A rotor assembly, a compressor and an air conditioner. The rotor assembly includes a first rotor, including a first working portion and a second working portion coaxially arranged, wherein the first working portion and the second working portion are rotatable about a first axis; the first working portion includes a plurality of first helical blades, with a first blade groove being formed between adjacent two of the plurality of first helical blades; at least one first air pressure groove is provided on a first end face of the first working portion away from the second working portion; and the first air pressure groove is configured to form a force in a predetermined direction along the first axis when rotating. The rotor assembly can reduce costs of the compressor, simplify structures of moving parts of the compressor, and improve performance and reliability of the compressor.

A fluid machine is provided with a first rotor having a first rotor first working portion and a first rotor second working portion, a second rotor having a second rotor first working portion configured to mesh with the first rotor first working portion and a second rotor second working portion configured to mesh with the first rotor second working portion and rotate independently from the second rotor first working portion.

A pair of co-operating screw rotors including a male rotor and a female rotor. The male rotor and the female rotor have helically extending lobes and intermediate grooves configured to intermesh with one another. Each groove of the female rotor has a first flank including at least three concave sections. A first section includes or is disposed immediately adjacent the radially innermost point of the groove. A second section is shaped as a circular arc with a radius having its center located outside the pitch circle. A third section is shaped as a circular arc with a radius having its center located outside the pitch circle. The radius of the third section is greater than the radius of the second section, which is greater than the radial distance between a pitch circle of the female rotor and the radially innermost point of the groove.

A blower may include a blower housing that may include a plurality of rotor chambers and a plurality of rotors. The plurality of rotors may be substantially identical and each may include a twist angle and a helix angle. The rotors and the blower housing may be configured to create internal fluid compression when the rotors are rotating at a first rotational speed and not to create internal fluid compression when the rotors are rotating at a second rotational speed. The rotors and the blower housing may be configured to create the internal fluid compression without backflow slots in the blower housing. The twist angle may include the angular displacement of lobes of the plurality of rotors between axial ends of the plurality of rotors. The helix angle may be a function of the twist angle and a pitch diameter of the plurality of rotors.

A compressor (22) comprises a housing (50) having a first port (26) and a second port (28). A male rotor (52) has a working portion (64) having a plurality of lobes (110) of a count (N.sub.M) and at least a first shaft portion (62) protruding beyond a first end (68) of the male rotor working portion and mounted for rotation about a first axis (500). A female rotor (54) has a working portion (66) having a plurality of lobes (112) of a count (N.sub.F) and mounted for rotation about a second axis (502) so as to be enmeshed with the male rotor working portion. An electric motor (56) is within the housing and has a stator (58) and a rotor (60) mounted to the first shaft portion. The compressor has no additional compressor rotors. The lobe count of the male rotor is less than the lobe count of the female rotor. A combined lobe count (N.sub.M+N.sub.F) is at least fifteen.

A screw rotor lead correction calculation device includes an initial data input section configured to input an error as a distance with respect to a reference lead at each axial position of a rotor groove portion of a screw rotor, and a processing machine input correction amount/position output section configured to compute and output, based on the error as the distance input to the initial data input section, a lead correction amount with respect to the reference lead and a lead correction starting position as an axial position for starting lead correction. With this configuration, correction data for obtaining a screw rotor with a high-accuracy lead can be obtained from a lead error with respect to a reference lead in a screw rotor obtained by ground finish of the material of the screw rotor.

A positive displacement device that converts energy, namely positive displacement compressors that rotate in a single rotational direction to displace working fluid contained in operating chambers. The device described herein is particularity advantageous for the ability to achieve high compression ratios in combination with high discharge pressure and high volumetric throughput in a single stage.

A vacuum pump rotor comprises at least one displacement element arranged on a rotor shaft. The rotor shaft comprises at least one shaft end for a bearing element to be arranged thereon. The rotor element, the at least one displacement element and the at least one shaft end are made from aluminum or an aluminum alloy.

A system for monitoring machine fluids is provided. The system includes a fluid handling unit configured to pump the fluid and the fluid handling unit includes at least one fluid handling element. A magnetic material on the at least one fluid handling element is configured to generate a magnetic field. A sensing element located within the magnetic field is configured to measure fluctuations in the magnetic field.

A rotor polishing device, including a housing with a space therein for holding rotors in need of polishing, an inlet for pumping a polishing lapper into the housing, and a rotational assembly for rotating the rotors during the polishing process. The rotor polishing device is useful for polishing rotors commonly used by rotary screw compression systems.