Constant torque

A constant torque, independent of speed.

  • rotational
  • Modelica Standard Library
  • 1 port
  • 1 parameter
BlockConstant torqueKindconstantTorqueLibraryRotational

Description

Applies a constant torque to the flange, independent of speed and direction.

Example

Clutch, backlash, and rotational sources A clutch that locks, gear backlash, a spring-damper coupling, and a load that steps its torque.

100 rad/s at 0.1 sDriveClose at 0.5 sClutchDriven 1 kg·m²Driven speedω ref 10 sin 2πtSpeed sourceBacklash 0.1 radInertia 0.01Speed behind backlash0.5 N·mTorque sourceCouplingInertia 0.02, damping 0.05Coupled speed0.4 N·mShaft loadLoad speed
In Gradara, select a Constant torque block and press F1, then choose Open example. It opens as a new model in My models, ready to run.

Also in this example:ConstantMechanical loadStepInertia & loadSpeed sensorSine waveSpring-damperBacklashInertia (ideal)ClutchTorque sourceSpeed sourceSpeed sensor (ideal)

Ports

Conserving terminals 1

  • shaftflangerotational

    Flange the torque acts on.

Parameters

  • Torquetau_constant1 N·m

    The torque, in N·m. A positive value accelerates the flange in the positive direction; a negative value acts as a load.

Equations

Modelica
flange.tau = −tau_constant

Implementation

Modelica Standard Library 4.1.0Modelica.Mechanics.Rotational.Sources.ConstantTorque
MSL documentation

Assumptions and limitations

  • The torque does not reverse with speed: a negative value used as a load drives an unpowered shaft backward instead of holding it.

See also

Select a block in Gradara and press F1 to open its page offline.