The selection of hub motor for robot is essentially the result of adapting the driving scheme to the development needs of robot. Compared with traditional centralized driving schemes, hub motor meets the requirements of modern robot for flexibility, integration, and intelligence in terms of layout, power, and control. The core reason could be explored from five dimensions.

Advantage of structural layout: saving body space and simplifying transmission structure

Traditional robot driver mostly use a transmission chain of "motor reducer transmission shaft wheel/joint", which requires extra space to arrange transmission components. This not only increases the overall weight of the machine body, but also increases the design complexity of the mechanical structure. The hub motor integrates the power, transmission, and braking devices inside the wheel, directly outputting power to the load end, eliminating a series of transmission components such as the intermediate transmission shaft and reducer, which is equivalent to combining the power unit and the execution unit into one.

This integrated design frees up a lot of available space for the robot body: on the one hand, it can accommodate more sensors, batteries, or control modules, improving the robot's endurance and perception ability; On the other hand, it greatly simplifies the mechanical structure of the robot chassis or motion joints, reducing the overall design and assembly difficulty, especially suitable for compact mobile robots such as service robots, AGV logistics robots, legged robot joints, and other scenarios.

Advantage of motion control: Independent control is more flexible

For quadruped robots, each joint is independently equipped with a hub motor, which can achieve more accurate torque control. Combined with the robot's attitude perception algorithm, it can quickly adjust the gait to adapt to uneven road surfaces and improve the walking stability of the robot. In addition, multi wheel independent drive can also achieve richer motion modes. For example, the omnidirectional mobile robot can achieve translation in any direction through the combination of Mecanum wheels and wheel motors, perfectly adapting to the precise positioning requirements in automated workshops.

Power efficiency advantage: low transmission loss, improved endurance

The energy utilization rate directly determines the endurance performance of robot and is one of the core performance indicators of mobile robot. In traditional centralized drive schemes, power needs to go through multiple links such as gear meshing and transmission shaft, each of which generates varying degrees of mechanical friction loss. The overall transmission efficiency is usually between 70% and 85%, and a lot of energy is wasted in the transmission process.

The hub motor directly drives the load, with the shortest power transmission path and no additional losses in intermediate links. The transmission efficiency can generally reach over 90%, and some high-efficiency solutions can even exceed 95%. The reduction of energy consumption directly brings two benefits: under the same battery capacity, the robot's range is longer; Under the same endurance requirements, smaller capacity batteries can be used to further reduce the weight and cost of the robot, forming a positive cycle.

Reliability and maintenance advantage: reduce failure points and lower maintenance cost

The more complex the mechanical structure, the more points of failure, and the higher the maintenance cost. The traditional drive scheme has a large number of gears, bearings, and transmission shaft components, which are prone to problems such as gear wear, lubricant leakage, and transmission looseness after long-term operation. Not only does it require regular maintenance, but once a fault occurs, the transmission system needs to be disassembled for troubleshooting, making maintenance difficult and resulting in long downtime.

The hub motor integrates power components, reduces a large number of detachable mechanical connection parts, significantly reduces the number of fault points in the whole machine, and has higher structural reliability. Moreover, the hub motor itself has good sealing properties and can adapt to relatively harsh working environments such as dust and humidity, reducing the impact of environmental factors on the power unit. For logistics AGV and outdoor inspection robot that operate continuously in industrial scenarios, higher reliability means lower operation and maintenance costs and longer effective working time, with significant economic advantages. However, wheel hub motors are not suitable for all robot scenarios. For example, heavy-duty industrial robot requires extremely high motor torque, and hub motor still has problem such as heavy weight and difficult heat dissipation. Traditional drive solutions still have advantages. But for most service, logistics, inspection, and consumer grade robots, the comprehensive advantages of wheel hub motors far exceed traditional solutions, naturally becoming one of the mainstream choices for robot driving.

Shenzhen Zhongling Technology Co., Ltd. is a company that has long been committed to the automation of motor and driver industries. Its products have been recognized and trusted by customers around the world due to their high stability, and it has been in a leading position in the industry. It has always adhered to the concept of continuous innovation to bring the best products to customers, a complete R&D and sales system, and provides customers with the best purchasing experience. It has a detailed product system and architecture.