Elemente de calcul la motoare rotative (NSU/Mazda – Felix Wankel)

Abstract

The aim of this paper is to present a short theory and calculus of the first designed internal-combustion engine in which power is transmitted directly to its rotating components, patented by the German engineer F. H. Wankel and developed by the NSU and Mazda car companies. The story started with the patenting of the petrol engine in 1886 – four-piston internal combustion engine – by the German engineer Karl Benz. During the WWII, the genius inventor Felix Wankel produced rotor shafts for German Air Forces. After the war, Felix Heinrich Wankel was offered a job in the German car company NSU and in 1957 the prototype of the rotary engine was ready. Wankel’s rotary engine is an internal combustion engine in which the piston (with a triangular shape) revolves around the axis slightly displaced from its center. It has fewer moving parts and fewer losses associated with them. In its rotation, the piston forms three chambers, whose volumes are constantly changing. The function of the engine is very stable and there is no vibration like in ordinary engines. The purpose of internal combustion is to reduce friction (no engine valves, camshafts, beating, cylinder head, etc.). This engine can have a much higher speed than the piston engine. From a small cylinder the power that is earned is bigger compared to the power of a piston engine. The only drawback is the high cost of gasoline and oil, as well as the very rapid deterioration of the rotor. The rotary Wankel engine is housed in many sport vehicles. In 1961, the NSU Wankel Company sold its patent to Mazda in order to be developed. In 1978 Mazda sport presented its brilliant model RX-7, which had 105 HP with its rotary engine, and could drive at the speed of 200 km/h, like Porsche and Ferrari. Mazda’s rotary engine is still used today in different sports models.