JP2013124764A - Sealing device of bearing for wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device of bearing for wheel which prevents a side lip of a back seal from being adsorbed to a slinger, prevents abnormal wear of the side lip and an increase in rotation torque and permits a longer life.SOLUTION: The sealing device of bearing for wheel includes: a seal plate 12 composed of a seal member 15 joined to a core metal 14 by cure adhesion; and a slinger 13 having a cylinder part 13a and a vertical plate part 13b extended to the outer side in the radial direction, wherein the seal member 15 includes a side lip 15b which is obliquely extended to the outer side in the radial direction and is brought into sliding contact with the vertical plate part 13b via an axial margin in the axial direction and a grease lip 15c which is brought into sliding contact with the cylindrical part 13a via a radial direction margin interference, a backup lip 16 is formed obliquely inward in the radial direction from a base part 15a between the side lip 15b and the grease lip 15c, the tip part is confronted with a corner part between the cylinder part 13a and the vertical plate part 13b and, when the interior of the bearing comes to a negative pressure, the backup lip 16 comes into contact with the cylindrical part 13a and prevents the side lip 15b from being adsorbed.

Description

  The present invention relates to a sealing device in a wheel bearing that rotatably supports a wheel of an automobile or the like with respect to a suspension device.

  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 with body mounting flange or wheel mounting flange formed directly on the outer periphery, third generation structure with one inner rolling surface formed directly on the outer periphery of the hub wheel, or constant velocity with the hub wheel 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 joint.

  In such a wheel bearing, a sealing device is mounted in order to prevent leakage of grease enclosed in the bearing and to prevent rainwater, dust, and the like from entering from the outside. When the temperature inside the bearing sealed by this sealing device rises, the air in the sealed space may pass through the sealing device and be discharged outside. In this case, after that, when the vehicle stops and the temperature in the sealed space decreases, the pressure in the sealed space becomes negative with respect to the external atmospheric pressure. It may be pressed and adsorbed. This can cause the tip of the seal lip to wear abnormally and shorten its life, generate a noise due to temperature rise, or increase the torque due to high contact surface pressure due to adsorption. is there.

  FIG. 11 shows a wheel bearing that solves these problems. The wheel bearing 50 includes an inner member 51, an outer member 52, and double-row balls 53, 53 accommodated between the members 51, 52 so as to roll freely. The inner member 51 includes a hub ring 54 and an inner ring 55 press-fitted into the hub ring 54.

  The hub wheel 54 integrally has a wheel mounting flange 56 for mounting the wheel W and the brake rotor B at one end, and a hub bolt 57 for fixing the wheel at a circumferentially equidistant position of the wheel mounting flange 56 is planted. It is installed. Further, one outer rolling surface 54a and a cylindrical small diameter step portion 54b extending in the axial direction from the inner rolling surface 54a are formed on the outer periphery of the hub wheel 54, and a serration 54c is formed on the inner periphery. Yes. The inner ring 55 is formed with the other inner rolling surface 55 a on the outer periphery, and is press-fitted and fixed to the small diameter step portion 54 b of the hub ring 54.

  The outer member 52 integrally has a vehicle body mounting flange 52b to be attached to the vehicle body (not shown) on the outer periphery, and has a double row facing the inner rolling surfaces 54a and 55a of the inner member 51 on the inner periphery. The outer rolling surfaces 52a and 52a are integrally formed. The double-row balls 53 and 53 are accommodated between the rolling surfaces 52a and 54a and 52a and 55a, and are held by the cages 58 and 58 so as to be freely rollable. In addition, sealing devices 59 and 60 are attached to the opening of the annular space formed between the outer member 52 and the inner member 51, and leakage of lubricating grease sealed inside the bearing, rainwater and Dust and the like are prevented from entering the bearing.

  As shown in FIG. 12, the sealing device 59 includes a cored bar member 61, an elastic member 62, and a slinger 63. The metal core member 61 and the elastic member 62 are fixed to each other and constitute a seal member 64. The cored bar member 61 is formed in an annular shape and has an L-shaped cross section. The core member 61 includes a cylindrical inner fitting fixing portion 61a and a radially extending portion 61b.

  The slinger 63 is formed in an annular shape, and has a cylindrical outer fitting fixing portion 63a, a flange portion 63b, and a bent extending portion 63c. The flange portion 63b is located axially outward from the radially extending portion 61b of the cored bar member 61, and faces the axial direction via a gap. The bent extending portion 63c extends from the radially outer end of the flange portion 63b to the radially extending portion 61b side in the axial direction, and extends to the external fitting fixing portion 63a side in the radial direction. doing.

  The elastic member 62 is formed in an annular shape, and covers the entire inner peripheral surface of the inner fitting fixing portion 61a and the entire outer end surface in the axial direction of the radially extending portion 61b connected to the inner peripheral surface of the inner fitting fixing portion 61a. It is fixed to cover. The elastic member 62 is made of a rubber material, and has a base 65, an axial lip 66, and a radial lip 67. The axial lip 66 extends from the base portion 65 to the radially inner fitting fixing portion 61a side and to the axially outer side. The end portion of the axial lip 66 overlaps both the flange portion 63b and the bent extension portion 63c in the axial direction.

  The radial lip 67 extends from the base portion 65 to the radially outer fitting fixing portion 63a side and to the axial flange portion 63b side. The radial lip 67 slides on the cylindrical outer peripheral surface of the external fitting fixing portion 63 a of the slinger 63.

  The axial lip 66 of the sealing device 59 operates as follows. That is, when the wheel bearing 50 is in an operating state by driving the vehicle, the axial lip 66 and the flange portion 63b are in contact with each other in the initial driving state, and the axial lip 66 is in contact with the bent extending portion 63c. Located at intervals.

  Thereafter, due to the operation of the vehicle, the temperature inside the bearing becomes high and the atmospheric pressure rises to a certain extent, and due to a difference in atmospheric pressure inside and outside the axial lip 66, the radial lip 66 acting on the axial lip 66 outwards. When the force is increased, the inner space of the axial lip 66 is deformed so as to become larger, away from the flange portion 63b, and comes into contact with the inner peripheral surface 68 of the bent extending portion 63c.

  After that, when the temperature inside the bearing is lowered to some extent due to the stop of the vehicle, the inner lip 66 is deformed so that the space inside the axial lip 66 is reduced by the restoring force of the axial lip 66, and away from the bending extension 63c, It contacts the flange part 63b again.

  In this manner, the axial lip 66 slides on the flange portion 63b or the bent extension portion 63c, and the member on which the axial lip 66 slides is a pressure between the atmospheric pressure of the sealed space sealed by the sealing device 59 and the external atmospheric pressure. Based on the magnitude of the difference, the wear of the axial lip 66 can be suppressed, and the torque caused by the contact surface pressure against the flange portion 63b can be reduced (see, for example, Patent Document 1).

JP 2010-190323 A

  However, in this conventional sealing device 59, the distal end portion of the flange portion 63b of the slinger 63 is bent at an acute angle at a predetermined angle to form the bent extension portion 63c, so the following problems are inherent. . That is, when the slinger 63 is formed by press working, the workability is poor, and therefore the number of work steps increases, and the work cost increases. In addition, it is difficult to ensure the dimensional accuracy of the bent extension portion 63 c, and a stable contact state with the axial lip 66 cannot be obtained.

  The present invention has been made in view of such circumstances, and suppresses the side lip of the pack seal from adsorbing to the slinger, prevents abnormal wear of the side lip and increases in rotational torque, and extends the service life. An object of the present invention is to provide a sealing device for a wheel bearing.

  In order to achieve such an object, the invention according to claim 1 of the present invention is such that an outer ring in which a double row outer rolling surface is integrally formed on the inner periphery, and an outer ring facing the double row outer rolling surface on the outer periphery. Mounted on a wheel bearing having a pair of inner rings formed with inner rolling surfaces and a double-row rolling element that is slidably accommodated between the rolling surfaces of the inner ring and the outer ring, In a sealing device for a wheel bearing for sealing an opening of an annular space formed between the outer ring and the inner ring, an annular seal plate and a slinger, each having a substantially L-shaped cross section and arranged to face each other, are provided. A cylindrical fitting portion that is press-fitted to the inner periphery of the end portion of the outer ring via a predetermined shimiro, and extends radially inward from the end portion of the fitting portion. A cored bar made of a steel plate by pressing from an inner diameter part, and the cored bar A sealing member integrally joined by vulcanization adhesion, and the slinger comprises a cylindrical portion that is press-fitted into the outer diameter of the inner ring, and a vertical plate portion that extends radially outward from the cylindrical portion, A seal member, a base portion covering the inner peripheral surface of the cored bar, and a side lip formed to be inclined radially outward from the base portion, and in sliding contact with the standing plate portion of the slinger via a predetermined axial squeeze A grease lip formed on the inner diameter side of the side lip so as to be inclined inward in the radial direction and opposed to the cylindrical portion of the slinger, and radially inward from the base between the grease lip and the side lip. When the back-up lip is inclined and the tip of the sling faces the corner of the slinger's cylindrical part and the standing plate part through a predetermined gap, the gap creates a pressure difference inside and outside the bearing. The slinger It is set so as to be in contact with either the cylindrical portion or the standing portion.

  Thus, in the wheel bearing sealing device that is mounted on the wheel bearing and seals the opening of the annular space formed between the outer ring and the inner ring, the cross section is formed in a substantially L shape and arranged opposite to each other. A cylindrical seal that is press-fitted into the inner periphery of the end of the outer ring via a predetermined shimiro, and an end of the fit A core bar formed by pressing from a steel plate and a seal member integrally bonded to the core bar by vulcanization adhesion, and the slinger is provided on the outer ring of the inner ring. It consists of a cylindrical part that is press-fitted into the diameter, and a standing plate part that extends radially outward from this cylindrical part, and a seal member that inclines radially outwardly from the base part that covers the inner peripheral surface of the cored bar Formed on the slinger's vertical plate. A side lip that is slidably contacted via a white surface, and a grease lip that is formed radially inwardly on the inner diameter side of the side lip and faces the cylindrical portion of the slinger, is provided between the grease lip and the side lip. A back-up lip is formed by inclining radially inward from the base, and its tip faces the corner of the slinger's cylindrical part and upright plate part via a predetermined gap, and the gap is pressured inside and outside the bearing. When the difference occurs, it is set so that either the cylindrical part or the standing plate part of the slinger is in contact, so the backup lip is not affected even if the pressure inside the bearing becomes positive or negative. Contacting either the vertical or cylindrical part of the slinger, air leakage from the inside of the bearing and the leakage of grease accompanying this air leakage are suppressed, and the side lip is Suppressed from being adsorbed to the gas to prevent an increase in abnormal wear and rotational torque of the side lip, it is possible to provide a sealing device for a wheel bearing which attained a long life.

  Preferably, as in the invention described in claim 2, when the rigidity of the backup lip is set to be smaller than that of the side lip and the grease lip, the pressure inside the bearing is either positive or negative. However, it is possible to reliably suppress the side lip from adsorbing to the slinger.

  Further, as in the invention described in claim 3, the angle formed by the inner peripheral surface of the backup lip and the cylindrical portion of the slinger is set in a range of 30 ° ≦ θ ≦ 60 °, and the backup lip If the angle formed between the outer peripheral surface and the standing plate portion of the slinger is set in a range of 30 ° ≦ θ ≦ 60 °, when a pressure difference is generated inside and outside the bearing, the cylindrical portion or the standing plate portion of the slinger Either one can be reliably contacted.

  If grease is applied to the sliding contact portion of the seal lip as in the invention described in claim 4, the lip wear is prevented and durability is improved, and the friction torque is reduced. Rotational torque can be reduced.

  Moreover, if the surface of the sliding contact surface of the seal lip is formed on a textured surface as in the invention described in claim 5, the grease is held in the recess of the surface to suppress lip wear and rotate. Torque can be reduced.

  Further, as in the invention described in claim 6, if innumerable dimples are formed by shot blasting on the lip sliding contact portion of the slinger, the lubricity on the sliding contact surface is improved and the lip sliding resistance is improved. As the rotation torque is reduced, the surface area is increased by the dimples, the holding power of the grease is increased, the wear of each lip and the heat generation of the lip sliding part are suppressed, and the sealing performance of the sealing device over a long period of time. And can increase durability.

  According to a seventh aspect of the present invention, the base portion of the seal member is formed to be inclined toward the distal end portion of the fitting portion of the core metal, and an annular recess is formed at the end portion. If the labyrinth seal is formed by the outer edge of the slinger standing plate facing this recess through a slight radial clearance and an axial clearance, rainwater, dust, etc. can enter the bearing from the outside. In addition to preventing, rainwater or dust that has entered once can be easily discharged to the outside by centrifugal force without staying in the sealing device, and the sealing performance can be improved.

  The wheel bearing sealing device according to the present invention includes an outer ring in which a double-row outer rolling surface is integrally formed on the inner periphery, and an inner rolling surface that faces the outer rolling surface of the double-row on the outer periphery. Mounted on a wheel bearing having a pair of inner rings and a double-row rolling element that is rotatably accommodated between the rolling surfaces of the inner ring and the outer ring, and the outer ring and the inner ring In a sealing device for a wheel bearing for sealing an opening of an annular space formed between, a pack seal comprising an annular seal plate and a slinger that are formed in a substantially L-shaped cross section and arranged to face each other. The seal plate is composed of a cylindrical fitting portion press-fitted into the inner periphery of the end portion of the outer ring via a predetermined shimiro, and an inner diameter portion extending radially inward from the end portion of the fitting portion. The cored bar is formed by pressing, and the cored bar is bonded by vulcanization. A sealing member joined to the inner ring, and the slinger includes a cylindrical portion that is press-fitted into the outer diameter of the inner ring, and a standing plate portion that extends radially outward from the cylindrical portion. A base that covers the inner peripheral surface of the cored bar, a side lip that is formed to be inclined radially outward from the base, and that is slidably in contact with the standing plate portion of the slinger via a predetermined axial direction shimiro; A grease lip is formed on the inner diameter side so as to be inclined inward in the radial direction, and is provided with a grease lip facing the cylindrical portion of the slinger. Between the grease lip and the side lip, the base lip is inclined inward in the radial direction from the base. When the lip is formed and the tip of the lip faces the corner of the cylindrical portion of the slinger and the vertical plate portion via a predetermined clearance, the clearance creates a pressure difference between the inside and the outside of the bearing. Department or standing board The back-up lip contacts either the slinger's vertical plate or cylindrical part, regardless of whether the pressure inside the bearing is positive or negative. In addition, air leakage from the inside of the bearing and the leakage of grease accompanying this air leakage are suppressed, and the side lip is prevented from adsorbing to the slinger, preventing abnormal wear of the side lip and an increase in rotational torque, It is possible to provide a wheel bearing sealing device that has a long service life.

It is a longitudinal section showing one embodiment of a wheel bearing provided with a sealing device concerning the present invention. It is a principal part enlarged view which shows one sealing device of FIG. It is explanatory drawing which shows a state when the internal pressure of the sealing device of FIG. 2 rises. It is explanatory drawing which shows a state when an internal pressure falls same as the above. It is a principal part enlarged view which shows the modification of the sealing device of FIG. It is a principal part enlarged view which shows the other modification of the sealing device of FIG. It is a principal part enlarged view which shows the other modification of the sealing device of FIG. It is a principal part enlarged view which shows the modification of the sealing device of FIG. It is a principal part enlarged view which shows the other modification of the sealing device of FIG. It is a principal part enlarged view which shows the modification of the sealing device of FIG. It is a longitudinal cross-sectional view which shows the wheel bearing provided with the conventional sealing device. It is a principal part enlarged view which shows the sealing device of FIG.

  An outer ring in which a double row outer rolling surface is integrally formed on the inner periphery, a pair of inner rings in which an inner rolling surface that faces the outer rolling surface of the double row is formed on the outer periphery, these inner rings, Mounted on a wheel bearing having a double-row rolling element accommodated between the rolling surfaces of the outer ring so as to roll freely, sealing an opening of an annular space formed between the outer ring and the inner ring In the wheel bearing sealing device, the cross section is formed by a pack seal formed of an annular seal plate and a slinger that are formed in a substantially L-shaped cross section and are opposed to each other, and the seal plate has an inner periphery of an end portion of the outer ring. A cylindrical fitting portion that is press-fitted through a predetermined scissors, an inner diameter portion that extends radially inward from the end portion of the fitting portion, and a metal core formed by pressing from a steel plate, And a sealing member integrally joined to the metal core by vulcanization adhesion. The slinger comprises a cylindrical portion that is press-fitted into the outer diameter of the inner ring, and a standing plate portion that extends radially outward from the cylindrical portion, and the base member that covers the inner peripheral surface of the core metal, A side lip formed to incline radially outward from the base, and slidably contact the slinger upright plate portion through a predetermined axial shimiro, and incline radially inward to the inner diameter side of the side lip. And a grease lip that is opposed to the cylindrical portion of the slinger, and a backup lip is formed between the grease lip and the side lip so as to incline radially inward from the base portion, and a tip portion of the grease lip is formed on the slinger. The gap between the cylindrical part and the standing plate part of the cylinder is opposed to the corner part of the standing plate part via a predetermined gap. When set , The rigidity of the backup lip is smaller than the side lip and grease lip.

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 provided with a sealing device according to the present invention, FIG. 2 is an enlarged view of a main part showing one sealing device of FIG. 1, and FIG. FIG. 4 is an explanatory view showing a state when the internal pressure of the sealing device of FIG. 2 is increased, FIG. 4 is an explanatory view showing a state when the internal pressure of the sealing device of FIG. 2 is lowered, and FIG. 5 is a modified example of the sealing device of FIG. FIG. 6 is an enlarged view of the main part showing another modification of the sealing device of FIG. 2, and FIG. 7 is an enlarged view of the main part showing another modification of the sealing device of FIG. 8 is an enlarged view of a main part showing a modification of the sealing device in FIG. 7, FIG. 9 is an enlarged view of a main part showing another modification of the sealing device in FIG. 2, and FIG. 10 is a modification of the sealing device in FIG. It is a principal part enlarged view which shows an example. 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).

  The wheel bearing 1 shown in FIG. 1 is referred to as the first generation, and an outer ring 2 integrally formed with tapered double-row outer rolling surfaces 2a and 2a that are outwardly opened on the inner circumference, and on the outer circumference. A pair of inner rings 3, 3 formed with a tapered inner rolling surface 3a opposite to the double-row outer rolling surfaces 2a, 2a, and a rolling device 4 between the rolling surfaces are freely movable. It has double row rolling elements (conical rollers) 5 and 5 accommodated therein.

  A large collar 3b for guiding the rolling element 5 is formed on the large diameter side of the inner raceway surface 3a of the inner ring 3, and a small collar 3c for preventing the rolling element 5 from dropping off on the small diameter side. Is formed. And it sets in the state by which the small diameter side end surface of a pair of inner ring | wheels 3 and 3 was faced | matched, and comprises the bearing 1 for back-to-back type wheels.

  The outer ring 2, the inner ring 3 and the rolling element 5 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. In addition, sealing devices 6 and 7 are attached to the opening portion of the annular space formed between the outer ring 2 and the pair of inner rings 3 and 3, and leakage of the lubricating grease sealed inside the bearing to the outside Prevents rainwater and dust from entering the bearing.

  Annular grooves 8 and 8 are formed on the inner circumferences of the ends on the small diameter side of the pair of inner rings 3 and 3, and a connecting ring 9 is attached to the annular grooves 8 and 8. This connecting ring 9 is formed by pressing a steel plate such as tool steel or spring steel into a substantially U-shaped cross section, and as a whole a ring shape with ends, and the surface is tempered or quenched to a range of 40 to 55 HRC. A curing process is applied.

  By elastically deforming the connecting ring 9 and mounting it in the annular grooves 8, the pair of inner rings 3, 3 are firmly integrated without play and the workability of disassembly / assembly can be simplified. In addition, since the pair of inner rings 3 and 3 that are press-fitted and fixed to the axle can be removed integrally during repair or the like, there is no problem that only the inner-side inner ring 3 remains on the axle.

  In addition, although what was comprised by the double row tapered roller bearing which used the tapered roller for the rolling element 5 as the wheel bearing 1 was illustrated here, it is not restricted to this, The double row angular ball which uses the ball for the rolling element 5 You may be comprised with the bearing. Further, the bearing structure is not limited to the illustrated first generation, for example, a second generation structure having a flange on the outer ring, a third generation structure in which an inner raceway surface is directly formed on the outer periphery of the hub ring, or A fourth generation structure in which inner rolling surfaces are directly formed on the outer periphery of the outer joint member of the hub wheel and the constant velocity universal joint may be used.

  The outer side sealing device 6 is constituted by an integral seal comprising a cored bar 10 press-fitted into the inner periphery of the end of the outer ring 2 and a seal member 11 integrally joined to the cored bar 10 by vulcanization adhesion. Yes. The core metal 10 has a substantially L-shaped cross section formed by press working from an austenitic stainless steel plate (JIS standard SUS304 type or the like) cold rolled steel plate (JIS standard SPCC type or the like). On the other hand, the seal member 11 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber) and has bifurcated radial lips 11 a and 11 b that are in sliding contact with the outer diameter of the inner ring 3. And the sealing member 11 wraps around and joins so that the outer surface of the metal core 10 may be covered, and what is called a half metal structure is comprised. Thereby, airtightness can be improved and the inside of a bearing can be protected.

  In addition to the exemplified NBR, the material of the seal member 11 includes, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc. having excellent heat resistance, and heat resistance and chemical resistance. Examples thereof include ACM (polyacrylic rubber), FKM (fluororubber), and silicon rubber, which are excellent in the above.

  As shown in an enlarged view in FIG. 2, the inner-side sealing device 7 constitutes a so-called pack seal including an annular seal plate 12 and a slinger 13 which are formed in a substantially L-shaped cross section and are arranged to face each other. doing. The seal plate 12 includes a cored bar 14 press-fitted into the outer ring 2 and a seal member 15 that is integrally vulcanized and bonded to the cored bar 14.

  The metal core 14 is formed by pressing austenitic stainless steel plate or cold rolled steel plate into a substantially L-shaped cross section, and a cylindrical fitting portion 14a that is press-fitted into the inner periphery of the end portion of the outer ring 2, and this fitting An inner diameter portion 14b extending radially inward from one end of the joint portion 14a is provided. And the front-end | tip part of the fitting part 14a of the metal core 14 is formed thinly, and the sealing member 15 wraps around and joins so that this front-end | tip part may be covered, and has comprised what is called a half metal structure.

  The seal member 15 is made of a synthetic rubber such as NBR, a base portion 15a that covers the inner peripheral surface of the fitting portion 14a of the core metal 14, and a side lip 15b that is formed to be inclined radially outward from the base portion 15a, The side lip 15b includes a grease lip 15c formed to be inclined toward the bearing outer side (slinger 13 side) and a backup lip 16 formed between the grease lip 15c and the side lip 15b. Yes. Examples of the material of the seal member 15 include HNBR, EPDM, ACM, FKM, or silicon rubber having excellent heat resistance in addition to the exemplified NBR.

  The slinger 13 is formed from a ferritic stainless steel plate (JIS standard SUS430, etc.), an austenitic stainless steel plate, or a cold-rolled steel plate that has been rust-proofed by press working, so that the inner ring 3 The cylindrical portion 13a is press-fitted into the outer diameter of the cylindrical portion 13a, and the upright plate portion 13b extends radially outward from the cylindrical portion 13a. Then, the side lip 15a of the seal member 15 is slidably contacted with the upright plate portion 13b via a predetermined axial nip, and the grease lip 15b is slidably contacted with the cylindrical portion 13a via a predetermined radial nip. .

  Note that the base portion 15a of the seal member 15 is formed to be inclined toward the distal end portion of the fitting portion 14a of the core metal 14, and an annular recess 17 is formed at this end portion. A labyrinth seal 18 is formed by the outer edge of the standing plate portion 13b of the slinger 13 facing the concave portion 17 through a slight radial clearance 18a and an axial clearance 18b. This prevents rainwater and dust from entering the inside of the bearing from the outside, and rainwater and dust that have entered once can be easily discharged to the outside by centrifugal force without staying in the sealing device. Can be improved.

  In the present embodiment, grease 19 is applied to the side lip 15b, the grease lip 15c, and the backup lip 16 described later. The grease 19 is the same as the grease filled for lubricating the bearing portion. Thereby, while preventing lip wear and improving durability, the friction torque is reduced, and the rotational torque of the sealing device 7 can be reduced.

  The grease 19 to be applied may be different from the grease enclosed in the bearing portion. In this case, by setting the base oil kinematic viscosity of the grease 19 to be equal to or lower than the base oil kinematic viscosity of the grease sealed in the bearing portion, the friction torque of the lip can be reduced and the rotational torque can be further reduced.

  Further, the elastic member 20 is integrally joined to the outer surface of the upright plate portion 13b from the end portion of the cylindrical portion 13a of the slinger 13 by vulcanization adhesion. The elastic member 20 is made of a synthetic rubber such as NBR similar to the seal member 15 and is formed to project radially inward from the cylindrical portion 13 a of the slinger 13, and a fitting portion between the outer diameter of the inner ring 3 and the slinger 13. Increases airtightness.

  Here, the backup lip 16 of the seal member 15 is formed so as to be inclined radially inward from the base portion 15a, and a tip portion thereof has a predetermined clearance at a corner portion between the cylindrical portion 13a and the standing plate portion 13b of the slinger 13. Are confronting each other. The inclination angle θ of the backup lip 16 is on the bisector of the angle formed by the cylindrical portion 13a and the standing plate portion 13b, that is, the angle formed by the center line of the backup lip 16 and the cylindrical portion 13a or the standing plate portion 13b is 45 °. Is preferred. Specifically, the angle θ1 formed by the inner peripheral surface 16a of the backup lip 16 and the cylindrical portion 13a of the slinger 13 is set in a range of 30 ° ≦ θ ≦ 60 °, and the outer peripheral surface 16b of the backup lip 16 and the slinger The angle θ2 formed by the 13 standing plate portions 13b is set in a range of 30 ° ≦ θ ≦ 60 °.

  When the inclination angle θ1 of the backup lip 16 is less than 30 ° with respect to the cylindrical portion 13a of the slinger 13, it becomes difficult to contact the standing plate portion 13b, and when it exceeds 60 °, it becomes difficult to contact the cylindrical portion 13a. Therefore, it is not preferable. Similarly, when the inclination angle θ2 of the backup lip 16 is less than 30 ° with respect to the standing plate portion 13b of the slinger 13, it becomes difficult to contact the cylindrical portion 13a, and when it exceeds 60 °, it contacts the standing plate portion 13. It becomes difficult.

  The rigidity of the backup lip 16 is set to be smaller than that of the side lip 15b and the grease lip 15c. When there is no pressure difference between the inside and outside of the bearing, the back-up lip 16 is in a non-contact state facing the slinger 13 through a predetermined clearance. When the internal pressure becomes positive due to the increase in the running rate during operation, that is, when the internal pressure> the external pressure (atmospheric pressure), as shown in FIG. 3, it comes into contact with the standing plate portion 13b of the slinger 13 and air flows from the bearing inside. Leakage and leakage of grease accompanying this air leakage are suppressed. On the other hand, when the inside of the bearing becomes negative pressure due to cooling due to operation stop or the like, that is, the internal pressure <the external pressure, the backup lip 16 comes into contact with the cylindrical portion 13a of the slinger 13 as shown in FIG. Suppressing the lip 15b from adsorbing to the slinger 13 is suppressed. When the pressure difference between the inside and outside of the bearing is eliminated, the backup lip 16 returns to the original non-contact state facing the slinger 13 through a predetermined clearance by the restoring force.

  As described above, in the present embodiment, the backup lip 16 is formed between the side lip 15b and the grease lip 15c, and the front end of the backup lip 16 is formed at the corner between the cylindrical portion 13a and the standing plate portion 13b of the slinger 13. Therefore, regardless of whether the pressure inside the bearing is positive or negative, the bearing contacts either the upright plate portion 13b or the cylindrical portion 13a of the slinger 13 and air from the inside of the bearing. Prevents grease from leaking and leakage due to this air leak, and suppresses the side lip 15b from adsorbing to the slinger 13, thereby preventing abnormal wear of the side lip 15b and an increase in rotational torque, thereby extending the service life. Thus, the sealing device 7 for the wheel bearing 1 can be provided.

  FIG. 5 shows a modification of the above-described sealing device 7 (FIG. 2). In this embodiment, only the properties of each lip are fundamentally different from those of the above-described embodiment, and other parts and parts having the same parts or parts having the same functions are denoted by the same reference numerals. Is omitted.

  The sealing device 21 constitutes a pack seal composed of an annular seal plate 12 ′ and a slinger 13 which are substantially L-shaped in cross section and arranged to face each other. The seal plate 12 ′ includes a metal core 14 and a seal member 15 ′ that is integrally vulcanized and bonded to the metal core 14.

  The seal member 15 ′ is made of a synthetic rubber such as NBR, a base portion 15a covering the inner peripheral surface of the fitting portion 14a of the core metal 14, and a side lip 15b ′ formed by inclining radially outward from the base portion 15a. And a grease lip 15c ′ formed to be inclined toward the inner diameter side of the side lip 15b ′, and a backup lip 16 ′ formed between the grease lip 15c ′ and the side lip 15b ′.

  Here, in the present embodiment, the surfaces of the side lip 15b ', the grease lip 15c', and the backup lip 16 'are formed on a textured skin (indicated by a two-dot chain line in the figure). The pear texture is formed by subjecting the product part of the mold to a sand shot treatment so that the pear texture is formed from the beginning, but the formed pear texture has a surface roughness of Ry 2 to 20, preferably Has a surface roughness of Ry4-14. As a result, grease is held in the recesses on the surface, so that lip wear can be suppressed and rotational torque can be reduced. Here, Rz refers to the ten-point average roughness of the JIS roughness shape parameter (JIS B0601-1994).

  FIG. 6 shows a modification of the above-described sealing device 7 (FIG. 2). Note that this embodiment basically differs from the above-described embodiment only in the properties of the slinger, and other detailed descriptions of the same parts and parts having the same functions or parts having the same functions are denoted by the same reference numerals. Omitted.

  The sealing device 22 forms a pack seal composed of an annular seal plate 12 and a slinger 13 'which are formed in a substantially L-shaped cross section and are arranged to face each other.

  The slinger 13 ′ is formed into a substantially L-shaped section by pressing from a ferritic stainless steel plate, an austenitic stainless steel plate, or a cold-rolled steel plate that has been rust-proofed, and is press-fitted into the outer diameter of the inner ring 3. It consists of a cylindrical portion 13a ′ and a standing plate portion 13b ′ extending radially outward from the cylindrical portion 13a ′.

  Here, in this embodiment, innumerable dimples are formed on the lip sliding contact portion of the slinger 13 'by shot blasting (indicated by a two-dot chain line in the figure). Although this dimple is not shown, the slinger 13 ′ is placed on the rotating jig, and the rotating jig is turned with the shot blasting nozzle facing the slinger 13 ′, so that a medium such as steel beads is used. Is carried out by spraying. Here, shot blasting is performed while moving the nozzle to a predetermined range under the conditions of a particle size of steel beads of 20 to 100 μm, an injection time of about 90 seconds, and an injection pressure of 1 to 3 kg / cm 2.

  The steel plate used as the material for the slinger 13 'usually has a surface roughness in the range of Ra 0.2 to 0.6, and the surface is roughened by shot blasting, specifically, Ra 1.0 to 5 .0 range. Ra is one of the JIS roughness shape parameters (JIS B0601-1994), and means the arithmetic average roughness, that is, the average value of the absolute value deviation from the average line.

  Innumerable dimples are thus formed in advance on the sliding contact surface of the slinger 13 ', so that the lubricity on the sliding contact surface is improved, the lip sliding resistance is reduced, the rotational torque is reduced, and the surface area is increased by the dimples. As a result, the holding power of the grease increases, wear of each lip and heat generation of the lip sliding portion are suppressed, and the sealing performance and durability of the sealing device 22 can be improved over a long period of time.

  FIG. 7 shows another modification of the above-described sealing device 7 (FIG. 2). Note that this embodiment basically differs from the above-described embodiment only in the configuration of the seal member, and other detailed descriptions of the same parts and parts having the same functions or parts having the same functions are denoted by the same reference numerals. Is omitted.

  The sealing device 23 constitutes a pack seal composed of an annular seal plate 24 and a slinger 25 which are substantially L-shaped in cross section and arranged to face each other. The seal plate 24 includes a metal core 14 and a seal member 26 that is integrally vulcanized and bonded to the metal core 14.

  The seal member 26 is made of synthetic rubber such as NBR, and includes a base portion 26a that covers the inner peripheral surface of the fitting portion 14a of the core metal 14, and a pair of side lips 26b that are formed to be inclined radially outward from the base portion 26a. 26c, a grease lip 26d formed on the inner diameter side of the side lips 26b, 26c, and an inclination toward the inner side of the bearing, and a backup lip 16 formed between the grease lip 26d and the side lip 26c. I have. Examples of the material of the seal member 26 include HNBR, EPDM, ACM, FKM, or silicon rubber having excellent heat resistance in addition to the exemplified NBR.

  The slinger 25 is made of a ferritic stainless steel plate (JIS standard SUS430 series, etc.), an austenitic stainless steel plate, or a cold-rolled steel plate that has been rust-proofed, and is formed into a substantially L-shaped section by pressing. 25a, a first standing plate portion 25b extending radially outward from the cylindrical portion 25a, and a second standing plate portion extending radially outward from the first standing plate portion 25b via a bent portion 25c 25d. Then, the side lip 26c on the inner diameter side of the seal member 26 is slidably contacted with the first standing plate portion 25b, and the side lip 26b on the outer diameter side is slidably contacted with the second standing plate portion 25d via a predetermined axial squeeze. At the same time, the grease lip 26d is slidably contacted with the cylindrical portion 25a via a predetermined radial squeeze.

  Thus, in the present embodiment, the pair of side lips 26b and 26c are formed with the first vertical plate portion 25b and the second vertical plate portion 25d formed with a step in the axial direction across the bent portion 25c of the slinger 25. Since they are in sliding contact with each other, the rigidity of the lip and the squeezing can be easily adjusted, and the sealing performance can be improved.

  Here, the backup lip 16 of the seal member 26 is formed to be inclined inward in the radial direction from the base portion 26a, and a tip portion thereof is predetermined at a corner portion of the cylindrical portion 25a of the slinger 25 and the first standing plate portion 25b. It is confronted through the gap.

  Further, the rigidity of the backup lip 16 is set smaller than that of the side lips 26b, 26c and the grease lip 26d, and when there is no pressure difference between the inside and outside of the bearing, it is in a non-contact state where the slinger 25 faces the slinger 25 through a predetermined clearance. However, when the inside of the bearing becomes a positive pressure due to the increase in the operating speed during operation, that is, the internal pressure> the external pressure, the first vertical plate portion 25b of the slinger 25 comes into contact with the air and the air leaks from the inside of the bearing. As a result, the grease is prevented from leaking. On the other hand, when the inside of the bearing becomes negative pressure due to cooling due to operation stop or the like, that is, the internal pressure <external pressure, the backup lip 16 contacts the cylindrical portion 25a of the slinger 25, and the pair of side lips 26b, 26c Adsorption to the slinger 25 is suppressed. Then, when the pressure difference between the inside and outside of the bearing is eliminated, the backup lip 16 returns to the original non-contact state facing the slinger 25 through a predetermined clearance by the restoring force.

  As described above, in this embodiment, the backup lip 16 is formed between the side lip 26c and the grease lip 26d, and the tip portion thereof is the cylindrical portion 25a of the slinger 25 and the first standing plate, as in the above-described embodiment. Since the corner faces the portion 25b through a predetermined gap, the first standing plate portion 25b or the cylindrical portion of the slinger 25 can be used regardless of whether the pressure inside the bearing is positive or negative. 25a is brought into contact with the inside of the bearing, and air leakage from the inside of the bearing and the leakage of grease accompanying this air leakage are suppressed, and the side lips 26b and 26c are prevented from adsorbing to the slinger 25, and the side lip 26b , 26c, and an increase in rotational torque can be prevented.

  FIG. 8 shows a modification of the above-described sealing device 23 (FIG. 7). Note that this embodiment basically differs from the above-described embodiment only in the configuration of the grease lip, and the same parts are denoted by the same reference numerals for the same parts or parts having the same functions. Is omitted.

  The sealing device 23 'constitutes a pack seal composed of an annular seal plate 24' and a slinger 25, which are substantially L-shaped in cross section and arranged to face each other. The seal plate 24 ′ includes a cored bar 14 and a seal member 26 ′ that is integrally vulcanized and bonded to the cored bar 14.

  The seal member 26 ′ is made of synthetic rubber such as NBR, a base portion 26 a that covers the inner peripheral surface of the fitting portion 14 a of the core metal 14, and a pair of side lips that are formed to be inclined radially outward from the base portion 26 a. 26b, 26c, a grease lip 26d 'formed on the inner diameter side of the side lips 26b, 26c and inclined toward the inner side of the bearing, and a backup formed between the grease lip 26d' and the side lip 26c. A lip 16 is provided.

  Then, the side lip 26c on the inner diameter side of the seal member 26 'is in sliding contact with the first upright plate portion 25b, and the side lip 26b on the outer diameter side is in sliding contact with the second upright plate portion 25d through a predetermined axial squeeze. At the same time, the grease lip 26d 'is opposed to the cylindrical portion 25a via a slight radial clearance S and is disposed in a non-contact state. Thereby, the rotational torque of the sealing device 23 'can be reduced.

  FIG. 9 shows another modification of the above-described sealing device 7 (FIG. 2). Note that this embodiment basically differs from the above-described embodiment only in the configuration of a part of the seal member, and the same reference numerals are given to the same parts or parts having the same functions or parts having the same functions. Detailed description is omitted.

  The sealing device 27 constitutes a pack seal composed of an annular seal plate 28 and a slinger 13 which are formed so as to have a substantially L-shaped cross section and are opposed to each other. The seal plate 28 includes a core metal 14 and a seal member 29 that is integrally vulcanized and bonded to the core metal 14.

  The seal member 29 is made of a synthetic rubber such as NBR, a base portion 29a that covers the inner peripheral surface of the fitting portion 14a of the core metal 14, and a side lip 29b that is formed to be inclined radially outward from the base portion 29a, On the inner diameter side of the side lip 29b, there are provided a grease lip 29c formed so as to be inclined toward the inner side of the bearing, and a backup lip 16 formed between the grease lip 29c and the side lip 29b.

  The side lip 29b on the inner diameter side of the seal member 29 is slidably contacted with the upright plate portion 13b via a predetermined axial shimiro, and the grease lip 29c is slidably contacted with the cylindrical portion 13a via a slight radial shimillo. Has been. Thereby, it is possible to suppress the side lip 29b from adsorbing to the slinger 13, and to prevent abnormal wear of the side lip 29b and an increase in rotational torque.

  FIG. 10 shows a modification of the above-described sealing device 27 (FIG. 9). Note that this embodiment basically differs from the above-described embodiment only in the configuration of a part of the seal member, and the same reference numerals are given to the same parts or parts having the same functions or parts having the same functions. Detailed description is omitted.

  The sealing device 27 ′ constitutes a pack seal composed of an annular seal plate 28 ′ and a slinger 13 which are substantially L-shaped in cross section and arranged to face each other. The seal plate 28 includes a cored bar 14 and a seal member 29 ′ that is integrally vulcanized and bonded to the cored bar 14.

  The seal member 29 ′ is made of synthetic rubber such as NBR, and includes a base portion 29a that covers the inner peripheral surface of the fitting portion 14a of the core metal 14, and a side lip 29b that is formed to be inclined radially outward from the base portion 29a. In addition, a grease lip 29c ′ formed to be inclined toward the bearing inward side and a backup lip 16 formed between the grease lip 29c ′ and the side lip 29b are provided on the inner diameter side of the side lip 29b. .

  The side lip 29b on the inner diameter side of the seal member 29 ′ is slidably contacted with the upright plate portion 13b via a predetermined axial nip, and the grease lip 29c ′ is placed on the cylindrical portion 13a with a slight radial clearance S. Are arranged in a non-contact state. Thereby, the rotational torque of the sealing device 27 'can be reduced.

  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 sealing device according to the present invention is for the inner ring rotating type, outer ring rotating type first generation, second generation, inner ring rotating type third generation, fourth generation first to third generation structure wheels. The present invention can be applied to a sealing device attached to a bearing.

DESCRIPTION OF SYMBOLS 1 Wheel bearing 2 Outer ring 2a Outer rolling surface 3 Inner ring 3a Inner rolling surface 3b Large collar part 3c Small collar part 4 Cage 5 Rolling body 6 Sealing device 7, 21, 22, 23, 23 ', 27 on the outer side 27 'Inner side sealing device 8 Annular groove 9 Connecting ring 10, 14 Core metal 11, 15, 15', 26, 26 ', 29, 29' Seal members 11a, 11b Radial lips 12, 12 ', 24, 24 ', 28, 28' Seal plates 13, 13 ', 25 Slinger 13a, 13a', 25a Cylindrical portion 13b, 13b 'Standing plate portion 14a Fitting portion 14b Inner diameter portions 15a, 26a, 29a Seal member base portions 15b, 15b' 26b, 26c, 29b Side lips 15c, 15c ', 26d, 26d', 29c, 29c 'Grease lips 16, 16' Backup lip 16a Backup lip inner peripheral surface 16b Backer Prep outer peripheral surface 17 Annular recess 18 Labyrinth seal 18a, S Radial clearance 18b Axial clearance 19 Grease 20 applied to lip Elastic member 25b First standing plate portion 25c Bending portion 25d Second standing plate portion 50 For wheels Bearing 51 Inner member 52 Outer member 52a Outer rolling surface 52b Car body side mounting flange 53 Ball 54 Hub wheels 54a, 55a Inner rolling surface 54b Small diameter step 54c Serration 55 Inner ring 56 Wheel mounting flange 57 Hub bolt 58 Cage 59 , 60 Sealing device 61 Metal core member 61a Inner fitting fixing part 61b Radial extension part 62 Elastic member 63 Slinger 63a Outer fitting fixing part 63b Flange part 63c Bending extension part 64 Seal member 65 Base 66 Axial lip 67 Radial lip 68 Bending Inner peripheral surface B of extension part Brake rotor W Wheel θ Backup Inclination angle of lip θ1 Angle formed by inner peripheral surface of backup lip and cylindrical portion of slinger θ2 Angle formed by outer peripheral surface of backup lip and vertical plate of slinger

Claims (7)

An outer ring in which a double row outer rolling surface is integrally formed on the inner periphery;
A pair of inner rings formed on the outer periphery with an inner rolling surface facing the double row outer rolling surface;
An annular space formed between the outer ring and the inner ring is mounted on a wheel bearing including a double row rolling element that is rotatably accommodated between the rolling surfaces of the inner ring and the outer ring. In a wheel bearing sealing device for sealing an opening,
It is composed of a pack seal made up of an annular seal plate and a slinger that are formed in a substantially L-shaped cross section and are opposed to each other, and the seal plate is press-fitted to the inner periphery of the end portion of the outer ring through a predetermined squeeze. A cylindrical fitting portion and an inner diameter portion extending radially inward from the end portion of the fitting portion, and a cored bar formed by pressing from a steel plate, and vulcanized adhesion to the cored bar. A joined seal member,
The slinger comprises a cylindrical portion that is press-fitted into the outer diameter of the inner ring, and a vertical plate portion that extends radially outward from the cylindrical portion,
A base part that covers the inner peripheral surface of the cored bar, and a side lip that is formed so as to be inclined radially outward from the base part, and that is in sliding contact with the standing plate part of the slinger via a predetermined axial shimiro And a grease lip formed on the inner diameter side of the side lip so as to incline radially inward and facing the cylindrical portion of the slinger,
A backup lip is formed between the grease lip and the side lip by inclining radially inward from the base, and a tip of the lip has a predetermined clearance at a corner between the cylindrical portion and the standing plate portion of the slinger. The wheel bearing is characterized in that the clearance is set so as to contact either the cylindrical portion or the vertical plate portion of the slinger when a pressure difference occurs between the inside and outside of the bearing. Sealing device.   The wheel bearing sealing device according to claim 1, wherein the rigidity of the backup lip is set to be smaller than that of the side lip and the grease lip.   The angle formed between the inner peripheral surface of the backup lip and the cylindrical portion of the slinger is set in a range of 30 ° ≦ θ ≦ 60 °, and the angle formed between the outer peripheral surface of the backup lip and the standing plate portion of the slinger Is set in the range of 30 ° ≦ θ ≦ 60 °.   The wheel bearing sealing device according to any one of claims 1 to 3, wherein grease is applied to a sliding contact portion of the seal lip.   The wheel bearing sealing device according to any one of claims 1 to 4, wherein a surface of the sliding contact surface of the seal lip is formed on a textured surface.   4. The wheel bearing sealing device according to claim 1, wherein innumerable dimples are formed by shot blasting at a lip sliding portion of the slinger. 5.   A base portion of the seal member is formed to be inclined toward a tip end portion of the fitting portion of the core metal, and an annular recess is formed at the end portion, and an outer edge of the standing plate portion of the slinger is formed in the recess. 2. The wheel bearing sealing device according to claim 1, wherein a labyrinth seal is formed through a slight radial clearance and an axial clearance.

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