Rotary machine

A rotary machine through which a working fluid passes, said machine including at least:

• a central shaft means having a radially outer peripheral surface provided with at least one lobe having a maximum radius relative to a longitudinal axis of the shaft means, said central shaft means having a longitudinally extending bore defining a fluid inlet passage and fluid outlet passage at axially opposite ends thereof;
• a duct defining member disposed in said bore which, together with a surface of said bore, defines a plurality of inlet passage portions and outlet passage portions, said inlet passage portions being longitudinally co-extensive with said outlet passage portions, and where said inlet passage extends to said plurality of inlet passage portions and said outlet passage extends from said plurality of outlet passage portions;
• an outer housing having an inner cylindrical surface surrounding the central shaft means, the inner surface having a radius approximately equal to said maximum radius;
• bearing means extending between the housing and central shaft means to provide for relative rotation therebetween;
• a plurality of gates movably mounted in the housing for movement between a retracted position at least substantially located in said housing-and an extended position protruding from said housing;
• said gates, central shaft means and housing co-operating to define at least two variable volume working chambers, the volumes of which change with relative rotation between the shaft means and housing about said axis;
• first duct means extending through said central shaft means between said inlet passage portions and said chambers at a position adjacent to said lobe on a first angular side thereof,
• second duct means extending through said central shaft means between said outlet passage portions and said chambers adjacent said lobe on the other angular side thereof to the first duct means;
• wherein relative rotation between said central shaft means and housing provides for movement of said working fluid through said chambers via said first and second duct means.