Theory for Transmission Error
The transmission Error node can optionally be added on gear pairs. In this node, the static transmission error can be specified and added in the rotation constraint of the gear pair. By default, there is no transmission on the gear pair and it is assumed to be an ideal pair.
The static transmission error could be due to geometrical errors and geometrical modifications, such as gear runouts, misalignments, tooth tip, and root relief.
Figure 3-23: Sketch of a pair of teeth, showing the point of contact and the direction in which the transmission error is interpreted.
The transmission error expression in this section is derived for a Gear Pair node.
To get equations specific to the Worm and Wheel node, replace “wheel” with “worm” and “pinion” with “wheel” everywhere.
To get equations specific to the Rack and Pinion node, replace “wheel” with “rack” everywhere.
The static transmission error can be defined as
(3-2)
where ewh and epn are the wheel and pinion transmission errors, respectively.
In Equation 3-2, ewh and epn are written as a function of respective mesh cycle. However, it is also possible to write them individually as a function of a full revolution.
Similarly, it is also possible to directly specify et as a function of the mesh cycle and a full revolution of a wheel or pinion.