Patent ID: 6508328
Filing Date: 2003-01-21
Classification: B60K,B60W,B60Y,E02F,F16H

Abstract:
A front wheel drive for a motor grader comprising an hydraulic motor connected to a front wheel of a motor grader, a source for providing high pressure hydraulic fluid to said hydraulic motor, an hydraulic bypass circuit in parallel with said hydraulic motor controlled to be opened or closed by a bypass valve, said bypass valve being a hydraulic logic element which is responsive to hydraulic motor conditions either side of said motor, said bypass valve being normally closed when said hydraulic motor conditions cause said hydraulic motor to drive said front wheel and said bypass valve assuming an open position when said hydraulic motor conditions change due to said front wheel overdriving said motor and wherein said bypass valve includes an electrically operated valve associated with said bypass valve, said electrically operated valve in one position allowing said bypass valve to respond to said hydraulic motor conditions and in a second position altering the hydraulic conditions sensed by said bypass valve and causing said bypass valve to move to an open position.