The technology behind the TQ HPR 120S
Specially designed for the demands of pedelecs and e-bikes, the high-performance TQ HPR 120S takes its engineering cues from the permanently excited direct-current motors used for the control of modern satellites. The motor's very densely wound core means losses are much lower than in comparable systems.
How the drive works
The electric machine drives an elliptical roller bearing. The oval contour moves 150 pins in a wave pattern between the inner gear (148 teeth) and the stationary external gear (152 teeth). The pins act as transmitters. Transmission takes place between the rotary motion of the bearing (input: motor) and the internal gear (output to the chain ring). All the pins are engaged around the entire circumference achieving power transmission that occurs in a minimum of installation space. The transmission gears down in only one stage with a ratio of 1:37. That is, at a pedaling frequency of 80 rpm, the electric machine is running at about 3000 rpm.
Thanks to the integrated freewheel, the bicycle can be pedaled just like a bike without a motor. When the drive is disengaged, no internal components are moving.