Volute tongue with bionic structure and volute using same

Abstract

The invention discloses a volute tongue with a bionic structure and a volute using the same. The outer contour lines of the volute tongue are respectively connected with molded lines in the volute and the inner walls of an expansion chamber; the volute tongue is provided with a plurality of wind guide tanks; and one end of each wind guide tank is connected with the molded lines in the volute, andthe other end of each wind guide tank is connected with the inner wall of the expansion chamber. The volute tongue and the volute provided by the invention are simple in structure and have the advantage of good noise reduction effect.

Description

technical field [0001] The invention relates to a volute tongue with a bionic structure and a volute case using the volute tongue. Background technique [0002] When the centrifugal fan is rotating, due to the existence of the volute tongue, the gap between the volute tongue and the edge of the blade outlet is much smaller than that of other parts of the volute. The rotating blade passage passes the volute tongue, and the air at the volute tongue will appear periodic pressure. And speed pulsation, produce higher rotating noise, its frequency is blade passing frequency f=Z·n / 60(Hz). High rotational noise usually forms unpleasant whistling noise, which pollutes the environment. For those equipment that require low noise, such as air conditioners, it will deteriorate the sound quality. [0003] Not only that, for centrifugal fans, the rotating noise usually indicates that the flow field at the outlet of the volute tongue is disturbed, causing the expansion of the recirculation...

AI Technical Summary

Problems solved by technology

High rotational noise usually forms unpleasant howling noise and pollutes the environment. For those equipment that require low noise, such as air conditioners, it will deteriorate the sound quality

[0003] Not only that, for centrifugal fans, the rotating noise usually indicates that the flow field at the outlet of the volute tongue is disturbed, causing the expansion of the recirculation area, which is most obvious at low flow rates. The disordered flow field increases the radial periodic pulsation force of the impeller, resulting in The radial swing increases, forming a vicious circle; this radial vibration will be transmitted to the shaft of the fan motor, causing the radial clearance of the front end bearing of the motor and the gap between the stator and rotor of the motor to change, resulting in disturbance of the magnetic field of the stator and rotor of the motor, resulting in 2, 4 times power frequency electromagnetic noise and tooth harmonic noise

[0004] The existing methods for reducing the discrete rotation noise of the centrifugal fan are: 1. Increase the gap t of the volute tongue; 2. Increase the radius r of the volute tongue; 3. Use an inclined volute tongue; 4. Use unequal distance blades or oblique 5. Use perforated plate volute tongue muffler, etc. Patent document CN1270281 discloses "stepped volute tongue noise reduction volute", which reduces noise to a certain extent; CN201277205Y discloses a "noise reduction centrifugal fan" , using double-layer volutes with micro-perforations and sound-absorbing volutes; CN101509506A discloses a "bionic coupling noise-eliminating and noise-reducing volute tongue", the above three structures are complex in design, difficult to manufacture, and do not consider fan rotation noise at the same time The design of the volute tongue and motor noise, the noise reduction effect is not ideal

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