A closed oil pump hydraulic system and construction machinery with the same

Abstract

The invention discloses a closed oil pump hydraulic system and engineering machinery having the same. The closed oil pump hydraulic system comprises a primer engine, a closed pump driven by the primer engine and used for outputting hydraulic power, an oil feeding pump driven by the primer engine and used for providing a control oil source and an oil feeding source to the operation of a closed pump, a pressure control device including an electric control valve arranged in an outlet of the oil feeding pump and used for controlling the pressure in the outlet of the oil feeding pump according to instructions, and an electric control device for monitoring a working state of the closed pump and controlling the connection and the disconnection of the electric control valve based on the working state of the closed pump. The closed oil pump hydraulic system can guarantee the pressure in the outlet of the oil feeding pump needed by the normal operation of the closed pump, and can realize the automatic operation of the oil feeding pump under lower pressure when the closed pump dose not work, so that the reduction of the energy consumption of the oil feeding pump is realized.

Description

technical field [0001] The invention relates to the technical field of construction machinery, in particular to a closed oil pump hydraulic system and construction machinery with the same. Background technique [0002] In the prior art, the closed oil pump hydraulic system consumes a lot of energy when the closed pump does not work (the closed pump swash plate is at zero position and there is no pressure output) and the engine is running. The reason is that although the closed pump is not working at this time, the charge pump is still in working condition. [0003] The charge pump is a quantitative gear pump. As long as the engine drives the oil pump to rotate, the charge pump will output hydraulic oil. The output hydraulic oil flow is related to the engine speed, and the output pressure depends on the set pressure value of the low-pressure relief valve at the outlet of the charge pump. The charge pump outputs hydraulic power during operation, which is the power consumed b...

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Problems solved by technology

However, if the closed pump assembly 2 is not working, there is no need to provide a control oil source and a supplementary oil source, and the pressure output by the charge pump only needs to be able to maintain the normal operation of the internal mechanical parts of the oil pump. At this time, most of the hydraulic power output by the charge pump is Useless work consumes engine output power

[0007] However, it can be seen from the previous description that in the prior art, it is very inconvenient and unrealistic to reduce power consumption by manually lowering the set pressure of the mechanical relief valve when the closed pump is not working.

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