JP2001020960A - Unit seal bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a unit seal bearing free to use a standard outer ring, simple in structure and easy in assembling. SOLUTION: A cross-section L shape shield plate 5 projected from an outer ring end surface is provided on an outer periphery 2a of an inner ring 2 projected in the axial direction from an end surface 1e of an outer ring 1. This bearing is provided with a ring double lip seal 6 having a side lip 6d an outer peripheral edge 6a of which is rubber-fitted in a groove 1a of the outer ring and to slide on and seal a sliding surface 5b for sealing of the shield plate, a radial lip 6e to slide on and seal an outer peripheral surface 2b of the inner ring and grease 7 and a ring seal 8 an outer peripheral edge 8a of which is rubber-fitted in a groove 1b of the outer ring and free to seal with the inner ring 2 within width of the outside ring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a unit seal bearing in which grease to be mounted on a vehicle wheel bearing or the like is sealed.

[0002]

2. Description of the Related Art A unit seal is mounted on a wheel bearing to prevent infiltration of muddy water. In a conventional unit seal, for example, in JP-A-09-229954, as shown in FIG. 8, unit seals 50 are provided at both ends of the bearing to prevent muddy water from entering the bearing. In this unit seal, an annular metal plate 55 having an L-shaped cross section is fitted to the outer periphery 52a of the inner ring 52, and two rubber radial lips 53b and 1 are fixed to the opposing outer ring 51 side by a metal core 53a. A lip seal 53 composed of a plurality of axial lips 53c is provided, and the radial lip 53b is slidably contacted with the radial surface 55a of the annular metal plate 55, and the axial lip 53a is slidably contacted with the axial surface 55b.

However, in the seal unit 50, since the core metal 53a is pressed into the inner diameter portion 51a of the outer ring 51 and the metal plate 55 is pressed into the outer peripheral surface 52a of the inner ring 52, the axial length of the inner diameter portion and the outer peripheral surface becomes longer. Further, the cylindrical surface has to be ground, which has been a factor of cost increase.
Also, at the time of assembly, the lip seal 53 and the metal plate 55 must be press-fitted into the bearing after assembling into one set of seals, and the process is complicated and troublesome. On the other hand, there are various other sealing mechanisms, but the most basic one is a groove 1a, 1b formed symmetrically in the width direction of the inner diameter surface at both ends of the bearing outer ring 1 as shown in FIG. The outer peripheral edge 8a is fitted with a rubber, and the seal slope 62c of the inner race 62 and the tip 8b are provided on the inner peripheral side thereof.
Is provided with an annular seal 8 made of a thin plate-like ring adapted to make a sliding contact or a labyrinth seal. Reference numeral 3 denotes a ball, and reference numeral 4 denotes a retainer. 9 is generally produced as a standard specification, has a simple structure, is easy to assemble, and is inexpensive. However, the muddy water performance as a wheel bearing seal was not satisfactory.

[0004] By the way, depending on the application, the mounting condition, etc. of the wheel bearing, it is not necessary to form a double lip structure with high sealing performance on both sides of the bearing, and one of them is a simple annular seal 8 as shown in FIG. In some cases, the other sealing function may be improved. For example, this is the case of the seal of the pulley unit bearing for preventing intrusion of seawater etc.,
In Japanese Unexamined Patent Publication No. 10-19101 shown in FIG. 10, an outer ring 1 is a standard outer ring for sealing as shown in FIG. 9, one of which is an annular seal 8, and the side that enters seawater is an annular ring of the remaining outer ring. There is disclosed a structure in which a groove 68 is used to fit the outer peripheral edge 68a thereof into rubber and fixed to the bearing outer ring 1, and a cover 68 which is closed from the outside is attached.

[0005]

However, the shaft end 62a of the shaft 62 corresponding to the inner ring shown in FIGS.
Is closed, and the seal structure of the inner ring and the outer ring on the shaft end side when the shaft penetrates like a wheel bearing is not disclosed. Therefore, the cover side is described in Japanese Patent Application Laid-Open
It is conceivable to substitute a double lip structure as described in JP-A-229954, but in this case, a standard or a standard-compliant outer ring cannot be used, the structure is complicated, the assembly is difficult, and the man-hour is increased. In addition, there is a problem that the cost increases.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a unit seal bearing having a small outer ring width, a simple structure including an annular seal and a double lip seal suitable for preventing muddy water from entering, and which can be easily assembled. It is. It is still another object of the present invention to provide a unit seal bearing using a standard or an outer ring conforming to the standard.

[0007]

According to the present invention, the outer peripheral edge is rubber-fitted into two grooves formed in the inner diameter surfaces near both ends of the bearing outer ring so as to have cross sections substantially symmetrical in the width direction. A seal bearing having a sealing mechanism with an inner ring on a peripheral side, at least one of which protrudes an inner ring in an axial direction from an end surface of an outer ring, and a sliding contact surface for sealing in an axial direction on an outer ring side is provided on an outer periphery of the inner ring protruding from an end surface of the outer ring. Providing a shield plate having
The outer peripheral edge is rubber-fitted into the groove of the outer ring on the shield plate side and is slid in contact with the sealing sliding surface of the shield plate and inclined in the direction in which the lid closes when muddy water intrudes from outside, that is, axial and radial from the inner ring side A side lip formed so as to expand conically outwardly, and a lid that slides in contact with the outer peripheral surface of the inner ring at a predetermined position between the side lip of the protruding inner ring and the retainer of the bearing to close the lid when muddy water intrudes from the outside An annular double lip seal having a radial lip formed so as to be conically narrowed from the outer ring side in the axially outward direction and the radially inward direction, and applying grease between the radial lip and the side lip. A unit seal shaft provided with an annular seal which is provided on the shield plate side and whose outer peripheral edge is rubber-fitted in the groove of the outer ring on the side opposite to the shield plate and which can be sealed with the inner ring within the width of the outer ring It solved the problem by providing a.

The annular seal is a so-called standard or substantially thin plate-like annular according to the standard as shown in FIG. 9, and it is needless to say that the structure is simple and easy to assemble and handle.
On the other hand, the annular double lip seal on the side that prevents muddy water intrusion has an outer peripheral edge whose outer peripheral diameter is rubber-fitted to the outer ring groove similar to the annular seal, and can be easily assembled and fixed to the outer ring groove. . In addition, the radial lip of the annular double lip seal is slidably in contact with the outer peripheral surface of the inner ring at a predetermined position between the side lip and the retainer, and is formed so as to conically narrow from the outer ring side in the axially outward direction and the radially inward direction. Even if the annular double lip seal is incorporated after the outer ring is assembled, the radial lip will not be deformed or damaged.

Further, grease can be easily applied between the radial lip and the side lip after assembling the annular double lip seal. When the shield plate is pressed into the inner ring after application, the side lip is formed so as to expand conically from the inner ring side in the axial and radial outward directions. A reliable seal is possible only by contact. Also, since the shield plate is only fitted to the inner ring, positioning is easy,
Easy adjustment of the amount of interference between the sliding surface for sealing and the side lip,
It is certain.

[0010] The groove of the bearing outer ring has a cross-sectional shape symmetrical in the width direction according to the standard or the standard, is suitable for mass production, the width of the outer ring can be reduced, and a standard or the standard outer ring can be used. Since the axial sliding contact surface is disposed outside the outer ring end surface, the size of the radial lip and the side lip is not limited and the sealing performance is easily secured.

Also, in the present invention, the short side of the metal plate having an L-shaped cross section is fitted to the inner race, and the sliding contact surface for sealing is formed on the opposite side of the long side of the L-shape. (Left side).

Further, in order to reduce the axial length on the inner ring side where the shield plate is fitted, the shield plate must be inverted L in section.
What is necessary is just to make it into a metal plate of a letter shape, fitting a short side to an inner ring, and making the sliding contact surface for sealing into the short side surface (right side of L shape) of the long side of inverted L shape.

Further, in order to match the lengths of the outer ring and the inner ring to enhance the compatibility in assembly, an inner diameter larger than the outer diameter of the outer peripheral edge of the annular double lip seal and an outer diameter equal to the outer diameter of the outer ring are required. The ring may be disposed in contact with the end surface of the outer race. Since the inner diameter hole of the ring is larger than the outer diameter of the annular double lip seal, it does not interfere with the ring when the outer peripheral edge of the annular double lip seal is fitted and assembled into the outer ring groove.

Further, if the standard or conforming standard outer ring is not used, depending on the quantity, equipment, etc., or the man-hour for assembling the outer ring with the ring, the ring may be integrated with the outer ring in order to obtain mounting compatibility. It may be formed.

[0015]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partial sectional view of a unit seal bearing according to a first embodiment of the present invention, and FIG. 2 is a partially enlarged sectional view of the same. In each drawing, the outer edge shape and the lip shape of the seal show a cross section in a free state before assembling into a bearing for the sake of explanation, and actually deform along the groove and the sliding contact surface. In the first embodiment of the present invention,
As shown in FIGS. 1 and 2, the seal bearing includes an outer ring 1, a ball 3, and an inner ring 2. The outer ring 1 is the same as the outer ring of a so-called standard seal bearing, and has two sealing grooves 1 having a cross-sectional shape symmetrical in the width direction on the inner diameter surface near both ends of the outer ring.
a, 1b are formed, and a raceway surface 1c on which the ball 3 rolls is formed along the center inner periphery. An inner ring rolling surface 2c on which the ball 3 rolls is provided on the outer periphery of the inner ring 2, and the inner ring end surface 2d is made the same as the outer ring end surface 1d on the left side in the drawing, and the other end 2e is closer to the other end surface 1e of the outer ring. It protrudes in the axial direction. A retainer 4 for maintaining the position of the ball 3 in the bearing is provided between the inner and outer rings.

As shown in the figure, an annular shield plate 5 having an L-shaped cross section is metal-fitted to the outer periphery 2a of the inner race protruding from the right outer race end face 1e and fixed to the inner race. The short side 5a of the L-shape of the shield plate 5 is fitted to the outer periphery 2a of the inner race, and a sealing sliding contact surface 5b is formed on the opposite short side (left side) of the long side 5c of the L-shape. The outer peripheral surface of the inner ring between the sliding contact surface 5b for the seal and the retainer 4 is ground to form a radial seal surface 2b. In addition, a seal slope 2c that has been finished by grinding is provided on the outer peripheral side of the inner ring near the inner ring end on the left side in the drawing.

As shown in the figure, an annular double lip seal 6 is positioned and fixed in the groove 1a of the outer ring 1 on the right shield plate 5 side by rubber fitting. The annular double lip seal 6 is formed of a rubber material with the cored bar 6f as a core, and a raised portion 6b inward from the outer peripheral edge 6a,
The annular portion 6c extends upward and to the right as viewed in the drawing, that is, a side lip 6d formed so as to extend in a conical shape in the axial and radial outward directions from the inner ring side, and extends downward and to the right as viewed in the drawing. A radial lip 6e is formed so as to be conically narrowed in the axially outward direction and the radially inward direction from the outer ring side. In other words,
Both the side lip 6d and the radial lip 6e are inclined in a direction in which the lid closes against muddy water entering from the shield plate 5 direction. The core metal 6f is the outer peripheral edge 6a
From the connection part of both lips.

As shown in FIG. 2, the axial distance between the sliding contact surface 5b for sealing of the shield plate 5 and the inner end 1a 'of the outer ring seal groove is L, and the inner end 1a' of the outer ring seal groove and the annular double lip seal are formed. Assuming that the axial distance from the side lip end 6d 'is H, δa = HL is the side lip 6 in the axial direction.
d. The fitting position of the shield plate 5 with respect to the inner ring is determined so that the amount of interference in the axial direction becomes an appropriate value. The radial lip 6e is slid in contact with the radial seal surface 2b on the outer peripheral surface of the inner ring while maintaining a radial interference amount δr. A lip grease 7 for lubricating the lip is enclosed by the side lip between the side lip 6d and the radial lip 6e.

As shown in FIG. 1, an annular seal 8 is positioned and fixed in the groove 1b on the left side of the outer race 1 by rubber fitting the outer peripheral edge 8a. The annular seal 8 is a so-called standard or substantially thin plate-like annular according to the standard, is formed of a rubber material around a cored bar 8d, and has an annular portion 8b and a lip 8c inward from an outer peripheral edge 8a. Are sequentially formed. The cored bar 8d is disposed from the outer peripheral edge 8a to the annular portion.

A method of assembling the unit seal bearing according to the first embodiment will be described. The inner ring 2, the outer ring 1, the ball 3, and the retainer 4 are assembled in advance similarly to a general bearing. Thereafter, the annular seal 8 is press-fitted, and the outer peripheral edge 8a of the annular seal is fitted and fixed in the groove 1b of the outer ring. Next, the annular double lip seal 6 is press-fitted, and the outer peripheral edge 6a of the annular double lip seal is fitted and fixed in the groove 1a of the outer ring.
Next, an appropriate amount of grease 7 is applied to the inner periphery (the lower side in the figure) of the side lip 6d. Finally, the shield plate 5 is fixed to the inner ring by metal fitting at a position where the side lip 6d and the sealing sliding contact surface 5b have a predetermined interference amount. Conversely, the annular seal side may be assembled after the annular double lip seal side is assembled.

Next, a second embodiment of the present invention will be described. FIG. 3 is a partial sectional view of a unit seal bearing according to a second embodiment of the present invention. In this figure, as in FIGS. 1 and 2 described above, the outer edge shape and the lip shape of the seal show a cross section in a free state before assembling into a bearing for the sake of explanation, and are actually deformed along the groove and the sliding contact surface. I do. The second embodiment of the present invention differs from the first embodiment in that the length of the annular double lip seal in the width direction is short. The other components are denoted by the same reference numerals and the description thereof is omitted. In the first embodiment, the annular double lip seal 6 includes a raised portion 6b, an annular portion 6c, and a side lip 6d from the outer peripheral edge 6a toward the inside.
Radial lips 6e are sequentially formed, and a cored bar 6f is located at a connection portion between the both lips from the outer peripheral edge 6a. On the contrary,
The annular double lip seal 16 of the second embodiment has no raised portion 6b, an outer peripheral edge 16a, an annular portion 16c, a side lip 16d, and a radial lip 16e are sequentially formed. Is located at the connection portion.

As much as the side lip 16d is short,
Since the mounting position of the shield plate 5 can be arranged close to the outer ring end face 1e, the axial length can be shortened. Also, the ring part 1
There is an advantage in that the space 17 formed by the side 6c, the side lip 16d, and the shield sliding contact surface 5b is narrowed, and the amount of dust and the like attached can be reduced.

The annular double lip seal 16 is shown in FIG.
(A), the annular portion 16c and the seal end face 16
h and make them contact each other and store or transport them on the stage.
Here, if the length of the side lip 16d in the axial direction is long, the tip 16g of the side lip may interfere with the cored bar 16f or the like and may be deformed to cause deterioration in performance. Therefore, as shown in FIG. 4A, the width dimension S of the annular portion 16c is determined.
Is set so that the core bar 16f does not contact the side lip 16g. In the first embodiment, in order to enhance the contact performance of the side lip, the side lip is increased,
The length in the length direction is increased. In this case, as shown in FIG. 4B, a raised portion 6b is provided, and the raised portion 6b and the seal end face 6h are brought into contact with each other and overlapped on a step. The width dimension S 'of the seal end face 6h and the raised portion 6b is set to a dimension such that the core metal 6f does not contact the side lip tip 6g.

Next, a third embodiment of the present invention will be described. FIG. 5 is a partial sectional view of a unit seal bearing according to a third embodiment of the present invention. This figure also shows the outer edge shape and the lip shape of the seal in a free state before assembling into a bearing for the sake of explanation, as in FIGS. Deform. In the third embodiment of the present invention, in the above-described first and second embodiments, the shield plate 5 has the short side 5a of the L-shape fitted to the outer periphery 2a of the inner race, and the long length of the L-shape. On the opposite short side (left surface) of the side 5c, the sliding contact surface 5b for sealing is formed. On the other hand, the shield plate 15 is a metal plate having an inverted L-shaped cross section, and the sliding contact surface 15b for sealing is formed in an inverted L shape. Short side 15a of long side 15c
(The right side of the L-shape). At this time, the radial lip 6e of the annular double lip seal 6 does not interfere with the short side 15a of the shield plate 15. Others are the same as those described above, and the description is omitted.

In the third embodiment, since the cross section of the shield plate is arranged in an inverted L-shape, the axial length on the inner ring side is small, and the overall structure can be made compact.

Next, a fourth embodiment of the present invention will be described. FIG. 6 is a partial sectional view of a unit seal bearing according to a fourth embodiment of the present invention. This figure also shows the outer edge shape and the lip shape of the seal in a free state before assembling into a bearing for the sake of explanation, as described above, and actually deforms along the groove and the sliding contact surface. The fourth embodiment of the present invention is different from the above-described first to third embodiments in that a ring 30 is provided.

The ring 30 has an annular double lip seal 6
Inner diameter hole 3 of inner diameter DN larger than outer diameter DL of outer peripheral edge 6a
0 a and an outer peripheral portion 30 b having the same outer diameter as the outer diameter DO of the outer peripheral portion 1 f of the outer ring 1. In addition, ring 3
The length of 0 is the same as the axial length La of the end face 1e of the outer race 1 and the end face 2e of the inner race. Other components are the same as those described above, and a description thereof will not be repeated. In such a configuration, when used as a replacement for a conventional seal unit bearing that is long in the axial direction, the length of the outer ring can be adjusted, so that compatibility is improved. Also, the outer ring groove 1a is assembled without causing the outer peripheral edge 6a of the annular double lip seal 6 to interfere with the ring.

FIG. 7 shows a fifth embodiment of the present invention. The outer ring 1 and the ring 30 shown in FIG. Reference numeral 31a denotes an inner diameter hole of the ring integrated with the outer ring, and 31b denotes an outer peripheral portion of the ring integrated with the outer ring. Details are the same as those in FIG. Note that FIG.
In the example shown in FIG. 7, the ring end face and the inner ring end face are made to be flush with each other when the ring is mounted, but an appropriate length of the ring may be selected depending on a place to be assembled.

[0029]

As described above, in the unit seal bearing of the present invention, an outer ring having a standard or standard-based seal groove is used, and one is a standard or standard-based annular seal, and the other is an annular seal. Since an annular double lip seal with higher sealing performance is provided, when used for automobile wheels, an annular double lip seal is arranged on the outside where muddy water enters, and an annular seal is installed on the opposite side (body side). Incorporation provides a unit seal bearing that has a simple structure and is easy to assemble. further,
Since a standard or an outer ring conforming to the standard can be used, the cost is low.

The annular seal has a simple structure,
It is easy to handle, has a standard thin plate-like ring shape, and is inexpensive. In addition, the annular double lip seal can be easily assembled and fixed in the outer ring groove.Furthermore, even if the annular double lip seal is incorporated after the inner ring outer ring is assembled, the radial lip will not be deformed or damaged, so assembly is easy and maintenance is easy. If easy.

Also, assembling of the annular double lip seal,
The unit seal can be easily configured by applying grease and press-fitting the shield plate, and the interference amount of the seal can be easily adjusted.
Since it is reliable, different interference amounts of the side lip can be set, the balance between the muddy water performance and the rotational torque due to the sealing friction force is simple, and the best sealing performance can be easily obtained.

Furthermore, the axial sliding contact surface is disposed outside the outer ring end surface, and there is no limitation on the size of the lip, so that the sealing performance can be easily ensured. it can.

Further, since only one shield plate having an L-shaped cross section is fitted to the inner ring side, a complicated process of assembling a seal outside and press-fitting between the inner and outer rings as in the related art is unnecessary. It became easy to automate. By making the shield plate have an inverted L-shaped cross section, the axial length can be shortened, so that the size of the wheel can be reduced.

Further, since the ring inner diameter hole does not interfere more than the outer diameter of the annular double lip seal, the ring can be easily assembled. In addition, by arranging the outer ring and the ring separately or integrally in the axial direction, the axial length can be adjusted appropriately and compatibility can be ensured, so it can be used as a replacement part for conventional seal bearings with long dimensions. is there.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of a unit seal bearing according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of FIG.

FIG. 3 is a partial sectional view of a unit seal bearing according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing a stacked state during storage and transfer of the annular double lip seal used in the embodiment of the present invention.

FIG. 5 is a partial sectional view of a unit seal bearing according to a third embodiment of the present invention.

FIG. 6 is a partial sectional view of a unit seal bearing according to a fourth embodiment of the present invention.

FIG. 7 is a partial sectional view of a unit seal bearing according to a fifth embodiment of the present invention.

FIG. 8 is a partial sectional view of a conventional unit seal bearing.

FIG. 9 is a partial sectional view of a conventional standard type seal bearing.

FIG. 10 is a partial cross-sectional view of a conventional seal bearing using a standard type outer ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 1a, 1b Groove 1d, 1e Outer ring end surface (both ends of outer ring) 2 Inner ring 2a Outer surface of inner ring 2b Outer surface of inner ring 5c, 15c Long side of shield plate 6, 16 Annular double lip seal 6a, 16a Annular double lip seal outer peripheral edge 6d, 16d Side lip 6e, 16e Radial lip 7 Grease 8 Annular seal 8a Annular seal outer peripheral edge 30 Ring 31 Ring (outer ring) 30a, 31a Inner hole of ring 30b, 31b Outer peripheral portion of ring DN Inner diameter of inner ring hole DL Outer peripheral edge outer diameter of annular double lip seal DO Outer ring outer diameter

Claims (5)

[Claims] An outer peripheral edge is rubber-fitted in two grooves formed in a cross-sectional shape symmetrical in the width direction on inner diameter surfaces near both end sides of a bearing outer ring, and a seal mechanism with the inner ring is provided on an inner peripheral side thereof. A seal bearing, comprising: an inner ring at least one of which protrudes axially from an outer ring end face; and a shield plate having an outer ring side axial sliding sliding contact surface provided on an outer periphery of the inner ring protruding from the outer ring end face. And a side lip that is rubber-fitted to the outer peripheral groove in the groove of the outer ring on the shield plate side and is in sliding contact with a sealing sliding contact surface of the shield plate and inclined in a direction in which the lid closes when muddy water intrudes from the outside. A radial lip that slides in contact with the outer peripheral surface of the inner ring at a predetermined position between the side lip of the protruding inner ring and the retainer of the bearing and is inclined in a direction in which the lid closes when muddy water intrudes from outside; And the side An annular double lip seal having grease applied between the lip and the outer peripheral edge of the outer ring provided on the anti-shield plate side and the outer ring groove on the anti-shield side, and sealing with the inner ring within the outer ring width. A unit seal bearing comprising: 2. The shield plate according to claim 1, wherein a short side of the metal plate having an L-shaped cross section is fitted to the inner race, and the sliding contact surface for sealing is a side opposite to the long side of the L-shape. The unit seal bearing according to claim 1, wherein: 3. The shield plate has a metal plate having an inverted L-shaped cross section, the short side of which is fitted to the inner race, and the sliding contact surface for sealing has an inverted L shape.
2. The unit seal bearing according to claim 1, wherein the unit seal bearing is formed to be a short side surface of a long side of the character. 4. A ring having an inner diameter hole larger than the outer diameter of the outer peripheral edge of the annular double lip seal and a ring having an outer peripheral portion having the same diameter as the outer diameter of the outer ring are arranged in contact with an end face of the outer ring. The unit seal bearing according to claim 1, 2 or 3, wherein 5. The unit seal bearing according to claim 4, wherein the ring is formed integrally with the outer ring.