F04C 2/3445

Rotary-piston machines or pumps having the characteristics covered by two or more groups [CPC: F04C2/02], [CPC: F04C2/08], [CPC: F04C2/22], [CPC: F04C2/24] or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups [CPC: F04C2/08] or [CPC: F04C2/22] and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member {the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation the vanes having the form of rollers, slippers or the like}