Simulation and implementation of a new crankshaft and connecting rod-type radial-plunger low-speed-high-torque hydraulic motor with digital distributor

Abstract

A new type of radial-plunger low-speed-high-torque (LSHT) hydraulic motor with digital distributor, which has ten high-speed solenoid on/off valves (HSVs) is proposed. It is a reconstructed hydraulic motor of the traditional one (Staffa motor). Compared with the traditional LSHT hydraulic motor with shaft or plane distribution mechanism, the operating principle of the new hydraulic motor is introduced and the distribution tables for both rotary directions are given at first. Then, the mathematical model of the new hydraulic motor is established by analysing piston dynamics for every section of angle. After that, the related simulations are made and the results show that the new hydraulic motor can work well with the digital distributor. The rotary speed of the new hydraulic motor can be easily changed by altering the duty cycle of the control signal which applies to the HSVs. To validate the feasibility of the proposed new hydraulic motor, the model machine is developed and the experiments are carried out. The experimental results demonstrate that the new hydraulic motor can rotate continuously with the digital distributor. In addition to that, the rotary speed and direction can also be easily changed by applying the proper control signal to the HSVs.