Abstract: There are still no complete and common design method on the secondary enveloping surface design of spatial conjugate meshing pair. The three-plane concurrent structuring method for the secondary enveloping surface of spatial conjugate meshing pair is put forward on the basis of continuous sliding contact and conjugate meshing. The production principle of secondary enveloping surface as well as the structuring method of two supplementary planes are described, while the diagram and analytic methods for three-plane concurrent point, the design step and application scope of three-plane concurrent structuring method are provided. The key technology of single screw compressor meshing pair is researched by three-plane concurrent structuring method and the five-point one-none view is provided for the hot topics of single screw conjugate compressor meshing pair. Meanwhile, the conclusions that the complete star wheel will replace floating star wheel, the metal star wheel will replace non-metal star wheel and processing single screw compressor meshing pair by multi-axis interlocking machine tool is the development direction for the processing and production of single screw compressor and single screw expander meshing pairs are obtained by combining the design example of secondary enveloping single screw compressor of double-oval surface.

Key words: Secondary enveloping surface, Single screw compressor, Single screw expander, Spatial conjugate meshing pair, Three-plane concurrent structuring method