Electro-hydraulic actuator

Abstract

The invention discloses an electro-hydraulic actuator. The electro-hydraulic actuator comprises a servo motor, an oil pump, a three-position four-way electromagnetic directional valve, an oil cylinder, a displacement sensor, a controller and a proportional velocity regulating valve. The inlet of the proportional velocity regulating valve is communicated with the oil pump, the outlet of the proportional velocity regulating valve is communicated with a port P of the three-position four-way electromagnetic directional valve, and the proportional velocity regulating valve is electrically connected with the controller. When the electro-hydraulic actuator works, the servo motor, the oil pump and the proportional velocity regulating valve jointly act, hydraulic oil is conveyed into the oil cylinder, due to the fact that the proportional velocity regulating valve can stably control the output flow of a system in an infinitely small mode, the oil cylinder can be made to stably operate at very low speed, the defect that the oil pump can not stably output hydraulic oil in the low-speed operation process caused by factors of the oil pump itself is overcome, and locating accuracy of the oil cylinder is guaranteed.

Description

technical field [0001] The invention relates to the technical field of actuators, in particular to an electro-hydraulic actuator. Background technique [0002] Actuators include electric actuators, pneumatic actuators and electro-hydraulic actuators, which are generally used to drive and control the operation of valves. [0003] Existing electro-hydraulic actuators use a single servo motor and oil pump to jointly drive the cylinder. However, the response speed and positioning accuracy of this cylinder speed control system have always been contradictory. When the response speed of the cylinder is fast, the The positioning accuracy of the last stage is poor, and when the positioning accuracy of the oil cylinder is required to be high, the response speed of the oil cylinder needs to be slowed down, and when the oil pump is running at a low speed, the internal leakage increases, and the volume ratio and displacement become unstable, resulting in The actual cylinder positioning ...

AI Technical Summary

Problems solved by technology

[0003] Existing electro-hydraulic actuators use a single servo motor and an oil pump to jointly drive the cylinder. However, the response speed and positioning accuracy of this cylinder speed control system have always been contradictory. When the response speed of the cylinder is fast, the The positioning accuracy of the last stage is poor, and when the positioning accuracy of the oil cylinder is required to be high, the response speed of the oil cylinder needs to be slowed down, and when the oil pump is running at a low speed, the internal leakage increases, and the volume ratio and displacement become unstable, resulting in The actual cylinder positioning effect is poor

[0004] In

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