External rotor motor equipped with low-noise wing-shaped heat dissipation blades

Abstract

An external rotor motor provided with low-noise wing-shaped heat dissipation blades comprises a motor control box, a flow guide cover plate, a motor stator and a motor rotor, the motor control box, the flow guide cover plate and the motor stator are connected through bolts, the motor rotor is connected with the motor stator through a bearing, and the motor rotor is provided with a heat dissipation impeller rotating synchronously. Heat dissipation ribs are arranged in the motor control box, motor heat dissipation holes are formed in the motor stator, the positions of the motor heat dissipation holes correspond to the positions of the heat dissipation ribs, and a plurality of wing-shaped blades are formed on the upper surface of the heat dissipation impeller; according to the scheme, the arc-shaped blades are optimally designed into the wing-shaped blades, the front edges of the wing-shaped blades are smooth, the rear edges of the wing-shaped blades are sharp, and due to the design, airflow can pass through the surfaces of the blades more smoothly, the pressure on the surfaces of the blades is more uniform, turbulent flow on the surfaces of the blades is reduced, and pneumatic noise is lowered; the flow separation phenomenon on the blade surface can be greatly reduced, turbulent flow and vortex in a flow channel are reduced, and energy loss is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of outer rotor motor with low-noise airfoil-shaped radiating blade. BACKGROUND

[0002] The outer rotor motor is often used as driving component for axial flow and centrifugal fan, which is widely used for equipment heat dissipation and building ventilation. The sensitivity to noise in such application is very high. The aerodynamic noise generated by motor cooling fan is the main source of motor noise. Therefore, controlling or reducing the noise value of motor cooling fan is an important noise reduction method. In addition to copper loss and iron loss of motor itself, the mechanical loss of cooling fan cannot be ignored. Therefore, reducing the loss of cooling fan is also an effective method to improve the efficiency of motor.

[0003] The current motor radiating blade is mainly designed with equal-thickness circular-arc blade. The blade surface pressure is not uniform without adopting streamline design, which cannot avoid local high pressure and low pressure area, resulting in increased turbulence on blade surface and increased noise. The equal-thickness circular-arc blade design will generate impact and flow separation loss at blade leading edge and trailing edge, which will enhance the flow separation phenomenon on blade surface, resulting in turbulence and vortex generation and increased energy loss. SUMMARY

[0004] In view of the above problems, the utility model provides an outer rotor motor with low-noise airfoil-shaped radiating blade.

[0005] To achieve the above purpose, the utility model provides an outer rotor motor with low-noise airfoil-shaped radiating blade, which comprises a motor control box, a flow guide cover plate, a motor stator and a motor rotor. The motor control box, the flow guide cover plate and the motor stator are connected by bolts. The motor rotor is connected with the motor stator through bearings. The motor rotor is provided with a synchronous rotating radiating impeller. The motor control box is provided with radiating ribs. The motor stator is provided with motor radiating holes. The position of the motor radiating holes corresponds to the position of the radiating ribs.

[0006] The upper surface of the radiating impeller is formed with a plurality of airfoil-shaped blades distributed in a circle. The airfoil-shaped blade is formed with a closed profile surface composed of blade leading edge, blade pressure surface, blade trailing edge and blade suction surface.

[0007] The suction surface of a single airfoil-shaped blade is taken as X axis, its vertical direction is taken as Y axis, and the blade leading edge is taken as origin to establish a Cartesian coordinate system. The chord length of the airfoil-shaped blade is taken as b, and the following equation is obtained.

[0008] The projection curve of the blade pressure surface satisfies the equation Y=B1X 4 + B2X 3 + B3X2 + B4X 1 Wherein, B1=7.529*10 -1 + 0.06, B2=-2.232*10 -2 + 0.03, B3=2.606*10 -4 + 4.44*10 -5 , B4=-1.144*10 -6 + 2.25*10 -5 ;

[0009] The blade inlet angle M of the airfoil blade is between 30-40°, the blade outlet angle N of the airfoil blade is between 25-35°, the end of the blade leading edge and the end of the blade trailing edge are all treated with a circular arc, the radius R1 of the blade leading edge is 1.15%*b, and the radius R2 of the blade trailing edge is 0.76%*b.

[0010] Further, the number of the airfoil blades is 9-15.

[0011] Further, the motor rotor and the heat dissipation impeller are made of aluminum alloy material and are formed through a die casting process.

[0012] The utility model discloses a low-noise airfoil heat dissipation blade configuration outer rotor motor has the advantages that:

[0013] 1. The circular arc blade is optimized to be an airfoil blade, the airfoil blade leading edge is smooth, and the trailing edge is sharp. This design can make the airflow pass through the blade surface more smoothly, make the blade surface pressure more uniform, reduce the turbulence generation of the blade surface and reduce the aerodynamic noise.

[0014] 2. The airfoil blade adopts a streamline design, which can greatly reduce the flow separation phenomenon of the blade surface, reduce the turbulence and vortex in the flow channel, reduce the energy loss and improve the impeller efficiency. DRAWINGS

[0015] Figure 1 It is a perspective view of a low-noise airfoil heat dissipation blade configuration outer rotor motor.

[0016] Figure 2 It is a partial structure view of a low-noise airfoil heat dissipation blade configuration outer rotor motor.

[0017] Figure 3 It is a schematic view of a conventional heat dissipation impeller.

[0018] Figure 4 It is a schematic view of a heat dissipation impeller with airfoil blades.

[0019] Figure 5 Fig. 1 is a schematic diagram for establishing a Cartesian coordinate system on the airfoil blade;

[0020] Figure 6 Fig. 2 is a schematic diagram for blade inlet angle M, blade outlet angle N, blade leading edge radius R1, and blade trailing edge radius R2 on the airfoil blade;

[0021] Figure 7 Fig. 3 is a static pressure simulation nephogram of a conventional cooling impeller and a cooling impeller with airfoil blades;

[0022] Figure 8 Fig. 4 is a noise test diagram of a conventional cooling impeller and a cooling impeller with airfoil blades.

[0023] In the figure: 1, motor control box; 2, cooling rib; 3, flow guide cover plate; 4, motor stator; 5, cooling impeller; 51, airfoil blade; 6, motor rotor; 7, motor cooling hole; 8, blade leading edge; 9, blade pressure surface; 10, blade trailing edge; 11, blade suction surface. DETAILED DESCRIPTION

[0024] As shown in Figure 1 , Figure 2 , Figures 4~6 , the utility model discloses a kind of low-noise airfoil cooling blades of outer rotor motor of configuration, including motor control box 1, flow guide cover plate 3, motor stator 4, motor rotor 6, motor control box 1, flow guide cover plate 3, motor stator 4 are connected by bolt, motor rotor 6 is connected by bearing with motor stator 4, motor rotor 6 is equipped with synchronous rotation cooling impeller 5, cooling rib 2 is provided in motor control box 1, motor cooling hole 7 is set on motor stator 4, the position of motor cooling hole 7 and the position of cooling rib 2 form corresponding, the upper surface of cooling impeller 5 is formed with multiple airfoil blades 51 in circumferential distribution, airfoil blade 51 is formed closed profile by blade leading edge 8, blade pressure surface 9, blade trailing edge 10, blade suction surface 11;With the suction surface of single airfoil blade 51 as X axis, its vertical direction is Y axis, and with blade leading edge 8 as original point, Cartesian coordinate system is established, and the chord length of this airfoil blade 51 is set as b, then the projection curve of blade pressure surface 9 satisfies equation Y=B1X 4 + B2X 3 + B3X 2 + B4X 1 , wherein, B1=7.529*10 -1 + 0.06, B2=-2.232*10 -2 + 0.03, B3=2.606*10 -4 + 4.44*10-5 B4 = -1.144*10 -6 + 2.25*10 -5 ;

[0025] The blade inlet angle M of the airfoil blade 51 is between 30-40°, the blade outlet angle N of the airfoil blade 51 is between 25-35°, the end of the blade leading edge 8 and the blade trailing edge 10 are both treated with a circular arc, the radius R1 of the blade leading edge 8 is 1.15%*b, and the radius R2 of the blade trailing edge 10 is 0.76%*b;

[0026] The number of the airfoil blade 51 is 9-15; the motor rotor 6 and the heat dissipation impeller 5 are made of aluminum alloy and are formed through a die casting process.

[0027] The circular arc blade is optimized as the airfoil blade in the scheme, the airfoil blade leading edge is smooth and the trailing edge is sharp, which can make the airflow pass through the blade surface more smoothly, make the blade surface pressure more uniform, reduce the turbulence on the blade surface, reduce the aerodynamic noise; the airfoil blade is designed in a streamline shape, which can greatly reduce the flow separation on the blade surface, reduce the turbulence and vortex in the flow passage, reduce the energy loss, and improve the impeller efficiency.

[0028] In specific use, the utility model is described in combination with the drawings for the convenience of understanding the utility model;

[0029] The airflow enters from the heat dissipation ribs 2 on the motor control box 1, passes through the flow guide cover plate 3 and the heat dissipation ribs 2 below, passes through the motor heat dissipation holes 7, enters the heat dissipation impeller 5, and is discharged by the centrifugal force generated during rotation, and the entering normal temperature airflow exchanges heat with the heat dissipation ribs 2 built in the motor control box 1, so that the motor is cooled.

[0030] See Figure 7 , Figure 7 It is the static pressure simulation nephogram of the conventional heat dissipation impeller and the heat dissipation impeller with the airfoil blade, the low pressure area of the suction surface of the airfoil blade is obviously reduced, and the flow separation of the suction surface is obviously improved;

[0031] See Figure 8 , Figure 8 It is the noise test diagram of the conventional heat dissipation impeller and the heat dissipation impeller with the airfoil blade, under the same conditions, the noise value, the design of the airfoil blade reduces the sound pressure level by 5dB(A), and the noise is obviously improved.

[0032] The above only describes the preferred embodiments of the utility model and is not used to limit the utility model. For those skilled in the art, the utility model can be changed and varied in various ways. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. An outer rotor motor with low-noise airfoil-shaped cooling vanes, comprising a motor control box (1), a flow guide cover plate (3), a motor stator (4), and a motor rotor (6), the motor control box (1), the flow guide cover plate (3), and the motor stator (4) being connected by bolts, the motor rotor (6) being connected with the motor stator (4) by a bearing, the motor rotor (6) being provided with a synchronously rotating cooling impeller (5), the motor control box (1) being provided with cooling ribs (2), and the motor stator (4) being provided with motor cooling holes (7) corresponding to the positions of the cooling ribs (2), characterized in that: the upper surface of the cooling impeller (5) is formed with a plurality of circumferentially distributed airfoil-shaped vanes (51), the airfoil-shaped vane (51) being formed with a closed profile surface by a vane leading edge (8), a vane pressure surface (9), a vane trailing edge (10), and a vane suction surface (11); a Cartesian coordinate system is established with the vane suction surface of a single airfoil-shaped vane (51) as an X-axis, a vertical direction thereof as a Y-axis, and the vane leading edge (8) as an origin, and the chord length of the airfoil-shaped vane (51) is set as b, so that M, the vane inlet angle of the airfoil-shaped vane (51), is between 30 and 40 degrees, N, the vane outlet angle of the airfoil-shaped vane (51), is between 25 and 35 degrees, the end portions of the vane leading edge (8) and the vane trailing edge (10) are arc-shaped, the radius R1 of the vane leading edge (8) is 1.15%*b, and the radius R2 of the vane trailing edge (10) is 0.76%*b. The number of the airfoil-shaped vanes (51) is 9-15. The projection curve of the blade pressure surface (9) satisfies the equation Y = B1X 4 + B2X 3 + B3X 2 + B4X 1 , wherein B1 = 7.529*10 -1 + 0.06, B2 = -2.232*10 -2 + 0.03, B3 = 2.606*10 -4 + 4.44*10 -5 , B4 = -1.144*10 -6 + 2.25*10 -5 ; The motor rotor (6) and the cooling impeller (5) are made of aluminum alloy and formed by die casting.

2. An external rotor motor configured with low noise airfoil shaped cooling vanes as claimed in claim 1 wherein: ​ 3. An external rotor motor configured with low noise airfoil shaped cooling vanes as claimed in claim 2 wherein: ​

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