Closed-type pump-controlled hydraulic system

Abstract

The invention provides a closed-type pump-controlled hydraulic system. The closed-type pump-controlled hydraulic system comprises an alternating-current servo motor, a two-way metering pump, two overflow valves and a hydraulic cylinder; an output shaft of the alternating-current servo motor is connected to an input shaft of the two-way metering pump through a coupler; the two-way metering pump is provided with two oil pumping ports including the first oil pumping port and the second oil pumping port, and the two overflow valves are connected to the two oil pumping ports of the two-way metering pump in a crossing mode respectively and connected with the two-way metering pump in parallel; an oil inlet of one overflow valve is connected with the first oil pumping port, and an oil outlet of one overflow valve is connected with the second oil pumping port; an oil inlet of the other overflow valve is connected with the second oil pumping port, and an oil outlet of the other overflow valve is connected with the first oil pumping port; the first oil pumping port of the two-way metering pump is connected to a first cylinder oil port of the hydraulic cylinder through a first oil way, and the second oil pumping port of the two-way metering pump is connected to a second cylinder oil port of the hydraulic cylinder through a second oil way. Therefore, the purpose of saving energy can be achieved by adjusting the rotation speed of the alternating-current servo motor, such as lowering the rotation speed of the alternating-current servo motor.

Description

technical field [0001] The invention belongs to the field of single-axis hydraulic drive, in particular, the invention relates to a closed pump control hydraulic system. Background technique [0002] The hydraulic system has the characteristics of large unit power-to-mass ratio, control precision and high cost performance, and is widely used in aerospace, engineering machinery, metallurgy and machine tools and other fields. The common type of hydraulic system control is the valve-controlled hydraulic system. The valve-controlled hydraulic system adopts servo valve or proportional valve control, which has fast dynamic response, but the system is sensitive to oil pollution, and the servo valve has high requirements for oil cleanliness, and the system There are a lot of overflow and throttling losses, and the oil temperature rises, so it needs to be equipped with a cooling device, which is suitable for small and medium power occasions that require high speed. [0003] Generall...

AI Technical Summary

Problems solved by technology

The common type of hydraulic system control is the valve-controlled hydraulic system. The valve-controlled hydraulic system adopts servo valve or proportional valve control, which has fast dynamic response, but the system is sensitive to oil pollution, and the servo valve has high requirements for oil cleanliness, and the system There are a lot of overflow and throttling losses, and the oil temperature rises, so it needs to be equipped with a cooling device, which is suitable for small and medium power occasions that require high speed

[0003] Generally speaking, a traditional hydraulic system needs to be equipped with a constant pressure oil source pumping station system, which includes a series of oil tanks, liquid level gauges, liquid temperature gauges, air filters, manifolds, pipelines, etc. For the hydraulic system with a single or double cylinder as the actuator, the system control is relatively easy, the movement to be realized is relatively simple, and the required flow is small. A pumping station system is equipped for the above-mentioned A single-cylinder or double-cylinder hydraulic system is obviously somewhat wasteful, which increases the overall cost of the hydraulic system and complicates the design of the hydraulic system

[0004] In addition, in some applications where the structural space is limited, the pumping station system cannot be accommodated due to the space limitation, which limits the application of the hydraulic system

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