JP2007132455A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel for facilitating assembling, and largely reducing assembling manhours, by reducing weight and the size of the device. <P>SOLUTION: This bearing device for the wheel of a fourth generation structure is constituted of a double row tapered roller bearing of a back face joining type. A cylindrical shaft part 23 is integrally formed in an outside joint member 16, and a hub wheel 12 and the outside joint member 16 are integrally and plastically joined by biting in a recess-projection part 17 formed in an inner diameter of the hub wheel 12 by diametrically expanding this shaft part 23. A cage 7 is formed by injection molding, and a column part 11 between pockets 10 is positioned on the inner diameter side more than a pitch circle diameter of a tapered roller 3. A width W of an inner diameter side opening part of the pocket 10 is set to a width guided without making the tapered roller 3 slip out to the inner diameter side by contacting with a tapered side surface of the column part 11. A large collar 2b for guiding the tapered roller 3 is integrally formed on the large diameter side of an outside rollingly traveling surface 2a of an outside member 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wheel bearing device including a double-row tapered roller bearing that rotatably supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that is lightweight and compact.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the speed universal joint.

  Here, wheel bearing devices consisting of double-row tapered roller bearings are used for relatively heavy vehicles such as trucks, so there is little need for light weight and compactness, and development is delayed compared to double-row angular contact ball bearings. Only the second generation structure has been developed. Recently, however, the demand for wagons such as one-box cars has increased, and there has been a demand for multi-functionality. Therefore, even in wheel bearing devices with large load capacity that require double-row tapered roller bearings, Compactness has been desired.

  An example of such a wheel bearing device is shown in FIG. This wheel bearing device 50 has a vehicle body mounting flange 51b integrally attached to a knuckle (not shown) on the outer periphery, and an outer side in which double row outer rolling surfaces 51a, 51a are formed on the inner periphery. A member 51, an inner member 55 having a double-row inner raceway surface 52a, 54a facing the outer-row outer raceway surfaces 51a, 51a on the outer periphery, and a double-row accommodated between the two raceway surfaces And the double row tapered roller bearings provided with retainers 57 and 57 for holding the double row tapered rollers 56 and 56 so as to roll freely.

  The inner member 55 integrally has a wheel mounting flange 53 for mounting a wheel (not shown) at one end, and faces the double-row outer rolling surfaces 51a, 51a of the outer member 51 on the outer periphery. One inner rolling surface 52a, a cylindrical small-diameter stepped portion 52b extending in the axial direction from the inner rolling surface 52a, and a hub wheel 52 in which a serration 52c for torque transmission is formed on the inner periphery, The inner ring 54 is press-fitted into the small-diameter step portion 52b of the hub wheel 52, and has an outer ring formed with the other inner rolling surface 54a facing the double row outer rolling surface 51a, 51a of the outer member 51 on the outer periphery. This constitutes the third generation structure on the drive wheel side.

  Hub bolts 60 for fastening the wheels are planted at equal intervals in the circumferential direction of the wheel mounting flange 53, and a seal 58 is provided at the opening of the annular space formed between the outer member 51 and the inner member 55. , 59 are installed to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust, etc. into the bearing from the outside.

Here, large flanges 52d and 54b for guiding the tapered rollers 56 are formed on the large diameter side of the inner raceway surfaces 52a and 54a of the hub ring 52 and the inner ring 54, but on the small diameter side, rollers are prevented from falling off. Gavel is not formed. Therefore, the retainer 57 holds the tapered roller 56 in the pocket 61 in a non-dropped state in an unassembled state. That is, the retainer 57 is formed by injection molding a synthetic resin. As shown in FIG. 7, the pillar 62 between the adjacent pockets 61 and 61 of the retainer 57 has a cross-sectional shape of the outer diameter side portion 62a on the inner diameter side. A trapezoidal shape that narrows toward the outside, and an inner diameter protruding portion 62b protrudes from the outer diameter side portion 62a. The width between the outer diameter side portions 62a and 62a of the pocket 61 is such that the tapered roller 56 is in contact with the tapered side surface of the column portion 62 and is guided without coming out to the outer diameter side. At the same time, the width W between the inner diameter protruding portions 62b and 62b is slightly narrower than the outer diameter of the corresponding portion of the tapered roller 56, and the tapered roller 56 is inserted into the pocket 61 from the inner diameter side by elastic deformation of the cage 57. In a state where the pressing is possible and the pressing is completed, the tapered roller 56 is in contact with the inner diameter protruding portion 62b so that the tapered roller 56 does not fall out to the inner diameter side as shown by a two-dot chain line. As a result, not only the number of parts and the product cost are reduced, but also the assembly by the automatic assembly apparatus is facilitated and the number of assembly steps is reduced.
JP-A-11-44322

  In such a conventional wheel bearing device 50, the tapered roller 56 is configured to come into contact with the inner diameter protruding portion 62b of the retainer 57 and not fall off naturally toward the inner diameter side, but between the inner diameter protruding portions 62b and 62b. When the width W is set narrow, it becomes difficult to push the tapered roller 56 into the pocket 61 from the inner diameter side due to elastic deformation of the cage 57. Therefore, in order to improve the assemblability and reliably prevent the tapered roller 56 from falling off, the inlet width W must be regulated to a predetermined width without variation, and such injection molding in consideration of mass productivity. Then there was a limit. Further, since the tapered roller 56 is inserted into the pocket 61 by elastically deforming the retainer 57, it is difficult to insert the tapered roller 56 at the same time, which increases the number of assembly steps and facilitates assembly and assembly by the automatic assembly apparatus. There was a limit to the significant reduction in man-hours.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a wheel bearing device that achieves weight reduction and compactness of the device and facilitates assembly and significantly reduces the number of assembly steps. It is said.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a body mounting flange integrally attached to the suspension on the outer periphery, and has a taper-shaped compound that opens outward on the inner periphery. The outer member formed with the outer rolling surface of the row and the wheel mounting flange for attaching the wheel to one end are integrated, and one of the tapered shapes facing the outer rolling surface of the double row on the outer periphery A hub ring formed with an inner rolling surface and a small-diameter step portion extending in an axial direction from the inner rolling surface, and a tapered shape fitted to the hub ring and facing the outer rolling surface of the double row on the outer periphery An inner member formed of an inner ring formed with the other inner rolling surface or an outer joint member of a constant velocity universal joint, and a rolling device interposed between both rolling surfaces of the inner member and the outer member via a cage. Formed by double row tapered rollers accommodated movably, the outer member and the inner member And a seal mounted at the opening of the annular space, and a rear bearing type double row tapered roller bearing, wherein the cage is formed by injection molding from a synthetic resin, and adjacent pockets The column portion between them is located on the inner diameter side of the pitch circle diameter of the tapered roller, and the width of the inner diameter side opening portion of the pocket is in contact with the tapered side surface of the column portion so that the inner diameter is the inner diameter. It is set to a width that can be guided without slipping out to the side.

  As described above, the outer member integrally having the vehicle body mounting flange on the outer periphery, the outer member having the double-row outer raceway formed on the inner periphery, and the wheel mounting flange integrally on the outer side end portion, The inner ring is formed of a hub ring in which one inner rolling surface is directly formed and an inner ring fitted to the hub ring and the other inner rolling surface is formed on the outer periphery or an outer joint member of a constant velocity universal joint. A seal attached to an opening of an annular space formed by a member, a double-row tapered roller that is rotatably accommodated between both rolling surfaces via a cage, and an outer member and an inner member And a third or fourth generation wheel bearing device comprising back-to-back type double row tapered roller bearings, wherein the cage is formed from a synthetic resin by injection molding, and a column portion between adjacent pockets Is located on the inner diameter side of the pitch circle diameter of the tapered roller, The width of the diameter side opening is set to a width that guides the tapered roller without contacting it with the tapered side surface of the column, and does not come out to the inner diameter side, so the dimensional accuracy of the cage is not strictly regulated. However, it is possible to hold the tapered roller by the outer rolling surface of the outer member and the cage and reliably prevent it from falling off the cage. Can be reduced.

  Preferably, as in the invention described in claim 2, the inner member does not have large ridges and small ridges at both ends of the inner rolling surface, and on the larger diameter side of the outer rolling surface of the outer member. If the large collar for guiding the tapered roller is integrally formed, the assemblability is improved, and the retainer moves and interferes with the seal in a state where the tapered roller is temporarily assembled to the outer member. Absent. Therefore, the seal can be prevented from being deformed or damaged due to the interference with the cage, and the sealing performance of the seal can be improved.

  According to a third aspect of the present invention, the inner member includes the hub wheel and an outer joint member fitted into the hub wheel, and the outer joint member includes a cup-shaped mouth portion. And a shoulder portion that forms the bottom of the mouse portion, the inner rolling surface is directly formed on the outer periphery, and a shaft portion that extends in the axial direction from the shoulder portion, and the end portion of the shaft portion is plastic. If the hub wheel and the outer joint member are integrally plastically bonded by deforming and tightening to the hub wheel, it is not necessary to tighten the nut tightly to control the preload, and it is lightweight and compact. The strength and durability of the hub wheel can be improved, and the preload amount can be maintained for a long time.

  Preferably, as in the invention according to claim 4, a hardened uneven portion is formed on the inner diameter of the hub wheel, and the hollow fitting portion formed at the end portion of the shaft portion is expanded in diameter. If the hub wheel and the outer joint member are integrally plastically joined by biting into the concavo-convex portion, the device can be further reduced in weight and size.

  Further, as in the invention according to claim 5, at least an inner side seal among the seals is a slinger that is press-fitted into the inner member, a core bar that is press-fitted into the outer member, and the core bar And an annular seal plate made of a vulcanized and bonded seal member, each having a substantially L-shaped cross-section, arranged opposite to each other, and the seal member having a side lip that is in sliding contact with the slinger If they are integrated, the sealing performance can be improved over a long period of time.

  The wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to the suspension device on the outer periphery, and is formed with a tapered double row outer rolling surface that opens outward on the inner periphery. The outer member and a wheel mounting flange for attaching the wheel to one end are integrated, and one tapered inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and the inner rolling surface. A hub wheel formed with a small-diameter step portion extending in the axial direction from the running surface, and the other tapered inner rolling surface that is fitted to the hub wheel and faces the outer rolling surface of the double row are formed on the outer periphery. An inner member composed of an outer joint member of an inner ring or a constant velocity universal joint, and a double row accommodated between the rolling surfaces of the inner member and the outer member via a retainer. An opening in the annular space formed by the tapered roller and the outer member and the inner member is mounted. In the wheel bearing device comprising a back-to-back type double-row tapered roller bearing, the cage is formed from a synthetic resin by injection molding, and a column portion between adjacent pockets is formed in the conical shape. Positioned on the inner diameter side of the pitch circle diameter of the roller, the width of the opening on the inner diameter side of the pocket is guided without coming out to the inner diameter side by contacting the tapered roller with the tapered side surface of the column portion. Since the width is set, even if the dimensional accuracy of the cage is not strictly regulated, the tapered roller is held by the outer rolling surface of the outer member and the cage, and it is reliably prevented from falling off the cage. Therefore, the assembly by the automatic assembly apparatus can be facilitated and the number of assembly steps can be greatly reduced.

  An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and formed with a tapered double row outer rolling surface opened outward on the inner periphery, and a wheel on one end A wheel mounting flange for integrally mounting, a tapered inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and a small diameter step portion extending in the axial direction from the inner rolling surface And an outer joint member of a constant velocity universal joint that is fitted to the hub wheel and has a tapered inner inner rolling surface that faces the outer rolling surface of the double row on the outer periphery. An inner member, a double-row tapered roller housed between the rolling surfaces of the inner member and the outer member via a cage, and the outer member and the inner member. And a seal attached to the opening of the annular space formed by In the wheel bearing device constituted by a row tapered roller bearing, the outer joint member includes a shoulder portion in which the inner rolling surface is directly formed on an outer periphery, and a cylindrical shaft portion extending in an axial direction from the shoulder portion. The hub ring and the outer joint member are integrally plastically bonded by forming the shaft portion with a diameter and hardening the inner diameter of the hub wheel so as to bite into the uneven portion formed. The cage is formed from synthetic resin by injection molding, the cage is formed from synthetic resin by injection molding, and the column part between adjacent pockets is located on the inner diameter side of the pitch circle diameter of the tapered roller, The width of the opening on the inner diameter side of the pocket is set to a width that guides the tapered roller without coming out to the inner diameter side by contacting the tapered side surface of the column portion, and on the outer side of the outer member. Previous to large diameter side of rolling surface Large rib for guiding the tapered rollers are integrally formed.

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 wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is taken along the line III-III of FIG. It is an expanded sectional view. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  This wheel bearing device is for a drive wheel called the third generation, and is a double row tapered roller accommodated in a freely rollable manner between the inner member 1, the outer member 2, and both members 1,2. 3 and 3. The inner member 1 includes a hub ring 4 and an inner ring 5 that is press-fitted into the hub ring 4 through a predetermined scissors.

  The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at one end, and has an inner rolling surface 4a on one outer side (tapered outer side) and the inner rolling surface. A small diameter step 4b extending in the axial direction from the surface 4a is formed, and a serration (or spline) 4c for torque transmission is formed on the inner periphery. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction. The inner ring 5 is formed with the other inner (inner side) inner raceway surface 5 a on the outer periphery, and is press-fitted into the small-diameter step portion 4 b of the hub ring 4. The inner ring 5 is made of high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core part by quenching. Note that conventional roller guide large collars and roller retaining small collars are not formed at both ends of the inner raceway surfaces 4a and 5a of the hub wheel 4 and the inner ring 5, and an outer side to be described later. A large collar 2b is integrally formed on the outer rolling surface 2a of the member 2.

  The hub wheel 4 is formed of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the like from an inner rolling surface 4a and a base 6b formed in an arc shape on the inner side of the wheel mounting flange 6. The surface hardness is hardened to a range of 58 to 64 HRC by induction hardening over the small diameter step 4b. As a result, the wear resistance of the base portion 6b which becomes the seal land portion of the seal 8 is improved, and the mechanical strength is sufficient with respect to the rotational bending load applied to the wheel mounting flange 6, and the inner ring 5 is fitted. The fretting resistance of the small-diameter step portion 4b that becomes the portion is improved.

  The outer member 2 integrally has a vehicle body mounting flange 2b to be attached to a knuckle (not shown) on the outer periphery, and faces the double row inner rolling surfaces 4a and 5a of the inner member 1 on the inner periphery. Each of the tapered double-row outer rolling surfaces 2a and 2a, which are open outwardly, is integrally formed. Double-row tapered rollers 3 and 3 are accommodated between these rolling surfaces, and are held by rollers 7 and 7 so as to roll freely. This outer member 2 is formed of medium carbon steel containing carbon 0.40 to 0.80 wt% such as S53C, and the double row outer rolling surfaces 2a and 2a have a surface hardness in the range of 58 to 64HRC by induction hardening. Has been cured.

  Further, seals 8 and 9 are attached to the opening of the annular space formed between the outer member 2 and the inner member 1. Specifically, the outer seal 8 is in sliding contact with the base 6 b of the wheel mounting flange 6, and the inner seal 9 is attached to the inner periphery of the end of the outer member 2 and the outer periphery of the inner ring 5. It consists of a seal. These seals 8 and 9 prevent the grease sealed inside the bearing from leaking outside and preventing rainwater, dust, and the like from entering the bearing from the outside. Although the third generation structure on the drive wheel side is illustrated here, the wheel bearing device according to the present invention is not limited to this, and any wheel bearing device in which the inner raceway surface is integrally formed on the hub wheel may be used. It may be on the driving wheel side.

  Here, in this embodiment, as shown in an enlarged view in FIG. 2, a large collar 2b for guiding the tapered roller 3 is integrally formed on the large diameter side of the outer rolling surface 2a of the outer member 2. . The outer seal 8 is mounted on the inner periphery of the large collar 2b. The cage 7 is formed by injection molding with a reinforcing material such as GF (glass fiber) added to a base of a thermoplastic resin such as PA (polyamide) 66. As shown in FIG. 3, the retainer 7 has a column portion 11 between adjacent pockets 10, 10 located on the inner diameter side of the pitch circle diameter (PCD) of the tapered rollers 3, and an inner diameter side opening of the pocket 10. The width W of the portion is set such that the tapered roller 3 is in contact with the tapered side surface of the column portion 11 and is guided without coming out to the inner diameter side. Thereby, even if the dimensional accuracy of the cage 7 is not strictly regulated, the tapered roller 3 is held by the outer rolling surface 2a of the outer member 2 and the cage 7 and reliably prevented from falling off the cage 7. can do.

  Also, in assembling the bearing, after the tapered rollers 3 are aligned with the outer raceway 2a of the outer member 2 at a predetermined interval, the retainer 7 has an inner diameter so that the tapered rollers 3 are simultaneously fitted in the pockets 10. Since the hub ring 4 and the inner ring 5 can be easily inserted by inserting them from both sides, the assembly by the automatic assembly apparatus can be facilitated and the number of assembly steps can be greatly reduced.

  Further, since the large flange 2b for guiding the tapered roller 3 is formed on the large diameter side of the outer rolling surface 2a of the outer member 2, the tapered roller 3 is incorporated in the outer member 2 in the state of the related art. Thus, the cage 7 does not move in the axial direction. Therefore, the cage 7 does not interfere with the seal 8 and the seal 8 is not deformed or damaged, so that the sealing performance of the seal 8 is not deteriorated.

  FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, and FIG. 5 is an explanatory view showing an assembling method of the wheel bearing device according to the present invention. In addition, the same code | symbol is attached | subjected to the site | part which has the same components same site | part as the embodiment mentioned above, or the same function, and detailed description is abbreviate | omitted.

  This wheel bearing device is referred to as a fourth generation, and includes a hub wheel 12, a double row rolling bearing 13 and a constant velocity universal joint 14 as a unit. The double row rolling bearing 13 includes an inner member 15, an outer member 2, and double row tapered rollers 3, 3 accommodated between the members 15, 2 so as to roll freely. The inner member 15 includes a hub ring 12 and an outer joint member 16 that is fitted into the hub ring 12 and is plastically coupled.

  The hub wheel 12 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at one end portion, and has one inner rolling surface 4a (outer side) tapered on the outer periphery, and this inner rolling. A small diameter step portion 12a extending in the axial direction from the surface 4a is formed. The hub wheel 12 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner raceway surface 4a and the base portion 6b on the inner side of the wheel mounting flange 6 to the small diameter step portion 12a. Thus, the surface hardness is set to a range of 58 to 64 HRC by induction hardening. Thereby, it has sufficient mechanical strength with respect to the rotational bending load loaded on the wheel mounting flange 6.

  Further, an uneven portion 17 is formed on the inner periphery of the hub wheel 12, and the surface is hardened by heat treatment so that the surface hardness is in the range of 54 to 64HRC. 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. In addition, the uneven part 17 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. In addition, in order to ensure good biting property, the tip of the concavo-convex portion 17 has a spire shape such as a triangular shape.

  The constant velocity universal joint 14 includes an outer joint member 16, a joint inner ring 18, a cage 19, and a torque transmission ball 20. The outer joint member 16 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and has a cup-shaped mouth portion 21, a shoulder portion 22 that forms the bottom portion of the mouth portion 21, and the shoulder portion 22. And a cylindrical shaft portion 23 extending in the axial direction are integrally formed. The shaft portion 23 is formed with an in-row portion 23a that is cylindrically fitted to the hub wheel 12 via a predetermined radial clearance, and a fitting portion 23b is formed at the end of the in-row portion 23a.

  A track groove 21 a having a curved portion extending in the axial direction is formed on the inner periphery of the mouse portion 21, and a track groove 18 a corresponding to the track groove 21 a is formed on the outer periphery of the joint inner ring 18. A torque transmission ball 20 is accommodated between the track grooves 21a and 18a via a cage 19. In addition, on the outer periphery of the shoulder portion 22, the other inner (inner side) inner rolling surface 16 a facing the double row outer rolling surfaces 2 a and 2 a is formed. And the surface hardness is hardened in the range of 58 to 64 HRC by induction hardening over the inner rolling surface 16a and the shaft portion 23 from the seal fitting portion where the track groove 21a and a seal 24 described later are in sliding contact. . Here, the fitting part 23b of the shaft part 23 is left raw after forging.

  Double row tapered rollers 3, 3 are accommodated between double row outer rolling surfaces 2a, 2a of outer member 2 and double row inner rolling surfaces 4a, 16a facing these, 7 is held so as to roll freely. Further, seals 24 and 24 are attached to both ends of the outer member 2 to prevent leakage of lubricating grease sealed inside the bearing and intrusion of rainwater, dust, etc. into the bearing from the outside. These double row rolling bearings 13 are so-called back-to-back type double row cones in which the action lines of the acting directions of the forces applied to the rolling surfaces 2a, 4a and 2a, 16a are separated in the axial direction toward the axial center. It constitutes a roller bearing.

  Here, in this embodiment, as in the above-described embodiment, the large collar 2b for guiding the tapered roller 3 is integrally formed on the large diameter side of the outer rolling surface 2a of the outer member 2, and the hub wheel 12 and the outer ring 2 are formed integrally. At both ends of the inner rolling surfaces 4a and 16a of the joint member 16, a roller guide large collar and a roller retaining small collar are not formed. The column portion 11 of the cage 7 is positioned on the inner diameter side of the pitch circle diameter of the tapered roller 3 to prevent the tapered roller 3 from dropping from the cage 7.

  The seal 24 is press-fitted into the base portion 6b of the wheel mounting flange 6, and is fitted into the large flange 2b of the outer member 2 so as to face the slinger 25, and is formed into a substantially L-shaped cross section. That is, a so-called pack seal is formed. The slinger 25 has a substantially L-shaped cross section by pressing from an austenitic stainless steel plate (JIS standard SUS304, etc.) or a rust-proof cold rolled steel plate (JIS standard SPCC, etc.). Is formed.

Next, the assembly method of the wheel bearing device according to the present embodiment will be described in detail with reference to FIG.
First, the tapered rollers 3 and 3 are aligned with the double-row outer rolling surfaces 2 a and 2 a of the outer member 2, and the cage 7 is in a state where the double-row tapered rollers 3 and 3 correspond to the pocket 10. Is elastically deformed and inserted from the inner diameter side. And the sealing board 26 which comprises the seal | sticker 24 is each mounted | worn with the both ends of the outer member 2. As shown in FIG. Thereafter, the slinger 25 constituting the seal 24 is press-fitted into the base portion 6b and the shoulder portion 22 of the wheel mounting flange 6, respectively, and the hub wheel 12 and the outer joint member 16 are inserted in the direction of the arrow from both sides of the outer member 2. Inserted. Then, the shoulder portion 22 of the outer joint member 16 is abutted against the end surface of the small-diameter step portion 12a of the hub wheel 12, and the shaft portion 23 is internally fitted to the hub wheel 12 until a butt state is reached. Further, a diameter expanding jig such as a mandrel is pushed into the inner diameter of the fitting portion 23b in the shaft portion 23 to increase the diameter of the fitting portion 23b, and the fitting portion 23b is bitten into the uneven portion 17 of the hub wheel 12. By caulking, the hub wheel 12 and the outer joint member 16 are integrally plastically joined to complete.

  With such a configuration, 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 device can be reduced in weight and size, and the strength and durability of the hub wheel 12 can be improved. In addition, the preload amount can be maintained for a long time. End caps 27 and 28 are attached to the open end portion of the hub wheel 12 and the hollow shaft portion 23 to prevent rainwater from entering the plastic joint portion and rusting the portion. The grease sealed in 21 is prevented from leaking outside.

  In the double row rolling bearing 13 composed of double row tapered roller bearings, the tapered rollers 3 and 3 rub against each other in the generatrix direction of each rolling surface when the bearing is assembled. It is difficult to secure. That is, the lubricant such as grease is retracted from the contact portions between these surfaces and becomes close to metal contact, and the friction coefficient of each contact portion increases. For this reason, the tapered rollers 3 and 3 are assembled in an unaligned state without smoothly moving to the large collars 2b and 2b guided. For example, even when the internal clearance should be negative, the positive internal clearance remains, and there is a possibility that a desired preload cannot be applied. In particular, when a so-called skew occurs in which the central axes of the tapered rollers 3 and 3 are inclined with respect to the normal rotation axis, such a problem becomes more prominent.

  In the present embodiment, in order to avoid such a problem, the hub wheel 12, the outer joint member 16, and the outer member 2 are relatively swung (reciprocating) or rotated in the above-described diameter expansion caulking process. Plastic bonding is performed while rotating in one direction. Actually, with the hub wheel 12 supported on the upper surface of the work table, the diameter expansion jig is pushed into the shaft portion 23 of the outer joint member 16 while the outer member 2 is swung with respect to the hub wheel 12. The two are plastically connected. By doing so, the double-row tapered rollers 3 and 3 are smoothly rubbed on the respective rolling surfaces and stably aligned with the large flanges 2b and 2b, and a predetermined preload can be applied with high accuracy.

  In addition to the configuration exemplified as the means for plastically coupling the hub wheel 12 and the outer joint member 16, for example, although not shown, the shaft portion of the outer joint member is fitted into the hub wheel, and the shaft portion A so-called swing caulking method may be employed in which the end portion is plastically deformed radially outward to form a caulking portion, and both members are fixed in the axial direction by the caulking portion.

  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 wheel bearing device according to the present invention can be applied to a wheel bearing device having a third or fourth generation structure in which a tapered inner rolling surface is directly formed on the outer periphery of a hub wheel.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is a principal part enlarged view of FIG. It is an expanded sectional view along the III-III line of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is explanatory drawing which shows the assembly method of the wheel bearing apparatus of FIG. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is an expanded sectional view which shows the roller assembly of FIG.

Explanation of symbols

1, 15 ... Inner member 2 ... Outer member 2a ...・ ・ ・ ・ ・ Outer rolling surface 2b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 鍔 鍔 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Tapered rollers 4, 12 ・··································································· Inner rolling surface 4b, 12a ... Serration 5 ... Inner ring 6 ... Wheel mounting flange 6a ... hub bolt 6b ... base 7 ...・ ・ ・ ・ Retainer 8, 9, 24 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 13 ・ ・ ・ ・ ・ ・Rolling bearings 14 ... constant velocity universal joints 16 ... outer joint members 17 ... ······································································ Joint inner ring 18a, 21a ...・ ・ ・ ・ ・ ・ ・ ・ ・ Cage 20 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 21 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse part 22・ ・ ・ ・ ・ ・ ・ ・ Shoulder 23 ・ ・ ・ ・ ・ ・ ・ ・ Shaft 23a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ In wax 23b ... fitting part 25 ... slinger 26 ...・ Seal plates 27, 28 ... End cap 50 ... ············· Bearing device 51 ··················· Outside member 51a Rolling surface 51b ..... Body mounting flange 52 ..... Hub wheels 52a, 54a ...・ ・ Inner rolling surface 52b ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter step 52c ・ ・ ・ ・ ・ ・ ・ ・ ・ Serrations 52d, 54b ・ ・ ・ ・ ・ ・... Daegu 53 ... Wheel mounting flange 54 ... Inner ring 55 ... .... Inner member 56 ... tapered rollers 57 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 60 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Hub bolt 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pocket 62 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Column 62a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ Outer diameter side part 62b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner diameter protruding part W ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inlet width

Claims (5)

An outer member integrally having a vehicle body mounting flange for being attached to a suspension device on the outer periphery, and having a tapered double row outer rolling surface formed outwardly on the inner periphery,
It has a wheel mounting flange for mounting the wheel at one end, and has one tapered inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and an axial direction from this inner rolling surface. A hub ring formed with an extending small-diameter stepped portion, and an inner ring or constant speed which is fitted to the hub ring and has a tapered inner inner rolling surface facing the outer rolling surface of the double row on the outer periphery. An inner member composed of an outer joint member of a universal joint;
A double-row tapered roller accommodated between the rolling surfaces of the inner member and the outer member so as to be freely rollable via a cage;
In a wheel bearing device comprising a back-to-back type double row tapered roller bearing, comprising a seal attached to an opening of an annular space formed by the outer member and the inner member,
The cage is formed of synthetic resin by injection molding, the column portion between adjacent pockets is positioned on the inner diameter side of the pitch circle diameter of the tapered roller, and the width of the inner diameter side opening of the pocket is the cone A bearing device for a wheel, wherein the roller is set to a width that is in contact with the tapered side surface of the column portion and guided without coming out to the inner diameter side.   A large flange for guiding the tapered roller is integrally formed on the large diameter side of the outer rolling surface of the outer member without having a large flange and a small flange on both ends of the inner rolling surface of the inner member. The wheel bearing device according to claim 1.   The inner member includes the hub wheel and an outer joint member fitted into the hub wheel. The outer joint member forms a cup-like mouth portion and a bottom portion of the mouth portion, The shoulder portion directly formed with the inner rolling surface and the shaft portion extending in the axial direction from the shoulder portion are integrally formed, and the end portion of the shaft portion is plastically deformed and crimped to the hub ring. The wheel bearing device according to claim 1 or 2, wherein the hub wheel and the outer joint member are integrally plastically coupled.   The hub wheel and the outer joint are formed by forming a hardened concave and convex portion on the inner diameter of the hub ring, and expanding the hollow fitting portion formed at the end of the shaft portion to bite into the concave and convex portion. The wheel bearing device according to claim 3, wherein the member is integrally plastically coupled.   At least an inner side seal of the seals is formed of a slinger that is press-fitted into the inner member, a metal core that is press-fitted into the outer member, and a seal member that is integrally vulcanized and bonded to the metal core. 5. Each of the sealing plates is formed in a substantially L-shaped cross section and arranged to face each other, and the sealing member integrally has a side lip that is in sliding contact with the slinger. The wheel bearing apparatus described in 1.

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