WO2018127970A1 - Fan, blower, and electric motor - Google Patents

Fan, blower, and electric motor Download PDF

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Publication number
WO2018127970A1
WO2018127970A1 PCT/JP2017/000271 JP2017000271W WO2018127970A1 WO 2018127970 A1 WO2018127970 A1 WO 2018127970A1 JP 2017000271 W JP2017000271 W JP 2017000271W WO 2018127970 A1 WO2018127970 A1 WO 2018127970A1
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WO
WIPO (PCT)
Prior art keywords
pitch angle
pitch
blades
fan
angles
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PCT/JP2017/000271
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French (fr)
Japanese (ja)
Inventor
裕介 奥出
誠司 羽下
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三菱電機株式会社
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2017/000271 priority Critical patent/WO2018127970A1/en
Publication of WO2018127970A1 publication Critical patent/WO2018127970A1/en

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    • 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
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing
    • F04D29/661—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps
    • F04D29/666—Combating cavitation, whirls, noise, vibration or the like; Balancing especially adapted for elastic fluid pumps by means of rotor construction or layout, e.g. unequal distribution of blades or vanes

Definitions

  • the present invention relates to a fan, a blower, and an electric motor.
  • a fan that generates an airflow includes a plurality of blades arranged at an equal pitch in the circumferential direction of the rotation shaft, and the airflow is generated by rotating the plurality of blades around the rotation shaft.
  • a fan in which a plurality of blades are arranged at an equal pitch is a so-called blade cutting sound or pure noise that is a noise whose fundamental frequency is a value obtained by the product of the number of rotations and the number of blades when the plurality of blades are rotated. Tone, which causes discomfort to the user.
  • Patent Document 1 In order to reduce noise, a fan is known in which a plurality of blades arranged in the circumferential direction of a rotating shaft are arranged at unequal pitches (Patent Document 1).
  • the pitch angle of the blades is different for each adjacent blade, and each pitch angle is aperiodically changed.
  • Patent Document 2 a method using a fan in which blades are arranged using a periodic pseudo-random array pattern is known.
  • a fan as a cooling fan for an electric motor that drives a vehicle
  • the cooling fan is connected to the axle, as the axle is rotated forward or reverse, the cooling fan is also rotated forward or reverse.
  • the cooling fan needs to have an equivalent noise reduction effect in both forward and reverse rotations.
  • Fans with blades arranged at unequal pitches and fans with blades arranged in a periodic pseudo-random arrangement are mixed with blades with different pitches. These patterns are different and an equivalent noise reduction effect cannot be achieved.
  • the present invention has been made in view of the above reasons, has a simple structure, is inexpensive, can greatly reduce noise, and exhibits a similar noise reduction effect during forward rotation and reverse rotation of the fan,
  • An object is to provide a blower and an electric motor.
  • a fan according to the present invention provides: A support member that rotates about a rotation axis; and n (n is an integer of 2 or more) blades that are attached to the support member and are arranged radially around the rotation axis.
  • the n blades are arranged around the rotation axis at n pitch angles, Any one of the n blades is used as a reference blade, and a first pitch angle is formed between the reference blade and a blade adjacent to the first direction of the circumference of the rotation shaft,
  • the first pitch angles are arranged in the m direction (m is an integer of 1 or more, n> m) in the first direction,
  • a second pitch angle different from the first pitch angle is formed by the reference blade and a blade adjacent to the second direction that is opposite to the first direction, and the second pitch angle is , N ⁇ m arranged in the second direction,
  • a first summed pitch angle obtained by summing m of the first pitch angles is different from a second summed pitch angle obtained by summing nm of the second pitch angles.
  • a fan, a blower, and an electric motor that have a simple structure, are inexpensive, can greatly reduce noise, and have the same noise reduction effect during forward rotation and reverse rotation of the fan. it can.
  • FIG. 1 is a schematic front view of a blower including a centrifugal fan according to Embodiment 1 of the present invention. Schematic sectional view taken along line AA in FIG. 1A The figure which shows the arrangement
  • FIG. 1A The figure which shows the arrangement
  • FIG. which shows the pitch angle of the blade
  • wing of a comparative example The figure which shows the arrangement
  • FIG. The figure which shows the arrangement
  • Schematic diagram of an electric motor provided with a centrifugal fan according to Embodiment 4 The figure which shows the arrangement
  • FIG. 1A and FIG. 1B show a blower 1 including a centrifugal fan according to the present embodiment.
  • the blower 1 includes a centrifugal fan 10, a housing 20 that houses the centrifugal fan 10, a rotating shaft 30 that rotates the centrifugal fan 10, a motor 40 that drives the rotating shaft 30, Is provided.
  • the centrifugal fan 10 includes a main plate 11 that is a support member and a plurality of blades 12.
  • the main plate 11 is a member that supports the plurality of blades 12, and is a member formed in a disk shape.
  • the main plate 11 is attached to the rotary shaft 30 when the rotary shaft 30 of the motor 40 is fixed through the center of the main plate 11.
  • the plurality of blades 12 are attached to one surface of the main plate 11 radially in the circumferential direction around the rotation shaft 30.
  • the plurality of blades 12 are radial blades in which each blade faces the radial direction.
  • the centrifugal fan 10 provided with such blades can be applied to a plate blower.
  • the attachment angle between the main plate 11 and the blades 12 is set to 90 °.
  • the housing 20 is a flat box-shaped member and accommodates the centrifugal fan 10 therein.
  • the housing 20 includes main walls 20a and 20b facing each other, and a side wall 20c surrounding a region between the main walls 20a and 20b.
  • Centrifugal fan 10 is housed inside housing 20 with rotating shaft 30 along the thickness direction of housing 20.
  • a suction port 21 is provided in the main wall 20 b of the housing 20 at a position facing the centrifugal fan 10.
  • a discharge port 22 is provided in a part of the side wall 20 c of the housing 20.
  • the blower 1 sucks air from the suction port 21 located on the extension line of the rotary shaft 30 of the centrifugal fan 10 as indicated by an arrow AR1 in FIG. 1B.
  • the sucked air is compressed in the housing 20 and discharged from a discharge port 22 provided in a direction orthogonal to the rotation shaft 30 of the housing 20 as indicated by an arrow AR2 in FIG. 1A.
  • the blower 1 is applied to various devices such as a ventilation fan and an air curtain. Moreover, the air blower 1 is applied to an air conditioner by disposing a heat exchanger in the vicinity of the discharge port 22 of the air blower 1.
  • the blades 12 and the main plate 11 of the centrifugal fan 10 are made of, for example, stainless steel, aluminum, titanium, or synthetic resin depending on the size or type of the device to be applied.
  • the arrangement of the blades 12 of the centrifugal fan 10 is as follows: (1) the total number n of blades is an odd number; (2) the pitch angle types are the first pitch angle ⁇ 1 and the second pitch. There are two types of angles ⁇ 2, the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are different, and (3) m first pitch angles ⁇ 1 are arranged side by side in the first direction. Pm pitch angles ⁇ 2 are arranged side by side in the second direction, and (4) there is one difference between the number of first pitch angles ⁇ 1 and the number of second pitch angles ⁇ 2. (5) The first summed pitch angle obtained by adding m first pitch angles ⁇ 1 is different from the second summed pitch angle obtained by adding nm second pitch angles ⁇ 2.
  • the number of blades of the centrifugal fan 10 is set to 11, and the blades W1 to W11 are arranged around the rotating shaft 30.
  • the blades W1 to W11 are arranged around the rotation axis 30, eleven pitch angles are formed.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are defined with any one of 11 blades as a reference blade.
  • the blade W1 is set as a reference blade
  • the blade W1 and the clockwise direction of the circumference of the blade W1 and the rotating shaft 30 (the X direction in the figure: hereinafter “first The pitch angle formed by the blades W2 adjacent to each other in the “direction X”) is defined as a first pitch angle ⁇ 1.
  • the pitch angle formed by the blade W1 and the blade W11 adjacent to the blade W1 and the counterclockwise direction of the circumference of the rotating shaft 30 (the Y direction in the drawing: hereinafter referred to as “second direction Y”). Is defined as a second pitch angle ⁇ 2.
  • the definition of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 is also defined in the following second to fourth embodiments.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2.
  • n is set to 11 and ⁇ is set to 1.3. Then, these values are applied to Equation 2 under the condition that the number of small pitch angles is increased by one. Then, since ⁇ can be derived as 28.8 °, a small pitch angle is determined to be 28.8 ° and a large pitch angle is determined to be 37.44 °. Assuming that the large pitch angle is the first pitch angle ⁇ 1 and the small pitch angle is the second pitch angle ⁇ 2, as shown in FIG. 2, the first pitch angle ⁇ 1 is the first pitch angle between the blades W1 and W6. Are arranged side by side in the direction X, and six second pitch angles ⁇ 2 are arranged in the second direction Y between the blades W1 and W6.
  • the pitch angles are 37.44 °, 37.44 °, 37.44 °, 37.44 °, 37.44 °, 28.8 °, 28.8 °, 28.8 °, 28.8 ° and 28.8 °.
  • the position of the pitch angle is specified by attaching numbers 1 to 11 along the first direction X.
  • the first total pitch angle is formed by arranging five first pitch angles ⁇ 1, and the second total pitch angle is formed by arranging six second pitch angles ⁇ 2.
  • the first summed pitch angle is different from the second summed pitch angle, and the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. Are arranged with the boundary line D1 as a boundary.
  • the blade characteristics of the centrifugal fan 10 having such a blade arrangement will be described in comparison with a comparative example.
  • blades of the centrifugal fan of the comparative example blades in which 11 blades are arranged at an equal pitch around the rotation axis (hereinafter referred to as “equal pitch blades”), and 11 blades are periodically simulated around the rotation axis.
  • Blades arranged according to a random arrangement hereinafter referred to as “periodic pseudo-random arrangement blades”.
  • FIG. 3 is a table showing the pitch angles of the equi-pitch blades, the periodic pseudo-random array blades, and the blades of the present embodiment in association with the pitch angle position numbers.
  • the numbers shown in the column of the pitch angle positions are numbers corresponding to the numbers of the pitch angle positions in FIG.
  • the pitch angle of the equal pitch blades is the same for all pitch angles. Specifically, eleven blades are arranged with a pitch angle of 32.73 °.
  • an M-type array is used as the periodic pseudo-random array of the periodic pseudo-random array blades.
  • the M system array is a binary number sequence of 0 and 1 having a period of 2 n ⁇ 1, the number of number sequences in one period is an odd number, and the difference between the numbers of “0” and “1” Is defined as 1.
  • “0” is associated with a large pitch angle
  • “1” is associated with a small pitch angle
  • the period is set to 11.
  • the numerical sequence indicated by the M-sequence is 110111100010. As shown in FIG.
  • the pitch angle based on this number sequence corresponds to the position of the pitch angle, 28.8 °, 28.8 °, 37.44 °, 28.8 °, 28.8 °, 28 8 °, 37.44 °, 37.44 °, 37.44 °, 28.8 ° and 37.44 °.
  • FIGS. 4A, 4B, and 4C show changes in sound pressure Pn (t) with the passage of time at arbitrary observation points of the equi-pitch blades, the periodic pseudo-random array blades, and the blades of the present embodiment, respectively.
  • FIG. 4A is a graph in which sound pressure P1 (t) of equal pitch blades is measured along time lapse t
  • FIG. 4B is a graph in which sound pressure P2 (t) of periodically pseudorandom array blades is measured along time lapse t
  • FIG. 4C is a graph obtained by measuring the sound pressure P3 (t) of the blade according to the present embodiment over time.
  • the vertical axis represents the value of the sound pressure P with the maximum value of the sound pressure set to 1 and the minimum value set to 0, and the horizontal axis represents the time t.
  • P1 (t) sin ( ⁇ t)
  • the maximum value of the sound pressure P1 is periodically generated when the blade passes through the observation point. Therefore, the maximum sound pressure is generated when each of the blades W1 to W11 passes through the observation point. Since the pitch angles of all the blades are equal, the maximum sound pressure is generated at equal time intervals.
  • the maximum sound pressure is generated at the timing when each of the blades W1 to W11 arrayed according to the M-system array passes the observation point. Since the blades are arranged in a periodic pseudo-random arrangement, the maximum sound pressure is generated according to the arrangement interval.
  • the blades W1 to W6 arranged at the first pitch angle ⁇ 1 and the blades W6 to W11 arranged at the second pitch angle ⁇ 2 The maximum sound pressure is generated at the timing of passing through.
  • the maximum sound pressure is generated according to the arrangement interval of the blades arranged at the first pitch angle ⁇ 1 and the arrangement interval of the blades arranged at the second pitch angle ⁇ 2.
  • FIG. 5 is a graph showing the relationship between amplitude and frequency obtained by FFT analysis.
  • the vertical axis represents amplitude
  • the horizontal axis represents frequency.
  • the equi-pitch blades showed a peak spectrum of 0.5 at a frequency of 550 Hz, which is a fundamental frequency obtained from a frequency of 50 Hz ⁇ total number of blades of 11.
  • the periodically pseudorandom array of vanes showed a peak spectrum of 0.3741005 at a frequency of 550 Hz.
  • the blade used in the present embodiment showed two peak spectra on the low frequency side and the high frequency side with a frequency of 550 Hz, and the higher peak spectrum was 0.28127575.
  • the peak spectrum value can be kept low and the peak value can be dispersed and the noise of the centrifugal fan 10 can be reduced as compared with the blades of the equal pitch blade and the periodic pseudo-random arrangement. It can be greatly reduced.
  • the centrifugal fan 10 is arranged such that the first summed pitch angle and the second summed pitch angle are biased around the rotation shaft 30. Noise can be greatly reduced. Further, since the centrifugal fan 10 is manufactured by applying only two types of pitch angles, the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2, the design of the centrifugal fan 10 is simplified and the manufacturing cost is reduced. Can be reduced.
  • the centrifugal fan 10 according to the present embodiment can be applied to various products that use the blower 1, for example, a ventilation fan or an air conditioner, by being incorporated in the blower 1, so that when these products are operated, Noise can be greatly reduced.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are set under the condition that the number of small pitch angles is increased by one.
  • the same effect can be obtained in another example (not shown) in which the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are set.
  • n is set to 11 and ⁇ is set to 1.3. These values are applied to the above equation 1. Then, since ⁇ can be derived as 28.12 °, a small pitch angle is calculated as 28.12 ° and a large pitch angle is determined as 36.56 °. If the large pitch angle is the first pitch angle ⁇ 1 and the small pitch angle is the second pitch angle ⁇ 2, six first pitch angles ⁇ 1 are arranged in the first direction X between the blades W1 and W7. In addition, five second pitch angles ⁇ 2 are arranged in the second direction Y between the blades W7 and W1.
  • the pitch angle is 36.56 °, 36.56 °, 36.56 °, 36.56 °, 36.56 °, 36.56 °, 28.12 °, 28.12 °, 28.12 °, 28.12 °, and 28.12 °.
  • the first total pitch angle is formed by arranging six first pitch angles ⁇ 1, and the second total pitch angle is formed by arranging five second pitch angles ⁇ 2.
  • the first summed pitch angle and the second summed pitch angle are different from each other, and the first summed pitch angle and the second summed pitch angle are arranged around the rotating shaft 30 in a biased manner.
  • the pitch angle is set under the condition that the number of large pitch angles is increased by one, the first combined pitch angle and the second combined pitch angle are biased around the rotating shaft 30, so that the centrifugal fan 10 noise can be greatly reduced.
  • centrifugal fan 10 of the present embodiment has an equivalent noise reduction effect in both cases where the rotating shaft 30 of the centrifugal fan 10 rotates forward and reverse.
  • the blade characteristics in the case of normal rotation and reverse rotation will be described below in comparison with a periodic pseudo-random array blade.
  • the pitch angle arrangement of the periodically pseudo-random array blades can be represented by an array of 110101100010, with a large pitch angle corresponding to “0” and a small pitch angle corresponding to “1”.
  • the centrifugal fan When the centrifugal fan is rotated forward once, the blades pass through the observation points in this order of arrangement, and the pattern of the sound pressure P2 (t) shown in FIG. 4B is shown.
  • the centrifugal fan is reversed once, the blades pass through the observation points in an arrangement order different from normal rotation of 01000111011. Therefore, the pattern of sound pressure generated differs between forward rotation and reverse rotation, and the noise reduction effect is also different.
  • the noise reduction effect may be reduced when the centrifugal fan is reversed.
  • the centrifugal fan 10 can be rotated in both the first direction X that is the forward rotation direction and the second direction Y that is the reverse rotation direction.
  • the direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
  • the pitch angle of the blades of the present embodiment is set to “0” as in the case of the pitch angle of the periodic pseudo-random array blades.
  • the small pitch angle is made to correspond to “1”.
  • the pitch angles of the blades of the present embodiment shown in FIG. 3 can be represented by an arrangement of 00000111111 from the pitch angle positions “1” to “11”.
  • the blade pattern when the centrifugal fan 10 continuously rotates forward or backward can be explained as follows.
  • the area around the rotation axis 30 is indicated by a first summed pitch angle area (hereinafter referred to as “A area”) obtained by adding five first pitch angles ⁇ 1 indicated by an array of 00000 and an array of 111111.
  • a area a first summed pitch angle area
  • B region a second summed pitch angle region obtained by summing six second pitch angles ⁇ 2.
  • the total number of blades is an odd number
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are set to different angles
  • the difference from the number of ⁇ 2 was 1.
  • the present invention is not limited to the number of blades and the number of pitch angles, and the total number of blades is an even number, and the number of first pitch angles ⁇ 1 is equal to the number of second pitch angles ⁇ 2. Also applies.
  • the arrangement of the blades of the centrifugal fan according to the present embodiment is as follows: (1) The total number n of blades is an even number; (2) The pitch angle types are the first pitch angle ⁇ 1 and the second pitch angle. There are two types, the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are different, and (3) m first pitch angles ⁇ 1 are arranged side by side in the first direction, and the second pitch angle ⁇ 2 Are arranged side by side in the second direction, (4) the number of first pitch angles ⁇ 1 is the same as the number of second pitch angles ⁇ 2, and (5) first The first total pitch angle obtained by adding m pitch angles ⁇ 1 and the second total pitch angle obtained by adding nm second pitch angles ⁇ 2 are different from each other.
  • the centrifugal fan of the present embodiment has the same basic configuration as the centrifugal fan 10 of the first embodiment.
  • the centrifugal fan 10 of the present embodiment can be rotated in both the first direction X that is the forward rotation direction and the second direction Y that is the reverse rotation direction.
  • the direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2.
  • n / 2 ⁇ ⁇ + n / 2 ⁇ ⁇ ⁇ ⁇ 360 ° (Formula 3)
  • n is the total number of blades
  • ⁇ is the angle of the small pitch angle
  • ⁇ is the ratio of the large pitch angle to the small pitch angle.
  • n is set to 10 and ⁇ is set to 1.3, and these values are applied to Equation 3. Then, since ⁇ can be derived as 31.3 °, a small pitch angle is determined to be 31.3 ° and a large pitch angle is determined to be 40.69 °. If the large pitch angle is the first pitch angle ⁇ 1 and the small pitch angle is the second pitch angle ⁇ 2, as shown in FIG. 6, the first pitch angle ⁇ 1 is the first pitch angle between the blades W1 and W6. The second pitch angle ⁇ 2 is arranged side by side in the second direction Y between the blades W1 and W6.
  • the pitch angle is 40.69 °, 40.69 °, 40.69 °, 40.69 °, 40.69 °, 40.69 °, 31.3 °, It is defined as 31.3 °, 31.3 °, 31.3 °, 31.3 °.
  • the first total pitch angle is formed by arranging five first pitch angles ⁇ 1, and the second total pitch angle is formed by arranging five second pitch angles ⁇ 2.
  • the first summed pitch angle and the second summed pitch angle are different, and the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. , They are arranged biased with respect to the boundary line D2.
  • the noise of the centrifugal fan 10 can be greatly reduced.
  • first total pitch angle in which five first pitch angles ⁇ 1 are arranged and the second total pitch angle in which five second pitch angles ⁇ 2 are arranged are arranged around the rotation axis 30, In both cases where the centrifugal fan 10 rotates forward and reversely, the same sound pressure pattern is generated, and an equivalent noise reduction effect is achieved.
  • the blade arrangement of the centrifugal fan according to the present embodiment is as follows: (1) The total number n of the blades is odd or even; (2) The pitch angle types are the first pitch angle ⁇ 1 and the second pitch. The first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are different, and (3) m first pitch angles ⁇ 1 are arranged in the first direction, and the second pitch angle The angle ⁇ 2 is arranged in a number of nm in the second direction, and (4) the difference between the number of the first pitch angles ⁇ 1 and the number of the second pitch angles ⁇ 2 is 2 or more, (5) The first summed pitch angle obtained by summing m first pitch angles ⁇ 1 is different from the angle of the second summed pitch angle obtained by summing nm second pitch angles ⁇ 2. It is characterized by.
  • the centrifugal fan of the present embodiment has the same basic configuration as the centrifugal fan 10 of the first embodiment.
  • the centrifugal fan 10 of the present embodiment can be rotated in both the first direction X that is the forward direction and the second direction Y that is the reverse direction.
  • the direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2.
  • n is set to 11
  • ⁇ is set to 1.3
  • a is set to 3 (the number of large pitch angles is three more than the number of small pitch angles).
  • ⁇ can be derived as 27.5 °, so that a small pitch angle is 27.5 ° and a large pitch angle is 35.7 °.
  • the first pitch angle ⁇ 1 is the first pitch angle between the blades W1 and W5.
  • the second pitch angle ⁇ 2 is arranged in the second direction Y between the blades W1 and W5.
  • the pitch angle is 27.5 °, 27.5 °, 27.5 °, 27.5 °, 35.7 °, 35.7 °, It is defined as 35.7 °, 35.7 °, 35.7 °, 35.7 °, and 35.7 °.
  • a first summed pitch angle is formed by adding four first pitch angles ⁇ 1
  • a second total pitch angle is formed by adding seven pitch angles ⁇ 2.
  • the first summed pitch angle is different from the second summed pitch angle
  • the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. Are arranged with the boundary line D3 as a boundary.
  • the centrifugal fan 10 is arranged so that the first summed pitch angle and the second summed pitch angle are biased around the rotation shaft 30.
  • the generated noise can be greatly reduced.
  • first total pitch angle in which four first pitch angles ⁇ 1 are arranged and the second total pitch angle in which seven second pitch angles ⁇ 2 are arranged are arranged around the rotation axis 30, In both cases where the centrifugal fan 10 rotates forward and reversely, the same sound pressure pattern is generated, and an equivalent noise reduction effect is achieved.
  • the first combined pitch angle and the second combined pitch angle are arranged so as to surround the entire circumference of the rotating shaft 30, and the first combined pitch angle and the second combined pitch angle are arranged. It was explained that the combined pitch angle is different.
  • the present invention is not limited to surrounding the entire circumference of the rotating shaft with only the first summing angle and the second summing angle, and the third summing of the first summing pitch angle and the second summing pitch angle is the third. May be formed, and two or more of the third total angles may be arranged around the rotation axis.
  • the centrifugal fan according to the present embodiment is mainly used as a cooling fan for electric motors for railway vehicles.
  • An electric motor for a railway vehicle including a centrifugal fan will be described with reference to FIG.
  • the electric motor 100 includes a frame 200, a stator 300, a rotor 400, a rotating shaft 500 that rotates integrally with the rotor 400, and a centrifugal fan 600 attached to the rotating shaft 500.
  • the frame 200 is disposed so as to surround the stator 300 and the rotor 400, and is formed with a suction port 201 through which air is sucked and a discharge port 202 through which the sucked air is discharged.
  • the stator 300 includes a stator core 301 and a stator coil 302 wound around the stator core 301, and the rotor 400 is disposed to face the stator 300.
  • a rotation shaft 500 is fixed through the central portion of the rotor 400.
  • One end of the rotating shaft 500 is connected to an axle (not shown) of the vehicle, and the rotating shaft 500 is rotated to rotate the axle. Both ends of the rotating shaft 500 are supported by bearings 501 provided on the frame 200.
  • the centrifugal fan 600 includes a plurality of blades 601, and the plurality of blades 601 are arranged radially around the rotation shaft 500.
  • centrifugal fan 600 attached to the rotating shaft 500 also rotates. While the rotating shaft 500 is rotating, the temperature of the components of the electric motor 100 rises due to the copper loss generated in the stator coil 302 and the iron loss due to the induced current generated in the rotor 400. Centrifugal fan 600 is rotated in accordance with rotation of rotating shaft 500, and air is introduced from suction port 201 by rotating centrifugal fan 600. As the introduced air passes through the electric motor 100 and is discharged from the discharge port 202, the inside of the electric motor 100 is cooled.
  • the electric motor 100 rotates the rotary shaft 500 according to the driving direction.
  • the rotary shaft 500 is rotated in the P direction as shown in FIG. 8 in the case of driving in the forward direction, and is rotated in the Q direction that is opposite to the P direction in the case of driving in the backward direction.
  • the arrangement of the blades of the centrifugal fan 600 is an unequal pitch arrangement or a periodic pseudo-random arrangement, when the rotary shaft 500 is viewed in a certain direction of the rotor 400 and from the opposite direction, The arrangement of the pitch angles of the blades is different.
  • Centrifugal fan 600 in the present embodiment can be suitably applied to a centrifugal fan that needs to rotate in the P direction and Q direction, specifically, to rotate forward and backward.
  • the P direction corresponds to the first direction shown in FIG. 9, and the Q direction corresponds to the second direction Y.
  • the blade arrangement of the centrifugal fan 600 is as follows: (1) the total number n of blades is an even number; (2) pitch angle types are the first pitch angle ⁇ 1 and the second pitch angle. There are two types of ⁇ 2, and the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are different, and (3) the first pitch angle ⁇ 1 is arranged side by side in the first direction, and the second pitch angle The angle ⁇ 2 is arranged side by side in the second direction, and (4) the first summed pitch angle obtained by adding the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 summed by q. (4) The first summed pitch angle and the second summed pitch angle are summed to form a third pitch angle, and the third pitch angle is set to the rotational axis. It is characterized by arranging two or more around.
  • the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 are uniquely determined by the above formula 4 or formula 5 by determining the total number of blades and the ratio of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2. Determined.
  • the number of first pitch angles ⁇ 1 and the number of second pitch angles ⁇ 2 are the same, and n is set to 12 and ⁇ is set to 1.3.
  • ⁇ can be derived as 26.1 °, so that the small pitch angle is 26.1 ° and the large pitch angle is 33.9 °.
  • the first pitch angle ⁇ 1 is between the blades W1 and W4 as shown in FIG. Are arranged side by side in the direction X, and the second pitch angle ⁇ 2 is arranged side by side in the second direction Y between the blades W1 and W11.
  • a first total pitch angle is formed by arranging three first pitch angles ⁇ 1, and a second total pitch angle is formed by arranging three second pitch angles ⁇ 2.
  • the first combined pitch angle is And the second total pitch angle are formed differently.
  • first summed pitch angle and the second summed pitch angle are summed to form a third summed pitch angle.
  • the third combined pitch angle is formed between W10 and W4 in the first direction X in FIG. Then, by forming this third combined pitch angle in the second direction Y of W10 and W4, two third combined pitch angles are formed around the rotation axis 500.
  • a region where the first summed pitch angle is formed is an A region
  • a region where the second summed pitch angle is formed is a B region
  • the method of arranging the A region and the B region is a method in which the periphery of the rotation axis 500 is first divided into four or more even regions, and then A and B are alternately arranged in the divided regions.
  • wing of FIG. 9 is demonstrated below using the said method.
  • FIG. 10A the region around the rotation axis 500 is divided into four regions. Then, the A area and the B area are alternately arranged in the four divided areas.
  • FIG. 10B shows an arrangement of areas when the area to be divided is 8 which is an even number of 4 or more. As shown in FIG. 10B, the region around the rotation axis 500 is divided into eight. In the area divided into eight, the A area and the B area are alternately arranged.
  • the noise of the centrifugal fan 600 is reduced. It can be greatly reduced.
  • the centrifugal fan 600 when the centrifugal fan 600 is continuously rotated, the A area and the B area appear alternately. That is, since the A region and the B region appear in the same pattern during forward rotation and reverse rotation of the centrifugal fan 600, the same noise reduction effect can be achieved in both the forward driving and the returning driving of the railway vehicle. .
  • Embodiments 1 to 4 the present invention has been described using a centrifugal fan, but the present invention can also be applied to fans other than the centrifugal fan.
  • the fan of the present invention can be applied to an axial fan, a diagonal fan, and a cross fan.
  • the attachment angle between the main plate 11 and the blade 12 is set to 90 °, but the present invention is not limited to such an attachment angle. It can be set as appropriate according to the type of fan.
  • the blades 12 are radial blades facing in the radial direction, but the present invention is not limited to such blades.
  • the present invention can also be applied to forward blades facing in the direction of rotation, and the forward blades can be applied to a multiblade fan.
  • the present invention can also be applied to a backward blade in which the blade is directed in the direction opposite to the rotation direction, and the backward blade can be applied to a turbofan.
  • the disk-shaped main plate 11 has been described as a support member, but the present invention is not limited to such a support member.
  • a cylindrical rotating shaft may be used as a support member, and a plurality of blades may be attached around the rotating shaft.
  • the value of a is set as a value where the number of large pitch angles is larger than the number of small pitch angles, but the number of small pitch angles may be set larger than the number of large pitch angles. .
  • the electric motor for the railway vehicle has been described as an example, but the vehicle driven by the electric motor is not limited to the railway vehicle.
  • the present invention may be any vehicle that uses an electric motor that rotates the axle forward and backward, and can be applied to, for example, an automobile.
  • the number of first pitch angles ⁇ 1 and the number of second pitch angles ⁇ 2 have been described as being the same number, but the number is not limited to the same number.
  • the difference in the number of the first pitch angle ⁇ 1 and the second pitch angle ⁇ 2 may be 1 or more.
  • the fan is described using the electric motor applied to the railway vehicle, but the fan described in the first to third embodiments may be used as the fan of the railway vehicle.
  • the present invention can be suitably used for a fan mounted on a blower or an electric motor.

Abstract

Provided is a centrifugal fan (10) in which: one blade from among 11 blades is configured as a reference blade (W1); a first pitch angle (θ1) is formed between the reference blade (W1) and a blade that is adjacent in a first direction (X) around a rotation shaft (30); and five of the first pitch angles (θ1) are arranged adjacently in the first direction (X). A second pitch angle (θ2) which differs from the first pitch angle (θ1) is formed between the reference blade (W1) and a blade that is adjacent in a second direction (Y) opposite the first direction (X), and six of the second pitch angles (θ2) are arranged adjacently in the second direction (Y). A first combined pitch angle obtained by adding up the five first pitch angles (θ1) and a second combined pitch angle obtained by adding up the six second pitch angles (θ2) are different from each other, and thus the noise of the centrifugal fan (10) is reduced.

Description

ファン、送風機、及び電動機Fan, blower, and electric motor
　本発明は、ファン、送風機、及び電動機に関する。 The present invention relates to a fan, a blower, and an electric motor.
　気流を発生するファンは、回転軸の周方向に等ピッチで配置された複数の羽根を備え、当該複数の羽根を回転軸の周りに回転させることで、気流を発生する。複数の羽根が等ピッチで配置されたファンは、複数の羽根が回転されることにより、回転数と羽根枚数との積で求められる値を基本周波数とする騒音である、いわゆる羽根切り音又はピュアトーン、を発生し、使用者に不快感を与える。  A fan that generates an airflow includes a plurality of blades arranged at an equal pitch in the circumferential direction of the rotation shaft, and the airflow is generated by rotating the plurality of blades around the rotation shaft. A fan in which a plurality of blades are arranged at an equal pitch is a so-called blade cutting sound or pure noise that is a noise whose fundamental frequency is a value obtained by the product of the number of rotations and the number of blades when the plurality of blades are rotated. Tone, which causes discomfort to the user.
　騒音を低減するために、回転軸の周方向に配置された複数の羽根を、不等ピッチで配置するファンが知られている（特許文献１）。特許文献１に開示されたファンは、羽根のピッチ角が隣接する羽根毎に異なり、各ピッチ角は非周期的に変化して配置される。 In order to reduce noise, a fan is known in which a plurality of blades arranged in the circumferential direction of a rotating shaft are arranged at unequal pitches (Patent Document 1). In the fan disclosed in Patent Document 1, the pitch angle of the blades is different for each adjacent blade, and each pitch angle is aperiodically changed.
　また、ファンの騒音を低減する他の方法として、特許文献２に示すように、周期的疑似ランダム配列の配列パターンを用いて、羽根が並べられたファンを用いる方法が知られている。 Also, as another method for reducing fan noise, as shown in Patent Document 2, a method using a fan in which blades are arranged using a periodic pseudo-random array pattern is known.
特開平１－１５５０９８号公報Japanese Unexamined Patent Publication No. 1-155098 特開平８－７４７８３号公報Japanese Patent Laid-Open No. 8-74783
　不等ピッチで羽根が配置されたファン、及び周期的疑似ランダム配列で羽根が配置されたファンでは、ピッチが相違する羽根が混在して配置されるため、構造が複雑となり、コストもかかる。また、ファンの騒音も大きく低減されるまでには至っていない。 In a fan in which blades are arranged at unequal pitches and a fan in which blades are arranged in a periodic pseudo-random arrangement, blades having different pitches are arranged in a mixed manner, resulting in a complicated structure and cost. Moreover, the noise of the fan has not been greatly reduced.
　また、車両を駆動させる電動機の冷却用ファンとして、ファンを用いる場合は、ファンの回転方向に応じた騒音対策が必要である。例えば、鉄道車両のように車両が往復運転される場合、車軸は、往路運転では正転され、復路運転では逆転される。冷却用ファンは、車軸に連結されているので、車軸が正転又は逆転されるにともない、冷却用ファンも正転又は逆転される。冷却用ファンは、正転と逆転の双方の回転において、同等な騒音低減効果を奏する必要がある。不等ピッチで羽根が配列されたファン、及び周期的疑似ランダム配列で羽根が配列されたファンは、ピッチが相違する羽根が混在して配置されているので、正転と逆転とでは、音圧のパターンが相違し、同等な騒音低減効果を奏することはできない。 Also, when using a fan as a cooling fan for an electric motor that drives a vehicle, it is necessary to take noise countermeasures according to the direction of rotation of the fan. For example, when the vehicle is reciprocated like a railway vehicle, the axle is rotated forward during forward travel and reverse during reverse travel. Since the cooling fan is connected to the axle, as the axle is rotated forward or reverse, the cooling fan is also rotated forward or reverse. The cooling fan needs to have an equivalent noise reduction effect in both forward and reverse rotations. Fans with blades arranged at unequal pitches and fans with blades arranged in a periodic pseudo-random arrangement are mixed with blades with different pitches. These patterns are different and an equivalent noise reduction effect cannot be achieved.
　本発明は、上記事由に鑑みてなされたものであり、構造が簡単で安価であり、騒音を大きく低減することができ、ファンの正転時と逆転時で同等の騒音低減効果を奏するファン、送風機、及び電動機を提供することを目的とする。 The present invention has been made in view of the above reasons, has a simple structure, is inexpensive, can greatly reduce noise, and exhibits a similar noise reduction effect during forward rotation and reverse rotation of the fan, An object is to provide a blower and an electric motor.
　上記目的を達成するために、本発明に係るファンは、
　回転軸を中心に回転する支持部材と、前記支持部材に取り付けられ、前記回転軸の周りに放射状に配置されたｎ枚（ｎは２以上の整数）の羽根と、を備え、前記回転軸を中心に前記支持部材が回転することで、前記ｎ枚の羽根が回転されて気流を生成するファンであって、
　前記ｎ枚の羽根は、ｎ個のピッチ角を隔てて前記回転軸の周りに配置され、
　前記ｎ枚の羽根のうち何れか１枚の羽根を基準羽根とし、当該基準羽根と、前記回転軸の周の第１の方向に隣り合う羽根と、で第１のピッチ角を形成し、当該第１のピッチ角は、前記第１の方向にｍ個（ｍは１以上の整数、ｎ＞ｍ）並んで配置され、
　前記基準羽根と、前記第１の方向と反対方向である第２の方向に隣り合う羽根と、で前記第１のピッチ角と異なる第２のピッチ角を形成し、当該第２のピッチ角は、前記第２の方向にｎ－ｍ個並んで配置され、
　前記第１のピッチ角をｍ個合算した第１の合算ピッチ角と、前記第２のピッチ角をｎ－ｍ個合算した第２の合算ピッチ角と、は異なる。 In order to achieve the above object, a fan according to the present invention provides:
A support member that rotates about a rotation axis; and n (n is an integer of 2 or more) blades that are attached to the support member and are arranged radially around the rotation axis. A fan for generating an air current by rotating the n blades by rotating the support member in the center;
The n blades are arranged around the rotation axis at n pitch angles,
Any one of the n blades is used as a reference blade, and a first pitch angle is formed between the reference blade and a blade adjacent to the first direction of the circumference of the rotation shaft, The first pitch angles are arranged in the m direction (m is an integer of 1 or more, n> m) in the first direction,
A second pitch angle different from the first pitch angle is formed by the reference blade and a blade adjacent to the second direction that is opposite to the first direction, and the second pitch angle is , N−m arranged in the second direction,
A first summed pitch angle obtained by summing m of the first pitch angles is different from a second summed pitch angle obtained by summing nm of the second pitch angles.
　本発明によれば、構造が簡単で安価であり、騒音を大きく低減することができ、ファンの正転時と逆転時で同等の騒音低減効果を奏するファン、送風機、及び電動機を提供することができる。 According to the present invention, it is possible to provide a fan, a blower, and an electric motor that have a simple structure, are inexpensive, can greatly reduce noise, and have the same noise reduction effect during forward rotation and reverse rotation of the fan. it can.
本発明の実施の形態１に係る遠心ファンを備える送風機の概略正面図1 is a schematic front view of a blower including a centrifugal fan according to Embodiment 1 of the present invention. 図１ＡのＡ－Ａ線での概略断面図Schematic sectional view taken along line AA in FIG. 1A 実施の形態１に係る遠心ファンの羽根の配列状態を示す図The figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 1. FIG. 実施の形態１に係る遠心ファンの羽根と比較例の羽根のピッチ角を示す図The figure which shows the pitch angle of the blade | wing of the centrifugal fan which concerns on Embodiment 1, and the blade | wing of a comparative example 等ピッチ羽根の音圧の変化を示すグラフGraph showing change in sound pressure of equal pitch blades 周期的疑似ランダム配列の羽根の音圧の変化を示すグラフGraph showing changes in sound pressure of blades with periodic pseudo-random arrangement 実施の形態１に係る遠心ファンの羽根の音圧の変化を示すグラフThe graph which shows the change of the sound pressure of the blade | wing of the centrifugal fan which concerns on Embodiment 1. 実施の形態１に係る遠心ファンの羽根と比較例の羽根との周波数と振幅の関係を示すグラフThe graph which shows the relationship between the frequency and amplitude of the blade | wing of the centrifugal fan which concerns on Embodiment 1, and the blade | wing of a comparative example 実施の形態２に係る遠心ファンの羽根の配列状態を示す図The figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 2. FIG. 実施の形態３に係る遠心ファンの羽根の配列状態を示す図The figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 3. 実施の形態４に係る遠心ファンを備える電動機の概要図Schematic diagram of an electric motor provided with a centrifugal fan according to Embodiment 4 実施の形態４に係る遠心ファンの羽根の配列状態を示す図The figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 4. 実施の形態４に係る遠心ファンの羽根の配列状態を示す他の図The other figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 4. 実施の形態４に係る遠心ファンの羽根の配列状態を示す他の図The other figure which shows the arrangement | sequence state of the blade | wing of the centrifugal fan which concerns on Embodiment 4.
　以下、本発明に係るファンの実施の形態を、遠心ファンを備える送風機を一例として図面を参照しながら詳細に説明する。 Hereinafter, embodiments of a fan according to the present invention will be described in detail with reference to the drawings, taking a blower provided with a centrifugal fan as an example.
（実施の形態１）
　本実施の形態に係る遠心ファンを備える送風機１を、図１Ａ、図１Ｂに示す。図１Ａおよび図１Ｂに示すように、送風機１は、遠心ファン１０と、遠心ファン１０を収納するハウジング２０と、遠心ファン１０を回転させる回転軸３０と、回転軸３０を駆動するモータ４０と、を備える。 (Embodiment 1)
FIG. 1A and FIG. 1B show a blower 1 including a centrifugal fan according to the present embodiment. As shown in FIGS. 1A and 1B, the blower 1 includes a centrifugal fan 10, a housing 20 that houses the centrifugal fan 10, a rotating shaft 30 that rotates the centrifugal fan 10, a motor 40 that drives the rotating shaft 30, Is provided.
　遠心ファン１０は、支持部材である主板１１と、複数の羽根１２と、からなる。主板１１は、複数の羽根１２を支持する部材であり、円板状に形成された部材である。主板１１は、主板１１の中心にモータ４０の回転軸３０が貫通して固定されることで、回転軸３０に取り付けられる。複数の羽根１２は、主板１１の一方の面に、回転軸３０を中心としてその周方向に放射状に取り付けられる。複数の羽根１２は、各羽根が半径方向を向いた径向き羽根である。このような羽根を備える遠心ファン１０は、プレート送風機に適用できる。また、主板１１と羽根１２との取付角度は、９０°に設定される。 The centrifugal fan 10 includes a main plate 11 that is a support member and a plurality of blades 12. The main plate 11 is a member that supports the plurality of blades 12, and is a member formed in a disk shape. The main plate 11 is attached to the rotary shaft 30 when the rotary shaft 30 of the motor 40 is fixed through the center of the main plate 11. The plurality of blades 12 are attached to one surface of the main plate 11 radially in the circumferential direction around the rotation shaft 30. The plurality of blades 12 are radial blades in which each blade faces the radial direction. The centrifugal fan 10 provided with such blades can be applied to a plate blower. The attachment angle between the main plate 11 and the blades 12 is set to 90 °.
　ハウジング２０は、扁平な箱状の部材であり、内部に遠心ファン１０を収容する。ハウジング２０は、互いに対向する主壁２０ａ、２０ｂと、主壁２０ａ、２０ｂの間の領域を囲む側壁２０ｃとを含む。遠心ファン１０は、回転軸３０がハウジング２０の厚さ方向に沿った状態で、ハウジング２０の内部に収容される。ハウジング２０の主壁２０ｂには、遠心ファン１０と対向する位置に、吸込口２１が設けられる。また、ハウジング２０の側壁２０ｃの一部には、吐出口２２が設けられる。 The housing 20 is a flat box-shaped member and accommodates the centrifugal fan 10 therein. The housing 20 includes main walls 20a and 20b facing each other, and a side wall 20c surrounding a region between the main walls 20a and 20b. Centrifugal fan 10 is housed inside housing 20 with rotating shaft 30 along the thickness direction of housing 20. A suction port 21 is provided in the main wall 20 b of the housing 20 at a position facing the centrifugal fan 10. A discharge port 22 is provided in a part of the side wall 20 c of the housing 20.
　送風機１は、遠心ファン１０がモータ４０により回転されることにより、図１Ｂの矢印ＡＲ１に示すように、遠心ファン１０の回転軸３０の延長線上に位置する吸込口２１から空気を吸い込む。吸い込まれた空気は、ハウジング２０内で圧縮されて、図１Ａの矢印ＡＲ２に示すように、ハウジング２０の回転軸３０に直交する方向に設けられた吐出口２２から吐出される。 When the centrifugal fan 10 is rotated by the motor 40, the blower 1 sucks air from the suction port 21 located on the extension line of the rotary shaft 30 of the centrifugal fan 10 as indicated by an arrow AR1 in FIG. 1B. The sucked air is compressed in the housing 20 and discharged from a discharge port 22 provided in a direction orthogonal to the rotation shaft 30 of the housing 20 as indicated by an arrow AR2 in FIG. 1A.
　送風機１は、様々な装置、例えば、換気扇、エアーカーテンに適用される。また、送風機１は、送風機１の吐出口２２の近傍に、熱交換器を配置することで、空気調和装置に適用される。 The blower 1 is applied to various devices such as a ventilation fan and an air curtain. Moreover, the air blower 1 is applied to an air conditioner by disposing a heat exchanger in the vicinity of the discharge port 22 of the air blower 1.
　遠心ファン１０の羽根１２と主板１１は、適用される装置の大小又は種類に応じて、例えば、ステンレス、アルミニウム、チタン、合成樹脂により製造される。 The blades 12 and the main plate 11 of the centrifugal fan 10 are made of, for example, stainless steel, aluminum, titanium, or synthetic resin depending on the size or type of the device to be applied.
　次に、本実施の形態に係る遠心ファン１０の羽根の配列について、図２を参照して説明する。 Next, the arrangement of the blades of the centrifugal fan 10 according to the present embodiment will be described with reference to FIG.
　本実施の形態に係る遠心ファン１０の羽根１２の配列は、（１）羽根の総枚数ｎが奇数であること、（２）ピッチ角の種類は、第１のピッチ角θ１と第２のピッチ角θ２の２種類であり、第１のピッチ角θ１と第２のピッチ角θ２は相違すること、（３）第１のピッチ角θ１は第１の方向にｍ個並べて配置され、第２のピッチ角θ２は第２の方向にｎ－ｍ個並べて配置されること、（４）第１のピッチ角θ１の数と、第２のピッチ角θ２の数と、の差が１個であること、（５）第１のピッチ角θ１をｍ個合算した第１の合算ピッチ角と、第２のピッチ角θ２をｎ－ｍ個合算した第２の合算ピッチ角と、が相違すること、を特徴とする。 The arrangement of the blades 12 of the centrifugal fan 10 according to the present embodiment is as follows: (1) the total number n of blades is an odd number; (2) the pitch angle types are the first pitch angle θ1 and the second pitch. There are two types of angles θ2, the first pitch angle θ1 and the second pitch angle θ2 are different, and (3) m first pitch angles θ1 are arranged side by side in the first direction. Pm pitch angles θ2 are arranged side by side in the second direction, and (4) there is one difference between the number of first pitch angles θ1 and the number of second pitch angles θ2. (5) The first summed pitch angle obtained by adding m first pitch angles θ1 is different from the second summed pitch angle obtained by adding nm second pitch angles θ2. Features.
　本実施の形態における遠心ファン１０の羽根枚数を１１枚と設定し、Ｗ１～Ｗ１１の羽根を、回転軸３０の周りに配置する。Ｗ１～Ｗ１１の羽根が回転軸３０周りに配置されることで、１１個のピッチ角が形成される。 In the present embodiment, the number of blades of the centrifugal fan 10 is set to 11, and the blades W1 to W11 are arranged around the rotating shaft 30. By arranging the blades W1 to W11 around the rotation axis 30, eleven pitch angles are formed.
　本実施の形態における第１のピッチ角θ１と第２のピッチ角θ２は、１１枚の羽根のうちの任意の１枚を基準羽根として定義される。図２に示すように、１１枚の羽根のうち羽根Ｗ１を基準羽根として設定し、羽根Ｗ１と、羽根Ｗ１と回転軸３０の周の時計回りの方向（図示のＸ方向：以下「第１の方向Ｘ」という。）に隣り合う羽根Ｗ２と、で形成されるピッチ角を、第１のピッチ角θ１と定義する。また、羽根Ｗ１と、羽根Ｗ１と回転軸３０の周の反時計回りの方向（図示のＹ方向：以下「第２の方向Ｙ」という。）に隣り合う羽根Ｗ１１と、で形成されるピッチ角を、第２のピッチ角θ２と定義する。第１のピッチ角θ１と、第２のピッチ角θ２の定義は、以下の実施の形態２～４においても同様に定義するものとする。 In the present embodiment, the first pitch angle θ1 and the second pitch angle θ2 are defined with any one of 11 blades as a reference blade. As shown in FIG. 2, among the 11 blades, the blade W1 is set as a reference blade, and the blade W1 and the clockwise direction of the circumference of the blade W1 and the rotating shaft 30 (the X direction in the figure: hereinafter “first The pitch angle formed by the blades W2 adjacent to each other in the “direction X”) is defined as a first pitch angle θ1. Further, the pitch angle formed by the blade W1 and the blade W11 adjacent to the blade W1 and the counterclockwise direction of the circumference of the rotating shaft 30 (the Y direction in the drawing: hereinafter referred to as “second direction Y”). Is defined as a second pitch angle θ2. The definition of the first pitch angle θ1 and the second pitch angle θ2 is also defined in the following second to fourth embodiments.
　第１のピッチ角θ１と第２のピッチ角θ２は、羽根の総枚数と、第１のピッチ角θ１と第２のピッチ角θ２の比を定めることにより、次の式により一意に定まる。 The first pitch angle θ1 and the second pitch angle θ2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle θ1 and the second pitch angle θ2.
　大きいピッチ角の個数を１つ多くする場合には、
　（ｎ－１）／２×θ＋（ｎ＋１）／２×Δ×θ＝３６０°（式１）
　小さいピッチ角の個数を１つ多くする場合には、
　（ｎ＋１）／２×θ＋（ｎ＋１）／２×Δ×θ＝３６０°（式２）
　と示すことができる。
　ここで、ｎは羽根の総枚数、θは小さいピッチ角の角度、Δは大きいピッチ角と小さいピッチ角の比率を示す。 When increasing the number of large pitch angles by one,
(N−1) / 2 × θ + (n + 1) / 2 × Δ × θ = 360 ° (Formula 1)
When increasing the number of small pitch angles by one,
(N + 1) / 2 × θ + (n + 1) / 2 × Δ × θ = 360 ° (Formula 2)
Can be shown.
Here, n is the total number of blades, θ is the angle of the small pitch angle, and Δ is the ratio of the large pitch angle to the small pitch angle.
　本実施の形態では、ｎを１１と、Δを１．３と設定する。そして、小さいピッチ角の個数を１つ多くする条件で、これらの値を、式２に当てはめる。すると、θは２８．８°と導き出せるので、小さいピッチ角が２８．８°、大きいピッチ角が３７．４４°と求められる。大きいピッチ角を第１のピッチ角θ１とし、小さいピッチ角を第２のピッチ角θ２とすると、図２に示すように、第１のピッチ角θ１は、羽根Ｗ１とＷ６との間に第１の方向Ｘに５個並んで配置され、第２のピッチ角θ２は、羽根Ｗ１とＷ６との間に第２の方向Ｙに６個並んで配置される。具体的には、羽根Ｗ１から回転軸３０の第１の方向Ｘに沿って、ピッチ角は、３７．４４°、３７．４４°、３７．４４°、３７．４４°、３７．４４°、２８．８°、２８．８°、２８．８°、２８．８°、２８．８°、２８．８°と定められる。各ピッチ角の位置を示すため、図２において、ピッチ角の位置を第１の方向Ｘに沿って１～１１の数字を付して位置を特定する。 In this embodiment, n is set to 11 and Δ is set to 1.3. Then, these values are applied to Equation 2 under the condition that the number of small pitch angles is increased by one. Then, since θ can be derived as 28.8 °, a small pitch angle is determined to be 28.8 ° and a large pitch angle is determined to be 37.44 °. Assuming that the large pitch angle is the first pitch angle θ1 and the small pitch angle is the second pitch angle θ2, as shown in FIG. 2, the first pitch angle θ1 is the first pitch angle between the blades W1 and W6. Are arranged side by side in the direction X, and six second pitch angles θ2 are arranged in the second direction Y between the blades W1 and W6. Specifically, along the first direction X of the rotating shaft 30 from the blade W1, the pitch angles are 37.44 °, 37.44 °, 37.44 °, 37.44 °, 37.44 °, 28.8 °, 28.8 °, 28.8 °, 28.8 °, 28.8 ° and 28.8 °. In order to indicate the position of each pitch angle, in FIG. 2, the position of the pitch angle is specified by attaching numbers 1 to 11 along the first direction X.
　第１のピッチ角θ１を５個並べることで、第１の合算ピッチ角を形成し、第２のピッチ角θ２を６個並べることで、第２の合算ピッチ角を形成する。第１の合算ピッチ角は、３７．４４×°５＝１８７．２°であり、第２の合算ピッチ角は、２８．８°×６＝１７２．８°である。このように、第１の合算ピッチ角と第２の合算ピッチ角とは相違し、第１の合算ピッチ角と第２の合算ピッチ角とは、図２に示すように、回転軸３０の周りに境界線Ｄ１を境に偏って配置される。 The first total pitch angle is formed by arranging five first pitch angles θ1, and the second total pitch angle is formed by arranging six second pitch angles θ2. The first summed pitch angle is 37.44 × ° 5 = 187.2 °, and the second summed pitch angle is 28.8 ° × 6 = 172.8 °. Thus, the first summed pitch angle is different from the second summed pitch angle, and the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. Are arranged with the boundary line D1 as a boundary.
　このような羽根の配列を備える遠心ファン１０の羽根特性を、比較例と対比して説明する。 The blade characteristics of the centrifugal fan 10 having such a blade arrangement will be described in comparison with a comparative example.
　比較例の遠心ファンの羽根として、１１枚の羽根を回転軸の周りに等ピッチで配置した羽根（以下、「等ピッチ羽根」という。）と、１１枚の羽根を回転軸周りに周期的疑似ランダム配列に従って配置した羽根（以下、「周期的疑似ランダム配列羽根」という。）と、を用いる。 As the blades of the centrifugal fan of the comparative example, blades in which 11 blades are arranged at an equal pitch around the rotation axis (hereinafter referred to as “equal pitch blades”), and 11 blades are periodically simulated around the rotation axis. Blades arranged according to a random arrangement (hereinafter referred to as “periodic pseudo-random arrangement blades”) are used.
　図３は、等ピッチ羽根と、周期的疑似ランダム配列羽根と、本実施の形態の羽根との、それぞれのピッチ角を、ピッチ角の位置の番号に対応付けて示した表である。図３において、ピッチ角の位置の欄に示された番号は、図２におけるピッチ角の位置の番号に対応する番号である。 FIG. 3 is a table showing the pitch angles of the equi-pitch blades, the periodic pseudo-random array blades, and the blades of the present embodiment in association with the pitch angle position numbers. In FIG. 3, the numbers shown in the column of the pitch angle positions are numbers corresponding to the numbers of the pitch angle positions in FIG.
　等ピッチ羽根のピッチ角は、図３に示すように、全てのピッチ角が同一である。具体的には、３２．７３°のピッチ角をもって１１枚の羽根が配置される。 As shown in FIG. 3, the pitch angle of the equal pitch blades is the same for all pitch angles. Specifically, eleven blades are arranged with a pitch angle of 32.73 °.
　周期的疑似ランダム配列羽根の周期的疑似ランダム配列として、本比較例では、Ｍ系配列を用いる。Ｍ系配列は、２ｎ－１の周期をもつ０と１との２値の数列であり、１つの周期の中の数列の数は奇数であり、「０」と「１」の数の差が１と定められる。比較例において、「０」と大きいピッチ角とを対応させ、「１」と小さいピッチ角とを対応させ、周期を１１と設定する。すると、Ｍ系配列で示される数列は、１１０１１１０００１０となる。この数列に基づくピッチ角は、図３に示すように、ピッチ角の位置に対応して、２８．８°、２８．８°、３７．４４°、２８．８°、２８．８°、２８．８°、３７．４４°、３７．４４°、３７．４４°、２８．８°、３７．４４°と定められる。 In this comparative example, an M-type array is used as the periodic pseudo-random array of the periodic pseudo-random array blades. The M system array is a binary number sequence of 0 and 1 having a period of 2 n −1, the number of number sequences in one period is an odd number, and the difference between the numbers of “0” and “1” Is defined as 1. In the comparative example, “0” is associated with a large pitch angle, “1” is associated with a small pitch angle, and the period is set to 11. Then, the numerical sequence indicated by the M-sequence is 110111100010. As shown in FIG. 3, the pitch angle based on this number sequence corresponds to the position of the pitch angle, 28.8 °, 28.8 °, 37.44 °, 28.8 °, 28.8 °, 28 8 °, 37.44 °, 37.44 °, 37.44 °, 28.8 ° and 37.44 °.
　等ピッチ羽根、周期的疑似ランダム配列羽根、及び本実施の形態の羽根の、任意の観測点での時間経過に伴う音圧Ｐｎ（ｔ）の変化を、それぞれ図４Ａ、４Ｂ、４Ｃに示す。図４Ａは、等ピッチ羽根の音圧Ｐ１（ｔ）を時間経過ｔに沿って測定したグラフ、図４Ｂは、周期的疑似ランダム配列羽根の音圧Ｐ２（ｔ）を時間経過ｔに沿って測定したグラフ、図４Ｃは、本実施の形態の羽根の音圧Ｐ３（ｔ）を時間経過ｔに沿って測定したグラフである。図４Ａ～４Ｃの縦軸は、音圧の最大値を１、最低値を０と設定した音圧Ｐの値を示し、横軸は時間ｔを示す。 FIGS. 4A, 4B, and 4C show changes in sound pressure Pn (t) with the passage of time at arbitrary observation points of the equi-pitch blades, the periodic pseudo-random array blades, and the blades of the present embodiment, respectively. FIG. 4A is a graph in which sound pressure P1 (t) of equal pitch blades is measured along time lapse t, and FIG. 4B is a graph in which sound pressure P2 (t) of periodically pseudorandom array blades is measured along time lapse t. FIG. 4C is a graph obtained by measuring the sound pressure P3 (t) of the blade according to the present embodiment over time. 4A to 4C, the vertical axis represents the value of the sound pressure P with the maximum value of the sound pressure set to 1 and the minimum value set to 0, and the horizontal axis represents the time t.
　等ピッチ羽根の場合、図４Ａに示すように、音圧Ｐ１（ｔ）の変化は、Ｐ１（ｔ）=sin(ωｔ）で示す正弦波で表される。音圧Ｐ１の最大値は、羽根が観測点を通過するときに周期的に発生する。したがって、最大の音圧は、羽根Ｗ１～Ｗ１１の各々の羽根が観測点を通過するときに発生する。全ての羽根のピッチ角は等しいので、等しい時間間隔で、最大の音圧が発生する。 In the case of equal pitch blades, as shown in FIG. 4A, the change in the sound pressure P1 (t) is represented by a sine wave represented by P1 (t) = sin (ωt). The maximum value of the sound pressure P1 is periodically generated when the blade passes through the observation point. Therefore, the maximum sound pressure is generated when each of the blades W1 to W11 passes through the observation point. Since the pitch angles of all the blades are equal, the maximum sound pressure is generated at equal time intervals.
　周期的疑似ランダム配列羽根の場合、図４Ｂに示すように、Ｍ系配列に従って配列された羽根Ｗ１～Ｗ１１の各々が観測点を通過するタイミングで、最大の音圧が発生する。羽根は周期的疑似ランダム配列で配置されているので、その配置間隔に応じて、最大の音圧が発生する。 In the case of a periodic pseudo-random array blade, as shown in FIG. 4B, the maximum sound pressure is generated at the timing when each of the blades W1 to W11 arrayed according to the M-system array passes the observation point. Since the blades are arranged in a periodic pseudo-random arrangement, the maximum sound pressure is generated according to the arrangement interval.
　本実施の形態の羽根の場合、図４Ｃに示すように、第１のピッチ角θ１で並べられた羽根Ｗ１～Ｗ６と、第２のピッチ角θ２で並べられた羽根Ｗ６～Ｗ１１が、観測点を通過するタイミングで、最大の音圧が発生する。第１のピッチ角θ１で配置された羽根の配置間隔と、第２のピッチ角θ２で配置された羽根の配置間隔に応じて、最大の音圧が発生する。 In the case of the blade according to the present embodiment, as shown in FIG. 4C, the blades W1 to W6 arranged at the first pitch angle θ1 and the blades W6 to W11 arranged at the second pitch angle θ2 The maximum sound pressure is generated at the timing of passing through. The maximum sound pressure is generated according to the arrangement interval of the blades arranged at the first pitch angle θ1 and the arrangement interval of the blades arranged at the second pitch angle θ2.
　このようにして求められた音圧のグラフを、回転数を５０Ｈｚ、羽根数を１１枚の条件のもと、ＦＦＴ（Fast Fourier Transform）解析をして、等ピッチ羽根、周期的疑似ランダム配列羽根、及び本実施の形態の各々の羽根について、周波数に対応する振幅値を求める。図５は、ＦＦＴ解析により求められた振幅と周波数の関係を示すグラフである。図５に示すグラフの縦軸は振幅、横軸は周波数である。グラフからわかるように、等ピッチ羽根は、周波数５０Ｈｚ×羽根総枚数１１枚で求められる基本周波数である周波数５５０Ｈｚで、ピークスペクトル０．５を示した。周期的疑似ランダム配列の羽根は、周波数５５０Ｈｚで、ピークスペクトル０．３７４１００５を示した。本実施の形態で使用した羽根は、周波数５５０Ｈｚを挟んで、低周波側と高周波側で、２つのピークスペクトルを示し、高い方のピークスペクトルは、０．２８１２５７５であった。 The sound pressure graph thus obtained is subjected to FFT (Fast Fourier Transform) analysis under the conditions of 50 Hz rotation speed and 11 blade counts. For each blade in the present embodiment, an amplitude value corresponding to the frequency is obtained. FIG. 5 is a graph showing the relationship between amplitude and frequency obtained by FFT analysis. In the graph shown in FIG. 5, the vertical axis represents amplitude, and the horizontal axis represents frequency. As can be seen from the graph, the equi-pitch blades showed a peak spectrum of 0.5 at a frequency of 550 Hz, which is a fundamental frequency obtained from a frequency of 50 Hz × total number of blades of 11. The periodically pseudorandom array of vanes showed a peak spectrum of 0.3741005 at a frequency of 550 Hz. The blade used in the present embodiment showed two peak spectra on the low frequency side and the high frequency side with a frequency of 550 Hz, and the higher peak spectrum was 0.28127575.
　本実施の形態の羽根の配列を使用すれば、等ピッチ羽根、周期的疑似ランダム配列の羽根と比較して、ピークスペクトルの値を低く抑えるとともに、ピーク値を分散でき、遠心ファン１０の騒音を大きく低減できる。 If the blade arrangement of the present embodiment is used, the peak spectrum value can be kept low and the peak value can be dispersed and the noise of the centrifugal fan 10 can be reduced as compared with the blades of the equal pitch blade and the periodic pseudo-random arrangement. It can be greatly reduced.
　以上説明したように、本実施の形態に係る遠心ファン１０は、第１の合算ピッチ角と第２の合算ピッチ角とが、回転軸３０の周りに偏って配置されるため、遠心ファン１０の騒音を大きく低減できる。また、ピッチ角の種類として、第１のピッチ角θ１と第２のピッチ角θ２の２種類のみを適用して、遠心ファン１０を製造するので、遠心ファン１０の設計も簡単となり、製造コストを低減できる。 As described above, the centrifugal fan 10 according to the present embodiment is arranged such that the first summed pitch angle and the second summed pitch angle are biased around the rotation shaft 30. Noise can be greatly reduced. Further, since the centrifugal fan 10 is manufactured by applying only two types of pitch angles, the first pitch angle θ1 and the second pitch angle θ2, the design of the centrifugal fan 10 is simplified and the manufacturing cost is reduced. Can be reduced.
　本実施の形態に係る遠心ファン１０は、送風機１に組み込むことで、送風機１を使用する各種の製品、例えば、換気扇、空気調和装置に適用することができるので、これらの製品を運転するときにも騒音を大きく低減できる。 The centrifugal fan 10 according to the present embodiment can be applied to various products that use the blower 1, for example, a ventilation fan or an air conditioner, by being incorporated in the blower 1, so that when these products are operated, Noise can be greatly reduced.
　上記の例は、小さいピッチ角の個数を１つ多くする条件で、第１のピッチ角θ１と第２のピッチ角θ２を設定したが、大きいピッチ角の個数を１つ多くする条件で、第１のピッチ角θ１と第２のピッチ角θ２を設定する他の例（図示はせず）でも、同様な効果を奏する。 In the above example, the first pitch angle θ1 and the second pitch angle θ2 are set under the condition that the number of small pitch angles is increased by one. However, under the condition that the number of large pitch angles is increased by one, The same effect can be obtained in another example (not shown) in which the first pitch angle θ1 and the second pitch angle θ2 are set.
　この例において、ｎを１１と、Δを１．３と設定する。そして、これらの値を、上記式１に当てはめる。すると、θは、２８．１２°と導き出せるので、小さいピッチ角が２８．１２°、大きいピッチ角が３６．５６°と求められる。大きいピッチ角を第１のピッチ角θ１、小さいピッチ角を第２のピッチ角θ２とすると、第１のピッチ角θ１は、羽根Ｗ１とＷ７の間に第１の方向Ｘに６個並んで配置され、第２のピッチ角θ２は、羽根Ｗ７とＷ１との間に第２の方向Ｙに５個並んで配置される。具体的には、回転軸３０の第１の方向Ｘに、ピッチ角は、３６．５６°、３６．５６°、３６．５６°、３６．５６°、３６．５６°、３６．５６°、２８．１２°、２８．１２°、２８．１２°、２８．１２°、２８．１２°と定められる。 In this example, n is set to 11 and Δ is set to 1.3. These values are applied to the above equation 1. Then, since θ can be derived as 28.12 °, a small pitch angle is calculated as 28.12 ° and a large pitch angle is determined as 36.56 °. If the large pitch angle is the first pitch angle θ1 and the small pitch angle is the second pitch angle θ2, six first pitch angles θ1 are arranged in the first direction X between the blades W1 and W7. In addition, five second pitch angles θ2 are arranged in the second direction Y between the blades W7 and W1. Specifically, in the first direction X of the rotating shaft 30, the pitch angle is 36.56 °, 36.56 °, 36.56 °, 36.56 °, 36.56 °, 36.56 °, 28.12 °, 28.12 °, 28.12 °, 28.12 °, and 28.12 °.
　第１のピッチ角θ１を６個並べることで、第１の合算ピッチ角を形成し、第２のピッチ角θ２を５個並べることで、第２の合算ピッチ角を形成する。第１の合算ピッチ角は、３６．５６°×６＝２１９．３７°であり、第２の合算ピッチ角は、２８．１２°×５＝１４０．６°である。このように、第１の合算ピッチ角と第２の合算ピッチ角とは相違し、第１の合算ピッチ角と第２の合算ピッチ角とは、回転軸３０の周りに偏って配置される。 The first total pitch angle is formed by arranging six first pitch angles θ1, and the second total pitch angle is formed by arranging five second pitch angles θ2. The first total pitch angle is 36.56 ° × 6 = 219.37 °, and the second total pitch angle is 28.12 ° × 5 = 140.6 °. As described above, the first summed pitch angle and the second summed pitch angle are different from each other, and the first summed pitch angle and the second summed pitch angle are arranged around the rotating shaft 30 in a biased manner.
　大きいピッチ角の個数を１つ多くする条件でピッチ角を設定した場合でも、第１の合算ピッチ角と第２の合算ピッチ角が、回転軸３０の周りに偏って配置されるため、遠心ファン１０の騒音を大きく低減できる。 Even when the pitch angle is set under the condition that the number of large pitch angles is increased by one, the first combined pitch angle and the second combined pitch angle are biased around the rotating shaft 30, so that the centrifugal fan 10 noise can be greatly reduced.
　また、本実施の形態の遠心ファン１０は、遠心ファン１０の回転軸３０が正転する場合と逆転する場合の双方の場合で、同等な騒音低減効果を奏する。正転と逆転の場合の羽根特性について、周期的疑似ランダム配列羽根と比較して、以下に説明する。 Also, the centrifugal fan 10 of the present embodiment has an equivalent noise reduction effect in both cases where the rotating shaft 30 of the centrifugal fan 10 rotates forward and reverse. The blade characteristics in the case of normal rotation and reverse rotation will be described below in comparison with a periodic pseudo-random array blade.
　周期的疑似ランダム配列羽根のピッチ角の並びは、上述したように、大きいピッチ角を「０」と、小さいピッチ角を「１」と対応させて、１１０１１１０００１０という配列で示すことができる。遠心ファンを１回正転させると、この配列の順序で羽根が観測点を通過して、図４Ｂに示す音圧Ｐ２（ｔ）のパターンを示す。この遠心ファンを１回逆転させると、０１０００１１１０１１という正転とは異なる配列の順序で、羽根が観測点を通過する。したがって、正転の場合と逆転の場合では、発生する音圧のパターンが相違し、騒音低減効果も異なる。一般的には、正転する場合を前提として羽根の配列を設計するので、遠心ファンが逆転した場合には、騒音低減効果が減少するおそれがある。 As described above, the pitch angle arrangement of the periodically pseudo-random array blades can be represented by an array of 110101100010, with a large pitch angle corresponding to “0” and a small pitch angle corresponding to “1”. When the centrifugal fan is rotated forward once, the blades pass through the observation points in this order of arrangement, and the pattern of the sound pressure P2 (t) shown in FIG. 4B is shown. When the centrifugal fan is reversed once, the blades pass through the observation points in an arrangement order different from normal rotation of 01000111011. Therefore, the pattern of sound pressure generated differs between forward rotation and reverse rotation, and the noise reduction effect is also different. In general, since the arrangement of the blades is designed on the assumption that the fan rotates forward, the noise reduction effect may be reduced when the centrifugal fan is reversed.
　本実施の形態の遠心ファン１０は、図２に示すように、正転方向である第１の方向Ｘと、反転方向である第２の方向Ｙとの、どちらにも回転させることができる。遠心ファン１０の用途及び使用者の要望に応じて、回転方向を決定する。 As shown in FIG. 2, the centrifugal fan 10 according to the present embodiment can be rotated in both the first direction X that is the forward rotation direction and the second direction Y that is the reverse rotation direction. The direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
　本実施の形態の羽根と周期的疑似ランダム配列羽根とを対比するため、本実施の形態の羽根のピッチ角を、周期的疑似ランダム配列羽根のピッチ角と同様に、大きいピッチ角を「０」と、小さいピッチ角を「１」と対応させる。図３に示す本実施の形態の羽根のピッチ角は、ピッチ角の位置「１」から「１１」まで、０００００１１１１１１という配列で示すことができる。遠心ファン１０が１回正転すると、この順序で羽根が観測点を通過して、図４Ｃに示す音圧Ｐ３（ｔ）のパターンを示す。この遠心ファン１０を１回逆転させると、１１１１１１０００００という配列の順序で、各羽根が観測点を通過する。遠心ファン１０が連続して正転又は逆転されることで、各々の配列パターンが繰り返し観測点を通過する。 In order to compare the blades of the present embodiment and the periodic pseudo-random array blades, the pitch angle of the blades of the present embodiment is set to “0” as in the case of the pitch angle of the periodic pseudo-random array blades. The small pitch angle is made to correspond to “1”. The pitch angles of the blades of the present embodiment shown in FIG. 3 can be represented by an arrangement of 00000111111 from the pitch angle positions “1” to “11”. When the centrifugal fan 10 rotates forward once, the blades pass through the observation points in this order, and the pattern of the sound pressure P3 (t) shown in FIG. 4C is shown. When the centrifugal fan 10 is reversed once, each blade passes through the observation point in the order of 1111110000000. As the centrifugal fan 10 is continuously rotated forward or reversely, each arrangement pattern repeatedly passes through the observation point.
　遠心ファン１０が連続して正転又は逆転する場合の羽根のパターンは、次のようにも説明できる。回転軸３０の周りは、０００００の配列で示される、第１のピッチ角θ１を５つ合算した第１の合算ピッチ角の領域（以下、「Ａ領域」という。）と、１１１１１１の配列で示される、第２のピッチ角θ２を６つ合算した第２の合算ピッチ角の領域（以下、「Ｂ領域」という。）と、に分割される。遠心ファン１０が連続回転すると、正転又は逆転の何れの場合でも、Ａ領域とＢ領域は、交互に観測点を通過する。したがって、遠心ファン１０が正転でも逆転でも、発生する音圧のパターンは同一であり、騒音低減効果も同等となる。 The blade pattern when the centrifugal fan 10 continuously rotates forward or backward can be explained as follows. The area around the rotation axis 30 is indicated by a first summed pitch angle area (hereinafter referred to as “A area”) obtained by adding five first pitch angles θ1 indicated by an array of 00000 and an array of 111111. And a second summed pitch angle region (hereinafter referred to as “B region”) obtained by summing six second pitch angles θ2. When the centrifugal fan 10 rotates continuously, the A region and the B region alternately pass through the observation points in either case of normal rotation or reverse rotation. Therefore, regardless of whether the centrifugal fan 10 rotates in the forward direction or in the reverse direction, the generated sound pressure pattern is the same, and the noise reduction effect is equivalent.
（実施の形態２）
　実施の形態１では、羽根の総枚数が奇数であり、第１のピッチ角θ１と第２のピッチ角θ２とが異なる角度に設定され、第１のピッチ角θ１の数と第２のピッチ角θ２の数との差異は、１であった。本発明は、このような羽根の枚数、ピッチ角の数には限定されず、羽根の総枚数が偶数であり、第１のピッチ角θ１の数と第２のピッチ角θ２の数が等しい場合にも適用される。 (Embodiment 2)
In the first embodiment, the total number of blades is an odd number, the first pitch angle θ1 and the second pitch angle θ2 are set to different angles, and the number of first pitch angles θ1 and the second pitch angle. The difference from the number of θ2 was 1. The present invention is not limited to the number of blades and the number of pitch angles, and the total number of blades is an even number, and the number of first pitch angles θ1 is equal to the number of second pitch angles θ2. Also applies.
　本実施の形態に係る遠心ファンの羽根の配列は、（１）羽根の総枚数ｎが偶数であること、（２）ピッチ角の種類は、第１のピッチ角θ１と第２のピッチ角の２種類であり、第１のピッチ角θ１と第２のピッチ角θ２は相違すること、（３）第１のピッチ角θ１は第１の方向にｍ個並べて配置され、第２のピッチ角θ２は第２の方向にｎ－ｍ個並べて配置されること、（４）第１のピッチ角θ１の数と、第２のピッチ角θ２の数と、が同一であること、（５）第１のピッチ角θ１をｍ個合算した第１の合算ピッチ角と、第２のピッチ角θ２をｎ－ｍ個合算した第２の合算ピッチ角と、が相違すること、を特徴とする。なお、本実施の形態の遠心ファンは、実施の形態１の遠心ファン１０と基本的構成は同一である。 The arrangement of the blades of the centrifugal fan according to the present embodiment is as follows: (1) The total number n of blades is an even number; (2) The pitch angle types are the first pitch angle θ1 and the second pitch angle. There are two types, the first pitch angle θ1 and the second pitch angle θ2 are different, and (3) m first pitch angles θ1 are arranged side by side in the first direction, and the second pitch angle θ2 Are arranged side by side in the second direction, (4) the number of first pitch angles θ1 is the same as the number of second pitch angles θ2, and (5) first The first total pitch angle obtained by adding m pitch angles θ1 and the second total pitch angle obtained by adding nm second pitch angles θ2 are different from each other. The centrifugal fan of the present embodiment has the same basic configuration as the centrifugal fan 10 of the first embodiment.
　本実施の形態の遠心ファン１０は、図６に示すように、正転方向である第１の方向Ｘと、反転方向である第２の方向Ｙとの、どちらにも回転させることができる。遠心ファン１０の用途及び使用者の要望に応じて、回転方向を決定する。 As shown in FIG. 6, the centrifugal fan 10 of the present embodiment can be rotated in both the first direction X that is the forward rotation direction and the second direction Y that is the reverse rotation direction. The direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
　本実施の形態に係る遠心ファン１０の羽根の配列について、図６を参照して説明する。 The arrangement of the blades of the centrifugal fan 10 according to the present embodiment will be described with reference to FIG.
　第１のピッチ角θ１と第２のピッチ角θ２は、羽根の総枚数と、第１のピッチ角θ１と第２のピッチ角θ２の比を定めることにより、次の式により一意に定まる。 The first pitch angle θ1 and the second pitch angle θ2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle θ1 and the second pitch angle θ2.
　ｎ／２×θ＋ｎ／２×Δ×θ＝３６０°（式３）
　ここで、ｎは羽根の総枚数、θは小さいピッチ角の角度、Δは大きいピッチ角と小さいピッチ角の比率を示す。 n / 2 × θ + n / 2 × Δ × θ = 360 ° (Formula 3)
Here, n is the total number of blades, θ is the angle of the small pitch angle, and Δ is the ratio of the large pitch angle to the small pitch angle.
　本実施の形態では、ｎを１０と、Δを１．３と設定し、これらの値を、式３に当てはめる。すると、θは、３１．３°と導き出せるので、小さいピッチ角が３１．３°、大きいピッチ角が４０．６９°と求められる。大きいピッチ角を第１のピッチ角θ１とし、小さいピッチ角を第２のピッチ角θ２とすると、図６に示すように、第１のピッチ角θ１は、羽根Ｗ１とＷ６との間に第１の方向Ｘに５個並んで配置され、第２のピッチ角θ２は、羽根Ｗ１とＷ６との間に第２の方向Ｙに５個並んで配置される。具体的には、回転軸３０の第１の方向Ｘに、ピッチ角は、４０．６９°、４０．６９°、４０．６９°、４０．６９°、４０．６９°、３１．３°、３１．３°、３１．３°、３１．３°、３１．３°と定められる。 In this embodiment, n is set to 10 and Δ is set to 1.3, and these values are applied to Equation 3. Then, since θ can be derived as 31.3 °, a small pitch angle is determined to be 31.3 ° and a large pitch angle is determined to be 40.69 °. If the large pitch angle is the first pitch angle θ1 and the small pitch angle is the second pitch angle θ2, as shown in FIG. 6, the first pitch angle θ1 is the first pitch angle between the blades W1 and W6. The second pitch angle θ2 is arranged side by side in the second direction Y between the blades W1 and W6. Specifically, in the first direction X of the rotating shaft 30, the pitch angle is 40.69 °, 40.69 °, 40.69 °, 40.69 °, 40.69 °, 31.3 °, It is defined as 31.3 °, 31.3 °, 31.3 °, 31.3 °.
　第１のピッチ角θ１を５個並べることで、第１の合算ピッチ角を形成し、第２のピッチ角θ２を５個並べることで、第２の合算ピッチ角を形成する。第１の合算ピッチ角は、４０．６９°×５＝２０３．４５°であり、第２の合算ピッチ角は、３１．３°×５＝１５６．５°である。このように、第１の合算ピッチ角と第２の合算ピッチ角とは相違し、第１の合算ピッチ角と第２の合算ピッチ角とは、図６に示すように回転軸３０の周りに、境界線Ｄ２を境として偏って配置される。 The first total pitch angle is formed by arranging five first pitch angles θ1, and the second total pitch angle is formed by arranging five second pitch angles θ2. The first combined pitch angle is 40.69 ° × 5 = 203.45 °, and the second combined pitch angle is 31.3 ° × 5 = 156.5 °. Thus, the first summed pitch angle and the second summed pitch angle are different, and the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. , They are arranged biased with respect to the boundary line D2.
　以上説明したように、羽根の総枚数が偶数枚であり、第１のピッチ角θ１の個数と第２のピッチ角θ２の個数とが同一であっても、第１の合算ピッチ角と第２の合算ピッチ角は偏って配置されるので、遠心ファン１０の騒音を大きく低減できる。 As described above, even if the total number of blades is an even number and the number of first pitch angles θ1 and the number of second pitch angles θ2 are the same, the first total pitch angle and the second pitch angle are the same. Therefore, the noise of the centrifugal fan 10 can be greatly reduced.
　また、第１のピッチ角θ１を５個並べた第１の合算ピッチ角と、第２のピッチ角θ２を５個並べた第２の合算ピッチ角が、回転軸３０周りに配置されるので、遠心ファン１０が正転する場合と逆転する場合の双方の場合で、同じ音圧パターンを生成し、同等な騒音低減効果を奏する。 In addition, since the first total pitch angle in which five first pitch angles θ1 are arranged and the second total pitch angle in which five second pitch angles θ2 are arranged are arranged around the rotation axis 30, In both cases where the centrifugal fan 10 rotates forward and reversely, the same sound pressure pattern is generated, and an equivalent noise reduction effect is achieved.
（実施の形態３）
　実施の形態１、２では、第１のピッチ角θ１と第２のピッチ角θ２の数が等しい場合、第１のピッチ角θ１と第２のピッチ角θ２の数の差が１である場合について説明した。しかしながら、本発明は、このようなピッチ角の数に限定されず、第１のピッチ角θ１と第２のピッチ角θ２の数の差が、２以上であってもよい。 (Embodiment 3)
In the first and second embodiments, when the numbers of the first pitch angle θ1 and the second pitch angle θ2 are equal, the difference between the numbers of the first pitch angle θ1 and the second pitch angle θ2 is 1. explained. However, the present invention is not limited to the number of such pitch angles, and the difference between the numbers of the first pitch angle θ1 and the second pitch angle θ2 may be two or more.
　本実施の形態に係る遠心ファンの羽根の配列は、（１）羽根の総枚数ｎが奇数又は偶数であること、（２）ピッチ角の種類は、第１のピッチ角θ１と第２のピッチ角の２種類であり、第１のピッチ角θ１と第２のピッチ角θ２は相違すること、（３）第１のピッチ角θ１は第１の方向にｍ個並べて配置され、第２のピッチ角θ２は第２の方向にｎ－ｍ個並べて配置されること、（４）第１のピッチ角θ１の数と、第２のピッチ角θ２の数と、の差が２以上であること、（５）第１のピッチ角θ１をｍ個合算した第１の合算ピッチ角と、第２のピッチ角θ２をｎ－ｍ個合算した第２の合算ピッチ角の角度と、が相違すること、を特徴とする。なお、本実施の形態の遠心ファンは、実施の形態１の遠心ファン１０と基本的構成は同一である。 The blade arrangement of the centrifugal fan according to the present embodiment is as follows: (1) The total number n of the blades is odd or even; (2) The pitch angle types are the first pitch angle θ1 and the second pitch. The first pitch angle θ1 and the second pitch angle θ2 are different, and (3) m first pitch angles θ1 are arranged in the first direction, and the second pitch angle The angle θ2 is arranged in a number of nm in the second direction, and (4) the difference between the number of the first pitch angles θ1 and the number of the second pitch angles θ2 is 2 or more, (5) The first summed pitch angle obtained by summing m first pitch angles θ1 is different from the angle of the second summed pitch angle obtained by summing nm second pitch angles θ2. It is characterized by. The centrifugal fan of the present embodiment has the same basic configuration as the centrifugal fan 10 of the first embodiment.
　本実施の形態の遠心ファン１０は、図７に示すように、正転方向である第１の方向Ｘと、反転方向である第２の方向Ｙとの、どちらにも回転させることができる。遠心ファン１０の用途及び使用者の要望に応じて、回転方向を決定する。 As shown in FIG. 7, the centrifugal fan 10 of the present embodiment can be rotated in both the first direction X that is the forward direction and the second direction Y that is the reverse direction. The direction of rotation is determined according to the application of the centrifugal fan 10 and the user's request.
　本実施の形態に係る遠心ファン１０の羽根の配列について、図７を参照して説明する。 The arrangement of the blades of the centrifugal fan 10 according to the present embodiment will be described with reference to FIG.
　第１のピッチ角θ１と第２のピッチ角θ２は、羽根の総枚数と、第１のピッチ角θ１と第２のピッチ角θ２の比を定めることにより、次の式により一意に定まる。 The first pitch angle θ1 and the second pitch angle θ2 are uniquely determined by the following expression by determining the total number of blades and the ratio of the first pitch angle θ1 and the second pitch angle θ2.
　大きいピッチ角の個数をａ個多くする場合には、（ａは、２以上）
　（ｎ－ａ）／２×θ＋（ｎ＋ａ）／２×Δ×θ＝３６０°（式４）
　小さいピッチ角の個数をａ個多くする場合には、（ａは、２以上）
　（ｎ＋ａ）／２×θ＋（ｎ＋ａ）／２×Δ×θ＝３６０°（式５）
　と示すことができる。
　ここで、ｎは羽根の総枚数、θは小さいピッチ角の角度、Δは大きいピッチ角と小さいピッチ角の比率を示す。 When increasing the number of large pitch angles by a, (a is 2 or more)
(Na) / 2 × θ + (n + a) / 2 × Δ × θ = 360 ° (Formula 4)
When increasing the number of small pitch angles by a (a is 2 or more)
(N + a) / 2 × θ + (n + a) / 2 × Δ × θ = 360 ° (Formula 5)
Can be shown.
Here, n is the total number of blades, θ is the angle of the small pitch angle, and Δ is the ratio of the large pitch angle to the small pitch angle.
　本実施の形態では、ｎを１１と、Δを１．３と、ａを３（大きいピッチ角の数が、小さいピッチ角の数より３個多い。）と、設定する。これらの値を、式４に当てはめることで、θは、２７．５°と導き出せるので、小さいピッチ角が２７．５°、大きいピッチ角が３５．７°と求められる。小さいピッチ角を第１のピッチ角θ１とし、大きいピッチ角を第２のピッチ角θ２とすると、図７に示すように、第１のピッチ角θ１は、羽根Ｗ１とＷ５との間に第１の方向Ｘに４個並んで配置され、第２のピッチ角θ２は、羽根Ｗ１とＷ５との間に第２の方向Ｙに７個並んで配置される。具体的には、回転軸３０の第１の方向Ｘに、ピッチ角は、２７．５°、２７．５°、２７．５°、２７．５°、３５．７°、３５．７°、３５．７°、３５．７°、３５．７°、３５．７°、３５．７°と定められる。 In the present embodiment, n is set to 11, Δ is set to 1.3, and a is set to 3 (the number of large pitch angles is three more than the number of small pitch angles). By applying these values to Equation 4, θ can be derived as 27.5 °, so that a small pitch angle is 27.5 ° and a large pitch angle is 35.7 °. Assuming that the small pitch angle is the first pitch angle θ1 and the large pitch angle is the second pitch angle θ2, as shown in FIG. 7, the first pitch angle θ1 is the first pitch angle between the blades W1 and W5. The second pitch angle θ2 is arranged in the second direction Y between the blades W1 and W5. Specifically, in the first direction X of the rotating shaft 30, the pitch angle is 27.5 °, 27.5 °, 27.5 °, 27.5 °, 35.7 °, 35.7 °, It is defined as 35.7 °, 35.7 °, 35.7 °, 35.7 °, and 35.7 °.
　第１のピッチ角θ１を４個並べることで、第１のピッチ角θ１を４個合算した第１の合算ピッチ角を形成し、第２のピッチ角θ２を７個並べることで、第２のピッチ角θ２を７個合算した第２の合算ピッチ角を形成する。第１の合算ピッチ角は、２７．５°×４＝１１０°であり、第２の合算ピッチ角は、３５．７°×７＝２４９．９°である。このように、第１の合算ピッチ角と第２の合算ピッチ角とは相違し、第１の合算ピッチ角と第２の合算ピッチ角とは、図７に示すように、回転軸３０の周りに、境界線Ｄ３を境に偏って配置される。 By arranging four first pitch angles θ1, a first summed pitch angle is formed by adding four first pitch angles θ1, and by arranging seven second pitch angles θ2, A second total pitch angle is formed by adding seven pitch angles θ2. The first summed pitch angle is 27.5 ° × 4 = 110 °, and the second summed pitch angle is 35.7 ° × 7 = 249.9 °. Thus, the first summed pitch angle is different from the second summed pitch angle, and the first summed pitch angle and the second summed pitch angle are around the rotation axis 30 as shown in FIG. Are arranged with the boundary line D3 as a boundary.
　以上説明したように、本実施の形態に係る遠心ファン１０は、第１の合算ピッチ角と第２の合算ピッチ角とが、回転軸３０の周りに偏って配置されるため、遠心ファン１０から発生する騒音を大きく低減できる。 As described above, the centrifugal fan 10 according to the present embodiment is arranged so that the first summed pitch angle and the second summed pitch angle are biased around the rotation shaft 30. The generated noise can be greatly reduced.
　また、第１のピッチ角θ１を４個並べた第１の合算ピッチ角と、第２のピッチ角θ２を７個並べた第２の合算ピッチ角が、回転軸３０周りに配置されるので、遠心ファン１０が正転する場合と逆転する場合の双方の場合で、同じ音圧パターンを生成し、同等な騒音低減効果を奏する。 In addition, since the first total pitch angle in which four first pitch angles θ1 are arranged and the second total pitch angle in which seven second pitch angles θ2 are arranged are arranged around the rotation axis 30, In both cases where the centrifugal fan 10 rotates forward and reversely, the same sound pressure pattern is generated, and an equivalent noise reduction effect is achieved.
（実施の形態４）
　実施の形態１～３で説明した遠心ファンにおいて、第１の合算ピッチ角と第２の合算ピッチ角とが回転軸３０の全周を囲んで配置され、第１の合算ピッチ角と第２の合算ピッチ角は異なると説明した。本発明は、回転軸の全周を第１の合算角度と第２の合算角度のみで囲むことに限定されず、第１の合算ピッチ角と第２の合算ピッチ角とを合算して第３の合算角度を形成し、この第３の合算角度を回転軸の周りに２以上配置してもよい。 (Embodiment 4)
In the centrifugal fan described in the first to third embodiments, the first combined pitch angle and the second combined pitch angle are arranged so as to surround the entire circumference of the rotating shaft 30, and the first combined pitch angle and the second combined pitch angle are arranged. It was explained that the combined pitch angle is different. The present invention is not limited to surrounding the entire circumference of the rotating shaft with only the first summing angle and the second summing angle, and the third summing of the first summing pitch angle and the second summing pitch angle is the third. May be formed, and two or more of the third total angles may be arranged around the rotation axis.
　本実施の形態に係る遠心ファンは、主に鉄道車両用の電動機の冷却ファンとして用いられる。遠心ファンを備える鉄道車両用の電動機について、図８を参照して説明する。 The centrifugal fan according to the present embodiment is mainly used as a cooling fan for electric motors for railway vehicles. An electric motor for a railway vehicle including a centrifugal fan will be described with reference to FIG.
　電動機１００は、フレーム２００と、固定子３００と、回転子４００と、回転子４００と一体に回転する回転軸５００と、回転軸５００に取り付けられた遠心ファン６００と、を備える。 The electric motor 100 includes a frame 200, a stator 300, a rotor 400, a rotating shaft 500 that rotates integrally with the rotor 400, and a centrifugal fan 600 attached to the rotating shaft 500.
　フレーム２００は、固定子３００と回転子４００を取り囲んで配置され、空気が吸込される吸込口２０１と、吸込された空気を吐出する吐出口２０２が形成されている。固定子３００は、固定子鉄心３０１と、固定子鉄心３０１に巻回された固定子コイル３０２とを含み、回転子４００は、固定子３００に対向して配置される。回転子４００の中心部には、回転軸５００が貫通して固定される。 The frame 200 is disposed so as to surround the stator 300 and the rotor 400, and is formed with a suction port 201 through which air is sucked and a discharge port 202 through which the sucked air is discharged. The stator 300 includes a stator core 301 and a stator coil 302 wound around the stator core 301, and the rotor 400 is disposed to face the stator 300. A rotation shaft 500 is fixed through the central portion of the rotor 400.
　回転軸５００のいずれか一方の端部は、車両の車軸（図示せず）に連結され、回転軸５００が回転されることで車軸が回転する。回転軸５００の両端部は、フレーム２００に設けられた軸受５０１により支持される。 One end of the rotating shaft 500 is connected to an axle (not shown) of the vehicle, and the rotating shaft 500 is rotated to rotate the axle. Both ends of the rotating shaft 500 are supported by bearings 501 provided on the frame 200.
　遠心ファン６００は、複数の羽根６０１を備え、複数の羽根６０１は、回転軸５００の周りに放射状に配置される。 The centrifugal fan 600 includes a plurality of blades 601, and the plurality of blades 601 are arranged radially around the rotation shaft 500.
　このような電動機１００において、固定子コイル３０２に電源（図示せず）から交流電流が入力されると、固定子鉄心３０１に回転磁界が発生し、この回転磁界により回転子４００に誘導電流が誘起される。回転子４００の周りに回転磁界が形成され、かつ回転子４００に誘導電流が発生することにより、回転子４００を回転軸５００周りに回転される電磁力が発生し、回転子４００が回転する。そして、回転子４００の回転により回転軸５００が回転し、車軸を回転させる。 In such an electric motor 100, when an alternating current is input to the stator coil 302 from a power source (not shown), a rotating magnetic field is generated in the stator core 301, and an induced current is induced in the rotor 400 by the rotating magnetic field. Is done. When a rotating magnetic field is formed around the rotor 400 and an induced current is generated in the rotor 400, an electromagnetic force that rotates the rotor 400 around the rotation axis 500 is generated, and the rotor 400 rotates. Then, the rotation shaft 500 is rotated by the rotation of the rotor 400 to rotate the axle.
　回転軸５００が回転すると同時に、回転軸５００に取り付けられた遠心ファン６００も回転する。回転軸５００の回転中は、固定子コイル３０２で発生する銅損と、回転子４００で生じる誘導電流による鉄損により、電動機１００の部品の温度が上昇する。遠心ファン６００は、回転軸５００の回転に伴い回転され、遠心ファン６００が回転されることで吸込口２０１から空気が導入される。導入された空気が電動機１００内を通過して吐出口２０２から吐出されることにより、電動機１００の内部は冷却される。 At the same time as the rotating shaft 500 rotates, the centrifugal fan 600 attached to the rotating shaft 500 also rotates. While the rotating shaft 500 is rotating, the temperature of the components of the electric motor 100 rises due to the copper loss generated in the stator coil 302 and the iron loss due to the induced current generated in the rotor 400. Centrifugal fan 600 is rotated in accordance with rotation of rotating shaft 500, and air is introduced from suction port 201 by rotating centrifugal fan 600. As the introduced air passes through the electric motor 100 and is discharged from the discharge port 202, the inside of the electric motor 100 is cooled.
　鉄道車両は、往路方向と、その反対の方向の復路方向に運転されるので、電動機１００は、運転の方向に応じて回転軸５００を回転駆動させる。回転軸５００は、往路方向の運転の場合には、図８に示すようにＰ方向に回転され、復路方向の運転の場合には、Ｐ方向と逆方向であるＱ方向に回転される。遠心ファン６００の羽根の配列が、不等ピッチ配列又は周期的疑似ランダム配列である場合には、回転軸５００を回転子４００のある方向に見た場合とその逆の方向から見た場合では、羽根のピッチ角の配列が異なる。したがって、回転軸５００をＰ方向に回転させたときに騒音を減少させる羽根の配列が、回転軸５００をＱ方向に回転させたときも同様に騒音を減少させるとは限らない。本実施の形態における遠心ファン６００は、Ｐ方向とＱ方向に回転、具体的には正転・逆転をする必要がある遠心ファンに好適に適用できる。Ｐ方向は、図９に示す第１の方向に対応し、Ｑ方向は、第２の方向Ｙに対応する。 Since the railway vehicle is driven in the forward direction and in the reverse direction, the electric motor 100 rotates the rotary shaft 500 according to the driving direction. The rotary shaft 500 is rotated in the P direction as shown in FIG. 8 in the case of driving in the forward direction, and is rotated in the Q direction that is opposite to the P direction in the case of driving in the backward direction. When the arrangement of the blades of the centrifugal fan 600 is an unequal pitch arrangement or a periodic pseudo-random arrangement, when the rotary shaft 500 is viewed in a certain direction of the rotor 400 and from the opposite direction, The arrangement of the pitch angles of the blades is different. Therefore, the arrangement of the blades that reduces the noise when the rotating shaft 500 is rotated in the P direction does not necessarily reduce the noise similarly when the rotating shaft 500 is rotated in the Q direction. Centrifugal fan 600 in the present embodiment can be suitably applied to a centrifugal fan that needs to rotate in the P direction and Q direction, specifically, to rotate forward and backward. The P direction corresponds to the first direction shown in FIG. 9, and the Q direction corresponds to the second direction Y.
　本実施の形態に係る遠心ファン６００の羽根の配列は、（１）羽根の総枚数ｎが偶数であること、（２）ピッチ角の種類は、第１のピッチ角θ１と第２のピッチ角θ２の２種類であり、第１のピッチ角θ１と第２のピッチ角θ２は相違すること、（３）第１のピッチ角θ１は第１の方向にｐ個並べて配置され、第２のピッチ角θ２は第２の方向にｑ個並べて配置されること、（４）第１のピッチ角θ１をｐ個合算した第１の合算ピッチ角と、第２のピッチ角θ２をｑ個合算した第２の合算ピッチ角と、が相違すること、（４）第１の合算ピッチ角と第２の合算ピッチ角を合算して第３のピッチ角を形成し、第３のピッチ角を回転軸の周りに２個以上並べて配置したこと、を特徴とする。 The blade arrangement of the centrifugal fan 600 according to the present embodiment is as follows: (1) the total number n of blades is an even number; (2) pitch angle types are the first pitch angle θ1 and the second pitch angle. There are two types of θ2, and the first pitch angle θ1 and the second pitch angle θ2 are different, and (3) the first pitch angle θ1 is arranged side by side in the first direction, and the second pitch angle The angle θ2 is arranged side by side in the second direction, and (4) the first summed pitch angle obtained by adding the first pitch angle θ1 and the second pitch angle θ2 summed by q. (4) The first summed pitch angle and the second summed pitch angle are summed to form a third pitch angle, and the third pitch angle is set to the rotational axis. It is characterized by arranging two or more around.
　本実施の形態に係る遠心ファン６００の羽根の配列について、図９を参照して説明する。 The arrangement of the blades of the centrifugal fan 600 according to the present embodiment will be described with reference to FIG.
　第１のピッチ角θ１と第２のピッチ角θ２は、羽根の総枚数と、第１のピッチ角θ１と第２のピッチ角θ２の比を定めることにより、上記の式４または式５により一意に定まる。本実施の形態では、第１のピッチ角θ１の個数と第２のピッチ角θ２の個数は同一とし、ｎを１２と、Δを１．３と、設定する。これらの値を、式４又は式５に当てはめることで、θは、２６．１°と導き出せるので、小さいピッチ角が２６．１°、大きいピッチ角が３３．９°と定められる。 The first pitch angle θ1 and the second pitch angle θ2 are uniquely determined by the above formula 4 or formula 5 by determining the total number of blades and the ratio of the first pitch angle θ1 and the second pitch angle θ2. Determined. In the present embodiment, the number of first pitch angles θ1 and the number of second pitch angles θ2 are the same, and n is set to 12 and Δ is set to 1.3. By applying these values to Equation 4 or Equation 5, θ can be derived as 26.1 °, so that the small pitch angle is 26.1 ° and the large pitch angle is 33.9 °.
　小さいピッチ角を第１のピッチ角θ１とし、大きいピッチ角を第２のピッチ角θ２とすると、第１のピッチ角θ１は、図９に示すように、羽根Ｗ１とＷ４との間に第１の方向Ｘに３個並べて配置され、第２のピッチ角θ２は、羽根Ｗ１とＷ１１との間に第２の方向Ｙに並べて配置される。第１のピッチ角θ１を３個並べることで第１の合算ピッチ角を形成し、第２のピッチ角θ２を３個並べることで第２の合算ピッチ角を形成する。第１の合算ピッチ角は、２６．１°×３＝７８．３°であり、第２の合算ピッチ角は、３３．９°×３＝１０１．７°であり、第１の合算ピッチ角と第２の合算ピッチ角は異なって形成される。さらに、第１の合算ピッチ角と第２の合算ピッチ角を合算して第３の合算ピッチ角を形成する。第３の合算ピッチ角は、図９において、第１の方向Ｘに、Ｗ１０とＷ４との間に形成される。そして、この第３の合算ピッチ角をＷ１０とＷ４の第２の方向Ｙに形成することで、第３の合算ピッチ角が、回転軸５００の周りに２つ形成される。 Assuming that the small pitch angle is the first pitch angle θ1 and the large pitch angle is the second pitch angle θ2, the first pitch angle θ1 is between the blades W1 and W4 as shown in FIG. Are arranged side by side in the direction X, and the second pitch angle θ2 is arranged side by side in the second direction Y between the blades W1 and W11. A first total pitch angle is formed by arranging three first pitch angles θ1, and a second total pitch angle is formed by arranging three second pitch angles θ2. The first combined pitch angle is 26.1 ° × 3 = 78.3 °, the second combined pitch angle is 33.9 ° × 3 = 101.7 °, and the first combined pitch angle is And the second total pitch angle are formed differently. Further, the first summed pitch angle and the second summed pitch angle are summed to form a third summed pitch angle. The third combined pitch angle is formed between W10 and W4 in the first direction X in FIG. Then, by forming this third combined pitch angle in the second direction Y of W10 and W4, two third combined pitch angles are formed around the rotation axis 500.
　本実施の形態の羽根の配列は、第１の合算ピッチ角が形成される領域をＡ領域とし、第２の合算ピッチ角が形成される領域をＢ領域とし、回転軸５００の周りをいくつかの領域に分割して、Ａ領域とＢ領域を交互に配置する配置方法によっても説明できる。 In the arrangement of the blades of the present embodiment, a region where the first summed pitch angle is formed is an A region, a region where the second summed pitch angle is formed is a B region, and there are several around the rotation axis 500. This can also be explained by an arrangement method in which the A area and the B area are alternately arranged.
　Ａ領域とＢ領域を配置する方法は、まず、回転軸５００の周りを４以上の偶数の領域に分割し、続いて、分割された領域にＡとＢを交互に並べる方法である。図９の羽根の配置について、当該方法を用いて、以下に説明する。 The method of arranging the A region and the B region is a method in which the periphery of the rotation axis 500 is first divided into four or more even regions, and then A and B are alternately arranged in the divided regions. The arrangement | positioning of the blade | wing of FIG. 9 is demonstrated below using the said method.
　図９で説明した第１の合算ピッチ角の領域をＡ領域とし、第２の合算ピッチ角の領域をＢ領域とすると、図９は、図１０Ａで示す図に置き換えられる。図１０Ａに示すように、回転軸５００の周りの領域を４つの領域に分割する。そして、４つに分割された領域に、Ａ領域とＢ領域を、交互に並べて配置する。 9 is replaced with the diagram shown in FIG. 10A, where the first summed pitch angle region described in FIG. 9 is the A region and the second summed pitch angle region is the B region. As shown in FIG. 10A, the region around the rotation axis 500 is divided into four regions. Then, the A area and the B area are alternately arranged in the four divided areas.
　分割する領域を４以上の偶数である８とした場合の領域の配列を、図１０Ｂに示す。図１０Ｂに示すように、回転軸５００の周りの領域を８つに分割する。８つに分割された領域に、Ａ領域とＢ領域を、交互に並べて配置する。 FIG. 10B shows an arrangement of areas when the area to be divided is 8 which is an even number of 4 or more. As shown in FIG. 10B, the region around the rotation axis 500 is divided into eight. In the area divided into eight, the A area and the B area are alternately arranged.
　Ａ領域とＢ領域を交互に配置することにより、遠心ファン６００が連続して正転又は逆転しても、Ａ領域とＢ領域が交互に現れるように回転するので、どちらに回転しても同等の音圧パターンを示す。 By alternately arranging the A region and the B region, even if the centrifugal fan 600 continuously rotates forward or reverse, the A region and the B region rotate so that they appear alternately. The sound pressure pattern is shown.
　以上説明したように、本実施の形態によれば、第１の合算ピッチ角と第２の合算ピッチ角とは、その角度が回転軸周りに異なって形成されるので、遠心ファン６００の騒音を大きく低減できる。 As described above, according to the present embodiment, since the first summed pitch angle and the second summed pitch angle are formed with different angles around the rotation axis, the noise of the centrifugal fan 600 is reduced. It can be greatly reduced.
　また、遠心ファン６００が連続して回転することにより、Ａ領域とＢ領域が交互に現れる。すなわち、遠心ファン６００の正転時も逆転時も同一のパターンでＡ領域とＢ領域が出現するので、鉄道車両の往路運転または復路運転のどちらの場合でも、同等な騒音の低減効果を達成する。 Further, when the centrifugal fan 600 is continuously rotated, the A area and the B area appear alternately. That is, since the A region and the B region appear in the same pattern during forward rotation and reverse rotation of the centrifugal fan 600, the same noise reduction effect can be achieved in both the forward driving and the returning driving of the railway vehicle. .
（変形例）
　以上、本発明の各実施の形態について説明したが、本発明は前述の各実施の形態によって限定されるものではない。 (Modification)
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.
　実施の形態１～４において、遠心ファンを用いて本発明を説明したが、本発明は、遠心ファン以外のファンにも適用できる。例えば、軸流ファン、斜流ファン、横流ファンにも、本発明のファンを適用できる。 In Embodiments 1 to 4, the present invention has been described using a centrifugal fan, but the present invention can also be applied to fans other than the centrifugal fan. For example, the fan of the present invention can be applied to an axial fan, a diagonal fan, and a cross fan.
　実施の形態１において、主板１１と羽根１２との取付角度は、９０°に設定されると説明したが、本発明は、このような取付角度に限定されない。ファンの種類に応じて適宜設定できる。 In Embodiment 1, it has been described that the attachment angle between the main plate 11 and the blade 12 is set to 90 °, but the present invention is not limited to such an attachment angle. It can be set as appropriate according to the type of fan.
　実施の形態１において、羽根１２は、半径方向を向いた径向き羽根であると説明したが、本発明は、このような羽根に限定されない。本発明は、回転方向を向いた前向き羽根も適用でき、前向き羽根は多翼送風機に適用できる。また、本発明は、羽根が回転方向と反対方向を向いた後向き羽根にも適用でき、後向き羽根はターボファンに適用できる。 In Embodiment 1, it has been described that the blades 12 are radial blades facing in the radial direction, but the present invention is not limited to such blades. The present invention can also be applied to forward blades facing in the direction of rotation, and the forward blades can be applied to a multiblade fan. The present invention can also be applied to a backward blade in which the blade is directed in the direction opposite to the rotation direction, and the backward blade can be applied to a turbofan.
　実施の形態１において、支持部材として円板状の主板１１を用いて説明したが、本発明は、このような支持部材に限定されない。ファンとして軸流ファンや斜流ファンを用いた場合には、円柱状の回転軸を支持部材として用い、この回転軸の周りに複数の羽根を取り付けてもよい。 In Embodiment 1, the disk-shaped main plate 11 has been described as a support member, but the present invention is not limited to such a support member. When an axial fan or a mixed flow fan is used as the fan, a cylindrical rotating shaft may be used as a support member, and a plurality of blades may be attached around the rotating shaft.
　実施の形態３において、ａの値を、大きいピッチ角の数が小さいピッチ角の数より大きい値として設定したが、小さいピッチ角の数が大きいピッチ角の数より大きい値として設定してもよい。 In the third embodiment, the value of a is set as a value where the number of large pitch angles is larger than the number of small pitch angles, but the number of small pitch angles may be set larger than the number of large pitch angles. .
　実施の形態４において、鉄道車両用の電動機を例に説明したが、電動機が駆動させる車両は、鉄道車両用には限定されない。本発明は、車軸を正転・逆転させる電動機を使用する車両であればよく、例えば、自動車にも適用できる。 In the fourth embodiment, the electric motor for the railway vehicle has been described as an example, but the vehicle driven by the electric motor is not limited to the railway vehicle. The present invention may be any vehicle that uses an electric motor that rotates the axle forward and backward, and can be applied to, for example, an automobile.
　実施の形態４において、第１のピッチ角θ１の数と、第２のピッチ角θ２の数は同数であると説明したが、個数は同数に限定されない。第１のピッチ角θ１と第２のピッチ角θ２の個数の差が１以上であってもよい。 In Embodiment 4, the number of first pitch angles θ1 and the number of second pitch angles θ2 have been described as being the same number, but the number is not limited to the same number. The difference in the number of the first pitch angle θ1 and the second pitch angle θ2 may be 1 or more.
　実施の形態４において、鉄道用車両に適用する電動機を用いてファンを説明したが、鉄道用車両のファンとして、実施の形態１～３に記載したファンを用いてもよい。 In the fourth embodiment, the fan is described using the electric motor applied to the railway vehicle, but the fan described in the first to third embodiments may be used as the fan of the railway vehicle.
　以上、本発明の各実施の形態および変形例について説明したが、本発明はこれらに限定されるものではない。本発明は、実施の形態及び変形例が適宜組み合わされたもの、それに適宜変更が加えられたものを含む。 As mentioned above, although each embodiment and modification of this invention were demonstrated, this invention is not limited to these. The present invention includes a combination of the embodiments and modifications as appropriate, and a modification appropriately added thereto.
　本発明は、送風機又は電動機に搭載されるファンに好適に利用できる。 The present invention can be suitably used for a fan mounted on a blower or an electric motor.
１　送風機、１０　遠心ファン、１１　主板、１２　羽根、２０　ハウジング、２０ａ，２０ｂ　主壁、２０ｃ　側壁、２１　吸込口、２２　吐出口、３０　回転軸、４０　モータ、１００　電動機、２００　フレーム、２０１　吸込口、２０２　吐出口、３００　固定子、３０１　固定子鉄心、３０２　固定子コイル、４００　回転子、５００　回転軸、５０１　軸受、６００　遠心ファン、６０１　羽根、Ｗ１　基準羽根 1 blower, 10 centrifugal fan, 11 main plate, 12 blades, 20 housing, 20a, 20b main wall, 20c side wall, 21 suction port, 22 discharge port, 30 rotary shaft, 40 motor, 100 motor, 200 frame, 201 suction port, 202 discharge port, 300 stator, 301 stator core, 302 stator coil, 400 rotor, 500 rotating shaft, 501 bearing, 600 centrifugal fan, 601 blade, W1 reference blade

Claims (8)

  1. 　回転軸を中心に回転する支持部材と、前記支持部材に取り付けられ、前記回転軸の周りに放射状に配置されたｎ枚（ｎは２以上の整数）の羽根と、を備え、前記回転軸を中心に前記支持部材が回転することで、前記ｎ枚の羽根が回転されて気流を生成するファンであって、
    　前記ｎ枚の羽根は、ｎ個のピッチ角を隔てて前記回転軸の周りに配置され、
    　前記ｎ枚の羽根のうち何れか１枚の羽根を基準羽根とし、当該基準羽根と、前記回転軸の周の第１の方向に隣り合う羽根と、で第１のピッチ角を形成し、当該第１のピッチ角は、前記第１の方向にｍ個（ｍは１以上の整数、ｎ＞ｍ）並んで配置され、
    　前記基準羽根と、前記第１の方向と反対方向である第２の方向に隣り合う羽根と、で前記第１のピッチ角と異なる第２のピッチ角を形成し、当該第２のピッチ角は、前記第２の方向にｎ－ｍ個並んで配置され、
    　前記第１のピッチ角をｍ個合算した第１の合算ピッチ角と、前記第２のピッチ角をｎ－ｍ個合算した第２の合算ピッチ角と、は異なる、ファン。     A support member that rotates about a rotation axis; and n (n is an integer of 2 or more) blades that are attached to the support member and are arranged radially around the rotation axis. A fan for generating an air current by rotating the n blades by rotating the support member in the center;
    The n blades are arranged around the rotation axis at n pitch angles,
    Any one of the n blades is used as a reference blade, and the reference blade and the blade adjacent in the first direction of the circumference of the rotation shaft form a first pitch angle, The first pitch angles are arranged in the m direction (m is an integer of 1 or more, n> m) in the first direction,
    A second pitch angle different from the first pitch angle is formed by the reference blade and a blade adjacent to the second direction that is opposite to the first direction, and the second pitch angle is , N−m arranged in the second direction,
    A fan, wherein a first summed pitch angle obtained by summing m of the first pitch angles is different from a second summed pitch angle obtained by summing nm of the second pitch angles.
  2. 　前記第１のピッチ角をもって配置されるｍ個のピッチ角の数と、前記第２のピッチ角をもって配置されるｎ－ｍ個のピッチ角の数と、は異なる、
    　請求項１に記載のファン。     The number of m pitch angles arranged with the first pitch angle is different from the number of nm pitch angles arranged with the second pitch angle.
    The fan according to claim 1.
  3. 　前記第１のピッチ角をもって配置されるｍ個のピッチ角の数と、前記第２のピッチ角をもって配置されるｎ－ｍ個のピッチ角の数と、は等しい、
    　請求項１に記載のファン。     The number of m pitch angles arranged with the first pitch angle is equal to the number of nm pitch angles arranged with the second pitch angle.
    The fan according to claim 1.
  4. 　回転軸を中心に回転する支持部材と、前記支持部材に取り付けられ、前記回転軸の周りに放射状に配置されたｎ枚（ｎは２以上の整数）の羽根と、を備え、前記回転軸を中心に前記支持部材が回転することで、前記ｎ枚の羽根が回転されて気流を生成するファンであって、
    　前記ｎ枚の羽根は、ｎ個のピッチ角を隔てて前記回転軸の周りに配置され、
    　前記ｎ枚の羽根のうち何れか１枚の羽根を基準羽根とし、当該基準羽根と、前記回転軸の周の第１の方向に隣り合う羽根と、で第１のピッチ角を形成し、当該第１のピッチ角は、前記第１の方向にｐ個（ｐは１以上の整数、ｎ＞ｐ）並んで配置され、
    　前記基準羽根と、前記第１の方向と反対方向である第２の方向に隣り合う羽根と、で前記第１のピッチ角と異なる第２のピッチ角を形成し、当該第２のピッチ角は、前記第２の方向にｑ個（ｑは１以上の整数、ｎ＞ｑ）並んで配置され、
    　前記第１のピッチ角をｐ個合算した第１の合算ピッチ角と、前記第２のピッチ角をｑ個合算した第２の合算ピッチ角と、は異なり、
    　前記第１の合算ピッチ角と前記第２の合算ピッチ角とを合算した第３のピッチ角を回転軸の周りに２以上並べて前記ｎ個のピッチ角を形成する、ファン。     A support member that rotates about a rotation axis; and n (n is an integer of 2 or more) blades that are attached to the support member and are arranged radially around the rotation axis. A fan for generating an air current by rotating the n blades by rotating the support member in the center;
    The n blades are arranged around the rotation axis at n pitch angles,
    Any one of the n blades is used as a reference blade, and a first pitch angle is formed between the reference blade and a blade adjacent to the first direction of the circumference of the rotation shaft, The first pitch angles are arranged side by side in the first direction by p (p is an integer of 1 or more, n> p),
    A second pitch angle different from the first pitch angle is formed by the reference blade and a blade adjacent to the second direction that is opposite to the first direction, and the second pitch angle is , Q (q is an integer of 1 or more, n> q) arranged in the second direction,
    A first summed pitch angle obtained by adding p first pitch angles is different from a second summed pitch angle obtained by adding q second pitch angles,
    A fan in which the n pitch angles are formed by arranging two or more third pitch angles obtained by adding the first combined pitch angles and the second combined pitch angles around a rotation axis.
  5. 　前記ファンは、遠心ファンである、
    　請求項１～４の何れか１項に記載のファン。     The fan is a centrifugal fan,
    The fan according to any one of claims 1 to 4.
  6. 　前記回転軸は、前記第１の方向と前記第２の方向との双方向に回転する、
    　請求項１～５の何れか１項に記載のファン。     The rotating shaft rotates in both directions of the first direction and the second direction;
    The fan according to any one of claims 1 to 5.
  7. 　請求項１～６の何れか１項に記載されたファンと、
    　前記回転軸を中心に前記支持部材を回転させるモータと、
    　を備える送風機。     A fan according to any one of claims 1 to 6,
    A motor for rotating the support member around the rotation shaft;
    Blower equipped with.
  8. 　フレームの内面に固定され、電源が供給されることで回転磁界を発生させる固定子と、
    　回転軸が貫通して固定され、前記回転磁界により回転される回転子と、
    　前記回転軸の一端に取り付けられた請求項１～６の何れか１項に記載のファンと、
    　を備える電動機。     A stator that is fixed to the inner surface of the frame and generates a rotating magnetic field when power is supplied;
    A rotor having a rotating shaft penetrated and fixed, and rotated by the rotating magnetic field;
    The fan according to any one of claims 1 to 6, which is attached to one end of the rotating shaft;
    An electric motor.
PCT/JP2017/000271 2017-01-06 2017-01-06 Fan, blower, and electric motor WO2018127970A1 (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3623637A1 (en) * 2018-09-14 2020-03-18 Yen Sun Technology Corp. Centrifugal fan
CN114223111A (en) * 2019-08-22 2022-03-22 日本电产株式会社 Outer rotor type motor

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US1893184A (en) * 1929-01-24 1933-01-03 Hoover Co Fan
GB2046360A (en) * 1979-03-31 1980-11-12 Aes Plastics Ltd Fluid impeller
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JPH05195996A (en) * 1992-01-16 1993-08-06 Hitachi Ltd Air compressor
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JP2005282500A (en) * 2004-03-30 2005-10-13 Toshiba Corp Fluid pump, cooling device and electric apparatus
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JP2015228768A (en) * 2014-06-02 2015-12-17 株式会社東芝 Rotary machine

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US1893184A (en) * 1929-01-24 1933-01-03 Hoover Co Fan
GB2046360A (en) * 1979-03-31 1980-11-12 Aes Plastics Ltd Fluid impeller
JPS5716297A (en) * 1980-07-02 1982-01-27 Toshiba Corp Multiblade fan
JPH05195996A (en) * 1992-01-16 1993-08-06 Hitachi Ltd Air compressor
JP2011231775A (en) * 2001-05-11 2011-11-17 Snecma Structure including rotor and fixed perturbation source, and method for reducing vibration of the structure
JP2003269363A (en) * 2002-03-15 2003-09-25 Mitsubishi Heavy Ind Ltd Tangential fan impeller and air conditioner
JP2005282500A (en) * 2004-03-30 2005-10-13 Toshiba Corp Fluid pump, cooling device and electric apparatus
JP2015228768A (en) * 2014-06-02 2015-12-17 株式会社東芝 Rotary machine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3623637A1 (en) * 2018-09-14 2020-03-18 Yen Sun Technology Corp. Centrifugal fan
CN114223111A (en) * 2019-08-22 2022-03-22 日本电产株式会社 Outer rotor type motor

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