International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

An experimental model of a safety clutch has been developed and manufactured, which will improve the efficiency of screw conveyors by increasing the axial displacement of the driven half-clutch with a jammed working body, while reducing dynamic loads during overload. When conducting a multifactorial experiment to determine the moment of operation T of the safety clutch of a screw conveyor, the variable factors were the angle of inclination of the working body to the horizon α, the rotation frequency of the screw working body n, and the time of increase in the resistance moment То. Based on the results of experimental studies, corresponding regression equations, response surfaces, and their two-dimensional cross-sections were constructed to establish the influence of controlled factors on the moment of operation of the safety clutch under extreme operating conditions. The obtained regression equation can be used to determine the moment of clutch engagement during the transportation of bulk and lump agricultural materials by a screw conveyor.

The article presents the design of a finger safety clutch with axial withdrawal of a jammed screw to remove it from the overload zone. The theoretical dependences of determining the change in torque during the operation of the finger safety clutch on the angle of relative rotation of the half couplings and the design and technological parameters of the engagement elements are presented. On the basis of force and kinetostatic analysis of the coupling, the nature and magnitude of the change in their torque at all stages of relative rotation of the coupling halves were determined. The developed and manufactured prototypes of the finger safety coupling made it possible to conduct a set of experimental studies. For the safety clutch of a screw conveyor, based on the analysis of theoretical and experimental test data, the adequacy of theoretical calculations and actual values of torques during the mechanism operation was compared.

The paper presents the constructions of finger safety clutch of screw conveyor, as well as the developed laboratory installation for conducting experimental studies in determining the optimal parameters and modes of operation of screw conveyor at overloaded working body. The results of experimental studies of the finger safety clutch are given, which allow to estimate the intensity of influence of this or that parameter on the torque value at different stages of its operation.

Micro-drilling (MD or мD) is type of machining (processing) technology used for the drilling of miniaturized parts of small diameter in micro-scale, ie. diameter in a range of a few microns to several hundred microns. In paper is given the dependence of axial efforts and torque on different modes of depth of drilling in micro-drilling with micro-drills from solid alloy VK60M with standard rake angle ω=300 and f=0.01 [mm/turn

In several metal forming processes, relation between stress and effective strain of the material must be known for obtaining important forming parameters such as forces and work, required for metal forming processes. Dependence of the flow stress on the effective strain is called the flow curve and is influenced by strain rate and temperature. In order to reach high quality and full functionality of the product, the characteristics of formed material must be determined as precisely as possible and flow stress is one of the main characteristic of the metal materials. In general, flow curves are determined by experiments such as tensile test, upsetting test and torsion test. The proper choice of testing method depends on the metal forming process to be simulated.
In this paper we present the experimental measurements of flow stress for stainless steel at elevated temperatures by using torsion test. In the experimental work a torque, temperature and number of twists of test pieces were measured. Also, the influence of forming parameters such as strain, strain rate and temperature on flow stress was analysed. Experimental results are presented in form of tables and diagrams. Finally, from experimental data the regression model was obtained for successful prediction of flow stress of stainless steel at elevated temperatures. The method of regression analysis allows with relatively small number of experiments the accurate information about the influence to mathematical model of the process.

The basics of applying the torque method for kinematic and power analysis of planetary gear trains are presented. With the help of the method, the speed ratios and efficiency of a real planetary gearbox are determined when operating on different gears (speeds).

In this paper a theoretical studies of instantaneous angular speed and torque fluctuation of diesel engine crankshaft have been conducted. It was evaluated the possibility to diagnose combustion related faults under stationary state.