GUARD 2440509 - Caterpillar

SUPPLEMENTAL STEERING SYSTEM (Typical Installation)
1. Oil pump for primary oil flow (standard steering pump). 2. Outlet in diverter valve for return of supplemental oil flow to tank. 3. Inlet in diverter valve for supply of oil from the primary pump. 4. Inlet in diverter valve for supplemental oil flow from the hydraulic tank. 5. Outlet in diverter valve for oil supply to the inlet of the valve for steering control. 6. Diverter valve. 7 and 10. Oil tubes, pump to diverter valve. 8 and 9. Oil tubes, diverter valve to hydraulic tank. 11. Oil pump for supplemental oil flow.The components of a supplemental steering system for wheel loaders or wheel tractors are: a pump (11), a diverter valve (6) and several oil tubes.When the tractor engine is running and the tractor is moving, the oil flow of the primary circuit is from pump (1) to diverter valve (6) and the oil flow of the supplemental circuit is from pump (11) to diverter valve (6). All of the primary oil flow from pump (1) goes through the diverter valve (6) and goes to the valve for steering control. The oil tube that makes a connection between valve (6) and the steering valve is out of view behind valve (6). The supplemental oil flow from pump (11) goes to the diverter valve (6) and adds to the oil flow from pump (1) to the steering valve, or goes directly to the hydraulic tank through oil tube (2). Engine rpm is the factor that changes the direction of supplemental oil flow through the diverter valve. When engine rpm becomes less than 900 to 1000, the diverter spool moves to send supplemental oil to become part of the steering circuit oil.The shaft of pump (11) is turned by the output shaft of the transmission. Machine motion in reverse turns the shaft of pump (11) in the opposite direction of the rotation caused by machine motion in the forward direction. A change in the direction of rotation of the pump shaft makes little change in the pump output.When the engine is running and the machine is not moving, all the steering system oil comes from pump (1). Primary circuit oil goes into diverter valve (6) through inlet (3) and goes through the valve to outlet (5). If the steering wheel is not turned, oil from outlet (5) goes to the control valve for steering before going back to the tank. When the steering wheel is turned, oil goes from the valve to the steering cylinders. Oil from the steering cylinders goes through the control valve before going back to the tank.When the machine is moving, oil flow for the supplemental system is from the hydraulic tank through tube (9) to diverter valve (6). A reversing spool (22) in the valve bore behind inlet (4) shifts for supplemental oil flow to either tube (10) or tube (7). [Each change in the direction of rotation of the shaft of pump (11) causes the reversing spool