A large variety of options for the internal valves of a hydraulic motor are available. Poppet valves, rotary valves, and port plates are common options, but each have drawbacks such as actuation force, complexity, leakage, or friction. An alternative type that is also common is spool valves. Spool valves require minimal actuation force and have low throttling losses if sized correctly. This paper compares two drive options for a mainstage spool valve: a hydraulic pilot from a rotary valve and mechanical actuation. Dynamic models of the two valve configurations are created to carry out design studies and evaluate the performance of the motor. Compressibility effects, viscous drag, and flow forces are included in the model. Simulations show that the rotary valve pilot operation causes an unacceptable lag in the motion of the spool that cannot be corrected without reducing performance when running in reverse. Furthermore, the rotary pilot stage drive results in the motor timing becoming retarded at higher operating speeds. For these reasons, mechanically actuated valves are preferred over pilot operated valves for hydraulic motors operated bidirectionally or across a wide speed range.
|Original language||English (US)|
|Title of host publication||ASME/BATH 2019 Symposium on Fluid Power and Motion Control, FPMC 2019|
|Publisher||American Society of Mechanical Engineers (ASME)|
|State||Published - 2020|
|Event||ASME/BATH 2019 Symposium on Fluid Power and Motion Control, FPMC 2019 - Longboat Key, United States|
Duration: Oct 7 2019 → Oct 9 2019
|Name||ASME/BATH 2019 Symposium on Fluid Power and Motion Control, FPMC 2019|
|Conference||ASME/BATH 2019 Symposium on Fluid Power and Motion Control, FPMC 2019|
|Period||10/7/19 → 10/9/19|
Bibliographical noteFunding Information:
This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Vehicle Technologies Office Award Number DE-EE0008335.