Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides structural and/or operational advantages in the rotary machine.

A spherical compressor is provided. A cylinder body and a cylinder head are combined to form a spherical inner cavity. A sliding chute swinging mechanism is arranged between a piston shaft and a piston shaft hole or between a turntable shaft and a turntable shaft hole. The turntable shaft is driven to rotate so that a piston swings along a sliding chute relative to the axis of the piston shaft hole, or a turntable swings along the sliding chute relative to the axis of the turntable shaft hole, so as to form a V1 working chamber and a V2 working chamber with alternatively variable volumes in the spherical inner cavity.

A spherical compressor is provided. A cylinder body and a cylinder head are combined to form a spherical inner cavity. A sliding chute swinging mechanism is arranged between a piston shaft and a piston shaft hole or between a turntable shaft and a turntable shaft hole. The turntable shaft is driven to rotate so that a piston swings along a sliding chute relative to the axis of the piston shaft hole, or a turntable swings along the sliding chute relative to the axis of the turntable shaft hole, so as to form a V1 working chamber and a V2 working chamber with alternatively variable volumes in the spherical inner cavity.

Rotary positive displacement machines based on trochoidal geometry, that comprise a helical rotor that undergoes planetary motion within a helical stator are described. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides structural and/or operational advantages in the rotary machine.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.

An apparatus including a first piston member rotatable about a first rotational axis and a rotor with a first chamber and pivotable about a second rotational axis. The first piston member extends across the first chamber. The rotor and first piston member are rotatable around the first rotational axis, and the rotor is pivotable about the second rotational axis to permit a relative pivoting motion between the rotor and the first piston member linked to the rotor rotating about the first rotational axis.

An apparatus including a first piston member rotatable about a first rotational axis and a rotor with a first chamber and pivotable about a second rotational axis. The first piston member extends across the first chamber. The rotor and first piston member are rotatable around the first rotational axis, and the rotor is pivotable about the second rotational axis to permit a relative pivoting motion between the rotor and the first piston member linked to the rotor rotating about the first rotational axis.

An apparatus including a first piston member rotatable about a first rotational axis and a rotor with a first chamber and pivotable about a second rotational axis. The first piston member extends across the first chamber. The rotor and first piston member are rotatable around the first rotational axis, and the rotor is pivotable about the second rotational axis to permit a relative pivoting motion between the rotor and the first piston member linked to the rotor rotating about the first rotational axis.

An apparatus including a first piston member rotatable about a first rotational axis and a rotor with a first chamber and pivotable about a second rotational axis. The first piston member extends across the first chamber. The rotor and first piston member are rotatable around the first rotational axis, and the rotor is pivotable about the second rotational axis to permit a relative pivoting motion between the rotor and the first piston member linked to the rotor rotating about the first rotational axis.

Sealing in rotary positive displacement machines based on trochoidal geometry that comprise a helical rotor that undergoes planetary motion within a helical stator is described. Seals can be mounted on the rotor, the stator, or both. The rotor can have a hypotrochoidal cross-section, with the corresponding stator cavity profile being the outer envelope of the rotor as it undergoes planetary motion, or the stator cavity can have an epitrochoidal cross-section with the corresponding rotor profile being the inner envelope of the trochoid as it undergoes planetary motion. In some embodiments, the geometry is offset in a manner that provides advantages with respect to sealing in the rotary machine. In multi-stage embodiments, the rotor-stator geometry remains substantially constant or varies along the axis of the rotary machine.