JP2002147474A - Wheel bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel bearing capable of preventing a deformation of an encoder lattice caused by a rust and a deterioration in a magnetic characteristic. SOLUTION: This wheel bearing comprises an inner member 1 and an outer member 2; a plurality of rolling elements 3 stored between these inner and outer members; a seal device 5 for sealing an annular space at an end between the inner and outer members 1, 2. The seal device 5 has a first and second annular seal plates 11, 12 mounted to different members of the inner member 1 and the outer member 2 respectively. Both seal plates 11, 12 comprise cylindrical parts 11a, 12a and standing plate parts 11b, 12b, are formed to an L shape of cross section and are opposed to each other. The first seal plate 11 is engaged with the member at a rotation side of the inner member 1 and the outer member 2. An elastic member 14 in which a magnetic substance powder is mixed is vulcanized and adhered to the standing plate part 11b. A recessed part 11bb recessed to an inner side of bearing is provided on the standing plate part 11b of the first seal plate 11 and the elastic member 14 is buried in this recessed part 11bb.

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. 5, in a wheel bearing in which a sealing device 105 is provided between an inner member 101 and an outer member 102 which come into contact with each other via a rolling element 103. A device in which an encoder grating 106 is integrated with a sealing device 105 has been proposed (for example, JP-A-6-281018). Sealing device 105
Are first and second seal plates 10 each having an L-shaped cross section.
7 and 108 are fitted to the inner member 101 and the outer member 102, respectively.
Is provided. The first seal plate 107 is called a slinger. The encoder lattice 106 is an elastic member mixed with magnetic powder, and is vulcanized and bonded to the first seal plate 107. 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.

A seal plate 107 serving as a slinger and an inner member 101 serving as a rotating wheel are fitted in a press-fit state.
Depending on the external environment, rust may be generated at this fitting portion. Wheel bearings are in a harsh environment where muddy water and the like fall down due to road surface conditions and the like, and particularly when used in an environment where salt muddy water and the like are exposed to rust, rust easily occurs. In the above wheel bearing, the outer diameter surface of the inner member 101 and the encoder grid 10
6, a gap G is formed between the gap G and the inner surface of the encoder grid 106 made of magnetic rubber. Degrades magnetic characteristics. For this reason, the detection accuracy of the magnetic sensor 110 may be reduced.

FIG. 6 shows another example in which a sealing device between a rotating member and a stationary member also serves as an encoder lattice (Japanese Patent Laid-Open No. Hei 6-281018). This sealing device 115
Is provided with a recess 107bb recessed inward in the axial direction in the upright portion 107b of the first seal plate 107, and the recess 107bb
An encoder lattice 106 made of magnetic rubber is provided on substantially the entire outward surface of the standing plate portion 107b so that a part of the encoder lattice 106 is partially buried. Further, the encoder lattice 106 is integrally formed with a lip 106a whose tip is in contact with the outer diameter surface of the shaft 111 to which the first seal plate 107 is fitted. The second seal plate 108 is fitted on the inner diameter surface of the outer member 102 made of a housing.

In the sealing device 115, since the lip 106a of the encoder lattice 106 is in contact with the shaft 111, water or muddy water intrudes inward in the axial direction from the fitting portion between the first seal plate 107 and the shaft 111. Can be blocked. However, the prevention of intrusion of water and the like by the lip 106a is as follows.
Initially, the effect is obtained, but if a certain degree of rusting occurs, the difference in the sealing effect due to the presence or absence of the lip 106a disappears, and since the lip 106a is integral with the encoder grid 106, the lip 106a When pressed, the influence on the deformation of the encoder grating 106 is rather increased. For this reason, as shown in the example of FIG. 5, a considerable amount of radial gap G is formed between the encoder lattice 106 of magnetic rubber and the member 101 to which the seal plate 107 is fitted. The effect is less. However, if the gap G is increased, the area of the encoder lattice main body made of magnetic rubber decreases, and it becomes impossible to obtain necessary magnetic characteristics.

SUMMARY OF THE INVENTION It is an object of the present invention to prevent deformation and magnetic deterioration of an encoder lattice due to rust generated at a fitting portion between a seal and a rotating member, and to provide a sufficient area of the encoder lattice to obtain necessary magnetic characteristics. The object of the present invention is to provide a bearing for a wheel which can ensure the performance.

[0007]

SUMMARY OF THE INVENTION 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 end portion between the inner and outer members. A seal device for sealing a space, wherein the seal device has first and second annular seal plates respectively attached to different ones of the inner member and the outer member. The plates are formed in an L-shaped cross section including a circumferential portion and an upright 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 sealing plate has a side lip sliding on the standing plate portion and a radial lip sliding on the cylindrical portion. A wheel bearing having an integral lip and having a cylindrical portion of the second seal plate and a tip end of an upright portion of the first seal plate facing each other with a slight radial spacing; A concave portion is provided in the standing plate portion of the seal plate inward of the bearing, and the elastic member is embedded in the concave portion. According to this configuration, an elastic member mixed with magnetic powder is vulcanized and bonded to the upright portion of the first seal plate, and magnetic poles are formed alternately in the circumferential direction. A grating is formed, and rotation can be detected by a magnetic sensor facing the grating. As for the seal between the inner and outer members, the sliding contact of each seal lip provided on the second seal plate and the tip of the upright plate portion of the first seal plate on the cylindrical portion of the second seal plate have a slight radial direction. It is obtained with a labyrinth seal constituted by facing each other with a gap. Since the elastic member serving as the encoder lattice is embedded in the recess of the upright portion of the first seal plate serving as the slinger,
Even if rust is generated at the fitting portion of the first seal plate of the rotating member, the elastic member is not pressed by the growth of the rust. Therefore, even in a severe environment where rust easily occurs, deformation and magnetic deterioration of the elastic member serving as the encoder grid can be prevented.

In the present invention, the depth of the recess provided in the upright portion of the first seal plate may be greater than the plate thickness of the first seal plate. By forming the recess deeply in this manner, the thickness of the elastic member serving as the encoder lattice can be increased, and magnetic characteristics can be easily ensured even if the surface of the elastic member facing the outside of the bearing is small.

In the present invention, the first seal plate has a curved portion projecting outward of the bearing between the cylindrical portion and the upright plate portion, and the projecting end face of the curved portion and the rotating side member are provided. May be located substantially in the same plane.
By providing the curved portion in this manner, the fitting portion of the first seal plate and the elastic member are blocked by the curved portion, and rust generated in the fitting portion is prevented from spreading to the formation portion of the elastic member. Is done.

In the present invention, the first seal plate has a bent overlapping portion projecting outward from the bearing between the cylindrical portion and the standing plate portion. The end surface of the rotation-side member may be located substantially in the same plane. Also in the case where the bent overlapping portion is provided in this manner, similarly to the curved portion, the fitting portion of the first seal plate and the elastic member are blocked by the bent overlapping portion, and the rust generated in the fitting portion is reduced. Is prevented from propagating to the formation portion of the elastic member. The bending overlapped portion may have a smaller thickness in the radial direction than the curved portion, so that the area of the elastic member serving as the encoder lattice can be increased,
It is easy to secure magnetic properties.

In the present invention, the end face of the elastic member facing the outside of the bearing and the end face of the rotating member may be located in substantially the same plane. With this configuration, the thickness of the elastic member can be sufficiently ensured without increasing the width of the wheel bearing.

In the present invention, an end face of the elastic member facing outward of the bearing is located substantially in the same plane as an end face of the cylindrical portion of the second seal plate facing outward of the bearing, or It may be slightly retracted inward of the bearing. In the case of this configuration, a labyrinth seal having a predetermined axial width is always maintained between the elastic member and the cylindrical portion of the second seal plate, and the sealing property is improved. Also, since it is only necessary to retract the elastic member, it is not necessary to apply a complicated shape processing to the seal plate, the shape of the seal plate may be simple, and without increasing the arrangement space of the sealing means,
Sealability can be improved.

In the present invention, the first sealing plate may be formed of a magnetic material and a steel plate having rustproofing properties. With this configuration, it is possible to secure a sufficient magnetic flux density in the first seal plate serving as the magnetic core of the encoder lattice, and to prevent rust at the fitting portion between the first seal plate and the rotating member. Is improved.

[0014]

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. Alternatively, it may be an assembly member in which the bearing inner ring or the bearing outer ring is combined with another component. Also, the inner member 1
May be an axis. 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 bearing inner ring has a pair of raceway surfaces 1a, 1a of each rolling element row. It consists of split type inner rings 1A and 1B. The inner rings 1A and 1B are fitted on the outer periphery of the shaft of the hub wheel 6, and constitute the inner member 1 together with the hub wheel 6. The inner member 1 is formed by integrating the hub wheel 6 and one inner ring 1B instead of the hub wheel 6 and the three-part assembly including the pair of split inner rings 1A and 1B as described above. It may be composed of two parts including a hub ring with a raceway surface and the other 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, the inner ring) of the constant velocity universal joint 7 is connected to the drive shaft. The outer member 2 is composed of a bearing outer ring, and is attached to a housing (not shown) composed of a knuckle or the like in a suspension device. The rolling elements 3 are held by a holder 4 for each row.

FIG. 3 is an enlarged view of the sealing device 5 with the magnetized encoder. 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, 1
2 are attached to the inner member 1 and the outer member 2 by press-fitting. Both seal plates 11, 1
2 are cylindrical portions 11a and 12a and standing plate portions 11b and 12 respectively.
and b are formed in an L-shaped cross section and face each other. The first seal plate 11 is fitted to the inner member 1, which is a member on the rotation side, of the inner member 1 and the outer member 2, and serves 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 is provided together with the first seal plate 11 with the magnetized encoder 2.
0, which is an encoder lattice, and has magnetic poles N and S (FIG. 2) formed alternately in the circumferential direction, and is a so-called rubber magnet. The magnetic poles N and S are the pitch circle diameter (PC
In D), it is formed so as to have a predetermined pitch p. 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. The elastic member 14 has a tip covering portion 14a that covers the tip inner surface from the tip portion of the standing plate portion 11b of the first seal plate 11.
have. Note that the front end cover portion 14a may be omitted.

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 number of these lips 16a to 16c may be arbitrary, but in the example of FIG.
6a and two radial lips 16c and 16b located inward and outward in the axial direction. Second seal plate 12
In the figure, an elastic member 16 is held in a fitting portion with the outer member 2 which is a fixed member. That is, the elastic member 1
6 has a tip covering portion 16d that covers from the inner diameter surface of the cylindrical portion 12a to the outer diameter of the tip portion.
6 d is interposed in the fitting portion between the second seal plate 12 and the outer member 2. The tip portion 12aa of the cylindrical portion 12a of the second seal plate 12 is thinner than the other portion of the cylindrical portion 12a and is bent obliquely toward the inside diameter.
The top cover 16d covers aa. Note that the distal end covering portion 16d may be separated from other portions of the elastic member 16.

The cylindrical portion 12a of the second seal plate 12 and the first
Of the sealing plate 11 with a slight radial gap, and the labyrinth seal 1
7. When the end covers 14a, 16d are provided on the elastic members 14, 16 of the first and second seal plates 11, 12, the gap between these end covers 14a, 16d is equal to the gap that constitutes the labyrinth seal 17. Become.

The upright portion 11b of the first seal plate 11 has
A recess 11bb recessed on the inner side of the bearing is provided.
The elastic member 14 is embedded in 1bb. The recess 11
The depth of bb is set to be greater than the thickness of the first seal plate 11. In the case of this embodiment, the first seal plate 1
A curved portion 11c projecting outward from the bearing is formed between the cylindrical portion 11a and the standing plate portion 11b, and the protruding end surface of the curved portion 11c is substantially the same as the end surface of the inner member 1 which is a member on the rotation side. They are located in the same plane. That is, they are located substantially in the same vertical plane with respect to the axis of the wheel bearing. Further, the end face of the elastic member 14 facing the outer side of the bearing is also located substantially in the same plane as the end face of the inner member 1 which is a member on the rotation side. Further, the end face of the elastic member 14 facing the outside of the bearing is positioned substantially in the same plane as the end face of the cylindrical portion 12a of the second seal plate 12 facing the outside of the bearing, or slightly. It is retracted inward.

An example of the material of each member will be described. Inner member 1,
Both the outer member 2 and the rolling elements 3 are made of carbon steel such as bearing steel. The first seal plate 11 is a steel plate that is a magnetic material and has rust prevention properties, and a magnetic steel plate such as a ferromagnetic material.
For example, a ferritic stainless steel sheet (JIS standard S
US430 series) or a rust-proofed rolled steel plate or the like. The second seal plate 12 is made of a steel plate, for example, a non-magnetic austenitic stainless steel plate (SUS30).
4 series) or a rust-proofed rolled steel plate.
For example, the first seal plate 11 may be a ferritic stainless steel plate, and the second seal plate 12 may be an austenitic stainless steel plate.

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.
Is formed, the elastic member 14 and the first seal plate 11 constitute a magnetized encoder 20 serving as a pulsar ring, and rotation can be detected by the magnetic sensor 15 facing the elastic member 14. As for the seal between the inner and outer members 1 and 2, the sliding contact of the seal lips 16 a to 16 c provided on the second seal plate 12 and the second seal plate 12
And a labyrinth seal 17 formed by the tip of the standing plate portion 11b of the first seal plate 11 facing the cylindrical portion 12a with a slight radial gap.

The upright portion 11b of the first seal plate 11 serving as a slinger has a recess 11bb recessed inwardly of the bearing, and the elastic member 14 serving as an encoder grid is embedded in the recess 11bb. Even if rust is generated at the fitting portion of the cylindrical portion 11a of the first seal plate 11 in the inner member 1, which is the rotating side member, the elastic member 14 is not pressed by the growth of the rust, Deformation of the member 14 and magnetic deterioration can be prevented. Therefore, the magnetic sensor 15
, The rotation detection accuracy is maintained. The depth of the recess 11bb provided in the upright portion 11b of the first seal plate 11 is as follows.
Since the thickness of the first seal plate 11 is made deeper than that of the first seal plate 11, the thickness of the elastic member 14 can be sufficiently obtained while the entire elastic member 14 is provided in the recess 11bb. Therefore, even if the area of the surface of the elastic member 14 in the axial direction is small, the magnetic characteristics can be secured. Between the cylindrical portion 11a and the upright portion 11b of the first seal plate 11, there is formed a curved portion 11c projecting outward from the bearing, and the protruding end face of the curved portion 11c is a rotating member. A certain inner member 1
Is located in substantially the same plane as the end face of the inner member 1, it is possible to prevent the rust generated at the fitting portion of the inner member 1 of the first seal plate 11 from spreading to the elastic member 14. Curved part 11c
Can also obtain a reinforcing effect of increasing the rigidity of the first seal plate 11. Since the end surface of the elastic member 14 facing the outer side of the bearing is substantially in the same plane as the end surface of the inner member 1 which is the rotation side member, the first seal plate 11 of the inner member 1 is also provided in this regard. Rust generated at the fitting part of the elastic member 1
4 is prevented.

In order to improve rust prevention performance, the first seal plate 11 is preferably formed of a magnetic material and a steel plate having rust prevention properties. By forming the first seal plate 11 from a magnetic material and a steel plate having rustproofing properties, a sufficient magnetic flux density can be secured in the first seal plate 11 serving as the magnetic core of the magnetized encoder. At the same time, the rust prevention at the fitting portion between the first seal plate 11 and the inner member 1 as the rotation side member is improved.

In the above-described embodiment, the curved portion 11c that protrudes outward from the bearing is formed between the cylindrical portion 11a and the upright portion 11b of the first seal plate 11, but this curved portion 11c is formed. Instead, as shown in FIG. 4, a bent overlapping portion 11d that protrudes outward from the bearing is formed, and the bent overlapping portion 11d is formed.
The projecting end surface of d may be substantially flush with the end surface of the inner member 1 that is the rotation-side member. Also in the case of such a configuration, it is possible to prevent the rust generated at the fitting portion of the inner member 1 of the first seal plate 11 from propagating to the elastic member 14 by the bending overlap portion 11d. Further, the bending overlapped portion 11d has a smaller radial thickness than the curved portion 11c, so that the area of the elastic member 14 serving as an encoder lattice can be increased, and magnetic characteristics can be easily secured. Become.

[0026]

According to the wheel bearing of the present invention, the first seal plate serving as a slinger has a concave portion which is recessed on the inner side of the bearing in the upright portion of the first seal plate, and an elastic member serving as an encoder lattice is embedded in the concave portion. Even if rust is generated at the fitting portion of the first seal plate on the rotating side member, the elastic member is not pressed by the growth of the rust, and the deformation and magnetic deterioration of the elastic member serving as the encoder lattice are prevented. Can be prevented. Therefore, even when used in a severe environment, the rotation detection accuracy by detecting the encoder grating is maintained.

[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 sectional view of a conventional example.

FIG. 6 is a sectional view of another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inner member 2 ... Outer member 3 ... Roller element 5 ... Seal device 11 ... First seal plate 11bb ... Concave portion 11c ... Bent portion 11d ... Bend overlapping portion 12 ... Second seal plate 11a, 12a ... Cylindrical portion 11b, 12b Standing plate portion 14 Elastic member 16a to 16c Lip portion N, S ... Magnetic pole

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3J016 AA01 BB03 CA01 CA06 3J101 AA02 AA32 AA43 AA54 AA62 BA73 EA02 EA06 EA74 EA78 FA08 FA60 GA03

Claims (7)

[Claims] 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 annular space between the inner and outer members; The apparatus has first and second annular seal plates respectively attached to different ones of the inner member and the outer member, and both seal plates have a circumferential portion, an upright portion, and a Are formed in an L-shaped cross section and face each other.
The seal plate is fitted to the rotating 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 interval; A bearing for a wheel, characterized in that a concave portion is provided in the portion on the inner side of the bearing, and the elastic member is embedded in the concave portion. 2. The wheel bearing according to claim 1, wherein the depth of the recess provided in the upright portion of the first seal plate is greater than the plate thickness of the first seal plate. 3. The first seal plate has a curved portion projecting outward from the bearing between the cylindrical portion and the upright plate portion, and a projecting end surface of the curved portion and an end surface of the rotating member. 3. The wheel bearing according to claim 1, wherein the bearings are located in substantially the same plane. 4. The first seal plate has a bent overlapping portion projecting outward from the bearing between the cylindrical portion and the upright plate portion, and a protruding end face of the bent overlapping portion and the rotation The wheel bearing according to claim 1 or 2, wherein an end surface of the side member is located in substantially the same plane. 5. The wheel bearing according to claim 1, wherein an end surface of the elastic member facing the outside of the bearing and an end surface of the rotating member are located in substantially the same plane. 6. An end surface of the elastic member facing outward of the bearing is located substantially in the same plane as an end surface of the cylindrical portion of the second seal plate facing outward of the bearing, or slightly. The wheel bearing according to any one of claims 1 to 5, wherein the wheel bearing retreats inward of the bearing. 7. The first sealing plate is made of a magnetic material and a steel plate having rustproofing properties.
The wheel bearing according to any one of the above.