Control system for spool valve avoiding mechanical stresses
AssigneeSchneider Electric Systems USA, Inc.
InventorsDimitri Petronella, Antoine Paulus
Life of this patent
Estimating the term…
Abstract
A fluid pressure controlled spool valve minimizes abrasion or sticking caused by a tilted orientation of a pressure plate forcing lands of a spool shaft to abrade or stick internally facing surfaces of a cylindrical barrel supporting the spool shaft. A permanent magnet is mounted on the pressure plate. A round head composed of a ferromagnetic material is formed on an end of a spool shaft and configured to be magnetically attracted to the permanent magnet. A magnetic attraction force vector produced on the round head of the spool shaft remains coaxial with an axis of the spool shaft, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft.
Claims16
A spool valve control, comprising:
- a housing including a first chamber for receiving a control fluid and a second chamber for supporting a spool shaft having an axis, the spool shaft configured to move along the axis;
- a flexible membrane separating the first and second chambers, configured to form a flexible barrier to the control fluid in the first chamber;
- a pressure plate in the second chamber against which the flexible membrane presses in response to changes in pressure of the control fluid;
- a permanent magnet mounted on the pressure plate in the second chamber;
- and
- a round head formed on an end of the spool shaft and composed of a ferromagnetic material, configured to be magnetically attracted to the permanent magnet;
- wherein a magnetic attraction force vector produced on the round head of the spool shaft by the permanent magnet, remains coaxial with the axis of the shaft, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft.
In a spool valve including a flexible membrane separating a control fluid chamber and an interior chamber, and a pressure plate in the interior chamber against which the flexible membrane presses in response to changes in pressure of control fluid in the control fluid chamber, a spool valve control, comprising:
- a permanent magnet mounted on the pressure plate in the interior chamber;
- and
- a round head formed on an end of a spool shaft in the interior chamber, the round head composed of a ferromagnetic material, configured to be magnetically attracted to the permanent magnet;
- wherein a magnetic attraction force vector produced on the round head of the spool shaft by the permanent magnet, remains coaxial with an axis of the spool shaft, when the pressure plate and the magnet are tilted with respect to the axis of the spool shaft.
Dependencies are inferred from the claim text.