Research On Force Coupled Radial Piston Motor

Hydraulic motors which is widely used now can be divided into two categories of radial force balance and radial force imbalance.Radial force balance motor is not affected by the lateral force,and in which the friction pair wear is less,service life is longer.But it can not be variable.The motor with imbalanced radial force can be variable,but the unbalanced force generated by the hydraulic oil will increase the force of the friction pair and it will easily damage the motor.This paper presents a force-coupled radial piston motor.The output shaft of the motor keep the radial force balanced.And the output torque is transformed by the coupling force.In one housing of the motor can form two motors inside and outside,in the condition of the input pressure and flow rate are constant.Besides,three torques and speeds can be output through different distribution methods.In this paper,the basic structure of the coupling type radial piston motor is designed.The working principle and new application direction of the motor are introduced.The speed control circuit of the torque coupling motor can output three levels of torque and rotation speed,which expands the application range of the circuit.So it can give an effect of reduce energy loss.The curve of the motor's guide rail was analyzed,and the expressions of the speed,acceleration and displacement of the guide rail curve under different motion laws were studied.The relationship between the guide rail curve and the torque and speed pulsation of the motor was analyzed.Through analysis of the instantaneous torque and speed of the motor,it was found that the distribution law of the amplitude of the guide rail curve when the motor torque and speed pulsation is zero is analyzed,and the contact stress between the guide rail curve and the roller is analyzed and solved.In this paper,the kinematic and dynamic characteristics of the motor friction pair are studied,and the velocity,acceleration and displacement characteristics of the motor's main moving parts are analyzed.The force forms and positions of the motor's plunger pair and the valve plate were analyzed,and the axial thrust of the inner and outer motor flow plates was calculated.The ANSYS simulation was performed on the plunger pair.The results showed that the plunger's deformation under the maximum force condition was small,and the structural strength satisfies the application requirements.This paper analyzed the leakage path of the motor and the leakage modes of the plunger pair and the valve plate.With the FLUENT software,the inner and outer motor flow channels were simulation analyzed.Through the result,it is found that the pressure loss of the fluid in the flow channel is small,the flow rate is low,about 3 m/s.Finally the prototype of the motor was machined,and the performance test bench for the motor was built.Through the test,the output characteristics of the motor under three working modes were tested,and also the volumetric efficiency.