In worm drive applications with precise transmission, the torsional stiffness of the worm gearbox is an important parameter for the positioning accuracy. Moreover, it influences the dynamic behavior of a worm gearbox. The torsional stiffness is a result of elasticities from all gearbox components along the load path. This leads to various options for an optimization of the torsional stiffness within the design process of a worm gearbox.

The influence of bearings, shafts, housing and the toothing on the torsional stiffness is subject of this article. Methods of Finite Element Analysis are used for modelling a worm gearbox with varying compositions of the gearbox components and elasticities. By varying the setup of stiffnesses, the sensitivity of the torsional stiffness to the individual components of the gearbox is determined.

An investigation of the distribution of elasticities within the gearbox for multiple gearbox dimensions and gear geometries gives information on the potential of the individual gearbox components for optimizing the torsional stiffness.