Provided is a seal device configured to prevent leakage of a fluid on an outer circumferential surface of a rotary shaft in a direction along an axis of the rotary shaft. The seal device includes an annular main body section disposed in a circumferential direction of the rotary shaft, and a plurality of at least two kinds of holes formed in an inner circumferential surface of the main body section opening and facing to the outer circumferential surface of the rotary shaft, and having different depths.

Provided is a seal device configured to prevent leakage of a fluid on an outer circumferential surface of a rotary shaft in a direction along an axis of the rotary shaft. The seal device includes an annular main body section disposed in a circumferential direction of the rotary shaft, and a plurality of at least two kinds of holes formed in an inner circumferential surface of the main body section opening and facing to the outer circumferential surface of the rotary shaft, and having different depths.

A rotation shaft supporting structure for an electric supercharger includes a rotation shaft that supports a compressor wheel, an electric motor including a motor rotator securely installed to the rotation shaft, and a stator for applying torque to the motor rotator. The supporting structure further includes a bearing provided on a bearing side end of the rotation shaft, which is adjacent to the compressor wheel, to support the rotation shaft, and a damper unit for absorbing shaft vibration of the rotation shaft. The compressor wheel is a wheel of a supercharging side, and the damper unit is provided at a shaft end on an opposite side to the bearing side.

A rotation shaft supporting structure for an electric supercharger includes a rotation shaft that supports a compressor wheel, an electric motor including a motor rotator securely installed to the rotation shaft, and a stator for applying torque to the motor rotator. The supporting structure further includes a bearing provided on a bearing side end of the rotation shaft, which is adjacent to the compressor wheel, to support the rotation shaft, and a damper unit for absorbing shaft vibration of the rotation shaft. The compressor wheel is a wheel of a supercharging side, and the damper unit is provided at a shaft end on an opposite side to the bearing side.

A method is provided for operating a fluid conveying device of a motor vehicle having at least one aerodynamic bearing. The method reduces the rotational speed of the aerodynamic bearing to a rest speed, wherein the rest speed is below a lifting speed, in which case the bearing builds up an air film for bearing free of mixed friction, and wherein the rest speed is above a lowering speed, in which case the bearing has reduced the air film such that mixed friction occurs. The fluid conveying device is operated at the rest speed.

A rotary device includes: a housing; an impeller disposed in the housing; a rotor disposed in the housing and configured to drive the impeller; and a labyrinth seal disposed between the impeller and the rotor in the housing and configured to control an amount of air injected through the impeller to cool the rotor. A flow path opening that penetrates through the rotor is formed inside the rotor along a rotational axis of the rotor and the labyrinth seal comprises a teeth portion having a predetermined number of steps provided in the labyrinth seal.

A blower includes a housing including an inlet and an outlet, a bearing-housing structure provided to the housing and adapted to rotatably support a rotor, a motor provided to the bearing-housing structure and adapted to drive the rotor, and an impeller provided to the rotor. The bearing-housing structure includes a bearing shaft having a bearing surface that rotatably supports the rotor. The bearing shaft provides only a single bearing of the non-ball bearing type for the rotor.

A blower includes a housing including an inlet and an outlet, a bearing-housing structure provided to the housing and adapted to rotatably support a rotor, a motor provided to the bearing-housing structure and adapted to drive the rotor, and an impeller provided to the rotor. The bearing-housing structure includes a bearing shaft having a bearing surface that rotatably supports the rotor. The bearing shaft provides only a single bearing of the non-ball bearing type for the rotor.

A method for controlling at least one radial blower in a cooling system, wherein the radial blower comprises a housing in which a shaft is rotationally mounted, which receives at least one impeller wheel of a compressor at one end, which is secured to the housing, and the housing comprises at least one radial bearing and at least one axial bearing via which the shaft is rotationally mounted in the housing, and said radial blower also comprises a motor which is driven by a rotor and a stator and which drives the shaft, wherein, by means of at least one laser Doppler vibrometer assigned to the shaft, operating points of the shaft are detected and forwarded to a controller for determining an operating status of the radial blower.

A method for controlling at least one radial blower in a cooling system, wherein the radial blower comprises a housing in which a shaft is rotationally mounted, which receives at least one impeller wheel of a compressor at one end, which is secured to the housing, and the housing comprises at least one radial bearing and at least one axial bearing via which the shaft is rotationally mounted in the housing, and said radial blower also comprises a motor which is driven by a rotor and a stator and which drives the shaft, wherein, by means of at least one laser Doppler vibrometer assigned to the shaft, operating points of the shaft are detected and forwarded to a controller for determining an operating status of the radial blower.