JPWO2014142225A1 - Impeller and axial flow blower using the same - Google Patents

Abstract

The rotor blade includes a boss portion having a cylindrical outer shape and a plurality of rotor blades attached radially to the boss portion. The rotor blade includes a first region having a first stagger angle distribution from an inner peripheral edge connected to the boss portion to a predetermined radial position, and a first stagger from the predetermined radial position adjacent to the first region to the outer peripheral edge. A second region having a second stagger angle distribution different from the angular distribution, and the second stagger angle distribution is from a maximum radial position where the stagger angle becomes a maximum in the second region toward the outer periphery. It has a distribution in which the stagger angle decreases.

Description

  The present invention relates to an impeller used in a ventilation fan or an air conditioner and an axial blower using the impeller.

  2. Description of the Related Art Conventionally, an axial blower used for a ventilation fan, an air conditioner, or the like has a configuration in which an opening having a bell mouth shape at the periphery is formed in a housing, and an impeller having a rotating blade is disposed in the opening. In this axial blower, a part of the rotor blade is disposed so as to protrude to a position higher than the height of the bell mouth mainly for noise reduction. Further, when the rotor blade is arranged so as not to protrude from the end portion of the bell mouth, noise reduction is achieved by forming a large curvature on the suction side of the bell mouth.

  Further, it has been proposed to reduce noise and increase efficiency by making the shape of the impeller rotor blades into a predetermined three-dimensional curved surface shape (see, for example, Patent Documents 1-3). Patent Document 1 discloses that the blades are formed at a predetermined angle with a straight line connecting the connection position with the boss portion and the peripheral edge portion, and noise is suppressed by being formed at a predetermined stagger angle. ing. Patent Document 2 discloses that noise is suppressed by reducing the forward tilt angle in the suction direction and increasing the forward rotation angle. In Patent Document 3, the first forward tilt angle of the first region from the boss portion to a predetermined position is made constant, and the second forward tilt angle of the second region on the outer peripheral side from the first region is set to be greater than the first forward tilt angle. Also disclosed is an axial blower having blades formed to be larger.

Japanese Patent Publication No.2000-2000 Japanese Patent Laid-Open No. 11-303794 Japanese Patent No. 3320994

  As in the above Patent Document 1-3, the blade shape is reduced to a predetermined three-dimensional solid shape to achieve low noise and high efficiency. However, sufficient consideration has not been given.

  The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide an axial blower that can achieve low noise and high efficiency in consideration of lateral suction. .

  The rotary blade of the present invention includes a boss portion having a cylindrical outer shape, and a plurality of rotary blades attached radially to the boss portion, and the rotary blade has a predetermined radial position from an inner peripheral edge connected to the boss portion. A first region having a first stagger angle distribution, and a second region having a second stagger angle distribution different from the first stagger angle distribution from a predetermined radial position adjacent to the first region to the outer periphery. The second stagger angle distribution has a distribution in which the stagger angle decreases from the maximum radius position where the stagger angle becomes a maximum in the second region toward the outer periphery.

  According to the rotor blade of the present invention, the stagger angle of the second region of the rotor blade having the lateral suction is changed to the second stagger angle distribution so as to have an angle adapted to the increase in the flow rate of the lateral suction. Since separation of the flow near the outer periphery can be prevented, it is possible to achieve a reduction in noise caused by side suction and an increase in efficiency.

It is a perspective view which shows Embodiment 1 of the axial-flow fan of this invention. It is a perspective view which shows Embodiment 1 of the axial-flow fan of this invention. It is an upper surface schematic diagram which shows Embodiment 1 of the impeller of this invention. It is a side surface schematic diagram which shows Embodiment 1 of the impeller of this invention. FIG. 3 is a cylindrical cross-sectional development view at a predetermined radial position of a rotary blade in the impeller of FIG. 2. It is a graph which shows stagger angle distribution of the rotary blade of FIG. FIG. 3 is a cylindrical cross-sectional development view at a radial position R1 of a first region of the rotor blade of FIG. 2. FIG. 3 is a cylindrical cross-sectional development view at a radial position R2 in a second region of the rotor blade of FIG. 2. It is a side surface schematic diagram which shows an example of the impeller of a comparative example. It is a schematic diagram which shows the relative velocity vector when not considering lateral suction. It is a schematic diagram which shows the relative velocity vector at the time of considering lateral suction. It is a schematic diagram which shows the relationship between the relative velocity vector and airflow in the impeller of FIG. It is a schematic diagram which shows the relationship between the relative velocity vector and airflow in the impeller of the comparative example of FIG. It is a graph which shows the specific noise characteristic at the time of using the impeller of FIG. 2, and the impeller of the comparative example of FIG. It is a graph which shows the fan efficiency characteristic at the time of using the impeller of FIG. 2, and the impeller of the comparative example of FIG. It is a graph which shows the difference of the minimum specific noise at the time of using the impeller of FIG. 2, and the impeller of the comparative example of FIG. It is a graph which shows the difference of the highest fan efficiency at the time of using the impeller of FIG. 2, and the impeller of the comparative example of FIG. It is the graph which compared height using the expanded sectional view for every different stagger angle in the outer periphery at the time of using the impeller of FIG. 2 and the impeller of the comparative example of FIG. It is a graph which shows the stagger angle distribution of the rotary blade in Embodiment 2 of the impeller of this invention. FIG. 19 is a cylindrical cross-sectional development view at a radial position R1 of the first region of the rotor blade of FIG. It is a graph which shows the fan efficiency characteristic at the time of using the impeller of FIG. 2, the impeller of the comparative example of FIG. 8, and the impeller of FIG. It is a graph which shows the fan efficiency characteristic at the time of using the impeller of FIG. 2, the impeller of the comparative example of FIG. 8, and the impeller of FIG.

  Hereinafter, an embodiment of an impeller of the present invention and an axial blower using the impeller will be described with reference to the drawings. FIG. 1 is a perspective view showing Embodiment 1 of the axial blower of the present invention. The axial blower 1 will be described with reference to FIG. 1A is a perspective view of the axial fan as viewed from the front, and FIG. 1B is a perspective view of the axial fan as viewed from the back. The axial blower 1 in FIG. 1 includes a housing 2, an impeller 10 that is rotatably disposed at a suction port, and a motor M that rotationally drives the impeller. The housing 2 is configured such that an opening 3 which is an air passage through which an impeller 10 is rotatably housed and an air flow generated by the impeller passes is formed, and an edge of the opening 3 is located upstream of the air flow. A bell mouth 4 is formed so that its diameter increases.

  The impeller 10 includes a boss portion 11 having a substantially cylindrical outer shape and a plurality of rotary blades 12 provided radially attached to the outer periphery of the boss portion 11. The boss portion 11 is connected to the motor M held by the housing 2 on the rotation axis CL. When the motor M is driven, the boss portion 11 rotates about the rotation axis CL in the direction of the arrow RR. Airflow in the A direction (see FIG. 3) is generated. In addition, although the impeller 10 of FIG. 1 has illustrated about the case where it has five rotary blades 12, the number of the rotary blades 12 may be three or other plural numbers.

  FIG. 2 is a schematic plan view showing the first embodiment of the impeller of the present invention, and FIG. 3 is a schematic side view showing the first embodiment of the impeller of the present invention. The rotor blades 12 will be described. 2 and 3 exemplify one rotor blade 12, other rotor blades 12 attached to the boss portion 11 have the same shape. 2 has a predetermined three-dimensional solid shape, and includes a front edge 12a located on the forward direction side of the rotation direction RR, and a rear edge 12b located on the opposite side of the rotation direction RR. The four sides of the inner peripheral edge 12c connected to the boss portion 11 and the outer peripheral edge 12d located on the housing 2 side are formed.

  The rotary blade 12 includes a first region AR1 having a first stagger angle distribution Dξ1 from the boss portion 11 to a predetermined radial position (boundary position) Rd, and a first stagger angle distribution from the boundary position Rd to the outer peripheral edge 12d. The second region AR2 has a second stagger angle distribution Dξ2 different from Dξ1. The boundary position Rd is set to, for example, the boundary position Rd = 0.7 × (Rt−Rb) with respect to the length in the radial direction from the position Rb on the inner peripheral edge 12c to the position Rt on the outer peripheral edge 12d. . Here, FIG. 4 is a developed cross-sectional view of the rotor blade 12 at an arbitrary point on a line connecting the midpoints of the leading edge 12a and the trailing edge 12b. As shown in FIG. 4, the stagger angle ξ is formed by a chord line SL connecting the leading edge 12a and the trailing edge 12b and a perpendicular line HL extending from the leading edge 12a of the rotating blade 12 in parallel with the rotation axis CL. It means the angle ξ.

  FIG. 5 is a graph showing an example of stagger angle distribution in the rotor blade 12 of FIG. In the line segment representing the distribution of the stagger angle ξ in FIG. 5, the left end of the line segment is the stagger angle ξb at the radial position Rb of the inner peripheral edge 12c connected to the boss portion 11, and the right end is the outer peripheral edge 12d. The stagger angle ξt at the radial position Rt is represented. In FIG. 5, the first stagger angle distribution Dξ1 in the first region AR1 has a distribution that gradually increases so that the stagger angle ξ is smoothly continuous, and in particular, the first stagger angle distribution. Dξ1 has a distribution in which the stagger angle ξ increases linearly (linearly) at a constant increase rate. The first stagger angle distribution Dξ1 is set, for example, to a stagger angle ξb = 58 ° at the radial position Rb of the inner peripheral edge 12c, and to a stagger angle ξd = 64.46 ° at the boundary position Rd. In one area AR1, the stagger angle ξ increases linearly.

  In the second stagger angle distribution Dξ2 in the second area AR2, the stagger angle ξ increases so that the increase rate of the stagger angle ξ gradually decreases from the boundary position Rd, and the maximum stagger angle ξ2max at the maximum radius position R2max. The stagger angle ξ gradually decreases from the maximum radius position Rmax toward the outer peripheral edge 12d, and the stagger angle ξt of the outer peripheral edge 12d of the second area AR2 becomes smaller than the maximum stagger angle ξ2max. It has a distribution (ξt <ξ2max). In other words, the second stagger angle distribution Dξ2 of the second area AR2 is such that the stagger angle ξ decreases from the maximum radius position R2max where the stagger angle ξ becomes a maximum in the second area AR2 toward the outer peripheral edge 12d. It has a distribution of a quadratic function. The stagger angle ξ2max, which is the maximum in the second area AR2, is also the maximum value of the stagger angle ξ of the entire rotor blade 12. The second stagger angle distribution Dξ2 increases, for example, from the stagger angle ξd = 64.46 ° at the boundary position Rd to the maximum stagger angle ξ2max at the maximum radius position R2max, and from the maximum radius position R2max toward the outer peripheral edge 12d. Thus, the stagger angle ξ decreases, and the stagger angle ξt of the outer peripheral edge 12d becomes 63.5 °. Note that the stagger angle distribution has a continuous curve or straight line distribution on the first area AR1, the second area AR2, and the boundary position Rd.

  As described above, the second region AR2 on the outer peripheral side of the rotor blade 12 has the second stagger angle distribution Dξ2 such that the stagger angle ξt of the outer peripheral edge 12d is smaller than the maximum radial position R2max. The angle is adapted to the increase in the flow rate of the lateral suction generated at the outer peripheral edge 12d, and the separation of the flow at the outer peripheral edge 12d can be prevented, so that the noise caused by the disturbance is reduced and the fan efficiency is increased. Can be achieved.

  The impeller 10 will be described below in comparison with a comparative example. In addition, the rotary blade 12 which has the stagger angle distribution (refer FIG. 5) mentioned above as Embodiment 1 shown below is used. On the other hand, FIG. 8 is a schematic view showing an example of a rotor blade 112 as a comparative example, and the rotor blade 112 of the comparative example will be described with reference to FIG. The rotor blade 112 of the comparative example also has a predetermined three-dimensional solid shape, similar to the rotor blade 12 of FIGS. 2 and 3, and includes a leading edge 112a positioned on the positive direction side of the rotation direction RR, and a rotation direction. It has a rear edge 112b located on the opposite side of the RR, an inner peripheral edge 112c connected to the boss 111, and an outer peripheral edge 112d located on the housing 2 side. The rotor blade 112 has a stagger distribution in which the stagger angle ξ increases linearly (linear function) from the position of the inner peripheral edge 112c to the position of the outer peripheral edge 112d as shown by the dotted line in FIG. Specifically, the rotor blade 112 has a diameter Rt = 260 (mm), a stagger angle ξt = 67.5 ° on the outer peripheral edge 112d side, and a stagger angle ξb = 58 ° on the boss 111 side. The stagger angle ξ between them has a stagger angle distribution that increases linearly with the blade diameter.

  Here, in FIG. 5, the stagger angle ξb at the position Rb of the inner peripheral edge 12c between the first embodiment and the comparative example is the same. The stagger angle ξ increases at a larger increase rate than the rotor blade 112 of the comparative example, as the rotor blade 12 of the first embodiment moves from the inner peripheral edge 12c toward the outer peripheral side. FIG. 6 is a blade cross-sectional development view showing the rotor blade 12 of the first embodiment and the rotor blade 112 of the comparative example at an arbitrary radial position R1 in the first region AR1. As shown in FIG. 6, in the first area AR1, the stagger angle ξ1 of the rotor blade 12 of Embodiment 1 is larger than the stagger angle ξc1 of the rotor blade 112 of the comparative example (ξ1> ξc1). Sleeping with respect to the rotation direction RR.

  In the second area AR2 of FIG. 5, the increase rate of the stagger angle ξ of the rotor blade 12 of the first embodiment gradually decreases, gradually approaching the stagger angle ξ of the rotor blade 112 of the comparative example, On the outer peripheral side (outer peripheral edge 12d) from the maximum radius position R2max, the stagger angle ξ of the rotor blade 12 of the first embodiment is smaller than the stagger angle ξ of the rotor blade 112 of the comparative example. FIG. 7 is a blade cross-sectional development view showing the rotary blade 12 of the first embodiment and the rotary blade 112 of the comparative example at the radial position R2 on the outer peripheral side from the maximum radial position R2max of the second region AR2. As shown in FIG. 7, the stagger angle ξ2 of the rotor blade 12 of the first embodiment is smaller than the stagger angle ξc2 of the rotor blade 112 of the comparative example at the radius position R2 on the outer peripheral side from the maximum radius position R2max. (Ξ2 <ξc2) and stands with respect to the rotation direction RR.

  9 and 10 are schematic diagrams showing the relationship between the blade cylinder cross-sectional view near the outer peripheral edge 12d and the velocity triangle. 9 shows the case where the lateral suction is not taken into account, and FIG. 10 shows the case where the lateral suction is taken into consideration, respectively. In the drawing, the flow velocity vector in the rotation axis direction (refer to the direction of arrow A in FIG. 3) is shown. The horizontal vectors corresponding to V and V10 and the rotational speed of the rotor blade 12 are represented by U, and the relative flow velocity vectors obtained by combining the flow velocity vectors V and V10 and the transverse vector U are represented by W and W10. As shown in FIG. 8, in the rotor blade 112 of the comparative example, the flow velocity vector V and the transverse vector that do not consider the lateral suction when it is assumed that the airflow flows along the blade element that is a line element on the same radius of the blade surface. Two-dimensional optimum design is performed based on U. Therefore, at the designed flow rate, the direction of the relative flow velocity vector W indicating the inflow flow into the rotor blade 112 substantially matches the leading edge 112a.

  However, in actuality, since there is an air flow from the outer peripheral edge 112d side, the flow rate is increased by adding the side suction flow from the blade side to the inflow from the leading edge 112a, resulting in a flow velocity vector V10 (> V). . For this reason, as shown in FIG. 10, the direction of the relative flow velocity vector W10 and the angle on the front edge 112a side of the rotor blade 112 are not matched.

  FIG. 11 is a schematic diagram showing the state of airflow when the direction of the relative flow velocity vector W10 and the angle of the leading edge 112a of the rotor blade 112 do not match. As shown in FIG. 11, in addition to the inflow from the front surface of the rotary blade 112 (in the direction of arrow A in FIG. 3), there is lateral suction from the bell mouth 4 side on the front edge 112a side. For this reason, air separation AC1 or the like occurs on the leading edge 112a side of the blade suction surface 112f, and the flow of the airflow does not match the shape of the rotating blade 112, and the turbulence is transferred to the trailing edge 112b while being disturbed. Also grows. Since the loss of these flows becomes large, the blower-noise characteristics are deteriorated.

  FIG. 12 is a schematic diagram showing the state of air flow when the direction of the relative flow velocity vector W10 and the angle of the leading edge 12a of the rotor blade 12 are matched. Since the rotor blade 12 has a predetermined stagger angle distribution (see FIG. 6), the stagger angle ξ in the vicinity of the outer peripheral edge 12d, which is greatly influenced by the lateral suction, has a distribution corresponding to the flow rate increase. . For this reason, even when there is a lateral suction, the direction of the relative flow velocity vector W10 and the angle of the leading edge 12a are in a compatible direction. Therefore, the airflow flows along the blade shape, and the separation is reduced, so that the flow loss is reduced and the deterioration of the blower-noise characteristics is also reduced.

FIG. 13 is a graph comparing specific noise characteristics and fan efficiency characteristics of the rotor blade 12 having the stagger angle distribution Dξ of the first embodiment and the rotor blade 112 having the stagger angle distribution of the comparative example. The specific noise K _S [dB] is expressed by the following formula when the air volume is Q [m ³ / min], the static pressure is P _s [Pa], and the noise characteristic (after A correction) is SPL _A [dB]. 1).

[Equation 1]
K _S = SPL _A -10 Log (Q · P _s ^2.5 ) (1)

As shown in FIG. 13, the specific noise K _S has low noise is attained in a wide range of air flow band compared to blades with straight stagger angle characteristics, low noise up -5 (dB) Can be achieved.

FIG. 14 is a graph comparing fan efficiency characteristics of the rotor blade 12 having the stagger angle distribution Dξ of the first embodiment and the rotor blade 112 having the stagger angle distribution of the comparative example. The fan efficiency E _s [%] can be expressed by the following formula (2) when the shaft power is P _w [W].

[Equation 2]
E _S = (P _s · Q) / (60 · P _w ) (2)

  As shown in FIG. 14, the fan efficiency can be increased to a maximum of +1 (point).

Figure 15 In the rotor blade 12 having a stagger angle distribution Dξ 4, the relationship between the minimum specific noise _{K S} when changing the stagger angle ξt of the outer peripheral edge 12d to from 57.5 to 66.5 ° It is the shown graph. In FIG. 15, it is possible to reduce noise in the range of 57.5 ° ≦ ξt ≦ 66.5 °. FIG. 16 shows the highest point of fan efficiency when the rotor blade 12 having the stagger angle distribution Dξ of FIG. 4 is changed within the stagger angle of the outer peripheral edge 12d within the range of 57.5 ° ≦ ξt ≦ 66.5 °. It is the graph which showed the relationship. As shown in FIG. 16, the blades having the staggered angle distribution of the present invention can achieve high efficiency in the range examined this time. More preferably, as can be seen from the graphs of FIGS. 15 and 16, when 60 ° ≦ ξt ≦ 63 °, the axial flow fan 1 can be efficiently operated while minimizing the generation of noise. Further, the height of the rotary blade 12 on the outer peripheral side of the rotary blade 12 can be made lower than that of the blade having the staggered angle distribution of the comparative example, and the joining with the motor M and the like are facilitated.

  FIG. 17 is a graph comparing heights using developed cross-sectional views for different stagger angles ξt at the outer peripheral edge 12d. Note that FIG. 17 shows a comparison in height when alignment is performed at a predetermined position (for example, the front edge 12a side). As the stagger angle ξt becomes smaller, the height difference between the leading edge 12a side and the trailing edge 12b side occurs, and the height of the rotary blade 12 becomes higher. In the first embodiment, it becomes higher than the comparative example. The height of the rotor 12 is subject to restrictions such as product height constraints and the relationship of gaps such as motor support. Since the height limit is uniform for each product from the relationship between each product form and other parts, it cannot be generally determined. On the other hand, when the stagger angle ξt is within the range of 57.5 to 66.5 °, the above-described height constraint can be accommodated, and the above-described low noise and high efficiency rotor blade 12 is provided. be able to. In particular, if 60 ° ≦ ξt ≦ 63 °, the axial flow fan 1 can be operated efficiently while minimizing the generation of noise.

Embodiment 2. FIG.
FIG. 18 is a graph showing Embodiment 2 of the stagger angle distribution of the rotor blades in the impeller of the present invention. The impeller having the staggered angle distribution shown in FIG. 18 is also configured to have a boss portion 11 and a plurality of rotating blades 12 as shown in FIGS. 18 is different from the stagger angle distribution of FIG. 5 in a first stagger angle distribution Dξ11 of the first area AR1. Also in FIG. 18, similarly to FIG. 5, the boundary position Rd is set to a position of Rd = 0.7 × (Rt−Rb), and the first stagger angle distribution Dξ11 is set by the boundary position Rd. The area AR1 is divided into a second area AR2 having a second stagger angle distribution Dξ2. Further, the discrepancy angle ξt of the outer peripheral edge 12d is set in a range of 57.5 ° ≦ ξt ≦ 66.5 °.

  In the first region AR1 of FIG. 18, the stagger angle ξ gradually decreases from the stagger angle ξ2b of the radial position Rb of the inner peripheral edge 12c, becomes the minimum stagger angle ξ1min at the minimum radius position R1min, and from the minimum radius position R1min. It gradually increases toward the stagger angle ξd of the boundary position Rd. The stagger angle ξ2b at the radial position Rb is the maximum value of the stagger angle ξ of the entire rotor blade 12. Specifically, the first stagger angle distribution Dξ1 is set, for example, to a stagger angle ξ2b = 72 ° of the radial position Rb of the inner peripheral edge 12c, and the stagger angle ξt = 63.5 of the radial position Rt of the outer peripheral edge 12d. Set to °.

  FIG. 19 is a developed sectional view of an arbitrary radial position R1 of the first region AR1 in the rotor blade having the staggered angle distribution of the second embodiment of FIG. As shown in FIG. 19, at the radial position R <b> 1, the rotary blade 12 is in a sleeping state as compared with a conventional blade having a staggered angle distribution.

  FIG. 20 is a graph comparing the specific noise characteristics and fan efficiency characteristics of the rotor blade 12 having the stagger angle distribution Dξ of the second embodiment and the rotor blade 112 having the stagger angle distribution of the comparative example, and FIG. 2 is a graph comparing fan efficiency characteristics of a rotor blade 12 having a stagger angle distribution Dξ of 2 and a rotor blade 112 having a stagger angle distribution of a comparative example. 20 and 21, there is a portion where the characteristics on the large air volume side deteriorate, but at the point of the intermediate air volume that is the actual use area, it is possible to further reduce noise and increase efficiency, and the conventional misalignment is achieved. Compared to a blade having an angular distribution, it is possible to reduce the noise by -6 (dB) at the maximum. The fan efficiency can be increased to a maximum of +2.4 (points).

  As described above, even when the stagger angle distribution Dξ1 of the first region AR1 as shown in FIG. 18 is provided, the stagger angle ξt of the outer peripheral edge 12d is smaller than the maximum radius position R2max as in the first embodiment. Since it has such a second stagger angle distribution Dξ2, it is set to an angle suitable for the increase in the flow rate of the lateral suction generated at the outer peripheral edge 12d, and flow separation at the outer peripheral edge 12d can be prevented. In addition, it is possible to achieve a reduction in noise caused by disturbance and an increase in fan efficiency. Further, the height of the rotary blade 12 on the outer peripheral side of the rotary blade 12 can be made lower than that of the blade having the staggered angle distribution of the comparative example, and the joining with the motor M and the like are facilitated. Further, by making the first stagger angle distribution Dξ11 shown in FIG. 18 for the first area AR1, it is possible to smoothly connect to the stagger angle ξ of the second area AR2, and it is possible to achieve a reduction in thickness. Become.

  The embodiment of the present invention is not limited to the above embodiment. For example, in the first and second embodiments, the case where the first area AR1 has the predetermined first stagger angle distributions Dξ1 and Dξ11 is illustrated, but the second stagger angle distribution Dξ2 of the second area AR2 is Any first meal as long as it has a distribution in which the gap angle ξ decreases from the maximum radius position R2max at which the gap angle ξ becomes a maximum in the two regions AR2 toward the outer peripheral edge 12d. A difference angle distribution may be adopted.

  Further, in the first embodiment, the case of the stagger angle ξb = 58 ° of the inner peripheral edge 12c is illustrated, and in the second embodiment, the case of the stagger angle ξ20b = 72 ° of the inner peripheral edge 12c is illustrated. The stagger angle ξb, ξ20b of 12c is preferably in the range of 58 ° to 72 °. This is because, in the rotor blade 12, the range that contributes most to the blowing performance is a region on the outer peripheral side located 0.7 to 1.0 times the radius, and the contribution of the inner peripheral edge 12c is lower than that on the outer peripheral side. This is because, on the inner peripheral side, it is structurally advantageous that the rotor blade 12 lies in relation to the boss portion 11.

  1 axial fan, 2 housing, 3 opening, 4 bell mouth, 10 impeller, 11, 111 boss part, 12, 112 rotor blade, 12a, 112a front edge, 12b, 112b rear edge, 12c, 112c inner periphery, 12d, 112d outer periphery, 112f blade suction surface, AC1 air separation, AC2 wake vortex, AR1 first area, AR2 second area, CL rotation axis, Dξ, Dξ1, Dξ11 first stagger angle distribution, Dξ2 first meal Difference angle distribution, HL perpendicular, M motor, R1 first region radius position, R2 second region radius position, RR rotation direction, Rb inner periphery radius position, Rd boundary position (predetermined radius position), Rt outer periphery Radial position, SL chord line, U horizontal vector, V, V10 flow velocity vector, W, W10 relative flow velocity vector, ξ stagger angle, ξb, ξ20b stagger angle of inner periphery, ξd Stagger angle at the boundary position, ξt Stagger angle at the outer periphery.

An impeller according to the present invention includes a boss portion having a cylindrical outer shape, and a plurality of rotor blades radially attached to the boss portion, and the rotor blade has a predetermined radius from an inner peripheral edge connected to the boss portion. A first region having a first stagger angle distribution to a position, and a second region having a second stagger angle distribution different from the first stagger angle distribution from a predetermined radial position adjacent to the first region to the outer periphery. has the door, the second meal difference angle distribution, from the maximum radial position where the local maximum stagger angle in the second region to the outer peripheral edge have a distribution stagger angle is decreased, the first meal difference angle The distribution has a distribution in which the stagger angle increases linearly from the boss portion toward the outer periphery .

Claims (12)

A boss having a cylindrical outer shape;
A plurality of rotor blades radially attached to the boss portion;
The rotor blade is
A first region having a first stagger angle distribution from an inner peripheral edge connected to the boss portion to a predetermined radial position;
A second region having a second stagger angle distribution different from the first stagger angle distribution from a predetermined radial position adjacent to the first region to an outer periphery;
The second stagger angle distribution has a distribution in which the stagger angle decreases toward the outer peripheral edge from a maximum radial position where the stagger angle becomes a maximum in the second region.   2. The second stagger angle distribution has a distribution in which a stagger angle is increased while an increase rate of the stagger angle is decreased from the predetermined radial position to the maximum radial position. Impeller.   3. The impeller according to claim 2, wherein the second stagger angle distribution has a stagger angle distribution that changes in a curved shape of a quadratic function.   The impeller according to any one of claims 1 to 3, wherein a stagger angle of the outer peripheral edge is in a range of 57.5 ° to 66.5 °.   The impeller according to any one of claims 1 to 4, wherein the first stagger angle distribution has a distribution in which a stagger angle increases from the boss portion toward an outer periphery.   The impeller according to claim 5, wherein the first stagger angle distribution has a distribution in which the stagger angle increases linearly.   The impeller according to any one of claims 1 to 6, wherein the first stagger angle distribution has the smallest minimum stagger angle among the rotor blades.   The first stagger angle distribution is reduced so that a decrease rate of the stagger angle decreases from the inner peripheral edge to the minimum radius position in the first region, and from the minimum radius position in the first region to the predetermined radius position. Then, the impeller according to any one of claims 1 to 4, which has a distribution in which the stagger angle gradually increases.   The impeller according to claim 8, wherein the rotor blade has a maximum stagger angle of the inner peripheral edge of the stagger angle of the rotor blade.   The impeller according to claim 8 or 9, wherein the first stagger angle distribution has a stagger angle distribution that changes in a curve of a quadratic function.   The impeller according to any one of claims 1 to 10, wherein a stagger angle of the inner peripheral edge is in a range of 58 ° to 72 °. The impeller according to any one of claims 1 to 11,
A motor for rotationally driving the boss portion of the impeller;
A blower comprising: a housing that rotatably houses the impeller and through which an airflow generated by the impeller passes.

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