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:
Feb. 29, 2000
Filed:
Oct. 17, 1997
Michael J Voigt, Chanhassen, MN (US);
Eaton Corporation, Cleveland, OH (US);
Abstract
A variable displacement pump assembly (11) of the type including a tiltable swashplate (29) to vary the pump displacement. The assembly includes a main control valve (43) having a housing (44). The assembly includes an input section (65) disposed between the valve housing (44) and the pump housing (61). The input section (65) defines a cylinder bore (77, 79) in which a piston member (81) is disposed and is connected by a mechanical input (59) to a valve spool (51) of the main control valve. The piston defines first (87) and second (89) piston chambers and a solenoid valve (105) is responsive to a remote electrical input signal (111, 113) to control the fluid pressure in the piston chambers, and therefore, the position of the valve spool (51). The mechanical linkage (91,99,101) between the piston (81), the valve spool (51) and the swashplate (29) is totally enclosed within the valve housing (44) and the body portion (67) of the input section, thus eliminating the need for remote mechanical control cables, and improving the reliability of the control system. The control of the present invention thus enables the vehicle operator to vary pump displacement by either a manual input to the main control valve (43) or by varying the electrical input signal (111, 113).