JP6730786B2 - Wheel bearing device - Google Patents

Description

The present invention relates to a wheel bearing device that rotatably supports a wheel of an automobile or the like with respect to a suspension device. More specifically, the sealability of a seal attached to the bearing portion is ensured and the torque of the bearing is reduced. And a bearing device for a wheel.

BACKGROUND ART Conventionally, a wheel bearing device for supporting a wheel of an automobile or the like rotatably supports a hub wheel for mounting the wheel via a double row rolling bearing, and there are a drive wheel and a driven wheel. For structural reasons, the inner wheel rotation method is generally used for drive wheels, and both the inner wheel rotation method and outer wheel rotation method are generally used for driven wheels. Further, the wheel bearing device has a structure called a first generation in which a wheel bearing, such as a double-row angular contact ball bearing, is fitted between a knuckle and a hub wheel that form a suspension device. A second generation structure in which a vehicle body mounting flange or a wheel mounting flange is directly formed on the outer circumference of a member, a third generation structure in which one inner raceway is directly formed on the outer circumference of a hub wheel, or a hub wheel, etc. It is roughly classified into a fourth generation structure in which inner raceways are directly formed on the outer circumference of the outer joint member of the universal joint.

In such a bearing device for a wheel, the grease enclosed in the bearing is prevented from leaking, and it is exposed to rainwater or muddy water directly. A seal having various sealing properties is attached. In recent years, the bearing device for a wheel of this type used under such a severe environment is required to have a longer life. Incidentally, among the seals, as the one having particularly improved sealing property, a seal member provided with a seal lip is attached to an outer member serving as a fixed side member, and the seal lip is slidably contacted with a slinger attached to the inner member. A composite type seal, a so-called pack seal, is commonly used.

Conventionally, various proposals have been made for seals having improved hermeticity, and a typical example of such a seal is shown in FIG. This seal 51 seals an annular space between an inner peripheral side member 52 formed of a bearing inner ring and the like and an outer peripheral side member 53 formed of a bearing outer ring and the like, and is attached to the inner peripheral side member 52 and the outer peripheral side member 53, respectively. And a ring-shaped seal plate 54 and a slinger 55 which are L-shaped in cross section and face each other.

The slinger 55 has a cylindrical portion 56 press-fitted into the outer diameter surface of the inner peripheral member 52, a standing wall portion 57 rising from the cylindrical portion 56, and a tip portion of the standing wall portion 57 along the axial direction A. A first bent portion 58 is formed by bending the seal plate 54 side. Further, the tip end portion of the first bent portion 58 is bent to the opposite side along the axial direction A to form a second bent portion 59, and the tip end portion is bent outward in the radial direction R to make a third bend. The part 60 is formed.

The seal plate 54 is formed by integrally joining a seal member 62 made of an elastic material such as rubber or synthetic resin to a core metal 61 having an L-shaped cross section by vulcanization adhesion. It is attached by press fitting to the inner diameter surface of. The seal member 62 is provided so as to cover the inside of the core metal 61, and has a first lip portion 63, a second lip portion 64, and a third lip portion 65. The first lip portion 63 is in sliding contact with the standing wall portion 57 of the slinger 55, and the second and third lip portions 64, 65 are in sliding contact with the cylindrical portion 56 of the slinger 55.

Crank-shaped labyrinth portions 66 and 67 are formed between the outer peripheral surfaces of the second bent portion 59 and the third bent portion 60 of the slinger 55 and the inner peripheral surface 62a of the seal member 62 to prevent intrusion of muddy water or the like from the outside. It can be prevented (for example, refer to Patent Document 1).

However, in this conventional seal 51, since the second and third lip portions 64 and 65 formed of two radial lips are slidably contacted with the cylindrical portion 56 of the slinger 55 via the radial direction interference, when the bearing is rotated, The rotation resistance (friction) increases due to the sliding resistance.

On the other hand, a seal 70 as shown in FIG. 7 is known as a seal with reduced rotational torque. The seal 70 includes a slinger 71 and an annular seal plate 72 which are arranged to face each other. The slinger 71 has a substantially L-shaped cross section, and includes a cylindrical portion 71a that is press-fitted into the inner ring 68, and a standing plate portion 71b that extends radially outward from the cylindrical portion 71a.

The seal plate 72 is attached to the outer member 69, and includes a core metal 73 and a seal member 74 vulcanized and adhered to the core metal 73, and is formed in an annular shape as a whole in a substantially L-shaped cross section. The cored bar 73 includes a cylindrical portion 73a that is fitted inside the end of the outer member 69, and a standing plate portion 73b that extends radially inward from the cylindrical portion 73a.

The seal member 74 is made of an elastic member such as nitrile rubber, has no radial lip, and has first and second side lips 74a and 74b that are in sliding contact with the standing plate portion 71b of the slinger 71. These first and second side lips 74a, 74b are formed so as to be inclined from the standing plate portion 73b of the cored bar 73 toward the outer diameter side, and their tips are slid on the standing plate portion 71b of the slinger 71 with an axial simming. It is touched. A labyrinth portion 75 is formed between the inner end portion 74c of the seal member 74 and the cylindrical portion 71a of the slinger 71. As a result, high sealing performance can be secured and the torque of the bearing can be reduced (see, for example, Patent Document 2).

JP, 2010-91036, A JP, 2007-100828, A

In such a conventional seal 70, the radial lip is eliminated and the sealing performance is improved by the two first and second side lips 74a and 74b. On the other hand, the radial lip is eliminated, so that it is enclosed inside the bearing. There is a possibility that the lubricating grease may leak to the outside through the labyrinth portion 75 and the first and second side lips 74a and 74b.

The present invention has been made in view of such a conventional problem, and assures high sealing performance while suppressing an increase in rotational torque of the seal, and prevents grease leakage to improve durability of the bearing. Another object of the present invention is to provide a bearing device for a wheel.

In order to achieve such an object, the invention according to claim 1 of the present invention has a vehicle body mounting flange integrally mounted on the outer periphery for attachment to a knuckle, and a double row outer rolling surface integrally formed on the inner periphery. The formed outer member, the inner member on the outer periphery of which the double row inner rolling surface facing the double row outer rolling surface is formed, and both rolling of the inner member and the outer member For a wheel provided with a double row rolling element housed between the surfaces so as to be rollable, and seals mounted on both side openings of an annular space formed between the outer member and the inner member. In the bearing device, the seal on the inner side of the seals is composed of a composite type seal composed of a slinger and an annular seal plate that are arranged to face each other, and the slinger is a cylinder fitted onto the inner member. And a standing plate portion extending radially outward from the cylindrical portion, the seal plate being press-fitted into the inner circumference of the inner end of the outer member, and vulcanization-bonded to the core metal. The sealing member is integrally joined by means of, and this sealing member does not have a radial lip that slidably contacts the cylindrical portion of the slinger with a radial squeeze, but extends from the inner edge portion of the core metal into a bifurcated shape. And a second side lip extending inward in the radial direction and a second side lip extending inward in the radial direction. These first and second side lips are provided on the slinger. While being slidably contacted to the plate portion with axial skeletons, an annular protrusion that curves from the outer edge of the standing plate portion of the slinger to the outer side, and faces the inner end surface of the outer member, A disk portion that extends radially outward from the end of the protrusion, and an annular umbrella member is press-fitted to the outer periphery of the inner end of the outer member, and from the inner end of the umbrella member The flange portion protruding outward in the radial direction and the disk portion of the slinger face each other through an axial clearance, and the tip of the metal core of the seal plate is axially arranged from the inner end surface of the outer member. And the slinger faces the seal plate, the inner end surface of the outer member, and the umbrella member through a U-shaped cross section to form a labyrinth portion.

As described above, in the wheel bearing device including the seals attached to both side openings of the annular space formed between the outer member and the inner member, the seals on the inner side of the seals are arranged to face each other. The slinger is composed of a composite type seal composed of a slinger and an annular seal plate, and the slinger has a cylindrical portion externally fitted to the inner member, and a standing plate portion extending radially outward from the cylindrical portion, The seal plate is composed of a cored bar press-fitted to the inner circumference of the inner side end of the outer member, and a seal member integrally bonded to the cored bar by vulcanization adhesion. There is no radial lip that slidably contacts with the radial direction, and it splits in a bifurcated form from the base part that wraps around the inner edge of the core metal and is joined to the first side lip that extends radially outward and inclines radially. The slanted second side lips are provided, and the first and second side lips are slidably contacted with the slinger standing plate by axial skeletons, respectively, and from the outer edge of the slinger standing plate to the outer side. An annular protrusion that extends in a curved shape and faces the inner end surface of the outer member, and a disc portion that extends radially outward from the end of this protrusion, An annular umbrella member is press-fitted to the outer circumference of the end portion, and the flange portion and the disk portion of the slinger projecting radially outward from the end portion on the inner side of the umbrella member face each other through the axial clearance, The tip of the core metal of the seal plate projects axially from the inner end surface of the outer member, and the slinger has a U-shaped cross section between the seal plate and the inner end surface of the outer member and the umbrella member. Since the labyrinth portion is configured to face each other via the wheel, it ensures high sealing performance while suppressing an increase in rotational torque of the seal, and prevents grease leakage to improve bearing durability. A bearing device can be provided.

Further, as in the invention according to claim 2 , a locking portion is formed at an end portion of the cylindrical portion of the slinger by bending outward in the radial direction, and the locking portion is formed on the base portion of the seal member. If they overlap each other in the radial direction through the axial clearance, it is possible to prevent the slinger and the seal plate from separating during the assembly process to the bearing and during transportation, and also to assemble both members into a unit to assemble the bearing. Therefore, the assembling ability can be simplified and the assembling accuracy can be improved.

Further, as in the invention according to claim 3 , the base portion of the seal member faces the cylindrical portion of the slinger via a radial clearance, and has an L-shaped cross section between the cylindrical portion and the locking portion of the slinger. If the labyrinth portion is formed, the leakage of the lubricating grease sealed inside the bearing can be further prevented and the durability of the bearing can be improved.

A bearing device for a wheel according to the present invention integrally has a vehicle body mounting flange for mounting on a knuckle on an outer periphery, and an outer member integrally formed with a double row outer rolling surface on an inner periphery, and an outer member on an outer periphery. An inner member having a double-row inner rolling surface facing the outer rolling surface of the double row, and an inner member rotatably accommodated between the inner rolling member and the outer rolling surface of the outer member. In a bearing device for a wheel, comprising a double row rolling element and seals mounted on both side openings of an annular space formed between the outer member and the inner member, an inner side of the seals. Is composed of a composite type seal composed of a slinger and an annular seal plate which are arranged to face each other, and the slinger has a cylindrical portion externally fitted to the inner member, and a radial outside of the cylindrical portion. And a sealing member integrally joined to the core by vulcanization bonding, the core being press-fitted into the inner circumference of the inner end of the outer member. , The sealing member does not have a radial lip that slidably contacts the cylindrical portion of the slinger with a radial interference, and is split into a forked shape from a base portion that is wrapped around the inner edge portion of the core metal and is inclined outward in the radial direction. A first side lip extending in a radial direction and a second side lip extending inward in a radial direction, and the first and second side lips slidably contact the standing plate portion of the slinger with an axial shamiro. In addition, an annular projecting portion that curves from the outer edge of the standing plate portion of the slinger to the outer side and faces the inner end surface of the outer member, and radially outward from the end portion of the projecting portion. A disc portion extending to the outer member, and an annular umbrella member is press-fitted to the outer periphery of the inner side end portion of the outer member, and a flange portion that projects radially outward from the inner side end portion of the umbrella member, The disk portions of the slinger face each other through an axial clearance, and the tip end of the core metal of the seal plate projects in the axial direction from the inner end surface of the outer member, and the slinger is the seal plate. Since the labyrinth portion is configured to face the inner end surface of the outer member and the umbrella member via a U-shaped cross section , the seal torque is high while suppressing an increase in rotational torque. It is possible to provide a bearing device for a wheel that ensures the sealing property and prevents grease from leaking to improve the durability of the bearing.

1 is a vertical cross-sectional view showing an embodiment of a wheel bearing device according to the present invention. It is a principal part enlarged view which shows the seal of the vehicle center side of FIG. It is a principal part enlarged view which shows the modification of the seal of FIG. It is a principal part enlarged view which shows the other modification of the seal of FIG. It is a principal part enlarged view which shows the other modification of the seal of FIG. It is a principal part enlarged view which shows the conventional seal. It is a principal part enlarged view which shows another conventional seal.

An outer member integrally formed with a vehicle body mounting flange for attachment to a knuckle on the outer periphery, and an outer member integrally formed with a double row outer rolling surface on the inner periphery, and a wheel mounting flange for attaching a wheel to one end. A hub wheel integrally formed with one inner raceway facing the double row outer raceway and a small diameter step extending axially from the inner raceway, and the hub wheel. An inner member formed of an inner ring that is press-fitted into a small-diameter step portion and has the other inner rolling surface that faces the outer rolling surfaces of the double row on the outer periphery, and both the inner member and the outer member. A double row rolling element accommodated between rolling surfaces so as to be freely rollable, and seals mounted on both side openings of an annular space formed between the outer member and the inner member are provided. In a bearing device for a wheel, a seal on an inner side of the seals is composed of a composite type seal composed of a slinger and an annular seal plate which are arranged to face each other, and the slinger is a cylinder fitted onto the inner ring. Part, a standing plate part extending radially outward from the cylindrical part, and an L-shape along the inner end shape of the outer member via a bent part extending from the outer edge of the standing plate part to the inner side. And a seal in which the sealing plate is provided with a umbrella-shaped portion, and the seal plate is press-fitted into the inner circumference of the inner end of the outer member, and the core metal is integrally bonded to the core metal by vulcanization adhesion. This seal member is formed of a member, and is divided into a forked shape from a base portion that is wrapped around and joined to an inner edge portion of the cored bar, and is inclined inward in the radial direction with a first side lip that is inclined and extends outward in the radial direction. And a second side lip extending in parallel with each other, and the first and second side lips are slidably contacted to the standing plate portion of the slinger with axial shimeros, respectively, and inside the end portion on the inner side of the outer member. An annular recess is formed around the circumference, and the bent portion and the umbrella portion of the slinger are arranged to face the recess of the outer member and the inner end surface and the outer peripheral surface of the outer member through a U-shaped cross section. The labyrinth portion is formed between the outer surface of the outer member and the outer surface of the end portion.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing an embodiment of a wheel bearing device according to the invention, FIG. 2 is an enlarged view of a main part of a seal on a vehicle center side of FIG. 1, and FIG. FIG. 4 is an enlarged view of an essential part showing another modification of the seal shown in FIG. 2, and FIG. 5 is an enlarged view of an essential part showing another modification of the seal shown in FIG. .. In the following description, the side closer to the outer side of the vehicle when assembled to the vehicle is called the outer side (left side in FIG. 1), and the side closer to the center is called the inner side (right side in FIG. 1).

The wheel bearing device shown in FIG. 1 is called the third generation on the driven wheel side, and is a double row rolling element that is accommodated between the inner member 1 and the outer member 2 and both members 1 and 2 in a rollable manner. (Ball) 3 and 3. The inner member 1 includes a hub wheel 4 and an inner wheel 5 press-fitted into the hub wheel 4.

The hub wheel 4 integrally has a wheel mounting flange 6 for mounting a wheel on an end portion on the outer side, and has one (outer side) inner raceway surface 4a on the outer periphery and an axial direction from the inner raceway surface 4a. A small-diameter step portion 4b extending in the direction is formed. Hub bolts 6a are planted in the wheel mounting flange 6 at equal positions in the circumferential direction.

The inner ring 5 has the other (inner side) inner raceway surface 5a formed on the outer circumference, is press-fitted into the small-diameter step portion 4b of the hub wheel 4 via a predetermined swage, and the end portion of the small-diameter step portion 4b is radially inserted. It is axially fixed to the hub wheel 4 in a state in which a preload is applied by a caulking portion 4c formed by plastically deforming outward in the direction.

The outer member 2 integrally has a vehicle body mounting flange 2b for mounting on a knuckle (not shown) that constitutes a suspension device on the outer circumference, and has inner rolling surfaces 4a, 5a of the inner member 1 on the inner circumference. Double row outer rolling surfaces 2a, 2a facing each other are formed. A double row rolling element 3, 3 is rotatably accommodated between the two rolling surfaces 2a, 4a and 2a, 5a via a cage 7. The outer member 2 is formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and at least double rows of the outer rolling surfaces 2a, 2a have a surface in the range of 58 to 64 HRC by induction hardening. Has been cured.

Seals 8 and 9 are attached to both ends of the outer member 2, and both side openings of an annular space formed between the outer member 2 and the inner member 1 are sealed. These seals 8 and 9 prevent the lubricating grease sealed inside the bearing from leaking to the outside and prevent rainwater, dust, and the like from entering the inside of the bearing from the outside.

The hub wheel 4 is formed of medium-high carbon steel containing 0.40 to 0.80 wt% of carbon such as S53C, and the inner surface of the inner raceway 4a and the inner side of the wheel mounting flange 6 that is the seal land portion of the seal 8 on the outer side. The surface is hardened by induction hardening from the base portion 6b on the side to the small diameter step portion 4b in the range of 58 to 64 HRC. In addition, the caulking portion 4c is left as the raw surface hardness after the forging process. As a result, the wear resistance of the base portion 6b on the inner side of the wheel mounting flange 6 serving as the seal land portion is improved, and the wheel mounting flange 6 has sufficient mechanical strength against the rotational bending load applied to the wheel mounting flange 6. The fretting resistance of the small-diameter step portion 4b, which is the fitting portion of the inner ring 5, is improved, and the plastic working can be smoothly performed without the occurrence of minute cracks or the like in the crimp portion 4c.

On the other hand, the inner ring 5 is made of high-carbon chrome steel such as SUJ2, and is hardened to the core portion by zub quenching in the range of 58 to 64 HRC. The rolling element 3 is made of high carbon chrome steel such as SUJ2, and is hardened to the core portion by zub quenching in the range of 62 to 67 HRC.

In addition, here, the bearing device for a wheel constituted by the double-row angular contact ball bearing using balls for the rolling elements 3 and 3 has been exemplified, but the present invention is not limited to this, and a compound device using tapered rollers for the rolling elements 3 and 3 is used. It may be constituted by row tapered roller bearings. Further, although the structure of the third generation is illustrated, the present invention is not limited to this, and any bearing device for an inner ring rotating type wheel may be used, and although not shown, a pair of inner rings is press-fitted into the hub ring at a small diameter step portion of the hub ring. Also, the so-called second generation structure or the fourth generation structure in which the inner races are directly formed on the outer circumference of the outer joint member of the hub wheel and the constant velocity universal joint may be used.

Here, the seal 8 on the outer side of the seals 8 and 9 is integrally joined to the core metal 10 press-fitted to the inner periphery of the outer end of the outer member 2 by vulcanization adhesion. It is configured as an integral type seal including a seal member 11 having a plurality of seal lips.

The core 10 is made of austenitic stainless steel sheet (JIS standard SUS304 series) or rustproof cold-rolled steel sheet (JIS standard SPCC series), etc., and has a cross-section of a press-worked cross section. It is formed in an L shape.

The inner seal 9 is composed of a slinger 12 and an annular seal plate 13 which are arranged to face each other, as shown in an enlarged view in FIG. The slinger 12 is formed from a ferromagnetic steel plate, for example, a ferritic stainless steel plate (JIS standard SUS430 series) or a rust-proof cold rolled steel plate by press working, and is press-fitted into the inner ring 5. End portion of the outer member 2 on the inner side through a cylindrical portion 12a, a standing plate portion 12b extending radially outward from the cylindrical portion 12a, and a bent portion 12c extending from the outer edge of the standing plate portion 12b to the inner side. The umbrella portion 12d is bent in an L-shape along the shape of the portion.

On the other hand, the seal plate 13 includes a cored bar 14 that is internally fitted to the inner end of the outer member 2, and a seal member 15 integrally joined to the cored bar 14 by vulcanization adhesion or the like. .. The cored bar 14 is formed from an austenitic stainless steel plate or a cold-rolled steel plate subjected to rust prevention into a substantially L-shaped cross section by press working, and is a cylindrical portion 14 a press-fitted to the inner periphery of the end of the outer member 2. And a standing plate portion 14b extending inward in the radial direction from the end portion of the cylindrical portion 14a.

The seal member 15 is made of an elastic member such as NBR (acrylonitrile-butadiene rubber), and extends from the base portion 15a that is wrapped around and joined to the inner edge portion of the standing plate portion 14b of the cored bar 14 to the inner peripheral surface of the cylindrical portion 14a of the cored bar 14. It has been spliced together. The seal member 15 is bifurcated from the base portion 15a, and has a first side lip (dust lip) 15b that extends obliquely outward in the radial direction and a second side lip (grease that extends obliquely inward in the radial direction). Slip) 15c. The first and second side lips 15b, 15c are in sliding contact with the standing plate portion 12b of the slinger 12 with a predetermined axial direction interference. Further, the sealing member 15 is wrapped around and fixed so as to cover the outer surface of the cylindrical portion 14a of the cored bar 14 formed to have a thin outer diameter at the tip end portion, and the outer peripheral surface of the outer member 2 is fixed. It has a so-called half metal structure that is elastically adhered to the inner circumference of the end. Thereby, the airtightness of the fitting portion between the outer member 2 and the seal 9 can be enhanced.

As the material of the seal member 15, in addition to the exemplified NBR, for example, HNBR (hydrogenated acrylonitrile butadiene rubber), EPDM (ethylene propylene rubber), etc. having excellent heat resistance, heat resistance, chemical resistance, etc. ACM (polyacrylic rubber), FKM (fluorine rubber), silicone rubber, and the like, which are excellent in heat resistance, can be exemplified.

Further, the magnetic encoder 16 is integrally joined to the side surface on the inner side of the standing plate portion 12b of the slinger 12 by vulcanization adhesion or the like. The magnetic encoder 16 is joined so as to be substantially flush with the inner side surface of the umbrella portion 12d so as to fill the step between the umbrella portion 12d and the standing plate portion 12b of the slinger 12, and is made of rubber or the like. Magnetic material powder such as ferrite is mixed into the elastomer, and the magnetic poles N and S are alternately magnetized in the circumferential direction to form a rotary encoder for detecting the rotational speed of the wheel. The term "substantially flush" as used herein means, for example, a design target value, and also includes a degree of error in the quality of each member and in joining, a state in which there is substantially no step, That is, a step caused by a processing error, an adhesion error, or the like should be allowed as a matter of course.

In the present embodiment, an annular recess 17 is formed on the inner periphery of the inner end of the outer member 2, and an annular groove 18 having a mortar-shaped cross section is formed on the outer periphery of the end, so that the bent portion 12c of the slinger 12 is formed. The umbrella portion 12d is arranged so as to cover the outer surface of the end portion of the outer member 2. The slinger 12 is opposed to the recess 17 of the outer member 2 and the inner end surface 2c and the outer peripheral surface of the end portion of the outer member 2 through a slight gap having a U-shaped cross section, and the labyrinth portion 19 is formed. Is composed of.

As described above, the seal member 15 does not include the conventional radial lip, and includes the bifurcated first and second side lips 15b and 15c that slidably contact the standing plate portion 12b of the slinger 12 with a predetermined axial interference. Since the sealant 9 is provided, a high sealing performance is ensured while suppressing an increase in the rotational torque of the seal 9, and at the same time, the lubricating grease sealed in the bearing by the second side lip 15c inclined inward in the radial direction from the base 15a. It is possible to provide a bearing device for a wheel that prevents leakage and improves the durability of the bearing.

In addition, since the annular recess 17 is formed on the inner circumference of the inner end of the outer member 2 and the labyrinth portion 19 is formed between the bent portion 12c of the slinger 12 and the umbrella portion 12d, it is possible to directly connect the outside from the outside. It is possible to prevent muddy water or the like from entering the first side lip 15b and ensure high sealing performance. Further, since the annular groove 18 is formed on the outer periphery of the end portion of the outer member 2, even if muddy water or the like enters the opening of the labyrinth portion 19 from the outside, it stays in the annular groove 18 and stays in the seal 9. It is possible to suppress the fluidization and further enhance the hermeticity.

FIG. 3 shows a modification of the seal 9 described above. Note that this embodiment is basically different from the above-described embodiment (FIG. 2) only in the shape of the slinger, and the same parts or parts having the same functions or parts or parts having the same function are designated by the same reference numerals. Description is omitted.

The seal 20 includes a slinger 21 and an annular seal plate 13 which are arranged to face each other. The slinger 21 is formed of a ferromagnetic steel plate, for example, a ferritic stainless steel plate, or a cold rolled steel plate subjected to rust prevention by press working, and a cylindrical portion 12a press-fitted into the inner ring 5, and the cylinder portion 12a. The standing plate portion 21a extending radially outward from the portion 12a, the overlapping portion 21b extending from the outer edge of the standing plate portion 21a to the outer side and entering the inner diameter side of the seal plate 13, and the outside from the end portion of the overlapping portion 21b. It is provided with an umbrella portion 21c that is bent and formed in an L-shape along the inner end shape of the square member 22. The magnetic encoder 16 is integrally joined to the inner side surface of the standing plate portion 21a of the slinger 21 by vulcanization adhesion or the like.

In the present embodiment, the annular groove 18 is formed on the outer periphery of the inner end of the outer member 22, and the overlapping portion 21b and the umbrella portion 21c of the slinger 21 cover the outer surface of the end of the outer member 22. It is located in. The slinger 21 is opposed to the seal plate 13 and the inner end surface 22c of the outer member 22 and the outer peripheral surface of the end portion of the outer member 22 with a slight U-shaped gap therebetween to form the labyrinth portion 23. doing.

As described above, the seal member 15 does not have the radial lip as in the prior art, as in the above-described embodiment, and has the bifurcated first and second slidable portions that slidably contact the standing plate portion 21a of the slinger 21 with a predetermined axial symmetry. Since the side lips 15b and 15c are provided, high sealing performance is ensured while suppressing an increase in the rotational torque of the seal 20, and the inside of the bearing is owing to the second side lip 15c inclined inward in the radial direction from the base 15a. It is possible to improve the durability of the bearing by preventing leakage of the lubricating grease sealed in.

Further, since the slinger 21 has the labyrinth portion 23 between the seal plate 13 and the inner end surface 22c of the outer member 22 and the outer peripheral surface of the outer end portion of the outer member 22, muddy water or the like can be directly supplied from the outside. It is possible to prevent the first side lip 15b from penetrating into the first side lip 15b and ensure a high sealing performance, and since the annular groove 18 is formed on the outer periphery of the end portion of the outer member 22, muddy water or the like from the outside is labyrinth. Even if it penetrates into the opening of the portion 23, it can be suppressed from staying in the annular groove 18 and flowing into the seal 20, and the sealing performance can be further enhanced.

FIG. 4 shows another modification of the seal 9 described above. Note that this embodiment is basically different from the above-described embodiment (FIG. 2) only in the configuration of the slinger and the seal plate, and other same parts or the same parts or parts or parts having the same function are given the same reference numerals. And detailed description is omitted.

The seal 24 includes a slinger 25 and an annular seal plate 33 that are arranged to face each other. The slinger 25 is formed from a ferromagnetic steel plate, for example, a ferritic stainless steel plate, or a cold rolled steel plate subjected to rust prevention by press working, and the cylindrical portion 12a press-fitted into the inner ring 5 and this cylinder. A standing plate portion 25a that extends radially outward from the portion 12a, and an annular projecting portion 25b that curves from the outer edge of the standing plate portion 25a to the outer side and that faces the inner end surface 27a of the outer member 27. , And a disc portion 25c extending radially outward from the end of the protruding portion 25b. The magnetic encoder 16 is integrally joined to the side surface of the slinger 25 on the inner side of the standing plate portion 25a by vulcanization adhesion or the like.

An annular umbrella member 28 is attached to the inner end of the outer member 27. The umbrella member 28 is formed by press working from an austenitic stainless steel plate or a cold-rolled steel plate subjected to rust prevention, and has a cylindrical portion 27a press-fitted to the outer periphery of the end of the outer member 27, and this cylindrical portion. A flange portion 28b protruding outward in the radial direction from an inner end portion of 28a is provided. The flange portion 28b and the disc portion 25c of the slinger 25 are opposed to each other with a slight axial clearance.

On the other hand, the seal plate 33 includes a cored bar 29 that is internally fitted to the inner end of the outer member 27, and the seal member 15 integrally joined to the cored bar 29 by vulcanization adhesion or the like. .. The cored bar 29 is formed from an austenitic stainless steel plate or a cold-rolled steel plate subjected to rust prevention into a substantially L-shaped cross section by press working, and is press-fitted into the inner periphery of the end part of the outer member 27, and the tip part thereof is formed. Is provided with a cylindrical portion 29a axially protruding from the inner end surface 27a of the outer member 27, and a standing plate portion 29b extending radially inward from the outer end of the cylindrical portion 29a.

In the present embodiment, an annular umbrella member 28 is press-fitted to the outer periphery of the inner end of the outer member 27, and the umbrella member 28, the protruding portion 25b of the slinger 25, and the disk portion 25c are outward. It is arranged so as to cover the outer surface of the end of the member 27. The slinger 25 is opposed to the seal plate 33, the inner end surface 27 a of the outer member 27, and the umbrella member 28 with a slight U-shaped gap therebetween, and constitutes a labyrinth portion 30. As a result, while suppressing an increase in the rotational torque of the seal 24, it is possible to prevent muddy water or the like from directly entering the first side lip 15b from the outside and ensure high sealing performance.

FIG. 5 shows another modification of the seal 9 described above. Note that this embodiment is basically different from the above-described embodiment (FIG. 2) only in the configuration of the slinger and the seal plate, and the same reference numerals are given to the same parts or parts having the same function or parts. And detailed description is omitted.

The seal 31 includes a slinger 32 and an annular seal plate 33 that are arranged to face each other. The slinger 32 is formed of a ferromagnetic steel plate, for example, a ferritic stainless steel plate, or a cold-rolled steel plate subjected to rust prevention by press working, and the cylindrical portion 12a press-fitted into the inner ring 5 and the cylinder portion 12a. L-shaped along the shape of the end portion on the inner side of the outer member 2 via the standing plate portion 12b extending radially outward from the portion 12a and the bent portion 12c extending from the outer edge of the standing plate portion 12b to the inner side. And an umbrella portion 12d formed in a bent shape, and the locking portion 32a is formed at the inner end of the cylindrical portion 12a by bending outward in the radial direction.

The locking portion 32a is formed by temporarily assembling the slinger 32 and the seal plate 33 and then plastically deforming the end of the cylindrical portion 12a. Since the locking portion 32a is arranged so as to radially overlap with a base portion 34a of a seal member 34 described later with a predetermined axial clearance, the locking portion 32a and the slinger 32 are sealed during the assembly process and transportation to the bearing. It is possible to prevent the plate 33 from being separated, and both members 32 and 33 can be unitized to be assembled into a bearing, so that the assemblability can be simplified and the assembling accuracy can be improved.

On the other hand, the seal plate 33 includes a cored bar 14 that is internally fitted to the inner end of the outer member 2 and a seal member 34 that is integrally joined to the cored bar 14 by vulcanization adhesion or the like. .. The seal member 34 is made of an elastic member such as NBR, and is joined to the inner peripheral surface of the cylindrical portion 14a of the core metal 14 from the base portion 34a which is joined to the inner edge portion of the standing plate portion 14b of the core metal 14 by being joined. Has been done.

The seal member 34 is bifurcated from the base portion 34a, and includes a first side lip 15b extending obliquely outward in the radial direction and a second side lip 15c extending obliquely inward in the radial direction. The first and second side lips 15b, 15c are slidably contacted with the standing plate portion 12b of the slinger 32 with a predetermined axial interference, and the base portion 34a has a small diameter with respect to the cylindrical portion 12a of the slinger 32. A labyrinth portion 35 having an L-shaped cross section is formed between the cylindrical portion 12a of the slinger 32 and the locking portion 32a, which are opposed to each other through the directional clearance.

In the present embodiment, as in the above-described embodiment, the slinger 32 has a slight U-shaped cross section with the recess 17 of the outer member 2, the inner end surface 2c, and the outer peripheral surface of the end portion of the outer member 2. Since the labyrinth portion 19 is formed so as to be opposed to each other through the clearance, it is possible to prevent muddy water or the like from entering the first side lip 15b from the outside directly and to ensure high sealing performance, and at the same time, the sealing member. 34 has the fork-shaped first and second side lips 15b and 15c which are abolished from the conventional radial lips and slidably contact the standing plate portion 12b of the slinger 32 with a predetermined axial interference. A high hermeticity can be secured while suppressing an increase in the rotational torque of 31. Further, the labyrinth portion 35 having an L-shaped cross section is formed between the second side lip 15c inclined inward in the radial direction from the base portion 34a and the cylindrical portion 12a of the slinger 32 and the locking portion 32a. The durability of the bearing can be improved by further preventing the leakage of the lubricating grease sealed inside the bearing.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all and is merely an example, and further various modifications may be made without departing from the scope of the present invention. It is needless to say that the scope of the present invention is shown by the description of the claims, and further, the equivalent meanings described in the claims and all modifications within the scope are Including.

INDUSTRIAL APPLICABILITY The wheel bearing device according to the present invention can be applied to inner ring rotating type wheel bearing devices of the first to fourth generations.

1 Inner member 2, 22, 27 Outer member 2a Outer rolling surface 2b Body mounting flanges 2c, 22c, 27a Inner end surface of outer member 3 Rolling element 4 Hub wheel 4a, 5a Inner rolling surface 4b Small diameter step Part 4c Caulking part 5 Inner ring 6 Wheel mounting flange 6a Hub bolt 6b Inner side base part 7 of wheel mounting flange Cage 8 Outer side seal 9, 20, 24, 31 Inner side seal 10, 14, 29 Core bar 11, 15, 34 Seal members 12, 21, 25, 32 Slinger 12a, 14a, 28a, 29a Cylindrical portion 12b, 14b, 21a, 25a, 29b Standing plate portion 12c Bending portion 12d, 21c Umbrella portion 13, 33 Seal plates 15a, 34a Base portion 15b of seal member First side lip 15c Second side lip 16 Magnetic encoder 17 Recess 18 Annular groove 19, 23, 30, 35 Labyrinth portion 21b Overlapping portion 28 Umbrella member 28b Collar portion 32a Locking portion 51, 70 Seal 52 Inner peripheral member 53 Outer peripheral member 54, 72 Seal plates 55, 71 Slinger 56, 71a, 73a Cylindrical part 57 Standing wall part 58 First bent part 59 Second bent part 60 Third bent part 61, 73 Core bar 62, 74 seal member 62a inner peripheral surface 63 of seal member 63 first lip portion 64 second lip portion 65 third lip portion 66, 67 labyrinth portion 68 inner ring 69 outer member 71b, 73b standing plate portion 74a first side lip 74b Second side lip 74c Inner end portion 75 of seal member Labyrinth portion

Claims (3)

An outer member integrally having a vehicle body mounting flange for mounting on a knuckle on the outer periphery, and an outer rolling surface integrally formed with double rows on the inner periphery,
An inner member on the outer periphery of which a double row inner rolling surface facing the double row outer rolling surface is formed,
A double row rolling element housed between both rolling surfaces of the inner member and the outer member so as to be rollable,
In a bearing device for a wheel, comprising seals mounted on both side openings of an annular space formed between the outer member and the inner member,
Of the seals, the seal on the inner side is composed of a composite type seal composed of a slinger and an annular seal plate that are arranged to face each other,
The slinger includes a cylindrical portion externally fitted to the inner member, and a standing plate portion extending radially outward from the cylindrical portion,
The seal plate, a cored bar press-fitted into the inner periphery of the inner side end of the outer member, and a seal member integrally joined to the cored bar by vulcanization adhesion,
This seal member has no radial lip that slidably contacts the cylindrical portion of the slinger with a radial direction, and is split into a forked shape from the base portion that wraps around the inner edge portion of the core metal and is inclined outward in the radial direction. A first side lip that extends and a second side lip that inclines radially inward are provided, and the first and second side lips are respectively slidably contacted to the standing plate portion of the slinger with an axial shimeiro. Along with
An annular projecting portion that curves from the outer edge of the standing plate portion of the slinger to the outer side and faces the inner end surface of the outer member, and a disc that extends radially outward from the end portion of this projecting portion. And an annular umbrella member is press-fitted into the outer periphery of the inner side end of the outer member, and the collar portion and the slinger circle projecting radially outward from the inner side end of the umbrella member. The plate portions are opposed to each other through an axial clearance, and the tip end of the core metal of the seal plate axially projects from the inner end surface of the outer member, and the slinger is attached to the seal plate and the outer side. A bearing device for a wheel, characterized in that a labyrinth portion is configured so as to face the inner end surface of the member and the umbrella member via a clearance having a U-shaped cross section . A locking portion is formed by bending outward in the radial direction at the end of the cylindrical portion of the slinger, and the locking portion radially overlaps with the base portion of the sealing member via an axial clearance. The bearing device for a wheel according to Item 1 . It said base of the seal member is opposed through the radial gap in the cylindrical portion of the slinger, to claim 2, labyrinth portion of the L-shaped cross section is formed between the cylindrical portion and the engaging portion of the slinger The wheel bearing device described.

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