JP6235256B2 - Wheel bearing device - Google Patents

Description

  The present invention relates to a full floating type wheel bearing device that rotatably supports driving wheels of a vehicle such as a truck with a double row rolling bearing.

  Many automobiles having a frame-structured body such as a truck adopt a conventional full floating type as an axle structure of a drive wheel. Also, recent drive wheel support structures are often adopted as a structure in which double row rolling bearings are unitized for the purpose of improving assemblability and reducing weight and size. As an example of the conventional structure, a wheel bearing device as shown in FIG. 14 is known.

  In this wheel bearing device, a drive shaft 52 connected to a differential (not shown) is inserted into an axle tube 51, and a wheel bearing 53 including a wheel bearing is mounted on the outer diameter surface of the axle tube 51. ing. A hub wheel 54 rotatably supported by the wheel bearing 53 is connected to a flange 56 of the drive shaft 52 via a hub bolt 55. Inner rings 57 and 58 of the wheel bearing 53 are fitted on the end of the axle tube 51 and fastened with a fixing nut 59, and an outer ring 60 of the wheel bearing 53 is fitted on the hub ring 54. Both ends are fixed in the axial direction with the flange 56 and the brake rotor 61 sandwiched therebetween.

  As shown in FIG. 15, the wheel bearing 53 includes an outer ring 60 in which tapered double-row outer rolling surfaces 60 a and 60 a that are outwardly opened on the inner circumference are integrally formed, and these double-rows on the outer circumference. Inner races 57, 58 formed with tapered inner rolling surfaces 57 a facing the outer rolling surfaces 60 a, 60 a, and double rows accommodated between the rolling surfaces via a cage 62 so as to roll freely. The tapered rollers 63 and 63 are provided. A large collar portion 57b for guiding the tapered roller 63 is formed on the large diameter side of the inner raceway 57a of the inner rings 57, 58, and a small collar for preventing the tapered roller 63 from falling off on the small diameter side. A portion 57c is formed. The pair of inner rings 57 and 58 are set in a state in which the end surfaces on the small diameter side are abutted to each other, and constitute a so-called back-to-back type wheel bearing.

  Seals 64 and 65 are attached to the openings of the annular space formed between the outer ring 60 and the pair of inner rings 57 and 58. The seal 64 prevents the differential oil from entering the bearing. This prevents leakage of the lubricating grease sealed inside the bearing and prevents rainwater and dust from entering the bearing from the outside.

  Annular grooves 66, 66 are formed at the small-diameter side ends of the pair of inner rings 57, 58, and a connecting ring 67 is attached to the annular groove 66, and an annular recess 68 is formed on the outer peripheral surface of the butted portion of the inner rings 57, 58. The first seal ring 69 is attached to the annular recess 68. An annular stepped portion 70 is formed at the large-diameter end of the inner ring 58, and a second seal ring 71 is attached.

  As shown in FIG. 16, the second seal ring 71 is formed by a cored bar 72 and an elastic member 73, and the elastic member 73 is brought into contact with the shoulder portion 51 a of the axle tube 51, and the inner ring 58 and the axle tube 51. A small gap between the two is blocked.

  The elastic member 73 is made of synthetic rubber, and is joined integrally so as to cover the outer diameter portion of the cored bar 72 by vulcanization adhesion, and a lip 73a that abuts the shoulder 51a formed in an arc shape through a predetermined shimiro. Have. The outer diameter d1 of the elastic member 73 is set to be slightly smaller than the inner diameter D1 of the annular step portion 70 (d1 <D1), and an annular protrusion 73b is formed at the end. And it mounts | wears with the cyclic | annular step part 70 in the state which elastically deformed this protrusion 73b. Thus, the rigidity is increased by the cored bar 72, so that the second seal ring 71 can be prevented from falling off during the conveyance of the bearing, and the elastic member 73 is pressed when the second seal ring 71 is press-fitted into the annular stepped portion 70. Can be prevented, and stable airtightness can be ensured (see, for example, Patent Document 1).

JP 2010-025216 A JP 2001-099172 A

  However, in such a conventional wheel bearing device, the rigidity of the second seal ring 71 is increased by the cored bar 72. On the other hand, if the left and right parts are mistakenly assembled at the time of assembly, the airtightness is remarkably reduced. To do. In addition, in this type of seal ring, for example, a simple one with a symmetrical shape such as a circular cross section and an X shape has been proposed, but this is effective against misassembly, but it is easy to come off, There is a problem in assemblability (see, for example, Patent Document 2).

  The present invention has been made in view of such conventional problems, and improves the workability at the time of disassembling and improves the desired airtightness even if the seal ring is misassembled at the time of assembling. An object of the present invention is to provide a full-floating type wheel bearing device having an improved height.

In order to achieve such an object, the invention according to claim 1 of the present invention includes an axle tube in which a drive shaft connected to a differential is inserted, and an outer fitting at an end step portion on the outer side of the axle tube. A wheel bearing composed of a double row rolling bearing that is fixed and rotatably supports the wheel, and the wheel bearing includes an outer member in which an outer race surface of the double row is integrally formed on the inner periphery; A pair of inner races having an inner race surface facing the outer race surface of the double row on the outer periphery, and freely rollable via a cage between the inner race and each raceway surface of the outer member. A double row of rolling elements housed therein, and a seal attached to an opening of an annular space formed between the outer member and the inner ring, and a shoulder portion of the axle tube of the pair of inner rings. An annular step is formed on the inner periphery of the inner ring at the inner side where it abuts, and a seal ring is mounted on this annular step. In the wheel bearing device of a full-floating type that is, the seal ring and the core material resin annular, integrally joined to this core, the shape having a thickness in either cross-sectional axis and the radial direction It is made of an elastic member, a notch or V-groove is formed on the circumferential surface of the core material, and a notch or a notch portion different from the notch at the same position on the circumference of the core material or A V-groove is formed, and the elastic member has an annular protrusion formed to protrude radially outward on an outer diameter, and has a protrusion formed in a bilaterally symmetrical shape protruding in the axial direction at both ends. These protrusions are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a shimiro.
According to a second aspect of the present invention, there is provided an axle tube in which a drive shaft connected to a differential is inserted, and an outer side end stepped portion of the axle tube that is externally fitted and fixed to support a wheel rotatably. A wheel bearing comprising a double row rolling bearing, and the wheel bearing comprises an outer member having a double row outer rolling surface integrally formed on an inner periphery, and an outer member of the double row on an outer periphery. A pair of inner rings formed with an inner rolling surface facing the running surface, and a double-row rolling element housed between the inner ring and each rolling surface of the outer member via a cage to be freely rollable And an end of an inner ring on the inner side that abuts against a shoulder of the axle tube of the pair of inner rings, and a seal mounted in an opening of an annular space formed between the outer member and the inner ring A full floating type with an annular step formed on the inner periphery and a seal ring attached to the annular step In the wheel bearing device of the present invention, the seal ring is composed of a resin-made annular core material and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. And a notch or V-groove is formed on the circumferential surface of the core member, and a part of the notch or V-groove is exposed from the elastic member, and the elastic member has an outer diameter. Have annular projections that protrude radially outward, and have projections that protrude in the axial direction at both ends and are formed symmetrically. It is brought into contact with the shoulder portion of the axle tube via a shimoshiro.

As described above, a full floating type wheel in which an annular step is formed on the inner periphery of the end of the inner ring on the inner side that abuts the shoulder of the axle tube of the pair of inner rings, and a seal ring is attached to the annular step. In the bearing device, the seal ring is composed of an annular core material made of resin and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. A notch or V-groove is formed on the surface on the circumference of the core member, and a notch or V-groove different from the notch is formed at the same position on the circumference of the core material. It has an annular projection formed on the outer diameter so as to project radially outward, and has a projection formed in a bilaterally symmetric shape projecting in the axial direction at both ends, and these projections are connected to the wall surface of the annular step portion. Since it is in contact with the shoulder portion of the axle tube via a shimoshiro, the axle It is possible to prevent the seal ring from falling off from the annular stepped portion before assembling, and to increase the volume of the elastic member to the maximum, to increase the compressible range and ensure stable airtightness Therefore, it is possible to provide a fully floating type wheel bearing device that can prevent intrusion of muddy water and leakage of differential oil, and can prevent the infiltration of differential oil into the bearing. Further, since the seal ring has a symmetrical shape, it is possible to ensure the desired airtightness and improve the reliability even in the case of incorrect assembly during assembly. Furthermore, when replacing, the seal ring can be easily removed from the annular step by applying a chisel or the like to the notch or V groove of the core material and folding it with a hammer. Can be improved.
Further, a full floating type wheel bearing in which an annular step is formed on the inner periphery of the inner ring end that abuts the shoulder of the axle tube of the pair of inner rings, and a seal ring is attached to the annular step. In the apparatus, the seal ring is composed of an annular core material made of resin and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. A notch or V-groove is formed on the surface on the circumference, a part of the notch or V-groove is exposed from the elastic member, and the elastic member is formed to protrude radially outward to the outer diameter. In addition to the annular projections, both ends have projections that are axially projecting in the axial direction, and these projections are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a shimishiro Seal ring before assembling to the axle tube. Can be prevented from falling off the annular step portion, and the volume of the elastic member can be increased to the maximum, and the compressible range can be increased to ensure stable airtightness. In addition, it is possible to provide a fully floating type wheel bearing device that can prevent the differential oil from leaking and prevent the differential oil from entering the bearing. Further, since the seal ring has a symmetrical shape, it is possible to ensure the desired airtightness and improve the reliability even in the case of incorrect assembly during assembly. Further, at the time of replacement, it becomes a mark when folding by hitting with a hammer with a chisel or the like applied to the notch or V groove of the core material, and workability can be improved.

Preferably, as in the invention described in claim 3 , an annular stealing portion is formed at a corner between the annular step portion and a wall surface of the annular step portion, and the annular protrusion of the seal ring is elastic. If it is deformed and attached to the annular step portion and accommodated in the stealing portion, it is possible to prevent the seal ring from falling off the annular step portion and to ensure airtightness.

Further, as in the invention described in claim 4 , a cylindrical straight portion is formed on the outer diameter of the seal ring, the annular protrusion is formed from the straight portion, and the outer diameter of the straight portion is If the diameter is set to be slightly smaller than the inner diameter of the annular step portion, the seal ring can be prevented from being damaged when mounted on the annular step portion, and stable airtightness can be secured.

Further, as in the invention according to claim 5 , if the seal ring has an annular core, the rigidity of the seal ring is increased and the annular shape can be maintained. Can be secured to prevent slipping out. Also, when replacing, the seal ring can be easily removed from the annular step by applying a chisel to the core material and smashing it with a hammer, so that it does not degrade workability during disassembly. It is possible to prevent dropping from the stepped portion.

A wheel bearing device according to the present invention is fitted to an axle tube in which a drive shaft connected to a differential is inserted, and is fitted and fixed to an end step portion on the outer side of the axle tube, and the wheel is rotatably supported. A wheel bearing comprising a double row rolling bearing, the wheel bearing comprising an outer member integrally formed with an outer rolling surface of the double row on the inner periphery, and an outer rolling of the double row on the outer periphery. A pair of inner rings formed with an inner rolling surface facing the surface, and a double-row rolling element accommodated between the inner rings and the rolling surfaces of the outer member via a cage, A seal mounted in an opening of an annular space formed between the outer member and the inner ring, and an inner side end of the inner ring that abuts against a shoulder of the axle tube of the pair of inner rings. A full floating type with an annular step formed around the circumference and a seal ring attached to the annular step In the bearing device for a wheel-flop, a core material of the sealing ring is made of a resin annular integrally joined to this core, an elastic member having a shape having a thickness in either cross-sectional axis and the radial direction A notch or V-groove is formed on the surface of the core material on the circumference, and a notch or V-groove different from the notch is formed at the same position on the circumference of the core material. The elastic member has an annular protrusion formed on the outer diameter so as to protrude radially outward, and has protrusions formed on both ends so as to protrude in the axial direction and symmetrically. Is brought into contact with the wall surface of the annular step portion and the shoulder portion of the axle tube via a shimoshiro, so that the seal ring can be prevented from dropping from the annular step portion before assembly to the axle tube. The volume of the elastic member can be increased to the maximum, A fully floating type wheel bearing device that can prevent muddy water and diff oil from leaking, and prevent diff oil from entering the bearing. Can be provided. Further, since the seal ring has a symmetrical shape, it is possible to ensure the desired airtightness and improve the reliability even in the case of incorrect assembly during assembly. Furthermore, when replacing, the seal ring can be easily removed from the annular step by applying a chisel or the like to the notch or V groove of the core material and folding it with a hammer. Can be improved.
Further, a full floating type wheel bearing in which an annular step is formed on the inner periphery of the inner ring end that abuts the shoulder of the axle tube of the pair of inner rings, and a seal ring is attached to the annular step. In the apparatus, the seal ring is composed of an annular core material made of resin and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. A notch or V-groove is formed on the surface on the circumference, a part of the notch or V-groove is exposed from the elastic member, and the elastic member is formed to protrude radially outward to the outer diameter. In addition to the annular projections, both ends have projections that are axially projecting in the axial direction, and these projections are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a shimishiro Seal ring before assembling to the axle tube. Can be prevented from falling off the annular step portion, and the volume of the elastic member can be increased to the maximum, and the compressible range can be increased to ensure stable airtightness. In addition, it is possible to provide a fully floating type wheel bearing device that can prevent the differential oil from leaking and prevent the differential oil from entering the bearing. Further, since the seal ring has a symmetrical shape, it is possible to ensure the desired airtightness and improve the reliability even in the case of incorrect assembly during assembly. Further, at the time of replacement, it becomes a mark when folding by hitting with a hammer with a chisel or the like applied to the notch or V groove of the core material, and workability can be improved.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a longitudinal cross-sectional view which shows the wheel bearing of FIG. 2A is an enlarged view of a main part showing the outer seal of FIG. 2, FIG. 2B is an enlarged view of a main part showing the inner seal of FIG. 2, and FIG. 2C is the first seal of FIG. It is a principal part enlarged view which shows a ring. It is a principal part enlarged view which shows the 2nd seal ring of FIG. It is a principal part enlarged view which shows the modification of the 2nd seal ring of FIG. FIG. 10 is an enlarged view of a main part showing another modification of the second seal ring of FIG. 4. It is a principal part enlarged view which shows the modification of the 2nd seal ring of FIG. FIG. 10 is an enlarged view of a main part showing another modification of the second seal ring of FIG. 4. (A) is a front view which shows the metal core simple substance of FIG. 8, (b) is sectional drawing along the IX-O-IX line of (a). (A) is a front view showing a modified example of the cored bar of FIG. 9, (b) is a cross-sectional view taken along line XX in (a), and (c) is a perspective view of (a). It is. (A) is a front view showing another modification of the cored bar of FIG. 9, (b) is a cross-sectional view taken along line XI-O-XI of (a), and (c) is a diagram of (a). It is a rear view. (A) is a front view showing another modification of the cored bar of FIG. 9, (b) is a sectional view taken along line XII-O-XII of (a), and (c) is of (a). It is a rear view. (A) is a front view showing another modification of the cored bar of FIG. 9, (b) is a sectional view taken along line XIII-O-XIII of (a), and (c) is a sectional view of (a). It is a rear view. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is an enlarged view which shows the wheel bearing of FIG. It is an enlarged view which shows the 2nd seal ring of FIG.

  A hub wheel integrally having a wheel mounting flange for mounting a wheel, an axle tube that is externally fitted to a drive shaft, and a multi-piece that is rotatably inserted into an outer diameter step portion of the axle tube and rotatably supports the hub wheel. A wheel bearing comprising a row rolling bearing, the wheel bearing comprising an outer ring integrally formed with a double row outer rolling surface on the inner periphery, and an outer rolling surface of the double row on the outer periphery. A pair of inner rings formed with opposed inner rolling surfaces, a double row rolling element housed between the rolling surfaces of the inner ring and the outer ring via a cage, the outer ring and the inner ring And an annular stepped portion on the inner periphery of the inner side end of the inner ring that abuts with the shoulder of the axle tube of the pair of inner rings. Full floating type wheel that is formed and seal ring is attached to this annular step In the bearing device, the seal ring is formed from a synthetic rubber to have a substantially rectangular cross section, and has a cylindrical straight portion with an outer diameter and an annular protrusion formed to protrude radially outward from the straight portion. The projections protrude in the axial direction and have symmetrical projections, and these projections are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a predetermined squeeze.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, FIG. 2 is a longitudinal sectional view showing a wheel bearing of FIG. 1, and FIG. 3 (a) is an outer side of FIG. FIG. 4B is a main part enlarged view showing the seal on the inner side in FIG. 2, FIG. 4C is a main part enlarged view showing the first seal ring in FIG. FIG. 5 is an enlarged view of the main part showing the second seal ring of FIG. 2, FIG. 5 is an enlarged view of the main part showing a modification of the second seal ring of FIG. 4, and FIG. 6 is the second seal of FIG. FIG. 7 is an enlarged view of the main part showing another modification of the second seal ring in FIG. 5, and FIG. 8 is another view of the second seal ring in FIG. FIG. 9A is a front view showing the cored bar alone in FIG. 8, FIG. 9B is a sectional view taken along line IX-O-IX in FIG. (A) in FIG. Front view showing a modified example of gold, (b) is a sectional view taken along line X-O-X in (a), (c) is a perspective view of (a), and FIG. The front view which shows the other modification of 9 cored bar, (b) is sectional drawing along the XI-O-XI line of (a), (c) is a rear view of (a), FIG. a) is a front view showing another modified example of the cored bar of FIG. 9, (b) is a cross-sectional view taken along the line XII-O-XII of (a), and (c) is a rear view of (a). FIG. 13 (a) is a front view showing another modification of the cored bar of FIG. 9, (b) is a sectional view taken along line XIII-O-XIII in (a), and (c) is It is a rear view of (a). 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).

  In this wheel bearing device, a drive shaft 2 connected to a differential (not shown) is inserted into an axle tube 1, and a wheel bearing 3 is mounted on the outer diameter surface of the axle tube 1. The hub wheel 4 is rotatably supported by the wheel bearing 3. The hub wheel 4 is connected to the flange 6 of the drive shaft 2 via a hub bolt 5. The wheel bearing 3 is fitted in the hub wheel 4 and is fitted on the outer end of the axle tube 1, and both ends of the wheel bearing 3 are clamped between the flange 6 and the brake rotor 7. It is fixed by tightening.

  As shown in an enlarged view in FIG. 2, the wheel bearing 3 is an outer ring (outer member) in which tapered double-row outer rolling surfaces 9 a and 9 a that are outwardly opened on the inner circumference are integrally formed. 9 and a pair of inner races 10, 11 having outer circumferential surfaces 10a, 9a facing the double rows of outer races 9a and 9a formed on the outer periphery, and a cage 12 between the two raceways. And double-row tapered rollers 13 and 13 accommodated so as to roll freely. A large flange portion 10b for guiding the tapered roller 13 is formed on the large diameter side of the inner raceway surface 10a of the inner rings 10, 11, and a small flange for preventing the tapered roller 13 from dropping off on the small diameter side. Part 10c is formed. And it sets in the state in which the end surface by the side of the small collar part 10c of a pair of inner ring | wheels 10 and 11 was faced | matched, and comprises the back-to-back type wheel bearing 3. FIG. The pair of inner rings 10 and 11 basically have the same specifications, but the structures on the large diameter side of the inner rings 10 and 11 are different.

  Seals 14 and 15 are attached to the openings of the annular space formed between the outer ring 9 and the pair of inner rings 10 and 11, and the seal 14 prevents the differential oil from entering the bearing. This prevents leakage of the lubricating grease sealed inside the bearing and prevents rainwater and dust from entering the bearing from the outside.

  As shown in an enlarged view in FIG. 3A, the outer-side seal 14 includes a core metal 16 press-fitted into the inner periphery of the end of the outer ring 9, and a seal integrally joined to the core metal 16 by vulcanization adhesion. It is composed of an integrated seal composed of the member 17. The metal core 16 has a substantially L-shaped cross section formed by cold-working from a cold-rolled steel plate (JIS standard SPCC system or the like). On the other hand, the seal member 17 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and has bifurcated radial lips 17 a and 17 b that are in sliding contact with the outer diameter of the inner ring 10.

  On the other hand, as shown in an enlarged view in FIG. 3B, the inner-side seal 15 is a so-called annular seal plate 18 and slinger 19 which are formed in a substantially L-shaped cross section and are arranged to face each other. It constitutes a pack seal. The seal plate 18 includes a cored bar 20 that is press-fitted into the inner periphery of the end of the outer ring 9, and a seal member 21 that is integrally vulcanized and bonded to the cored bar 20. The core metal 20 has a substantially L-shaped cross section formed from a cold-rolled steel plate by pressing.

  The seal member 21 is made of a synthetic rubber such as NBR, and is formed with a pair of side lips 21a and 21b formed to be inclined outward in the radial direction, and inclined to the inner side of the bearing on the inner diameter side of the side lip 21b. And a grease lip 21c.

  The slinger 19 is formed into a substantially L-shaped section by press working from an austenitic stainless steel sheet (JIS standard SUS304 system, etc.) or a rust-proof cold rolled steel sheet, and is press-fitted into the outer diameter of the inner ring 11. The cylindrical portion 19a and a standing plate portion 19b extending radially outward from the cylindrical portion 19a. The pair of side lips 21a and 21b of the seal member 21 are in sliding contact with the upright plate portion 19b, and the grease lip 21c is in sliding contact with the cylindrical portion 19a. In addition, although the double row tapered roller bearing which used the tapered roller for the rolling element 13 was illustrated as the wheel bearing 3 here, it is comprised not only in this but the double row angular ball bearing which uses the ball for the rolling element. Also good.

  The outer ring 9, the inner rings 10, 11 and the tapered roller 13 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching. In addition, annular grooves 22 and 22 are formed at the small diameter side ends of the pair of inner rings 10 and 11, and a connecting ring 23 is attached to the annular grooves 22. As shown in an enlarged view in FIG. 3 (c), the connecting ring 23 is formed into a ring-shaped end as a whole by pressing a steel plate such as tool steel or spring steel into a substantially U-shaped cross section. The surface is subjected to curing treatment in the range of 40 to 55 HRC by tempering or quenching.

  Further, annular recesses 24 and 24 are respectively formed on the outer peripheral surfaces of the butted portions of the pair of inner rings 10 and 11, and the first seal ring 25 is mounted on the annular recesses 24 and 24 in a straddled state. The first seal ring 25 is formed by a core metal 26 and an elastic member 27. The cored bar 26 is formed from a cold-rolled steel plate by pressing to have a substantially L-shaped cross section, a cylindrical part 26a, a flange part 26b extending radially outward from one end of the cylindrical part 26a, and a cylindrical part It consists of a flange 26c extending radially inward from the other end of 26a. The inner diameter d2 of the flange portion 26c is set to be smaller than the outer diameter D2 of the small flange portion 10c of the inner ring 10 (d2 <D2).

  As a result, the rigidity of the cored bar 26 is increased, and it goes without saying that deformation during press-fitting can be suppressed. When the inner ring 11 on the inner side is press-fitted into the inner diameter of the first seal ring 25, Even if the center ring is misaligned with the inner ring 11 and the first seal ring 25 is pushed by the end face of the inner ring 11, the collar part 26c of the core metal 26 is securely attached to the small collar part 10c of the inner ring 10. As a result of the collision, positioning and fixing can be performed with high accuracy without causing a large positional shift, and the step of the annular recess 24 can be minimized.

  When the inner ring 11 on the inner side is press-fitted into the inner diameter of the first seal ring 25, grease, preferably the same grease as that filled in the bearing, is applied to the inner circumference of the first seal ring 25 in advance. Accordingly, it is possible to improve the insertability and to prevent displacement due to press-fitting. In the present embodiment, an example in which two annular ridges are provided as inner diameter protrusions is shown, but the present invention is not limited to two annular protrusions, and a plurality of inner diameter protrusions may be provided.

  The elastic member 27 is made of synthetic rubber such as NBR, and is integrally joined to the cored bar 26 by vulcanization adhesion. On the inner periphery of the elastic member 27, two annular ridges 27a and 27b are formed to straddle and abut on both sides of the butted portion, respectively, and a predetermined radial shimiro is applied to the outer peripheral surface of the annular recess 24. Through elastic contact. Thereby, sealing performance improves and it can prevent reliably that differential oil penetrate | invades into a bearing inside from the butt | matching part of a pair of inner rings 10 and 11. FIG. In addition to NBR, the elastic member 27 is made of, for example, HNBR (hydrogenated acrylonitrile-butadiene rubber), EPDM (ethylene / propylene rubber), ACM, FKM (fluoro rubber), etc. Or silicon rubber etc. can be illustrated. In particular, ACM, FKM, EPM, and silicone rubber, which are excellent in heat resistance and chemical resistance, are preferred for applications that contact this type of differential oil.

  Here, in the present embodiment, an annular step portion 28 is formed at the large-diameter side end portion of the inner ring 11 on the inner side, and a second seal ring 29 is attached (see FIG. 2). The second seal ring 29 is made of synthetic rubber such as NBR, and is attached to an annular space formed between the annular step portion 28 and the shoulder portion 1a of the axle tube 1 as shown in an enlarged view in FIG. A slight gap between the inner ring 11 and the axle tube 1 is blocked.

  The second seal ring 29 is formed from a synthetic rubber such as NBR with a substantially rectangular cross section, and is formed with a cylindrical straight portion 29a having an outer diameter and projecting radially outward from both ends of the straight portion 29a. It has a pair of annular protrusions 30, 30, and a protrusion 31 that is gradually reduced in diameter toward the central portion in the axial direction. Here, the “substantially rectangular cross section” means a shape having a certain thickness in both the axial direction and the radial direction, and becomes a rectangular shape when an external formation site such as a protrusion is not taken into consideration. Say. By making the cross section rectangular in this way, a certain elastic force can be applied both in the axial direction and in the radial direction.

  An annular stealing portion 28b is formed at the corner between the annular step portion 28 and the wall surface 28a, and the protrusion 30 on the outer side (the left side in the figure) of the pair of protrusions 30 and 30 is elastically deformed to form the annular step portion. 28 and is accommodated in the stealing portion 28b. The outer diameter of the straight portion 29a is set to be slightly smaller than the inner diameter of the annular step portion 28, and the outer diameter d3 of the second seal ring 29 is slightly larger than the inner diameter D3 of the annular step portion 28. (The diameter is 0.05 to 0.20 mm) (d3> D3), and the height of the protrusion 30 is set to 1 mm or more so as to surely prevent dropping. Thereby, it is possible to prevent the second seal ring 29 from falling off the annular step portion 28 before assembly to the axle tube 1.

  Further, the second seal ring 29 has left and right symmetrical protrusions 32 and 32 formed to protrude in the axial direction at both ends. These protrusions 32 and 32 are brought into contact with the wall surface 28a and the shoulder portion 1a of the annular step portion 28 through a predetermined shimiro, respectively. As a result, the volume of the elastic member can be maximized, the range of compressibility can be increased and stable airtightness can be secured, so that intrusion of muddy water and leakage of differential oil can be prevented, and It is possible to provide a fully floating type wheel bearing device that can prevent the infiltration of differential oil into the bearing. Further, in the present embodiment, since the second seal ring 29 is formed symmetrically only in the axial direction (left and right), the desired airtightness is ensured against the incorrect assembly during assembly and the reliability is improved. be able to. Here, the second seal ring 29 having the protrusions formed in the axial direction at both ends is only required to be formed symmetrically at least in the axial direction (left and right) in the seal cross-sectional shape. ) May be asymmetric. This is sufficient from the viewpoint of misassembly, and it is sufficient to have symmetry only in the axial direction, and the radially upward protrusion 30 is necessary to prevent the outer ring from falling off, but the downward protrusion 31 is This is because it is not essential from the viewpoint of the rigidity of the seal.

  As the material of the second seal ring 29, in addition to the exemplified NBR, for example, HNBR, EPDM, etc. excellent in heat resistance, ACM, FKM, silicon rubber, etc. can be exemplified. In particular, ACM, FKM, EPM, and silicone rubber, which are excellent in heat resistance and chemical resistance, are preferred for applications that contact this type of differential oil.

  The seal ring 33 shown in FIG. 5 is a modification of FIG. 4 and is basically the same as the above-described second part of the second seal ring 29 except that the same part or part having the same function is used. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  The second seal ring 33 attached to the annular step portion 28 is made of synthetic rubber such as NBR, is formed in a substantially rectangular cross section, and has an annular shape formed on the outer diameter so as to protrude radially outward from the central portion in the axial direction. It has a protrusion 34 and has a protrusion 31 that is gradually reduced in diameter toward the central portion in the axial direction. The protrusion 34 is elastically deformed and attached to the annular step portion 28, and is accommodated in the stealing portion 28b. The outer diameter d3 of the second seal ring 33 is set to be slightly larger than the inner diameter D3 of the annular step portion 28, and the height of the protrusion 34 is set to 1 mm or more, like the second seal ring 29 described above. Has been. This prevents the second seal ring 33 from falling off the annular step portion 28 before assembling to the axle tube 1 as in the above-described embodiment, and is also desirable for erroneous assembly during assembly. Airtightness can be ensured and reliability can be improved, and the number of forcibly removed portions from the mold can be reduced to improve releasability, and cost can be reduced by improving moldability.

  The seal ring 35 shown in FIG. 6 is another modification of FIG. 4 and is basically the same as the second seal ring 29 described above except for the presence or absence of a core material, and other parts having the same parts or the same functions. The same reference numerals are given to the parts and the detailed description thereof is omitted.

  The second seal ring 35 includes a core member 36 and an elastic member 37 that is integrally vulcanized and bonded to the core member 36 and made of synthetic rubber such as NBR. The elastic member 37 is formed in a substantially rectangular cross section, has a pair of annular protrusions 30 and 30 formed to protrude radially outward on the outer diameter, and protrusions 32 formed to protrude in the axial direction at both ends. 32.

  The cross section of the core material 36 is formed by press working from a cold rolled steel sheet or the like. The core material 36 may be made of a resin, for example, formed by injection molding a thermoplastic synthetic resin such as PA (polyamide) 66 filled with a fibrous reinforcing material such as GF (glass fiber). Also good. As a result, the rigidity of the second seal ring 35 is increased and the annular shape can be maintained, so that the protrusion 30 can be secured and the removal force can be improved. When a resin core material is used, the second seal ring 35 can be easily attached to the annular step portion 28 by applying a chisel or the like to the core material 36 and hitting it with a hammer to break (break) it at the time of replacement. Therefore, it is possible to improve the workability at the time of disassembling and prevent the annular stepped portion 28 from dropping off.

  The seal ring 38 shown in FIG. 7 is a modification of FIG. 5 and basically differs from the above-described second seal ring 33 only in the presence or absence of the core material, and other parts and parts having the same parts or the same functions. Are denoted by the same reference numerals, and detailed description thereof is omitted.

  The second seal ring 38 includes a core member 36 and an elastic member 39 that is integrally vulcanized and bonded to the core member 36 and made of synthetic rubber such as NBR. The elastic member 39 is made of synthetic rubber such as NBR, has a substantially rectangular cross section, and has an annular protrusion 34 that protrudes radially outward from the outer diameter. By adopting such a configuration, it is possible to improve the workability at the time of disassembly, prevent the drop from the annular step portion 28, and reduce the cost by improving the mold release property.

  Next, a modification of the second seal ring 29 of FIG. 4 is shown in FIG. This seal ring 40 is basically the same as the part or part having the same part or the same function except for the shape of a part of the second seal ring 29 and the presence or absence of the core material. Reference numerals are assigned and detailed description thereof is omitted.

  The seal ring 40 includes a cored bar (core material) 41 and an elastic member 42. The elastic member 42 is formed of a synthetic rubber such as NBR and has a substantially rectangular cross section, and is integrally joined so as to cover the outer diameter portion of the cored bar 41 by vulcanization adhesion. The elastic member 40 includes a cylindrical straight portion 42a having an outer diameter, and annular protrusions 42b formed to project radially outward from an end portion of the straight portion 42a. The ring-shaped projections 32 and 32 are in contact with the wall surface 28a and the shoulder portion 1a through a predetermined shimiro. The outer diameter d4 of the straight portion 42a is set to be slightly smaller than the inner diameter D3 of the annular step portion 28 (d4 <D3). Thereby, when attaching the 2nd seal ring 40 to the cyclic | annular step part 28, it can prevent that the elastic member 42 is damaged and can ensure the stable airtightness.

  On the other hand, the core metal 41 is formed into a disk shape by pressing from an austenitic stainless steel plate or a cold-rolled steel plate that has been rust-proofed, and as shown in FIGS. 9 (a) and 9 (b), A plurality of (in this case, four) cutout portions 41a are formed on the circumference. At the time of replacement, the second seal ring 40 can be easily removed from the annular step portion 28 by applying a chisel or the like to the notch 41a of the metal core 41 and hitting it with a hammer. In addition to improving the workability, it is possible to ensure the desired airtightness and to improve the reliability against misassembly during assembly. In addition, it is preferable that a part of the notch 41a is exposed from the elastic member 42 so as to become a mark when the metal core 41 is folded. In addition, here, the cored bar 41 provided with a plurality of notches 41a is illustrated as an example, but the present invention is not limited to this, and the notch 41a may be provided at one location. In addition, although the thing of the left-right asymmetric shape was shown here as a modification of embodiment of FIG. 4, a right-left symmetrical shape may be used like FIG.

  FIG. 10 shows a modification of the cored bar 41 of FIG. The core metal (core material) 43 is formed into a disk shape by press working from an austenitic stainless steel plate or a cold-rolled steel plate treated with rust, as shown in (a) to (c), Plural (here, four) V-grooves 43a are formed on the circumference equally. Thereby, without lowering the rigidity of the core metal 43, it is possible to easily fold it by hitting it with a hammer with a chisel or the like against the V groove 43a of the core metal 43 at the time of replacement.

  FIG. 11 shows another modification of the cored bar 41 of FIG. This metal core (core material) 44 is formed into a substantially L-shaped section by pressing from an austenitic stainless steel plate or a cold-rolled steel plate treated with rust, and is shown in (a) and (b). As described above, a plurality of (four in this case) notch portions 41a are arranged on the circumference equally, and another notch portion as shown in (c) is provided at another portion at the same position as the notch portion 41a. 44a is formed. Thereby, the intensity | strength difference in the circumferential direction can be made to the metal core 44, and it can make it easier to fold.

  FIG. 12 shows another modification of the cored bar 41 of FIG. This metal core (core material) 45 is formed into a substantially L-shaped section by press working from an austenitic stainless steel plate or a cold-rolled steel plate treated with rust, and is shown in (a) and (b). As described above, a plurality of (here, four) V-grooves 43a are equally arranged on the circumference, and notches 44a as shown in (c) are formed in other parts at the same position as the V-grooves 43a. ing. Thereby, the intensity | strength difference in the circumferential direction can be made to the metal core 45, and it can make it easier to fold.

  FIG. 13 shows another modification of the cored bar 41 of FIG. This metal core (core material) 46 is formed into a substantially L-shaped section by pressing from an austenitic stainless steel plate or a cold-rolled steel plate treated with rust, and is shown in (a) and (b). Thus, a plurality of (in this case, four) cutouts 41a and V-grooves 43a, and other parts at the same position as the cutouts 41a and V-grooves 43a are arranged on the circumference equally (c). A notch 44a is formed as shown in FIG. Thereby, the strength difference in the circumferential direction of the cored bar 46 can be increased, and the cored bar 46 can be more easily folded.

  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 full floating type wheel bearing device on the side of a driving wheel in which wheel bearings are mounted in openings of a driving shaft and an axle tube.

DESCRIPTION OF SYMBOLS 1 Axle tube 1a Shoulder part 2 Drive shaft 3 Wheel bearing 4 Hub wheel 5 Hub bolt 6 Flange 7 Brake rotor 8 Fixing nut 9 Outer member 9a Outer rolling surface 10 Outer side inner ring 11 Inner side inner ring 10a Inner rolling surface 10b Large collar part 10c Small collar part 12 Cage 13 Tapered roller 14 Outer side seal 15 Inner side seal 16, 20, 26 Core metal 17, 21 Seal member 17a, 17b Radial lip 18 Seal plate 19 Slinger 19a, 26a Cylindrical Part 19b Standing plate part 21a, 21b Side lip 21c Grease lip 22 Annular groove 23 Connecting ring 24 Annular recess 25 First seal ring 26b, 26c Ridge part 27, 37, 39, 42 Elastic member 27a, 27b Annular ridge 28 Annular Stepped portion 28a Wall surface 28b of annular stepped portion Ring-shaped stealing portion 29, 33, 35, 38, 40 Second Seal ring 29a, 42a Straight part 30, 31, 32, 34, 42b Protrusion 36, 41, 43, 44, 45, 46 Core material 41a, 44a Notch part 43a V groove 51 Axle tube 51a Shoulder part 52 Drive shaft 53 Wheel bearing 54 Hub wheel 55 Hub bolt 56 Flange 57, 58 Inner ring 57a Inner rolling surface 57b Large flange 57c Small flange 59 Fixed nut 60 Outer ring 60a Outer rolling surface 61 Brake rotor 62 Cage 63 Tapered rollers 64, 65 Seal 66 annular groove 67 connecting ring 68 annular recess 69 first seal ring 70 annular step 71 second seal ring 72 core metal 73 elastic member 73a lip 73b protrusion d1 outer diameter d2 of elastic member d3 inner diameter d3 second Seal ring outer diameter d4 Elastic member outer diameter D1, D3 Annular step inner diameter D2 Small collar outer diameter

Claims (5)

An axle tube in which a drive shaft connected to the differential is inserted;
A wheel bearing comprising a double row rolling bearing that is externally fitted and fixed to an end step portion on the outer side of the axle tube and rotatably supports the wheel;
This wheel bearing is an outer member in which a double row outer rolling surface is integrally formed on the inner periphery,
A pair of inner rings formed on the outer periphery with an inner rolling surface facing the double row outer rolling surface;
A double row rolling element housed between the inner ring and each rolling surface of the outer member via a cage to be freely rollable,
A seal attached to an opening of an annular space formed between the outer member and the inner ring,
A full floating type wheel bearing in which an annular step is formed on the inner periphery of the inner ring end that abuts the shoulder of the axle tube of the pair of inner rings, and a seal ring is attached to the annular step. In the device
The seal ring is composed of a resin-made annular core material and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. A notch or V groove is formed on the upper surface, and a notch or V groove different from the notch is formed at the same position on the circumference of the core material. While having an annular protrusion formed to protrude radially outward in the diameter,
Protrusions that protrude in the axial direction at both ends and are formed symmetrically are provided, and these protrusions are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a shimiro. Wheel bearing device. An axle tube in which a drive shaft connected to the differential is inserted;
A wheel bearing comprising a double row rolling bearing that is externally fitted and fixed to an end step portion on the outer side of the axle tube and rotatably supports the wheel;
This wheel bearing is an outer member in which a double row outer rolling surface is integrally formed on the inner periphery,
A pair of inner rings formed on the outer periphery with an inner rolling surface facing the double row outer rolling surface;
A double row rolling element housed between the inner ring and each rolling surface of the outer member via a cage to be freely rollable,
A seal attached to an opening of an annular space formed between the outer member and the inner ring,
A full floating type wheel bearing in which an annular step is formed on the inner periphery of the inner ring end that abuts the shoulder of the axle tube of the pair of inner rings, and a seal ring is attached to the annular step. In the device
The seal ring is composed of a resin-made annular core material and an elastic member that is integrally joined to the core material and has a thickness in both the axial direction and the radial direction. A notch or V-groove is formed on the upper surface, a part of the notch or V-groove is exposed from the elastic member, and the elastic member protrudes radially outward to the outer diameter. Having an annular protrusion formed,
Protrusions that protrude in the axial direction at both ends and are formed symmetrically are provided, and these protrusions are in contact with the wall surface of the annular stepped portion and the shoulder portion of the axle tube via a shimiro. Wheel bearing device. An annular stealing portion is formed at a corner between the annular step portion and a wall surface of the annular step portion, and an annular protrusion of the seal ring is elastically deformed and attached to the annular step portion, and the stealing portion a bearing device for a wheel according to claim 1 or 2 is housed in. A cylindrical straight portion is formed on the outer diameter of the seal ring, the annular protrusion is formed from the straight portion, and the outer diameter of the straight portion is set to be slightly smaller than the inner diameter of the annular step portion. The wheel bearing device according to any one of claims 1 to 3 . The wheel bearing device according to any one of claims 1 to 4, wherein the seal ring includes an annular core member.

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