Avaliação estrutural de um cardan rígido industrial aplicado na transmissão de movimento entre eixos perpendiculares

Abstract

In this work, the methodology used in the stress analysis on components of an industrial rigid cardan shaft is described, connecting shafts misaligned by an angle of 90º according to boundary conditions of a particular application. The objective of the analysis is to evidence the influence of the misalignment angle of the universal joints in the transmission of torque and angular velocity and to analyze the set through fatigue criteria. Three misalignment conditions were compared for the same application, being 15º, 30º and 45º. The gimbal error is a characteristic of the universal joints that when angled, they transmit rotary motion unevenly on their output shaft, even though the input motion is uniform. A cardan shaft mounted under certain installation conditions will transmit motion uniformly on its output shaft. However, even in this case, the central body of the cardan, located between the two universal joints, will still be subjected to a sinusoidal variation of torque and angular velocity, presenting peaks that are repeated twice at each complete revolution of the system. The sinusoidal behavior of the torque verified in the central body in the condition of 45º presented amplitude of 378 N.m and maximum value of 1512 N.m. For 15º, the amplitude was 37 N.m and the maximum value was 1107 N.m. The cyclical variation of loads in the components of the central body contributes to the reduction of the life of the set, for 45º a finite life of 22 hours was estimated for the cardan, while for the other misalignmet conditions the fatigue safety fator was calculated. [resumo fornecido pelo autor]