JP2011080575A - Bearing device for wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device for a wheel lowered in torque while securing the sealing performance of a seal. <P>SOLUTION: The seal 8 includes a core metal 12 having a fitting part 12a fitted into an outer member 5, and an inner diameter part 12b extended radially inward; and a seal member 13 having a side lip 13a integrally joined to the core metal 12 and extended inclining radially outward, a dust lip 13b extended inclining radially outward at the inner diameter side, and a grease lip 13c extended inclining to the inner side of a bearing. A base 6b of a wheel mounting flange 6 is formed in a circular arc shape. The dust lip 13b comes in slide-contact with the base 6b with an axial margin, and the grease lip 13c comes in slide-contact with the base with a radial margin. The thickness B of the side lip 13a is set larger than the thickness C of the dust lip 13b, and the tip edge is formed in an inclined surface extended along the shape of the base to face the base through a slight facing clearance A, thus forming a labyrinth seal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like with respect to a suspension device, and more particularly to a wheel bearing device that achieves low torque while ensuring 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 supports a hub wheel for mounting a wheel rotatably via a double row rolling bearing, and includes 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. Further, the wheel bearing device has a structure called a first generation in which a wheel bearing composed of a double row angular ball bearing or the like is fitted between a knuckle and a hub wheel constituting a suspension device. Second generation structure in which body mounting flange or wheel mounting flange is formed directly on the outer periphery of the member, third generation structure in which one inner rolling surface is directly formed on the outer periphery of the hub wheel, or hub wheel, etc. It is roughly classified into a fourth generation structure in which the inner rolling surface is directly formed on the outer periphery of the outer joint member of the speed universal joint.

  Since these wheel bearing devices are disposed at sites where muddy water or the like is easily applied, a sealing device is attached so as to seal between the outer member and the inner member. Here, when the bearing damage situation of the market-recovered product is verified, the damage due to the malfunction of the sealing device occupies more than the original bearing life resulting from peeling or the like. Generally, in a sealing device, a seal member having a seal lip is attached to an outer member serving as a stationary member, and the seal lip is slidably contacted with an outer peripheral surface of the inner member.

  Conventionally, various seal structures for reducing torque have been proposed. An example of such a seal structure is shown in FIG. The seal 50 includes three side lips 54, a dust lip 55, and a grease lip 56 that are concentric with each other and close the outer end opening of the inner space 53 between the inner peripheral surface of the outer ring 51 and the hub ring 52. ing. Of the three seal lips provided on the seal 50, the side lip 54 provided on the outermost diameter side is inclined in a direction positioned radially outward toward the tip edge, and the tip edge is a hub wheel. The wheel mounting flange 57 provided on the outer peripheral surface 52 is in sliding contact with the inner surface inner diameter portion of the wheel mounting flange 57 in a state having a squeeze δ1 (= 0.35 to 1.4 mm) over the entire periphery.

  The dust lip 55 provided in the middle is formed on a curved surface portion 58 provided at a continuous portion between the inner surface of the wheel mounting flange 57 and the outer peripheral surface of the hub wheel 52 with the leading edge facing away from the inner space 53. In this state, the entire surface is in sliding contact with shimeiro δ2 (= 0.09 to 1.0 mm).

  On the other hand, the grease lip 56 provided closest to the inner space 53 is close to the outer peripheral surface of the hub wheel 52 with a labyrinth clearance 59 in a state where the tip edge is directed to the inner space 53. Alternatively, they are in sliding contact with a shimoshiro δ3. Shimeshiro δ3 is regulated within a range of −0.2 to +0.35 mm. Thereby, by reducing or eliminating the frictional resistance between the tip edge of the grease lip 56 and the outer peripheral surface of the hub wheel 52, the rotational resistance of the hub wheel 52 is reduced while ensuring the sealing performance, The driving performance is improved (for example, see Patent Document 1).

JP 2003-222145 A

  However, in such a conventional seal 50, the frictional resistance between the tip edge of the grease lip 56 and the outer peripheral surface of the hub wheel 52 is reduced, thereby ensuring the sealing performance and reducing the rotational resistance of the hub wheel 52. However, when the grease lip 56 is not in contact, the airtightness from the inside of the bearing to the outside is lowered, and when the pressure inside the bearing rises due to the rise in the bearing temperature during operation, air can easily escape to the outside of the bearing. In this case, when the temperature is lowered, the side lip 54 and the dust lip 55 are attracted to the outer peripheral surface of the hub wheel 52, and there is a possibility that the frictional resistance is increased and the torque is increased. On the other hand, in the case of the wheel bearing device of the drum brake specification, the outer side of the bearing is surrounded by brake parts, and the inner side is not directly exposed to foreign matters such as muddy water.

  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 that achieves a reduction in torque while ensuring a necessary sealing performance.

  In order to achieve such an object, the invention described in claim 1 of the present invention has a vehicle body mounting flange integrally attached to the knuckle constituting the suspension device on the outer periphery, and double row outward rotation on the inner periphery. An outer member integrally formed with a running surface, a wheel mounting flange for attaching a wheel to one end, and an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery; A hub wheel formed with a small-diameter step extending in the axial direction from the inner rolling surface, and an inner rolling that is fitted to the small-diameter step of the hub wheel and faces the other of the double-row outer rolling surface. An inner member formed of an outer ring member of an inner ring or a constant velocity universal joint having a surface formed thereon, and a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member Attached to both end openings of the annular space formed between the outer member and the inner member. A seal member on the outer side of the seal, a cylindrical fitting portion that is press-fitted into the inner periphery of the end portion of the outer member, and a radially inner portion from the fitting portion. A metal core having an inner diameter extending in the direction, a side lip integrally joined to the metal core, and extending in a radially outward direction, and extending in a radially outward direction on the inner diameter side of the side lip. And a base member on the inner side of the wheel mounting flange is formed in a curved surface having an arc-shaped cross section. The base or the wheel mounting flange The dust lip is slidably contacted with a predetermined axial squeezing force on the inner side surface, and the grease lip is slidably contacted with a predetermined radial squeezing force. But opposed through a slight opposing gap relative to the inner side surface of the base or the wheel mounting flange, labyrinth seals are formed.

  Thus, in the wheel bearing device provided with the seals mounted on the opening portions at both ends of the annular space formed between the outer member and the inner member, the outer seal of the seals is the outer member. A cylindrical fitting portion that is press-fitted into the inner periphery of the end portion, a metal core having an inner diameter portion that extends radially inward from the fitting portion, and is integrally bonded to the metal core and inclined radially outward A side lip that extends in the direction of the lip, a dust lip that extends obliquely outward in the radial direction on the inner diameter side of the side lip, and a seal member that integrally extends to incline toward the inner side of the bearing. The base part on the inner side of the flange is formed into a curved surface having an arc cross section, and the dust lip is slidably contacted with the base part or the side surface on the inner side of the wheel mounting flange with a predetermined axial direction, and the grease lip has a predetermined radial direction. The labyrinth seal is constructed with the side lip facing the base or the inner side surface of the wheel mounting flange via a slight gap, and the labyrinth seal is constructed. It is possible to provide a wheel bearing device that achieves low torque while ensuring.

  According to a second aspect of the present invention, the thickness of the side lip is set to be greater than the thickness of the dust lip, and the tip edge thereof is formed on an inclined surface along the shape of the base portion. In this case, the labyrinth width can be set long, and the sealing performance can be improved.

  Further, as in the invention described in claim 3, the tip end portion of the side lip may be bent and extend radially outward, and the bent portion may be formed in an arc shape along the shape of the base portion. Further, as in the invention described in claim 4, the side lip is bent outwardly in the radial direction, and the bent portion is formed linearly along the inner side surface of the wheel mounting flange. May be. Thereby, a labyrinth width becomes long and a sealing performance can be improved further.

  Further, as in the invention described in claim 5, if the outer diameter of the tip end portion of the side lip is formed larger than the outer diameter of the end portion of the outer member, the outer peripheral surface of the outer member is It is possible to reliably prevent the muddy water that has flowed through the side lip from flowing out downward and entering the tip. Therefore, the muddy water resistance of the seal can be increased, and stable sealing performance can be maintained over a long period of time.

  Further, as in the sixth aspect of the present invention, if fine unevenness is formed on the surface of the side lip and is set to be rougher than the surface roughness of the dust lip, even if it contacts the base during load application Because of the fine unevenness formed on the surface, grease is held on the contact surface, maintaining a good lubrication state and preventing lip wear, so that the desired opposing clearance can be maintained over a long period of time. Can be maintained.

  In addition, as in the seventh aspect of the present invention, if grease is previously applied to the surface of the side lip, a good lubrication state can be obtained by the grease even if it contacts the base portion under load.

  Further, as in the invention according to claim 8, the seal member is fixed by wrapping around the inner diameter portion of the cored bar to a part of the fitting portion by vulcanization adhesion, and radially outward to the outer diameter portion. And the outer diameter of the convex portion is larger than the outer diameter of the fitting portion of the core metal, and is elastically deformed into the inner periphery of the end portion of the outer member and press-fitted. If it is done, the airtightness of the fitting part of the core metal with the outer member is improved, and muddy water or the like can be prevented from entering from the fitting part from the outside.

  Further, as in the invention described in claim 9, the seal member has a flat portion at an end portion on the outer side, and a step between the outer diameter of the flat portion and the outer diameter of the side lip is 1.35 mm or more. Further, as in the invention described in claim 10, a flat portion is formed between the side lip and the dust lip, and the width dimension is set to 1.35 mm or more. May be. Thereby, at the time of seal assembly, the press-fitting jig can be pressed against the flat portion of the seal member without interfering with the side lip, and the seal can be easily press-fitted into the outer member.

  Further, as in the invention according to claim 11, the dust lip is formed so that a sliding contact surface between the dust lip and the hub wheel is on an outer diameter side with respect to an arcuate curved surface range of the base portion, and the wheel If the inner side surface of the mounting flange is slidably contacted with a predetermined axial squeezing force, it is possible to easily suppress unevenness of the dust lip, and to achieve stable sealing and low torque. it can.

  A wheel bearing device according to the present invention has a vehicle body mounting flange integrally attached to a knuckle constituting a suspension device on an outer periphery, and an outer side in which a double row outer rolling surface is integrally formed on an inner periphery. A member and a wheel mounting flange for attaching a wheel to one end, and an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and an axial direction from the inner rolling surface A hub ring formed with an extending small-diameter step portion, and an inner ring that is fitted to the small-diameter step portion of the hub ring and has an inner rolling surface that faces the other of the outer rolling surfaces of the double row, or is freely adjustable. An inner member composed of an outer joint member of the joint, a double row rolling element that is rotatably accommodated between both rolling surfaces of the inner member and the outer member, and the outer member and the inner member. A wheel shaft provided with seals mounted at both ends of an annular space formed between In the apparatus, the outer side seal of the seals includes a cylindrical fitting portion that is press-fitted into the inner periphery of the end portion of the outer member, and a core bar having an inner diameter portion that extends radially inward from the fitting portion. , And a side lip integrally joined to the mandrel and extending obliquely outward in the radial direction, a dust lip extending obliquely outward in the radial direction on the inner diameter side of the side lip, and an inner side of the bearing It is made of a seal member integrally having an inclined and extending grease lip, and a base portion on the inner side of the wheel mounting flange is formed in a curved surface having a circular arc cross section, and the dust lip is formed on the base portion or the inner side surface of the wheel mounting flange. Is slidably contacted with a predetermined axial direction shim, the grease lip is slidably contacted via a predetermined radial direction shimoshiro, and the side lip is connected to the base or the wheel. Provided is a labyrinth seal that faces a side surface on the inner side of the flange with a slight opposing gap, and thus provides a wheel bearing device that achieves low torque while ensuring the sealing performance of the seal. be able to.

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 part of FIG. FIG. 3 is an enlarged view showing a single seal of FIG. 2. It is a principal part enlarged view which shows the modification of the seal part of FIG. It is a principal part enlarged view which shows the other modification of the seal | sticker part of FIG. It is a principal part enlarged view which shows another modification same as the above. It is a principal part enlarged view which shows another modification same as the above. It is a principal part enlarged view which shows the conventional seal structure.

  A vehicle body mounting flange to be attached to the knuckle on the outer periphery, an outer member in which a double row outer rolling surface is integrally formed on the inner periphery, and a wheel mounting flange to mount a wheel on one end A hub wheel integrally formed and having an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small-diameter step portion extending in the axial direction from the inner rolling surface, and the hub wheel An inner member made of an inner ring that is press-fitted into a small-diameter step portion of the inner diameter through a predetermined squeeze and has an inner rolling surface that faces the other of the outer rolling surfaces of the double row on the outer periphery, and the inner member Mounted on both ends of an annular space formed between the outer member and the inner member, and a double row rolling element accommodated between both rolling surfaces of the outer member. A wheel bearing device including a seal, wherein the seal on the outer side of the seal is A cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer member, a core bar having an inner diameter portion extending radially inward from the fitting portion, and the core bar integrally bonded to the core From a seal member integrally including a side lip extending outwardly inclined, a dust lip extending inclined outward in the radial direction, and a grease lip extending inclined inward of the bearing on the inner diameter side of the side lip The base portion on the inner side of the wheel mounting flange is formed into a curved surface having an arcuate cross section, and the dust lip is slidably contacted with the base portion with a predetermined axial squeeze, and the grease lip is passed through the predetermined radial shimeoshiro In addition to sliding contact, the side lip thickness is set to be greater than the thickness of the dust lip, and the tip edge thereof is formed on an inclined surface along the shape of the base portion, so that it is slightly against the base portion. Opposed via a counter clearance labyrinth seals are formed.

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, FIG. 2 is an enlarged view of a main part showing a seal portion of FIG. 1, and FIG. 3 is an enlarged view showing a single seal of FIG. 4 is an enlarged view of a main part showing a modification of the seal part of FIG. 2, FIG. 5 is an enlarged view of a main part showing another modification of the seal part of FIG. 2, and FIG. 6 is a seal of FIG. FIG. 7 is an enlarged view of a main part showing another modification of the seal part in FIG. 2. 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 called the third generation for driving wheels, and includes an inner member 3 composed of a hub wheel 1 and an inner ring 2 press-fitted into the hub wheel 1, and a double row of inner members 3. And an outer member 5 inserted through rolling elements (balls) 4 and 4.

  The hub wheel 1 integrally has a wheel mounting flange 6 for attaching a wheel (not shown) to an end portion on the outer side, one (outer side) inner rolling surface 1a on the outer periphery, and this inner rolling. A small diameter step 1b extending in the axial direction from the surface 1a is formed, and a serration (or spline) 1c for torque transmission is formed on the inner periphery. Further, hub bolts 6 a are implanted at circumferentially equidistant positions of the wheel mounting flange 6. The inner ring 2 is formed with the other (inner side) inner rolling surface 2a on the outer periphery, and is press-fitted and fixed to the small-diameter step portion 1b of the hub ring 1 through a predetermined shimiro.

  The hub wheel 1 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and includes an inner rolling surface 1a and an inner side of a wheel mounting flange 6 that becomes 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 6b to the small diameter step 1b. On the other hand, the inner ring 2 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.

  The outer member 5 integrally has a vehicle body mounting flange 5b to be attached to a knuckle (not shown) constituting a suspension device on the outer periphery, and the inner rolling surfaces 1a and 2a of the inner member 3 on the inner periphery. Opposing double-row outer rolling surfaces 5a and 5a are integrally formed. Between these rolling surfaces 5a, 1a and 5a, 2a, double-row rolling elements 4, 4 are accommodated via a cage 7 so as to roll freely.

  The outer member 5 is made of medium and high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least the double row outer rolling surfaces 5a and 5a are hardened in the range of 58 to 64 HRC by induction hardening. Has been processed. In addition, seals 8 and 9 are attached to both ends of the annular space formed between the outer member 5 and the inner member 3, and leakage of the lubricating grease enclosed in the bearing to the outside and from the outside It prevents rainwater and dust from entering the bearing.

  The seal 9 on the inner side of the seals 8 and 9 is disposed opposite to each other, and is an annular seal plate 10 that is press-fitted into the inner periphery of the inner end of the outer member 5 serving as a fixed member via a predetermined shimiro. The so-called pack seal is composed of a slinger 11 which is press-fitted into the outer diameter of the inner ring 2 serving as a rotation side member through a predetermined scissors. The outer-side seal 8 includes a cored bar 12 press-fitted into the inner periphery of the outer-side end portion of the outer member 5 through a predetermined shimiro, and a seal member 13 joined to the cored bar 12. It is composed of an integral seal.

  The metal core 12 of the seal 8 is formed into an annular shape by pressing from a steel plate having rust-preventing ability, such as an austenitic stainless steel plate (JIS standard SUS304 type) or a cold rolled steel plate (JIS standard SPCC type). Is formed. A cylindrical shape in which the core 12 is formed from a steel plate having this type of rust-preventing ability by press working, the cross section is formed in an approximately L shape, and is formed into an annular shape as a whole, and is press-fitted into the inner periphery of the end of the outer member 5 The fitting portion 12a and an inner diameter portion 12b that is bent and extends radially inward from the fitting portion 12a.

  On the other hand, the seal member 13 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) and is integrally joined to the core metal 12 by vulcanization adhesion. As shown in an enlarged view in FIG. 2, the seal member 13 extends sidewardly with a side lip 13a extending obliquely outward in the radial direction and slightly inclined outwardly in the radial direction on the inner diameter side of the side lip 13a. The dust lip 13b and a grease lip 13c extending incline toward the bearing inward side are integrally provided.

  A base 6b on the inner side of the wheel mounting flange 6 is formed in a curved surface having an arc-shaped cross section, and a dust lip 13b is slidably contacted with the base 6b with a predetermined axial direction and a grease lip 13c is determined with a predetermined radial direction. It is slid through. Here, the side lip 13a is opposed to the base portion 6b via a slight gap A to form a labyrinth seal. Here, the opposing clearance A is set in the range of 0 to 1.0 mm.

  The side lip 13a and the dust lip 13b can reduce the torque while ensuring the desired sealing performance. Even when the internal pressure increases due to the temperature rise of the bearing, the inside of the bearing can be connected via the grease lip 13c. The air does not flow out, and the dust lip 13b and the grease lip 13c are not adsorbed to the base 6b when the bearing is cooled. Therefore, an increase in the rotational torque of the hub wheel 1 due to adsorption can be prevented, and a desired sealing performance can be secured, and the seal 8 can be improved in sealing performance and durability, thereby extending the life of the bearing.

  In addition to NBR, the material of the seal member 13 is excellent in heat resistance and chemical resistance, such as HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc., which have excellent heat resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber.

  In the present embodiment, the thickness B of the side lip 13a is set to be greater than the thickness C of the dust lip 13b (B ≧ C), and the tip edge is formed on an inclined surface along the shape of the base portion 6b. . Thereby, a labyrinth width can be set long and a sealing performance can be improved.

  Further, fine irregularities are formed on the surface of the side lip 13a, which is set to be rougher than the surface roughness of the other dust lip 13b and the grease lip 13c (indicated by cross-hatching in the figure), and grease is applied in advance. ing. The side lip 13a may come into contact with the base portion 6b when a load is applied. However, due to the fine unevenness formed on the surface, grease is held on the contact surface, and a good lubrication state is maintained and the lip is maintained. Since wear can be prevented, the desired facing clearance A can be maintained over a long period of time.

  In addition, although the wheel bearing apparatus comprised by the double row angular contact ball bearing which used the ball for the rolling element 4 was illustrated here, this invention is not limited to this, The double row using the tapered roller for the rolling element 4 You may be comprised with the tapered roller bearing. Furthermore, it is not limited to the illustrated third generation structure, but may be a fourth generation structure.

  FIG. 3 shows the seal 8 as a single unit. Here, the seal member 13 is fixed by wrapping around a part of the fitting portion 12a from the inner diameter portion 12b of the cored bar 12 by vulcanization adhesion. And the flat part 14 is formed in the edge part of an outer side, and the convex part 15 which protrudes to radial direction outward is formed in the outer diameter part. The outer diameter of the convex portion 15 is formed to be larger than the outer diameter of the fitting portion 12a of the core metal 12, and is elastically deformed and press-fitted into the inner periphery of the end portion of the outer member 5. Thereby, the airtightness of the fitting part 12a of the metal core 12 with the outer member 5 is improved, and muddy water or the like can be prevented from entering from the fitting part 12a from the outside.

  Further, the step F between the outer diameter of the flat portion 14 and the outer diameter of the side lip 13a is set to 1.35 mm or more. As a result, when the seal is assembled, a press-fitting jig (not shown) is pressed against the flat portion 14 of the seal member 13 without interfering with the side lip 13a, and the seal 8 can be easily press-fitted into the outer member 5. .

  A seal 16 shown in FIG. 4 is a modification of the seal 8 of FIG. The seal 16 basically differs from the seal 8 only in the configuration of the side lip of the seal member, and other parts and parts having the same parts or parts having the same functions are designated by the same reference numerals. Is omitted.

  The seal 16 is an integral seal comprising a cored bar 12 press-fitted into the inner periphery of the outer side end of the outer member 5 via a predetermined shimiro, and a seal member 17 integrally joined to the cored bar 12. It consists of

  The seal member 17 is made of a synthetic rubber such as NBR and is integrally joined from the inner diameter portion 12b of the cored bar 12 to a part of the fitting portion 12a by vulcanization adhesion. The seal member 17 includes a side lip 17a having a distal end portion 18 bent and extended radially outward, a dust lip 13b extending obliquely outward in the radial direction toward the inner diameter side of the side lip 17a, and a bearing inner side. A grease lip 13c extending in an inclined manner is integrally provided.

  Here, the tip 18 of the side lip 17a is formed in an arc shape along the shape of the base 6b. And it opposes through slight opposition gap A with respect to base 6b, and constitutes a labyrinth seal. Thereby, a labyrinth width becomes long and a sealing performance can be improved further.

  Further, as in the above-described embodiment, fine irregularities are formed on the surface of the tip portion 18 of the side lip 17a (indicated by cross hatching in the figure), which is rougher than the surface roughness of the other dust lip 13b and grease lip 13c. It is set and grease is applied in advance.

  A seal 19 shown in FIG. 5 is another modification of the seal 8 of FIG. The seal 19 is basically different only in the configuration of the side lip of the seal 8 and the seal member, and other parts and parts having the same parts or parts having the same functions are designated by the same reference numerals. Is omitted.

  The seal 19 is an integral seal comprising a cored bar 12 press-fitted into the inner periphery of the outer side end of the outer member 5 via a predetermined shimiro, and a seal member 20 integrally joined to the cored bar 12. It consists of

  The seal member 20 is made of a synthetic rubber such as NBR, and is integrally joined from the inner diameter part 12b of the cored bar 12 to a part of the fitting part 12a by vulcanization adhesion. The seal member 20 is inclined to the radially inwardly extending side lip 20a, to the inner diameter side of the side lip 20a, to the radially inwardly extending dust strip 13b, and to the bearing inward side. It has a grease lip 13c extending in an integral manner.

  Here, the side lip 20a is opposed to the base portion 6b through a slight gap A to form a labyrinth seal, and the outer diameter of the end portion of the side lip 20a is larger than the outer diameter of the end portion of the outer member 5. It is formed so as to have a large diameter and protrude by D. Accordingly, it is possible to reliably prevent the muddy water flowing along the outer peripheral surface of the outer member 5 from being received by the side lip 20a and flowing downward and entering the tip portion. Therefore, the muddy water resistance of the seal 19 can be increased, and a stable sealing performance can be maintained over a long period of time.

  Further, a flat portion 14 'is formed between the side lip 20a and the dust lip 13b, and the width dimension E is set to 1.35 mm or more. Thereby, when the seal is assembled, a press-fitting jig (not shown) is pressed against the flat portion 14 ′ of the seal member 19 without interfering with the side lip 20 a, and the seal 19 can be easily press-fitted into the outer member 5. it can.

  Further, as in the embodiment described above, fine irregularities are formed on the surface of the side lip 20a (indicated by cross hatching in the figure), and the surface roughness is set to be rougher than the surface roughness of the other dust lip 13b and grease lip 13c. The grease is applied in advance.

  A seal 21 shown in FIG. 6 is another modification of the seal 8 of FIG. The seal 21 basically differs only in the configuration of the side lip of the seal 8 and the seal member, and other parts and parts having the same parts or parts having the same functions are designated by the same reference numerals. Is omitted.

  The seal 21 is an integrated seal comprising a cored bar 12 press-fitted into the outer periphery of the outer side end of the outer member 5 via a predetermined shimiro, and a seal member 22 integrally joined to the cored bar 12. It consists of

  The seal member 22 is made of synthetic rubber such as NBR, and is joined integrally from the inner diameter portion 12b of the cored bar 12 to a part of the fitting portion 12a by vulcanization adhesion. The seal member 22 includes a side lip 22a having a distal end portion 23 bent and extended radially outward, a dust lip 13b extending obliquely outward in the radial direction on the inner diameter side of the side lip 22a, and a bearing inward A grease lip 13c extending incline toward the side is integrally provided.

  Here, the front end 23 of the side lip 22a is formed in a straight line along the inner side surface 6c of the wheel mounting flange 6 and confronts it through a slight gap A to form a labyrinth seal. And the outer diameter of the front-end | tip part 23 of the side lip 22a is formed larger than the outer diameter of the edge part of the outer member 5, and it is set so that only D may protrude. Accordingly, it is possible to reliably prevent the muddy water flowing along the outer peripheral surface of the outer member 5 from being received by the side lip 22 a and flowing downward and entering the tip portion 23. Therefore, the mud water resistance of the seal 21 can be increased and a stable sealing performance can be maintained over a long period of time. Further, a flat portion 14 'is formed between the side lip 22a and the dust lip 13b, and the width dimension E is set to 1.35 mm or more.

  Further, as in the above-described embodiment, fine irregularities are formed on the surface of the tip 23 of the side lip 22a (indicated by cross hatching in the figure), which is rougher than the surface roughness of the other dust lip 13b and grease lip 13c. The grease is applied in advance while being set.

  A seal 24 shown in FIG. 7 is another modification of the seal 8 of FIG. The seal 24 basically differs from the seal 8 only in the configuration of the seal member, and other parts and portions having the same parts or functions having the same functions are denoted by the same reference numerals and detailed description thereof is omitted. .

  The seal 24 is an integral seal comprising a cored bar 12 press-fitted into the inner periphery of the outer side end of the outer member 5 via a predetermined shimiro, and a seal member 25 integrally joined to the cored bar 12. It consists of

  The seal member 25 is made of synthetic rubber such as NBR, and is joined integrally from the inner diameter portion 12b of the cored bar 12 to a part of the fitting portion 12a by vulcanization adhesion. The seal member 25 is inclined to the radially inwardly extending side lip 25a, to the inner diameter side of the side lip 25a, to the radially inwardly extending dust strip 25b, and to the bearing inward side. It has a grease lip 25c extending in an integral manner.

  Here, the dust lip 25b is formed slightly outside the arcuate curved surface range G of the base portion 6b by H, and is slidably contacted with the side surface 6c of the wheel mounting flange 6 with a predetermined axial direction. At the same time, the grease lip 13c is slidably contacted with the base portion 6b via a predetermined radial shimiro. Thus, since the dust lip 25b is slidably contacted with the flat side surface 6c, it is possible to easily suppress unevenness of the shimoshiro, and to achieve stable sealing performance and torque reduction.

  Further, the side lip 25a is opposed to the side surface 6c of the wheel mounting flange 6 through a slight clearance A to constitute a labyrinth seal. Thus, since the side lip 25a faces the flat side surface 6c, the labyrinth clearance can be easily adjusted and managed, and stable sealing performance and low torque can be achieved.

  Further, as in the above-described embodiment, the outer diameter of the end portion of the side lip 25a is formed larger than the outer diameter of the end portion of the outer member 5, and is set so as to protrude by D, and the side lip 25a Fine irregularities are formed on the surface (indicated by cross-hatching in the figure), which is set to be rougher than the surface roughness of the other dust strips 25b and grease lips 25c.

  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. 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 is a third generation in which a seal is attached to an opening of an annular space formed between an inner member serving as a rotating member and an outer member serving as a stationary member. It can be applied to a fourth-generation wheel bearing device.

DESCRIPTION OF SYMBOLS 1 Hub wheel 1a, 2a Inner rolling surface 1b Small diameter step part 1c Serration 2 Inner ring 3 Inner member 4 Rolling body 5 Outer member 5a Outer rolling surface 5b Car body mounting flange 6 Wheel mounting flange 6a Hub bolt 6b Inner wheel mounting flange Side base portion 6c Inner side surface 7 of wheel mounting flange Cage 8, 16, 19, 21, 24 Outer side seal 9 Inner side seal 10 Seal plate 11 Slinger 12 Core metal 12a Fitting portion 12b Inner diameter portion 13, 17, 20, 22, 25 Seal members 13a, 17a, 20a, 22a, 25a Side lip 13b, 25b Dustrip 13c, 25c Grease lip 14, 14 'Flat portion 15 Protruding portion 18, 23 Side lip tip 50 Seal 51 Outer ring 52 Hub ring 53 Internal space 54 Side lip 55 Dustrip 56 Glee Slip 57 Wheel mounting flange 58 Curved surface part 59 Labyrinth clearance A Opposite clearance between dust lip and base B Side lip thickness C Dustrip thickness D Side lip protrusion E Seal member flat width F Flat part outer diameter and side Step G with the outer diameter of the lip Arc-shaped curved surface range H of the base portion Amount of separation δ1, δ2, δ3 from the base portion of the dust lip

Claims (11)

An outer member integrally having a vehicle body mounting flange for being attached to a knuckle constituting a suspension device on the outer periphery, and an outer rolling surface of a double row integrally formed on the inner periphery;
A wheel mounting flange for integrally mounting a wheel at one end, an inner rolling surface facing one of the outer rolling surfaces of the double row on the outer periphery, and a small diameter step extending in the axial direction from the inner rolling surface The outer ring of the inner ring or the constant velocity universal joint formed with the inner ring surface that is fitted to the hub wheel formed with the portion and the small diameter step portion of the hub wheel and that faces the other of the outer surface of the double row. An inner member made of a joint member;
A double row rolling element housed in a freely rolling manner between the rolling surfaces of the inner member and the outer member;
In a wheel bearing device comprising a seal mounted at both ends of an annular space formed between the outer member and the inner member,
The outer side seal of the seals has a cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer member, a cored bar having an inner diameter portion extending radially inward from the fitting portion, and this A side lip that is integrally joined to the metal core and extends obliquely outward in the radial direction, a dust lip extending obliquely outward in the radial direction on the inner diameter side of the side lip, and inclined toward the inner side of the bearing The wheel mounting flange is formed of a seal member integrally having an extending grease lip, and a base portion on the inner side of the wheel mounting flange is formed in a curved surface having an arcuate cross section. The grease lip is slidably contacted through a predetermined radial direction,
The wheel bearing device according to claim 1, wherein the side lip is opposed to the base or the inner side surface of the wheel mounting flange via a slight facing clearance to form a labyrinth seal.   2. The wheel bearing device according to claim 1, wherein a thickness of the side lip is set larger than a thickness of the dust lip, and a leading edge thereof is formed on an inclined surface along the shape of the base portion.   2. The wheel bearing device according to claim 1, wherein a distal end portion of the side lip is bent outward in a radial direction, and the bent portion is formed in an arc shape along the shape of the base portion.   The wheel bearing device according to claim 1, wherein the side lip is bent and extended radially outward, and the bent portion is formed in a straight line along the inner side surface of the wheel mounting flange.   The wheel bearing device according to any one of claims 1 to 4, wherein an outer diameter of a distal end portion of the side lip is formed larger than an outer diameter of an end portion of the outer member.   3. The wheel bearing device according to claim 1, wherein fine irregularities are formed on a surface of the side lip and set to be rougher than a surface roughness of the dust lip.   The wheel bearing device according to any one of claims 1 to 6, wherein grease is previously applied to a surface of the side lip.   The seal member wraps around and adheres to a part of the fitting portion from the inner diameter portion of the core metal by vulcanization adhesion, and a convex portion protruding radially outward is formed on the outer diameter portion. 2. The wheel bearing device according to claim 1, wherein the outer diameter of the portion is formed larger than the outer diameter of the fitting portion of the cored bar, and is elastically deformed and press-fitted into the inner periphery of the end portion of the outer member. .   9. The wheel for a vehicle according to claim 8, wherein the seal member has a flat portion at an end on the outer side, and a step between the outer diameter of the flat portion and the outer diameter of the side lip is set to 1.35 mm or more. Bearing device.   The wheel bearing device according to claim 1 or 2, wherein a flat portion is formed between the side lip and the dust lip, and a width dimension thereof is set to 1.35 mm or more.   The dust lip is formed so that the sliding contact surface between the dust lip and the hub wheel is on the outer diameter side with respect to the arcuate curved surface range of the base portion. The wheel bearing device according to claim 1 or 2, wherein the wheel bearing device is slidably contacted with an axial direction.

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