definition
strict definition
helical gear traction
Geared traction elevators whose hoisting sheave is driven by wheels with teeth angled relative to their axes.
Helical gear traction elevators are geared traction elevators in which the gears driving the sheave are in the form of wheels whose teeth are aligned diagonally with respect to the axis of rotation.
The diagonal alignment of the wheel teeth identifies the helical gearing. The gear train turns the sheave that moves the traction cables.
Worm gear traction instead uses a screw-like worm meshing with a wheel. Both use gearing between the motor and the traction sheave.