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:
Dec. 08, 1998
Filed:
Aug. 08, 1997
Kevin D Schroeder, Minneapolis, MN (US);
Maynard W Marts, Bloomington, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A variable displacement axial piston pump (11) having a tiltable swashplate (33) to vary pump displacement by a manual input lever (43). The pump includes a neutral centering device (45) in which a cam member (57) is fixed to the end of one trunnion member (35). The cam member (57) defines three cam surfaces (65), each having a minimum displacement portion (67) and at least one maximum displacement portion (69). In engagement with each of the cam surfaces (65) is a follower element (79) supported by a cam follower holder (73), both of which are biased by a set of Belleville washers (75), toward the cam member (57). The present invention provides a neutral centering device which is balanced and simple to assemble, not requiring any special fixtures or holders for preloading a biasing spring, but which is able to provide a substantially constant return torque.