JP2009014180A - Pack seal rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pack seal having improved performance while preventing an increase of seal torque even when consisting of a plurality of lip seals, and to provide a rolling bearing to which the pack seal is applied. <P>SOLUTION: The pack seal comprises a sectionally L-shaped core metal 3 having a seal member integrally provided and formed of an elastic material having a side lip seal 4 and a main lip seal 3, and an annular portion 33 integrally provided extending from one end 32 of an cylinder portion 31 in the direction of the outer diameter, a cylinder portion 21 opposed to the cylinder portion of the core metal and having slide contact with the front end of the main lip seal, and a slinger 2 integrally provided extending from one end 22 of the cylinder portion in the direction of the outer diameter, opposed to the annular portion of the core metal, and sectionally L-shaped at the annular portion 23 having slide contact with the front end of the side lip seal. All or part of a base end 52 of the main lip seal is formed adjacent to all or part of a base end 42 of the side lip seal, and the front end 51 of the main lip seal is linked with the front end 41 of the side lip seal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pack seal that seals the inside and outside of an object to be protected, and more particularly, to an improvement in the performance of a pack seal used for a hub unit bearing.

  Conventionally, for example, in hub unit bearings that suspend automobile wheels, in order to prevent the intrusion of muddy water and the like from the outside of the bearing and to prevent the lubricating oil from flowing out from the inside of the bearing, the inside of the bearing is sealed from the outside of the bearing. Pack seal is arranged. In addition, when the pack seal is arranged on the hub unit bearing, the area where the pack seal of the hub unit bearing is arranged is narrow and the size of the pack seal is relatively small. Therefore, a plurality of lip seals should be provided on the pack seal. The sealing performance is improved.

  As such a pack seal, conventionally, as shown in FIG. 5 (a), an annular portion 23 is integrally extended in an outer diameter direction from one end 22 of the cylindrical portion 21, and is configured in an L shape in cross section. The slinger 2 and the metal core 3 that is formed in an L-shape in cross-section by integrally extending the annular portion 33 in the outer diameter direction from one end 32 of the cylindrical portion 31 are formed in one cylindrical portion 21 and the other cylindrical portion. While the part 31 is opposed, one annular part 23 and the other annular part 33 are arranged to face each other, and the cored bar 3 is a seal made of an elastic material provided integrally with the cored bar 3. The member 3a constitutes a lip seal. Further, as shown in FIG. 5B, the metal core 3 may have a circular ring portion 33 having a stepped portion 34.

In the case of the pack seal shown in FIG. 5, the side lip seal 4, the main lip seal 5, and the oil lip seal 6 are integrally formed of the same material.
The side lip seal 4 has a base end portion 42 that is integrally fixed to the inner peripheral end 33 a of the core metal 3, and a tip end portion 41 that extends from the base end portion 42 toward the annular portion 23. Is in sliding contact with the inner peripheral surface 23a.
The main lip seal 5 includes a base end portion 52 that is integrally fixed to the inner peripheral end 33a of the core metal 3, and the base end portion 52 to the one end 22 side of the cylindrical portion 21 (the ring portion 23 extending side). The leading end 51 extending toward the inner surface is in sliding contact with the inner peripheral surface 21 a of the cylindrical portion 21.
The oil lip seal 6 has a base end portion 62 fixed integrally to the inner peripheral end 33a of the core metal 3 and a tip end portion 61 extending from the base end portion 62 toward the free end side of the cylindrical portion 21 in a cylindrical shape. The portion 21 is in sliding contact with the inner peripheral surface 21 a.

  At this time, the base end portion 52 of the main lip seal 5 and the base end portion 62 of the oil lip seal 6 are formed close to each other, and the base end portion 52 and the base end portion 62 and the base end portion of the side lip seal 4 are formed. A constriction 7 having a small thickness in the direction orthogonal to the annular portion 23 of the slinger 2 is formed between the slinger 2 and the ring portion 42. When the tip portion 41 of the main lip seal 5 is moved due to wear or the like by the constriction 7, the movement amount of the main lip seal 5 is absorbed by the deformation of the constriction 7, and the tip portion 51 of the main lip seal 5 is It does not move in conjunction.

In the pack seal having such a configuration, the side lip seal 4 and the main lip seal 5 extend in the direction of the annular portion 23 of the slinger 2 to serve as a dust seal that prevents intrusion of muddy water from the outside. The oil lip seal 6 extends in a direction opposite to the direction of the annular portion 23 of the slinger 2 to serve as an oil seal that prevents the lubricating oil from flowing out from the inside.
In Patent Document 1, an elastic ring is fitted on the outer diameter side of the main lip seal, and the main lip seal is always pressed against the inner peripheral surface 21a of the cylindrical portion 21 of the slinger 2, so that the function of the dust seal can be reliably achieved. The configuration is disclosed. Also in this case, the base end portion of the main lip seal and the base end portion of the oil lip seal are formed close to each other, and a constricted portion is formed between the base end portion and the base end portion of the side lip seal. The main lip seal is formed so as not to be affected by the movement of the side lip seal.

Japanese Patent Laid-Open No. 11-93961

However, in recent years, the problem of environmental protection and the problem of soaring fuel have caused the consumption of power due to the rotational torque of the hub unit bearing to be a problem when the hub unit bearing is rotated. In this case, the seal torque when the lip seal (the side lip seal 4, the main lip seal 5, and the oil lip seal 6) is in sliding contact with the slinger 2 occupies a large part that causes the rotational torque of the hub unit bearing to increase. .
In view of this, the applicant of the present application, in the conventional pack seal 1, the tip portions 41 and 51 of both the side lip seal 4 and the main lip seal 5 that play the role of dust seal are always in sliding contact with the slinger 2, and the seal torque We focused on the fact that the loss of power by increasing.

That is, when the front end 41 of the side lip seal 4 is in sliding contact with the inner peripheral surface 23 a of the annular portion 23 of the slinger 2, the front end 51 of the main lip seal 5 is the inner peripheral surface of the cylindrical portion 21 of the slinger 2. 21a is always in sliding contact. At this time, the front end portion 41 of the side lip seal 4 is not worn, and the front end portion 41 is in a healthy state in which the role of the dust seal is sufficiently fulfilled by sliding contact with the slinger 2. Therefore, the function of the main lip seal 5 as a dust seal is not necessary. Therefore, the seal torque generated by the sliding contact between the main lip seal 5 and the slinger 2 becomes a rotational torque that is increased unnecessarily for the hub unit bearing.
Further, since the main lip seal 5 and the slinger 2 are in sliding contact with each other even when the role as a dust seal is not yet required, the front end portion 51 of the main lip seal 5 is worn wastefully, and the side lip seal 4 When the front end portion 41 of the main body is worn and cannot function as a dust seal, the front end portion 51 of the main lip seal 5 has already been worn out, and the main lip seal 5 may not be able to perform the role of a dust seal sufficiently. .
Therefore, in the state where the side lip seal 4 is alive and muddy water or the like from the outside of the bearing has not reached the main lip seal 5, the tightening allowance of the main lip seal 5 is reduced, and the main lip seal 5 and the slinger 2 It is desired to reduce the rotational torque of the hub unit bearing and the wear of the main lip seal 5 by reducing the seal torque. However, such a technique is not known at present.

  An object of the present invention is to provide a pack seal with improved performance by preventing an increase in seal torque even if a plurality of lip seals are provided, and to provide a rolling bearing to which the pack seal is applied. is there.

  In order to achieve the above object, the technical means achieved by the present invention includes at least a seal member made of an elastic material having a side lip seal and a main lip seal, and has an outer diameter from one end of the cylindrical portion. An annular part integrally extending in the direction to form an L-shaped cross-sectional view, a cylindrical part facing the cylindrical part of the cored bar and having the main lip seal slidably contacted, and the cylinder A slinger that is integrally extended in an outer diameter direction from one end of the portion, and is configured in an L shape in cross-section with an annular portion that is opposed to the annular portion of the core metal and that is in sliding contact with the tip portion of the side lip seal; In this pack seal, all or part of the base end portion of the main lip seal is formed close to all or part of the base end portion of the side lip seal, and the tip end portion of the main lip seal is the side lip seal. Interlocking with the tip of the It resides in that the pack seal according to claim. In addition, the front end includes an oil lip seal that is in sliding contact with the cylindrical portion of the slinger, and the base end of the oil lip seal, the base end of the side lip seal, and the base end of the main lip seal are separately provided. The tip of the oil lip seal may not be interlocked with the tip of the side lip seal and the tip of the main lip seal. Moreover, it is good also as a rolling bearing which applied the above-mentioned pack seal.

  According to the present invention, even if a plurality of lip seals are provided, it is possible to prevent an increase in seal torque, to provide a pack seal with improved performance, and to provide a rolling bearing to which the pack seal is applied. it can.

Hereinafter, pack seal 1 concerning one embodiment of the present invention is explained based on an accompanying drawing. Note that the pack seal 1 of the present embodiment has a feature in the configuration of the lip seal, and the core metal 3 and the slinger 2 can use the pack seal 1 having a conventional configuration. The description will focus on the structure of a certain lip seal, and the description of the structure of the core metal 3 and slinger 2 will be omitted.
The configuration of the hub unit bearing is the same as the configuration of a conventional general hub unit bearing. For example, a fixed ring (for example, an outer ring) fixed to the vehicle body side and an inner side of the outer ring so as to be relatively rotatable with the outer ring. A rotating wheel (for example, an inner ring) provided oppositely and connected (fixed) to the wheel side and rotating together with the wheel; and a plurality of rolling elements rotatably incorporated in a double row (for example, two rows) between the inner and outer wheels A configuration including the above is applicable.

In the lip seal according to the present embodiment, as shown in FIG. 1A, the side lip seal 4 and the main lip seal 5 are integrally formed of the same material. In this embodiment, an elastic material such as nitrile rubber or acrylic rubber is used as a material for forming the lip seal. The material for forming the lip seal is not limited to this, and any material may be used as long as it can slide in contact with the slinger 2 and seal the inside of the bearing. For example, it may be formed of rubber, plastic, synthetic resin, or the like.
As in the conventional case, the pack seal functions as a dust seal that prevents intrusion of muddy water and the like from the outside by extending the side lip seal 4 and the main lip seal 5 toward the annular portion 23 of the slinger 2. As a result, the inside of the bearing is sealed.

The side lip seal 4 includes a base end portion 42 integrally fixed to the inner peripheral end 33a of the core metal 3, and a tip end portion 41 extending from the base end portion 42 toward the annular portion 23 of the slinger 2. The slinger 2 is in sliding contact with the inner peripheral surface 23 a of the annular portion 23.
The main lip seal 5 includes a base end portion 52 that is integrally fixed to the inner peripheral end 33a of the core metal 3, and one end 22 side of the cylindrical portion 21 of the slinger 2 extending from the base end portion 52 (an extension of the annular portion 23). The tip 51 extending toward the side) is in sliding contact with the inner peripheral surface 21 a of the cylindrical portion 21 of the slinger 2.

As a characteristic configuration of the pack seal according to the present embodiment, the entire base end portion 52 of the main lip seal 5 is formed in close proximity to all the base end portions 42 of the side lip seal 4, and the main lip seal The branch part 9 where the base end part 52 of 5 and the base end part 42 of the side lip seal 4 branch is formed thick (see dimension D1 in the figure).
The relationship between the tightening margin of the side lip seal 4 (see the solid line and dimension D3 in FIG. 2) and the tightening margin of the main lip seal 5 (see the solid line and dimension D4 in FIG. 2) is D3> D4. Have Further, the rigidity of the side lip seal 4 and the main lip seal 5 is set so that the rigidity of the side lip seal 4 is higher than the rigidity of the main lip seal 5.

  When the slinger 2 is fitted to the side lip seal 4 and the main lip seal 5 thus configured, as shown by the two-dot chain line in FIG. 1 and FIG. The distal end portion 41 of the side lip seal 4 extending in the outer diameter direction is pushed up counterclockwise when contacting the inner peripheral surface 23a of the annular portion 23 of the slinger 2 (see the counterclockwise arc arrow in the figure) When the tip 51 of the main lip seal 5 extending toward the cylindrical portion 21 abuts against the inner peripheral surface 21a of the cylindrical portion 21 of the slinger 2 while being slidably contacted while being deformed along the inner peripheral surface 23a, It is pushed up counterclockwise (refer to the left-pointed arc arrow in the figure), and comes into sliding contact with deformation along the inner peripheral surface 21a.

  At this time, the side lip seal 4 is set to have high rigidity and has a larger tightening allowance than the main lip seal 5, so that the tip 41 of the side lip seal 4 is pushed up counterclockwise. As a result, a large counterclockwise force is generated. Further, the force generated in the side lip seal 4 acts to move the base end portion 42 of the side lip seal 4 counterclockwise. That is, the branch portion 9 formed by the base end portion 42 of the side lip seal 4 and the base end portion 52 of the main lip seal 5 is lifted counterclockwise in conjunction with the side lip seal 4.

Since the base end portion 52 of the main lip seal 5 extends from the branch portion 9, the base end portion 52 of the main lip seal 5 is also counterclockwise when the branch portion 9 is lifted counterclockwise. Lifted to. As a result, the front end portion 51 of the main lip seal 5 moves in conjunction with the side lip seal 4.
In this case, the front end portion 51 of the main lip seal 5 is pulled up in a direction away from the inner peripheral surface 21a of the cylindrical portion 21 of the slinger 2. Therefore, the tightening allowance of the main lip seal 5 is smaller than before the pull-up. . Therefore, since the contact between the front end portion 51 of the main lip seal 5 and the inner peripheral surface 21a of the cylindrical portion 21 of the slinger 2 is weakened, the lip torque is reduced and the wear of the front end portion 51 can be reduced.

  At this time, since the main lip seal 5 is set to be lower in rigidity than the side lip seal 4, a clockwise tensile stress (a counterclockwise arc arrow B in FIG. 3) is applied to the distal end portion 51 of the main lip seal 5. The main lip seal 5 is deformed into an arc shape protruding in the counterclockwise direction (see the clockwise arc arrow A in FIG. 3). By this deformation, the front end portion 51 of the main lip seal 5 is opposed to the inner peripheral surface 21a of the cylindrical portion 21 of the slinger 2 (see the broken line in the figure) at a sharp intersection angle. When the crossing angle between the front end 51 of the main lip seal 5 and the inner peripheral surface 21a of the cylindrical part 21 of the slinger 2 is sharp (see the solid line in the figure), the crossing angle (see the dimension D6 in the figure) Since the contact is made with a width shorter than the contact width (see the dimension D5 in the figure) in the case where is not standing (see the two-dot chain line in the figure), the lip torque of the main lip seal 5 is further reduced.

  Further, as wear of the tip portion 41 of the side lip seal 4 progresses (see FIG. 4), the shape of the tip portion 41 of the side lip seal 4 is shortened by scraping the tip (reference numeral 41a in the figure). 41), the tip 41 of the side lip seal 4 is thereby gradually moved clockwise. When the distal end portion 41 of the side lip seal 4 moves clockwise, the base end portion 42 (branch portion 9) also moves clockwise, and the main lip seal 5 formed integrally with the branch portion 9 also rotates counterclockwise. Moving. Thereby, the front-end | tip part 51 of the main lip seal 5 is pulled down in the direction which approaches the internal peripheral surface 21a of the cylindrical part 21 of the slinger 2 (refer the code | symbol 51a and the code | symbol 51 in a figure), and the main lip seal 5 gradually , Get back the original allowance. Until this time, since the wear of the main lip seal 5 has been reduced, the role of the dust seal can be sufficiently fulfilled in place of the worn side lip seal 4. Therefore, the effect of extending the life of the dust seal composed of the side lip seal 4 and the main lip seal 5 can be obtained.

In this embodiment, the case where the main lip seal 5 is formed in the vicinity of the base end portion 52 and the base end portion 42 of the side lip seal 4 is described. As long as 51 is interlocked with the front end portion 41 of the side lip seal 4, the configuration is not limited to this, and other configurations may be used. For example, although not shown, the entire base end portion 52 of the main lip seal 5 may be formed close to a part of the base end portion 42 of the side lip seal 4. That is, the base end portion 52 of the main lip seal 5 may extend from the inner diameter side of the side lip seal 4.
In another example, although not shown, a part of the base end portion 52 of the main lip seal 5 may be formed close to the entire base end portion 42 of the side lip seal 4. That is, the base end portion 42 of the side lip seal 4 may extend from the inner diameter side of the main lip seal 5.

In the pack seal according to the present embodiment, in addition to the base end portion 42 and the main lip seal 5 of the side lip seal 4, an oil lip that prevents the lubricating oil from flowing out from the inside of the bearing is provided at the inner peripheral end 33 a of the core 3. A seal 6 is provided. The oil lip seal 6 includes a base end portion 62 integrally fixed to the inner peripheral end 33a of the core metal 3, and a tip end portion extending from the base end portion 62 toward the free end side of the cylindrical portion 21 of the slinger 2. 61 is in sliding contact with the inner peripheral surface 21 a of the cylindrical portion 21 of the slinger 2.
Also, the base end portion 42 of the side lip seal 4 and the base end portion 52 of the main lip seal 5 and the base end portion 62 of the oil lip seal 6 are constricted in a direction perpendicular to the cylindrical portion 21 of the slinger 2. 8 is formed. In this case, the thickness of the constriction 8 (see dimension D2 in the figure) is the thickness of the branch portion 9 of the base end part 42 of the side lip seal 4 and the base end part 52 of the main lip seal 5 (in the figure). The thickness is smaller than the dimension D1).

  Thereby, when the side lip seal 4 is pushed up counterclockwise by the tightening margin, the branch portion 9 formed to be thick is not easily deformed, so that the base end portion 42 (branch portion 9) moves. The amount concentrates on the constriction 8 having a small thickness and low rigidity, and the constriction 8 is deformed so as to rise to the right shoulder in the figure. Therefore, when the constriction 8 is deformed, the movement amount of the branch portion 9 is not transmitted to the oil lip seal 6, and the oil lip seal 6 is affected by the interlocking of the side lip seal 4 and the main lip seal 5. Without any restriction, it can serve as an oil seal with a set tightening allowance.

In the present embodiment, the case where the side lip seal and the main lip seal as the dust seal are arranged as the lip seal arranged on the pack seal 1 is not limited to this, but three or more dust seals are arranged. May be. Even in such a case, the tightening margin of the side lip seal raises the other dust seals counterclockwise, reducing the seal torque and wear, and as the side lip seal wears, the other dust seals , Acts as a dust seal instead of a side lip seal.
At that time, when a plurality of lips that are in sliding contact with the inner peripheral surface 23a of the annular portion 23 of the slinger 2 are provided, the rigidity of the lips and the tightening allowance are made different so that the rigidity is improved in the initial state. A weakly set lip seal torque and wear may be reduced.
In this embodiment, the case where the pack seal 1 is provided with the oil lip seal 6 serving as an oil seal has been described. However, the present invention is not limited to this, and the oil lip seal 6 may not be provided.

The core metal 3 and the slinger 2 provided in the pack seal 1 in the present embodiment are not limited to the shapes shown in FIGS. 1 and 2, and other general core bars and slinger may be used. For example, a conventional metal core and slinger as shown in FIG. 5 may be applied.
In addition, when the pack seal 1 in this embodiment is applied to a hub unit bearing, the rotational torque of the pack seal 1 can be reduced, so that power is not spoiled and an effect of improving fuel consumption is expected. can do. Furthermore, since the inside of the bearing is sealed for a long period of time, the vehicle quality is improved by extending the replacement time of the pack seal (extending the life). Further, the pack seal 1 in the present embodiment is also applicable to bearing units other than the hub unit bearing as long as it is a bearing unit in which a reduction in rotational torque and a long-life pack seal are desired.

It is sectional drawing which shows the pack seal by this invention. It is explanatory sectional drawing which shows the change of the shape of the side lip seal and main lip seal before and after fitting the slinger of a pack seal. It is an expanded sectional view which shows the change of the shape of a main lip seal. It is an expanded sectional view which shows the change of the shape of a main lip seal. It is explanatory sectional drawing which shows the conventional pack seal, (a) shows the example by which the annular part of the metal core was formed in linear form, (b) shows the example which has a step part in the annular part of the metal core Indicates.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pack seal 2 Slinger 3 Metal core 4 Side lip seal 5 Main lip seal 21 Cylindrical part 22 of a slinger 23 One end of a cylindrical part of a slinger 23 Annular part 31 of a core metal 32 A cylindrical part of a core metal 32 One end 33 of a cylindrical part of a core metal Gold ring part 3a Seal member 41 Side lip seal distal end 42 Side lip seal proximal end 51 Main lip seal distal end 52 Main lip seal proximal end

Claims (3)

At least a seal member made of an elastic material having a side lip seal and a main lip seal is integrally provided, and an annular portion is integrally extended in an outer diameter direction from one end of the cylindrical portion so as to have an L shape in cross section. A structured mandrel,
A cylindrical portion facing the cylindrical portion of the core metal, and a tip portion of the main lip seal slidably in contact with each other, and extending integrally from one end of the cylindrical portion in the outer diameter direction, facing the annular portion of the core metal In a pack seal consisting of a slinger configured in an L shape in cross-section with an annular portion in which the tip of the side lip seal is in sliding contact,
All or part of the base end portion of the main lip seal is formed close to all or part of the base end portion of the side lip seal, and the tip end portion of the main lip seal is interlocked with the tip end portion of the side lip seal. Pack seal characterized by that. Including an oil lip seal whose tip is in sliding contact with the cylindrical portion of the slinger,
The base end of the oil lip seal is provided integrally with the base end of the side lip seal and the base end of the main lip seal, and the tip of the oil lip seal is the tip of the side lip seal and the main lip. The pack seal according to claim 1, wherein the pack seal is not interlocked with a tip portion of the seal.   A rolling bearing to which the pack seal according to claim 1 is applied.

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