A heat pump including a two-stage, high speed fluid compressor including a case having a fluid inlet and a compressed fluid outlet and containing a shaft rotatably mounted about a longitudinal axis, a first compression wheel and a second compression wheel mounted back-to-back on the shaft, the first compression wheel forming a first compression stage and the second compression wheel forming a second compression stage, and a motor positioned between the first compression wheel and the second compression wheel and arranged to rotate the shaft. The case includes an inner through housing extending coaxially to the longitudinal axis and inside which is arranged at least the motor, the inner housing having an inner wall arranged to form, with the motor, channels between at least the inner wall and the motor to cool the motor.

A motor according to an embodiment of the present invention includes a rotary shaft; a rotor mounted on the rotary shaft; a stator surrounding an outer periphery of the rotor; an impeller mounted on the rotary shaft to be spaced apart from the rotor; a bearing housing positioned between the impeller and the rotor and formed with a through-hole through which the rotary shaft passes; and a gas bearing disposed in the bearing housing, wherein a thickness of the gas bearing is equal to or greater than 50% of a gap between an inner surface of the bearing housing and an outer peripheral surface of the rotary shaft and is equal to or less than 0.3 mm.

An electric motor-driven compressor includes a housing assembly comprising a motor housing and a compressor housing mounted thereto. The compressor housing contains a centrifugal compressor wheel that is mounted on a shaft of the motor rotor and also defines an air inlet that leads air into the compressor wheel, and a volute that collects the compressed air. Air bearings rotatably support the shaft. Cooling air passages are defined in the housing assembly for supplying cooling air to the air bearings. A diffuser between the exit of the compressor wheel and the volute serves to diffuse the compressed air. The compressor includes a heat shield formed separately from the compressor housing and the motor housing and disposed between them. The heat shield defines one wall of the diffuser and also cooperates with the housing assembly to define part of the cooling air passages for the cooling air supplied to the bearings.

A bearing system and method may include a bearing element that may have a first surface. A mating element may have a second surface that may face the first surface. A fluid film interface may be defined between the first and the second surfaces. The mating element may rotate about an axis and relative to the bearing element. An axial direction may be defined parallel to the axis. A radial direction may be defined perpendicular to the axis. The first surface may have a profile that may vary in the axial direction and that may varies in the radial direction. The profile may direct a fluid present in the fluid film interface in a direction or directions having circumferential and/or axial components.

A compressor having a housing and a rotor, the rotor having a compressor impeller at least on one side; a compressor chamber being configured between the compressor impeller and the housing; the rotor being rotationally mounted; an annular sealing channel being configured between the rotor and the housing; the sealing channel being routed from the compressor chamber to a lower-pressure zone; at least two throttling sections being provided in the sealing channel; in each of the two throttling sections, in the direction of flow viewed from the compressor chamber to the lower-pressure zone, a first section having a reduction in the cross section of the sealing channel being first provided, and a second section having an enlargement of the cross section of the sealing channel being subsequently provided.

This invention prevents seizure of a dynamic pressure gas bearing caused upon swinging contact between a motor shaft and a sleeve and an increase in contact friction torque. It also detects rotation of auxiliary bearings. A motor includes auxiliary bearings in series with a dynamic pressure gas bearing, and a non-contact detent torque generation mechanism parallel to the auxiliary bearings suppresses rotation of the auxiliary bearings. Where Ta denotes rotation-time viscous friction torque of the dynamic pressure gas bearing, Tka denotes contact friction torque possibly causing damage to the dynamic pressure gas bearing, Tb denotes rotation friction torque of the auxiliary bearings, and Td.sub.max denotes maximum torque generated when rotation of the auxiliary bearings is suppressed by the non-contact detent torque generation mechanism, (Ta+Tka)>(Tb+Td.sub.max)>(Ta), and the rotation detecting means detects the rotation of the auxiliary bearings.

A centrifugal compressor includes a motor that rotates a rotary shaft of a compressor impeller, a motor housing that houses the motor, a compressor housing that houses the compressor impeller and includes an intake port and a discharge port, an gas bleed port that is provided closer to the discharge port than the compressor impeller in a flow direction in the compressor housing, a cooling gas line which is connected to the gas bleed port and through which a part of compressed gas compressed by the compressor impeller passes, a cooling liquid line of which at least a part is provided in the motor housing and through which cooling liquid of which the temperature is lower than the temperature of the compressed gas passes, and a heat exchanger that is disposed on the cooling gas line and the cooling liquid line.

A pressproof fan structure includes: a fan frame having an upper case and a lower case; a support shaft having one end inserted into the lower case, and the other end protruding out from the upper case; an oil-retaining bearing having a bearing hole, in which the support shaft is fitted; a rotor assembly fitted around and connected with the oil-retaining bearing; a restriction member fitted around the support shaft near the oil-retaining bearing; a thrust member fitted around the support shaft near the oil-retaining bearing; and a stator assembly disposed on the lower case near the oil-retaining bearing without contacting.

The invention relates to a turbo compressor (10), in particular for a fuel cell system (1). The turbo compressor (10) has a first compressor unit (101) and a second compressor unit (102). The first compressor unit (101) comprises a first compressor (11) arranged on a first shaft (14) drivable by a drive unit (20). The second compressor unit (102) comprises a second compressor (12) and an exhaust gas turbine (13). The second compressor (12) and the exhaust gas turbine (13) are arranged on a second shaft (24).

The invention relates to a turbo compressor (10), in particular for a fuel cell system (1). The turbo compressor (10) has a first compressor unit (101) and a second compressor unit (102). The first compressor unit (101) comprises a first compressor (11) arranged on a first shaft (14) drivable by a drive unit (20). The second compressor unit (102) comprises a second compressor (12) and an exhaust gas turbine (13). The second compressor (12) and the exhaust gas turbine (13) are arranged on a second shaft (24).