JP2022126301A - Wheel bearing device - Google Patents

Abstract

To provide a structure capable of using a pack seal as an outer side seal member, in a wheel bearing device using an inner member composed of a hub ring having an inside raceway surface on the outer side and an inner ring having an inside raceway surface on the inner side.SOLUTION: A hub ring 3 has a cylindrical seal supporting portion 3e that extends from an inner side base end portion of a wheel attaching flange to the inner side and opposes to an outer peripheral surface of the outer side end portion 2f of an outer ring 2. An outer side seal member 7 is a pack seal disposed between an outer peripheral surface of the outer side end portion 2f of the outer ring 2 and an inner peripheral surface of the seal supporting portion 3e.SELECTED DRAWING: Figure 2

Description

The present invention relates to a wheel bearing device.

A wheel bearing device is provided with sealing members on the inner side and the outer side between the outer member and the inner member to suppress the infiltration of foreign matter such as muddy water and the leakage of grease to the outside. ing. In a so-called third-generation wheel bearing device using an inner member composed of a hub ring having one inner raceway surface and an inner ring having the other inner raceway surface, the inner seal member includes: A pack seal is used in which a seal ring fitted to the outer member and a slinger fitted to the inner ring are combined. On the other hand, as the outer side seal member, a seal ring fitted to the outer member is used due to structural restrictions.

A seal ring of a general outer side seal member has three lips, a side lip, an intermediate lip and a grease lip. In such an outer side seal, when the pressure between the lips changes due to a change in temperature or the like, there is a risk that the lips will be attracted to each other and come into close contact. If the lips are in close contact with each other, the lips cannot maintain a desired contact state, resulting in an increase in rotational torque.

As a countermeasure, for example, in Patent Document 1, a reinforcing member is provided from the base end of the intermediate lip to the base end of the grease lip.

JP 2013-60975 A

However, Patent Document 1 aims at suppressing the adhesion of the intermediate lip and the grease lip to the sliding contact surface of the hub wheel, and does not disclose a configuration for suppressing the close contact between the side lip and the intermediate lip. . As described above, it is difficult for the outer-side seal member composed only of the seal ring to suppress the close contact of all the lips.

The present invention uses a pack seal as an outer-side seal member in a wheel bearing device using an inner member composed of a hub ring having an outer-side inner raceway surface and an inner ring having an inner-side inner raceway surface. The purpose is to realize a configuration that can

A wheel bearing device of the present invention is a hub wheel having an outer member having a double-row outer raceway surface on the inner circumference, a wheel mounting flange on the outer end, and a small diameter stepped portion extending in the axial direction on the outer circumference. and an inner ring press-fitted into the small-diameter stepped portion of the hub ring, having an outer-side inner raceway surface facing the outer-side outer raceway surface on the hub ring, and an inner-side outer raceway on the inner ring. an inner member having an inner raceway surface facing the surface; a double-row rolling element rollably accommodated between the raceway surfaces of the outer member and the inner member; and an outer side seal member for closing an outer side open end of the annular space formed by the member and the inner member, the hub wheel extending from the inner side base end portion of the wheel mounting flange toward the inner side and extending toward the inner side. It has a cylindrical seal support portion facing the outer peripheral surface of the outer side end portion of the outer member, and the outer side seal member is positioned between the outer peripheral surface of the outer side end portion of the outer member and the inner side of the seal support portion. It is characterized by being a pack seal arranged between the peripheral surface.

According to the present invention, in a wheel bearing device using an inner member composed of a hub ring having an outer-side inner raceway surface and an inner ring having an inner-side inner raceway surface, a pack seal is used as the outer-side seal member. can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the wheel bearing apparatus of one Embodiment. FIG. 2 is an enlarged view of the periphery of the outer side seal member in FIG. 1; FIG. 4 is an enlarged cross-sectional view of the slinger periphery of the outer ring fitted with the slinger. FIG. 4 is an enlarged cross-sectional view of the periphery of the seal ring of the hub wheel fitted with the seal ring; FIG. 4 is an enlarged cross-sectional view around the slinger and seal ring during assembly of the outer ring and the hub ring;

[Overall Configuration of Wheel Bearing Device]
The overall configuration of a wheel bearing device 1 will be described with reference to FIG. In the following description, the inner side indicates the vehicle body side of the wheel bearing device 1 when attached to the vehicle body, and the outer side indicates the wheel side of the wheel bearing device 1 when attached to the vehicle body. . The axial direction means the direction along the rotation axis A of the wheel bearing device 1 . The radially outer side represents the direction away from the rotation axis A of the wheel bearing device 1 . The radially inner side represents a direction approaching the rotation axis A of the wheel bearing device 1 .

As shown in FIG. 1, a wheel bearing device 1 rotatably supports a wheel in a suspension system of a vehicle such as an automobile. The wheel bearing device 1 has a configuration called a third generation, and includes an outer ring 2, a hub ring 3, an inner ring 4, rolling elements 5, an inner side seal member 6, and an outer side seal member 7. , an encoder ring 8 and a cap 9 .

An outer ring 2 as an outer member supports a hub ring 3 and an inner ring 4 . An inner side fitting surface 2b for fitting the cap 9 is provided on the inner peripheral surface of the inner side end portion 2g of the outer ring 2 . An outer-side fitting surface 2c for fitting the outer-side seal member 7 is provided on the outer peripheral surface of the outer-side end portion 2f of the outer ring 2 . A fitting surface 2 h for fitting the inner side seal member 6 is provided on the inner peripheral surface of the outer ring 2 facing the inner ring 4 . An outer peripheral surface 2e of the outer ring 2 is integrally provided with a vehicle body attachment flange 2d for attachment to a knuckle of a suspension system (not shown). The inner peripheral surface of the outer ring 2 is provided with double-row outer raceway surfaces 2a, 2a on its inner side and outer side in the circumferential direction.

The inner member is composed of the hub ring 3 and the inner ring 4 . A small-diameter stepped portion 3a extending in the axial direction is provided at the inner end portion of the outer peripheral surface of the hub wheel 3 . A wheel mounting flange 3b for mounting a wheel is integrally provided on the outer side end of the hub wheel 3. As shown in FIG. A hub bolt 3c is press-fitted into the wheel mounting flange 3b for fastening the hub wheel 3 and the wheel or the brake device. An outer inner raceway surface 3d is provided on the outer peripheral surface of the hub wheel 3 to face the outer raceway surface 2a.

The hub wheel 3 has a cylindrical seal support portion 3e that extends from the inner base end portion of the wheel mounting flange 3b toward the inner side and faces the outer fitting surface 2c of the outer ring 2. As shown in FIG. A fitting surface 3f parallel to the rotation axis A for fitting the outer side seal member 7 is provided on the inner peripheral surface of the seal support portion 3e.

The inner ring 4 is press-fitted into the small-diameter stepped portion 3 a of the hub ring 3 . The outer peripheral surface of the inner ring 4 is provided with an inner raceway surface 4a facing the inner raceway surface 2a. A fitting surface 4 b for fitting the inner side seal member 6 is provided on the outer peripheral surface of the inner ring 4 . An inner side fitting surface 4d for fitting the encoder ring 8 is provided on the outer peripheral surface of the inner side end portion 4c of the inner ring 4 .

The inner-side rolling elements 5 are rollably sandwiched between the inner raceway surface 4 a of the inner ring 4 and the inner-side outer raceway surface 2 a of the outer ring 2 . The outer-side rolling elements 5 are rotatably sandwiched between the inner raceway surface 3 d of the hub wheel 3 and the outer-side raceway surface 2 a of the outer ring 2 . That is, the inner-side rolling elements 5 and the outer-side rolling elements 5 are rotatably accommodated between the raceway surfaces of the outer member and the inner member. Thus, in the wheel bearing device 1 , the outer ring 2 , the hub ring 3 , the inner ring 4 , and the double-row rolling elements 5 constitute a double-row angular contact ball bearing. Note that the wheel bearing device 1 may constitute a double-row tapered roller bearing instead of the double-row angular contact ball bearing.

The inner-side sealing member 6 and the outer-side sealing member 7 are sealing members that close the open end of the annular space S formed by the outer member and the inner member. The inner side seal member 6 is attached to an inner side opening end formed between the outer ring 2 and the inner ring 4 in the annular space S. As shown in FIG. On the other hand, the outer-side seal member 7 is attached to an outer-side opening end formed between the outer ring 2 and the hub wheel 3 in the annular space S. As shown in FIG.

The encoder ring 8 has a support member 81 and a magnetic encoder 82 . The support member 81 is, for example, an annular body made of a steel plate, and is fitted to the inner side fitting surface 4 d of the inner ring 4 . The magnetic encoder 82 is made of synthetic rubber or the like in which magnetic poles (N and S poles) are alternately arranged in the circumferential direction so that the magnetism changes alternately in the circumferential direction. bonded to the surface. The magnetic encoder 82 is detected by a rotational speed sensor (not shown), which is a magnetic sensor.

The cap 9 is a member that closes the inner side open end of the outer ring 2 and supports the rotational speed sensor. The cap 9 is, for example, a disk made of steel plate, and is fitted to the inner fitting surface 2b of the outer ring 2 . The cap 9 protects the encoder ring 8 by preventing foreign matter such as muddy water from entering from the outside.

[Outer side seal member]
FIG. 2 is an enlarged view of the periphery of the outer side seal member 7 in FIG. The outer side seal member 7 is a pack seal having a slinger 71 and a seal ring 72 . The slinger 71 is, for example, an annular body made of steel, and has an outer fitting portion 711 and an outer plate portion 712 . The outer fitting portion 711 is a cylindrical portion fitted onto the outer side fitting surface 2c of the outer ring 2 . The outer plate portion 712 is a donut plate-shaped portion extending radially outward from the inner side end portion of the outer fitting portion 711 .

The seal ring 72 has a metal core 73 and an elastic member 74 . The cored bar 73 is, for example, an annular body made of a steel plate, and has an inner fitting portion 731 and an inner plate portion 732 . The inner fitting portion 731 is a cylindrical portion that is internally fitted to the fitting surface 3 f of the hub wheel 3 . The inner plate portion 732 is a donut plate-shaped portion extending radially inward from the outer end portion of the inner fitting portion 731 .

The elastic member 74 is made of synthetic rubber, for example, and is fixed to the metal core 73 by vulcanization adhesion or the like. The elastic member 74 covers the inner side surface, the tip surface, and the outer side surface of the inner plate portion 732 through the tip surface and the inner peripheral surface from the outer peripheral surface in the vicinity of the tip portion of the inner fitting portion 731 of the core metal 73 . ing.

The elastic member 74 has two side lips 741 and 742 and one grease lip 743 . The side lips 741 and 742 extend radially outward and toward the inner side, and their tip portions are in contact with the outer plate portion 712 of the slinger 71 . The side lips 741 and 742 prevent foreign matter such as muddy water from entering the annular space S from the outside. The grease lip 743 extends radially inward and outward, and its tip is in contact with or close to the outer fitting portion 711 of the slinger 71 . The grease lip 743 prevents the grease in the annular space S from leaking to the outside.

[Seal support part]
The tip of the inner side end portion 3g of the seal support portion 3e of the hub wheel 3 is located on the inner side of the tip of the outer side end portion 2f of the outer ring 2 and the outer side end portion of the outer raceway surface 2a on the outer side. Located on the outer side.

[Positioning part]
The outer ring 2 has a positioning portion 2i for axially positioning the slinger 71 on the outer peripheral surface of the outer end portion 2f. The positioning portion 2i is a portion protruding radially outward from the outer peripheral surface of the outer side end portion 2f. As long as the positioning portion 2i is arranged along the circumferential direction, it may be an annular body, or may be a plurality of projections arranged at predetermined intervals. The protrusion amount (height) of the positioning portion 2i is sufficient as long as it can contact the inner side surface of the outer plate portion 712 of the slinger 71 . The slinger 71 fitted to the outer ring 2 from the outer side is axially positioned by contacting the positioning portion 2i.

[Assembly process]
In the assembly process of the wheel bearing device 1 , the outer side seal member 7 is assembled before the outer ring 2 and the hub wheel 3 are assembled. Specifically, as shown in FIG. 3, the slinger 71 is press-fitted into the outer ring 2 in parallel with the axial direction from the outer side toward the inner side. Then, as shown in FIG. 4, the seal ring 72 is press-fitted into the hub wheel 3 in parallel with the axial direction from the inner side to the outer side. Thereafter, as shown in FIG. 5, the outer ring 2 fitted with the slinger 71 and the hub wheel 3 fitted with the seal ring 72 are assembled.

Thereby, the slinger 71 and the seal ring 72 form a pack seal. That is, in the wheel bearing device 1, the outer ring 2 fitted with the slinger 71 and the hub wheel 3 fitted with the seal ring 72 are assembled, and the outer ring 2 and the hub wheel 3 are assembled. , the slinger 71 and the seal ring 72 constitute a pack seal.

As described above, the side lips 741 and 742 extend radially outward and inner, and the grease lip 743 extends radially inward and outer. Therefore, in assembling the outer ring 2 and the hub wheel 3, when the slinger 71 and the seal ring 72 are assembled in the axial direction, the side lips 741 and 742 and the grease lip 743 come into contact with the slinger 71 while maintaining their extending directions. do. That is, the side lips 741 and 742 and the grease lip 743 are not reversed. In other words, it can be said that the side lips 741 and 742 and the grease lip 743 extend in a direction in which they are not reversed when the outer ring 2 and hub wheel 3 are assembled.

According to the above-described embodiment, a pack seal can be used as the outer side seal member 7 by providing the seal support portion 3e in the hub wheel 3 in the third generation wheel bearing device. By using the pack seal, it is possible to suppress adsorption of the lip due to temperature changes, etc., as compared with the conventional configuration that requires the use of only the seal ring. Therefore, it is possible to solve the problem that the lip cannot maintain the desired contact state and the rotational torque increases.

The above-described embodiment merely shows a typical form of the present invention, and various modifications can be made without departing from the gist of the present invention.

1 wheel bearing device 2 outer ring (outer member)
2a outer raceway surface 2i positioning portion 3 hub wheel (inner member)
3a small diameter stepped portion 3b wheel mounting flange 3d, 4a inner raceway surface 3e seal support portion 4 inner ring (inner member)
5 rolling elements 7 outer seal member 71 slinger 72 seal ring 73 core metal 74 elastic member 741, 742 side lip (lip)
743 grease lip (lip)
S annular space

Claims (6)

an outer member having a double-row outer raceway surface on its inner circumference;
A hub wheel having a wheel mounting flange on an outer side end portion and a small diameter stepped portion extending axially on the outer periphery; an inner member having an outer-side inner raceway surface facing the outer raceway surface, and having an inner-side inner raceway surface facing the inner-side outer raceway surface on the inner ring;
a double-row rolling element rollably accommodated between the raceway surfaces of the outer member and the inner member;
an outer-side sealing member that closes an outer-side open end of an annular space formed by the outer member and the inner member;
The hub wheel has a cylindrical seal support portion extending from the inner base end portion of the wheel mounting flange toward the inner side and facing the outer peripheral surface of the outer end portion of the outer member,
The wheel bearing device, wherein the outer side seal member is a pack seal arranged between an outer peripheral surface of the outer side end portion of the outer member and an inner peripheral surface of the seal support portion. 2. The wheel bearing device according to claim 1, wherein the inner side end portion of the seal support portion is positioned closer to the outer side than the outer raceway surface on the outer side. The outer-side sealing member is
a slinger fitted to the outer peripheral surface of the outer-side end of the outer member;
2. A seal ring composed of a core metal fitted to the inner peripheral surface of the seal supporting portion and an elastic member fixed to the core metal and having a plurality of lips. 3. The wheel bearing device according to 2. 4. The wheel bearing device according to claim 3, wherein the outer member has a positioning portion for axially positioning the slinger on the outer peripheral surface of the outer end portion. 5. The wheel bearing device according to claim 3, wherein the outer member fitted with the slinger and the hub wheel fitted with the seal ring are assembled together. . 6. The wheel bearing device according to claim 5, wherein the plurality of lips extend in a direction in which they are not reversed when the outer member and the hub wheel are assembled.

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