Shape Variations Influence on Load Capacity of Cardan Joint Cross Shaft

Abstract

Design of the machine elements’ optimal shape due to stress concentration is one of the major problems in the design of power transmitters. Analyze of shape variations influence on load capacity of Cardan joint’ cross shaft, as one of the elements of mechanical power transmitter is presented in this paper. Functional tasks of power transmitters with Cardan shafts are to transmit power and motion between shafts with variable mutual position of axis or with axis which are forming certain angle. Load capacity of Cardan joint is highly influenced by design parameters which define form of cross shaft. Maximal stress act at the zone of cross shaft’ section changing from central part to the branches and represent critical stress for the whole power transmitter. Critical stress at cross shaft was determined, in this paper, by analytical approach and verified by finite element method. By the variations of geometrical parameters and repetitions of numerical calculations of stresses with invariant load conditions, the optimal fillet in critical section of cross shaft was created in order to obtain minimal stress concentration.