JP7243181B2 - hub unit bearing - Google Patents

Description

The present invention relates to hub unit bearings, and more particularly to seal members for hub unit bearings.

The space around the hub unit bearing is surrounded by the rotating hub flange and brake rotor, so the air drawn up by the hub flange and brake rotor becomes an air current that flows along the stationary backing plate and outer ring. In addition, a stronger rotating air current is generated around the outer ring while the vehicle is running.

While the vehicle is running, the water droplets that have entered the space around the hub unit bearing are taken in by the rotating airflow and rotate (circumferential motion). Since rotating water droplets adhere to the outer ring, it is almost impossible for the water droplets to flow vigorously in the axial direction on the outer diameter surface of the outer ring. It is important to prevent water droplets entrained in the rotating airflow from approaching the sliding contact of the seal lip.

As a conventional hub unit bearing designed to improve the water resistance of the outboard side seal member, it is equipped with an outboard side seal member that seals between the outer ring and the hub ring, and the outboard side seal member extends from the outer diameter surface of the outer ring. Also known is an annular dam portion that projects radially outward, and a cylindrical eaves portion that projects axially from the dam portion and is formed to surround the outer ring (see, for example, Patent Document 1).

JP 2018-162832 A

However, although the outboard-side seal member described in Patent Document 1 described above can block the water droplets flowing axially on the outer diameter surface of the outer ring, the water droplets taken in by the rotating air flow do not reach the sliding contact of the seal lip. I couldn't keep them from getting closer.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a hub unit bearing capable of preventing water droplets taken in by a rotating airflow from approaching the sliding contact of a seal lip. It is in.

The above objects of the present invention are achieved by the following configurations.
(1) an outer ring member, an inner ring member provided rotatably with respect to the outer ring member via a plurality of rolling elements, a retainer that holds the plurality of rolling elements at approximately equal intervals in the circumferential direction, and the outer ring A hub unit bearing comprising: a seal member closing an outboard side of a bearing internal space between the member and the inner ring member, wherein the inner ring member is a plate extending radially outward from an outer diameter surface thereof. The seal member has an annular core fixed to the inner diameter surface of the outboard side end of the outer ring member, and an elastic seal portion fixed to the core. The elastic seal portion includes at least one contact lip formed on the inner diameter side of the core bar and slidingly contacting the inner ring member, and an outer diameter side of the core bar formed on the outboard side end portion of the outer ring member. a dam portion projecting radially outward from the outer diameter surface of the hub unit bearing, wherein the dam portion is formed with a plurality of projections.
(2) The elastic seal portion further has a non-contact lip provided radially outside the at least one contact lip, and the plurality of projections are formed on the non-contact lip. A hub unit bearing according to (1).
(3) an outer ring member, an inner ring member provided rotatably with respect to the outer ring member via a plurality of rolling elements, a retainer that holds the plurality of rolling elements at approximately equal intervals in a circumferential direction, and the outer ring; A hub unit bearing comprising: a seal member closing an outboard side of a bearing internal space between the member and the inner ring member, wherein the inner ring member is a plate extending radially outward from an outer diameter surface thereof. The seal member has an annular core fixed to the inner diameter surface of the outboard side end of the outer ring member, and an elastic seal portion fixed to the core. , the elastic seal portion includes at least one contact lip formed on the inner diameter side of the core metal and in sliding contact with the inner ring member, and a non-contact lip provided radially outside the at least one contact lip. and wherein the non-contact lip is formed with a plurality of protrusions.
(4) Any one of (1) to (3), wherein the plurality of protrusions is a vortex generator that turbulates a rotating airflow generated around the outer ring member when the flange rotates. 1. A hub unit bearing according to claim 1.

According to the present invention, the rotating airflow generated around the outer ring member when the flange portion rotates can be made turbulent by the plurality of protrusions that serve as vortex generators formed on the weir portion and the non-contact lip of the seal member. Therefore, it is possible to prevent water droplets taken in by the rotating airflow from approaching the sliding contact of the seal lip.

1 is a cross-sectional view illustrating a first embodiment of a hub unit bearing according to the present invention; FIG. 2 is an enlarged cross-sectional view of the periphery of the sealing member shown in FIG. 1; FIG. FIG. 5 is an enlarged cross-sectional view for explaining a first modification of the sealing member of the first embodiment; FIG. 7 is an enlarged cross-sectional view for explaining a second modification of the seal member of the first embodiment; FIG. 11 is an enlarged cross-sectional view for explaining a third modification of the sealing member of the first embodiment; FIG. 11 is an enlarged cross-sectional view for explaining a fourth modification of the sealing member of the first embodiment; FIG. 11 is an enlarged cross-sectional view for explaining a fifth modification of the sealing member of the first embodiment; FIG. 11 is an enlarged cross-sectional view for explaining a sixth modification of the sealing member of the first embodiment; FIG. 11 is an enlarged cross-sectional view for explaining a seventh modification of the sealing member of the first embodiment; FIG. 5 is an enlarged cross-sectional view of the periphery of a seal member for explaining a hub unit bearing according to a second embodiment of the present invention;

Hereinafter, each embodiment of the hub unit bearing according to the present invention will be described in detail based on the drawings.

(First embodiment)
First, a first embodiment of a hub unit bearing according to the present invention will be described with reference to FIGS. 1 to 9. FIG.

A hub unit bearing 10 of this embodiment is a hub unit bearing for a driven wheel, and as shown in FIG. A plurality of members arranged in two rows so as to be able to roll between the inner diameter surface of the outer ring member 11 and the outer diameter surfaces of the hub ring 12 and the inner ring 13. balls (rolling elements) 14, a pair of cages 15 for holding the two rows of balls 14 at regular intervals in the circumferential direction, and an outer ring member 11 and an inner ring member (hub ring 12, inner ring 13). A seal member 16 for closing the outboard side of the bearing internal space 10a therebetween and a cap 17 for closing the inboard side of the bearing internal space 10a are provided. In addition, the outboard side is the left side in FIG. 1, which is the outside in the width direction when assembled in the automobile, and the inboard side is the right side in FIG. 1, which is the center side in the width direction.

Two parallel rows of outer ring raceway surfaces 11a, 11a are formed on the inner diameter surface of the outer ring member 11 so as to be spaced apart from each other. Inner ring raceway surfaces 12a and 13a are formed on the outer diameter surfaces of the hub wheel 12 and the inner ring 13 so as to correspond to the outer ring raceway surfaces 11a and 11a of the outer ring member 11, respectively. A plurality of balls 14 rotatably held by a retainer 15 are arranged at equal intervals in the circumferential direction on two rows of raceways composed of the outer ring raceway surfaces 11a, 11a and the inner ring raceway surfaces 12a, 13a. there is

The plurality of balls 14 contact the outer ring raceway surfaces 11a, 11a and the inner ring raceway surfaces 12a, 13a with a back-to-back contact angle (DB) to form a double-row angular contact ball bearing. This allows the hub wheel 12 and the inner ring 13 to rotate with respect to the outer ring member 11 .

A small-diameter stepped portion 12b is formed at the inboard-side end portion of the hub wheel 12. After the inner ring 13 is fitted onto the small-diameter stepped portion 12b, the end portion of the small-diameter stepped portion 12b is crimped radially outward. By doing so, the inner ring 13 is fixed to the hub ring 12 . Further, by pressing the inner ring 13 by caulking, a proper preload is applied.

The hub wheel 12 is a substantially cylindrical member, and a plate-shaped flange portion 12c extending radially outward from the outer diameter surface is formed at the outboard side end portion of the hub wheel 12 . A plurality of hub bolts 12d for fastening a tire wheel, a brake rotor, etc. (not shown) are provided on the flange portion 12c at regular intervals in the circumferential direction.

As shown in FIG. 2, the seal member 16 is made of an annular metal core 20 that is press-fitted and fixed to the inner diameter surface of the outboard side end of the outer ring member 11, and rubber, elastomer, or the like that is fixed to the metal core 20. and an elastic seal portion 30 .

The core metal 20 is formed by stamping and bending a metal plate such as a steel plate, and includes a cylindrical portion 21 fixed to the inner diameter surface of the outer ring member 11 and an outboard of the cylindrical portion 21 . It has an outer diameter collar portion 22 extending radially outward from the side end portion, and an inner diameter collar portion 23 folded back from the inboard side end portion of the cylindrical portion 21 toward the outboard side and extending radially inward. The cylindrical portion 21 of the core bar 20 is press-fitted and fixed to the inner peripheral surface of the outer ring member 11 , and the side surface of the outer diameter collar portion 22 on the inboard side is elastically attached to the end surface of the outer ring member 11 on the outboard side. They are abutted with a part of the seal portion 30 interposed therebetween.

The elastic seal portion 30 has first to third contact lips 31 to 33 , one non-contact lip 34 and one weir portion 35 .

The first contact lip 31 is formed so as to be inclined from the inner diameter side end portion of the inner diameter collar portion 23 of the core bar 20 toward the inboard side and radially inward. The second contact lip 32 is formed so as to be inclined from the inner diameter side end portion of the inner diameter collar portion 23 of the core bar 20 toward the outboard side and radially outward. The third contact lip 33 is provided radially outward of the second contact lip 32 and is formed so as to incline from the side surface of the inner diameter collar portion 23 of the core metal 20 toward the outboard side and radially outward. The first to third contact lips 31 to 33 are formed along the entire circumference of the seal member 16. As shown in FIG. The tip portions of the first to third contact lips 31 to 33 are in sliding contact with the outer diameter surface and the axial side surface of the hub wheel 12 over the entire circumference. 1 to 10, the shapes of the first to third contact lips 31 to 33 indicate the free state of the seal member 16. As shown in FIG.

The non-contact lip 34 is provided radially outward of the third contact lip 33 and is formed so as to be inclined radially outward from the outer diameter side end of the outer diameter collar portion 22 of the core metal 20 toward the outboard side. It is A non-contact lip 34 is formed over the entire circumference of the seal member 16 . The tip of the non-contact lip 34 closely faces the inboard-side side surface of the flange portion 12c of the hub wheel 12 to form a labyrinth seal with the flange portion 12c.

The weir portion 35 is formed radially outward from the outer diameter side end portion of the outer diameter collar portion 22 of the core bar 20 . The dam portion 35 is formed to protrude radially outward from the outer diameter surface of the outboard side end portion of the outer ring member 11 . The dam portion 35 is formed over the entire circumference of the seal member 16 . The inboard-side side surface of the outer diameter collar portion 22 abuts against the outboard-side end surface of the outer ring member 11 with a part of the dam portion 35 interposed therebetween.

As shown in FIG. 2, a plurality of protrusions 40 are formed on the side surface of the weir portion 35 on the inboard side. The plurality of protrusions 40 are vortex generators that turbulate the rotating airflow generated around the outer ring member 11 when the flange portion 12c rotates (when the vehicle travels).

The plurality of protrusions 40 are formed in a line at approximately equal intervals over the entire circumference of the dam portion 35 . Also, the projection 40 is provided at a position radially outside the non-contact lip 34 . Moreover, the protrusion 40 is formed in a partially spherical shape (substantially hemispherical shape). The shape of the projection 40 is not limited to a partial spherical shape (substantially hemispherical shape), and various shapes such as a cylindrical shape, a columnar shape, a polygonal columnar shape, and embossed characters can be selected. In addition, the arrangement of the projections 40 is not limited to a form in which a plurality of projections 40 are formed at approximately equal intervals over the entire circumference. 4) groups may be intermittently formed in the circumferential direction.

As described above, according to the hub unit bearing 10 of the present embodiment, the plurality of protrusions 40 that serve as vortex generators formed on the weir portion 35 of the seal member 16 cause the outer ring member 11 to rotate when the flange portion 12c rotates. The rotating airflow generated around (especially around the weir portion 35) can be made turbulent. Therefore, the rotating air current containing water droplets is prevented from entering radially inwardly of the non-contact lip 34, and the water droplets taken in by the rotating air current are prevented from reaching the sealing lips (first to third contact lips 31 to 33). can be prevented from approaching the sliding contact.

Next, as a first modified example of the present embodiment, as shown in FIG. 3 , a plurality of projections 40 may be formed in two rows on the side surface of the weir portion 35 on the inboard side. In this modification, the plurality of projections 40 are arranged in two rows in a zigzag pattern along the circumferential direction on the inboard side surface of the dam portion 35 . Note that the arrangement of the plurality of protrusions 40 is not limited to two rows, and may be three or more rows.

Next, as a second modified example of the present embodiment, as shown in FIG. 4, a plurality of projections 40 may be formed in a row on the side surface of the weir portion 35 on the outboard side. Also in this case, the plurality of protrusions 40 may be formed in two or more rows as in the first modified example described above.

Next, as a third modified example of the present embodiment, as shown in FIG. 5 , a plurality of projections 40 may be formed in one row on the outer diameter surface of the dam portion 35 . However, in the case of this modified example, due to the positional relationship of the parting plane PL of the mold, forcible punching occurs during vulcanization molding, and the projection 40 cannot be enlarged.

Next, as a fourth modified example of the present embodiment, as shown in FIG. 6, a plurality of projections 40 are formed on the outer diameter surface of the dam portion 35, and the top portions of the projections 40 are located on the inboard side of the dam portion 35. may be formed so as to be positioned on an extension line of the side surface of the In this case, the protrusion 40 is formed in the shape of approximately a quarter of a sphere. In addition, in the case of this modification, by arranging the dividing plane PL of the mold on the extension line of the side surface of the inboard side of the dam portion 35, the protrusion 40 can be enlarged while avoiding forced removal during vulcanization molding. be able to.

Next, as a fifth modified example of the present embodiment, as shown in FIG. 7, a plurality of projections 40 are formed on the outer diameter surface of the dam portion 35, and the top portions of the projections 40 are located on the outboard side of the dam portion 35. may be formed so as to be positioned on an extension line of the side surface of the In this case, the protrusion 40 is formed in the shape of approximately a quarter of a sphere. In addition, in the case of this modification, by arranging the parting plane PL of the molding die on the extension line of the side surface of the outboard side of the dam 35, the protrusion 40 can be enlarged while avoiding forced removal during vulcanization molding. be able to.

Next, as a sixth modified example of the present embodiment, as shown in FIG. 8, a plurality of projections 40 may be formed from the side surface of the dam portion 35 on the inboard side to the outer diameter surface. In this case, the protrusion 40 is formed approximately three-quarters spherical. According to this modification, since the projections 40 protrude from both the inboard side surface and the outer diameter surface of the weir portion 35, the rotational airflow is made turbulent compared to the configurations shown in FIGS. By enhancing the effect, it is possible to further prevent water droplets taken in by the rotating airflow from approaching the sliding contact points of the seal lips (first to third contact lips 31 to 33). In addition, in the case of this modification, by arranging the dividing plane PL of the mold on the extension line of the side surface of the inboard side of the dam portion 35, the protrusion 40 can be enlarged while avoiding forced removal during vulcanization molding. be able to.

Next, as a seventh modified example of the present embodiment, as shown in FIG. 9, a plurality of projections 40 may be formed from the side surface of the dam portion 35 on the outboard side to the outer diameter surface. In this case, the protrusion 40 is formed approximately three-quarters spherical. According to this modification, since the protrusions 40 protrude from both the outboard side surface and the outer diameter surface of the weir portion 35, the rotating airflow is turbulent compared to the configurations shown in FIGS. By enhancing the effect, it is possible to further prevent water droplets taken in by the rotating airflow from approaching the sliding contact points of the seal lips (first to third contact lips 31 to 33). In addition, in the case of this modification, by arranging the parting plane PL of the molding die on the extension line of the side surface of the outboard side of the dam 35, the protrusion 40 can be enlarged while avoiding forced removal during vulcanization molding. be able to.

(Second embodiment)
Next, with reference to FIG. 10, a hub unit bearing according to a second embodiment of the present invention will be described. The same or equivalent parts as those of the first embodiment are denoted by the same reference numerals in the drawings, and the description thereof will be omitted or simplified.

In this embodiment, as shown in FIG. 10, a plurality of projections 40 are not formed on the dam portion 35, and instead, a plurality of projections 40 serving as vortex generators are provided at the tip of the outer diameter surface of the non-contact lip 34. A protrusion 41 is formed.

The plurality of protrusions 41 are formed in a line at approximately equal intervals over the entire circumference of the non-contact lip 34 . Moreover, the protrusion 41 is formed in a cylindrical shape. The shape of the projection 40 is not limited to a cylindrical shape, and various shapes such as a partial spherical shape (substantially hemispherical shape), a cylindrical shape, a polygonal prism shape, and embossed characters can be selected. In addition, the arrangement of the projections 41 is not limited to the form in which the plurality of projections 41 are formed at approximately equal intervals over the entire circumference. 4) groups may be intermittently formed in the circumferential direction. Also, the plurality of protrusions 41 may be formed in two or more rows.

As described above, according to the hub unit bearing 10 of the present embodiment, the plurality of projections 41 acting as vortex generators formed on the non-contact lip 34 of the seal member 16 cause the outer ring member 11 to rotate when the flange portion 12c rotates. (particularly around the labyrinth seal) can be turbulent. Therefore, the rotating air current containing water droplets is prevented from entering radially inwardly of the non-contact lip 34, and the water droplets taken in by the rotating air current are prevented from reaching the sealing lips (first to third contact lips 31 to 33). can be prevented from approaching the sliding contact.
Other configurations and effects are the same as those of the first embodiment.

It should be noted that the present invention is not limited to the examples illustrated in the above embodiments, and can be modified as appropriate without departing from the gist of the present invention.
For example, both the plurality of projections formed on the weir portion of the first embodiment and the plurality of projections formed on the non-contact lip of the second embodiment may be provided. In this case, the effect of making the rotating airflow turbulent can be enhanced, and water droplets taken into the rotating airflow can be further prevented from approaching the sliding contact of the seal lip.
Further, in the case of the first embodiment, the non-contact lip may be omitted.
Further, the hub unit bearing is not limited to the hub unit bearing for driven wheels shown in FIG. 1, and may be a hub unit bearing for driving wheels.

REFERENCE SIGNS LIST 10 hub unit bearing 10a bearing inner space 11 outer ring member 11a outer ring raceway surface 12 hub ring (inner ring member)
12a inner ring raceway surface 12c flange portion 13 inner ring (inner ring member)
13a inner ring raceway surface 14 ball (rolling element)
15 retainer 16 sealing member 17 cap 20 core metal 21 cylindrical portion 22 outer diameter flange 23 inner diameter flange 30 elastic seal portion 31 first contact lip 32 second contact lip 33 third contact lip 34 non-contact lip 35 weir portion 40 Protrusion (vortex generator)
41 protrusion (vortex generator)

Claims (4)

an outer ring member, an inner ring member rotatably provided with respect to the outer ring member via a plurality of rolling elements, a retainer that holds the plurality of rolling elements at substantially equal intervals in a circumferential direction, the outer ring member and the A hub unit bearing comprising: a seal member closing an outboard side of a space inside the bearing between the inner ring member,
The inner ring member has a plate-like flange portion extending radially outward from its outer diameter surface,
The seal member includes an annular core metal fixed to the inner diameter surface of the outboard side end portion of the outer ring member, and an elastic seal portion fixed to the core metal,
The elastic seal portion includes at least one contact lip formed on the inner diameter side of the core bar and slidingly contacting the inner ring member, and an outer diameter side of the core bar formed on the outboard side end portion of the outer ring member. a dam portion protruding radially outward from the outer diameter surface,
a plurality of projections are formed on the weir ,
The weir portion is formed along the entire circumference of the sealing member,
A hub unit bearing , wherein the plurality of projections are intermittently formed on the surface of the inboard side surface of the dam portion . the elastic seal further has a non-contact lip provided radially outward of the at least one contact lip;
2. The hub unit bearing according to claim 1, wherein the plurality of protrusions are formed on the outer surface of the non-contact lip. an outer ring member, an inner ring member rotatably provided with respect to the outer ring member via a plurality of rolling elements, a retainer that holds the plurality of rolling elements at substantially equal intervals in a circumferential direction, the outer ring member and the A hub unit bearing comprising: a seal member closing an outboard side of a space inside the bearing between the inner ring member,
The inner ring member has a plate-like flange portion extending radially outward from its outer diameter surface,
The seal member includes an annular core metal fixed to the inner diameter surface of the outboard side end portion of the outer ring member, and an elastic seal portion fixed to the core metal,
The elastic seal portion has at least one contact lip that is formed on the inner diameter side of the core bar and is in sliding contact with the inner ring member, and a non-contact lip that is provided radially outside the at least one contact lip. death,
A hub unit bearing, wherein a plurality of protrusions are formed on the outer surface of the non-contact lip. The plurality of protrusions according to any one of claims 1 to 3, wherein the plurality of protrusions are vortex generators that turbulate a rotating airflow generated around the outer ring member when the flange portion rotates. hub unit bearings.

Images