An electrical fan and an electric appliance are provided. The fans has a driving structure, an impeller, a wind hood and a diffuser. The impeller has a cover plate installed on the driving structure. The wind hood is covered on the impeller and has an air inlet and an air outlet communicated to each other. The diffuser is located at one end of the impeller facing the air outlet. The diffuser has a first protrusion connected to the driving structure. The first protrusion protrudes in a direction of the wind hood. The diameter of an end of the first protrusion adjacent the cover plate is smaller than the diameter of an end away from the cover plate. The diffuser has an inner ring arm connected to the first protrusion and an outer ring arm sleeved outside the inner ring arm.

An object of the present invention is to provide a bearing structure of a turbocharger that can prevent generation of unusual noise and a decrease in operation efficiency and that can reduce manufacturing costs. The bearing structure of a turbocharger to accomplish such an object, includes a rotor shaft, a ball bearing, a retainer, and a housing. The rotor shaft is provided with a turbine impeller mounted on a first end and a compressor impeller mounted on a second end.

The ball bearing includes an inner ring and an outer ring that are supported in relatively rotatable manner. The retainer holds the outer ring. Between the inner ring and an outer peripheral surface of the rotor shaft, oil in a film state is interposed to form an oil film damper.

An object of the present invention is to provide a bearing structure of a turbocharger that can prevent generation of unusual noise and a decrease in operation efficiency and that can reduce manufacturing costs. The bearing structure of a turbocharger to accomplish such an object, includes a rotor shaft, a ball bearing, a retainer, and a housing. The rotor shaft is provided with a turbine impeller mounted on a first end and a compressor impeller mounted on a second end.

The ball bearing includes an inner ring and an outer ring that are supported in relatively rotatable manner. The retainer holds the outer ring. Between the inner ring and an outer peripheral surface of the rotor shaft, oil in a film state is interposed to form an oil film damper.

An assembly is provided that includes a shaft, a bearing, a stator seal element, a rotor seal element and a shield. The shaft extends along an axis. The bearing supports the shaft and receives lubrication fluid. The stator seal element circumscribes the shaft. The rotor seal element is mounted on the shaft axially between the bearing and the stator seal element. The rotor seal element forms a seal with the stator seal element. The shield substantially prevents the lubrication fluid from traveling axially away from the bearing onto the rotor seal element.

A shaftless fan includes a fan stator, a vane rotor and a rolling bearing. The rolling bearing is installed between the fan stator and the vane rotor and includes an inner ring, an outer ring, and a plurality of rolling elements rollably installed between the inner and outer rings, and the inner and outer rings of the rolling bearing are rotated in opposite direction with respect to each other, so that the vane rotor can be rotated on the fan stator to connect the fan stator with the vane rotor through the rolling bearing, so as to achieve the shaftless effect.

A shaftless fan includes a fan stator, a vane rotor and a rolling bearing. The rolling bearing is installed between the fan stator and the vane rotor and includes an inner ring, an outer ring, and a plurality of rolling elements rollably installed between the inner and outer rings, and the inner and outer rings of the rolling bearing are rotated in opposite direction with respect to each other, so that the vane rotor can be rotated on the fan stator to connect the fan stator with the vane rotor through the rolling bearing, so as to achieve the shaftless effect.

The present invention relates to a vacuum pump comprising a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor during rotation of the drive shaft, a back-up bearing assembly for limiting said movement and a sensor for sensing when said movement is limited by the back-up bearing assembly.

The present invention relates to a vacuum pump comprising a vacuum pumping mechanism comprising a rotor supported for rotation by a drive shaft, a first bearing assembly for controlling movement of the rotor during rotation of the drive shaft, a back-up bearing assembly for limiting said movement and a sensor for sensing when said movement is limited by the back-up bearing assembly.

A bearing structure of a turbocharger includes a rotor shaft, two angular ball bearings, a retainer, a housing, and an oil film damper. Each of the angular ball bearings includes an inner ring and an outer ring that are supported in relatively rotatable manner. The rotor shaft is inserted into the inner ring. The retainer holds the outer ring. The housing houses therein the rotor shaft, the angular ball bearings, and the retainer to constitute a bearing housing. The oil film damper is formed of oil in a film state and is interposed between the inner ring and an outer peripheral surface of the rotor shaft. The inner ring is configured to rotate with rotation of the rotor shaft via the oil film damper.

A bearing structure of a turbocharger includes a rotor shaft, two angular ball bearings, a retainer, a housing, and an oil film damper. Each of the angular ball bearings includes an inner ring and an outer ring that are supported in relatively rotatable manner. The rotor shaft is inserted into the inner ring. The retainer holds the outer ring. The housing houses therein the rotor shaft, the angular ball bearings, and the retainer to constitute a bearing housing. The oil film damper is formed of oil in a film state and is interposed between the inner ring and an outer peripheral surface of the rotor shaft. The inner ring is configured to rotate with rotation of the rotor shaft via the oil film damper.