JP2012218490A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel for reducing cost, and preventing the occurrence of deformation and a very small crack when excessive stress is generated in a gear member.SOLUTION: This bearing device for the wheel is provided by fixing an inner ring 7 in the axial direction to a hub wheel 4, in a state of applying a predetermined bearing preload by a caulking part 10 formed by plastically deforming an end part of a small diameter step part 4b of the hub wheel 4 outside in the radial direction, and the driving switching gear member 18 is pressed in and fixed to the inner side of a seal 11 on an outer diameter surface 7b of the inner ring 7.

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and more particularly to a wheel bearing device having a clutch function for switching a wheel between driving and non-driving.

  In some four-wheel drive vehicles, a front wheel or a rear wheel can be selectively switched to a driven wheel by a clutch function provided in a wheel bearing device. FIG. 9 shows a conventional example of such a wheel bearing device with a clutch function. This wheel bearing device includes an outer member 50 attached to the vehicle body side, and an inner member having an inner rolling surface 55a facing the double-row outer rolling surfaces 50a, 50a on the inner periphery of the outer member 50. 51 and double-row tapered rollers 52, 52 interposed between the opposing rolling surfaces 50a, 55a. The inner member 51 includes a hub ring 54 having a wheel mounting flange 53 and two inner rings 55 and 56 that are fitted to the outer periphery of the hub ring 54 in the axial direction. Each row has inner rolling surfaces 55a, 55a in each row. A shaft portion of an outer joint member (not shown) of a constant velocity universal joint serving as a drive shaft is rotatably supported on the inner circumference of the hub wheel 54 via bearings 57 and 58.

  Of the two inner rings 55, 56 that are press-fitted into the outer periphery of the hub ring 54, the inner ring 56 on the inner end side is formed with a gear part 56a on the outer periphery, and a spline-like part 56b is formed on the inner periphery of the end part. Yes. A spline-shaped portion 54a is formed on the outer periphery of the inner end portion of the hub wheel 54, and the spline-shaped portion 56b of the inner ring 56 is engaged with the spline-shaped portion 54a. The inner end portion of the hub ring 54 is a flange-shaped caulking portion 54 b that presses the large end surface of the inner ring 56, and the inner ring 56 is fixed to the hub wheel 54 in the axial direction by the caulking portion 54 b.

  A ring-shaped slide gear 60 that meshes with a gear portion 59 formed on the outer joint member is selectively meshed with the gear portion 56a of the inner ring 56 by sliding in the axial direction. A driving force is transmitted from the outer joint member to the wheels via the inner ring 56 and the hub ring 54 in a state where the gear portion 56 a of the inner ring 56 and the gear portion 59 of the outer joint member are connected via the slide gear 60. . That is, at this time, the wheel supported by the hub wheel 54 becomes a drive wheel. In a state where the slide gear 60 is not meshed with the gear portion 56a of the inner ring 56, the driving force is not transmitted to the wheel, and the wheel supported by the hub wheel 54 at this time becomes a driven wheel.

  In such a configuration, the outer peripheral portion of the inner ring 56 is formed with the gear portion 56a that can be engaged with the slide gear 60 that meshes with the gear portion 59 of the outer joint member, so that the slide gear 60 is engaged with the gear portion 56a. A clutch function can be provided depending on the presence or absence. Further, since the gear portion 56a is formed integrally with the inner ring 56, fretting wear does not occur. For this reason, it is possible to sufficiently secure an axial force for clamping the inner ring 56 to the hub ring 54 to prevent bearing play, and to prevent a stick-slip sound from the inner ring 56 at the time of sudden start (for example, Patent Document 1). reference.).

JP 2005-138653 A

  However, in this conventional wheel bearing device, the spline-like portion 56b is formed on the inner periphery of the end portion of the inner ring 56, and the spline-like portion 54a meshing with the spline-like portion 56b is formed on the hub wheel 54. Therefore, when the inner end portion of the hub wheel 54 is plastically deformed to form the caulking portion 54b, it is difficult to form the caulking portion 54b radially outward along the spline-like portion 56b, and caulking defects such as microcracks occur. There is a fear.

  The present invention has been made in view of such circumstances, and provides a wheel bearing device in which cost reduction is achieved and excessive stress is generated in a gear member to prevent deformation and microcracking. The purpose is that.

  In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally attached to the knuckle constituting the suspension device on the outer periphery, and double row outer rolling on the inner periphery. A hub wheel having an outer member integrally formed with a surface, a wheel mounting flange for mounting a wheel at one end, and a cylindrical small-diameter step portion extending in the axial direction on the outer periphery; and An inner member having at least one inner ring press-fitted into a small-diameter step portion of the hub wheel through a predetermined shimoshiro and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery. And a double-row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member via a cage, in the wheel bearing device, A gear member for switching the drive is press-fitted and fixed to the inner end.

  In this way, the outer member integrally having the vehicle body mounting flange on the outer periphery, the outer member in which the double row outer rolling surface is integrally formed on the inner periphery, and the wheel mounting flange on the one end are integrated, and on the outer periphery. A hub wheel formed with a cylindrical small-diameter step portion extending in the axial direction, and at least one inner ring press-fitted into the small-diameter step portion of the hub ring through a predetermined shimoshiro, and outer rows of double rows on the outer periphery An inner member in which a double row inner rolling surface facing the surface is formed, and a double row of the inner member and the outer member that are accommodated so as to be able to roll through a retainer between the rolling surfaces of the inner member and the outer member. In a wheel bearing device including a rolling element, a drive switching gear member is press-fitted and fixed to the inner side end of the inner member, so that the cost is reduced and excessive stress is applied to the gear member. To provide a bearing device for a wheel that prevents deformation and microcracking from occurring. It can be.

  Preferably, in a state in which a predetermined bearing preload is applied by a caulking portion formed by plastically deforming an end portion of the small-diameter step portion of the hub wheel radially outward as in the invention described in claim 2. If the inner ring is fixed in the axial direction with respect to the hub ring, the end of the small-diameter stepped portion of the hub ring may be radially outward without adversely affecting the molding when forming the crimped portion. It can be plastically deformed, can prevent caulking defects such as microcracks in the caulking portion, and can maintain the initially set bearing preload for a long period of time.

  According to a third aspect of the present invention, a predetermined bearing preload is applied by a fixed nut in which a male screw is formed on the outer periphery of the end portion of the small-diameter step portion of the hub wheel, and a female screw that is screwed to the male screw is formed. In this state, if the inner ring is fixed in the axial direction with respect to the hub ring, a desired axial force can be applied to the inner ring simply by fastening the fixing nut with a predetermined tightening torque. Even if the inner ring wall thickness is not set to be thicker than necessary, excessive stress is not generated in the gear member and the inner ring by the caulking process, and durability can be ensured.

  According to a fourth aspect of the present invention, a seal is attached to an opening portion of an annular space formed between the outer member and the inner ring, and an inner surface of the seal on the outer diameter surface of the inner ring. The gear member may be press-fitted and fixed to the side.

  Further, as in the invention according to claim 5, if the gear member is press-fitted and fixed to a small-diameter portion formed smaller in diameter than an outer-diameter surface into which the seal is press-fitted among outer-diameter surfaces of the inner ring. As a result, the distance for press-fitting the seal is shortened, the assembly workability is improved, and the cost can be reduced.

  Preferably, as in the invention described in claim 6, the outer diameter surface into which the seal of the inner ring is press-fitted and the small-diameter portion into which the gear member is press-fitted are simultaneously ground by a grindstone of a general-purpose grindstone. As a result, the processing time can be shortened and the cost can be reduced.

  Further, as in the invention described in claim 7, if the outer diameter surface of the caulking portion is formed flat by machining and the gear member is press-fitted and fixed to the outer diameter surface, the weight and the size can be reduced. Can be achieved, and excessive stress is not generated in the gear member by the caulking process, thereby ensuring durability.

  Further, as in the invention described in claim 8, an outer joint member constituting a constant velocity universal joint is coupled to the inner member, and a gear portion is formed on the outer joint member. A drive switching actuator having a slide gear that engages with each gear member is formed on the inner periphery, and is fitted and fixed to the knuckle, and a seal is mounted between the inner end of the actuator and the outer joint member. Then, the space can be effectively utilized, the bearing portion can be effectively sealed, and the weight and size can be reduced.

  Further, as in the invention described in claim 9, a part of the fitting surface of the gear member and the inner ring forms a serration or the like that is hardened by heat treatment on the inner ring outer diameter, that is, the inner ring outer diameter. If the joining method of tightly fitting while cutting the inner diameter of the gear member which is not hardened is adopted, both can be coupled in a compact manner and the driving force can be reliably transmitted.

  Further, as in the invention described in claim 10, if the gear member and the inner ring are laser welded, the driving force can be reliably transmitted between the gear member and the inner ring.

  Further, as in the invention described in claim 11, at least a part of the fitting surface of the inner ring and the hub ring may be press-cut joined.

  Further, as in the invention described in claim 12, a key groove may be formed on a fitting surface between the inner ring and the hub ring, and a key may be attached to the key groove.

Further, as in the invention described in claim 13, the crimping portions of the inner ring and the hub ring may be laser-welded.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a knuckle constituting a suspension device on an outer periphery, and an outer side in which a double row outer rolling surface is integrally formed on an inner periphery. And a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end thereof and having a cylindrical small-diameter step portion extending in the axial direction on the outer periphery, and a small-diameter step portion of the hub wheel having a predetermined diameter An inner member comprising at least one inner ring that is press-fitted through a nip and having a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery; and the inner member and the outer member In a wheel bearing device comprising a double row rolling element that is slidably accommodated between both rolling surfaces of a side member via a cage, a drive switching is provided at the inner side end of the inner member. The gear member is press-fitted and fixed. , It is possible to provide a wheel bearing apparatus that prevents the deformation or microcracks excessive stress is generated in the gear member occurs.

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 explanatory drawing which shows the assembly procedure of the gear member which concerns on this invention. It is explanatory drawing which shows the other assembly procedure of a gear member same as the above. It is a principal part enlarged view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a principal part enlarged view which shows the modification of the inner ring | wheel of FIG. FIG. 7 is an enlarged view of a main part showing another modification of the inner ring in FIG. 5. It is a principal part enlarged view which shows 3rd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus.

  An outer member integrally having a vehicle body mounting flange to be attached to a knuckle constituting a suspension device on the outer periphery, a double row tapered outer rolling surface formed integrally on the inner periphery, and a wheel on one end A hub wheel integrally having a wheel mounting flange for mounting a wheel, and a hub wheel formed with a small diameter step portion extending in the axial direction from the wheel mounting flange via a shoulder portion, and a predetermined squeeze to a small diameter step portion of the hub wheel An inner member composed of a pair of inner rings that are press-fitted through and formed with a tapered inner rolling surface facing the double row outer rolling surface, and both rolling of the inner member and the outer member. A double row tapered roller accommodated in a rollable manner via a cage between the surfaces, and a seal attached to both side openings of the annular space formed between the outer member and the inner member. The end of the small diameter step of the hub wheel is plastically deformed radially outward. In the wheel bearing device in which the inner ring is fixed in the axial direction with respect to the hub ring in a state where a predetermined bearing preload is applied by the caulking portion formed in this manner, the outer ring of the inner side of the inner ring On the radial surface, a drive switching gear member is press-fitted and fixed to the inner side of the seal.

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 a procedure for assembling a gear member according to the present invention. FIG. 4 is an explanatory view showing another assembly procedure of the gear member. 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 wheel bearing device is used on the drive wheel side, and includes an inner member 1 and an outer member 2, and double-row tapered rollers 3 and 3 accommodated between both members 1 and 2 so as to roll freely. Yes. The inner member 1 includes a hub ring 4 and a pair of inner rings 5 and 7 plastically coupled to the hub ring 4. The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at an end portion on the outer side, and has a cylindrical shape that extends in the axial direction from the wheel mounting flange 6 to the outer periphery via a shoulder portion 4a. The small diameter step 4b is formed. Further, hub bolts 6 a for fixing the wheels at the circumferentially equidistant positions of the wheel mounting flange 6 are planted.

  Each of the pair of inner rings 5 and 7 has a tapered inner rolling surface 5a formed on the outer periphery, and is press-fitted into the small-diameter step portion 4b of the hub wheel 4 via a predetermined squeeze. And the large collar parts 5b and 7b for guiding the tapered roller 3 to the large diameter side of these inner side rolling surfaces 5a are formed, and the small collar part for preventing the tapered roller 3 from dropping off on the small diameter side. 5c and 7c are formed to constitute a back-to-back double row tapered roller bearing set in a state where the small end faces 5d and 7d (front end faces) of the inner rings 5 and 7 are butted together.

  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 is a tapered double row outer rolling surface 2a, 2a opened outward on the inner periphery. Are integrally formed. The double-row tapered rollers 3 and 3 are accommodated between the rolling surfaces via a cage 8 so as to freely roll. Further, an annular groove 9 is formed on the outer diameter surface fitted into the knuckle, and an elastic ring (not shown) such as an O-ring is attached to the annular groove 9, thereby airtightness of the fitting portion with the knuckle. Can be improved.

  The hub wheel 4 is formed of medium-high carbon steel (carbon steel for SC system mechanical structure of JIS standard) containing 0.40 to 0.80 wt% of carbon such as S53C, and has a high frequency extending from the shoulder 4a to the small diameter step 4b. A predetermined hardened layer is formed in the range of surface hardness of 58 to 64 HRC by quenching. Further, the inner rings 5 and 7 and the tapered roller 3 are made of high carbon chrome bearing steel such as SUJ2, and are hardened in the range of 58 to 64 HRC to the core part by quenching. In addition, the crimping part 10 mentioned later is used as the unhardened part with the surface hardness after forging. This facilitates caulking and prevents the occurrence of microcracks during processing, and has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6, and the durability of the hub wheel 4. Improves.

  The outer member 2 is formed of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, as in the case of the hub wheel 4, and at least the double-row outer raceway surfaces 2a and 2a are formed on the surface by induction hardening. A predetermined curing process is performed in the range of 58 to 64 HRC. Seals 11, 11 are attached to the opening of the annular space formed between the outer member 2 and the inner rings 5, 7, leakage of the lubricating grease sealed inside the bearing, rainwater, dust, etc. from the outside Is prevented from entering the inside of the bearing.

  As shown in an enlarged view in FIG. 2, the seal 11 is formed of a so-called pack seal including a slinger 12 and an annular seal plate 13 that are arranged to face each other. Slinger 12 can be an austenitic stainless steel plate (JIS standard SUS304, etc.), a ferritic stainless steel plate (JIS standard SUS430, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC, etc.). And a cylindrical portion 12a having a substantially L-shaped cross section by press working and press-fitted into the large collar portion 7b (5b) of the inner rings 5 and 7, and a standing plate portion extending radially outward from the cylindrical portion 12a 12b.

  On the other hand, the seal plate 13 includes a cored bar 14 fitted into the end of the outer member 2 and a seal member 15 integrally joined to the cored bar 14 by vulcanization adhesion. The cored bar 14 is formed in a substantially L-shaped cross section by pressing from an austenitic stainless steel plate or a cold-rolled steel plate that has been rust-proofed.

  The seal member 15 is made of a synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and has a side lip 15a extending inclining radially outward, a grease lip 15c extending in a bifurcated manner toward the inner diameter side, and a dust lip 15b. Is integrated. The side lip 15a is in sliding contact with the side surface of the standing plate portion 12b of the slinger 12 via a predetermined axial shimiro, and the grease lip 15c and the dust lip 15b are in sliding contact with the cylindrical portion 12a via a predetermined radial shimillo. ing. In addition to the exemplified NBR, the seal member 15 is made of, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which have excellent heat resistance, and heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  The integration of the hub wheel 4 and the inner rings 5 and 7 is achieved by pressing the inner rings 5 and 7 into the small-diameter step portion 4b of the hub wheel 4 via a predetermined shimiro, and the end of the small-diameter step portion 4b in the radial direction. This is performed by a caulking portion 10 formed by plastic deformation outward.

  In the present embodiment, by performing the rotation of the bearing portion during caulking, the tapered roller 3 squeezes up with the rotation and is guided to the large flange portion 7b (5b). Can be stored stably. Here, the double row tapered roller bearing in which the rolling element is composed of the tapered roller 3 is illustrated, but the wheel bearing device according to the present invention is not limited to this. For example, although not illustrated, a ball is used for the rolling element. It may be composed of double row angular contact ball bearings.

  Further, on the inner periphery of the hub wheel 4, a shaft portion of an outer joint member constituting a constant velocity universal joint (not shown) is rotatably supported via rolling bearings 16 and 17. Out of these rolling bearings 16, 17, the outer side rolling bearing 16 is a deep groove ball bearing, and the inner side rolling bearing 17 is a shell-shaped needle roller bearing.

  Here, a ring-shaped gear member 18 is press-fitted into the large collar portion (outer diameter surface) 7b of the inner ring 7 on the inner side through a predetermined radial shimiro. A ring-shaped slide gear 20 that meshes with a gear portion 19 of an outer joint member (not shown) is selectively meshed with the gear member 18 by sliding in the axial direction. A driving force is transmitted from the constant velocity universal joint to the wheels via the inner ring 7 and the hub wheel 4 in a state where the gear member 18 of the inner ring 7 and the gear portion 19 of the outer joint member are connected via the slide gear 20. The That is, at this time, the wheel supported by the hub wheel 4 is a driving wheel. Further, when the slide gear 20 is not engaged with the gear member 18 of the inner ring 7, the driving force is not transmitted to the wheels, and at this time, the wheel supported by the hub wheel 4 becomes a driven wheel and is switched between four wheels and two wheels. Is selectively performed.

  In this embodiment, since the gear member 18 is press-fitted and fixed to the large collar portion (outer diameter surface) 7b of the inner ring 7, it is prevented that excessive stress is generated in the gear member 18 to cause deformation or micro cracks. In addition, when the caulking portion 10 is formed, the end portion of the small diameter step portion 4b of the hub wheel 4 can be plastically deformed radially outward without adversely affecting the molding. Thus, it is possible to prevent the occurrence of caulking defects such as micro cracks and maintain the initially set bearing preload for a long period of time.

  Although not shown, so-called press-cut joining is adopted in which serrations and the like hardened by heat treatment are formed on the outer diameter of the inner ring, and the inner diameter of the gear member not hardened by this serration is tightly fitted while cutting. Thus, both can be combined in a compact manner and the driving force can be reliably transmitted. Further, the inner ring and the gear member may be integrally joined by laser welding or the like. Similarly, the hub ring and the inner ring may be press-cut joined. In this case, only the outer diameter portion of the inner ring is cured by high-frequency heat treatment, and the inner diameter portion needs to be left as raw material.

  Here, in this embodiment, as shown in FIG. 3, after the caulking portion 10 is formed and the inner ring 7 is fixed in the axial direction, the gear member 18 is press-fitted and fixed to the large collar portion 7 b of the inner ring 7. . As a result, it is possible to reliably prevent the gear member 18 from being deformed or micro-cracked due to excessive stress due to plastic working, and to avoid the influence of hoop stress generated in the large collar portion 7b of the inner ring 7 by caulking. can do. On the other hand, as shown in FIG. 4, the caulking portion 10 may be formed after the gear member 18 is press-fitted and fixed to the large collar portion 7 b of the inner ring 7. In this case, by restricting the hoop stress of the inner ring 7 due to the caulking process, it is possible to prevent a press-fitting problem due to excessive excessive stress that is a concern when the gear member 18 is press-fitted.

  FIG. 5 is an enlarged view showing a main part of a second embodiment of the wheel bearing device according to the present invention. The second embodiment is basically different from the first embodiment described above only in the inner ring fixing means, and the same reference numerals are given to other parts, parts having the same functions or parts having the same functions. Detailed description will be omitted.

  In the wheel bearing device, the inner ring 7 on the inner side is fixed in the axial direction in a state where a predetermined bearing preload is applied by a fixing nut 21. Specifically, a male screw 23a is formed on the outer periphery of the small-diameter step portion 23 of the hub wheel 22, and a fixing nut 21 having a female screw 21a screwed to the male screw 23a is fastened with a predetermined tightening torque. Thus, a desired axial force is applied to the inner ring 7.

  In the present embodiment, since the inner ring 7 is not fixed by the caulking portion 10 as in the above-described embodiment, the gear member 18 is obtained by caulking without setting the inner ring 7 to be thicker than necessary. In addition, excessive stress is not generated in the inner ring 7 and durability can be ensured.

  FIG. 6 shows a modification of the inner ring 7 described above. The inner ring 24 includes a small diameter portion 24a that is formed to have a slightly smaller diameter than the large collar portion (outer diameter surface) 7b to which the seal 11 is attached. The small diameter portion 24a is ground simultaneously with the large collar portion (outer diameter surface) 7b by a general-purpose grindstone. Thereby, while being able to shorten processing time, the distance which press-fits the slinger 12 which comprises the seal | sticker 11 becomes short, assembly workability | operativity improves and cost reduction can be achieved.

  FIG. 7 shows another modification of the inner ring 7 described above. The inner ring 25 is provided with a large collar portion (outer diameter surface) 25a having a reduced width dimension and only a space in which the seal 11 is mounted. The outer diameter surface 26a of the caulking portion 26 that fixes the inner ring 25 is formed flat by machining such as turning, and the gear member 18 is press-fitted and fixed to the outer diameter surface 26a. Thereby, while being able to achieve lightweight and compactness, excessive stress is not generated in the gear member 18 by caulking, and durability can be ensured.

  FIG. 8 is an enlarged view showing a main part of a third embodiment of the wheel bearing device according to the present invention. Note that the third embodiment is basically different from the first embodiment described above only in the configuration of the inner ring and the presence or absence of a seal, and other parts or parts having the same function or the same function are used. The same reference numerals are assigned and detailed description is omitted.

  In this wheel bearing device, no seal is attached to the opening of the annular space formed between the outer member 2 and the inner ring 27 on the inner side, and the four-wheel / two-wheel switching actuator 28 described later is provided. It is installed. Specifically, the switching actuator 28 is fitted and fixed to the knuckle 29, and a slide gear 20 that meshes with the gear portion 19 of the outer joint member 30 constituting the constant velocity universal joint is formed on the inner periphery. The slide gear 20 is selectively meshed by sliding in the axial direction. That is, in the state where the gear member 18 of the inner ring 27 and the gear portion 19 of the outer joint member 30 are connected via the slide gear 20, the driving force is transmitted from the constant velocity universal joint to the wheel via the inner ring 27 and the hub ring 4. (Not shown).

  The seal 31 attached to the switching actuator 28 includes a cored bar 32 fitted into an end portion on the inner side of the switching actuator 28 and a seal member 33 integrally joined to the cored bar 32 by vulcanization adhesion. . The core metal 32 is formed in a substantially L-shaped cross section by press working from an austenitic stainless steel plate or a cold-rolled steel plate that has been rust-proofed.

  Further, the seal member 33 is made of synthetic rubber such as NBR, and integrally includes a side lip 33a extending inclined outward in the radial direction and a dust lip 33b extending inclined toward the inner diameter side. A garter spring 34 is mounted. The side lip 33a is in sliding contact with the side surface of the shoulder 35 of the outer joint member 30 via a predetermined axial shimiro, and the dust lip 33b is in sliding contact with the outer peripheral surface of the shoulder 35 via a predetermined radial shimillo. ing. In the present embodiment, since the seal 31 is attached to the switching actuator 28 by effectively using the space instead of the outer diameter surface of the inner ring 27, the bearing portion can be effectively sealed, and the weight / Compactness can be achieved.

  In the embodiment described above, the gear member 18 is press-fitted and fixed to the inner ring or the caulking portion. However, the present invention is not limited to this, but, for example, the key groove is formed on the outer diameter surface of the inner ring and the inner diameter surface of the gear member. And driving torque may be transmitted via keys mounted in these key grooves, or the inner ring and the caulking portion may be joined together by laser welding or the like. Thereby, creep of a gear member can be prevented reliably. Further, in order to avoid a press-fitting problem due to excessive squeezing, the gear member may be pre-heated to a predetermined temperature before press-fitting and press-fitted in a state where it has been thermally expanded by a predetermined amount.

  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.

  In the wheel bearing device according to the present invention, a gear member that selectively switches between four wheels and two wheels is fixed to an inner member having a hub wheel and an inner ring fitted to the hub wheel. It can be applied to a wheel bearing device having a third generation structure.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 2a Outer rolling surface 2b Car body mounting flange 3 Tapered roller 4, 22 Hub wheel 4a, 35 Shoulder part 4b, 23 Small diameter step part 5, 7, 24, 25, 27 Inner ring 5a Inner rolling Surface 5b, 7b, 25a Large flange portion 5c, 7c Small flange portion 5d, 7d Small end surface 6 Wheel mounting flange 6a Hub bolt 8 Cage 9 Annular groove 10, 26 Clamping portion 11, 31 Seal 12 Slinger 12a Cylindrical portion 12b Standing plate Part 13 Seal plate 14, 32 Metal core 15, 33 Seal member 15a, 33a Side lip 15b, 33b Dustrip 15c Grease lip 16, 17 Rolling bearing 18 Gear member 19 Gear part 20 of outer joint member 20 Slide gear 21 Fixing nut 21a Female thread 23a Male thread 24a Small diameter portion 26a Outer diameter surface 28 of the crimping portion Switching actuator 29 Knuckle 30 Outer joint member 34 Data spring 50 outer member 50a outer rolling surface 51 inner member 52 tapered roller 53 wheel mounting flange 54 hub wheel 54a, 56b spline-like portion 54b crimping portion 55, 56 inner ring 55a inner rolling surface 56a, 59 gear portion 57, 58 Bearing 60 Slide gear

Claims (13)

An outer member integrally having a vehicle body mounting flange for being attached to a knuckle constituting a suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and having a cylindrical small-diameter stepped portion extending in the axial direction on the outer periphery, and a small diameter stepped portion of the hub wheel via a predetermined squeezing An inner member formed of at least one inner ring press-fitted and formed with a double-row inner rolling surface facing the double-row outer rolling surface on the outer periphery;
In a wheel bearing device comprising a double-row rolling element that is accommodated so as to roll freely between both rolling surfaces of the inner member and the outer member via a cage,
A wheel bearing device, characterized in that a drive switching gear member is press-fitted and fixed to an inner side end of the inner member.   The inner ring is fixed in the axial direction with respect to the hub wheel in a state where a predetermined bearing preload is applied by a crimping portion formed by plastically deforming an end portion of the small-diameter step portion of the hub wheel radially outward. The wheel bearing device according to claim 1, wherein   A male screw is formed on the outer periphery of the end portion of the small-diameter step portion of the hub ring, and the inner ring is applied to the hub ring in a state where a predetermined bearing preload is applied by a fixing nut formed with a female screw that is screwed to the male screw. The wheel bearing device according to claim 1, wherein the wheel bearing device is fixed in the axial direction.   A seal is attached to an opening of an annular space formed between the outer member and the inner ring, and the gear member is press-fitted and fixed to the inner side of the seal on the outer diameter surface of the inner ring. The wheel bearing apparatus in any one of 1 thru | or 3.   The wheel bearing device according to claim 4, wherein the gear member is press-fitted and fixed to a small-diameter portion formed to have a smaller diameter than an outer-diameter surface into which the seal is press-fitted among outer-diameter surfaces of the inner ring.   The wheel bearing device according to claim 5, wherein an outer diameter surface into which the seal of the inner ring is press-fitted and a small-diameter portion into which the gear member is press-fitted are simultaneously ground by a grindstone of a general-purpose grindstone.   The wheel bearing device according to claim 2, wherein an outer diameter surface of the caulking portion is formed flat by machining, and the gear member is press-fitted and fixed to the outer diameter surface.   An outer joint member constituting a constant velocity universal joint is coupled to the inner member, a gear portion is formed on the outer joint member, and a slide gear that meshes with the gear portion and the gear member is formed on the inner periphery. The wheel switching actuator according to any one of claims 1 to 3, wherein the drive switching actuator is fitted and fixed to the knuckle, and a seal is mounted between the inner end of the actuator and the outer joint member. Bearing device.   The wheel bearing device according to claim 1, wherein a part of a fitting surface between the gear member and the inner ring is press-cut joined.   The wheel bearing device according to claim 1, wherein the gear member and the inner ring are laser-welded.   The wheel bearing device according to claim 1, wherein at least a part of a fitting surface between the inner ring and the hub ring is press-cut joined.   The wheel bearing device according to claim 1, wherein a key groove is formed in a fitting surface between the inner ring and the hub ring, and a key is mounted in the key groove.   The wheel bearing device according to claim 1, wherein the caulking portion between the inner ring and the hub ring is laser-welded.

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