Rack and pinion

Rack and pinion link properties implement a rack and pinion 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 pinion and rack 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 pinion is not modelled

Definition

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

Source interface

Type	Moving interface (Fourier)
Topologies	Side faces of the rack
Location	Along the pitch line
u direction	Axial, along the pitch line
v direction	Transversal
w direction	Normal, towards the pinion

Target interface

Type	Stationary interface (6dof)
Topologies	Peripheral face of the pinion
Location	Center of pinion
u direction	Axial, along the pitch line of the rack
v direction	Parallel to the v-direction of the source interface
w direction	Parallel to the w-direction of the source interface

Recommended link settings

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

Parameters

Parameter	Unit	Description
Pinion radius	m	Radius of the pitch line of the pinion
Contact stiffness	N/m	Stiffness of the contact between the teeth
Contact damping	Ns/m	Damping of the contact between the teeth