The future of the motor will be “brushless” after all! The advantages and disadvantages, function and life of brushless motors! |

Summary

Brushless DC motors have flooded into various industries like a mad wave, becoming a well-deserved rising star in the motor industry. Can we make a bold guess – in the future, the motor industry will enter the “brushless” era?

Brushless DC motors do not have brushes and commutators, hence their name. It consists of a motor body and a driver, and is a typical mechatronic product. As a “newcomer” in the motor industry, although the history of brushless DC motors entering China is not long, and the price is higher than that of brushed motors, due to the obvious advantages of brushless motors, the development momentum can be described as rapid. After entering China, it was quickly favored by industries such as home appliances, automobiles, ships and machinery, and occupied a place in various industries and developed rapidly.

Why do brushless motors have a place?

The low price is undoubtedly the focus of the industry’s attack on brushless motors, so why can it still occupy a place in the motor market in a short period of time? In fact, this is similar to Apple’s. As long as the use effect and quality can be guaranteed, it can attract loyal consumers. For example, the price of Apple’s electronic products is higher than the average, but the market is still hot. Obviously, when quality and price can only be chosen, consumers with purchasing power will still give priority to the effect of use.

advantage:

(1) Brushless, low interference

The brushless motor removes the brush, and the most direct change is that there is no electric spark generated when the brushed motor is running, which greatly reduces the interference of the electric spark to the remote control radio equipment.

(2) Low noise and smooth operation

The brushless motor has no brushes, the friction force is greatly reduced during operation, the operation is smooth, and the noise will be much lower. This advantage is a huge support for the stability of the model.

(3) Long life and low maintenance cost

Without the brush, the wear of the brushless motor is mainly on the bearing. From a mechanical point of view, the brushless motor is almost a maintenance-free motor. When necessary, only need to do some dust removal maintenance. By comparing the previous and the next, you will know the advantages of the brushless motor over the brushed motor, but everything is not absolute. The brushless motor has excellent low-speed torque performance and large torque. The performance characteristics of the brushless motor are irreplaceable, but In terms of the ease of use of brushless motors, with the trend of cost reduction of brushless controllers and the development and market competition of brushless technology at home and abroad, the brushless power system is in the stage of rapid development and popularization, which also greatly promotes development of the model movement.

shortcoming:

(1) The friction is large and the loss is large

Old model friends have encountered this problem when playing with brushed motors in the past, that is, after using the motor for a period of time, it is necessary to turn on the motor to clean the carbon brushes of the motor, which is time-consuming and labor-intensive, and the maintenance intensity is no less than a household cleaning.

(2) The heat is large and the life is short

Due to the structure of the brushed motor, the contact resistance between the brush and the commutator is very large, resulting in a large overall resistance of the motor, which is easy to generate heat, and the permanent magnet is a heat-sensitive element. If the temperature is too high, the magnetic steel will be demagnetized. , so that the performance of the motor is degraded and the life of the brushed motor is affected.

(3) Low efficiency and low output power

The heating problem of the brushed motor mentioned above is largely due to the fact that the current does work on the internal resistance of the motor, so the electric energy is converted into heat energy to a large extent, so the output power of the brushed motor is not large, and the efficiency is not high.

The role of brushless motors

A brushless motor is also a device that converts electrical energy into mechanical energy. By consuming electrical energy, mechanical energy can be obtained to achieve certain purposes. What is the use of a brushless motor in general? It can be used in the small home appliance industry, such as the common electric fan. In fact, the brushless motor converts electrical energy into mechanical energy, and the electric fan will turn and bring you a cool feeling. In addition, the lawn mower in the garden industry actually uses a brushless motor. In addition, electric drills in the power tool industry also use brushless motors. The role of the brushless motor is to convert electrical energy into mechanical energy, so that it can play a role in everyone’s life and improve everyone’s quality of life.

Now brushless DC motor has been able to fully replace the speed regulation of DC motor, frequency converter + frequency conversion motor speed regulation, asynchronous motor + reducer speed regulation. It combines all the advantages of traditional DC motors while eliminating the carbon brush and slip ring structure, and has excellent torque characteristics. It has good torque performance at medium and low speed, large starting torque and small starting current, stepless speed regulation, wide speed regulation range, and strong overload capacity. Moreover, the current life of conventional brushed motors is about 10,000 hours, and the lifespan of brushless DC motors is several times longer.

In addition, because the brushless motor itself has no excitation and carbon brush losses, the multi-stage deceleration loss is eliminated, and the comprehensive power saving rate can reach 20%~60%, so the price difference with ordinary motors can only rely on power saving. After one year, the purchase cost will be recovered. In addition, the government has been advocating energy conservation and environmental protection in recent years. Brushless motors can be said to be the trend of motor development.

Post time: Jul-13-2022