JP2011226620A - Wheel supporting rolling bearing unit with seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a wheel supporting rolling bearing unit with a seal ring, capable of effectively preventing entry of foreign matter such as high viscous muddy water into an inner space 15 mounted with a rolling element 4.SOLUTION: The rolling bearing unit is mounted with an inner diameter side seal ring 17a having three seal lips between an inner circumferential surface of an outer end of an outer ring 2 and an outer circumferential surface of an intermediate part of a hub 3, and also an outer diameter side seal ring 18a with a canopy-like lip 20a on the outer circumferential surface of the outer end of the outer ring 2. Further, a drainage hole 21a is formed at a part positioned below a vehicle in a state of being installed to the vehicle, in the canopy-like lip 20a, and an opening width related to the circumferential direction of the drainage hole 21a is set to be 0.8% or more of the entire circumferential length of the canopy-like lip. This configuration can prevent clogging of a foreign matter such as high viscous muddy water in the opening of the drainage hole 21a, thus solving the problem.

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 present invention provides a wheel bearing rolling bearing unit with a seal ring that can effectively prevent foreign matter such as muddy water having high viscosity from entering the internal space where the rolling elements are installed.

  The wheels of the automobile are supported rotatably with respect to the suspension device by a wheel bearing rolling bearing unit 1 with a seal ring as shown in FIG. 16, 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, tapered rollers are used as the rolling elements. May be 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 internal space 15 cannot be sealed with the cover 16 as shown in FIG.

  In view of such circumstances, conventionally, various structures have been considered as a seal structure for the outer end opening of the internal space 15. FIG. 17 shows the structure described in Patent Document 1. In the case of the illustrated example, an inner diameter side seal ring 17 is mounted between the outer peripheral surface of the outer end of the outer ring 2 and the outer peripheral surface of the outer end of the inner ring 8 a constituting the hub 3. By mounting the outer diameter side seal ring 18 on the surface, the outer end opening of the inner space 15 is sealed. Of these, the outer diameter side seal ring 18 includes a cored bar 19 and a bowl-shaped lip 20 each formed in a substantially cylindrical shape. Of these, the core 19 is made of a metal plate such as a stainless steel plate, and is fitted and fixed to the outer end of the outer ring 2. The hook-shaped lip 20 is made of an elastic material such as rubber, and its base end portion is coupled and fixed to the outer end portion of the core metal 19 by insert molding or the like. The inner surface is slid over the entire circumference. Further, a drain hole 21 is provided in a portion located below the vehicle in the assembled state to the vehicle in the axially intermediate portion of the core metal 19. Accordingly, foreign matters such as rain water and muddy water that have entered the annular seal space 22 between the bowl-shaped lip 20 and the inner diameter side seal ring 17 are discharged to the outside through the drain hole 21.

  In the case of a wheel bearing rolling bearing unit with a seal ring having a conventional seal structure having such a seal structure, the collar-like lip 20 is slidably contacted with the inner surface of the rotary flange 12 over the entire circumference. Foreign matters such as rain water, muddy water, and sand particles are blocked by the bowl-shaped lip 20 and do not easily enter the portion where the inner diameter side seal ring 17 is installed. Therefore, compared to the case where the bowl-shaped lip 20 is not provided, foreign matter is less likely to enter the internal space 15. In addition, the foreign matter can be prevented from being caught in the sliding contact portion between the tip edge of the seal lip constituting the inner diameter side seal ring 17 and the outer peripheral surface of the outer end of the inner ring 8a. Damage to the leading edge can be prevented. For this reason, the sealing performance by each of these seal lips can be ensured over a long period of time.

  However, in the case of the conventional structure having the above-described structure, it is possible to sufficiently prevent the entry of foreign matter such as muddy water into the internal space 15 under severe conditions such as traveling on rough terrain. It becomes difficult. For example, when traveling on rough terrain such as muddy ground and wetland, highly viscous muddy water (hereinafter referred to as “highly viscous muddy water”) is splashed by the wheels and directly adheres to the surface of the outer diameter side seal ring 18. there is a possibility. In such a case, the highly viscous muddy water passes through the sliding contact portion between the tip edge of the bowl-shaped lip 20 and the inner surface of the rotary flange 12 and the drain hole 21 provided in the core metal 19. There is a possibility of entering the seal space 22. The high-viscosity mud that has entered in this manner has a high viscosity, unlike ordinary rainwater and mud, so that it is difficult to be discharged to the outside through the drain hole 21 and the drain hole 21 may be clogged. In particular, as in the case of the above-described conventional structure, when the size of the opening of the drain hole 21 is set to be extremely small from the viewpoint of preventing foreign matter from entering through the opening, high viscosity is obtained. Muddy water may clog the opening early. As a result, high-viscosity muddy water accumulates in the seal space 22, and even when a material having excellent sealing performance is used as the inner diameter side seal ring 17, the high-viscosity muddy water enters the internal space 15. It becomes difficult to prevent completely.

Moreover, in the case of the said conventional structure, it cannot be said that the rigidity of the said bowl-shaped lip 20 is sufficient from the surface which prevents the penetration | invasion of high viscous mud water and mud itself as mentioned above. In general, a hook-like lip for closing the outer end opening of the internal space has a large amount of protrusion in the axial direction, so that it is difficult to ensure sufficient rigidity due to its structure. Further, the hook-shaped lip has its tip edge closely adjacent to or slidably contacted with the inner surface of the rotation side flange at a radially outward position as compared with other seal lips. Therefore, it is possible to prevent generation of unpleasant noise (sliding contact noise), increase in rotational torque, and the like due to a change in the positional relationship between the leading edge of the bowl-shaped lip and the inner surface of the rotating flange. Accordingly, the rigidity of the bowl-shaped lip is often set small. As described above, the rigidity of the hook-shaped lip has not been sufficiently increased so far. However, when traveling on the rough terrain as described above, rainwater, etc. There is a possibility that high-viscosity mud water and mud itself, which are heavy in weight, collide vigorously. For this reason, when the rigidity of the bowl-shaped lip is not sufficient, the bowl-shaped lip is greatly elastically deformed, and highly viscous muddy water or mud enters from between the tip edge of the bowl-shaped lip and the inner surface of the rotating flange. It becomes easy to do. Further, in the case of the conventional structure, the metal contact portion between the inner peripheral surface of the cored bar 19 constituting the outer diameter side seal ring 18 and the outer peripheral surface of the outer end portion of the outer ring 2 is exposed to the outside. There is also a possibility that foreign matters such as rain water and muddy water may enter through this portion.
As other prior art documents related to the present invention, there are inventions described in Patent Documents 2 to 5. However, none of the inventions described in Patent Documents 2 to 5 can sufficiently solve the above-described problems.

JP 2007-270960 A JP 2007-64356 A JP 2007-2884 A JP 2007-64459 A JP 2008-261409 A

  In view of the circumstances as described above, the present invention has been invented to realize a wheel bearing rolling bearing unit with a seal ring that can effectively prevent foreign matter such as highly viscous mud from entering the internal space where the rolling elements are installed. Is.

Each of the wheel support rolling bearing units with a seal ring according to the present invention is similar to the above-described wheel support rolling bearing unit with a seal ring shown in FIG. 16, and includes an outer ring, a hub, and a plurality of rolling elements. And a flange and a seal ring.
Of these, the outer ring has an outer ring raceway on the inner peripheral surface and does not rotate while being supported by the suspension device.
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 on 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 to support and fix the wheel to the hub.
The seal ring is for closing the outer end opening of the inner space existing between the inner peripheral surface of the outer ring and the outer peripheral surface of the hub, and is a core fixed to the outer end portion of the outer ring. It is comprised from gold | metal | money and the sealing material made from an elastic material reinforced with this core metal. Of these, the sealing material has at least one sealing lip that is in sliding contact with the inner surface of the flange or the outer peripheral surface of the hub over the entire periphery.

In particular, in the case of the rolling bearing unit with a wheel support with a seal ring according to claim 1, the tip thereof is more radially outward than the seal lip provided on the outermost radial direction among the seal lips. A hook-like lip having an edge that is in close proximity to or in sliding contact with the inner side surface of the flange is provided integrally with or separately from the seal ring.
In addition, a drainage hole is provided in a portion of the bowl-shaped lip located below the vehicle in the assembled state to the vehicle, and the opening width in the circumferential direction of the drainage hole is set to the total circumferential length of the bowl-shaped lip. 0.8% or more (preferably 15% or less).

Further, in the case of the rolling bearing unit for supporting a wheel with a seal ring according to claim 2, the fitting cylinder portion in which the core metal constituting the seal ring is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring. And an annular portion bent at a right angle from the axial outer end edge of the fitting tube portion to the outside in the radial direction.
In addition, the base end of the sealing lip is disposed radially outward from the sealing lip provided at the outermost radial direction, and the base end of the sealing material is covered with the annular base. In a continuous state, a hook-like lip is provided with its front end edge in close proximity or slidably contacting the inner surface of the flange over the entire circumference.
And the outer peripheral edge part of the said annular ring part is located in radial direction outward rather than the inflection point (starting point of bending) of this bowl-shaped lip and the said annular ring-shaped base part.

Further, in the case of the rolling bearing unit for supporting a wheel with a seal ring according to claim 3, the fitting cylinder portion in which the core metal constituting the seal ring is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring. And an annular portion bent at a right angle from the axial outer end edge of the fitting tube portion to the outside in the radial direction.
Further, among the seal lips, the seal material is disposed more radially outward than the seal lip provided at the outermost radial direction and radially outward from the outer peripheral surface of the outer end portion of the outer ring. A flange-like lip is provided in which the tip end edge of the ring-shaped base part covering the ring part is continuously opposed or slid over the entire circumference of the inner surface of the flange. .
Further, a rib-shaped rigid reinforcing portion is provided in a state of being continuous inward from the base end portion of the bowl-shaped lip.

Furthermore, in the case of the rolling bearing unit with a wheel support with a seal ring according to claim 4, the outer peripheral surface and the outer end surface of the outer ring are made continuous by the chamfered portion.
Further, the metal core constituting the seal ring is fitted into a fitting cylinder portion that is fitted and fixed to the inner peripheral surface of the outer end of the outer ring, and perpendicularly outward in the radial direction from an axial outer end edge of the fitting cylinder portion. It is assumed that it is provided with an annular part that is bent in a circle. In addition, the outer diameter of the annular ring is made larger than the outer diameter of the outer end of the outer ring, and the inner surface of the annular ring is directly abutted against the outer end of the outer ring.
Further, among the seal lips, the seal material is disposed more radially outward than the seal lip provided at the outermost radial direction and radially outward from the outer peripheral surface of the outer end portion of the outer ring. A flange-like lip is provided in which the tip end edge of the ring-shaped base part covering the ring part is continuously opposed or slid over the entire circumference of the inner surface of the flange. .
In addition, a dam portion having a conical concave shape whose inner peripheral surface shape matches the outer peripheral surface shape of the chamfered portion is provided at a portion located on the inner side of the annular portion at the proximal end portion of the bowl-shaped lip. The inner peripheral surface of the weir portion is brought into contact with the chamfered portion over the entire periphery.

According to the rolling bearing unit for supporting a wheel with a seal ring of the present invention configured as described above, a highly viscous mud is placed in the internal space where the rolling elements are installed even under severe conditions such as traveling on uneven terrain. It is possible to effectively prevent the entry of foreign substances such as.
That is, in the case of the invention described in claim 1 of the present invention, the opening width in the circumferential direction of the drain hole formed in the bowl-shaped lip is 0.8% or more of the total circumferential length of the bowl-shaped lip. And big enough. For this reason, even when a foreign matter such as highly viscous mud enters the seal space, the opening of the drain hole can be prevented from being clogged, and the foreign matter can be efficiently discharged to the outside through the drain hole. Therefore, it is possible to effectively prevent foreign matters such as highly viscous mud from reaching the internal space where the rolling elements are installed.
In addition, in the case of the inventions described in claims 2 and 3 of the present invention, since the rigidity of the bowl-shaped lip can be sufficiently increased, foreign matter such as highly viscous mud or mud is formed on the outer peripheral surface of the bowl-shaped lip. Even in the case of a collision, it is possible to effectively prevent the hook-shaped lip from being greatly elastically deformed. Further, the protruding amount of the hook-shaped lip in the axial direction can be increased. For this reason, it is possible to prevent foreign matters such as highly viscous muddy water and mud from entering the seal space. Therefore, it is possible to effectively prevent foreign matters such as highly viscous mud and mud from entering the internal space where the rolling elements are installed.
Furthermore, in the case of the invention described in claim 4 of the present invention, the metal contact portion between the outer end surface of the outer ring and the inner side surface of the annular ring part constituting the core metal is arranged on the base end side of the bowl-shaped lip. The provided weir can cover the entire circumference. For this reason, it can prevent effectively that foreign materials, such as rain water and muddy water, penetrate | invade through this metal contact part. Therefore, it is possible to effectively prevent foreign matters such as rainwater and muddy water from entering the internal space where the rolling elements are installed.
As described above, in any of the inventions described in claims 1 to 4, even when the usage environment is severe, such as traveling on rough terrain, the highly viscous mud water or the like is placed in the internal space where the rolling elements are installed. It is possible to effectively prevent foreign matter from entering.

FIG. 17 is an enlarged cross-sectional view corresponding to the portion of FIG. 16 showing a first example of an embodiment of the present invention. The schematic diagram which shows the state which took out the outer diameter side seal ring and was seen from the right side of FIG. FIG. 3B is a schematic diagram (B) showing a second example of the embodiment of the present invention, and is an enlarged view (A) corresponding to a portion of FIG. 2 and viewed from below (A). Schematic views (B) and (A) showing a third example of the embodiment of the present invention, showing enlarged views (A) and (A) corresponding to part (a) of FIG. B Enlarged sectional view (C). The enlarged view equivalent to the (i) part of FIG. 2 which shows the same 4th example. The figure similar to FIG. 3 which shows the said 5th example. The figure similar to FIG. 1 which shows the 6th example. The figure similar to FIG. 1 which shows the said 7th example. The figure similar to FIG. 1 which shows the 8th example. The figure similar to FIG. 1 which shows the 9th example. FIG. 11 is an enlarged sectional view of a portion C in FIG. 10. The figure similar to FIG. 1 which shows the 10th example of embodiment of this invention. The figure similar to FIG. 1 which shows the 11th example. The figure similar to FIG. 1 which shows the 12th example. The double section expanded sectional view of 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. FIG. 17 is an enlarged cross-sectional view corresponding to the portion of FIG. 16 showing an example of a conventional structure.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to claim 1. The feature of this example is the structure of the portion that efficiently discharges foreign matter such as highly viscous muddy water into the outside (annular seal space 22a) of the bowl-shaped lip 20a. Since the configuration and operation effect other than the seal structure of the outer end opening portion of the internal space 15 including the configuration of the wheel bearing rolling bearing unit are substantially the same as those of the conventional structure described above, overlapping explanation and The illustration is omitted or simplified, and the characteristic part of this example will be described below.

  Also in the case of this example, the hook-shaped lip 20a is provided separately from the inner diameter side seal ring 17a attached between the outer peripheral surface of the outer end portion of the outer ring 2 and the outer peripheral surface of the intermediate portion of the hub 3. That is, also in this example, the inner diameter side seal ring 17a is mounted between the outer 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 the outer end of the outer ring 2 is also mounted. An outer diameter side seal ring 18a provided with the flange-shaped lip 20a is mounted on the outer peripheral surface.

  The inner diameter side seal ring 17a is composed of a cored bar 23 and a sealing material 24 each formed in an annular shape. Of these, the core 23 is made of a metal plate and is fitted and fixed to the outer end of the outer ring 2. The sealing material 24 is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 23 by adhesion or the like by injection molding or compression molding. The sealing material 24 includes three contact-type seal lips 25a, 25b, and 25c. Of these seal lips 25a to 25c, two seal lips 25a and 25b, called the outer lip side and the middle, called side lips, slidably contact with the inner surface of the rotation side flange 12 over the entire circumference. I am letting. On the other hand, the inner peripheral side seal lip 25c called a radial lip is in sliding contact with the outer peripheral surface of the intermediate portion of the hub 3 over the entire periphery.

  On the other hand, the outer diameter side seal ring 18a includes a cored bar 19a and the collar-shaped lip 20a. The core metal 19a is formed by bending a metal plate such as a stainless steel plate, and includes a cylindrical portion 26 that is fitted and fixed to the outer end portion of the outer ring 2, and an outer edge of the cylindrical portion 26. The ring portion 27 is bent at a right angle outward in the radial direction. The bowl-shaped lip 20a is made of an elastic material such as an elastomer such as rubber, and is provided on the outermost radial direction of the seal lips 25a, 25b, 25 constituting the inner diameter side seal ring 17a. It is located radially outward from the seal lip 25a. The hook-shaped lip 20a has a base end portion fixedly coupled to the annular ring portion 27, and a tip edge thereof is in sliding contact with the inner side surface of the rotation-side flange 12 over the entire circumference. More specifically, the tip edge of the flange-shaped lip 20a is slid to the radially outer portion of the inner surface of the rotating flange 12 rather than the portion provided with the step portion 28 having a concave arcuate cross section. Touching. In the case of this example, the tip of the bowl-shaped lip 20a is formed in a partially conical cylindrical shape that is inclined in a direction in which the outer diameter increases as it approaches the inner surface of the rotation-side flange 12. The thickness is reduced from the proximal side to the distal side. Furthermore, in the case of this example, the entire outer surface of the annular portion 27 is covered by the base end portion of the bowl-shaped lip 20a. This prevents the ring portion 27 (core metal 19a) from being rusted by being exposed to foreign matter such as highly viscous mud that has entered the seal space 22a. Further, a nose gasket 48 bulging (protruding) radially inward is formed on the inner peripheral edge of the portion of the base end portion of the bowl-shaped lip 20a that covers the outer surface of the annular ring portion 27, Foreign matter such as muddy water is prevented from entering the gap between the outer peripheral surface of the outer end 2 of the outer ring 2 and the inner peripheral surface of the cylindrical portion 26. FIG. 1 and FIGS. 7, 8, and 9 described later show the shape of the nose gasket 48 in a free state. In the case of this example, a continuous portion (base) of a portion of the hook-shaped lip 21a that covers the outer surface of the annular portion 27 and a portion that protrudes outward in the axial direction while being bent from this portion. The inflection point between the end and the end is smoothly continuous. As a result, capillary action is prevented, and water such as water droplets adhering to the bowl-shaped lip 20a (the outer surface and inner peripheral surface thereof) can be efficiently guided to the drain hole 21a described later. Further, from the viewpoint of improving the drainage, the surface of the bowl-shaped lip 20a can be subjected to water repellent treatment.

In the case of this example, a drainage hole 21a opened at the leading edge of the bowl-shaped lip 20a is provided in a portion of the bowl-shaped lip 20a that is positioned below the vehicle when assembled to the vehicle. Yes. The drain hole 21a has a shape such that the middle part or the tip edge of the bowl-shaped lip 20a is cut out into a substantially trapezoidal shape (semi-elliptical shape). Particularly in the case of this example, the size of the opening of the drain hole 21a is made sufficiently larger than that of the above-described conventional structure in order to improve the discharge performance of the highly viscous mud water. Specifically, the opening width L _21a in the circumferential direction of the drain hole 21a, approximately 1/120 to the entire peripheral length L 15% 0.8% or more of _all the following {L _all of the eave-shaped lip 20a 1/6 and the central angle θ is about 3 to 60 degrees. In the example shown in the figure, 10% (1/10) of L _all and the central angle θ is regulated to 36 degrees}. Also, the opening width W _21a in the axial direction of the drain hole 21a, is smaller than the height H ₂₈ in the axial direction of the stepped section _{28 (W 21a <H 28)} .

In the case of this example having the above-described configuration, it is sufficient that foreign matter such as highly viscous mud water enters the internal space 15 where the rolling elements are installed even under severe conditions such as traveling on rough terrain. Can be prevented.
That is, in this example, the opening width L _21a in the circumferential direction of the drain hole 21a formed in the bowl-shaped lip 20a is set to 0.8% or more of the total circumferential length L _all of the bowl-shaped lip 20a. It is big enough. For this reason, even when foreign matter such as highly viscous muddy water enters the seal space 22a through the sliding contact portion between the tip edge of the bowl-shaped lip 20a and the inner surface of the rotary flange 12 and the drain hole 21a. The opening of the drain hole 21a can be effectively prevented from being clogged with foreign matter such as high-viscosity mud, and the foreign matter such as high-viscosity mud can be efficiently discharged to the outside through the drain hole 21a. For example, when the vehicle is stopped, foreign matter such as highly viscous mud water that has entered the seal space 22a flows down to the road surface due to the action of gravity, and is quickly discharged to the outside through the drain hole 21a. On the other hand, when the vehicle is running, foreign matter such as highly viscous muddy water that has entered the seal space 22a flows down to the road surface due to the action of gravity, and the tip edge of the bowl-shaped lip 20a and the rotation. It gathers in the sliding contact part with the inner surface of the side flange 12 and its vicinity. And most of them are discharged from the drain hole 21a as they are, and the rest are rotated along the inner peripheral surface of the tip edge portion of the bowl-shaped lip 20a by the inner surface of the rotating flange 12. Then, while reaching the lower portion of the bowl-like lip 20a again, it is discharged from the drain hole 21a to the outside along the inner surface of the rotary flange 12 by the action of centrifugal force and gravity. In this way, in this example, foreign matter such as highly viscous mud that has entered the seal space 22a through the drain hole 21a can be efficiently discharged. For this reason, it is possible to prevent foreign matter such as highly viscous mud from accumulating in the seal space 22a, and it is difficult for foreign matter such as highly viscous muddy water to reach the portion where the inner diameter side seal ring 17a is installed. As a result, it is possible to effectively prevent foreign matters such as highly viscous mud water from entering the internal space 15 in which the rolling elements 4 are installed.

Further, in the case of this example, the opening width W _21a in the axial direction of the drain hole 21a is made smaller than the height dimension H ₂₈ in the axial direction of the step portion 28, so that it enters through the drain hole 21a. It is possible to prevent foreign matter such as highly viscous mud from directly adhering to the seal lip 25a provided on the outermost side (side closer to the outside) of the inner diameter side seal ring 17a. For this reason, it is possible to effectively prevent foreign matter such as highly viscous muddy water from being caught in the sliding contact portion between the tip edge of the seal lip 25a and the inner surface of the rotary flange 12, and the inner diameter side seal ring 17a. The seal performance can be secured over a long period of time. Therefore, it is possible to effectively prevent foreign matters such as highly viscous mud from entering the internal space 15 from such a surface.

It should be noted that foreign matter such as highly viscous muddy water is generated when the vehicle is traveling at a low speed or immediately before stopping, such as the inner surface of the rotating flange 12, the outer peripheral surface of the hook-shaped lip 20a, and the tips of the hook-shaped lips 20a. When adhering to a sliding contact portion between the edge and the inner side surface of the rotation side flange 12, most of it flows down the road surface side along the inner side surface of the rotation side flange 12. However, in the case of this example, since the drain hole 21a is provided with the opening facing the road surface, foreign matters such as highly viscous muddy water flowing down as described above may be the opening of the drain hole 21a. Does not enter the seal space 22a. Further, as the opening width L _21a of the drain hole 21a is increased, the amount of foreign matter such as highly viscous mud that enters the seal space 22a through the drain hole 21a increases. Since the foreign matter such as the highly viscous mud that has entered can be efficiently discharged to the outside through the drain hole 21a, the increase in the amount of intrusion does not become a problem. However, from the viewpoint of reducing the intrusion amount of foreign matter itself, it is preferable to use the wheel bearing rolling bearing unit with seal ring of this example for a driven wheel surrounded by a drum brake.

In the above description, a contact seal type structure in which the tip edge of the bowl-shaped lip 20a is slidably contacted with the inner surface of the rotary flange 12 over the entire circumference has been described. It can also be applied to labyrinth seals and shields. The drain hole 21a formed in the bowl-shaped lip 20a has the shape shown in the figure if the opening width L _{21a in} the circumferential direction is 0.8% or more of the total circumferential length L _all of the bowl-shaped lip 20a. Without limitation, various shapes can be adopted. The drain hole 21a is not limited to a structure provided in the lower part of the bowl-shaped lip 20a, and a plurality of drain holes 21a may be provided. Further, the bowl-shaped lip 20a can be provided integrally with the inner diameter side seal ring 17a (seal material 18a). In this case, it is possible to reduce the number of parts and the number of assembly steps, and the cost of the rolling bearing unit for supporting the wheel with the seal ring can be reduced.

[Second Example of Embodiment]
FIG. 3 shows a second example of the embodiment of the present invention, which also corresponds to claim 1. The feature of this example is that the structure of the first example of the embodiment described above is devised to increase the rigidity around the opening of the drain hole 21b formed in the bowl-shaped lip 20b. That is, in the case of this example, the thickness around the opening of the drain hole 21b of the bowl-shaped lip 20b is increased as it approaches the opening of the drain hole 21b. Forming. In the case of this example, the thick portion 29 is formed by increasing the thickness of the outer peripheral surface side of the bowl-shaped lip 20a (raising the outer peripheral surface side).

In the case of this example having such a configuration, the rigidity around the opening of the drain hole 21b can be increased. For this reason, foreign matter such as highly viscous muddy water adhering to the inner peripheral surface of the bowl-shaped lip 20b can be stably guided to the opening of the drain hole 21b along the inner peripheral surface, and stable discharge performance. Can be demonstrated. In addition, since the peripheral portion of the opening of the drain hole 21b can be prevented from being drowned, the sealing performance can be improved.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Third example of embodiment]
FIG. 4 shows a third example of the embodiment of the present invention, which also corresponds to the first aspect. Also in the case of this example, similarly to the case of the second example of the above-described embodiment, the rigidity of the peripheral portion of the drain hole 21c formed in the bowl-shaped lip 20c is increased. Particularly in the case of this example, only the thickness of the outer peripheral edge of the lower part of the bowl-shaped lip 20c is increased as it approaches the opening of the drain hole 21c. A rib-like thick portion 29a is formed in the vicinity. Also in this example, the thick portion 29a is formed by increasing the thickness of the outer peripheral surface of the bowl-shaped lip 20c. In the case of this example having such a configuration, the material cost of the elastic material constituting the bowl-shaped lip 20c can be suppressed lower than in the case of the second example, and the wheel bearing rolling bearing unit with seal ring can be suppressed. Cost reduction.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Fourth Example of Embodiment]
FIG. 5 shows a fourth example of the embodiment of the present invention, which also corresponds to the first aspect. In the case of this example, the portion located below the vehicle in the assembled state to the vehicle in the middle portion or the tip edge portion of the cone-shaped bowl-shaped lip 20d is cut linearly (for example, with a horizontal plane) A drain hole 21d is formed in the portion by cutting it off in a parallel plane. In the case of this example having such a configuration, the drain hole 21d can be easily processed, and the processing cost can be reduced.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Fifth Example of Embodiment]
FIG. 6 shows a fifth example of the embodiment of the present invention, which also corresponds to the first aspect. In the case of this example, a part of the inner peripheral surface of the saddle-shaped lip 20e, which is located below the vehicle in the assembled state to the vehicle, is recessed radially outward ( By partially inflating the outer peripheral surface radially outward), a tunnel-like drain hole 21e is formed in the portion. In the case of this example having such a configuration, the sliding between the peripheral edge portion 30 of the drain hole 21e and the inner side surface of the rotation side flange 12 (see FIG. 1) among the front edge of the bowl-shaped lip 20e. The contact state can be made three-dimensionally. For this reason, the sliding contact state between the peripheral edge portion 30 of the opening and the inner side surface of the rotation-side flange 12 can be stabilized.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Sixth Example of Embodiment]
FIG. 7 shows a sixth example of the embodiment of the present invention, which also corresponds to the first aspect. The feature of this example is that the shape of the stepped portion 28a provided on the inner surface of the rotation side flange 12 is devised, and foreign matters such as highly viscous muddy water that has entered the seal space 22b are efficiently discharged to the outside. For this reason, in the case of this example, the step portion 28a has a substantially U-shaped cross-section, and this step portion 28a functions as a so-called screw-back against foreign matter such as highly viscous mud. That is, in the case of this example, the seal space 22b is passed through the sliding contact portion between the tip edge of the bowl-shaped lip 20a and the inner surface of the rotary flange 12 and the drain hole 21a formed in the bowl-shaped lip 20a. Foreign matter such as highly viscous mud that has entered the inside can be rebounded radially outward by the step portion 28a. For this reason, foreign matter such as highly viscous muddy water is prevented from directly adhering to the inner diameter side seal ring 17a (seal lip 25a) installed 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. In addition, foreign matter such as highly viscous mud that has entered can be discharged to the outside through the drain hole 21a at an early stage.
In addition to the substantially U-shaped cross-sectional shape of the stepped portion 28a, for example, a substantially L-shaped cross-sectional shape may be adopted to change the traveling direction of the invading foreign matter (from the radial direction to the axial direction). it can. Even when such a configuration is adopted, substantially the same effect as that obtained when the substantially U-shape is adopted can be obtained.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Seventh example of embodiment]
FIG. 8 shows a seventh example of the embodiment of the present invention, which also corresponds to the first aspect. The feature of this example is that the slinger 31 is fitted on the outer peripheral surface of the intermediate portion of the hub 3 so that the shape of the stepped portion 28 provided on the inner side surface of the rotation side flange 12 is left as it is, and foreign matter such as highly viscous mud water that has entered. Is efficiently discharged to the outside. In the case of this example, the slinger 31 is formed by bending a metal plate such as a stainless steel plate so as to have a substantially L-shaped cross section and an overall ring shape. The ring portion 33 is bent radially outward from the end edge, and the rebound portion 34 is bent slightly from the outer peripheral edge of the ring portion 33 into a crank shape. In such a slinger 31, the cylindrical portion 32 is externally fitted to the outer peripheral surface of the intermediate portion of the hub 3 with an interference fit, whereby a part of the circular ring portion 33 and the rebound portion 34 are attached to the rotating flange 12. It is fixed to the hub 3 in a state where it abuts against the inner surface.

  Also, in this state, of the seal lips 25a to 25c constituting the inner diameter side seal ring 17a, the tip edge of the seal lip 25c, which is a radial lip, is slidably contacted with the outer peripheral surface of the cylindrical portion 32, and is also an axial lip. The leading edges of the seal lips 25a, 25b are brought into sliding contact with the inner surface of the circular ring portion 33, respectively. Further, the tip edge of the flange-shaped lip 20a constituting the outer diameter side seal ring 18a is in a radially outer portion than the rebound portion 34, and is in sliding contact with the inner surface of the rotation side flange 12 over the entire circumference. .

In the case of the present example having the above-described configuration, a sliding contact portion between the tip edge of the bowl-shaped lip 20a and the inner side surface of the rotation-side flange 12 by the bounce portion 34 provided on the slinger 31 and the flange Foreign matter such as highly viscous mud that has entered through the drain hole 21a formed in the lip 20a can be rebounded radially outward. For this reason, it is possible to effectively prevent foreign matter such as highly viscous mud from adhering to the inner diameter side seal ring 17a (seal lip 25a), and it is possible to quickly discharge the foreign matter that has entered through the drain hole 21a. Further, in the case of this example, since it is not necessary to process the rotating flange 12, the processing cost can be reduced and the problem of stress and the like due to the complicated shape of the stepped portion 28 can be obtained. It never happens.
About another structure and an effect, it is the same as that of the case of the 1st example of embodiment mentioned above.

[Eighth Example of Embodiment]
FIG. 9 shows an eighth example of the embodiment of the present invention, which also corresponds to the first aspect. Also in the case of this example, as in the case of the seventh example of the embodiment described above, the slinger 31a is used to efficiently discharge foreign matter such as highly viscous mud that has entered the seal space 22c. In the case of this example, the slinger 31a has a substantially J-shaped cross section and is configured in a substantially annular shape as a whole, and is provided with a rebound portion 34a on the inner peripheral edge thereof. The slinger 31a having such a configuration is fixed to the inner surface of the rotation side flange 12 by using a stud 13 for supporting and fixing the wheel. In the case of this example, the leading edge of the bowl-shaped lip 20a is made to face and face the inner side surface of the ring-shaped main body 35 constituting the slinger 31a over the entire circumference.

  Also in the case of this example having such a configuration, the bounce portion 34a provided in the slinger 31a causes a minute gap between the tip edge of the bowl-shaped lip 20a and the inner side surface of the rotation-side flange 12, and the bowl-like shape. Foreign matter such as highly viscous mud that has entered through the drain hole 21a formed in the lip 20a can be rebounded radially outward. For this reason, it is possible to effectively prevent foreign matter such as highly viscous mud from adhering to the inner diameter side seal ring 17a (seal lip 25a), and it is possible to quickly discharge the foreign matter that has entered through the drain hole 21a. Further, since it is not necessary to process the step portion 28 provided on the rotation side flange 12, the processing cost can be reduced, and problems such as stress are caused due to the complicated shape of the step portion 28. It never happens. In the case of this example, the assembling work of the slinger 31a can be facilitated, and the assembling cost can be reduced.

[Ninth Embodiment]
10 to 11 show a ninth example of the embodiment of the invention corresponding to claim 2. The feature of this example is that the radial position of the outer peripheral edge portion of the annular ring portion 40 constituting the core metal 37 is regulated in order to increase the rigidity of the bowl-shaped lip 20f. Since the configuration and operation effects other than the seal structure of the outer end opening of the internal space 15 including the configuration of the wheel bearing rolling bearing unit are substantially the same as the conventional structure described above, the overlapping description and illustration are Omitted or simplified, the characteristic part of this example will be described below.

  In the case of this example, the hook-shaped lip 20 f is provided integrally with a seal ring 36 mounted between the outer peripheral surface of the outer end portion of the outer ring 2 and the outer peripheral surface of the intermediate portion of the hub 3. The seal ring 36 is composed of the core metal 37 and the seal member 38, and the core metal 37 is formed by bending a metal plate such as a mild steel plate, The ring portion 40 is bent radially outward from the outer end edge of the fitting tube portion 39, and the bent portion 41 is bent into a crank shape from the inner end edge of the fitting tube portion 39. Yes. Of these, the fitting tube portion 39 is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring 2, and the inner surface of the annular portion 40 is connected to the outer end surface of the outer ring 2 with the sealing material 38 ( Of which is abutted via an annular base 42).

  The sealing material 38 is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the core metal 37 by adhesion or the like by injection molding or compression molding. The sealing material 38 includes three contact-type seal lips 25a, 25b, and 25c, and the bowl-shaped lip 20f. Each of the seal lips 25a to 25c is in sliding contact with the inner peripheral surface of the rotary flange 12 or the outer peripheral surface of the intermediate portion of the hub 3 over the entire circumference, and the respective base end portions of the seal lips 25a to 25c. It is connected to a bent portion 41 constituting the core metal 37. On the other hand, the flange-shaped lip 20f is provided radially outward from the seal lip 25a provided most radially outward of the seal lips 25a to 25c. In a state where the base end portion is continuous with the annular base portion 42 covering the annular portion 40 constituting the core metal 37, the tip end edge thereof is slid and contacted with the inner surface of the rotation side flange 12 over the entire circumference. I am letting.

In particular, in the case of this example, the outer diameter dimension of the circular ring portion 40 is sufficiently large (in this case, sufficiently larger than the outer diameter dimension of the outer end portion of the outer ring 2), and The outer peripheral edge portion of the annular ring portion 40 is positioned radially outward from the inflection point (the fold line starting point portion shown in FIG. 11) between the lip 20f and the annular base portion 42. ing. As a result, as shown in the figure, the outer peripheral edge portion of the annular ring portion 40 is located at the root portion (base end portion) of the bowl-shaped lip 20f. In addition, the thickness t ₄₀ of the portion located radially outward from the inflection point in the annular portion ₄₀ is 0.1 mm or more, and the seal ring 36 at the inflection point portion has a thickness t ₄₀ or more. is set to 90% of the thickness T _alpha follows the axial direction _{(0.1mm ≦ t ≦ 0.9T α)} . The thickness t ₄₀ becomes smaller than 0.1 mm, the metal core 37 stiffness of itself is lowered, it becomes difficult to increase the rigidity of the eave-shaped lip 20f. On the contrary, when the plate thickness t ₄₀ is larger than 90% of the thickness dimension T _α , the thickness of the sealing material 38 (annular base portion 42) becomes relatively small (thinner), and again It becomes difficult to sufficiently increase the rigidity of the bowl-shaped lip 20f. In addition, the flow of the material (elastic material) when the sealing material 38 is molded also deteriorates.

In the case of this example having the above-described configuration, since the rigidity of the bowl-shaped lip 20f can be sufficiently increased, even when highly viscous mud water or mud itself collides with the outer peripheral surface of the bowl-shaped lip 20f vigorously. Thus, it is possible to effectively prevent the hook-shaped lip 20f from being greatly elastically deformed. For this reason, it is possible to prevent foreign matters such as highly viscous muddy water and mud from entering the seal space 22c. Further, the protruding amount of the hook-shaped lip 20f in the axial direction can be increased. Accordingly, it is possible to effectively prevent foreign matters such as highly viscous mud water and mud from entering the internal space 15 in which the rolling elements 4 are installed. In the case of this example, since the width dimension in the radial direction of the circular ring portion 40 is large, when the seal ring 36 is assembled (press-fitted) to the outer end portion of the outer ring 2, a seal press-fitting jig is used. Since the front end surface is easily pressed against the annular portion 40 (via the sealing material 38), the workability of the assembling work is good.
In the above description, the tip edge of the hook-like lip 20f is described in the case where the tip edge of the hook-like lip 20f is slidably contacted with the inner side surface of the rotary flange 12. However, the tip edge of the hook-like lip 20f is A labyrinth seal may be provided at the portion facing the inner surface of the rotation side flange 12 in proximity. Further, the shape of the bowl-shaped lip 20f is not limited to the structure shown in the figure, and various shapes can be used as long as the outer peripheral edge of the annular portion 40 is located radially outward from the inflection point. Can be adopted. Furthermore, the structure of this example and the structures of the first to eighth examples of the embodiment described above can be combined as appropriate.

[Tenth example of embodiment]
FIG. 12 shows a tenth example of the embodiment of the present invention corresponding to the third aspect. Also in the case of this example, like the case of the ninth example of the embodiment described above, the hook-shaped lip 20g is mounted between the outer peripheral surface of the outer end of the outer ring 2 and the outer peripheral surface of the intermediate portion of the hub 3. It is provided integrally with the seal ring 36a. The seal ring 36a is composed of a core metal 37a and a seal material 38a, and the core metal 37a is formed by bending a metal plate such as a mild steel plate, and includes a fitting tube portion 39a, An annular portion 40a that is bent radially outward from the outer end edge of the fitting tube portion 39a, and a bent portion 41a that is bent into a crank shape from the inner end edge of the fitting tube portion 39a. . Of these, the fitting tube portion 39a is fitted and fixed to the inner peripheral surface of the outer end of the outer ring 2, and the inner surface of the annular portion 40a is connected to the outer end surface of the outer ring 2 with the sealing material 38a ( It is abutted via an annular base 42a).

  The sealing material 38a is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 37a by bonding or the like by injection molding or compression molding. The sealing material 38a includes three contact-type seal lips 25a, 25b, and 25c, and the bowl-shaped lip 20g. Each of the seal lips 25a to 25c 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. Is coupled to the bent portion 41a constituting the core metal 37a. On the other hand, the bowl-shaped lip 20g has a thick cylindrical shape and is provided radially outward from the seal lip 25a provided most radially outward of the seal lips 25a to 25c. Of the sealing material 38a, with the base end portion continuous to the annular base portion 42a that covers the ring portion 40a that constitutes the core metal 37a, the front end edge is on the inner surface of the rotary flange 12. It is made to face and oppose all over the circumference through a minute gap.

  In particular, in the case of this example, as in the case of the ninth example described above, the outer diameter of the annular portion 40a is not increased, and the outer diameter of the annular portion 40a is set to the outer end portion of the outer ring 2. It is almost the same as the outer diameter. And the outer-diameter side half part 43 of the said annular | circular shaped base part 42a which is not reinforced by this annular part 40a is provided in the radial direction outward rather than the outer periphery part of this annular part 40a. For this reason, in the case of this example, the thickness dimension in the axial direction of the outer diameter side half 43 is sufficiently large (the plate of the annular portion 40a is larger than the thickness dimension in the axial direction of the inner diameter side half 44). The rigidity of the outer diameter side half 43 is sufficiently secured.

  In the case of this example, the base end portion of the bowl-shaped lip 20 g is continued to the outer peripheral edge portion of the outer diameter side half portion 43. In this state, the flange-shaped lip 20g is positioned radially outward from the outer peripheral surface of the outer end portion of the outer ring 2. Further, the outer side surface of the outer diameter side half 43 and the inner peripheral surface of the bowl-shaped lip 20g are smoothly continued. As a result, capillarity is prevented, and water such as water droplets adhering to the outer surface of the outer diameter side half 43 and the inner peripheral surface of the bowl-shaped lip 20g is removed from the leading edge of the bowl-shaped lip 20g and the rotation-side flange. 12 so that it can be efficiently guided to the minute gap between the inner surface of the twelve. Also in the case of this example, the outer surface of the outer diameter side half 43 and the inner peripheral surface of the bowl-shaped lip 20g may be subjected to water repellent finishing. Further, as the outer side surface of the outer diameter side half portion 43 and the inner peripheral surface of the bowl-shaped lip 20g are smoothly connected, the thickness of the bowl-shaped lip 20g in the radial direction is made larger than that of the tip portion. It is enlarged at the base end. Further, the thickness in the radial direction of the tip end portion is substantially the same as the thickness in the axial direction of the outer diameter side half portion 43. In particular, in the case of this example, the rib-shaped rigid reinforcing portion 45 having substantially the same shape as the hook-shaped lip 20g is provided in a state continuously inward from the base end of the hook-shaped lip 20g. It is provided around the circumference. As a result, the thick section of the seal ring 36a is substantially T-shaped, which is composed of only the sealing material 38a (the outer diameter side half 43, the bowl-shaped lip 20g, and the rigid reinforcing portion 45) on the outer diameter side half of the seal ring 36a. A shape part is provided.

  Also in the case of this example having the above-described configuration, the rigidity of the bowl-shaped lip 20g can be sufficiently increased as in the case of the ninth example. For this reason, even when highly viscous mud or mud itself collides with the outer peripheral surface of the bowl-shaped lip 20g vigorously, it is possible to effectively prevent the bowl-shaped lip 20g from being elastically deformed. For this reason, it is possible to prevent foreign matters such as highly viscous muddy water and mud from entering the seal space 22d. Accordingly, it is possible to effectively prevent foreign matters such as highly viscous mud water and mud from entering the internal space 15 in which the rolling elements 4 are installed. Such a wheel support bearing unit with a seal ring provided with the seal ring 36a of the present example can exert its effect even more when used in combination with a disc brake in which a stepping stone or the like is likely to be generated as the vehicle travels. . That is, intrusion of stepping stones can be effectively prevented.

  In the case of this example, since the outer diameter of the annular portion 40a constituting the core metal 37a can be reduced, the weight of the core metal 37a can be reduced and the cost can be reduced by reducing the amount of metal material used. I can plan. Further, the processing of the core bar 37a is facilitated, and the joining work of the sealing material 38a to the core bar 37a is facilitated. For this reason, the manufacturing efficiency can be improved and the manufacturing cost can be reduced.

  Furthermore, in the case of this example, since the outer peripheral surface of the seal ring 36a is a single cylindrical surface, the seal rings 36a stacked in the axial direction are difficult to be eccentric during so-called stick-wrap packaging. For this reason, it is easy to perform bar-wrapping and the transportability (transportability) of each of the seal rings 36a can be improved. Further, even when each seal ring 36a wrapped in a bar is set in a constant distribution device, the seal rings 36a stacked in the axial direction are not easily eccentric. For this reason, the mounting workability of the seal ring 36a can be improved.

When the seal rings 36a are stacked in the axial direction, the seal-like lips 20g and the seal-like lips 20g and the seal lips 25a and 25b, which are axial lips, do not come into contact with a part of the adjacent seal rings 36a. The length dimension in the axial direction of the rigid reinforcing portion 45 can also be regulated. By adopting such a configuration, it is possible to prevent the seal lips 25a and 25b from being deformed even when stick-wrapped, and to easily hold the grease previously applied to the lips 25a and 25b. Yes.
It should be noted that the structure of this example, the structure of the ninth example of the above-described embodiment, and further the structure of the first to eighth examples can be combined as appropriate.

[Eleventh example of embodiment]
FIG. 13 shows an eleventh example of the embodiment of the present invention, which also corresponds to the third aspect. In the case of this example, unlike the case of the tenth example of the above-described embodiment, the bowl-shaped lip 20h is a partial cone that is inclined in a direction in which the outer diameter increases as it approaches the inner surface of the rotation side flange 12. In addition to the cylindrical shape, the thickness in the radial direction is reduced from the proximal side toward the distal side. In the case of this example, the leading edge of the flange-shaped lip 20h is in sliding contact with the inner surface of the rotary flange 12 over the entire circumference. In the case of this example having such a configuration, it is possible to prevent foreign matter such as highly viscous muddy water from entering the seal space 22e and to enter the seal space 22e as compared to the case of the tenth example. The foreign matter such as the highly viscous muddy water can be guided to the tip edge side of the bowl-shaped lip 20h by using the inner peripheral surface (inclined surface) of the bowl-shaped lip 20h. For this reason, when a drainage hole is formed in the bowl-shaped lip 20h, foreign matters such as highly viscous mud can be efficiently discharged to the outside through the drainage hole.
About another structure and an effect, it is the same as that of the case of the 10th example of embodiment mentioned above.

[Twelfth example of embodiment]
14 to 15 show a twelfth example of the embodiment corresponding to claims 2 and 4. The feature of this example is to prevent foreign matter such as rainwater and muddy water from entering the internal space 15 through the contact portion between the metal of the outer end surface of the outer ring 2 and the ring part 40b constituting the cored bar 37b. In the structure. Also in the case of this example, the hook-shaped lip 20 i is provided integrally with a seal ring 36 b mounted between the outer peripheral surface of the outer end portion of the outer ring 2 and the outer peripheral surface of the intermediate portion of the hub 3. The seal ring 36b is composed of the core metal 37b and the sealing material 38b, and the core metal 37b is formed by bending a metal plate such as a mild steel plate, and includes a fitting tube portion 39b. The ring portion 40b is bent radially outward from the outer end edge of the fitting tube portion 39b, and the bent portion 41b is bent from the inner end edge of the fitting tube portion 39b into a crank shape. Yes. Of these, the fitting tube portion 39b is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring 2, and the inner side surface of the annular portion 40b is directly abutted against the outer end surface of the outer ring 2. . In the case of this example, the outer peripheral surface of the outer end 2 and the outer end surface of the outer ring 2 are continuous by a chamfer 46.

  The sealing material 38b is made of an elastic material such as an elastomer such as rubber, and is bonded and fixed to the cored bar 37b by bonding or the like by injection molding or compression molding. The sealing material 38b includes three contact-type seal lips 25a, 25b, 25c and the bowl-shaped lip 20i. Each of the seal lips 25a to 25c 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. Is coupled to the bent portion 41b constituting the core metal 37b. On the other hand, the bowl-shaped lip 20i is provided radially outward from the seal lip 25a provided most radially outward among the seal lips 25a to 25c. In the state where the base end portion is continued to the annular base portion 42b that covers the outer surface of the annular portion 40b that constitutes the core metal 37b, the distal end edge is formed on the inner surface of the rotary flange 12 over the entire circumference. It is in contact with slid. In the case of this example, the hook-like lip 20 i is provided radially outward from the outer peripheral surface of the outer end portion of the outer ring 2.

  As in the case of the ninth example of the above-described embodiment, the outer peripheral edge portion of the annular portion 40b is located radially outward from the inflection point between the flange-like lip 20i and the annular base portion 42b. Is located. In particular, in the case of this example, the inner peripheral surface shape matches the outer peripheral surface shape of the chamfered portion 46 in the portion located on the inner side of the annular portion 40b in the base end side portion of the bowl-shaped lip 20i. A dam 47 having a conical concave shape is provided. The inner peripheral surface of the dam portion 47 is brought into contact with the chamfered portion 46 over the entire circumference.

In the case of this example having the above-described configuration, the weir provided with a metal contact portion between the outer end surface of the outer ring 2 and the inner side surface of the circular ring portion 40b on the base end side of the bowl-shaped lip 20i. The portion 47 can cover the entire circumference. For this reason, it can prevent effectively that foreign materials, such as rain water and muddy water, penetrate | invade through this metal contact part. Further, in the case of this example, a plurality of window holes (not shown) for suppressing the cored bar 37b at the time of vulcanization molding are provided on the outer surface of the annular base portion 42b constituting the sealing material 38b in the circumferential direction. . For this reason, since the sealing material 38b can be vulcanized while the core bar 37b is supported from both side surfaces, the positional accuracy of the sealing material 38b can be stabilized. Accordingly, it is possible to stabilize the tightening allowance of each of the seal lips 25a to 25c and the tightening allowance (or minute gap) of the hook-shaped lip 21i.
It should be noted that the structure of this example and the structures of the first to eleventh examples of the above-described embodiment can be combined as appropriate.
About another structure and an effect, it is the same as that of the case of the 1st example and 9th example of embodiment mentioned above.

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-14c Seal ring DESCRIPTION OF SYMBOLS 15 Internal space 16 Cover 17, 17a Inner diameter side seal ring 18, 18a Outer diameter side seal ring 19, 19a Core metal 20, 20a-20i Corrugated lip 21, 21a-21e Drain hole 22, 22a-22e Seal space 23 Core metal 24 Seal material 25a to 25c Seal lip 26 Cylindrical part 27 Annular part 28, 28a Step part 29, 29a Thick part 30 Opening peripheral part 31, 31a Slinger 32 Cylindrical part 33 Circular part 34, 34a Bounce part 35 Main part 36, 36a, 36b Seal ring 37, 37a, 3 b Core metal 38, 38a, 38b Sealing material 39, 39a, 39b Fitting cylinder part 40, 40a, 40b Ring part 41, 41a, 41b Bent part 42, 42a, 42b Ring-shaped base part 43 Outer diameter side half part 44 Inner diameter Side half 45 Rigid reinforcement 46 Chamfer 47 Weir 48 Nose gasket

Claims (4)

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. The seal ring includes a cored bar fixed to the outer end of the outer ring, and a sealing material made of an elastic material reinforced by the cored bar. At least slidably contact the inner surface or the outer peripheral surface of the hub Having one sealing lip, in the sealing ring with the wheel supporting rolling bearing unit,
Of the above-mentioned seal lips, a flange-like lip whose tip edge is closely opposed or slid over the entire circumference of the inner surface of the flange more radially outward than the seal lip provided radially outward Is provided integrally or separately from the seal ring, and a drainage hole is provided in a portion of the bowl-shaped lip located below the vehicle when assembled to the vehicle. A rolling bearing unit for supporting a wheel with a seal ring, characterized in that the opening width in the circumferential direction is 0.8% or more of the total circumferential length of the bowl-shaped lip. 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. The seal ring includes a cored bar fixed to the outer end of the outer ring, and a sealing material made of an elastic material reinforced by the cored bar. At least slidably contact the inner surface or the outer peripheral surface of the hub Having one sealing lip, in the sealing ring with the wheel supporting rolling bearing unit,
A fitting tube portion in which the core metal is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring; and an annular portion bent at a right angle radially outward from an axial outer end edge of the fitting tube portion; With
Among the sealing lips, the base end portion is made to be continuous with the annular base portion that covers the annular portion of the sealing material more radially outward than the sealing lip provided on the outermost radial direction. In this state, a hook-like lip is provided in which the tip edge thereof is closely opposed or slid over the entire inner surface of the flange.
A rolling bearing unit for supporting a wheel with a seal ring, characterized in that an outer peripheral edge portion of the annular ring portion is located radially outward from an inflection point between the flange-shaped lip and the annular ring-shaped base portion. 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. The seal ring includes a cored bar fixed to the outer end of the outer ring, and a sealing material made of an elastic material reinforced by the cored bar. At least slidably contact the inner surface or the outer peripheral surface of the hub Having one sealing lip, in the sealing ring with the wheel supporting rolling bearing unit,
A fitting tube portion in which the core metal is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring; and an annular portion bent at a right angle radially outward from an axial outer end edge of the fitting tube portion; With
Among the sealing lips, the circle of the sealing materials is more radially outward than the sealing lip provided at the outermost radial direction and radially outer than the outer peripheral surface of the outer end of the outer ring. In a state where the base end portion is continuous with the annular base portion covering the ring portion, a hook-like lip is provided in which the tip edge thereof is closely opposed or slid over the entire inner surface of the flange,
A rolling bearing unit for supporting a wheel with a seal ring, characterized in that a rib-like rigidity reinforcing portion is provided in a state of being continuous inward from the base end portion of the bowl-shaped lip. 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. The seal ring includes a cored bar fixed to the outer end of the outer ring, and a sealing material made of an elastic material reinforced by the cored bar. At least slidably contact the inner surface or the outer peripheral surface of the hub Having one sealing lip, in the sealing ring with the wheel supporting rolling bearing unit,
The outer peripheral surface and outer end surface of the outer ring of the outer ring are continuous by the chamfered portion,
A fitting tube portion in which the core metal is fitted and fixed to the inner peripheral surface of the outer end portion of the outer ring; and an annular portion bent at a right angle radially outward from an axial outer end edge of the fitting tube portion; The outer diameter of the annular part is larger than the outer diameter of the outer end of the outer ring, and the inner side of the annular part is directly abutted against the outer end of the outer ring. And
Among the sealing lips, the circle of the sealing materials is more radially outward than the sealing lip provided at the outermost radial direction and radially outer than the outer peripheral surface of the outer end of the outer ring. In a state where the base end portion is continuous with the annular base portion covering the ring portion, a hook-like lip is provided in which the tip edge thereof is closely opposed or slid over the entire inner surface of the flange,
A dam portion having a conical concave shape whose inner peripheral surface shape matches the outer peripheral surface shape of the chamfered portion is provided in a portion located on the inner side of the annular ring portion at the proximal end portion of the bowl-shaped lip. A wheel bearing rolling bearing unit with a seal ring, wherein the inner peripheral surface of the weir portion is in contact with the chamfered portion over the entire circumference.

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