The cruising range enhances the artifact, the hub motor is getting closer and closer to us
What are the technical barriers to the application of hub motors to electric vehicles? What kind of breakthrough is needed to achieve scale? How does it help improve the cruising range?
Hub motors are not a new technology. Almost all low-speed two-wheeled electric motorcycles and electric bicycles use hub motors.
■ What is a hub motor?
The hub motor is a device that directly mounts the motor on the wheel end (integrated inside the hub) for directly driving the drive wheel to drive the body. This device is not new. As early as 1898, the first car designed by Dr. Ferdinand Porsche was an electric car that used two wheel hub motors to drive the front wheels. It was only subject to the heavy and heavy lead-acid batteries of that era, which were not widely used.
■ Not only the cruising range, but also the improvement of dynamic performance, the advantage of the hub motor is also obvious
First, the loss of power by the reduction gear and the differential is eliminated. The transmission system often loses a part of the power during the transmission of power. For the fuel vehicle, the result may be that the fuel consumption is 1-2, but for the electric vehicle, the direct impact is the cruising range. In an era when battery prices are so high, cruising range can be almost directly converted into money. Therefore, if the wheel motor directly drives the vehicle to move, the loss of the power of the reducer and the differential is completely reduced, and the cruising range can be effectively improved.
Secondly, after driving the vehicle directly by the hub motor, if it is a two-wheel drive, the power is provided by two motors, and if it is a four-wheel drive power, it is provided by four motors. The benefits of such a decentralized drive, like the multi-cylinder engine of a conventional fuel vehicle, the power of a single motor can be small, and the volume and weight can be reduced. Not only the energy loss caused by the single motor drive plus transmission system is lower, but also the operating load of each motor can be reduced, so that the operation is more stable and the backup power is more sufficient.
Furthermore, with the hub motor, whether it is a two-wheel drive or a four-wheel drive, the power output of each drive wheel can be easily controlled by the controller. It won't break down because a single wheel slips like a traditional model with a differential. For the handling of intense driving, it is also easy to achieve the torque distribution of the front and rear wheels or the left and right wheels, so that each wheel can get the best grip performance. None of this will result in energy losses due to complex transmissions and differentials.
Finally, the hub motor also avoids the loss of energy in the transmission system for kinetic energy recovery, and can recover the braking force to the greatest extent. If properly matched, it can even recover more than 90% of the braking energy. This will further increase the cruising range of the vehicle.
