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.

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.

A transmission between a drive shaft and a driven shaft comprises a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on a drive shaft. The housing comprises two separated chambers, i.e. a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber, whereby the first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel the second chamber is formed, whereby the form of the second chamber is such that when the gearwheel in question rotates, a gas flow is created around this gearwheel which causes a negative pressure in the channel by the venturi effect.

The arrangement comprises a hydraulic machine with at least two operating cylinders, the hydraulic machine comprising a rotor part configured to be connected to the steered wheel and a stator part having main enclosures open in a receiving interface, and a pivot device that defines a pivot axis of the stator part and has main outer orifices linked to the main enclosures of the hydraulic machine in a connection interface. The arrangement further comprises a pilot line linked to a pilot chamber which has a pilot inlet in the receiving interface and the pilot line is formed in the pivot device and extends between an outer pilot orifice present in this device and a pilot opening located in the connection interface.

Rotary positive displacement machines with 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 multi-stage embodiments, the rotor-stator geometry remains substantially constant along the axis of the rotary machine. In other multi-stage embodiments, the rotor-stator geometry varies along the axis of the rotary machine.

Rotary positive displacement machines with 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 multi-stage embodiments, the rotor-stator geometry remains substantially constant along the axis of the rotary machine. In other multi-stage embodiments, the rotor-stator geometry varies along the axis of the rotary machine.

An engine includes a housing defining an annular bore and a piston assembly disposed within the annular bore. The engine also includes a rotary valve comprising a circular faceplate and a wall structure disposed at an outer periphery of the faceplate, a portion of the at least one rotary valve disposed within the annular bore, and a rotary drive mechanism connected to the rotary valve and configured to rotate the rotary valve between a first position to align an opening of the wall structure with the annular bore to allow the piston of the piston assembly to travel within the annular bore from a first location relative to the rotary valve to a second location relative to the rotary valve and a second position to define a chamber relative to the piston of the piston assembly at the second location.

An engine includes a housing defining an annular bore and a piston assembly disposed within the annular bore. The engine also includes a rotary valve comprising a circular faceplate and a wall structure disposed at an outer periphery of the faceplate, a portion of the at least one rotary valve disposed within the annular bore, and a rotary drive mechanism connected to the rotary valve and configured to rotate the rotary valve between a first position to align an opening of the wall structure with the annular bore to allow the piston of the piston assembly to travel within the annular bore from a first location relative to the rotary valve to a second location relative to the rotary valve and a second position to define a chamber relative to the piston of the piston assembly at the second location.

Rotary positive displacement machines with 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 multi-stage embodiments, the rotor-stator geometry remains substantially constant along the axis of the rotary machine. In other multi-stage embodiments, the rotor-stator geometry varies along the axis of the rotary machine.

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.