The hub motor refers to the direct assembly of the motor assembly integrated with the reducer in the hub. Just looking at the definition of in-wheel motors, you may feel a little unfamiliar. In fact, the hub motor is not a new technology. It has a history of more than 100 years since its birth, and it is still widely used. It's just not applied to cars, but to the electric bicycles that we are most accustomed to.
Note that the rear wheel of the electric bicycle is driven by an integrated sealed hub motor. Most of the electric bicycles on the market are driven by this kind of rear wheel hub motor. Why are in-wheel motors so widely used in electric bicycles but rarely used in cars? The reason is because electric bicycles are two-wheeled and cars are four-wheeled.
Because the electric bicycle adopts the layout of one front, one rear and two wheels, there is no speed difference between the two wheels side by side like a car. Moreover, the shock-absorbing suspension of the electric bicycle is placed outside the hub, just like the shock-absorbing hydraulic spring on the side of the rear wheel above, and there is no space limitation. Therefore, an e-bike can seal the entire package of the wheel hub motor. In this way, a good dustproof and waterproof effect can be achieved, and the service life of the in-wheel motor can be improved. The application of in-wheel motors greatly reduces the body structure of electric bicycles, is light and compact, reduces self-weight and increases cruising range. These advantages make electric bicycles show explosive growth and have a huge market.
In-wheel motor technology is also known as in-wheel motor technology. Its biggest feature is that the power unit, transmission and braking device are integrated into the hub, which greatly simplifies the mechanical part of the electric vehicle. The in-wheel motor drive system is mainly divided into two structural types according to the rotor type of the motor: inner rotor type and outer rotor type. Among them, the outer rotor type adopts a low-speed outer rotor motor, the maximum speed of the motor is 1000-1500r/min, without a reduction device, and the speed of the wheels is the same as that of the motor; while the inner rotor type adopts a high-speed inner rotor motor, equipped with a reducer with a fixed transmission ratio , In order to obtain higher power density, the speed of the motor can be as high as 10000r/min. With the advent of more compact planetary gear reducers, inner-rotor in-wheel motors are more competitive in power density than low-speed outer-rotor types.