Hydraulic circuits are typically controlled by throttling valves or variable displacement pump/motors. The first method throttles fluid for a desired pressure output and excess energy is lost through heat. While variable displacement pumps are more efficient, they are often large and expensive. An alternate method is the switch-mode control of hydraulic circuits through high-speed on-off valves. The proposed on-off valve design makes use of a continuously rotating disc to modulate flow between on and off states; the average power output or pulse duration is determined by the relative phase shift between the input and output ports. The addition of a directional valve to the the high-speed three-way valve allows any fixed displacement actuator to behave like a virtually variable displacement unit that is capable of four-quadrant control. In this paper a mathematical model focusing on the throttling, compressibility, internal leakage and viscous friction losses is developed and utilized to optimize the valve design for highest efficiency.

This content is only available via PDF.
You do not currently have access to this content.