Electro hydraulic actuator for butterfly valve

Abstract

The invention provides an electro hydraulic actuator for a butterfly valve. The electro hydraulic actuator comprises a shell, an electronic control part and a hydraulic system. The electronic control part comprises a controller, a displayer, control switches and an angle sensor, wherein the displayer, the control switches and the angle sensor are connected with the controller. The hydraulic system comprises a bidirectional gear quantitive hydraulic pump, an AC servo motor, one-way valves, a pressure oil tank, a double-liquid-control one-way valve, a gear rack type hydraulic cylinder and the butterfly valve. The AC servo motor is connected with the controller, and an output shaft of the AC servo motor is connected with an input shaft of the quantitive hydraulic pump. The pressure oil tank is communicated with a low-pressure oil suction port of the quantitive hydraulic pump through the one-way valves. Two outlets of the quantitive hydraulic pump are communicated with the hydraulic cylinder through the double-liquid-control one-way valve. The angle sensor is fixed to the upper portion of the hydraulic cylinder. One end, extending out of the hydraulic cylinder, of a rotation shaft is connected with a rotation shaft of the angle sensor. An output shaft of the hydraulic cylinder is connected with a rotation shaft of the butterfly valve. A hydraulic cylinder drive is high in response speed, the integration of the hydraulic cylinder is high, and the electro hydraulic actuator has high market competitiveness.

Description

technical field [0001] The invention relates to a valve driving actuator, in particular to an electro-hydraulic actuator for a butterfly valve. Background technique [0002] The valve drive actuator is an intelligent power device, which can quickly and stably control the working position of valves and other control components accurately, and is widely used in important fields such as electric power, metallurgy, and aerospace. Traditional valve actuators can be divided into pneumatic actuators, electric actuators and electro-hydraulic actuators. Pneumatic actuators use gas as the power medium. The biggest advantage is that it is clean and safe, and has low requirements for the use environment. However, due to the compressibility of gas, the control accuracy is low, and the compressed air pressure is low and the volume is large. Electric actuators use motors to drive gears or worm gears to output rotation or linear motion, which can output relatively constant large driving fo...

AI Technical Summary

Problems solved by technology

[0003] The traditional servo valve-controlled electro-hydraulic actuator adjusts the flow direction and flow of hydraulic oil through the electro-hydraulic servo valve, and controls the controlled object with linear displacement or angular displacement, output force or output torque, and has a large output driving force and fast response. Fast, high control precision, stable operation, etc., but it also has obvious shortcomings:

[0004] 1. Traditional electro-hydraulic servo valves are particularly sensitive to contaminated hydraulic oil

Contaminated hydraulic oil will accelerate the wear of the electro-hydraulic servo valve, which will lead to the failure of the servo valve and shorten the service life of the servo valve

[0005] 2. The valve control system needs a set of constant pressure hydraulic oil tank, the volume of the hydraulic oil tank is relatively large, thus increasing the volume and complexity of the system

[0006] 3. Since the hydraulic system is controlled by a throttle valve, the valve control system has a large throttling and heat generation, a large load utilization pressure loss, serious energy loss, and low efficiency

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