DC Motors, Key Driver Solution in Nonindustrial Robotics

Electric motors are widely used in robotics, but in nonindustrial applications, DC types are the top choice as driving solutions. Compared to AC units, DC motors have advantages in high starting torque, constant torque, and quick starting, reversing and stopping. They have circuits that are easier to control, with three ways of varying their speed to requirement, and come in smaller and more lightweight configurations than AC types. Based on the same reactive power used, DC motors are compatible with electronic components. They are also called such because they can run on batteries, which is critical to applications where mobility is a must.

In the DC motor segment, there are brushed and brushless types, with the latter – referred to as “BLDC” – increasingly popular because they are smaller, lighter, quieter and more durable.

In China, BLDC motors currently dominate shipments and manufacturers’ R&D agenda. Suppliers interviewed by Global Sources believe that they will gradually replace brushed and stepper types as the standard in this application in the next few years. Brushed units, however, will continue to be produced as a low-priced alternative.

Rise of nonindustrial robots

Robots are no longer exclusive to factories, but are finding increasing use in the consumer, enterprise, hospitality, healthcare, agriculture and autonomous vehicle spheres performing easy to complex tasks.

Globally, the market for nonindustrial robotics is projected to reach more than $230 billion by 2025, according to Timothy Owen in a report on Statista. “The industrial robotics market has traditionally represented the robotics industry and has been led by Japanese and European robotics manufacturers, but has given way to non-industrial robots, such as personal assistant robots, customer service robots, autonomous vehicles, and unmanned aerial vehicles (UAVs).”

The Chinese Institute of Electronics (CIE) gives a more conservative but nonetheless upbeat assessment, placing the robotics industry worldwide at $51.3 billion in 2022 and predicting it to exceed $65 billion by 2024. In its report, the market scale of industrial robots was $19.5 billion, service robots $21.7 billion and special robots $10 billion. In 2024, the respective values will be $23 billion, $29 billion and $13 billion, or a clear majority of $42 billion for the nonindustrial segment.

IEC said that China’s robotics market reached $17.4 billion in 2022 and will continue to expand in the next two or three years. By 2024, industrial and service robots are expected to narrow their gap based on respective estimates of $11 billion and $10 billion.

China’s DC motor supplier pool

Anticipating higher demand from the robotics market, Chinese manufacturers will sustain efforts to improve the performance of their DC motors while increasing their production capacity.

Some companies are investing in expansion projects. Guangdong Lepu allotted $36 million to the construction of a new factory with a total area of 20,677sqm. Once fully operational in the next one or two years, this facility will mostly be producing micromotors, and robotic and servo motors and is expected to generate a total turnover of about $88.23 million.

There are hundreds of suppliers of DC motors in China and more than half can cater to the robotics industry. Over 60 percent of these companies are domestically owned and most are small and midsize enterprises offering entry-level and midrange products. The leaders include Shenzhen Topband, Zhaowei Electric and Duowei Electric.

The foreign players with factories in China are mainly from the US, Europe and Japan. ABB, Nidec, Faulhaber and HDD are some of them.

In addition to robotics, all suppliers offer motors used in consumer electronics, vehicles, home appliances and medical devices.

Many companies are found in Changzhou, Ningbo, Suzhou, Kunshan, Shenzhen, Dongguan and Zhongshan.

China-made DC motors

Mainstream DC motors from Chinese manufacturers are brushed and brushless types in CW and CCW variants. These have a rated voltage of 3 to 24V, torque of 1gf.cm to 50kgf.cm, speed of 5 to 2,000rpm and efficiency of over 85 percent. In terms of diameter, the range is 3.4 to 38mm.

All products have built-in protection from over- and undervoltage, and overcurrent. Water-resistant units are available, usually with at least an IP65 rating.

Most companies offer DC motors that are CE-approved, UL-listed and RoHS-compliant.

Customization is widely practiced and extends to buyers’ preferred sources of stators, rotors, drivers and cases to be used.

So far, the cost of materials and components remains stable and is expected to keep prices of DC motors generally unchanged throughout 2023.

Here are DC motors for robotics applications, manufactured by suppliers vetted by Global Sources