A gear pump includes a housing, at least one gear set and a plurality of end plates. The gear set may be positioned between the end plates so that side surfaces of the gears face corresponding side surfaces of the end plates. The side surfaces of the end plates may have a plurality of spiral grooves positioned directly adjacent the side surface of the gears. The plurality of spiral grooves may have a logarithmic shape. Thus arranged, when the gears rotate, fluid in the pump is forced along the lengths of the spiral grooves, creating a local high pressure region that forces fluid between the side surfaces of the gears and the end plates, minimizing or eliminating contact therebetween. In some embodiments the plurality of spiral grooves may be positioned on bearing surfaces of the pump instead of end plates.

A gear pump includes a housing, at least one gear set and a plurality of end plates. The gear set may be positioned between the end plates so that side surfaces of the gears face corresponding side surfaces of the end plates. The side surfaces of the end plates may have a plurality of spiral grooves positioned directly adjacent the side surface of the gears. The plurality of spiral grooves may have a logarithmic shape. Thus arranged, when the gears rotate, fluid in the pump is forced along the lengths of the spiral grooves, creating a local high pressure region that forces fluid between the side surfaces of the gears and the end plates, minimizing or eliminating contact therebetween. In some embodiments the plurality of spiral grooves may be positioned on bearing surfaces of the pump instead of end plates.

A gear pump includes a pair of gears that meshes with each other, two rotational shafts inserted into the respective gears that rotate together with gears, a pair of side plates arranged adjacent to both side surfaces of the gears, each having two through-holes forming bearings of the two shafts, a seal block that abuts against the pair of side plates and covers a part of the pair of gears, a pump assembly having the gears, the two shafts, the pair of side plates, and the seal block, and a case having a recess to accommodate the pump assembly. A line passing through an arc center of a cylindrical surface inscribed in the facing surface of the case, and parallel to the two shafts, forms a rotating axis. When the pump assembly rotates about the rotating axis, one of the of side plates contacts the inner wall of the case.

A gear pump includes a pair of gears that meshes with each other, two rotational shafts inserted into the respective gears that rotate together with gears, a pair of side plates arranged adjacent to both side surfaces of the gears, each having two through-holes forming bearings of the two shafts, a seal block that abuts against the pair of side plates and covers a part of the pair of gears, a pump assembly having the gears, the two shafts, the pair of side plates, and the seal block, and a case having a recess to accommodate the pump assembly. A line passing through an arc center of a cylindrical surface inscribed in the facing surface of the case, and parallel to the two shafts, forms a rotating axis. When the pump assembly rotates about the rotating axis, one of the of side plates contacts the inner wall of the case.

The invention relates to a spindle compressor without operating fluid in the working space with a 2-tooth spindle rotor and a 3-tooth spindle rotor in a surrounding compressor housing-and preferably non-parallel rotation axes of the two spindle rotors, in particular for use in compression refrigeration machines. In order to improve the degree of efficiency while providing flexible power adjustment, it is proposed according to the invention that a multi-stage spindle compressor be used as a refrigerant compressor, whose compressor housing and whose spindle rotors are cooled via a partial-flow branch-off of liquid refrigerant from the refrigerant main flow circuit, wherein the compressor housing is cooled in a controlled manner by means of refrigerant evaporation, with the refrigerant vapor being subsequently fed to the inlet, and that, for power adjustment, there are also post-inlet feeds into the working space in addition to the inlet feed, and also pre-outlet discharges in addition to the outlet discharge from the outlet space, each with their own regulating device.

A compressor assembly includes a motor which drives one or more compressor rotors having an oil circulation system including an oil reservoir, an oil cooler and an oil filter, an oil-pump for circulating oil from the oil reservoir to components to be cooled and/or lubricated and back to the oil reservoir wherein the motor has a motor jacket with channels extending in axial directions parallel to the axial direction of a motor shaft in which oil of the oil circulation system circulates.

A compressor assembly includes a motor which drives one or more compressor rotors having an oil circulation system including an oil reservoir, an oil cooler and an oil filter, an oil-pump for circulating oil from the oil reservoir to components to be cooled and/or lubricated and back to the oil reservoir wherein the motor has a motor jacket with channels extending in axial directions parallel to the axial direction of a motor shaft in which oil of the oil circulation system circulates.

A compressor device including a compressor element which is at a fluid duct outlet provided with an adapter of acoustic impedance which includes an adapter inlet duct and an adapter outlet duct interconnected by means of an adapter intermediate duct part which encloses at least one expansion chamber. A maximum opening with an equivalent diameter of the adapter intermediate duct part is substantially larger than a minimum opening of the adapter inlet duct with an equivalent diameter.

A compressor device including a compressor element which is at a fluid duct outlet provided with an adapter of acoustic impedance which includes an adapter inlet duct and an adapter outlet duct interconnected by means of an adapter intermediate duct part which encloses at least one expansion chamber. A maximum opening with an equivalent diameter of the adapter intermediate duct part is substantially larger than a minimum opening of the adapter inlet duct with an equivalent diameter.

The present invention concerns a volumetric compressor (1) that can be used, preferably, for producing equipment and/or a plant for the suction of material in liquid, solid, powder or slurry form. The compressor according to the invention comprises a body (2) defining an operative chamber (5), a suction section (51) and a discharge section (52) of an operating fluid. The compressor further comprises at least two lobe rotors (8A. 8B), the lobes (81A. 81B) of which are housed inside said operative chamber (5), cach rotor (8A. 8B) rotating around a corresponding longitudinal rotation axis (101A. 101B). The compressor comprises a first header (6) and a second header (6) which delimit on opposite sides the operative chamber (5): cach header comprises a bank (61, 61) connected to the body (2) and configured to support the rotors (8A, 8B) and a cover (62, 62) connected to the bank (61, 61) so as to define an inner volume (65, 65) comprised between the cover (62, 62) and the bank (61, 61) and designed to house, in use, a lubricating bath. According to the invention the compressor comprises a generator unit for generating a forced flow of cooling gas and, for at least one of the headers (6, 6), the bank (61, 61) defines a cooling chamber (70, 70) physically separated from the operative chamber (5) and from the inner volume of lubricant. Said chamber (70, 70) comprises an inlet (71, 71) and an outlet (72, 72) for a cooling gas, where said inlet communicates with the generator unit of the forced flow of said cooling gas.