JP2011089558A - Wheel bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel bearing device for improving the muddy water resistance of a seal and maintaining stable sealing by preventing the wear of lips. <P>SOLUTION: The seal 8 includes a core metal 13 constituted of a cylindrical fitting portion 13a pressed into the end inner periphery of an outward member 10 and an inner diameter portion 13b extending inward in the radial direction, and a synthetic rubber seal member 14 vulcanizedly adhered to the core metal 13 and having the side lip 14a obliquely extending outward in the radial direction, the dust lip 14b obliquely extending from the inner diameter side thereof outward in the radial direction and the grease lip 14c obliquely extending inward in the radial direction. A base portion 4a of a wheel mounting flange 4 is formed into a sectionally circular curved surface, and the side lip 14a and the dust lip 14b have slide contact with the base portion 4a via a predetermined axial margin. A stepped part 16 is formed on the base portion 4a, and the stepped part 16 is arranged outward in the radial direction to cover the front end of the side lip 14a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension device, and more specifically, to improve the muddy water resistance of a seal mounted on a bearing portion, to prevent lip wear and to improve the sealing performance. The present invention relates to a bearing device for a wheel that improves the above.

  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.

  These bearing portions are fitted with seals to prevent leakage of grease sealed inside the bearings and to prevent intrusion of rainwater, dust and the like from the outside. In recent years, the maintenance of automobiles has become more maintenance-free, and even longer bearing life has been demanded for wheel bearing devices. However, there are many cases in which rainwater, dust, or the like intrudes into the bearing and damages the bearing due to a sealing failure or a decrease in sealing performance. Therefore, it is possible to improve the bearing life by improving the sealing performance of the seal.

  Conventionally, various seals with improved sealing performance have been proposed. A typical example of such a seal is shown in FIG. The seal 50 includes a slinger 51 and an annular seal plate 52 that are arranged to face each other. The slinger 51 is formed into a substantially L-shaped section by pressing from a steel plate, and a cylindrical portion 51a that is press-fitted into the outer diameter of an inner ring (not shown), and extends radially outward from the cylindrical portion 51a. It consists of a standing plate portion 51b.

  On the other hand, the seal plate 52 is formed in a substantially L-shaped cross section, and includes a cored bar 53 and a seal member 54 vulcanized and bonded to the cored bar 53. The metal core 53 is formed from a steel plate by press working, and has a cylindrical fitting portion 53a that is press-fitted into the inner diameter of an outer member (not shown), and extends radially inward from the fitting portion 53a. It consists of an inner diameter part 53b. The seal member 54 is made of an elastic member, is formed to be inclined radially outward from the inner diameter portion 53b of the core metal 53, and has a side lip 54a whose tip is slidably contacted with the standing plate portion 51b of the slinger 51 with a predetermined squeeze, and a slinger Radial lips 54b and 54c that are in sliding contact with the cylindrical portion 51a.

  Further, the sealing member 54 wraps around and is fixed to the outer surface of the fitting portion 53a of the cored bar 53, and is brought into close contact with the outer member to improve airtightness. Further, the labyrinth seal 55 is configured by the outer edge of the standing plate portion 51b of the slinger 51 and the seal member 54 facing each other through a slight radial clearance, and rainwater, dust, etc. are directly applied to the side lip 54a from the outside. Prevents and improves sealing performance.

  Here, the outer side surface B of the standing plate portion 51 b of the slinger 51 is retracted inward from the end surface A of the seal plate 52. That is, since L> 0, the labyrinth seal 55 having a predetermined axial width is always maintained between the standing plate portion 51b of the slinger 51 and the seal member 54 of the seal plate 52, and the arrangement space of the seal 50 is reduced. The sealing property can be improved without increasing the size (for example, see Patent Document 1).

JP 2001-65704 A

  However, in such a conventional seal 50, as shown in an enlarged view in FIG. 10, when muddy water or the like flows into the sliding contact portion between the side lip 54a and the standing plate portion 51b of the slinger 51, the sliding contact is obtained in a long-term use. There is a possibility that muddy water adheres to the part and bites sand in the muddy water, thereby promoting lip wear. Thereby, there existed a problem that the stable sealing performance could not be maintained over a long period of time.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a wheel bearing device capable of improving the muddy water resistance of a seal and preventing lip wear and maintaining stable sealing performance. And

  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 a wheel for attaching a wheel to one end. An inner member having a hub wheel integrally having a mounting flange and having an outer circumferential surface formed with a double-row inner rolling surface facing the double-row outer rolling surface, and the inner member and the outer 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 the rolling surfaces via a cage. In the wheel bearing device including the seal, at least one of the seals is a cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer member, and radially inward from the fitting portion. A cored bar having an inner diameter extending to the core and a support vulcanized and bonded to the cored bar and extending obliquely outward in the radial direction. A synthetic rubber sealing member having a drip, and a stepped portion is formed on the mating member in sliding contact with the side lip, and the stepped portion is arranged radially outward so as to cover the tip of the side lip. Has been.

  As described above, in the wheel bearing device including the seals mounted on the opening portions at both ends of the annular space formed between the outer member and the inner member, at least one of the seals is the outer member. A core fitting that is press-fitted into the inner periphery of the end of the rim, and a cored bar that includes an inner diameter part that extends radially inward from the fitting part, and is vulcanized and bonded to the cored bar and is inclined radially outward. And a synthetic rubber sealing member having a side lip that extends in a step, and a stepped portion is formed on a mating member that the side lip is in sliding contact with. Therefore, even if muddy water or the like flows, it does not stay in the sliding contact portion of the side lip and flows down and is discharged, and muddy water adheres to this sliding contact portion and lip wear is not promoted. , Improve the muddy water resistance of the seal, long-term Over and it is possible to provide a wheel bearing apparatus which can maintain stable sealing performance.

  In addition, as in the invention described in claim 2, the inner member has one inner rolling surface of the double-row inner rolling surface 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 constant velocity universal joint that is fitted to the hub wheel formed with a portion, and the other inner rolling surface of the double row inner rolling surface that is fitted to the small-diameter step portion of the hub wheel. The base portion on the inner side of the wheel mounting flange is formed in a curved surface having an arc shape in cross section, and the side lip is slidably contacted with the base portion with a predetermined axial direction squeezing, and the inner diameter of the side lip A dust lip extending obliquely outward in the radial direction and a grease lip extending inclined inward in the radial direction may be formed on the side.

  Further, as in the invention described in claim 3, the side surface on the inner side of the wheel mounting flange and the end surface on the outer side of the outer member are opposed to each other through a slight axial clearance to form a labyrinth seal. If this is the case, muddy water or the like is not directly applied to the seal, and the sealing performance and durability of the seal are improved.

  According to a fourth aspect of the present invention, the seal is composed of a pack seal composed of a slinger and an annular seal plate arranged to face each other, and the slinger is externally fitted to the inner member. A cylindrical portion and a standing plate portion extending radially outward from the cylindrical portion, the seal plate is composed of the cored bar and a seal member, and the side lip is formed on the standing plate portion of the slinger. If the flange that becomes the stepped portion protrudes in the axial direction on the standing plate portion of the slinger, even if muddy water or the like flows into the sliding contact portion of the side lip Without staying, it flows downward and is discharged, and muddy water does not adhere to the sliding contact portion to promote lip wear, and the wear resistance of the side lip can be improved.

  Further, as in the fifth aspect of the present invention, if a labyrinth seal is configured such that the flange portion of the slinger and the seal member face each other through a slight radial clearance, the flange portion and the seal member The width of the confrontation becomes long, and it is possible to improve the sealing performance by preventing rainwater, dust, etc. from directly falling on the side lip from the outside.

  According to a sixth aspect of the present invention, the second lip is inclined radially outwardly toward the inner diameter side of the side lip, and is in sliding contact with the standing plate portion of the slinger via a predetermined axial clearance. If a grease lip extending inward in the radial direction and in sliding contact with the cylindrical portion of the slinger via a predetermined radial nip is formed, the sealing performance of the seal is further improved.

  Preferably, as in the invention according to claim 7, if a stepped portion is formed on the standing plate portion of the slinger so as to cover the tip portion of the side lip on the inner diameter side, for example, the outer diameter side Even if muddy water or the like flows through the side lip, it does not directly contact the sliding contact portion of the side lip, and muddy water adheres to the sliding contact portion and lip wear is not promoted.

  Further, if the slinger is formed by pressing from a steel plate having rust prevention ability as in the invention described in claim 8, the cost is reduced and the slinger is generated over a long period of time. Rust can be suppressed and durability and sealability can be improved.

  Further, as in the ninth aspect of the invention, if the stepped amount of the stepped portion is set to be larger than the axial dimension of the tip end portion of the side lip, muddy water is directly applied to the sliding contact portion of the side lip. The muddy water does not adhere and bites the sand in the muddy water, and lip wear is not promoted.

  Further, as in the invention according to claim 10, the end portion of the fitting portion of the cored bar is formed to be thinner and reduced in diameter than other portions, and the sealing member is formed on the outer surface of the end portion of the fitting portion. If the wrap around and is fixed, the fixing force of the seal member becomes strong, and the airtightness of the fitting portion with the outer member can be maintained over a long period of time.

  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 at both ends of an annular space formed between the inner member and the inner member, at least one of the seals is provided on the inner periphery of the end of the outer member. A cored bar made of a press-fitted cylindrical fitting part and an inner diameter part extending radially inward from the fitting part, and a side lip that is vulcanized and bonded to the cored bar and extends obliquely outward in the radial direction And a stepped portion is formed on the mating member with which the side lip is slidably contacted. Since the stepped portion is arranged radially outward so as to cover the tip of the side lip, even if muddy water or the like flows, it flows out and is discharged downward without staying in the sliding contact portion of the side lip. It is possible to provide a wheel bearing device that does not promote lip wear due to muddy water adhering to the sliding contact portion, enhances the muddy water resistance of the seal, and can maintain stable sealing performance over a long period of time. it can.

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 the seal | sticker part of the outer side of FIG. It is an enlarged view which shows the lip | sliding contact part of FIG. It is a longitudinal cross-sectional view which shows 2nd Embodiment of the wheel bearing apparatus which concerns on this invention. It is a principal part enlarged view which shows the seal part of the inner side of FIG. It is an enlarged view which shows the lip | sliding contact part of FIG. It is a principal part enlarged view which shows the modification of FIG. It is an enlarged view which shows the lip | sliding contact part of FIG. It is a longitudinal cross-sectional view which shows the seal | sticker single-piece | unit of the conventional wheel bearing apparatus. It is an enlarged view which shows the lip | sliding contact part of FIG.

  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 wheel having an outer periphery and one inner rolling surface facing the outer rolling surface of the double row, and a small-diameter step portion extending in an axial direction from the inner rolling surface, and the hub wheel An inner member comprising an inner ring that is press-fitted into a small-diameter step portion and has the other inner rolling surface facing the outer rolling surface of the double row on the outer periphery, and both rolling of the inner member and the outer member. A double-row rolling element accommodated between the running surfaces via a cage, and a seal attached to both end openings of an annular space formed between the outer member and the inner member; In the wheel bearing device comprising: the outer seal of the seals is the outer member A cylindrical fitting part press-fitted into the inner periphery of the end part, and a cored bar made of an inner diameter part extending radially inward from the fitting part, and vulcanized and bonded to the cored bar and inclined radially outward. A side lip extending inward, a dust lip extending radially outward on the inner diameter side of the side lip, and a synthetic rubber sealing member having a grease lip extending inclined inward in the radial direction, The base part on the inner side of the wheel mounting flange is formed in a curved surface having an arc-shaped cross section, and the side lip and dust lip are in sliding contact with this base part via a predetermined axial direction shimoshiro, and a stepped part is formed in the base part And this step part is arrange | positioned radially outward so that the front-end | tip part of the said side lip may be covered.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 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 a seal part on the outer side of FIG. 1, and FIG. It is an enlarged view which shows a lip | sliding contact part. 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 and an outer member 10, and double row rolling elements (balls) 7 and 7 accommodated between the members 1 and 10 so as to be freely rollable. The third generation is configured. The inner member 1 includes a hub ring 2 and an inner ring 3 that is press-fitted and fixed to the hub ring 2.

  The hub wheel 2 integrally has a wheel mounting flange 4 for mounting a wheel at an end portion on the outer side, one (outer side) inner rolling surface 2a on the outer periphery, and an axial direction from the inner rolling surface 2a. A cylindrical small-diameter step portion 2b is formed, and a serration (or spline) 2c for torque transmission is formed on the inner periphery. Further, hub bolts 5 are planted in the circumferentially equidistant positions of the wheel mounting flanges 4. The inner ring 3 is formed with the other (inner side) inner rolling surface 3a on the outer periphery, and is press-fitted into the small-diameter step portion 2b of the hub ring 2 through a predetermined squeeze.

  The hub wheel 2 is made of medium and high carbon steel containing carbon of 0.40 to 0.80 wt% such as S53C, and the wheel mounting flange 4 serving as a seal land portion of the outer side seal 8 to be described later, including the inner rolling surface 2a. The surface is hardened in the range of 58 to 64 HRC by induction quenching from the base 4a on the inner side to the small diameter step 2b. On the other hand, the inner ring 3 and the rolling element 7 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 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 7, 7 are accommodated via a cage 6 so as to roll freely. 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 both ends of the outer member 10 to seal the opening of the annular space formed between the outer member 10 and the inner member 1. The seals 8 and 9 prevent leakage of the lubricating grease sealed inside the bearing and intrusion of rainwater and dust from the outside into the bearing.

  The seal 9 on the inner side of the seals 8 and 9 is constituted by a so-called pack seal composed of a slinger 11 and an annular seal plate 12 arranged to face each other. On the other hand, as shown in FIG. 2, the seal 8 on the outer side includes a core bar 13 press-fitted through a predetermined shimiro to the inner periphery of the outer side end portion of the outer member 10 serving as a fixed side member, and the core bar. 13 and a seal member 14 joined to 13.

  The core metal 13 is formed by pressing an austenitic stainless steel plate (JIS standard SUS304 type) or a cold rolled steel plate (JIS standard SPCC type, etc.) from a steel plate having anti-corrosive ability. 10 having a cylindrical fitting portion 13a press-fitted into 10 and an inner diameter portion 13b formed by bending inward in the radial direction from the fitting portion 13a. It is formed in an annular shape. If the core metal 13 is formed from a steel plate having this type of rust prevention ability by press working, rusting of the core metal 13 can be suppressed over a long period of time, and durability and sealability can be improved. .

  The seal member 14 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and is integrally joined to the cored bar 13 by vulcanization adhesion. The seal member 14 is joined so as to cover the exposed surface from the fitting portion 13 a having a reduced diameter of the core metal 13 to the inner diameter portion 13 b, and radially outward from the inner diameter portion 13 b of the core metal 13. A side lip 14a extending obliquely, a dust lip 14b extending obliquely outward in the radial direction on the inner diameter side of the side lip 14a, and a grease lip 14c extending inclined toward the bearing inward side. Yes.

  The base portion 4a on the inner side of the wheel mounting flange 4 is formed in a curved surface having an arc-shaped cross section. The side lip 14a and the dust lip 14b are slidably contacted with the base portion 4a with a predetermined axial squeeze, and the grease lip 14c is predetermined. Are in sliding contact with each other through a radial shimoshiro. In addition to NBR, the material of the seal member 14 is excellent in heat resistance and chemical resistance, such as HNBR (hydrogenated acrylonitrile butadiene rubber) and EPDM (ethylene propylene rubber), which have excellent heat resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber.

  Here, in this embodiment, the side surface 4b on the inner side of the wheel mounting flange 4 and the end surface 10c on the outer side of the outer member 10 face each other with a slight axial clearance, and the labyrinth seal 15 is formed. A stepped portion 16 is formed on the base portion 4a which is a sliding contact portion of the side lip 14a. As shown in an enlarged view in FIG. 3, the stepped amount δ of the stepped portion 16 is set to be larger than the axial dimension W of the distal end portion of the side lip 14a (δ> W). As a result, muddy water or the like is not directly applied to the seal 8 and the sealing performance is improved. For example, even if muddy water or the like flows through the labyrinth seal 15, it flows downward without staying in the sliding contact portion of the side lip 14a. It is discharged and muddy water does not adhere to this sliding contact portion, and lip wear is not promoted. Therefore, it is possible to provide a wheel bearing device that can increase the mud water resistance of the seal 8 and maintain stable sealing performance for 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 7 was illustrated here, this invention is not limited to this, The double row using the tapered roller for the rolling element 7 You may be comprised with the tapered roller bearing. Furthermore, it is not limited to the illustrated third generation structure, but may be a first, second generation structure, or a fourth generation structure.

  4 is a longitudinal sectional view showing a second embodiment of the wheel bearing device according to the present invention, FIG. 5 is an enlarged view of a main part showing a seal part on the inner side of FIG. 4, and FIG. 7 is an enlarged view showing a lip sliding contact portion, FIG. 7 is an enlarged view of a main portion showing a modification of FIG. 5, and FIG. 8 is an enlarged view showing the lip sliding contact portion of FIG. This embodiment basically differs from the above-described embodiment only in the configuration of the seal on the inner side, and other parts having the same parts or the same functions as those of the above-described embodiments are denoted by the same reference numerals. Detailed description is omitted.

  The inner-side seal 17 is constituted by a pack seal composed of a slinger 18 and an annular seal plate 19 arranged to face each other. As shown in FIG. 5, the annular seal plate 19 includes a core metal 20 having a substantially L-shaped cross section and a seal member 21 joined to the core metal 20.

  The metal core 20 is formed by pressing from a steel plate having an antirust function, such as an austenitic stainless steel plate (JIS standard SUS304 type) or a cold rolled steel plate (JIS standard SPCC type). It consists of a cylindrical fitting portion 20a that is press-fitted into the member 10, and an inner diameter portion 20b that is formed by bending inward in the radial direction from the fitting portion 20a, and has a substantially L-shaped cross section as a whole. It is formed in an annular shape.

  The seal member 21 is made of synthetic rubber such as NBR, and is integrally joined by vulcanization bonding from the end of the fitting portion 20a of the core metal 20 to the inner diameter portion 20b, and from the inner diameter portion 20b of the core metal 20 in the radial direction. A pair of side lips 21a, 21b extending inclining outward and a grease lip 21c extending inclining toward the bearing inward side are integrally provided. In addition, the edge part of the fitting part 20a of the metal core 20 is formed thinner than another part, and is diameter-reduced. And the sealing member 21 goes around and is fixed to the outer surface of the end portion of the fitting portion 20a. Thereby, the adhering force of the seal member 21 is strengthened, and the airtightness of the fitting portion with the outer member 10 can be maintained over a long period of time.

  Slinger 18 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), austenitic stainless steel plate (JIS standard SUS304 series, etc.), cold rolled steel plate (JIS standard SPCC type, etc.), etc. A cylindrical portion 18a that is formed by press working from a steel plate having a function and is press-fitted into the outer diameter of the inner ring 3, and a vertical plate portion 18b that extends radially outward from the cylindrical portion 18a. It has a letter shape and is formed in an annular shape as a whole.

  The pair of side lips 21a, 21b of the seal member 21 are slidably contacted with the standing plate portion 18b of the slinger 18 with a predetermined axial squeezing force, and the grease lip 21c has a predetermined radial squeezing force with respect to the cylindrical portion 18a of the slinger 18. Are in sliding contact with each other. In addition to NBR, examples of the material of the seal member 21 include HNBR, EPDM, etc. excellent in heat resistance, ACM, FKM, silicon rubber, etc. excellent in heat resistance and chemical resistance. Can do.

  Here, in the present embodiment, a flange portion 23 that is a stepped portion is formed on the outer side surface of the upright plate portion 18 b that is a sliding contact portion of the side lip 21 a so as to protrude in the axial direction, and the flange portion 23 of the slinger 18. The labyrinth seal 22 is configured so that the seal member 21 and the seal member 21 face each other through a slight radial clearance. As a result, the width of the labyrinth seal 22 formed between the flange 23 and the seal member 21 is increased, and rainwater or dust is prevented from directly falling on the side lip 21a from the outside to improve the sealing performance. ing. As shown in FIG. 6 in an enlarged manner, the stepped amount δ of the flange portion 23 is set to be larger than the axial dimension W of the distal end portion of the side lip 21a (δ> W). As a result, even if muddy water or the like flows through the labyrinth seal 22, it flows out downward without staying in the sliding contact portion of the side lip 21a, and muddy water adheres to this sliding contact portion to promote lip wear. It will never be done.

  FIG. 7 shows a modified example of the seal 17 described above. This modification basically differs only in the configuration of the slinger, and other parts having the same parts or the same functions are denoted by the same reference numerals and detailed description thereof is omitted.

  The seal 24 is constituted by a pack seal composed of a slinger 25 and an annular seal plate 26 arranged to face each other. The annular seal plate 26 includes a cored bar 20 having a substantially L-shaped cross section, and a seal member 27 joined to the cored bar 20.

  The seal member 27 is made of synthetic rubber such as NBR, and is integrally joined by vulcanization adhesion from the end of the fitting portion 20a of the core metal 20 to the inner diameter portion 20b, and from the inner diameter portion 20b of the core metal 20 in the radial direction. A pair of side lips 27a and 21b extending inclining outward and a grease lip 21c extending inclining toward the bearing inward side are integrally provided.

  Slinger 25 is a ferritic stainless steel plate (JIS standard SUS430 series, etc.), austenitic stainless steel plate (JIS standard SUS304 series, etc.), cold rolled steel plate (JIS standard SPCC type, etc.), etc. A cylindrical portion 18a formed by pressing from a steel plate having a function and press-fitted into the outer diameter of the inner ring 3, and a standing plate portion 25a extending radially outward from the cylindrical portion 18a. It has a letter shape and is formed in an annular shape as a whole. If the slinger 25 is formed from a steel plate having this kind of rust prevention ability by press working, the rusting of the slinger 25 can be suppressed over a long period of time, and the durability and the sealing performance can be improved.

  The pair of side lips 27a, 21b of the seal member 27 are slidably contacted with the standing plate portion 25a of the slinger 25 with a predetermined axial squeeze, and the grease lip 21c has a predetermined radial squeeze with the cylindrical portion 18a of the slinger 25. Are in sliding contact with each other.

  Here, in this embodiment, the collar part 28 used as the step part protrudes and is formed in the side surface of the outer side of the standing board part 25a used as the sliding contact part of the side lip 27a. As shown in an enlarged view in FIG. 8, the stepped amount δ of the flange portion 28 is set to be larger than the axial dimension W of the distal end portion of the side lip 27a (δ> W). Thereby, the labyrinth seal 22 formed between the collar portion 28 and the seal member 27 can prevent foreign matters such as muddy water from entering the seal 24 from the outside, and improve the sealing performance. For example, even if muddy water or the like flows through the labyrinth seal 22, it flows out downward without staying in the sliding contact portion of the side lip 27a, and muddy water adheres to this sliding contact portion to promote lip wear. It will never be done.

  Further, a stepped portion 29 is formed so as to protrude from the side surface on the outer side of the upright plate portion 25a serving as the sliding contact portion of the side lip 21b on the inner diameter side. The stepped amount δ of the stepped portion 29 is set to be larger than the axial dimension of the tip portion of the side lip 21b (δ> W). Thereby, even if muddy water or the like flows through the side lip 27a on the outer diameter side, it does not directly contact the sliding contact portion of the side lip 21b, and muddy water adheres to this sliding contact portion and lip wear is promoted. There is nothing.

  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 can be applied to first to fourth generation wheel bearing devices in which a seal is attached to an opening of an annular space formed between an outer member and an inner member.

DESCRIPTION OF SYMBOLS 1 Inner member 2 Hub wheel 2a, 3a Inner rolling surface 2b Small diameter step part 2c Serration 3 Inner ring 4 Wheel mounting flange 4a Inner side base 4b of wheel mounting flange Side surface 5 of wheel mounting flange 5 Hub bolt 6 Cage 7 Rolling element 8 Outer side seals 9, 17, 24 Inner side seal 10 Outer member 10a Outer rolling surface 10b Car body mounting flange 10c Outer member end surfaces 11, 18, 25 Slinger 12, 19, 26 Seal Plates 13, 20 Core bars 13a, 20a Fitting portions 13b, 20b Inner diameter portions 14, 21, 27 Seal members 14a, 21a, 21b, 27a Side lips 14b Dustrips 14c, 21c Grease lips 15, 22 Labyrinth seals 16, 29 steps Attached part 18a Cylindrical part 18b, 25a Standing plate part 23, 28 Gutter part 50 Seal DESCRIPTION OF SYMBOLS 1 Slinger 51a Cylindrical part 51b Standing plate part 52 Sealing plate 53 Core metal 53a Fitting part 53b Inner diameter part 54 Seal member 54a Side lip 54b, 54c Radial lip 55 Labyrinth seal A End face B of a slinger Side L Slinger retreat amount W Side lip tip axial dimension δ Stepped amount

Claims (10)

An outer member in which a double row outer rolling surface is integrally formed on the inner periphery;
An inner member comprising a hub wheel integrally having a wheel mounting flange for mounting a wheel at one end, and an inner member formed with a double row inner raceway facing the outer row of the double row 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 at both ends of an annular space formed between the outer member and the inner member,
At least one of the seals includes a cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer member, and a cored bar made of an inner diameter portion extending radially inward from the fitting portion, A synthetic rubber sealing member having a side lip that is vulcanized and bonded to the mandrel and that extends obliquely outward in the radial direction, and a stepped portion is formed on the mating member that is in sliding contact with the side lip. The wheel bearing device is characterized in that the portion is disposed radially outward so as to cover the tip of the side lip.   The inner member has a hub ring formed on the outer periphery with one inner rolling surface of the double row inner rolling surface and a small-diameter step extending in the axial direction from the inner rolling surface, and the hub wheel It consists of an outer joint member of an inner ring or a constant velocity universal joint that is fitted to a small-diameter step portion and has the other inner rolling surface of the double row inner rolling surface formed on the outer periphery, and on the inner side of the wheel mounting flange. The base is formed into a curved surface having a circular cross section, and the side lip is slidably contacted with the base with a predetermined axial squeeze, and the dust lip extends radially inwardly toward the inner diameter side of the side lip. The wheel bearing device according to claim 1, wherein a grease lip extending in a radially inwardly inclined manner is formed.   The wheel bearing according to claim 1 or 2, wherein a side surface on the inner side of the wheel mounting flange and an end surface on the outer side of the outer member are opposed to each other through a slight axial clearance, and a labyrinth seal is formed. apparatus.   The seal is composed of a pack seal composed of a slinger and an annular seal plate arranged to face each other, and the slinger is externally fitted to the inner member, and radially outward from the cylindrical portion. And the seal plate is constituted by the cored bar and the seal member, and the side lip is slidably contacted with the vertical plate portion of the slinger via a predetermined axial shimiro, and the slinger 2. The wheel bearing device according to claim 1, wherein a flange portion serving as the stepped portion is formed on the upright plate portion so as to protrude in the axial direction.   The wheel bearing device according to claim 4, wherein a labyrinth seal is configured by the flange portion of the slinger and the seal member facing each other through a slight radial clearance.   A second side lip extending radially inwardly on the inner diameter side of the side lip and extending inward in the radial direction with a second side lip slidably in contact with the standing plate portion of the slinger via a predetermined axial clearance; The wheel bearing device according to claim 4 or 5, wherein a grease lip is formed in sliding contact with the cylindrical portion of the slinger via a predetermined radial squeeze.   The wheel bearing device according to claim 6, wherein a stepped portion is formed on the standing plate portion of the slinger so as to cover a tip portion of the side lip on the inner diameter side.   The wheel bearing device according to any one of claims 4 to 7, wherein the slinger is formed by pressing from a steel plate having rust prevention ability.   The wheel bearing device according to any one of claims 1, 4, and 7, wherein a stepped amount of the stepped portion is set to be larger than an axial dimension of a tip portion of the side lip.   The end portion of the fitting portion of the cored bar is formed to be thinner and reduced in diameter than other portions, and the seal member wraps around and is fixed to the outer surface of the end portion of the fitting portion. Wheel bearing device.

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