Abstract: 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.

Abstract: A fan motor includes a motor including a stationary portion and a rotating portion arranged to rotate about a rotation axis extending in a vertical direction; an impeller including a plurality of blades, and arranged to rotate together with the rotating portion; a housing arranged to house the motor and the impeller therein; and a plurality of lead wires each of which is connected to the motor and is arranged to extend radially outward.

Abstract: A floor pump includes a main body and a supporting device. The supporting device includes a base and a first leg. The base is fixed to the main body and has a first stopping flange and a second stopping flange. The first leg is pivotally connected to the base to approach or move away from the base. The first leg has a front end and a rear end. When the first leg is approached to the base, the first leg is limited by the first and second stopping flanges to a folded position or an unfolded position. When the first leg is in the folded position, the front end is approached to the main body. When the first leg is in the unfolded position, the front end is distal away from the main body.

Abstract: The present disclosure provides an inflation product with a built-in air pump, including an air pump (1), a connection piece (2) and an inflation product (15). The inflation product (15) includes a through hole (151) penetrating from inside to outside, the connection piece (2) is fixed at an opening of the through hole (151), the air pump (1) and the connection piece (2) are detachably connected, and the through hole (151) is provided for the air pump (1) to protrude into with a front end of the air pump (1) exposed outside the through hole (151). The front end of the air pump (1) includes an air inlet (3) in which a normally-closed switch is mounted, and an air inlet sealing cover (5) for driving the normally-closed switch (4) to be pressed down is covered on the air inlet (3).

Abstract: A pump device, in particular submersible pump device, has at least one bearing receptacle which is configured for receiving a drive shaft end bearing, wherein the bearing receptacle has at least one cooling channel for receiving at least one cooling fluid.

Abstract: Described herein is a work tool (100) comprising: a motor (125) provided with a drive shaft (130), a casing (195) containing the motor (125) and provided with at least one inlet opening (235) and with at least one outlet opening (240), an implement (135) positioned outside the casing (195) and kinematically connected with the drive shaft (130), and a fan (245) kinematically connected to the drive shaft (130) and able to generate a flow of air from the inlet opening (235) towards the outlet opening (240) of the casing (195) passing in heat exchange relationship with the motor (125), wherein said fan (245) is contained inside the casing (195) in a space located between the motor (125) and the implement (135).

Abstract: An inner peripheral surface of an upper plate of a first case has a first inclined surface that faces an outer peripheral surface of a seal holding member of a motor in a radial direction of a rotary shaft. An inner peripheral surface of a seal fixing member has a second inclined surface that also faces the outer peripheral surface of the seal holding member in the radial direction. The outer peripheral surface has third and fourth inclined surfaces along an axial direction of the rotary shaft. An outside diameter on sides of the third and fourth inclined surfaces that are far from each other is greater than an outside diameter on sides of the third and fourth inclined surfaces that are near each other. A sealing member is installed in an annular space that is surrounded by the first, second, third, and fourth inclined surfaces.

Abstract: A permanent magnet alternator is adapted to be connected to an engine and has a stator, a driven plate, and a rotor. The stator is mounted on the engine. The driven plate is connected to an output shaft in front of the engine and covers the stator. Multiple ventilation holes are formed through the driven plate such that air can remove heat from the stator via the ventilation holes. The rotor is fixed in the rotor recess and has a magnet-mounting ring and multiple magnets. The magnets are mounted on the magnet-mounting ring. An annular radial gap is formed between the magnetic mounting ring and a wall of the rotor recess. The magnet-mounting ring is fixed to the driven plate using ring fasteners such that radial position of the magnet-mounting ring can be adjusted. Therefore, the alternator vibrates less, has better heat dissipation and reduces weight.

Abstract: A modular adaptive performance fan may be provided for use in ventilation and cooling application. The modular adaptive performance fan may include an outer shroud, an inlet shroud, an inner hub, an impeller, a plurality of stator vane inserts, a diffuser cone, and a drive system. The modular adaptive performance fan may be configured to provide different performance and noise values desirable for different applications. Different characteristic performance curves with different BEP may be obtained by changing the geometry of the fan through the use of modular components.

Abstract: A pump assembly and components therefor including an impeller which has flow inducer elements on an inner surface of a front shroud thereof, a flow directing device or strainer having passageways for delivering material to the impeller and at least one flow circulating passageway and a pump casing having an intake section with flow distribution vanes in the region of a feed opening adjacent the intake section.

Abstract: A blower assembly for an airflow medium, such as in a heating, ventilation, and air conditioning (HVAC) system. The blower assembly has a case defining an airflow inlet and an airflow outlet. An airflow generator is mounted within the case. Rotation of the airflow generator draws airflow into the case through the airflow inlet, directs airflow through the case, and pushes airflow out of the case through the airflow outlet. The motor is entirely within the case and is mounted on an upstream side of the airflow generator with respect to direction of airflow produced by the airflow generator through the case.

Abstract: A housing (17) of a fan (1) has an inflow-side end surface (2), an outflow-side end surface (16), and a wall ring (15). The wall ring 15 extends in a direction of an axis (12) from one of the end surfaces (2) to the other (16) and adjoins a fan passage. A fan wheel (10) is arranged in the fan passage. A grid (3) is arranged on the inflow-side end surface (2). The grid has a hub (8) positioned centrally in the fan passage. Primary struts (4) extend in the radial direction between the hub (8) and the edge of the fan passage. Secondary struts (6) intersect the primary struts (4).

Abstract: A centrifugal blower assembly includes a scroll wall, a pair of opposing sidewalls, and an adjustable cutoff plate. The scroll wall is positioned between the pair of opposing sidewalls such that the scroll wall and opposing sidewalls together define a blower chamber and a blower outlet. The scroll wall extends circumferentially between a cutoff point to an end point and defines a cutout extending circumferentially from the cutoff point. The scroll wall, the pair of opposing sidewalls, and the cutoff point define a blower outlet. The blower outlet defines a blower outlet area. The adjustable cutoff plate is adjustably positioned within the cutout to define a notch defining a notch area. The notch area and the blower outlet area define a total blower outlet area.

Abstract: A fan includes: a housing; and an impeller with an axis and a plurality of blades, the impeller mounted inside the housing; and a plurality of outlets from the housing, each outlet including a cutoff with a top and a bottom. A line between the top and bottom of each cutoff is not parallel to the axis of the impeller.

Abstract: An electrical connector for connecting a motor and a cable connector, includes an electrically insulating main body and a plurality of electrical terminals. The main body includes a front side and a rear side configured to be engaged with a corresponding cable connector. The front side of the main body includes a mounting portion, which is configured to be stably mounted on the seat, so that the electrical terminals can be placed in a stable connection with corresponding motor terminals.

Abstract: Diagonal fan having a fan housing, within which an external-rotor motor and an impeller are accommodated, wherein the external-rotor motor has a stator and a rotor which at least partly surrounds the stator, and an axial flow duct runs between the fan housing and the external-rotor motor as far as a discharge opening, surrounding the external-rotor motor, of the diagonal fan, through which duct, during operation, air which is drawn in by means of the impeller can be conveyed to the discharge opening, and wherein the impeller is integrated in the rotor.

Abstract: A fan motor includes a motor including a stationary portion and a rotating portion arranged to rotate about a rotation axis extending in a vertical direction; an impeller including a plurality of blades, and arranged to rotate together with the rotating portion; a housing arranged to house the motor and the impeller therein; and a plurality of lead wires each of which is connected to the motor and is arranged to extend radially outward.

Abstract: A blower apparatus includes a propeller fan configured to rotate about a rotational axis, and a bell mouth annularly disposed to surround the propeller fan as seen in a direction of the rotational axis of the propeller fan. The bell mouth includes a flare portion located downstream of the propeller fan The flare portion has at least one first part and at least one second part. The first part has a first inner circumferential surface region. The second part as a second inner circumferential surface region. A first length of the first part inner circumferential surface region in the direction of the rotational axis is greater than a second length of the second part inner circumferential surface region in the direction of the rotational axis.

Abstract: A binary cycle power generation system includes a working fluid circulation line, an evaporator, an expander, an energy recovery apparatus, a condenser, and a pump. The pump includes a casing, a rotary shaft, and impellers. The casing is hollow and has an end wall at an end in a longitudinal direction. The rotary shaft has an axis extending in the longitudinal direction of the casing, is supported on the end wall, has at least a part that is in the casing, and rotates owing to a torque. The impellers are attached to the rotary shaft one after another in the longitudinal direction. The pump is arranged in such a way that the axis of the rotary shaft intersects a vertical direction.

Abstract: A housing assembly is adapted for housing fully pre-wired printed circuit boards populated with diverse electrical components. The housing assembly includes multiple nipples and an optimized geometry for mounting to or mounting within commonly available conduit-related fixtures in a variety of installation configurations. These installation configurations allow for simpler wire routing where voltage separation is required, for greater accessibility to gang junction box cover plates on gang junction boxes to which the housing assembly is mounted, and for more installation options for wide range of common gang junction boxes as compared to existing housings.

Abstract: A centrifugal pump, of the submersed or submersible type, includes a hydraulic part, with a hollow body inside which there is at least one impeller, a motor enclosed within a motor casing that isolates the motor from the pumping liquid, adapted to drive the impeller in rotation via a rotation transmission shaft. The centrifugal pump further includes an open compartment that spaces the motor casing from the hollow body that contains the at least one impeller and hydraulic sealing elements between the open compartment and the motor casing.

Abstract: A centrifugal blower for an air conditioning system in a motor vehicle may include a centrifugal fan with an electric motor, which may drive a fan wheel in rotation. The centrifugal blower may also include a motor bracket for the electric motor, which may receive the centrifugal fan internally and may have a collar extending outward in a radial direction. An encircling water protection ring may be arranged internally on the collar, the water protection ring extending upward in an axial direction. The motor bracket may be configured as a hollow part with an interior annular water collection channel arranged beneath the collar, and may have a floor tilted radially outward. The at least one opening may be disposed at a transition from the collar to the water protection ring, by which water may drain into the water collection channel. The water collection channel may include at least one drain.

Abstract: A pumping system featuring a pump chamber configured with a central portion having a tangential outlet, and configured with a tubular coupling end portion having inwardly flexible rim portions on one side; and a mounting base, having a circular portion with an inner circumferential rim configured to receive and engage the inwardly flexible rim portions of the tubular coupling portion of the pump chamber so as to be rotationally coupled to the pumping chamber so that the pumping chamber may be rotated 360° in relation to the mounting base.

Abstract: Fan assemblies, and in particular fan wheels and stator assemblies for fan assemblies, are disclosed. In one embodiment, the fan wheel includes a wheel back having an outer surface forming one of a curved dome-shape and a truncated cone-shape. The fan wheel may also include a plurality of fan blades radially spaced about and mounted to the outer surface of the wheel back. In one embodiment, each of the fan blades is formed from a segment of an airfoil-shaped aluminum extrusion defining at least one internal cavity. The fan blade first ends can be provided with a compound cut profile with at least one curved cut such that the first end of the blade is mounted flush to the wheel back outer surface. The stator assembly can also be provided with a plurality of stator blades formed from airfoil-shaped aluminum extrusion segments and provided with compound cut profiles.

Abstract: Methods and systems are provided for diagnosing fuel vapor leaks due to un-latching of quick connectors in interfaces of a fuel vapor system. In one example, a method may include using positive pressure generated in the intake manifold by reverse rotation of the engine unfueled, to detect un-latching of quick connectors in the fuel vapor system. After the positive pressure test, a negative pressure test is performed on the fuel vapor system to confirm any un-latching of quick connectors.

Abstract: A mounting system for an industrial compression system including a first component close-coupled to a second component includes a first support for the first component. The first support is configured to resist movement of the first component in a first direction substantially horizontal relative to the first component, a second direction substantially vertical relative to the first component, and an axial direction relative to the first component. The mounting system also includes a second support for the second component. The second support is configured to resist movement of the second component in a first direction substantially horizontal relative to the second component and a second direction substantially vertical relative to the second component, wherein the second support permits movement of the second component in an axial direction relative to the second component.

Abstract: A water pump includes: a lower casing; a shaft fixed to the center of the lower casing; a stator disposed in the lower casing; an outer rotor that is arranged at a predetermined gap to the outer circumferential surface of the stator and is rotatably supported on the fixed shaft; an upper casing that is sealably mounted on an upper side of the lower casing in which an inlet and an outlet are formed; an impeller that is disposed in the upper casing and that is rotatably supported on the fixed shaft; and a power transmission unit that is installed between the impeller and the rotor and transmits the rotational force of the rotor to the impeller by a magnetic force, to prevent water from being introduced into the lower casing, and to allow the fixed shaft to rotatably support the rotor, as well as to rotatably support the impeller.

Abstract: An air compressor includes a compression unit, a drive unit, a tank unit, and a control circuit unit. The compression unit is configured to generate a compressed air and provided with a handle positioned above a center of gravity of the air compressor. The drive unit is configured to drive the compression unit. The tank unit is disposed below the compression unit and includes a plurality of air tanks configured to reserve the compressed air. The compressed air reserved in the tank unit has a pressure value. The control circuit unit is configured to detect the pressure value of the compressed air reserved in the tank unit and to control the drive unit to drive the compression unit.

Abstract: A micropump structure including a main body, at least one water room partitioning board, at least one fan propeller and at least one drive unit. The main body has at least one water room, an inlet and an outlet. The inlet and the outlet are disposed on a circumference of the main body in communication with the water room. The water room partitioning board is disposed in the water room to divide the water room into at least one water incoming section and at least one water discharging section. The fan propeller is disposed in the water room. The drive unit is disposed in the main body. The water room partitioning board enhances the flow guiding efficiency of the micropump and reduces the axial height of the micropump so that the working efficiency is promoted and less room is occupied.

Abstract: An axial fan and a fan rotor are provided as well as a method of manufacturing same, wherein the rotor hub includes an outer shell having on its outside a hub surface which is essentially rotational-symmetrical about the center axis of the rotor hub; and wherein the rotor hub has a front end and a rear end and a diverging section there between, where the radius of the hub surface in the diverging section is increased by the distance to the front end on the hub; and wherein the rotor hub and the blades are made as separate metal parts; and wherein the rotor blades are securely mounted to the diverging section on the hub surface.

Abstract: This electric fan has a rotation shaft that is provided rotatably with respect to a stator, a rotor yoke provided on the rotation shaft and formed in a bottomed cylindrical shape so as to cover the stator from a front surface, and a bracket that fixes the stator to a fan shroud and is formed so as to cover a rear surface of the stator, with a fan body provided so as to integrally rotate with the rotation shaft and the rotor yoke. The fan body has a fan boss formed in a bottomed cylindrical shape so as to cover the rotor yoke from a front surface, and a plurality of blades that is provided protruding radially from an outer circumferential surface of the fan boss. A first labyrinth portion is provided between an opening portion of the fan boss and the fan shroud.

Abstract: An axial flow fan includes a first lead wire engaging portion configured to be engaged with a plurality of lead wires such that the lead wires are pulled out therefrom into an outer space defined between a first flange and a second flange of a fan housing, a second lead wire engaging portion configured to be engaged with the plurality of lead wires such that the lead wires are pulled out toward the other side in the axial direction where the second flange is positioned, and a third lead wire engaging portion configured to be engaged with the plurality of lead wires such that the lead wires are pulled out in the axial direction toward one side where the first flange is positioned. The third lead wire engaging portion is formed in the first flange at a given distance from the first lead wire engaging portion.

Abstract: A cooling fan structure includes a hub, a rotary shaft, a fan seat, and a stator assembly. The fan seat is provided on around a front end corresponding to a rear end of the hub with a forward protruded annular rim portion and a sunken annular groove portion adjoining an inner lower side of the rim portion. The protruded annular rim portion reduces a gap between the hub and the fan seat to reduce the amount of air flowing into the hub via the gap and accordingly prevents external foreign matters from invading the hub via the same gap to adversely damage components inside the hub or cause a stuck hub; and the groove portion provides an additional space for receiving invaded and accumulated foreign matters to thereby reduce the possibility of a stuck hub. With these arrangements, the cooling fan can have prolonged service life.

Abstract: A compressor and an air conditioner having the compressor, and a protective cover of a connecting terminal of the compressor is installed while spaced apart from a barrier of the connecting terminal. The protective cover is additionally provided with a noise preventing member. Vibration generated from the compressor is delivered to the protective cover via the barrier, but as the protective cover is provided to be spaced apart from the barrier, the vibration is delivered to the barrier through the noise preventing member. Thus, regardless of the state of vibration of the compressor, noise being generated by the protective cover is minimized.

Abstract: A ventilation system includes a blower wheel (1) and a drive motor (9) with an external rotor (9b). The blower wheel (1) includes a central part (3) having a cylindrical wall (11) and defines a housing (13) to house the external rotor (9b). The blower wheel (1) further includes a frontal wall (15) comprising an opening (17) so as to exhibit a degree of openness that is greater than a predefined degree of openness.

Abstract: A fan (1) consisting of an electric external rotor motor (2) and of a fan wheel (4), the external rotor motor (2) consisting of a stator (6) encapsulated with an insulating material (14), and a rotor (8) carrying the fan wheel (4) enclosing the stator (6) in a pot-shaped manner. The rotor (8) having ventilation openings in a front wall (18). The stator (6) having projecting fins (24) on a front area (22) arranged and distributed over the circumference which is opposite the ventilation openings (20). A gap (34) between a circumferential rim (36) of the rotor (18) opposite the front wall (18) and a stator carrier (38) forms a passage for a cooling air current flowing around the stator (6) during operation. During operation, the cooling air is swirled intensively between the ventilation openings (20) and the projecting fins (24) for cooling the motor.

Abstract: A shroud comprises a frame having a main opening delimited by a main wall and at least one secondary opening delimited by a secondary opening, for the passage of a cooling air flow; a ventilator mounting system associated with the frame to support the ventilator at the main opening; a panel for closing the secondary opening, connected to the frame and movable, by rotation, between a lowered position and a raised position; the shroud comprises a pin, defining the axis of rotation of the panel, extending through the secondary opening and having a first and a second end respectively connected to a first and a second section of the secondary wall, opposite each other, a pair of hooks being provided in the panel for connection to the pin.

Abstract: An electric compressor includes an inverter cover. The inverter cover has a metal plate that is arranged to cover an inverter (a circuit board). The metal plate has bolt insertion holes, through which metal bolts for fixing the inverter cover to a suction housing are passed. The head of each bolt contacts a flange portion, which is the periphery of the corresponding bolt insertion hole. The inverter cover is formed of plastic by being molded in a mold, using the metal plate as a core.

Abstract: A latching device for a pump housing for production of a releasable latched connection between two housing parts has, on a first housing part, an elongate latching hook comprising a latching protrusion on the upper side and introduction chamfers on the upper side and on the underside. A latching opening is provided in the second housing part and comprises a latching tongue defining the latching opening outwardly, the latching protrusion abutting this latching tongue. An introduction web is arranged on the underside of the latching opening and comprises an introduction chamfer for the latching hook. Two securing tongues engage laterally in the latching opening and protrude via a free tongue end into the path of the latching hook when said latching hook is inserted into the latching opening. They prevent an undesired automatic release of the latched connection caused by movement of the latching hook in a downwards direction.

Abstract: A device for blowing air by a nozzle assembly includes a base seat for generating an air stream to supply air flow and a nozzle assembly supported by the base seat and comprising a slot-shaped opening for blowing air. An airflow passage is connected between the base seat and the nozzle assembly. An intake end of the airflow passage is opened on the outer surface of the base seat, and an output end is connected to the nozzle assembly by a pivot component. An intake end of the nozzle assembly is connected to an output end of the base seat by the pivot component. An impeller and an electric motor for driving the impeller to rotate are provided within the base seat. The nozzle assembly is rotatably fixed on the base seat by the pivot component.

Abstract: A pressure monitoring system allows for more accurate and reliable measurement of the pressure inside of a tube in a pump. The pressure monitoring system prevents movement of the tubing or a change in size of the tubing due to external forces applied to the pump, eliminating inaccuracies due to handling of the pump during use.

Abstract: Systems and methods for maintaining a desired differential pressure between a cooling oil of an electric motor and a process gas working fluid of a compressor connected axially to the electric motor. The cooling oil acts as a coolant for the motor compartment of the electric motor and the gas working fluid acts as a coolant for the rotor compartment of the electric motor. At least one bellow is configured to provide two sealed compartments in a pressure equalizer and a spring means is configured to add a differential pressure to the cooling oil, assuring no leaks between the two fluids flows from the cooling oil to the process gas working fluid and no contact of the process gas working fluid with the electric motor stator, in particular electric motor laminations and electric motor windings.

Abstract: A magnetic-drive coupling pump configuration including an attachment/detachment mechanism allowing simple and reliable positioning and fixation is provided. Thrust-direction positioning and radial-direction positioning are achieved, respectively, by surface contact of a convex portion of a pump unit (10) inserted up to a predetermined position in a concave portion (31) of a drive motor unit (30), and contact between an outer circumferential surface of the convex portion (11) and an inner circumferential surface of the concave portion (31).

Abstract: A housing of a fan motor according to the invention includes: board members provided at an interval in a rotational axis direction of a fan; a coupling portion which couples the board members to each other; a protrusion portion which is protruded toward a space other than an air course from the coupling portion, the space being between the board members other than the air courses; and a fixing portion which fixes a terminal that is provided in the protrusion portion and is connected to a wiring from a power source that supplies electricity to a motor. Other member, which crosses in an extending direction of the terminal from the protrusion portion to an edge portion of the board member, is not provided.

Abstract: A lead wire engaging structure includes a first engaging portion and a second engaging portion. One end of the first engaging portion and one end of the second engaging portion are integrally provided at a first mounting portion integrally provided at a second casing wall portion. The first engaging portion forms a first gap between the first engaging portion and the second casing wall portion, and engages four lead wires in cooperation with the second casing wall portion. The first gap allows the four lead wires to pass therethrough. The second engaging portion forms a second gap between the second engaging portion and the first engaging portion. The second gap allows the four lead wires to pass therethrough. The other end portion of the first engaging portion and the other end portion of the second engaging portion are coupled to each other by a coupling portion.

Abstract: Embodiments of the invention provide an impeller for an electric blower including an upper plate integrated with a blade portion which is provided with a coupling protrusion, and a lower plate provided with a coupling hole corresponding to the coupling protrusion of the blade portion. The upper plate integrated with the blade and the lower plate are made of a thermoplastic resin, and the coupling protrusion of the blade portion is inserted into the coupling hole of the lower plate and is fused and fixed.

Abstract: The invention relates to a system and method of providing a compressor mechanism having a front housing, center housing and rear housing. The center housing includes an integrated compressor bearing support and compressor base surface that divides the housing into cantilevered wall sections. The system and method constructed in this manner provides a compact structure for an electric compressor with the ability to reduce noise vibration harshness.

Abstract: A bearing bracket including a metal base and a bushing is provided. The metal base has an opening at its central portion. The bushing of the bearing bracket is made of plastic. The bushing encloses an axial portion or/and a radial portion of the metal base by injection molding. Furthermore, the bearing bracket further includes an anti-vibration member disposed on at least one side surface of the metal base.

Abstract: A sealed compressor includes a centrifugal impeller above a rotor to synchronously rotate. A refrigerant rises through a rotor air hole, flows in an upper space, and flows out from a discharge pipe. The centrifugal impeller includes an oil separation plate on the rotor, and plural vanes standing on the oil separation plate, and forms inter-vane flow passages between adjacent vanes, and a vane inner flow passage that guides refrigerant from the rotor air hole to inner entrances of the inter-vane flow passages. Outer exits of the inter-vane flow passages are disposed along an entire circumference, and refrigerant increased in pressure while passing through the inter-vane flow passages flows out from the outer exits to the upper space. The oil separation plate closes a short-circuit passage through which the refrigerant directly flows from the vane inner flow passages to the discharge pipe without passing through the inter-vane flow passages.

Abstract: An air exchange fan, includes: a frame provided with an opening, a helicoid housing with an air suction inlet disposed in the frame, an air blower disposed in the helicoid housing, and, a circuit board box mounted at the air suction inlet side, wherein a silencing plate is mounted above the outer peripheral of the air suction inlet, the silencing plate has a streamlining structure formed by outwardly expanding from the air suction inlet in an axial direction of a rotation axis of the air blower, the rotation axis of which serving as the center, within a range that is from a tongue of the helicoid housing to a location with a 90 degrees angled from the tongue in a direction opposing to the rotation direction of the air blower, and the silencing plate has a curved chamfered shape which mates with the peripheral shape of the air suction inlet.