JP2012131452A - Wheel supporting rolling bearing unit with sealing ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To materialize a structure which enhances seal properties by a sealing ring to develop a good contaminant invasion preventing effect into internal space installing a rolling element, and also has an excellent durability without increasing rotational resistance.SOLUTION: An edge part of a labyrinth lip 21a is positioned radially outward of a stage part 25 provided on an inside face of a rotating flange 12, and also the edge part of the labyrinth lip 21a is radially superposed on the stage part 25. The inside face at the edge part of the labyrinth lip 21a is in proximity opposed to an outside face of the stage part 25 throughout the entire circumference. Further, a water shut off part 34 projecting radially outward from an outside edge of the outer end of an outer wheel 2 is provided by part of sealing materials 18a, and also an inside face of a hood part 35 provided on an inside face of an outer diameter end part of the water shut off part 34 is opposed to an outside face of an outer end part of the outer wheel 2 throughout the entire circumference.

Description

  The present invention relates to an improvement of a wheel bearing rolling bearing unit with a seal ring for supporting a vehicle wheel on a suspension device. Specifically, the sealing performance of the seal ring is improved to improve the effect of preventing foreign matter from entering the rolling element installation space, and the rolling bearing unit for wheel support with seal ring having excellent durability is increased in rotational resistance. It will be realized without any problems. Moreover, the structure which can aim at the improvement of the handleability and transportability of a seal ring as needed is implement | achieved.

  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. 7, 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. The rolling elements 4 and 4 are held by the cages 11 and 11 between the inner ring raceways 10 and 10 and the outer ring raceways 6 and 6, respectively. It is provided so that it can roll freely.

  Further, a rotation side flange 12 corresponding to the flange described in the claims is provided in a portion of the hub body 7 that is close to the outer end and protrudes from the outer end opening of the outer ring 2. 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.

  A seal ring 14 is mounted between the inner peripheral surface of the outer end of the outer ring 2 and the outer peripheral surface of the intermediate portion of the hub 3, and exists between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3. The outer end opening of the internal space 15 provided with the plurality of rolling elements 4 and 4 is closed. In addition, by closing the 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 inner end opening, and the inner space 15 can be filled. Prevents leakage of grease to the outside. 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 wheel bearing rolling bearing unit with a seal ring incorporated in a heavy automobile, a tapered roller is used as each rolling element. Sometimes used. Further, in order to connect and fix the hub body and the inner ring, the inner end portion of the hub body is radially outward instead of the structure in which the nut 9 is screwed and fixed to the inner end portion of the hub body 7 as shown in the figure. The inner end surface of the inner ring that is externally fitted to the hub body can be suppressed by a caulking portion formed by plastic deformation. 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, the seal of the outer end opening of the inner space where each rolling element is installed is provided by a seal ring 14 provided between the inner peripheral surface of the outer end of the outer ring and the outer peripheral surface of the intermediate portion of the hub body. Plan. On the other hand, regarding the seal of the inner end opening 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 and the outer peripheral surface of the inner end of the inner ring. In the case of a drive wheel, a combination seal ring is provided between the two and a combination seal ring.

  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 end openings of the internal space 15. In particular, with regard to the seal ring for sealing the outer end opening of the internal space 15, the foreign matter guided radially inward along the inner surface of the rotation-side flange 12 enters the internal space 15. In order to prevent this, excellent sealing performance is required. Moreover, the outer end opening of the inner 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 outer end opening of the internal space 15. For example, Patent Document 1 describes a seal ring including three seal lips in which a tip end portion is slidably contacted with an inner surface of a rotation side flange or an outer peripheral surface of an intermediate portion of a hub over the entire circumference. However, in the case of a seal ring having such a configuration, if the use conditions become severe, there is a possibility that sufficient sealing performance cannot be exhibited. That is, a comparison is made from the clearance between the outer end surface of the outer ring and the inner side surface of the rotation side flange provided to prevent the outer end surface of the outer ring and the inner surface of the rotation side flange from contacting (metal contact). Foreign matter such as large sand particles enters, and this foreign matter enters the sliding contact portion between the tip edge of the seal lip constituting the seal ring and the inner side surface of the rotation side flange, and abnormal wear or the like occurs in this sliding contact portion. May cause damage.
On the other hand, in Patent Document 2, in order to prevent foreign matter from entering through the gap between the outer end surface of the outer ring and the inner surface of the rotation side flange, a contact-type is applied to the large-diameter side portion of the combined seal ring. A structure for adding a seal lip is disclosed. However, in such a structure, the seal torque increases, and the rotational resistance of the wheel bearing rolling bearing unit with seal ring increases. For this reason, the driving performance and fuel consumption performance of the automobile are lowered, which is not preferable.

In view of such circumstances, conventionally, it has been considered to provide a labyrinth seal further outward in the radial direction than the seal lip positioned on the outermost radial direction (see, for example, Patent Documents 3 to 7). Of these, in the case of the conventional structure described in Patent Document 3, three seal lips having the tip part slidably brought into contact with the inner side surface of the rotation side flange or the intermediate part outer peripheral surface of the hub over the entire circumference. Of these, a labyrinth slip is provided further radially outward than a seal lip provided on the outermost radial direction, and a labyrinth seal is formed between the leading edge of the labyrin slip and the inner side surface of the rotation side flange.
However, in the case of such a conventional structure, the leading edge of the labyrin slip and the inner surface of the rotating side flange are simply made close to each other in the axial direction. The labyrinth seal formed between the rotary side flange and the inner surface of the rotation side flange has a structure having a path in a radial direction that easily matches the scattering direction of muddy water or the like. In order to ensure the sealing performance by such a radial labyrinth seal, it is necessary to increase the thickness of the tip edge portion of the labyrinth slip to ensure the total length of the labyrinth seal. Therefore, it is difficult to secure the full length sufficiently long. Further, when the outer ring and the hub are relatively inclined by an external force such as a load applied from the contact portion between the tire and the road surface, and the leading edge of the labyrin slip and the inner side surface of the flange are in contact with each other, The rotational resistance (seal torque) of the hub increases. In order to prevent this, even when the hub and the outer ring are relatively inclined, the leading edge of the labyrin slip is not in contact with the leading edge of the labyrin slip and the inner surface of the flange. It is necessary to secure a gap between the flange and the inner surface of the flange. Therefore, it is difficult to exhibit sufficient sealing performance even when the use conditions become severe. In the case of the conventional structure described in Patent Document 3, the outer diameter of the seal ring is smaller than the outer diameter of the outer peripheral surface of the outer end of the outer ring. However, it drops along the outer peripheral surface of the outer ring and onto the outer peripheral surface of the labyrinth slip, and easily enters the labyrinth seal.

In order to solve the above-described problems, there is a technique described in Patent Document 8. One example of the conventional structure according to Patent Document 8 will be described with reference to FIGS.
The seal ring 14a incorporated in the wheel bearing rolling bearing unit with a seal ring having the conventional structure includes a metal core 17 and a seal material 18. The core metal 17 is formed by bending a metal plate such as a mild steel plate. The fitting tube 22 and an annular ring bent radially inward from the outer edge of the fitting tube 22. A portion 23 and a bent portion 24 bent inward from the inner peripheral edge of the ring portion 23 are provided. Of these, the fitting tube portion 22 is externally fitted and fixed to the outer peripheral surface of the outer end portion of the outer ring 2, and the inner side surface of the circular ring portion 23 is abutted against the outer end surface of the outer ring 2. Yes.

  The sealing material 18 is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 17, and constitutes a labyrinth seal with three contact-type seal lips 19a, 19b, and 19c. The labyrinth slip 21 is provided. Each of the seal lips 19a to 19c is in sliding contact with the inner surface of the rotation side flange 12 or the outer peripheral surface of the intermediate portion of the hub 3 over the entire circumference. 8 and FIGS. 1, 2, and 5 described later show the shapes of the seal lips 19a to 19c in a free state.

  On the other hand, the labyrinth slip 21 is provided further radially outward than the seal lip 19a provided on the outermost radial direction, and the formation position thereof is provided on the inner side surface of the rotation side flange 12. It is restricted in relation to the stepped portion 25. In addition, this step part 25 is the same as the thick part 26 provided in the base end part (root part) of this rotation side flange 12 in order to ensure the bending rigidity with respect to the moment load added to the said rotation side flange 12. This is a portion where a thin portion 27 having a thickness smaller than that of the thick portion 26 is provided in a portion near the tip.

  The labyrinth slip 21 (the front end portion or the base end portion thereof) is positioned radially outward from the step portion 25 as described above, and the leading half portion and the step portion 25 of the labyrin slip 21 are axially disposed. Superimposed. Then, the inner peripheral surface of the tip end portion of the labyrinth slip 21 and the outer peripheral surface of the step portion 25 are closely opposed over the entire periphery. Thus, in the case of the illustrated conventional structure, a radial labyrinth seal 28 a is formed between the leading edge of the labyrinth slip 21 and the inner surface of the rotary flange 12, and this radial labyrinth seal is formed. An axial labyrinth seal 28b is formed between the inner peripheral surface of the tip of the labyrin slip 21 and the outer peripheral surface of the step portion 25 in a state of being bent inward in the axial direction from 28a.

  As shown in FIG. 9, cuts 29 and 29 each reaching the leading edge of the labyrin slip 21 are formed at a plurality of locations in the circumferential direction of the front half of the labyrin slip 21 as described above. Further, in the first half of the labyrinth slip 21, in a state where the wheel bearing rolling bearing unit 1 with a seal ring (see FIG. 7) is assembled to the vehicle, As shown in (A) and (B), a drain having a rectangular (or semi-elliptical) opening formed by thinning a portion between the circumferentially adjacent cuts 29, 29. A hole 30a (30b) is provided.

  In the case of the conventional structure as described above, since a plurality of cuts 29 and 29 are provided in the first half of the labyrin slip 21, the leading edge of the labyrin slip 21 and the inner surface of the flange 12 should be in contact with each other. Even in this case, an increase in the rotational resistance of the hub 3 can be suppressed. In addition, since the increase in rotational resistance can be suppressed in this way, the gap between the leading edge of the labyrinth slip 21 and the inner surface of the flange 12 can be set smaller.

  In addition, the outer peripheral surface of the labyrinth slip 21 is cylindrical, and the outer diameter is larger than the outer diameter of the outer end portion of the outer ring 2. Further, in the sealing material 18 constituting the seal ring 14a, the fitting cylindrical portion 22 constituting the cored bar 17 is covered with a portion continuous inward from the base end portion of the labyrin slip 21, and the portion A dam portion 31 for blocking water intrusion is formed. Further, the inner peripheral surface of the front half of the labyrinth slip 21 has a conical concave shape that is inclined in a direction in which the inner diameter dimension increases toward the tip edge, thereby preventing foreign matter such as muddy water entering the inner diameter side of the labyrinth slip 21. The guide surface is used to guide the press-fitting jig while facilitating discharge. The inner peripheral surface of the base half of the labyrinth slip 21 is cylindrical.

In the case of a wheel bearing rolling bearing unit with a seal ring having a conventional structure having the above-described configuration, the sealing performance by the seal ring 14a is improved, and the foreign matter to the internal space 15 in which the rolling elements 4 are installed is improved. The wheel bearing rolling bearing unit 1 with a seal ring (see FIG. 7) having a good invasion preventing effect and excellent durability can be realized without increasing the rotational resistance.
That is, in the case of the conventional structure shown in the figure, since the radial labyrinth seal 28a and the axial labyrinth seal 28b as described above are provided, the total length of the labyrinth seal is related to the above-mentioned Patent Document 3. Can be long enough compared to the structure. Furthermore, since the labyrinth slip 21 is positioned radially outward, the tip of the labyrinth slip 21 can be brought close to and opposed to a portion having a high peripheral speed on the inner side surface of the rotating flange 12. Thus, the labyrinth effect by the labyrinth slip 21 can be improved.

  Further, as described above, since the weir portion 31 having an outer diameter larger than the outer peripheral surface of the outer end portion of the outer ring 2 is provided, the moisture adhering to the outer peripheral surface of the outer ring 2 is affected by the outer peripheral surface of the outer ring 2. And reaching the outer peripheral surface of the labyrinth slip 21 can be prevented. Therefore, it is possible to prevent moisture adhering to the outer peripheral surface of the outer ring 2 from entering the labyrinth seal.

  Further, in the case of the conventional structure shown in the figure, since the plurality of cuts 29 and 29 are formed in the first half of the labyrin slip 21, the outer ring 2 and the hub 3 are displaced relative to each other. Even when the tip of the labyrinth slip 21 and the inner surface of the rotary flange 12 are in sliding contact (contact), it is possible to prevent the circumferential stress from acting on the labyrinth slip 21. For this reason, in order to improve the sealing performance by the labyrin slip 21, the rigidity of the labyrin slip 21 is ensured, and the distance between the labyrin slip 21 and the hub 3 is shortened, so that the labyrin slip 21 and the hub 3 are reduced. Even when they are in sliding contact with each other, an increase in seal torque can be suppressed, and heat generation at the sliding contact portion can also be suppressed. Therefore, the inner surface of the flange 12 and the tip of the labyrinth slip 21 can be brought closer to each other, so that sufficient sealing performance can be secured in this example.

  Further, in the case of the conventional structure shown in the figure, the thickness dimension of the labyrinth slip 21 is secured and its rigidity is increased, so that foreign matters such as water droplets and pebbles are vigorously applied to the outer peripheral surface of the labyrinth slip 21. Even in the event of a collision, the labyrin slip 21 can be prevented from elastically deforming radially inward, and the foreign matter can be prevented from entering the inner diameter side of the labyrin slip 21. Further, since the inner peripheral surface of the tip half of the labyrin slip 21 is inclined in a direction in which the inner diameter increases toward the tip edge, even when foreign matter such as moisture enters the inner diameter side of the labyrin slip 21 This foreign matter can be effectively discharged toward the outside. Further, among the first half of the labyrinth slip 21, in a state where the wheel bearing rolling bearing unit 1 with a seal ring (see FIG. 7) is assembled to the vehicle, there are a plurality of portions located below the vehicle. Since the water drain hole 30a (30b) is provided, foreign matter such as moisture that has entered can be discharged to the outside through the water drain holes 30a (30b). For this reason, in the case of the conventional structure shown in FIGS. 8 to 10, it is possible to prevent water from being accumulated in the space between the labyrinth slip 21 and the seal lip 19a provided on the outermost radial direction.

However, even in the case of the conventional structure as described above, when the moisture blocked by the dam portion 31 provided so as to cover the outer peripheral surface of the outer ring 2 exceeds the allowable amount, There is a possibility of entering the labyrinth seals 28a and 28b through the outer peripheral surface of the seal ring 14a.
Further, when the rolling bearing unit 1 with a wheel support with a seal ring (see FIG. 7) is in use, foreign matter such as pebbles and muddy water splashed up by the wheel fixed to the rotation side flange 12 can be removed from the drain hole 30a ( 30b), it may enter the inner diameter side of the labyrinth slip 21 and adhere to the inner surface of the rotating flange 12. And the foreign material once adhered to the rotation side flange 12 on the inner diameter side of the labyrinth slip 21 is prevented from being discharged to the external space by the sealing effect of the labyrinth seals 28a and 28b.

JP-A-9-287619 US Pat. No. 5,831,675 JP 2003-120703 A JP 2007-177814 A Japanese Utility Model Publication No. 7-34226 Japanese Patent Laid-Open No. 2007-1000082 Japanese Utility Model Publication No. 7-44805 JP 2010-210085 A

  In view of the circumstances as described above, the present invention improves the sealing performance by the seal ring, further improves the effect of preventing foreign matter from entering the rolling element installation space, and has a wheel ring with a seal ring having excellent durability. This invention was invented to realize a bearing unit without increasing the rotational resistance. Moreover, an object of this invention is to implement | achieve the structure which can aim at the improvement of the handleability and transportability of a seal ring as needed.

The wheel support rolling bearing unit with a seal ring of the present invention includes, for example, an outer ring, a hub, a plurality of rolling elements, like the wheel support rolling bearing unit with a seal ring of the conventional structure shown in FIG. A flange and a seal ring.
The hub has an inner ring raceway at a portion of the outer peripheral surface facing the outer ring raceway, and is arranged concentrically with the outer ring.
Each of the rolling elements is provided between the outer ring raceway and the inner ring raceway so as to freely roll.
The flange is provided at a portion of the outer peripheral surface of the hub that protrudes outward from the outer end opening of the outer ring, and is used for supporting and fixing the wheel to the hub. .
The seal ring closes an outer end opening of an internal space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub.
Furthermore, the said flange consists of the thick part provided in the base end part, and the thin part provided in the front end part by the step part formed in the inner surface.
The seal ring includes a metal core fixed to the outer end of the outer ring and an elastic seal material reinforced by the metal core. The seal material is provided at least one seal lip that is in sliding contact with the inner surface of the flange or the outer peripheral surface of the hub over the entire circumference, and more radially outward than the seal lip, and its tip A hook-shaped labyrinth slip is provided, which is opposed to the inner surface of the flange over the entire circumference and forms a non-contact type labyrinth seal between the tip and the inner surface of the flange.

In the case of the rolling bearing unit for supporting a wheel with a seal ring according to the present invention, the tip of the labyrin slip is positioned radially outward from the step, and the tip and the step of the labyrin slip. Are overlapped in the radial direction so that the inner peripheral surface of the tip of the labyrin slip is closely opposed to the stepped portion (the outer peripheral surface thereof) over the entire periphery. In addition, among the sealing materials constituting the seal ring, an outer diameter dimension larger than an outer diameter dimension of an outer peripheral surface of the outer end portion of the outer ring is provided in a portion continuous inward from the base end portion of the labyrin slip. And the water stop part which protrudes to radial direction outward rather than the outer periphery of the outer end surface of the said outer ring | wheel is provided.
In particular, in the rolling bearing unit for supporting a wheel with a seal ring according to the present invention, the radially outer end or intermediate portion of the inner surface of the water stop portion, the inner peripheral surface on the outer peripheral surface of the outer ring, A collar portion is provided opposite to each other via an annular gap extending around the circumference.

  Further, when the present invention is carried out, preferably, as in the invention described in claim 2, a portion of the leading half of the labyrinth slip that is positioned below the vehicle in the assembled state to the vehicle is water. A hole is provided. In the seal ring, a scraping portion is provided at a position immediately above the drain hole provided in the assembled state in the vehicle, with a leading edge closely adjacent to the inner surface of the flange.

Further, when the present invention is carried out, it is preferable that, as in the invention described in claim 3, the outer periphery of the inner-half-side half projected from the outer-diameter-side half in the axial direction with respect to the outer-diameter-side half. The surface is a small-diameter portion, and the outer peripheral surface of this outer-diameter half and the outer peripheral surface of the labyrin slip are the single-cylindrical large-diameter portion. Further, the height in the radial direction of the step surface formed between the small diameter portion and the large diameter portion is made equal to the thickness in the radial direction of at least the first half portion of the labyrin slip.
Furthermore, the axial length of the small diameter portion is longer than the axial length of the leading half (outer half) of the labyrin slip, and a plurality of seal rings are overlapped in the axial direction, A groove is formed over the entire circumference between the step surface of one seal ring of a pair of seal rings adjacent in the axial direction and the leading edge of the labyrin slip of the other seal ring. To be formed.

According to the wheel bearing rolling bearing unit with a seal ring of the present invention configured as described above, the sealing performance by the seal ring is improved and the rolling element installation space is improved, as in the conventional structure shown in FIG. It is possible to realize a rolling bearing unit for supporting a wheel with a seal ring, which further improves the effect of preventing foreign matter intrusion and has excellent durability without increasing the rotational resistance.
In particular, in the case of the present invention, among the sealing materials constituting the seal ring, the portion that continues inward from the base end portion of the labyrin slip is larger than the outer diameter of the outer peripheral surface of the outer end portion of the outer ring. A water stop portion having a large outer diameter dimension and projecting radially outward from the outer peripheral edge of the outer end surface of the outer ring is provided, and further, at a radially outer end portion or an intermediate portion of the inner side surface of the water stop portion, A collar portion is provided so that the inner circumferential surface extends over the entire circumference and is opposed to the outer circumferential surface of the outer ring via an annular gap extending over the entire circumference. Therefore, as compared with the conventional structure shown in FIG. 8, it is possible to block the moisture adhering to the outer peripheral surface of the outer ring, which tries to enter the labyrinth seals along the outer peripheral surface of the outer ring. The capacity can be increased. Furthermore, this moisture flow direction can be converted to the opposite direction. Therefore, it is possible to effectively prevent moisture adhering to the outer peripheral surface of the outer ring from entering the labyrinth seal.
As a result, in the case of the present invention, the sealing performance by the seal ring is improved, the foreign matter intrusion prevention effect into the rolling element installation space is improved, and the wheel bearing rolling bearing unit with seal ring having excellent durability is obtained. This can be achieved without increasing the rotational resistance.

  According to the second aspect of the present invention, foreign matter such as pebbles and muddy water is passed through the drainage hole by the scraping portion provided immediately above the drainage hole in the assembled state to the vehicle. Can be prevented from entering. Even if these foreign matters enter the inner diameter side of the labyrinth slip, the foreign matter attached to the inner surface of the rotation side flange can be scraped out to the external space through the drain hole by the scraping portion.

Further, according to the invention according to claim 3, in the state in which a plurality of seal rings are stacked, the outer peripheral surface of each of the seal rings is a single cylindrical surface except for the portion where the groove is formed. At the time of so-called bar winding packaging, the above-described seal rings stacked in the axial direction are not easily eccentric.
In addition, when assembling the wheel bearing rolling bearing unit with seal ring according to the present invention, the nail of the distributor is hooked into the concave groove portion in a state in which each of the stick-wrapped seal rings is set in the distributor. Etc., it is possible to easily separate the seal rings wrapped in the above-mentioned bar winding.

The expanded sectional view equivalent to the a section of Drawing 7 showing the 1st example of an embodiment of the invention. Similarly, the expanded sectional view equivalent to the b section of Drawing 7 in a drain hole formation position. Cc sectional drawing of FIG. The partial expanded sectional view which shows the 2nd example of embodiment of this invention which shows the some seal ring stacked in the axial direction for the transportation. The figure similar to FIG. 1 which shows the 3rd example of embodiment of this invention. Similarly, 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 equivalent to the a section of Drawing 7 showing an example of the conventional structure. Similarly, the figure which shows a part of tip half part of a labyrin slip in the state seen from radial direction. Similarly, the figure similar to FIG. 9 which shows two examples of the shape of a drain hole.

[First example of embodiment]
1-3 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. Note that the feature of this example is that the water-stopping portion 34 and the soot for preventing water adhering to the outer peripheral surface of the outer ring 2 from passing through the outer peripheral surface of the outer ring 2 and entering the inner diameter side of the labyrin slip 21a. The structure of the portion 35 and foreign matters such as pebbles and muddy water are prevented from entering the inner diameter side of the labyrin slip 21a through the drain hole 30a (30b). In the case of intrusion, the scraped portion 36 has a structure for discharging these foreign matters to the outer diameter side of the labyrinth slip 21a. The structure and operation effect other than the seal ring 14b including the structure of the wheel bearing rolling bearing unit are substantially the same as those of the conventional structure shown in FIGS. Description and illustration are omitted or simplified, and the characteristic part of this example will be described below.

  Also in this example, the seal ring 14b is composed of a core metal 17a and a seal material 18a. The cored bar 17a is formed by bending a metal plate such as a mild steel plate. The fitting cylinder 22a and an annular ring bent radially outward from the outer edge of the fitting cylinder 22a. A portion 23a, a bent portion 24a folded back in the radial direction and axially outward from the inner end edge of the fitting tube portion 22a, and an inner portion in the axial direction from the outer peripheral edge of the ring portion 23a. A cylindrical portion 37 that is bent in the direction, and the fitting cylindrical portion 22a is fixed to the inner peripheral surface of the outer end portion of the outer ring 2 by an internal fitting and the inner side surface of the annular portion 23a is fixed. The outer ring 2 is abutted against the outer end surface of the outer ring 2 with a part of the sealing material 18a interposed therebetween.

  The sealing material 18a is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 17a. The sealing material 18a constitutes a labyrinth seal with three contact-type seal lips 19a, 19b, and 19c. The labyrinth slip 21a is provided. Each of the seal lips 19a to 19c is slidably contacted with the inner surface of the rotation side flange 12 or the outer peripheral surface of the intermediate portion of the hub 3 over the entire circumference.

  The outer peripheral surface of the labyrinth slip 21a is cylindrical, and its outer diameter is sufficiently larger than the outer diameter of the outer peripheral surface of the outer end portion of the outer ring 2. Furthermore, in the case of this example, the water stop part 34 and the collar part 35 are provided with the sealing material 18a which comprises the said seal ring 14b. Of these, the water stop 34 is a portion that is continuous inward from the base end of the labyrinth slip 21a, and of the circular ring portion 23a that constitutes the core metal 17a, than the outer peripheral edge of the outer ring 2 of the outer ring 2. It is configured by covering a portion protruding radially outward. The flange 35 is configured by covering a cylindrical portion 37 that is bent inward in the axial direction from the outer edge of the circular ring portion 23a. The inner diameter of the flange 35 is larger than the outer diameter of the outer peripheral surface of the outer end of the outer ring 2, and an annular gap is formed between the inner peripheral surface of the flange 35 and the outer end of the outer ring 2. 47 is provided over the entire circumference. In other words, the entire outer circumference of the outer end portion of the outer ring 2 is surrounded on three sides by the outer end portion outer peripheral surface of the outer ring 2, the water stop portion 34, and the flange portion 35, and is axially A concave groove having an inner opening is formed.

  Further, as in the conventional structure, as shown in FIG. 9, cut lines 29 and 29 each reaching the leading edge of the labyrin slip 21a are formed at a plurality of circumferential positions in the tip half of the labyrin slip 21a. ing. Further, the wheel support rolling bearing unit 1 with a seal ring (see FIG. 7) of the leading half of the labyrin lip 21a is assembled to the vehicle, and the portion (FIG. As shown in A) or (B), a drain hole 30a having a rectangular (or semi-elliptical) opening formed by removing a portion between the circumferentially adjacent cuts 29, 29. (30b) is provided.

  In the case of the present example, among the seal ring 14b, the wheel support rolling bearing unit 1 with a seal ring (see FIG. 7) is used in a position directly above the drain hole 30a (30b) in FIGS. A scraping portion 36 is provided as shown in FIG. The scraped portion 36 is a scraped portion that protrudes from the portion covering the outer surface of the annular ring portion 23a to the inner surface of the thick portion 26 of the rotating flange 12 among the elastic material constituting the seal ring 14b. It consists of surface portions 38, 38 and a concave surface portion 39 which is located radially inward of the opening of the drain hole 30a (30b) and is provided so as to be continuous with both of the scraped surfaces. These scraped surface portions 38, 38 and the concave surface portion 39 are inclined in a direction toward the radially outer side as at least the tip end portions are directed outward in the axial direction. Then, the scraped edge portions 40, 40 and the concave edge portion 41 formed at the leading edges of the scraped surface portions 38, 38 and the concave surface portion 39 are respectively connected to the thick wall portion 26 of the rotary side flange 12. It is close to the side.

In the case of this example, the angle θ formed by the two scraped edges 40, 40 and the rotation direction α of the rotary flange 12 is an acute angle (preferably about 20 to 40 degrees). Further, the outer peripheral surfaces of the outer diameter side tip portions of the both scraped surface portions 38, 38 are protruded radially outward from the thick portion 26 of the rotation side flange 12.
In the case of this example, the scraping portion 36 is located immediately above the opening of the drain hole 30a (30b) when the wheel bearing rolling bearing unit 1 with seal ring (see FIG. 7) is in use. A concave surface portion 39 provided in the portion to be recessed is recessed inward in the radial direction.

In the case of the rolling ring bearing unit with a seal ring of this example having the above-described configuration, the effect of preventing foreign matter from entering the inner diameter side of the labyrinth slip 21a is improved. Even when a foreign substance enters and adheres to the inner surface of the rotation side flange 12, a structure that can easily discharge the foreign substance can be realized.
That is, the outer peripheral surface of the outer end portion of the outer ring 2, the water stop portion 34 projecting radially outward from the outer peripheral edge of the outer end portion of the outer ring 2, and the outer diameter of the outer end portion of the outer ring 2. An annular gap 47 is provided around the outer end portion of the outer ring 2 by the flange portion 35 having a large inner diameter. For this reason, it is possible to prevent the water adhering to the outer peripheral surface of the outer ring 2 from reaching the outer peripheral surface of the labyrin slip 21a by the water stop portion 34. Furthermore, when the water blocked by the water stop 34 exceeds an allowable amount (volume of the annular gap 47), the water newly entering the water stop 34 along the outer ring 2 A part of the water in the annular gap 47 is pushed out. The pushed water is guided to the inner surface of the water stop 34 and the inner surface of the flange 35, the flow direction is reversed, and the outer surface of the outer ring 2 is axially inward. It is pushed back toward. Therefore, in the case of this example, as compared with the conventional structure as shown in FIG. 8, the moisture adhering to the outer peripheral surface of the outer ring 2 travels along the outer peripheral surface of the seal ring 14b, and the labyrinth seals 28a, 28b. It is possible to improve the effect of preventing intrusion.

Further, in the case of this example, the outer peripheral surface of the distal end portion on the outer diameter side of the pair of scraping surface portions 38, 38 constituting the scraping portion 36 provided immediately above the drain hole 30a (30b) It protrudes outward in the radial direction from the thick portion 26 of the rotation side flange 12. For this reason, both scraped surface portions 38, 38 enter the inside of the labyrin slip 21 a in the radial direction and adhere foreign matter such as pebbles and muddy water adhering to the inside surface of the rotating side flange 12 to the rotating side flange 12. In accordance with the rotational motion of the labyrinth, it is scraped out into the outer space on the outer diameter side of the labyrinth slip 21a. As a result, the amount of foreign matter existing on the inner diameter side of the labyrinth slip 21a can be suppressed to a small level, and the durability of the rolling bearing unit with seal ring 1 can be improved.
Furthermore, in the case of this example, the concave portion 39 of the scraping portion 36 located immediately above the drain hole 30a (30b) is recessed inward in the radial direction, so that the seal ring 14b and the rotation side flange are formed. Among the inner side surfaces of 12, foreign matters such as pebbles and muddy water repelled by the wheel fixed to the rotation side flange 12 can be efficiently collected on the outer diameter side portion of the scraping portion 36. And such a foreign material can make it difficult to adhere to the inner surface of the rotation side flange 12.

The scraping portion 36 as described above is formed integrally with the sealing material 18a when the sealing material 18a is injection molded or compression molded.
The drain hole 30a (30b) and the scraping portion 36 are a plurality of portions positioned below the vehicle when the wheel bearing rolling bearing unit 1 with a seal ring (see FIG. 7) is assembled to the vehicle. It may be provided at a location. In such a case, when the seal ring 14b is assembled, the pressing surface 32 existing in the portion of the sealing material 18a that covers the outer surface of the annular portion 23a is pressed by a seal pressing jig. In order to properly incorporate the seal ring 14b, the adjacent scraping portions 36 are discontinuous (a pressing surface 32 for pressing by a seal pressing jig is secured between the adjacent scraping portions 36).

[Second Example of Embodiment]
FIG. 4 shows a second example of an embodiment of the present invention corresponding to claims 1 and 3. In the case of this example, the inner diameter side half is protruded inward in the axial direction with respect to the outer diameter side half of the flange portion 35a, and the outer peripheral surface of the inner diameter side half is the small diameter portion 43. The outer peripheral surface of the outer diameter side half of the flange portion 35a and the outer peripheral surface of the labyrinth slip 21b are a large cylindrical portion 44 having a single cylindrical surface shape. Further, the height h of the step surface 45 between the small diameter portion 43 and the large diameter portion 44 is set to the thickness t (thickness) of the portion that is thinner than the base half portion at the tip half portion of the labyrin slip 21b. ) And errors that do not cause practical problems such as unavoidable manufacturing errors, are substantially equal (h≈t).
Further, the axial length W of the small diameter portion 43 is longer than the axial length D of the tip half of the labyrin slip 21b (W> D). For this reason, a plurality of seal rings 14c and 14c are overlapped in the axial direction while fitting the small diameter portion 43 and the leading half of the labyrinth slip 21b with the stepped surface 45 of one seal ring 14c. The recessed groove portions 46 are formed between the leading edge of the labyrin slip 21b of the other seal ring 14c.

As a result, in a state where the plurality of seal rings 14c and 14c are overlapped in the axial direction, the outer peripheral surface of each of the seal rings 14c and 14c is a single cylindrical surface except for the portion where the concave groove portions 46 and 46 are formed. It becomes a shape. For this reason, at the time of so-called bar winding packaging, the seal rings 14c and 14c stacked in the axial direction are not easily eccentric. For this reason, it is possible to facilitate stick-wrap packaging, and the transportability (transportability) of each seal ring 14c can be improved.
Further, when assembling the wheel bearing rolling bearing unit with seal ring according to the present invention, if the seal rings 14c, 14c wrapped around the rod are removed from the packaging and set in the distribution device, the groove 46 is formed in the groove 46. The hook-wrapped seal ring 14c can be easily separated by, for example, hooking the claw of the distribution device.
Other configurations and operational effects are substantially the same as in the case of the first example described above.

[Third example of embodiment]
FIGS. 5-6 has shown the 3rd example of embodiment of this invention corresponding to only Claim 1. FIG. In the case of this example, the labyrinth slip 21c is inclined in the direction toward the radially outer side as it goes toward the axially outer side. Moreover, the lip part 42 is formed in the inner end surface of the water stop part 34a. In an assembled state to the wheel support rolling bearing unit, the inner peripheral edge (tip edge) of the lip 42 contacts the outer peripheral surface of the outer ring 2 with a predetermined pressing force. For this reason, it can prevent more reliably that foreign materials, such as a water droplet, penetrate | invade from between the outer end part of this outer ring | wheel 2, and the said water stop part 34a.
Also, as shown in FIG. 6, a plurality of seal rings 14d and 14d are overlapped. As a result of the stick-wrapping as described above, even when the leading edge of the labyrin slip 21c is elastically deformed radially inward as shown by the phantom line in FIG. 6, the leading edge and the flange of the labyrin slip 21c The axial length of the fitting tube portion 22b is secured so that the inner end face of 35b does not interfere. As a result, the tip edge of the labyrinth slip 21c can be hardly damaged during the stick-wrapping, and the transportability (transportability) of each of the seal rings 14d and 14d can be improved.

  In the case of the first to third examples of the above-described embodiment, the seal ring is shaped to be fitted and fixed to the outer ring, but the shape of the seal ring is shaped to be fitted and fixed to the outer ring. It can also be. Further, the inventions described in claims 1 to 3 can be implemented in combination (simultaneously).

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-14d Seal ring 15 Internal space 16 Cover 17, 17a, 17b Core metal 18, 18a, 18b Sealing material 19a-19c Seal lip 21, 21a-21c Labyrin slip 22, 22a, 22b Fitting cylinder part 23, 23a, 23b Ring part 24, 24a Bent part 25 Step part 26 Thick part 27 Thin part 28a Radial labyrinth seal 28b Axial labyrinth seal 29 Cut line 30a, 30b Drain hole 31 Weir part 32 Press surface 33 Tip part 34 Water stop part 35, 35a, 35b collar part 36 scraping part 37 cylindrical part 38 Scratched surface part 39 Concave surface part 40 Scraped edge part 41 Concave edge part 42 Lip part 43 Small diameter part 44 Large diameter part 45 Step surface 46 Concave groove part 47 Annular gap

Claims (3)

The outer ring has an outer ring raceway on the inner peripheral surface and does not rotate while being supported by the suspension device, and the inner ring raceway is disposed in a portion of the outer peripheral surface facing the outer ring raceway, and is arranged concentrically with the outer ring. A hub, a plurality of rolling elements provided between the outer ring raceway and the inner ring raceway so as to be capable of rolling, and a portion of the outer peripheral surface of the hub projecting outward from the outer end opening of the outer ring. A flange for supporting and fixing the wheel to the hub, and a seal ring for closing the outer end opening of the internal space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub. Prepared,
The flange is formed by continuously forming a thick portion provided at the proximal end portion and a thin portion provided at the distal end portion by a step portion formed on the inner surface, and the seal ring includes It consists of a metal core fixed to the outer end of the outer ring and a sealing material made of an elastic material reinforced by this metal core, and this sealing material is arranged on the entire inner surface of the flange or the outer peripheral surface of the hub. At least one seal lip that is in slidable contact with the seal lip, and further provided radially outward from the seal lip, with its tip end closely facing the inner surface of the flange over the entire circumference, and the tip end and flange A labyrinth slip that forms a labyrinth seal with the inner surface of the labyrinth, and the tip of the labyrin slip is positioned radially outward from the step, and the tip and the step of the labyrin slip Are overlapped in the radial direction so that the inner peripheral surface of the tip end portion of the labyrin slip is closely opposed to the step portion over the entire circumference, and the base end of the labyrin slip among the sealing materials constituting the seal ring. A water stop portion having a larger outer diameter than the outer peripheral surface of the outer end portion of the outer ring and protruding outward in the radial direction from the outer peripheral edge of the outer end surface of the outer ring is provided in a portion that continues inward from the portion. In the wheel bearing rolling bearing unit with seal ring,
Provided at the radially outer end or intermediate portion of the inner surface of the water stop portion, and has a flange portion with the inner peripheral surface opposed to the outer peripheral surface of the outer ring with an annular gap extending over the entire circumference. A rolling bearing unit for wheel support with seal ring.   In the first half of the labyrinth slip, a drain hole is provided in a portion located below the vehicle in the assembled state to the vehicle, and in a state immediately above the drain hole in the assembled state to the vehicle. The rolling bearing unit for supporting a wheel with a seal ring according to claim 1, further comprising a scraping portion provided on the seal ring and having a leading edge closely adjacent to the inner surface of the flange.   A small-diameter portion that is an outer peripheral surface of the inner-diameter-side half projecting inward in the axial direction with respect to the outer-diameter-side half of the flange portion, and an outer-peripheral surface of the outer-diameter-side half and the labyrin slip. The radial height of the step portion formed between the large-diameter portion having a single cylindrical surface shape is equal to the thickness in the radial direction of at least the first half of the labyrin slip, and the small-diameter A pair of seal rings adjacent in the axial direction in a state where the axial length of the portion is longer than the axial length of the first half of the labyrin slip and a plurality of seal rings are overlapped in the axial direction A groove is formed over the entire circumference in the circumferential direction between the step surface of one of the seal rings and the tip edge of the labyrin slip of the other seal ring. It is described in any one of Claims 1-2. Seal ring with the wheel supporting rolling bearing unit.

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