JP2008151311A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device with a seal having improved sealing performance, for maintaining bearing performance over a long period. <P>SOLUTION: A magnetic encoder 16 is adhered to part of a rising plate portion 10b of a slinger 10, and its inner peripheral face has a predetermined clearance to an inner ring 5 and its outer peripheral face has a predetermined clearance to the outer peripheral face of the rising plate portion 10b. Namely, on the peripheral face of the rising plate portion 10b in the radially outward direction, a surface exposed portion 10c having a surface exposed thereto is provided instead of the magnetic encoder 16. On the other hand, a seal member 15 is adhered to an inner end 14d of a core metal 14 and has a seal lip 15a extending in inclination to the radially inward direction. The seal lip 15a has sliding contact with the surface exposed portion 10c of the slinger 10 to prevent the direct entry of rainwater or dust into the seal 8. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like, and more particularly to a wheel bearing device that improves the sealing performance of a seal.

  2. Description of the Related Art Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like is such that a hub wheel for mounting a wheel is rotatably supported via a rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, an inner ring rotation method is generally used for driving wheels, and an inner ring rotation method and an outer ring rotation method are generally used for driven wheels. As the wheel bearing device, a double-row angular ball bearing having a desired bearing rigidity, exhibiting durability against misalignment, and having a small rotational torque from the viewpoint of improving fuel efficiency is often used. On the other hand, double row tapered roller bearings are used in vehicles such as off-road cars and trucks that have a heavy vehicle body weight.

  Since these wheel bearing devices are arranged at sites where muddy water or the like is likely to be applied, a seal device is mounted, and the space between the outer member and the inner member is sealed. Generally, in a sealing device, a sealing member having a sealing lip is attached to an outer member serving as a stationary member, and the sealing lip is slidably contacted with an outer peripheral surface of the inner member. In particular, in a vehicle that is driven in a poor environment such as an off-road car or a pickup truck, various means for further improving the sealing performance are taken.

  Patent Document 1 discloses a sealing device that improves such sealing performance. In this example, a slinger having an L-shaped cross section formed from a cylindrical portion fixed to the outer peripheral surface of the inner member and a standing plate portion extending radially from the outer end of the cylindrical portion toward the outer member. And a cylindrical portion fixed to the inner peripheral surface of the outer member and a seal ring formed with an inner peripheral lip that is in sliding contact with the inner surface of the slinger, wherein the slinger is formed of a low friction resin material. Yes. Thus, high sealing performance is realized by sliding the inner peripheral lip on the slinger surface.

In such a sealing device, a magnetized rubber encoder for detecting the rotational speed of a wheel for an anti-lock brake system (ABS) may be provided on the side surface on the inner side of the standing plate portion of the slinger. . A rotational speed sensor is disposed opposite to the rubber encoder, and the speed of the vehicle is detected. On the other hand, the present applicant has devised an invention in which a backup seal is newly mounted on the side end portion of the outer member with the aim of further improving the sealing performance of the wheel bearing device. In this example, a seal lip provided on the backup seal slidably contacts the peripheral surface of the rubber encoder.
JP 2002-227857 A

  However, since the seal lip of such a backup seal is in sliding contact with the peripheral surface of the rubber encoder, there is a problem such as friction between the seal lip and the rubber encoder, and a sufficient sealing effect may not be obtained. In addition, the seal lip may interfere with a rotational speed sensor arranged to face the encoder, and the sealing performance may be deteriorated.

  This invention is made | formed in view of such a situation, and aims at the improvement of the sealing performance of a seal | sticker, and it aims at providing the wheel bearing apparatus which can maintain bearing performance over a long period of time. .

  In order to achieve such an object, the present invention has an outer member integrally formed with a vehicle body mounting flange to be attached to a suspension device on the outer periphery, and an outer member formed with a double row outer rolling surface on the inner periphery, and one end portion. A hub ring integrally having a wheel mounting flange for mounting a wheel on the outer periphery, and a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring An inner member having a double-row inner rolling surface opposed to the double-row outer rolling surface on the outer periphery, and a cage between the inner member and the outer member. In a wheel bearing device comprising a double-row rolling element housed so as to be freely rollable via a seal attached to an opening of an annular space formed by the outer member and the inner member, The inner side seal has a substantially L-shaped cross section and is pressed against the inner periphery of the end of the outer member. An annular seal plate formed of a cored bar and a seal member integrally joined to the cored bar, a cylindrical part press-fitted into the outer periphery of the inner member, and extends radially outward from the cylindrical part. And a slinger comprising a standing plate portion, and a radially outer peripheral surface of the standing plate portion is exposed on the inner side surface of the standing plate portion of the slinger. An encoder is arranged so as to be a surface exposed portion, a backup seal is provided on the inner side of the inner side seal, and this backup seal is a cylindrical fitting that is press-fitted into the outer periphery of the end of the outer member. A disk portion extending radially inward from the fitting portion and closely contacting a part of the end portion of the outer member, a cylindrical portion extending from the disk portion to the inner side, and the cylindrical portion Further, a core composed of an inner end portion extending radially inward And a seal member integrally joined to the mandrel, the seal member extending inward in the radial direction, and integrally including a seal lip that is in sliding contact with the surface exposed portion of the slinger. Adopted.

  Thus, since the encoder is disposed so as to have the surface exposed portion on the side surface of the slinger, the seal lip of the backup seal can be brought into sliding contact with the surface exposed portion. As a result, problems such as friction caused when the seal lip is brought into sliding contact with the peripheral surface of the encoder can be reduced, better sealing performance of the seal can be obtained, and bearing performance can be maintained over a long period of time. it can.

  Further, in the present invention, the outer peripheral surface of the end portion of the outer member into which the fitting portion of the core metal of the backup seal is fitted is processed to have a small diameter by the thickness of the core metal of the backup seal. You can also. Thereby, the core metal of the backup seal does not interfere with the knuckle.

  In the present invention, since the core metal of the backup seal and the seal member of the backup seal are located radially outward of the encoder, even when a rotational speed sensor is arranged on the inner side of the encoder, The backup seal and the rotation speed sensor do not interfere.

  Further, according to the present invention, if the slinger is formed by press working from a steel plate having rust prevention ability, it is possible to prevent rusting over a long period of time and maintain a stable sealing property.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a suspension device on an outer periphery, an outer member having a double row outer rolling surface formed on an inner periphery, and one end portion. From a hub ring integrally having a wheel mounting flange for mounting a wheel and having a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring And an inner member in which a double row inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a cage is provided between both rolling surfaces of the inner member and the outer member. In a wheel bearing device comprising: a double row of rolling elements housed so as to be freely rollable via; and a seal attached to an opening of an annular space formed by the outer member and the inner member. The inner seal has a substantially L-shaped cross section and is press-fitted into the inner periphery of the end of the outer member. An annular seal plate made of a cored bar and a sealing member integrally joined to the cored bar, a cylindrical part press-fitted into the outer periphery of the inner member, and extends radially outward from the cylindrical part. And a slinger comprising a standing plate portion, and a radially outer peripheral surface of the standing plate portion is exposed on the inner side surface of the standing plate portion of the slinger. An encoder is arranged so as to be a surface exposed portion, a backup seal is provided on the inner side of the inner side seal, and this backup seal is a cylindrical fitting that is press-fitted into the outer periphery of the end of the outer member. A disk portion extending radially inward from the fitting portion and closely contacting a part of the end portion of the outer member, a cylindrical portion extending from the disk portion to the inner side, and the cylindrical portion Further, a metal core comprising an inner end portion extending radially inward And a seal member integrally joined to the mandrel, and the seal member extends inwardly in the radial direction and integrally includes a seal lip that is in sliding contact with the surface exposed portion of the slinger. The seal lip of the backup seal can be slidably brought into contact with the surface exposed portion, the sealing performance of the seal can be improved, and the bearing performance can be maintained over a long period of time.

  A body mounting flange for mounting to the suspension device on the outer periphery is integrated, an outer member with a double row outer raceway formed on the inner periphery, and a wheel mounting flange for mounting a wheel on one end A hub ring having a small-diameter step portion formed on the outer periphery, and an outer joint member of an inner ring or a constant velocity universal joint fitted to the small-diameter step portion of the hub ring. An inner member in which a double row of inner rolling surfaces facing the running surface is formed, and a compound member that is rotatably accommodated via a cage between both rolling surfaces of the inner member and the outer member. In a wheel bearing device including a rolling element in a row and a seal attached to an opening of an annular space formed by the outer member and the inner member, the inner side seal has a substantially L cross section. A metal core and press-fitted into the inner periphery of the end of the outer member; A slinger comprising: an annular seal plate formed of a combined seal member; a cylindrical portion press-fitted into the outer periphery of the inner member; and a standing plate portion extending radially outward from the cylindrical portion. And an encoder is arranged on the inner side surface of the standing plate portion of the slinger so as to be a surface exposed portion where a radially outer circumferential surface of the standing plate portion is exposed. A backup seal is provided on the inner side of the inner side seal, and the backup seal is a cylindrical fitting portion that is press-fitted into the outer periphery of the end portion of the outer member, and a radially inward direction from the fitting portion. A disc portion that is in close contact with a part of the end portion of the outer member, a cylindrical portion that extends from the disc portion to the inner side, and an inner end portion that extends further radially inward from the cylindrical portion. The cored bar, and the cored bar Consists sealing member extends inclined seal member radially inward, integrally has a sliding contact seal lip on the surface exposed portion of the slinger.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the present invention, and FIG. 2 is an enlarged view of a main part showing a seal of FIG. In the following description, the side closer to the outer side of the vehicle in a state assembled to the vehicle is referred to as the outer side (left side in the drawing), and the side closer to the center is referred to as the inner side (right side in the drawing).

  This wheel bearing device is for a drive wheel called a second generation, and is composed of a hub wheel 1 and a wheel bearing 2, and the wheel bearing 2 is composed of an outer member 3, a double row rolling element ( A pair of inner rings 5 and 5 that are fitted through tapered rollers 4 and 4.

  The hub wheel 1 integrally has a wheel mounting flange 6 for mounting a wheel (not shown) at one end, and a cylindrical small-diameter step portion 1a extending in the axial direction from the wheel mounting flange 6 is formed on the outer periphery. A serration (or spline) 1b for torque transmission is formed on the inner periphery. Hub bolts 6a are planted on the wheel mounting flange 6 at equal intervals in the circumferential direction. The wheel bearing 2 is press-fitted into the small-diameter step portion 1a of the hub wheel 1 through a predetermined shimiro, and a predetermined portion is formed by a crimping portion 1c formed by plastically deforming an end portion of the small-diameter step portion 1a radially outward. It is fixed in the axial direction with respect to the hub wheel 1 with the bearing preload applied.

  The hub wheel 1 is made of medium carbon steel containing 0.40 to 0.80 wt% of carbon, such as S53C, and has a small diameter step from a base 6b formed in an arc shape on the inner side of the wheel mounting flange 6 via a shoulder 1d. The surface hardness is hardened in the range of 58 to 64 HRC by induction hardening over the part 1a. Thereby, it has sufficient mechanical strength with respect to the rotational bending load applied to the wheel mounting flange 6, and the fretting resistance of the small-diameter step portion 1 a serving as the fitting portion of the inner rings 5, 5 is improved.

  The outer member 3 integrally has a vehicle body mounting flange 3b to be attached to a knuckle (not shown) on the outer periphery, and has a tapered double row outer rolling surface 3a that opens outward on the inner periphery. 3a is integrally formed. The outer member 3 is formed of medium carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and at least the double row outer rolling surfaces 3a and 3a have a surface hardness of 58 to 64 HRC by induction hardening. Hardened to range.

  On the other hand, on the outer periphery of the inner ring 5, there are tapered inner rolling surfaces 5a and 5a facing the double-row outer rolling surfaces 3a and 3a, and rolling elements on the larger diameter side of the inner rolling surfaces 5a and 5a. The large collars 5b and 5b for guiding 4 and the small collar 5c for preventing the rolling elements 4 from falling off are formed on the small diameter side. The inner ring 5 and the rolling element 4 are made of high carbon chrome steel such as SUJ2, and are hardened in the range of 58 to 64 HRC up to the core part by quenching. And the double-row rolling elements 4 and 4 are accommodated between both rolling surfaces of the outer member 3 and a pair of inner ring | wheels 5 and 5, and are hold | maintained by the holder | retainers 7 and 7 so that rolling is possible. The wheel bearing 2 is constituted by a so-called back-to-back type double row tapered roller bearing that abuts against the shoulder 1d of the hub wheel 1 and that the small flanges 5c of the inner ring 5 abut each other in a butted state.

  Further, seals 8 and 8 are attached to an opening of an annular space formed between the outer member 3 and the inner ring 5. These seals 8 and 8 prevent the grease sealed inside the bearing from leaking to the outside and preventing rainwater, dust, etc. from entering the bearing from the outside. As shown in an enlarged view in FIG. 2, the seal 8 constitutes a so-called pack seal, which is a composite seal composed of an annular seal plate 9 and a slinger 10 having a substantially L-shaped cross section and arranged to face each other. is doing. The seal plate 9 includes a metal core 11 that is press-fitted into the inner periphery of the end of the outer member 3 and a seal member 12 that is integrally joined to the metal core 11 by vulcanization adhesion. The core metal 11 is formed by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a cold rolled steel plate (JIS standard SPCC type or the like).

  On the other hand, the slinger 10 is formed by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like). The cylindrical portion 10a is press-fitted into the large collar 5b, and the upright plate portion 10b extends radially outward from the cylindrical portion 10a. Thereby, the slinger 10 has rust prevention ability and can prevent rusting over a long period of time. The pair of side lips 12a and 12b are in sliding contact with the standing plate portion 10b of the slinger 10, and the radial lip 12c is in sliding contact with the cylindrical portion 10a.

  A magnetic encoder 16 in which magnetic powder such as ferrite is mixed in an elastomer such as rubber is integrally vulcanized and bonded to the inner side surface of the standing plate portion 10 b of the slinger 10. The magnetic encoder 16 is bonded to a part of the standing plate portion 10b of the slinger 10. The inner circumferential surface thereof has a predetermined clearance with the inner ring 5, and the outer circumferential surface thereof is the outer circumferential surface of the standing plate portion 10b. And with a certain clearance. That is, the surface exposed portion 10c where the magnetic encoder 16 is not provided and the surface is exposed is provided on the outer circumferential surface of the standing plate portion 10b in the radial direction.

  The magnetic encoder 16 has magnetic poles N and S alternately magnetized in the circumferential direction, and constitutes a rotary encoder for detecting wheel rotation speed. A rotational speed sensor 17 is opposed to the inner side of the magnetic encoder 16 via a predetermined axial clearance. The rotational speed sensor 17 incorporates a magnetic detection element such as a Hall element, a magnetoresistive element (MR element) or the like that changes its characteristics according to the direction of flow of magnetic flux, and a waveform shaping circuit that adjusts the output waveform of the magnetic detection element. It consists of IC.

  In the present embodiment, a backup seal 13 is further press-fitted to the outer periphery of the end portion of the outer member 3. The backup seal 13 includes a metal core 14 and a seal member 15 that is integrally vulcanized and bonded to the metal core 14. The core 14 is formed in a cup shape by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) or a rust-proof cold rolled steel plate (JIS standard SPCC type or the like), A cylindrical fitting portion 14a that is press-fitted and fixed to the outer periphery of the inner side end portion of the outer member 3, and extends radially inward from the fitting portion 14a and is in close contact with the inner side end portion of the outer member 3 And a cylindrical portion 14c extending from the circular plate portion 14b to the inner side, and an inner end portion 14d extending further radially inward from the cylindrical portion 14c.

  On the other hand, the seal member 15 is joined to the inner end portion 14d of the core metal 14 and has a seal lip 15a extending inclining radially inward. The seal lip 15 a is in sliding contact with the surface exposed portion 10 c of the slinger 10 and prevents rainwater, dust, and the like from directly entering the seal 8. Thereby, even if it uses in a poor environment, the sealing performance of the seal | sticker 8 can be improved and the wheel bearing apparatus which can maintain bearing performance over a long period of time can be provided. In addition, the seal lip 15a is in sliding contact with the surface exposed portion 10c of the slinger 10 unlike the sliding contact with the peripheral surface of the magnetic encoder 16, so that problems such as friction are reduced and a sufficient sealing effect is obtained. Furthermore, since the seal lip 15a is in sliding contact with the surface exposed portion 10c of the slinger 10, the seal lip 15a does not interfere with the rotational speed sensor 17.

  In addition, although the 2nd generation structure by the side of a drive wheel was illustrated here, the wheel bearing apparatus which concerns on this invention may not be this but may be a driven wheel side, and 3rd or 4th generation structure It may be. Further, in the present embodiment, the double row tapered roller bearing using the tapered roller as the rolling element 4 is exemplified, but it is needless to say that the double row angular contact ball bearing using a ball as the rolling element 4 may be used. .

  The embodiment of the present invention has been described above, but the present invention is not limited to such an embodiment, and is merely an example, and various modifications can be made without departing from the scope of the present invention. Of course, the scope of the present invention is indicated by the description of the scope of claims, and further, the equivalent meanings described in the scope of claims and all modifications within the scope of the scope of the present invention are included. Including.

  The wheel bearing device according to the present invention can be applied to a wheel bearing device having a second to fourth generation structure in which a seal is attached to a bearing end portion, regardless of whether it is for a driving wheel or a driven wheel.

It is a longitudinal section showing one embodiment of a wheel bearing device concerning the present invention. It is a principal part enlarged view which shows the seal | sticker of FIG.

Explanation of symbols

1 ... hub wheel 1a ... small diameter step 1b ... ············ Serration 1c ·······················································・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Shoulder 2 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel Bearing 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Outer member 3a ... Outer rolling surface 3b ... .... Body mounting flange 4 ... Rolling element 5 ...・ Inner ring 5a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 5b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Otsuchi 5c ・...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 6a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... hub bolt 6b ... base 7 ...・ Retainer 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal 9 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Seal plate 10 ・... Slinger 10a ... ... Cylindrical part 10b ... ····································································································· ... Core bars 12, 15 ... Seal members 12a, 12b ...・ Side lip 12c ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Radial lip 13 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Backup seal 14a ・ ・ ・······················································ ......・ ・ ・ ・ ・ ・ ・ ・ ・ Cylindrical part 14d ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner end part 15a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・..Seal lip 16 ... Magnetic encoder 17 ... Rotational speed sensor

Claims (4)

An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, and having a double row outer rolling surface formed on the inner periphery;
A hub wheel integrally having a wheel mounting flange for mounting a wheel at one end and a small-diameter stepped portion formed on the outer periphery, and an inner ring fitted to the small-diameter stepped portion of the hub wheel or the outer side of the constant velocity universal joint An inner member formed of a joint member, and formed on the outer periphery with a double-row inner rolling surface facing the double-row outer rolling surface;
A double row rolling element housed between the rolling surfaces of the inner member and the outer member so as to be freely rollable via a cage;
In the wheel bearing device provided with a seal attached to an opening of the annular space formed by the outer member and the inner member,
The inner side seal has a substantially L-shaped cross section and is a core metal press-fitted into the inner periphery of the end of the outer member, and an annular seal plate integrally formed with the core metal And a slinger comprising: a cylindrical portion press-fitted into the outer periphery of the inner member; and a standing plate portion extending radially outward from the cylindrical portion;
On the inner side surface of the standing plate portion of the slinger, an encoder is disposed so as to be a surface exposed portion where a radially outer circumferential surface of the standing plate portion is exposed,
A back-up seal is provided on the inner side of the inner-side seal, and the back-up seal is a cylindrical fitting portion that is press-fitted into the outer periphery of the end portion of the outer member, and radially inward from the fitting portion. A disc portion extending and closely contacting a part of the end portion of the outer member; a cylindrical portion extending from the disc portion to the inner side; and an inner end portion extending further radially inward from the cylindrical portion. It comprises a metal core and a seal member integrally joined to the metal core, and this seal member extends inwardly in the radial direction and integrally has a seal lip that is in sliding contact with the surface exposed portion of the slinger. A wheel bearing device characterized by that.   2. The outer peripheral surface of the end portion of the outer member into which the fitting portion of the core metal of the backup seal is fitted is processed so as to have a small diameter corresponding to the thickness of the core metal of the backup seal. Wheel bearing device.   The wheel bearing device according to claim 1 or 2, wherein the core metal of the backup seal and the seal member of the backup seal are located radially outward of the encoder. The wheel bearing device according to any one of claims 1 to 3, wherein the slinger is formed by press working from a steel plate having rust prevention ability.

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