JP2002267680A - Bearing for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bearing for wheel in which a foreign matter is hard to be caught between a magnetometric sensor and an encoder grating and in which the encoder grating is not damaged even when the foreign matter is caught. SOLUTION: The bearing for wheel is composed of an inside member 1, an outside member 2, a plurality of rolling bodies 3 which are housed between the inside member and the outside member and a seal device 5 which airtightly seals the end part of a ring-shaped space between the inside member 1 and the outside member 2. The seal device 5 is provided with a first ring-shaped seal plate 11 and a second ring-shaped seal plate 12 which are attached respectively to the mutually different members from among the inside member 1 and the outside member 2. Both seal plates 11, 12 are formed to be cross-sectional L-shapes composed of cylindrical parts 11a, 12a and erect plate parts 11b, 12b so as to be faced. The first seal plate 11 is fitted to the retation-side member from among the inside member 1 and the outside member 2. An elastic member 14 with which a magnetic substance powder is mixed is vulcanized and bonded to the erect plate part 11b. A protective cover 18 which is made of a nonmagnetic substance is installed at the outside of the elastic member 14 so as to be opposed to the elastic member while keeping a prescribed air gap. The speed of rotation of the wheel bearing is detected via the protective cover 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing for a wheel in an automobile or the like, and more particularly to a bearing for a wheel in which an encoder lattice for detecting rotation is integrated.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 9, in a wheel bearing in which a sealing device 105 is provided between an inner member 101 and an outer member 102 which are in rolling contact with a rolling element 103, an encoder grid 106 is provided on the sealing device 105. (For example, Japanese Patent Application Laid-Open No. 6-281018).
issue). The sealing device 105 fits the first and second seal plates 107 and 108, each having an L-shaped cross section, with the inner member 101 and the outer member 102, respectively, and attaches the lip 109 to the second seal plate 108. It is provided. The first seal plate 107 is called a slinger. The encoder grating 106 is an elastic member mixed with magnetic powder,
Is vulcanized and adhered to the seal plate 107 of FIG. The encoder grating 106 is formed by alternately forming magnetic poles in the circumferential direction, and is detected by the magnetic sensor 110 disposed in a face-to-face manner.

[0003]

However, in the above configuration, if a foreign substance such as a stone is caught in the gap between the magnetic sensor 110 and the encoder grid 106, the encoder grid 106 may be damaged.

[0004] It is an object of the present invention to provide a wheel bearing in which foreign matter is hardly caught between a magnetic sensor and an encoder grid, and the encoder grid is not damaged even if biting occurs.

[0005]

A wheel bearing according to the present invention comprises an inner member and an outer member, a plurality of rolling elements housed between the inner and outer members, and an annular space between the inner and outer members. A first and second annular sealing plates respectively attached to different ones of the inner member and the outer member. The seal plates are formed in an L-shaped cross section including a cylindrical portion and an upright plate portion and face each other, and the first seal plate is fitted to the rotation-side member of the inner member and the outer member. The upright portion is arranged on the outer side of the bearing, and an elastic member mixed with magnetic powder is vulcanized and bonded to the upright portion, and the elastic member has magnetic poles formed alternately in the circumferential direction. ,
The second seal plate integrally has a side lip slidingly contacting the upright plate portion and a radial lip slidingly contacting the cylindrical portion, and the cylindrical portion of the second seal plate and the upright plate portion of the first seal plate. In the wheel bearing facing the tip of the elastic member with a small radial gap, a protective cover made of a non-magnetic material is provided on the outer side of the elastic member with a predetermined air gap,
The number of rotations is detected via the protective cover. According to this configuration, the protective cover is provided on the outer side of the elastic member forming the encoder lattice, and the rotation speed is detected via the protective cover. The foreign matter is prevented from being caught in the cover by the protective cover. Even if a foreign object is caught between the protective cover and the magnetic sensor, the foreign object does not contact the elastic member, and the elastic member serving as the encoder lattice is not damaged. Since the protective cover faces the elastic member forming the encoder lattice with a predetermined air gap, the rotation of the elastic member is not hindered by the protective cover. Further, since the protective cover is made of a non-magnetic material, it does not hinder detection of the encoder lattice by the magnetic sensor.

In the present invention, the protective cover may be attached to a fixed member of the inner member and the outer member. With this configuration,
Since the protection cover does not rotate and the protection cover and the magnetic sensor, which are both stationary, face each other, the rotation prevents foreign matter from being caught between the protection cover and the magnetic sensor.

In the present invention, the first seal plate may be fitted to an inner member which is a rotating member of the outer member and the inner member. A wheel bearing according to a third aspect of the present invention is the wheel bearing according to the first aspect, wherein the first seal plate is fitted to the inner member.

In the present invention, a small labyrinth gap may be formed between the protective cover and the rotating member of the inner member and the outer member. By forming the labyrinth gap in this way, it is possible to prevent dust and the like from entering the bearing from between the protective cover and the rotation-side member without hindering rotation of the rotation-side member.

In the present invention, a seal lip may be integrally formed at the tip of the protective cover, and the seal lip may be brought into sliding contact with the end face of the rotating member of the inner member and the outer member. By providing the seal lip on the protective cover in this way, it is possible to prevent dust and the like from entering the bearing from between the protective cover and the rotating member.

[0010] In the present invention, the protective cover may be fitted to an end outer diameter surface of the outer member. Thus, when the protective cover is fitted to the end outer diameter surface of the outer member, unlike the case where it is fitted to the end inner diameter surface of the outer member,
A space for attaching the protective cover to the end of the annular space between the inner member and the outer member is not required, and the cross-sectional height of the seal device including the first and second seal plates can be secured. .

In the present invention, rubber for sealing may be integrally formed on the mounting portion of the protective cover. With this configuration, it is possible to prevent dust and the like from entering the bearing from the mounting portion of the protective cover.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This embodiment is an example in which the present invention is applied to a wheel bearing used for supporting driving wheels, and is an example in which a magnetized encoder also serves as a seal slinger. As shown in FIG. 1, the wheel bearing includes an inner member 1 and an outer member 2.
And a plurality of rolling elements 3 housed between the inner and outer members 1 and 2 and sealing devices 5 and 13 for sealing an end annular space between the inner and outer members 1 and 2. Sealing device 5 at one end
Has a magnetized encoder 20. Inner member 1
The outer member 2 has the raceway surfaces 1a, 2a of the rolling elements 3, and each raceway surface 1a, 2a is formed in a groove shape. The inner member 1 and the outer member 2 are members on the inner peripheral side and the outer peripheral side rotatable with respect to each other via the rolling elements 3, respectively. good. Further, the inner member 1 may be a shaft. The rolling element 3 is formed of a ball or a roller. In this example, a ball is used.

The wheel bearing is a double row rolling bearing, more specifically, a double row angular contact ball bearing. The inner ring of the bearing is fitted to the hub wheel 6 and the outer diameter of the end of the hub wheel 6. And a separate inner ring 1A. A raceway surface 1a of each rolling element row is formed on the hub wheel 6 and the separate inner ring 1A.

One end (for example, an outer ring) of a constant velocity universal joint 7 is connected to the hub wheel 6, and a wheel (not shown) is attached to a flange portion 6 a of the hub wheel 6 with a bolt 8. The other end (for example, inner ring) of the constant velocity universal joint 7 has a drive shaft (not shown).
Linked to The outer member 2 is formed of a bearing outer ring having a flange 2b, and is attached to a housing 10 formed of a knuckle or the like. The outer member 2 is a raceway surface 2 of both rolling element rows.
a, 2a. The rolling elements 3 are held by a holder 4 for each row. Inner member 1 and outer member 2
Is closed at one end, that is, the end on the center side of the axle, by the seal device 5 described above. The end of the annular space between the outer member 2 and the hub wheel 6 is sealed with another sealing device 13.

FIG. 3 shows the sealing device 5 in an enlarged manner. The seal device 5 has first and second annular seal plates 11 and 12 attached to the inner member 1 and the outer member 2, respectively. These seal plates 11 and 12 are each provided with the inner member 1.
And it is attached by fitting to the outer member 2 in a press-fit state. The two seal plates 11 and 12 are respectively cylindrical portions 11
a, 12a and the standing plate portions 11b, 12b are formed in an L-shaped cross section and face each other. The first seal plate 11 is
The inner member 1 and the outer member 2 are fitted into the inner member 1 which is a member on the rotation side, and serve as a slinger. The upright portion 11b of the first seal plate 11 is disposed on the outer side of the bearing, and an elastic member 14 mixed with magnetic powder is vulcanized and bonded to a side surface on the outer side. The elastic member 14 serves as an encoder grid that forms the magnetized encoder 20 together with the first seal plate 11, and has magnetic poles N and S alternately arranged in the circumferential direction.
(FIG. 2) is formed, which is a so-called rubber magnet.
The magnetic poles N and S are formed to have a predetermined pitch p in a pitch circle diameter (PCD). By arranging the magnetic sensor 15 as shown in FIG. 2 so as to face the elastic member 14 of the magnetized encoder 20, a rotary encoder for detecting the wheel rotation speed is configured. Magnetic sensor 1
5 is attached to the vehicle body.

The second seal plate 12 is a first seal plate 1
One side lip 16a slidingly contacting the upright plate portion 11b and radial lips 16b and 16c slidingly contacting the cylindrical portion 11a are integrally provided. These lips 16a to 16c are provided as a part of the elastic member 16 which is vulcanized and bonded to the second seal plate 12. The second seal plate 12 holds the elastic member 16 in a fitting portion with the outer member 2 which is a fixed-side member. The cylindrical portion 12a of the second seal plate 12 and the tip of the standing plate portion 11b of the first seal plate 11 are opposed to each other with a small radial gap, and a labyrinth seal 17 is formed by the gap.

A protective cover 18 made of a non-magnetic material facing the elastic member 14 with a predetermined air gap G is provided on the outer side of the elastic member 14 serving as an encoder lattice, that is, between the elastic member 14 and the magnetic sensor 15. Are located. The magnetic sensor 15 detects the wheel rotation speed via the protective cover 18. The protective cover 18 is formed in an L-shaped cross section including a ring-shaped side plate portion 18a facing in the axial direction and a cylindrical portion 18b extending from an outer diameter edge of the side plate portion 18a. The protective cover 18 is attached to an outer diameter surface of an end portion of the outer member 2 which is a fixed member of the inner member 1 and the outer member 2 by fitting the cylindrical portion 18b into a press-fit state. ing. The protective cover 18 is extended to a position where the inner diameter of the side plate portion 18a faces the end surface of the inner member 1 which is a member on the rotating side, and the gap between the inner diameter portion of the side plate portion 18a and the inner member 1 is formed. A labyrinth gap 19 is formed at the bottom.

According to the wheel bearing of this configuration, the elastic member 14 mixed with the magnetic powder is vulcanized and bonded to the upright portion 11b of the first seal plate 11, and the magnetic poles N and S are alternately arranged in the circumferential direction.
Are formed, the elastic member 14 and the first seal plate 11 constitute the magnetized encoder 20, and the rotation can be detected by the magnetic sensor 15. Although the protective cover 18 is interposed between the magnetized encoder 20 and the magnetic sensor 15, since the protective cover 18 is made of a non-magnetic material,
It does not affect the flow path of the magnetic flux, and there is no problem of lowering the accuracy of the rotation speed detection by the magnetic sensor 15. Regarding the seal between the inner and outer members 1 and 2, the first seal plate mainly contacts the sliding portions of the seal lips 16 a to 16 c provided on the second seal plate 12 and the cylindrical portion 12 a of the second seal plate 12. 11 and a labyrinth seal 17 formed by the front ends of the upright portions 11b facing each other with a slight radial gap. Further, since the labyrinth gap 19 is formed between the inner member 1 and the protective cover 18, dust and the like can be prevented from entering the bearing from between the inner member 1 and the protective cover 18, and the sealing property is improved. Is improved.

In this wheel bearing, since the protective cover 18 made of a nonmagnetic material is interposed between the elastic member 14 constituting the encoder lattice and the magnetic sensor 15, the foreign matter is present in the gap between the elastic member 14 and the magnetic sensor 15. Is prevented from biting. Even if a foreign substance is caught between the protective cover 18 and the magnetic sensor 15, the foreign substance does not contact the elastic member 14, and the elastic member 14 serving as the encoder lattice is not damaged. Since the magnetic sensor 15 is made of a harder material than rubber or the like, there is little problem of damage due to foreign matter being caught.

Further, since the protective cover 18 is attached to the outer member 2 which is a fixed-side member, the protective cover 1
8 does not rotate, and the protective cover 1 is rotated by the rotation.
There is no intrusion of foreign matter between the magnetic sensor 8 and the magnetic sensor 15. Since a predetermined air gap G is formed between the protective cover 18 and the elastic member 14, the protective cover 18 does not hinder the rotation of the elastic member 14 and the inner member 1 to which the elastic member 14 is attached. Further, since the magnetic sensor 15 may be brought into contact with the protective cover 18, the adjustment of the air gap between the magnetic sensor 15 and the elastic member 14 is greatly facilitated. Further, since the protective cover 18 is fitted to the outer diameter surface at the end of the outer member 2, unlike the case where the protective cover 18 is fitted to the inner diameter surface at the end of the outer member 2, the inner member 1 and the outer member 2 are different. A space for attaching the protective cover 18 to the end of the annular space between them becomes unnecessary, and the sectional height of the seal device 5 including the first and second seal plates 11 and 12 can be secured.

FIG. 4 shows another embodiment of the present invention.
This embodiment is different from the above-described embodiment shown in FIGS. 1 to 3 in that the seal lip 2
1 are integrally formed, and the seal lip 21 is brought into sliding contact with the end face of the inner member 1 which is a member on the rotation side. The seal lip 21 is made of an elastic material such as rubber. In the case of rubber, the seal lip 21 is formed integrally with the protective cover 18 by vulcanization bonding. The inner end of the protective cover 18 has a bent portion bent away from the inner member 1 so that the seal lip 21 can be attached thereto. Is installed. Therefore, no labyrinth seal is provided between the inner diameter edge of the protective cover 18 and the end surface of the inner member 1. Other configurations in this embodiment are the same as those in the above embodiment.

When the seal lip 21 is provided on the protective cover 18 as described above, the seal between the inner member 1 and the protective cover 18 is a contact seal, so that the sealability is further improved as compared with the case of using a labyrinth seal. improves.

FIG. 5 and FIG. 6 show still another embodiment of the present invention. This embodiment is an example applied to a wheel bearing for supporting a driven wheel. Also in this example, the magnetized encoder is of a type that also serves as a seal slinger. In this example, the shaft portion 36 of the hub wheel 36 forming a part of the inner member 1
a is not connected to the constant velocity joint, unlike the above embodiment of FIGS. The protective cover 18 is formed in the shape of a cap with a bottom, and the shaft portion 3 inside the vehicle body of the inner member 1 is formed.
6a. The bottom plate of the protection cover 18
A flat plate-like side plate portion 18a on the outer periphery facing the elastic member 14
And a cap portion 18c that protrudes outward following the inner peripheral edge of the side plate portion 18a. The cylindrical portion 18b on the outer periphery of the protective cover 18 is fitted into the end outer diameter surface of the outer member 2 in a press-fit state, as in each of the above-described embodiments. 2 attached. In this embodiment, the inner member 1 is a member on the rotation side, the outer member 2 is a member on the fixed side, and other configurations are the same as those in the above-described embodiment shown in FIGS. .

In the case of this embodiment, the protective cover 18
Since it is also used as a cover that covers the end of the inner member 1 that is a member on the rotation side, a dedicated cover for the inner member 1 can be omitted, and the number of parts can be reduced accordingly. In other words, the elastic member 1 is attached to the end face cover of the conventionally provided inner member.
By providing a portion serving as a protective cover facing 4, the end face cover can also be used as the protective cover,
A dedicated protective cover for the elastic member 14 is not required. Also,
Since the protection cover 18 is attached to the outer member 2 and covers the inner space 1 from the annular space between the inner and outer members 1 and 2 integrally, the sealing performance of the bearing is further improved.

FIG. 7 shows still another embodiment of the present invention. This embodiment differs from the embodiment of FIG. 6 in that the sealing rubber 22 is formed integrally with the mounting portion of the protective cover 18. The sealing rubber 22 is provided from the outer diameter surface to the end surface of the cylindrical portion 18b which is a portion for attaching the protective cover 18 to the outer member 1, and is formed integrally with the protective cover 18 by vulcanization bonding or the like. . The housing 10 connected to the flange 2 b of the outer member 2 is fitted to the outer diameter surface of the end of the outer member 2 via the rubber 22 of the protective cover 18. In this manner, the rubber 22 is provided on the protective cover 18, and the rubber 22 is provided between the outer member and the housing 10 for mounting the rubber.
In the case where the sealing is performed, the sealing performance of the bearing is further improved.
Other configurations in this embodiment are the same as those in the embodiment shown in FIG.

FIG. 8 shows still another embodiment of the present invention. This embodiment is different from the embodiment shown in FIG. 7 in that the rubber 22 is provided on the outer periphery of the protective cover 18, and the end of a cylindrical portion 18 b which is a portion for attaching the protective cover 18 to the outer member 2 is provided. The standing plate portion 18d that rises along the flange 2b of the outer member 2 is formed to be extended.
The sealing rubber 22A is integrally formed on the side surface 8d. The sealing rubber 22A is integrally formed on the protective cover 18 by vulcanization bonding or the like. Rubber 22A for sealing
Is in close contact with the surface of the housing 10 that faces in the axial direction, and seals the space between the outer member 2 and the housing 10.

As shown in FIGS. 7 and 8, the structure in which rubber 22 and 22A are provided to seal the space between the outer member 2 and the housing 10 is such that the wheel bearings are for driving wheels. It can also be applied when

[0028]

According to the wheel bearing of the present invention, a protective cover made of a non-magnetic material is provided on the outer side of an elastic member serving as an encoder lattice with a predetermined air gap, and the number of revolutions is reduced through the protective cover. Since the detection is performed, it is difficult for foreign matter to bite between the magnetic sensor and the encoder grid, and even if biting occurs, the encoder grid is prevented from being damaged.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a wheel support device provided with a wheel bearing according to an embodiment of the present invention.

FIG. 2 is a partial front view of an elastic member serving as the encoder lattice.

FIG. 3 is a partial sectional view of the wheel bearing.

FIG. 4 is a partial cross-sectional view of a wheel bearing according to another embodiment of the present invention.

FIG. 5 is a cross-sectional view of a wheel support device provided with a wheel bearing according to still another embodiment of the present invention.

FIG. 6 is a partial sectional view of the wheel bearing.

FIG. 7 is a partial sectional view of a wheel bearing according to still another embodiment of the present invention.

FIG. 8 is a partial sectional view of a wheel bearing according to still another embodiment of the present invention.

FIG. 9 is a partial sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inner member 2 ... Outer member 3 ... Roller element 5 ... Seal device 11 ... First seal plate 12 ... Second seal plate 11a, 12a ... Cylinder portion 11b, 12b ... Stand plate portion 14 ... Elastic member 16a ... Side lip 16b, 16c ... Radial lip 18 ... Protective cover 18b ... Cylindrical part 18c ... Cap part 19 ... Labyrinth gap 21 ... Seal lip 22,22A ... Rubber for sealing G ... Air gap

Claims (7)

[Claims] 1. A wheel comprising: an inner member and an outer member; a plurality of rolling elements housed between the inner and outer members; and a seal device for sealing an end of an annular space between the inner and outer members. A sealing device, wherein the sealing device has first and second annular seal plates respectively attached to different ones of the inner member and the outer member. The first portion is formed in an L-shaped cross section including a cylindrical portion and an upright portion, and faces each other.
The seal plate is fitted to the rotating side member of the inner member and the outer member, the upright portion is disposed on the outer side of the bearing, and the magnetic powder is mixed in the upright portion. The elastic member is vulcanized and bonded, and the elastic member is alternately formed with magnetic poles in the circumferential direction. The second seal plate integrally includes a side lip slidingly contacting the upright plate portion and a radial lip slidingly contacting the cylindrical portion. A wheel bearing having a cylindrical portion of the second seal plate and a tip of an upright portion of the first seal plate facing each other with a slight radial gap; A wheel bearing characterized in that a protective cover made of a non-magnetic material is provided facing the air gap, and the rotational speed is detected through the protective cover. 2. The wheel bearing according to claim 1, wherein the protective cover is attached to a fixed member of the inner member and the outer member. 3. A wheel comprising: an inner member and an outer member; a plurality of rolling elements housed between the inner and outer members; and a seal device for sealing an end of an annular space between the inner and outer members. A sealing device, wherein the sealing device has first and second annular seal plates respectively attached to different ones of the inner member and the outer member. The first portion is formed in an L-shaped cross section including a cylindrical portion and a three-dimensional portion and faces each other.
The seal plate is fitted to the inner member, the upright portion is arranged on the outer side of the bearing, and an elastic member mixed with magnetic powder is vulcanized and bonded to the upright portion. The elastic member has magnetic poles formed alternately in the circumferential direction, and the second seal plate integrally has a side lip slidingly contacting the upright plate portion and a radial lip slidingly contacting the cylindrical portion. 3. The wheel bearing according to claim 1, wherein the cylindrical portion and the tip of the upright portion of the first seal plate face each other with a slight radial gap. 4. The wheel according to claim 1, wherein a small labyrinth gap is formed between the protective cover and the rotating member of the inner member and the outer member. bearing. 5. The sealing cover according to claim 1, wherein a sealing lip is integrally formed at a tip end of the protective cover, and the sealing lip is slidably contacted with an end surface of a rotating member of the inner member and the outer member. 5. The wheel bearing according to any one of 4. 6. The wheel bearing according to claim 1, wherein the protective cover is fitted to an end outer diameter surface of an outer member. 7. The wheel bearing according to claim 1, wherein sealing rubber is integrally formed with the mounting portion of the protective cover.