COMPONENT OPERATION / Priority Valve When steering is operated: NOTE: Orifice D in the steering valve is a variable orifice so that the open area becomes large in proportion to the steering wheel rotation angle. 1. The spool in the steering valve moves at the moment when the steering wheel is rotated, so that orifice D is opened. 2. Pressure oil in the circuit between orifice D in the steering valve and chamber A and port CF in the priority valve flows to the gerotor. 3. As pressure oil flows to the gerotor, pressure in the circuit between chamber A and port CF in the priority valve and orifice D in the steering valve decreases so that the spool in the priority valve moves to the right. 4. The spool in the priority valve becomes stable at the position where pressure oil flows to the steering valve in proportion to the orifice D open area. 5. At this time, pressure oil from the main pump flows to the steering valve and the control valve respectively through the spool. 6. Pressure oil from the main pump flows to the gerotor through the spool and the sleeve in the steering valve. 7. The gerotor delivers pressure oil while rotating as a hydraulic motor. Pressure oil from gerotor flows to the steering cylinder and the machine turns.
T3-1-4
