The key to balancing a tunnel fan rotor is to find out where the impeller is, determine the mass of the extra counterweight, and find the balance by drawing. Specific steps are as follows:

 

(1) Turn on the tunnel fan, measure the fan amplitude A0 at point m that can well reflect the fan vibration after the fan is running stably with a vibrator, and stop the machine after recording;

 

 

 

(2) The front plate, rear plate and circumference of the impeller are divided into 1 point, 2 points and 3 points respectively.

(3) The self-made clamp P is clamped at a point, and its quality depends on the size of the fan impeller. Generally MP=150-300g, repeat procedure 1, measure the amplitude A1 of point m

 

 

 

(4) Adjust the position of block p to point 2 and point 3, repeat step 3, and measure the amplitudes A2 and A3 of point m in sequence

 

 

 

(5) In the figure, A0 is the radius, O is the center of the circle, and the circle is divided into three parts: O1, O2, and O3; O1 is the center, A1 is the radius; O2 is the center, A2 is the radius; O3 is the center, and A3 is Radius; the above three arcs intersect with B, which are C and D respectively;

 

 

 

(7) For BCD, point O4 is a light point, connect O4, extend the intersection circle O to point O5, point O5 is a point with a heavy iron block, the length of O4 is l, and point O5 is m=MP×A0/2L;

 

 

 

(8) Find the actual O5 point on the front plate, rear plate and circumference of the impeller of the tunnel fan, and weld an iron block with a weight of m to complete the dynamic balance of the tunnel fan.

 

 

 

However, there is one more issue that needs to be clarified. When the fan is used, the bearing vibrates little when starting and produces noise. However, as the running time increases, the dust in the blower will adhere to the impeller unevenly, and the vibration that damages the dynamic balance bearing of the blower will gradually increase. When the vibration reaches the allowable maximum value of 11 mm/s (the amplitude value indicates the allowable maximum value is as follows), the inspection (dust removal, rebalancing) must be stopped.