JPH0835524A - Sealing device for bearing - Google Patents

Abstract

PURPOSE:To prevent a chatter noise of seal from occurring by contacting a lip with a sealing groove from a radial direction and also providing a vertical part extending in the radial direction on part of the lip and also on the bearing ring side of the other side than the sliding contact part with a bearing ring. CONSTITUTION:A lip 12 is contacted with a sealing groove 14 from a radial direction, also a vertical piece 11 extending in the radial direction is provided on part of the lip 12 and also on an outer wheel 2 side than a contact piece 10, and moreover, the surface roughness of a seal surface 15 slidingly contacting the contact piece 10 of the lip 12 is set to a 1S-6S degree, consequently, the occurrence of a chatter noise due to stick slipping can be prevented. Also the vertical part 11 extending in the radial direction is provided to strengthen the rigidity of the lip 12, consequently, eliminating lowering of the elasticity of the lip 12 due to strengthening rigidity and also causing malfunction such as reduction a sealing function or increase of shaft torque.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device for preventing leakage of a lubricant from the inside of a bearing and intrusion of foreign matter from the outside, and more particularly to a contact type sealing device.

[0002]

2. Description of the Related Art As one of bearing sealing devices, there is a contact type device in which a lip is brought into contact with a seal groove provided in a rotating ring to seal between the lip and the ring.

This type of sealing device is shown, for example, in FIG.
As shown in (a), a substantially annular seal body (22) is attached to a mounting groove (21) provided on the inner peripheral surface of the outer ring (20), and a lip (23) of the seal body (22) is attached to the inner ring ( It is configured by slidingly contacting a seal groove (25) formed on the outer peripheral surface of 24).

[0004]

In the contact type sealing device, slippage occurs between the lip (23) and the seal groove (25). Therefore, depending on the usage conditions of the bearing, so-called stick-slip may occur at the sliding contact portion between the two, and the lip (23) may vibrate by self-excitation to generate a jarring squeal.

Therefore, an object of the present invention is to provide a bearing sealing device capable of preventing the generation of such a seal squeal.

[0006]

In order to achieve the above object, in the present invention, in a bearing sealing device having a lip which is in sliding contact with a seal groove provided in one of the bearing rings, the lip is provided from the radial direction to the seal groove. In addition to the contact, a vertical portion extending in the radial direction is provided on a part of the lip and on the other race ring side from the sliding contact portion with the race ring.

Further, in a bearing sealing device having a lip which is in sliding contact with a seal groove provided on one of the bearing rings, the lip is brought into contact with the seal groove in the radial direction, and the surface roughness of the seal groove is from 1S to I decided to set it to 6S.

In a bearing sealing device having a lip which is in sliding contact with a seal groove provided on one raceway ring, the lip is brought into contact with the seal groove in the radial direction, and a part of the lip slides on the raceway ring. A vertical portion extending in the radial direction may be provided on the other raceway side of the contact portion, and the surface roughness of the seal groove may be set to 1S to 6S.

[0009]

[Function] According to the research conducted by the applicant, the following three factors have been clarified as the causes of the squeaking noise.

When the sealing device is an axial contact type, squeaking noise is likely to occur. Here, the axial contact type means that the lip (23) is brought into contact with the seal groove (25) from the axial direction, as shown in FIG. 3 (a).
On the other hand, as shown in FIG. 2B, the lip (23 ')
In the radial contact type sealing device in which is contacted with the seal groove (25 ') in the radial direction, stick-slip is unlikely to occur, and the squeaking noise is effectively suppressed. As shown in FIG. 1, the sealing device of the present invention is a radial contact type in which the lip (12) is brought into contact with the sealing surface (15) in the radial direction, so that the generation of squeaking noise can be prevented.

When the rigidity of the lip is insufficient, a squeaking sound is likely to occur. When the rigidity of the lip is insufficient, the lip that rotates along with the inner ring is greatly deformed due to the influence of centrifugal force, and it is considered that the slip area of the lip and the inner ring changes and the stick-slip phenomenon easily occurs. . In order to increase the rigidity of the lip, it is easy to make the lip thicker or shorter, but this reduces the elasticity of the lip, which may cause adverse effects such as a decrease in sealing function and an increase in axial torque. In the present invention, since the vertical portion extending in the radial direction is provided on a portion of the lip and on the other bearing ring side from the sliding contact portion with the bearing ring, the lip volume is increased, and thus the elasticity of the lip is increased. The rigidity can be increased in the radial direction without decreasing

If the surface roughness of the seal groove is too small, a squeaking noise is likely to occur. That is, in order to prevent the generation of squeaking noise, the seal groove needs to have an appropriate surface roughness. Conventionally, the seal groove is mirror-finished from the viewpoint of suppressing wear and the surface roughness is as small as possible (smaller than 1S).
However, if the surface roughness is reduced in this way, stick slip easily occurs. On the other hand, if the surface roughness is excessively large, the wear of the seal groove and the lip will be accelerated, and it is necessary to consider this point as well. In the sealing device of the present invention, since the surface roughness of the seal groove is 1S or more,
The stick-slip phenomenon can be prevented. On the other hand, since the surface roughness of the seal groove is 6S or less, the wear of the seal groove and the lip does not pose a problem.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a ball bearing will be described below with reference to FIGS.

As shown in FIG. 1, the ball bearing has an inner ring (1), an outer ring (2), a plurality of balls (not shown) interposed between the inner and outer rings (1) and (2), and the balls at equal intervals. It is composed of a retainer (3) for holding and a sealing device (5) arranged at both ends of the gap between the inner and outer rings (1), (2).

The sealing device (5) is composed of a seal body (6) made of synthetic rubber material and a metal cored bar (7) for reinforcing the seal body (6), and its outer diameter end is The outer ring (2) is fitted into the mounting grooves (8) provided on the inner diameters of both ends.

At the inner diameter end of the seal body (6), a contact piece (10) having the inner diameter inclined to the outside of the bearing, and the contact piece (1
A lip (12) including a vertical portion (11) integrally formed on the outer ring side (outer diameter side) of (0) is provided. The vertical part (11)
The contact piece (10) has a thickness substantially equal to that of the contact piece (10) and is formed in an annular shape in the radial direction. In this embodiment, the contact piece (10)
Is tilted to the outside of the bearing, but it may be tilted to the side of the retainer (3) on the contrary.

Sealing grooves (14) are formed on the outer diameter portions of both ends of the inner ring (1). The seal groove (14) is composed of a seal surface (15) substantially parallel to the outer diameter surface of the inner ring (1) and a taper surface (16) forming a downward inclined surface toward the outside of the bearing. Of these, at least the seal surface (15) is different from the conventional mirror finish, and has a polished finish with a surface roughness of about 1S to 6S (0.2a to 1.0a).

The contact surface (15) of the lip (12) is in contact with the sealing surface (15). That is, this sealing device (5)
Is a radial contact type in which the lip (12) is brought into contact with the seal groove (14) from the radial direction.

As described above, according to the present invention, the lip (12) is brought into contact with the seal groove (14) from the radial direction, and
A vertical portion (11) extending in the radial direction is provided on a part of the lip (12) and on the outer ring (2) side of the contact piece (10),
Moreover, since the surface roughness of the seal surface (15) that is in sliding contact with the contact piece (10) of the lip (12) is set to about 1S to 6S (0.2a to 1.0a), the squeal noise caused by stick-slip Occurrence can be prevented. Further, since the vertical portion (11) extending in the radial direction is provided to enhance the rigidity of the lip (12), the elasticity of the lip (12) does not decrease with the increase in rigidity and the sealing function decreases. There is no possibility of causing a problem such as an increase in shaft torque.

Although the above description applies the present invention to a ball bearing, the present invention can be widely applied to rolling bearings in general regardless of the inner ring rotating type and the outer ring rotating type. Also, the same effect can be obtained by fitting the seal body (6) to the inner ring (1) and sliding the lip (12) into the seal groove provided on the outer ring (2).

[0021]

As described above, according to the present invention, it is possible to avoid the stick-slip phenomenon that occurs at the sliding contact portion between the lip and the bearing ring, and to reliably generate annoying squeaking sound due to this with a simple structure. Can be prevented.

In order to confirm this effect, a conventional axial contact type sealing device (FIG. 3 (a)) and a sealing device according to the present invention (a radial contact type sealing device having a vertical portion (11):
2) (a) and (b) when the outer ring was rotated and the squeaking noise was generated.
The result shown in FIG. Among them, (a) is an experimental result of a conventional axial contact type sealing device (sealing groove surface roughness = 1 s), and (b) is an experimental result of the sealing device according to the present invention. (Roughness of seal groove surface =
3s).

From the results of this experiment, in the sealing device of the present invention, the squeaking noise can be surely eliminated within the range of the rotation speed n = 2000 to 7000 rpm and the bearing temperature of 30 to 140 ° C., while the sealing of the axial contact type is used. It can be understood that the device produces a squeal under the same conditions.

In addition, in FIG. 2B, the data of the degreased seal products (shown by Δ) are also shown in parallel with the seal groove (1
This is because if oil is present in 4), slipping will improve and stick-slip will be less likely to occur, making it impossible to correctly evaluate the stick-slip suppressing effect.

[Brief description of drawings]

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

FIG. 2 is a graph showing a result of a comparative experiment between a conventional sealing device and a sealing device according to the present invention.

3A and 3B are cross-sectional views showing a conventional sealing device, FIG. 3A shows an axial contact type sealing device, and FIG. 3B shows a radial contact type sealing device.

[Explanation of symbols]

 1 Inner ring 2 Outer ring 5 Sealing device 6 Seal body 10 Contact piece 11 Vertical part 12 Lip 14 Seal groove 15 Sealing surface

Claims (3)

[Claims] 1. A bearing sealing device comprising a lip which is in sliding contact with a seal groove provided on one of the bearing rings, wherein the lip is brought into contact with the seal groove in a radial direction, and
A bearing sealing device, wherein a vertical portion extending in the radial direction is provided on a part of the lip and on the other race ring side of the sliding contact portion with the race ring. 2. A sealing device for a bearing, comprising a lip which is in sliding contact with a seal groove provided on one of the bearing rings, wherein the lip is brought into contact with the seal groove in the radial direction,
A bearing sealing device, wherein the surface roughness of the seal groove is set to 1S to 6S. 3. A bearing sealing device having a lip that is in sliding contact with a seal groove provided on one of the bearing rings, wherein the lip is brought into contact with the seal groove in the radial direction,
A vertical portion that is a part of the lip and that extends in the radial direction is provided on the other raceway side of the sliding contact portion with the raceway ring,
A bearing sealing device, wherein the surface roughness of the seal groove is set to 1S to 6S.