Centrifugal fan for high-efficiency, low-noise, ultra-high specific speed motor

Abstract

A centrifugal fan for a high-efficiency, low-noise, ultra-high specific speed motor, including a front cover, a rear cover and fan blades. The front cover and the rear cover are respectively provided with slots at the front and back, and the slots are along the front cover and the rear. The circumferential direction of the cover plate corresponds to and evenly arranges several fan blades between the corresponding slots of the front cover plate and the rear cover plate, the middle part of the front cover plate is the air inlet, and the outer periphery between the front cover plate and the rear cover plate The edge is the air outlet, and the middle part of the rear cover is provided with a shaft sleeve; the radius of the single-arc airfoil of the fan blade is 250-300mm, the installation angle of the fan blade inlet is 20-25°, and the installation angle of the fan blade outlet is 15-20°. The air inlet attack angle is ‑3°, the air outlet lag angle is 2°, and the hub ratio is 0.7. The fan blade designed by the invention has excellent aerodynamic performance and effectively reduces the mechanical loss of the motor. At the same time, it is verified by experiments that the overall noise of the motor using the fan is reduced by 2dB, which meets the low noise requirement of the motor.

Description

technical field [0001] The invention belongs to the technical field of motors, and in particular relates to a centrifugal fan for a high-efficiency, low-noise and ultra-high specific speed motor. Background technique [0002] The fan is the head element of the motor ventilation system. It maintains the required air volume of the motor together with the head action of the rotor rotation and cools the motor. The design and selection of the motor fan directly affects the performance indicators such as the temperature rise, efficiency and noise of the motor. Due to the diversity and particularity of the motor ventilation structure, the selection of conventional axial fans or centrifugal fans often cannot meet the requirements of motor performance indicators. . For example, the external air duct cooling system of a box-type motor requires an air-cooled fan that requires axial inlet air and radial air outlet. The air volume and air pressure parameters are determined according to ...

AI Technical Summary

Problems solved by technology

The design and type selection of the motor fan directly affect the temperature rise, efficiency, noise and other performance indicators of the motor. Due to the diversity and particularity of the motor ventilation structure, the selection of conventional axial flow fans or centrifugal fans often cannot meet the performance requirements of the motor.

For example, the external air passage cooling system of a box-type motor requires an air-cooling fan with axial air inlet and radial air outlet. The air volume and air pressure parameters are determined according to the ventilation and heat dissipation of the motor and the wind resistance coefficient of the external air passage. It is necessary to select a fan with a specific speed of 32. According to the specific speed selection, this fan belongs to the typical selection range of axial flow fans with large flow coefficient and small pressure coefficient. Due to the axial flow in and out of the axial flow fan, the air impacts the wind cover, the air path is not smooth, and large eddy current losses occur, resulting in The fan has low efficiency and high aerodynamic noise, which cannot meet the performance requirements of the motor. Therefore, an air-cooled centrifugal fan with axial air inlet and radial air outlet must be selected; the centrifugal fan with a specific speed of 32 has exceeded the limit of a conventional centrifugal fan with a specific speed of 16. For this kind of ultra-high specific speed centrifugal fan with large flow coefficient and small pressure coefficient, it is rare in China. Double-suction centrifugal fan is usually used in China. Its structure is complicated, and installation and maintenance are inconvenient. To meet the ideal demand, it is necessary to design and develop a high-efficiency, low-noise, ultra-high specific speed centrifugal fan to meet the performance requirements of the motor

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