Digital Radial Piston Variable Displacement Pump, Constant Power Control Study

The radial piston pump can adopt manual-control or electro-hydraulic proportional control to realize the control of constant flow, constant pressure, constant power and load sensitivity etc. This paper is a new attempt at the control mode of the radial piston pump. With the study of the JBP-63 radial piston pump and using microcomputer and high-speed-on/off-valve, regulate the machine of the radial piston pump, constant power control can be achieved.Digital-Pump hydraulic circuit controlled by high-speed-on/off-valve is a new hydraulic system of high efficiency. It has the highest efficiency and the greatest energy sources saving among all kinds of circuits. The digital-pump is a promising hydraulic control component because it has many excellences such as good protection from pollution, good repetition, less effect by friction non-linearity and lag than analog system, convenient connection to the computer and no need the D/A conversion as analog machine.The main contents of this paper include: Design the hardware circuit with the core of the 8031 single-chip microcomputer, mainly including the drive circuit of high-speed-on/off-valve, sampling circuit, A/D conversion circuit, display circuit; establish the static and dynamic mathematics model of the system based on the system principle; through simulating software-MATLAB/simulink, get the static and dynamic response curves of the Digital-Pump under constant power; get the flux simulation curves through changing the parameter of the Kv; and find out the law of how the pump's structure parameter of the Kv to influence the system's dynamic response through analysis of the simulated curves; educe the conclusion that hydraulic controlled power match radial-piston-pump system is equivalent to the vibration characteristic and digital-axial-piston-pump system is equivalent to the inertia characteristic compared with the reference.