JP2009287651A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for wheel having a sealing member appropriately sealing the inside of the bearing, in a bearing device for a wheel fixing an internal member and rotating an external member. <P>SOLUTION: The bearing device 1 for wheel has the external member 3 as a rotating side member, the internal member 2, and a rolling body 4, and the sealing member 16. The sealing member 16 is constituted of a slinger 19 and a seal member. The slinger 19 includes a cylinder part 19a and an outward flange part 19b. The seal member is constituted of a shape maintaining member 18 fitted in the outward member 3, an elastic seal 17 adhering integrally with the shape maintaining member 18 by cure adhesion. Axial lips 17a, 17b, 17c disposed to the elastic seal 17 are formed to be inclined on an inner diameter side, and their ends are brought into slide-contact with the slinger 19 with a predetermined margin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wheel bearing device, and more particularly to a wheel bearing device that fixes an inner member and rotates an outer member.

  A conventional rolling bearing is disclosed in, for example, Japanese Patent Laid-Open No. 2005-321070 (Patent Document 1). Referring to FIG. 3, a rolling bearing 101 disclosed in the publication includes an inner ring 102 that rotates integrally with a wheel hub (not shown), an outer ring 103 that is fixed to a knuckle (not shown), an inner ring 102, and an outer ring. A plurality of rolling elements 104 disposed between the inner ring 102 and the inner ring 102 and the outer ring 103;

The sealing member 105 seals the inside of the bearing by bringing a seal member 105a attached to the outer ring 103 as a fixed side raceway and a slinger 105b attached to the inner race 102 as a rotation side raceway into contact with each other.
JP 2005-321070 A

  In the rolling bearing 101 having the above-described configuration, the inner ring 102 may be used as a non-rotating side race and the outer ring 103 may be used as a rotation side race. In this case, the seal member 105 a is deformed by receiving a centrifugal force accompanying the rotation of the outer ring 103. In the case of FIG. 3, the interference between the sealing member 105a and the slinger 105b is reduced. As a result, the inside of the bearing may not be properly sealed.

  Accordingly, an object of the present invention is to provide a wheel bearing device having a sealing member capable of appropriately sealing the inside of the bearing in a wheel bearing device in which an inner member is fixed and an outer member is rotated.

  In the wheel bearing device according to the present invention, an outer member having a double-row outer rolling surface formed on the inner periphery, and a double-row inner rolling surface facing the double-row outer rolling surface are formed on the outer periphery. Between the outer member, the inner member and the inner member and the outer member, the double row rolling elements accommodated between the rolling surfaces of the inner member and the outer member via a cage. And an outer member is a rotation side member. The sealing member includes a slinger having a substantially L-shaped cross section and an annular sealing member. The slinger includes a cylindrical portion that is fitted and fixed to the outer diameter surface of the inner member, and an outward flange portion that protrudes radially outward from one axial end of the cylindrical portion. The seal member includes a shape holding member fitted in the outer member and an elastic seal integrally vulcanized and bonded to the shape holding member, and the axial lip provided on the elastic seal has an inner diameter. It is characterized in that it is inclined to the side, and its tip is in sliding contact with the slinger with a predetermined allowance.

  When the outer member is rotated, a centrifugal force radially outward acts on the axial lip. As a result, the tightening allowance between the axial lip and the outward flange portion increases. As a result, the inside of the wheel bearing device can be properly sealed. Further, the sealing performance of the sealing member is further improved by moving the sliding contact portion between the axial lip and the outward flange portion away from the outside of the bearing.

  Preferably, the seal member includes a plurality of axial lips. Thereby, the sealing performance of the sealing member is further improved.

  Preferably, the outward flange portion is located on the axially inner side of the wheel bearing with respect to the axial lip. As a result, against the intrusion of muddy water from the outside of the wheel bearing, it acts in the direction of increasing the tightening margin between the axial lip and the slinger, so that the axial lip does not lift up against the slinger and the sealing member The sealing performance is further improved.

  Preferably, the slinger includes a locking portion that protrudes radially outward from an end portion on the other side in the axial direction to prevent separation of the seal member. Thereby, since decomposition | disassembly of a sealing member can be prevented, the attachment to the wheel bearing apparatus becomes easy.

  More preferably, the outer diameter of the locking portion is larger than the inner diameter of the seal member and smaller than the inner diameter of the shape holding member. Thereby, since the latching part can be formed in advance and the seal member can be assembled while being elastically deformed, the assembly of the sealing member is simplified.

  Preferably, at least one of the slinger and the shape holding member is made of stainless steel. Stainless steel is effective for rust prevention of the portions of the slinger and shape retaining member that come into contact with the outside air.

  Preferably, the seal member is made of any material selected from nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorinated rubber. Any of the above materials is suitable as a material for the seal member.

  According to this invention, it is possible to obtain a wheel bearing device having a sealing member whose sealing performance does not deteriorate due to the centrifugal force accompanying the rotation of the outer member.

  A wheel bearing device (hereinafter referred to as “wheel hub bearing”) according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2. 1 is a view showing the wheel hub bearing 1, and FIG. 2 is an enlarged view around the sealing member 16 of FIG.

  First, referring to FIG. 1, a wheel hub bearing 1 supports a driven wheel of an automobile, and includes an inner member 2 as a non-rotating side race ring and an outer member 3 as a rotation side race ring. A plurality of balls 4 as rolling elements disposed between the inner member 2 and the outer member 3, a cage 5 that holds an interval between the adjacent balls 4, and the inner member 2 and the outer member 3. The sealing member 16 which seals both axial direction both ends is provided. The type of the bearing is not particularly limited, but in this embodiment, a double-row angular ball bearing is adopted.

  The inner member 2 is fitted and fixed to a fixed axle (not shown), and has first and second inner rolling surfaces 2a and 2b on the outer diameter surface. The outer member 3 protrudes from the first and second outer rolling surfaces 3a, 3b and the outer diameter surface at positions facing the first and second inner rolling surfaces 2a, 2b of the inner diameter surface, and the wheels ( And a wheel mounting flange 3c that holds the wheel (not shown), and rotates integrally with the wheel.

  The inner member 2 and the outer member 3 having the above-described configuration are formed of, for example, medium carbon steel (S53C) having a carbon content of 0.40 to 0.80 wt%, and surface hardness is obtained by induction hardening. HRC is set in the range of 58-64.

  A plurality of balls 4 are provided between the first inner rolling surface 2a and the first outer rolling surface 3a and between the second inner rolling surface 2b and the second outer rolling surface 3b. Has been placed. Further, grease as a lubricant is sealed in a space surrounded by the inner member 2, the outer member 3, and the sealing member 16 (referred to as “bearing internal space”).

  When the automobile travels on rough roads or rainy weather, the wheel hub bearing 1 having the above configuration comes into contact with a large amount of muddy water. Therefore, by adopting a sealing member 16 according to an embodiment of the present invention as shown in FIG. 2 as a sealing member for sealing the wheel hub bearing 1, it is possible to prevent a decrease in sealing performance. In the above embodiment, the example in which the sealing member 16 is disposed at both axial ends of the wheel hub bearing 1 has been described. However, the present invention is not limited to this, and the effect of the present invention can be obtained by disposing at least one. be able to.

  Next, the configuration of the sealing member 16 will be described with reference to FIG. The sealing member 16 includes an elastic seal 17, a cored bar 18 as a shape maintaining member (collectively referred to as “seal member”), and a slinger 19.

  The elastic seal 17 has three axial lips 17 a, 17 b, and 17 c that extend toward the rotation axis of the wheel hub bearing 1. That is, the inner diameter dimensions of the axial lips 17a, 17b, and 17c are gradually reduced toward the tip.

  The cored bar 18 includes a cylindrical portion 18a that fits into the inner diameter surface of the outer member 3, and an inward flange portion 18b that protrudes radially inward from one axial side (right side in FIG. 2) of the cylindrical portion 18a. Have. The elastic seal 17 is vulcanized and bonded to the cored bar 18. That is, the metal core 18 functions as a shape holding member that fixes the elastic seal 17 to the outer member 3 and holds the shape of the elastic seal 17.

  The slinger 19 is a member having a substantially L-shaped cross section, and includes a cylindrical portion 19a fitted and fixed to the outer diameter surface of the inner member 2, and one axial end portion of the cylindrical portion 19a (see FIG. 2) that protrudes radially outward from the left side in FIG. 2 and a locking portion that protrudes radially outward from the other axial end (right side in FIG. 2) to prevent separation of the seal member. 19c.

  The elastic seal 17 is made of synthetic rubber such as nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluorinated rubber (FKM). On the other hand, the metal core 18 and the slinger 19 are made of stainless steel such as austenitic stainless steel (SUS304). Stainless steel is effective for rust prevention of a portion (exposed portion) that comes into contact with the outside air of the cored bar 18 and slinger 19.

  The sealing member 16 having the above configuration seals the bearing interior by the axial lips 17a, 17b, 17c and the outward flange portion 19b being in sliding contact with a predetermined tightening margin. More specifically, the tips of the axial lips 17a, 17b, 17c inclined toward the inner diameter side come into contact with the outward flange portion 19b.

  Here, when the outer member 3 is rotated, a centrifugal force radially outward acts on the axial lips 17a, 17b, and 17c. Thereby, the interference with the axial lips 17a, 17b, 17c and the outward flange portion 19b increases. As a result, the inside of the wheel hub bearing 1 can be properly sealed.

  The sealing performance of the sealing member 16 is further improved by providing the elastic seal 17 with a plurality of axial lips 17a, 17b, 17c. However, the effect of the present invention can be obtained even if only one axial lip is provided.

  Further, the outward flange portion 19b is located on the inner side in the axial direction of the wheel hub bearing 1 with respect to the elastic seal 17 (left side in FIG. 2). By keeping the sliding contact portion between the axial lips 17a, 17b, and 17c and the outward flange portion 19b away from the outside of the bearing, the sealing performance of the sealing member 16 can be further improved. However, even if the outward flange portion 19b is disposed on the axially outer side (the right side in FIG. 2) of the wheel hub bearing 1 with respect to the elastic seal 17, the effect of the present invention can be obtained.

  Further, when the axial lips 17a, 17b, and 17c are inclined toward the inner diameter side and the outward flange portion 19b is disposed on the inner side of the elastic seal 17, the axial lips 17a, 17b, and 17c are muddy water or the like that tends to enter from the outside. Is pressed against the outward flange portion 19b. That is, since the fastening margin between the axial lips 17a, 17b, and 17c and the outward flange portion 19b increases, the sealing performance of the sealing member 16 is further improved.

  Further, the outer diameter of the locking portion 19c is set larger than the inner diameter of the elastic seal 17 and smaller than the inner diameter of the inward flange portion 18b. As a result, the locking portion 19c is formed in advance, and the sealing member 16 can be assembled by elastically deforming the elastic seal 17.

  However, you may extend the latching | locking part 19c to the radial direction outer side from the internal diameter end of the inward flange part 18b. In this case, after the seal member and the slinger 19 are assembled, the end portion of the cylindrical portion 19a must be bent to form the locking portion 19c. On the other hand, since a labyrinth effect is produced between the inward flange portion 18b and the locking portion 19c, the sealing performance of the sealing member 16 is improved.

  In addition, in said embodiment, although 2nd generation structure was illustrated as the wheel hub bearing 1, this invention is not limited to this, The wheel bearing apparatus which concerns on this invention illustrated if it was an outer ring | wheel rotation system The present invention can also be applied to a wheel bearing device other than the second generation structure. In the case of the first and second generations, the seal according to the present invention can be applied not only to the inner side but also to the outer side.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range or equivalent range as the present invention.

  The present invention is advantageously used in a wheel bearing device that fixes an inner member and rotates an outer member.

It is a figure which shows the wheel hub bearing which concerns on one Embodiment of this invention. It is an enlarged view of the sealing member of FIG. It is a figure which shows the conventional rolling bearing.

Explanation of symbols

1 wheel hub bearing, 2 inner member, 2a, 2b inner rolling surface, 3 outer member, 3a, 3b outer rolling surface, 3c wheel mounting flange, 4 ball, 101 rolling bearing, 102 inner ring, 103 outer ring, 104 Rolling element, 5 cage, 16, 105 sealing member, 17 elastic seal, 17a, 17b, 17c axial lip, 18 cored bar, 18a, 19a cylindrical part, 18b inward flange part, 19 slinger, 19b outward flange part, 19c Locking part, 105a Seal member, 105b Slinger.

Claims (7)

An outer member having a double row outer raceway formed on the inner periphery;
An inner member in which an inner rolling surface of a double row facing the outer rolling surface of the double row is formed on the outer periphery;
A double row rolling element housed between the rolling surfaces of the inner member and the outer member via a cage so as to roll freely;
In a wheel bearing device, comprising: a sealing member attached to an opening of an annular space formed between the outer member and the inner member, wherein the outer member is a rotation side member;
The sealing member includes a slinger having a substantially L-shaped cross section and an annular seal member.
The slinger includes a cylindrical portion that is fitted and fixed to the outer diameter surface of the inner member, and an outward flange portion that protrudes radially outward from one axial end of the cylindrical portion,
The seal member includes a shape holding member fitted in the outer member and an elastic seal integrally bonded to the shape holding member, and an axial lip provided on the elastic seal has an inner diameter. A wheel bearing device, wherein the wheel bearing device is formed so as to be inclined to the side, and the tip is in sliding contact with the slinger with a predetermined allowance.   The wheel bearing device according to claim 1, wherein the seal member includes a plurality of the axial lips.   The wheel bearing device according to claim 1, wherein the outward flange portion is located on an axially inner side of the wheel bearing with respect to the axial lip.   4. The wheel bearing device according to claim 1, wherein the slinger includes a locking portion that protrudes radially outward from an end portion on the other side in the axial direction and prevents separation of the sealing member.   The wheel bearing device according to claim 4, wherein an outer diameter dimension of the locking portion is larger than an inner diameter dimension of the seal member and smaller than an inner diameter dimension of the shape holding member.   The wheel bearing device according to claim 1, wherein at least one of the slinger and the shape maintaining member is formed of stainless steel.   The wheel seal device according to any one of claims 1 to 6, wherein the seal member is formed of any material selected from nitrile rubber, hydrogenated nitrile rubber, acrylic rubber, and fluorinated rubber.

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