JPS62171520A - Bearing seal - Google Patents

Abstract

PURPOSE:To obtain a bearing seal which can accomplish strong sealing effect with low sliding torque by mixing soluble filler with elastic material forming a seal lip, and eluting the soluble filler to the outside during or after molding to provide fine elution trace. CONSTITUTION:Soluble filler is mixed with elastic material (a) such as synthetic rubber or synthetic resin forming a seal lip 1 of a bearing seal B, and during the process of molding the bearing seal B, or after molding, the soluble filler is eluted. Thus, elution trace having fine space is formed. The elution trace reduces a contact surface and forms a lot of cavities, so that even if there is a difference in pressure between the inside and the outside of a bearing A, an elastic body (a) of a sliding portion is elastically deformed to be decompressed and relaxed in a short time. Accordingly, a strong sealing effect with low sliding torque can be accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a bearing seal for sealing a bearing, and specifically relates to a bearing seal having a pressure reducing device.

(Prior art) Conventionally, when the pressure inside the bearing increases or decreases due to the rotation of the shaft, etc., the seal that seals it is pressed strongly against the sliding surface of the bearing or the wall of the mounting groove in response to the increase or decrease in the pressure inside the bearing, causing sliding noise. Otherwise, vibration etc. were generated, which significantly accelerated wear.

As a countermeasure to this problem, a reinforcing plate with through holes is baked onto the inner surface of the main body made of an elastic material such as the one disclosed in Utility Model Publication No. 45-26492, and four parts are provided with notches that open due to the suction phenomenon caused by the negative pressure inside the bearing. A seal body with a suction cut or a space part in the circumferential direction between the fixing part of the seal plate and the fixing groove of the outer ring as in Utility Model Publication No. 47-35142, and the seal plate is connected to the inside of the bearing. A sealing plate has been developed that has a first groove that communicates with the outside of the bearing and a second groove that communicates with the outside of the bearing so that the inside and outside of the bearing are always in communication.

[Problem that the invention sought to solve]

However, the above-mentioned structure requires very complicated and careful molding work, and the tolerance range for finished dimensions is narrow, which is unavoidable.
The sealed body having a suction cut No. 92 required a high degree of skill and precision to open the suction cut, and therefore the shape was not suitable for mass production.

In addition, in the sealing plate of Utility Model Publication No. 47-35142, the inside and outside are always in communication through the U-groove provided, so when a pressure difference occurs, it can be easily alleviated, but if the internal temperature rises. Naturally, the grease sealed inside the hair ring will reduce its viscosity, causing the problem that it will flow out from the open U-groove, and furthermore, if the inside becomes under negative pressure, moisture from the outside will drop.・It had serious drawbacks that were unacceptable, such as the risk of inhaling foreign objects into the bearing.

In view of these drawbacks, the present invention provides a bearing seal having a seal lip that operates only when pressure is generated without being constantly open and communicating, thereby alleviating the pressure difference between the inside and outside, and also reducing the sliding torque. This is what we provide.

A detailed description will be given below with reference to the drawings.

[Means for solving problems]

The present invention relates to a bearing seal B for sealing a bearing A used in a rotating part such as a shaft as shown in FIG. A soluble filler is mixed with the body material a, and the soluble filler is eluted during or after the molding process of the bearing seal B.
It is characterized by the provision of elution traces 2 with minute spaces as shown in the figure.

Regarding the elution method, depending on the characteristics of the soluble filler used, if it is liquid soluble, a solvent is used, and if it is heat soluble, elution is carried out by heating.

[Effect]

The method for manufacturing the bearing seal B of the present invention includes mixing a soluble filler into a portion of the elastic material a of the same type that forms the bearing seal B;
At least the soluble filler is molded so that it will not break and flow out, and is melted and released to the outside. Naturally, when this happens, a space is created in the volume occupied by the soluble filler before elution, and countless fine elution traces 2 are formed as shown in FIG. This elution trace 2 is not limited to the surface of the seal lip 1, but if each of the soluble fillers is in contact with each other even a little, the contact area becomes a passage and elutes one after another, so it is possible to form a space deep down, forming a spongy shape. Even objects can be shaped.

As mentioned above, the seal lip 1 having the elution trace 2 of the bearing seal formed in this way has an actual surface of −A1 cm.
Therefore, the sliding area of the sliding part is greatly reduced.

(Example) In carrying out the present invention, since the soluble filler is partially blended and mixed, it can be obtained by a normal simple molding method without any special molding process, and the amount of elution, i.e., the amount of elution Adjustment 2 can be made by adjusting the amount of the soluble filler mixed in, or by adjusting the elution means such as temperature, concentration, or time.

This bearing seal can also be installed in a bearing seal B' having a plurality of seal lips 1' as shown in FIG. It is possible to create various shapes such as changing the outer lip or not providing an outer lip at all, and there is a large tolerance range for the mounting location. As mentioned above, the contact area of the trace 2 is greatly reduced and many cavities are formed, so even if heat is transferred from rotation or an ambient heat source and a pressure difference occurs between the inside and outside of the bearing A, the sliding part remains unchanged. The elastic body a deforms flexibly to relieve the decompression in a short time and has the function of measuring the air opening inside and outside.

In addition, the seal lip 1 normally comes into contact with the bearing A to perform a sealing action, and at this time, the elution trace 2 serves as a lubricant holding hole to provide appropriate lubrication to the sliding part and prevent sliding. This further reduces torque.

In addition, in order to design a bearing seal B with low sliding torque, a lip flex part that is thin and has precise dimensions was required, but with the present invention, low contact pressure can be obtained over a wide range, so precision can be achieved. A stable sealing force can be obtained with rough dimensional accuracy without using a complicated structure, and the moldability is extremely good.

As explained above, the present invention provides an ideal bearing seal that reduces pressure only when there is a pressure difference between the inside and outside to make the pressure the same, and normally provides a strong sealing effect with low sliding torque. This is what we provide.

[Brief explanation of drawings]

FIG. 1 is a cross-section [Ti diagram] of the bearing seal of the present invention fitted into a bearing. FIG. 2 is an enlarged partial sectional view of FIG. 1. FIG. 6 is a sectional view showing another embodiment of the present invention.

Claims (3)

[Claims] (1) A bearing seal B made of an elastic body such as synthetic rubber or synthetic resin used to seal the bearing A; seal lip 1 of the bearing seal B;
A soluble filler b is mixed with an elastic material a forming the bearing seal B, and the soluble filler b is eluted to the outside during or after the forming of the bearing seal B, thereby creating fine elution traces 2. bearing seal. (2) The bearing seal according to claim 1, characterized in that the soluble filler b is heated and eluted to form fine elution traces 2. (3) The bearing seal according to claim 1, wherein the soluble filler b is eluted with a solvent D to form fine elution traces 2.