The invention concerns a rotary volumetric machine with three pistons comprising an enclosure forming a stator in which there moves a rotating assembly forming a rotor comprising a crankshaft that mechanically engages with the pistons, the rotating assembly defining, inside said enclosure, six chambers of variable volume of which the volume varies when the rotating assembly rotates, each of the pistons delimiting, with the enclosure, a variable volume chamber called the extrados chamber and two consecutive pistons delimiting, with the enclosure and the crankshaft, a variable-volume chamber called the intrados chamber. The geometry of the pistons and of the crankshaft is designed such that each intrados chamber has a capacity greater than or equal to the capacity of the extrados chambers.

A concentric rotary fluid machine includes a first body and a second body that are rotatable relative to each other and coaxially arranged one inside the other. A plurality of gates are supported by the second body in gate pockets. Each gate pocket includes: a gate retention recess that receives a gate cylinder of a gate; a gate seal recess that receives a sealing portion of a gate; and an intervening land. The sealing portion is configured to reciprocate up and down within a corresponding gate seal recess while maintaining contact with the recess and the second body. A plurality of lobes on the first body cause the gates to swing about respective swing axes as the first body rotates relative to the second body. The lobes and the lands are configured so that a lobe forms a substantial seal against a land when in mutual radial alignment.

A concentric rotary fluid machine includes a first body and a second body that are rotatable relative to each other and coaxially arranged one inside the other. A plurality of gates are supported by the second body in gate pockets. Each gate pocket includes: a gate retention recess that receives a gate cylinder of a gate; a gate seal recess that receives a sealing portion of a gate; and an intervening land. The sealing portion is configured to reciprocate up and down within a corresponding gate seal recess while maintaining contact with the recess and the second body. A plurality of lobes on the first body cause the gates to swing about respective swing axes as the first body rotates relative to the second body. The lobes and the lands are configured so that a lobe forms a substantial seal against a land when in mutual radial alignment.

A pump comprises a housing having an inner contour wall defining a fluid chamber. A rotor mechanism is positioned within the fluid chamber and comprises a belt and a rotatable rotor assembly. The belt is mounted to the rotor assembly. A movement imparting assembly imparts a rotational movement to the rotor assembly. The belt engages the inner contour wall during rotation. The housing includes intake and outtake ports in communication with the fluid chamber providing for intake of fluid therein and exhaust of fluid therefrom.

A pump comprises a housing having an inner contour wall defining a fluid chamber. A rotor mechanism is positioned within the fluid chamber and comprises a belt and a rotatable rotor assembly. The belt is mounted to the rotor assembly. A movement imparting assembly imparts a rotational movement to the rotor assembly. The belt engages the inner contour wall during rotation. The housing includes intake and outtake ports in communication with the fluid chamber providing for intake of fluid therein and exhaust of fluid therefrom.