JP2017101755A - Wheel bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing device having attained improved durability and low resistance property.SOLUTION: A wheel bearing device 1 includes an outward member 2, an inward member 3, a rolling body 6 and seal members 7, 10. Out of a double row of rolling bodies 6, between an inner side ball row 6a and an outer side ball row 6b, a wall member 12 is arranged, and a characteristic of grease Gi sealed in an annular space Ai inside the wall member 12 and a characteristic of grease Go sealed in an annular space Ao outside the wall member 12 are different from each other.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wheel bearing device. More specifically, the present invention relates to a wheel bearing device that realizes improved durability and low resistance.

  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 inner member is disposed inside the outer member, and a rolling element is interposed between the outer member and the inner member. Therefore, when dust or the like (including rain water or muddy water in addition to sand dust) enters the wheel bearing device, the rolling elements are damaged and the bearing life is shortened. Therefore, the wheel bearing device is equipped with a pair of seal members at both ends of the annular space formed between the outer member and the inner member in order to prevent intrusion of dust and the like.

  By the way, such a wheel bearing device forms a double-row angular contact ball bearing. More specifically, in the wheel bearing device, a double row angular contact ball bearing is constituted by an inner side ball row and an outer side ball row among the double row rolling elements. In the wheel bearing device, grease is sealed in an annular space formed between the outer member and the inner member. For example, as described in Patent Document 1.

  The wheel bearing device described in Patent Document 1 includes an outer member, an inner member, a rolling element interposed between the outer member and the inner member, and between the outer member and the inner member. And a pair of seal members attached to both ends of the formed annular space. Further, in the wheel bearing device described in Patent Document 1, a wall member is disposed between the inner side ball row and the outer side ball row. The wall member has a substantially cylindrical shape and occupies a part of the annular space formed between the outer member and the inner member. Therefore, such a wheel bearing device can reduce the amount of grease enclosed in the annular space. Further, such a wheel bearing device can reduce the stirring resistance of grease.

  However, as described in Patent Document 2 (paragraph (0007)), the wheel bearing device applies a strong load to the rolling surface of each ball on the inner side and the raceway surface of the inner and outer rings. The rolling surface and the raceway surface of the inner and outer rings have a property of higher surface pressure than the outer side. For this reason, it is necessary to enclose high-viscosity grease that does not cause oil film breakage even at high surface pressures.However, high-viscosity grease has high stirring resistance, and there is still a problem that torque is high due to the stirring resistance of the grease. It was. Therefore, there has been a demand for a wheel bearing device that reduces wear resistance of grease while preventing wear of each ball on the inner side and its rolling surface. That is, there has been a demand for a wheel bearing device that achieves improved durability and improved low resistance.

JP 2010-127324 A JP 11-091308 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 that realizes improved durability and improved low resistance.

  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 on one end, and extends axially on the outer periphery. A double-row inner rolling surface comprising a hub wheel formed with a small-diameter step portion and at least one inner ring press-fitted into the small-diameter step portion of the hub wheel, and facing the double-row outer rolling surface on the outer periphery. An inner member in which the outer member is formed, a double-row rolling element interposed between the rolling surfaces of the outer member and the inner member, the outer member, and the inner member. A pair of seal members mounted at both ends of an annular space formed between the inner and outer ball rows of the double row rolling elements. Wall member is arranged and enclosed in the annular space on the inner side of the wall member Characteristics of the grease sealed in the annular space on the outer side than the characteristic and the wall member of the grease is different, but.

  In the present invention, high-viscosity grease is enclosed in the annular space on the inner side of the wall member, and low-viscosity grease is enclosed in the annular space on the outer side of the wall member.

  In the present invention, the wall member is fixed in a state of being sandwiched between a wall surface formed on the hub wheel and an end surface of the inner ring.

  In the present invention, the wall member is fixed in a state where it is press-fitted into the outer periphery of the hub wheel.

  In the present invention, the wall member is fixed in a state where it is press-fitted into the inner periphery of the outer member.

  In the present invention, a seal lip is provided on the wall member, and the seal lip shields a gap passage that connects the annular space on the inner side of the wall member and the annular space on the outer side of the wall member. is there.

  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 wall member is disposed between the inner side ball row and the outer side ball row of the double row rolling elements. The characteristics of the grease sealed in the annular space on the inner side of the wall member and the characteristics of the grease sealed in the annular space on the outer side of the wall member are different. Thereby, this wheel bearing device can implement | achieve the lubrication environment suitable for each of an inner side ball row | line | column and an outer side ball row | line | column. Therefore, this wheel bearing device can realize improved durability and improved low resistance.

  In the wheel bearing device according to the present invention, high-viscosity grease is enclosed in the annular space on the inner side of the wall member, and low-viscosity grease is enclosed in the annular space on the outer side of the wall member. Thereby, this wheel bearing device can implement | achieve the lubrication environment suitable for protection of each ball | bowl on the inner side, and its rolling surface. At the same time, the wheel bearing device can realize a lubrication environment suitable for reducing the stirring resistance of grease due to rolling of the balls on the outer side. Therefore, this wheel bearing device can realize improved durability and improved low resistance.

  The wheel bearing device according to the present invention is fixed in a state where the wall member is sandwiched between the wall surface formed on the hub wheel and the end surface of the inner ring. Thereby, this wheel bearing apparatus can fix a wall member reliably, although it is a simple structure.

  The wheel bearing device according to the present invention is fixed in a state where the wall member is press-fitted into the outer periphery of the hub wheel. Thereby, this wheel bearing apparatus can fix a wall member reliably, although it is a simple structure.

  The wheel bearing device according to the present invention is fixed in a state where the wall member is press-fitted into the inner periphery of the outer member. Thereby, this wheel bearing apparatus can fix a wall member reliably, although it is a simple structure.

  The wheel bearing device according to the present invention is provided with a seal lip on the wall member. The seal lip shields the gap passage connecting the annular space on the inner side of the wall member and the annular space on the outer side of the wall member. Thereby, this wheel bearing device can suppress mixing of the grease sealed in the annular space on the inner side of the wall member and the grease sealed in the annular space on the outer side of the wall member.

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 expanded sectional view which shows the principal part structure of the wheel bearing apparatus which is 1st embodiment. The expanded sectional view which shows the principal part structure of the bearing apparatus for wheels which is 2nd embodiment. The expanded sectional view which shows the principal part structure using the wall member which can be applied to the wheel bearing apparatus which is 2nd embodiment. The expanded sectional view which shows the principal part structure of the bearing apparatus for wheels which is 3rd embodiment. The expanded sectional view which shows the principal part structure using the wall member which can be applied to the wheel bearing apparatus which is 3rd embodiment. The expanded sectional view which shows the principal part structure using the wall member which can be applied to the wheel bearing apparatus which is 3rd embodiment.

  Below, the wheel bearing apparatus 1 which is 1st embodiment of the wheel bearing apparatus which concerns on this invention using FIGS. 1-4 is demonstrated. 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 0.40 to 0.80 wt% of carbon such as S53C formed in a bottomed 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. A wheel mounting flange 4 b is integrally formed at the other end of the hub wheel 4. Hub bolts 4d are provided on the wheel mounting flange 4b at circumferentially equidistant positions. Further, on the outer periphery of the hub wheel 4, an inner rolling surface 4c is formed in an annular shape. The hub wheel 4 is induction-hardened from the small-diameter step portion 4a to the inner rolling surface 4c, and is hardened so that the surface hardness is 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 4b. The inner rolling surface 4 c faces the outer rolling surface 2 d 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 fitted into the small-diameter step portion 4a of the hub wheel 4, and the inner raceway surface 5a is configured 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 4b. 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 (hereinafter referred to as “one side ball row 6a”) and an outer side ball row (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 as rolling elements are held in an annular 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, which are rolling elements, are held in an annular shape by a cage. The other-side ball row 6b is accommodated so as to be freely rollable between an inner rolling surface 4c formed on the hub wheel 4 and an outer rolling surface 2d of the outer member 2 facing the inner rolling surface 4c. 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). In addition, although the wheel bearing apparatus 1 comprises a double row angular contact ball bearing, it is not limited to this. For example, a double row tapered roller bearing or the like may be configured. The wheel bearing device 1 is a third-generation wheel bearing device in which the inner raceway surface 4c of the other side ball row 6b is directly formed on the outer periphery of the hub wheel 4, but is not limited thereto. The second generation structure in which the pair of inner rings 5 are press-fitted and fixed to the hub ring 4 or the first ring constituted by the outer ring that is the outer member 2 without the hub ring 4 and the inner ring 5 that is the inner member. It may be a generation structure.

  The one-side seal member 7 is attached to the inner side end portion of the annular space A 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, which prevents the grease G from leaking and prevents the entry of dust and the like.

  The other side sealing member 10 is attached to the outer side end portion of the annular space A 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 e of the hub wheel 4. The side plate portion 111b faces the curved surface portion 4f and the side surface portion 4g of the hub wheel 4 (refers to the end surface of the wheel mounting flange 4b). 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 4g of the hub wheel 4 through the oil film. Further, the axial lip 112b contacts the curved surface portion 4f of the hub wheel 4 through an oil film. The outer axial lip 112c also contacts the side surface portion 4e of the hub wheel 4 through the oil film. In this way, the other-side seal member 10 prevents the grease G from leaking and prevents intrusion of dust and the like.

  Next, the wheel bearing device 1 according to the first embodiment will be described in detail with reference to FIG. FIG. 5 is an enlarged cross-sectional view showing the main structure of the wheel bearing device 1. 5A is an enlarged view of the region R. FIG.

  In the wheel bearing device 1 according to the first embodiment, the wall member 12 is disposed between the one-side ball row 6a and the other-side ball row 6b in the double row rolling elements 6. The wall member 12 has a substantially cylindrical shape centered on the rotation axis C of the inner member 3 (see FIGS. 1 and 2). The length La of the wall member 12 is the same as or slightly larger than the axial dimension Lb of the fitting portion 4h. Therefore, the wheel bearing device 1 is fixed in a state where the wall member 12 is sandwiched between the wall surface 4 f formed on the hub wheel 4 and the end surface 5 f of the inner ring 5. The wall member 12 has a smaller outer diameter Ra than the inner diameter Rb of the outer member 2. Therefore, in the wheel bearing device 1, a clearance passage P is formed between the outer peripheral surface of the wall member 12 and the inner peripheral surface of the outer member 2.

  In addition, the wheel bearing device 1 has the characteristics of the grease Gi enclosed in the annular space Ai on the inner side of the wall member 12 and the characteristics of the grease Go enclosed in the annular space Ao on the outer side of the wall member 12. Is different. Therefore, the wheel bearing device 1 can realize a lubrication environment suitable for each of the inner side ball row (one side ball row 6a) and the outer side ball row (other side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  More specifically, in the wheel bearing device 1 according to the present invention, the rolling surface of each ball on the inner side and the raceway surface of the inner and outer rings have a higher surface pressure than the outer side. A high-viscosity grease Gi that does not cause oil film breakage even at high surface pressure is enclosed in the annular space Ai on the side, and a low-viscosity grease Go is enclosed in the annular space Ao on the outer side of the wall member 12. As a result, the wheel bearing device 1 is lubricated suitable for protecting each ball on the inner side (each ball in the one-side ball row 6a) and its rolling surface (the inner rolling surface 5a and the outer rolling surface 2c). The environment can be realized. At the same time, the wheel bearing device 1 can realize a lubrication environment suitable for reducing the grease stirring resistance caused by rolling of the outer balls (balls of the other-side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  Furthermore, the wheel bearing device 1 according to the present invention is fixed in a state where the wall member 12 is sandwiched between the wall surface 4 f formed on the hub wheel 4 and the end surface 5 f of the inner ring 5. As a result, the wheel bearing device 1 can reliably fix the wall member 12 with a simple structure.

  Next, the wheel bearing device 1 according to the second embodiment will be described in detail with reference to FIG. FIG. 6 is an enlarged cross-sectional view showing the main structure of the wheel bearing device 1. 6A is an enlarged view of the region R. FIG.

  Also in the wheel bearing device 1 according to the second embodiment, the wall member 12 is arranged between the one side ball row 6a and the other side ball row 6b in the double row rolling elements 6. The wall member 12 has a substantially cylindrical shape centered on the rotation axis C of the inner member 3 (see FIGS. 1 and 2). The wall member 12 has an inner diameter dimension ra that is the same as or slightly smaller than the outer diameter dimension rb of the fitting portion 4h. Therefore, the wheel bearing device 1 is fixed in a state where the wall member 12 is press-fitted into the outer periphery of the hub wheel 4. The wall member 12 has a smaller outer diameter Ra than the inner diameter Rb of the outer member 2. Therefore, in the wheel bearing device 1, a clearance passage P is formed between the outer peripheral surface of the wall member 12 and the inner peripheral surface of the outer member 2.

  In addition, the wheel bearing device 1 has the characteristics of the grease Gi enclosed in the annular space Ai on the inner side of the wall member 12 and the characteristics of the grease Go enclosed in the annular space Ao on the outer side of the wall member 12. Is different. Therefore, the wheel bearing device 1 can realize a lubrication environment suitable for each of the inner side ball row (one side ball row 6a) and the outer side ball row (other side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  More specifically, in the wheel bearing device 1 according to the present invention, high-viscosity grease Gi is sealed in the annular space Ai on the inner side of the wall member 12, and the annular space Ao on the outer side of the wall member 12. A low-viscosity grease Go is enclosed. As a result, the wheel bearing device 1 is lubricated suitable for protecting each ball on the inner side (each ball in the one-side ball row 6a) and its rolling surface (the inner rolling surface 5a and the outer rolling surface 2c). The environment can be realized. At the same time, the wheel bearing device 1 can realize a lubrication environment suitable for reducing the grease stirring resistance caused by rolling of the outer balls (balls of the other-side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  Furthermore, the wheel bearing device 1 according to the present invention is fixed in a state where the wall member 12 is press-fitted into the outer periphery of the hub wheel 4. As a result, the wheel bearing device 1 can reliably fix the wall member 12 with a simple structure.

  The wall member 12 may be formed as shown in FIG. That is, the wall member 12 may be formed such that an annular steel plate is bent by pressing and the axial cross section is formed in an approximately L shape. In this case, the wall member 12 is formed with a cylindrical fitting portion 12 a and a disc-shaped side plate portion 12 b extending from one end of the wall member 12 toward the outer member 2. Even in the case of such a structure, it is possible to improve durability and improve low resistance. Moreover, weight reduction can also be realized. As a result, the moment of inertia becomes smaller.

  Next, the wheel bearing device 1 according to the third embodiment will be described in detail with reference to FIG. FIG. 8 is an enlarged cross-sectional view showing the main structure of the wheel bearing device 1. 8A is an enlarged view of the region R. FIG.

  Also in the wheel bearing device 1 according to the third embodiment, the wall member 12 is disposed between the one-side ball row 6a and the other-side ball row 6b in the double row rolling elements 6. The wall member 12 has a substantially cylindrical shape centered on the rotation axis C of the inner member 3 (see FIGS. 1 and 2). The wall member 12 has an outer diameter Ra that is the same as or slightly larger than the inner diameter Rb of the fitting portion 2h. Therefore, the wheel bearing device 1 is fixed in a state where the wall member 12 is press-fitted into the inner periphery of the outer member 2. The wall member 12 has a larger inner diameter ra than the outer diameter rb of the hub wheel 4. Therefore, in the wheel bearing device 1, a clearance passage P sandwiched between the inner peripheral surface of the wall member 12 and the outer peripheral surface of the inner member 3 (hub wheel 4) is formed.

  In addition, the wheel bearing device 1 has the characteristics of the grease Gi enclosed in the annular space Ai on the inner side of the wall member 12 and the characteristics of the grease Go enclosed in the annular space Ao on the outer side of the wall member 12. Is different. Therefore, the wheel bearing device 1 can realize a lubrication environment suitable for each of the inner side ball row (one side ball row 6a) and the outer side ball row (other side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  More specifically, in the wheel bearing device 1 according to the present invention, high-viscosity grease Gi is sealed in the annular space Ai on the inner side of the wall member 12, and the annular space Ao on the outer side of the wall member 12. A low-viscosity grease Go is enclosed. As a result, the wheel bearing device 1 is lubricated suitable for protecting each ball on the inner side (each ball in the one-side ball row 6a) and its rolling surface (the inner rolling surface 5a and the outer rolling surface 2c). The environment can be realized. At the same time, the wheel bearing device 1 can realize a lubrication environment suitable for reducing the grease stirring resistance caused by rolling of the outer balls (balls of the other-side ball row 6b). Therefore, this wheel bearing device 1 can realize improvement in durability and improvement in low resistance.

  Furthermore, the wheel bearing device 1 according to the present invention is fixed in a state in which the wall member 12 is press-fitted into the inner periphery of the outer member 2. As a result, the wheel bearing device 1 can reliably fix the wall member 12 with a simple structure. The wheel bearing device 1 is advantageous in that the moment of inertia is small because the wall member 12 is fixed to the outer member 2 which is a fixed component, not the inner member 3 (hub wheel 4) which is a rotating component. There is an effect.

  The wall member 12 may be formed as shown in FIG. That is, the wall member 12 may be formed such that an annular steel plate is bent by pressing and the axial cross section is formed in an approximately L shape. In this case, the wall member 12 is formed with a cylindrical fitting portion 12a and a disc-shaped side plate portion 12b extending from one end thereof toward the inner member 3 (hub wheel 4). Even in the case of such a structure, it is possible to improve durability and improve low resistance. Moreover, weight reduction can also be realized.

  Next, the structure applicable to the wheel bearing apparatus 1 of each embodiment mentioned above is demonstrated using FIG. FIG. 10 is an enlarged cross-sectional view showing the main structure of the wheel bearing device 1. FIG. 10A is an enlarged view of the region R.

  The wheel bearing device 1 according to the present embodiment is obtained by adding a technical idea to the wheel bearing device 1 according to the third embodiment. In the wheel bearing device 1, a seal rubber 13, which is an elastic member, is vulcanized and bonded to the side plate portion 12 b of the wall member 12.

  Seal rubber 13 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 13 is formed with a radial lip 13a as a seal lip. The radial lip 13 a is close to the outer peripheral surface 4 i of the hub wheel 4.

  Thus, in the wheel bearing device 1 according to the present invention, the wall member 12 is provided with the seal lip (radial lip 13a). The seal lip (radial lip 13a) shields the gap passage P connecting the annular space Ai on the inner side of the wall member 12 and the annular space Ao on the outer side of the wall member 12. As a result, the wheel bearing device 1 suppresses mixing of the grease Gi enclosed in the annular space Ai on the inner side with respect to the wall member 12 and the grease Go enclosed in the annular space Ao on the outer side of the wall member 12. be able to.

DESCRIPTION OF SYMBOLS 1 Wheel bearing apparatus 2 Outer member 3 Inner member 4 Hub ring 5 Inner ring 6 Rolling element 6a Ball row (one side ball row)
6b Ball row (other side ball row)
7 Seal member (one side seal member)
8 Seal Ring 81 Core Bar 82 Seal Rubber 9 Slinger 10 Seal Member (Other Side Seal Member)
11 Seal ring 111 Core metal 112 Seal rubber 12 Wall member A Annular space Ai Annular space Ao Annular space C Rotating shaft G Grease Gi Grease Go Grease

Claims (6)

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 at one end thereof 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 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 roll freely;
In a wheel bearing device comprising: a pair of seal members attached to both ends of an annular space formed between the outer member and the inner member;
A wall member is disposed between the inner side ball row and the outer side ball row among the double row rolling elements,
A wheel bearing device, wherein a characteristic of grease sealed in the annular space on the inner side of the wall member is different from a characteristic of grease sealed in the annular space on the outer side of the wall member.   The wheel bearing according to claim 1, wherein high-viscosity grease is enclosed in the annular space on the inner side of the wall member, and low-viscosity grease is enclosed in the annular space on the outer side of the wall member. apparatus.   The wheel bearing device according to claim 1 or 2, wherein the wall member is fixed in a state of being sandwiched between a wall surface formed on the hub wheel and an end surface of the inner ring.   The wheel bearing device according to claim 1 or 2, wherein the wall member is fixed in a state of being press-fitted into an outer periphery of the hub wheel.   The wheel bearing device according to claim 1 or 2, wherein the wall member is fixed in a state of being press-fitted into an inner periphery of the outer member.   The seal member is provided with a seal lip, and the seal lip shields a gap passage that connects the annular space on the inner side of the wall member and the annular space on the outer side of the wall member. The wheel bearing device according to claim 5.

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