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 pump body assembly, fluid machinery, and a heat exchange device. The pump body assembly includes: at least two structure members; a cylinder (20) disposed between the two structure members; and a piston assembly disposed in the cylinder (20). The piston assembly includes a piston sleeve (40) and a piston (50) slidably disposed in the piston sleeve (40); an upper end surface of the piston sleeve (40) fits and is limited by a lower end surface of one structure member disposed above the piston sleeve (40), so as to prevent the piston sleeve (40) from displacing along a radial direction relative to the one structure member, thereby effectively solving a problem in prior art that working efficiency of the pump body assembly is affected because the piston sleeve (40) of the pump body assembly is prone to eccentrically rotate.

A pump body assembly, fluid machinery, and a heat exchange device. The pump body assembly includes: at least two structure members; a cylinder (20) disposed between the two structure members; and a piston assembly disposed in the cylinder (20). The piston assembly includes a piston sleeve (40) and a piston (50) slidably disposed in the piston sleeve (40); an upper end surface of the piston sleeve (40) fits and is limited by a lower end surface of one structure member disposed above the piston sleeve (40), so as to prevent the piston sleeve (40) from displacing along a radial direction relative to the one structure member, thereby effectively solving a problem in prior art that working efficiency of the pump body assembly is affected because the piston sleeve (40) of the pump body assembly is prone to eccentrically rotate.

A pump housing of an oil pump includes a suction port that supplies oil to a pump room, a discharge port that discharges oil from the pump room, and a seal portion that suppresses leakage of oil from the pump room to outside of the pump room. A shaft of the oil pump includes a small diameter portion and a large diameter portion having different diameters, the small diameter portion is connected to the inner rotor, and the shaft and the inner rotor integrally rotate. The seal portion is in contact with a side surface of the inner rotor extending in a diameter direction of the shaft, and also extends to a region in the diameter direction on an inner side smaller than the large diameter portion in the diameter direction.

A pump housing of an oil pump includes a suction port that supplies oil to a pump room, a discharge port that discharges oil from the pump room, and a seal portion that suppresses leakage of oil from the pump room to outside of the pump room. A shaft of the oil pump includes a small diameter portion and a large diameter portion having different diameters, the small diameter portion is connected to the inner rotor, and the shaft and the inner rotor integrally rotate. The seal portion is in contact with a side surface of the inner rotor extending in a diameter direction of the shaft, and also extends to a region in the diameter direction on an inner side smaller than the large diameter portion in the diameter direction.

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.

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.

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.