JP2606871Y2 - Sealing device for rolling bearings - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION A sealing device for a rolling bearing according to the present invention is, for example, a hard disk drive (HDD).
And a video tape recorder (VTR) used in a state of being incorporated in a miniature bearing which constitutes a rotation supporting portion.

[0002]

2. Description of the Related Art A rotation supporting portion of an HDD, a VTR or the like is constituted by a rolling bearing. The rolling bearing is configured as shown in FIG. The outer race 1 has an outer raceway 2 on its inner peripheral surface, and the inner race 3 has an inner raceway 4 on its outer peripheral surface. A plurality of rolling elements 5 and 5 are provided between the outer raceway 2 and the inner raceway 4 so as to freely roll, so that the outer race 1 and the inner race 3 can rotate relative to each other. Each of the rolling elements 5, 5 is rotatably held by a holder 6.

The plurality of rolling elements 5, 5 between the inner raceway 4 and the outer raceway 2 inside the rolling bearing, which constitutes the rotation support portion of the HDD or VTR, etc.
Grease is sealed in the portion provided with 5 to lubricate the outer raceway 2 and the inner raceway 4 and the rolling elements 5, 5. Therefore, it is necessary to incorporate a sealing device into the rolling bearing to prevent the grease from leaking to the outside, and to separate the inside of the rolling bearing from the outside.

[0004] As the above-mentioned sealing device, those having various structures are conventionally known.
4-68048, 58-112773,
JP-A-2-92117, JP-A-62-16792
No. 6, publication No. 6, etc. and further shows a sealing device generally used conventionally. In the case of this known sealing device, the outer peripheral edge of a shield plate 7 made of a metal plate into a ring shape is caulked to a locking groove 8 formed at the inner peripheral surface end of the outer ring 1. That is, as shown in FIG. 3, in a state where a raw plate 9 made in advance with a small diameter is positioned inside the locking concave groove 8, the folded portion 10 formed on the outer peripheral edge of the raw plate 9 is It is pressed against a step 11 that partitions the inside of the locking groove 8.
As a result, the folded portion 10 is plastically deformed and enters into the locking groove 8 as shown in FIG. 4, and the outer peripheral edge of the shield plate 7 is supported and fixed in the locking groove 8. Become.

Further, Japanese Utility Model Laid-Open No. 49-114350 discloses a sealing device as shown in FIG. In the case of the sealing device described in this publication, a plurality of locking projections 13 are formed on the outer peripheral surface of the cylindrical portion 12 formed on the outer peripheral edge of the shield plate 7a. Then, the shield plate 7a is supported inside the outer ring 1 by engaging the locking projection 13 with the edge of the locking groove 8 formed at the end of the inner peripheral surface of the outer ring 1. I have.

[0006] Japanese Utility Model Publication No. 5-16411 discloses a sealing device as shown in FIG. In the case of the sealing device described in this publication, the folded portion 14 is provided on the outer peripheral edge of the shield plate 7b, and the metal plate constituting the shield plate 7b is located outside (the opposite side to the rolling element installation portion; (Right side). The shield plate 7b is supported inside the outer race 1 by elastically engaging the folded portion 14 with the locking groove 8 formed at the end of the inner peripheral surface of the outer race 1.

Further, US Pat. No. 4,183,592 discloses a sealing device as shown in FIG. In the case of the sealing device described in this specification, tapered surfaces 15 whose inner diameter decreases toward the opening edge are formed at both ends of the inner peripheral surface of the outer ring 1. The outer peripheral edge of the shield plate 7c is elastically pressed against the tapered surface 15 to support the shield plate 7c inside the outer ring 1.

[0008]

However, in the case of the conventional sealing devices for rolling bearings configured as described above, there are the following points to be solved.

First, in the case of the structure of the first example shown in FIGS. 3 and 4, not only the manufacturing cost is increased but also the outer ring 1 is deformed. That is,

In order to support and fix the shield plate 7 inside the outer ring 1, the folded portion 10 is plastically deformed (caulked).
A process is required. As a result, the mounting operation of the shield plate 7 becomes troublesome, and a complicated device is required for the caulking operation, which leads to an increase in the cost of the rolling bearing incorporating the sealing device. or,

As the folded portion 10 is plastically deformed, the folded portion 10 strongly presses a portion of the outer ring 1 where the locking groove 8 is formed outward in the diameter direction. As a result, a part of the outer ring 1 is elastically deformed in a direction in which the diameter increases. The amount of deformation based on this elastic deformation is
The outer ring 1 of the rolling bearing is not uniform in the circumferential direction.
Alternatively, when the inner race 3 rotates at a high speed, harmful vibrations and the like are likely to be generated based on the rotational imbalance or the subtle undulation on the surface of the outer race 2. In particular, since the thickness of the outer ring 1 has been reduced due to the recent miniaturization of HDDs and the like, the above-described elastic deformation has become a problem.

Also, in the case of the second and fourth examples shown in FIGS. 5 and 7, the outer peripheral edge of the cylindrical portion 12 (in the case of the second example) or the shield plate 7c (the fourth example). Outer ring 1)
Some were formed engagement grooves 8 at a portion of, for pressing strongly diametrically outward, a portion of the outer ring 1 is elastically deformed in a direction in which the diameter increases, detrimental vibration is likely to occur Become.

Further, in the case of the structure of the third example shown in FIG. 6, the elastic deformation of the outer race 1 can be prevented, but harmful plastic deformation is liable to occur on the shield plate 7b when the shield plate 7b is mounted. That is, in the case of the structure of the third example, when the outwardly turned portion 14 is engaged with the locking groove 8,
The shield plate 7b must be pressed while the jig is in contact with the narrow area of the edge of the folded portion 14.

In the case of the shield plate 7b incorporated in a miniature bearing or the like, the shield plate 7b is made of a thin metal plate having a thickness of 0.16 mm or less. With the pushing work,
A part of the folded portion 14 is easily plastically deformed. Since plastic deformation due to such a cause occurs non-uniformly in the circumferential direction, harmful vibrations and the like are likely to occur when the outer ring 1 rotates at high speed.

The sealing device for a rolling bearing according to the present invention eliminates any of the above-mentioned disadvantages.

[0016]

The sealing device for a rolling bearing according to the present invention comprises an outer ring having an outer raceway at an intermediate portion of an inner peripheral surface, an inner ring having an inner raceway at an intermediate portion of an outer peripheral surface, and the outer raceway and the inner raceway. And a plurality of rolling elements rotatably provided between the outer raceway and the inner raceway to separate a portion provided with the plurality of rolling elements from the outside. .

In the sealing device for a rolling bearing according to the present invention, a locking groove formed on the inner peripheral end of the outer ring over the entire circumference of the inner peripheral surface and the outer peripheral edge thereof are formed. A shield plate which is locked in the locking groove and whose inner peripheral edge is close to the outer peripheral end of the inner ring.

The locking groove is formed by partitioning the outer ring raceway side by a step having a relatively large step and the opening end side of the outer ring by a projection having a relatively small step. is there. The shield plate is made of a metal plate in an annular shape, and an elastically deformable folded portion made by folding the metal plate around its outer peripheral edge is provided at the radially intermediate portion of the folded portion with the outer ring. Are formed in the direction perpendicular to the central axis of the flat surface. The shield plate has a gap between the outer peripheral edge and the locking groove, with the folded portion facing the opposite side of the step portion and the locking groove. To
It is locked in the interposed state .

[0019]

According to the sealing device for a rolling bearing of the present invention configured as described above, the outer ring is hardly elastically deformed even if the shield plate is mounted. That is, the outer peripheral edge of this shield plate is locked
Lock the outer edge of this shield plate with the groove
There is a gap between the bottom of the groove and this shield plate.
The outer peripheral edge does not press the bottom surface of the locking groove. Follow
The force acting on the end of the outer ring outward in the diameter direction is slightly suppressed.
Therefore, the elastic deformation of the outer ring can be suppressed. Also, when the folded portion is pushed into the locking groove in order to mount the shield plate on the outer ring, the jig and the shield plate can be brought into contact with a large area by hitting the jig against the flat surface portion. Therefore, a part of the shield plate is not plastically deformed with the mounting operation. As a result, even when the outer ring and the shield plate are rotated at a high speed, harmful vibrations and the like do not occur due to the rotational imbalance and the undulation of the outer ring track. Moreover, the above
The flat surface is in a plane direction perpendicular to the center axis of the outer ring.
The jig that hits this flat surface because it is wide
The shape of the tip surface also exists in a direction perpendicular to its central axis.
Simple, and the jig processing cost does not increase.
No. Further, since it is not necessary to perform a caulking operation to mount the shield plate, the manufacturing cost of the rolling bearing incorporating the sealing device can be reduced.

[0020]

FIG. 1 shows an embodiment of the present invention. The basic configuration of a rolling bearing incorporating a sealing device, and the operation itself for preventing grease leakage by the sealing device are the same as those of the conventional structure, and therefore, redundant description is omitted, and the sealing device which is the object of the present invention will be described below. The part will be described.

At the end of the inner peripheral surface of the outer ring 1, a locking groove 16 is provided.
The inner peripheral surface is formed over the entire circumference. The locking groove 16 is a step 17 having a relatively large step on the outer ring raceway 2 side (the left side in FIG. 1), and has a relatively small step on the opening end side (the right side in FIG. 1) of the outer ring 1. Each of the ribs 18 is partitioned by a ridge 18.

On the other hand, a shield plate 19 for separating a portion provided with a plurality of rolling elements 5, 5 between the outer raceway 2 and the inner raceway 4 from the outside is formed of a metal plate such as a stainless steel plate or a carbon steel plate. It is made in a ring shape. An elastically deformable hollow folded portion 20 is formed on the outer peripheral edge of the shield plate 19. The folded portion 20 is formed such that the outer peripheral portion of the metal plate constituting the shield plate 19 has a U-shaped cross section 180 degrees.
It is made by folding back. This folded part 20
Is made elastically deformable so that the dimension in the thickness direction (left-right direction in FIG. 1) can be contracted.

In the embodiment shown in FIG.
0 is separated from the side of the main body of the shield plate 19. A plurality of slits (not shown) are formed at a plurality of positions in the circumferential direction of the folded portion 20 from the inner peripheral edge of the folded portion 20 toward the outside in the diametrical direction. Divided into multiple directions. Thus, the folded portion 20 is easily elastically deformed in the thickness direction. The elasticity of the folded portion 20 depends on whether or not the edge is separated from the side surface, whether or not to provide a slit, and if so, the number of slits, and the number of the shield plate 19.
It can be arbitrarily adjusted according to the thickness and hardness of the metal plate for forming the metal sheet, the thickness of the folded portion 20, and the like.

The diametrical direction of the folded portion 20 (FIG. 1)
In the middle portion, a flat surface portion 21 is formed which extends in a surface direction perpendicular to the center axis of the outer ring 1 (vertical direction and front / back direction in FIG. 1). A front end face of a pushing jig, which will be described later, is allowed to abut on an outer surface (the right side surface in FIG. 1) of the flat surface portion 21 with a large area.

In the illustrated embodiment, the shield plate 1 is used.
By providing the inclined surface portion 22 at the intermediate portion in the diameter direction of 9,
The inner half (the lower half in FIG. 1) of the shield plate 19 is bulged outward in the width direction of the rolling bearing (the right side in FIG. 1).
By expanding the inner half in this way, the volume of the space 23 sandwiched between the pair of left and right shield plates 19 locked at the axial ends of the outer ring 1 increases, and the space 23 is held in the space 23. Grease can be secured.

When the sealing device for a rolling bearing according to the present invention is constructed, the shield plate 19 constructed as described above is formed at the end of the inner peripheral surface of the outer race 1 and has the shape as described above. It is locked in the groove 16. At this time, the folded portion 20
The shield plate 19 is assembled inside the outer race 1 in a state where is directed outward (the side opposite to the rolling elements 5 and 5 installation part).
After the assembling, in a state where the outer peripheral edge of the shield plate 19 is locked in the locking groove 16, the folded portion 20 and the protruding ridge 18 abut.

According to the rolling bearing sealing device of the present invention configured as described above, the outer race 1 is hardly elastically deformed even when the shield plate 19 is mounted. That is, the shield plate 19 is locked inside the outer ring 1 by the engagement between the folded portion 20 formed on the outer peripheral edge thereof and the locking groove 16 formed on the inner peripheral surface end of the outer ring 1. However, a gap 24 exists between the outer peripheral surface of the folded portion 20 and the bottom of the locking groove 16 in the locked state. Therefore, the folded portion 20 is formed of the outer ring 1.
There is almost no increase in the outside diameter of the. If the elasticity of the folded portion 20 and the width of the locking groove 16 are made appropriate, a sufficient frictional force acts between the folded portion 20 and the locking groove 16. Therefore, the shield plate 19 does not rotate with respect to the outer race 1.

When the folded portion 20 is pushed into the locking groove 16 in order to mount the shield plate 19 on the outer ring 1,
A pressing jig having a flat pressing surface at the end is abutted against the flat surface portion 21 to push the shield plate 19 toward the inside of the outer ring 1. Due to this pushing operation, the folded portion 20 is elastically deformed, and the folded portion 20 and the locking groove 16 are engaged. In this pushing operation, the pressing surface of the jig and the shield plate 19 are engaged. Flat surface 21
Abut on a large area. Therefore, there is no plastic deformation of a part of the shield plate 19 during the mounting operation. Moreover,
The flat surface portion 21 is perpendicular to the center axis of the outer ring 1.
Abutting against this flat surface portion 21
The shape of the tip of the pushing jig is also
It can be a simple thing that exists at right angles to the axis.
There is no increase in the processing cost of the pressing jig.

As described above, as a result of the outer ring 1 not being elastically deformed and the shield plate 19 being not plastically deformed, even when the bearing is rotated at a high speed, harmful vibration is caused by the rotational imbalance or the undulation of the outer ring raceway 2. Will not occur.

Further, since there is no need to perform a caulking operation for mounting the shield plate 19, the manufacturing cost of the rolling bearing incorporating the sealing device can be reduced.

[0031]

Since the sealing device for a rolling bearing of the present invention is constructed and operates as described above, it is possible to obtain a high-performance rolling bearing with a sealing device which is less likely to cause vibration and the like at a relatively low cost.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an example of a rolling bearing.

FIG. 3 is a partial cross-sectional view showing a structure of a first example of a conventional sealing device before a shield plate is caulked.

FIG. 4 is a partial cross-sectional view similarly showing a state after crimping.

FIG. 5 is a partial sectional view showing a second example of the conventional sealing device.

FIG. 6 is a partial cross-sectional view showing the third example.

FIG. 7 is a partial cross-sectional view showing the fourth example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer ring 2 Outer ring raceway 3 Inner ring 4 Inner ring raceway 5 Rolling element 6 Cage 7, 7a, 7b, 7c Shield plate 8 Locking groove 9 Raw plate 10 Folding part 11 Step part 12 Cylindrical part 13 Locking projection 14 Folding part 15 Tapered surface 16 Locking concave groove 17 Step 18 Projection 19 Shield plate 20 Folding portion 21 Flat surface 22 Inclined surface 23 Space 24 Gap

Continuation of the front page (56) References JP-A 3-43120 (JP, U) JP-A 5-58954 (JP, U) JP-A 54-77842 (JP, U) JP-A 62-107115 (JP) , U)

Claims (1)

(57) [Scope of request for utility model registration] 1. An outer race having an outer raceway at an intermediate portion of an inner peripheral surface, an inner racer having an inner raceway at an intermediate portion of an outer peripheral surface, and a plurality of rolling members rotatably provided between the outer raceway and the inner raceway. A sealing device for a rolling bearing, which is incorporated in a rolling bearing composed of a moving body and separates a portion provided with the plurality of rolling elements between the outer raceway and the inner raceway from the outside, wherein an inner peripheral end of the outer race is provided. A locking groove formed over the entire circumference of the inner peripheral surface and an outer peripheral edge thereof are locked in the locking concave groove, and the inner peripheral edge is brought close to an end of the outer peripheral surface of the inner ring. A shield plate, and the locking groove is partitioned by a step having a relatively large step on the outer ring raceway side, and a ridge having a relatively small step on the opening end side of the outer ring. The shield plate is made of a metal plate in an annular shape, and has An elastically deformable folded portion made by folding the metal plate, a flat surface portion extending in a plane direction perpendicular to the center axis of the outer ring is formed at a radially intermediate portion of the folded portion, respectively. There, the shield plate is in the locking groove, the outer peripheral edge of the folded portion in a state toward the opposite to the step portion, that
A gap was interposed between the outer peripheral edge and the bottom of the locking groove.
Sealing device for rolling bearings locked in a state .