JP2007285468A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prolong bearing service life by effectively preventing the entry of muddy water in a bearing space in a bearing device for a wheel equipped with a rotation sensor. <P>SOLUTION: The tip of an annular part 15b of a slinger 15 is axially inclined inward. A magnetic rubber 17 mounted on the outer surface side of the annular part 15b of the slinger 15 is turned around to the inner surface side of the annular part 15b by increasing the wall thickness at the tip of the annular part 15b axially inclined inward. A radial clearance 16 is formed so as to be axially extended between a rubber member 14 of a seal member 12 and the magnetic rubber 17 whose wall thickness is increased at the tip of the annular part 15b axially inclined inward. By so doing, the entry of muddy water in a bearing space can be effectively prevented to prolong a bearing service life. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device.

  A wheel bearing device for supporting a wheel of an automobile has an outer member having a double row raceway surface on the inner diameter side, and a double row raceway surface facing each raceway surface on the outer member on the outer diameter side. There is an inner member and rolling elements arranged in a double row in a bearing space between the outer member and the inner member, and one of the outer member and the inner member is a vehicle body. The fixing member attached to the side is the rotating member attached to the wheel side. In such a wheel bearing device, one end side or both end sides of the bearing space are sealed by a sealing means so that muddy water or the like does not enter the bearing space between the outer member and the inner member. In the case where only one end side of the bearing space is sealed by the sealing means, the other end side is sealed by a cap or the like outside the bearing portion.

  In recent years, ABS (Antilock Brake System) or the like is often incorporated in order to improve the running stability of a car, and a rotation sensor for detecting the rotation of the wheel for the control is mounted on the wheel bearing device. ing. In such a wheel bearing device equipped with a rotation sensor, a sealing means for sealing one end side of the bearing space is mounted on the fixed member side, and a sealing member having a plurality of seal lips and mounted on the rotating member side. , And a slinger having an annular portion that forms a radial clearance between the seal member and the seal member, and at least one of the seal lips is brought into contact with the inner surface side of the annular portion of the slinger, and the circumferential direction The magnetic rubber magnetized on the plurality of magnetic poles is attached to the outer surface side of the annular portion of the slinger, and the magnetic rubber attached to the outer surface side of the annular portion is used as the magnetic encoder of the rotation sensor (for example, Patent Document 1).

Japanese Patent Laid-Open No. 2004-60751 (FIG. 6)

  In the wheel bearing device equipped with the rotation sensor as described in Patent Document 1, muddy water or the like scattered outside is blocked to some extent by the ring portion of the slinger, and between the tip of the ring portion and the seal member. Muddy water or the like entering from the radial gap is blocked by a seal lip that comes into contact with the inner surface of the annular portion. The number and form of the seal lips for blocking the muddy water and the like are variously devised. However, it is difficult to completely block muddy water entering from the radial gap, and a part of the seal lip enters the bearing space.

  For this reason, the bearing life of the wheel bearing device is not due to the rolling fatigue life of a normal bearing, but due to the defective phenomenon caused by the muddy water entering the bearing space, that is, the occurrence of flaws due to the biting of mud, Often exhausted due to rust. This trend has also been confirmed by a survey of market collections.

  Accordingly, an object of the present invention is to effectively prevent muddy water from entering a bearing space and extend the bearing life in a wheel bearing device equipped with a rotation sensor.

  In order to solve the above problems, the present invention has an outer member having a double row raceway surface on the inner diameter side and a double row raceway surface facing each raceway surface on the outer member on the outer diameter side. An inner member and rolling elements arranged in a double row in a bearing space between the outer member and the inner member, and one of the outer member and the inner member is disposed on the vehicle body side. A fixing member to be attached, the other is a rotating member attached to the wheel side, and one end side of a bearing space between the outer member and the inner member is attached to the fixing member side and has a plurality of seal lips And a slinger that is mounted on the rotating member side and has a ring portion that forms a radial gap between the seal member and the seal member, and at least one of the seal lips is connected to the ring portion of the slinger Seal with sealing means to contact the inner surface of the In a wheel bearing device in which magnetic rubber magnetized by a plurality of magnetic poles in the circumferential direction is attached to the outer surface side of the ringer ring part, the tip of the ringer ring part is inclined inward in the axial direction. The magnetic rubber attached to the outer surface side of the ring portion of the slinger is increased in thickness at the tip of the ring portion inclined inward in the axial direction, and wraps around the inner surface side of the ring portion. A configuration was adopted in which the radial gap was formed to extend in the axial direction between the magnetic rubber whose thickness was increased at the tip of the annular portion and the seal member.

  That is, the tip of the ring portion of the slinger is inclined inward in the axial direction, and the magnetic rubber attached to the outer surface side of the ring portion of the slinger is moved at the tip of the ring portion inclined inward in the axial direction. Formed to extend the radial gap in the axial direction between the magnetic rubber and the sealing member that has increased thickness and wraps around the inner surface of the annular portion, and that is thickened at the tip of the annular portion. This effectively prevents muddy water from entering the bearing space and extends the bearing life.

  In the wheel bearing device of the present invention, the tip of the ring portion of the slinger is inclined inward in the axial direction, and the magnetic rubber attached to the outer surface side of the ring portion of the slinger is inclined inward in the axial direction. Thicken the wall at the tip of the annular part and wrap around the inner surface of the annular part. Since it is formed to extend in the direction, it is possible to effectively prevent muddy water from entering the bearing space and extend the bearing life.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the wheel bearing device includes an outer member 1 having double-row raceway surfaces 2 a and 2 b on the inner diameter side, and double-row facing each raceway surface 2 a and 2 b of the outer member 1. As an inner member 3 having raceway surfaces 4a and 4b on the outer diameter side, and rolling elements arranged in a double row in a bearing space between the outer member 1 and the inner member 3 and held by the cage 5 The outer member 1 is a fixed member attached to the vehicle body side by a flange 7, and the inner member 3 is a constant velocity joint or a rotating member attached to the axle by an axle hole 8 on the inner diameter surface. A wheel is attached to a flange 9 provided on the inner member 3 with a hub bolt 10. The track surface 4 b on the inboard side of the inner member 3 is provided on the outer diameter surface of a separate inner ring 3 a that is externally fitted and fixed to the inner member 3.

  Further, the outboard side of the bearing space between the outer member 1 and the inner member 3 is sealed with a seal member 11 mounted on the outer member 1 side, and the inboard side of the bearing space is the outer member. It is sealed by a sealing means comprising a seal member 12 mounted on one side and a slinger 15 mounted on an inner ring 3a on the inner member 3 side.

  As shown in FIG. 2, the sealing member 12 of the sealing means includes a core metal 13 fitted into the inner surface end of the outer member 1 and a rubber member 14 fitted to the core metal 13. The rubber member 14 is formed with two seal lips 14a that contact an inner surface of an annular portion 15b of a slinger 15 to be described later and one seal lip 14b that contacts an outer diameter surface of a cylindrical portion 15a of the slinger 15. ing. The slinger 15 rises from the end of the cylindrical portion 15a and the cylindrical portion 15a that is externally fitted to the end portion of the outer diameter surface of the inner ring 3a, and the distal end forms a radial clearance 16 between the rubber member 14 of the seal member 12. A magnetic rubber 17 magnetized by a plurality of magnetic poles in the circumferential direction is attached to the outer surface of the annular portion 15b by a vulcanization adhesion. Yes.

  The tip of the annular portion 15b of the slinger 15 is formed so as to be inclined inward in the axial direction, and the magnetic rubber 17 vulcanized and bonded to the outer surface of the annular portion 15b is inclined inward in the axial direction. The tip of the annular portion 15b is formed so as to increase in thickness and wrap around the inner surface. The magnetic rubber 17 having increased thickness at the end of the annular portion 15b and the rubber member 14 of the seal member 12 are formed. A radial gap 16 is formed extending in the axial direction. Therefore, intrusion of muddy water scattered outside into the bearing space is effectively prevented.

  3A and 3B show modifications of the seal member 12, respectively. 3A, the rubber member 14 of the seal member 12 has a seal lip 14a that contacts the inner surface of the annular portion 15b of the slinger 15, and an outer diameter surface of the cylindrical portion 15a of the slinger 15. Two seal lips 14b that come into contact with each other are formed. Further, in the modification of FIG. 3B, the seal lip 14c on the bearing inner side of the two seal lips 14b contacting the outer diameter surface of the cylinder 15a in the modification of FIG. Thus, the rotational torque can be reduced while preventing leakage of the high-viscosity grease sealed in the bearing space. Further, since gas leakage is allowed, even if the air in the bearing space expands due to a temperature rise, the outer diameter surface of the cylindrical portion 15a of the slinger 15 is caused by the pressure of the expanded air. It is not pressed by.

  In the embodiment described above, the outer member is a fixed member attached to the vehicle body side, the inner member is a rotating member attached to the wheel side, and the track surface on the inboard side is provided on a separate inner ring. The wheel bearing device according to the present invention can also be applied to an outer member as a rotating member and an inner member as a fixed member, and these modes are not limited to those in the embodiment. Further, the number, form and slinger form of the seal lip of the seal member in the bearing space sealing means are not limited to those of the embodiment.

A longitudinal sectional view showing an embodiment of a wheel bearing device Sectional drawing which expands and shows the sealing means which seals the inboard side of the bearing space of FIG. a and b are sectional views showing modifications of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer member 2a, 2b Track surface 3 Inner member 3a Inner ring 4a, 4b Track surface 5 Cage 6 Ball 7 Flange 8 Axle hole 9 Flange 10 Hub bolt 11, 12 Seal member 13 Core metal 14 Rubber members 14a, 14b, 14c Seal lip 15 Slinger 15a Cylindrical part 15b Annular part 16 Radial gap 17 Magnetic rubber

Claims (1)

  An outer member having a double-row raceway surface on the inner diameter side, an inner member having a double-row raceway surface facing the raceway surface of the outer member on the outer diameter side, and the outer member and the inner member Rotating body comprising rolling elements arranged in a double row in a bearing space between the members, one of the outer member and the inner member being fixed to the vehicle body side, and the other being mounted to the wheel side One end side of the bearing space between the outer member and the inner member is mounted on the fixed member side, and a seal member having a plurality of seal lips is mounted on the rotating member side. A slinger having a ring portion that forms a radial gap at the tip thereof, and at least one of the seal lips is sealed by a sealing means that contacts an inner surface side of the ring portion of the slinger, In the circumferential direction on the outer surface side of the ring part of the slinger In the wheel bearing device attached with magnetic rubber magnetized to several magnetic poles, the tip of the annular part of the slinger is inclined inward in the axial direction, and attached to the outer surface side of the annular part of the slinger. Magnetic rubber is increased in thickness at the tip of the annular portion inclined inward in the axial direction and wraps around the inner surface of the annular portion, and the magnetic rubber is increased in thickness at the tip of the annular portion. A wheel bearing device, wherein the radial gap is formed to extend in the axial direction between the seal member and the seal member.

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