Toro Groundsmaster 5900 Series - Page 126

Athree(3)sectiongearpumpiscoupledtothepiston(traction)pump.The
gearpumpsectionfurthestfromthepistonpumpsupplieshydraulicowtothe
steering,cuttingdeckliftandtractionchargecircuits.Hydraulicowfromthenal
pumpsectionisdirectedtotheappropriatecircuitsbyapressurecompensator
valvelocatedinthesteering/deckliftcontrolmanifold.
Anadjustablecounterbalancevalve(RV3)inthesteering/deckliftcontrol
manifoldmaintainsbackpressureonthedeckliftcylinderstoallowsomeofthe
cuttingdeckweighttobetransferredtothetractionunittoimprovetraction.A
reliefvalve(RV2)locatedinthesteering/deckliftcontrolmanifoldlimitslift/lower
circuitpressureto103bar(1500PSI).
Eachofthecuttingdecks(front,rightandleft)canbeloweredindependentlywith
theuseofthree(3)decklift/lowerswitchesonthearmrestconsole(Figure40).
PressingthefrontofaswitchprovidesaninputfortheslaveToroElectronic
Controller(TEC)toloweracuttingdeck.Thecontrollerprovideselectrical
outputstosolenoidsinthesteering/deckliftcontrolmanifoldtoallowappropriate
valveshifttocauseacuttingdecktolower.
Whenthecuttingdecksareinastationaryposition,allsolenoidsinthe
steering/deckliftcontrolmanifoldarede−energized.Inthisposition,theow
fromthenalgearpumpsectionisby−passedthroughsolenoidvalve(S1),
thecounterbalancevalve(RV3),thechargeoillterandthenisroutedtothe
tractionchargecircuit.
Note:Toloweracuttingdeck,thetractionspeedneedstobeinlowrange(mow)
andtheoperatorseatmustbeoccupied.
FrontCuttingDeckLower
Tolowerthefrontcuttingdeck,thefrontofthecenterconsoleswitchis
depressed.TheswitchactsasaninputtotheslaveTECwhichprovidesan
electricaloutputtosolenoidvalveS6inthesteering/deckliftcontrolmanifold.
EnergizedsolenoidvalveS6shiftstoallowapassageforoilowfromthebarrel
endofthefrontdeckliftcylinders.Theweightofthecuttingdeckcausesthefront
deckliftcylinderstoretractandlowerthefrontcuttingdeck.
Whenthedeckswitchisreleased,thecontrolmanifoldsolenoidisde−energized
andtheliftcylindersandfrontcuttingdeckareheldinposition.
RightCuttingDeckLower
Tolowertherightwingdeck,thefrontoftherightconsoleswitchisdepressed
toactasaninputtotheslaveTEC.Thecontrollerprovidesanelectricaloutput
tosolenoidvalvesS1,S8andS9inthesteering/deckliftcontrolmanifold.The
energizedsolenoidvalvesshifttoallowapassageforcircuitoilowtotherod
endoftherightwingdeckliftcylinder.ShiftedS1preventsoilowfromreturning
directlytothetractionchargecircuit.ShiftedS8allowsanoilpathtotheshaft
endoftheliftcylindertoretracttheliftcylinderandlowertherightwingdeck.Oil
fromtheretractingcylinderowsthroughoriceOR7tocontrolthedropspeedof
thecuttingdeck.FlowisthendirectedthroughtheshiftedS9,counterbalance
valve(RV3)andthenisroutedtothetractionchargecircuit.
Whenthedeckswitchisreleased,thecontrolmanifoldsolenoidsare
de−energizedandtheliftcylinderandrightwingdeckareheldinposition.
HydraulicSystem:HydraulicFlowDiagrams
Page5–26
Groundsmaster
®
5900&5910
16227SLRevB