This is a model of a pump with volumes, variable displacement setting, friction, and internal and external leakage. The axial speed is proportional to the flow rate:



The torque is proportional to the pressure difference:



where

		:	Mass flow rate
		:	Fluid density
D		:	Maximum displacement
u		:	Displacement setting
		:	Pressure difference between the ports
		:	Torque
		:	Angular velocity

The signal is limited to +/-1 and controls the flow according to the table below:

u>=1		:	Maximum flow from port a to port b
u=0		:	Only leakage flow from port a to port b
u<=-1		:	Maximum flow from port b to port a

Limitations

Volumetric efficiency is not included in the model.

Reference

Industrial Hydraulics Manual, 5th ed., Maumee, OH: Eaton Hydraulics Training Services, 2008 p. 164.

medium	Value: Oil() Type: Medium Description: Medium in the component
D	Value: Type: Volume (m³) Description: Displacement per revolution
externalLeakage	Value: 1e-12 Type: PressureDependentLeakage (m³/(s·Pa)) Description: Leakage between cylinders
internalLeakage	Value: 1e-12 Type: PressureDependentLeakage (m³/(s·Pa)) Description: Leakage between cylinders
frictionD	Value: 1 Type: RotationalDampingConstant (N·m·s/rad) Description: Viscous friction
J	Value: 1 Type: MomentOfInertia (kg·m²) Description: Moments of inertia
tankPressure	Value: 100000.0 Type: Pressure (Pa) Description: Tank pressure
V	Value: 0.0001 Type: Volume (m³) Description: Volume