Id Var Mot $—$ Ideal variable displacement motor

This component describes an ideal motor with variable displacement.

Implementation

The torque, tau, is given by:

tau = Dmotor $\cdot$ factor $\cdot$ sig $\cdot$ (port_A.p - port_B.p) / (2 $\cdot$ $\mathrm{\pi }$)

The flow rate, q, is given by:

q = Dmotor $\cdot$ factor $\cdot$ sig $\cdot$ w / (2 $\cdot$ $\mathrm{\pi }$)

The commanded relative displacement volume of the motor is input at commandSignal, [-1 ... 1]. If the inlet pressure is lower than the atmospheric pressure, the delivered flow rate becomes smaller (that is, the value of factor decreases). Flow from port_A to port_B is considered positive.

Variables used in the above equations

 tau Torque $\left[\mathrm{Nm}\right]$. q Flow rate at the outlet port $\left[\frac{{m}^{3}}{s}\right]$. sig $\left\{\begin{array}{cc}-1& \mathrm{commandSignal}<-1\\ 1& \mathrm{commandSignal}>1\\ \mathrm{commandSignal}& \mathrm{otherwise}\end{array}\right\$ Dmotor Displacement per revolution $\left[{m}^{3}\right]$. w Angular velocity $\left[\frac{\mathrm{rad}}{s}\right]$. factor Pressure dependent variable. Equals 1 at normal running conditions and 0 at vapor pressure.

Assumptions

Ideal motor (that is, no losses).

Connections

 Name Description Modelica ID ${\mathrm{port}}_{A}$ Port A, where oil flows into the component ($0, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_A ${\mathrm{port}}_{B}$ Port B, where oil leaves the component ($q<0$, ${p}_{B}<{p}_{A}$ means $0<\mathrm{Δp}$) port_B ${\mathrm{flange}}_{a}$ flange_a ${\mathrm{flange}}_{b}$ flange_b $\mathrm{oil}$ oil $\mathrm{commandSignal}$ Input signal commands relative displacement volume commandSignal

Parameters

 Name Default Units Description Modelica ID ${\mathrm{ΔT}}_{\mathrm{system}}$ $0$ $K$ Temperature offset from system temperature dT_system ${\mathrm{D}}_{\mathrm{motor}}$ ${10}^{-4}$ ${m}^{3}$ Maximum displacement per revolution Dmotor