JP2010025216A - Drive wheel supporting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a drive wheel supporting device capable of preventing slurry from intruding therein and differential oil from leaking, and preventing the differential oil from intruding into a bearing. <P>SOLUTION: In this drive wheel supporting device, an annular recess 24 is formed at each of a pair of inner rings 10, 11, a first seal ring 25 is fitted to the annular recess, an annular step 26 is formed at the end inner periphery of the inner ring 11 on the inner side, and a second seal ring 27 is fitted to the annular step. The first seal ring 25 includes a core 28 which is formed in a generally L-shape in cross section and has a cylindrical part 28a and a flange 28b extending radially outward and an elastic member 29 joined to the core 28. Two lines of annular ridges 29a, 29b brought into contact with both sides of the abutting portion of the pair of inner rings 10, 11 are formed at the inner periphery of the elastic member 29, respectively. The width dimension a of one annular ridge 29a is larger than the width dimension b of the other annular ridge 29b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive wheel support device that rotatably supports a drive wheel 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. 13 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 double row tapered roller bearing 53 is mounted on the outer diameter surface of the axle tube 51. . A hub wheel 54 rotatably supported by the double row tapered roller bearing 53 is connected to a flange 56 of the drive shaft 52 via a hub bolt 55. A pair of left and right inner rings 57 of the double-row tapered roller bearing 53 are coupled by a connecting ring 58 and are fitted on the end of the axle tube 51 and are fastened and fixed by a fixing nut 59. The outer ring 60 of the double-row tapered roller bearing 53 is fitted into the hub ring 54 and is fixed in the axial direction with both ends thereof being sandwiched between the flange 56 and the brake rotor 61. In the annular space between the inner and outer rings 57 and 60, double-row tapered rollers 62 are rotatably accommodated by a cage 63, and seals 64 and 64 'are attached to both ends to seal the bearing interior. .

As shown in FIG. 14, an annular step 65 is formed at the inner end of the inner ring 57, and a seal ring 66 made up of an O-ring as a second sealing ring is attached. The slight gap between the inner ring 57 and the axle tube 51 is blocked by contacting the angular radius of the shoulder 67 of the stepped portion of the outer diameter of the axle tube 51. This prevents infiltration of muddy water and leakage of differential oil from the slight gap. As shown in FIG. 15, an annular recess 68 is formed on the outer peripheral surface of the abutting portion of the pair of inner rings 57, 57, and a seal ring 69 as a first sealing ring is attached to the annular recess 68. The seal ring 69 is formed of a core metal 69a and an elastic member 69b, and two annular ridges 70 are formed on the inner periphery of the elastic member 69b so as to straddle both sides of the butted portion. ing. This prevents the differential oil from entering the bearing.
JP 2001-99172 A

  However, in such a conventional wheel bearing device, although the seal ring 66 as the second sealing ring is mounted on the annular step portion 65 of the inner ring 57, the positioning is not complete, and there is a possibility that the seal ring 66 may fall off when the bearing is conveyed. there were. On the other hand, a seal ring 69 as a first seal ring is mounted in an annular recess 68 formed on the outer peripheral surface of the butted portion of the pair of inner rings 57, 57, but the seal ring 69 is press-fitted into one inner ring 57. After that, the other inner ring 57 is press-fitted into the inner diameter of the seal ring 69, and therefore, when the axial centers of the seal ring 69 and the other inner ring 57 do not match, the seal ring 69 is pushed by the end face of the inner ring 57. Therefore, the position of the seal ring 69 may be shifted. In particular, the seal ring 69 has a problem in terms of reliability because it is difficult to confirm whether or not the seal ring 69 is mounted at a proper position after assembly.

  The present invention has been made in view of such conventional problems, and provides a drive wheel support device that can prevent the intrusion of muddy water and the leakage of differential oil, and can prevent the ingress of differential oil into the bearing. The purpose is to do.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes a hub wheel integrally having a wheel mounting flange for mounting a wheel, an axle tube externally fitted to a drive shaft, and the axle tube. And a wheel bearing comprising a double row rolling bearing that rotatably supports the hub wheel, and the wheel bearing has a double row outer rolling surface on the inner periphery. Is formed integrally with the outer ring, a pair of inner rings formed on the outer periphery with an inner rolling surface facing the outer rolling surface of the double row, and a cage is provided between the rolling surfaces of the inner ring and the outer ring. A plurality of rolling elements accommodated so as to be freely rollable, and a seal attached to an opening of an annular space formed between the outer ring and the inner ring, and an outer peripheral surface of the butted portion of the pair of inner rings An annular recess is formed, and a first seal ring is attached to the annular recess, In the driving wheel support device in which an annular step is formed on the inner periphery of the inner ring on the inner side of the pair of inner rings, and the second seal ring is attached to the annular step, the first seal ring includes: A metal core having a cylindrical portion and a flange portion extending radially outward from the cylindrical portion is integrally joined to the metal core by vulcanization bonding. And an elastic member made of synthetic rubber.

  As described above, an annular recess is formed on the outer peripheral surface of the abutting portion of the pair of inner rings, the first seal ring is mounted on the annular recess, and an annular step is formed on the inner periphery of the inner ring on the inner side of the pair of inner rings. In the drive wheel support device in which the second seal ring is mounted on the annular step portion, the first seal ring is formed into a substantially L-shaped cross section by pressing from a steel plate, and is cylindrical. And a cored bar having a flange extending radially outward from the cylindrical part, and an elastic member made of synthetic rubber integrally joined to the cored bar by vulcanization adhesion. By increasing the rigidity to suppress deformation during press-fitting and ensuring positioning accuracy, the reliability can be improved and the infiltration of differential oil into the bearing can be reliably prevented.

  Preferably, in the invention described in claim 2, if the annular protrusions straddling and abutting on both sides of the butted portions of the pair of inner rings are respectively formed on the inner periphery of the elastic member, The airtightness of the seal ring 1 can be improved.

  Further, as in the third aspect of the invention, if a means for generating a difference in fitting force is provided between the annular ridges, the first seal ring is previously press-fitted into the annular recess of one inner ring. Thereafter, when the other inner ring is press-fitted into the inner diameter of the first seal ring, the first seal ring will not be displaced due to this difference in fitting force, and positioning accuracy can be ensured.

  Moreover, like invention of Claim 4, the width dimension of one cyclic | annular ridge among the said cyclic | annular ridges may be set larger than the width dimension of the other cyclic | annular ridge.

  Moreover, like the invention of Claim 5, the protrusion amount of one annular protrusion may be set larger than the protrusion amount of the other annular protrusion among the said annular protrusions.

  Further, as in the invention described in claim 6, the outer diameter of the annular recess in one inner ring of the pair of inner rings may be set larger than the outer diameter of the annular recess in the other inner ring.

  According to a seventh aspect of the present invention, the metal core is a first cylindrical portion that is press-fitted into the annular concave portion of the inner ring, and a first cylindrical portion that is formed to have a slightly larger diameter from the first cylindrical portion. If the second cylindrical portion is provided, the rigidity of the core bar is secured to prevent deformation at the time of press-fitting, and the first seal ring is previously press-fitted into the annular recess of one inner ring, and then the first seal When the other inner ring is press-fitted into the inner diameter of the ring, the first seal ring is not displaced due to the difference in the fitting force.

  Further, as in the invention described in claim 8, if the annular ridges are further formed with annular ridges smaller than these annular ridges, the sealing performance of the first seal ring is improved, It is possible to reliably prevent the differential oil from entering the bearings from the butted portions of the pair of inner rings.

  As in the ninth aspect of the invention, if the inner diameter side thickness of the elastic member in the first seal ring is set smaller than the step of the annular recess, the first seal ring When the other inner ring is press-fitted into the inner diameter, even if there is a misalignment between the first seal ring and the inner ring and the first seal ring is pushed by the end face of the inner ring, Therefore, it can be positioned and fixed with high accuracy without causing a large displacement.

  Further, as in the invention described in claim 10, the core bar includes a flange portion extending radially inward from the cylindrical portion, and the inner diameter of the flange portion of the inner ring in which the annular recess is formed. If the outer diameter is set to be smaller than the outer diameter on the small diameter side, the rigidity of the core metal is further increased, so that deformation during press-fitting can be suppressed, and when the other inner ring is press-fitted into the inner diameter of the first seal ring, Even if there is a misalignment between the seal ring 1 and the inner ring and the first seal ring is pushed by the end face of the inner ring, the collar part of the core bar will securely collide with the annular recess of the inner ring. Therefore, positioning and fixing can be performed with high accuracy without causing a large positional shift.

  Further, as in the invention described in claim 11, the second seal ring includes a cored bar formed by pressing from a steel plate, and a synthetic rubber integrally joined to the cored bar by vulcanization adhesion The elastic member comprises a lip that abuts against the shoulder portion of the axle tube, an annular protrusion that protrudes radially on the outer diameter portion, and an annular protrusion that protrudes axially on the end portion. If the protrusions are formed and these protrusions are attached to the annular step portion in an elastically deformed state, the positioning can be accurately fixed, and the second seal ring can be loosened when the bearing is conveyed or assembled. Therefore, reliability can be improved.

  Further, as in a twelfth aspect of the present invention, the annular step portion of the inner ring includes a first annular step portion and a second annular step portion having a smaller diameter than the first annular step portion. In addition, the second seal ring is formed by pressing a steel plate with an outer diameter cylindrical portion, a flange portion extending radially inward from the outer diameter cylindrical portion, and an inner diameter extending from the flange portion toward the bearing inward side. A metal core formed in a substantially crank shape in cross section having a cylindrical portion, and an elastic member comprising a synthetic rubber integrally joined to the metal core by vulcanization adhesion, and having a lip that contacts the shoulder portion of the axle tube; If the inner diameter cylindrical portion of the second seal ring is attached to the second annular step portion, the hermeticity is improved, and the second seal ring is used at the time of bearing transportation, assembly, and the like. It does not wobble and can improve reliability.

  The drive wheel support device according to the present invention is inserted into a hub wheel integrally having a wheel mounting flange for mounting a wheel, an axle tube externally fitted to the drive shaft, and an outer diameter step portion of the axle tube, A wheel bearing comprising a double row rolling bearing that rotatably supports the hub wheel, and the wheel bearing comprises an outer ring having an inner periphery integrally formed with a double row outer rolling surface, and an outer periphery. A pair of inner races formed with inner raceways facing the outer raceway surfaces of the double row, and a plurality of inner races that are rotatably accommodated between the raceways of the inner race and the outer race via a cage. A ring-shaped rolling element, and a seal attached to an opening of an annular space formed between the outer ring and the inner ring. And a first seal ring is attached to the inner ring of the pair of inner rings. In the drive wheel support device in which an annular step portion is formed on the inner periphery of the end portion of the inner ring, and the second seal ring is mounted on the annular step portion, the first seal ring has a cross section formed by pressing from a steel plate. Is formed in a substantially L-shape, and has a cylindrical part and a core part extending radially outward from the cylindrical part, and an elastic member made of a synthetic rubber integrally joined to the core part by vulcanization adhesion, Therefore, it is possible to improve the reliability by increasing the rigidity of the core bar to suppress the deformation at the time of press-fitting and ensuring the positioning accuracy, and to surely prevent the diff oil from entering the bearing. .

  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 recess formed in the outer peripheral surface of the abutting portion of the pair of inner rings, and the first seal ring is attached to the annular recess. In addition, an annular stepped portion is provided on the inner periphery of the inner ring on the inner side of the pair of inner rings. In the drive wheel support device, the second seal ring is mounted on the annular step portion, and the first seal ring is formed in a substantially L-shaped section by pressing from a steel plate, and the cylindrical portion And a cored bar having a flange extending radially outward from the cylindrical part, and an elastic member made of synthetic rubber integrally joined to the cored bar by vulcanization adhesion, Two annular ridges straddling and abutting on both sides of the butted portions of the pair of inner rings are formed on the circumference, and the width dimension of one of the annular ridges is the other annular shape. It is set larger than the width dimension of the ridge.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a drive wheel support device according to the present invention, FIG. 2 is a longitudinal sectional view showing a bearing for the wheel, and FIG. 4 is an enlarged view of a main part showing a modified example of the first seal ring of FIG. 3, FIG. 5 is an enlarged view of a main part showing another modified example of FIG. 3, and FIG. FIG. 7 is an enlarged view of a main part showing another modification of the first seal ring shown in FIG. 3, and FIG. 8 is another view of the first seal ring shown in FIG. FIG. 9 is an enlarged view of a main part showing a portion B of FIG. 2, FIG. 10 is an enlarged view of a main part showing a modified example of the second seal ring of FIG. 9, and FIG. FIG. 12 is an enlarged view of a main part showing another modification of the second seal ring of FIG. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  In this drive wheel support device, a drive shaft 2 connected to a differential (not shown) is inserted into an axle tube 1, and a double row tapered roller bearing 3 is mounted on the outer diameter surface of the axle tube 1. . A hub wheel 4 rotatably supported by the double row tapered roller bearing 3 is connected to a flange 6 of the drive shaft 2 via a hub bolt 5. The double-row tapered roller bearing 3 is fitted in the hub wheel 4 and is fitted on the outer end of the axle tube 1, and both ends thereof are clamped between the flange 6 and the brake rotor 7, and the fixing nut 8. It is fixed by tightening.

  As shown in FIG. 2, the double-row tapered roller bearing 3 includes an outer ring 9 integrally formed with tapered double-row outer rolling surfaces 9a and 9a that are outwardly opened on the inner circumference, and an outer ring 9 on the outer circumference. A pair of inner rings 10 and 11 formed with tapered inner rolling surfaces 10a facing the double-row outer rolling surfaces 9a and 9a, and a roller 12 between the rolling surfaces so as to be freely rollable. The double row tapered rollers 13 and 13 are accommodated. 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 where the small diameter side end surfaces of a pair of inner rings 10 and 11 were abutted, and it constitutes what is called a back-to-back type double row tapered roller bearing. 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.

  The outer-side seal 14 is constituted by an integral seal composed of a core metal 16 press-fitted into the inner periphery of the end of the outer ring 9 and a seal member 17 integrally joined to the core metal 16 by vulcanization adhesion. . The seal member 17 is made of a synthetic rubber such as ACM (polyacrylic rubber) or 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. The metal core 16 has a substantially L-shaped cross-section by pressing from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). Is formed.

  The inner-side seal 15 forms a so-called pack seal including an annular seal plate 18 and a slinger 19 which are formed in a substantially L-shaped cross section and are arranged to face each other. 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 metal core 20 is substantially L-shaped in cross section by pressing from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). Is formed.

  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.

  Slinger 19 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.). A cylindrical portion 19a that is formed and press-fitted into the outer diameter of the inner ring 11 and a standing plate portion 19b that extends 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.

  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. Annular grooves 22, 22 are formed at the small diameter side ends of the pair of inner rings 10, 11, and a connecting ring 23 is attached to the annular grooves 22. This connecting ring 23 is formed into a generally ring-shaped ring shape by pressing a steel plate such as tool steel or spring steel, as a whole in a ring shape with a cross-section, and the surface is tempered or quenched to a range of 40 to 55 HRC. A curing process is applied. Here, a double-row tapered roller bearing using a tapered roller as a rolling element has been illustrated, but the present invention is not limited to this, and a double-row angular ball bearing using a ball as the rolling element may be used.

  Here, in the present embodiment, an annular recess 24 is formed on the outer peripheral surfaces of the butted portions of the pair of inner rings 10 and 11, and a first seal ring 25 is attached to the annular recess 24. An annular step 26 is formed at the large-diameter end of the inner ring 11 on the inner side, and a second seal ring 27 is attached.

  As shown in an enlarged view in FIG. 3, the first seal ring 25 is formed of a core metal 28 and an elastic member 29. The first seal ring 25 straddles and abuts on both sides of the butted portion on the inner periphery of the elastic member 29. Two annular ridges 29a and 29b are respectively formed. The core 28 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.). And is formed of a cylindrical portion 28a and a flange portion 28b extending radially outward from the cylindrical portion 28a. Thereby, while ensuring the rigidity of the metal core 28, it is possible to prevent deformation at the time of press-fitting and to secure desired accuracy such as roundness. 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 29 is made of synthetic rubber such as NBR and is integrally joined to the cored bar 28 by vulcanization adhesion. Of the annular ridges 29a and 29b, the width dimension a of the outer-side annular ridge 29a is set larger than the width dimension b of the inner-side annular ridge 29b (a> b). Thereby, a difference in fitting force occurs between the annular ridges 29a and 29b, and the positioning accuracy can be ensured. That is, there is a difference in the fitting force when the inner ring 11 is press-fitted into the inner diameter of the first seal ring 25 after the first seal ring 25 is press-fitted into the annular recess 24 of the outer ring 10 in advance. The first seal ring 25 is not displaced by this press-fitting. That is, due to the difference in fitting force, the left end surface of the seal ring 25 does not contact the stepped portion of the inner ring 10 during assembly (FIG. 3). Instead of positioning the seal ring 25 against the stepped portion when the seal ring 25 is press-fitted into the inner ring 10, the seal ring 25 is positioned with the positioning jig so that the small-diameter side end surface of the inner ring 10 and the right end surface of the seal ring 25 are positioned. Damage or deformation of the ring 25 can be prevented.

  Further, the thickness c on the inner diameter side of the elastic member 29 in the first seal ring 25 is set smaller than the step d of the annular recess 24 of the pair of inner rings 10 and 11 (c <d). Thereby, when the inner ring 11 on the inner side is press-fitted into the inner diameter of the first seal ring 25, there is a misalignment between the first seal ring 25 and the inner ring 11, and the first seal ring is formed by the end surface of the inner ring 11. 25, the cored bar 28, which is more rigid than the elastic member 29, abuts the annular recess 24 of the inner ring 10, so that a large positional shift does not occur. By adopting such a configuration, it is possible to reliably prevent the differential oil from entering the bearings from the butted portions of the pair of inner rings 10 and 11. In addition to NBR, the elastic member 29 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.

  A first seal ring 30 shown in FIG. 4 shows a modification of FIG. The first seal ring 30 basically differs from the first seal ring 25 described above only in the configuration of the annular ridges of the elastic member, and has the same components and the same function as the above-described embodiment. The same reference numerals are given to the parts and the detailed description thereof is omitted.

  The first seal ring 30 is formed by a cored bar 28 and an elastic member 31, and two annular convex ridges 31 a that straddle and abut both sides of the butted portion on the inner periphery of the elastic member 31. , 31b are formed. The elastic member 31 is made of synthetic rubber such as ACM and is integrally joined to the cored bar 28 by vulcanization adhesion. The protrusion amount e of the annular protrusion 31a on the outer side of the annular protrusions 31a and 31b is set larger than the protrusion amount f of the annular protrusion 31b on the inner side (e> f). Thereby, a difference in fitting force is further generated between the annular ridges 31a and 31b, and positioning accuracy can be further ensured.

  The embodiment shown in FIG. 5 is another modification of FIG. 3 and basically differs only in the configuration of the annular recess of the inner ring. Are given the same reference numerals and their detailed description is omitted.

  In the present embodiment, annular recesses 24 and 24 ′ are formed on the outer peripheral surfaces of the butted portions of the pair of inner rings 10 and 11 ′, and a first seal ring 25 is attached to the annular recesses 24 and 24 ′. The protrusions of the annular ridges 29a and 29b are the same, but the outer diameter D1o of the annular recess 24 in the inner ring 10 on the outer side is larger than the outer diameter D1i of the annular recess 24 'in the inner ring 11' on the inner side. The large diameter is set by the difference g (radius) (D1o> D1i). Thereby, a difference in fitting force is further generated between the annular ridges 29a and 29b, and the positioning accuracy can be further ensured.

  The embodiment shown in FIG. 6 is another modification. Annular recesses 24a and 24 are formed on the outer peripheral surfaces of the butted portions of the pair of inner rings 10 'and 11, respectively, and a first seal ring 32 is attached to the annular recesses 24a and 24.

  The first seal ring 32 is formed of a core metal 33 and an elastic member 34, and two annular convex ridges 34a that straddle and abut on both sides of the butted portion on the inner periphery of the elastic member 34, 34b is formed. The metal core 33 has a substantially L-shaped cross section by pressing from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). A first cylindrical portion 33a that is press-fitted into the annular recess 24a of the inner ring 10 ', a second cylindrical portion 33b that has a slightly larger diameter than the first cylindrical portion 33a, and a second And a flange portion 28b extending radially outward from the cylindrical portion 33b. Thereby, the rigidity of the cored bar 33 can be secured to suppress deformation during press-fitting, and desired accuracy such as roundness can be secured.

  On the other hand, the elastic member 34 is made of synthetic rubber such as ACM, and is integrally joined from the second cylindrical portion 33b of the cored bar 33 to the flange portion 28b by vulcanization adhesion. The annular ridges 34a and 34b have the same width dimension and protrusion amount. In this embodiment, since the metal core 33 is metal-fitted into the annular recess 24a of the outer side inner ring 10 ′, the first seal ring 32 is previously press-fitted into the annular recess 24a of the outer side inner ring 10 ′. Since a difference occurs in the fitting force when the inner ring 11 on the inner side is press-fitted into the inner diameter of the first seal ring 32, the first seal ring 32 can be prevented from being displaced due to the press-fitting.

  A first seal ring 35 shown in FIG. 7 shows another modification of FIG. The first seal ring 35 basically differs from the first seal ring 25 described above only in the configuration of the cored bar. The same reference numerals are assigned and detailed description thereof is omitted.

  The first seal ring 35 is formed of a cored bar 36 and an elastic member 29, and two annular convex ridges 29a that straddle and abut both sides of the butted portion on the inner periphery of the elastic member 29. 29b are formed. The metal core 36 has a substantially L-shaped cross section by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). And is formed of a cylindrical portion 28a, a flange portion 28b extending radially outward from the cylindrical portion 28a, and a flange portion 36a extending radially inward from the cylindrical portion 28a. The inner diameter d2 of the flange portion 36a is set to be smaller than the outer diameter D2o on the small end side of the inner ring 10 (d2 <D2o).

  As a result, the rigidity of the cored bar 36 is further increased and it is possible to suppress deformation during press-fitting. Of course, when the inner ring 11 on the inner side is press-fitted into the inner diameter of the first seal ring 35, the first seal ring 35 is pressed. Even if there is a misalignment between the inner ring 11 and the inner ring 11 and the end face of the inner ring 11 pushes the first seal ring 35, the flange portion 36 a of the core metal 36 is surely inserted into the annular recess 24 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 35, grease, preferably the same grease as that filled in the bearing, is applied to the inner circumference of the first seal ring 35 in advance. Accordingly, it is possible to improve the insertability and to prevent displacement due to press-fitting.

  A first seal ring 37 shown in FIG. 8 shows a modification of FIG. The first seal ring 37 is basically different from the first seal ring 35 described above only in the configuration of the elastic member. The first seal ring 37 has the same parts or the same functions as those of the embodiment described above. The same reference numerals are assigned and detailed description thereof is omitted.

  The elastic member 38 of the first seal ring 37 is integrally joined to the metal core 36 by vulcanization adhesion, and the inner periphery of the elastic member 38 has two strips that straddle both sides of the butted portion. Annular ridges 29a and 29b, and annular ridges 38a and 38b are formed on the annular ridges 29a and 29b, respectively. Thereby, the sealing performance of the first seal ring 37 is improved, and it is possible to reliably prevent the diff oil from entering the bearings from the butted portions of the pair of inner rings 10 and 11.

  That is, since this type of first seal ring 37 is used for a wheel bearing of a vehicle having a large axial load such as a truck, the outer diameter is larger than that of a normal passenger car system seal ring (φ70 or more). Therefore, even if the shape of the cored bar 36 is devised to achieve high rigidity, it is difficult to ensure accuracy such as roundness after press-fitting, and the first seal ring 37 itself may be elliptical. In this case, it is assumed that it is impossible to secure an appropriate squeeze by the annular ridges 29a and 29b of the elastic member 38. Here, it is conceivable to set the shimiro of the annular ridges 29a and 29b to be large. However, in this case, a portion where the shimeshio is excessive occurs, not only the workability of the press-fitting process is deteriorated, but also the annular ridges 29a. 29b may be damaged. As in the present embodiment, the smaller annular ridges 38a and 38b are formed on the annular ridges 29a and 29b, so that such problems can be avoided and the first seal ring 37 after press-fitting can be avoided. Even when the roundness is poor, an appropriate squeeze can be secured by these small annular ridges 38a and 38b, and therefore a desired sealing property can be secured.

  Next, the second seal ring 27 attached to the annular step portion 26 formed at the large diameter side end portion of the inner side inner ring 11 will be described. As shown in an enlarged view in FIG. 9, the second seal ring 27 is formed of a cored bar 39 and an elastic member 40, and the elastic member 40 is brought into contact with the shoulder portion 1 a of the axle tube 1, and the inner ring 11. And a small gap between the axle tube 1 is blocked.

  The core bar 39 is substantially L-shaped in 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. On the other hand, the elastic member 40 is made of synthetic rubber such as ACM, and is integrally joined so as to cover the outer diameter portion of the cored bar 39 by vulcanization adhesion, and is attached to a shoulder portion 1a formed in an arc shape through a predetermined shimiro. It has a lip 40a that abuts. The outer diameter d3 of the elastic member 40 is set to be slightly smaller than the inner diameter D3i of the annular step portion 26 (d3 <D3i), and an annular protrusion 40b is formed at the end. And it mounts | wears with the cyclic | annular step part 26 in the state which elastically deformed this protrusion 40b. Thereby, when the 2nd seal ring 27 is press-fit in the annular step part 26, it can prevent that the elastic member 40 is damaged and can ensure the stable airtightness.

  The second seal ring 41 shown in FIG. 10 is a modification of FIG. 9 and is basically different in the shape of a part of the elastic member. The same reference numerals are assigned and detailed description thereof is omitted.

  The second seal ring 41 is formed of a cored bar 39 and an elastic member 42. The elastic member 42 has a lip 40a that contacts the shoulder 1a of the axle tube 1 and a protrusion 40b on the outer diameter portion. ing. Further, an annular protrusion 42 a is formed on the end portion of the elastic member 42 so as to protrude in the axial direction, and is mounted on the wall surface of the annular step portion 26 in an elastically deformed state. The protrusion 40b of the outer diameter portion is set to have a protrusion amount h1 of 0.5 mm or less in order to prevent damage during press-fitting. Further, the protrusion amount h2 of the protrusion 42a at the end is set to be larger than the difference between the width L1 of the bump 26a of the annular step portion 26 and the width L2 of the protrusion 40b of the outer diameter portion (h2 ≧ L1). -L2). As a result, the positioning and fixing can be performed accurately, and the second seal ring 41 does not wobble at the time of bearing conveyance, assembly, or the like, and the reliability can be improved.

  A second seal ring 43 shown in FIG. 11 is another modification of FIG. 9 and is formed of a core metal 44 and an elastic member 45. The core 44 has a substantially L-shaped cross section by pressing from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). And a cylindrical portion 44a that is press-fitted into the annular step portion 26, and an inner diameter portion 44b that extends radially inward from the cylindrical portion 44a.

  The elastic member 45 integrally has a lip 45a that is in contact with the shoulder portion 1a of the axle tube 1, and the end of the cylindrical portion 44a of the cored bar 44 is reduced in diameter so that a part of the elastic member 45 wraps around. The fitting part 45b is formed by vulcanization adhesion. By this fitting portion 45b and the cylindrical portion 44a of the cored bar 44, the second seal ring 43 can be accurately positioned and fixed with respect to the annular step portion 26, and the airtightness is improved. For example, the second seal ring 43 does not wobble, and the reliability can be improved.

  A second seal ring 46 shown in FIG. 12 is another modification of FIG. 9 and is formed of a core metal 47 and an elastic member 48. A first annular step portion 49 and a second annular step portion 50 having a smaller diameter than the first annular step portion 49 are formed at the large-diameter side end portion of the inner ring 11 ″. A second seal ring 46 is attached to 50. Note that the core metal of the second seal ring 46 in FIG.

  The core metal 47 of the second seal ring 46 can be pressed from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). The cross section is formed in a substantially crank shape, the outer diameter cylindrical portion 47a, the flange portion 47b extending radially inward from the outer diameter cylindrical portion 47a, and the inner diameter cylinder portion 47c extending from the flange portion 47b to the bearing inward side. have.

  On the other hand, the elastic member 48 is made of a synthetic rubber such as ACM, and is integrally joined so as to cover the entire surface of the cored bar 47 by vulcanization adhesion, and comes into contact with the shoulder portion 1a formed in an arc shape through a predetermined shimiro. The lip 48a and the fitting part 48b press-fitted into the second annular step part 50 are integrally provided. By adopting such a configuration, the hermeticity is further improved, and the second seal ring 46 does not wobble at the time of bearing conveyance, assembly, or the like, and the reliability can be improved.

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

  The 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.

It is a longitudinal cross-sectional view which shows one Embodiment of the driving wheel support apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the wheel bearing of FIG. It is a principal part enlarged view which shows the A section of FIG. It is a principal part enlarged view which shows the modification of the 1st seal ring shown in FIG. FIG. 9 is an enlarged view of a main part showing another modification of FIG. 3. It is a principal part enlarged view which shows another modification same as the above. It is a principal part enlarged view which shows the other modification of the 1st seal ring shown in FIG. It is a principal part enlarged view which shows the other modification of the 1st seal ring shown in FIG. It is a principal part enlarged view which shows the B section of FIG. It is a principal part enlarged view which shows the modification of the 2nd seal ring of FIG. It is a principal part enlarged view which shows the other modification of the 2nd seal ring of FIG. FIG. 10 is an enlarged view of the main part showing another modification of the second seal ring of FIG. It is a longitudinal cross-sectional view which shows the conventional drive wheel support apparatus. It is a principal part enlarged view which shows the 2nd sealing ring of FIG. It is a principal part enlarged view which shows the 1st sealing ring of FIG. 13 same as the above.

Explanation of symbols

1 ... Axle tube 1a ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Drive shaft 3・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double-row tapered roller bearing 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheel 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub bolt 6・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Flange 7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Brake rotor 8 ... Fixing nut 9 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Outer ring 9a ......... Outer rolling surface 10, 10 '... .......... Outer side inner ring 11, 11 ', 11 "... Inner ring 10a on the inner side ... inner rolling surface 10b ... ············································ ......・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Conical roller 14 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outer seal 15 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal on inner side 16, 20, 28, 33, 36, 39, 44, 47 ・ ・ ・ ・ ・ ・ ・ ・ ・ Core Gold 17, 21 ... Sealing member 18 ... ································································· Slinger 19a, 28a, 44a ... ················ Cylindrical portion 19b , 21b ..... side lip 21c ... Grease lip 22 ... .... Annular groove 23 ... Connecting rings 24, 24 ', 24a ... ····················································· 1・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Annular step 26a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Nusumi part 27, 41, 43, 46 ... Second seal ring 28b, 36a, 47b ... ......... 29, 31, 34, 38, 40, 42, 45, 48 ... ... Elastic members 29a, 29b, 31a, 31b, 34a, 34b, 38a, 38b ・ ・ annular ridge 33a ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ First cylindrical part 33b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・Second cylindrical portion 40a, 45a, 48a ... Lip 40b, 42a ...・ ・ ・ ・ ・ ・ Projection 44b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner diameter part 45b, 48b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・························· Fitting part 47a・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner cylindrical part 49 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ First annular step 50 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ second annular Part 51 ... Axle tube 52 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Drive shaft 53 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Double row tapered roller bearing 54 ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub Wheel 55 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Hub bolt 56 ... Flange 57 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 58 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Connecting ring 59 ... Fixing nut 60 ... ... ... outer ring 61 ... brake rotor 62 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Taper roller 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 64 , 64 '.................. Seal 65 ...・ ・ ・ ・ ・ ・ ・ Ring step part 66, 69 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal ring 67 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 68 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ annular Recessed portion 69a ......... Core metal 69b ...・ ・······· Elastic member 70 ·······························・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Width dimension c of the annular ridge ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Thickness d of elastic member ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Projection amount of annular ridge g ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Diameter difference d2 of outer diameter of annular recess ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Core Inner diameter d3 of the gold collar ........................... The outer diameters D1i and D1o of the elastic members ... · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner diameter h1, h2 of the annular step ... Projection amount L1・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Width of protrusion

Claims (12)

A hub wheel integrally having a wheel mounting flange for mounting a wheel; an axle tube externally fitted to the drive shaft;
A wheel bearing comprising a double row rolling bearing that is fitted into the outer diameter step portion of the axle tube and rotatably supports the hub wheel,
This wheel bearing has an outer ring 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 rolling surfaces of the inner ring and the outer ring via a cage;
A seal attached to an opening of an annular space formed between the outer ring and the inner ring,
An annular recess is formed on the outer peripheral surface of the butted portion of the pair of inner rings, and a first seal ring is attached to the annular recess,
In the drive wheel support device in which an annular step is formed on the inner periphery of the inner ring on the inner side of the pair of inner rings, and a second seal ring is attached to the annular step.
The first seal ring is formed by pressing a steel plate into a substantially L-shaped cross section, and has a cylindrical part and a core part having a cylindrical part extending radially outward from the cylindrical part. A drive wheel support device comprising: an elastic member made of synthetic rubber joined together by vulcanization adhesion.   2. The drive wheel support device according to claim 1, wherein annular ridges are formed on the inner circumference of the elastic member so as to straddle and abut on both sides of the butted portions of the pair of inner rings.   The drive wheel support device according to claim 1, wherein means for generating a difference in fitting force is provided between the annular ridges.   The drive wheel support device according to claim 3, wherein a width dimension of one of the annular ridges is set larger than a width dimension of the other annular ridge.   The drive wheel support device according to claim 3, wherein a protrusion amount of one annular protrusion among the annular protrusions is set larger than a protrusion amount of the other annular protrusion.   The drive wheel support device according to claim 3, wherein an outer diameter of an annular recess in one inner ring of the pair of inner rings is set to be larger than an outer diameter of the annular recess in the other inner ring.   The said metal core is provided with the 1st cylindrical part press-fit in the cyclic | annular recessed part of the said inner ring | wheel, and the 2nd cylindrical part formed in the slightly large diameter from this 1st cylindrical part. The drive wheel support device described.   The drive wheel support device according to any one of claims 1 to 7, wherein an annular ridge smaller than these annular ridges is formed on the annular ridge.   9. The drive wheel support device according to claim 1, wherein a thickness of an elastic member on an inner diameter side of the first seal ring is set to be smaller than a step of the annular recess.   The core bar includes a flange portion extending radially inward from the cylindrical portion, and the inner diameter of the flange portion is set to be smaller than the outer diameter on the small diameter side of the inner ring in which the annular recess is formed. The drive wheel support device according to any one of claims 1 to 6 and 8.   The second seal ring is formed of a cored bar formed by pressing from a steel plate and an elastic member made of synthetic rubber integrally joined to the cored bar by vulcanization adhesion. A lip that contacts the shoulder of the axle tube, an annular protrusion that protrudes radially on the outer diameter part, and an annular protrusion that protrudes axially on the end part, and these protrusions are formed on the annular step. The drive wheel support device according to claim 1, wherein the drive wheel support device is mounted in an elastically deformed state on the part.   The annular step portion of the inner ring is composed of a first annular step portion and a second annular step portion having a smaller diameter than the first annular step portion, and the second seal ring is made of steel plate. It was formed into a substantially crank shape in cross section having an outer diameter cylindrical portion, a flange extending radially inward from the outer diameter cylindrical portion, and an inner diameter cylindrical portion extending from the flange toward the bearing inward by pressing. It is composed of a mandrel and an elastic member made of synthetic rubber integrally joined to the mandrel by vulcanization and having a lip that contacts the shoulder of the axle tube. The drive wheel support device according to any one of claims 1 to 10, wherein an inner diameter cylindrical portion of the second seal ring is mounted.

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