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:
Oct. 03, 2000
Filed:
May. 19, 1998
Wayne B Wenker, Eden Prairie, MN (US);
Marvin L Bernstrom, Eden Prairie, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A rotary fluid pressure device (11) comprising a gerotor motor of the type including a spool valve member (51) cooperating with a housing (13) to define a nominal valve overlap (X). The motor has a drive shaft (53) for transmitting the rotational movement of a gerotor star (27) to the spool valve member (51) and output shaft (49), such that, under high torque loads, the drive shaft (53) is subjected to drive twist, which would normally effect valve timing. In accordance with the invention, the spool valve member (51) and the housing are provided with a valve overlap (Y) which is substantially greater than the nominal overlap (X). The star (27) defines, on its profile (85), first (87) and second (89) recesses which permit communication between the minimum (30) and maximum (32) volume transition chambers and the respective expanding (29) and contracting (31) volume chambers (FIG. 8). The result is an improvement in both mechanical and volumetric efficiency, as well as smoother operation at low speed and high pressure.