A cleaner reduces noise. The cleaner includes a motor, a fan including a number Z of blades and rotatable at a rotational speed N, indicating revolutions per minute, about a rotation axis by the motor, a cover having an inlet located frontward from the fan, and a number V of ribs located in the inlet. The ribs extend in a radial direction from the rotation axis and are arranged in a circumferential direction about the rotation axis. The fan is rotatable to produce noise having a frequency f.sub.NZ of 20,000 Hz or higher, and f.sub.NZ=(m−k×V)×N/60 and m=n×Z+k×V, where n is an order, m is an integer, and k is an integer.

A power tool having a built-in fan, the fan including a plurality of blades at uneven pitches. The fan includes a centrifugal fan which blows out air in all radial directions. The fan is provided with means for correcting unstable outflow which may be caused by the uneven pitches between the blades. The blades have unevenly configured inducers for correcting unstable outflow.

A product that includes a compressor, a housing and a vibration isolation mount located between the compressor and the housing. The compressor includes an impeller, a first inlet located upstream of the impeller, a first outlet located downstream of the impeller, a second inlet located downstream of the first outlet, and a second outlet located downstream of the second inlet. During operation, fluid enters the compressor via the first inlet and exits the compressor via the first outlet. The mount creates a restriction between the compressor and the housing that causes fluid exiting the first outlet to re-enter the compressor via the second inlet.

Provided is a vibration reduction device for stator vanes (30) positioned behind rotor blades (28) in a turbo machine, comprising an annular base member (80) having a cylindrical shape concentric around a central axis of the casing and supporting base ends of the stator vanes which extend radially inward from an inner circumferential surface of the base member, an elastomeric damping member (100) surrounding and in slidable contact with an outer circumferential surface of the base member, and a preloading member (102) surrounding an outer circumferential surface of the elastomeric damping member and configured to apply a preload directed radially inward to the elastomeric damping member.

A blower can be positioned in a wellbore. The blower rotatably drives or is driven by a fluid produced through the well bore. An electric machine can be positioned downhole of the blower, the electric machine configured to rotatably drive or be driven by the blower. A bearing shaft couples the blower and the electric machine. The bearing shaft transfers rotation between the blower and the electric machine. A passive magnetic radial bearing assembly magnetically supports the bearing shaft.

HVLP (High Velocity Low Pressure) motor-driven fans and other types of fans, blowers and vacuums take advantage of different thermal and mechanical properties of dissimilar materials used in the motor-driven fans. The dissimilar materials include aluminum for a stacked arrangement of fan wheels and spacers, steel for a shaft that supports the fan wheels and spacers, and a polymeric adhesive. In some examples, the polymeric adhesive is trapped between the aluminum and steels parts. Compared to steel and aluminum, the adhesive has a relatively high coefficient of thermal expansion but relatively low strength such that thermal expansion of the adhesive exerts additional clamping pressure during startup and during high temperature operation. The additional clamping pressure reduces vibration and eliminates other causes of fan or motor failure.

A stator damper is disclosed. The stator damper has a body section and a damper finger. The body section rests against a stator assembly and a portion of each damper finger rests against a compressor casing. The stator damper is radially compressed between the stator assembly and the compressor casing. Thus, the stator damper exerts a radial force against the stator assembly. In this manner, relative motion of the stator assembly is damped.

A stabilizing arrangement for a rotating shaft including a shaft being arranged substantially vertically in a machine so as to rotate during machine operation, first pressure delivery system for delivering a fluid pressure, in particular of a fluid circulating inside the machine, at a first location of the machine. First location is close to the shaft and part of first pressure delivery system is arranged at first location so as to exert a lateral pulling or pushing action on the shaft.

Turbomachines such as air dynamometers are disclosed that include a radial outflow compressor and gas collector. In some examples, the gas collector is designed as a separate component that is coupled to the machine, such as coupled to a frame. In some examples, the collector and frame are intentionally spaced and coupled at discrete points to minimize the transfer of mechanical and thermal energy therebetween. Aspects of the present disclosure also include turbomachines that include at least one impeller bypass flow path for the direct transfer of air between ambient and a location in the collector downstream of the impeller blades. In some examples, such flowpath(s) may allow for the inflow of external ambient air into the collector.

A fan device includes a frame, a stability maintenance assembly, a shaft, an impeller, and a driving assembly. The frame includes a base and a bearing seat protruding from the base and having an accommodation space. The stability maintenance assembly is disposed in the accommodation space and includes a bearing and a magnet arranged coaxially. The bearing is located above the magnet and magnetized by the magnet. The shaft is disposed through the magnet and the bearing. The impeller is fixed to the shaft so as to be rotatable relative to the frame via the shaft and the bearing. The driving assembly includes a stator and a rotor. The stator is sleeved on the bearing seat of the frame, the rotor is mounted on the impeller and surrounds the stator, and the driving assembly is configured to drive the impeller to rotate relative to the frame.