A rotary machine, for directing a quantity of fluid from an inlet to an outlet, comprises one or more elliptical or near-elliptical rotors having planetary rotation within a housing. The interior cavity of the housing comprises an inverse apex region that is in contact with the rotor during its rotation. In various embodiments the rotor and housing can be symmetric or asymmetric in cross-section. Features are described that can improve the operation of the machine for various end-use applications. Such features include cut-outs that are fluidly connected to the inlet or outlet ports of the machine, mechanisms for reducing variation in output flow rate from the rotary machine, linings for the interior cavity of the housing, pressure relief mechanisms, dynamic apex seals and other sealing mechanisms.

A hermetic compressor may include a cylinder having an elliptical inner circumferential surface; a roller eccentric from the inner circumferential surface; and at least one vane withdrawn towards the inner circumferential surface when the roller is rotated to divide a compression chamber. On the basis of a contact point where the inner circumferential surface and an outer circumferential surface are closest, a first center line passes through a center of the cylinder, an ellipse positioned at a first side of the first center line and forming the inner circumferential surface is a first ellipse, a center point of the first ellipse is a first center point, an ellipse positioned at a second side of the first center line and forming the inner circumferential surface is a second ellipse, a center point of the second ellipse is a second center point, and the first center point and the second center point are spaced apart from the center.

Vacuum pump (1), comprising a housing (2) having an inlet (4) and an outlet (6) and defining a chamber (8) within the housing (2), a rotor (10) for rotational movement about a rotational axis (AR) within the chamber (8), and at least a first and a second vane (22, 24) received in respective first and seconds slots (16, 18) formed in the rotor (10). The first and second slots (16, 18) are substantially parallel to each other, and a length (L.sub.V) of each vane (22, 24) is larger than a length (L.sub.S) of the respective slot. Production method of such a vacuum pump.

A rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by a first eccentricity and the rotor has a peripheral outer surface having a peritrochoid inner envelope configuration defined by a second eccentricity larger than the first eccentricity. Also, a rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by an eccentricity, and a rotor with a peripheral outer surface between adjacent ones of the apex portions being inwardly offset from a peritrochoid inner envelope configuration defined by the eccentricity. The engine may have an expansion ratio with a value of at most 8. The rotary engine may be part of a compound engine system.

The utility model relates to internal cycloidal gear mechanisms and can be used in various branches of mechanical engineering as working members of hydraulic machines (pumps and engines), compressors, internal combustion engines, as well as in planetary gearboxes, in particular in technical systems for drilling and repairing oil and gas wells. The problems to be solved by the utility model include the improvement of the quality of the process of designing working members having a cycloidal tooth profile, as well as the substantiation of the conditions for modifying cycloidal face profiles (by choosing the required combination of dimensionless gearing coefficients) in order to achieve the maximum or minimum open area of the gerotor mechanism having a different kinematic ratio.

The utility model relates to internal cycloidal gear mechanisms and can be used in various branches of mechanical engineering as working members of hydraulic machines (pumps and engines), compressors, internal combustion engines, as well as in planetary gearboxes, in particular in technical systems for drilling and repairing oil and gas wells. The problems to be solved by the utility model include the improvement of the quality of the process of designing working members having a cycloidal tooth profile, as well as the substantiation of the conditions for modifying cycloidal face profiles (by choosing the required combination of dimensionless gearing coefficients) in order to achieve the maximum or minimum open area of the gerotor mechanism having a different kinematic ratio.

Disclosed is a vane pump comprising a cam ring accommodated in a pump housing, a rotor accommodated rotatably with respect to a rotational shaft in the cam ring, and a plurality of vanes coupled to the rotor to discharge fluid, wherein the cam ring has a ring shaped inner profile varied between a maximum radius (Rmax) and a minimum radius (Rmin) in a circumferential direction with respect to the rotational shaft, and the ring shaped inner profile comprises: a cycloid curve passing through a maximum radius point; a circular arc passing through a minimum radius point; and a tangent line connecting the cycloid curve to the circular arc with a tangential curvature.

Provided is an internal gear pump. The shape of any one of a plurality of external teeth and a plurality of internal teeth of the pump is formed on the basis of formulae (1)-(5).
r=rodr.Math.cos ,Formula (1):
Px=(rodr)+1/4dr{1cos(2)},Formula (2):
Py=1/4dr{2+sin(2)},Formula (3):
Qx=Pxr.Math.cos ,Formula (4):
Qy=Py+r.Math.sin Formula (5):.

Vacuum pump (1), comprising a housing (2) having an inlet (4) and an outlet (6) and defining a chamber (8) within the housing (2), a rotor (10) for rotational movement about a rotational axis (AR) within the chamber (8), and at least a first and a second vane (22, 24) received in respective first and seconds slots (16, 18) formed in the rotor (10). The first and second slots (16, 18) are substantially parallel to each other, and a length (L.sub.V) of each vane (22, 24) is larger than a length (L.sub.S) of the respective slot. Production method of such a vacuum pump.

A rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by a first eccentricity and the rotor has a peripheral outer surface having a peritrochoid inner envelope configuration defined by a second eccentricity larger than the first eccentricity. Also, a rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by an eccentricity, and a rotor with a peripheral outer surface between adjacent ones of the apex portions being inwardly offset from a peritrochoid inner envelope configuration defined by the eccentricity. The engine may have an expansion ratio with a value of at most 8. The rotary engine may be part of a compound engine system.