MOTOR GRADER Russian patent published in 1999 - IPC

FIELD: construction and road-building machinery and equipment. SUBSTANCE: motor grader relates to hydraulic drives of motor graders. Motor grader has main frame and drawbar frame which are interconnected by means of drawbar frame moving hydraulic cylinder and two drawbar frame lifting hydraulic cylinders. Piston spaces of drawbar lifting hydraulic cylinders are connected with piston space of drawbar moving hydraulic cylinder through two non-return valves. Rod space of this hydraulic cylinder is connected with pressure valve which in its turn is connected through two non-return valves with rod spaces of mouldboard lifting hydraulic cylinders. Ratio of cross-section areas of rod spaces and piston spaces of hydraulic cylinders must meet following requirement: S_p1/S_r1 ≤ S_p2/S_n2, where S_p1 - cross-section area of piston space of drawbar lifting hydraulic cylinder, S_r1 - cross-section area of rod space of drawbar frame lifting hydraulic cylinder, S_p2 - cross-section area of piston space of drawbar frame moving hydraulic cylinder, S_r2 - cross-section area of rod space of drawbar frame moving hydraulic cylinder. Aforesaid arrangement of hydraulic drive is more reliable and quick-acting so as to protect motor grader mouldboard. EFFECT: higher efficiency. 2 dwg