Spool Valve Stability and Sealing Land Deformation
Sprache des Vortragstitels:
Englisch
Original Tagungtitel:
International Scientific-Technical Conference on Hydraulic and Pneumatic Drives and Control (NSHP 2023)
Sprache des Tagungstitel:
Englisch
Original Kurzfassung:
In the development of spool valves with narrow sealing lands problems with spool sticking were encountered. In previous investigations of this phenomenon bending deformation has been identified as cause. Bending creates a conical sealing gap destabilizing the centered spool position. This leads to substantial lateral forces pressing the spool to the bore and creating high friction forces. In a patent a sealing land modification was proposed which is able to reverse this effect and to stabilize the centric spool position.
In the current paper thorough analyses of the sealing land elastic deformations by the front side and by the sealing gap pressure, their influences on the gap pressure field and on resulting lateral forces are presented. Non-dimensionalization is applied to lower the number of system parameters and to obtain results as generic as possible. Finite Element models for deformation and gap pressure are developed to solve the associated field problems.
Results show that shear deformation of sealing lands with a relatively small radial extension can create a stabilizing conical gap in its center section. General results are presented showing the magnitude of this effect in dependence on design and material parameters, also in comparison to the effect of the gap pressure field and to manufacturing tolerances.
Forschungs-