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 +1,77 @@
+within Modelica.Mechanics.Rotational.Components;
+model FreeWheel "Ideal freewheel"
+  extends Modelica.Mechanics.Rotational.Interfaces.PartialTwoFlanges;
+  SI.AngularVelocity w_rel(start=0) "Relative angular velocity (= flange_a.w - flange_b.w)";
+  SI.Torque tau "Torque between flanges (= flange_a.tau)";
+  Boolean free( start=false) "Indicates freewheeling";
+  Real s(start=0) "Auxilliary variable";
+  parameter SI.Torque tauRes=1e-5 "Residual friction coefficient";
+  parameter SI.AngularVelocity wRes=1e-5 "Residual relative speed coefficient";
+protected
+  constant SI.AngularVelocity unit_w=1;
+  constant SI.Torque unit_tau=1;
+equation
+  w_rel = der(flange_a.phi) - der(flange_b.phi);
+  tau =  flange_a.tau;
+  tau = -flange_b.tau;
+  free = w_rel <= 0;
+  w_rel = s*unit_w*(if free then 1 else tauRes/unit_tau);
+  tau   = s*unit_tau*(if free then wRes/unit_w 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}}),
+        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),
+                            Text(
+            extent={{70,-10},{80,-20}},
+            textColor={128,128,128},
+          textString="w"),  Text(
+            extent={{-20,80},{-10,70}},
+            textColor={128,128,128},
+          textString="tau"),Line(
+            points={{-70,-20},{0,0},{20,70}},
+            thickness=0.5),     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>
+The ideal freewheel can be considered as a mechanical diode:
+</p>
+<ul>
+<li>flange_a driving: Torque is transfer with a residual difference of angular veolcity of the flanges.</li>
+<li>flange_b driving: The flanges move independently except a residual friction torque.</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 +1,44 @@
+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 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
+    linearSpeedDependentTorque(
+    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.Mechanics.Rotational.Components.Inertia inertia1(J=1)
+    annotation (Placement(transformation(extent={{-30,-10},{-10,10}})));
+  Modelica.Blocks.Sources.Sine sine(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(linearSpeedDependentTorque.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(sine.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: 
+Inertia1 is driven with a prescribed sinusoidal speed. Inertia2 is coupled to inertia1 by an ideal freewheel.
+Inertia2 is accelerated as long as flange_a is driven. When freewheeling occurs a speed dependent torque decelerates inertia2. 
+</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
-Original file line number
+Diff line change
@@ Expand Up / @@ -2,6 +2,7 @@ Fixed @@
     Inertia
     Disc
     Coupling
+    FreeWheel
     Spring
     Damper
     SpringDamper
@@ Expand Down @@