Research On Characteristics Of Hydraulic Digital Rotary Valve With Double Spool Driven By Double Motors

Hydraulic servo system is widely used in automotive,aerospace,mining and other industrial fields because of its advantages such as stepless speed change,large speed range,frequent starting and reversing,and large transmission power.However,due to the impact of the working environment Affected,the oil is easily contaminated,which affects the system operation.As the core component of the hydraulic system,the performance of hydraulic valves affects the stability of the system.At present,most of the servo valves on the market have complex structures and are sensitive to oil pollution,and dual-motor-driven dual-spools are more difficult than single-motor-controlled single-spools.However,the single-spool servo valve currently cannot achieve multiple control effects by only rotating the spool.In response to the above problems,this paper proposes a new type of dual-motor-driven dual-spool hydraulic digital rotary valve.Through the knowledge of fluid mechanics,the mathematical model of the dual-motor-driven dual-spool hydraulic digital rotary valve is established,and the dual-motor-driven dual-spool hydraulic hydraulic The flow area formula of the valve port of the digital rotary valve establishes the functional relationship between the spool rotation angle and the flow rate,and the rationality of the formula is verified through Fluent simulation analysis and experiment.According to the mechanical strength theory,the theoretical strength of the dual-motor-driven dual-spool hydraulic digital rotary valve spool is checked.After calculation,the tensile stress of the spool is 30 MPa,and the compressive stress is41.1 MPa,which is far less than the allowable material.Stress,so meet the requirements of use.Using ANSYS to perform stress analysis on the valve core,the simulation results show that the simulation value is close to the theoretical calculation result,which verifies that the valve core material can meet the requirements of use.Use the knowledge of mechanics to analyze the torque received by the valve core during operation,and obtain the functional relationship between the rotation angle of the valve core and the load torque T1 and load p L.Use the software Fluent to simulate the torque received by the valve core.The comparison between the simulation value and the theoretical value verifies the correctness of the load torque formula.Use Matlab / Simulink to simulate and analyze the dynamic characteristics of the rotary valve,and analyze the frequency characteristics and step characteristics of the rotary valve under different damping B and moment of inertia J.It can be concluded that: by increasing the damping reasonably,reducing the rotation Inertia can improve the stability of the system and reduce the adjustment time of the system;the dynamic characteristics after PID adjustment are better than those before PID adjustment.The response time has changed from 20 s to 2 s,and the amplitude margin has changed from 12 s to 4 s.The increase of 1.2 d B to 19.1 d B greatly improves the stability and response speed of the system.An experimental platform for a dual-motor-driven dual-spool hydraulic digital rotary valve was built,and the correctness of the flow formula and the hydraulic torque formula was verified through the comparison of experimental data and theoretical data.