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.

Compact smoke or air diluter for high-temperature flue gas and contaminated air for being mounted at the top of or integrated in a chimney stack or a ventilation system that dilutes and dissipates high-temperature flue gas or contaminated air in the atmosphere, and ensures a normative draw/sub-atmospheric pressure defined on the basis of preceding requirements to or from connected functional applications consisting of cooling unit/ventilator part: Cooling pipe 9 mounted inserted in cooling top 12. Motor 1 mounted in interior cooling cup 4. The motor shaft is caused to continue out through a circular opening at the bottom of interior cooling cup 4 in a dimension that allows cooling air to pass below the motor 1, past the motor shaft, and out through the opening to exterior cooling cup 5. Between the bottom of interior cooling cup 4 and exterior cooling cup 5, there is, on the motor shaft, securely mounted a cooling medium 8. Through a hole at the bottom of exterior cooling cup 5, the motor shaft is caused to continue, where, at the end, there is mounted a ventilator medium holder 11, on which the ventilator medium 3 is mounted.

An electric blower includes an air blowing unit including a mixed-flow fan to generate a current of air, a motor to rotate the mixed-flow fan, and a housing including a first portion surrounding the mixed-flow fan in a circumferential direction, and a second portion surrounding the motor in the circumferential direction. The inner diameter of the second portion is smaller than the inner diameter of the first portion.

A blower includes a housing, and an impeller and a motor received in the housing. The motor drives the impeller to rotate. The motor includes a stator and a rotor. The stator includes a stator core and windings wound around the stator core. The stator core includes a yoke and teeth extending from the yoke. A distal end of each of the teeth forms a tooth tip, with a slot opening formed between each two adjacent tooth tips. The rotor includes a permanent magnet forming a plurality of magnetic poles. The stator and the rotor define an air gap therebetween. A circumferential width of the slot opening is equal to or less than two times of a radial width of the air gap.

An electric blower includes a centrifugal impeller, a diffuser including stationary vanes on a discharge side of the centrifugal impeller, a motor configured to drive the centrifugal impeller, a fan case configured to cover the centrifugal impeller and the diffuser, a housing case joined to the fan case, and return guide vanes that guide air which has been guided by the stationary vanes to an inner surface of the fan case radially inward through a space under the diffuser. The housing case includes an annular lower plate portion located axially below the diffuser. Each return guide vane is continuous with an upper surface of the annular lower plate portion. An upper end of each return guide vane is located axially opposite to the diffuser.

An apparatus for cooling is disclosed. One apparatus includes a motor body and a shaft extending through the motor body and configured to rotate in response to operation of the motor body. The shaft includes a first through-hole extending axially between a first end of the shaft and a second end of the shaft. The first through-hole is configured to receive a fluid to cool the motor body.

A fan is described, with the aid of which a volume flow and/or a mass flow of a medium moved by the fan (1) can be determined. This fan comprises an electric motor (2) and an impeller (3) driven by the electric motor (2), wherein the impeller (3) moves a gaseous medium in a media flow from an inflow side (5) to an outflow side (7). The fan additionally comprises a pressure sensor system, a speed ascertainment system, and an evaluation unit. The pressure sensor system is designed to ascertain an actual pressure difference (Δp*) between a first region (10) and a second region (13), wherein the first region (10) and/or the second region (13) is/are formed in the electric motor (2), wherein a pressure (p.sub.A) prevails in the first region (10), which corresponds to a pressure (p.sub.1) present on the inflow side, wherein a pressure (p.sub.B) prevails in the second region (13), which corresponds to a pressure (p.sub.2) present on the outflow side. The speed ascertainment system is designed to ascertain an actual speed (n) of the impeller (3). The evaluation unit is finally designed to quantitatively determine a mass flow and/or a volume flow of the medium based on the actual pressure difference (Δp*), the actual speed (n), and a pressure characteristic curve of the fan (1).

Furthermore, an electric motor for this fan and a corresponding method are disclosed.

A motor assembly having a rotational axis includes a motor housing comprising a plurality of cooling openings extending therethrough and defining a chamber. The motor assembly also includes a stator fixedly coupled to the motor housing and positioned within the chamber. A rotor is coupled to at least one of the motor housing and the stator, wherein the rotor is configured to rotate about the axis and is positioned within the chamber. The motor assembly includes a fan having a first inlet side on a first axial side of the fan and a second inlet side on a second, opposing, axial side of the fan. The fan is configured to draw cooling air in a first direction through the at least one cooling opening into the first inlet side, and the fan is also configured to draw cooling air in a second, opposite direction into the second inlet side.

A medical, in particular dental-medical, fan for extracting or compressing a gaseous working fluid, in particular air, comprises a compressor unit with an outer housing, which comprises an inlet opening for the working fluid and an outlet opening for the working fluid, which are fluidically connected to one another, and which defines a compressor sector and a drive sector.

A blower unit can include an outer housing, an inlet subassembly, a fan subassembly, an outlet subassembly, and a grommet. The outer housing can have an aperture extend along a first axis between first and second ends. The inlet subassembly can be received in the first end of the aperture. The fan subassembly can be received in the aperture adjacent to the inlet subassembly and include at least one wire. The outlet subassembly can be received in the second end. The grommet can be positioned between at least part of the second end and the outlet subassembly. The at least one wire can extend through the grommet. The grommet can seal against the at least one wire. The grommet can seal between the outer housing and the outlet subassembly.