Axial fan

Abstract

The invention provides an axial flow fan which can improve P-Q characteristics. An axial fan (100) is provided with a housing (10) in which a flow path (130) communicating from an air suction port (11) to an air discharge port (12) is formed, and an impeller (20) which is disposed inside the housing (10), is provided with a hub portion (21) and a plurality of rotor blades (30), and is rotatable about a shaft, the plurality of rotor blades having a leading edge portion (33) and a trailing edge portion (34), the trailing edge portion (34) including a first portion (37) disposed on the inner peripheral side and a second portion (38) disposed on the outer peripheral side, and the first portion (37) and the second portion (38) being disposed on the outer peripheral side. The second portion (38) includes an inclined surface inclined at an angle different from that of the first portion (37), and the inclined surface of the second portion (38) is inclined such that the wing thickness of the second portion (38) is thinner than that of the first portion (37).

Description

Technical Field

[0001] This invention relates to an axial flow fan. Background Technology

[0002] For example, an axial fan has: a hub that is driven to rotate by receiving an external rotational force; and a plurality of blades extending radially around the hub (see, for example, Patent Document 1). On the negative pressure side of the blades of the axial fan of Patent Document 1, a recess is formed to thin the blade wall thickness.

[0003] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2010-242665 Summary of the Invention The problem that the invention aims to solve In axial fans, the aim is to improve the airflow-static pressure characteristics. The "airflow-static pressure characteristics" are also known as the "PQ characteristics".

[0004] The purpose of this invention is to provide an axial fan that can improve airflow-static pressure characteristics.

[0005] Methods for solving problems One aspect of the present invention relates to an axial fan comprising: The housing has an intake port and an exhaust port, and an internal flow path is formed connecting the intake port to the exhaust port. The impeller, which is disposed within the housing, is rotatable about an axis. The impeller has a hub and The multiple moving wings formed on the hub portion The plurality of moving wings have: The leading edge portion is located on the intake port side. The rear edge portion is located on the exhaust port side. The trailing edge includes: The first part is located on the inner circumferential side. The second part is located on the outer periphery. The second part includes an inclined surface that is tilted at a different angle than the first part. The inclined surface of the second part is inclined in such a way that the wing thickness in the second part is thinner than the wing thickness in the first part.

[0006] The effects of the invention This invention provides an axial fan that can improve airflow-static pressure characteristics. Attached Figure Description

[0007] 【 Figure 1[Image] is a cross-sectional view showing an example of an axial fan according to an embodiment.

[0008] 【 Figure 2 [This is a side view showing an example of an axial fan impeller.]

[0009] 【 Figure 3 This is a perspective view showing an example of an axial fan impeller from the rear.

[0010] 【 Figure 4 [This is a front view showing an example of an axial fan impeller.]

[0011] 【 Figure 5 [Image] is a rear view showing an example of an axial fan impeller.

[0012] 【 Figure 6 [This is a cross-sectional view showing an example of the rotor blade of an impeller.]

[0013] 【 Figure 7 This is a magnified side view showing an example of the trailing edge of a rotor.

[0014] 【 Figure 8 This is an enlarged side view showing an example of a moving wing.

[0015] 【 Figure 9 [This is a magnified front view showing an example of an impeller.]

[0016] 【 Figure 10 This is a magnified side view showing an example of the trailing edge of a rotor.

[0017] 【 Figure 11 This is a top view showing an example of a moving wing. Detailed Implementation

[0018] Non-limiting embodiments of the present invention will be described with reference to the accompanying drawings. Furthermore, in the drawings, identical or corresponding components or parts are labeled with identical or corresponding reference numerals. Repeated descriptions of identical or corresponding components or parts are omitted below. Additionally, components or parts in the drawings are not necessarily drawn to scale. Therefore, those skilled in the art can arbitrarily determine specific dimensions by referring to the following non-limiting embodiments. Furthermore, the following embodiments are not intended to limit the invention, but rather to illustrate it. Additionally, the features and combinations thereof described in the embodiments are not necessarily essential features of the invention.

[0019] [Axial flow fan involved in the implementation] Figure 1This is a cross-sectional view illustrating an example of an axial fan 100 according to an embodiment. In the drawing, the X-axis, Y-axis, and Z-axis directions, which intersect each other perpendicularly, are sometimes shown. The Z-axis direction is the direction in which shaft 15 extends. The X-axis and Y-axis directions are radial. Shaft 15 is an example of a shaft. When referred to only as "axial direction," it refers to the direction in which shaft 15 extends. Furthermore, when referred to only as "radial," it refers to the radial direction of shaft 15, that is, the direction perpendicular to the axial direction. Radial direction includes both the X-axis and Y-axis directions.

[0020] Furthermore, the terms "upper" and "lower" are sometimes used in this specification. In this case, the vertical direction refers to the direction in which the shaft 15 extends; the side closer to the intake port 11 is referred to as "upper," and the side closer to the exhaust port 12 is referred to as "lower." However, the actual configuration of the axial fan 100 may or may not follow this convention. The shaft 15 may be configured vertically or horizontally.

[0021] In addition, the terms "intake port side" and "exhaust port side" are sometimes used in this specification. "Intake port side" refers to the side closer to the intake port. "Exhaust port side" refers to the side closer to the exhaust port.

[0022] Figure 1 The axial fan 100 shown is a fan used for cooling electronic equipment such as servers. The axial fan 100 is mounted on the housing of the electronic equipment and supplies air into the housing, thereby cooling the electronic equipment inside. The application of the axial fan 100 is not limited to cooling electronic equipment; it can also be used for other purposes. The axial fan 100 can deliver air. The axial fan 100 can also deliver gases other than air.

[0023] The axial fan 100 includes a housing 10, a shaft 15, an impeller 20, a base 50, and a motor 60. The axial fan 100 includes a plurality of moving blades 30 formed on the impeller 20 and fixed blades 70 formed on the inner circumferential surface of the housing 10. The impeller 20 includes a hub 21, a plurality of moving blades 30, and a cylinder 40.

[0024] [case] An air intake 11 and an exhaust 12 are formed on the housing 10. The air intake 11 and the exhaust 12 are opposite each other in the Z-axis direction.

[0025] The shell 10 can be formed in a cuboid shape. The shell 10 can also be formed in a cube shape. The shell 10 can be formed in a cylindrical shape or other shapes. Flanges or supports can be formed on the shell 10.

[0026] Inside the housing 10, a flow path 130 is formed from the intake port 11 to the exhaust port 12. Furthermore, in the Z-axis direction, the side closer to the intake port 11 is referred to as "upstream," and the side closer to the exhaust port 12 is referred to as "downstream." Additionally, in the Z-axis direction, the side closer to the intake port 11 is sometimes referred to as "front," and the side closer to the exhaust port 12 as "rear."

[0027] The housing 10 houses an impeller 20, a base 50, a motor 60, and a fixed blade 70. Inside the housing 10, the impeller 20, motor 60, and base 50 are arranged sequentially, starting from the side closest to the intake port 11. The base 50 is positioned near the exhaust port 12.

[0028] [Intake and exhaust ports] The intake port 11 and the exhaust port 12 are positioned opposite each other in the Z-axis direction. The intake port 11 may be the most upstream end of the flow path 130. The exhaust port 12 may be the most downstream end of the flow path 130.

[0029] [axis] Shaft 15 extends along the Z-axis. Shaft 15 is the rotating shaft of motor 60. Shaft 15 is rotatably supported by housing 10. Shaft 15 has end 15a and end 15b. Ends 15a and 15b are the ends of shaft 15 in the length direction. End 15a is disposed on the side near intake port 11, and end 15b is disposed on the side near exhaust port 12.

[0030] [Bearings] The axial fan 100 includes a pair of bearings 16 and 17 that rotatably support the shaft 15. The bearings 16 and 17 are spaced apart in the Z-axis direction. Bearing 16 is located near the intake port 11, and bearing 17 is located near the exhaust port 12. Bearings 16 and 17 may be, for example, rolling bearings. Bearings 16 and 17 are fixed to the housing 10, for example, via a base portion 50.

[0031] The axial fan 100 may include, for example, a bearing support member 18 that holds a pair of bearings 16, 17. The bearing support member 18 extends along the Z-axis. The end of the bearing support member 18 on the exhaust port 12 side is fixed to the base portion 50. The bearing support member 18 includes a cylindrical portion. The pair of bearings 16, 17 are held inside the cylindrical portion of the bearing support member 18. A shaft 15 supported by the pair of bearings 16, 17 is disposed inside the cylindrical portion of the bearing support member 18. The end 15a of the shaft 15 on the intake port 11 side protrudes further toward the intake port 11 side in the Z-axis direction than the cylindrical portion of the bearing support member 18.

[0032] [Base section] The base portion 50 is disposed inside the housing 10. The base portion 50 is positioned near the exhaust port 12 in the Z-axis direction. A portion of the base portion 50 may be disposed inside the exhaust port 12.

[0033] The base portion 50 supports the motor 60, bearing support member 18, a pair of bearings 16 and 17, shaft 15, and impeller 20. The base portion 50 is fixed to the housing 10, for example, via a fixing wing 70. The base portion 50 includes, for example, a boss portion 51, a hub portion 52, and a cylindrical portion 53. Viewed from the Z-axis direction, the boss portion 51 is located at the center of the housing 10. The boss portion 51 supports the end of the bearing support member 18 on the exhaust port 12 side. The boss portion 51 is, for example, cylindrical. The boss portion 51, hub portion 52, and cylindrical portion 53 are, for example, integrally formed.

[0034] The hub portion 52 is, for example, disc-shaped. The thickness direction of the hub portion 52 is along the Z-axis. Viewed from the Z-axis direction, the boss portion 51 is disposed at the radial center of the hub portion 52. Viewed from outside the exhaust port 12 in the Z-axis direction, the hub portion 52 is formed to cover the motor 60.

[0035] The cylindrical portion 53 is connected to the outer peripheral side of the hub portion 52. The cylindrical portion 53 protrudes from the hub portion 52 toward the intake port 11 in the Z-axis direction. A downstream portion of the flow path 130 is formed between the outer peripheral surface of the cylindrical portion 53 and the inner peripheral surface of the housing 10.

[0036] The base portion 50 is fixed to the housing 10 via a fixed wing 70. The cylindrical portion 53 is connected to the housing 10 via the fixed wing 70. The base portion 50 may also be supported by the housing 10 via, for example, a radially extending rod-shaped member.

[0037] [Fixed-wing] Multiple fixed winglets 70 extend radially from the inner circumferential surface of the housing 10 toward the outer circumferential surface of the cylindrical portion 53 of the base portion 50. The length of the multiple fixed winglets 70 in the Z-axis direction can, for example, be the same as the length of the cylindrical portion 53 of the base portion 50.

[0038] The multiple fixed wing 70 can also be formed in a helical shape with an angle relative to the axis 15 in the circumferential direction. The fixed wing 70 can be formed to the rear end position of the housing 10 in the Z-axis direction. The rear end position of the housing 10 can also be the position of the exhaust port 12. As described above, the fixed wing 70 connects the base portion 50 and the housing 10 in the radial direction.

[0039] [motor] The motor 60 is disposed inside the cylindrical portion 40 of the impeller 20. The motor 60 has a rotor 61 and a stator 62. The stator 62 is radially disposed further inward than the rotor 61. The rotor 61 is radially disposed further outward than the stator 62.

[0040] The rotor 61 has a magnet 63 arranged radially outward from the stator 62 and an iron core (rotor yoke) 64. The iron core 64 includes a disc portion and a cylindrical portion. The disc portion is fixed to the end 15a of the shaft 15 on the intake port 11 side. The cylindrical portion protrudes from the disc portion toward the exhaust port 12 side in the Z-axis direction. The magnet 63 is, for example, cylindrical. The magnet 63 is fixed to the inner circumferential surface of the cylindrical portion of the iron core 64.

[0041] The stator 62 is radially disposed inside the magnet 63. The stator 62 includes, for example, an insulator (insulator) 65, an iron core (stator core) 66, and a coil 67. The stator 62 is fixed to the outer peripheral surface of the bearing support member 18. The iron core 66 is, for example, annular and fixed to the outer peripheral surface of the bearing support member 18. The coil 67 is disposed on both sides of the iron core 66 in the Z-axis direction. The insulator 65 is disposed radially covering the coil 67. The insulator 65 is radially disposed between the coil 67 and the magnet 63.

[0042] The rotor 61, impeller 20 and shaft 15 rotate as a whole.

[0043] [impeller] Figure 2 This is a side view showing an example of the impeller 20 of an axial fan 100. Figure 3 This is a perspective view showing an example of the impeller 20 of the axial fan 100 from the rear. Figure 4 This is a front view showing an example of the impeller 20 of an axial fan 100. Figure 5 This is a rear view showing an example of the impeller 20 of an axial fan 100. (See image) Figures 1 to 5 The impeller 20 shown, as described above, includes a hub 21 and multiple rotor blades 30. The hub 21 includes a cylindrical section 40. Figure 1 As shown, a flow path 130 is formed radially between the outer peripheral surface of the impeller 20 and the inner peripheral surface of the housing 10.

[0044] [Wheel hub] The hub portion 21 includes a head 22 and a cylindrical portion 40. The head 22 is, for example, disc-shaped. The head 22 is the portion of the hub portion 21 on the side of the air intake 11. The outer periphery of the head 22 is connected to the cylindrical portion 40. The head 22 may also be, for example, dome-shaped. The head 22 may be curved in cross-section along the Z-axis. The head 22 is configured to cover the opening on the side of the air intake 11 of the cylindrical portion 40.

[0045] [Cylinder section] The cylindrical portion 40 protrudes from the head 22 toward the exhaust port 12 in the Z-axis direction. The cylindrical portion 40 is positioned closer to the intake port 11 than the cylindrical portion 53 of the base portion 50. The cylindrical portion 40 of the impeller 20 and the cylindrical portion 53 of the base portion 50 are arranged in the Z-axis direction. The outer peripheral surface of the cylindrical portion 40 of the impeller 20 and the outer peripheral surface of the cylindrical portion 53 of the base portion 50 are formed at the same position in the radial direction.

[0046] [Moving Wing] Multiple moving blades 30 protrude radially outward from the hub portion 21. The multiple moving blades 30 are formed on the hub portion 21. "Formed on the hub portion 21" means formed relative to the hub portion 21. The multiple moving blades 30 protrude radially outward from the outer peripheral surface of the head 22 and the outer peripheral surface of the cylinder portion 40. For example, five moving blades 30 are formed. The multiple moving blades 30 are formed continuously in the circumferential and Z-axis directions of the impeller 20. The number of moving blades 30 is not limited to five.

[0047] Figure 6 This is a cross-sectional view showing an example of the rotor blade 30 of the impeller 20. Figure 6 A cross-section of the moving blade 30 along the circumference of the impeller 20 is shown. The circumference of the impeller 20 can also be the direction of rotation of the impeller 20. For example... Figure 6 As shown, the movable wing 30 has a leading edge 31 and a trailing edge 32. The leading edge 31 is the upstream end, which is the end on the side of the air intake 11. The trailing edge 32 is the downstream end, which is the end on the side of the exhaust port 12.

[0048] The movable wing 30 has a leading edge portion 33 and a trailing edge portion 34. The leading edge portion 33 is the portion of the movable wing 30 on the side of the leading edge 31. The trailing edge portion 34 is the portion of the movable wing 30 on the side of the trailing edge 32. The leading edge portion 33 includes the leading edge 31 and includes a portion further downstream than the leading edge 31. The trailing edge portion 34 includes the trailing edge 32 and includes a portion further upstream than the trailing edge 32.

[0049] The movable wing 30 has a first surface 35 and a second surface 36. The first surface 35 and the second surface 36 are opposite each other in the thickness direction of the movable wing 30. The first surface 35 is the back surface of the movable wing 30 and is the low-pressure side surface. The second surface 36 is the ventral surface of the movable wing 30 and is the high-pressure side surface. The first surface 35 is the surface on the side of the air intake 11 in the Z-axis direction, and the second surface 36 is the surface on the side of the exhaust port 12.

[0050] [The first and second parts of the posterior margin] The trailing edge portion 34 includes a first portion 37 and a second portion 38. The first portion 37 includes the inner circumferential side of the trailing edge portion 34. The second portion 38 includes the outer circumferential side of the trailing edge portion 34. The inner circumferential side refers to the radially extending cylindrical portion 40 side of the impeller 20. The outer circumferential side refers to the radially extending inner circumferential surface side of the housing 10 of the impeller 20.

[0051] The second part 38 has a thinner wing thickness than the first part 37. In the trailing edge 34 of the movable wing 30, the outer peripheral side of the second part 38 has a thinner wing thickness than the inner peripheral side of the first part 37. The movable wing 30 has a second part 38 with a thinner wing thickness on the outer peripheral side in the trailing edge 34. Furthermore, the thinner wing thickness portion can also be described as a portion that has been cut off compared to the thicker wing thickness portion. Furthermore, the thinner wing thickness portion can also be described as a cut. Furthermore, the surface of the thinner wing thickness portion can also be described as a cutting surface. Even if it is not actually cut, it can be described as a cutting surface. "The second part 38 has a thinner wing thickness than the first part 37" can also mean, for example, such as... Figure 10 As shown, when viewed radially, the second portion 38 includes a portion that is thinner than the first portion 37, but does not include a portion that is thicker than the first portion 37.

[0052] [Leg edge configuration] like Figure 5 As shown, when viewed from the Z-axis direction, the trailing edge 32 is arranged to be radially inclined relative to the cylindrical portion 40. The radial direction is the direction that intersects perpendicularly with the outer circumferential surface of the cylindrical portion 40. The outer circumferential side of the trailing edge 32 is positioned closer to the leading edge 31 in the circumferential direction of the cylindrical portion 40 than the inner circumferential side of the trailing edge 32.

[0053] Furthermore, among the multiple adjacent circumferentially adjacent winglets 30, a portion of the trailing edge 34 of one winglet 30 overlaps with a portion of the leading edge 33 of another winglet 30. Viewed from the Z-axis direction, the trailing edge 32 of one winglet 30 intersects the leading edge 31 of another winglet 30. In other words, when viewed from the Z-axis direction, in the rotational direction of the cylinder 40, the trailing edge 32 of the front winglet 30 is configured to intersect the leading edge 31 of the rear winglet 30.

[0054] In the rotation direction of the cylinder 40, the inner circumferential side of the trailing edge 32 of the front movable wing 30 is positioned further rearward than the inner circumferential side of the leading edge 31 of the rear movable wing 30. In the rotation direction of the cylinder 40, the outer circumferential side of the trailing edge 32 of the front movable wing 30 is positioned further forward and spaced apart from the outer circumferential side of the leading edge 31 of the rear movable wing 30.

[0055] In the rotational direction of the cylinder 40, the trailing edge 32 of the second part 38 is positioned further toward the leading edge 33 than the trailing edge 32 of the first part 37. In other words, in the rotational direction of the cylinder 40, the trailing edge 32 of the second part 38 is positioned in front of the trailing edge 32 of the first part 37.

[0056] [The angle of the first side in Part Two] Next, refer to Figure 7 The angle of the first surface 35 of the second part 38 of the moving wing 30 will be explained. Figure 7This is an enlarged side view showing an example of the trailing edge 34 of the rotor 30. Figure 7 The trailing edge 34 of the rotor 30 is shown radially outward.

[0057] exist Figure 7 The diagram shows straight lines L1 to L3, formed by dashed lines. Line L1 is a straight line along the UV surface, which intersects perpendicularly to the Z-axis. The UV surface is parallel to the U-axis and V-axis. The U-axis is one of the radial directions, and the V-axis is a direction that intersects perpendicularly to both the Z-axis and U-axis. The U-axis is the radial direction connecting two points at the same position along the Z-axis (the axial direction of the hub 21), as shown below. Figure 9 As shown, the radial direction is the front end position P15 of the inclined surface of the second part 38 at the outer periphery 30a of the moving wing 30, which connects the shaft center PO of the hub 21 to the outer periphery 30a of the moving wing 30.

[0058] Straight line L2 is a tangent to surface 35a on the upstream side (leading edge side) of the first surface 35 of the moving wing 30. For example... Figure 7 As shown, it can also be a straight line along the ZV plane, and when viewed from the U-axis direction, it is a tangent to the surface 35a on the upstream side (leading edge side) of the first surface 35 of the rotor 30. The upstream side surface 35a is a surface further upstream than the second part 38. The upstream side surface 35a can also be a surface of a normal shape (a normal profile surface) that has not been thinned (cut). In addition, the straight line L2 can also be a line passing through the area described later. Figure 8 Positions P13 and P15 are located in the virtual plane along the Z-axis, along the tangent to surface 35a.

[0059] Line L3 is a tangent to the first surface 35b in the second part 38 of the wing 30. The first surface 35b is contained within the second part 38. Surface 35a is an example of a first region. First surface 35b is an example of a second region.

[0060] Lines L2 and L3 intersect line L1 at different angles θ1 and θ2. Angle θ1 is the angle at which lines L1 and L2 intersect. Angle θ1 is the smaller of the angles at which lines L1 and L2 intersect. As mentioned above, line L2 is a tangent to surface 35a on the upstream side (leading edge side) of the first surface 35 of the wing 30. Figure 6 As shown, the first surface 35 is curved. Line L2 is the tangent line with the largest angle θ1 relative to line L1 among the tangent lines tangent to surface 35a upstream of the first surface 35. Line L2 can also be the tangent line at the position closest to position P15 upstream of position P15. Angle θ2 is the angle at which line L1 intersects line L3. Angle θ2 is the smaller of the angles at which line L1 and line L3 intersect. Angle θ2 is an angle larger than angle θ1. Angle θ2 can also be less than or equal to angle θ1 + 20°. The angle difference Δθ between angle θ2 and angle θ1 can, for example, be a maximum of 20°.

[0061] The angle difference Δθ between angle θ2 and angle θ1 is the angle at which lines L2 and L3 intersect. The angle difference Δθ can be, for example, between 2 and 20 degrees, or between 3 and 10 degrees. The angle difference Δθ is an example of the tilt angle of the second region relative to the first region.

[0062] [Range of inclined surfaces in the axial direction] Next, refer to Figure 8 This describes the range of the inclined surface (part 38) in the axial direction (Z-axis direction) of the impeller 20. Figure 8 This is an enlarged side view showing an example of the moving wing 30. Figure 8 The image shows the total length L4 of the impeller 20 in the Z-axis direction. The total length L4 of the impeller 20 in the Z-axis direction is the length from the front end position P11 of the hub portion 21 of the impeller 20 to the rear end position P12 of the cylinder portion 40.

[0063] Figure 8 The figure shows the total length L5 of multiple moving wings 30 in the Z-axis direction. The total length L5 of the moving wings 30 in the Z-axis direction can also be the length from position P13 at the leading edge 31 at the outer periphery 30a of the moving wings 30 to position P14 at the trailing edge 32.

[0064] The leading edge 31, position P13, is positioned in the Z-axis direction closer to the exhaust port 12 (rear and below) than the front end position P11 of the impeller 20. The trailing edge 32, position P14, is positioned in the Z-axis direction closer to the intake port 11 (front and above) than the rear end position P12 of the impeller 20. The total length L5 of the rotor 30 in the Z-axis direction is shorter than the total length L4 of the impeller 20 in the Z-axis direction.

[0065] Figure 8 The diagram shows the length L6 of the inclined surface of the second part 38 in the Z-axis direction. The length L6 of the inclined surface of the second part 38 in the Z-axis direction can also be the length from the front end position P15 to the rear end position P16 of the inclined surface. Position P15 can be, for example, a position on the outer periphery 30a. Position P16 is a position further inward than the outer periphery 30a.

[0066] In the Z-axis direction, the length L6 of the inclined surface of the second part 38 can be more than 5% and less than 35% of the total length L5 of the outer periphery of the moving wing 30, or more than 10% and less than 25%.

[0067] [The extent of the inclined surface relative to the entire length of the outer perimeter] Next, refer to Figure 9 This indicates the extent of the inclined surface relative to the full length R1 of the outer perimeter 30a. Figure 9 This is a magnified front view showing an example of impeller 20. Figure 9This is a diagram of the impeller 20 viewed from the side of the intake port 11 towards the Z-axis.

[0068] Figure 9 The diagram shows the total length R1 of the outer periphery 30a of the rotor 30. The total length R1 of the outer periphery 30a of the rotor 30 is the length in the circumferential direction of the impeller 20 from position P13 at the leading edge 31 to position P14 at the trailing edge 32. Positions P13 and P14 are positions on the outer periphery 30a.

[0069] Figure 9 The diagram shows the length R2 of the inclined surface of the second portion 38 at the outer periphery 30a. The length R2 of the inclined surface of the second portion 38 is the length from the front end position P15 to the rear end position P14 of the inclined surface. Positions P15 and P14 are on the outer periphery 30a.

[0070] In the rotation direction of the impeller 20, the length R2 of the inclined surface of the second part 38 can be, for example, more than 5% and less than 35% of the total length R1 of the outer periphery 30a of the moving blade 30, or more than 5% and less than 25%.

[0071] [Angle of inclination of the inclined plane relative to the baseline] Next, refer to Figure 10 This describes the angle of inclination θ3 of the inclined plane relative to the second part 38 of the straight line L1, which serves as the baseline. Figure 10 This is an enlarged side view showing an example of the trailing edge 34 of the rotor 30. Figure 10 The tilt angles θ3 to θ5 are shown in the figure. Figure 10 This is, for example, a diagram showing the rotor 30 viewed in the U-axis direction (radial). As mentioned above, the U-axis direction is the radial direction connecting the shaft center PO and position P15 (see reference). Figure 9 ).

[0072] Inclination angle θ3 is the inclination angle of the inclined surface (first surface 35) of the second part 38 relative to the line L1. Inclination angle θ4 is the inclination angle of the second surface 36 of the second part 38 relative to the line L1. Inclination angle θ5 is the inclination angle of the first surface 35 of the first part 37 relative to the line L1.

[0073] Angle θ6 is the angle between the inclined surface of the second part 38 and the first part 37 of the first surface 35. Angle θ6 can be, for example, more than 2 degrees and less than 20 degrees, or more than 3 degrees and less than 10 degrees. The first part 37 is the first part disposed on the inner peripheral side, and the second part 38 is the second part disposed on the outer peripheral side.

[0074] [Length of the inclined surface along the trailing edge] Next, refer to Figure 11 This indicates the length of the inclined surface of the second part 38 in the direction along the trailing edge 32. Figure 11This is a top view showing an example of the rotor 30. Figure 11 The lengths L11 and L12 are shown. Length L11 is the length of the trailing edge 32, which is the length from the position P17 of the inner periphery to the position P14 of the outer periphery 30a.

[0075] Length L12 is the length of the inclined surface of the second part 38 along the trailing edge 32. Length L12 is the length from position P16 to position P14a. Length L12 can be, for example, more than 10% and less than 100%, more than 10% and less than 50%, or more than 20% and less than 40% of length L11. Furthermore, the trailing edge 32 can be formed as a straight line or as a curve when viewed along the wing thickness direction. Additionally, position P14a is the position on the outer perimeter 30a, or it can be the position closest to the trailing edge 32 on the inclined surface of the second part 38.

[0076] [Machining method for impeller 20] The impeller 20 can be machined, for example, using a forming mold. The shape of the rotor 30 can be formed using a forming mold, or it can be formed by cutting or grinding, for example. There are no restrictions on the machining method of the impeller 20. Furthermore, there are no restrictions on the material of the impeller 20.

[0077] [Effects of the axial flow fan described in the implementation method] The axial flow fan 100 according to the embodiment includes: a housing 10 having an intake port 11 and an exhaust port 12, and having a flow path 130 formed inside communicating from the intake port 11 to the exhaust port 12; and an impeller 20 disposed within the housing 10 and rotatable about an axis, the impeller 20 having a hub portion 21 and a plurality of moving blades 30 formed on the hub portion 21. The plurality of moving blades 30 have a leading edge portion 33 disposed on the intake port 11 side and a trailing edge portion 34 disposed on the exhaust port 12 side. The trailing edge portion 34 includes a first portion 37 disposed on the inner peripheral side and a second portion 38 disposed on the outer peripheral side. The second portion 38 includes an inclined surface inclined at a different angle than the first portion 37. The blade thickness of the second portion 38 is thinner than the blade thickness of the first portion 37. The inclined surface of the second portion 38 is inclined in such a way that the blade thickness in the second portion 38 is thinner than the blade thickness of the first portion 37.

[0078] In this axial flow fan 100, an inclined surface is formed on the outer periphery of the trailing edge 34 of the rotor 30, forming a second portion 38 with a thickness thinner than the inner periphery. With this axial flow fan 100, the airflow-static pressure characteristics can be improved. The axial flow fan 100 can improve fan efficiency and increase airflow. Furthermore, by forming the second portion 38 with a thickness thinner than the inner periphery on the outer periphery, the acoustic and vibration performance of the axial flow fan 100 is improved. Improved acoustic and vibration performance refers to reduced vibration and noise. The axial flow fan 100 can suppress vibration and noise.

[0079] In the axial fan 100, the trailing edge 32 of the second part 38 is positioned further toward the leading edge 33 in the rotational direction (circumferential direction) of the impeller 20 than the trailing edge 32 of the first part 37. With this configuration, the airflow-static pressure characteristics and the acoustic-vibration characteristics can be improved.

[0080] Furthermore, in the axial fan 100, a plurality of rotor blades 30 have a first surface 35 disposed on the side of the intake 11 in the Z-axis direction and a second surface 36 disposed on the side of the exhaust 12 in the Z-axis direction. The first surface 35 includes a first region on the leading edge 31 side and a second region on the trailing edge 32 side. The second portion 38 has a second region containing an inclined surface that is inclined at a different angle relative to the first region. The inclined surface of the second region is inclined in a manner that is thinner than the blade thickness in the first region.

[0081] Viewed radially, the tilt angle (angle difference Δθ) of the second region relative to the first region can be between 2 and 20 degrees, or between 3 and 10 degrees. With this configuration, the axial flow fan 100 can achieve improvements in both airflow-static pressure characteristics and acoustic-vibration characteristics. Furthermore, the aforementioned radial direction is along... Figure 9 The radial direction of the U-axis is shown. As described above, the U-axis direction is the radial direction of two points at the same position on the axis (Z-axis direction) connecting the hub 21, and is the radial direction of the position PO of the axis connecting the hub 21 and the front end position P15 of the inclined surface of the second part 38 at the outer periphery 30a of the moving wing 30.

[0082] Furthermore, in the axial fan 100, in the Z-axis direction, the length L6 of the second part 38 can be more than 5% and less than 35% of the length L5 from the leading edge 31 to the trailing edge 32 at the outer periphery 30a of the plurality of moving blades 30, or more than 10% and less than 25%.

[0083] Furthermore, in the axial flow fan 100, in the rotation direction of the impeller 20, the length R2 of the second portion 38 at the outer periphery 30a of the plurality of moving blades 30 can be more than 5% and less than 35% of the total length R1 of the outer periphery 30a, or more than 5% and less than 25%.

[0084] Furthermore, in the axial flow fan 100, in the direction extending from the trailing edge 32 of the rotor 30, the length of the second portion 38 at the trailing edge 32 can be more than 10% and less than 100%, more than 10% and less than 50%, or more than 20% and less than 40% of the total width of the rotors 30. In the axial flow fan 100, in the direction extending from the trailing edge 32, the length L12 of the second portion 38 can be more than 10% and less than 100%, more than 10% and less than 50%, or more than 20% and less than 40% of the length L11 corresponding to the total width of the rotor 30. Additionally, in the second portion 38, the position closest to the trailing edge 32 can be position P14 on the trailing edge 32, or it can be position P14a offset from the trailing edge 32 towards the forward edge (see reference). Figure 11 The trailing edge 32 of the moving wing 30 can extend in the radial direction at the location where the trailing edge 32 is located.

[0085] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Various modifications and substitutions can be applied to the above embodiments without departing from the scope of the present invention. Furthermore, the features described separately can be combined as long as they do not create technical contradictions.

[0086] In the above embodiment, it is described that an inclined surface is formed on the first surface 35 on the outer periphery of the trailing edge 34 of the moving wing 30, but an inclined surface (cutting surface) may also be formed on the second surface 36 on the outer periphery of the trailing edge 34.

[0087] In the above embodiment, an example is shown where the trailing edge 34 and leading edge 33 of adjacent rotor blades 30 in the rotational direction overlap when viewed in the Z-axis direction. However, the trailing edge 34 and leading edge 33 of adjacent rotor blades 30 in the rotational direction may not overlap. The trailing edge 34 and leading edge 33 of adjacent rotor blades 30 in the rotational direction may be arranged at intervals.

[0088] In the above embodiment, an example is shown where the trailing edge 32 and the leading edge 31 of adjacent rotor blades 30 in the rotation direction of impeller 20 intersect each other when viewed in the Z-axis direction, but the trailing edge 32 and the leading edge 31 may not intersect.

[0089] This international application claims priority based on Japanese Patent Application No. 2023-147821, filed on September 12, 2023, and incorporates the entire contents of Japanese Patent Application No. 2023-147821 into this international application.

[0090] [Attached image labels] 100…Axial fan, 10…Casing, 11…Inlet, 12…Exhaust, 15…Shaft, 20…Impeller, 21…Hub, 30…Propeller, 30a…Outer periphery, 31…Leading edge, 32…Trail edge, 33…Leading edge, 34…Trail edge, 35…First surface, 36…Second surface, 37…First part (the first part located on the inner periphery), 38…Second part (the second part located on the outer periphery), 40…Cylinder, PO…Shaft (the shaft of the hub), P15…Position of the front end of the inclined surface, U…U-axis (radial), X…X-axis, Y…Y-axis, Z…Z-axis (axial).

Claims

1. An axial flow fan, comprising: The housing has an intake port and an exhaust port, and an internal flow path is formed connecting the intake port to the exhaust port. The impeller, which is disposed within the housing, is rotatable about an axis. The impeller has a hub and a plurality of moving blades formed on the hub. The plurality of moving blades have a leading edge portion disposed on the air intake side and a trailing edge portion disposed on the exhaust port side. The trailing edge includes a first portion disposed on the inner peripheral side and a second portion disposed on the outer peripheral side. The second part includes an inclined surface that is tilted at a different angle than the first part. The inclined surface of the second part is inclined in such a way that the wing thickness in the second part is thinner than the wing thickness in the first part.

2. The axial fan according to claim 1, wherein in the rotation direction of the impeller, the trailing edge of the second portion is disposed on the leading edge side compared to the trailing edge of the first portion.

3. The axial flow fan according to claim 1 or 2, wherein the plurality of moving blades have: The first surface is axially positioned on the intake side, and The second surface is disposed on the exhaust port side in the axial direction. The first surface includes a first region on the leading edge side of the rotor and a second region on the trailing edge side of the rotor. The second part includes the second region. The second region of the first surface includes the inclined surface, which is inclined at a different angle relative to the first region. The inclined surface of the second region is inclined in a manner that is thinner than the wing thickness in the first region.

4. The axial flow fan according to claim 3, when viewed radially from two points at the same position axially connected in the hub, has an inclination angle of 2 degrees or more and 20 degrees or less relative to the second region of the first region, wherein the radial direction is the direction of the position of the front end of the inclined surface of the second part of the second portion connecting the axis of the hub and the outer periphery of the moving blade.

5. The axial flow fan according to any one of claims 1 to 4, wherein, in the axial direction, the length of the second portion is more than 5% and less than 35% of the length from the leading edge to the trailing edge of the outer periphery of the plurality of moving blades.

6. The axial flow fan according to any one of claims 1 to 5, wherein, in the rotational direction of the impeller, the length of the second portion of the outer periphery of the plurality of moving blades is more than 5% and less than 35% of the total length of the outer periphery.

7. The axial fan according to any one of claims 1 to 6, wherein in the direction extending from the trailing edge of the rotor blades, the length of the second portion of the trailing edge is more than 10% and less than 100% of the total width of the plurality of rotor blades.

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