Impellers, blowers, and air conditioners

Abstract

The impeller comprises a boss portion provided on the axis of rotation and a blade provided on the outer circumference of the boss portion. The blade has a leading edge portion which is the edge forward in the direction of rotation, a trailing edge portion which is the edge backward in the direction of rotation, an outer circumference end portion which is the edge on the outer circumference side, and an inner circumference end portion which is the edge on the inner circumference side. The cross section obtained by cutting the blade with a cylinder centered on the axis of rotation is defined as the chord direction cross section. In the chord direction cross section, the line segment connecting the leading edge portion and the trailing edge portion is defined as the chord, and the angle between the axis of rotation and the chord is defined as the misalignment angle. The misalignment angle is considered positive when the trailing edge portion of the blade is inclined toward the negative pressure surface side of the blade. The chord direction cross section includes a first chord direction cross section and a second chord direction cross section which is further outward than the first chord direction cross section. The misalignment angle of the blade decreases from the inner circumference end portion to the first chord direction cross section and increases from the first chord direction cross section to the second chord direction cross section.

Description

[Technical Field]

[0001] This disclosure relates to impellers, blowers, and air conditioners. [Background technology]

[0002] The efficiency of an impeller is improved by distributing airflow across the entire impeller. For example, Patent Document 1 discloses an impeller in which the offset angle is reduced so that the wing becomes more upright from the inner circumference to the outer circumference. The offset angle is the angle of the wing chord with respect to the axis of rotation. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2001-174022 [Overview of the project] [Problems that the invention aims to solve]

[0004] In Patent Document 1, the offset angle decreases from the inner circumference to the outer circumference in the radial direction, so that the wing is angled upwards towards the outer edge of the wing. In this case, the airflow does not flow along the wing at the outer circumference, resulting in reduced airflow efficiency. Therefore, there is a need to improve the overall efficiency of the impeller.

[0005] This disclosure aims to provide highly efficient impellers, blowers, and air conditioners. [Means for solving the problem]

[0006] The impeller according to this disclosure comprises a boss portion provided on a rotation axis and a blade provided on the outer circumference of the boss portion, the blade having a leading edge portion which is the edge forward in the direction of rotation, a trailing edge portion which is the edge backward in the direction of rotation, an outer peripheral end portion which is the edge on the outer circumference side, and an inner peripheral end portion which is the edge on the inner circumference side, the cross section obtained by cutting the blade with a cylinder centered on the rotation axis is defined as the chord direction cross section, and in the chord direction cross section, the line segment connecting the leading edge portion and the trailing edge portion is defined as the chord, and the rotation The angle between the axis of rotation and the chord is defined as the misalignment angle, and the misalignment angle is defined as positive when the trailing edge of the wing is inclined toward the negative pressure surface of the wing, the chord direction cross section includes a first chord direction cross section and a second chord direction cross section located on the outer circumference of the first chord direction cross section, the misalignment angle of the wing decreases from the inner circumference end to the first chord direction cross section and increases from the first chord direction cross section to the second chord direction cross section, and the distance from the axis of rotation to the inner circumference end is defined as r b Let r be the distance from the rotation axis to the outer peripheral end. t The distance from the rotation axis to the first code direction cross section is defined as r d Let α be a constant, and let αr be the distance from the rotation axis to the second code direction cross section. d When this is the case, r b <r d ≤0.5r t The α = 1.01, and a drainage point is provided at the leading edge of the wing, at the position closest to the suction side within the range from the inner circumferential end to the second chord direction cross section. Therefore, the drainage location is a recessed portion on the negative pressure side of the wing. It is.

[0007] Furthermore, the blower according to this disclosure comprises the impeller described above and a casing having a bell mouth that surrounds the impeller from the radially outer side, wherein, when the height of the casing is Hb and ε is 0.5, the impeller is surrounded in a virtual plane that is axially distanced by εHb from the suction side and the discharge side of the casing, respectively.

[0008] Furthermore, the air conditioner according to this disclosure comprises the impeller described above, and a heat exchanger that performs heat exchange between the air supplied by the impeller and a refrigerant circulating inside. [Effect of the Invention]

[0009] According to the impeller, the blower, and the air conditioner according to the present disclosure, since the stagger angle of the impeller blades decreases from the inner peripheral end to the outer peripheral end and then increases, the work on the inner peripheral side of the blades is improved, the air flow flows on the outer peripheral side of the blades without loss, and the overall efficiency of the impeller can be increased. [Brief Description of the Drawings]

[0010] [Figure 1] [[ID=1']]It is a perspective view showing a blower according to Embodiment 1 of the present disclosure. [Figure 2] It is a projection view in a plane perpendicular to the rotation axis of the impeller according to Embodiment 1 of the present disclosure. [Figure 3] It is a schematic diagram for explaining the stagger angle of the blades according to Embodiment 1 of the present disclosure. [Figure 4] It is a schematic diagram for explaining the stagger angle at the inner peripheral end of the impeller according to Embodiment 1 of the present disclosure. [Figure 5] It is a schematic diagram for explaining the stagger angle in the cross section in the first chord direction of the impeller according to Embodiment of the present disclosure. <000010 / > [Figure 6] It is a schematic diagram for explaining the stagger angle in the cross section in the second chord direction of the impeller according to Embodiment 1 of the present disclosure. [Figure 7] It is a graph showing the relationship between the flow rate and the efficiency obtained with the impeller according to Embodiment 1 of the present disclosure. [Figure 8] It is a projection view in a plane perpendicular to the rotation axis of the impeller according to Embodiment 2 of the present disclosure. [Figure 9] It is a projection view in a plane parallel to the rotation axis of the impeller according to Embodiment 2 of the present disclosure. [Figure 10] It is a perspective view of the impeller according to Embodiment 2 of the present disclosure. [Figure 11] It is a projection view in a plane perpendicular to the rotation axis of the impeller according to Embodiment 3 of the present disclosure. [Figure 12] It is a perspective view of the impeller according to Embodiment 3 of the present disclosure. [Figure 13]This is a schematic diagram illustrating the misalignment angle at the inner circumferential end of an impeller according to Embodiment 4 of the present disclosure. [Figure 14] This is a schematic diagram illustrating the misalignment angle in the first code direction cross-section of the impeller according to Embodiment 4 of the present disclosure. [Figure 15] This is a schematic diagram illustrating the misalignment angle in the second chord direction cross-section of the impeller according to Embodiment 4 of the present disclosure. [Figure 16] This is a projection view of the impeller according to Embodiment 4 of the present disclosure, in a state where the impellers are stacked in the direction of the rotation axis, on a plane perpendicular to the rotation axis. [Figure 17] This is a cross-sectional view showing a blower according to Embodiment 5 of the present disclosure. [Figure 18] This is a perspective view of an air conditioner according to Embodiment 6 of the present disclosure. [Modes for carrying out the invention]

[0011] The embodiments for implementing this disclosure will be described with reference to the attached drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and redundant explanations are simplified or omitted as appropriate. In the following description, for convenience, the positional relationships of each structure may be expressed based on the illustrated state. This disclosure is not limited to the following embodiments, and within the scope of not departing from the spirit of this disclosure, any combination of embodiments, any modification of any component of each embodiment, or any omission of any component of each embodiment is possible. In addition, in each drawing, the dimensional relationships or shapes of each component may differ from those of the actual components. Furthermore, the positional relationships between each component, such as the top-down relationship, are, in principle, those when installed in a usable state. However, in order to facilitate understanding, terms indicating direction, such as "up," "down," "right," "left," "front," and "back," are used as appropriate, but these notations are merely for the convenience of explanation and do not limit the arrangement and orientation of the device or parts. Furthermore, although chamfering is not shown in the following drawings, the same effect can be obtained by performing chamfering. In other words, for example, the same effect can be obtained whether a chamfered edge (C chamfer) or a rounded edge (R chamfer) is applied.

[0012] Embodiment 1. Figure 1 is a perspective view showing a blower 100 according to Embodiment 1 of the present disclosure. Figure 2 is a projection view of the impeller 10 according to Embodiment 1 of the present disclosure in a plane perpendicular to the rotation axis 11. Figures 1 and 2 show the configuration of the blower 100 as seen from the intake side, i.e., the pressure surface 25 side of the blades 20. In Figures 1 and 2, and the drawings described later, the thick black arrows represent the rotation direction of the impeller 10, i.e., the rotation direction of the boss portion 12 and the blades 20, which are part of the impeller 10. Also, in Figures 1 and 2, and the drawings described later, the thick white arrows represent the overall airflow direction when the impeller 10 rotates. The blower 100 according to Embodiment 1 is an axial flow blower that blows air in a direction along the rotation axis 11.

[0013] As shown in Figures 1 and 2, the blower 100 has a casing 80 and an impeller 10. The casing 80 has a substantially cylindrical bell mouth 81. The impeller 10 is positioned on the inner circumference side of the bell mouth 81. The impeller 10 is provided to be rotatable about a rotation axis 11. The blower 100 also has a drive unit, such as a motor (not shown), that rotates the impeller 10.

[0014] The impeller 10 has a boss portion 12 provided on the rotation shaft 11 and a plurality of blades 20 provided on the outer circumference of the boss portion 12. The boss portion 12 has a substantially cylindrical shape. A drive shaft (not shown) of the drive unit is connected to the center of the boss portion 12. The boss portion 12 rotates around the rotation shaft 11 by the transmission of rotational driving force from the drive unit via the drive shaft.

[0015] Multiple blades 20 are arranged on the outer circumference of the boss portion 12 at generally equal angular intervals. Each of the multiple blades 20 protrudes generally radially from the outer peripheral wall 121 of the boss portion 12. More specifically, each of the multiple blades 20 protrudes outward from the outer peripheral wall 121 of the boss portion 12 so as to be tilted forward in the rotational direction of the impeller 10 with respect to the radial direction around the rotation axis 11. In the figure, an impeller 10 having three blades 20 is shown as an example, but the number of blades 20 that the impeller 10 has may be other than three.

[0016] Each of the multiple wings 20 has a leading edge 21, a trailing edge 22, an outer peripheral end 23, and an inner peripheral end 24. The leading edge 21 is the edge of the wing 20 that is on the front side in the direction of rotation. The trailing edge 22 is the edge of the wing 20 that is on the rear side in the direction of rotation. The outer peripheral end 23 is the edge of the wing 20 that is on the outer side. The inner peripheral end 24 is the edge of the wing 20 that is on the inner side. The inner peripheral end 24 has a shape that follows the outer peripheral wall 121 of the boss portion 12 and is connected to the outer peripheral wall 121.

[0017] The outer peripheral end portion 23 and the leading edge portion 21 are adjacent to each other via the outer peripheral front end portion 23a. The outer peripheral end portion 23 and the trailing edge portion 22 are adjacent to each other via the outer peripheral rear end portion 23b. The inner peripheral end portion 24 and the leading edge portion 21 are adjacent to each other via the inner peripheral front end portion 24a. The inner peripheral end portion 24 and the trailing edge portion 22 are adjacent to each other via the inner peripheral rear end portion 24b.

[0018] Each of the plurality of blades 20 has a pressure surface 25 and a suction surface 26 (see FIG. 3 etc.). The pressure surface 25 is the surface on the front side in the rotation direction among the two surfaces that the blade 20 has. When the blade 20 rotates, air is pushed by the pressure surface 25. The suction surface 26 is the surface on the rear side in the rotation direction among the two surfaces that the blade 20 has, and is the surface on the back side of the pressure surface 25. Since FIGS. 1 and 2 show the configurations of the blower 100 and the impeller 10 as viewed from the pressure surface 25 side, the suction surface 26 is not shown in FIGS. 1 and 2.

[0019] The plurality of blades 20 rotate about the rotation axis 11 together with the boss portion 12. When the plurality of blades 20 rotate, as indicated by the white thick arrow in FIG. 1, air is sucked into the blower 100 from the back side of the paper along the rotation axis 11. The air sucked into the blower 100 is blown out from the blower 100 to the front side of the paper along the rotation axis 11.

[0020] Here, a plurality of cylindrical cross-sections of the blade 20 about the rotation axis 11 are defined as chord direction cross-sections. The chord direction cross-sections include, for example, a first chord direction cross-section 41 and a second chord direction cross-section 42 on the outer peripheral side with respect to the rotation axis relative to the first chord direction cross-section 41. That is, among the chord direction cross-sections, any cross-section is referred to as the first chord direction cross-section 41 and the second chord direction cross-section 42 in order from the one closer to the rotation axis 11.

[0021] Also, in the following description, the distance from the rotation axis 11 to the inner peripheral end portion 24 is r [[ID=I7]] b and the distance from the rotation axis 11 to the outer peripheral end portion 23 is r t Let it be. The distance from the rotation axis 11 to the first chord direction cross-section 41 is r dThe distance from the rotation axis 11 to the second code direction cross-section 42 is αr d Let α be a constant.

[0022] Figure 3 is a schematic diagram illustrating the offset angle 31 of the blade 20 according to Embodiment 1 of the present disclosure, and shows an arbitrary cross-section in the direction of the code. In Figure 3, the vertical direction represents the direction along the rotation axis 11, the lower side represents the suction side, and the upper side represents the discharge side.

[0023] As shown in Figure 3, the line segment connecting the leading edge 21 and the trailing edge 22 is the chord 30, and the angle between the axis of rotation 11 and the chord 30 is the offset angle 31. The offset angle 31 is positive when the trailing edge 22 of the blade 20 is inclined toward the negative pressure surface 26. Note that in Figure 3, a general blade 20 is shown for the sake of simplicity in explaining the offset angle 31 of the blade 20, and it may differ from the blade 20 that constitutes the impeller 10 of this disclosure. For example, the blade 20 may be flatter than shown, or it may be curved to have one or more inflection points.

[0024] Figure 4 is a schematic diagram illustrating the misalignment angle 31 at the inner circumference end 24 of the impeller 10 according to Embodiment 1 of this disclosure. Figure 5 is a schematic diagram illustrating the misalignment angle 31 in the first chord-direction cross section 41 of the impeller 10 according to Embodiment 1 of this disclosure. Figure 6 is a schematic diagram illustrating the misalignment angle 31 in the second chord-direction cross section 42 of the impeller 10 according to Embodiment 1 of this disclosure.

[0025] As shown in Figures 4 to 6, each of the multiple wings 20 has a shape in which the offset angle 31 decreases from the inner circumferential end 24 to the first chord direction cross section 41, and then increases from the first chord direction cross section 41 to the second chord direction cross section 42. For example, the offset angle 31 decreases monotonically from the inner circumferential end 24 to the first chord direction cross section 41, and then increases monotonically from the first chord direction cross section 41 to the second chord direction cross section 42.

[0026] The offset angle 31 is configured to always decrease from the inner circumference end 24 to the first code direction cross section 41, and to always increase from the first code direction cross section 41 to the second code direction cross section 42. The offset angle 31 may decrease more abruptly or more slowly in a part of the section from the inner circumference end 24 to the first code direction cross section 41 than in other parts. Also, the offset angle 31 may increase more abruptly or more slowly in a part of the section from the first code direction cross section 41 to the second code direction cross section 42 than in other parts.

[0027] The offset angle 31 increases monotonically, for example, from the second chord-direction cross section 42 toward the outer peripheral end 23 of the wing 20. The offset angle 31 from the second chord-direction cross section 42 toward the outer peripheral end 23 can be arbitrary.

[0028] Thus, the blades 20 of the impeller 10 are configured such that the offset angle 31 of the blades 20 decreases from the inner circumference end 24 to the first chord-direction cross section 41, and increases from the first chord-direction cross section 41 to the second chord-direction cross section 42. That is, in the first chord-direction cross section 41, the offset angle 31 takes its minimum value in the range from the inner circumference end 24 to the second chord-direction cross section 42.

[0029] The misalignment angle 31 of the blade 20 is constantly decreasing from the inner circumference end 24 to the first chord direction cross section 41. That is, the misalignment angle 31 at the first chord direction cross section 41 is smaller than the misalignment angle 31 at the inner circumference end 24. As the chord 30 of the blade 20 at the first chord direction cross section 41 is enlarged, the work done by the blade 20 near the first chord direction cross section 41 is increased. As a result, the work done on the inner circumference end 24 side of the blade 20, between the inner circumference end 24 and the outer circumference end 23, can be increased, enabling higher efficiency of the blower 100.

[0030] Furthermore, the offset angle 31 of the wing 20 is constantly increasing from the first chord-direction cross section 41 to the second chord-direction cross section 42. The magnitude of the rotational component of the airflow passing through the leading edge 21 of the wing 20 is proportional to the distance from the axis of rotation 11, so it is smaller on the inner circumference end 24 side and larger on the outer circumference end 23 side. If the magnitude of the component of the airflow passing through the leading edge 21 of the wing 20 along the axis of rotation 11 is constant, the angle between the airflow and the axis of rotation 11 increases from the inner circumference end 24 to the outer circumference end 23.

[0031] Therefore, by increasing the offset angle 31 of the blade 20 from the first chord-direction cross section 41 to the second chord-direction cross section 42, the airflow that has passed through the leading edge 21 side flows along the blade 20, and separation is suppressed, thereby achieving high efficiency. In this way, work is improved on the inner circumference end 24 side of the blade 20, and airflow can be passed without loss on the outer circumference end 23 side, thus improving the overall airflow efficiency of the impeller 10.

[0032] Here, the position of the first code direction cross section 41 is r b <r d ≤0.5r t The following is set to be true. The first code direction cross section 41 is located, for example, near the position of the inner circumference end 24, which is the connection point between the boss portion 12 and the wing 20. Also, in the impeller 10, the boss portion 12 has, for example, a maximum radius of 0.5r t Therefore, the position of the first code direction cross section 41 is r b <r d ≤0.5r t It is set up so that the following is true.

[0033] The position of the second code direction cross section 42 is αr d For example, it is set such that α = 1.01 holds true. α can be a very small amount, for example, α = 1.001, and more preferably α = 1.000001.

[0034] By appropriately setting the positions of the first chord-direction cross section 41 and the second chord-direction cross section 42, the misalignment angle 31 of the blade 20 on the inner circumference end 24 side can be reduced. As a result, the airflow drawn into the impeller 10 can flow along the blade 20, thus obtaining a highly efficient impeller 10.

[0035] Furthermore, the value obtained by normalizing the distance from the inner circumference end 24 to the first code direction cross section 41 by the distance from the rotation axis 11 to the outer circumference end 23 is (r d -r b ) / r t (r d -r b ) / r t The gradient Δγ / Δr, which is the ratio of the increment of the misalignment angle 31 relative to Δγ / Δr, should be Δγ / Δr < -π / 2, and more preferably Δγ / Δr < 0. By setting it in this way, the work done on the inner circumference end 24 side of the blade 20 can be increased without expanding the boss portion 12 in the direction of the rotation axis 11, thereby obtaining a greater effect of improving the efficiency of the blade 20.

[0036] Figure 7 is a graph showing the relationship between airflow and efficiency obtained with the impeller 10 according to Embodiment 1 of this disclosure. As a comparative example, Figure 7 shows the relationship between airflow and efficiency obtained with the impeller 10 of a general axial flow fan. In Figure 7, the example shows the relationship between airflow and efficiency when using the impeller 10 according to Embodiment 1, for example. As shown in Figure 7, the efficiency of the impeller 10 in the example is improved compared to the comparative example.

[0037] In the comparative example, a typical axial flow fan improves the efficiency of the impeller 10 by distributing airflow across the entire impeller 10. More specifically, the efficiency of the impeller 10 is improved by having work done on the blades 20 near the rotating shaft 11 where torque is low, and by reducing the load on the blades 20 near the outer peripheral ends 23 of the blades 20. In order to increase the work done on the blades 20 near the rotating shaft 11, it is necessary to increase the length of the chord 30 while suppressing the misalignment angle 31 of the blades 20.

[0038] For example, as a comparative example, an impeller 10 has been proposed in which multiple blades 20 are joined at their roots, and the joined region is shaped to blow air as it rotates, thereby enabling forward airflow even near the rotation center of the blades 20 and improving the airflow capacity. In such an impeller 10, unless the boss portion 12 is enlarged in the direction of the rotation axis 11, the work of the blades 20 near the rotation axis 11 cannot be further improved, that is, the work on the inner circumference end 24 side of the blades 20 cannot be increased, and an improvement in the efficiency of the impeller 10 cannot be expected. In contrast, the impeller 10 according to Embodiment 1 increases the work on the inner circumference end 24 side of the blades 20, making the blades 20 highly efficient.

[0039] As described above, the impeller 10 according to Embodiment 1 has a configuration in which the offset angle 31 of the blade 20 decreases from the inner circumference end 24 to the first chord direction cross section 41, and increases from the first chord direction cross section 41 to the second chord direction cross section 42. Therefore, the work on the inner circumference side of the blade 20 is improved, and airflow can be passed without loss on the outer circumference side of the blade 20. Furthermore, by decreasing the offset angle 31 at the inner circumference end 24, the chord 30 can be increased towards the first chord direction cross section 41, increasing the work done by the blade 20 and enabling high efficiency. Also, from the first chord direction cross section 41 to the second chord direction cross section 42, the offset angle 31 increases, causing airflow that has passed the leading edge 21 to flow along the blade 20, suppressing separation at the outer circumference end 23 of the blade 20 and resulting in high efficiency. In this way, it is possible to increase the overall efficiency of the impeller 10 while suppressing the increase of the boss portion 12.

[0040] Furthermore, the distance from the rotation axis 11 to the first chord-direction cross section 41 is equal to or less than half the distance from the rotation axis 11 to the outer peripheral end 23. Also, the distance from the rotation axis 11 to the second chord-direction cross section 42 is α times the distance from the rotation axis 11 to the outer peripheral end 23, where α is, for example, 1.01. By setting it in this way, the misalignment angle 31 of the blade 20 on the inner peripheral end 24 side of the blade 20 is reduced, and the airflow drawn into the impeller 10 can flow along the blade 20, thus obtaining a highly efficient impeller 10.

[0041] Embodiment 2. Figure 8 is a projection view of the impeller 10 according to Embodiment 2 of this disclosure in a plane perpendicular to the rotation axis 11. The impeller 10 according to Embodiment 2 differs from Embodiment 1 in that it is equipped with a drainage location 50. In Embodiment 2, parts common to Embodiment 1 are given the same reference numerals and their descriptions are omitted, and the explanation will focus on the differences from Embodiment 1. As shown in Figure 8, the drainage location 50 is provided on the leading edge 21 of the blade 20 in the first code direction cross section 41.

[0042] Figure 9 is a projection view of the impeller 10 according to Embodiment 2 of the present disclosure in a plane parallel to the rotation axis 11. As shown in Figure 9, the drainage location 50 is located on the suction side, i.e., on the first code direction cross-section 41, in the range from the inner circumference end 24 to the second code direction cross-section 42.

[0043] Specifically, the blade 20 has a configuration in which the offset angle 31 decreases from the inner circumference end 24 to the first chord-direction cross section 41, and increases from the first chord-direction cross section 41 to the second chord-direction cross section 42, with the drainage point 50 located on the suction side. The drainage point 50 is a recessed portion on the negative pressure surface 26 side, and its deepest part is located on the first chord-direction cross section 41. In other words, the drainage point 50 is located at the leading edge 21, r from the rotation axis 11. d It is located at this distance.

[0044] Figure 10 is a perspective view of the impeller 10 according to Embodiment 2 of the present disclosure. As shown in Figure 10, when the impeller 10 is operated to blow airflow vertically upward, rain or dust that falls around the drainage point 50 is guided to the drainage point 50 via the drainage channel 51. In this way, the impeller 10 is provided with a drainage point 50, which improves drainage performance.

[0045] Generally, an impeller 10 is composed of a cylindrical boss portion 12 and blades 20 provided on the outer circumference of the boss portion 12. The efficiency of the impeller 10 is improved by blowing airflow through the entire impeller 10. The boss portion 12 that constitutes the impeller 10 does not contribute to airflow, so the airflow performance of the impeller 10 can be improved by reducing the size of the boss portion 12 and increasing the size of the blades 20. However, when the impeller 10 is installed to blow air in a vertically upward direction, the boss portion 12 also serves to protect structures positioned vertically downward from rain or dust, such as a drive unit (not shown) like a motor. Therefore, an impeller 10 having a small-diameter boss portion 12 perpendicular to the rotation axis 11 cannot be used, and improvement in the efficiency of the impeller 10 cannot be expected.

[0046] The impeller 10 of Embodiment 2 has a configuration in which the entire blade 20, from the outer peripheral end 23 of the blade 20 to the center of the rotation axis 11, performs the work, and also has a drainage point 50. This makes it possible to use a small-diameter boss portion 12, enabling both high efficiency of the impeller 10 and improved drainage.

[0047] Furthermore, if the impeller 10 is installed to blow air vertically upward and the motor is positioned vertically below it, in sub-zero temperatures, when the impeller 10 is stopped, rain discharged from the leading edge 21 of the blade 20 may form icicles. In this case, if the icicles become connected to the motor, it is conceivable that the impeller 10 and the motor will lock up at the start of operation and will not rotate. Therefore, the position of the drainage point 50, i.e., r d It is preferable that r is a larger value than that of the upstream structure. For example, if the upstream structure is a motor, then r d It is preferable that this value is greater than the outer radius of the motor.

[0048] With this configuration, rainwater that could form icicles will pass through the drainage channel 51 and be drained from the drainage point 50, thus preventing icicles from forming at the drainage point 50 and thus preventing the blade 20 from connecting to the motor. In other words, this configuration prevents the impeller 10 and the motor from being locked together by icicles.

[0049] As described above, in the impeller 10 according to Embodiment 2, a drainage point 50 is provided at the position closest to the suction side within the range from the inner circumference end 24 to the second cord direction cross section 42. Therefore, it is possible to achieve both high efficiency by having the entire blade 20, from the outer circumference end 23 to the rotation axis 11, perform the work, and improved drainage performance.

[0050] Embodiment 3. Figure 11 is a projection view of the impeller 10 according to Embodiment 3 of this disclosure in a plane perpendicular to the rotation axis 11. Figure 12 is a perspective view of the impeller 10 according to Embodiment 3 of this disclosure. The impeller 10 according to Embodiment 3 differs from Embodiments 1 and 2 in the configuration of the plurality of blades 20. In Embodiment 3, parts common to Embodiments 1 and 2 are denoted by the same reference numerals and their descriptions are omitted, and the description will focus on the differences from Embodiments 1 and 2.

[0051] As shown in Figures 11 and 12, the multiple blades 20 of the impeller 10 are connected to adjacent blades 20 and to the entire area of ​​the third chord direction cross section 43 from the inner circumference end 24. The third chord direction cross section 43 is at a distance of r from the rotation axis 11. s This is a cross-section in the direction of the code. At this time, r b <r s <r d Multiple wings 20 are connected to adjacent wings 20 from the inner circumference end 24 to the third chord direction cross section 43.

[0052] In any cross-sectional area in the third cross-section 43 from the inner circumferential end 24, adjacent blades 20 have an offset angle 31. That is, the blades 20 have an arbitrary inclination with respect to the axis of rotation 11. Also, the blades 20 always have an arbitrary thickness. Therefore, in any cross-sectional area in the third cross-section 43, a step 205 is formed at the connection point of adjacent blades 20. The step 205 is formed from the inner circumferential end 24 to the third cross-section 43 toward the drainage point 50.

[0053] Therefore, when the impeller 10 is operated to blow airflow vertically upward, rain or dust that falls on the inner circumference end 24 and its surroundings is discharged to the drainage point 50 via the step 205. As a result, further improvements in drainage performance can be achieved. The edge portion of the step 205 can also serve as a drainage channel 51 even if it is rounded or chamfered, thus achieving a similar effect.

[0054] The step 205 is formed from the inner circumference end 24 to the third code direction cross section 43, extending from the rotation axis 11 to the outer circumference end 23. Therefore, the third code direction cross section 43 only needs to be between the inner circumference end 24 and the first code direction cross section 41, r b <r s <r d This holds true.

[0055] The wing 20 and the boss portion 12 are smoothly connected, for example, at the upper and lower surfaces of the boss portion 12. The boss portion 12 and the wing 20 do not necessarily have to be smoothly connected, and other configurations are possible. That is, the boss portion 12 may be, for example, a substantially cylindrical shape with height in the direction of the rotation axis 11. By smoothly connecting the boss portions 12, the height of the boss portion 12 along the rotation axis 11 becomes approximately the same as the thickness of the wing 20, thereby suppressing the height of the boss portion 12.

[0056] As described above, in the impeller 10 according to Embodiment 3, adjacent blades 20 of the impeller 10 are connected from the inner circumferential end 24 to the third chord direction cross section 43. In other words, adjacent blades 20 are connected over the entire area from the inner circumferential end 24 to the third chord direction cross section 43. As a result, air is blown in conjunction with rotation in the region where multiple blades 20 are connected, and forward airflow is possible even near the rotation center of the blades 20, thereby improving the airflow capacity. Furthermore, the blades 20 have an offset angle 31 from the inner circumferential end 24 to the third chord direction cross section 43, and a step 205 is created at the connection point with adjacent blades 20. Therefore, the step 205 becomes a drainage channel 51, improving drainage.

[0057] Embodiment 4. Figure 13 is a schematic diagram illustrating the misalignment angle 31 at the inner circumference end 24 of the impeller 10 according to Embodiment 4 of this disclosure. Figure 14 is a schematic diagram illustrating the misalignment angle 31 at the first chord-direction cross-section 41 of the impeller 10 according to Embodiment 4 of this disclosure. Figure 15 is a schematic diagram illustrating the misalignment angle 31 at the second chord-direction cross-section 42 of the impeller 10 according to Embodiment 4 of this disclosure. The impeller 10 according to Embodiment 4 differs from Embodiments 1 to 3 in the configuration of the blades 20 at the inner circumference end 24. In Embodiment 4, parts common to Embodiments 1 to 3 are denoted by the same reference numerals and their descriptions are omitted, and the explanation focuses on the differences from Embodiments 1 to 3.

[0058] As shown in Figures 13 to 15, the blade 20 has a misalignment angle 31 that is 90 degrees at the inner circumference end 24, decreases from the inner circumference end 24 to the first chord-direction cross section 41, and then increases from the first chord-direction cross section 41 to the second chord-direction cross section 42. Note that Figures 13 to 15 show a general blade 20 for the sake of simplicity in explaining the misalignment angle 31 of the blade 20, and may differ from the blade 20 that constitutes the impeller 10 of this disclosure.

[0059] At the inner circumference end 24 of the wing 20, the offset angle 31 is 90 degrees, which reduces the height of the boss portion 12 to which the wing 20 is connected along the axis of rotation 11. In other words, if the distance from the top surface to the bottom surface, which is the height of the boss portion 12, is at least equal to the distance from the pressure surface 25 to the negative pressure surface 26, which is the thickness of the wing 20, then the inner circumference end 24 of the wing 20 can be connected to the boss portion 12. To put it another way, since the height of the boss portion 12 along the axis of rotation 11 depends on the inner circumference end 24 of the wing 20, the offset angle 31 of the wing 20 being 90 degrees at the inner circumference end 24 allows for an increase in the chord 30 of the wing 20 in the first chord direction cross section 41.

[0060] Furthermore, the wing 20 and the boss portion 12 are smoothly connected at the upper and lower surfaces of the boss portion 12. The shape of the boss portion 12 such that the upper and lower surfaces are at approximately the same height as the pressure surface 25 and negative pressure surface 26 at the inner circumference end 24 of the wing 20. In other words, if the distance between the pressure surface 25 and the negative pressure surface 26 of the wing 20 is defined as the thickness of the wing 20, the height of the boss portion 12 along the rotation axis 11 can be approximately the thickness of the wing 20. As a result, the height of the boss portion 12 is suppressed, and the number of wings 20 that can be stacked and transported can be increased, thus improving productivity.

[0061] For example, to increase the work done by the blade 20 near the rotation axis 11, the offset angle 31 of the blade 20 needs to be reduced, which requires increasing the chord length. However, a blade 20 with a reduced offset angle 31 and increased chord length will have an increased height of the boss portion 12 in the direction of the rotation axis 11. As a result, the overall volume of the impeller 10 increases.

[0062] In contrast, in the impeller 10 of Embodiment 4, the misalignment angle 31 of the blades 20 is 90 degrees at the inner circumference end 24, so the height of the boss portion 12 can be reduced to the absolute minimum. This increases the work done on the inner circumference end 24 side of the blades 20 without expanding the boss portion 12 in the direction of the rotation axis 11, thereby increasing the efficiency of the blades 20, and the overall volume of the impeller 10 is reduced, making it possible to conserve resources by reducing the amount of material used in the impeller 10.

[0063] Figure 16 is a projection view of a plane perpendicular to the rotation axis 11 in a state in which impellers 10 according to Embodiment 4 of this disclosure are stacked in the direction of the rotation axis 11. As shown in Figure 16, the impellers 10 are shipped in a state in which multiple impellers 10 are stacked in the direction of the rotation axis 11. Since the height of the boss portion 12 of the impeller 10 can be set to approximately the distance from the pressure surface 25 to the negative pressure surface 26 of the blade 20, the number of impellers 10 that can be stacked in the direction of the rotation axis 11 can be increased to the maximum extent possible. In other words, the number of impellers 10 that can be transported at one time can be increased.

[0064] For example, if the height of the boss portion 12 in the direction of the rotation axis 11 increases, the number of impellers 10 that can be stacked in the direction of the rotation axis 11 when multiple impellers 10 are transported stacked in that direction will be limited. With the impeller 10 according to Embodiment 4, the height of the boss portion 12 in the direction of the rotation axis 11 can be suppressed, which increases the number of impellers 10 that can be stacked in the direction of the rotation axis 11, thereby reducing the transportation cost of the impellers 10. As a result, the overall efficiency of the impeller 10 can be increased without increasing the size of the boss portion 12 in the direction of the rotation axis 11.

[0065] In the impeller 10 according to Embodiment 4 described above, the misalignment angle 31 of the blades 20 is 90 degrees at the inner circumference end 24. This improves the work on the inner circumference side of the blades 20, and if the distance from the top surface to the bottom surface, which is the height of the boss portion 12, is at least equal to the distance from the pressure surface 25, which is the thickness of the blade 20, to the negative pressure surface 26, the inner circumference end 24 of the blade 20 can be connected to the boss portion 12. As a result, the height of the boss portion 12 is suppressed, and the number of blades 20 that can be stacked and transported can be increased, thus improving productivity.

[0066] Furthermore, because the blades 20 are smoothly connected to the boss portion 12, the height of the boss portion 12 in the direction of the rotation axis 11 is reduced to the absolute minimum, thereby suppressing the overall volume of the impeller 10 and enabling resource conservation by reducing the amount of material used in the impeller 10. In addition, since the height of the boss portion 12 in the direction of the rotation axis 11 can be made approximately the distance from the pressure surface 25 to the negative pressure surface 26 of the blades 20, the number of impellers 10 stacked in the direction of the rotation axis 11 can be increased to the absolute minimum, and consequently, the number of blades 20 that can be transported at one time can be increased. Therefore, it is possible to reduce the transportation cost of the blades 20.

[0067] Embodiment 5. Figure 17 is a cross-sectional view showing a blower 100 according to Embodiment 5 of the present disclosure. Embodiment 5 differs from Embodiments 1 to 4, which relate to the impeller 10, in that it relates to the blower 100. In Embodiment 5, parts common to Embodiments 1 to 4 are given the same reference numerals and their descriptions are omitted, and the explanation will focus on the differences from Embodiments 1 to 4. Figure 17 is a cross-sectional view of an arbitrary plane parallel to the rotation axis 11 and passing through the rotation axis 11.

[0068] As shown in Figure 17, the blower 100 comprises a casing 80 having a bell mouth 81 and an impeller 10 positioned on the inner circumference side of the bell mouth 81. The impeller 10 is, for example, an impeller 10 according to Embodiments 1 to 4. However, in Figure 17, the impeller 10 is shown in the same way as the trajectory of a typical blade 20 when it is rotated.

[0069] The casing 80 has a shape such that, for example, it is approximately cylindrical, and on both the suction side 80a and the discharge side 80b, the distance from the rotating shaft 11 increases as it moves away from the casing 80. The configuration of the casing 80 is not particularly limited, and it can have any shape as long as, for example, the distance from the rotating shaft 11 does not decrease as it moves away from the casing 80. In other words, the entire casing 80 may be cylindrical.

[0070] In Figure 17, the dotted lines on the upper and lower impellers 10 indicate the limits of the range in which the effect of the impeller 10 can be obtained when the impeller 10 is moved downwards (towards the intake side 80a) and upwards (towards the discharge side 80b), respectively. In Figure 17, the virtual plane S is a plane that is located at a distance of εHb from the casing 80 in the direction of the rotation axis 11, assuming that the height of the casing 80 is defined as Hb, and extends in a direction perpendicular to the rotation axis 11. If the impeller 10 is within the virtual plane S, that is, even when it is moved away from the casing 80 in the direction of the rotation axis 11, the effect of the impeller 10 can be exerted as long as it is within the range of εHb on the suction side 80a and the discharge side 80b. In this case, ε should be 0.5.

[0071] Thus, according to the configuration of Embodiment 5, a blower 100 can be obtained that enables high efficiency of the impeller 10 and improved productivity.

[0072] In the blower 100 according to Embodiment 5 described above, the impeller 10 is surrounded within a virtual plane S that is axially separated by εHb from the intake side 80a and the discharge side 80b of the casing 80. Therefore, it is possible to obtain a blower 100 with improved productivity without impairing the effect of the impeller 10, namely, the effect of increasing the overall efficiency of the impeller 10 while suppressing the increase in the boss portion 12.

[0073] Embodiment 6. Figure 18 is a perspective view of an air conditioner 200 according to Embodiment 6 of this disclosure. Embodiment 6 differs from Embodiments 1 to 4, which relate to the impeller 10, or Embodiment 5, which relates to the blower 100, in that it relates to an air conditioner 200. In Embodiment 6, parts common to Embodiments 1 to 5 are denoted by the same reference numerals and their descriptions are omitted, and the explanation will focus on the differences from Embodiments 1 to 5.

[0074] The air conditioner 200 is, for example, an outdoor unit of a multi-split air conditioner for a building. As shown in Figure 18, the air conditioner 200 has a blower 100 equipped with an impeller 10 according to any of Embodiments 1 to 4. The air conditioner 200 also has a housing 203.

[0075] An air outlet 202 is formed at the top of the housing 203 for discharging outdoor air to the outside of the air conditioner 200 inside the housing 203. Intake ports 201 are formed on each side of the housing 203 for drawing in outdoor air. The intake ports 201 do not need to be present on all four sides of the housing 203. Also, the intake ports 201 may be formed on a part of the side of the housing 203, or they may be formed to cover the entire side.

[0076] Inside the housing 203, a blower 100 and a heat exchanger 204 are provided in the air passage from the intake port 201 to the outlet port 202. The blower 100 is positioned on the intake side of the outlet port 202 and downstream of the heat exchanger 204 in the airflow. The heat exchanger 204 performs heat exchange between the air drawn into the housing 203 from the outside and the refrigerant flowing inside the heat exchanger 204. For example, during heating, it absorbs heat from the air, and during cooling, it releases heat to the air.

[0077] When the impeller 10 of the blower 100 rotates, air from outside the housing 203 is drawn into the housing 203 through the intake port 201. The air drawn into the housing 203 is supplied to the heat exchanger 204, and as it passes through the heat exchanger 204, it absorbs heat and its temperature decreases, or it becomes subject to heat dissipation and its temperature increases, and is then blown out to the outside of the housing 203 through the outlet port 202.

[0078] As described above, the blower 100 enables increased efficiency and improved productivity of the impeller 10. The air conditioner 200 according to Embodiment 6 comprises the impeller 10 and the heat exchanger 204, and the air supplied by the impeller 10 exchanges heat with the refrigerant circulating inside the heat exchanger 204. Therefore, the air conditioner 200 according to Embodiment 6 can improve power efficiency and productivity.

[0079] As described above, the air conditioner 200 according to Embodiment 6 performs heat exchange between the air supplied by the impeller 10 and the refrigerant circulating inside the heat exchanger 204. The impeller 10 is highly efficient due to the shape in which the offset angle 31 of the blades 20 changes from the inner circumference end 24 to the second chord direction cross section 42, resulting in good power efficiency and an air conditioner 200 with improved productivity.

[0080] Furthermore, embodiments 1 to 6 can be combined as appropriate.

[0081] The various aspects of this disclosure are summarized below as an appendix.

[0082] (Note 1) A boss portion located on the axis of rotation, A wing provided on the outer circumference of the boss portion, Equipped with, The aforementioned wing is The leading edge is the front edge in the direction of rotation, The rear edge portion, which is the rear edge portion in the direction of rotation, The outer edge, which is the outer edge, The inner edge, which is the inner circumference end, It has, The cross-section obtained by cutting the aforementioned wing with a cylinder centered on the rotation axis is defined as the cross-section in the direction of the chord. In the aforementioned cross-section in the direction of the chord, the line segment connecting the leading edge and the trailing edge is defined as the chord, and the angle between the axis of rotation and the chord is defined as the misalignment angle. The aforementioned misalignment angle is defined as positive when the trailing edge of the wing is inclined toward the negative pressure surface side of the wing. The code direction cross section includes a first code direction cross section and a second code direction cross section located on the outer periphery of the first code direction cross section. The offset angle of the wing decreases from the inner circumference end to the first chord direction cross section, and increases from the first chord direction cross section to the second chord direction cross section. Impeller. (Note 2) The distance from the rotation axis to the inner circumference end is r b year, The distance from the rotation axis to the outer peripheral end is r t year, The distance from the rotation axis to the first code direction cross section is r d year, Let α be a constant. The distance from the rotation axis to the second code direction cross section is αr d In that case, r b <r d ≤0.5r t And, α = 1.01 The impeller described in Appendix 1. (Note 3) A drainage point is provided at the leading edge of the wing, at a position closest to the suction side within the range of the cross-section in the second chord direction from the inner circumferential end. The impeller described in Appendix 1 or 2. (Note 4) The distance from the rotation axis is r s When the aforementioned cross-section in the code direction is defined as the third cross-section in the code direction, r b <r s <r d And, The adjacent wings are connected from the inner circumferential end to the third chord direction cross section. The impeller described in Appendix 2. (Note 5) The offset angle of the wing is 90 degrees at the inner circumference end. The impeller described in one of the appendices 1-4. (Note 6) The boss portion and the wing are smoothly connected. The impeller described in one of the appendices 1-5. (Note 7) The impeller described in any one of the appendices 1 to 6, The impeller is surrounded by a casing having a bell mouth from the radially outer side, Equipped with, If the height of the casing is Hb and ε is 0.5, The impeller is surrounded in a virtual plane that is axially separated by εHb from the suction side and discharge side of the casing, respectively. Blower. (Note 8) The impeller described in any one of the appendices 1 to 6, A heat exchanger that performs heat exchange between the air supplied by the impeller and the refrigerant circulating inside, An air conditioner equipped with [a specific feature]. [Explanation of Symbols]

[0083] 10 Impeller, 11 Rotating shaft, 12 Boss section, 20 Blade, 21 Leading edge, 22 Trailing edge, 23 Outer circumference end, 23a Outer circumference front end, 23b Outer circumference rear end, 24 Inner circumference end, 24a Inner circumference front end, 24b Inner circumference rear end, 25 Pressure surface, 26 Negative pressure surface, 30 Chord, 31 Corner, 41 First chord direction cross section, 42 Second chord direction cross section, 43 Third chord direction cross section, 50 Drainage point, 51 Drainage channel, 80 Casing, 80a Intake side, 80b Outlet side, 81 Bell mouth, 100 Blower, 121 Outer circumference wall, 200 Air conditioner, 201 Intake port, 202 Outlet port, 203 Housing, 204 Heat exchanger, 205 Step.

Claims

1. A boss portion located on the axis of rotation, A wing provided on the outer circumference of the boss portion, Equipped with, The aforementioned wing is The leading edge is the front edge in the direction of rotation, The rear edge portion, which is the rear edge portion in the direction of rotation, The outer edge, which is the outer edge, The inner edge, which is the inner circumference end, It has, The cross-section obtained by cutting the aforementioned wing with a cylinder centered on the rotation axis is defined as the cross-section in the direction of the chord. In the aforementioned cross-section in the direction of the chord, the line segment connecting the leading edge and the trailing edge is defined as the chord, and the angle between the axis of rotation and the chord is defined as the misalignment angle. The aforementioned misalignment angle is defined as positive when the trailing edge of the wing is inclined toward the negative pressure surface side of the wing. The code direction cross section includes a first code direction cross section and a second code direction cross section located on the outer periphery of the first code direction cross section. The offset angle of the wing decreases from the inner circumference end to the first chord direction cross section, and increases from the first chord direction cross section to the second chord direction cross section. The distance from the rotation axis to the inner circumference end is r ｂ year, The distance from the rotation axis to the outer peripheral end is r ｔ year, The distance from the rotation axis to the cross section in the first code direction is r. ｄ year, Let α be a constant. The distance from the rotation axis to the second code direction cross-section is αr ｄ In that case, r ｂ <r ｄ ≤0.5r ｔ And, α = 1.01, A drainage point is provided at the leading edge of the wing, at a position closest to the suction side within the range of the cross section in the direction of the second chord from the inner circumferential end. The aforementioned drainage location is This is the recessed portion on the negative pressure surface side of the wing. Impeller.

2. The distance from the rotation axis is r ｓ When the aforementioned cross-section in the code direction is defined as the third cross-section in the code direction, r ｂ <r ｓ <r ｄ and The adjacent wings are connected from the inner circumference end to the third chord direction cross section. The impeller according to claim 1.

3. The offset angle of the wing is 90 degrees at the inner circumference end. The impeller according to claim 1 or 2.

4. The boss portion and the wing are smoothly connected. The impeller according to claim 1 or 2.

5. An impeller according to claim 1 or 2, The impeller is surrounded by a casing having a bell mouth from the radially outer side, Equipped with, If the height of the casing is Hb and ε is 0.5, The impeller is surrounded in a virtual plane that is axially separated by εHb from the suction side and the discharge side of the casing, respectively. Blower.

6. An impeller according to claim 1 or 2, A heat exchanger that performs heat exchange between the air supplied by the impeller and the refrigerant circulating inside, An air conditioner equipped with [a specific feature].

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