An in-refrigerator blower configured to drive cold air to refrigerator storage rooms with reduced vibration and reduced noise. The in-refrigerator blower includes a drive device, a drive device accommodation portion, and a support portion coupled to the drive device accommodation portion and configured to extend in a radial direction. A plurality of blades extend in a direction different from an extension direction of the support portion. Each of the blades has an entrance angle in the range of 39°-49°, an exit angle in the range of 29.5° to 34.5° in one example. The number of the blades is greater than seven and smaller than nine.

An axial machining tool includes a cutter holder, a collet, a dust blower nut, and a cutter. The cutter holder has a receiving groove. The collet is extended into the receiving groove and has a containing space. The dust blower nut is sleeved on the collet and has a body, at least one blade, and a positioning element. The body has a threaded hole, a connecting groove, and at least one engaging groove. The threaded hole and the connecting groove are formed in the body and communicate with each other. The at least one engaging groove is formed on the body. The at least one blade is detachably mounted in the at least one engaging groove. The positioning element is mounted to the body and positions the at least one blade on the body. The cutter is extended into the containing space. A dust blower nut is also provided.

A fan is suitable for an air-guiding system of an outboard motor including an internal combustion engine and a covering hood bounding an engine interior space. The engine drives the fan, which is connected to an upright shaft journal projecting beyond an upper side of a housing of the engine. The covering hood has air flow openings, and the fan influences the air flows in the covering hood interior space. A flywheel, fixedly attached to the upright shaft journal, carries a fan wheel of the fan. The fan wheel is set in place from above, and the flywheel carries the fan wheel for conjoint rotation. Airflows enter the interior space via an inlet opening and a first conducting device, and the airflows, under the action of the fan, act upon at least parts of surfaces of the internal combustion engine and the auxiliary units to cool the internal combustion engine.

A vacuum pump comprising a turbomolecular stage and a drag stage, the vacuum pump comprising a stator and a rotor. The rotor comprises a turbomolecular rotor and a drag rotor attached together. The turbomolecular rotor comprises a hub from which a plurality of blades extend, the hub comprising a mounting portion for mounting to a spindle of a motor and a hollow cylindrical portion, the hollow cylindrical portion extending from the mounting portion towards an outlet end of the turbomolecular stage. The drag rotor comprises a cylindrical skirt and an attachment part extending away from the cylindrical skirt, the attachment part extending within the hollow cylindrical portion of the hub of the turbomolecular rotor and being attached thereto at a point that is closer to the mounting portion than to the outlet end of the turbomolecular rotor.

A blower device includes a rotor rotatable about a central axis extending in a vertical direction, an impeller attached to the rotor, and an annular ring centered on the central axis. The rotor includes a rotor cylindrical portion that extends in the axial direction and a flange that extends radially outward from the rotor cylindrical portion. The impeller includes an annular impeller base centered on the central axis. The ring is connected to the impeller base in the axial direction. The flange is held between the impeller base and the ring in the axial direction.

An arrangement of an impeller (1) on an electrical motor, in particular on an external rotor motor (8), whereby the torque of the motor is transferred to the impeller (1) by means of a torsion-proof connection between the rotor (8) of the motor and the impeller (1) and/or its impeller hub (3), is characterised in that the connection of the impeller (1) to the motor (8) results from physical and/or chemical interactions between an adhesive medium (10) and the contact surfaces (5) of the impeller hub (3) and of the motor (8), which face each other, whereby the adhesive medium (10) fills, at least partially, an intermediate space (9) that is formed between the impeller (1) and the motor (8) by the given play.

A rotary working component for use in a pump, compressor, blower or the like having an impeller, rotor, fan blade or other similar component includes a metallic insert and a composite structure overmolded on the metallic insert. The metallic insert can include an aperture adapted to mount the rotary working component to a drive shaft and a fluted catenoid or truncated spherical or spheroid outer surface having smooth contours between fluted regions thereof.

An electric blower includes: an electric motor portion including a rotation shaft; a centrifugal impeller; and a heat dissipating portion connecting the centrifugal impeller and the rotation shaft. A boss portion of the centrifugal impeller is provided with a first hole extending in an extending direction of the rotation shaft. The heat dissipating portion includes a first portion connected to an inner circumferential surface of the first hole, and a second portion connected to the first portion in the extending direction and located outside the first hole. A length of the heat dissipating portion in the extending direction is longer than a length of the first hole in the extending direction.

An electric blower (10) is disclosed as including a brushless motor (16), and an axial fan (18, 18C) driven by the motor, the motor being operable at a first speed of rotation of 15,000 revolutions per minute (rpm) and a second speed of rotation of 18,000 rpm, the axial fan including a hub (34C) and a plurality of fan blades (36C) engaged with the hub, the hub having a hub diameter (ϕ.sub.H), the axial fan having an outer diameter (ϕ.sub.T), and $\frac{{\varphi }_H}{{\varphi }_T}$
being between substantially 0.6 and substantially 0.65.

An arrangement of an impeller (3) on a rotating part, preferably on an electric motor (1), in particular on an external rotor motor, wherein the torque of the motor (1) is transmitted to the impeller (3) by a rotationally secure connection between the rotor (2) of the motor (1) and the impeller (3) or its impeller hub (4), and wherein the connection is created by means of a press fit between the impeller hub (4) and the rotor (2), with integration of a sleeve (6) which is preferably securely assigned to the impeller hub (4) and which takes up mechanical stresses, is characterized in that the sleeve (6) is polygonal and is pressed onto the surface of the rotor (2), with at least minor deformation, forming axial contact surfaces. Also specified is a method for producing such an arrangement.