The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 26, 1985
Filed:
Jan. 10, 1983
Merle R Showalter, Madison, WI (US);
Automotive Engine Associates, Madison, WI (US);
Abstract
A liquid flow control servo valve where the flow controlling element is a magnetically loaded hydrostatic step bearing. An electromagnet has a central liquid passage 3 through it, and flow from this passage 3 is closed off by a magnetically permeable flat plate which has a planar surface matching a corresponding planar surface of the electromagnet. Pressure from passage 3 floats the plate on a thin liquid film in the manner of a hydrostatic step bearing, and the film thickness of this liquid film rapidly adjusts until the hydrostatic bearing pressure force W balances the magnetic forces on the plate. This variation in film thickness adjusts flow rate past the plate. The flow and pressure drop across the hydrostatic bearing plate rapidly adjusts to coil current in the low hysteresis electromagnet, so that P across the plate varies nearly in proportion to coil current I. The geometry of the hydrostatic bearing can be tailored to produce a wide range of viscous damping characterization using conventional squeeze film equations. So long as flow in the step bearing is laminar, the ratio of critical damping produced by the valve in a particular installation is invariant over a wide operating range of flows and fluid viscosities.