Theoretical Analysis of Internal Epitrochoidal and Hypotrochoidal Machines

In this article, a complete and original method to analyse both the epitrochoidal and the hypotrochoidal rotary machines is presented. The internal trochoidal machines consist of two rotors: the first rotor is an envelope of a trochoid, the second rotor is its conjugate. In particular, in this article, the profiles of the trochoidal rotor and its conjugate are expressed by original and particularly synthetic equations using a method based on the theory of gearing. Then the geometry of these machines is completely defined by the choice of four non-dimensional parameters. Once these parameters are selected, the geometric and kinematic characteristics of the rotor profiles are obtained in an original analytic form; hence, the main theoretical performance indexes are computed by a proper method. The results of the analysis allow us to choose the best geometric configuration for a specific application.