Study On The Flow Distribution And Speed Control Characteristics Of Digital Flow Distribution Cycloidal Hydraulic Motor

Cycloidal hydraulic motor as a hydraulic power actuator,has the advantages of high power density and overload protection performance,so it is widely used in road rollers,sweepers and other special vehicles and other construction machinery.The existing cycloidal motor basically adopts the form of mechanical flow distribution with shaft flow distribution and end flow distribution as the main parts.The mechanical flow distribution mechanism requires high machining accuracy and is prone to oil leakage after wear,so the mechanical efficiency and volumetric efficiency cannot be improved.In addition,the mechanical flow distribution mechanism can only achieve a single flow distribution,which can not cope with the demand of real-time speed regulation under different working conditions,and often need to be combined with additional components such as control valves or variable pumps to form a pump-controlled or valve-controlled speed regulation system.Based on this,this paper proposes the use of solenoid valve sets to replace the traditional mechanical flow distribution structure,combined with computer digital control technology to achieve a digital flow distribution and speed control scheme for the cycloidal motor,and establish a mathematical model of the valve-motor integration,build a digital flow distribution cycloidal hydraulic motor prototype and the corresponding measurement and control system,in simulation and experiment to study its flow distribution and speed control characteristics.The specific tasks completed are.(1)Analysis of the digital flow distribution and speed control mechanism of the cycloidal hydraulic motor.Through the analysis of the correspondence between the mechanical flow distribution cycloidal motor runner and the engagement chamber,the principle scheme of digital flow distribution by solenoid valve is proposed,and on the basis of this,the solenoid valve working time sequence state table of cycloidal motor under different steering is obtained,which lays the foundation for the establishment of mathematical model and the subsequent development of the prototype measurement and control system.(2)The mathematical model of digital flow distribution cycloidal motor is established and simulated.The mutual coupling between the subsystems of the solenoid valve is analyzed,and the solenoid valve flow model is established on this basis.Combined with the kinematics and dynamics analysis of the cycloidal motor meshing subsystem,a valve-motor dynamic speed model with PWM signal as input and motor speed as output is obtained.The model is simulated and analyzed in terms of flow distribution and speed control characteristics,which provides theoretical guidance and basis for the subsequent development and experimental verification of the motor prototype.(3)Development of the digital motor prototype and the corresponding measurement and control system.The selection of solenoid valve and angle sensor was completed,and the digital motor prototype was built by combining the motor flow distribution characteristics.On this basis,the data acquisition and measurement and control system required for the prototype experiment was developed,mainly including hardware system and software system.The hardware system mainly consists of information acquisition module and PWM signal driving module,while the software system mainly consists of angle information reading module,PWM signal generation and flow distribution module.(4)Experimental verification of the motor prototype.With the help of the hydraulic test bench,the digital motor prototype was experimentally studied,mainly testing the motor flow distribution characteristics,speed regulation characteristics and low speed characteristics.The experimental results show that it is feasible to use solenoid valves to achieve digital flow distribution and speed regulation of the cycloidal motor.