Individual viewpoint, fan of lampblack machine, electric fan, exhaust fan, bathroom warm fan even air conditioning belongs to fan kind of home appliance product, these home appliance taste those who want to rely on the high speed of impeller to rotate drive air to flow fast ability to realize working purpose.
According to the ratio of the diameter of the fan impeller to the width of the disc, namely, "length-diameter ratio", the impeller can be divided into "single-sided dynamic balance type" impeller and "double-sided dynamic balance type" impeller.
2.1 when the diameter of the impeller is 7~10 times larger than the width of the impeller (i.e. the projected thickness on the side of the impeller), i.e. the length-diameter ratio is greater than l/10~1/7, it belongs to the single-sided dynamic balance impeller., electric fan, exhaust fan, etc all belong to this type, in this case, if find there impeller dynamic imbalance, only need to random part of the center of mass is located in the impeller diameter on the installation quality of a correction of the same moment, you can restore the deviation from the impeller axis of center of mass to the axis of position, make the impeller in balance (see figure 1).

2.2 for the impeller whose length-diameter ratio is less than 1/10~1/7, the above method is not applicable. The impeller whose length-diameter ratio is less than 1/10~1/7 belongs to "double-sided balanced" impeller.In double-sided balanced impeller, when the impeller is in the state of no power drive, if there are two equal mass configuration on both ends of the axis and the axis is symmetric, then the center of mass of the impeller does not show deviation from the axis of rotation, and the impeller is actually in a state of "static balance".However, once the impeller enters the high-speed rotating state, the centrifugal force generated by the two materials will constitute a couple, and the inertia axis of the impeller and the rotation axis will no longer coincide, resulting in strong vibration of the impeller's bearing;Or the two masses are not symmetrical, and the inertia axis and rotation axis are inclined, so the center of mass of the impeller deviates from the axis, and the vibration of the impeller increases obviously when it rotates.This is in the two - sided dynamic balance impeller in the most common dynamic imbalance.To eliminate this dynamic imbalance of the impeller, at least two planes need to be installed to correct the mass (see figure 2).
In addition, the fan type electrical appliances product impeller is generally a "cantilever" the rotor structure, which is only at one end of the impeller connected to the motor spindle bearing, wheel is in a suspended state, can be regarded as a structural mechanics on the cantilever beam structure, this is when to carry out the dynamic balance of lampblack analysis (see figure 2) can not be ignored.

After knowing the type of dynamic balance of the impeller, we can judge the type of dynamic balance of the lampblack machine impeller belongs to cantilever type two-sided dynamic balance impeller.In the design, manufacture, installation, application and maintenance of lampblack machine, it is very critical to realize the type of dynamic balance of lampblack machine impeller.
2.3 according to the collected data of lampblack machine impeller, it is believed that most of the impeller selected in the current lampblack machine production should belong to cantilever type double-sided dynamic balance impeller.From the author apart, measured by the various lampblack machine impeller, it seems, at this stage of lampblack machine impeller diameter is usually around 200 mm (slightly smaller in diameter is 190 mm, slightly larger diameter is 220 mm), in accordance with the "single balance type" and "double balance" type of impeller impeller partition method, if the calculation is based on the 210 mm diameter of the impeller, the impeller of the width (due to the widely adopted in the machine of oil absorption smoke is centrifugal impeller, look from flank the state its width is very obvious) shall be between 21 and 30 mm;That is to say, when the width of the impeller of the lampblack machine is no more than 30mm, diameter of 210mm of the impeller can be used to balance the impeller in a single-sided way to balance the center of mass, in order to ensure that the lampblack machine in high-speed operation will not be due to the impeller dynamic balance of abnormal vibration phenomenon.The author has been paying careful attention to the dynamic balance of the impeller of the range hood.In the structure of dissembling and measure all kinds of oil absorption, will pay special attention to oil absorption structure characteristics of the impeller, and in zhejiang, jiangsu, guangdong and other oil absorption plant investigation, to specifically know the manufacturer's control in the impeller dynamic balance problems, and observed that some manufacturers are actually adopt the way of dealing with single balanced impeller dynamic balance to deal with double-sided balance dynamic balancing problem of type impeller.
In fact, this problem is very easy to find: if the impeller belongs to the two-sided dynamic balance type, then the impeller should be observed at least 2 balanced pieces;If the impeller belongs to the type of dynamic balance between two sides, and only one balancing sheet is observed, it can be considered that the way to deal with the dynamic balance of the impeller is not appropriate.