JP2009197883A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device for actualizing the longer life of a bearing by improving the sealing performance and durability of a seal. <P>SOLUTION: The seal 9 includes an annular seal plate 13 consisting of a core metal 15 internally suitable for the end of an outward member 10 and a seal member 16 integrally bonded to the core metal 15 with cure adhesion and having a plurality of seal lips 16a, 16b, 16c, and an approximately cross-section L-shaped slinger 14 opposed to the seal plate 13 and consisting of a cylindrical portion 14a externally suitable for an inner ring 3 and a rising plate portion 14b extending from the cylindrical portion 14a outward in the radial direction. In the inside surface of the slinger 14 with which the seal lips 16a, 16b, 16c have sliding contact, a number of approximately circular recesses 19 are formed at diameters ψ of 10-30 μm in a range of depths of 1-5 μm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like, and more particularly, a wheel equipped with a seal having a sufficient sealing property for a long period of time even in an environment where a large amount of foreign matter such as rainwater and muddy water exists. The present invention relates to a bearing device.

  Since the wheel bearing device that supports the wheel of the automobile rotatably with respect to the suspension device is in an environment where it is directly exposed to rainwater, muddy water, etc., it is strong so that this rainwater, muddy water, etc. does not enter the inside of the bearing. A seal having a sealing property is attached. In recent years, this type of wheel bearing device used in such a harsh environment has been required to have a longer service life. Damage due to seal failure accounts for more than the bearing life. Accordingly, various wheel bearing devices have been proposed in which the sealability and durability of the seal are improved to improve the bearing life.

  The wheel bearing device shown in FIG. 8 is a typical example of this. This is a wheel bearing device on the drive wheel side, and integrally has a vehicle body mounting flange 51b attached to the vehicle body (not shown) on the outer periphery, and double row outer rolling surfaces 51a and 51a are formed on the inner periphery. The outer member 51 and the wheel mounting flange 53 to which a wheel (not shown) is attached at one end are integrally formed, and one inward rolling facing the double row outer rolling surfaces 51a, 51a is provided on the outer periphery. A running surface 52a, a cylindrical small diameter step portion 52b extending in the axial direction from the inner rolling surface 52a, and a hub wheel 52 having a torque transmission serration 52c formed on the inner periphery, and the small diameter step portion 52b And an inner ring 55 that is press-fitted and has the other inner rolling surface 55a formed on the outer periphery. A hub bolt 54 for mounting a wheel (not shown) is implanted at a circumferentially equidistant position of the wheel mounting flange 53 of the hub wheel 52.

  A double row of balls 56 is accommodated by a cage 57 between the double row outer raceway surfaces 51a and 51a and the inner raceway surfaces 52a and 55a opposite to each other. Seals 59 and 60 are respectively attached to the openings of the annular space formed between the inner member 58 formed of the hub ring 52 and the inner ring 55 and the outer member 51, and sealed inside the bearing. This prevents leakage of lubricating grease and intrusion of rainwater and muddy water into the bearing from the outside.

  Of these seals 59, 60, the seal 60 mounted between the outer member 51 and the inner ring 55 is fitted into the outer member 51 serving as a fixed raceway, as shown in FIG. Are fitted on an annular seal plate 63 composed of a cored bar 61 formed on the cored bar 61 and a sealing member 62 vulcanized and bonded to the cored bar 61, and an inner ring 55 serving as a rotating raceway. A cylindrical portion 64a formed in a letter shape and press-fitted into the outer diameter of the inner ring 55, and a slinger 64 including a standing plate portion 64b extending radially outward from the cylindrical portion 64a are provided.

  The seal member 62 is made of an elastic member such as rubber, and includes three seal lips, that is, a side lip 62a, a grease lip 62b, and an intermediate lip 62c, and the end edge of the side lip 62a is the inner surface of the standing plate portion 64b of the slinger 64. The tip edges of the remaining grease lip 62b and intermediate lip 62c are in sliding contact with the cylindrical portion 64a of the slinger 64. The seal plate 63 and the tip of the standing plate portion 64b of the slinger 64 are opposed to each other through a slight radial clearance, and the labyrinth seal 65 is configured up to this clearance.

Further, a friction reducing film 66 for reducing the sliding resistance of each lip is formed on the entire surface of the slinger 64. The friction reducing coating 66 is formed of a polyamide such as 6 nylon or 12 nylon, a synthetic resin having low friction such as polytetrafluoroethylene or polyethylene, or a diamond-like carbon film. As a result, the sliding resistance is reduced without reducing the contact pressure of each lip, and the rotational torque is reduced. Further, lip wear is reduced by the low friction between the slinger 64 and each lip, heat generation at the lip sliding portion is suppressed, and durability of the seal 60 is improved (see, for example, Patent Document 1).
JP 2002-227856 A

  However, in such a conventional seal 60, if the friction reducing coating 66 formed on the entire surface of the slinger 64 is made of a synthetic resin, the sliding resistance is reduced, but the surface hardness is low, and the lips 62a, 62b are low. , 62c and the slinger 64, foreign matter or the like enters the slinger 64 over a long period of time, resulting in poor reliability. On the other hand, if the friction reducing coating 66 is a diamond-like carbon film, it cannot be said that the binding force to the slinger 64 is sufficient, and there is a risk of peeling in the long term, resulting in insufficient reliability.

  The present invention has been made in view of such a conventional problem, and an object of the present invention is to provide a wheel bearing device in which the sealing performance and durability of a seal are enhanced to extend the life of the bearing.

  In order to achieve such an object, the invention according to claim 1 of the present invention includes an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and an outer rolling of the double row on the outer periphery. An inner member in which a double row inner rolling surface facing the surface is formed, and a double row accommodated between the rolling surfaces of the inner member and the outer member via a retainer so as to roll freely. In the wheel bearing device comprising: a rolling element; and a seal attached to an opening of an annular space formed between the outer member and the inner member, at least one of the seals is: A cored bar fitted into the end of the outer member, and an annular seal plate made of a seal member integrally bonded to the cored bar by vulcanization and having a plurality of seal lips, and opposed to the seal plate A cylindrical portion that is disposed and externally fitted to the inner member, and extends radially outward from the cylindrical portion. And a slinger formed substantially L-shaped cross-section comprising a standing portion, minute recesses on the inner surface of the slinger which the seal lip is in sliding contact are innumerable forms.

  Thus, in the wheel bearing device including the seal mounted in the opening of the annular space formed between the outer member and the inner member, at least one of the seals is the outer member. An annular seal plate made of a sealing member having a plurality of sealing lips integrally joined to the core by vulcanization adhesion, and a core metal fitted into the end, and opposed to the sealing plate. A slinger formed in a substantially L-shaped cross section consisting of a cylindrical part fitted on the member and a standing plate part extending radially outward from the cylindrical part, and a minute amount on the inner surface of the slinger with which the seal lip slides Since there are innumerable recesses, grease accumulates in the recesses, the lubricity on the sliding surface is improved, the lip sliding resistance is reduced, the rotational torque is reduced, and the slinger and each lip Due to low friction Slinger and abrasion of the lip can be suppressed. Further, the heat generation of the lip sliding portion is suppressed, and the sealing performance and durability of the seal can be improved over a long period of time, and a wheel bearing device that extends the life of the bearing can be provided.

  Preferably, as in the invention described in claim 2, if the recess is formed in a substantially circular shape having a diameter of 10 to 30 μm and a depth of 1 to 5 μm, the sliding contact between the seal lip and the slinger Even when the grease is difficult to reach on the surface and the lubrication condition is thin, the grease accumulates in the recess and the lubricity on the sliding surface is improved.

  Further, as in the invention described in claim 3, if the recess has a hardness equal to or greater than the surface hardness of the slinger and is formed by shot blasting with a substantially spherical shot, it is smooth. A circular recess is formed, and the surface hardness of the lip sliding contact surface is increased to suppress wear of the slinger and each lip.

  According to a fourth aspect of the present invention, the seal member includes a side lip that extends obliquely outward in the radial direction, a grease lip formed in a forked shape, and an intermediate lip. And the intermediate lip may be in sliding contact with the cylindrical portion of the slinger, and the side lip may be in sliding contact with the standing plate portion of the slinger.

  According to a fifth aspect of the present invention, the seal member includes a grease lip and a pair of side lips that extend radially incliningly, and the side lip is formed on the standing plate portion of the slinger. If the grease lip is slidably contacted with the cylindrical portion of the slinger, the sealing performance can be improved.

  If the grease lip faces the cylindrical portion of the slinger through a predetermined radial clearance and a labyrinth seal is formed as in the invention described in claim 6, the lip sliding resistance is small. Thus, the rotational torque can be suppressed.

  Further, as in the invention described in claim 7, if the grease lip is abolished and an annular space is formed between the seal member and the cylindrical portion of the slinger, the grease on the sliding contact surface of the side lip As a result, the lip sliding resistance is further reduced, and the rotational torque of the seal can be greatly suppressed.

  The wheel bearing device according to the present invention includes an outer member in which a double row outer rolling surface is integrally formed on an inner periphery, and a double row inner rolling that faces the outer rolling surface of the double row on an outer periphery. An inner member having a surface formed thereon, a double row rolling element housed between the rolling surfaces of the inner member and the outer member via a cage, and the outer member; In a wheel bearing device including a seal mounted in an opening of an annular space formed between the inner member and at least one of the seals is fitted into an end of the outer member. An annular seal plate made of a seal member integrally bonded to the core metal by vulcanization and having a plurality of seal lips, and disposed opposite to the seal plate, and fitted on the inner member. And a substantially L-shaped cross section comprising a cylindrical portion and a standing plate portion extending radially outward from the cylindrical portion Since there are innumerable minute recesses on the inner surface of the slinger where the seal lip is slidably contacted, grease accumulates in the recesses and lubricity on the slidable contact surface is improved. The lip sliding resistance is reduced, the rotational torque is reduced, and wear of the slinger and each lip is suppressed by the low friction between the slinger and each lip. Further, the heat generation of the lip sliding portion is suppressed, and the sealing performance and durability of the seal can be improved over a long period of time, and a wheel bearing device that extends the life of the bearing can be provided.

  An outer member integrally having a vehicle body mounting flange to be attached to the suspension device on the outer periphery, a double row outer rolling surface formed integrally on the inner periphery, and a wheel mounting flange for attaching a wheel to one end And a hub wheel in which one inner rolling surface facing the outer rolling surface of the double row is formed on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub An inner member formed of an inner ring press-fitted into a small-diameter step portion of the ring and having the other inner rolling surface opposed to the outer rolling surface of the double row on the outer periphery; and the inner member and the outer member A double-row rolling element accommodated between the rolling surfaces via a cage, and a seal attached to an opening of an annular space formed between the outer member and the inner member. In the wheel bearing device comprising: the seal on the inner side of the seal, the outer portion A metal core that is fitted into the end of the metal plate, and an annular seal plate that is integrally joined to the metal core by vulcanization adhesion and includes a seal member having a plurality of seal lips, and is disposed opposite to the seal plate, An inner surface of the slinger having a cylindrical portion fitted on the inner ring and a slinger formed in a substantially L-shaped cross section comprising a standing plate portion extending radially outward from the cylindrical portion, the seal lip being in sliding contact with the slinger In addition, innumerable substantially circular recesses having a diameter of 10 to 30 μm and a depth of 1 to 5 μm are formed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a longitudinal sectional view showing a first embodiment of a wheel bearing device according to the present invention, FIG. 2 is an enlarged view of a main part showing one seal part of FIG. 1, and FIG. The perspective view which shows the slinger of 2 and (b) are the schematic diagrams which show the inner surface of the slinger of (a). In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is referred to as the outer side (left side in FIG. 1), and the side closer to the center is referred to as the inner side (right side in FIG. 1).

  This wheel bearing device is for a drive wheel, and includes an inner member 1, an outer member 10, and double-row rolling elements (balls) 6 and 6 accommodated between both members 1, 10, and the third generation. The structure is called. The inner member 1 includes a hub ring 2 and an inner ring 3 that is press-fitted into the hub ring 2 through a predetermined scissors.

  The hub wheel 2 integrally has a wheel mounting flange 4 for attaching a wheel (not shown) to an end portion on the outer side, one (outer side) inner rolling surface 2a on the outer periphery, and this inner rolling. A cylindrical small-diameter step 2b extending in the axial direction from the surface 2a is formed, and a serration (or spline) 2c for torque transmission is formed on the inner periphery. Further, hub bolts 5 are implanted at equal circumferential positions of the wheel mounting flange 4. The inner ring 3 is formed with the other (inner side) inner rolling surface 3a on the outer periphery, and is press-fitted and fixed to the small-diameter step portion 2b of the hub ring 2 via a predetermined shimiro.

  The hub wheel 2 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and includes an inner rolling surface 2a and an inner side of a wheel mounting flange 4 serving as a seal land portion of a seal 8 to be described later. The surface is hardened in the range of 58 to 64 HRC by induction hardening from the base 4a to the small diameter step 2b. On the other hand, the inner ring 3 and the rolling element 6 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 portion by quenching.

  The outer member 10 integrally has a vehicle body mounting flange 10b to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and the inner rolling surfaces 2a and 3a of the inner member 1 on the inner periphery. Opposing double-row outer rolling surfaces 10a and 10a are integrally formed. Between these rolling surfaces 10a, 2a and 10a, 3a, double row rolling elements 6, 6 are accommodated via a cage 7 so as to be freely rollable. This outer member 10 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least double row outer raceway surfaces 10a and 10a are surfaced in the range of 58 to 64HRC by induction hardening. Has been cured. Seals 8 and 9 are attached to the opening of the annular space formed between the outer member 10 and the inner member 1, and leakage of the lubricating grease sealed inside the bearing to the outside, rainwater and It prevents dust and the like from entering the bearing. In addition, although the double row angular contact ball bearing which used the ball for the rolling element 6 was illustrated here, this invention is not restricted to this, The double row tapered roller bearing which uses the tapered roller for the rolling element 6 may be sufficient. .

  The seal 8 on the outer side of the seals 8 and 9 is constituted by an integral seal composed of a core metal 11 and a seal member 12 integrally joined to the core metal 11 by vulcanization adhesion. The core metal 11 is formed by pressing a cold-rolled steel plate (JIS standard SPCC system or the like).

  On the other hand, the seal member 12 is made of synthetic rubber such as nitrile rubber and is integrally joined to the core metal 11 by vulcanization adhesion. The seal member 12 includes a side lip 12a formed to be inclined outward in the radial direction, and a pair of radial lips 12b and 12c formed in a bifurcated shape. The base portion 4a of the wheel mounting flange 4 is formed in a curved surface having an arc-shaped cross section, and the side lip 12a is slidably contacted with the base portion 4a with a predetermined axial direction shim, and the radial lips 12b and 12c have a predetermined radial direction It is in sliding contact.

  Further, as shown in an enlarged view in FIG. 2, the inner-side seal 9 is constituted by a so-called pack seal including an annular seal plate 13 and a slinger 14. The seal plate 13 includes a cored bar 15 attached to the outer member 10 and a seal member 16 integrally joined to the cored bar 15 by vulcanization adhesion. The metal core 15 is formed into a substantially L-shaped cross section by pressing from a cold rolled steel plate (JIS standard SPCC system or the like), and is a cylindrical fitting portion that is press-fitted into the inner periphery of the end of the outer member 10. 15a and an inner diameter portion 15b extending radially inward from the fitting portion 15a. The seal member 16 is made of a synthetic rubber such as nitrile rubber, and has a side lip 16a extending obliquely outward in the radial direction, a grease lip 16b and an intermediate lip 16c formed in a bifurcated shape. In addition, as a material of the sealing member 16, other than nitrile rubber, fluororubber and acrylic rubber can be exemplified.

  On the other hand, the slinger 14 includes a cylindrical portion 14a that is press-fitted into the outer diameter of the inner ring 3, and a standing plate portion 14b that extends radially outward from the cylindrical portion 14a. The side lip 16a of the seal member 16 is in sliding contact with the upright plate portion 14b, and the grease lip 16b and the intermediate lip 16c are in sliding contact with the cylindrical portion 14a. Further, the outer edge of the standing plate portion 14 b in the slinger 14 is opposed to the seal plate 13 through a slight radial clearance to form a labyrinth seal 17.

  Further, a magnetic encoder 18 in which magnetic material powder such as ferrite is mixed in an elastomer such as rubber is integrally joined to the inner side surface of the standing plate portion 14b by vulcanization adhesion or the like. The magnetic encoder 18 has magnetic poles N and S alternately magnetized in the circumferential direction to constitute a rotary encoder for detecting the rotational speed of the wheel.

  The slinger 14 is a ferritic stainless steel plate (JIS standard SUS430, etc.), an austenitic stainless steel plate (JIS standard SUS304, etc.), or a rust-proof cold rolled steel plate (JIS standard SPCC). The cross section is formed in a substantially L shape by press working from the system. Thereby, even if the slinger 14 is exposed to rain water, muddy water, or the like, or even if rain water, muddy water or the like enters the fitting portion with the inner ring 3, the slinger 14 can be prevented from rusting.

  Here, as shown in FIG. 3A, innumerable recesses 19 are formed on the inner surface of the slinger 14 which is a sliding contact surface of the side lip 16a, the grease lip 16b and the intermediate lip 16c. As schematically shown in (b), the recess 19 is formed in a substantially circular shape by a shot blasting process with a diameter d = φ10-30 μm and a depth W = 1-5 μm. This shot blasting process has a hardness equal to or higher than the surface hardness of the slinger 14 and is performed, for example, by spraying a 20-200 μm shot having a substantially spherical shape at an injection speed of 50 m / sec or more. Examples of the shot material include steel balls, ceramics, glass, and the like.

  By forming innumerable recesses 19 on the sliding contact surface of the slinger 14, grease accumulates in the recesses 19, the lubricity on the sliding contact surface is improved, the lip sliding resistance is reduced, and the rotational torque is reduced. And the wear of the slinger 14 and each lip 16a, 16b, 16c is suppressed by the low friction between the slinger 14 and each lip 16a, 16b, 16c. Further, the heat generation of the lip sliding portion is suppressed, and the sealability and durability of the seal 9 can be improved over a long period of time, and a wheel bearing device that extends the life of the bearing can be provided.

  FIG. 4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 5A is an enlarged view showing one seal unit of FIG. 4, and FIGS. These are the enlarged views which show the modification of the seal | sticker of (a). In addition, the same code | symbol is attached | subjected to the component and site | part which has the same component same part as embodiment mentioned above, or the same function, and detailed description is abbreviate | omitted.

  This wheel bearing device is referred to as the first generation, and is accommodated in an inner member 20 and an outer member 21 comprising a pair of inner rings 3 and 3 and between the members 20 and 21 via a cage 7 so as to be able to roll. A double-row angular contact ball bearing of the back-to-back type is provided.

  The outer member 21 is made of a high carbon chrome steel such as SUJ2, and is hardened in the range of 58 to 64 HRC up to the core portion by quenching. Seals 22 and 23 are attached to the opening of the annular space formed between the outer member 21 and the inner member 20, and leakage of the lubricating grease sealed inside the bearing to the outside and from the outside It prevents rainwater and dust from entering the bearing.

  The outer-side seal 22 is constituted by an integral seal composed of a cored bar 24 and a seal member 25 integrally joined to the cored bar 24 by vulcanization adhesion. The core metal 24 is formed by press-working a cold rolled steel plate (JIS standard SPCC system or the like). The seal member 25 is made of synthetic rubber such as nitrile rubber and is integrally joined to the core metal 24 by vulcanization adhesion. The seal member 25 has a pair of radial lips 25a and 25b formed in a bifurcated shape, and is in sliding contact with the outer diameter surface of the inner ring 3 with a predetermined radial direction.

  Further, the inner seal 23 includes an annular seal plate 26 and a slinger 14 as shown in an enlarged view in FIG. The seal plate 26 includes a cored bar 15 attached to the outer member 21 and a seal member 27 integrally joined to the cored bar 15 by vulcanization adhesion. The seal member 27 is made of an elastic member such as synthetic rubber, and has a pair of side lips 27a and 27b and a grease lip 16b extending obliquely outward in the radial direction.

  Here, in the same manner as in the above-described embodiment, innumerable recesses 19 are formed on the inner surface of the slinger 14 which is a sliding contact surface between the side lips 27a and 27b and the grease lip 16b. By forming such innumerable recesses 19 on the sliding contact surface of the slinger 14, a pair of side lips 27 a and 27 b, particularly on the sliding contact surface between the side lip 27 a located on the outer side and the slinger 14. Even under the rare lubrication conditions in which the grease is difficult to reach, the grease accumulates in the recess 19, the lubricity at the sliding contact surface is improved, the lip sliding resistance is reduced, the rotational torque is reduced, and the slinger 14 and each of the lubrication conditions are reduced. Wear is suppressed by low friction with the lips 27a, 27b, and 16b.

  FIGS. 5B to 5D show a modification of (a). The seal 28 shown in (b) is basically different only in that the grease lip 16b in the seal 23 of (a) is a non-contact type. That is, the seal member 29 of the seal 28 has a pair of side lips 27a, 27b extending in a radially outward direction and a grease lip 29a, and the grease lip 29a is formed on the cylindrical portion 14a of the slinger 14 in a predetermined radial direction. A labyrinth seal is formed through the gap δ. Innumerable recesses 19 are formed on the inner surface of the slinger 14. Thereby, the lubricity on the sliding surface is improved, the lip sliding resistance is reduced, and the rotational torque is further reduced.

  The seal 30 shown in (c) is basically different only in that the seal 9 and the grease lip 16b shown in FIG. 2 are configured as a non-contact type. In other words, the seal member 31 has a side lip 16a, an intermediate lip 16c, and a grease lip 31a that extend obliquely outward in the radial direction. The grease lip 31a provides a predetermined radial clearance δ in the cylindrical portion 14a of the slinger 14. And a labyrinth seal is formed. Thereby, while ensuring a desired sealing performance, lip sliding resistance becomes small and rotational torque can be suppressed.

  Further, the seal 32 shown in (d) has a pair of side lips 27a, 27b in which the seal member 33 extends while inclining radially outward. The above-described grease lip is eliminated, and the cylindrical portion 14a of the slinger 14 is removed. An annular space is formed between the two. Innumerable recesses 19 are formed in the standing plate portion 14b of the inner surface of the slinger 14. Thereby, the supply of grease to the sliding surfaces of the side lips 27a and 27b is improved, the lip sliding resistance is further reduced, and the rotational torque of the seal 32 can be greatly suppressed.

  FIG. 6 is a longitudinal sectional view showing a third embodiment of the wheel bearing device according to the present invention. This embodiment is called a second generation for a driven wheel, and includes an outer member 34, a pair of inner rings 3, 3, and double row rolling elements 6, 6 to constitute a back-to-back type double row angular ball bearing. Has been. In addition, the same code | symbol is attached | subjected to the component and site | part which has the same component same part as embodiment mentioned above, or the same function, and detailed description is abbreviate | omitted.

  The outer member 34 integrally has a wheel mounting flange 4 at an outer end on the outer periphery, and a double row outer rolling surface is integrally formed on the inner periphery. The outer member 34 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C. A shield 35 and a seal 26 are attached to the opening of the annular space formed between the outer member 34 and the pair of inner rings 3 and 3, and leakage of the lubricating grease sealed inside the bearing is prevented. This prevents rainwater and dust from entering the bearing from the outside. The shield 35 having a labyrinth seal with the inner ring 3 mainly prevents the lubricating grease sealed inside the bearing from leaking to the outside. Although not shown, an end cap is attached to the outer end portion of the outer member 34 to prevent foreign matters such as rainwater from entering the bearing from the outside.

  As described above, the inner-side seal 26 has a strong sealing property by the pair of side lips 27a and 27b of the seal member 27, and is in sliding contact with the innumerable recesses 19 formed on the inner surface of the slinger 14. Lubricity on the surface is improved, lip sliding resistance is reduced, and rotational torque can be suppressed.

  FIG. 7 is a longitudinal sectional view showing a fourth embodiment of the wheel bearing device according to the present invention. This embodiment is called a fourth generation, and includes an outer member 10, an inner member 36, and double-row rolling elements 6 and 6, and a back-to-back type double-row angular ball bearing is configured. The inner member 36 includes a hub ring 37 and an outer joint member 39 of a constant velocity universal joint 38 that is integrally plastically coupled to the hub ring 37. In addition, the same code | symbol is attached | subjected to the component and site | part which has the same component same part as embodiment mentioned above, or the same function, and detailed description is abbreviate | omitted.

  The hub wheel 37 integrally has a wheel mounting flange 4 at an end portion on the outer side, and an inner raceway surface 2a and a cylindrical small diameter step portion 37a extending in the axial direction from the inner raceway surface 2a are formed on the outer periphery. And the uneven part 40 is formed in the inner periphery. The concavo-convex portion 40 is formed in the shape of an iris knurl, and a plurality of annular grooves formed independently by turning or the like and a plurality of axial grooves formed by broaching or the like are crossed grooves configured to be substantially orthogonal, Or it consists of the crossing groove | channel comprised by the helical groove | channel inclined mutually. In addition, the concave and convex portion 40 is formed to have a steeple shape such as a triangular shape at the tip of the convex portion in order to ensure good biting property, which will be described later, and is hardened to a predetermined surface hardness by induction hardening. Yes. The hub wheel 37 is made of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon, such as S53C, and is 58 by induction hardening from the inner rolling surface 2a to the small diameter step portion 37a from the base portion 4a. The surface is hardened in the range of ~ 64HRC.

  On the other hand, the constant velocity universal joint 38 includes a joint inner ring 41 inserted in the outer joint member 39, a cage 42, and a torque transmission ball 43. The outer joint member 39 is integrally formed with a cup-shaped mouth portion 44, a shoulder portion 45 serving as a bottom portion of the mouth portion 44, and a hollow shaft portion 46 extending in the axial direction from the shoulder portion 45. . An inner side rolling surface 45 a on the inner side is directly formed on the outer periphery of the shoulder portion 45. Further, the shaft portion 46 is formed with an in-row portion 46a that is cylindrically fitted to the small-diameter step portion 37a of the hub wheel 37, and a fitting portion 46b at the end of the in-row portion 46a.

  The outer joint member 39 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and has a surface in the range of 58 to 64 HRC by induction hardening from the shoulder portion 45 to the outer peripheral surface of the shaft portion 46. Has been cured. In addition, the fitting part 46b is made into the surface hardness after a forge process.

  Then, the shaft portion 46 is internally fitted until the shoulder portion 45 of the outer joint member 39 abuts on the small diameter step portion 37a of the hub wheel 37, and a diameter expanding jig such as a mandrel is placed on the outer side on the inner diameter of the fitting portion 46b. By pushing in and expanding the fitting portion 46b, the fitting portion 46b is plastically deformed and bite into the concavo-convex portion 40 of the hub wheel 37 and caulked, and the hub wheel 37 and the outer joint member 39 are plastically coupled and integrated. It has become. As a result, loosening of the coupling portion can be prevented, and the initially set bearing preload can be maintained over a long period of time. Reference numerals 47 and 48 are end caps attached to the outer end of the hub wheel 37 and the shoulder 45 of the outer joint member 39, and prevent foreign matter such as rainwater and dust from entering the joint from the outside. At the same time, the lubricating grease enclosed in the joint is prevented from leaking to the outside. Seals 8 and 9 are attached to the opening of the annular space formed between the outer member 10 and the inner member 36, and leakage of the lubricating grease sealed inside the bearing and rainwater from the outside And dust are prevented from entering the bearing.

  Also in this embodiment, the inner side seal 9 is provided with a powerful hermetic seal by the pair of side lips 27a and 27b of the seal member 27 and the countless number formed on the inner surface of the slinger 14 as in the above-described embodiment. The recess 19 improves the lubricity on the sliding contact surface, reduces the lip sliding resistance, suppresses wear, and improves the sealing performance and durability of the seal 9 over a long period of time.

  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 first generation to a fourth generation structure in which a seal is attached to an opening of an annular space.

It is a longitudinal section showing a 1st embodiment of a bearing device for wheels concerning the present invention. It is a principal part enlarged view which shows one seal part of FIG. (A) is a perspective view which shows the slinger of FIG. (B) is a schematic diagram which shows the inner surface of the slinger of (a). It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. (A) is an enlarged view which shows one seal | sticker single-piece | unit of FIG. (B)-(d) is an enlarged view which shows the modification of the seal | sticker of (a). It is a longitudinal cross-sectional view which shows 3rd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows 4th Embodiment of the wheel bearing apparatus which concerns on this invention. It is a longitudinal cross-sectional view which shows the conventional wheel bearing apparatus. It is a principal part enlarged view of FIG.

Explanation of symbols

1, 20, 36 ... inner member 2, 37 ... hub wheels 2a, 3a, 45a ... Inner rolling surface 2b, 37a ... Small diameter step 2c ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Serration 3 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner ring 4 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Wheel mounting flange 4a ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Base 5 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ Hub bolt 6 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Rolling element 7 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ Retainer 8, 22 ......... Seal 9, 23, 28, 30, 32 on outer side ..... Inner side seal 10, 21, 34 ... Outer member 10a ... · · Outer rolling surface 10b ·················· Body mounting flange 11, 15, 24 12, 16, 25, 27, 29, 31, 33 .. Seal members 12a, 16a, 27a, 27b... Side lips 12b, 12c, 25a, 25b... Radial lip 13 , 26 ... Seal plate 14 ... Slinger 14a ... ... Cylindrical part 14b ..... Standing plate part 15a ... ... Mating 15b ..... Inner diameter parts 16b, 29a, 31a .... Grease lip 16c ... Intermediate lip 17 ... Labyrinth seal 18 ... Magnetic encoder 19 ... Recess 35 ...・ ・ Shield 38 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Constant velocity universal joint 39 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Outside Joint member 40 ... Uneven portion 41 ... Joint inner ring 42・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Cage 43 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Torque transmission ball 44 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Mouse unit 45 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Shoulder 46 ... Shaft 46a ... ... In-row part 46b ......... Fitting part 47, 48 ... End cap 51... Outer member 51 a... Outer rolling surface 51 b・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Car body mounting flange 52 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Hub wheels 52a, 55a ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner rolling surface 52b ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Small diameter Portion 53 ... Wheel mounting flange 54 ... Hub bolt 55 ... ... inner ring 56 ... 57 ball 57 ...・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Retainer 58 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Inner members 59, 60 ・ ・ ・ ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ Seal 61 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Core 62 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・... Seal member 62a ... Side lip 62b ... Grease lip 62c・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Intermediate lip 63 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・.... Seal plate 64 ..... Slinger 64a ...・ Cylindrical part 64b ..... Standing plate part 65 ..... Labyrinth seal 66 ……………… Friction-reducing coating d ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recess diameter W・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recess depth δ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Diameter gap

Claims (7)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
An inner member in which a double row inner rolling surface facing the outer row rolling surface of the double row is formed on the outer periphery;
A double row rolling element housed between the rolling surfaces of the inner member and the outer member so as to be freely rollable via a cage;
In a wheel bearing device comprising a seal mounted in an opening of an annular space formed between the outer member and the inner member,
At least one of the seals is an annular member comprising a core member fitted into an end of the outer member, and a seal member integrally joined to the core member by vulcanization and having a plurality of seal lips Formed in a substantially L-shaped cross section comprising a sealing plate, a cylindrical portion that is disposed opposite to the sealing plate, and is fitted on the inner member, and a vertical plate that extends radially outward from the cylindrical portion. A wheel bearing device comprising: a slinger, wherein an infinite number of minute recesses are formed on an inner surface of the slinger that is in sliding contact with the seal lip.   The wheel bearing device according to claim 1, wherein the recess is formed in a substantially circular shape having a diameter of 10 to 30 μm and a depth of 1 to 5 μm.   3. The wheel bearing device according to claim 1, wherein the recess has a hardness equal to or greater than a surface hardness of the slinger and is formed by shot blasting using a substantially spherical shot. 4.   The seal member has a side lip that extends obliquely outward in the radial direction, a grease lip and an intermediate lip formed in a bifurcated shape, and the grease lip and the intermediate lip are slidably contacted with the cylindrical portion of the slinger. The wheel bearing device according to any one of claims 1 to 3, wherein the side lip is slidably contacted with a standing plate portion of the slinger.   The seal member has a grease lip and a pair of side lips extending obliquely outward in the radial direction, the side lip is slidably contacted with the standing plate portion of the slinger, and the grease lip is The wheel bearing device according to any one of claims 1 to 3, wherein the wheel bearing device is in sliding contact with the cylindrical portion.   The wheel bearing device according to claim 4 or 5, wherein the grease lip is opposed to the cylindrical portion of the slinger via a predetermined radial clearance to form a labyrinth seal.   The wheel bearing device according to claim 5, wherein the grease lip is eliminated and an annular space is formed between the seal member and a cylindrical portion of the slinger.

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