Technical difficulties and application areas of in-wheel motors

01. Introduction

In-wheel motors integrate two or more motors inside the wheel hub. The drive modes can be divided into reduction drive and direct drive.

Reduction drive wheel hub motors mostly use an inner rotor structure to achieve reduction drive. Due to the high motor speed, a reducer is required to reduce the output speed and increase torque to meet the output needs of the wheels.

Direct drive types mostly use an external rotor structure to achieve direct drive without the need for a reduction mechanism, which can reduce the weight of the drive system. However, when an electric vehicle equipped with a direct drive hub motor starts, the torque starts to rise from zero, resulting in poor acceleration.

02. Application fields of in-wheel motors

1. New energy vehicles: In-wheel motor technology is one of the key technologies to achieve more efficient and environmentally friendly vehicle drive and power transmission.

2. Intelligent networked cars: Combined with intelligent networked technology, it improves the intelligence, safety and comfort of vehicles.

3. Special vehicles: such as driverless vehicles, subway vehicles, light rail vehicles, etc., providing efficient and stable power transmission.

4. Engineering machinery: used in excavators, forklifts, loaders, etc. to improve power performance and efficiency.

5. Aerospace field: such as drones, satellites, etc., providing advanced power transmission technology.

6. Electric vehicles: In-wheel motor technology has been applied to electric vehicles equipped with front wheels and has been used in fields such as mining transport vehicles. Most well-known car companies have begun to adopt in-wheel motor technology.

7. Electric bicycles and electric scooters: Hub motors make these small electric vehicles lighter, more flexible, and easier to maneuver.

8. Electric motorcycles and electric wheelchairs: The independent driving capability of the hub motor makes it suitable for these fields.

9. Large mining dump trucks: Hub motor technology has significant advantages in improving transportation efficiency and reducing operating costs.

10. Logistics vehicles, buses, and buses: The application of in-wheel motor technology is gradually increasing to improve the electrification and intelligence of vehicles.

03. Working principle of hub motor

The wheel hub motor is a permanent magnet synchronous motor. "Wheel motor" and "wheel hub motor" are distinguished by the position of the motor installed on the wheel. "In-wheel motor" is a motor designed to integrate the "power system, transmission system, and braking system" of the car.

04. The future prospects of in-wheel motors

With the continuous expansion of the new energy vehicle market and technological advancement, in-wheel motors will be more widely used in the future. It is expected that by 2025, the market penetration rate of in-wheel motors in the field of new energy vehicles (including passenger cars and commercial vehicles) will reach about 10%, showing its huge market potential. Although in-wheel motor technology faces some challenges, its future development prospects are very broad. As technology continues to advance and costs decrease, in-wheel motors will play a more important role in electric vehicles and other fields.