A key component of switch-mode hydraulic circuits is a high-speed two-position three-way valve with a variable duty cycle. This paper presents a new valve architecture that consists of two valve spools that are axially driven by crank-slider mechanisms. By phase shifting the two crank links, which are on a common crankshaft, the duty cycle of the valve is adjusted. The two spools split and re-combine flow such that two switching cycles occur per revolution of the crankshaft. Because the spools move in a near-sinusoidal trajectory, the peak spool velocities are achieved at mid-stroke where the valve land transitions across the ports, resulting in short valve transition times. The spool velocity is lower during the remainder of the cycle, reducing viscous friction losses. A dynamic model is constructed of this new valve operating at 120 Hz switching frequency in a switch-mode circuit. The model is used to illustrate design trade-offs and minimize energy losses in the valve. The resulting design solution transitions to the on-state in 5% of the switching period and the combined leakage and viscous friction in the valve dissipate 1.7% of the total power at a pressure of 34.5MPa and volumetric flow rate of 22.8L/min.
- Fluid Power Systems and Technology Division
Crank-Slider Spool Valve for Switch-Mode Circuits
- Views Icon Views
- Share Icon Share
- Search Site
Yudell, AC, Koktavy, SE, & Van de Ven, JD. "Crank-Slider Spool Valve for Switch-Mode Circuits." Proceedings of the ASME/BATH 2015 Symposium on Fluid Power and Motion Control. ASME/BATH 2015 Symposium on Fluid Power and Motion Control. Chicago, Illinois, USA. October 12–14, 2015. V001T01A056. ASME. https://doi.org/10.1115/FPMC2015-9606
Download citation file: