3. STEERING VALVE 3. STEERING VALVE (EHPS ; Electro Hydraulic Power Steering) 1) 1) STRUCTURE STRUCTURE The main spool in the steering valve (EHPS) can either be activated by the pilot unit or by the joy- stick selected through the shuttle valves on each end of the main spool.
Joystick steering(opt) 1 6 L CL CR R T TS LS EF P PS 2 3 4 5 7 8 9 10 11 12 EF P LS T Hydraulic circuit 13 14 15 17 18 16 75795SE17 1 To tank 2 To emergency system 3 To main control valve 4 From main pump 5 To steering unit P port 6 From steering unit T port 7 From steering unit L port 8 Shock & suction valve (left side) 9 To steering cylinder (left side) 10 To steering cylinder (right side) 11 Shock & suction valve (right side) 12 From steering unit R port 13 Relief valve 14 Check valve 15 Main steering spool 16 Pressure reducing valve 17 Metering spool 18 Priority spool 5-6 stick Joystick steering(opt) oller CL CR Steering valve Shock valves ELECTRONICS block Suction valves L 2 4 Main spool R 1 3 S3 KV2 KV1 12bar P CF EF 30bar Pressure reducing valve T Steering valve ELECTRONICS block 2 4 Main spool 1 3 S3 KV1 1 CF EF RONICS Steering valve block Main spool S3 KV1 1 Shock valves Suction valves 4 3 L KV2 2bar R P S3 KV1 1 30bar Pressure reducing valve T