JP2015113895A - Seal ring, and seal ring-provided rolling bearing unit for supporting wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure capable of effectively preventing generation of cracking caused by ozone deterioration, in a weir portion 22a disposed on a part often exposed to ozone in a use state, in a seal material 18a constituting a seal ring 14b.SOLUTION: A plurality of radial recessed grooves 26 are formed on an axial outer side face of a weir portion 22a, at equal intervals in the circumferential direction. Each recessed groove 26 has a circular arc-shaped cross-section. A deformation portion 27 formed on a part between the recessed grooves 26 adjacent in the circumferential direction, of an axial outer part of the weir portion 22a, can be easily contracted in the circumferential direction. Thus tensile stress in the circumferential direction generated on a surface side part of the weir portion 22a can be reduced, and the problem can be solved.

Description

  The present invention relates to an improvement in a seal ring used in an environment exposed to outside air and a rolling bearing unit for supporting a wheel with a seal ring for supporting a vehicle wheel on a suspension.

  The wheels of the automobile are rotatably supported with respect to the suspension device by a wheel bearing rolling bearing unit 1 with a seal ring as shown in FIG. 9, for example. The wheel bearing rolling bearing unit 1 with a seal ring is configured such that a hub 3 is rotatably supported via a plurality of rolling elements 4 and 4 on the inner diameter side of an outer ring 2. Of these, the outer ring 2 is provided with a stationary-side flange 5 on the outer peripheral surface for supporting and fixing to the suspension device, and double row outer ring raceways 6 and 6 on the inner peripheral surface. The hub 3 has a hub body 7 and an inner ring 8 combined and fixed by nuts 9 and has double-row inner ring raceways 10 and 10 on the outer peripheral surface. Further, a plurality of the rolling elements 4 and 4 are held between the inner ring raceways 10 and 10 and the outer ring raceways 6 and 6 by a plurality of retainers 11 and 11 for each row. It is provided so that it can roll freely.

  Further, a portion near the outer end in the axial direction of the hub body 7 and a portion protruding from the outer end opening in the axial direction of the outer ring 2 is provided with a rotation side flange 12 corresponding to the flange described in the claims. ing. A base end portion of a plurality of studs 13 is supported and fixed to the rotation side flange 12, and the wheels constituting the wheel can be supported and fixed to the rotation side flange 12 by the studs 13.

  Further, a seal ring 14 is mounted between the inner peripheral surface of the outer end of the outer ring 2 in the axial direction and the outer peripheral surface of the intermediate portion of the hub 3 in the axial direction, and the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3. And closes the axially outer end opening of the internal space 15 in which the rolling elements 4 and 4 are provided. In addition, by covering the axial inner end opening of the outer ring 2 with a cover 16, foreign matter such as dust and rainwater can be prevented from entering the inner space 15 from the axial inner end opening, and the inner space 15. Prevents leakage of grease filled inside. Note that “inner” in the axial direction refers to the center in the width direction in the assembled state in the vehicle, and “outer” refers to the outer side in the width direction.

  In the illustrated example, balls are used as the rolling elements 4 and 4. However, in the case of a rolling bearing unit for supporting a wheel with a seal ring incorporated in a heavy automobile, a tapered roller is used as each rolling element. May be used. Further, in order to connect and fix the hub body and the inner ring, instead of the structure in which the nut 9 is screwed and fixed to the axial inner end of the hub main body 7 as shown in the drawing, the axial inner end of the hub main body is changed to the diameter. The inner end surface in the axial direction of the inner ring that is externally fitted to the hub body can also be suppressed by a caulking portion formed by plastic deformation outward in the direction. Furthermore, since the illustrated example is a wheel bearing rolling bearing unit with a seal ring for driven wheels (FR wheel, RR vehicle, front wheel of MR vehicle, rear wheel of FF vehicle), the hub body 7 is a solid body. In the case of a rolling bearing unit for supporting wheels with a seal ring for driving wheels (FR wheel, RR vehicle, rear wheel of MR vehicle, front wheel of FF vehicle, all wheels of 4WD vehicle) A spline hole is provided so as to penetrate the hub body in the axial direction.

  In any structure, with respect to the seal of the axial outer end opening of the inner space where each rolling element is installed, the seal is provided between the inner peripheral surface of the outer ring in the axial direction and the outer peripheral surface of the hub body in the axial direction. The seal ring 14 provided is used. On the other hand, regarding the seal of the inner end opening in the axial direction of the inner space, in the case of a driven wheel, the cover 16 as shown, or the inner peripheral surface of the inner end of the outer ring in the axial direction and the axial direction of the inner ring By using a combination seal ring installed between the inner end portion and the outer peripheral surface, in the case of a drive wheel, a combination seal ring is used.

  In order to sufficiently prevent foreign matter from entering the internal space 15 and prevent leakage of grease filled in the internal space 15, it is necessary to sufficiently seal both axial end openings of the internal space 15. is there. In particular, with regard to the seal ring for sealing the axially outer end opening of the internal space 15, the foreign matter guided radially inward along the axially inner side surface of the rotation side flange 12 is the internal space. In order to prevent it from entering 15, excellent sealing performance is required. In addition, the axially outer end opening of the internal space 15 cannot be sealed with the cover 16 as shown in FIG.

In view of such circumstances, conventionally, various types of seal rings have been considered as seal rings for sealing the axially outer end opening of the annular inner space in which the rolling elements are installed. FIG. 10 shows a seal ring 14a described in Patent Document 1.
The seal ring 14a includes a cored bar 17 and a sealing material 18 each formed in an annular shape. The core metal 17 is made of a metal plate, and has a cylindrical fitting cylinder portion 19 fitted and fixed to the inner peripheral surface of the outer end 2 in the axial direction, and the outer end in the axial direction of the fitting cylinder portion 19. An annular portion 20 bent at a right angle from the portion toward the outer side in the radial direction, and folded back 180 degrees from the inner end in the axial direction of the fitting tube portion 19 toward the outer side in the axial direction and toward the inner side in the radial direction. And a bent inner diameter support portion 21. The sealing material 18 is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the core metal 17 by vulcanization adhesion, and an annular dam portion 22 covering the circumference of the annular portion 20. And a base 23 supported on the outer surface in the axial direction of the inner diameter support portion 21, and three seal lips 24 a, 24 b, 24 c provided in a state of extending from the base 23.

  In the case of the conventional seal ring 14a having the above-described configuration, the weir portion 22 provided at the radially outer end portion is projected radially outward from the outer peripheral surface of the outer ring 2 in the axial direction outer end portion. ing. Thereby, it is possible to effectively prevent (damage) moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2 from entering the inner space 15 along the outer peripheral surface of the outer ring 2.

However, in the case of the seal ring 14a, the following problems are caused by shrinkage of the volume of the sealing material 18 due to vulcanization reaction, diffusion of volatile additives, cooling, and the like during vulcanization molding. May occur.
When the volume of the sealing material 18 shrinks, among the sealing material 18, for example, the seal lips 24 a to 24 c that are not bonded to the core metal 17 can be deformed to a state where no tensile stress is generated. On the other hand, for example, the dam part 22 and the base part 23 bonded to the core metal 17 cannot be deformed in this way, so that a residual tensile stress is generated in the part. A large residual tensile stress is generated in a portion overlapping the annular portion 20 constituting the core metal 17 in the axial direction. In addition, the tensile stress generated in this way is localized in the surface portion where the influence of the orientation and cross-linking of rubber molecules is exerted on the sealing material 18 rather than the inner portion directly bonded to the core metal 17. Tend to be larger. Further, as shown in FIG. 11, both ends in the radial direction (upper and lower ends in FIG. 11) of the sealing material 18 can be deformed in the radial direction, so that the residual tensile stress can be reduced. However, the sealing material 18 is formed in a continuous state over the entire circumference, and since there is no end portion (open portion) in the circumferential direction, tensile stress in the circumferential direction tends to remain. As a result, a large residual tensile stress in the circumferential direction is likely to occur in the surface side portion of the dam portion 22.

  Further, as an elastic material for forming a sealing material, a rubber composition in which an additive is appropriately blended with nitrile rubber or the like is widely used. However, such a rubber composition has a defect of ozone deterioration. In particular, diene vulcanized rubber such as acrylonitrile butadiene rubber (NBR), which is widely used in seal rings mounted on wheel bearing rolling bearing units, is exposed to ozone and rubber when exposed to ozone under tensile stress. It reacts with the molecule and the molecular chain is cut, and it is easy to generate a crack in a direction perpendicular to the stress direction. In addition, ozone is known to increase in concentration at locations where the vehicle has a lot of exhaust gas, where mercury lamps or xenon lamps are lit, and roads are typical of locations where ozone concentration is high.

  Accordingly, the weir portion 22 of the seal ring 14a is not only susceptible to circumferential residual tensile stress on the surface portion thereof, but is exposed to the outside when exposed to the attached state of the seal ring 14a. Since it is easy to be done, there is a possibility that a crack in the radial direction (perpendicular to the circumferential direction) is likely to occur.

  In order to solve the problem due to ozone degradation as described above, for example, Patent Document 2 discloses that waxes having a melting point of about 55 to 70 ° C. are added to 0.5 parts by weight of carboxylated acrylonitrile butadiene rubber. A technique of adding about 2 parts by weight is disclosed. However, even when the rubber composition is devised in this way, low melting point waxes may gradually escape from the rubber material due to an increase in bearing internal temperature during use. For this reason, in the long term, it is difficult to effectively prevent the occurrence of cracks due to ozone degradation by simply adding waxes, and the cracks develop and become the root part of the seal lip (eg side lip). In the case of reaching the above, the tightening force by the seal lip is lowered, and the required sealing performance may not be obtained.

JP 2012-97817 A JP 2002-372061 A

  In the present invention, in view of the circumstances as described above, cracks due to ozone deterioration occur in the weir portion that is disposed in the portion that is easily exposed to ozone in the use state among the sealing materials that constitute the seal ring. The structure which can prevent effectively is realized.

Among the seal ring and the rolling bearing unit for supporting a wheel with a seal ring according to the present invention, the seal ring according to the present invention is used in the environment exposed to the outside air and the outer peripheral surface of the inner ring-side bearing ring member rotating during use. It is used to close the end opening of the internal space that exists between the inner peripheral surface of the outer diameter side race ring member that does not rotate, and the core metal and the elasticity that is vulcanized and bonded to the core metal And a sealing material made of material.
Of these, the metal core is made of a metal plate and has an annular shape as a whole, and has a fitting tube portion, an annular portion, and an inner diameter support portion.
The fitting tube portion is cylindrical and is fitted and fixed to the inner peripheral surface of the end portion of the outer diameter side race ring member. The annular portion is provided in a state of being bent radially outward from one axial end portion of the fitting cylindrical portion, and the other axial side surface is an end surface of the outer diameter side race ring member. It is abutted directly or through a part of the sealing material. Furthermore, the inner diameter support part is provided radially inward from the fitting cylinder part in a state of being continuous with the other axial end of the fitting cylinder part.
The sealing material has a weir part, a base part, and at least one seal lip.
The dam portion covers the annular portion and causes the outer peripheral edge portion of the dam portion to protrude outward in the radial direction from the outer peripheral surface of the end portion of the outer diameter side race ring member in the mounted state of the seal ring. The base portion is supported on one side surface in the axial direction of the inner diameter support portion. Furthermore, the seal lip is provided in a state of extending from the base portion, and in a mounted state of the seal ring, the tip edge thereof is slidably contacted with the surface of the inner diameter side race ring member over the entire circumference.
In particular, in the seal ring of the present invention, a plurality of radial grooves (for example, a semicircular cross section or a U-shaped cross section concave groove) such as a circumference are provided on one side surface in the axial direction of the dam portion. It is formed in several places at equal intervals.

  When the seal ring of the present invention as described above is implemented, for example, as in the invention described in claim 2, a non-contact lip that protrudes toward one side in the axial direction on one side surface in the axial direction of the weir portion. Or the dam part lip which is a contact lip is provided in the state which crosses the said each ditch | groove in the circumferential direction.

  When implementing the seal ring of the present invention, for example, as in the invention described in claim 3, one or more circumferential grooves are formed on one side surface of the weir portion in the axial direction.

On the other hand, the rolling bearing unit for wheel support with a seal ring of the present invention has an outer ring raceway on the inner peripheral surface and does not rotate while being supported by the suspension device, and the outer ring is an outer diameter side race ring member, A hub having an inner ring raceway at a portion facing the outer ring raceway on the outer peripheral surface, and being an inner diameter side race ring member disposed concentrically with the outer ring, for example, a hub configured by combining a hub body and an inner ring Among a plurality of rolling elements (for example, balls or rollers) provided between the outer ring raceway and the inner ring raceway so as to be freely rollable, and an outer peripheral surface of the hub, Also, a flange for supporting and fixing the wheel to the hub provided in a portion protruding outward in the axial direction, and an axis of the internal space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub And a seal ring that closes the direction outer end opening.
And in the case of the rolling bearing unit for wheel support with a seal ring of this invention, the said seal ring is used as the seal ring of this invention mentioned above.

According to the seal ring and the wheel bearing-equipped rolling bearing unit of the present invention having the above-described configuration, the seal ring constituting the seal ring is disposed in a portion that is easily exposed to ozone in use. It is possible to effectively prevent cracks due to ozone deterioration from occurring in the weir part.
That is, in the present invention, a plurality of radial grooves are formed on one side surface in the axial direction of the weir portion. For this reason, it is possible to easily deform (shrink) the portion existing between the concave grooves in the circumferential direction in the axial one side portion of the dam portion in the circumferential direction. Therefore, the tensile stress in the circumferential direction of the one axial side portion of the dam portion can be released, and the residual tensile stress in the circumferential direction generated in the axial one side portion of the dam portion can be reduced. As a result, it is possible to effectively prevent the weir portion from cracking due to ozone degradation.
In addition, since the surface area of the elastic material is large even though the volume of air is small in each of the concave grooves, the concave grooves are not easily affected by ozone degradation, and these concave grooves do not become a starting point for cracks in ozone degradation.

The expanded sectional view of the part equivalent to the A section of FIG. 9 which shows the 1st example of embodiment of this invention. Similarly, the partial front view of the dam part shown in the state seen from the left side of FIG. The figure similar to FIG. 1 which abbreviate | omits an outer ring | wheel and a hub and shows the 2nd example of embodiment of this invention. The same figure as FIG. The figure similar to FIG. 3 which shows the 3rd example of embodiment of this invention. The same figure as FIG. The figure similar to FIG. 3 which shows the 4th example of embodiment of this invention. The same figure as FIG. Sectional drawing which shows an example of the rolling bearing unit for wheel support with a seal ring used as the object of this invention. The expanded sectional view of the part corresponded to the A section of FIG. 9 which shows the seal ring of a conventional structure. The schematic diagram shown in order to demonstrate the aspect which a sealing material shrinks.

[First example of embodiment]
A first example of the embodiment of the present invention will be described with reference to FIGS. The feature of this example is a structure for preventing the occurrence of cracks due to ozone degradation in the weir 22a of the sealing material 18a constituting the seal ring 14b. As for the wheel bearing rolling bearing unit equipped with such a seal ring 14b, the same structure as that shown in FIG. 9 can be adopted, and various conventionally known structures can be adopted. Illustration and description of the entire rolling bearing unit are omitted, and the seal ring 14b will be described in detail below.

  The seal ring 14b includes a cored bar 17a and a sealing material 18a each formed in an annular shape. Of these, the metal core 17a is made of a metal plate such as a stainless steel plate, and has a cylindrical fitting cylinder portion 19a that is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring 2 in the axial direction. Annular portion 20a bent substantially at right angles from the outer end in the axial direction toward the outer side in the radial direction, and folded back 180 degrees into a substantially U shape from the inner end in the axial direction of the fitting tube portion 19a toward the outer side in the axial direction. And an inner diameter support portion 21a bent inward in the radial direction. Further, in the mounted state of the seal ring 14b (in a state in which the fitting cylinder portion 19a is fitted and fixed to the inner peripheral surface of the outer end portion in the axial direction of the outer ring 2), the outer peripheral edge portion of the circular ring portion 20a is It protrudes radially outward from the outer circumferential surface of the axial outer end portion, and the axial inner side surface of the circular ring portion 20a is part of the sealing material 18a with respect to the axial outer end surface of the outer ring 2 ( It is abutted through a weir 22a) which will be described later.

  The sealing material 18a is made of a diene vulcanized rubber such as acrylonitrile butadiene rubber (NBR) (or a rubber composition obtained by blending a hydride thereof with a reinforcing material such as carbon black, a crosslinking chemical or a plasticizer). The cored bar 17a is bonded and fixed by vulcanization adhesion. The sealing material 18a includes an annular flat plate-like weir 22a that covers the circumference of the annular portion 20a, a base portion 23a that is supported on the axially outer side surface of the inner diameter support portion 21a, and a base portion 23a. Three contact-type seal lips 24d, 24e, and 24f provided in a state of extending (the base end portion is continuous) are provided. The weir portion 22a covers both the axial side surfaces and the outer peripheral edge portion of the annular portion 20a, and the outer diameter side half of the portion covering the axial inner surface of the annular portion 20a, An annular-shaped thick portion 25 having a slightly thicker axial thickness than the inner half is provided. When the seal ring 14b is mounted, the inner half of the dam portion 22a that covers the inner surface in the axial direction of the annular portion 20a is elastically applied to the outer end surface in the axial direction of the outer ring 2. And the inner peripheral edge of the thick wall portion 25 is elastically contacted with the outer peripheral surface of the outer peripheral edge of the outer ring 2 over the entire circumference. Each of the seal lips 24 d to 24 f is slidably contacted with the outer peripheral surface of the hub 3 in the axial direction in the axial direction or the inner surface in the axial direction of the rotation side flange 12 over the entire circumference. 1 and FIGS. 3, 5, and 7 to be described later show the shapes of the seal lips 24d to 24f in a free state.

  Particularly in the case of this example, radial concave grooves 26 and 26 are formed on the outer surface in the axial direction of the dam portion 22a over the entire circumference at equal intervals in the circumferential direction. Further, by forming these concave grooves 26, 26 over the entire radial width of the axially outer side surface of the dam portion 22a, the radial ends of the concave grooves 26, 26 are formed on the dam portion 22a. Openings are made in the inner peripheral edge and the outer peripheral edge, respectively. The cross-sectional shape of each of the concave grooves 26, 26 is an arc shape (semi-circular, semi-elliptical, U-shaped, etc.), and such a cross-sectional shape does not change in the radial direction. The groove depth D of each of the concave grooves 26, 26 is about 1/10 to 1/3 times the axial thickness dimension X of the radially outer end of the weir 22a {D = (1 / 10 to 1/3) X, the example shown is D = (1/5) X}. In the case of this example, by forming each of the concave grooves 26, 26, the circumferential direction in the axially outer portion of the dam portion 22a (the range of the axial thickness D from the axially outer surface). With respect to the above, deformed portions 27 are formed in a portion between the concave grooves 26, 26.

In the case of this example having the above-described configuration, the dam portion 22a disposed in the portion of the sealing material 18a constituting the seal ring 14b that is easily exposed to ozone in the use state is deteriorated by ozone. It is possible to effectively prevent the occurrence of cracks due to.
That is, in the case of this example, a plurality of radial concave grooves 26, 26 are formed on the outer surface in the axial direction of the weir portion 22a. For this reason, in the axially outer portion of the weir portion 22a, the deforming portions 27, 27 existing between the concave grooves 26, 26 adjacent to each other in the circumferential direction are deformed (contracted) in the circumferential direction. Easy to do. More specifically, both end portions in the circumferential direction of the respective deformation portions 27 and 27 are opened to the respective concave grooves 26 and 26 (the deformation portions 27 and 27 are discontinuous in the circumferential direction). Therefore, these deformation permission portions 27, 27 can be easily contracted in the circumferential direction. Accordingly, the tensile stress in the circumferential direction can be released particularly with respect to the surface side portion of the weir portion 22a where the circumferential tensile stress is likely to occur, and the residual tensile stress in the circumferential direction can be reduced. As a result, it is possible to effectively prevent the dam portion 22a from being cracked due to ozone degradation. In the case of this example, the cross-sectional shape of each of the concave grooves 26 and 26 is an arc shape. Therefore, even when the deformed portions 27 and 27 are deformed in the circumferential direction, the concave grooves 26 and 26 are formed. , 26 can be prevented from concentrating stress, and cracks and the like can be effectively prevented from occurring.
In addition, since the surface area of the rubber is large in the concave grooves 26 and 26 even though the volume of air is small, the concave grooves 26 and 26 are not easily affected by ozone deterioration. There will never be.
With respect to other configurations and operational effects including the point that foreign matter such as muddy water can be prevented from entering the internal space 15 along the outer peripheral surface of the outer ring 2 by the dam portion 22a, the conventional structure described above is used. Same as the case.

[Second Example of Embodiment]
A second example of the embodiment of the present invention will be described with reference to FIGS. The feature of this example is that all of the circumferential grooves 28 are formed in the radially intermediate portion (radially central portion in the illustrated example) of the dam portion 22b in the axial direction outer surface of the sealing material 18b constituting the seal ring 14c. It is in the point which was provided around the circumference. Such a circumferential groove 28 is formed so as to cross the radial intermediate portion of the radial grooves 26, 26 in the circumferential direction, and the cross-sectional shape is also an arc shape (semi-circular, semi-elliptical, U-shaped etc.). In the case of this example, by providing such a circumferential groove 28, the deformed portions 27a, 27a provided in the portion between the grooves 26, 26 in the circumferential direction are deformed on the outer diameter side. The portions 29 and 29 and the inner diameter side deformable portions 30 and 30 are each divided into two in the radial direction.

In the case of this example having the above-described configuration, each of the deformable portions 27a and 27a is divided into two in the radial direction with the circumferential groove 28 interposed therebetween, so the radial width of the weir portion 22b. Even when the dimensions are large, the deformation portions 27a and 27a (the outer diameter side deformation portion 29 and the inner diameter side deformation portion 30) can be easily deformed in the radial direction. For this reason, it is possible to effectively release the tensile stress in the radial direction.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

[Third example of embodiment]
A third example of the embodiment of the present invention will be described with reference to FIGS. The feature of this example is that the dam portion lip 31 protruding toward the outer side in the axial direction is provided on the entire circumference of the radially intermediate portion of the dam portion 22c in the axial direction outer surface of the sealing material 18c constituting the seal ring 14d. It is in the point which set up. Such a weir lip 31 is a labyrinth slip (non-contact lip), and its tip edge is opposed to the inner side surface in the axial direction of the rotation side flange 12 (see FIGS. 1 and 9) through a minute gap. Yes.

  In addition, with the provision of the dam lip 31, the radial concave grooves 26 a and 26 a are formed on the outer diameter side concave grooves 32 and 32 on the radially outer side of the dam lip 31 and the dam lip 31. It divides | segments into the inner diameter side ditch | groove 33, 33 of radial direction inner side. Outer diameter side concave grooves 32, 32 are formed on the outer peripheral edge of the dam portion lip 31 on the flat surface portion provided on the outer side in the radial direction of the dam portion lip 31 among the outer surfaces in the axial direction of the dam portion 22c. It is formed radially from the base of the part. On the other hand, the inner diameter side concave grooves 33, 33 are provided when the seal ring 14d provided on the radially inner side of the dam portion lip 31 in the axially outer surface of the dam portion 22c is press-fitted. The flat surface portion pressed by the tool is formed radially from the root portion of the inner peripheral edge portion of the dam portion lip 31. The outer diameter-side concave grooves 32, 32 and the inner diameter-side concave grooves 33, 33 are formed in the same phase and have the same cross-sectional shape. In the case of this example, by providing the weir lip 31, the portion between the grooves 26 a, 26 a in the circumferential direction (the portion between the outer diameter side grooves 32, 32 and the inner diameter side groove) The deformed portions 27b and 27b formed in the portion between 33 and 33 are continuously in the circumferential direction by the weir lip 31 at the radial intermediate portion.

Also in the case of this example having the above-described configuration, both ends in the circumferential direction of the deformable portions 27b and 27b are the concave grooves 26a and 26a (the outer diameter side concave grooves 32 and the inner diameter side concave grooves 33). Therefore, the deformation portions 27b and 27b can be easily deformed in the circumferential direction. Therefore, it is possible to effectively prevent the weir portion 22c from cracking due to ozone degradation.
It should be noted that the outer diameter side concave grooves 32 and 32 and the inner diameter side concave grooves 33 and 33 can be arranged with a phase shift or have different cross-sectional shapes.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

[Fourth Example of Embodiment]
A fourth example of the embodiment of the present invention will be described with reference to FIGS. The feature of this example is that three circumferential grooves 28a, 28b, and 28c are added to the structure of the third example of the embodiment described above. Specifically, in the sealing material 18d constituting the seal ring 14e, the portion adjacent to the radially outer side and the radially inner side of the root portion of the dam portion lip 31 formed on the axially outer surface of the dam portion 22d, The circumferential grooves 28a and 28b are formed respectively. Further, a circumferentially recessed groove 28c is formed in a radially inward portion of the axially outer surface of the dam portion 22d, and a radially intermediate portion (in the illustrated example, a radially central portion) of the radially inner grooves 33, 33. Is formed in a state crossing in the circumferential direction. In the case of this example, the cross-sectional shapes of the circumferential grooves 28a to 28c are all arc-shaped and have the same shape. Further, by providing these circumferential grooves 28a to 28c, the deformed portions 27b and 27b provided in the portion between the radial grooves 26a and 26a in the circumferential direction can be replaced with the outer diameter deformed portions 29a and 29a. The intermediate deformation portions 34 and 34 and the inner diameter side deformation portions 30a and 30a are each divided into three in the radial direction.

  In the case of this example having the above-described configuration, the dam portion lip 31 is provided at the portion between the concave grooves 26a, 26a by the circumferential concave grooves 28a, 28b. 27b can be made independent (separated) in the radial direction. For this reason, it is possible to prevent the deformation in the circumferential direction of each of the deformation portions 27 b and 27 b (particularly the portion existing in the vicinity of the radial direction of the dam lip 31) from being transmitted to the dam lip 31. Therefore, it is possible to effectively prevent the weir lip 31 from being deformed so as to wave in the radial direction.

Further, since each of the deformed portions 27b and 27b is divided into three in the radial direction by the respective circumferential grooves 28a to 28c, each of the deformed portions 27b and 27b can be used even when the radial width dimension of the weir portion 22d is large. The portions 27b and 27b (the outer diameter side deformation portion 29a, the intermediate deformation portion 34, and the inner diameter side deformation portion 30a) can be easily deformed in the radial direction. For this reason, it is possible to effectively release the tensile stress in the radial direction.
About another structure and an effect, it is the same as that of the case of the 1st example of the said embodiment.

  When carrying out the present invention, the number of radial concave grooves formed on one axial side surface (axial outer surface) of the weir portion constituting the sealing material and the cross-sectional shape are not limited to the illustrated structure, and are elastic. It can be changed as appropriate according to the type of material, the use environment of the seal ring, and the like. For example, the cross-sectional shape of the groove is similar to the radial direction, and the cross-sectional area of the groove increases (or decreases) toward the radially outer side, or the width dimension (opening width) in the circumferential direction is Further, the shape can be increased (or decreased) toward the outer side in the radial direction.

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit for wheel support with seal ring 2 Outer ring 3 Hub 4 Rolling element 5 Static side flange 6 Outer ring raceway 7 Hub body 8 Inner ring 9 Nut 10 Inner ring raceway 11 Cage 12 Rotation side flange 13 Stud 14, 14a-14e Seal ring DESCRIPTION OF SYMBOLS 15 Internal space 16 Cover 17, 17a Core metal 18, 18a-18d Sealing material 19, 19a Fitting cylinder part 20, 20a Ring part 21, 21a Inner diameter support part 22, 22a-22d Weir part 23, 23a Base part 24a-24f Seal lip 25 Thick part 26, 26a Groove 27, 27a, 27b Deformed part 28, 28a-28c Circumferential groove 29 Outer diameter side deformed part 30 Inner diameter side deformed part 31 Weir part lip 32 Outer diameter side recessed groove 33 Inner diameter Side groove 34 Intermediate deformation part

Claims (4)

End opening of the internal space existing between the outer peripheral surface of the inner ring-side bearing ring member that rotates during use and the inner peripheral surface of the outer-diameter bearing ring member that does not rotate during use in an environment exposed to outside air Used to block
It comprises a cored bar and a sealing material made of an elastic material vulcanized and bonded to the cored bar,
Of these, the metal core is made of a metal plate and formed into an annular shape as a whole, and includes a cylindrical fitting tube portion that is fitted and fixed to the inner peripheral surface of the end portion of the outer diameter side race ring member, and this fitting. An annular ring that bends radially outward from one axial end of the combined cylinder, and abuts the other side in the axial direction against the end surface of the outer race-side bearing ring member directly or through part of the sealing material Part and an inner diameter support part provided radially inward from the fitting cylinder part in a state continuous to the other axial end part of the fitting cylinder part,
The seal material covers the annular portion, and an outer peripheral edge portion protrudes radially outward from an outer peripheral surface of the end portion of the outer diameter side race ring member, and an axial direction of the inner diameter support portion A base portion supported on one side surface, and provided with a state extending from the base portion, and having at least one seal lip that slides the tip edge thereof around the entire surface of the inner diameter side race ring member A seal ring,
A seal ring, wherein a plurality of radial grooves are formed on one side surface in the axial direction of the weir portion.   2. The seal ring according to claim 1, wherein a weir lip that protrudes toward one axial side is provided on one side surface in the axial direction of the weir portion so as to cross each of the concave grooves in the circumferential direction.   3. The seal ring according to claim 1, wherein a circumferential groove is formed on one side surface of the dam portion in the axial direction. It has an outer ring track on the inner peripheral surface and does not rotate while being supported by the suspension device, and an outer ring that is an outer diameter side track ring member, and an inner ring track on the outer peripheral surface facing the outer ring track. A hub that is an inner diameter raceway member disposed concentrically with the outer ring, a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway, and a peripheral surface of the hub. Among them, a flange for supporting and fixing a wheel to the hub, which is provided in a portion protruding outward in the axial direction from the axial outer end opening of the outer ring, an inner peripheral surface of the outer ring, and the hub A seal ring that closes the axially outer end opening of the internal space existing between the outer peripheral surface of
A rolling bearing unit for supporting a wheel with a seal ring,
A rolling bearing unit for supporting a wheel with a seal ring, wherein the seal ring is the seal ring according to any one of claims 1 to 3.

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