Research On Double Row Type Bent Axis Fixed Displacement Axial Piston Pump

With the continuous development of industrial technology and the requirement of environmental protection policy,the relatively serious vibration and noise of hydraulic system have become an urgent problem to be solved.Axial piston pump is widely used in various hydraulic systems,and it is the main noise source of hydraulic system.The flow pulsation is the main cause of the noise of axial piston pump,so how to reduce the axial piston pump's flow pulsation has become the key research of the hydraulic industry.The bent axis type variable displacement axial piston pump uses the structural design with double row pistons,on the one hand,it can reduce the flow pulsation of the axial piston pump by increasing the number of pistons,and on the other hand,it can improve the usage efficiency of the cylinder,and it can keep the compact structure of the cylinder.This thesis has conducted in-depth theoretical study,simulation optimization and experimental research of the double row type bent axis fixed displacement axial piston pump.In this thesis,the influence of the different arrangement of the cylinder piston bores on the theoretical flow pulsation characteristics of the double row type pump is studied.Considering the characteristic of the theoretical output flow and the compactness of the cylinder,the arrangement of the cylinder piston bores is come up with,which the number of the inside row pistons are 5,and the number of the outside row pistons are 10,and the alternate angle of the inside and the outside row pistons is ?/10.The mathematical model of cylinder size optimization is established,and the structural dimensions of the cylinder is optimized.Based on the change of the space posture of the tapered pistons during the synchronous rotation of the cylinder and the shaft,the driving characteristic of the double row type pump's cylinder is studied on the basis of the driving characteristic of the single row type bent axis axial piston pump's cylinder.Through the different value of the inside and the ouside row tapered pistons,the three types of driving characteristic of the cylinder are come up with,which are the cylinder is driven by the inside pistons alone,and the cylinder is driven by the outside pistons alone,and the cylinder is driven by both the inside and the outside pistons.Based on the analysis of the kinematic characteristics of the double row type pump and the mechanics model of the friction pair,this thesis designs the theoretical prototype of the double row type pump which is transformed by using the existing single row type bent axis fixed displacement axial piston pump.By combining the different advantages of the ADAMS,the AMESim and the ANSYS,this thesis constructs a virtual prototype of double row type pump with rigid-flexible coupling and liquid-solid coupling.The dynamic characteristic,pressure flow characteristic and stress distribution of partial parts are obtained,and the theoretical prototype of the double row type pump is simulated and optimized.The simulation results show that the flow pulsation of the double row type pump is significantly reduced compared with the existing single row type pump.At the end of this thesis,the test scheme of the theoretical prototype of the double row type pump is developed,and the feasibility of the structural design of the double row type pump is verified by the bench test of the theoretical prototype.The practical characteristic of the theoretical prototype is obtained.The experimental results show that the theoretical prototype of the double row type pump can establish normal pressure flow characteristics,and meet the test performance requirements.In this thesis,the structural design with double row pistons reduces the flow pulsation of the axial piston pump and keeps the compact structure of the cylinder of the axial piston pump.In this thesis,the double row type pump is simulated and optimized by virtual prototype,and the theoretical prototype of the double row type pump is designed and processed.The feasibility of the structural design of the double row type pump is verified by bench test.This thesis is favorable to the vibration and noise reduction and the high-pressure and the high-speed development of the axial piston pump.