Hydraulically driven low-temperature reciprocating pump capable of reducing influence of low temperature on piston rod seal

Abstract

The invention discloses a hydraulically driven low-temperature reciprocating pump capable of reducing influence of low temperature on a piston rod seal. The hydraulically driven low-temperature reciprocating pump comprises a cylinder body, a pump body and a piston rod, wherein the pump body is internally provided with a low-temperature medium storage tank, and an opening of the pump body is provided with an end cover fixedly connected with the pump body; the cylinder body is arranged above the pump body; one end of the piston rod penetrates through the end cover and extends to a cylinder bodycavity, and reciprocates in the cylinder body cavity; the piston rod is provided with a rubber sealing ring for oil sealing; and a heat-insulating and radiation-proof protective sleeve is provided between the cylinder body and the end cover. The hydraulically driven low-temperature reciprocating pump capable of reducing the influence of the low temperature on the piston rod seal provided by the invention has many advantages such as ensuring the sealing life of the rubber sealing ring, preventing frosting at the opening of the pump body, and reducing the friction between the piston rod and thecavity.

Description

technical field [0001] The invention relates to the field of hydraulically driven low-temperature reciprocating pumps, in particular to a hydraulically driven low-temperature reciprocating pump capable of reducing the impact of low temperature on the piston rod seal. Background technique [0002] The hydraulically driven reciprocating pump has a wide range of uses. Compared with the traditional reciprocating pump, the crank linkage mechanism is removed, and the hydraulic cylinder is used for driving and hydraulic control. It can have long strokes and low stroke times, which greatly improves the working performance. However, hydraulically driven reciprocating pumps also require a piston rod that reciprocates axially in the pump working chamber. [0003] The hydraulically driven reciprocating pumps described above have particular application in those cryogenic pumps involving extremely high pressures. For example, cryopumps for media such as liquid nitrogen or liquid methane ...

AI Technical Summary

Problems solved by technology

[0004] The hydraulically driven cryogenic reciprocating pump, the driving end is connected to the storage tank of the cryogenic pump, and the piston rod at the driving end is generally sealed with an oil seal. Because the piston rod at the driving end will be affected by the low temperature of the low temperature medium, the surface temperature of the piston rod at the driving end will drop. , As a result, the seal of the oil seal is affected by the low temperature, the elasticity of the polyurethane or rubber oil seal is reduced, the entire oil seal becomes hard and brittle, and the seal fails, resulting in leakage of hydraulic oil

Existing hydraulically driven low-temperature reciprocating pumps increase the temperature area by lengthening the piston rod length, but due to the increase in the volume of the piston rod, the hydraulic power remains unchanged, which will reduce the frequency of piston rod activity, and the seal will still be subject to a certain low temperature. There is also electric heating to solve the influence of connecting rod surface temperature, but the structure of electric heating is more complicated

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