Hybrid power system for recovering potential energy of movable arm of excavating machine

Abstract

The invention discloses a hybrid power system for recovering the potential energy of a movable arm of an excavating machine. A check valve I, an auxiliary box, a motor, an electricity storing unit, a motor controller, a pressure sensor I, a pressure sensor II, a hydraulic motor, a clutch, a main controller and a check valve II are added on the basis of the conventional excavating machine; and an engine, the motor, the hydraulic motor and a master variable pump are combined into a power system through the auxiliary box. When the movable arm is lowered, oil flows back in two channels, a first oil backflow channel is connected into the hydraulic motor, a second oil backflow channel is connected into the master variable pump, and the hydraulic motor and the master variable pump are used for transmitting power to the power system respectively. The motor has an electricity generating function; by controlling the motor, the function of generating electricity through absorbed energy or providing driving energy through output energy can be realized, and the aim of energy conservation can be fulfilled; and the hybrid power system has the advantages of a small number of used elements, small element specification and low cost.

Description

technical field [0001] The invention relates to an excavator power system, in particular to an excavator arm potential energy recovery hybrid power system. Background technique [0002] When the arm of a traditional hydraulic excavator is lowered, the lowering position of the entire working device can be converted into heat and wasted through hydraulic throttling, and its energy loss accounts for about 20% of the total energy consumption of the operation. Currently adopting a hybrid scheme is considered to be an effective solution. [0003] At present, domestic research on the hybrid power of excavators has been started, and some patent achievements have been proposed, the main types of which are: [0004] (1) Connect the oil return of the rodless chamber of the boom cylinder to the hydraulic motor, and the hydraulic motor drives the generator to generate electricity, and the electric energy is stored in the energy storage element or drives the motor connected to the engine...

AI Technical Summary

Problems solved by technology

When the boom is lowered, the maximum oil return volume is close to twice the flow rate of the two main pumps, and the pressure is only 1 / 4 of the working pressure of the system. Therefore, it is necessary to equip a pump with a large specification, but the high-pressure capacity of the pump cannot be used, and the boom is lowered. The speed fine-tuning control performance is also not good

[0005] (2) Connect the oil return from the rodless chamber of the boom cylinder to the accumulator, but the oil pressure is low and it is difficult to be used. Due to the large amount of oil return from the rodless chamber of the boom cylinder, the accumulator is required to be bulky, and the actual The application is difficult. The oil return pressure of the rodless chamber of the boom cylinder is related to the attitude position of the working device, and the pressure change can reach more than double. The actual accumulator matching can only be considered according to the minimum pressure, so that the energy cannot be fully recovered.

[0006] (3) The oil return from the rodless chamber of the boom cylinder directly drives the hydraulic motor and then drives the hydraulic pump to store it in the accumulator in the form of high pressure. When in use, the oil from the accumulator is incorporated into the outlet of the main pump. This scheme uses many components. , large specifications, high cost, not only affect the adjustment characteristics of the load sensitive pump during use, but also the pressure of the accumulator is inconsistent with the pressure required by the working oil cylinder, and even the oil in the accumulator cannot flow out when the working pressure is high

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