EP2275689A1 - Centrifugal fan - Google Patents

Centrifugal fan Download PDF

Info

Publication number
EP2275689A1
EP2275689A1 EP09746628A EP09746628A EP2275689A1 EP 2275689 A1 EP2275689 A1 EP 2275689A1 EP 09746628 A EP09746628 A EP 09746628A EP 09746628 A EP09746628 A EP 09746628A EP 2275689 A1 EP2275689 A1 EP 2275689A1
Authority
EP
European Patent Office
Prior art keywords
blade
main plate
air
centrifugal fan
trailing edge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP09746628A
Other languages
German (de)
English (en)
French (fr)
Inventor
Shingo Ohyama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Publication of EP2275689A1 publication Critical patent/EP2275689A1/en
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
    • F04D29/30—Vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/28—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps
    • F04D29/281—Rotors specially for elastic fluids for centrifugal or helico-centrifugal pumps for radial-flow or helico-centrifugal pumps for fans or blowers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/0007—Indoor units, e.g. fan coil units
    • F24F1/0018—Indoor units, e.g. fan coil units characterised by fans
    • F24F1/0022—Centrifugal or radial fans
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2210/00—Working fluids
    • F05D2210/10—Kind or type
    • F05D2210/12—Kind or type gaseous, i.e. compressible
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05D2240/301—Cross-sectional characteristics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/30—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor
    • F05D2240/303—Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor related to the leading edge of a rotor blade

Definitions

  • the present invention relates to a centrifugal fan, and more particularly, to the structure of impeller blades for a centrifugal fan.
  • centrifugal fans such as backwardly curved blade fans generate undesirable noise. Accordingly, reduction of noise in centrifugal fans has been sought.
  • various techniques have been developed for reducing air flow noise from centrifugal fans.
  • a typical design approach for reducing air flow noise is to increase the outer diameter of the impeller of a fan.
  • an increased diameter of the fan impeller reduces the number of rotations of the fan impeller. This reduces the flow velocity of the air flow discharged by the fan impeller.
  • the level of the air flow noise is proportional to the sixth power of the flow velocity.
  • the use of the airfoil blades does not necessarily eliminate the flow separation over the entire surfaces of the blades. That is, noise caused by trailing vortices at the trailing edges of the blades is not reduced.
  • the flow velocity of the discharged air flow varies along the span direction of each blade. That is, an uneven velocity distribution of air flow exists between the main plate and the side plate.
  • dimples or serrations are formed over the entire surface of each blade to reduce noise (for example, refer to Patent Document 2).
  • separation of air flow is further efficiently reduced, so that turbulence due to separation will be segmented. This further suppresses the development of trailing vortices. As a result, the noise caused by any trailing vortex is reduced.
  • this configuration can neither prevent an uneven velocity distribution of air flow on each blade between the main plate and the side plate along the span direction of the blade, nor suppress the generation of trailing vortices. Therefore, the noise caused by trailing vortices cannot be effectively prevented. Further, the configuration disadvantageously complicates the manufacturing process for surface machining and drawing of the blades.
  • the length of the blade is less than a blade having no cut out portion. This reduces the amount of work that each blade applies to an air flow.
  • This technique is effective in a centrifugal fan in which the blade width is sufficiently small in relation to the outer shape, as described in Patent Document 3. Specifically, cutting out of the blades prevent separation of drawn-in air flow in a part of each blade in the vicinity of the side plate, and the air flow is allowed to flow along the part.
  • the technique is not necessarily effective in a normal centrifugal fan, which has wide blades, that is, not in a case where the influence of separation near the side plate is not dominant.
  • the ratio of the outer diameter of the main plate of the impeller to the outer diameter of the side plate of the impeller is set to 1.2 to 1.6. Therefore, when the blades are enlarged with a small increase in the length, a noise reduction effect cannot be achieved. In contrast, when the length is excessively increased, the flow characteristics will be degraded.
  • the outer diameter of the main plate of the impeller is twenty percent greater than the outer diameter of the side plate.
  • an impeller having blades with three-dimensional shapes improves the load distribution on the blade surface and pressure fluctuations of air flow through between the blades.
  • a centrifugal fan employing blades having a three-dimensional shape and an air conditioner using the centrifugal fan will now be described with reference to Figs. 25 to 32 .
  • Fig. 25 illustrates an air conditioner 1 using a centrifugal fan having an impeller.
  • the air conditioner 1 is a ceiling embedded type, and includes a casing 2 accommodating various components, and a decorative panel 3 provided underneath the casing 2. More specifically, the casing 2 of the air conditioner 1 is fitted in an opening formed in a ceiling U of an air conditioned room, and the decorative panel 3 is arranged along the ceiling U.
  • the casing 2 is a box-like body having a lower opening. When viewed in the plan view, the casing 2 has an octagonal shape with short sides and long sides arranged alternately.
  • the casing 2 has a substantially octagonal top plate 21 with alternately arranged long sides and short sides, and a side wall plate 22 extending downward from the periphery of the top plate 21.
  • the decorative panel 3 is shaped as a rectangular plate in the plan view.
  • the panel 3 has an air inlet 31 and air outlets 32.
  • the air inlet 31 is substantially located at the center of the decorative panel 3 and draws air from the air conditioned room.
  • the air outlets 32 blows out air from the casing 2 into the air conditioned room.
  • the decorative panel 3 is arranged such that each of its sides corresponds to one of the long sides of the top plate 21 of the casing 2.
  • the air inlet 31 is a substantially square opening.
  • each air outlet 32 is an elongated rectangular opening along a side of the decorative panel 3.
  • the air inlet 31 includes an air intake grill 33 and a filter 34 for removing dust in the air drawn into the air inlet 31.
  • a horizontal flap 35 is provided at each air outlet 32.
  • the horizontal flap 35 can be swung about an axis extending along the longitudinal direction of the air outlet 32.
  • the horizontal flap 35 is a rectangular blade-like member extending along the longitudinal direction of the air outlet 32.
  • Each horizontal flap 35 is supported at both ends in the longitudinal direction with a support pins (not shown) so as to be rotatable. The horizontal flap 35 is thus capable of changing the direction of flow of air blown out of the air outlet 32.
  • An air blower 4 and a heat exchanger 6 are arranged in the casing 2.
  • the air blower 4 draws air into the casing 2 from the air conditioned room through the air inlet 31 of the decorative panel 3.
  • the heat exchanger 6 is arranged to surround the air blower 4.
  • the air blower 4 is a backwardly curved blade fan, which is a centrifugal fan to which the present invention is applied.
  • the air blower 4 includes a fan motor (impeller driving means) 41 and an impeller 42 coupled to the shaft (rotary shaft) of the fan motor 41.
  • the fan motor 41 is provided at the center of the top plate 21 of the casing 2 and is oriented downward.
  • the heat exchanger 6 is a cross-inner-tube type heat exchanger, which is formed by bending a tube to surround the air blower 4.
  • the heat exchanger 6 is connected to an outdoor unit (not shown) installed outside the house through refrigerant piping.
  • the heat exchanger 6 functions as an evaporator during the cooling operation, and as a condenser during the heating operation.
  • the heat exchanger 6 performs heat exchange with air that is drawn into the casing 2 by the air blower 4 through the air inlet 31, so as to cool the air during the cooling operation, and heat the air during the heating operation.
  • a drain pan 7 is provided below the heat exchanger 6.
  • the drain pan 7 receives drain water, which is produced when water in air is condensed on the surface of the heat exchanger 6.
  • the drain pan 7 is attached to the lower part of the casing 2.
  • the drain pan 7 has an air inlet portion 71 communicating with the air inlet 31 of the decorative panel 3, air outlet portions 72 corresponding to the air outlets 32 of the decorative panel 3, and a drain water receiving groove 73 that is formed to surround the lower part of the heat exchanger 6 to receive drain water.
  • a bellmouth 5 is provided at the air inlet portion 71 of the drain pan 7.
  • the bellmouth 5 guides air drawn in through the air inlet 31 of the decorative panel 3 to the impeller 42 of the air blower 4.
  • Fig. 26 is a perspective view showing the appearance of the impeller 42.
  • Fig. 27 is a side view of the impeller 42 shown in Fig. 3 .
  • the impeller 42 is mainly formed by a disk-shaped main plate 43, an annular side plate 45 separated from the main plate 43, and a plurality of blades 44 arranged between the main plate 43 and the side plate 45.
  • the main plate 43 is coupled to a shaft 41a of the fan motor 41.
  • the blades 44 are arranged along the main plate 43 at predetermined angular intervals about the shaft 41 a of the fan motor 41.
  • the main plate 43 is a synthetic resin member.
  • a substantially truncated cone shaped bulge 43a is formed at the center of the main plate 43.
  • the bulge 43a protrudes toward the air inlet 31.
  • a main plate cover 46 is fixed at a position spaced from the lower surface of the main plate 43.
  • the main plate cover 46 covers a cooling air hole.
  • Radially arranged guide blades 46a are provided on the side of the main plate cover 46 that faces the main plate 43. The guide blades 46a cause part of the air blown out of the impeller 42 to flow about the main plate 43 by means of the difference between the static pressure in the space between the main plate 43 and the casing 2 and the static pressure in the space between the main plate 43 and the side plate 45.
  • This part of the blown out air passes through the space about the fan motor 41 to cool the fan motor 41. Thereafter, the air is blown toward the space inside the impeller 42 through the cooling air hole of the main plate 43 and the guide blades 46a of the main plate cover 46.
  • the side plate 45 has a diameter that gradually decreases from the outer circumference toward the center opening.
  • the side plate 45 is a bell shaped resin member that protrudes toward the air inlet 31.
  • Fig. 28 is a perspective view of the blade 44 as seen from the left rear.
  • Fig. 29 is a projection view of the blade 44 of Fig. 28 , as viewed from above.
  • Fig. 30 is a side view of the blade 44 of Fig. 28 with section lines 31A-31A to 31E-31E.
  • Figs. 31 (a) to 31 (e) are cross-sectional views taken along lines 31A-31A to 31E-31E.
  • Fig. 32 is a schematic view illustrating an operation of the blade 44.
  • the blades 44 are resin members that are molded separately from the main plate 43 and the side plate 45. One end face of each blade 44 is fixed to the main plate 43, and another end face is fixed to the side plate 45. When viewed from the side of the impeller 42, the end of the blade 44 that faces the side plate 45 is inclined rearward than the end close to the main plate 43 as shown in Fig 28 .
  • the blade 44 is formed such that these ends cross each other to substantially form an X as shown in Fig. 29 . In other words, the blade 44 has a three-dimensional shape that extends parallel to the rotary shaft while being twisted between the main plate 43 and the side plate 45.
  • the edge at the leading side in the rotation direction of the blade 44 which is a three-dimensional blade, or a leading edge 44a extends from the end close to the main plate 43 to a predetermined position close to the side plate 45 with substantially a constant radius.
  • the blade 44 as an inclined edge from the predetermined position close to the side plate 45, while retreating outward with a gradually decreasing radius.
  • the edge of the blade 44 on the trailing side of the rotation direction R, or the trailing edge 44b has a shape formed by a straight line that extends parallel to the rotation from the position close to the main plate 43 and the position close to the side plate 45.
  • the trailing edge 44b of the blade 44 has a shape formed by connecting the ends between the main plate 43 and the side plate 45, noise is still generated by the influence of the trailing vortex.
  • the amount of air flow F 2 which flows along the curvature of the side plate 45 is small in the entire air flow drawn in from a part of the blade 44 in the vicinity of the side plate 45.
  • main flow F 1 which is drawn in from the center of the side plate 45, has a great amount.
  • the main flow F 1 flows in an area close to the main plate 43 in a concentrated manner because of its velocity vector. Therefore, the flow velocity distribution of the blown out air flow at the outlet of the blade 44 is not constant along the span direction of the blade 44. Also, it is not possible to reduce the trailing vortex generated at a position downstream of the trailing edge 44b of the blade 44. As a result, noise is still generated by the influence of the trailing vortex.
  • a centrifugal fan that includes a plurality of blades having a three-dimensional shape, a main plate, an annular side plate, and blade actuating means for rotating the blades via the main plate.
  • One end face of each blade in the span direction is fixed to the main plate, such that the blades are spaced at predetermined intervals along the circumferential direction.
  • the annular side plate is provided at the other end faces of the blades in the span direction.
  • the radial length of an outer end portion of each blade at a part close to the main plate is set longer than the radial length of an outer end portion of the blade at a part close to the side plate.
  • This configuration significantly improves the velocity distribution of a main flow portion in an air flow that flows in a concentrated manner at a part of the blade close to the main plate. Accordingly, the static pressure-flow rate characteristics of the fan are improved in the entire flow rate range, which increases the discharged air volume. Also, the specific noise characteristics of the air blower are significantly improved, so that the influence of a trailing vortex generated at the trailing edge of a part of each three-dimensional blade close to the main plate is relatively reduced. As a result, noise caused by trailing vortices is effectively reduced.
  • the radial length of the outer end portion of each blade close to the main plate be set longer than the radial length of the outer end portion of each blade close to the side plate, so that air flow flowing past each blade effectively receives work from the blade at a part of the blade close to the main plate, and that the velocity of the air flow along the span direction of each blade is effectively developed at a part of the blade close to the main plate.
  • This configuration significantly improves the velocity distribution of a main flow portion in air flow that flows in a concentrated manner at a part of the blade close to the main plate. Accordingly, the static pressure-flow rate characteristics of the fan are improved over the entire flow rate range, which increases the discharged air volume. Also, the specific noise characteristics of the air blower are significantly improved, so that the influence of a trailing vortex generated at the trailing edge of a part of each three-dimensional blade close to the main plate is relatively reduced. As a result, noise caused by trailing vortices is effectively reduced.
  • the radial length of the outer end portion of each blade close to the main plate be set longer than the radial length of the outer end portion of each blade close to the side plate by extending the trailing edge of the blade rearward with respect to the air flow.
  • Extending the trailing edge of the blade rearward with respect to the air flow significantly improves the velocity distribution in the main flow portion of air flow that flows in a concentrated manner at a part of the blade close to the main plate. Accordingly, the static pressure-flow rate characteristics of the fan are improved in the entire flow rate range, which increases the blown air volume. Also, the specific noise characteristics of the air blower are significantly improved, so that the influence of a trailing vortex generated at the trailing edge of a part of each three-dimensional blade close to the main plate is relatively reduced. As a result, noise caused by trailing vortices is effectively reduced.
  • the trailing edge be extended such that its length is gradually increased toward the main plate.
  • the trailing edge of each blade has a tapered shape that becomes wider from the side plate toward the main plate. Therefore, the shape of the trailing edge of each blade is a suitable shape that is adapted to changes in the velocity distribution of the main flow that flows in a concentrated manner at a part of the blade close to the main plate.
  • the substantially tapered shape, which becomes gradually wider from the side plate toward the main plate, may be a shape that changes linearly or a shape that changes in a curve.
  • the trailing edge be extended in a curved manner, and that the trailing edge have a bulge in a part close to the main plate such that there is at least one inflection point in the curved part.
  • the trailing edge is preferably extended rearward by a length that corresponds to the velocity distribution of the main flow of the air flow at the trailing edge.
  • the shape of the extended trailing edge is further suitable for changes in the velocity distribution of the main flow, so that the fan performance is further improved.
  • a step that is extended forward by a predetermined length be formed at a part of the leading edge of the blade close to the main plate.
  • the diameter of the main plate is preferably increased in accordance with the extension of the blades.
  • the centrifugal fan is preferably configured as an air blower of the indoor unit of an air conditioner.
  • the air blower of an air conditioner indoor unit is required to have a large air volume and to be silent because of its intended use. Therefore, a centrifugal fan according to the present invention is optimal as the air blower of an air conditioner indoor unit because of its small size, high air flow performance, and low noise.
  • the present invention provides a compact and quiet centrifugal fan that generates a large air volume and is therefore suitable as an air blower for an air conditioner indoor unit.
  • centrifugal fan according to one embodiment of the present invention and an air conditioner using the centrifugal fan will be described with reference to the drawings.
  • Fig. 1 is a perspective view showing the appearance of an air conditioner 1 using a centrifugal fan according to one embodiment of the present invention (ceiling part is omitted).
  • the air conditioner 1 is a ceiling embedded type, and includes a casing 2 accommodating various components, and a decorative panel 3 provided underneath the casing 2. More specifically, the casing 2 of the air conditioner 1 is fitted in an opening formed in a ceiling U of an air conditioned room as shown in Fig. 2 (a longitudinal cross-sectional view of the air conditioner 1), and a decorative panel 3 is arranged along the ceiling U.
  • the casing 2 is a box-like body having a lower opening. When viewed in the plan view, the casing 2 has an octagonal shape with short sides and long sides arranged alternately.
  • the casing 2 has a substantially octagonal top plate 21 with alternately arranged long sides and short sides, and a side wall plate 22 extending downward from the periphery of the top plate 21.
  • the decorative panel 3 is shaped as a rectangular plate in the plan view.
  • the panel 3 has an air inlet 31 and air outlets 32.
  • the air inlet 31 is substantially located at the center of the decorative panel 3 and draws air from the air conditioned room.
  • the air outlets 32 discharges air from the casing 2 into the air conditioned room.
  • the decorative panel 3 is arranged such that each of its sides corresponds to one of the long sides of the top plate 21 of the casing 2.
  • the air inlet 31 is a substantially square opening.
  • each air outlet 32 is an elongated rectangular opening along a side of the decorative panel 3.
  • the air inlet 31 includes an air intake grill 33 and a filter 34 for removing dust in the air drawn into the air inlet 31.
  • a horizontal flap 35 is provided at each air outlet 32.
  • the horizontal flap 35 can be swung about an axis extending along the longitudinal direction of the air outlet 32.
  • the horizontal flap 35 is a rectangular blade-like member extending along the longitudinal direction of the air outlet 32.
  • Each horizontal flap 35 is supported at both ends in the longitudinal direction with a support pins (not shown) so as to be rotatable. The horizontal flap 35 is thus capable of changing the direction of flow of air discharged from the air outlet 32.
  • An air blower 4 and a heat exchanger 6 are arranged in the casing 2.
  • the air blower 4 draws air into the casing 2 from the air conditioned room through the air inlet 31 of the decorative panel 3.
  • the heat exchanger 6 is arranged to surround the air blower 4.
  • the air blower 4 is a backwardly curved blade fan, which is a centrifugal fan to which the present invention is applied.
  • the air blower 4 includes a fan motor (impeller driving means) 41 and an impeller 42 coupled to the shaft (rotary shaft) of the fan motor 41.
  • the fan motor 41 is provided at the center of the top plate 21 of the casing 2 and is oriented downward. The detailed structure of the impeller 42 will be discussed below.
  • the heat exchanger 6 is a cross-inner-tube type heat exchanger, which is formed by bending a tube to surround the air blower 4.
  • the heat exchanger 6 is connected to an outdoor unit (not shown) installed outside the house through refrigerant piping.
  • the heat exchanger 6 functions as an evaporator during the cooling operation, and as a condenser during the heating operation.
  • the heat exchanger 6 performs heat exchange with air that is drawn into the casing 2 by the air blower 4 through the air inlet 31, so as to cool the air during the cooling operation, and heat the air during the heating operation.
  • a drain pan 7 is provided below the heat exchanger 6.
  • the drain pan 7 receives drain water, which is produced when water in air is condensed on the surface of the heat exchanger 6.
  • the drain pan 7 is attached to the lower part of the casing 2.
  • the drain pan 7 has an air inlet portion 71 communicating with the air inlet 31 of the decorative panel 3, air outlet portions 72 corresponding to the air outlets 32 of the decorative panel 3, and a drain water receiving groove 73 that is formed to surround the lower part of the heat exchanger 6 to receive drain water.
  • a bellmouth 5 is provided at the air inlet portion 71 of the drain pan 7.
  • the bellmouth 5 guides air drawn in through the air inlet 31 of the decorative panel 3 to the impeller 42 of the air blower 4.
  • the air conditioner 1 of the present embodiment has an air passage from the air inlet 31 of the decorative panel 3 to the four air outlets 32 via the filter 34, the bellmouth 5, the drain pan 7, the air blower 4, and the heat exchanger 6.
  • the air conditioner 1 draws in air in the air conditioned room and performs heat exchange between the drawn in air and the refrigerant at the heat exchanger 6. Thereafter, the air conditioner 1 discharges air, the temperature of which has been adjusted, to the four sides of the air conditioned room through the air passage.
  • Fig. 3 is a perspective view showing the appearance of the impeller 42.
  • Fig. 4 is a side view of the impeller 42 shown in Fig. 3 .
  • Fig. 5 is a diagram showing the impeller 42 installed as shown in Fig. 4 , as viewed from above.
  • the impeller 42 is mainly formed by a disk-shaped main plate 43, an annular side plate 45 separated from the main plate 43, and a plurality of blades 44 arranged between the main plate 43 and the side plate 45.
  • the main plate 43 is coupled to a shaft 41a of the fan motor 41.
  • the blades 44 are arranged along the main plate 43 at predetermined angular intervals about the shaft 41 a of the fan motor 41.
  • the rotation direction of the impeller 42 is shown by arrow R in Fig. 5 .
  • the main plate has an outer diameter Db'.
  • the main plate 43 is a synthetic resin member.
  • a substantially truncated cone shaped bulge 43a is formed at the center of the main plate 43.
  • the bulge 43a protrudes toward the air inlet 31.
  • a main plate cover 46 is fixed at a position spaced from the lower surface of the main plate 43.
  • the main plate cover 46 covers a cooling air hole.
  • Radially arranged guide blades 46a are provided on the side of the main plate cover 46 that faces the main plate 43.
  • the guide blades 46a cause part of the air blown out of the impeller 42 to flow about the main plate 43 by means of the difference between the static pressure in the space between the main plate 43 and the casing 2 and the static pressure in the space between the main plate 43 and the side plate 45. This part of the discharged air passes through the space about the fan motor 41 to cool the fan motor 41. Thereafter, the air is blown to the space inside the impeller 42 through the cooling air hole of the main plate 43 and
  • the side plate has an outer diameter Da.
  • the side plate 45 has a shaper that gradually decreases from the outer circumference toward the center opening.
  • the side plate 45 is a bell shaped resin member that protrudes toward the air inlet 31.
  • Fig. 6 is a side view of the blade 44 as seen from the direction of the negative pressure surface.
  • Fig. 7 is a projection view of the blade 44 of Fig. 6 , as viewed from above.
  • Fig. 8 is a perspective view of the blade 44 of Fig. 6 , as viewed from above and the left rear.
  • Fig. 9 is a side view of the blade 44 of Fig. 6 , with section lines 10A-10A to 10E-10E from a lower part to an upper part (from the end close to the main plate 43 to the end close to the side plate 45).
  • Figs. 6 is a side view of the blade 44 as seen from the direction of the negative pressure surface.
  • Fig. 7 is a projection view of the blade 44 of Fig. 6 , as viewed from above.
  • Fig. 8 is a perspective view of the blade 44 of Fig. 6 , as viewed from above and the left rear.
  • Fig. 9 is a side view of the blade 44 of Fig. 6
  • FIG. 10(a) to 10(e) are cross-sectional views taken along lines 10A-10A to 10E-10E of Fig 9 , respectively.
  • Fig. 11 is a cross-sectional view showing a characteristic of the blade 44 (difference from the prior art shape shown in Figs. 25 to 32 ).
  • Fig. 11 is a comparison between Fig. 10 and the cross-sectional view of Fig. 31 taken along line 31B-31B.
  • the blades 44 are resin members that are molded separately from the main plate 43 and the side plate 45. One end face of each blade 44 is fixed to the main plate 43, and another end face is fixed to the side plate 45. When viewed from the side of the impeller 42, the end of the blade 44 that faces the side plate 45 is inclined rearward than the end close to the main plate 43 as shown in Fig 28 .
  • the blade 44 is formed such that these ends cross each other to substantially form an X as shown in Fig. 29 . In other words, the blade 44 has a three-dimensional shape that extends parallel to the rotary shaft while being twisted between the main plate 43 and the side plate 45.
  • the edge at the leading side in the rotation direction of the blade 44 which is a three-dimensional blade, or a leading edge 44a extends from the end close to the main plate 43 to a predetermined position close to the side plate 45 with substantially a constant radius.
  • the blade 44 as an inclined edge from the predetermined position close to the side plate 45, while retreating outward with a gradually decreasing radius.
  • the end of the blade 44 on the opposite side of the rotation direction R, or the trailing edge 44b, has a shape different from that of the prior art blade. Unlike the prior art shown in Figs.
  • the trailing edge 44b does not have a shape formed by a straight line (perpendicular to the main plate 43) that extends parallel to the rotation axis from the end close to the main plate 43 and the end close to the side plate 45.
  • the trailing edge 44b is extended rearward with respect to air flow such that the degree of extension increases from the end close to the side plate 45 toward the main plate 43.
  • the radial length (Rb' in Fig. 5 ) of the trailing edge 44b of the main plate 43 of the blade 44 through which main flow F 1 of the centrifugal fan flows is set longer than the radial length (Ra in Fig. 5 ) of the trailing edge 44b at a part close to the side plate 45 of the blade 44.
  • the velocity distribution of air flow along the span direction of the blade 44 effectively develops in a part close to the main plate 43, at which the flow rate is greater.
  • the trailing edge 44b is extended without changing the basic shape of the three-dimensional blade, but rather in conformity with the shape of the three-dimensional blade.
  • the outer diameter Db' ( Fig. 12 ) of the expanded main plate 43 is preferably determined such that the amount of extension of the trailing edge 44b is less than or equal to 10% of the original diameter Db.
  • the amount of extension of the trailing edge 44b is preferably less than or equal to 10% of the outer diameter Da of the side plate 45.
  • the outer diameter Db' of the main plate 43 is enlarged by approximately 5% compared to the outer diameter Db of the prior art main plate 43 shown in Figs. 28 to 32 .
  • the inlet angle, the outlet angle, the attaching angle, and the skew angle of a blade element of the blade 44 that is close to the main plate 43 are maintained to the same values as those in the original blade 44 shown in Figs. 28 to 32 . Therefore, as shown in, for example, the perspective view of Fig. 8 , the blade 44 of the present embodiment is enlarged at the attachment position on the side corresponding to the trailing edge 44b bulges in the direction of rotation.
  • the outer diameter of the main plate 43 is increased.
  • the velocity distribution of the main flow F 1 which flows in a concentrated manner in the vicinity of the main plate 43, is significantly improved compared to the flow F 2 in the vicinity of the side plate 45. Accordingly, the static pressure-flow rate characteristics (P-Q characteristics) of the blade 44 is improved over the entire flow rate range, which increases the discharged air volume. Also, the specific noise characteristics are significantly improved, so that the influence of a trailing vortex generated at the trailing edge 44b of a part of each three-dimensional blade 44 close to the main plate 43 is relatively reduced. As a result, the noise caused by trailing vortices is effectively reduced.
  • the trailing edge 44b is extended further rearward toward the main plate 43. As shown in Fig. 12 , the trailing edge 44b is also extended so that it becomes gradually longer from the side plate 45 toward the main plate 43. That is, the trailing edge 44b of the blade 44 has a tapered shape that is linearly enlarged from the side plate 45 toward the main plate 43. Accordingly, the velocity distribution at the outlet of the blade 44 effectively develops in the main flow F 1 . Therefore, the influence of the wake flow generated at a part of the trailing edge 44b close to the main plate 43 is relatively weakened.
  • the shape of the trailing edge 44b is more suitable for changes in the velocity distribution of the main flow F 1 , in which the flow rate increases toward the main plate 43. That is, the shape of the blade 44 is optimized for the velocity distribution of air flow, so that the fan performance is improved.
  • each blade has the three-dimensional shape as described above (see Figs. 7 and 8 ).
  • the load distribution on the surface of the blade 44 and the pressure fluctuation of air flow through between the blades 44 are significantly improved.
  • Patent Document 3 discloses a blade that is shortened by cutting out a part close to the side plate. This reduces the flow separation at the part of the blade close to the side plate, thereby equalizing the velocity distribution at the outlet of the blade.
  • the length of the blade is less than a blade having no cut out portion. This reduces the amount of work that each blade applies to the air flow.
  • the blade 44 itself is not shortened. On the contrary, the area of the blade 44 is increased. The present embodiment there does not have such a drawback and effectively increases the work of the blade 44.
  • This technique is effective in a centrifugal fan in which the blade width is sufficiently small in relation to the outer shape, as described in Patent Document 3. Specifically, cutting out of the blades prevent separation of drawn-in air flow in a part of each blade in the vicinity of the side plate, and the air flow is allowed to flow along the part.
  • the technique is not necessarily effective in a normal centrifugal fan, which has wide blades, that is, not in a case where the influence of separation near the side plate is not dominant.
  • the present embodiment does not have these drawbacks of the prior art.
  • the ratio of the diameter of the impeller at the side close to the main plate to the diameter of the impeller at the side close to the side face is set to 1.2 to 1.6. Therefore, when the blades are enlarged with a small increase in the length, noise reduction effect cannot be achieved. In contrast, when the length is excessively increased, the flow characteristics will be degraded.
  • the diameter of the impeller at the end close to the main plate is twenty percent greater than the diameter at the side plate.
  • This structure is not advantageous over the technique in which the size of the fan is simply increased. Enlargement of the size by twenty percent or more goes entirely against desired goals that have been sought in the first place in the prior art, which are size reduction and lowered noise.
  • the trailing edge 44b is extended further rearward toward the main plate 43. As shown in Fig. 12 , the trailing edge 44b is also extended so that it becomes gradually longer from the side plate 45 toward the main plate 43.
  • the trailing edge 44b of each blade 44 has a tapered shape that becomes wider from the side plate 45 toward the main plate 43.
  • the trailing edge 44b is more suitable for changes in the velocity distribution of the main flow F 1 , which flows in a concentrated manner in the vicinity of the main plate 43.
  • the outer diameter of the main plate 43 is increased.
  • Example c was an impeller having three-dimensional blades, or the blades 44 of the present embodiment in which the enlargement factor of the outer diameter Db' of the main plate 43 (extension factor of the width of the trailing edge 44b rearward with respect to air flow) was 5%.
  • Example d was an impeller having three-dimensional blades, or the blades 44 of the present embodiment in which the enlargement factor of the outer diameter Db' of the main plate 43 was 10%.
  • the prior art Example a, or comparison example was an impeller having the prior art blades shown in Figs. 27 to 32 .
  • the prior art Example b was equivalent to the fan of the prior Example a in which the diameter of the fan was increased by 5%.
  • the improvement of the two properties significantly improved the specific noise characteristics of the Examples c and d, for example, as shown in Fig. 15 .
  • the properties of the Examples c and d were clearly improved in comparison with the prior art Example b, in which the diameter of the fan was evenly increased.
  • the impeller according to the present embodiment is superior in terms of increased air volume and lowered noise, and is capable of being reduced in size.
  • the shape of enlargement (extension) of the trailing edge 44b of the blade 44 is not limited to the linear shape (tapered shape corresponding to a linear function) as described above.
  • the extension may be shaped as a curve of a quadratic function for a parabola.
  • This curved shape of the trailing edge 44b is selected in consideration of the deviation of the velocity distribution of air flow discharged from the impeller. Specifically, the trailing edge 44b of the blade 44 is extended further in the radial direction toward the main plate 43 from the side plate 45.
  • the trailing edge 44b of each blade 44 has a tapered shape of a quadratic function that becomes wider in an arcuate manner from the side plate 45 toward the main plate 43.
  • the trailing edge 44b of the blade 44 is suitable for the velocity distribution of the main flow F 1 , which flows in a concentrated manner in the vicinity of the main plate 43 as shown in Fig. 16 .
  • the shape of the trailing edge 44b of the blade 44 is further effectively optimized for the velocity distribution of the main flow F 1 , so that the fan performance is improved.
  • the trailing edge 44b may be formed such that there is at least one inflection point in the curved part as shown in Fig 17 .
  • the trailing edge 44b has a bulge in the vicinity of the main plate 43.
  • the enlargement of the trailing edge 44b at the end face close to the main plate 43 is slightly shorter than the maximally extended part (but, at least greater than or equal to the end of the trailing edge 44b close to the side plate 45).
  • This configuration suppresses the development of the shear layer, thereby improving the fan performance.
  • the leading edge 44a of the blade 44 may be formed stepwise (in the present embodiment, two steps) toward the inside of the impeller 42. Specifically, the leading edge 44a may have first and second steps 44c, 44d.
  • the first and second steps 44c, 44d prevent the air flow from separating from the negative pressure surface of the blade 44. In this manner, the first and second steps 44c, 44d contribute to further reduction of air flow noise of the air blower 4.
  • the negative pressure surface refers to a surface of the blade 44 that faces inward of the impeller 42.
  • the surface opposite to the negative pressure surface, that is, a surface of the blade 44 that faces outward of the impeller 42 is referred to as a positive pressure surface.
  • the lengths La ⁇ Lb, Lc ⁇ Ld of the first and second steps 44, 44d are set to be 0.09 to 0.18 times the original chord lengths L 1 , L 2 , L 3 of the blade 44 in the span direction. That is, the length of the first step 44c, which is the lower step, varies along the span direction in a range between 0.15 times the length L 1 (La) and 0.2 times the length L 1 (Lb), and the length of the second step 44d, which is the upper step, varies along the span direction in a range between 0.08 times the length L 2 (Lc) and 0.1 times the length L 3 (Ld).
  • the blade 44 according to the third modification with trapezoid steps will be discussed as an Example d.
  • the above described example of Figs. 1 to 12 with none of the first and second steps 44c, 44c on the leading edge 44a will be expressed as an example c (without trapezoid steps).
  • a comparison Example b is the one with the first and second steps 44c, 44d formed in the prior art blade.
  • Example c and Example d are compared, the specific noise characteristics are lowered in the entire flow region.
  • the Example c achieves a reduction of at least 1.1 [dBA] at the minimum specific noise characteristic point.
  • the centrifugal fan according to the embodiment shown in Figs. 1 to 12 is designed such that air flow that passes through the impeller flows below the blade 44 compared to the prior art Example a. Therefore, the longitudinal vortex generated by the first and second steps 44c, 44d of the leading edge 44a further effectively prevents separation.
  • the Example c is inferior to the comparison Example b in terms of the aerodynamic characteristics in the low air volume region.
  • the first and second steps 44c, 44d improved the characteristics in the low air volume region compared to the comparison Example b. Accordingly, in comparison with the comparative Example b, the aerodynamic characteristics of the Example d were improved in the entire air volume range. Consequently, the centrifugal fan using the Example d according to the third modification of the present invention was capable of generating a greater amount of air volume at the same static pressure.
  • the centrifugal fan according to the third modification of the present embodiment generates lower noise than a conventional centrifugal fan, and is capable of increasing the air volume at the same static pressure. This enables development of a compact and quiet fan.
  • the use of the centrifugal fan realizes a compact air conditioner that runs quietly while maintaining greater air volume.
  • the first and second steps 44c, 44d of the third modification may be combined with the second modification.
  • the present invention can be applied to impellers in centrifugal fans of various types (for example, backwardly-curved blade types, sirocco types, and straight radial blade types). In these cases, the fan performance is sufficiently improved.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
EP09746628A 2008-05-14 2009-05-13 Centrifugal fan Withdrawn EP2275689A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008126940 2008-05-14
PCT/JP2009/058938 WO2009139422A1 (ja) 2008-05-14 2009-05-13 遠心送風機

Publications (1)

Publication Number Publication Date
EP2275689A1 true EP2275689A1 (en) 2011-01-19

Family

ID=41318788

Family Applications (1)

Application Number Title Priority Date Filing Date
EP09746628A Withdrawn EP2275689A1 (en) 2008-05-14 2009-05-13 Centrifugal fan

Country Status (7)

Country Link
US (1) US20110023526A1 (ja)
EP (1) EP2275689A1 (ja)
JP (1) JPWO2009139422A1 (ja)
KR (1) KR20100134011A (ja)
CN (1) CN101990604A (ja)
AU (1) AU2009247219A1 (ja)
WO (1) WO2009139422A1 (ja)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2829733A4 (en) * 2013-05-10 2015-10-28 Lg Electronics Inc CENTRIFUGAL
US10662968B2 (en) 2013-05-10 2020-05-26 Lg Electronics Inc. Method of manufacturing centrifugal fan
EP3916239A1 (de) * 2020-05-28 2021-12-01 ebm-papst Mulfingen GmbH & Co. KG Gebläserad mit dreidimensional gekrümmten laufradschaufeln
EP3922860A4 (en) * 2019-02-07 2022-02-16 Mitsubishi Electric Corporation CENTRIFUGAL AIR FAN AND AIR CONDITIONING WITH IT
CN114174726A (zh) * 2019-09-24 2022-03-11 东芝开利株式会社 冷冻循环装置的室内机以及叶轮
US11566634B2 (en) 2018-10-31 2023-01-31 Carrier Corporation Arrangement of centrifugal impeller of a fan for reducing noise

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9004868B2 (en) * 2010-05-19 2015-04-14 The New York Blower Company Industrial fan impeller having a tapered blade and method
CN103477084B (zh) * 2011-04-12 2017-11-17 三菱电机株式会社 涡轮风扇以及空调机
US8998588B2 (en) 2011-08-18 2015-04-07 General Electric Company Segmented fan assembly
JP5988776B2 (ja) * 2012-08-29 2016-09-07 三菱電機株式会社 遠心送風機及びこの遠心送風機を備えた空気調和機
WO2014061094A1 (ja) * 2012-10-16 2014-04-24 三菱電機株式会社 ターボファンおよび空気調和機
JP5811134B2 (ja) * 2013-04-30 2015-11-11 ダイキン工業株式会社 空気調和機の室内ユニット
JP5783214B2 (ja) * 2013-09-30 2015-09-24 ダイキン工業株式会社 遠心送風機及びこれを備えた空気調和機
JP6250145B2 (ja) * 2014-05-09 2017-12-20 三菱電機株式会社 遠心送風機及び電気掃除機
CN104279188B (zh) * 2014-10-29 2017-08-01 珠海格力电器股份有限公司 离心式风机及具有其的空调器
KR20160063743A (ko) * 2014-11-27 2016-06-07 삼성전자주식회사 원심송풍기용 팬조립체 및 이를 구비한 공기조화장치
DE102014226298A1 (de) * 2014-12-17 2016-06-23 Mahle International Gmbh Gebläse
JP6621194B2 (ja) 2015-06-03 2019-12-18 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． ターボファン及びこのターボファンを用いた送風装置
ITUB20152807A1 (it) * 2015-08-03 2017-02-03 Ma Ti Ka S R L Ventola per forni per la cottura di alimenti
EP3324052A1 (en) * 2016-11-18 2018-05-23 Sogefi Air & Cooling (SAS) Impeller for a fluid pump
WO2018151013A1 (ja) * 2017-02-20 2018-08-23 株式会社デンソー 遠心送風機
JP6747402B2 (ja) * 2017-08-11 2020-08-26 株式会社デンソー 送風機
WO2019106761A1 (ja) * 2017-11-29 2019-06-06 三菱電機株式会社 遠心ファンおよび回転電機
JP7207933B2 (ja) * 2018-10-15 2023-01-18 日立建機株式会社 建設機械
JP7040493B2 (ja) * 2019-04-25 2022-03-23 株式会社デンソー 遠心ファンおよびその遠心ファンを備えた送風機
CN113906220B (zh) * 2019-06-13 2023-09-15 三菱电机株式会社 轴流风扇、送风装置及制冷循环装置
JP7482332B2 (ja) * 2021-07-30 2024-05-13 三菱電機株式会社 羽根車及び遠心送風機
WO2023032762A1 (ja) * 2021-09-02 2023-03-09 株式会社デンソー 遠心ファン
CN113803290B (zh) * 2021-09-17 2024-01-19 苏州西热节能环保技术有限公司 一种火电机组风机进风区降阻方法
CN114370427A (zh) * 2021-12-17 2022-04-19 广东美的白色家电技术创新中心有限公司 叶轮、离心风机及吸油烟机
CN114321005B (zh) * 2022-03-01 2022-05-13 佛山市南海九洲普惠风机有限公司 一种低噪前弯离心风机叶轮

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60156997A (ja) * 1984-01-26 1985-08-17 Nippon Denso Co Ltd 遠心式送風機用フアン
JP2537987B2 (ja) * 1988-09-06 1996-09-25 松下冷機株式会社 遠心送風機
JP3055238B2 (ja) 1991-09-03 2000-06-26 松下電器産業株式会社 電動送風機
JPH0979184A (ja) * 1995-09-14 1997-03-25 Matsushita Electric Ind Co Ltd 電動送風機
JP3544325B2 (ja) * 1999-11-10 2004-07-21 三菱電機株式会社 遠心形送風機の羽根車および空気調和機
JP4037084B2 (ja) * 2000-11-02 2008-01-23 株式会社共立 中空品成形法によって組立てるためのブロワファン分割体
JP3711891B2 (ja) 2001-05-17 2005-11-02 ダイキン工業株式会社 送風機用羽根車
JP4432474B2 (ja) 2003-11-27 2010-03-17 ダイキン工業株式会社 遠心送風機の羽根車及びそれを備えた遠心送風機
JP3953085B1 (ja) * 2006-03-08 2007-08-01 ダイキン工業株式会社 遠心送風機用羽根車のブレード、ブレード支持回転体、遠心送風機用羽根車、及び遠心送風機用羽根車の製造方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2009139422A1 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2829733A4 (en) * 2013-05-10 2015-10-28 Lg Electronics Inc CENTRIFUGAL
US9995311B2 (en) 2013-05-10 2018-06-12 Lg Electronics Inc. Centrifugal fan
US10662968B2 (en) 2013-05-10 2020-05-26 Lg Electronics Inc. Method of manufacturing centrifugal fan
US11566634B2 (en) 2018-10-31 2023-01-31 Carrier Corporation Arrangement of centrifugal impeller of a fan for reducing noise
EP3922860A4 (en) * 2019-02-07 2022-02-16 Mitsubishi Electric Corporation CENTRIFUGAL AIR FAN AND AIR CONDITIONING WITH IT
CN114174726A (zh) * 2019-09-24 2022-03-11 东芝开利株式会社 冷冻循环装置的室内机以及叶轮
CN114174726B (zh) * 2019-09-24 2023-08-15 东芝开利株式会社 冷冻循环装置的室内机以及叶轮
EP3916239A1 (de) * 2020-05-28 2021-12-01 ebm-papst Mulfingen GmbH & Co. KG Gebläserad mit dreidimensional gekrümmten laufradschaufeln
US11506220B2 (en) 2020-05-28 2022-11-22 Ebm-Papst Mulfingen Gmbh & Co. Kg Fan wheel with three dimensionally curved impeller blades

Also Published As

Publication number Publication date
JPWO2009139422A1 (ja) 2011-09-22
US20110023526A1 (en) 2011-02-03
AU2009247219A1 (en) 2009-11-19
CN101990604A (zh) 2011-03-23
KR20100134011A (ko) 2010-12-22
WO2009139422A1 (ja) 2009-11-19

Similar Documents

Publication Publication Date Title
EP2275689A1 (en) Centrifugal fan
KR102518997B1 (ko) 이중 반전 팬
US8721280B2 (en) Propeller fan
KR100985958B1 (ko) 다익 팬
JP5549772B2 (ja) プロペラファン及びこれを備える空気調和機
WO2013150673A1 (ja) 空気調和装置の室内機
WO2009113338A1 (ja) 空気調和機
WO2014080494A1 (ja) 空気調和機
AU2009237152A1 (en) Turbofan and air conditioner
WO2012086147A1 (ja) 貫流ファン及び空気調和機の室内機
JP2009203897A (ja) 多翼送風機
JPH1144432A (ja) 空気調和機
KR101826359B1 (ko) 횡류팬 및 공기 조화기
US10690142B2 (en) Blade of cross-flow fan
JP2001003899A (ja) 送風機及びこれを用いた空気調和機並びに空気清浄機
KR101883502B1 (ko) 횡류팬 및 공기 조화기
WO2020110967A1 (ja) プロペラファン
EP2280176B1 (en) Cross flow fan and air conditioner equipped with same
KR20080092034A (ko) 팬 및 쉬라우드의 조립체
CN114483648A (zh) 叶片的设计方法、叶片及离心风机
JP5774206B2 (ja) 空気調和装置の室内機
JP3387987B2 (ja) 多翼送風ファン
WO2016121144A1 (ja) プロペラファン、送風機および冷凍サイクル装置の室外機
WO2020110968A1 (ja) プロペラファン
WO2020110969A1 (ja) プロペラファン

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20100915

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA RS

RIN1 Information on inventor provided before grant (corrected)

Inventor name: OHYAMA, SHINGO

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

DAX Request for extension of the european patent (deleted)
18W Application withdrawn

Effective date: 20110726