Table Of ContentHYDROSTATIC
TRANSMISSIONS
AND ACTUATORS
HYDROSTATIC
TRANSMISSIONS
AND ACTUATORS
OPERATION, MODELLING
AND APPLICATIONS
GustavoKouryCosta
DepartmentofMechanics–FederalInstituteofEducation,ScienceandTechnology,Recife,
Pernambuco,Brazil
NarimanSepehri
DepartmentofMechanicalEngineering–UniversityofManitoba,Winnipeg,Manitoba,
Canada
Thiseditionfirstpublished2015
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LibraryofCongressCataloging-in-PublicationData
Costa,GustavoK.
Hydrostatictransmissionsandactuators/GustavoK.Costa,DepartmentofMechanicsFederalInstituteof
Education,ScienceandTechnology,Recife,Pernambuco,Brazil,NarimanSepehri,DepartmentofMechanical
Engineering–UniversityofManitoba,Winnipeg,Manitoba,Canada.
pagescm
Includesbibliographicalreferencesandindex.
ISBN978-1-118-81879-4(hardback)
1.Oilhydraulicmachinery.2.Fluidpowertechnology.3.Hydrostatics.4.Powertransmission.5.Actuators.
I.Sepehri,Nariman.II.Title.
TJ843.C672015
620.1′06–dc23
2015022962
AcataloguerecordforthisbookisavailablefromtheBritishLibrary.
ISBN:9781118818794
Setin10/12ptTimesLTStdbySPiGlobal,Chennai,India
1 2015
To Flávia Maria, my beloved wife
Gustavo Koury Costa
To Aresh, Parisa and Anoush, the joys of my life
Nariman Sepehri
Contents
Preface xiii
Acknowledgements xvii
AbouttheCompanionWebsite xix
1 IntroductiontoPowerTransmission 1
1.1 TransmissionRatio 1
1.1.1 Generalities 1
1.1.2 Definition 3
1.1.3 Classification 3
1.2 MechanicalTransmissions 4
1.2.1 GearTrains 4
1.2.2 Gearboxes 6
1.2.3 Efficiency 8
1.2.4 ContinuouslyandInfinitelyVariableTransmissions 11
1.3 HydraulicTransmissions 15
1.4 HydrostaticTransmissions 19
1.4.1 OperationalPrinciples 19
1.4.2 FormalDefinitionofHydrostaticTransmissions 32
1.4.3 ClassificationofHydrostaticTransmissions 34
1.4.4 EfficiencyConsiderations 40
1.5 HydromechanicalPower-SplitTransmissions 40
1.5.1 GeneralClassification 41
1.5.2 TransmissionRatio 42
1.5.3 LockupPoint 44
1.5.4 PowerRelations 44
1.6 MechanicalandHydrostaticActuators 51
1.6.1 MechanicalActuators 51
1.6.2 HydrostaticActuators 52
viii Contents
1.6.3 HydrostaticActuationVersusValveControl 53
1.6.4 MultipleCylinderActuators 55
Exercises 56
References 57
2 FundamentalsofFluidFlowsinHydrostaticTransmissions 59
2.1 FluidProperties 59
2.1.1 Viscosity 59
2.1.2 Compressibility 64
2.2 FluidFlowinHydraulicCircuits 79
2.2.1 FlowRegimes 79
2.2.2 InternalFlowinConduits 81
2.2.3 FlowThroughOrifices 85
2.2.4 LeakageFlowinPumpsandMotors 87
2.2.5 OtherLossModels 93
Exercises 94
References 96
3 HydrostaticPumpsandMotors 98
3.1 HydrostaticandHydrodynamicPumpsandMotors 98
3.2 HydrostaticMachineOutput 102
3.2.1 AverageInput–OutputRelations 102
3.2.2 InstantaneousPumpOutput 104
3.2.3 InstantaneousMotorOutput 112
3.2.4 FurtherEfficiencyConsiderations 116
3.3 HydrostaticPumpandMotorTypes 117
3.3.1 RadialPistonPumpsandMotors 117
3.3.2 AxialPistonPumpsandMotors 119
3.3.3 GearPumpsandMotors 128
3.3.4 VanePumpsandMotors 130
3.3.5 DigitalDisplacementPumpsandMotors 131
3.4 EnergyLossesatSteady-StateOperation 135
3.4.1 EnergyBalances 135
3.4.2 OverallEfficiencies 138
3.4.3 SimplifiedEfficiencyEquations 138
3.4.4 EfficiencyRelations 139
3.5 ModellingPumpandMotorEfficiencies 141
3.5.1 PerformanceCurves 141
3.5.2 VolumetricEfficiencyModelling 144
3.5.3 OverallEfficiencyModelling 154
3.5.4 MechanicalEfficiency 160
Exercises 162
References 164
Description:"Hydrostatic Transmissions and Actuators takes a pedagogical approach and begins with an overview of the subject, providing basic definitions and introducing fundamental concepts. Hydrostatic transmissions and hydrostatic actuators are then examined in more detail with coverage of pumps and motors,
