What is a hub motor?

A hub motor is an electric motor that is attached to the wheel of a vehicle. It is often used on electric bicycles and is a fundamental part of the wheel. The hub motor is mainly used around the axle to connect the end of the spokes, to accommodate the brake disc and in the case of the rear as a support for the flywheel, to transmit the movement of the transmission to the wheel and ultimately to rotate the wheel. There are also many different types of hub motors, which can be divided into four categories according to motor type: brushless gearless motors, brushless gear motors, brushed gearless and brush gear motors. They are divided into two-shaft motors and single-shaft motors according to the way of shaft output.

Five main functions of wheel motors are below:

1. Bearings and drives are necessary functions of hub motors
2. The load is rely on the bearing to center the rotor and stator. The drive is the outer rotor directly attached to the hub for direct drive.
3. Electronic differential speed control
4. The rear wheels of the vehicle need to slip, and the slip of the rear wheels is calculated according to the rotation angle of the front wheel servo, which is done by the electronic differential.
5. Brake Energy Recovery
6. During the braking process of electric vehicles, the motor is in the power generation state, and the braking energy is converted into electrical energy and stored in the energy storage device to realize energy regeneration.
7. Motor Cooling
8. There are two types of cooling methods for wheel motors: air-cooled and water-cooled.
9. Braking System Integration
10. The braking system includes electric brakes and friction brakes, and the integration of friction brakes is generally disc brakes.

Conclusion

Hub motor drive technology, also known as wheel-mounted motor technology, has various features such as simple structure, low cost, low torque pulsation, robustness, no position sensor, etc. It mainly has five main functions. Hub motors are extremely widely used in the electric vehicle industry. Its most important feature is the integration of power, transmission and braking devices into the hub, thus greatly simplifying the mechanical components of electric vehicles.