, and the 3rd generation structure which fixes the inner ring | wheel 7 to the axial direction by the crimping part 6 is comprised. The inner ring 7 is made of high carbon chrome bearing steel such as SUJ2, and an inner rolling surface 7a on the inboard side of the double row rolling bearing 2 is formed on the outer periphery thereof, and is formed directly on the outer periphery of the hub wheel 1. The inner rolling surface 1a constitutes a double row of inner rolling surfaces 1a, 7a. And it hardens in the range of 54-64 HRC to a core part by submerged hardening.

  The double row rolling bearing 2 includes an outer member 8, an inner member 9, and double row rolling elements (balls) 10, 10. The outer member 8 is attached to a vehicle body (not shown) on the outer periphery. A vehicle body mounting flange 8a is integrally formed, and double-row outer rolling surfaces 8b and 8b are formed on the inner periphery. Here, the inner member 9 indicates the hub wheel 1 and the inner ring 7. Double-row rolling elements 10 and 10 are accommodated between the rolling surfaces 8b, 1a and 8b and 7a, respectively, and are held by the retainers 11 and 11 so as to be freely rollable. Seals 12 and 13 are attached to the ends of the double row rolling bearing 2 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust, and the like from the outside. The outer member 8 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the outer member 8 is formed on the mating surfaces of the double row outer rolling surfaces 8b and 8b and the seals 12 and 13. Thus, the hardened layer is formed with a surface hardness in the range of 54 to 64 HRC. As the heat treatment, local heating is preferable, and quenching by high-frequency induction heating that can set the hardened layer depth relatively easily is preferable. Here, the double-row rolling bearing 2 is exemplified as a double-row angular ball bearing in which the rolling elements 10 and 10 are balls. However, the double-row rolling bearing 2 is not limited to this and may be a double-row tapered roller bearing using a tapered roller as the rolling element. good.

  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 integrally includes a cup-shaped mouth portion 14a, a shoulder portion 14b that forms the bottom of the mouth portion 14a, and a shaft portion 18 that extends in the axial direction from the shoulder portion 14b. A serration (or spline) 18a is formed on the outer peripheral surface of the shaft portion 18, and a female screw 18b is formed on the inner peripheral surface. Here, the serration 18a is provided with a twist angle inclined at a predetermined angle with respect to the axis. The outer joint member 14 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes a track groove formed on the inner periphery of the mouth portion 14a and the shoulder portion 14b. A hardened layer having a surface hardness in the range of 58 to 64 HRC is formed by induction hardening over the base portion of the shaft portion 18.

  Then, the shaft portion 18 of the outer joint member 14 is fitted into the hub wheel 1 until the shoulder portion 14b contacts the inner end surface of the crimping portion 6 of the hub wheel 1, and the serration 18a of the shaft portion 18 is inserted into the serration 5 of the hub wheel 1. Is press-fitted. Thereby, a desired preload can be given to the fitting part of serrations 5 and 18a, and the play of the circumferential direction can be killed. Finally, the fixing bolt 20 is screwed into the female screw 18b of the shaft portion 18 via the plate 19 that contacts the outer end surface 1c of the hub wheel 1, so that the hub wheel 1 and the outer joint member 14 are coupled in the axial direction. Here, even if a torsion angle is formed on the serration 18a of the shaft portion 18, if the overall length of the serration 18a of the shaft portion 18 is about 1/2 to 1/3, it can be easily fitted to the serration 5 of the hub wheel 1. The outer joint member 14 can be easily pulled into the hub wheel 1 by tightening the fixing bolt 20.

  In a test conducted by the present applicant, when an M12 fixing bolt is used, an axial force of 15 kN (tightening torque 50 Nm) or more is present between the inner end surface of the crimped portion 6 and the shoulder portion 14 b of the outer joint member 14. It has been verified that if a stick-slip sound is generated and the axial force is set to less than 15 kN, preferably 13 kN (tightening torque 40 Nm) or less, the generation of abnormal noise is eliminated. Therefore, in the present embodiment, when the fixing bolt 20 is tightened and the outer joint member 14 is pulled into the hub wheel 1, a predetermined axial force (axial force 15 kN in the case of M12) is exceeded. After pulling 14 into the hub wheel 1, the fixing bolt 20 is loosened and set to a predetermined axial force (axial force 13 kN in the case of M12) or less, and the locking cap 21 is attached to the fixing bolt 20. Although the axial force varies depending on the size and specification of the fixing bolt 20, the generation of abnormal noise can be effectively prevented by appropriately setting the axial force.

  As shown in FIG. 3, the locking cap 21 has a hat shape in which a central portion is formed into a convex shape by pressing a steel plate, and an outer diameter is substantially equal to the outer diameter of the plate 19 (see FIG. 1). ing. The locking cap 21 is formed with a polygonal surface at the center, a fitting hole 21a into which the head hexagonal surface of the fixing bolt 20 is fitted, and a plurality (three) of long holes 21b in the circumferential direction. Has been. At the time of assembly, as shown in FIG. 1, with the circular hole 19b of the plate 19 and the screw hole 1d formed in the outer end surface 1c of the hub wheel 1, the locking cap 21 is attached to the fixing bolt 20, The bolt 22 is fastened by aligning the long hole 21 b with the circular hole 19 b of the plate 19. Thereby, loosening of the fixing bolt 20 can be reliably prevented. The loosening prevention means is not limited to the exemplified one, and for example, a simple means in which a loosening prevention cap made of a steel plate press is engaged with the fixing bolt and the plate by caulking or the like may be used.

  On the other hand, the plate 19 has a disk shape as shown in FIG. 4, and has a female screw 19a screwed to the fixing bolt 20 in the center and a plurality of circular holes 19b in the outer peripheral portion. The female screw 19a is set to the same pitch as the screw pitch of the fixing bolt 20.

  Here, a torsion angle is provided in the serration 18a of the shaft portion 18 and a preload is applied to the fitting portion with the serration 5 of the hub wheel 1. However, the present invention is not limited to this. For example, the serration of the shaft portion 18 is provided. The tooth thickness of 18a and the tooth thickness of serration 5 of hub wheel 1 may be formed to be tight, and both serrations 5 and 18a may be press-fitted to apply a preload to the fitting portion.

  In the present embodiment, an elastic ring 23 made of rubber or the like is inserted into the outer peripheral portion of the caulking portion 6 of the hub wheel 1 so as to close the annular space formed between the inner ring 7 and the shoulder portion 14b. . Further, the elastic ring 23 is pressed by an ABS (anti-lock brake system) pulsar ring 24 press-fitted into the outer peripheral surface of the shoulder 14b, thereby preventing the elastic ring 23 from falling off. The pulsar ring 24 is formed by pressing a steel plate and has an uneven surface 24a on the outer peripheral surface, and detects the rotational speed of the wheel against a sensor (not shown). The elastic ring 23 may be integrally baked and bonded to the pulsar ring 24.

Next, when repairing the above-described embodiment, the point of the disassembling work will be described with reference to FIG.
1. First, the bolt 22 is removed, the locking cap 21 attached to the fixing bolt 20 is removed, and then the fixing bolt 20 and the plate 19 fastened to the outer end surface 1c of the hub wheel 1 are removed from the apparatus, and the shaft of the outer joint member 14 is removed. The bolt 25 is fixed to the end face of the portion 18 to close the female screw 18b. In addition, the thing for plugging up the internal thread 18b is not limited to the bolt 25, but may be a jig fitted into the internal thread 18b.
2. Next, the plate 19 is brought into contact with the outer end surface 1c of the hub wheel 1, the phases of the circular holes 19b of the plate 19 and the screw holes 1d formed in the outer end surface 1c of the hub wheel 1 are matched, and the screw holes 1d are aligned with each other. The bolts 22 are fastened to fix the plate 19 to the outer end surface 1 c of the hub wheel 1. Instead of the plate 19, a disassembly jig having the same specifications as the plate 19 may be used.
3. Finally, when the fixing bolt 20 is screwed into the female screw 19a of the plate 19, the tip of the fixing bolt 20 comes into contact with the bolt 25, and the outer joint member 14 is gradually separated from the hub wheel 1. Therefore, even if preload is applied to the serration fitting portion, the hub wheel 1 and the outer joint member 14 can be easily disassembled without using a disassembly device such as a press machine.

  In this embodiment, the internal clearance of the rolling bearing 2 is used as a negative clearance to improve the bearing rigidity, and the inner ring 7 is fixed to the hub wheel 1 in the axial direction by the crimping portion 6, and this negative clearance is maintained for a long time. Therefore, a so-called self-retain structure that can be maintained is adopted. Therefore, the bearing part can be made into a subunit, and not only the bearing part can be standardized, but also it is not necessary to tighten the bearing part firmly with a nut or the like as in the prior art, so that it can be easily incorporated into a vehicle. be able to. In addition, preload is applied to the fitting portions of the serrations 5 and 18a to kill the backlash in the circumferential direction, and the fixing bolt 20 is set to a predetermined axial force or less and fastened. In addition, it is possible to prevent the occurrence of stick-slip noise on the contact surface between the caulking portion 6 of the hub wheel 1 and the shoulder portion 14b of the outer joint member 14.

  Further, since the locking cap 21 is mounted on the head of the fixing bolt 20, it is possible to reliably prevent the fixing bolt 20 from loosening. As a result, it is possible to prevent an axial clearance from being generated on the contact surface between the caulking portion 6 of the hub wheel 1 and the shoulder portion 14b of the outer joint member 14, and to suppress fretting wear on the contact surface. Can do. Furthermore, since the annular space formed between the inner ring 7 and the shoulder portion 14b is closed with the elastic ring 23, the sealing performance between the crimping portion 6 and the shoulder portion 14b is remarkably improved, and rainwater or the like It is possible to reliably prevent the serration fitting portion from rusting due to the intrusion, and the durability of the apparatus can be significantly improved.

  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 is a drive wheel bearing device in which a constant velocity universal joint and a self-retained wheel bearing that rotatably supports the drive wheel with respect to the suspension device are unitized. Applicable.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a principal part side view of FIG. (A) is a front view which shows the locking cap which concerns on this invention. (B) is a cross-sectional view of the above. It is sectional drawing which shows the plate which concerns on this invention. It is explanatory drawing which showed the point of the disassembly work 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. It is a longitudinal cross-sectional view which shows the conventional other bearing apparatus for drive wheels. It is a longitudinal cross-sectional view which shows an example of the power transmission device incorporating the bearing apparatus for drive wheels.

Explanation of symbols

1 ... hub wheel 1a, 7a ... inner rolling surface 1b ...・ Small-diameter step 1c ......... Outer end face 1d ......... Screw hole 2 ... .... Double row rolling bearing 3 ... Constant velocity universal joint 4 ... Wheel mounting flange 5, 18a ········· Serration 6 ·············································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outside member 8a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 8b ・ ・ ・ ・ ・ ・ ・ ・・ Outer rolling surface 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner member 10 ・ ・ ・ ・ ・ ・ ・ ・ Rolling body 11 ············································································· Outer joint member 14a・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse 14b ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 15 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Fitting inner ring 16 ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ Cage 17 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 18 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shaft 18b, 19a ... Female thread 19 ... Plate 19b ... Round hole 20 ... ·········································································································· Fitting hole 21b・ ・ ・ ・ ・ ・ ・ ・ ・ Long holes 22, 25 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Bo G ... 23 Elastic ring 24 ... Pulsar ring 24a ... Uneven 100 ... Drive shaft 101 ... Sliding type constant velocity universal joint 102 ...・ Differential 103 ・ ・ ・ ・ ・ ・ ・ ・ Fixed constant velocity universal joint 104 ・ ・ ・ ・ ・ ・ ・ ・ Wheel bearing device 105 ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ Drive wheels 106, 110 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 107 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double row rolling bearing 108 ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ Outer joint member 109 ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 111 ・ ・ ・ ・ ・ ・ ・ ・ Clamping sections 112, 114 ・ ・ ・ ・ ・ ・ ・ ・Serration 113 ... ···········nut

Claims (7)

A double row rolling bearing and a wheel mounting flange at one end are integrally formed, one inner rolling surface of the double row rolling bearing on the outer periphery, and a small cylindrical diameter extending in an axial direction from the inner rolling surface A hub ring having a stepped portion and serrations formed on the inner periphery, and a separate inner ring fitted on the small-diameter stepped portion and formed on the outer periphery with the other inner rolling surface of the double row rolling bearing. And a cup-shaped mouth portion, a shoulder portion that forms the bottom portion of the mouth portion, and a shaft portion that extends in the axial direction from the shoulder portion, and is integrally fitted to the hub wheel via serrations, etc. An outer joint that constitutes a speed universal joint, and the inner ring extends in the axial direction with respect to the hub ring by a crimped portion formed by plastically deforming the end of the small-diameter stepped portion of the hub ring radially outward. In addition to being fixed, the inner end surface of the caulking portion and the shoulder portion of the outer joint member are brought into contact with each other In state, the hub wheel and the outer joint member in removably coupled driving wheel bearing apparatus,
Preload is applied to the serration fitting portion between the shaft portion and the hub wheel, and the shaft portion is formed on the shaft portion through a plate that is detachably fixed to the outer end surface of the hub wheel and has a female screw in the center. It screwed an internal thread in the fixing bolt that is, the hub wheel and Rutotomoni the outer joint member is attached at a predetermined axial force, upon degradation, screwed the fixing bolt into the internal thread of the plate, internal thread of the shaft portion A bearing device for a drive wheel, wherein the outer joint member is separated from the hub wheel by abutting against a bolt fitted to the hub wheel .   The drive wheel bearing device according to claim 1, wherein the serration of the shaft portion of the outer joint member is provided with a torsion angle inclined by a predetermined angle with respect to the axis.   The drive wheel bearing device according to claim 1 or 2, wherein the plate has a disc shape, and a circular hole corresponding to a screw hole formed in an outer end surface of the hub wheel is formed in an outer peripheral portion.   4. The drive wheel bearing device according to claim 1, wherein a locking means is provided between the fixing bolt and the plate.   The loosening-preventing means has a hat shape in which a central portion is formed in a convex shape by pressing a steel plate, a fitting hole that fits in the center of the head of the fixing bolt, and a plurality of elongated holes in the outer peripheral portion. The drive wheel bearing device according to claim 4, comprising a formed locking cap and a bolt that fastens the locking cap to the plate through the long hole.   The drive wheel bearing device according to any one of claims 1 to 5, wherein an elastic ring is mounted in an annular space formed between an end surface of the inner ring and a shoulder portion of the outer joint member. The drive wheel bearing device according to claim 6, wherein a pulsar ring is attached to a shoulder portion of the outer joint member, and one end of the pulsar ring is engaged with the elastic ring.

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