Deere & Company
Closed loop feedback circle drive systems for motor graders

Abstract:

A closed loop feedback circle drive system utilized onboard a motor grader includes an operator input device, a blade, and a multi-speed hydraulic motor having a motor output shaft. The motor output shaft is mechanically linked to blade such that motor output shaft rotation drives rotation of the blade about a blade rotation axis. A controller is operably coupled to the operator input device and to the multi-speed hydraulic motor. The controller is configured to: (i) receive blade rotation commands via the operator input device to rotate the blade about the rotation axis in a commanded manner; and (ii) control the multi-speed hydraulic motor to implement the blade rotation commands, while repeatedly adjusting the rotational speed of the motor output shaft to reduce variations in a rotational velocity of the blade due to changes in blade loading conditions occurring during motor grader operation.