JP2009073252A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely arrange a pair of seal members at predetermined positions so as to make confirmation of the positions unnecessary; and to reduce a dimension of a device body in the axial direction. <P>SOLUTION: A wheel bearing device comprises an outer race 38 supported in a fixed state on the outside, an inner race 40 provided on the inner diameter side of the outer race 38, a plurality of balls 44 supported to be capable of rolling between the outer race 38 and the inner race 40, a pair of retainers 46 holding the balls 44 to make them freely roll, and a pair of the seal members 48 composed of annular bodies arranged nearly in parallel between two ball lines composed of the inside line and the outside line. A projection part 56 of the seal member 48 is fitted to a recessed part 58 of the retainer 46 and bonded thereto using adhesive. The seal members 48 are integrally fixed to the retainers 46 thereby. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for supporting a wheel on a vehicle body such as an automobile, and more particularly to a wheel bearing device provided with a hub bearing having a mechanism for adjusting tire air pressure.

  2. Description of the Related Art Conventionally, there has been known a mechanism for controlling the air pressure of a tire to a predetermined pressure by flowing in and out of pressurized air through an air circulation passage provided in a wheel hub bearing.

  For example, Patent Document 1 has two ball rows in which a plurality of balls held by a cage so as to roll freely are arranged in parallel in an annular shape between an outer race and a split inner race. A bearing device is disclosed in which a pair of sealing devices for forming an air flow passage between rows are mounted substantially in parallel.

In the bearing device disclosed in Patent Document 1, a pair of sealing devices that are provided separately and independently from a cage, a ball, and the like and have a bilaterally symmetric shape are replaced with two rows of bearing balls each composed of an outer bearing ball row and an inner bearing ball row. By mounting between the rows, the air circulation passage formed between the pair of sealing devices is kept airtight.
US Pat. No. 5,503,480 (FIG. 1)

  However, in the bearing device disclosed in Patent Document 1, when assembling the bearing device, each of the split inner races is fitted from the outside and incorporated, so that the pair of independently formed sealing devices are in a predetermined position. That is, there is a problem in that it is difficult to perform assembling operation at a predetermined position between two bearing ball rows composed of an outer bearing ball row and an inner bearing ball row.

  Further, in the bearing device disclosed in Patent Document 1, temporarily, a pair of sealing devices is temporarily installed at a predetermined position between two bearing ball rows composed of an outer bearing ball row and an inner bearing ball row. Even so, it is difficult to confirm whether the pair of sealing devices are correctly assembled at predetermined positions or not.

  Furthermore, in the bearing device disclosed in Patent Document 1, a configuration is adopted in which a pair of sealing devices formed independently are provided between two bearing ball rows composed of an outer bearing ball row and an inner bearing ball row. In addition, since it is necessary to provide a sufficient distance between a pair of balls and cages on the left and right, the axial dimension (dimension in the width direction) of the main body including the outer race and the inner race is large. There is a problem of becoming.

  As the axial dimension increases, the distance between the operating points of the two bearings consisting of the outer bearing ball row and the inner bearing ball row is separated, so that a desired rated load cannot be obtained, and it is a peripheral component. There is a possibility that the desired suspension performance cannot be exhibited by affecting the layout of the hub and spindle. In addition, due to the increase in the axial dimension, there is another problem that it is difficult to divert existing parts, making it impossible to share parts, and increasing the weight of peripheral parts of the hub.

  The present invention has been made in view of the various points described above, and it is possible to reliably arrange a pair of seal members at predetermined positions so that the position thereof is not required and to reduce the axial dimension of the apparatus main body. An object of the present invention is to provide a wheel bearing device capable of achieving the above.

  In order to achieve the above-described object, the present invention provides a first rolling part and a second rolling part in which a plurality of rolling elements are rotatably held by a retainer between an outer race and an inner race in an axial direction. And a pair of seal members each having a lip portion in contact with the inner surface of the outer race and the outer surface of the inner race, along the axial direction between the first rolling portion and the second rolling portion. Each of the outer race and the inner race is provided with an air communication path including a radial through-hole that opens between the pair of seal members arranged in parallel. An air flow path in which airtightness is maintained between the outer surface of the outer race and the inner surface of the inner race by the air communication path and an air communication portion formed between the pair of seal members arranged in parallel. The pair of seal members arranged in parallel is fixed to a retainer provided on a rolling portion on the side where the seal member is adjacent, of the first rolling portion and the second rolling portion. It is characterized by being.

  In this case, for example, a protrusion that protrudes a predetermined length along the axial direction is provided on the annular side surface of the seal member, and a recess is formed on the annular side surface of the retainer that faces the seal member. The seal member is integrally fixed to the retainer by fitting the recess into the recess.

  In this way, in the present invention, the sealing member is integrated with the retainer in advance, as compared with the prior art in which a pair of separately formed sealing devices is incorporated at a predetermined position between the two rows of bearing balls. The seal member is mounted in a state where the seal member is positioned at a predetermined position simply by incorporating a retainer between the outer race and the inner race.

  Therefore, in the present invention, the assembling work of the sealing member as in the prior art is not necessary, and the positioning of the sealing member is not necessary. As a result, in the present invention, the assembly process in the wheel bearing device can be simplified and the manufacturing process can be simplified.

  Further, in the present invention, the seal member is fixed integrally with the retainer in advance, and the seal member is mounted in a state where the seal member is positioned at a predetermined position simply by incorporating the retainer between the outer race and the inner race. It is unnecessary to confirm whether or not the seal member is mounted at a predetermined position, and it is possible to reliably prevent the displacement of the seal member.

  Furthermore, in the present invention, since the seal member is integrally fixed to the retainer in advance, the separation distance between the seal member and the retainer is reduced, so that a sufficient separation distance is provided between the rolling elements and the retainers arranged in close proximity. It becomes unnecessary to set the axial dimension of the entire wheel bearing device.

  Therefore, in the present invention, by reducing the axial dimension of the entire wheel bearing device, it becomes possible to make the distance between the operating points of the two bearings composed of the first rolling part and the second rolling part close to each other. Can be obtained. In addition, the degree of freedom in layout of peripheral components (for example, hubs, spindles, etc.) can be increased, and desired suspension performance can be exhibited. In addition, by reducing the axial dimension, it is possible to divert existing parts and reduce the manufacturing cost by sharing parts, while reducing the weight of peripheral parts. Can be planned.

  Provided is a wheel bearing device in which a pair of seal members is securely arranged at a predetermined position so that confirmation of the position is unnecessary, and the axial dimension of the apparatus main body can be reduced.

  Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. FIG. 1 is a schematic longitudinal sectional view of a wheel drive system in which a wheel bearing device according to an embodiment of the present invention is incorporated, and FIG. 2 is a portion along the axial direction of a hub bearing provided in the wheel drive system. It is an enlarged vertical sectional view.

  As shown in FIG. 1, the wheel drive system 10 includes a hub 12 to which a wheel of an automobile or the like is attached, a hub bearing 14 including a wheel bearing device integrally incorporated in a part of the outer peripheral surface of the hub 12, An outer ring member 18 having a shaft portion 16 fitted inside the hub 12, a knuckle 22 locked to the outer peripheral surface of the hub bearing 14 via a clip ring 20, and a tire air chamber (not shown) are added. And an air supply mechanism 26 for supplying pressurized air.

  The outer ring member 18 constitutes a bar field type constant velocity joint connected to one end portion of a drive shaft 28 to which rotational driving force from an engine or the like (not shown) is transmitted, and the other end portion of the drive shaft 28 Is connected to another constant velocity joint (not shown) connected to a differential device (not shown).

  A through hole 30 is formed in the substantially central portion of the hub 12 along the axial direction, and a serration groove (or spline groove) is formed on the inner peripheral surface of the through hole 30 substantially in parallel with the axis of the through hole 30. It is engraved.

  A mounting flange 12a is formed on the outer peripheral surface of the hub 12 so as to expand radially outward. A brake disk 34, a wheel 36, and the like are mounted on the mounting flange 12a via a hub bolt 32.

  The knuckle 22 is fixed to a column of a vehicle suspension system (not shown), and the hub bearing 14 and the hub 12 are fitted to the inner diameter portion of the knuckle 22. Accordingly, since the hub bearing 14 (an outer race 38 to be described later) is fixed to a vehicle body (not shown) via the knuckle 22, an inner race 40 and a hub described later provided on the inner diameter side of the outer race 38 by the hub bearing 14. The outer ring member 12 and the outer ring member 18 are rotatably supported with respect to a vehicle body (not shown).

  As shown in FIG. 2, the hub bearing 14 is composed of a single cylindrical body connected to the knuckle 22 and is supported in a fixed state, and two divided and provided on the inner diameter side of the outer race 38. And an inner race 40 configured by connecting cylindrical bodies in series along the axial direction. Note that the opening portions at both ends along the axial direction of the outer race 38 and the inner race 40 are closed by an annular seal 42.

  Further, the hub bearing 14 is rotatably held between the outer race 38 and the inner race 40, and a plurality of balls (rolling elements) 44 constituting two ball rows arranged in an annular shape and in the left-right direction. The ball 44 arranged annularly on the outer side and the inner side is arranged substantially in parallel between a pair of left and right retainers 46 that hold the balls 44 by means of a spherical concave surface (not shown) and two ball rows consisting of the inner side and the outer side. And a pair of sealing members 48 made of an annular body.

  In this case, in FIG. 2, the first rolling portion 50 a is configured by the ball 44 interposed between the left outer race 38 and the left inner race 40, and the right outer race 38 and the right inner race 40 are The second rolling part 50b is constituted by the balls 44 interposed therebetween, and the first rolling part 50a and the second rolling part 50b are arranged in parallel along the axial direction.

  Each of the pair of seal members 48 has a symmetrical shape, and is arranged in parallel with a predetermined distance in the axial direction between the first rolling part 50a and the second rolling part 50b. Lip portions that contact the inner wall surfaces of the outer race 38 and the inner race 40 are provided on the outer diameter and inner diameter edges of each seal member 48.

  The lip portion is bifurcated into a substantially Y-shaped longitudinal cross section, and includes an air seal lip 54a that hermetically seals an air communication portion 52, which will be described later, an outer race 38, an inner race 40, and a ball 44. And a grease lip 54b for holding a lubricating grease that penetrates the moving surface to form a lubricating coating. The lip portion can be increased in the number of lips and the shape of the lip can be changed in order to improve the sealing performance.

  Further, as shown in FIGS. 3 and 4, the annular side surface portion of each seal member 48 adjacent to the retainer 46 has a protruding portion 56 protruding by a predetermined length in the axial direction at a predetermined interval along the circumferential direction. A plurality are formed apart from each other. A plurality of concave portions 58 having a rectangular cross section are formed on the annular side surface portion of the retainer 46 facing the seal member 48 so as to be spaced apart from each other by a predetermined distance along the circumferential direction corresponding to the projection portion 56 (see FIG. 3).

  In this case, the plurality of protrusions 56 of the seal member 48 are fitted to the plurality of recesses 58 formed on the annular side surface portion of the retainer 46 and bonded using an adhesive, whereby the seal member 48 is bonded. Is integrally fixed to the retainer 46 (see FIG. 5). The seal member 48 is preferably formed of a material such as nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), or fluorine rubber (FKM). The retainer 46 is preferably formed of, for example, a resin material such as laminated phenol resin or fiber reinforced composite resin (FRP), or a metal material such as stainless steel.

  As a method for fixing the seal member 48 to the annular side surface portion of the retainer 46, as shown in FIG. The annular projection 60 is formed on the annular side surface of the seal member 48a, and the annular projection 60 of the seal member 48a is mounted and fixed to the annular groove 62 formed on the annular side surface of the retainer 46a. Good.

  As shown in FIG. 1, the air supply mechanism 26 includes a first air pipe member 66 having one end connected to an air supply source (not shown) and the other end connected to a pipe connection 64 of the knuckle 22 and the knuckle. 22, a first passage 68 that is formed inside the pipe connection portion 64 and communicates with the pipe connection portion 64, and a through hole that extends along the radial direction of the outer race 38, and communicates with the first passage 68. 70, an air communication part 52 closed by a pair of annular seal members 48 communicating with the first air communication path 70 and facing each other, and two inner races 40 communicated and divided with the air communication part 52 A second air communication passage 72 formed on the mating surface, a second passage 74 formed by bending inside the hub 12 and communicating with the second air communication passage 72, and communicating with the second passage 74. A passage is formed inside A second air piping member 78 connected to a pipe connecting portion 76 provided in the hub 12 and a tire air chamber (not shown) into which a part of the second air piping member 78 is inserted and pressurized air is supplied. And have.

  In this case, the pressurized air supplied through the first air piping member 66 includes the first passage 68 of the knuckle 22, the first air communication passage 70 of the outer race 38, the air communication portion 52 between the pair of seal members 48, the inner race. The tire air chamber (not shown) is supplied to the tire air chamber (not shown) sequentially via the second air communication path 72 between the 40, the second passage 74 of the hub 12 and the second air piping member 78, and the tire air pressure is predetermined via a control mechanism (not shown). Controlled by pressure.

  The first air communication path 70 and the second air communication path 72 are provided at a plurality of locations (for example, 8 locations) spaced apart from each other by a predetermined angle along the circumferential direction (see FIG. 3). Further, an annular groove that circulates along the inner wall of the knuckle 22 is formed at one end of the first passage 68 that communicates with the first air communication passage 70, and the first air communication passage 70 and the first passage 68. A set of annular seals 80 is provided to maintain the airtightness of the communication part. Furthermore, an annular groove is formed at one end portion of the second passage 74 communicating with the second air communication passage 72, and the airtightness of the communication portion between the second air communication passage 72 and the second passage 74 is maintained. A set of annular seals 82 is provided.

  The outer ring member 18 is integrally formed with a cup portion 84 formed in a cup shape on one end side and a columnar shaft portion 16 formed on the other end side and fitted in the through hole 30 of the hub 12. Formed.

  Serrations are formed on the outer peripheral surface of the shaft portion 16, and when the shaft portion 16 is inserted into the through hole 30 of the hub 12, the shaft portion 16 is fitted into the serration groove of the through hole 30. That is, the serration of the shaft portion 16 and the serration groove of the hub 12 mesh with each other, the outer ring member 18 is serrated to the hub 12, and the outer ring member 18 rotates relative to the hub 12. Is in a regulated state. For this reason, when the rotational driving force is transmitted through the constant velocity joint, the outer ring member 18 and the hub 12 rotate integrally.

  Further, when the shaft portion 16 is inserted into the through hole 30 in the outer ring member 18, the bottom surface portion of the cup portion 84 of the outer ring member 18 contacts and presses the side end surface of the inner race 40 of the hub bearing 14. Thus, it is positioned at a predetermined position along the axial direction. Then, the outer ring member 18 is fixed to the hub 12 by fastening a lock nut 86 to the distal end portion of the shaft portion 16.

  An inner ring 88 having an outer peripheral surface formed in a substantially spherical shape is attached to the drive shaft 28 at the inner diameter portion of the outer ring member 18. A plurality of steel balls 90 are provided between the inner ring 88 and the outer ring member 18 so as to be spaced apart at equal angles along the circumferential direction, and the steel balls 90 are freely rotatable on a holding window 92 a of the holding member 92. And is provided so as to engage with a track groove 94 formed on the inner diameter surface of the outer ring member 18.

  The wheel drive system 10 in which the wheel bearing device according to the present embodiment is incorporated is basically configured as described above. Next, the operation and effects thereof will be described.

  A rotational driving force generated by an engine or the like (not shown) is transmitted to the drive shaft 28 from another constant velocity joint (not shown), and the inner ring 88 spline-fitted to the drive shaft 28 rotates integrally. Then, the outer ring member 18 of the constant velocity joint rotates in a predetermined direction through a track groove 94 with which a plurality of steel balls 90 provided on the outer periphery of the inner ring 88 are engaged.

  Since the outer ring member 18 is engaged with the inside of the through hole 30 of the hub 12 via a serration formed in the shaft portion 16, the outer ring member 18 is connected to the outer race 38 fixed to the vehicle body (not shown) via the knuckle 22. The race 40, the hub 12, the brake disc 34, the wheel 36, and the like integrally rotate relative to each other.

  In the present embodiment, the sealing member 48 is fixed to the concave portions 58 formed on the annular side surface portions of the retainer 46 by fixing a plurality of projection portions 56 provided projecting laterally on the annular side surface portion of the sealing member 48. 48 and the retainer 46 are integrated. Therefore, in the present embodiment, the seal member 48 is previously provided with respect to the retainer 46 in comparison with the prior art in which a pair of independently formed sealing devices is incorporated at a predetermined position between the two rows of bearing balls. Since the sealing member 48 is mounted in a state where it is fixed at a predetermined position only by incorporating the retainer 46 between the outer race 38 and the inner race 40, the assembling work of the sealing member 48 as in the prior art is performed. Is unnecessary, and positioning of the seal member 48 is unnecessary. As a result, in this embodiment, the assembly work in the hub bearing 14 can be simplified and the manufacturing process can be simplified.

  In the present embodiment, for example, a retainer 46 formed of a resin material or a metal material and a seal member 48 formed of, for example, a rubber material are separately provided, and the seal member is provided to the retainer 46. The retainer 46 and the seal member 48 are integrally assembled by fixing the 48 with a fitting and an adhesive, but the present invention is not limited to this, and the retainer 46 and the seal member 48 are not limited thereto. Are integrally formed of the same material or different materials.

  For example, when the retainer 46 and the seal member 48 are integrally formed of the same material, the retainer 46 and the seal member 48 are integrally formed as a molded product by plastic molding (resin molding) using a mold (not shown). A combined single composite shape can be obtained. Further, for example, when the retainer 46 and the seal member 48 are molded from different materials, a preformed seal member 48 is inserted into the mold cavity, and a molding material different from the seal member 48 is inserted into the cavity. It is preferable that the retainer 46 and the seal member 48 are molded together by flowing into the container. In order to secure the sealing performance of the sealing member 48, a reinforcing material such as a metal may be placed in the sealing member 48 and molded.

  Further, in this embodiment, the seal member 48 is fixed integrally with the retainer 46 in advance, and the seal member 48 is positioned at a predetermined position simply by incorporating the retainer 46 between the outer race 38 and the inner race 40. Therefore, it is not necessary to confirm whether or not the seal member 48 is mounted at a predetermined position, and the positional displacement of the seal member 48 can be reliably prevented.

  Furthermore, in this embodiment, the seal member 48 is fixed in advance to the retainer 46 in advance, and the separation distance between the seal member 48 and the retainer 46 is reduced. It is not necessary to set a sufficient separation distance between them, and the axial dimension of the entire hub bearing 14 can be set small.

  Therefore, in this embodiment, the distance between the operating points of the two bearings including the first rolling part 50a and the second rolling part 50b can be made closer by reducing the axial dimension of the entire hub bearing 14. Thus, a sufficient load rating can be obtained. Further, it is possible to increase the degree of freedom in layout of the peripheral component parts such as the hub 12 and a spindle 98 (see FIG. 8) to be described later, and to exhibit desired suspension performance. In addition, by reducing the axial dimension, it is possible to divert existing parts and reduce the manufacturing cost by sharing parts, and reduce the weight of hub peripheral parts to reduce weight. Can be achieved.

  Next, FIG. 7 shows a wheel drive system 10a in which a hub bearing 14a according to a modification is incorporated. The same components as those of the hub bearing 14 shown in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the hub bearing 14a according to this modification, one of the divided left inner rings 40 is deleted to directly form the ball rolling surface 96 on the outer peripheral surface of the hub 12, thereby further reducing the number of parts. The feature is that the manufacturing cost is reduced. Reference numeral 40a indicates an inner race block on which a ball rolling surface is formed.

  Next, a wheel driven system 10b incorporating a hub bearing 14b according to another modification is shown in FIG.

  This wheel driven system 10 b has a spindle 98 fixed to a vehicle body (not shown), and an air passage 100 is formed along the axial direction of the spindle 98. It is provided so that pressurized air is supplied into the tire air chamber via a third air piping member 104 connected to a pipe connecting portion 102 provided on the outer peripheral surface of the hub 12. Further, the outer race 38 is removed, and a ball rolling surface 106 is formed on the inner wall of the through hole 30 of the hub 12.

  The operation and effect of the hub bearings 14a and 14b according to the modification shown in FIGS. 7 and 8 are the same as those of the hub bearing 14 shown in FIG.

1 is a schematic longitudinal sectional view of a wheel drive system in which a wheel bearing device according to an embodiment of the present invention is incorporated. FIG. 4 is a partially enlarged longitudinal sectional view along an axial direction of a hub bearing provided in the wheel drive system. FIG. 3 is an exploded perspective view of an inner race, a retainer, and a seal member that constitute the hub bearing. It is a perspective view of the said sealing member seen from the projection part side. It is a partially cutaway perspective view showing a state in which the protrusion of the seal member is inserted into the recess of the inner race. It is a disassembled perspective view of the seal member and retainer which concern on a modification. It is a partially abbreviate | omitted longitudinal cross-sectional view of the wheel drive system incorporating the hub bearing which concerns on a modification. FIG. 10 is a partially omitted longitudinal sectional view of a wheel driven system in which a hub bearing according to another modification is incorporated.

Explanation of symbols

10 Wheel drive system 12 Hub 14 Hub bearing (wheel bearing device)
38 Outer race 40 Inner race 44 Ball (rolling element)
46 Retainer 48 Sealing member 54a Air seal lip 54b Grease lip 56 Projection 58 Recess

Claims (2)

Between the outer race and the inner race, a first rolling part and a second rolling part, in which a plurality of rolling elements are rotatably held by a retainer, are provided along the axial direction, respectively.
A pair of seal members having lip portions that are in contact with the inner surface of the outer race and the outer surface of the inner race are spaced apart from each other by a predetermined distance along the axial direction between the first rolling portion and the second rolling portion. Placed in parallel,
Each of the outer race and the inner race is provided with an air communication path including a radial through-hole that opens between the pair of seal members arranged in parallel.
The air communication path and the air communication portion formed between the pair of seal members arranged in parallel form an air flow path in which airtightness is maintained between the outer surface of the outer race and the inner surface of the inner race. And
The pair of seal members arranged in parallel is fixed to the retainer provided in the adjacent rolling portion of the first rolling portion and the second rolling portion. A wheel bearing device. The wheel bearing device according to claim 1,
The annular side surface portion of the seal member is provided with a protruding portion that protrudes by a predetermined length along the axial direction, and the annular side surface portion of the retainer that faces the seal member has a recess in which the protruding portion is fitted. A wheel bearing device formed.

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