A heat dissipation fan and a motor size selection method thereof

Abstract

The application relates to a method for selecting the size of a motor of a heat dissipation fan. A matching motor can be quickly and correctly selected through a relational expression A*D*S=2.63B*C(1+ / -15%), and the overall shape of a fan frame is determined, so that the fan provided with the motor has proper air volume and air pressure.

Description

TECHNICAL FIELD

[0001] The present application relates to a heat dissipation fan and a motor size selection method thereof. BACKGROUND

[0002] Please refer to Figure 1 Chinese Patent No. CN104141620B "Axial flow heat dissipation fan and motor size selection method thereof", the axial flow heat dissipation fan includes a fan frame 1, a stator set 2 and a fan wheel 3, the stator set 2 is arranged inside the fan frame 1, the fan wheel 3 is rotatably arranged on the stator set 2, so as to drive the fan wheel 3 to rotate by means of the stator set 2. The fan frame 1 has a flow channel 11 inside, the flow channel 11 extends along the axial direction of the fan frame 1, the two ends of the flow channel 11 are the air inlet and the air outlet of the fan frame 1, the flow channel 11 has a minimum inner diameter A, the stator set 2 has a maximum outer diameter B, and A = (2.58B-9.54) ± 15%, the maximum outer diameter B of the stator is greater than 10mm, the designer can quickly and correctly select the matching fan frame and motor, the fan can produce appropriate air volume and air pressure, and the axial flow heat dissipation fan can have good fan performance.

[0003] However, the variable of the above relationship is the minimum inner diameter A of the flow channel, but the overall shape of the overall fan frame 1 and the motor cannot be directly determined only by the minimum inner diameter A of the flow channel. In the axial flow fan, the factors actually affecting the air volume and the air pressure are not only the flow channel shape (the minimum inner diameter A of the flow channel) mentioned in the patent, but also the actual wind sweeping area of the fan blade, the actual effective height of the stator assembly and other factors. In actual research and design, the minimum inner diameter A of the flow channel is relatively easy to determine. Therefore, the relationship disclosed in the patent cannot correctly develop a fan with good performance.

[0004] Specifically, since the axial flow heat dissipation fan is generally used to be installed in electronic equipment, in the development and design process, the axial flow heat dissipation fan is generally designed based on a fixed and limited internal space reserved in the electronic equipment. As described in the patent, a suitable maximum outer diameter B of the stator can be designed based on only the minimum inner diameter A of the flow channel, or a suitable minimum inner diameter A of the flow channel can be designed based on only the maximum outer diameter B of the stator. It is impossible to achieve this. SUMMARY

[0005] The purpose of the present application is to provide a heat dissipation fan and a motor size selection method thereof, which can quickly and correctly select a matching motor, so as to ensure that the heat dissipation fan assembled with the motor can produce appropriate air volume and air pressure during operation, thereby having good fan performance.

[0006] The purpose of the present application is achieved by the following technical solutions:

[0007] A motor size selection method of a cooling fan, comprising: step one: providing a cooling fan, the cooling fan having a fan frame, a stator assembly and a rotor assembly, the stator assembly and the rotor assembly being arranged in the fan frame, the rotor assembly comprising a fan wheel, the fan wheel comprising a hub and a plurality of fan blades, the stator assembly comprising a steel sheet set and a coil set wound on the steel sheet set; step two: selecting a maximum outer diameter A of the fan wheel, i.e. a maximum outer diameter of the rotor assembly, and then selecting a maximum height D of the plurality of fan blades; step three: selecting a maximum effective height C of the stator assembly, i.e. a maximum height of the coil set; step four: selecting a speed coefficient S, and the outer diameter B of the stator assembly being calculated according to the relationship: "A*D*S=2.63B*C(1±15%)"; wherein, when the rated speed of the cooling fan is higher than 10,000 rpm, the speed coefficient S is 1.2, and when the rated speed of the cooling fan is lower than or equal to 10,000 rpm, the speed coefficient S is 0.8.

[0008] Further, the maximum outer diameter A of the fan wheel is greater than or equal to 25 mm and less than or equal to 90 mm.

[0009] Further, the maximum effective height C of the stator assembly is greater than or equal to 3 mm and less than 25 mm.

[0010] Further, the maximum height D of the fan blade is greater than or equal to 4 mm and less than or equal to 25 mm.

[0011] The application also includes a cooling fan, comprising a fan frame, a stator assembly and a fan wheel, the fan frame having a shaft pipe formed therein, the shaft pipe being hollow and open upward; the fan frame is provided with an axial flow channel, the shaft pipe being formed in the flow channel, and the stator assembly being arranged in the flow channel of the fan frame and comprising a steel sheet set and a coil set wound on the steel sheet set; the fan wheel is rotatably arranged in the shaft pipe and spaced from the stator assembly to form a magnetic gap, the fan wheel comprising a hub and a plurality of fan blades extending outward from the hub; wherein the fan wheel has a maximum outer diameter A, the fan blades have a maximum height D, the stator assembly has a maximum effective height C, the maximum effective height C being the maximum height of the coil set, and the outer diameter B of the stator assembly satisfying the relationship: "A*D*S=2.63B*C(1±15%), wherein S is a speed coefficient, the speed coefficient S being 1.2 when the rated speed of the fan wheel is greater than 10,000 rpm, and the speed coefficient S being 0.8 when the rated speed of the fan wheel is less than or equal to 10,000 rpm.

[0012] Further, a magnetic assembly is fixed to the inner surface of the hub and is arranged corresponding to the stator assembly to form the magnetic gap, the hub is fixed to the rotating shaft, and the rotating shaft is rotatably combined in the shaft tube.

[0013] Further, the outer diameter B of the stator assembly is the maximum outer diameter of the steel sheet group.

[0014] Further, the maximum outer diameter A of the fan wheel is greater than 25 mm and less than 90 mm.

[0015] Further, the maximum effective height C of the stator assembly is greater than or equal to 3 mm and less than or equal to 25 mm.

[0016] Further, the maximum height D of the fan blade is greater than or equal to 4 mm and less than or equal to 25 mm.

[0017] Compared with the prior art, the application has the following beneficial effects: the matching motor can be quickly and correctly selected, so that the heat dissipation fan provided with the motor has proper air volume and air pressure. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a schematic diagram of a fan in the prior art;

[0019] Figure 2 is a schematic diagram of a cross section of a heat dissipation fan in the preferred embodiment of the application;

[0020] Figure 3 is a schematic diagram of a top view of a heat dissipation fan in the preferred embodiment of the application. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the application more clear, the application will be further described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and do not limit the application.

[0022] In order to illustrate the technical scheme described in the application, the following will be described by specific embodiments.

[0023] As shown in Figures 2 to 3 is a schematic diagram of a heat dissipation fan disclosed in the application, the heat dissipation fan comprises a fan frame 10 and a stator assembly and a rotor assembly arranged in the fan frame 10, wherein the stator assembly and the rotor assembly form a motor. In the application, the heat dissipation fan is an axial fan heat dissipation fan.

[0024] Specifically, the fan frame 10 is formed with an axle pipe 13, which is hollow and open upward, and the stator assembly is sleeved on the axle pipe 13. The rotor assembly includes a fan wheel, a magnetic assembly 1122 and a rotating shaft 1121. The fan wheel includes a hub 121 and a plurality of fan blades 122. The magnetic assembly 1122 is arranged on the inner annular surface of the hub 121 and is correspondingly arranged with the stator assembly. The rotating shaft 1121 is fixedly connected with the hub 121. The stator assembly has an axle hole. The stator assembly is sleeved on the outer periphery of the axle pipe 13 through the axle hole. The rotating shaft 1121 of the rotor assembly is arranged in the axle pipe 13. The rotor assembly is driven to rotate by the stator assembly.

[0025] Specifically, the stator assembly includes a base plate (not numbered), a steel sheet group 1111, an insulating sleeve group 1112 and a coil group 1114. The base plate is sleeved on the outer periphery of the axle pipe 13. The coil group 1114 is powered to drive the rotor assembly to rotate. The steel sheet group 1111 includes a plurality of steel sheets arranged in a stacked manner and an insulating sleeve group 1112 integrally fixed to the outer periphery of the plurality of steel sheets arranged in a stacked manner. The coil group 1114 is wound on the steel sheet group 1111 in a specific pattern to form a plurality of magnetic shoes (not numbered). In this application, the specific structure of the stator assembly is a known technology in the industry, which will not be described in detail here.

[0026] Specifically, the rotor assembly is sleeved on the outer periphery of the stator assembly, and a plurality of fan blades 122 are arranged around the outer periphery of the hub 121. In this application, the plurality of fan blades 122 can be integrally formed with the hub 121 by injection molding (for example, the hub 121 is made of metal material, and the fan blades 122 are made of plastic material; or the hub 121 is made of plastic material, and the fan blades 122 are made of plastic material; or the hub 121 is made of plastic material, and the fan blades 122 are made of metal material). In other embodiments, the plurality of fan blades 122 and the hub 121 can also be manufactured by assembly (for example, the hub 121 is made of metal material, and the fan blades 122 are made of metal material, which are fixed by welding, etc.).

[0027] Please refer to Figure 2 and in combination with Figure 3 It is defined that the maximum outer diameter of the rotor assembly is A in the embodiment of the application. The maximum outer diameter of the steel sheet group 1111 is defined as B. The maximum height of the coil group 1114 is defined as C (that is, the maximum effective height of the stator assembly). The maximum height of the fan blade 122 is defined as D. In addition, the maximum radial width of the cooling fan is defined as W, and the maximum axial height of the axial cooling fan is defined as L.

[0028] In principle, the larger the size of the heat dissipation fan, the greater the air volume it can generate, and the better the heat dissipation effect. However, the heat dissipation fan disclosed in the present application is generally used to be installed in an electronic device, and its size is restricted by the internal space of the electronic device. During the development and design process, the heat dissipation fan is generally designed based on a fixed and limited internal space reserved in the electronic device. In other words, the maximum radial width W and the maximum axial height L of the finally designed heat dissipation fan are determined by the size of the internal space reserved in the electronic device.

[0029] That is, in actual setting, the A value, the C value, the D value, and the B value can be obtained by simple design calculation based on the maximum size (W, L) of the axial flow heat dissipation fan that can be designed. For example, the maximum outer diameter A of the rotor assembly can be obtained by subtracting the thickness of the outer frame wall of the fan frame 10 from the maximum radial width W of the axial flow heat dissipation fan that can be designed, and then subtracting the design gap reserved between the inner wall surface of the outer frame wall of the fan frame 10 and the rotor assembly. The thickness of the outer frame wall of the fan frame 10 is determined by the required structural strength and material (i.e., there is a minimum design value), and the design gap reserved between the inner wall surface of the outer frame wall of the fan frame 10 and the rotor assembly is also a parameter that needs to be controlled in the design (i.e., there is a minimum design value), which is basically a constant value that can be controlled in the design. Therefore, the maximum value of the maximum outer diameter A of the rotor assembly that can be designed is basically a value that can be obtained by simple design calculation.

[0030] Similarly, based on the existence of the design maximum value of the maximum radial width W and the maximum axial height L, the design maximum value of the C value and the D value can also be obtained by simple design calculation.

[0031] Under the premise that the A value, the C value, and the D value are determined, the size of the B value will directly affect the air volume performance of the axial flow heat dissipation fan. In principle, the larger the B value is designed, the greater the driving force the motor can generate, but the design space left for the fan blade 122 will become smaller, and the driving area of the fan blade 122 will also affect the size of the air volume. The smaller the B value is designed, the smaller the driving force the motor can generate, but the design space left for the fan blade 122 will become larger. Therefore, how to balance the two is the key to the design of the present application, and solving this problem can realize the rapid selection of the size of the motor.

[0032] In the product design verification process, the specific dimensions (A value, B value, C value and D value) of the axial flow cooling fan which can achieve the preset air volume and air pressure during operation and has good fan performance are measured, the change trend of A value, B value, C value and D value is compared, and the change trend of the values is analyzed by using statistical analysis and regression analysis, and the following relationship is obtained: A*D*S=2.63B*C (1±15%), and B value is greater than or equal to 12 mm; wherein S is a speed coefficient, that is, the rated speed of the pre-designed axial flow cooling fan, and satisfies: when the rated speed is greater than 10,000 rpm, the speed coefficient S is selected as 1.2, and when the rated speed is less than or equal to 10,000 rpm, the speed coefficient S is selected as 0.8.

[0033] In addition, the maximum outer diameter A is preferably 25-90 mm (including the end value); the maximum effective height C is preferably 3-25 mm (including the end value); and the maximum height D is preferably 4-25 mm (including the end value).

[0034] Accordingly, the present design can provide a motor size selection method for a cooling fan, and the steps are as follows:

[0035] Step 1: according to the actual design requirements, a cooling fan with a maximum radial width W and a maximum axial height L is set;

[0036] Step 2: the A value, C value and D value are obtained by design calculation;

[0037] Step 3: according to the actual design requirements, the speed coefficient S is selected, when the required design rated speed is greater than 10,000 rpm, the speed coefficient S is selected as 1.2, and when the required design rated speed is less than or equal to 10,000 rpm, the speed coefficient S is selected as 0.8.

[0038] Step 4: the A value, C value, D value and S value are substituted into the relationship formula "A*D*S=2.63B*C (1±15%), B≥12 mm", and the actual effective design range of B value is calculated.

[0039] In this way, the designer can quickly and correctly select a matching motor to ensure that the cooling fan assembled with the motor can generate appropriate air volume and air pressure during operation, thereby having good fan performance. The maximum outer diameter A of the fan wheel is greater than or equal to 25 mm and less than or equal to 90 mm, the maximum effective height C of the stator assembly is greater than or equal to 3 mm and less than or equal to 25 mm, and the maximum height D of the fan blade is greater than or equal to 4 mm and less than or equal to 25 mm.

[0040] In addition, for the cooling fan with high fan performance requirements, the relationship formula "A*D*S=2.63B*C (1±10%), B≥12 mm" must be met.

[0041] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0042] Furthermore, it should be appreciated that each of the embodiments described herein is not required, but rather, merely exemplary. Accordingly, the embodiments described herein are not intended to be limiting, but rather, are exemplary and are merely representative of the subject matter described herein.

Claims

1. A method of selecting a size of a motor for a heat dissipating fan, characterized by, It includes: Step 1: provide a cooling fan, the cooling fan has a fan frame (10), a stator assembly and a rotor assembly, the stator assembly and the rotor assembly are arranged in the fan frame (10), the rotor assembly includes a fan wheel, the fan wheel includes a hub (121) and a plurality of fan blades (122), the stator assembly includes a steel sheet group (1111) and a coil group (1114) wound on the steel sheet group (1111); Step 2: select the maximum outer diameter A of the fan wheel, that is, the maximum outer diameter of the rotor assembly, and then select the maximum height D of the plurality of fan blades (122); Step 3: select the maximum effective height C of the stator assembly, that is, the maximum height of the coil group (1114); Step 4: select the speed coefficient S, the value of the outer diameter B of the stator assembly is calculated by the relationship "A*D*S=2.63B*C(1±15%)"; Wherein, when the rated speed of the cooling fan is higher than ten thousand revolutions per minute, the speed coefficient S is 1.2, and when the rated speed of the cooling fan is less than or equal to ten thousand revolutions per minute, the speed coefficient S is 0.8; The maximum outer diameter A of the fan wheel is greater than or equal to 25mm and less than or equal to 90mm; The maximum effective height C of the stator assembly is greater than or equal to 3mm and less than or equal to 25mm; The maximum height D of the plurality of fan blades (122) is greater than or equal to 4mm and less than or equal to 25mm.

2. A heat dissipating fan characterized by, It includes: A fan frame (10) provided with an axially extending flow channel and an axle pipe (13) formed in the flow channel; A stator assembly arranged in the flow channel of the fan frame (10), including a steel sheet group (1111) and a coil group (1114) wound on the steel sheet group (1111); A fan wheel (12) rotatably arranged in the axle pipe (13) and spaced from the stator assembly to form a magnetic induction gap, the fan wheel (12) includes a hub (121) and fan blades (122) extending outward from the outer periphery of the hub (121); wherein, The fan wheel (12) has a maximum outer diameter A; In the axial direction of the axle pipe (13), the fan blade (122) has a maximum height D, and the stator assembly has a maximum effective height C, which is the maximum height of the coil group (1114); The outer diameter B of the stator assembly satisfies the relationship "A*D*S=2.63B*C(1±15%)", wherein S is the speed coefficient; Wherein, when the rated speed of the fan wheel (12) is greater than ten thousand revolutions per minute, the speed coefficient S takes the value 1.2, and when the rated speed of the fan wheel (12) is less than or equal to ten thousand revolutions per minute, the speed coefficient S takes the value 0.8; The outer diameter B of the stator assembly is the maximum outer diameter of the steel sheet group (1111); The maximum outer diameter A of the fan wheel (12) is greater than or equal to 25mm and less than or equal to 90mm; The maximum effective height C of the stator assembly is greater than or equal to 3mm and less than or equal to 25mm; The maximum height D of the fan blade (122) is greater than or equal to 4mm and less than or equal to 25mm.

3. The heat dissipating fan according to claim 2, wherein, Further comprising a magnetic assembly (1122) and a rotating shaft (1121), the magnetic assembly (1122) is fixed to the inner ring surface of the hub (121) and is correspondingly arranged with the stator assembly to form the magnetic gap, the hub (121) is fixed with the rotating shaft (1121), and the rotating shaft (1121) is rotationally combined in the shaft tube (13).

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