液压开心与闭心系统JOHNDEERE

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,*,4 - Open & Closed Center Systems,JOHN DEERE,Open & Closed Center,Basic,Hydraulics Certification,Module,4,1,OPEN CENTER VALVE,CLOSED CENTER VALVE,Tank,Tank,PUMP,PUMP,SPOOL VALVES,2,OPEN CENTER VALVE,Reservoir,Fixed,Pump,Control,Valve,Cylinder,w,w,Relief,Valve,HOLD,(IN NEUTRAL),Hydraulic system with gear pump,3,Reservoir,Fixed,Pump,Control,Valve,Cylinder,w,w,Relief,Valve,OPEN CENTER VALVE,RETRACT,(RETRACT),Hydraulic system with gear pump,4,Directional,control valve,(open center),RESERVOIR,RELIEF VALVE,FIXED,DISPL.,PUMP,#1,#2,#3,OPEN CENTER WITH,SERIES CONNECTION,In neutral the oil passes through the valves in series and returns to the reservoir.,4 - Open & Closed Center Systems,5,5,Directional,control valve,(open center),RESERVOIR,RELIEF VALVE,FIXED,DISPL.,PUMP,#1,#2,#3,OPEN CENTER WITH,SERIES CONNECTION,When the valve is,operated, the return,is closed,Only one valve will operate with,high pressure oil,4 - Open & Closed Center Systems,6,Note: Oil displaced from rod end of cylinder,is available to the #2 valve,0 PSI,Low Pressure,To valve #2,*,*,*,6,OPEN CENTER WITH,SERIES / PARALLEL,CONNECTION,RETURN WHEN IN NEUTRAL,PARALLEL PATH,RESERVOIR,FIXED,DISPL.,PUMP,#2,#1,x,All valves in neutral,#3,4 - Open & Closed Center Systems,7,7,When any valve is operated, the return,is closed and oil is available to all valves,through the parallel line.,RETURN,PARALLEL PATH,RESERVOIR,FIXED,DISPL.,PUMP,#3,x,#2,#1,OPEN CENTER WITH,SERIES / PARALLEL,CONNECTION,4 - Open & Closed Center Systems,8,8,When two or more valves are activated,at once, the cylinder with the smaller load,operates first,CONNECTION,OPEN CENTER WITH,SERIES / PARALLEL,RETURN,PARALLEL PATH,RESERVOIR,FIXED,DISPL.,PUMP,When the valve is,operated, the return,is closed,RETURN,4 - Open & Closed Center Systems,9,9,CLOSED CENTER VALVE,Reservoir,Control,Valve,Cylinder,HOLD,Variable,Displacement,Pump,(IN NEUTRAL),10,CLOSED CENTER VALVE,(RETRACT),Reservoir,Control,Valve,Cylinder,RETRACT,Variable,Displacement,Pump,11,CLOSED CENTER SYSTEM,Variable Displacement Pump,Charge Pump,When two or more,valves are activated,at once, the cylinder,with the smaller,load operates first,12,JOHN DEERE,PRO-TECH,Basic,Hydraulics Certification,Module 4,13,