Hydraulic hybrid power system of excavator

Abstract

The invention relates to a hydraulic hybrid power system of an excavator, belonging to excavators. An engine of the hydraulic hybrid power system is sequentially and mechanically connected with a hydraulic variable output pump, a driving mechanism hydraulic pump / motor. The oil outlet port of the hydraulic variable pump is communicated with an oil inlet port of a main control valve and an oil inlet port of a second overflow valve; the main control valve is respectively communicated with a first wheel motor, a second wheel motor, a bucket arm cylinder, a bucket cylinder, and the oil inlet port and the oil outlet port of a boom cylinder; a one-way valve is respectively communicated with a fifth oil return port of the main control valve and the oil inlet port of a hydraulic motor; a swing mechanism hydraulic pump / motor is connected mechanically with a rotary table; an oil outlet port of a third two-position two-way shuttle valve is communicated with the oil inlet port of a driving mechanism hydraulic motor; and all the oil outlet ports are communicated with an oil tank. The system has the advantages of simple structure, mature technology, high reliability, low cost and stable and accurate control, and the reduction of the energy loss of a hydraulic system and capability of recycling the inertial potential energy of a swing mechanism with low oil consumption.

Description

technical field [0001] The invention relates to an excavator, in particular to a hydraulic hybrid power system of the excavator. Background technique [0002] With the rapid development of industrial technology worldwide, the problems of energy shortage and environmental pollution are becoming more and more serious. Among construction machinery, hydraulic excavators have gradually become the main objects of widespread concern due to their large usage, high fuel consumption, and poor emissions. During the working process of the hydraulic excavator, the up and down swing of the boom, arm and bucket and the rotary motion of the slewing mechanism are relatively frequent, and the inertia of each moving part is relatively large, so a large amount of energy will be released when decelerating and braking. This part of energy is usually consumed on the valve port of the hydraulic valve, which not only wastes energy, but also leads to heating of the system and reduction of component ...

AI Technical Summary

Problems solved by technology

Current hybrid excavators usually use batteries to store energy, but the battery technology has a low power density, which makes it difficult to instantly charge and amplify the current of the battery, resulting in low efficiency of the power system and low energy recovery, while supercapacitors and fuel cells have obvious problems. Issues such as cost and technical security

[0003] Existing excavators generally have problems such as high fuel consumption, high emissions, low system efficiency, and the inertial potential energy and potential energy of heavy objects during deceleration and braking are converted into heat energy and are wasted.

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