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.

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.

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.

The fluid transfer apparatus includes a rotor housing for forming a fluid compression space having the shape of an epitrochoid surface; a rotor eccentrically rotates inside the fluid compression space by being eccentrically coupled to a rotation shaft; and a rotor housing cover covering the fluid compression space of the rotor housing and including a rotation shaft penetration hole formed at the center of the cover, and a first cover fluid channel and second cover fluid channel are symmetrically formed on the opposite sides of each other with the rotation shaft penetration hole in the middle, wherein a plurality of rotor housing covers are arranged to be spaced apart from each other, one rotor housing is arranged between every two rotor housing covers, one rotor is arranged in the fluid compression space of each rotor housing, and each rotor is arranged to face a different direction from a neighboring rotor.

The fluid transfer apparatus includes a rotor housing for forming a fluid compression space having the shape of an epitrochoid surface; a rotor eccentrically rotates inside the fluid compression space by being eccentrically coupled to a rotation shaft; and a rotor housing cover covering the fluid compression space of the rotor housing and including a rotation shaft penetration hole formed at the center of the cover, and a first cover fluid channel and second cover fluid channel are symmetrically formed on the opposite sides of each other with the rotation shaft penetration hole in the middle, wherein a plurality of rotor housing covers are arranged to be spaced apart from each other, one rotor housing is arranged between every two rotor housing covers, one rotor is arranged in the fluid compression space of each rotor housing, and each rotor is arranged to face a different direction from a neighboring rotor.

Single expander device working with two working media in a two-stage organic Rankine cycle, which has a cylinder body, a rotor disposed inside the cylinder body and provided with a number of slip sheets in a radial direction of the cylinder body, and a rotary shaft fixedly connected to the center of the rotor, with the outer profile of the cylinder body defined by two mathematical equations.

A pump assembly that has a first pump and a second pump for pumping lubricant, both pumps being integrated into a single housing. A drive shaft is provided that drives both pumps. Both the first pump and the second pump have a gear or rotor that is rotated by the drive shaft. Each of the pumps have an inlet provided on the housing to receive input from a source outside the housing and an outlet. The housing has a wall that is common to both pumps. The first pump is provided on a first side of the wall and the second pump is provided on the second, opposite side. The gears or rotors of the pumps may be provided in pockets provided on the first and second sides of the wall. The drive shaft extends through the wall and connects to each of the drive gears or rotors.

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.

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.