Provided is a scroll compressor capable of reducing a shaft voltage and achieving space savings for the entire apparatus. A scroll compressor 100 includes a rotor 32 that is stored in a motor casing 14; a stator 31 that is stored in the motor casing 14, and drives the rotor 32 to rotate; a rotary shaft 12 that is held by bearings 33 and 34, and rotates integrally with the rotor 32; an end bracket 16 through which one end portion of the rotary shaft 12 passes, and which seals the motor casing 14; an orbiting scroll 44 that supports the other end portion of the rotary shaft 12, and orbits as the rotary shaft 12 rotates; a fixed scroll 43 that is disposed facing the orbiting scroll 44; a suction type cooling fan 13 which is fixed to one end portion of the rotary shaft 12 while being apart by a clearance from the end bracket 16, and which suctions outside air through a suction port provided in an end surface 132A of a fan cover 132, and generates cooling wind for cooling the fixed scroll 43 or the orbiting scroll 44 in the fan cover 132, as a rotary vane 131 accommodated in the fan cover 132 rotates; and a discharge brush 60 which is fixed to the end bracket 16 facing the cooling fan 13, and one end of which is in contact with the rotary shaft 12.

A stator of a dry vacuum pump is provided, the pump having at least two rotors to rotate in a synchronised manner in opposite directions in a central housing to drive a gas to be pumped between a suction inlet and a delivery outlet, the stator including an outer part made of cast iron containing less than 5% nickel, and a stator insert wherein is arranged the central housing configured to receive the at least two rotors, the stator insert containing at least 10% nickel, the outer part of the stator having been cast on the stator insert. There is also provided a rotary shaft configured to bear and drive in rotation at least one rotor of a vacuum pump, a dry vacuum pump having at least one such stator and/or at least one such shaft, and a method for manufacturing such a stator and/or such a rotary shaft.

A fluid gear pump gear arranged to rotate about a first axis. The fluid gear pump gear includes a concentrically disposed first hub portion and a plurality of first teeth radially projecting and circumferentially spaced about the first hub portion, the first hub portion and the first teeth being coated with a vapor-deposited of cavitation resistant coating. The gear also includes a first shaft on which the first hub portion is carried.

An object of the invention is to provide a compressor that includes a corrosion-resistant film formed on the surface of a casing having a complicated shape. A compressor pumps gas in a compression chamber formed by a casing, the casing is made of cast iron, and a layer made of a mixture of iron nitride and a compound of iron, nitrogen, and carbon and an oxide layer made of triiron tetraoxide are formed on the surface of the casing. Accordingly, since the corrosion resistance of the casing, which includes a film formed by a gas soft-nitriding treatment and an oxidation treatment, is improved, the generation of rust is suppressed. Therefore, it is possible to provide a compressor in which galling or sticking caused by rust occurs less.

A compression device includes: a compressor including a casing, a rotor that is housed in a rotor chamber inside the casing and compresses gas by rotating, a bearing that is provided inside the casing and supports a rotor shaft so that the rotor is rotatable, and a first shaft-sealing part and a second shaft-sealing part that are provided to line up between the rotor chamber and the bearing in the casing to seal a periphery of the rotor shaft; a first supply line adapted to supply injection oil to the rotor chamber; a second supply line that is provided independent of the first supply line to supply lubrication oil to the bearing; a third supply line adapted to supply sealing gas to the first shaft-sealing part; and a fourth supply line adapted to supply the second shaft-sealing part with sealing oil to be used for sealing.

The pump includes a pumping chamber within a sealed internal chamber, a pump inlet connected to the pumping chamber, a pump outlet connected to the pumping chamber, and a rotational pumping element configured to pump the corrosive fluid from the pump inlet to the pump outlet. The rotational pumping element is within the pumping chamber. The pump includes a drive shaft for driving the rotational pumping element. The drive shaft is completely within the sealed internal chamber. The drive shaft is configured for magnetically coupling to an external motor. A pump housing forms the sealed internal chamber. The rotational element, the pumping chamber, and the pump housing are formed from any one a conductive plastic, a non-conducting plastic with conducting particles, a semi-conducing ceramic, and combinations thereof. The drive shaft is formed from the semi-conducting ceramic.

The pump includes a pumping chamber within a sealed internal chamber, a pump inlet connected to the pumping chamber, a pump outlet connected to the pumping chamber, and a rotational pumping element configured to pump the corrosive fluid from the pump inlet to the pump outlet. The rotational pumping element is within the pumping chamber. The pump includes a drive shaft for driving the rotational pumping element. The drive shaft is completely within the sealed internal chamber. The drive shaft is configured for magnetically coupling to an external motor. A pump housing forms the sealed internal chamber. The rotational element, the pumping chamber, and the pump housing are formed from any one a conductive plastic, a non-conducting plastic with conducting particles, a semi-conducing ceramic, and combinations thereof. The drive shaft is formed from the semi-conducting ceramic.

Liquid ring pumps are used to pump a variety of fluid types. Corrosive fluids are easily handled by the work fluid but can cause corrosion of pumping mechanisms. The present invention provides a magnetically driven liquid ring pump with corrosion resistant pumping mechanisms which achieves a longer time between service intervals.

In order to prevent deterioration in performance of an oil-free screw compressor and scuffing caused by rust, surfaces of both male and female rotors are coated with heat-resistance coatings containing a solid lubricant. A coating contains Polyimide resin to which Molybdenum disulfide, as a solid lubricant, and Aluminum oxide and Titanium oxide, as additives, are added. Accordingly, it is possible to realize a coating that is higher in heat resistance and longer in lifetime than a conventional one.

A refrigerant compressor includes a compression mechanism portion, a drive portion, a crankshaft, a main bearing and an auxiliary bearing that support the crankshaft, and a sealed container that accommodates therein the compression mechanism portion, the drive portion, the crankshaft, the main bearing, and the auxiliary bearing. The auxiliary bearing is configured of an antifriction bearing and provided in an auxiliary bearing housing attached to the sealed container. The auxiliary bearing housing includes an opening for inserting the auxiliary bearing on the drive portion side, and includes a housing cover covering the opening. An insulating sleeve configured of an insulating material is provided between the crankshaft and the auxiliary bearing. The insulating sleeve includes a cylinder portion located between the crankshaft and the auxiliary bearing, and a flange portion located between the auxiliary bearing and the housing cover and extended in an outer diameter direction.