JP2023059571A - Wheel bearing device - Google Patents

Abstract

To provide a wheel bearing device capable of suppressing the entry of foreign matters such as muddy water spreading from a flange part into a bearing space without the need to enlarge the bearing space.SOLUTION: The wheel bearing device includes an outward member 2, an inward member 1 having a flange part 6, double row rolling elements rollingly stored between both the rolling surfaces of the inward member 1 and the outward member 2 via a cage, and a seal device 10 mounted to the end of the annular space of a bearing. An external seal 30 for covering a clearance in the axial direction formed between an outer side end 22 of the outward member 2 and a flange part 6 side of a hub ring 4 is mounted to the flange part 6, The external seal 30 has a base part 30p mounted to the flange part 6, and an eaves part 30a extending from the base part 30p to the inner side while inclining in the inner diameter direction.SELECTED DRAWING: Figure 5

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel bearing device for rotatably supporting a wheel of an automobile or the like with respect to a suspension system, and more particularly to a wheel bearing device for suppressing the intrusion of muddy water or the like into the sliding portion of a seal lip of a seal device. is.

2. Description of the Related Art In vehicles such as automobiles, wheel bearing devices are used to support wheels. A wheel bearing device includes an outer member attached to a knuckle on the vehicle body side, an inner member having a flange portion to which a wheel is attached on the outer side of the vehicle body in the axial direction, and between the outer member and the inner member. It has a plurality of intervening rolling elements and a retainer that holds the plurality of rolling elements. Such a wheel bearing device is provided with a seal device mounted in an annular space formed between the outer member and the inner member to prevent foreign matter such as muddy water from entering the annular space. I'm in.

In the wheel bearing device, muddy water or the like may flow along the outer peripheral surface of the outer member from the knuckle or the like of the vehicle body to which the outer member is attached and flow toward the outer side of the vehicle body. Patent Literature 1 discloses a wheel bearing device that prevents muddy water or the like flowing along the outer peripheral surface of the outer member from reaching the seal lip of the seal device.

This conventional wheel bearing device will be described with reference to FIG. In the conventional wheel bearing device, the sealing device 150 is mounted on the outer side of the annular space formed between the outer member 160 and the inner member 161 . The inner member 161 is composed of a hub wheel 162 and a separate inner ring (not shown) fitted on the hub wheel 162 . The hub wheel 162 integrally has a wheel mounting flange 163 for mounting a wheel (not shown) on the outer end thereof, and the wheels are fixed at the equidistant positions on the circumference of the wheel mounting flange 163. A hub bolt (not shown) is installed. The outer circumference of the hub wheel 162 is formed with an outer side (one) inner raceway surface 162a and a small-diameter stepped portion (not shown) extending axially from the inner raceway surface 162a. An inner ring (not shown) having the other inner raceway surface is press-fitted into the inner ring.

An outer raceway surface 160a is formed on the inner circumference of the outer member 160 so as to face the inner raceway surface 162a. A rolling element 165 is rotatably accommodated via a retainer 166 between the rolling surfaces 162a and 160a.

The sealing device 150 includes a slinger 151 and an annular sealing member 152 that contacts the slinger 151 .

The slinger 151 includes an inner cylindrical portion 151a press-fitted into the outer diameter surface 162b of the hub wheel 162, a standing plate portion 151b extending radially outwardly from the inner cylindrical portion 151a, and extending from the outer diameter end of the standing plate portion 152b to the vehicle body. and an outer cylindrical portion 151c extending toward the inner side of the housing.

The sealing member 152 has a metal core 153 and a rubber elastic member 152 r fixed to the metal core 153 . The core metal 153 has an outer cylindrical portion 153b fitted to the outer peripheral surface of the outer end portion of the outer member 160, and an upright plate portion 153a radially extending from the outer end portion of the outer cylindrical portion 153b. ing.

The elastic member 152r includes a seal lip portion 152b extending outward and contacting the upright portion 151b of the slinger 151, a seal lip portion 152b extending toward the inner side and contacting the inner cylindrical portion 151a of the slinger 151, and an outer cylindrical portion of the metal core 153. and an outer seal portion 152c extending toward the inner side along the portion 153b.

The inner peripheral side of the outer cylindrical portion 151c of the slinger 151 and the outer peripheral side of the outer seal portion 152c face each other with a gap g in the radial direction.

In the seal device 150 described above, the clearance g between the outer cylindrical portion 151c of the slinger 151 and the outer seal portion 152c of the seal member 152 is used as a labyrinth clearance, and foreign matter such as muddy water enters the sliding contact portions of the seal lips 152a and 152b. restrain from doing.

However, in the seal device of Patent Document 1 described above, it is necessary to attach the slinger 151 by press-fitting the inner cylindrical portion 151 a into the outer diameter surface 162 b of the hub wheel 162 . Therefore, a space is required for mounting the slinger 151 between the outer end of the outer member 160 and the flange portion 163 of the hub wheel 162 . As a result, there is a drawback that the distance between the outer end of the outer member 160 and the inner member 161 facing the outer member 160 is increased.

Japanese Patent Laid-Open No. 2002-100002 discloses a wheel bearing device that reduces the intrusion of foreign matter into a seal device on the inner side of a vehicle. This wheel bearing device has a hub 172 and a knuckle 171 having a shaft portion 177 extending from a base portion 171a toward the outer side of the vehicle body, as shown in FIG. An outer ring 173 a is press-fitted to the inner peripheral side of the hub 172 and an inner ring 173 b is fixed to the outer peripheral side of the shaft portion 177 . Tapered rollers 173c are accommodated between the outer ring 173a and the inner ring 173b, and the hub 172 is rotatably supported with respect to the shaft portion 177. As shown in FIG. A sealing device 174 is provided on the inner end surface of the hub 177 to prevent foreign matter from entering the bearing space.

A wheel speed sensor rotor 178 that rotates integrally with the hub 172 is provided on the outer periphery of the hub 172 inside the vehicle body.

A die cover 175 is fixed to the base portion 171 a of the knuckle 171 by bolts 176 to prevent foreign matter such as muddy water from entering through the knuckle 171 .

The doubt cover 175 extends from the base portion 171 a toward the outer side so as to cover the rotor 178 .

By attaching the dust cover 175 so that the front end portion of the dust cover 175 protrudes outward from the rotor 178 in this way, even if, for example, muddy water falls down along the dust cover 175 as foreign matter, it does not enter the inside of the hub 172. can be reduced.

However, the dust cover disclosed in Patent Document 2 cannot prevent muddy water or the like from entering the bearing space, which runs along the hub 172 from the outer side of the vehicle body to the inner side.

JP 2019-19865 A JP 2010-149618 A

The wheel bearing device of Patent Document 1 described above has drawbacks such as the need to increase the annular space formed between the outer member 160 and the inner member 161 . Further, in Patent Document 2 described above, it is not possible to sufficiently prevent foreign matter such as muddy water from entering the bearing space from the outer side of the vehicle body to the inner side, for example, along the flange portion.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a wheel bearing device capable of suppressing the intrusion of foreign matter such as muddy water running along the flange portion into the bearing space without enlarging the bearing space.

The wheel bearing device of the present invention, which solves the above problems, comprises an outer member integrally formed with a double-row outer raceway surface on its inner circumference and a double-row outer raceway surface on its outer circumference facing the double-row outer raceway surface. an inner member having a row of inner raceway surfaces formed thereon; double-row rolling elements that are rollably accommodated via a retainer between the raceway surfaces of the inner member and the outer member; A wheel hub having sealing devices attached to both ends of an annular space formed between the outer member and the inner member, wherein the inner member integrally has a flange portion at one end to which a wheel is attached. in the wheel bearing device in which hub bolts are implanted at equidistant positions in the circumferential direction of the flange portion, formed between the outer side end portion of the outer member and the flange portion side of the hub ring An external seal that covers the gap in the axial direction is attached to the flange portion, and the external seal includes a base portion that is attached to the flange portion and an eave portion that extends from the base portion toward the inner diameter direction at an angle. characterized by having

Further, the distance between the tip of the eaves portion of the external seal and the outer peripheral surface of the outer member is set to be larger than 0.5 mm and smaller than 1.0 mm, and the end of the tip of the external seal is formed. and the outer peripheral surface of the outer member.

Further, the distance between the tip portion of the outer seal and the outer end portion of the outer member may be set within a range of more than 0.5 mm and less than 5 mm.

Further, the hub bolt has a shaft portion implanted in the flange and a head portion provided on the shaft portion, and a mounting hole into which the hub bolt is inserted is provided in the base portion of the external seal, The hub bolt may be inserted through the attachment hole of the base portion, and the outer seal may be sandwiched and fixed between the head portion of the hub bolt and the flange portion.

The hub bolt has a shaft portion implanted in the flange and a cylindrical head portion provided on the shaft portion, and an arcuate cutout for fitting the head portion of the hub bolt into the base of the outer seal. A portion may be provided into which the head of the hub bolt and the cutout portion of the base are fitted so that the outer seal is attached to the flange portion.

A stepped portion may be formed on the outer peripheral surface of the head of the hub bolt, and a stepped portion that engages with the stepped portion on the outer peripheral surface of the head may be formed in the notch.

Further, the head portion of the hub bolt may be provided with a tapered portion whose diameter is reduced toward the flange portion, and the notch portion may be formed with a tapered surface expanding from the head portion toward the flange portion. .

A protrusion may be provided on the outer periphery of the head of the hub bolt, and the notch may be formed with a recess engaging with the protrusion.

As described above, in the wheel bearing device according to the present invention, the outer seal covering the axial gap formed between the outer side end portion of the outer member and the flange portion side of the hub wheel is provided on the flange portion. By attaching to, it is possible to prevent foreign matter such as muddy water traveling along the flange portion and foreign matter such as muddy water traveling from the outer member side from reaching the sliding portion of each seal lip of the outer side seal device. . As a result, wear of the outer seal lip due to muddy water can be suppressed, and the service life of the outer seal device can be extended. In addition, since the outer seal is not installed in the annular space formed between the outer member and the inner member, but is attached to the flange portion on the outer diameter side of the annular space, it is necessary to increase the space of the bearing space. Therefore, the size of the wheel bearing device can be reduced.

1 is a perspective view showing a wheel bearing device according to a first embodiment of the present invention; FIG. 1 is a plan view showing an external seal used in a vehicle bearing device according to a first embodiment of the invention; FIG. FIG. 3 is an enlarged cross-sectional view of a main part taken along line AA of FIG. 2; 1 is a longitudinal sectional view showing a wheel bearing device according to a first embodiment of the present invention; FIG. FIG. 2 is a partially enlarged view showing an outer-side seal portion of the wheel bearing device according to the first embodiment of the present invention; FIG. 2 is a partial enlarged view showing the outer side bolt seating surface portion and the external seal portion of the wheel bearing device of the first embodiment of the present invention; Fig. 2 is a perspective view showing a wheel bearing device according to a second embodiment of the present invention; FIG. 6 is a plan view showing an external seal used in the vehicle bearing device of the second embodiment of the invention; FIG. 9 is a cross-sectional view taken along line AA of FIG. 8; FIG. 5 is a perspective view showing an external seal used in a vehicle bearing device according to a second embodiment of the invention; FIG. 6 is a vertical cross-sectional view showing a wheel bearing device according to a second embodiment of the present invention; FIG. 5 is a partially enlarged view showing a first external seal portion engaged with the head portion of the hub bolt of the wheel bearing device according to the second embodiment of the present invention; FIG. 5 is a partially enlarged view showing a second external seal portion engaged with the head portion of the hub bolt of the wheel bearing device according to the second embodiment of the present invention; FIG. 5 is a partially enlarged view showing a third external seal portion engaged with the head portion of the hub bolt of the wheel bearing device according to the second embodiment of the present invention; FIG. 5 is a partial enlarged view showing Modification 1 of the first external seal portion engaged with the head portion of the hub bolt of the wheel bearing device of the second embodiment of the present invention; FIG. 11 is a partially enlarged view showing Modification 2 of the first external seal portion engaged with the head portion of the hub bolt of the wheel bearing device of the second embodiment of the present invention; FIG. 11 is a partial enlarged view showing Modified Example 3 of the first external seal portion engaged with the head portion of the hub bolt of the wheel bearing device of the second embodiment of the present invention; It is a partially enlarged view showing a conventional wheel bearing device. FIG. 10 is a partially enlarged view showing an outer-side sealing portion in a conventional wheel bearing device;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the side closer to the outside of the vehicle body when attached to the vehicle body is referred to as the outer side (left side in FIG. 4), and the side closer to the center is referred to as the inner side (right side in FIG. 4).

The wheel bearing device shown in FIGS. 1 and 4 is for a so-called third generation drive wheel, and is attached to a suspension device (knuckle) provided on the vehicle body side of a vehicle to rotatably support the wheel. do. The wheel bearing device includes an inner member 1, an outer member 2, and balls 3, 3 as double-row rolling elements housed between the members 1, 2 so as to be free to roll.

The wheel bearing device includes a sealing device 10 mounted on the outer side in the axial direction and a sealing device 9 mounted on the inner side in the axial direction. In this wheel bearing device, the axial direction is a direction parallel to the central axis C (see FIG. 4) of the wheel bearing device. A radial direction is a direction perpendicular to the axial direction.

The outer member 2 has a cylindrical main body portion 21 and a flange portion 2b for fixing to the vehicle body, which is provided so as to extend radially from the main body portion 21 . In this embodiment, four flange portions 2b are provided. The flange portion 2b is provided with screw holes 2c through which bolts for fixing to the vehicle body are inserted.

The outer member 2 is attached to a knuckle (not shown), which is a vehicle body member, by means of the flange portion 2b. As a result, the wheel bearing device including the outer member 2 is fixed to the vehicle body.

The flange portion 6 is provided with a bolt seat surface 61 at a position where the hub bolt 7 is implanted. A hub bolt 7 is planted in. A shaft portion 70 of the hub bolt 7 is formed with a spline 70a.

A head portion 71 of a hub bolt is positioned on the inner side of the flange portion 6, and a screw thread of the hub bolt 7 is positioned on the outer side. In this embodiment, five bolt bearing surfaces 61 are provided at equidistant positions on the flange portion 6 in the circumferential direction, and five hub bolts 7 are implanted at equidistant positions on the flange portion 6 in the circumferential direction.

As will be described later, an external seal 30 is attached to the flange portion 6 to cover an axial gap formed between the outer end portion of the outer member 2 and the flange portion 6 side.

The vehicle bearing device will be further described with reference to FIG. An inner member 1 of a vehicle bearing device comprises a hub wheel 4 and an inner ring 5 press-fitted into the hub wheel 4 .

The hub wheel 4 integrally has a flange portion 6 at one end for mounting a wheel, and has an outer inner raceway surface 4a on the outer periphery and a cylindrical small-diameter step extending axially from the inner raceway surface 4a. A portion 4b is formed, and serrations (or splines) 4d for torque transmission are formed on the inner circumference.

As described above, the bolt bearing surfaces 61 are provided at equidistant positions in the circumferential direction of the flange portion 6, and the hub bolts 7 are driven into the mounting holes 61a provided in the bolt bearing surfaces 61, and the hub bolts 7 are implanted. ing. The inner ring 5 has an inner raceway surface 5a formed on its outer circumference, and is press-fitted to the small-diameter stepped portion 4b of the hub wheel 4 with a predetermined interference. The hub bolt 7 has a shaft portion 70 that is driven into the bolt seat surface 61 and a head portion 71 that contacts the bolt seat surface 61 .

The outer member 2 is integrally formed with double rows of outer raceway surfaces 2a, 2a facing the inner raceway surfaces 4a, 5a of the inner member 1 on the inner periphery thereof. Between the rolling surfaces 4a, 2a and 5a, 2a, double rows of balls 3, 3 as rolling elements are rotatably accommodated via retainers 8. As shown in FIG.

Sealing devices 9 and 10 are attached to both ends of the outer member 2 to seal both ends of the annular space formed between the outer member 2 and the inner member 1 . The seal devices 9 and 10 prevent the lubricating grease sealed inside the bearing from leaking to the outside and prevent muddy water, dust, etc. from entering the bearing from the outside.

Here, the inner-side sealing device 9 is composed of a so-called pack seal composed of a slinger 91 and an annular seal plate 92 arranged to face each other.

As shown in an enlarged view in FIG. 5, the outer side sealing device 10 includes a core metal 13 having a substantially L-shaped cross section and a seal body fixed to the core metal 13. 14. The sealing device 10 is attached to the outer member 2 by fitting the cylindrical portion 13 a of the core metal 13 to the inner diameter surface of the outer member 2 .

The seal body 14 is made of synthetic rubber such as NBR (acrylonitrile-butadiene rubber), and includes a pair of side lips 14a and 14b as seal lips extending radially outward at an angle. and a grease lip 14c as a seal lip extending obliquely. The side lips 14a, 14b and the grease lip 14c contact an outer diameter surface 4c formed by extending from the inner raceway surface 4a of the hub wheel 4 toward the outer side. The side lips 14a and 14b prevent dust and muddy water from entering from the outside, and the grease lip 14c prevents leakage of the enclosed lubricant.

In this embodiment, an external seal 30 is attached to the flange portion 6 to cover the axial gap formed between the outer end portion 22 of the outer member 2 and the flange portion 6 side of the hub wheel 4 . . The external seal 30 has an annular base portion 30P attached to the flange portion 6, and an eaves portion 30a extending from the base portion 30p toward the inner side while being inclined in the radial direction. The eaves portion 30 a of the external seal 30 is formed between the outer side end portion 22 of the outer member 2 and the flange portion 6 side of the hub wheel 4 in the axial direction when the external seal 30 is attached to the flange portion 6 . It is shaped to cover the gap.

As shown in FIG. 3, the external seal 30 in the first embodiment is provided with mounting holes 30b corresponding to the mounting holes 61a of the bolt bearing surface 61 in the annular base portion 30p. The eaves portion 30a of the external seal 30 is formed by bending from the inner peripheral side of the annular base portion 30p so as to obliquely extend toward the inner peripheral side. When the outer seal 30 is sandwiched between the head portion 71 of the hub bolt 7 and the bolt seat surface 61 and attached to the flange portion 6, the eaves portion 30a extends from the annular base portion 30p in the inner diameter direction at an angle, It is bent so as to be arranged along the outer peripheral surface of the outer member 2 .

As shown in FIG. 6, the eaves portion 30a of the external seal 30 rises obliquely from the base portion 30p in contact with the bolt bearing surface 61 toward the inner side at an angle α. By providing an oblique angle to the eaves portion 30a, the external seal 30 is configured so that mud or the like does not accumulate. The angle α is in the range of 15° to 75°. 6, illustration of the spline of the shaft portion 70 of the hub bolt 7 is omitted.

As shown in FIGS. 5 and 6, the external seal 30 is formed by inserting the hub bolt 7 through the mounting hole 30b and driving the shaft portion 70 of the hub bolt 7 formed with the spline 70a into the mounting hole 61a of the bolt seat surface 61. As shown in FIGS. When implanted, the base portion 30p of the external seal 30 is sandwiched between the bolt bearing surface 61 and the head portion 71 of the hub bolt 7, and the external seal 30 is fixed to the flange portion 6. As shown in FIG.

As shown in FIG. 6, a clearance F formed between the tip of the eaves portion 30a of the external seal 30 and the outer peripheral surface of the body portion 21 of the outer member 2 is configured to form a labyrinth clearance. there is This gap F is set in the range of 0.5 mm to 1.0 mm. If the gap is less than 0.5 mm, there is a risk that the eaves portion 30a of the external seal 30 and the outer peripheral surface of the main body portion 21 will come into contact with each other when they are relatively displaced due to the precision of the parts and the load. Therefore, it is preferable to set the gap F to 0.5 mm or more. Further, if the gap F exceeds 1.0 mm, the labyrinth effect is reduced, so the gap F is preferably 1.0 mm or less. By forming the labyrinth gap in this way, it is possible to suppress the entry of foreign matter from between the eaves portion 30 a and the outer peripheral surface of the main body portion 21 .

A distance E between the outer end portion 22 of the outer member 2 and the tip portion of the eaves portion 30a of the external seal 30 is set within a range of 0.5 mm to 5 mm. The lower limit of 0.5 mm of the distance E is set in consideration of a dimension equal to or greater than the size of the chamfered shape of the outer side end portion 22, and the upper limit of 5 mm is set in consideration of material costs and the like.

The external seal 30 is made of corrosion-resistant stainless steel (SUS) with a plate thickness of 0.2 mm to 3 mm and is formed by pressing.

By providing the external seal 30 in this manner, it is possible to prevent muddy water or the like from reaching the sliding portions of the seal lips of the seal device 10 . As a result, wear of the seal lip due to muddy water can be suppressed, and the service life of the seal device can be extended. Moreover, since the external seal 30 is not installed in the bearing space, it is not necessary to take up a large space in the bearing space.

Further, the tip portion of the eaves portion 30a of the external seal 30 is arranged with a gap from the outer peripheral surface of the outer member 2 . This eliminates the need for machining the outer peripheral surface of the outer member 2 .

Next, a wheel bearing device according to a second embodiment of the present invention will be described with reference to FIGS. 7 to 12. FIG. The same reference numerals are given to the same parts as in the first embodiment, and the description thereof will be omitted.

This second embodiment differs from the first embodiment in the configuration of the external seal. The outer seal 30 of the first embodiment is fixed to the flange portion 6 with the base portion 30p sandwiched between the bolt seat surface 61 of the flange portion 6 and the head portion 71 of the hub bolt 7. As shown in FIG. On the other hand, in the external seal 30s of the second embodiment, the notch 30c is provided in the base portion 30p, and the notch 30c is formed in the outer periphery of the cylindrical head portion 71 of the hub bolt 7 implanted in the bolt bearing surface 61. is fitted to be attached to the flange portion 6. - 特許庁

As shown in FIGS. 9 to 11, the outer seal 30s of the second embodiment has a circular shape corresponding to the outer circumference of a cylindrical bolt head 71 implanted in the bolt bearing surface 61 on the outer circumference side of the base portion 30p. An arc-shaped notch 30c is provided. The eaves portion 30a provided on the inner peripheral side of the external seal 30s is obliquely bent in the same manner as in the first embodiment.

A peripheral edge portion 30d on the outer peripheral side of the external seal 30s is bent toward the outer side in the axial direction.

The external seal 30s of the second embodiment has a height at which the tip of the peripheral edge portion 30d comes into contact with the bolt bearing surface 61 when the notch portion 30c is fitted into the bolt head portion 71 implanted in the bolt bearing surface 61. is formed to be That is, the outer periphery of the external seal 30s is formed to be large by the mounting height with respect to the bolt bearing surface 61, and a peripheral edge portion 30d is formed by pressing so as to be substantially orthogonal to the outer side.

Furthermore, as shown in FIGS. 8 and 10, when the outer seal 30s of the second embodiment is fitted with the notch 30c on the outer peripheral surface of the bolt head 71 implanted in the bolt bearing surface 61, A notch 30f is provided to facilitate mounting.

The bolt head 71 implanted in the bolt bearing surface 61 of the flange portion 6 is aligned with the notch portion 30c of the outer seal 30s, and the outer seal 30s is pushed toward the outer side while being bent. The notch 30c of the outer seal 30s is fitted into the bolt head 71 implanted in the bolt bearing surface 61, thereby fixing the outer seal 30s. When the notch 30c of the external seal 30s is fitted into and engaged with the bolt head 71 implanted in the bolt bearing surface 61, the notch 30c of the external seal 30s is fitted into the peripheral surface of the bolt head 71. As shown in FIG. When the notch portion 30c of the outer seal 30s is fitted into the bolt head portion 71, the notch portion 30c of the outer seal 30s is formed so as to prevent the outer seal 30s from falling off the flange portion 6 even when the flange portion 6 rotates. Each dimension is set. As shown in FIG. 11, when the notch 30c of the outer seal 30s is fitted into the bolt head 71 and the outer seal 30s is attached to the flange portion 6, the outer seal 30s is positioned on the outer side of the outer member 2. It covers the axial gap formed between the end portion 22 and the flange portion 6 side of the hub wheel 4 .

In the second embodiment, as shown in FIGS. 7 and 12, the bolt head 71 is provided with a stepped portion 71a having a reduced diameter toward the bolt seat surface 61, and the peripheral edge portion 30d of the notch portion 30c is also provided with a stepped portion 71a. A stepped portion 30k protruding to the outer peripheral side is provided corresponding to 71a. When the notch portion 30c is fitted into the head portion 71 of the hub bolt 7, the external seal 30 is removed from the head portion 71 of the hub bolt 7 by the step portion 71a of the head portion 71 and the step portion 30k of the peripheral edge portion 30d of the external seal 30. can be prevented from coming off.

Thus, in the second embodiment, the notch 30c provided in the external seal 30s is fitted into the bolt head 71, and the external seal 30s is attached to the bolt seating surface 61 side of the flange portion 6. As shown in FIG. In the first embodiment, the external seal 30 is sandwiched between the bolt bearing surface 61 and the head portion 71 of the hub bolt 7 and attached. Therefore, after assembling the external seal 30, the external seal 30 alone cannot be replaced. On the other hand, in the second embodiment, the external seal 30 is simply held by fitting the notch 30c into the head 71 of the hub bolt 7, so the external seal 30 can be retrofitted or removed. can be done.

Also, the outer seal 30s may be divided into two or more parts in the circumferential direction. By constructing two or more parts, the external seal 30s can be easily attached and detached.

Next, another specific example of engaging the notch 30c provided in the outer seal 30s with the bolt head 71 will be described with reference to FIGS. 13 and 14. FIG.

In the specific example shown in FIG. 13, a peripheral portion 30d of the outer seal 30s bent toward the outer side is formed in a tapered shape expanding in the radial direction. A head portion 71 of the hub bolt 7 is provided with a tapered portion 71 t whose diameter is reduced toward the bolt bearing surface 61 . When the cutout portion 30c is fitted into the head portion 71 of the hub bolt 7, the outer seal 30 is removed from the head portion 71 of the hub bolt 7 due to the tapered shape of the tapered portion 71t of the head portion 71 and the peripheral edge portion 30d of the outer seal 30. You can prevent it from coming off.

In the specific example shown in FIG. 14, the notch 30c of the external seal 30s is provided with a recess 30e, and the head 71 of the hub bolt 7 is provided with a protrusion 71b that engages with the recess 30e. The recess 30e of the notch 30c and the projection 71b of the head 71 of the hub bolt 7 are engaged to fix the external seal 30s to the bolt head 71. As shown in FIG.

Next, modified examples of the outer seal 30s will be described with reference to FIGS. 15 to 17. FIG.

In the modification shown in FIG. 15, a brush 30h is attached to the eaves portion 30a of the outer seal 30s, and the outer seal 30s is attached so that the brush 30h contacts the outer peripheral surface of the outer member 2. FIG. Intrusion of muddy water or the like is further prevented by attaching the brush 30h. Further, since the brush 30h is provided at a position facing the outer peripheral surface of the outer member 2 of the eaves portion 30a, there is no problem even if the eaves portion 30a contacts the outer peripheral surface of the main body portion 21 of the outer member 2.

Next, in the modification shown in FIGS. 16 and 17, an elastic member 30g is attached to the eaves portion 30a of the external seal 30s. In Modified Example 2 shown in FIG. 17, the tip of the external seal 30s is formed in a triangular cross section, and the elastic member 30g is also formed in a triangular shape to match the triangular shape. 17, the tip of the external seal 30s is formed to have a rectangular cross section, and the elastic member 30g is also formed to have a U-shape so as to cover the tip of the rectangular eaves portion 30a. there is As shown in FIGS. 16 and 17, by attaching the elastic member 30g to the outer seal 30s, there is no problem even if it comes into contact with the outer peripheral surface of the outer member 2, and the dimensional accuracy of the outer seal 30s has a margin.

Further, in the above-described embodiment, the outer seal 30 (30s) is formed in an annular shape. In this case, in consideration of water resistance, it is preferable to cover the space between the outer member and the flange portion for more than half the circumference.

Further, in the above-described embodiment, the external seal 30 is sandwiched and fixed between the bolt head 71 and the flange portion 6, but it may be configured to be directly attached to the flange 7 with a bolt or the like.

The present invention is by no means limited to the above-described embodiments, and can of course be embodied in various forms without departing from the gist of the present invention. and includes equivalents and all changes within the scope of the claims.

Reference Signs List 1 : Inner member 2 : Outer member 2a : Outer raceway surface 2b : Flange 3 : Ball 4 : Hub ring 6 : Flange 61a : Mounting hole 7 : Hub bolt 71 : Head 8 : Cage 9 : Seal device 10: Seal device 30: External seal 30a: Eaves 30b: Mounting hole 30c: Notch 30d: Peripheral edge 30p: Base

Claims (8)

an outer member integrally formed with a double-row outer raceway surface on its inner circumference; an inner member with an outer circumference formed with a double-row inner raceway surface facing the double-row outer raceway surface; A double-row rolling element, which is rollably accommodated via a retainer between both rolling surfaces of the inner member and the outer member, is formed between the outer member and the inner member. and sealing devices attached to both ends of the annular space, the inner member having a hub wheel integrally having a flange portion to which a wheel is attached at one end portion, and hub bolts being installed at the circumferentially equidistant positions of the flange portion. In a wheel bearing device implanted with
an external seal is attached to the flange portion to cover an axial gap formed between the outer end portion of the outer member and the flange portion side of the hub wheel;
The wheel bearing device, wherein the outer seal has a base portion attached to the flange portion, and an eaves portion extending from the base portion toward the inner side so as to be inclined in an inner diameter direction. The distance between the tip of the eaves of the external seal and the outer peripheral surface of the outer member is set to be larger than 0.5 mm and smaller than 1.0 mm, and the eaves of the external seal and the outer 2. The wheel bearing device according to claim 1, wherein a labyrinth gap is formed between the member and the outer peripheral surface thereof. 3. The distance between the tip portion of the outer seal and the outer end portion of the outer member is set to a range larger than 0.5 mm and smaller than 5 mm. wheel bearing device. The hub bolt has a shaft portion implanted in the flange and a head portion provided on the shaft portion,
The base portion of the outer seal is provided with a mounting hole into which the hub bolt is inserted, the hub bolt is inserted into the mounting hole of the base portion, and the outer seal is formed between the head portion of the hub bolt and the flange portion. The wheel bearing device according to any one of claims 1 to 3, wherein the bearing device is sandwiched and fixed. The hub bolt has a shaft portion implanted in the flange and a columnar head portion provided on the shaft portion,
The base of the outer seal is provided with an arc-shaped notch into which the head of the hub bolt is fitted, the head of the hub bolt and the notch of the base are fitted, and the outer seal is attached to the flange. A wheel bearing device according to any one of claims 1 to 3, characterized in that: 6. The hub bolt according to claim 5, wherein a stepped portion is formed on the outer peripheral surface of the head portion of the hub bolt, and the notch portion is formed with a stepped portion that engages with the stepped portion on the outer peripheral surface of the head portion. wheel bearing device. A head portion of the hub bolt is provided with a tapered portion whose diameter is reduced toward the flange portion, and the notch portion is formed with a tapered surface that widens from the head portion toward the flange portion. The wheel bearing device according to claim 5. 6. A wheel bearing device according to claim 5, wherein a projection is provided on the outer circumference of the head of said hub bolt, and said notch is formed with a recess that engages with said projection.

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