1. Home
  2. Knowhow

How to increase the power of DC motor?

Date:2023-08-08   Author:XINDA MOTOR
This should be considered from three aspects, that is, the design and manufacturing price range, and how to create a motor with greater power On the basis of the existing finished motor, how to increase the power? Divided into two major measures, transforming existing motors, generally targeting old motors. Change the motor ventilation and heat dissipation method for new motors.

The usual way to design and manufacture motors with higher power is to increase the iron core, increase the cross-sectional area of the winding, increase the voltage, and increase the number of turns of the winding.

For the old motors of existing finished products, the power can be increased through transformation. The insulation level of old motors is generally low, and the maximum temperature resistance is only 130 degrees. The motor can be repaired by using new insulation materials with a temperature resistance of 180 degrees or even 200 degrees, and the power of the motor can be increased. In addition, the thickness of the previous insulation material is relatively large, and a new type of insulation material with a smaller thickness can be used, so that the cross-sectional area of the winding can be appropriately increased, and the power can also be increased.

For existing finished products and new machines, there is not much room for transformation and it is not cost-effective. But the motor has a characteristic, that is, for a motor that can run for a long time (more than 8 hours), the output power is not its maximum power, and the rated power is often only half of the maximum power.

This is because when the motor is energized and running, the winding will heat up and the temperature will rise. When the temperature rises above the withstand temperature of the winding insulation material, the insulation material will be damaged, which is commonly known as motor burnout. In order not to cause the temperature of the motor to be too high, it is necessary to allow the motor to run at reduced power instead of working at the maximum power state.

Therefore, for a finished motor that leaves the factory, in addition to specifying the rated power, rated temperature rise or temperature, rated parameters such as voltage, current , ambient temperature, and heat dissipation method must also be specified. In fact, these rated parameters are ultimately to ensure that the motor temperature does not exceed the standard.

To this end, as long as we can control the temperature and not exceed the standard, it is still feasible to increase the motor power appropriately. For example, to reduce the ambient temperature, the rated operating ambient temperature of the general motor is 40 degrees, so the power can be increased to run at zero ambient temperature. Another thing is to change the heat dissipation method. If it is natural cooling, it should be changed to forced ventilation cooling. If it is only the ventilation cooling of the shell, it can be changed to internal forced ventilation cooling. These measures can increase the power of the motor to run, while keeping the temperature not exceeding the standard.

The specific implementation is generally at the carbon brush end of the DC motor, and a ventilation pipe is installed to connect the blower, so that the wind is forced into the motor and comes out from the other end of the motor. Since the carbon brush and commutator are the main heating components of the DC motor, the air should be taken in from this end.

After this transformation, it is no problem to increase the power by 20%. In actual operation, as long as the temperature does not exceed the standard, the power can continue to be increased. And this method is not limited to DC motors, AC motors are also applicable.

To increase the power of a DC motor can be considered from two aspects, one is to increase the input voltage, and the other is to reduce the motor impedance and increase the input current. However, for a certain finished motor, the voltage and current already have rated values, so the increase of the motor power must be limited to the upper limit of the rated value. In other words, the motor power cannot be increased arbitrarily. Overloading is not worth the candle.