JP3342750B2 - 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) in which it is incorporated in a miniature bearing that 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. 1 showing an embodiment of the present invention. The outer race 1 has an outer raceway 2 on the inner peripheral surface of the intermediate part. The inner race 3 has an inner raceway 4 on the outer peripheral surface of the intermediate part. 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. 5, in a state where the base plate 9 made in advance with a small diameter is located inside the locking groove 8, the folded portion 10 formed on the outer peripheral edge of the base 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, enters the locking groove 8 as shown in FIG. 6, 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.

Japanese Utility Model Publication No. Hei 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 side opposite to the rolling element installation portion; FIG. 8). (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. 5 and 6, 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, in a radially outward direction. As a result, a part of the outer ring 1 is elastically deformed in a direction in which the diameter increases. Since the amount of deformation due to this elastic deformation becomes non-uniform in the circumferential direction, when the outer ring 1 or the inner ring 3 of the rolling bearing rotates at high speed, it is based on the rotational imbalance or the outer ring raceway 2. Harmful vibrations and the like are likely to occur due to subtle undulations on the surface. In particular, HDDs in recent years
The miniaturization of the etc., because it has smaller wall thickness of the outer ring 1, the above-mentioned such elastic deformation has become a problem.

Also, in the case of the second and fourth examples shown in FIGS. 7 and 9, 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)
Of the outer ring 1 is elastically deformed in the direction of increasing the diameter, and harmful vibrations and the like are likely to occur.

Further, in the case of the structure of the third example shown in FIG. 8, 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, since the folded portion 14 faces outward, when the folded portion 14 is engaged with the locking groove 8, the jig is pushed into the folded portion 14. In this state, the shield plate 7b must be pressed.

In the case of the shield plate 7b incorporated in a miniature bearing or the like, since the shield plate 7b is made of a thin metal plate having a thickness of 0.16 mm or less, when the jig and the folded portion 14 are brought into contact in a small area, A part of the folded portion 14 tends to be plastically deformed with the pushing operation. 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]

A 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 surface end of the outer ring over the entire 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.

[0018] The locking groove has a <br/> the outer ring raceway of the intermediate portion in the axial direction, have a relatively large step, the outer ring
0 to 1 with respect to an imaginary plane orthogonal to the central axis of
In step portion is 0 degree, also the open end side of the outer ring, have a relatively small step, on the surface existing in the intermediate portion
The inclination angle with respect to a virtual plane orthogonal to the central axis of the outer ring is
Each is separated by a ridge portion of 40 to 60 degrees . Further, the shield plate is made of a metal plate in a ring shape, and a flat portion is formed at least in the outer half in the diameter direction, and the metal plate is folded over 180 degrees at the outer peripheral edge of the flat portion. > Each elastically deformable folded part is formed. Then, the shield plate is convexly curved at the intermediate portion of the folded portion in the locking groove .
The portion in a state to abut on the stepped portion, in which lock the outer peripheral edge thereof.

[0019]

According to the rolling bearing sealing device of the present invention configured as described above, the outer race is hardly elastically deformed even when the shield plate is mounted. Also, when the folded portion is pushed into the locking concave groove in order to mount the shield plate on the outer race, the jig and the shield plate can be brought into contact with a large area by abutting the jig against the flat 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. 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]

1 to 4 show an embodiment of the present invention. The basic configuration of a rolling bearing incorporating a sealing device and the action itself of preventing grease leakage by the sealing device are the same as those of the conventional structure, and therefore, duplicate 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. As shown in detail in FIG. 3, the locking concave groove 16 is formed with a cylindrical intermediate portion 25.
Outer raceway 2 side of the axial end at the stepped portion 17 having a relatively large step (the right side in FIG. 3), butt similarly having a relatively small step to the opening end portion side of the outer ring 1 (the left side in FIG. 3) It is divided by the ridge portion 18.

The width W _{16 of} the locking groove ₁₆ and the step 17
, The inclination angle θ 18 of the inner surface of _the ridge _{18 and the} like are determined by design in accordance with the shape and size of the folded portion 20 of the shield plate 19 described later. For example, when the present invention is applied to a miniature bearing having an inner diameter of 4 mm and an outer diameter of about 9 mm, the width W ₁₆ is set to about 0.25 to 0.35 mm (preferably 0.27 to 0.33 mm), and the inclination angle θ ₁₇ is about 0 to 10 degrees (preferably 6 to 8 degrees), and the inclination angle θ ₁₈ is about 40 to 60 degrees (preferably 45 to 55 degrees).
Degrees). Further, the inner diameter r of the ridge 18 is slightly (for example, 0.1 mm) smaller than the outer diameter R of the shield plate 19 (FIG. 4).
About 0.01 to 0.04 mm, more preferably 0.015 to
0.03 mm) smaller (r <R). In this case, the shield plate 19 uses a stainless steel plate having a thickness of 0.08 mm.

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 made of a metal plate such as a stainless steel plate or a carbon steel plate. As shown in detail in FIG.
The outer half of the shield plate 19 in the diameter direction (the lower half of the cross section shown in FIG. 4) is a flat portion 21. An end surface of a pushing jig, which will be described later, is allowed to abut on an outer surface (the right side surface in FIG. 4) of the flat portion 21 with a large area.
The inner half of the shield plate 19 in the diameter direction (the upper half of the cross section shown in FIG. 4) is a curved portion 22 having a circular cross section. The portion corresponding to the curved portion 22 may be flat. However, the presence of the curved portion 22 increases the sectional modulus of the shield plate 19 and makes the shield plate 19 hard to deform.

Further, an elastically deformable hollow folded portion 20 is formed on the outer peripheral edge of the flat portion 21. The folded portion 20 is formed by folding the outer peripheral portion of the metal plate constituting the shield plate 19 beyond 180 degrees , and is elastically deformed to have a dimension in the thickness direction (the left-right direction in FIG. 4). Is contractible.

In the illustrated embodiment, the folded portion 2
0 and the side surface of the flat portion 21 are separated from each other.
In addition, slits 23 are formed at a plurality of locations (for example, nine locations) in the circumferential direction of the folded portion 20 to divide the folded portion 20 into a plurality of locations (for example, 9) in the circumferential direction. 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 the slits 23 are provided, and if so, the number thereof, the thickness and hardness of the metal plate for forming the shield plate 19. ,
The thickness can be arbitrarily adjusted according to the thickness of the folded portion 20 and the like.

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 attached to the inside of the outer race 1 in a state where is directed inward (the rolling elements 5 and 5 installation side). After assembling, in a state where the outer peripheral edge of the shield plate 19 is locked in the locking groove 16, the shield plate 19 becomes convex at an intermediate portion of the folded portion 20.
The curved portion and the step 17 come into contact with each other.

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 tip is abutted against the flat 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. The flat portion 21 contacts with a large area. Therefore, there is no plastic deformation of a part of the shield plate 19 during the mounting operation.

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.

In the illustrated example, the shield plate 19 is mounted on only one side of the outer ring 1 (the right side in FIG. 1), but if necessary, the shield plate 19 may be mounted on both sides of the outer ring 1. Of course.

[0032]

Since the sealing device for a rolling bearing according to 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 sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of the lower part of FIG.

FIG. 3 is an enlarged view of a portion A in FIG. 1;

FIG. 4 is a partial sectional view of a shield plate.

FIG. 5 is a partial cross-sectional view showing a structure of a first example of a conventional sealing device in a state before a shield plate is caulked.

FIG. 6 is a partial cross-sectional view similarly showing a state after crimping.

FIG. 7 is a partial sectional view showing a second example of the conventional sealing device.

FIG. 8 is a partial sectional view showing the third example.

FIG. 9 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 groove 17 Stepped portion 18 Protrusion 19 Shield plate 20 Folded portion 21 Flat portion 22 Curved portion 23 Slit 24 Gap 25 Intermediate portion

Continuation of the front page (56) References JP-A-61-52417 (JP, A) JP-A-62-167926 (JP, A) JP-A-54-68048 (JP, U) JP-A-58-112773 (JP) , U) Japanese Utility Model Hei 2-92117 (JP, U) Japanese Utility Model Utility Model Utility Model No. 49-114350 (JP, U) Japanese Utility Model Application Hei 5-16411 (JP, Y2) (58) Fields surveyed (Int. Cl. ⁷ , DB Name) F16C 19/00-19/56 F16C 33/30-33/82

Claims (1)

(57) [Claims] 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. and a shield plate, the engaging groove is an outer ring raceway of the intermediate portion in the axial direction, have a relatively large step, directly on the central axis of the outer ring
In step portion is an inclined angle of 0-10 degrees with respect to interlinking virtual plane, also the open end side of the outer ring, have a relatively small step, the center of the outer ring surface to be present in the intermediate portion
Angle of inclination to virtual plane perpendicular to axis is 40-60 degrees
In ridges is, which was partitioned respectively, the shield plate is made into a circular ring shape by a metal plate, a flat portion at least in the diameter direction outer halves, the outer peripheral edge of the flat portion, the metal An elastically deformable folded portion formed by folding the plate over 180 degrees is formed respectively. The shield plate is provided in the locking groove and in the folded portion .
A sealing device for a rolling bearing, wherein an outer peripheral edge thereof is locked in a state where a convexly curved portion at an intermediate portion is brought into contact with the step portion.