Reciprocating movement type internal pressure compensation sealing piece

Abstract

The invention discloses a reciprocating movement type internal pressure compensation sealing piece which comprises a cylinder body and an end cover, wherein a middle piston is arranged between a first piston and a second piston; the edge of the middle piston is provided with an annular sealing piece; the upper and lower ends of the annular sealing piece are provided with raised positioning parts; the outer side of the middle of the annular sealing piece are provided with a raised sealing part which is matched with an inner wall of the cylinder body; grooves matched with the raised sealing part are formed in the first piston and the second piston; and a sealing cavity is formed between the annular sealing piece and the middle piston. According to the reciprocating movement type internal pressure compensation sealing piece, the sealing cavity formed between the sealing piece and the middle piston is utilized and is matched with a one-way valve, and a medium can be filled in and discharged from the cavity according to a gap between the sealing piece and the cylinder body and the working pressure during the operation, so that an optimal sealing state is achieved. A sealing medium with pressure is injected and is matched with a dynamic compensation function of self-elongation of a sealing material, so that a dynamic sealing effect is achieved.

Description

technical field [0001] The invention relates to a seal, in particular to a reciprocating internal pressure compensation type sealing device. Background technique [0002] Seals have been widely used in hydraulic transmission and pneumatic industries. Among them, the role of reciprocating or rotating seals in machinery and equipment is even more critical, because the use conditions of seals at this time are complex and the sealing requirements are high. For this reason, engineers and technicians have designed and manufactured various Some of the dynamic seals suitable for different usage requirements have become standard seals, and their varieties have been serialized, but it is difficult to meet the usage requirements and selectivity in actual engineering applications. Especially in the environment of long pipelines, high pressure and vibration, the working sealing structure, even if it is sealed, it is difficult to ensure long-term use. Once leakage occurs, the light one w...

AI Technical Summary

Problems solved by technology

Among them, the role of reciprocating or rotating seals in machinery and equipment is even more critical, because the use conditions of seals at this time are complex and the sealing requirements are high. For this reason, engineers and technicians have designed and manufactured various Dynamic seals suitable for different use requirements, some have become standard seals, and their varieties have been serialized, but it is difficult to meet the use requirements and selectivity in actual engineering applications

Especially in the environment of long pipelines, high pressure and vibration, the working sealing structure, even if it is sealed, it is difficult to ensure long-term use. Once leakage occurs, the light one will leak, which will affect the performance of the equipment; In severe cases, equipment may be damaged or personnel may be injured

On the other hand, once the assembly is completed, the seal will be packaged in the structure, even if the seal is damaged during the assembly process, it is difficult to find, and sometimes the reliability of the seal cannot be guaranteed after passing the airtight inspection

[0003] Chinese patent 93212688.X provides an internal pressure combined seal hydraulic cylinder, which can use the pressure medium to deform the combined seal ring to compensate for the collapse of the working surface, but because the return seal ring will retract, it needs to be installed on both sides of the piston Both need to be equipped with a combined sealing ring, and the friction between the sealing ring and the cylinder body is relatively large, and the energy loss is also large

[0004] Chinese patent 200820228215.9 provides an internal pressure type automatic compensation piston, which solves the problem of shrinkage of the sealing colloid during the return stroke by setting a one-way valve and a serrated annular step, but the cooperation between the sealing colloid and the cylinder body forms a wedge-shaped structure, The friction force is relatively large, and the structure is relatively complex, involving the combination of composite materials, and the processing is difficult

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