How to choose vibration motor for screening equipment

How to determin power of the vibration motor for a device

The vibration motor is the power source of the vibrating screen. The power of the vibration motor should be selected according to the power required by the equipment, and try to make the vibration motor run under the rated load.

1. When choosing, you should pay attention to the following two points:

(1) If the power of the vibration motor is too small. The phenomenon of “small horse-drawn cart” will appear, causing the vibration motor to be overloaded for a long time. Its insulation is damaged due to heat, and even the vibration motor is burned.
(2) If the power of the vibration motor is selected too large, the phenomenon of “big horse-drawn trolley” will appear, the output mechanical power cannot be fully utilized, and the power factor and efficiency are not high, which is not only unfavorable to users and the power grid, but also cause power waste.

2. To correctly select the power of the vibration motor, the following calculations or comparisons must be carried out:

(1) For the continuous working mode of constant load, if the power of the load (that is, the power on the production mechanical shaft) Pl (kw) is known, the power P (kw) of the required vibration motor can be calculated as follows: P=P1/n1n2

n1=efficiency of production machinery; n2=efficiency of vibration motor or transmission efficiency.

The power obtained by the above formula is not necessarily the same as the product power. Therefore, the rated power of the selected vibration motor should be equal to or slightly larger than the calculated power.

Example: The power of a production machine is 3.95kw, and the mechanical efficiency is 70%. If a vibration motor with an efficiency of 0.8 is selected, how many kw should the power of the vibration motor be?

Solution: P=P1/ n1n2=3.95/0.7*0.8=7.1kw

Because there is no 7.1kw this – specification. So choose 7.5kw vibration motor.

 

(2) Vibration motors with short-term work quotas. Compared with the vibration motor with the same power and continuous work rating. The maximum torque is large, the weight is small, and the price is low. Therefore, when conditions permit, the vibration motor with short-term work quota should be selected as far as possible.

(3) For a vibration motor with a rated intermittent operation, the selection of its power should be based on the size of the load duration rate, and a vibration motor specially used for intermittent operation should be selected. The formula for calculating the load continuous string Fs% is:
FS%=tg/(tg+t1)×100%
tg=working time, t1=stop time min; tg+t1 is working cycle time min.