JP2549339Y2 - Bearing seal - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing seal mounted on a bearing and sealing the inside and the outside of the bearing, and more specifically, to a bearing seal capable of reducing a pressure difference between the inside and the outside.

[0002]

2. Description of the Related Art Conventionally, a seal member provided with a vent hole to provide air permeability between the inside and the outside of a bearing according to a change in atmospheric pressure caused by the temperature inside the bearing has been implemented. A structure as shown in JP-B-46-32492 (shown in FIG. 3) can be mentioned. This structure is applied to a bearing seal B of a type in which the outer peripheral edge 5 is fixed to the outer ring a1 of the bearing a and the inner peripheral edge 6 is slidably contacted with the inner ring a2. A filter 8 such as felt is inserted into the vent hole 7.
Is installed to deal with internal and external pressure differences.

[0003]

However, in the felt type ventilation structure as described above, even if a breathing action is obtained, the penetration of moisture which promotes the generation of rust cannot be prevented,
It was a defect that could even give up its role as a sealing material. That is, the filter 8 itself, such as a felt, causes wetness and gradually impregnates the inside of the water, and when the water is kept at a certain level or more, the water is easily drawn into the inside by the respiratory action.

To avoid this, a seal ring (not shown) having a vent plug made of a porous member having micropores has been developed as disclosed in Japanese Utility Model Laid-Open Publication No. 48-43058. Even in the same manner as described above, such as allowing intrusion of moisture into the interior by aeration and suction from moisture impregnation,
Rust generation cannot be completely prevented. The present invention eliminates many of these drawbacks, and prevents bearing lip heat, which is one of the major drawbacks of contact hermetically sealed bearing seals that come into contact with each other, to prevent the seal lip from forming. It is intended to provide.

[0005]

The present invention will be described with reference to the drawings. As shown in FIG. 1, a seal mounted on a rotating bearing and slidingly contacting a fitting portion 1 fixed to the bearing a1 or a2. A bearing seal A having a lip 2, wherein a through hole 3 penetrating the inside and the outside of the bearing seal A is provided in a part of the bearing seal A, and a polytetrafluoroethylene sheet 41 having a continuous porous structure and a nonwoven fabric 42 are bonded together. The ventilation sheet 4 formed as described above is disposed in the through hole 3.

[0006]

The present invention has the following excellent functions with the above structure. That is, the polytetrafluoroethylene sheet 41 used in the present invention has a fine porous structure obtained by stretching a polytetrafluoroethylene material formed in a sheet shape and has a fine void inside. The pores are present in a mutually continuous state, and the properties of the structural material are high in thermal stability, exhibit fine filtration separation properties, and have excellent water repellency.

This polytetrafluoroethylene sheet 4
1 and a nonwoven fabric 42 formed by compressing hairs and fibers are laminated to form the ventilation sheet 4, so that the polytetrafluoroethylene sheet 41 having a large water contact angle does not cause a capillary phenomenon and has high water repellency. As shown, the continuous fine pores allow air to permeate, and the non-woven fabric 42 located on the outside also allows air to permeate in the same manner as described above, so that no pressure difference is generated between the inside and the outside of the bearing. Is kept free of moisture. As a matter of course, the polytetrafluoroethylene sheet 41 and the nonwoven fabric 42 constituting the ventilation sheet 4 show a high filtering effect on the dust that is scattered and attached, and do not allow even fine dust to enter.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to carry out the present invention, as shown in FIG. 1, when a nonwoven fabric 42 is arranged on the outer side of a bearing a, clogging of the polytetrafluoroethylene sheet 41 by fine dust is prevented. This nonwoven fabric 4
When grease 2 is positioned inside, grease in bearing a,
It prevents oil and the like from directly contacting the polytetrafluoroethylene sheet 41 and prevents clogging of the continuous porous portion with oil. Furthermore, in order to obtain the above-mentioned respective excellent effects, it is also possible to dispose the nonwoven fabric 42 on both sides of the polytetrafluoroethylene sheet 41, and this structure can be a perfect filter material for inside and outside.

The present invention is applicable to a flat type bearing seal A as shown in FIG. 1 to a fitting type oil seal C as shown in FIG.
In this structure, the ventilation sheet 4 can be arranged apart from the seal lip 2, so that the ventilation function without affecting other parts can be achieved.

[0010]

According to the present invention, since the bearing seal A itself has gas permeability, no negative pressure is generated in the seal lip 2 from the inside of the bearing, and the seal lip 2 is prevented from being scraped and abraded, thereby greatly extending the seal life. Further, since the ventilation sheet 4 has high water repellency, it completely blocks moisture and protects the inside of the bearing from rust.

[0011]

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional structure that does not use the present invention.

[0012]

[Explanation of symbols]

 A bearing seal C oil seal a bearing 1 fitting part 2 seal lip 3 through hole 4 ventilation sheet 41 polytetrafluoroethylene sheet 42 non-woven fabric

Claims (2)

(57) [Scope of request for utility model registration] 1. A bearing seal A having a fixed fitting portion 1 and a seal lip 2 slidingly contacting the bearing seal A, a part of the bearing seal A is provided with a through hole 3 penetrating the inside and the outside thereof. A bearing seal characterized in that a ventilation sheet (4) formed by laminating a polytetrafluoroethylene sheet (41) and a nonwoven fabric (42) having a structure is provided in the through hole (3). 2. The bearing seal according to claim 1, wherein a non-woven fabric is bonded to both surfaces of the polytetrafluoroethylene sheet to form a ventilation sheet.