==========
Gear drive
==========

Gear drive link properties implement a toothed gear drive. Only the linear elastic behaviour is modelled, non-linearities are neglected. The simplifications are:

- any kind of backlash is neglected
- the force pushing the gears apart (due to the pressure angle of the teeth) is not modelled and has to be added as load in an analysis if desired
- irregular transmission due to the teeth is not modelled
- local deformation of the gears is not modelled

----------
Definition
----------

Source and target interfaces should be chosen as shown in following figure:

   .. image:: media/lp_gear.png
      :alt: Gear drive link definition
      :scale: 100 %


^^^^^^^^^^^^^^^^^^^^
Source interface
^^^^^^^^^^^^^^^^^^^^

==============  ===========================================================================================
Type            Stationary interface (6dof)
Topologies      Peripheral face of the source gear
Location        Center of the source gear
u direction     Axial, along the axis of rotation of the source gear
v direction     Aligned with the v-direction of the target gear
w direction     Resulting direction
==============  ===========================================================================================

^^^^^^^^^^^^^^^^^^^^
Target interface
^^^^^^^^^^^^^^^^^^^^

==============  ===========================================================================================
Type            Stationary interface (6dof)
Topologies      Peripheral face of the target gear
Location        Center of the target gear
u direction     Axial, along the axis of rotation of the target gear
v direction     Aligned with the v-direction of the source gear, pointing from the target to the source gear
w direction     Parallel to the w-direction of the source gear
==============  ===========================================================================================

^^^^^^^^^^^^^^^^^^^^^^^^^
Recommended link settings
^^^^^^^^^^^^^^^^^^^^^^^^^

==========================  ==========================
Use ground for source       unchecked
Location master             none
Orientation master          either source or target
==========================  ==========================

----------
Parameters
----------

===================  =========  ===========  =======================================================================
Parameter            Unit       Symbol       Description
===================  =========  ===========  =======================================================================
Source gear radius   m          :math:`r_S`  Radius of the pitch line of the source gear
Target gear radius   m          :math:`r_T`  Radius of the pitch line of the target gear
Contact stiffness    N/m        :math:`k`    Stiffness of the contact between the gears including tooth compliance
Contact damping      Ns/m       :math:`d`    Damping of the contact between the gears including tooth compliance
===================  =========  ===========  =======================================================================