CONTROLLED TESTING OF BELT TRANSMISSIONS AT DIFFERENT LOADS

The presented paper provides the alternative options for determining the condition of belt gear based on the testing and monitoring. In order to carry out experimental measurements, a newly developed device for testing, monitoring and diagnostics of belt drives was designed, as well as the possibility of determination of limit states by extreme loads. The designed measuring stand allows to determine the point of destruction of the belt for an extreme load. The process of the belt measurement was to set the predetermined input revolutions of the driving motor by means of the Altivar 71 (FM1) frequency inverter connected to the driving electric motor. The next step in defining the input parameters was to set the load on the driven electric motor. The load on the driven motor was achieved by the torsional moment set by means of the Altivar 71 (FM2) frequency inverter connected to the driven electric motor. In the paper, the analytical calculation is processed. The article mainly points to the innovation of the stand for testing belt transmissions.

Structural Synthesis and Analysis of Mechanisms with an Output Link Performing Two Rotational and One Translational Movements

The article considers mechanisms based on a hinged flat parallelogram with an additional link, ensuring the ability to maintain the insertion point of the tool installed on the output link. A rotational kinematic pair coupled to the base allows the plane of rotation of the articulated parallelogram to change the angle of inclination. The proposed design should have a greater load capacity than the available analogues, since the rotational kinematic pair mating the articulated parallelogram with the base is made in the form of two semi-axes, and the output link is located between the intermediate links of this parallelogram. The equality of the rotation angles of the output link and the intermediate links of the articulated parallelogram is ensured by the presence of additional links or belt drives. Three-dimensional models of these mechanisms are presented, and their structural synthesis is carried out in various modifications. Depending on the modification, it becomes possible to apply such mechanisms not only in industry, including additive technologies, but also in the field of medicine during surgical operations and in the study of plasma properties.

Development of Jacketing Machine

Flat Belt is manufactured almost all over the world. In the Transmission Industries, Flat Belt is almost available in every part. In modern trend demand has been significantly increased. To fulfil the increased demand for flat belt, jacketing operation of flat Belt must be paced up. In traditional jacketing processes which are carried out manually take more time, labour work and also provide damage to industry growth. To overcome this and to minimize stress on workers, an attempt has been made to design a jacketing machine for flat belt, which is simple in design and can be handled by the common man. The demand for a flat belt jacketing machine is higher and it is time to respond to the problem raised. Designing and fabricating such types of functional machines is important to save money instead of investing money and time buying labor and conventional tool. Since metal resources are declining and their products are very expensive as compared to rubber, it’s preferable to use Rubber flat belts rather than using chains for transmission. As per the studies, it is easier and economical to use belt drives replacing chain drives and it is good for the future without disturbing the ecosystem. Study shows that while analyzing the force and power for machines the designer takes the help of analysis software. The cost of software for analysis is high. So there is requirement to find simple formula. In this paper the various theories regarding bending are reviewed, formulae for force and power calculation are collected and finally a case study is taken where we have put together all the results of these formulae. Our main concern is to reduce the human effort required in jacketing of flat belt and also to save the time, labour work, lead time, and move towards the partial automation. The machine has been designed and developed to minimize the cost of production and increase the efficiency.

Non-reloading coal transportation in the eastern inclined shaft of “Raspadskaya” mine

The planned increase in the mine output from 6.5 to 13.6 million tons per year has set the task of reconstructing a conveyor transport in the eastern inclined shaft of the Raspadskaya mine. The roadway length is 4100 m; the reduced inclination angle is +7°40´. An attempt was made to combine all the positive global practices in one project: the distribution of drive power along the length of a conveyor belt, minimizing the capital cost of implementation. Within the framework of this article, an approach to choosing the speed of a con-veyor belt is discussed, a comparative analysis of the two most com-mon types of intermediate “tripper-type” and “belt-to-belt” drives is given; calculation of a belt conveyor with intermediate “belt-to-belt” drives providing non-reloading conveying in the eastern inclined shaft. Pull force calculations showed that a conveyor belt with four interme-diate “belt-to-belt” drives can be implemented as follows: belt width – 1400 mm, belt speed – 4.0 m/s, mono-material load-carrying belt – PVG-4000, mono-material drive belt – PVG-1400, 2-pulley drive units when mounted on one side: head drive power – 2×1000 = 2000 kW, intermediate drive power – 2×1600 = 3200 kW. Thus, the use of a conveyor belt with four intermediate “belt-to-belt” drives in the in-clined shaft will give the following results: non-reloading transporta-tion over the entire length of the shaft, reducing the additional degra-dation of transported coal due to the exclusion of reloading points, minimizing costs through the use of less durable belts, minimizing costs of sinking an inclined shaft of a smaller cross-section.

V-belt transmissions of agricultural machines

The article is devoted to the analysis of design features and operating conditions of V-belt trans-missions of agricultural machinery. When designing these gears, it is recommended to give prefer-ence to gears made according to an open circuit or with a tension roller located outside the belt con-tour, to avoid cross and semi-cross gears, as well as multi-pulley gears with crossing shaft axles. To make the wider use of more progressive types of belts. It was shown that the features of V-belt transmissions of agricultural machinery require clarification of the methods for calculating trans-missions with progressive types of V-belts and automatic belt tensioning methods. It was noted that special attention should be paid to transmissions with multi-profile belts, which calculation has not been sufficiently reflected in domestic regulatory documents. The advantages of such belts are es-pecially noticeable under variable and shock loading. Based on the analysis, the recommendations for clarifying the calculation of belt drives with multi-profile belts were given. Analytical dependencies are proposed for determining the value of the nominal power transmitted by one belt (stream) of a multi-profile belt, allowing automation of the calculation of V-belt transmissions of agricultural machinery. For gears with a tension or guide roller that add an extra (sometimes reverse) bend of the belt, it is proposed to determine the coeffi-cient taking into account different degrees of bending on the pulleys according to a graph built tak-ing into account the linear hypothesis of summation of damages. It is recommended to calculate gears with spring-loaded tensioning rollers and design tensioning devices for such transmissions using a special method that takes into account the belt tensioning method. At the same time, the required value of the pre-tension of the belt can be significantly re-duced, which will have a positive effect on its resource, without losing the traction capacity of the transmission itself. Expressions are given for finding the value of the pre-tension of belts, both for gears with tension due to the elasticity of the belt, and for gears with spring-loaded tension rollers. Conclusions and directions for further research are formulated.

THEORETICAL STUDY OF THE NOISE EMISSION OF THE FLEXIBLE CONNECTION OF THE ABRASIVE BELT-GRINDING WOODWORKING MACHINES

This paper presents the results of theoretical studies of the drive belting and grinding belts` acoustic characteristics as elements of flexible connections, that fundamentally distinguishes them from bobbin sanding and cylinder-grinding woodworking machines. It also has the significant differences in comparison with other sources in terms of stiffness and tension forces. The choice of the noise source models is justified by the characteristic features of the kinematics of the machine tools and the grinding technological process. The arrangement of the machines` acoustic system of chosen group suggests that the main sources of energy radiation are: grinding belts and belt drives of the work pieces and grinding units, ground work pieces, electric motors. It is compared the expected noise levels with sanitary standards for determining the excess and the sources that generate them. These data are the main information for the acoustic calculation and design of the noise reduction systems of the above sources at the design stage in such woodworking equipment, and it also determines the acoustic efficiency of the noise protection systems and consider to design these systems in accordance with the implementation of the sanitary noise standards at the machine operator workplaces.