JP4807208B2 - Multi-blade blower - Google Patents

Description

  The present invention relates to a multi-blade fan used mainly in a ventilation fan installed on a ceiling.

  Conventionally, this type of multi-blade blower has a bell mouth-like suction port formed on one side, a spiral scroll casing having a suction suction port and a discharge port having an inner diameter equal to or greater than the blade inner diameter, and a scroll casing. A driving device such as an electric motor provided on the opposite side of the internal suction port, a main plate fixed perpendicular to the rotation shaft of the driving device, a plurality of blades disposed on the suction side and the driving device side of the main plate, It is known that a ring-shaped side plate is provided on both sides or one end of the blade, and a main plate is provided with a ventilation hole for air to flow from the suction side to the drive device side (see, for example, Patent Document 1). ).

  Hereinafter, the multiblade fan will be described with reference to FIG. As shown in the figure, a spiral scroll casing 101 has a bell mouth suction port 102 formed on one side, and a suction orifice 103 and discharge port 104 having an inner diameter equivalent to the blade inner diameter D1, and an electric motor 105 facing the suction port 102. Have. Further, in the scroll casing 101, a main plate 107 fixed perpendicularly to the shaft 106 of the electric motor 105, a plurality of blades 108 disposed on the suction side and the driving device side of the main plate 107, and end portions of the blades 108 are provided. A multi-blade impeller 111 having a ring-shaped side plate 109 to be fixed and a ventilation hole 110 for air to flow through the main plate 107 is provided.

With the above configuration, when the multi-blade impeller 111 is rotated by applying a driving force to the shaft 106 from the electric motor 105, the suction air 112 passes through the suction port 102 of the suction orifice 103, and is pressurized by the blade 108. As the fluid flows out of the fluid and passes through the spiral scroll casing 101, the dynamic pressure is gradually converted into a static pressure and discharged to the discharge port 104.
Japanese Patent No. 3507758

  In such a conventional multi-blade blower, there is no problem when the electric motor 105 is arranged inside the scroll casing 101, but a part of the electric motor 105 is isolated from the air passage when used in a place of high temperature and high humidity. If necessary, a dent is provided on the electric motor 105 side of the scroll casing 101 so as not to increase the thickness of the main body, and the length of the blade 108 on the electric motor 105 side must be shortened to avoid interference. There is a problem that the axial length of the multi-blade impeller 111 is shortened and the blowing capacity is reduced, and the clearance between the scroll casing 101 and the blade 108 is increased, so that the air discharged from the multi-blade impeller 111 flows back again. As a result, the air blowing efficiency decreases, and the air does not easily flow from the ventilation hole 110 to the blade 108 on the electric motor 105 side. Even if a part of the motor 105 is isolated from the air passage, the thickness of the main body is thin, the length of the blade 108 is not shortened, backflow is prevented, and the inflow to the blade 108 on the motor 105 side is prevented. It is required to increase the air blowing efficiency and reduce the noise.

  The present invention solves such a conventional problem, and even if a part of the motor is isolated from the air passage, the thickness of the main body is thin, the blade length is long, the backflow is prevented, and the motor side blade is prevented. An object of the present invention is to provide a multiblade fan that can increase the inflow to improve the blowing efficiency and reduce noise.

  In order to achieve the above object, the blower of the present invention has a scroll casing configured by sandwiching a spiral side wall between a suction plate having a bell mouth-like suction port and a top plate facing the suction plate, and the scroll casing. A multi-blade impeller enclosed in a scroll casing substantially concentrically with the suction port provided in the side wall of the slab, and an electric motor that rotates the multi-blade impeller, and the multi-blade impeller is fixed to the rotation shaft A part of the drive unit is equipped with an electric motor installed outside the top plate, the top plate is equipped with a substantially cone-shaped dent toward the inside of the scroll casing at the part where the drive unit is installed, and the multi-blade impeller rotates A main plate fixed perpendicularly to the shaft, a plurality of suction side blades disposed on the suction side of the main plate, a motor side blade disposed on the motor side, and a ventilation hole for air to flow through the main plate In the multi-blade fan provided, Blade end motivation side blades is obtained by a than the top of the recessed portion is set along the motor side projecting and the recessed portion multiblade blower.

  By this means, a part of the drive part of the electric motor is isolated from the air passage, and even if a recessed part is provided to reduce the axial dimension of the multiblade fan, the length of the motor side blade can be increased. A multiblade fan capable of improving the air blowing efficiency is obtained.

  Another means is a multi-blade blower in which the gap between the top plate and the blade end of the motor side blade is reduced so that the air discharged from the multi-blade impeller does not flow back to the multi-blade impeller again. .

  By this means, a backflow from the gap between the top plate and the motor side blade can be suppressed, and a multiblade blower that can improve the blowing efficiency can be obtained.

  The other means is that the inner diameter of the suction side blade is equal to or less than the inner diameter of the suction port, the outer diameter is large, and the suction port and the suction side blade are overlapped in the axial direction at a predetermined interval. The blade is a multi-blade fan provided with a notch.

  By this means, a backflow from the gap between the suction port and the suction side blade can be suppressed, and a multiblade fan that can improve the blowing efficiency can be obtained.

  Another means is a multi-blade fan whose main plate is substantially conical.

  By this means, the multi-blade fan can be obtained which can smooth the inflow from the ventilation hole to the motor side blade, increase the inflow to the motor side blade, and improve the air blowing efficiency.

  Another means is a multi-blade blower in which the inner diameter of the suction side blade is gradually reduced toward the motor side.

  By this means, the work of the suction side blade increases toward the motor side, whereby the flow in the rotation axis direction can be promoted, the inflow to the motor side blade can be increased, and the blowing efficiency can be improved. A multiblade fan is obtained.

  Another means is a multiblade fan in which the suction side blade and the motor side blade have different axial cross-sectional shapes.

  By this means, a multi-blade blower that can increase the inflow to the motor side blade by improving the axial cross-sectional shape according to the flow state of each of the suction side blade and the motor side blade and improve the air blowing efficiency. can get.

  Another means is a multiblade fan in which the number of suction side blades and the number of blades on the motor side are different.

  By this means, a multiblade blower that can increase the inflow to the motor side blade and improve the air blowing efficiency by making the number of blades in accordance with the flow state of each of the suction side blade and the motor side blade is obtained. .

  Another means is a multiblade blower in which the inner diameter of the motor side blade is smaller than the inner diameter of the suction side blade.

  By this means, the portion smaller than the inner diameter of the suction side blade of the motor side blade scrapes the air flowing in from the ventilation hole, so that the inflow to the motor side blade can be increased and the air blowing efficiency can be improved. Is obtained.

  Another means is a multiblade fan in which the suction side corner of the motor side blade is cut out.

  By this means, air collision to the suction side corners can be suppressed, so that air can smoothly flow into the motor side blade, and a multiblade blower that can improve the blowing efficiency is obtained.

  Another means is a multiblade blower in which suction blades and motor blades are alternately arranged in the circumferential direction.

  By this means, since the suction side blade and the motor side blade do not cross the closest part of the scroll casing at the same time, the interference noise with the closest part can be suppressed, and a multiblade fan capable of reducing noise can be obtained. It is done.

  Another means is a multiblade fan in which the number of ventilation holes is not a divisor of the number of suction side blades.

  By this means, since the frequency of the pressure fluctuation sound due to the ventilation hole and the pressure fluctuation sound due to the blade is difficult to overlap, a multiblade fan capable of suppressing noise can be obtained.

  According to the present invention, even if a part of the electric motor is isolated from the air passage, the main body thickness is thin, the blade length is long, the backflow is prevented, the inflow to the electric motor side blade is increased, and the blowing efficiency is improved. A multiblade fan that can reduce noise can be provided.

  The invention according to claim 1 of the present invention includes a scroll casing configured by sandwiching a spiral side wall between a suction plate having a bell mouth-like suction port and a top plate facing the suction plate, and a side wall of the scroll casing A multi-blade impeller enclosed in a scroll casing, concentrically with the suction port, and an electric motor that rotates the multi-blade impeller. Is equipped with an electric motor installed on the outside of the top plate, the top plate is provided with a concave portion having a substantially cone shape toward the inside of the scroll casing at the portion where the drive unit is installed, and the multi-blade impeller is provided on the rotating shaft. A main plate fixed vertically, a plurality of suction side blades disposed on the suction side of the main plate, a motor side blade disposed on the motor side, and a ventilation hole for air to flow through the main plate In a wing blower, the motor side blur The blade end of the blade is a multi-blade fan that protrudes toward the motor side from the top of the dent portion and is along the dent portion. A part of the motor drive unit is isolated from the air path, Even if a dent portion is provided to reduce the axial dimension of the blower, the length of the motor-side blade can be increased, and air blowing efficiency can be improved.

  In addition, the gap between the top plate and the blade end of the motor side blade is made small so that the air discharged from the multi-blade impeller does not flow back to the multi-blade impeller again. Backflow from the gap between the motor side blades can be suppressed, and air blowing efficiency can be improved.

  In addition, the suction blade is not larger than the inner diameter of the suction port, the outer diameter is the same or larger, and the suction blade and the suction blade are notched in the axial direction so as to overlap in the axial direction with a predetermined distance. It has the effect | action that it can suppress the backflow from the clearance gap between a suction inlet and a suction side braid | blade, and can improve ventilation efficiency.

  Moreover, the main plate is a multi-blade fan with a substantially conical shape, and the inflow from the ventilation hole to the motor side blade can be smoothed, the inflow to the motor side blade is increased, and the air blowing efficiency It has the effect | action that can be improved.

  In addition, it is a multi-blade blower in which the inner diameter of the suction side blade is gradually reduced toward the motor side, and the work in the suction side blade increases toward the motor side, thereby promoting the flow in the rotation axis direction. It is possible to increase the inflow to the motor side blade and to improve the blowing efficiency.

  In addition, the suction blade and the motor blade are multi-blade fans having different axial cross-sectional shapes, and the electric motor is configured by changing the axial cross-sectional shape according to the flow state of each of the suction blade and the motor blade. The inflow to the side blades is increased, and the air blowing efficiency can be improved.

  In addition, it is a multi-blade blower with different numbers of suction side blades and motor side blades. By making the number of blades according to the flow state of each of the suction side blades and the motor side blades, inflow into the motor side blades It has the effect | action that it can increase and ventilation efficiency can be improved.

  In addition, since the inner diameter of the motor side blade is a multiblade blower smaller than the inner diameter of the suction side blade, a portion smaller than the inner diameter of the suction side blade of the motor side blade is used to scrape air flowing in from the ventilation holes. It has the effect that the inflow to the motor side blade can be increased and the air blowing efficiency can be improved.

  In addition, it is a multi-blade blower with the suction side corner of the motor side blade cut out, and air can be prevented from colliding with the suction side corner, so air flows smoothly into the motor side blade. And has the effect of improving the air blowing efficiency.

  Moreover, the suction blade and the motor blade are multi-blade and multi-blade fans arranged alternately in the circumferential direction, and the suction blade and the motor blade do not cross the closest part of the scroll casing at the same time. Therefore, interference noise with the closest part can be suppressed, and the noise can be reduced.

  In addition, it is a multi-blade blower whose number of ventilation holes is not a divisor of the number of suction side blades, and it is difficult to overlap the pressure fluctuation sound due to the ventilation holes and the pressure fluctuation sound due to the blades, so noise is suppressed. Has the effect of being able to

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, a multiblade fan 1 used as a ventilation fan for ventilating a high-temperature and high-humidity space such as a bathroom includes an outer shell 3 having an open lower surface 2, a scroll casing 4 included in the outer shell 3, and a scroll A multi-blade impeller 5 included in the casing 4 and an electric motor 6 that rotates the multi-blade impeller 5 are configured. The scroll casing 4 has, for example, a suction plate 8 having an outer diameter of 230 mm × 250 mm, a height of 150 mm, a bell mouth-shaped suction port 7 having an inner diameter of 132 mm on the surface facing the lower surface 2, and a top plate facing the suction plate 8. 9 and sandwiching a spiral side wall 10, and a discharge port 11 is provided on the side wall 10 of the scroll casing 4. The electric motor 6 includes a driving unit 12 having an outer diameter of 90 mm, a shaft 13 serving as a rotating shaft, a power supply line 14 for sending electricity to the driving unit 12, and a drawing hole 15 for drawing the power supply line 14 from the driving unit 12. For the purpose of preventing the deterioration of the part 12, a part of the driving part 12 is installed outside the top plate 9 so as to isolate the high-temperature and high-humidity air flowing in the scroll casing 4 from the drawing hole 15 of the driving part 12. The shaft 13 protrudes into the scroll casing 4 from a hole provided in the top plate 9. The top plate 9 of the scroll casing 4 is provided with a concave portion 17 having a substantially cone shape toward the inside of the scroll casing 4 at a portion where the drive unit 12 is installed in order to reduce the height of the multiblade fan 1. The indented portion 17 has, for example, a maximum outer diameter of 140 mm, an outer diameter of 166 mm at the top 16, and a height of 35 mm.

  The multi-blade impeller 5 includes, for example, a main plate 18 having a substantially conical outer diameter of 170 mm with an angle of 18 degrees, 50 suction-side blades 19 arranged in an annular shape on the suction side of the main plate 18, an electric motor The main plate is provided with 50 motor-side blades 20 arranged on the 6 side and six substantially fan-shaped ventilation holes 21 for air to flow through the main plate 18 so as to be substantially concentric with the suction port 7. 18 is vertically fixed to the shaft 13 of the electric motor 6. The blade end 22 of the electric motor side blade 20 protrudes toward the electric motor 6 from the top 16 of the indentation portion 17, and the blade end 22 of the electric motor side blade 20 has a gap with the top plate 9 and the indentation of the top plate 9. Each of the gaps with the portion 17 has a shape along, for example, 3 mm. In the vertical cross section of the motor-side blade 20, the substantially cone-shaped indentation portion 17 and a part of the motor-side blade 20 overlap from the blade end 22 of the motor-side blade 20 toward the main plate 18. overlapping.

  Further, the inner diameter Da (132 mm) of the suction side blade 19 is equal to the suction port inner diameter Di, the suction side blade outer diameter Db is 170 mm, which is larger than the suction port inner diameter Di, and the suction port 7 and the suction side blade 19 are 3 mm. The suction side blade 19 is provided with a notch 23 so as to overlap in the axial direction while maintaining a gap, and the axial overlapping portion 24 of the suction port 7 and the suction side blade 19 is configured.

  Here, the gap is set to 3 mm, which prevents the collision with the suction port 7 and the top plate 9 and reduces the gap due to axial blurring and unbalance due to manufacturing errors of the multiblade impeller 5 having an outer diameter of 170 mm. It is because it is suitable for.

  With this configuration, when the multiblade impeller 5 fixed to the electric motor 6 rotates, a part of the air guided from the suction port 7 to the multiblade impeller 5 passes between the suction side blades 19. Further, a part passes through between the motor side blades 20 through the ventilation holes 21 of the main plate 18, and both of them merge to reach the scroll chamber 25 and are discharged to the outside from the discharge port 11. The blade end 22 protrudes toward the electric motor 6 from the top 16 of the indented portion 17 and has a shape along the indented portion 17 with a gap of 3 mm. Therefore, a part of the drive unit 12 of the electric motor 6 is provided. Even when the dent portion 17 is provided in the top plate 9 in order to reduce the axial dimension of the multiblade blower 1, the length of the motor side blade 20 can be increased, and the blowing efficiency Can be improved.

  Further, since the gap between the top plate 9 and the blade end 22 of the motor side blade 20 is as small as about 3 mm, for example, backflow from the gap between the top plate 9 and the blade end 22 of the motor side blade 20 can be suppressed, and the air blowing efficiency Can be improved. Here, the gap between the top plate 9 and the blade end 22 of the motor side blade 20 is about 3 mm, but the gap that can suppress the backflow from the gap between the top plate 9 and the blade end 22 of the motor side blade 20 can be suppressed. If it is.

  Further, since the suction port 7 and the suction side blade 19 have the overlapping portion 24 in the axial direction, the backflow from the gap can be suppressed, and the blowing efficiency can be improved.

  Further, since the main plate 18 of the multi-blade impeller 5 has a substantially conical shape with an angle of 18 degrees, the inflow from the ventilation hole 21 to the motor side blade 20 can be made smooth, and the motor side blade 20 Inflow into the air can be increased, and the air blowing efficiency can be improved.

  Moreover, since the number of the ventilation holes 21 is six and is not a divisor of the number of the suction side blades 19, the frequency of the pressure fluctuation sound caused by the ventilation holes 21 and the pressure fluctuation sound caused by the suction side blade 19 do not overlap. Noise can be suppressed.

(Embodiment 2)
As shown in FIG. 2, the suction-side blade inner diameter Da of the multiblade blower 1 is configured to gradually decrease toward the electric motor 6. The configuration that decreases for a while toward the electric motor 6 side only needs to be able to promote the flow of the air flowing in from the suction port 7 in the direction of the rotation axis toward the ventilation hole 21. For example, the suction-side blade inner diameter Da of the suction-side blade 19 Is φ132 mm, and the suction-side blade inner diameter Da of the suction-side blade 19 may be φ122 mm.

  With this configuration, the work of the suction side blade 19 increases toward the motor 6, so that the air flowing from the suction port 7 can promote the flow in the rotation axis direction toward the ventilation hole 21, and the motor side blade The inflow to 20 can be increased and the air blowing efficiency can be improved.

(Embodiment 3)
As shown in FIG. 3, the suction side blade 19 of the multi-blade impeller 5 has an axial cross-sectional shape that is close to the suction port 7 and has no obstruction, so that the inlet angle 26 is 63 degrees and the outlet angle 27 is 15 degrees. Since the motor side blade 20 has obstacles that cause pressure loss with respect to the inflow of the ventilation holes 21 and the dents 17 of the top plate 9, the axial cross-sectional shape has an entrance angle 26 of 52. The outlet angle 27 has a shape suitable for resisting a pressure loss of 25 degrees.

  With this configuration, it is possible to make the axial cross-sectional shape in accordance with the flow state of each of the suction side blade 19 and the electric motor side blade 20, increase the inflow to the electric motor side blade 20, and improve the blowing efficiency. it can.

(Embodiment 4)
As shown in FIG. 4, the suction blades 19 of the multi-blade impeller 5 are close to the suction port 7 and there are no obstructions, so 47 blades are used to increase the area between the blades so as to be suitable for a high air volume. Since there are obstacles that cause pressure loss with respect to the inflow of the vent hole 21 and the recessed portion 17 of the top plate 9, the area between the blades is narrowed so that the flow follows the blade 20 on the motor side so that the pressure loss can be countered. It consists of 52 sheets.

  With this configuration, the number of blades in accordance with the flow states of the suction side blade 19 and the motor side blade 20 is increased, so that the inflow to the motor side blade 20 can be increased and the blowing efficiency can be improved.

(Embodiment 5)
As shown in FIG. 5, the motor-side blade inner diameter Dc of the multi-blade impeller 5 is 126 mm, which is smaller than the suction-side blade inner diameter Da (132 mm), and the suction-side corner portion 28 of the motor-side blade 20 is notched. It is the composition that was written.

  With this configuration, the portion smaller than the inner diameter of the suction side blade 19 of the motor side blade 20 scrapes the air flowing in from the ventilation holes 21, so that the inflow to the motor side blade 20 is increased and the blowing efficiency can be improved. it can.

  Further, since the corner 28 on the suction side of the motor-side blade 20 is notched, air collision can be suppressed to the corner 28 on the suction-side, so that air can smoothly flow into the motor-side blade 20. It is possible to improve the ventilation efficiency.

(Embodiment 6)
As shown in FIG. 6, the suction blades 19 and the motor blades 20 of the multi-blade impeller 5 are the same in number of 50 each, and the motor blades 20 are disposed between the circumferential blades of the suction blade 19. It becomes the composition.

  With this configuration, since the suction side blades 19 and the motor side blades 20 are alternately arranged in the circumferential direction, the suction side blades 19 and the motor side blades 20 do not cross the closest portion of the scroll casing 4 at the same time. Interference noise with the approaching portion can be suppressed, and noise can be reduced.

  Even if a part of the motor is isolated from the air path, the thickness of the main body is thin, the blade length is long, the backflow is prevented, the inflow to the motor side blade is increased, the blowing efficiency is improved, and the noise is reduced. The present invention provides a multiblade fan that can be reduced.

The figure which shows the multiblade fan of Embodiment 1 of this invention ((a) sectional side view, (b) front fragmentary sectional view) Side sectional view which shows the multiblade fan of Embodiment 2 of this invention The figure which shows the multiblade impeller of Embodiment 3 of this invention ((a) Sectional drawing of a suction | inhalation side blade, (b) Sectional drawing of a motor side blade) The perspective view of the multiblade impeller of Embodiment 4 of the present invention Sectional side view which shows the multiblade fan of Embodiment 5 of this invention The figure which shows the multiblade impeller of Embodiment 6 of this invention ((a) perspective view, (b) sectional drawing) Side sectional view showing a conventional multiblade fan

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Multiblade blower 2 Lower surface 3 Outer 4 Scroll casing 5 Multiblade impeller 6 Electric motor 7 Suction port 8 Suction plate 9 Top plate 10 Side wall 11 Discharge port 12 Drive part 13 Shaft 14 Power line 15 Lead-out hole 16 Top 17 Indentation part 18 Main plate DESCRIPTION OF SYMBOLS 19 Suction side blade 20 Motor side blade 21 Ventilation hole 22 Blade end Da Suction side blade inner diameter Di Suction port inner diameter Db Suction side blade outer diameter 23 Notch 24 Superposition part 25 Scroll chamber 26 Inlet angle 27 Outlet angle Dc Electric motor side blade inner diameter 28 Corner 29 Nearest part

Claims (11)

A scroll casing configured by sandwiching a spiral side wall between a suction plate provided with a bell mouth-shaped suction port and a top plate facing the suction plate; a discharge port provided on the side wall of the scroll casing; A multi-blade impeller enclosed in the scroll casing and concentrically with the suction port; and an electric motor for rotating the multi-blade impeller. The multi-blade impeller is fixed to a rotating shaft, and a part of a drive unit is An electric motor installed on the outer side of the top plate, the top plate is provided with a recessed portion having a substantially cone shape toward the inner side of the scroll casing at a portion where the driving unit is installed, and the multi-blade impeller includes the rotating shaft A main plate fixed perpendicularly to the main plate, a plurality of suction side blades disposed on the suction side of the main plate, a motor side blade disposed on the motor side, and a vent hole for air to flow through the main plate. Multi-wing feeding with In machine, multi-blade fan in which the blade end of the motor side blade along the than the top projecting to the motor side and the recessed portion of the recess. The multiblade blower according to claim 1, wherein a gap between the top plate and the blade end of the motor side blade is made small so that air discharged from the multiblade impeller does not flow back to the multiblade impeller again. The suction blade is notched so that the inner diameter of the suction blade is less than or equal to the inner diameter of the suction port and the outer diameter is large, and the suction port and the suction blade overlap in the axial direction with a predetermined distance. The multiblade fan according to claim 1 or 2 provided. The multi-blade fan according to any one of claims 1 to 3, wherein the main plate is substantially conical. The multiblade fan according to any one of claims 1 to 4, wherein an inner diameter of the suction side blade is gradually reduced toward the motor side. The multiblade fan according to any one of claims 1 to 5, wherein the suction side blade and the motor side blade have different axial sectional shapes. The multiblade fan according to any one of claims 1 to 6, wherein the number of suction side blades and number of motor side blades are different. The multiblade fan according to any one of claims 1 to 7, wherein an inner diameter of the electric motor side blade is smaller than an inner diameter of the suction side blade. The multiblade fan according to claim 8, wherein a suction side corner portion of the motor side blade is cut out. The multiblade fan according to any one of claims 1 to 9, wherein the suction side blades and the motor side blades are alternately arranged in the circumferential direction. The multiblade fan according to any one of claims 1 to 10, wherein the number of ventilation holes is not a divisor of the number of suction side blades.

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