modelica · AHaumer · Jun 26, 2022 · Jul 4, 2022 · Jul 4, 2022 · Jul 4, 2022
diff --git a/Modelica/Mechanics/Rotational/Components/FreeWheel.mo b/Modelica/Mechanics/Rotational/Components/FreeWheel.mo
@@ -0,0 +1,114 @@
+within Modelica.Mechanics.Rotational.Components;
+model FreeWheel "Ideal freewheel"
+  extends Modelica.Mechanics.Rotational.Interfaces.PartialCompliant;
+
+  SI.AngularVelocity w_rel(start=0)
+    "Relative angular velocity (= der(phi_rel))";
+  Boolean free(start=false) "Indicates freewheeling";
+
+  parameter SI.Torque tauRes=1e-5 "Residual friction coefficient";
+  parameter SI.AngularVelocity wRes=1e-5 "Residual relative velocity coefficient";
+
+protected
+  Real s(start=0, final unit="1") "Auxilliary variable";
+  constant SI.AngularVelocity unitAngularVelocity=1;
+  constant SI.Torque unitTorque=1;
+
+equation
+  w_rel = der(phi_rel);
+  free = w_rel >= 0;
+  w_rel = -s*unitAngularVelocity*(if free then 1 else tauRes/unitTorque);
+  tau   = -s*unitTorque*(if free then wRes/unitAngularVelocity else 1);
+
+  annotation (
+    Icon(graphics={
+        Rectangle(
+          lineColor={64,64,64},
+          fillColor={192,192,192},
+          fillPattern=FillPattern.HorizontalCylinder,
+          extent={{-100,-10},{-30,10}}),
+        Rectangle(
+          lineColor={64,64,64},
+          fillColor={255,255,255},
+          fillPattern=FillPattern.HorizontalCylinder,
+          extent={{-30,-60},{-10,60}}),
+        Rectangle(
+          lineColor={64,64,64},
+          fillColor={255,255,255},
+          fillPattern=FillPattern.HorizontalCylinder,
+          extent={{10,-60},{30,60}}),
+        Rectangle(
+          lineColor={64,64,64},
+          fillColor={192,192,192},
+          fillPattern=FillPattern.HorizontalCylinder,
+          extent={{30,-10},{100,10}}),
+        Rectangle(
+          lineColor={64,64,64},
+          extent={{-30,-60},{-10,60}}),
+        Rectangle(
+          lineColor={64,64,64},
+          extent={{10,-60},{30,60}}),
+        Polygon(
+          points={{-10,30},{50,0},{-10,-30},{-10,30}},
+          fillPattern=FillPattern.Solid),
+        Text(extent={{-152,60},{148,100}},
+          textString="%name",
+          textColor={0,0,255})}),
+    Diagram(graphics={
+        Polygon(
+          points={{-4,70},{0,80},{4,70},{-4,70}},
+          lineColor={128,128,128},
+          fillColor={128,128,128},
+          fillPattern=FillPattern.Solid),
+        Line(
+          points={{0,80},{0,-80}},
+          color={128,128,128}),
+        Line(
+          points={{-80,0},{80,0}},
+          color={128,128,128}),
+        Polygon(
+          points={{70,4},{80,0},{70,-4},{70,4}},
+          lineColor={128,128,128},
+          fillColor={128,128,128},
+          fillPattern=FillPattern.Solid),
+        Line(
+          points={{-70,-20},{0,0},{20,70}},
+          thickness=0.5),
+        Text(
+          extent={{60,-10},{80,-20}},
+          textColor={128,128,128},
+          textString="w_rel"),
+        Text(
+          extent={{-20,80},{-10,70}},
+          textColor={128,128,128},
+          textString="tau"),
+        Text(
+          extent={{20,60},{40,50}},
+          textColor={128,128,128},
+          textString="wRes"),
+        Text(
+          extent={{-60,-20},{-40,-30}},
+          textColor={128,128,128},
+          textString="tauRes")}),
+    Documentation(info="<html>
+<p>
+An idealized model of a&nbsp;freewheel. Compared to
+<a href=\"modelica://Modelica.Mechanics.Rotational.Components.OneWayClutch\">OneWayClutch</a>
+it is modeled in a&nbsp;simplified way referring to
+<a href=\"Modelica.Electrical.Analog.Ideal.IdealDiode\">an&nbsp;idealized
+model of electrical diode</a>.
+This means in particular that there exist two cases indicated
+by the variable <code>free</code> and distinguished as follows.
+</p>
+<ul>
+  <li>
+    <code>flange_a</code> is driving (<code>free&nbsp;= false</code>): torque is
+    transferred with a&nbsp;residual difference <code>wRes</code> of relative angular
+    velocity of the flanges.
+  </li>
+  <li>
+    <code>flange_b</code> is driving (<code>free&nbsp;= true</code>): the flanges move
+    independently except a&nbsp;residual friction torque <code>tauRes</code>.</li>
+</ul>
+</html>"));
+end FreeWheel;
diff --git a/Modelica/Mechanics/Rotational/Components/package.order b/Modelica/Mechanics/Rotational/Components/package.order
@@ -2,6 +2,7 @@ Fixed
 Inertia
 Disc
 Coupling
+FreeWheel
 Spring
 Damper
 SpringDamper

diff --git a/Modelica/Mechanics/Rotational/Examples/DemoFreeWheel.mo b/Modelica/Mechanics/Rotational/Examples/DemoFreeWheel.mo
@@ -0,0 +1,43 @@
+within Modelica.Mechanics.Rotational.Examples;
+model DemoFreeWheel "Demonstrate freewheel"
+  extends Modelica.Icons.Example;
+  Modelica.Mechanics.Rotational.Components.FreeWheel freeWheel
+    annotation (Placement(transformation(extent={{0,-10},{20,10}})));
+  Modelica.Mechanics.Rotational.Components.Inertia inertia1(J=1)
+    annotation (Placement(transformation(extent={{-30,-10},{-10,10}})));
+  Modelica.Mechanics.Rotational.Components.Inertia inertia2(J=1,
+    phi(start=0, fixed=true),
+    w(start=0, fixed=true))
+    annotation (Placement(transformation(extent={{30,-10},{50,10}})));
+  Modelica.Mechanics.Rotational.Sources.LinearSpeedDependentTorque torqueLoad(
+    tau_nominal=-5,
+    TorqueDirection=false,
+    w_nominal=1) annotation (Placement(transformation(extent={{80,-10},{60,10}})));
+  Modelica.Mechanics.Rotational.Sources.Speed speed(exact=true)
+    annotation (Placement(transformation(extent={{-60,-10},{-40,10}})));
+  Modelica.Blocks.Sources.Sine signalSpeed(amplitude=5, f=5) annotation (Placement(transformation(extent={{-90,-10},{-70,10}})));
+equation
+  connect(freeWheel.flange_b, inertia2.flange_a)
+    annotation (Line(points={{20,0},{30,0}}, color={0,0,0}));
+  connect(torqueLoad.flange, inertia2.flange_b) annotation (Line(points={{60,0},{50,0}}, color={0,0,0}));
+  connect(inertia1.flange_a, speed.flange)
+    annotation (Line(points={{-30,0},{-40,0}}, color={0,0,0}));
+  connect(inertia1.flange_b, freeWheel.flange_a)
+    annotation (Line(points={{-10,0},{0,0}}, color={0,0,0}));
+  connect(signalSpeed.y, speed.w_ref) annotation (Line(points={{-69,0},{-62,0}}, color={0,0,127}));
+  annotation (experiment(
+      Interval=0.001,
+      Tolerance=1e-06,
+      StopTime=1),
+    Documentation(info="<html>
+<p>
+Demonstration of an ideal freewheel: 
+The inertia <code>inertia1</code> is driven with a&nbsp;prescribed sinusoidal velocity.
+Load inertia <code>inertia2</code> is coupled to <code>inertia1</code> by an ideal
+freewheel. <code>inertia2</code> is accelerated as long as its <code>flange_a</code>
+is driven. When freewheeling occurs, i.e.
+<code>inertia2.w</code>&nbsp;&ge; <code>inertia1.w</code>, a&nbsp;velocity dependent
+load torque decelerates <code>inertia2.w</code>.
+</p>
+</html>"));
+end DemoFreeWheel;
diff --git a/Modelica/Mechanics/Rotational/Examples/package.order b/Modelica/Mechanics/Rotational/Examples/package.order
@@ -15,4 +15,5 @@ EddyCurrentBrake
 GenerationOfFMUs
 OneWayClutch
 OneWayClutchDisengaged
+DemoFreeWheel
 Utilities
diff --git a/...rces/Reference/Modelica/Mechanics/Rotational/Examples/DemoFreeWheel/comparisonSignals.txt b/...rces/Reference/Modelica/Mechanics/Rotational/Examples/DemoFreeWheel/comparisonSignals.txt
@@ -0,0 +1,5 @@
+time
+inertia1.w
+inertia2.w
+freeWheel.w_rel
+freeWheel.tau
diff --git a/ModelicaTest/Rotational.mo b/ModelicaTest/Rotational.mo
@@ -978,6 +978,25 @@ they were not deleted yet.")}));
       offset=0,
       startTime=0.75)
       annotation (Placement(transformation(extent={{60,-230},{40,-210}})));
+    Modelica.Mechanics.Rotational.Components.FreeWheel freeWheel
+      annotation (Placement(transformation(extent={{-50,-268},{-30,-248}})));
+    Modelica.Mechanics.Rotational.Components.Inertia inertia21(
+      J=1,
+      phi(start=0, fixed=true),
+      w(start=0, fixed=true))
+      annotation (Placement(transformation(extent={{-20,-268},{0,-248}})));
+    Modelica.Mechanics.Rotational.Sources.LinearSpeedDependentTorque
+      linearSpeedDependentTorque1(
+      tau_nominal=-5,
+      TorqueDirection=false,
+      w_nominal=1)
+      annotation (Placement(transformation(extent={{30,-268},{10,-248}})));
+    Modelica.Mechanics.Rotational.Sources.Speed speed1(exact=true)
+      annotation (Placement(transformation(extent={{-110,-268},{-90,-248}})));
+    Modelica.Mechanics.Rotational.Components.Inertia inertia22(J=1)
+      annotation (Placement(transformation(extent={{-80,-268},{-60,-248}})));
+    Modelica.Blocks.Sources.Sine sine8(amplitude=5, f=5)
+      annotation (Placement(transformation(extent={{-140,-268},{-120,-248}})));
   equation
     connect(inertia.flange_b, idealGear.flange_a) annotation (Line(
         points={{-60,90},{-50,90}}));
@@ -1139,7 +1158,19 @@ they were not deleted yet.")}));
       annotation (Line(points={{-119,-220},{-112,-220}}, color={0,0,127}));
     connect(step.y, torque2.tau)
       annotation (Line(points={{39,-220},{32,-220}}, color={0,0,127}));
-    annotation (experiment(StopTime=0.9), Diagram(coordinateSystem(preserveAspectRatio=true, extent={{-180,-240},{180,160}})));
+    connect(freeWheel.flange_b, inertia21.flange_a)
+      annotation (Line(points={{-30,-258},{-20,-258}}, color={0,0,0}));
+    connect(linearSpeedDependentTorque1.flange, inertia21.flange_b)
+      annotation (Line(points={{10,-258},{0,-258}}, color={0,0,0}));
+    connect(inertia22.flange_a, speed1.flange)
+      annotation (Line(points={{-80,-258},{-90,-258}}, color={0,0,0}));
+    connect(inertia22.flange_b, freeWheel.flange_a)
+      annotation (Line(points={{-60,-258},{-50,-258}}, color={0,0,0}));
+    connect(sine8.y, speed1.w_ref)
+      annotation (Line(points={{-119,-258},{-112,-258}}, color={0,0,127}));
+    annotation (experiment(StopTime=0.9), Diagram(coordinateSystem(preserveAspectRatio=true, extent={{-180,
+              -280},{180,160}})),
+      Icon(coordinateSystem(extent={{-180,-280},{180,160}})));
   end AllComponents;
 
   model TestBearingConversion