On the issue of limiting the irregular motion of a technological machine within specified limits

Abstract

Introduction. The problem of regulating speed fluctuations for any mechanism is essential, because the time interval of this movement is the working time during which the main technological operation is performed. In this case, the question may arise about the regulation of motion speeds both during acceleration, idling of the machine, and during the execution of the main technological operation. The main qualitative indicator of the satisfactory operation of any machine is the motion irregularity ratio, the value of which depends on the ratio of the maximum, minimum and average speeds of the drive shaft. Particularly acute is the problem of determining the motion irregularity ratio of the machine, taking into account the characteristics of the motor. In this case, the machine is considered as a system consisting of a single mass. The elasticity of the elements included in the machine is neglected. An analysis of the scientific literature in this area indicates that insufficient attention is paid to the study of rotation irregularities and its influence on the dynamics of mechanisms, especially when it comes to solving equations taking into account the characteristics of the motor. The purpose of this work is to develop a methodology that allows determining and regulate the non-uniform rotation of the drive shaft, taking into account the characteristics of the motor, the forces of useful resistance and the inertia of the masses of the mechanism. The relevance of the study is due to the lack of a unified methodology that allows adjusting the non-uniform rotation of the drive shaft at the stage of designing mechanisms of this type. Theory and methods. It is proposed to use the Lagrange equation of the second kind to determine the equation of machine motion in differential form. Mathematical simulation is carried out using the Mathcad and KOMPAS-3D application packages. Results and discussion. A methodology is presented that makes it possible to regulate the non-uniform rotation of the shaft. The CAE of the Mathcad system are used to determine the value of the irregularity ratio and patterns of change in these indicators are identified for total operating values that are in the range of 22-46 Nm. An analysis of the results of the calculations performed indicates that the irregularity ratio of the drive shaft rotation is 0.101. It is possible to change this ratio by changing the reduced moment of inertia by installing an additional flywheel or changing the torque of the motor shaft. The obtained results of the research made it possible to develop specific recommendations for the modernization of the drive designs for machines for mixing bulk materials and to outline ways for further research in this direction.