Toro Groundsmaster 5900 Series - Page 123

Athree(3)sectiongearpumpiscoupledtothepiston(traction)pump.The
gearpumpsectionfurthestfromthepistonpumpsupplieshydraulicowtothe
steering,cuttingdeckliftandtractionchargecircuits.Hydraulicowfromthenal
pumpsectionisdirectedtotheappropriatecircuitsbyapressurecompensator
valvelocatedinthesteering/deckliftmanifold.
Anadjustablecounterbalancevalve(RV3)inthesteering/deckliftcontrol
manifoldmaintainsbackpressureonthedeckliftcylinderstoallowsomeofthe
cuttingdeckweighttobetransferredtothetractionunittoimprovetraction.A
reliefvalve(RV2)locatedinthesteering/deckliftmanifoldlimitslift/lowercircuit
pressureto103bar(1500PSI).
1
2
3
g287732
Figure40
1.Leftdeckraise/lowerswitch3.Rightdeckraise/lowerswitch
2.Frontdeckraise/lowerswitch
Eachofthecuttingdecks(front,rightandleft)canberaisedindependentlywith
theuseofthree(3)deckraise/lowerswitchesonthearmrestconsole(Figure
40).PressingtherearofaswitchprovidesaninputfortheslaveToroElectronic
Controller(TEC)toraiseacuttingdeck.Thecontrollerprovideselectricaloutputs
tosolenoidsinthesteering/deckliftmanifoldtoallowappropriatevalveshiftto
causeacuttingdecktoraise.
Whenthecuttingdecksareinastationaryposition,allsolenoidsinthe
steering/deckliftmanifoldarede−energized.Inthisposition,theowfrom
thenalgearpumpsectionisby−passedthroughsolenoidvalve(S1),the
counterbalancevalve(RV3),thechargeoillterandthenisroutedtothetraction
chargecircuit.
Note:Toraiseacuttingdeck,theenginemustberunning.Also,theoperator
seathastobeoccupiedortheparkingbrakemustbeappliedwiththetraction
pedalinneutral.
FrontDeckRaise
Toraisethefrontdeck,therearofthecenterconsoleswitchisdepressed.The
switchactsasaninputtotheslaveTECwhichprovidesanelectricaloutputto
solenoidvalvesS1andS5inthesteering/deckliftmanifold.Theenergized
solenoidvalvesshifttoallowapassageforcircuitoilowtothebarrelendof
thefrontdeckliftcylinders.ShiftedS1preventsoilowfromreturningdirectly
tothetractionchargecircuit.ShiftedS5allowsanoilpaththroughoriceOR4
(tocontrolraisingspeed),thecheckvalveatOR5andtothebarrelendofthe
liftcylinderstoextendtheliftcylindersandraisethefrontdeck.Oilfromthe
extendingcylindersreturnstothehydraulicreservoir.
Whenthedeckswitchisreleased,themanifoldsolenoidsarede−energizedand
thefrontdeckliftcylindersandfrontdeckareheldinposition.
Groundsmaster
®
5900&5910
Page5–23
HydraulicSystem:HydraulicFlowDiagrams
16227SLRevB