An axial flow fan with a hub ratio of 0.5

Abstract

The present invention discloses an axial flow fan with a hub ratio of 0.5, comprising a casing, a motor and an impeller; the motor is installed in the casing through a motor barrel; the impeller is connected to the output shaft of the motor through a hub, and the ratio of the diameter of the hub to the diameter of the impeller is 1:2; the impeller is composed of a plurality of curved blades, the middle of the blades is connected to the hub; the angle α between the curved surface of the blade and the middle of the blade is 18-25°; the thickness A of the circumferential section of the blade is 152-155 mm. In the axial flow fan with a hub ratio of 0.5, after the airflow passes through the impeller, it is exhausted to the rear of the casing. When the motor drives the impeller to rotate, the airflow enters the impeller axially from the air inlet, and is pushed by the impeller to increase the energy of the airflow, thereby increasing the flow rate, total pressure and static pressure of the airflow, thereby increasing the wind speed.

Description

Technical Field

[0001] The invention relates to the technical field of fans, in particular to an axial flow fan with a hub ratio of 0.5. Background Art

[0002] Axial flow fans are widely used. The airflow of axial flow fans is in the same direction as the axial direction of the fan blades. For example, electric fans and air conditioner outdoor fans are axial flow fans. They are called "axial flow" because the airflow flows parallel to the fan shaft. Axial flow fans with a hub ratio of 0.5 are usually used in situations where the flow rate requirements are high and the pressure requirements are low. Axial flow fans with a hub ratio of 0.5 have a simple structure but very high data requirements. They can be used for ventilation in general factories, warehouses, offices, residences, etc. They can also be used for air coolers (air coolers), evaporators, condensers, sprayers, etc.

[0003] The flow rate, total pressure and static pressure of the fan are all important parameters that affect the quality of the fan. The existing axial flow fan with a hub ratio of 0.5 has low flow rate, low total pressure and low static pressure. The wind speed is low in the duct with the same cross-section, and the fan suction is insufficient. Users have to choose a larger model and a higher power fan, which increases costs and wastes electricity. Summary of the invention

[0004] In view of the above-mentioned defects, the object of the present invention is to provide an axial flow fan with a hub ratio of 0.5, so as to increase the flow rate, total pressure and static pressure of the airflow, thereby reducing costs and reducing the waste of electric energy.

[0005] To achieve this object, the present invention adopts the following technical solution: an axial flow fan with a hub ratio of 0.5, including a casing, a motor and an impeller;

[0006] The motor is installed in the housing through a motor cylinder;

[0007] The impeller is connected to the output shaft of the motor through a hub, and the ratio of the diameter of the hub to the diameter of the impeller is 1:2;

[0008] The impeller is composed of a plurality of curved blades, the middle of the blades is connected to the hub; the angle α between the curved surface of the blades and the middle of the blades is 18-25°; the thickness A of the circumferential section of the blades is 152-155 mm.

[0009] Preferably, the impeller is provided with 8 blades, and the blades are symmetrically arranged on the circumferential outer surface of the hub.

[0010] Preferably, a fairing is provided at the air inlet inside the casing, and a rectifier is provided at the air outlet inside the casing. The fairing is fixed at the front end of the impeller and rotates with the impeller, and the rectifier is fixed at the rear end of the motor barrel; the fairing is hemispherical, and the rectifier is truncated conical.

[0011] Preferably, an S-shaped guide vane is provided between the inner wall of the casing and the outer surface of the motor barrel, the guide vane is evenly distributed circumferentially along the outer surface of the motor barrel, and the middle part of the guide vane is provided with a first arc surface and a second arc surface at both ends along the horizontal axis direction of the casing.

[0012] Preferably, the included angles between the first curved surface and the second curved surface of the guide vane and the middle portion of the guide vane are both 17-25°.

[0013] Preferably, the number of guide vanes provided between the inner wall of the casing and the outer surface of the motor barrel is 8.

[0014] Preferably, a distance B from the middle of the impeller blades to the connection between the hub and the output shaft of the motor is 58-59 mm.

[0015] Preferably, the diameter of the impeller is 998-999 mm, and the diameter of the casing is 1014-1015 mm.

[0016] Beneficial effects of the present invention: The airflow of the 0.5 hub ratio axial flow fan passes through the impeller and is exhausted to the rear of the casing. When the motor drives the impeller to rotate, the airflow enters the impeller axially from the air inlet, and is pushed by the impeller to increase the energy of the airflow, thereby increasing the flow rate, total pressure and static pressure of the airflow, thereby increasing the wind speed.

[0017] The angle α between the curved surface of the blade of the impeller and the middle of the blade affects the path of the wind flow through the surface of the blade, thereby affecting the wind pressure. Different from the existing fan impeller, the angle α between the curved surface of the blade of the impeller and the middle of the blade is 18-25°, which can enable the airflow flowing through the curved surface of the blade to obtain more energy, thereby converting it into wind speed.

[0018] The circumferential cross-sectional thickness A of the impeller blades affects the time and distance that the wind flows over the surface of the blades 31. Unlike existing fan impellers, the circumferential cross-sectional thickness A of the impeller blades is 152 to 155 mm, which enables the airflow flowing over the curved surface of the blades to obtain more energy, thereby converting it into wind speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of an embodiment of the present invention;

[0020] Figure 2 is a front view of an impeller and a hub in one embodiment of the present invention;

[0021] Figure 3 is a right side view of an impeller and a hub in one embodiment of the present invention;

[0022] Figure 4 is a schematic structural diagram of a blade in one embodiment of the present invention;

[0023] Among them: 1 casing; 2 motor; 3 impeller; 4 motor cylinder; 5 hub; 11 fairing; 12 fairing body; 31 blades; 41 guide vanes. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0025] like Figure 1-4 As shown, an axial flow fan with a hub ratio of 0.5 includes a casing 1, a motor 2 and an impeller 3;

[0026] The motor 2 is installed in the housing 1 through the motor cylinder 4;

[0027] The impeller 3 is connected to the output shaft of the motor 2 via a hub 5, and the ratio of the diameter of the hub 5 to the diameter of the impeller 3 is 1:2;

[0028] The impeller 3 is composed of a plurality of curved blades 31, the middle of the blade 31 is connected to the hub 5; the angle α between the curved surface of the blade 31 and the middle of the blade 31 is 18-25°; the circumferential section thickness A of the blade 31 is 152-155 mm.

[0029] In the axial flow fan with a hub ratio of 0.5, the airflow passes through the impeller 3 and is exhausted to the rear of the housing 1. When the motor 2 drives the impeller 3 to rotate, the airflow enters the impeller 3 axially from the air inlet, and is pushed by the impeller 3 to increase the energy of the airflow, thereby increasing the flow rate, total pressure and static pressure of the airflow, thereby increasing the wind speed.

[0030] The angle α between the curved surface of the blade 31 of the impeller 3 and the middle of the blade 31 affects the path of the wind flowing through the surface of the blade 31, thereby affecting the wind pressure. Different from the existing fan impeller, the angle α between the curved surface of the blade 31 of the impeller 3 and the middle of the blade 31 is 18-25°, which can enable the airflow flowing through the curved surface of the blade 31 to obtain more energy, thereby converting it into wind speed.

[0031] The circumferential cross-sectional thickness A of the blades 31 of the impeller 3 affects the time and distance of the wind flowing over the surface of the blades 31. Unlike the existing fan impellers, the circumferential cross-sectional thickness A of the blades 31 of the impeller 3 is 152-155 mm, which can enable the airflow flowing over the curved surface of the blades 31 to obtain more energy, thereby converting it into wind speed.

[0032] Preferably, the impeller 3 is provided with eight blades 31 , and the blades 31 are symmetrically arranged on the circumferential outer surface of the hub 5 .

[0033] The eight blades 31 are symmetrically arranged on the circumferential outer surface of the hub 5. When rotating, the wind speed of the airflow in the casing 1 can be kept uniform, and the wind speed of the local airflow will not be too large to cause the fan to be unbalanced.

[0034] Preferably, a fairing 11 is provided at the air inlet inside the casing 1, and a rectifying body 12 is provided at the air outlet inside the casing 1. The fairing 11 is fixed at the front end of the impeller 3 and rotates with the impeller 3, and the rectifying body 12 is fixed at the rear end of the motor barrel 4; the fairing 11 is semi-spherical, and the rectifying body 12 is truncated conical.

[0035] The fairing 11 is set to be a semisphere, the fairing body 12 is set to be a truncated cone and gradually shrinks along the direction of the air outlet, and the end of the fairing body 12 is in an arc shape, so that the air intake condition is more perfect and the noise of the fan is reduced. The fairing 11 installed in front of the impeller 3 constitutes an axial flow fire duct. The axial flow fan with a hub ratio of 0.5 takes in air from the air inlet direction, and the rotational kinetic energy is recovered by the fairing 11 and the impeller 3 and converted into total pressure. The air flow rate, total pressure and static pressure are increased through the fairing body 12.

[0036] Preferably, an S-shaped guide vane 41 is provided between the inner wall of the casing 1 and the outer surface of the motor barrel 4, and the guide vane 41 is evenly distributed circumferentially along the outer surface of the motor barrel 4, and the middle part of the guide vane 41 is provided with a first arc surface and a second arc surface at both ends along the horizontal axis direction of the casing 1.

[0037] The S-shaped structure of the guide vane 41 can convert the deflected airflow into axial flow, and at the same time guide the airflow into the air outlet, further converting the kinetic energy of the airflow into pressure energy, so that the ventilation effect is obvious and safe, and the wind can be delivered to the designated area.

[0038] Preferably, the included angles between the first curved surface and the second curved surface of the guide vane 41 and the middle portion of the guide vane 41 are both 17-25°.

[0039] When the included angle between the first and second curved surfaces of the guide vane 41 and the middle portion of the guide vane 41 is 17-25°, the guide vane 41 has the best flow guiding effect and can effectively convert the deflected airflow into axial flow.

[0040] Preferably, the number of guide vanes 41 provided between the inner wall of the casing 1 and the outer surface of the motor barrel 4 is 8.

[0041] The number of the guide vanes 41 corresponds to the number of the blades 31 of the impeller 3. When the impeller 3 rotates, the airflow enters the impeller 3 axially from the air inlet, is pushed by the impeller 3 so that the energy of the airflow is increased, and then flows into the guide vanes 41. The guide vanes 41 deflect the airflow into axial flow and guide the airflow into the air outlet, further converting the kinetic energy of the airflow into pressure energy.

[0042] Preferably, a distance B from the middle of the blades 31 of the impeller 3 to the connection between the hub 5 and the output shaft of the motor 2 is 58-59 mm.

[0043] When the distance B is 58-59 mm, the deflected airflow blown out from the impeller 3 can accurately fall on the first arc surface of the guide vane 41 close to the impeller 3, thereby improving the guiding effect of the guide vane 41 and effectively converting the deflected airflow into axial flow.

[0044] Preferably, the diameter of the impeller 3 is 998-999 mm, and the diameter of the casing 1 is 1014-1015 mm.

[0045] The diameter of the impeller 3 matches the diameter of the casing 1, which reduces the gap between the impeller 3 and the casing 1, increases the flow rate, total pressure and static pressure of the airflow, and thus increases the wind speed.

[0046] Since the same fan will show different performance under different working conditions, the existing axial flow fan is measured under different working conditions. The measured data are shown in Table 1:

[0047] Table 1:

[0048]

[0049] Similarly, the axial flow fan with a hub ratio of 0.5 in this embodiment is measured under the same working conditions, and the measured data are shown in Table 2:

[0050] Table 2:

[0051]

[0052]

[0053] Comparing the data in Table 1 and Table 2, under the same power, the flow rate, total pressure and static pressure of this embodiment in various working conditions are higher than those of the axial flow fan in the prior art.

[0054] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific implementations of the present invention without paying creative labor, and these methods will fall within the scope of protection of the present invention.

Claims

1. An axial flow fan with a hub ratio of 0.5, comprising a casing, a motor and an impeller; characterized in that: The motor is installed in the housing through a motor cylinder; The impeller is connected to the output shaft of the motor through a hub, and the ratio of the diameter of the hub to the diameter of the impeller is 1:2; The impeller is composed of a plurality of curved blades, the middle of the blades being connected to the hub; the angle α between the curved surface of the blades and the middle of the blades is 18 to 25°; the thickness A of the circumferential section of the blades is 152 to 155 mm; An S-shaped guide vane is provided between the inner wall of the casing and the outer surface of the motor barrel, the guide vane is evenly distributed along the circumference of the outer surface of the motor barrel, and the middle part of the guide vane is provided with a first curved surface and a second curved surface at both ends along the horizontal axis direction of the casing respectively; The included angles between the first curved surface and the second curved surface of the guide vane and the middle part of the guide vane are both 17-25 degrees.

2. The axial flow fan with a hub ratio of 0.5 according to claim 1, characterized in that: The impeller is provided with 8 blades, and the blades are symmetrically arranged on the circumferential outer surface of the hub.

3. The axial flow fan with a hub ratio of 0.5 according to claim 2, characterized in that: The air inlet inside the casing is provided with a fairing, the air outlet inside the casing is provided with a rectifier, the fairing is fixed to the front end of the impeller and rotates with the impeller, and the rectifier is fixed to the rear end of the motor barrel; the fairing is semi-spherical, and the rectifier is truncated conical.

4. The axial flow fan with a hub ratio of 0.5 according to claim 1, characterized in that: The number of guide vanes arranged between the inner wall of the casing and the outer surface of the motor barrel is 8.

5. The axial flow fan with a hub ratio of 0.5 according to claim 4, characterized in that: The distance B from the middle of the impeller blades to the connection between the hub and the output shaft of the motor in a direction parallel to the output shaft is 58-59 mm.

6. The axial flow fan with a hub ratio of 0.5 according to claim 5, characterized in that: The diameter of the impeller is 998-999 mm, and the diameter of the casing is 1014-1015 mm.

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