JP2017144984A - Bearing device for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing device for a wheel configured so that precompression of a bearing structure does not vary regardless of a difference in fastening force.SOLUTION: In a bearing device 1 for a wheel, in which a mounting hole of a universal joint is formed in a hub wheel 4 and an inner-side end part of the hub wheel 4 is folded back to outside in a radial direction to caulk an inner wheel 5, a large diameter hole part 4k leading to the mounting hole of the universal joint is formed on the inner-side end surface of the hub wheel 4, and the hub wheel 4 is fastened to the universal joint 12 in a state where a face spline 4s formed on a bottom surface 4m of the large diameter hole part 4k is fitted to a face spline 12s formed on an end surface 12m of an enclosure 12k constituting the universal joint 12.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a wheel bearing device. Specifically, the present invention relates to a wheel bearing device in which the preload of the rolling bearing structure does not change regardless of the difference in fastening force.

  2. Description of the Related Art Conventionally, a wheel bearing device that rotatably supports a wheel in a suspension device such as an automobile is known. In the wheel bearing device, an outer member is fixed to a knuckle constituting the suspension device. Further, in the wheel bearing device, a double row rolling element is interposed inside the outer member, and the inner member is supported by the rolling element. In this way, the wheel bearing device constitutes a rolling bearing structure, and the wheel attached to the inner member is rotatable.

  By the way, the wheel bearing device has a specification in which a universal joint is fitted to the center of the inner member and the universal joint is fastened with a bolt so that the wheel can be driven (wheel for driving wheel). Bearing device). In such a wheel bearing device, the inner member is composed of a hub wheel and an inner ring fitted to a small-diameter step portion of the hub wheel, and the inner end of the hub wheel is bent radially outward. In some cases, the inner ring is caulked (see, for example, Patent Document 1). Then, when the face spline formed on the caulking portion and the face spline formed on the universal joint are fitted like the wheel bearing device described in Patent Document 1, the caulking portion is deformed according to the fastening force of the bolt. However, there is a problem that the amount of bearing clearance changes due to the displacement of the inner ring. That is, there is a problem that the preload of the rolling bearing structure (the load applied in advance to the bearing structure so that the bearing gap is zero or less) changes according to the difference in the fastening force.

JP 2012-96749 A

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a wheel bearing device in which the preload of the bearing structure does not change regardless of the difference in fastening force.

  That is, the present invention integrally has an outer member in which a double row outer rolling surface is integrally formed on the inner periphery and a wheel mounting flange for mounting the wheel, and a small diameter step portion extending in the axial direction on the outer periphery. And at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and a double-row inner rolling surface facing the double-row outer rolling surface is formed on the outer periphery. An inner member, and a double-row rolling element interposed between the rolling surfaces of the outer member and the inner member so as to freely roll, and a universal joint mounting hole is formed in the hub wheel. In a wheel bearing device, wherein the inner side end of the hub wheel is bent radially outward to caulk the inner ring, the large diameter connected to the universal joint mounting hole on the inner side end surface of the hub ring. A hole is formed on the bottom surface of the large-diameter hole. In a state where the face splines formed on an end surface of the housing constituting the face splines and the universal joint fitted, it said universal joint is fastened to the hub wheel is intended.

  The present invention is such that the large-diameter hole portion is formed inside the small-diameter stepped portion, and the bottom surface of the large-diameter hole portion is located on the outer side with respect to the inner side end surface of the inner ring.

  The present invention includes a seal member that closes a gap between an inner peripheral surface of the large-diameter hole and an outer peripheral surface of the housing.

  As effects of the present invention, the following effects can be obtained.

  That is, in the wheel bearing device according to the present invention, the large-diameter hole portion connected to the universal joint mounting hole is formed on the inner side end face of the hub wheel. Then, the hub wheel and the universal joint are fastened in a state where the face spline formed on the bottom surface of the large-diameter hole and the face spline formed on the end surface of the casing constituting the universal joint are fitted. According to this invention, since the load due to the fastening force is not applied to the crimped portion, the crimped portion is not deformed, and consequently the inner ring is not displaced. Therefore, the preload of the rolling bearing structure does not change regardless of the difference in fastening force.

  In the wheel bearing device according to the present invention, the large-diameter hole portion is formed inside the small-diameter step portion. And the bottom face of a large diameter hole part exists in an outer side rather than the inner side end surface of an inner ring | wheel. According to this invention, since the distortion due to the fastening force is not transmitted to the crimping portion, the crimping portion is not deformed, and consequently the inner ring is not displaced.

  The wheel bearing device according to the present invention includes a seal member that closes a gap between the inner peripheral surface of the large-diameter hole and the outer peripheral surface of the housing. According to this invention, it is possible to prevent muddy water or the like from entering the universal joint mounting hole and to suppress the generation of rust.

The perspective view which shows the whole structure of the wheel bearing apparatus. Sectional drawing which shows the whole structure of the wheel bearing apparatus. The expanded sectional view which shows the partial structure of the wheel bearing apparatus. The expanded sectional view which shows the partial structure of the wheel bearing apparatus. The figure which shows the structure which fastens a wheel bearing apparatus and a universal joint. The figure which shows the state which fastened the wheel bearing apparatus and the universal joint. The figure which shows the state which fastened the universal joint with the other wheel bearing apparatus. The expanded sectional view which shows the wheel bearing apparatus which comprised the sealing member. The figure which shows the structure which fastens a wheel bearing apparatus and a universal joint. The figure which shows the state which fastened the wheel bearing apparatus and the universal joint. The figure which shows the state which fastened the universal joint with the other wheel bearing apparatus. The expanded sectional view which shows the wheel bearing apparatus which comprised the sealing member.

  Below, the wheel bearing apparatus 1 which concerns on this invention is demonstrated using FIGS. 1-4. 2 is a cross-sectional view taken along the line AA in FIG. 3 and 4 are enlarged views of a partial region in FIG.

  The wheel bearing device 1 supports a wheel rotatably in a suspension device such as an automobile. The wheel bearing device 1 includes an outer member 2, an inner member 3 (hub wheel 4 and inner ring 5), a rolling element 6, a seal member 7 (hereinafter referred to as “one-side seal member 7”), and a seal member 10 (hereinafter “ (Referred to as “other-side seal member 10”). In the following, “one side” represents the vehicle body side of the wheel bearing device 1, that is, the inner side. The “other side” represents the wheel side of the wheel bearing device 1, that is, the outer side.

  The outer member 2 supports the inner member 3 (hub wheel 4 and inner ring 5). The outer member 2 is made of a medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C formed in a substantially cylindrical shape. An enlarged diameter portion 2 a is formed at one end of the outer member 2. An enlarged diameter portion 2 b is formed at the other end of the outer member 2. On the inner periphery of the outer member 2, an outer rolling surface 2c and an outer rolling surface 2d are formed in an annular shape so as to be parallel to each other. The outer rolling surface 2c and the outer rolling surface 2d are subjected to induction hardening, and are hardened so that the surface hardness is in the range of 58 to 64 HRC. It should be noted that a knuckle attachment flange 2e for being attached to a knuckle constituting the suspension device is integrally formed on the outer periphery of the outer member 2.

  The inward member 3 rotatably supports a wheel (not shown). The inner member 3 includes a hub ring 4 and an inner ring 5.

  The hub wheel 4 is made of medium-high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C formed in a substantially cylindrical shape. A small diameter step 4 a is formed at one end of the hub wheel 4. An inner ring 5 is press-fitted into the small diameter step 4a. Further, the small diameter step portion 4a is formed with a caulking portion 4b of the inner ring 5 by bending the inner side end portion radially outward. A wheel mounting flange 4 c is integrally formed on the outer periphery of the hub wheel 4. Bolt holes 4d are provided at equal intervals on a concentric circle centering on the rotation axis L of the inner member 3 in the wheel mounting flange 4c, and hub bolts 4e are inserted into the respective bolt holes 4d. In addition, a universal joint mounting hole 4f penetrating from the inner side to the outer side is provided at the center of the hub wheel 4. Further, on the outer periphery of the hub wheel 4, an annular inner rolling surface 4 g is formed. The hub wheel 4 is induction-hardened from the small-diameter step portion 4a through the inner rolling surface 4g to the seal land portion (consisting of a shaft surface portion 4h, a curved surface portion 4i, and a side surface portion 4j described later), and has a surface hardness. Is cured so as to be in the range of 58 to 64 HRC. Thereby, the hub wheel 4 has sufficient mechanical strength and durability against the rotational bending load applied to the wheel mounting flange 4c. The inner rolling surface 4g faces the outer rolling surface 2d of the outer member 2.

The inner ring 5 is made of a high carbon chrome bearing steel such as SUJ2 formed in a substantially cylindrical shape.
On the outer periphery of the inner ring 5, an inner rolling surface 5a is formed in an annular shape. That is, the inner ring 5 is press-fitted into the small-diameter step portion 4a of the hub wheel 4, and constitutes an inner rolling surface 5a on the outer periphery of the small-diameter step portion 4a. The inner ring 5 is subjected to so-called quenching and is cured so as to be in the range of 58 to 64 HRC up to the core. Thereby, the inner ring 5 has sufficient mechanical strength and durability against the rotational bending load applied to the wheel mounting flange 4c. The inner rolling surface 5 a faces the outer rolling surface 2 c of the outer member 2.

  The rolling element 6 is interposed between the outer member 2 and the inner member 3 (hub wheel 4 and inner ring 5). The rolling element 6 has an inner side ball row 6a (hereinafter referred to as “one side ball row 6a”) and an outer side ball row 6b (hereinafter referred to as “other side ball row 6b”). The one side ball row 6a and the other side ball row 6b are made of high carbon chrome bearing steel such as SUJ2. The one-side ball row 6a and the other-side ball row 6b are subjected to so-called quenching and are cured so as to be in the range of 58 to 64 HRC up to the core portion. In the one-side ball row 6a, a plurality of balls are held in a ring shape by a cage. The one-side ball row 6a is accommodated so as to be freely rollable between an inner rolling surface 5a formed on the inner ring 5 and an outer rolling surface 2c of the outer member 2 facing the inner rolling surface 5a. In the other side ball row 6b, a plurality of balls are held in a ring shape by a cage. The other-side ball row 6b is accommodated so as to roll freely between an inner rolling surface 4g formed on the hub wheel 4 and an outer rolling surface 2d of the outer member 2 facing the inner rolling surface 4g. In this way, the one-side ball row 6a and the other-side ball row 6b constitute a double-row angular ball bearing with the outer member 2 and the inner member 3 (hub wheel 4 and inner ring 5). The wheel bearing device 1 is a third-generation wheel bearing device in which the inner rolling surface 4g of the other-side ball row 6b is directly formed on the outer periphery of the hub wheel 4, but is not limited thereto. And a second generation structure in which a pair of inner rings 5 are press-fitted and fixed to the hub wheel 4, or an outer ring and an inner member that are the outer members 2 that do not include the hub wheel 4 and that do not have the knuckle mounting flange 2e on the outer periphery. A first generation structure composed of a pair of inner rings 5 may be used.

  The one-side seal member 7 is attached to the inner side end portion of the annular space S formed between the outer member 2 and the inner member 3. The one-side seal member 7 includes an annular seal ring 8 and an annular slinger 9.

  The seal ring 8 is configured to be integrated with the outer member 2 by being fitted into the enlarged diameter portion 2 a of the outer member 2. The seal ring 8 includes a cored bar 81 and a seal rubber 82 that is an elastic member.

  The cored bar 81 is a ferritic stainless steel plate (JIS standard SUS430 or the like), an austenitic stainless steel plate (JIS standard SUS304 or the like), or a rust-proof cold rolled steel plate (JIS standard SPCC system or the like). It consists of The cored bar 81 is formed by bending an annular steel plate by press work and has an axial cross section that is substantially L-shaped. Thereby, the cored bar 81 is formed with a cylindrical fitting part 81a and a disk-like side plate part 81b extending from one end thereof toward the inner member 3 (inner ring 5). The fitting portion 81a and the side plate portion 81b intersect each other substantially perpendicularly, and the fitting portion 81a faces a fitting portion 9a of a slinger 9 described later. Further, the side plate portion 81b faces a side plate portion 9b of the slinger 9 described later. A seal rubber 82, which is an elastic member, is vulcanized and bonded to the fitting portion 81a and the side plate portion 81b.

  Seal rubber 82 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyacrylic rubber) excellent in heat resistance and chemical resistance, It is made of synthetic rubber such as FKM (fluoro rubber) or silicon rubber. The seal rubber 82 is formed with a radial lip 82a, an inner axial lip 82b, and an outer axial lip 82c which are seal lips.

  The slinger 9 is fitted to the outer periphery of the inner member 3 (the outer periphery of the inner ring 5) and is configured integrally with the inner member 3.

  Slinger 9 is a ferritic stainless steel sheet (JIS standard SUS430 series, etc.), austenitic stainless steel sheet (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel sheet (JIS standard SPCC system, etc.). It is configured. The slinger 9 is formed by bending an annular steel plate by press working and has an axial cross section formed in a substantially L shape. Thereby, the slinger 9 is formed with a cylindrical fitting portion 9a and a disc-shaped side plate portion 9b extending from the end portion toward the outer member 2. The fitting portion 9a and the side plate portion 9b intersect each other vertically, and the fitting portion 9a faces the fitting portion 81a of the seal ring 8 described above. Further, the side plate portion 9b faces the side plate portion 81b of the seal ring 8 described above. The side plate portion 9b is provided with a magnetic encoder 9c.

  The one-side seal member 7 is disposed so that the seal ring 8 and the slinger 9 face each other. At this time, the radial lip 82a contacts the fitting portion 9a of the slinger 9 through the oil film. Further, the axial lip 82b contacts the side plate portion 9b of the slinger 9 through the oil film. The outer axial lip 82c also contacts the side plate portion 9b of the slinger 9 through the oil film. In this way, the one-side seal member 7 constitutes a so-called pack seal, and prevents entry of dust and the like and leakage of grease.

  The other side sealing member 10 is attached to the outer side end portion of the annular space S formed between the outer member 2 and the inner member 3. The other-side seal member 10 includes an annular seal ring 11.

  The other-side seal member 10 is configured to be integrated with the outer member 2 by being fitted into the enlarged diameter portion 2 b of the outer member 2. The seal ring 11 includes a metal core 111 and a seal rubber 112 that is an elastic member.

  The core metal 111 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), an austenitic stainless steel sheet (JIS standard SUS304 series, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC system, etc.). It consists of The core metal 111 is formed in a substantially C shape in an axial sectional view by bending an annular steel plate by press working. Thereby, the metal core 111 is formed with a cylindrical fitting portion 111a and a disk-shaped side plate portion 111b extending from one end thereof toward the inner member 3 (hub wheel 4). The fitting part 111 a and the side plate part 111 b intersect with each other while being curved, and the fitting part 111 a faces the shaft surface part 4 h of the hub wheel 4. The side plate portion 111b faces the curved surface portion 4i and the side surface portion 4j of the hub wheel 4 (refers to the end surface of the wheel mounting flange 4c). A seal rubber 112 that is an elastic member is vulcanized and bonded to the side plate portion 111b.

  Seal rubber 112 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyacrylic rubber) excellent in heat resistance and chemical resistance, It is made of synthetic rubber such as FKM (fluoro rubber) or silicon rubber. The seal rubber 112 is formed with a radial lip 112a, an inner axial lip 112b, and an outer axial lip 112c which are seal lips.

  The other-side seal member 10 is disposed so that the seal ring 11 and the hub wheel 4 face each other. At this time, the radial lip 112a contacts the shaft surface portion 4h of the hub wheel 4 through the oil film. Moreover, the axial lip 112b contacts the curved surface portion 4i of the hub wheel 4 through an oil film. The outer axial lip 112c also contacts the side surface portion 4j of the hub wheel 4 through the oil film. In this way, the other side sealing member 10 prevents intrusion of dust and the like and leakage of grease.

  Next, the wheel bearing device 1 according to the first embodiment will be described in detail with reference to FIGS. 5 and 6. FIG. 5 shows a structure for fastening the universal joint 12 to the wheel bearing device 1. FIG. 6 shows a state where the universal joint 12 is fastened to the wheel bearing device 1. 6A is an enlarged view of the region R. FIG.

  In the wheel bearing device 1 according to the first embodiment, a large-diameter hole portion 4k connected to the universal joint mounting hole 4f is formed on the inner side end face of the hub wheel 4. The large-diameter hole 4k is a substantially cylindrical space, and its bottom surface 4m is perpendicular to the rotation axis L. The inner peripheral surface 4n has a cylindrical shape with the rotation axis L as the center. The hub wheel 4 constituting the wheel bearing device 1 has a universal joint mounting hole 4f passing through the center of the bottom surface 4m, and a face spline 4s is formed around it. Here, the face spline 4s indicates a concavo-convex shape formed radially around the universal joint mounting hole 4f. The universal joint 12 corresponding to such a wheel bearing device 1 has a structure similar to that of the conventional one, and includes a drive shaft that transmits rotational power and a joint portion of the drive shaft. The joint portion has a housing 12k that holds and accommodates various components. The casing 12k constituting the universal joint 12 has a bolt hole 12h formed at the center of the end face 12m, and a face spline 12s formed around the bolt hole 12h. Here, the face spline 12s indicates a concavo-convex shape formed radially around the bolt hole 12h. Therefore, when the center bolt 13 is inserted into the universal joint mounting hole 4f and fastened to the bolt hole 12h, the housing 12k is fitted inside the large diameter hole 4k, and the face of the large diameter hole 4k is obtained. The spline 4s and the face spline 12s of the housing 12k are fitted. At this time, the parts of the universal joint 12 do not come into contact with the crimped portion 4b.

  As described above, in the wheel bearing device 1 according to the present invention, the large-diameter hole portion 4k connected to the universal joint mounting hole 4f is formed on the inner side end face of the hub wheel 4. The hub wheel 4 and the universal joint are engaged with the face spline 4s formed on the bottom surface 4m of the large-diameter hole 4k and the face spline 12m formed on the end surface of the casing 12k constituting the universal joint 12. 12 concludes. According to this invention, since the load due to the fastening force is not applied to the caulking portion 4b, the caulking portion 4b is not deformed and consequently the inner ring 5 is not displaced. Therefore, the preload of the rolling bearing structure does not change regardless of the difference in fastening force. Moreover, since the large-diameter hole 4k is formed in the hub wheel 4, the wheel bearing device 1 according to the present invention achieves weight reduction compared to the conventional product.

  In addition, in the wheel bearing device 1, the large-diameter hole portion 4k is formed inside the small-diameter step portion 4a, and the bottom surface 4m of the large-diameter hole portion 4k is on the outer side than the inner-side end surface 5m of the inner ring 5. It is a feature. This is because the distortion of the small-diameter step portion 4a is not transmitted to the caulking portion 4b when the center bolt 13 is used for fastening.

  Thus, in the wheel bearing device 1 according to the present invention, the large-diameter hole portion 4k is formed inside the small-diameter step portion 4a. The bottom surface 4m of the large-diameter hole 4k is located on the outer side with respect to the inner side end surface 5m of the inner ring 5. According to this invention, since the distortion due to the fastening force is not transmitted to the caulking portion 4b, the caulking portion 4b is not deformed and consequently the inner ring is not displaced.

  Next, the wheel bearing device 1 having a partially different shape will be described.

  FIG. 7 shows a state in which the universal joint 12 is fastened with another wheel bearing device 1. FIG. 7A is an enlarged view of the region R.

  The wheel bearing device 1 according to the present embodiment has a conical shape in which the bottom surface 4m of the large-diameter hole 4k is inclined with respect to the rotation axis L. A universal joint mounting hole 4f passes through the center of the bottom surface 4m, and a face spline 4s is formed therearound. The universal joint 12 corresponding to the wheel bearing device 1 has a housing 12k that holds and accommodates various components. The housing 12k has a conical end surface 12m. A bolt hole 12h is formed at the center of the end face 12m, and a face spline 12s is formed around the bolt hole 12h. Therefore, when the center bolt 13 is inserted into the universal joint mounting hole 4f and fastened to the bolt hole 12h, the housing 12k is fitted inside the large diameter hole 4k, and the face of the large diameter hole 4k is obtained. The spline 4s and the face spline 12s of the housing 12k are fitted. Such a wheel bearing device 1 also has the same effects as the wheel bearing device 1 according to the first embodiment.

  Next, a structure applicable to the wheel bearing device 1 will be described.

  FIG. 8 shows the wheel bearing device 1 provided with the seal member 14. (A) and (B) of Drawing 8 show composition from which an embodiment differs mutually.

  The seal rubber as the seal member 14 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyethylene excellent in heat resistance and chemical resistance). (Acrylic rubber), FKM (fluoro rubber), or synthetic rubber such as silicon rubber.

  As shown in FIG. 8A, the wheel bearing device 1 according to the present invention includes a seal member 14 that closes a gap between the inner peripheral surface 4n of the large-diameter hole 4k and the outer peripheral surface 12n of the housing 12k. doing. According to this invention, it is possible to prevent muddy water or the like from entering the universal joint mounting hole 4f and suppress the generation of rust.

  On the other hand, as shown in FIG. 8B, a seal member 14 that closes the gap between the caulking portion 4b and a part of the housing 12k may be provided. Even in this case, it is possible to prevent intrusion of muddy water or the like into the universal joint mounting hole 4f and suppress the generation of rust.

  Next, the wheel bearing device 1 according to the second embodiment will be described in detail with reference to FIGS. 9 and 10. FIG. 9 shows a structure for fastening the wheel bearing device 1 and the universal joint 12. FIG. 10 shows a state where the wheel bearing device 1 and the universal joint 12 are fastened. FIG. 10A is an enlarged view of the region R.

  The wheel bearing device 1 is different in structure from the wheel bearing device 1 according to the first embodiment. More specifically, a pair of inner rings 5 are press-fitted into the small diameter step 4a. The hub wheel 4 is crimped to the inner ring 5 by bending its inner side end portion radially outward. The rolling element 6 has an inner side tapered roller row 6a (hereinafter referred to as "one side roller row 6a") and an outer side tapered roller row 6b (hereinafter referred to as "other side roller row 6b"). The one-side roller row 6a and the other-side roller row 6b constitute a double-row tapered roller bearing with the outer member 2 and the inner member 3 (hub wheel 4 and inner ring 5).

  Also in the wheel bearing device 1 according to the second embodiment, a large-diameter hole portion 4k connected to the universal joint mounting hole 4f is formed on the inner side end face of the hub wheel 4. The large-diameter hole 4k is a substantially cylindrical space, and its bottom surface 4m is perpendicular to the rotation axis L. The inner peripheral surface 4n has a cylindrical shape with the rotation axis L as the center. The hub wheel 4 constituting the wheel bearing device 1 has a universal joint mounting hole 4f passing through the center of the bottom surface 4m, and a face spline 4s is formed around it. Here, the face spline 4s indicates a concavo-convex shape formed radially around the universal joint mounting hole 4f. The universal joint 12 corresponding to such a wheel bearing device 1 has a structure similar to that of the conventional one, and includes a drive shaft that transmits rotational power and a joint portion of the drive shaft. The joint portion has a housing 12k that holds and accommodates various components. The casing 12k constituting the universal joint 12 has a bolt hole 12h formed at the center of the end face 12m, and a face spline 12s formed around the bolt hole 12h. Here, the face spline 12s indicates a concavo-convex shape formed radially around the bolt hole 12h. Therefore, when the center bolt 13 is inserted into the universal joint mounting hole 4f and fastened to the bolt hole 12h, the housing 12k is fitted inside the large diameter hole 4k, and the face of the large diameter hole 4k is obtained. The spline 4s and the face spline 12s of the housing 12k are fitted. At this time, the parts of the universal joint 12 do not come into contact with the crimped portion 4b.

  As described above, in the wheel bearing device 1 according to the present invention, the large-diameter hole portion 4k connected to the universal joint mounting hole 4f is formed on the inner side end face of the hub wheel 4. The hub wheel 4 and the universal joint are engaged with the face spline 4s formed on the bottom surface 4m of the large-diameter hole 4k and the face spline 12m formed on the end surface of the casing 12k constituting the universal joint 12. 12 concludes. According to this invention, since the load due to the fastening force is not applied to the caulking portion 4b, the caulking portion 4b is not deformed and consequently the inner ring 5 is not displaced. Therefore, the preload of the rolling bearing structure does not change regardless of the difference in fastening force. Moreover, since the large-diameter hole 4k is formed in the hub wheel 4, the wheel bearing device 1 according to the present invention achieves weight reduction compared to the conventional product.

  In addition, in the wheel bearing device 1, the large-diameter hole portion 4k is formed inside the small-diameter step portion 4a, and the bottom surface 4m of the large-diameter hole portion 4k is on the outer side than the inner-side end surface 5m of the inner ring 5. It is a feature. This is because the distortion of the small-diameter step portion 4a is not transmitted to the caulking portion 4b when the center bolt 13 is used for fastening.

  Thus, in the wheel bearing device 1 according to the present invention, the large-diameter hole portion 4k is formed inside the small-diameter step portion 4a. The bottom surface 4m of the large-diameter hole 4k is located on the outer side with respect to the inner side end surface 5m of the inner ring 5. According to this invention, since the distortion due to the fastening force is not transmitted to the caulking portion 4b, the caulking portion 4b is not deformed and consequently the inner ring is not displaced.

  Next, the wheel bearing device 1 having a partially different shape will be described.

  FIG. 11 shows a state in which the universal joint 12 is fastened with another wheel bearing device 1. FIG. 11A is an enlarged view of the region R.

  The wheel bearing device 1 according to the present embodiment has a conical shape in which the bottom surface 4m of the large-diameter hole 4k is inclined with respect to the rotation axis L. A universal joint mounting hole 4f passes through the center of the bottom surface 4m, and a face spline 4s is formed therearound. The universal joint 12 corresponding to the wheel bearing device 1 has a housing 12k that holds and accommodates various components. The housing 12k has a conical end surface 12m. A bolt hole 12h is formed at the center of the end face 12m, and a face spline 12s is formed around the bolt hole 12h. Therefore, when the center bolt 13 is inserted into the universal joint mounting hole 4f and fastened to the bolt hole 12h, the housing 12k is fitted inside the large diameter hole 4k, and the face of the large diameter hole 4k is obtained. The spline 4s and the face spline 12s of the housing 12k are fitted. Such a wheel bearing device 1 also has the same effects as the wheel bearing device 1 according to the second embodiment.

  Next, a structure applicable to the wheel bearing device 1 will be described.

  FIG. 12 shows the wheel bearing device 1 provided with the seal member 14. (A) and (B) of Drawing 12 show composition from which an embodiment differs mutually.

  The seal rubber as the seal member 14 is NBR (acrylonitrile-butadiene rubber), HNBR (hydrogenated acrylonitrile-butadiene rubber) excellent in heat resistance, EPDM (ethylene propylene rubber), ACM (polyethylene excellent in heat resistance and chemical resistance). (Acrylic rubber), FKM (fluoro rubber), or synthetic rubber such as silicon rubber.

  As shown in FIG. 12A, the wheel bearing device 1 according to the present invention includes a seal member 14 that closes a gap between the inner peripheral surface 4n of the large-diameter hole 4k and the outer peripheral surface 12n of the housing 12k. doing. According to this invention, it is possible to prevent muddy water or the like from entering the universal joint mounting hole 4f and suppress the generation of rust.

  On the other hand, as shown in FIG. 12B, a seal member 14 that closes the gap between the caulking portion 4b and a part of the housing 12k may be provided. Even in this case, it is possible to prevent intrusion of muddy water or the like into the universal joint mounting hole 4f and suppress the generation of rust.

DESCRIPTION OF SYMBOLS 1 Wheel bearing apparatus 2 Outer member 2c Outer rolling surface 2d Outer rolling surface 3 Inner member 4 Hub wheel 4a Small diameter step part 4b Caulking part 4c Wheel mounting flange 4f Universal joint mounting hole 4g Inner rolling surface 4k Large diameter Hole 4s Face spline 4m Bottom surface 4n Inner peripheral surface 5 Inner ring 5a Inner rolling surface 6 Rolling body 12 Universal joint 12k Housing 12s Face spline 12m End surface 12n Outer peripheral surface 13 Center bolt 14 Seal member L Rotating shaft S Annular space

Claims (3)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel, and having a small diameter step portion extending in the axial direction on the outer periphery, and at least one inner ring press-fitted into the small diameter step portion of the hub ring; An inner member in which a double row inner rolling surface facing the outer row rolling surface of the double row is formed on the outer periphery;
A double-row rolling element interposed between the rolling surfaces of the outer member and the inner member so as to be freely rollable, and
A universal joint mounting hole is provided in the hub wheel,
In the wheel bearing device in which the inner side end of the hub wheel is bent radially outward to caulk the inner ring,
A large-diameter hole connected to the universal joint mounting hole is formed on the inner side end surface of the hub wheel,
The hub wheel and the universal joint are fastened in a state where the face spline formed on the bottom surface of the large-diameter hole and the face spline formed on the end surface of the casing constituting the universal joint are fitted. A wheel bearing device characterized by   The said large diameter hole part is formed in the inner side of the said small diameter step part, and the bottom face of the said large diameter hole part exists in an outer side rather than the inner side end surface of the said inner ring | wheel. Wheel bearing device.   The wheel bearing device according to claim 1, further comprising a seal member that closes a gap between an inner peripheral surface of the large-diameter hole and an outer peripheral surface of the housing.

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