The self-ventilated motor (10) comprises a casing (12) having an air inlet opening (18) and an air outlet opening (20) and delimiting an air passage between the air inlet opening (18) and the air outlet opening (20), drive means (13) comprising a shaft (22) housed in the casing (12), a ventilation propeller (24) connected to the shaft (22) upon rotation and housed in the air passage, and a noise reduction device (26). The noise reduction device (26) comprises a first noise reduction member (28), attached to the casing (12) at the air inlet opening (18), a second noise reduction member (30) arranged on the ventilation propeller (24), and a third noise reduction member (32) fixed to the casing (12) at the air outlet opening (20).

A blower device includes an impeller that is rotatable around a rotary shaft extending in an up-down direction; a motor that rotationally drives the impeller; a motor housing accommodating the motor; a cylindrical member disposed outwardly of the housing in a radial direction; and an impeller case accommodating the impeller. A gap is formed between the housing and the cylindrical member. Stationary blades are provided on one of the outer side surface of the housing and the inner side surface of the cylindrical member, and protrude towards the other side surface. At an outer portion of the housing in the radial direction, the blades are disposed side by side in a circumferential direction, and form air-current paths. At least one of the blades includes a protrusion that protrudes from a surface of the at least one of the blades facing the radial direction and contacts the other side surface.

A blower device includes the following elements. An impeller rotates around a central axis. A motor includes a stator and rotates the impeller positioned above the motor. A motor housing houses the stator. A fan casing forms a first flow passage. An upper side of the fan casing covers the impeller and has a suction inlet. A lower side of the fan casing has an evacuate outlet communicating with the suction inlet via the first flow passage. A flow inlet is provided in the motor housing farther downward than a top surface of the stator. The flow inlet communicates with the first flow passage. The motor housing has a second flow passage extending upward from the flow inlet and communicating with a space farther upward than the stator.

A fan device includes the following elements. An impeller rotates around a central axis. A motor rotates the impeller positioned above the motor. A motor housing houses the motor. A fan casing forms a flow passage. An upper side of the fan casing covers the impeller and has a suction inlet. A lower side of the fan casing has an evacuate outlet communicating with the suction inlet via the flow passage. The impeller includes a base unit enlarged downward and plural blades arranged on the base unit. An impeller projection is formed on a bottom surface of the base unit. A groove denting downward is formed on a top surface of the motor housing. At least part of the impeller projection is housed within the groove.

A fan device includes an impeller rotating around a central axis and a motor disposed farther downward than the impeller. The impeller includes a base unit enlarged downward and plural blades disposed on a peripheral surface of the base unit. Upper portions of the blades are positioned at a leading end of a rotating direction with respect to lower portions. In an outer end portion on a front surface of each blade at the leading end of the rotating direction, a radial-direction component of a normal unit vector of an upper end portion of the blade is smaller than that of a lower end portion, assuming that an outer peripheral side of the blade is a positive direction. A thickness of a root of the lower end portion is larger than that of the upper end portion.

A centrifugal compressor that reduces pressure loss of fluid blown out from an impeller to improve efficiency is provided. The centrifugal compressor includes: a rotary shaft 5 rotatably supported by a casing 2; an impeller 6 provided on the rotary shaft 5 for blowing out fluid sucked from a suction port 10 in a radial direction of the rotary shaft 5; a return channel 13 for reversing the fluid blown out from the impeller 6 toward an axis line L of the rotary shaft 5; and a discharge port 16 positioned on the axis line L of the rotary shaft 5 for discharging the fluid having passed through the return channel 13 in a direction along the axis line L.

A number of fan assemblies are shown. Configurations are shown that include one or more diffusers. Diffuser locations and specific diffuser configurations are described that improve one or more fan assembly characteristics, including, but not limited to fan efficiency.

A hand dryer for drying a user's hands by means of an airflow discharged through an air outlet on the hand dryer. The airflow is generated by a motor-driven fan unit. The fan unit is supported by resilient support member in contact with the fan unit, the support member having a vertex, which vertex makes said contact with the fan unit.

An air circulator includes a housing having a first inlet and a first outlet, an oblique-flow fan disposed in the housing, and a motor rotating the oblique-flow fan. An outer wall of the housing includes a first outer wall extending in a front-rear direction and a second outer wall having the first inlet and extending from an edge of the first inlet towards the first outer wall to be enlarged in a radially outward direction. An outer surface of the second outer wall comprises a first surface that extends towards the first outer wall to be rounded outwards, and forms a surface continuous with an outer surface of the first outer wall, thus guiding air flowing along an outside of the first inlet so that the air flows forwards along the outer surface of the first outer wall.

A motor assembly has a motor having a rotor and a stator. An impeller is connected to a rotary shaft of the rotor and a housing is disposed between the impeller and the motor and surrounding an upper side of the motor. A diffuser discharges air, which is suctioned by the impeller, along an outer surface of the housing. A heat dissipation cover covers an outer surface of the motor. The heat dissipation cover includes an inner cover spaced apart from the outer surface of the motor and forming an inside-cover flow channel that air flows through and an outer cover having a diameter greater than that of the inner cover and forming an outside-cover flow channel through which air flows along the outer surface thereof.