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.
Introduction. Existing mixing devices operate at a constant angular velocity of the working body. During this process, there are zones in which there may be no movement of material, which leads to a decrease in the quality of the finished product. When the working body moves with a variable angular rate, the inertia forces, when changing its sign, contribute to the creation of conditions under which the mixture will lose contact with the blade and move to new levels of movement, and this helps to improve the quality and intensity of the mixing process. The purpose of the work is to improve the quality of the processed mixture on horizontal blade (kneading) machine. Methods. Theoretical studies are carried out using the basic provisions of the theory of machines and mechanisms, structural and parametric synthesis, kinematic analysis, mathematical and computer simulation. Results and discussion. In accordance with the proposed method, the synthesis of the cam-rocker mechanism is carried out, which made it possible to select the main dimensions for the cam mechanism: the minimum radius and center distance. For the synthesis of the rocker group, the parameters of the synthesized cam mechanism are used and, using the main parameters for the rocker group (the size of the input link, the angle of the second arm initial position and rocker centre line, equal to 90°). The rocker arm span angle is obtained equal to 103°. As a result of the kinematic calculation, it is found that the dwell time of the working shafts is within 80°. The quality of the mixture can be assessed by the angle of the stagnation zone, which is formed during the movement of granular material. Under static conditions, it is equal to 0.846°, and at variable angular rate — 0.550°. It is theoretically confirmed that inertial forces that change sign four times in one cycle will provide shaking and rebound of the mixed mass from the blades, which, in turn, will significantly improve the quality of the mixture.
A textbook with a laboratory workshop on inorganic chemistry contains voluminous theoretical material presented using tables, graphs and reference schemes. At the end of each chapter, control questions, fifteen variants of individual tasks, tests for self-control, laboratory experiments are offered. In the last chapter, compact diagrams-summaries on the main sections of general chemistry are placed as auxiliary material. The appendix provides the necessary reference data. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for students studying in technical specialties and areas of training, as well as for students of specialized classes.
No abstract
The issues of synthesis, analysis, dynamics and strength calculations of the technological machine mechanisms are considered in the monograph. A significant attention in the work is paid to the general approach to the synthesis of mechanisms of various classes, taking into account the technological load. The monograph may be of interest to a wide range of specialists involved in the development of technological equipment, and may also be useful for students and graduate students of technical universities, as well as for design engineers of machine-building enterprises. This research was funded by Russian Science Foundation project N 23-29-00945, https://rscf.ru/en/project/23-29-00945/.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.