Motor grader or the like with hydraulic control system for circle gear

摘要

A motor grader including a main frame mounted on steerable wheels, a drawbar frame mounted on the main frame, a working implement carried by a circle gear rotatably mounted on the drawbar frame and a hydraulic control circuit is described. An improvement in the control of the working implement is disclosed in which continuous downward force is exerted on the circle gear at all times during operation by hydraulic rams. Preferred embodiments of the invention are described wherein the force is exerted by hydraulic means including wear surfaces in contact with the circle gear and wherein the hydraulic control circuit is adapted to provide automatic operation.