Positive displacement machine, more particularly pump, and method for fabricating such pump

A positive displacement pump, comprising;

• a first support member having mounted thereon a plurality of displacement chambers;
• a second support member having mounted thereon a plurality of displacement vanes, each of said displacement vanes being associated with a corresponding one of said displacement chambers,
• a plurality of inlet and outlet channels for directing a fluid medium into and out of said displacement chambers,
• a common central drive operable to transmit a driving force having radial and tangential components to one of said first support or said second support, for producing relative circular motion between said displacement chambers and associated displacement vanes,
• said displacement chambers and displacement vanes being radially spaced from said drive and having inner and outer surface respectively in proximate adjacent relationship;
• said outer surface defining a path about said inner surface wherein said outer surface encompasses said inner surface substantially 360.degree. therearound, and said inner surface defines a path substantially coextensive with and adjacent to said outer surface path;
• and wherein
• said inner and outer surfaces are essentially continuously curved, defining shapes which generally continuously widen in the direction radially outwardly from said central drive.