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:
Aug. 27, 1991
Filed:
Apr. 24, 1989
Keith R Carlson, Big Lake, MN (US);
Dwight B Stephenson, Savage, MN (US);
Timothy A Hjelsand, Saint Louis Park, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A hydrostatic power steering device is disclosed, which may be either a fluid controller (15) or a torque generator 111. The device is of the type including a housing (19;135) defining a fluid inlet port (29;113) and a return port (31;115). The device includes valve means (36;171) defining a neutral position and a first operating position. The device includes a gerotor mechanism (23;143) for imparting follow-up movement to the valve means in response to fluid flow through the gerotor, and a follow-up mechanism (49,51;183,185) transmits the follow-up movement to the valve means. The valve means defines a return fluid region (87,89,31g;205,197,157) which comprises part of the main fluid path. The return fluid region is isolated from the follow-up means and from the interior of the valving. The device includes a case drain port (99;219) in fluid communication with the interior of the valving such that the return port of the device may be connected to a downstream, pressurized device, while the interior of the valving (case drain region) is maintained at a relatively low pressure to avoid damage to seals (59;140) and bearings (57;142).