Hydraulic type energy recovery system for potential energy of boom of excavator

Abstract

A hydraulic type energy recovery system for potential energy of a boom of an excavator comprises a variable motor, two variable pumps, an energy accumulator, a control valve, an ECU, a pressure sensor, a revolution speed transducer, a hydraulic cylinder, an oil tank and an engine. Aiming at solving the problems that a great deal of potential energy of a boom of an existing hydraulic excavator under the working condition of severe change is wasted, a hydraulic type energy recovery system is arranged in parallel on the basis of not changing a hydraulic system and the operation performance of the existing excavator; the hydraulic type energy recovery system can recover the potential energy generated when the boom is released downwards, achieve flow regeneration of the boom in order to reduce oil consumption of the hydraulic excavator, and achieve the purpose of saving energy and reducing consumption.

Description

【Technical field】 [0001] The invention relates to the technical field of energy saving of hydraulic excavators, in particular to an excavator arm potential energy hydraulic energy recovery system using a hydraulic accumulator as an energy storage element and a variable variable motor-variable pump as an energy conversion element. 【Background technique】 [0002] During the working process of the hydraulic excavator, the boom swings up and down frequently. The working device of the hydraulic excavator is heavy and has a large inertia. However, during deceleration and braking, a large amount of potential energy of the working device is mostly converted into heat energy at the main valve orifice, which not only causes energy waste, but also leads to an increase in system temperature and a reduction in the life of hydraulic components. [0003] At present, the research on energy recovery is mainly concentrated in the field of automobiles, and the research on energy recovery in th...

AI Technical Summary

Problems solved by technology

However, there are three aspects that need to be further improved in this scheme: ① Problems in speed controllability: when the boom begins to descend, the fixed motor-variable pump speed is low, and the response time for the outlet pressure of the variable pump to be established is relatively long. In the interior, the load of the motor is close to 0, and the moment of inertia of the fixed motor-variable pump is very small, and the speed of the fixed motor cannot be controlled by adjusting the displacement of the variable pump, resulting in poor speed stability when it starts; ② In terms of energy recovery efficiency Problems in the aspect: the rotational speed of the energy conversion unit composed of quantitative motor-variable pump depends on the speed at which the boom is lowered. When the speed is low, the rotational speed of the energy conversion unit is low so that its volumetric efficiency is low. The speed of the conversion unit also fluctuates accordingly, resulting in the quantitative motor-variable pump not working in the high-efficiency area, and the system efficiency needs to be further improved; Unstable outlet pressure will lead to excessive suction or throttling loss

In addition, the system requires major changes to the hydraulic system of the traditional excavator, and the operating performance is different from the original system.

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