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2.Theprocessofenergytransformationinhydraulicgearmachines
TheeffectivepowerN
etransferredintothesystemisdefinedasaproductof
torqueM
sontheshaftofthemotorandangularvelocityω
s,namely:
N
e±M
slω
s
(2.22)
BycomparingeffectivepowerN
etoinletpowerN
s,thetotalefficiencyn
sof
themotoris:
K1
s
N
N
e
s
(2.23)
Aftertransformationssimilartotheonesutilizedforthepump,thefollowing
dependencyisobtained:
n
s±n
vsln
hms
(2.24)
Itmeansthatthetotalefficiencyn
softhemotorisaproductofvolumetriceffi-
ciencyn
vsandhydraulic-mechanicalefficiencyn
hms.Figure2.7cpresentsthecurves
oftheefficiencyofthemotorwhicharesimilartothecurvesoftheefficiencyof
thepumpshowninFigure2.5c.
2.3.Conclusions
Tosumup,afewdesignconclusionscanbedrawn.Firstofall,itisnecessarytofor-
mulateaconceptofthedesignsolutionforahydraulicgearmachine.Itisnecessary
todecidewhetherthemachineissupposedtoworkasapumporasahydraulicmotor.
Itisrelatedtotheproperenergytransformationinmachines.Inthecaseofapump,
thetransformationisofmechanicalenergyintohydraulicenergy,andinthecaseof
amotor-thetransformationofhydraulicenergyintomechanicalenergy.Next,itis
necessarytocreateageneralmodelofthemachine,whichallowtocarryouttheanaly-
sisofenergytransformationinthemachine.Finally,itiscrucialtodecidewhattypes
ofcharacteristicsdescribingthetransformationsandwhatformulaeforthedetermin-
ingofthosecharacteristicsshouldbeemployed.