JPH034858Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the structure of a mechanical seal that seals the rotating shaft of a machine body in a low-pressure, low-speed device.

[Conventional technology] Conventionally, mechanical seals attached to this type of low PV device have a mating ring fixed to the housing side of the machine body and a sliding surface of this mating ring that is elastically pressed. Currently, the seal ring is fixed to the rotating shaft side that is biased and comes into sliding contact with each other, and the seal ring is formed of rigid bodies.

[Problems to be solved by the invention] However, with the conventional structure described above,
Since the sliding surfaces of the mating ring and seal ring are rigid, not only precision is required for the finished surface, but also the airtightness is poor due to scratches and wear caused by surface roughness and deformation due to heat generation. Furthermore, if foreign matter intervenes between these sliding surfaces, the sliding surfaces will separate from each other due to the presence of foreign matter, reducing sealing performance and causing problems such as increased leakage when operation is stopped. Ta.

[Purpose of the invention] The present invention was made under the above circumstances, and its purpose is to improve the airtightness and sealing performance of the sliding surface without requiring precision of the finished surface. Our goal is to provide a mechanical seal that enables

[Means for Solving the Problems] In order to solve the above-mentioned problems, the mechanical seal of the present invention includes a rotating-side seal ring that is hermetically attached to the outer peripheral surface of the rotating shaft and slides into contact with the non-rotating mating ring. is made of a rubber material, a metal drive band is embedded within the seal ring, and the outer circumference and back surface of the seal ring are held by a casing that receives the axial biasing force of a spring. It is something.

[Function] According to the present invention, since the seal ring is made of a rubber material, its sliding surface is in good contact with the sliding surface of the mating ring due to the flexibility of the rubber material, and both sliding surfaces Even if a foreign object intervenes between them, the resulting gap is absorbed by the elasticity of the rubber material, so the sliding surfaces will not separate from each other. In addition, since the metal drive band is embedded in this seal ring, the rubber material on the inner circumference side of this drive band can be provided with a sufficient tightening margin for the rotating shaft, and the outer circumference of the seal ring The shape of the rubber material is maintained by the casing that holds the back surface and the drive band, and the rubber material does not escape when compressed in the axial direction by the biasing force of the spring, so sufficient sealing surface pressure is applied to the sliding surface. can do.

[Embodiment] Hereinafter, the present invention will be described in detail with reference to an illustrated embodiment.

Figure 1 shows low pressure and low speed (low PV value) according to the present invention.
This figure shows a schematic configuration of a mechanical seal applied to equipment. In the figure, 1 is a housing of a machine body, and a rotating shaft 2 is inserted into the housing. and,
A mating ring 4 made of a rigid metal body is attached to the inner periphery of the housing 1 of this machine via an O-ring 3.
A seal ring 5 is rotatably and slidably contacted on the sliding surface 4a of the mating ring 4.

That is, the seal ring 5 has a packing part 51 that seals the outer periphery of the rotating shaft 2 and an outer diameter cylindrical part 52 that comes into sliding contact with the sliding surface 4a of the mating ring 4, which are integrally formed of a rubber material. It consists of a cylindrical ring body 50 having a double tube structure, and a drive band 53 made of a metal ring is integrally provided at an intermediate portion between the packing part 51 and the outer diameter cylindrical part 52. This drive band 53 is designed to provide a shimmy margin at the contact portion of the packing portion 51 with the rotating shaft 2, thereby providing a sealing function between the rotating shaft 2 and the seal ring 5. It's something you have to have.

In addition, 6 in the figure is a casing that holds the seal ring 5, and this casing 6 is attached to the mating ring by the biasing force of a spring 8 biased via a spring suppressing member 7 fixed to the rotating shaft 2. 4 side, thereby elastically pressing the sliding surface at the tip of the outer diameter cylindrical portion 52 of the seal ring 5 against the sliding surface 4a of the mating ring 4. The casing 6 and the drive band 53 maintain the shape of the seal ring 5 made of a rubber material, and the axial direction of the outer diameter cylindrical portion 52 due to the biasing force of the spring 8 Since the rubber material does not escape when compressed, sufficient sealing surface pressure can be applied to the sliding surface.

By the way, according to the above-mentioned mechanical seal according to the present invention, as a result of testing the amount of oil leakage when the operation is stopped using engine oil as the sealing liquid and a pressure of 1 kg/cm ² G, it was found that As shown in Figure 2, the mechanical seal of the present invention (prototype:
Δ) is a conventional mechanical seal (prot:
Compared to ●), there was almost no sudden leakage.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that various modifications may be made without changing the gist of the present invention.

[Effects of the invention] As is clear from the above explanation, according to the present invention, since the seal ring is made of rubber material, the sliding surfaces are brought into good contact with each other, and separation of the sliding surfaces due to the intervention of foreign matter is prevented. In addition, by providing a tightening margin with the drive band embedded in the seal ring, the airtightness with the rotating shaft is improved.Moreover, the seal ring made of rubber material is prevented by the casing and the drive band. Since the rubber material retains its shape and does not escape when compressed in the axial direction, it is possible to obtain good sealing performance and has the excellent effect of reducing leakage when the operation is stopped. It is.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional side view of a main part showing an embodiment of a mechanical seal according to the present invention, and FIG. 2 is an explanatory diagram showing the test results of the amount of oil leakage when the operation is stopped. 4...Mating ring, 4a...Sliding surface,
5... Seal ring, 50... Ring body, 51...
...Packing part, 52...Outer diameter cylindrical part.

Claims (1)

[Scope of utility model registration request] The seal ring on the rotating side that is airtightly attached to the outer peripheral surface of the rotating shaft and makes sliding contact with the non-rotating mating ring is made of a rubber material, and a metal drive band is embedded within the seal ring, and the axial biasing force of the spring is A mechanical seal characterized in that a casing that receives the seal ring holds the outer peripheral part and the back part of the seal ring.