Design of loboid gear pairs using involute discretization

Loboid gears are used in rotary pump applications mainly in positive displacement pneumatic compressors (i.e. Roots blowers) in which high volumetric capacity and smooth running are of major importance. This paper approaches the problem of numerically defining the meshing surfaces of such loboid gears using the newly developed theory of involute discretization. According to this approach, every gear tooth of any form can be discretized in infinitesimal involute segments therefore rendering the determination of the path of contact and the geometry of the meshing teeth of the conjugate gears easy and straightforward, using the well-known properties of the involute. The achieved savings in programming time and effort are considerable compared to the standard Theory of Gearing and other form-specific gear tooth geometrical formulae.