A screw compressor includes a compressor main body, a male rotor having a screw-like male tooth shape and a female rotor having a screw-like female tooth shape meshing with the screw-like male tooth shape or the male rotor. The male and female motors are provided within the compressor main body. A motor casing is operably connected to the compressor main body, and a high speed electric motor provided within the motor casing. The motor includes a motor rotor, a motor stator and a motor shaft for driving at least one of the male and female rotors. A speed ratio of the motor shaft and the at least one of the male and female rotors driven by the motor shaft is in a range of 2:1 to 1:2.

Oil free screw compressor

PROBLEM TO BE SOLVED: To provide a fuel cell device having a cost competitiveness by realizing reduction in the number of components and the working processes of the components without making air suction interfere with each other. SOLUTION: A heat radiation fan 51 is equipped at a heat radiation device 47 which cools by forced convection the exhaust heat when the exhaust heat from a reforming device 2 and a fuel cell 3 is not utilized by an external heat utilization equipment 7. Further, although the air suction part of a ventilation fan 52 for ventilating the inside of the package 41 is made independent respectively, that is placed adjacently as an air suction port 82, 83. Although the air suction port of the heat radiation fan 51 and the ventilation fan 52 are made independent respectively, these are placed adjacently as an air suction port 82, 83, thereby, performance deterioration of the heat radiating device 47 and the ventilation fan 52 can be avoided without making air suction interfere with each other. COPYRIGHT: (C)2006,JPO&NCIPI

Fuel cell device

The present invention relates to a fuel cell vehicle capable of efficiently cooling a fuel stack and supplying sufficient reactant gas to the fuel stack with only a single air supply means.

Fuel cell vehicle

An oilless screw compressor incorporating water-cooled cooling units for cooling compressed air discharged from compressor bodies having a pair of male and female screw rotors which can be rotated in a contactless and oilless manner, the cooling units comprising a plate type heat-exchanger, and the amount of cooling water for the plate type heat-exchanger being adjustable. With this configuration, a difference between a temperature during load operation and a temperature upon automatic stopping and during unload operation of the compressor can be reduced, so that the cooling unit can be restrained from being damaged or broken within a short period, thereby it is possible to provide a highly reliable oilless screw compressor.

Oilless screw compressor

The invention comprises a method and apparatus for reducing the noise generated by compressors, including Roots-type blowers. The invention has particular use for reducing noise generated by compressors used in mechanical ventilators, though the advantages thereof may be realized in many different applications. One embodiment of the invention comprises a noise-attenuating gas flow path for a compressor contained in a portable ventilator housing. In one embodiment, the gas flow path comprises a plurality of chambers interconnected by flow tubes. The flow path is folded so as to fit into the limited space of a portable ventilator housing. The dimensions of the chambers and the flow tubes are selected so that an impedance mismatch is created between the chambers and the flow tubes. In one embodiment of the invention, the flow path comprises one or more perforated tubes located in one or more of the chambers. The perforated tube has a port through which gas is accepted and at least one exterior tube through which gas exits. Impedance mismatches are created between the inlet chamber and the exterior tubes and between the exterior tubes and the chamber in which the perforated tube is located, which are useful in attenuating noise. One embodiment of the invention comprises a noise attenuating mounting system for a compressor. The mount system comprises flexible mounts that cooperate to dampen vibrations generated by the compressor.

Method and apparatus for attenuating compressor noise

An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.

Oil free screw compressor operating at variable speeds and control method therefor

In an oil-free type screw compressor including a low-pressure-stage compressor main body and a high-pressure-stage compressor main body, when the power of an motor is transmitted to an oil pump via a gear to start the pump, the lubrication oil stored in an oil sump formed at the bottom of a gear casing flows through an oil strainer. A part of the oil is introduced to an oil cooler, while the rest is introduced to a junction portion by bypassing the oil cooler. Further, a part of the oil introduced to the oil cooler is directed to the junction portion. After adjusting the temperature of the oil appropriately, it is introduced to a lubrication portion of the compressor, while the oil cooled by the oil cooler using the full capacity thereof is introduced to oil jackets of the compressor main bodies via different passages.

Oil free type screw compressor

PROBLEM TO BE SOLVED: To excellently arrange radiators for reducing a size of a fuel cell automobile, in which supply of a compressed air controlled to be about 80 degC to a mounted fuel cell main body is necessary, and air-cooled after-cooler is required as a discharge air temperature from an air compressor reaches about 200 degC, while a radiator for cooling the fuel cell main body and car-cooler capacitor are also required SOLUTION: The air-cooled after-cooler 4 for cooling high temperature air from the air compressor 3 and the fuel cell cooling radiator 9 are integrated together and arranged on the cooling air downstream side of the car-cooler capacitor 10 A single cooling fan 5 can be used in common for these radiators Consequently, a heat radiation system of the fuel cell automobile is reduced in size and weight, and fuel cell automobile can be provided at a low cost

Hitoshi Nishimura

Papers

Oil free screw compressor

Oilless screw compressor

Oil free screw compressor operating at variable speeds and control method therefor

Oil free type screw compressor

Fuel cell automobile