Modeling of design clearances in a compressor with four co-rotating rotors

During the development of a prototype for a new compressor with four co-rotating rotors, it became necessary to correct the rotor geometry to create appropriate design clearances. Due to the shape of the rotors and the complex nature of their interaction, such a correction required an analysis of the impact of corrective undercuts on the clearance size. The article presents the results of the analysis and a three-stage correction procedure algorithm developed based on it.At the Department of Fundamentals of Machinery Design at the Lublin University of Technology, a prototype of a new compressor with four co-rotating screw rotors was developed, manufactured, and tested [1, 2]. In this compressor, the positive displacement working space is created between four parallel rotors rotating in the same direction at the same angular velocity, whose surfaces move relative to each other at a very small distance without touching. To ensure free rotational movement of the rotors without mutual friction, it is necessary for the clearance between the rotors to account for their potential thermal and force-induced deformations, as well as to consider inaccuracies in rotor surface machining and displacements caused by bearing clearances. (…)

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