This patent contains two transmission modes, as shown in the cross section. The first is to put the motor in the middle, use the universal joint connecting rod to transmit the power to the driving shaft, and then drive the rear wheel through the gear set. This way helps to reduce the body volume and balance the center of gravity. BMW Vision DC sports car motorcycle is expected to adopt this driving mode.
The second method also uses a universal joint, but the motor is placed off the center line and on the same line as the drive shaft. This method is beneficial to improve efficiency and reduce wear, but the disadvantage is that the motor takes up too much space and needs extra counterweight to balance the center of gravity.
The patent also points out that the electric motorcycle BMW has a planetary gear set built in the rear wheel for speed change and makes the motor work in the best working condition. It can be seen from the real shot of Vision DC Roadster that the rear wheel of this motorcycle can swing up and down to absorb shock, so a universal joint is needed to drive the motorcycle. The brake disc of motorcycle is in the same direction as the transmission shaft. The car body is made of carbon fiber connecting rods.
IT House learned that BMW Vision DC Roadster electric motorcycle adopts lightweight design, and its body is made of aluminum alloy and carbon fiber, with a battery capacity of 12.7Wh and a battery life of 159km. If this car can be mass-produced, it will become the world's first electric motorcycle driven by a transmission shaft.