Markus Resch, Rudolf Scheidl,
"Oil stiction in hydraulic valves - an experimental investigation"
, in D. N. Johnston and A. R. Plummer: Fluid Power and Motion Control, FPMC 2008, Seite(n) 457-468, 9-2008, ISBN: 9780861971503
Oil stiction in hydraulic valves - an experimental investigation
Sprache des Titels:
Fluid Power and Motion Control, FPMC 2008
Oil stiction arises whenever two surfaces form a narrow gap filled with oil. For fast
switching hydraulic valves with flat anchor solenoids this stiction force may degrade the
valve opening response significantly.
In spite of a vast literature on oil sticking - about 100 papers from different engineering
fields have been studied - an adequate model of the stiction process in hydraulic valves is
missing. Some research work has been done in the area of compressor valves where oil
stiction often reduces reliability. Most of the literature found concerns basic research
addressing adhesion, surface tension, fingering, etc.. The authors’ research intends to
combine and extend the existing knowledge to get an appropriate model of the stiction
process in hydraulic valves. The calculation of the maximum stiction force and some design
rules to avoid the stiction force are the main final objectives.
To understand the fundamentals and to check theories a test rig has been built. This test rig
can generate the very fast separation of two parallel plates by a servo-valve controlled short
stroke hydraulic cylinder and is equipped with sensors for the gap size, the separation
speed, and the stiction force. First stiction measurements between parallel plates were done.
For small gaps the measured stiction force curves correspond to those computed from the
Reynold’s equation, known as Stefan’s force in literature. For larger gaps, however,
additional effects, like fluid inertia, become significant and need a refined computational