JP2024123777A - Wheel bearing device - Google Patents

Abstract

To provide a bearing device for a wheel capable of stably fitting pressure to an outward member of a sealing device.SOLUTION: An outer side seal member 10 of a bearing device 1 for a wheel comprises: a core grid 11 having a fitting part 111 fitted with an inner periphery of an outer side opening 2b of an outer ring 2 and an inner part 112 extending to an inside diameter side from an outer side end of the fitting part 111; and a seal member 12 having a first side lip 12b and a second side lip 12c integrally jointed to the core grid 11 and extending toward a wheel mounting flange 3b from the inner part 112 of the core grid 11, and a plane part 12d extending toward an outside diameter from a base end of the second side lip 12c positioned on an outermost diameter side, and faced to an outer side. An outside diameter end 121 of the second side lip 12c is positioned on an inner diameter side by 1 mm or more than an outside diameter end 122 of the plane part 12d.SELECTED DRAWING: Figure 3

Description

The present invention relates to a wheel bearing device.

Conventionally, wheel bearing devices that support the wheels rotatably in the suspension of an automobile or the like are known. The wheel bearing device is provided with a sealing device that closes the open end of the annular space formed by the outer member and the inner member to prevent the intrusion of foreign matter such as muddy water.

For example, the sealing device disclosed in Patent Document 1 is made up of a core bar having a fitting portion that fits into the inner peripheral surface of the outer member and an inner portion that extends from the fitting portion toward the inner diameter side, a side lip that extends from the inner portion of the core bar toward the wheel mounting flange side, and a cover portion that extends from the base end of the side lip located on the outermost diameter side toward the outer diameter side to cover the core bar.

In the seal member of such a sealing device, the outer diameter of the cover portion is formed to be larger than the outer diameter of the side lip located on the outermost side, and for example, the outer diameter end of the side lip is set to be located 1 mm on the inner diameter side of the outer diameter end of the cover portion. In this case, the cover portion has a nose portion that protrudes outward from the flat portion, and the outer diameter end of the nose portion is the outer diameter end of the cover portion, so that the radial distance from the outer diameter end of the nose portion to the outer diameter end of the side lip is set to be 1 mm.

On the other hand, the cover portion has a flat portion that faces the wheel mounting flange side in the axial direction between the outer diameter end of the cover portion and the outer diameter end of the side lip, and when the sealing device is pressed into the outer member, the flat portion of the seal member is pressed with a pressing jig to press the sealing device into the outer member.

JP 2007-224941 A

However, because the distance from the outer diameter end of the nose portion to the outer diameter end of the side lip was set to 1 mm, the distance from the outer diameter end of the flat portion to the outer diameter end of the side lip was less than 1 mm.

In this way, the distance from the outer diameter end of the flat portion to the outer diameter end of the side lip was set to a value smaller than 1 mm, so the area of the flat portion pressed by the press-fitting tool was small, and there was a risk that the sealing device could not be stably pressed into the outer member.

The present invention was made in consideration of the above situation, and provides a wheel bearing device that ensures the area of the flat surface that is pressed by the press-fitting tool, and allows the sealing device to be stably pressed into the outer member.

That is, the wheel bearing device comprises an outer member having a double-row outer raceway surface on its inner circumference, a hub wheel having a wheel mounting flange for mounting a wheel at one axial end thereof and a small diameter step extending in the axial direction on its outer circumference, and at least one inner ring press-fitted into the small diameter step of the hub wheel, an inner member having a double-row inner raceway surface facing the double-row outer raceway surface, double-row rolling elements accommodated in a rollable manner between the raceway surfaces of the outer member and the inner member, and a sealing device closing an opening end on one axial end side of an annular space formed by the outer member and the inner member. A wheel bearing device comprising: a core having a fitting portion that fits into the inner peripheral surface at one axial end of the outer member, and an inner portion that extends from the axial end of the fitting portion toward the inner diameter side; a side lip that is integrally joined to the core and extends from the inner portion of the core toward the wheel mounting flange; and a seal member that extends from the base end of the side lip located on the outermost diameter side toward the outer diameter side and has a flat portion that faces the axial end side, and the outer diameter end of the side lip is located 1 mm or more toward the inner diameter side of the outer diameter end of the flat portion.

According to the present invention, it is possible to ensure a large area of the flat surface of the sealing member, and the sealing device can be stably pressed into the outer member.

1 is a side cross-sectional view showing a wheel bearing device. 2 is a side cross-sectional view showing an outer seal member and its surrounding area in the wheel bearing device. FIG. FIG. 4 is a side cross-sectional view showing an outer seal member. FIG. 4 is a side cross-sectional view showing an outer end portion of the outer ring. 5 is a side cross-sectional view showing the outer seal member being press-fitted into an outer opening of the outer ring by a press-fitting jig. FIG.

Below, the embodiment of the present invention will be explained with reference to the attached drawings.

[Wheel bearing device]
A wheel bearing device 1 shown in FIG. 1 is one embodiment of a wheel bearing device according to the present invention, which rotatably supports a wheel in a suspension system of a vehicle such as an automobile.

In the following description, the axial direction refers to the direction along the rotation axis X of the wheel bearing device 1. The outer side refers to one side in the axial direction, which is the wheel side of the wheel bearing device 1 when it is attached to the vehicle body, and the inner side refers to the other side in the axial direction, which is the vehicle body side of the wheel bearing device 1 when it is attached to the vehicle body.

The wheel bearing device 1 has a configuration called the third generation, and includes an outer ring 2 as the outer member, a hub wheel 3 and an inner ring 4 as the inner members, two rolling rows of inner ball rows 5 and outer ball rows 6, an outer seal member 10, and a cap 17.

An inner side opening 2a is formed at the inner side end of the outer ring 2 into which the cap 17 can be fitted. An outer side opening 2b is formed at the outer side end of the outer ring 2 into which the outer side seal member 10 can be fitted.

The annular space S formed by the outer ring 2 and the hub wheel 3 is sealed by fitting an outer seal member 10 into the outer opening 2b, which is the outer opening end of the annular space S, and fitting a cap 17 into the inner opening 2a, which is the inner opening end of the annular space S.

The inner peripheral surface of the outer ring 2 is formed with an inner outer raceway surface 2c and an outer outer raceway surface 2d. The outer peripheral surface of the outer ring 2 is integrally formed with a vehicle body mounting flange 2e for mounting the outer ring 2 to a vehicle body member. The vehicle body mounting flange 2e is fastened to the vehicle body member by a fastening member such as a bolt.

The inner end of the hub wheel 3 has a small diameter step 3a formed on the outer circumferential surface, which is smaller in diameter than the outer end. The outer end of the hub wheel 3 has a wheel mounting flange 3b formed integrally therewith for mounting a wheel. The wheel mounting flange 3b has multiple bolt holes 3f formed therein. Hub bolts 3i for fastening the hub wheel 3 to a wheel or a brake component can be pressed into the bolt holes 3f.

The outer peripheral surface of the hub wheel 3 is provided with an outer inner raceway surface 3c that faces the outer outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner raceway surface 3c is formed by the hub wheel 3 on the outer side of the inner member.

A seal land portion 3d is formed on the inner side of the base end of the wheel mounting flange 3b, against which the outer seal member 10 slides. The inner raceway groove 3c is located adjacent to the inner side of the seal land portion 3d in the axial direction. The wheel mounting flange 3b has a flange surface 3e that faces the inner side.

The flange surface 3e is located on the outer diameter side of the seal land portion 3d. The seal land portion 3d is located on the inner side of the flange surface 3e in the axial direction, and a step portion 3g is formed between the flange surface 3e and the seal land portion 3d.

The inner ring 4 is provided on the small diameter step 3a of the hub ring 3. The inner ring 4 is fixed to the small diameter step 3a of the hub ring 3 by press fitting and crimping. The inner ring 4 applies preload to the inner ball row 5 and the outer ball row 6, which are the rolling rows. The inner ring 4 has an inner end face 4b at its inner end.

The inner end of the hub wheel 3 is formed with a crimped portion 3h that is crimped to the inner end face 4b of the inner ring 4. The inner ring 4 is fixed in the axial direction by the crimped portion 3h. The crimped portion 3h is formed by plastically deforming the inner end of the small diameter step portion 3a toward the outer diameter side.

The outer peripheral surface of the inner ring 4 is provided with an inner side inner raceway surface 4a that faces the inner side outer raceway surface 2c of the outer ring 2. In other words, the inner side of the inner member is formed by the inner ring 4 as the inner raceway surface 4a.

The inner ball row 5 and outer ball row 6, which are rolling rows, are formed by a plurality of balls 7, which are rolling bodies, held by a cage 8. The inner ball row 5 is rollably sandwiched between the inner raceway surface 4a of the inner ring 4 and the outer raceway surface 2c on the inner side of the outer ring 2. The outer ball row 6 is rollably sandwiched between the inner raceway surface 3c of the hub ring 3 and the outer raceway surface 2d on the outer side of the outer ring 2. In other words, the inner ball row 5 and the outer ball row 6 are housed in a rollable manner between the raceway surfaces of the outer member and the inner member.

In the wheel bearing device 1, a double-row angular ball bearing is formed by the outer ring 2, the hub ring 3, the inner ring 4, the inner ball row 5, and the outer ball row 6. Note that the wheel bearing device 1 may be formed as a double-row tapered roller bearing instead of a double-row angular ball bearing.

A support ring 15 formed with an L-shaped cross section is fitted to the inner end of the inner ring 4. The support ring 15 has a cylindrical portion 15a that is press-fitted onto the outer diameter of the inner ring 4 and a standing portion 15b that extends radially outward from the cylindrical portion 15a, and a magnetic encoder 16 is integrally joined to the inner side of the standing portion 15b by vulcanization adhesion.

A rotational speed sensor is placed in a position facing the magnetic encoder 16 on the inner side of the cap 17, and the rotational speed sensor detects the displacement of the magnetic encoder 16, making it possible to detect the rotational speed of the inner ring 4.

[Outer seal member]
As shown in Figures 2 and 3, the outer seal member 10 includes a core metal 11 that is fitted onto the inner circumference of the outer end portion of the outer ring 2, and a seal member 12 that is integrally joined to the core metal 11.

The core metal 11 is made of, for example, a steel plate, and has a cylindrical fitting portion 111 that fits into the inner circumference of the outer side opening 2b of the outer ring 2, and an inner portion 112 that extends from the inner side end of the fitting portion 111 toward the inner diameter side.

The inner portion 112 has an outer inclined portion 112a that is bent from the outer end of the fitting portion 111 and extends obliquely toward the outer side and the inner diameter side, an outer annular portion 112b that extends from the outer end of the outer inclined portion 112a toward the inner diameter side, an inner inclined portion 112c that extends obliquely from the inner diameter side end of the outer annular portion 112b toward the inner side and the inner diameter side, and an inner annular portion 112d that extends from the inner end of the inner inclined portion 112c toward the inner diameter side.

The seal member 12 is made of an elastic material such as synthetic rubber, and is bonded to the core metal 11 by vulcanization adhesion. The seal member 12 has a radial lip 12a, a first side lip 12b, a second side lip 12c, a flat portion 12d, and a nose portion 12e.

The radial lip 12a extends radially inward and toward the inner side from the inner annular portion 112d of the core metal 11 and is in sliding contact with the seal land portion 3d.

The first side lip 12b extends from the inner annular portion 112d of the core metal 11 toward the outer side and radially outward, which is the wheel mounting flange 3b side, on the outer diameter side of the radial lip 12a. The first side lip 12b is in sliding contact with the seal land portion 3d. The first side lip 12b is an example of a side lip.

The second side lip 12c extends radially outward from the boundary between the outer annular portion 112b and the inner inclined portion 112c of the core metal 11, toward the outer side of the wheel mounting flange 3b. The second side lip 12c is in sliding contact with the seal land portion 3d. The second side lip 12c is an example of a side lip. The second side lip 12c is also an example of a side lip located at the outermost side.

In the radial direction, the distance from the rotation axis X to the outer diameter end 121 at the tip of the second side lip 12c is R1.

The flat portion 12d extends from the base end of the second side lip 12c toward the outer diameter side and faces the outer side. The outer side surface of the flat portion 12d is formed in a flat shape. The outer side surface of the flat portion 12d is a surface along a direction perpendicular to the axial direction. The flat portion 12d is joined from the outer annular portion 112b to the outer inclined portion 112a of the core metal 11.

The outer diameter end 122 of the flat portion 12d is located on the outer diameter side of the outer diameter end 121 of the second side lip 12c. In the radial direction, the distance from the rotation axis X to the outer diameter end 122 of the flat portion 12d is R2.

The distance difference between the distance R1 of the outer diameter end 121 of the second side lip 12c and the distance R2 of the outer diameter end 122 of the flat surface portion 12d is D, and the distance difference D is set to 1 mm or more. In other words, the outer diameter end 121 of the second side lip 12c is located 1 mm or more toward the inner diameter side than the outer diameter end 122 of the flat surface portion 12d.

The nose portion 12e is joined to the outer inclined portion 112a of the core metal 11, is located on the inner side of the flat portion 12d, and protrudes outward from the fitting portion 111 of the core metal 11. The outer diameter end of the nose portion 12e is located on the outer diameter side of the outer diameter end 122 of the flat portion 12d.

When the fitting portion 111 of the core 11 is fitted to the inner peripheral surface of the outer opening 2b of the outer ring 2, the nose portion 12e is pressed toward the inner diameter side by the inner peripheral surface of the outer opening 2b and is elastically deformed.

The nose portion 12e, which has been pressed toward the inner diameter side and elastically deformed, bulges toward the outer side compared to when it is not elastically deformed, but does not protrude toward the outer side beyond the flat portion 12d. In other words, the outer end of the nose portion 12e, which has been pressed toward the inner diameter side and elastically deformed, is located in the same position as the outer side surface of the flat portion 12d in the axial direction, or is located closer to the inner side than the outer side surface of the flat portion 12d.

[Outer ring]
As shown in Figures 2 and 4, the outer end face 2e of the outer ring 2 extends axially outerward beyond the outer diameter end of the seal land portion 3d, and a retreat portion 2f is formed on the inner diameter side of the outer end face 2e of the outer ring 2 that faces the step portion 3g of the hub wheel 3.

The recess 2f is formed in a curved shape that is concave toward the step 3g, and prevents interference between the outer ring 2 and the step 3g of the hub wheel 3 when the outer end surface 2e of the outer ring 2 is extended outward beyond the outer diameter end of the seal land portion 3d.

The outer ring 2 has a tapered surface 2g at the outer end of the outer opening 2b, which increases in diameter toward the outer side. The recessed portion 2f is located on the outer side of the tapered surface 2g, and an R-chamfered portion 2h is formed between the tapered surface 2g and the recessed portion 2f.

The R-chamfered portion 2h is located at the outer end of the tapered surface 2g and faces the seal land portion 3d of the hub wheel 3. The R-chamfered portion 2h is formed by R-chamfering the connection portion between the tapered surface 2g and the retreat portion 2f, and has a curved shape that is convex toward the seal land portion 3d. The R-chamfered portion 2h has a curved shape with a curvature radius of 0.5 mm or more. At the R-chamfered portion 2h, the inner peripheral surface of the outer ring 2 expands in diameter as it moves toward the outer side.

[Press-fitting the outer seal member into the outer ring]
5, when fitting the outer seal member 10 into the outer opening 2b of the outer ring 2, the outer seal member 10 is pressed toward the inner side by a press-fitting jig P and press-fitted into the outer opening 2b, thereby fitting the outer seal member 10 into the outer opening 2b. The press-fitting jig P is formed of, for example, an annular member extending along the axial direction.

In this case, the press-fitting jig P is brought into contact with the portion of the flat surface portion 12d of the seal member 12 that is radially outward of the second side lip 12c, and the outer seal member 10 is press-fitted by the press-fitting jig P. This allows the outer seal member 10 to be press-fitted into the outer opening 2b without the press-fitting jig P interfering with the second side lip 12c.

In addition, the outer diameter end 121 of the second side lip 12c is located 1 mm or more toward the inner diameter side of the outer diameter end 122 of the flat surface portion 12d, so that the area of the portion of the flat surface portion 12d that the press-fitting jig P abuts against can be made large, and the outer seal member 10 can be stably pressed into the outer ring 2.

When the outer seal member 10 is pressed into the outer opening 2b, the nose portion 12e, which protrudes radially outward beyond the fitting portion 111 of the core metal 11, moves from the outer side to the inner side, contacting the R-chamfered portion 2h, the tapered surface 2g, and the outer opening 2b in that order, and is gradually compressed. This prevents the nose portion 12e from suddenly deforming elastically, and prevents damage to the nose portion 12e, such as rubber breakage.

In particular, the R-chamfered portion 2h has a curved shape with a radius of curvature of 0.5 mm or more. Therefore, when the nose portion 12e comes into contact with the R-chamfered portion 2h and elastically deforms, the nose portion 12e that elastically deforms and bulges toward the outer side is allowed to escape toward the outer diameter side, suppressing sudden elastic deformation and making it less likely that damage such as rubber breakage will occur.

In addition, because the tapered surface 2g is located on the inner side of the R-chamfered portion 2h, the nose portion 12e that has passed the R-chamfered portion 2h is gradually compressed toward the inner diameter as it moves toward the inner side, suppressing sudden elastic deformation and making it less likely that damage such as rubber breakage will occur.

Furthermore, the nose portion 12e, which is pressed into the outer side opening 2b and elastically deformed, does not protrude further toward the outer side than the flat portion 12d, so it does not interfere with the pressing tool P that presses the flat portion 12d during pressing, and damage to the nose portion 12e, such as rubber breakage, can be prevented.

Although the embodiments of the present invention have been described above, the present invention is in no way limited to these embodiments, which are merely examples, and it goes without saying that the present invention can be embodied in various other forms without departing from the spirit of the present invention. The scope of the present invention is indicated by the claims, and further includes the equivalent meanings set forth in the claims, and all modifications within the scope of the claims.

REFERENCE SIGNS LIST 1 Wheel bearing device 2 Outer ring 2a Inner opening 2b Outer opening 2c (Inner) outer raceway surface 2d (Outer) outer raceway surface 2f Tapered surface 2h R-chamfered portion 3 Hub ring 3b Wheel mounting flange 3c Inner raceway surface 4 Inner ring 4a Inner raceway surface 5 Inner ball row 6 Outer ball row 10 Outer seal member 11 Core 12 Seal member 12b First side lip 12c Second side lip 12d Flat portion 12e Nose portion 111 Fitting portion 112 Inner portion D Distance difference (between outer diameter end of second side lip and outer diameter end of flat portion)

Claims (3)

an outer member having a double row outer raceway surface on an inner periphery thereof;
an inner member including a hub wheel having a wheel mounting flange at one axial end thereof for mounting a wheel, and a small diameter stepped portion extending in the axial direction on an outer periphery thereof, and at least one inner ring press-fitted into the small diameter stepped portion of the hub wheel, the inner member having a double row inner raceway surface facing the double row outer raceway surfaces;
a double row of rolling elements rollably accommodated between the raceway surfaces of the outer member and the inner member;
a sealing device that closes an open end on one axial end side of an annular space formed by the outer member and the inner member,
The sealing device includes:
a core bar having a fitting portion that is fitted to an inner peripheral surface at one axial end of the outer member and an inner portion that extends from the one axial end of the fitting portion toward an inner diameter side;
a seal member having a side lip that is integrally joined to the core metal and extends from the inner side of the core metal toward the wheel mounting flange side, and a flat portion that extends from a base end of the side lip that is located on the outermost diameter side toward the outer diameter side and faces one axial end side,
A wheel bearing device in which an outer diameter end of the side lip is located 1 mm or more on the inner diameter side of the outer diameter end of the flat portion. the outer member has an inner circumferential surface at one axial end portion into which the fitting portion of the core metal is fitted, the inner circumferential surface having a tapered surface that increases in diameter toward the one axial end portion,
2. The wheel bearing device according to claim 1, wherein one axial end of the tapered surface has a curved shape with a radius of curvature of 0.5 mm or more when viewed in the circumferential direction. the seal member has a nose portion located on the other axial end side of the flat portion and protruding radially outward from the fitting portion of the core metal,
3. The wheel bearing device according to claim 1, wherein the nose portion is elastically deformed by being pressed against the inner circumferential surface when the fitting portion is fitted to the inner circumferential surface of the outer member, and does not protrude axially beyond the flat portion.

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