Abstract: A swashplate assist mechanism for dynamically varying swashplate moments in a multiple piston hydraulic unit includes a valve means disposed in the swashplate and defining a variable orifice for metering fluid from at least one of the pistons; and means for generating a control error signal to the valve means so as to adjust the size of the variable orifice based upon the control error signal. When fluid is metered from a leading piston to a trailing piston near one or more of the pressure transition zones, or when fluid is metered from a trailing piston to a leading piston near the opposite transition zones, the swashplate moments can be reduced.
Type:
Grant
Filed:
February 2, 2001
Date of Patent:
July 2, 2002
Assignee:
Sauer-Danfoss Inc.
Inventors:
Kerry G. Geringer, Dennis M. Greene, Jeff L. Herrin, Richard L. Otto