modelGearConstantEfficiency
Gearbox with constant efficiency w/o inertia
Extends from Modelica.Mechanics.Rotational.Icons.Gear (Icon of a rotational gear), Modelica.Mechanics.Rotational.Interfaces.PartialElementaryTwoFlangesAndSupport2 (Partial model for a component with two rotational 1-dim. shaft flanges and a support used for textual modeling, i.e., for elementary models).
Information
This is a simple model of a gearbox with constant efficiency without inertia.
The relationship between torque at flange_a and flange_b is different depending on whether flange_a or flange_b is driving.
To avoid a step in the relationship, efficiency rises from a threshold p_min towards zero to 1; i.e.at speed zero, torque at flange_b is ratio * torque at flange_a.
if p_a > 0 then // flange_a is driving
tau_a*ratio*(1 -(1 - eta)*min(1, p_a/p_min)) + tau_b = 0;
else // flange_b is driving
tau_a*ratio + tau_b*(1 -(1 - eta)*min(1, p_b/p_min)) = 0;
end if;
Losses are fed to the optional heatPort.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | ratio | Transmission ratio (flange_a.phi/flange_b.phi) | |
| Real | eta | Constant efficiency | |
| Modelica.Units.SI.AngularVelocity | w_min | Speed limit for regularization w.r.t. flange_a | |
| Modelica.Units.SI.Torque | tau_min | Torque limit for regularization w.r.t. flange_a | |
| Boolean | useSupport (from PartialElementaryTwoFlangesAndSupport2) | false | = true, if support flange enabled, otherwise implicitly grounded |
| Boolean | useHeatPort | false | =true, if heatPort is enabled |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Flange_a | flange_a (from PartialElementaryTwoFlangesAndSupport2) | Flange of left shaft | |
| Flange_b | flange_b (from PartialElementaryTwoFlangesAndSupport2) | Flange of right shaft | |
| Support | support (from PartialElementaryTwoFlangesAndSupport2) | Support/housing of component | |
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort | Optional port to which dissipated losses are transported in form of heat |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Angle | phi_a | Angle between flange a and support | |
| Modelica.Units.SI.Angle | phi_b | Angle between flange b and support | |
| Modelica.Units.SI.AngularVelocity | w_a | Angular velocity between flange a and support | |
| Modelica.Units.SI.AngularVelocity | w_b | Angular velocity between flange b and support | |
| Modelica.Units.SI.Torque | tau_a | Torque at flange a | |
| Modelica.Units.SI.Torque | tau_b | Torque at flange b | |
| Modelica.Units.SI.Torque | tau_f | Friction torque | |
| Modelica.Units.SI.Power | p_a | Power at flange a | |
| Modelica.Units.SI.Power | p_b | Power at flange b | |
| Modelica.Units.SI.Power | lossPower | Loss power leaving component via heatPort (> 0, if heat is flowing out of component) | |
| Real | eff | Efficiency |