Abstract: A refrigerant pump includes a thin-walled hermetic vessel and a thick-walled hermetic vessel having an end inserted into and secured to an end of the thin-walled hermetic vessel. A stator of an electric motor unit is fitted outside the thin-walled hermetic vessel, while a rotor of the electric motor unit is accommodated inside the thin-walled hermetic vessel. A pump mechanism is fitted inside the thick-walled hermetic vessel, and a rotational force of the rotor is transmitted to the pump mechanism by the drive shaft.

Abstract: A semiconductor cooling device includes a cold plate for cooling a semiconductor element, a condenser, and an inverter-controlled refrigerant pump, all of which are fluid connected in series with each other to define a refrigerating cycle. The semiconductor cooling device also includes a fan for cooling the condenser, a temperature detector disposed in proximity to the semiconductor element, and a controller for controlling the refrigerant pump and the fan. The controller controls the number of revolutions of the refrigerant pump and that of the fan depending on a value measured by the temperature detector.

Abstract: A semiconductor cooling device includes at least one cold plate for cooling a semiconductor element, a condenser adapted to be cooled by a fan, and a refrigerant pump. The refrigerant pump is electrically connected to an inverter controller that controls the number of revolutions of the refrigerant pump.

Abstract: A heat radiator includes a heat absorbing element, a heat radiating element, and a pump connected with the heat absorbing element and the heat radiating element to define a closed circuit. The pump circulates a refrigerant through the closed circuit. The heat absorbing element includes a heat-exchanging portion for transferring heat generated by a heating element to the refrigerant, a cover joined to a peripheral edge of the heat-exchanging portion to define a refrigerant flow channel therebetween, and one or more connecting members disposed within the refrigerant flow channel and having opposite ends joined to the heat-exchanging portion and the cover, respectively, to connect the heat-exchanging portion and the cover with each other.

Abstract: A semiconductor cooling device includes a cold plate for cooling a semiconductor element, a condenser, and an inverter-controlled refrigerant pump, all of which are fluid connected in series with each other to define a refrigerating cycle. The semiconductor cooling device also includes a fan for cooling the condenser, a temperature detector disposed in proximity to the semiconductor element, and a controller for controlling the refrigerant pump and the fan. The controller controls the number of revolutions of the refrigerant pump and that of the fan depending on a value measured by the temperature detector.

Abstract: A refrigerant pump employed in a semiconductor cooling device includes a sealed casing, an electric motor having a stator disposed outside the sealed casing and a rotor disposed within the sealed casing, a pump mechanism juxtaposed with the electric motor, and a drive shaft for transmitting a rotational force of the rotor to the pump mechanism. The stator is positioned closer to the pump mechanism than the rotor is.

Abstract: A semiconductor cooling device includes a cold plate for cooling a semiconductor element, a condenser, and a positive-displacement refrigerant pump. The cold plate, condenser and refrigerant pump are fluid connected in series with each other to define a refrigerating cycle. A centrifugal refrigerant pump can be used in place of the positive-displacement refrigerant pump. In this case, it is preferred that a receiver tank be interposed between the condenser and the refrigerant pump.

Abstract: A cooling device for cooling a semiconductor element includes at least one cold plate utilizing a copper plate for cooling a semiconductor element, a condenser utilizing a plurality of flat micro-tubes, a refrigerant pump for circulating a refrigerant, and a fan for cooling the condenser. The cold plate, the condenser, and the refrigerant pump are fluid connected to define a refrigerant circulating circuit.

Abstract: A refrigerant pump includes a thin-walled hermetic vessel and a thick-walled hermetic vessel having an end inserted into and secured to an end of the thin-walled hermetic vessel. A stator of an electric motor unit is fitted outside the thin-walled hermetic vessel, while a rotor of the electric motor unit is accommodated inside the thin-walled hermetic vessel. A pump mechanism is fitted inside the thick-walled hermetic vessel, and a rotational force of the rotor is transmitted to the pump mechanism by the drive shaft.

Abstract: A semiconductor cooling device includes at least one cold plate for cooling a semiconductor element, a condenser adapted to be cooled by a fan, and a refrigerant pump. The refrigerant pump is electrically connected to an inverter controller that controls the number of revolutions of the refrigerant pump.

Abstract: A cooling device for cooling a semiconductor element includes at least one cold plate utilizing a copper plate for cooling a semiconductor element, a condenser utilizing a plurality of flat micro-tubes, a refrigerant pump for circulating a refrigerant, and a fan for cooling the condenser. The cold plate, the condenser, and the refrigerant pump are fluid connected to define a refrigerant circulating circuit.

Abstract: It is an object of the present invention to improve the efficiency of a scroll gas compressor by operating a bypass at a proper compression ratio. To achieve the object, the present invention is constituted so that at least one pair of bypass holes whose one ends are opened in a compression chamber currently performing compression nearby a discharge vent and whose other ends communicate with a discharge chamber are asymmetrically arranged on a panel board. This structure makes it possible to improve the efficiency of the compressor by operating the bypass at an optimum compression ratio even if a difference is observed between pressure rises of a pair of symmetric compressed spaces under the compression process.

Abstract: Base wraps 21a and 31a of a fixed scroll 20 and orbiting scroll 30 both have spiral lengths that satisfy specified compression ratio in low speed drive region. Spiral shaped extension wraps 21b and 31b are provided for at least one of the base wraps 21a and 31a, extended from the spiral end position thereof, and a displacement is effected in the direction in which the thickness of the wraps 21 and 31 becomes thinner, at least at either the inner walls of the extension wraps 21b and 31b or at the outer walls of the wraps 21 and 31 in opposition thereto, making the interrelationship greater.

Abstract: A scroll compressor has a check valve assembly for selectively opening and closing a discharge port and allowing a fluid to flow only from the discharge port towards a discharge chamber. A stationary end plate mounted in the scroll compressor has a plurality of bypass holes defined therein at locations symmetrical in terms of pressure. The plurality of bypass holes are open to compression chambers closest to the discharge port and communicate with the discharge chamber. The stationary end plate also has at least one bypass valve for selectively opening and closing the bypass holes and allowing the fluid to flow only from the compression chambers towards the discharge chamber through the bypass holes. The bypass holes are serviceable to prevent an excessive compression and are positioned so as not to be closed by an orbiting scroll wrap immediately after the compression chambers closest to the discharge port have communicated with the discharge port.