Toro Groundsmaster 3320-D - Hydraulic Flow Diagrams; Traction Circuit (Machine Serial Number below 316000000)

HydraulicFlowDiagrams
TractionCircuit(MachineSerialNumberbelow316000000)
ForwardDirection
Thehydrostatictransmissioninputshaftisrotatedbyadriveshaftoffthefrontof
theenginecrankshaft.Pushingthetopofthetractionpedalrotatesthevariable
displacementpumpswashplateinthetransmissiontocreateaowofuid.This
uidisdirectedtothexeddisplacementmotorinthetransmissionwhichturns
thefrontaxleinputshafttodrivethefrontwheelsintheforwarddirection.
Fluidowingfromthemotorreturnstothevariabledisplacementpumpandis
continuouslypumpedthroughtheclosedtractioncircuitaslongasthetraction
pedalispushed.
Agerotorchargepumpinthehydrostatprovidesaconstantsupplyofcharge
uidtotheclosedlooptractioncircuitforlubricationandtomakeupforuidthat
islostduetointernalleakageinthetransmissionpumpandmotor.Thecharge
pumptakesitssuctionthroughalterfromthereservoir(frontaxle).Charge
pumpowisdirectedtothelowpressuresideoftheclosedlooptractioncircuit.
Chargepressureislimitedto482to1,034kPa(70to150psi)bythecharge
pressurereliefvalveinthetransmission.Chargepressurecanbemonitoredat
thetransmissionchargepumptestport.Chargepumpowinexcessoftraction
circuitchargeneedsprovideshydraulicowforthesteeringandliftcircuits.
Groundsmaster
®
3280-D/3320
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HydraulicSystem:HydraulicFlowDiagrams
05138SLRevB