Abstract: A speed reducer of the invention is a lever-typer speed reducer, which is configured to comprise a lever gear (4) which corresponds to an input gear of the conventional single-stage spur gear reducer but functions essentially in different manner, and a fulcrum gear (6), to increase a speed reduction ratio provide a self-locking feature and a stepless regulation of speed reduction by way of reducing or controlling the distance between a fulcrum (E) and a load bearing point (F).

Abstract: The present invention relates to the transistor type universal driving which has three shafts as transistor, i.e. driving shaft, driven shaft and control shaft and can provide non-step speed reduction, non-step speed increase, overloading adaptation control, automatic and remote control. The structural character of the transistor type universal driving is that the control shaft is suitably combined to the fixed support point of the speed reducer which contains the fixed support point.