JP6201769B2 - Rolling bearing unit for seal ring and wheel support with seal ring - Google Patents

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. 12, for example. This wheel support rolling bearing unit 1 with a seal ring is provided with a hub 3 corresponding to an inner diameter side bearing ring member of the claims on an inner diameter side of an outer ring 2 corresponding to the outer diameter side bearing ring member of the claims. These are supported rotatably via a plurality of rolling elements 4 and 4. 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. 13 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 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), widely used in seal rings mounted on wheel bearing rolling bearing units, is 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.

  Therefore, the weir portion 22 of the seal ring 14a is not only susceptible to residual tensile stress on the surface portion, but also exposed to the outside when exposed to the attached state of the seal ring 14a. Cracks may occur due to ozone degradation. When such a crack occurs in the radial direction (perpendicular to the circumferential direction), the crack progresses radially inward and reaches the root portion of the seal lip (for example, the side lip). The tightening force due to the seal lip may be reduced, and the required sealing performance may not be obtained.

JP 2012-131458 A

  In view of the circumstances as described above, the present invention makes it possible for moisture such as muddy water adhering to the outer peripheral surface of the outer diameter side ring member to enter the internal space along the outer peripheral surface of the outer diameter side ring member. It can be effectively prevented, and even when used in an environment where it is easily exposed to ozone, the required sealing performance can be sufficiently maintained without lowering the tension of the sealing lip due to ozone deterioration. Realize the structure.

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. Is used to close the end opening of the internal space existing between the inner peripheral surface of the outer diameter side raceway member that does not rotate, and the cored bar is vulcanized and bonded to the cored bar. An inner diameter side sealing material and an outer diameter side sealing material made of elastic material.
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. It bends radially outward from one axial end of the combined cylinder, and its outer peripheral edge protrudes radially outward from the outer peripheral surface of the end of the outer diameter side race ring member. and indirect manner abutted annular portion side through the outer diameter side seal member to the end face of the outer diameter side raceway ring member, in this state continuous in the axial direction other end portion of the fitting tube And an inner diameter support portion provided radially inward from the fitting cylinder portion.
The inner diameter side sealing material is provided with a base portion supported on one side surface in the axial direction of the inner diameter support portion and a state extending from the base portion, and a tip edge thereof is provided around the surface of the inner diameter side bearing ring member. It has at least one seal lip to be brought into sliding contact.
Particularly in the seal ring of the present invention, the cored bar is made of a metal having rust prevention properties.
Further, the outer diameter side sealing material covers both the axial side surfaces and the outer peripheral edge of the annular portion, and of the outer diameter side sealing materials, covers the axial side surfaces of the annular portion. The inner diameters of these parts are equal to each other.
The inner diameter side sealing material and the outer diameter side sealing material are discontinuous in the radial direction.
In addition, an exposed portion whose surface is directly exposed to the outside between the outer peripheral edge portion of the inner diameter side sealing material and the inner peripheral edge portion of the outer diameter side sealing material, of one side surface in the axial direction of the annular ring portion. It is formed all around.

When the seal ring of the present invention as described above is implemented, for example, as in the invention described in claim 2, the axial direction from the outer peripheral edge portion of the annular portion to the radially outer end portion of the cored bar. A bent portion is formed in a state of extending to the other side .
Also, when practicing this onset bright, for example as in the invention described in claim 3, in the axial direction one side of the outer diameter side seal member is provided with a radially outer lip extending in the axial direction on one side .
Further, when carrying out the present invention, such as described above, for example as in the invention described in claim 4, the inner diameter side seal member, made of an elastic material having conductivity. And this inner diameter side sealing material is made to contact the surface of the said outer diameter side bearing ring member and the said inner diameter side bearing ring member, respectively.

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 roll freely, 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 rolling bearing unit for supporting a wheel with a seal ring of the present invention having the above-described configuration, water such as muddy water adhering to the outer peripheral surface of the outer diameter side race ring member is removed from the outer diameter side race ring. It is possible to effectively prevent the member from entering the internal space along the outer peripheral surface of the member, and even when used in an environment where it is easily exposed to ozone in the state of use, the tightening force due to the seal lip is reduced due to ozone deterioration. Without fail, the required sealing performance can be sufficiently maintained.

First, the reason why it is possible to effectively prevent moisture such as muddy water adhering to the outer peripheral surface of the outer diameter side raceway member from entering the inner space along the outer peripheral surface of the outer diameter side raceway member is The outer peripheral edge of the cored bar constituting the metal core protrudes radially outward from the outer peripheral surface of the end of the outer diameter side ring member, and the other side surface in the axial direction is the end surface of the outer diameter side ring member. This is because while being indirectly provided to abut against annular portion through the radially outer sealing member. That is, even when water such as muddy water adhering to the outer peripheral surface of the outer diameter side race ring member flows to the end along the outer peripheral surface of the outer diameter side race ring member, Of the side surface, the portion that protrudes radially outward from the outer peripheral surface of the end portion of the outer diameter side race ring member can effectively prevent the moisture from entering the internal space.

Moreover, even when used in an environment that is easily exposed to ozone in use, the reason why the required sealing performance can be sufficiently maintained without lowering the tightening force due to the seal lip based on ozone deterioration is Of the one side surface in the axial direction of the annular ring portion, the exposed portion that is not covered by the inner diameter side sealing material is disposed on the entire circumference at a position radially outer than the outer peripheral edge portion of the inner diameter side sealing material provided with the seal lip. This is because it forms a sword. That is, in the case of the present invention, the exposed portion is provided at a position closer to the outside than the inner diameter side sealing material and easily exposed to ozone. In other words, the inner diameter side sealing material is disposed at a radially inner position that is not easily exposed to ozone. Further, among the inner diameter side seal member, or eliminate the portion covering the axial piece side surface of the annular portion, or for small, it is possible to reduce the residual tensile stress acting on the inner diameter side seal member. For this reason, it can prevent that the crack based on ozone degradation generate | occur | produces in the said inner diameter side sealing material. Also, as in the present onset bright, wherein the inner diameter side seal member separately, even in the case where the outer diameter side seal member radially outer end portion of the annular portion, the outer diameter side and inner diameter side seal member Since the exposed portion is provided between the seal material (not continuous in the radial direction), cracks based on ozone degradation generated in the outer diameter side seal material have progressed radially inward, It does not reach the root of the seal lip of the inner diameter side sealing material. Therefore, it is possible to prevent the tightening force by the seal lip of the inner diameter side sealing material from being lowered. In the case of the present invention, the metal core is made of a metal having rust prevention properties. For this reason, it is possible to prevent the exposed portion provided on the annular portion of the core bar from being rusted by moisture.

The expanded sectional view equivalent to the A section of FIG. 12 which shows the 1st example of the reference example regarding this invention. The figure similar to FIG. 1 which shows the 1st example of embodiment of this invention . The figure similar to FIG. 1 which shows the 2nd example of the reference example regarding this invention . The figure similar to FIG. 1 which shows the 2nd example of embodiment of this invention . The figure similar to FIG. 1 which shows the 3rd example of the reference example regarding this invention . The figure similar to FIG. 1 which shows the 3rd example of embodiment of this invention . The figure similar to FIG. 1 which shows the 4th example of the reference example regarding this invention . The figure similar to FIG. 1 which shows the 5th example of the reference example regarding this invention . The figure similar to FIG. 1 which shows the 4th example of embodiment of this invention . The figure similar to FIG. 1 which shows the 6th example of the reference example regarding this invention . The figure similar to FIG. 1 which shows the 7th example of the reference example regarding this invention . 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 equivalent to the A section of Drawing 12 showing an example of conventional structure.

[First example of reference example ]
FIG. 1 shows a first example of a reference example related to the present invention. The feature of this reference example is a structure for preventing cracks due to ozone deterioration in the inner diameter side sealing material 25 constituting the seal ring 14b. As for the wheel bearing rolling bearing unit to which such a seal ring 14b is mounted, the same structure as shown in FIG. 12 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 is composed of a cored bar 17a and an inner diameter side sealing material 25 each formed in an annular shape.
Of these, the metal core 17a is made of a rust-proof metal plate such as a stainless steel plate, and includes a fitting tube portion 19a, an annular portion 20a, a curved portion 36, a bent portion 26, and an inner diameter support portion 21a. And.
The fitting cylinder portion 19a is a cylindrical portion provided at the radial intermediate portion of the cored bar 17a, and is fitted and fixed to the inner peripheral surface of the outer end portion 2 in the axial direction.
The circular ring portion 20a is provided in a state of being bent at a substantially right angle from the axially outer end portion of the fitting tube portion 19a toward the radially outer side, and an outer peripheral edge portion of the circular ring portion 20a is formed on the outer ring 2. It protrudes radially outward from the outer circumferential surface of the axially outer end portion.
The curved portion 36 has a circular arc shape in cross section, and exists in a portion between the fitting tube portion 19a and the annular portion 20a.
The bent portion 26 has an arc cross section and extends to the radially outer end of the cored bar 17a so as to bend radially outward and axially inward from the outer peripheral edge of the annular portion 20a. It is provided in the state.
Further, the inner diameter support portion 21a is folded back 180 degrees into a substantially U shape (substantially U shape) from the inner end portion in the axial direction of the fitting tube portion 19a toward the outer side in the axial direction, and toward the inner side in the radial direction. It is provided in a bent state.

The inner diameter side sealing material 25 is made of diene vulcanized rubber such as acrylonitrile butadiene rubber (NBR), for example, and is bonded and fixed to the metal core 17a by vulcanization adhesion. The inner diameter side sealing material 25 includes a base portion 23a supported on the inner peripheral surface of the bending portion 36 and the fitting tube portion 19a, and an outer surface in the axial direction of the inner diameter support portion 21a, and extends from the base portion 23a. Three contact-type seal lips 24d, 24e, and 24f provided in a state where they are extended (the base end portion is continuous) are provided.
In the case of this reference example, the radial position of the outer peripheral edge portion of the inner diameter side sealing material 25 is set to a position that is substantially aligned with the inner peripheral edge portion of the annular ring portion 20a, and the axially outer side of the annular ring portion 20a. No sealing material is provided on the side surface and the inner side surface in the axial direction. For this reason, the exposed portion 27 whose entire surface is directly exposed to the outside (not covered by the inner diameter side sealing material 25) is entirely exposed on the entire axially outer surface of the ring portion 20a (the range extending over the entire radial direction width). Is provided.

  The seal ring 14b as described above is in an attached state (a state in which the fitting cylinder portion 19a is fitted and fixed to the inner peripheral surface of the outer circumferential portion of the outer ring 2). While directly abutting against the outer end surface of the outer ring 2 in the axial direction, the front end edges of the seal lips 24d to 24f are all on the outer peripheral surface in the axial direction of the hub 3 or the inner surface in the axial direction of the rotary flange 12. It touches the circumference. FIG. 1 and FIGS. 2 to 11 described later show the shapes of the seal lips 24d to 24f in a free state.

In the case of this reference example having the above-described configuration, it is possible to effectively prevent moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2 from entering the internal space 15 along the outer peripheral surface of the outer ring 2. In addition, even when used in an environment that is easily exposed to ozone in the usage state, it is necessary without reducing the tightening force by the seal lips 24d to 24f of the inner diameter side sealing material 25 due to ozone deterioration. The sealing performance can be maintained sufficiently.

First, the reason why it is possible to effectively prevent 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 is the core constituting the seal ring 14b. An annular ring whose outer peripheral edge protrudes radially outward from the outer peripheral surface of the end of the outer ring 2 and whose axial inner surface is directly abutted against the axial outer end of the outer ring 2 on the gold 17a. This is because the portion 20a is provided. That is, even when moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2 flows to the end portion along the outer peripheral surface of the outer ring 2, the outer ring 2 is out of the axial inner side surfaces of the circular ring portion 20a. The portion protruding outward in the radial direction from the outer peripheral surface of the end portion can effectively prevent the moisture from entering the internal space 15 (can be dammed). In the case of this reference example, a bent portion 26 having a circular arc cross section is provided at the radially outer end of the cored bar 17a. For this reason, it is possible to prevent moisture that has flowed to the end portion along the outer peripheral surface of the outer ring 2 from getting over the annular portion 20a.

Further, even when used in an environment that is easily exposed to ozone in a use state, it is required without the tightening force by the seal lips 24d to 24f of the inner diameter side sealing material 25 being reduced due to ozone deterioration. The reason why the sealing performance can be sufficiently maintained is that the outer peripheral edge portion of the inner diameter side sealing material 25 is positioned at a portion aligned with the inner peripheral edge portion of the circular ring portion 20a, and the outer circumferential surface of the circular ring portion 20a This is because the exposed portion 27 that is not provided with the sealing material is formed over the entire periphery. That is, in the case of the present reference example, the inner diameter side sealing material 25 having the respective seal lips 24d to 24f is likely to generate a tensile stress in the circumferential direction and to be exposed to ozone. The side is not covered. For this reason, it is possible to prevent the inner diameter side sealing material 25 from being cracked due to ozone degradation. In the case of this reference example, the core metal 17a is made of a metal having rust prevention properties. Therefore, it is possible to prevent the ring portion 20a and the bent portion 26 from being rusted by moisture.

[ First example of embodiment]
FIG. 2 shows a first example of the embodiment of the present invention. In the case of the seal ring 14c of this example, the position of the outer peripheral edge portion of the inner diameter side sealing material 25a is positioned more radially outward than the inner diameter side sealing material 25 of the first example of the reference example described above. That is, in the case of this example, the inner diameter side sealing material 25a covers the radially inner end portion of the outer circumferential surface of the annular ring portion 20a constituting the cored bar 17b. As a result, the outer peripheral edge of the inner diameter side sealing member 25a is positioned at the radially intermediate portion (the inner end portion) of the annular ring portion 20a. Then, such an inner diameter side sealing material 25a is divided into a radially inner end portion of the annular outer surface of the annular portion 20a, an inner peripheral surface of the bending portion 36 and the fitting tube portion 19a, and the inner diameter support portion 21a. Is supported on the outer surface in the axial direction. In the case of this example, a bent portion as in the first example of the reference example is not provided at the radially outer end portion of the cored bar 17b. Instead, concerning the annular portion 20a, it is larger than the projecting amount of the radially outward from the end portion outer peripheral surface of the outer ring 2 of the first example.

Of the outer surface in the axial direction of the annular portion 20a of the metal core 17b, the outer portion in the radial direction from the outer peripheral edge portion of the inner diameter side seal member 25a (the axially intermediate portion of the outer surface in the axial direction of the annular portion 20a). Part) is provided with an exposed part 27a.
The outer circumferential surface of the outer ring portion 20a is covered with a radially outer portion than the exposed portion 27a, and the outer peripheral edge of the outer ring 2 is radially outer than the outer circumferential surface of the outer ring 2 in the axial direction. An outer diameter side sealing material 28 protruding in the direction is provided. Specifically, the outer-diameter side sealing material 28 covers a portion extending from a radial intermediate portion to a radial outer end portion on both axial sides of the annular portion 20a, and an outer peripheral edge portion. . Then, in the mounted state of the seal ring 14c, the inner half of the outer diameter side sealing material 28 that covers the inner side surface in the axial direction of the annular portion 20a is the outer end surface in the axial direction of the outer ring 2. It is made to contact elastically with the outer diameter side portion of. In the case of this example, the inner diameter of the portion of the outer diameter side sealing material 28 that covers the inner surface in the axial direction of the annular portion 20a is made equal to the inner diameter of the portion that also covers the outer surface in the axial direction. ing. In the case of this example, the inner diameter side sealing material 25a and the outer diameter side sealing material 28 are each made of a diene vulcanized rubber such as acrylonitrile butadiene rubber (NBR). However, the inner diameter side sealing material 25a and the outer diameter side sealing material 28 can be made of different materials.

In the case of this example having the above-described configuration, the inner diameter side half of the outer diameter side sealing material 28 covering the inner surface in the axial direction of the annular ring portion 20a is outside the axial direction of the outer ring 2. It is elastically brought into contact with the outer diameter side portion of the end face. For this reason, it is possible to more effectively prevent moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2 from entering the internal space 15 along the outer peripheral surface of the outer ring 2.
In the case of this example, even if cracks due to ozone degradation occur in the outer diameter side sealing material 28 covering the radial outer end of the annular ring portion 20a, the outer diameter side sealing material 28 and the Since the exposed portion 27a is provided between the inner diameter side sealing material 25a (there is a discontinuous portion constituted by the exposed portion 27a), the crack propagates radially inward and the inner diameter The root portions of the seal lips 24d to 24f of the side seal material 25a are not reached. Accordingly, the tightening force by the seal lips 24d to 24f is not reduced. The structure, operation, and effects of other parts are the same as those of the first example of the reference example described above.

[ Second example of reference example ]
FIG. 3 shows a second example of a reference example relating to the present invention. In the case of the seal ring 14d of the present reference example, the inner diameter side sealing member 25 has the same structure as that of the first example of the reference example described above, and the cored bar 17b has the same structure as that of the first example of the embodiment.
Of the outer diameter side sealing material 28a provided so as to cover the periphery of the radially outer end portion of the annular ring portion 20a constituting the core metal 17b, a portion covering the axial inner side surface of the annular ring portion 20a. Is made smaller than the inner diameter of the portion covering the outer surface in the axial direction. Then, in the mounted state of the seal ring 14d, the inner half of the outer diameter side sealing material 28a that covers the inner surface in the axial direction of the annular portion 20a is the outer end surface in the axial direction of the outer ring 2. Is elastically brought into contact with the entire surface (range over the entire radial width).

In the case of the present reference example having the above-described configuration, the inner peripheral edge portion of the outer diameter side sealing material 28a covering the inner side surface in the axial direction of the annular portion 20a is the diameter of the annular portion 20a. It is positioned at the inner end in the direction (portion aligned with the inner peripheral edge), and the inner diameter side half of the portion is elastically brought into contact with the entire outer surface of the outer ring 2 in the axial direction. Therefore, it is more effective than the first example of the above-described embodiment that moisture such as muddy water adhering to the outer peripheral surface of the outer ring 2 enters the internal space 15 along the outer peripheral surface of the outer ring 2. Can be prevented. Further, when the seal ring 14d is assembled, it is possible to effectively prevent the seal ring 14d from being inclined, so that the fitting cylinder portion 19a of the seal ring 14d can be easily press-fitted into the outer ring 2. . Construction and operation and effects of the other parts are the same as the first example of the first example and reference example of the embodiment described above.

[ Second Example of Embodiment]
FIG. 4 shows a second example of the embodiment of the present invention. In the case of the seal ring 14e of this example, the inner diameter side sealing material 25 and the cored bar 17a have the same structure as the first example of the reference example described above.
Further, an outer diameter side sealing material 28b is provided so as to cover the periphery of the radially outer end portion of the cored bar 17a (the radially outer end portion of the bent portion 26 and the annular portion 20a). Then, in the mounted state of the seal ring 14e, the inner diameter side half of the outer diameter side sealing material 28b covering the inner surface in the axial direction of the annular ring portion 20a is connected to the outer end surface in the axial direction of the outer ring 2. It is elastically brought into contact with the outer diameter side portion. In the outer diameter side sealing material 28b, the inner peripheral edge of the portion that covers the inner surface in the axial direction of the annular portion 20a is the diameter of the annular portion 20a as in the second example of the reference example described above. It is also possible to adopt a structure located at the inner end in the direction. Construction and operation and effects of the other parts are the same as the first example of the first example and reference example of the embodiment described above.

[ Third example of reference example ]
FIG. 5 shows a third example of the reference example related to the present invention. In the case of the seal ring 14f of this reference example, the inner diameter side sealing material 25 and the cored bar 17a have the same structure as the first example of the reference example described above.
Further, in a state of covering the radially outer end portion (radially outward portion of the exposed portion 27a) of the annular portion 20a of the annular portion 20a of the cored bar 17a and the axially outer surface of the bent portion 26, respectively. An outer diameter side sealing material 28c is provided. Such an outer diameter side sealing material 28c includes a base portion 29 supported on the axially outer surface of the annular portion 20a and the axially outer surface of the bent portion 26, and extends axially outward from the base portion 29. It has an outer diameter side lip 30 provided in the extended state. In the case of this reference example, the outer peripheral surface of the outer diameter side lip 30 has a conical cylindrical shape, and the outer diameter dimension thereof is larger than the outer diameter dimension of the outer peripheral surface of the outer ring 2 in the axial direction outer end portion. .

  In addition, the position of the distal end portion of the outer diameter side lip 30 is set to the thick portion 31 provided on the proximal end portion (root portion) of the axial side surface of the rotation side flange 12 and also to the distal end portion. It is provided and is regulated by the relationship with the stepped portion 33 that is continuous with the thin portion 32 having a smaller thickness than the thick portion 31. That is, the front half of the outer diameter side lip 30 is positioned radially outward from the stepped portion 33, and the front half of the outer diameter side lip 30 and the stepped portion 33 are overlapped in the radial direction. ing. Thus, a radial labyrinth seal 34 is formed between the distal end edge of the outer diameter side lip 30 and the axial inner side surface of the rotation side flange 12, and is continuous with the radial labyrinth seal 34. Thus, an axial labyrinth seal 35 is formed between the inner peripheral surface of the front half of the outer diameter side lip 30 and the outer peripheral surface of the stepped portion 33.

In the case of the present reference example having the above-described configuration, the outer diameter side lip 30 is provided in the outer diameter side sealing material 28c, and the outer diameter side lip 30 and the step portion 33 of the rotation side flange 12 are provided. Are provided with the labyrinth seals 34 and 35. For this reason, of the seal lips 24d to 24f constituting the inner diameter side sealing material 25, foreign matters such as dust and moisture may enter the position where the seal lip 24d provided on the outermost radial direction is provided. It can be prevented. As a result, the sealing performance of the seal ring 14f can be improved. The structure, operation, and effects of other parts are the same as those of the first example of the reference example described above.

[ Third example of embodiment]
FIG. 6 shows a third example of the embodiment of the present invention. In the case of the seal ring 14g of this example, the inner diameter side sealing material 25a and the cored bar 17b have the same structure as that of the first example of the embodiment described above.
Further, the outer diameter side sealing material 28d has the same structure as the outer diameter side sealing material 28 of the first example of the above-described embodiment (covering the radially outer end of the ring portion 20a) and a base portion 29a. Of the base portion 29a, the outer peripheral side lip 30 is formed so as to extend outward in the axial direction from a portion covering the axially outer side surface of the annular ring portion 20a constituting the cored bar 17b. . The arrangement state of the outer diameter side lip 30 (relation with the step portion 33) is the same as in the third example of the reference example described above. Construction and operation and effects of the other parts are the first example of the first example and reference example of the embodiment described above, and is similar to the third example.

[ Fourth Reference Example ]
FIG. 7 shows a fourth example of the reference example relating to the present invention. In the case of the seal ring 14h of this reference example, the inner diameter side sealing member 25 has the same structure as that of the first example of the reference example described above, and the cored bar 17b has the same structure as that of the first example of the embodiment.
The outer diameter side sealing material 28e includes a base portion 29b having the same structure as the outer diameter side sealing material 28a of the second example of the reference example described above, and an annular portion constituting the cored bar 17b of the base portion 29b. It comprises an outer diameter side lip 30 formed so as to extend axially outward from a portion covering the axially outer surface of 20a. The arrangement state of the outer diameter side lip 30 is the same as that of the third example of the reference example described above. The structure, operation, and effects of the other parts are the same as those of the first example, the second example, and the third example of the reference example described above.

[ Fifth Reference Example ]
FIG. 8 shows a fifth example of the reference example relating to the present invention. In the case of the seal ring 14i of the present reference example, a through-hole 37 is formed in at least one place in the circumferential direction of the curved portion 36 of the cored bar 17c (preferably a plurality of places at equal intervals in the circumferential direction).
Further, the inner diameter side sealing material 25b is made of an elastic material imparted with conductivity by adding a conductivity imparting agent to diene vulcanized rubber such as acrylonitrile butadiene rubber (NBR). As the conductivity imparting agent, for example, metal powders such as copper and silver, carbon particles such as carbon black, or ion conductivity imparting agents can be used.

A part of the inner diameter side sealing material 25b made of the material as described above is protruded from the outer peripheral surface of the bending portion 36 through the through hole 37 formed in the cored bar 17c. Specifically, a connection protrusion 38 is formed at a position aligned with the through hole 37 in the outer peripheral surface of the inner diameter side sealing material 25b in a state of projecting radially outward from the outer peripheral surface. Yes.
Then, the base half of the connection protrusion 38 is disposed inside the through hole 37, and the tip half of the connection protrusion 38 projects radially outward from the curved portion 36. It is made to contact | abut to the chamfering part formed in the axial direction outer end surface inner peripheral part. FIG. 8 shows the shape of the connection protrusion 38 in a free state.
Also in the case of this reference example, the end edges of the seal lips 24d to 24f of the inner diameter side sealing material 25b are all around the outer peripheral surface of the hub 3 in the axial direction or the inner surface in the axial direction of the rotation side flange 12. Slid in contact with

In the case of this reference example having the above configuration, the inner diameter side sealing material 25b having conductivity is brought into contact with the outer ring 2 and the hub 3. For this reason, even when static electricity (current) generated in the vehicle flows into the wheel bearing rolling bearing unit 1 (see FIG. 12), the current flows between the outer ring 2 and the hub 3 on the inner diameter side. It can flow (conduct) through the sealing material 25b. Therefore, even when the current flows into the wheel support rolling bearing unit 1, a potential difference is generated between the outer ring 2 and the hub 3, so that the rolling surfaces of the rolling elements 4, 4 and the outer ring, It is possible to prevent a discharge phenomenon (spark) from occurring instantaneously between the inner ring raceways 6 and 10. As a result, it is possible to prevent radio noise and malfunction of an in-vehicle electronic device that may occur due to the spark. The cored bar 17c and the inner diameter side sealing material 25b are vulcanized and bonded by an insulating adhesive (for example, phenol resin adhesive, epoxy resin adhesive, etc.). Thus, no current flows from the outer ring 2 to the inner diameter side sealing material 25b. Although not shown in the figure, the front half of the connecting projection 38 (the portion protruding radially outward from the curved portion 36) is continuously extended over the entire circumference by the annular continuous portion, and this annular continuous The outer peripheral surface of the portion can be brought into contact with the chamfered portion of the outer ring 2 over the entire circumference. When such a structure is adopted, the conductivity between the outer ring 2 and the hub 3 can be improved, and the sealing performance between the metal core 17c and the outer ring 2 can be improved. The structure, operation, and effects of the other parts are the same as those of the first and third examples of the reference example described above.

[ Fourth Example of Embodiment]
FIG. 9 shows a fourth example of the embodiment of the present invention. In the case of the seal ring 14j of this example, the through-hole 37a is formed in at least one place (preferably a plurality of places at equal intervals in the circumferential direction) at the radially inner end of the annular portion 20a of the core metal 17c. ing. A part of the inner diameter side sealing material 25c is protruded from the inner side surface in the axial direction of the annular portion 20a through the through hole 37a.
Specifically, a connecting protrusion 38a is formed in a radially inward end of the inner diameter side sealing material 25c at a position aligned with the through hole 37a in a state of protruding inward in the axial direction from the portion. Has been. In the present example also, the inner diameter side sealing material 25c is made of an elastic material imparted with conductivity.

The base half of the connection protrusion 38a is disposed inside the through hole 37a, and the front half protrudes inward in the axial direction from the radially inner end of the inner side surface of the annular portion 20a. In this state, the tip end is brought into contact with the axially outer end surface of the outer ring 2.
Also in the case of this example, the tip edges of the seal lips 24d to 24f of the inner diameter side sealing material 25c are all around the outer peripheral surface of the hub 3 in the axial direction or the inner surface in the axial direction of the rotary flange 12. It is in contact with slid. The structure, operation, and effects of other parts are the same as those of the third example of the above-described embodiment , the first example of the reference example, and the fifth example.

[ Sixth example of reference example ]
FIG. 10 shows a sixth example of the reference example related to the present invention. In the case of the seal ring 14k of the present reference example, at least one place in the circumferential direction of the continuous portion 39 between the axial inner end portion of the fitting cylinder portion 19a of the cored bar 17d and the radial outer end portion of the inner diameter support portion 21a. Through holes 37b are formed (preferably at a plurality of positions at equal intervals in the circumferential direction). A part of the inner diameter side sealing material 25d is protruded radially outward from the outer peripheral surface of the continuous portion 39 through the through hole 37b.
Specifically, the connection protrusion 38b is formed in the axially inner end portion of the outer peripheral surface of the inner diameter side sealing material 25d at a position aligned with the through-hole 37b and protruding radially outward from the portion. Has been. Also in the case of this reference example, the inner diameter side sealing material 25d is made of an elastic material imparted with conductivity. The structure, operation, and effects of other parts are the same as those of the first example, the fourth example, and the fifth example of the reference example described above.

[ Seventh example of reference example ]
FIG. 11 shows a seventh example of the reference example relating to the present invention. In the case of the seal ring 14m of the present reference example, the through hole 37 (see FIG. 8) as in the fifth example of the reference example described above is not formed in the cored bar. For this reason, in the case of the present reference example, a part of the inner diameter side sealing material 25e is hung from the radially inner end portion of the inner diameter support portion 21a of the core bar 17a to the radially outer end portion. This part is used as the connection part 40 by providing it along the line. The radially outer end of the connection portion 40 is brought into contact with the inner peripheral surface of the outer ring 2. Also in the case of this reference example, the inner diameter side sealing material 25e is made of an elastic material imparted with conductivity. Further, the tip edges of the respective seal lips 24d to 24f of the inner diameter side sealing material 25e are brought into sliding contact with the outer peripheral surface of the hub 3 in the axial direction or the inner surface in the axial direction of the rotary flange 12 over the entire circumference. . In this way, the inner diameter side sealing material 25e having conductivity is brought into contact with the outer ring 2 and the hub 3. The structure, operation, and effects of the other parts are the same as those of the first example, the third example, and the fifth example of the reference example described above.

In carrying out the present invention, the structure of each example of the above-described embodiment and the structure of each reference example can be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit for wheel support with seal ring 2 Outer ring 3 Hub 4 Rolling body 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-14m Seal ring 15 Rolling element arrangement space 16 Cover 17, 17a, 17b, 17c, 17d, 17e Core metal 18, 18b, 18c, 18d, 18e, 18f Sealing material 19, 19a Fitting cylinder part 20, 20a Ring part 21, 21a Inner diameter Support part 22 Weir part 23, 23a Base part 24a, 24b, 24c, 24d, 24e, 24f Seal lip 25, 25a, 25b, 25c, 25d, 25e Inner diameter side sealing material 26 Bent part 27, 27a Exposed part 28, 28a, 28b , 28c, 28d, 28e Outer diameter side sealing material 29, 29 , 29b base 30 radially outer lip 31 thick portion 32 thin portion 33 stepped portion 34 labyrinth seal 35 labyrinth seal 36 bend 37, 37a, 37b through holes 38, 38a, 38b connected projection 39 continuous portion 40 connecting portions

Claims (5)

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 seal ring der, which is used to block the,
A cored bar, and an inner diameter side sealing material and an outer diameter side sealing material made of an elastic material each vulcanized and bonded to the cored bar,
Of these, the metal core is made of a metal plate having rust prevention properties, and is formed into an annular shape as a whole, and is a cylindrical fitting tube that is fitted and fixed to the inner peripheral surface of the end of the outer diameter side race ring member. And the outer peripheral edge of the outer peripheral side ring member protrudes radially outward from the outer peripheral surface of the outer diameter side race ring member. and indirect manner abutted annular portion of the axial direction other side via the outer diameter side seal member to the end face of the outer diameter side raceway ring member, the axial end portion of the fitting tube It has an inner diameter support portion provided radially inward from the fitting tube portion in a continuous state,
The inner diameter side sealing material is provided with a base portion supported on one side surface in the axial direction of the inner diameter supporting portion and a state extending from the base portion, and a tip edge thereof is provided on the entire surface of the inner diameter side bearing ring member. der those having at least one sealing lip of the sliding contact over is,
The outer diameter side sealing material covers both the axial side surfaces and the outer peripheral edge of the annular portion, and the portion of the outer diameter side sealing material that covers both axial sides of the annular portion. Are equal to each other,
Wherein the inner diameter side seal member and the outer diameter side seal member is discontinuous with respect to the radial direction, of the axial one side of the annular portion, the outer diameter side seal with the outer peripheral edge of the inner diameter side seal member A seal ring characterized in that an exposed portion whose surface is directly exposed to the outside is formed over the entire circumference between the inner peripheral edge portion of the material .   2. The seal ring according to claim 1, wherein a bent portion is formed at a radially outer end portion of the cored bar in a state of extending from an outer peripheral edge portion of the annular ring portion to the other side in the axial direction. Axially one side of the outer diameter side seal member, the outer diameter side lip extending in the axial direction on one side is provided, the sealing ring described in any one of claims 1-2.   The inner diameter side sealing material is made of a conductive elastic material, and the inner diameter side sealing material is in contact with the outer diameter side race ring member and the inner diameter side race ring member, respectively. The seal ring described in any one of 1 to 3. 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 rolling bearing unit for supporting a wheel with a seal ring, comprising a seal ring that closes an axially outer end opening of an internal space existing between the outer peripheral surface of
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 4 .

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