Industry news

Heating problem of power tools brushless motor

It is normal for power tool brushless motor to generate heat during working, but they have a certain control range. Some users feel if there is a problem when they find fever. In fact, we need understand the cause of the fever from several aspects.

The coil has resistance, and the current flows through the power loss;
The magnetic field of the iron core has a "hysteresis loop", and part of the magnetic energy transformed by electric energy continues to be transformed into heat energy;
The iron core still has eddy currents, and part of the magnetic energy transformed by electric energy turns into electric current and then into heat energy;
There is friction between mechanical rotating parts, and part of the kinetic energy converted from electrical energy continues to be converted into heat energy.
Generator overload causes the load current and voltage to exceed the rated value
Load power factor is too low, Adjust the load so that the excitation current does not exceed the rated value
Speed is too low, Adjust the speed to the rated value
There is a partial short circuit in a winding of the generator. Find the short circuit, correct or replace the coil
The downwind duct is blocked, remove the obstacles, disassemble the motor, and completely clear the air ducts

It is normal for the power tools brushless motor to heat up to 70-90℃, as long as it is less than 130℃, there is no problem. If you really feel overheated, set the current of the driver to about 70% of the rated current of the motor or reduce the speed of the motor. . When there is no fault, it will also heat up under normal circumstances. Of course, the normal heating temperature will not be too high.

If we understand the reason for the heating of the power tools brushless motor, we can reasonably control it. If the temperature exceeds the normal range, stop work in time, make corresponding inspections, and solve the issue.

42mm bldc motor