Tension Roller Research Articles

Justification of the parameters of the effective design of the centering tension roller of the conveyor belt

The article provides a structural diagram and principles of operation of the centering tensioning device of the belt conveyor. Based on theoretical research, the parameters of the centering device of the belt conveyor have been substantiated. Production tests substantiated the technical and economic indicators of the belt conveyor with the recommended centering tensioner.

Thermal diagnostics of mechanical gear elements of combine harvester

The work carried out practical testing of the technology of thermal diagnostics of belt gear elements of the grating mill drive of the combine harvester. The basis of the technology is the principle of using the coefficient of the temperature ratio on the surface of the diagnosed unit and temperature in the friction zone, expressed through the coefficient of proportionality of the finite element model. The peculiarity of the thermal diagnostics, in this case, is to compare the temperature in the friction zone with the maximum allowable temperature for the direct contact zone in the mechanical transmission unit. The object of the study is the tensioning roller of the drive of the grating mill of the first stage of the CLAAS TUCANO 580 combine harvester with 6203-2RS TIMKEN bearings. The result of the numerical experiment showed a significant effect on the temperature in the friction zone of the operational parameters - radial force and rotational speed. The use of 3D-modeling made it possible to determine the key parameter of the proposed thermal diagnostics technology - the proportionality coefficient of the finite-element model k=0.489. The temperature of the bearing assembly of the tension roller was measured periodically, using a non-contact method during harvesting in the 2020 season. For the period of regular observations of 128 moto-hours, the value of the maximum temperature growth rate in the friction zone Vτ=0.025 °C/min and the maximum temperature in the friction zone 69.5 °C, taking into account the ambient air temperature, were determined. No failures of the diagnosed unit were found. In the process of application of thermal diagnostics technology, no errors of the first kind are recorded, which indicates the effectiveness of the proposed technology.

Impregnation modeling and preparation optimization of continuous glass fiber reinforced polylactic acid filament for 3D printing

AbstractContinuous glass fiber reinforced polylactic acid (CGF/PLA) composites were prepared by 3D printing technology in this study. The multi‐roll melt impregnation mold was manufactured according to the melt impregnation model. CGF/PLA filament was prepared by a melt impregnation device, and then used to prepare CGF/PLA composite materials by the self‐modified 3D printer device. The full impregnation of the fibers was achieved by the action of the coverage angle of the tension roller in the impregnation mold. The effects of the total coverage angle, traction speed, fiber content, and impregnation temperature on the fiber impregnation effect and 3D printed product performance were studied. The bending strength, tensile strength, impact strength, and interlayer shear strength of the printed sample reached 312, 220, 154, and 14 MPa, respectively. The strategy in this study can effectively improve the impregnation effect of PLA resin on CGFs and promote the development and application of 3D printing technology in the field of high‐performance composite manufacturing.

V-belt transmissions of agricultural machines

The article is devoted to the analysis of design features and operating conditions of V-belt transmissions of agricultural machinery. When designing these gears, it is recommended to give preference to gears made according to an open circuit or with a tension roller located outside the belt contour, 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 transmissions 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 especially 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 coefficient taking into account different degrees of bending on the pulleys according to a graph built taking 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 reduced, 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.

RESEARCH OF CONSTRUCTIVE-TECHNOLOGICAL PARAMETERS OF WORKING BODY FOR SCATTERING BULK MATERIALS

Machines used in world practice for surface application of mineral fertilizers are often equipped with centrifugal devices with vertical or horizontal location of the axis of rotation. Having high productivity and reliability of technological process, they cannot always provide reception of a necessary dose and uniformity of scattering of fertilizers on width. In Ukraine, currently produced machines for the application of mineral fertilizers, which we have not previously produced. Since about 2/3 of all available mineral fertilizers, as well as most of the limestone and gypsum-containing materials are applied in a continuous manner, it is necessary to have a certain fleet of machines for applying fertilizers available to consumers. Fertilizer application in a continuous manner is carried out by land and aviation. One of the main agrotechnical requirements for machines for the application of bulk materials (mineral fertilizers) is their uniform distribution on the field surface. From uneven application of fertilizers, the reduction in grain yield reaches 10 ... 15%. The main disadvantages of the machine for applying mineral fertilizers are: imperfect design of the spreading mechanism, which leads to uneven scattering of fertilizers on the field surface; a large number of gears, which affects the metal content and cost of manufacture and complicates the design. Chain transmissions that drive the spreading device and the conveyor (during operation the chain is stretched, which requires the use of tension rollers, and take-off from the sprockets, especially on the drive of the spreading device); significant uneven application of fertilizers due to imperfect design of the spreading disc. The main reason for the low quality of fertilizer distribution by scattering machines, most researchers see a significant impact on the technological process of external random factors: field relief, wind speed and direction, humidity, elastic, frictional, hygroscopic and particle size distribution of fertilizers. Therefore, the improvement of the technological process of fertilizer scattering, in order to ensure a given uniformity of their distribution on the field surface in the conditions of real functioning, is an urgent scientific and practical task. In order to eliminate these shortcomings, a new spreading working body is proposed.

Development of a Constructive Scheme to Justify the Parameters of a Belt Drive with a Driven Composite Pulley and with Elastic Elements

The article presents a constructive scheme and the principle of operation of the developed belt drive with a composite driven pulley with elastic elements. The technique and electrotsenometric scheme of the experimental setup for changing the loading and driving conditions of the recommended belt drive with composite driven pulleys with a rubber shock absorber are presented. The results of experimental studies on the loading of the shafts and the rotational speed of the transmission pulleys for various rubber grades used in composite pulleys are presented. The results of full-factor experiments to optimize the parameters of a belt drive, as well as the results of production tests of a cleaning machine, in the drive of which the recommended belt drive is used, are presented. Full-factor experiments substantiated the values of the rotational speed of the drum, the tension roller eccentricity and the stiffness coefficient of the elastic element, which provides a high cleaning effect.

On the Issue of Determining the Engine Power of Tensioners When Winding Products Made of «Wet» Composite Material

Products made by the method of «wet» winding from composite material are widely used in various indus-tries. The quality of future products is largely determined by the tension with which the «wet» tape is placed on the product. Until now, the electric motor of the tensioning device was selected from the condition of providing the specified maximum tension value of the composite tape, without taking into account the specific features of the tensioning device used and the geometry of the wound product. However, when winding a product with a complex geometric shape, dynamic moments occur in the electric drive, which cause additional heating of the engine. The paper analyzes the tensioning devices used for winding. They are grouped into two classes: linear and angular movement of tension rollers. For the considered tensioning devices, analytical expressions are ob-tained that relate the tension during winding with the force that the Executive electric motor must provide in static and dynamic modes. A method for selecting the drive power of tensioning devices is proposed, which takes into account the features of winding composite products made of «wet» composite material. As an exam-ple, the drive of a tensioning device is calculated when winding a pressure cylinder with a diameter of 0.2 m. the Calculations are carried out taking into account the possibility of using a worm self-braking gearbox or a planetary gearbox. Graphs of the dependence of static and dynamic moments on the motor shaft are plotted. It is shown that the use of a worm gearbox requires a more powerful drive, but when using a planetary gearbox, the electric motor must be able to stand under full load. The results obtained in this work can be used in the de-sign of new winding equipment or modernization of existing ones.

Influence of Belt Transmission Parameters on the Stiffness of the Elastic Elements of the Driven Pulley and Tensioning Roller

The article presents the ways of wide use of belt drives with variable and gear ratios in the drive mechanisms of technological machines. The scheme and principle of operation of the belt drive with composite driven pulleys and a tension roller are given, the necessary variable driving modes of the driven pulley are allowed. Analytical methods for determining the stiffness of the elastic elements of the driven pulley and tensioning roller are given. Based on the analysis of the plotted dependencies, the recommended values of the parameters of the considered belt drive for technological machine drives are substantiated. Production experiments and test results of the 1-CCC (Cotton Cleaning Complex) machine with the recommended belt drive justified the system parameters.

A parametric study on the dynamics of two-span roll-to-roll microcontact printing system

The recent trend towards micro-patterning of thin film webs brought stricter manufacturing tolerances than traditionally admissible vibration levels. Therefore, one has to consider roll-to-roll (R2R) systems with their system dynamics model encompassing all systems’ components, namely, the axially moving web(s), the rotating rolls and other accessories. In this study, the dynamic characteristics of an axially moving web in a two-span R2R system are investigated. Influence of geometrical parameters on the R2R dynamics and the parametric resonances of the moving web is presented. The time variations of web axial speed and web-transmitted tension are rigorously obtained by solving the web tension–roller angular speed equation, which is obtained from the conservation of mass law. The effects of system parameters such as length of the web, inertia of idler roll and radius of the rewinding/unwinding roll on the angular speed and web-transmitted tension have been discussed. The axially moving web was modelled as a string, which was mathematically represented by a second-order hyperbolic partial differential equation. The effect of the frequency of the disturbance at the roll on the web dynamics is also discussed. The transverse vibration response at selected points on the web shows higher frequency fluctuations corresponding to lower transport axial speed. It is noted that instability in the transverse response will occur when the first and second frequencies of the oscillation converge.

Theoretical and Experimental Study of Non-Steady-State Pipe Reduction Process Using a Tesa 20-102 Mill

We describe the results of an experimental study of longitudinal and transverse variations in wall thickness at the ends of pipes after rolling in a stretch-reducing mill (SRM). We found that the largest “contribution” to the scatter in wall thickness comes from internal hexagon produced in the pipes by the reduction-mill drawing schedule and the roll pass design. A mathematical model was developed based on current high-speed SRM mode calculation procedures, and the plastic tension coefficients, rolling diameters, and roller speeds for each SRM stand in steady-state rolling mode were calculated. The pipe wall thicknesses calculated using the mathematical model were similar to those obtained experimentally. The accuracy of the pipe inside diameter was determined.

Innovative design of reel-to-reel hot embossing system for production of plastic microlens array films

This paper reports an innovative design of reel-to-reel hot embossing system for the production of plastic microlens array films. The novel system mainly consists of a reel-to-reel mechanism with tension rollers, a gas-assisted hot embossing module and a vacuum-assisted de-molding unit. During this new process operation, a thin steel mold with large-area micro-circular hole array pattern was fixed on the bottom hot plate of this system. The part of plastic film roll was placed on the mold by tension rollers. Under the proper processing conditions, the softened polymer will just partially fill the micro-circular holes of the mold and, due to surface tension, form a convex lens surface. After a proper cooling process, the plastic film with a large-area microlens array pattern was de-molded from the mold by reverse pressure activated through the vacuum system. In this way, a roll of plastic film with a large-area microlens array can be successfully fabricated. In addition, the sag height, curvature, and focal length of the fabricated microlens arrays could be changed and controlled. The embossing by gas pressure is uniform and the de-molding by a vacuum system is running smooth. This technique shows great potential for mass production of plastic optical films with various large-area microlens arrays.

Intelligent Control of Technique by Means of Capacitive Sensors on Automatic Winder

Concerning the intelligent control of technique parameters in weaving preparation process known as automatic winder in textile production, the yarn tension, yarn defects, running speed and acceleration are key technique parameters which should be carefully monitored and controlled. The linear and rotating speed will definitely affect the dynamic tension of warp yarn during the winding process. The acceleration of the tension device on automatic winder and tension roller will affect the swing speed and amplitude, eventually influence the value and abirritation of dynamic tension. The capacitive transducer is used to detect yarn defects for improvement of yarn quality, in addition such sensor is qualified to monitor the acceleration of dynamic tension regulator. The principle and designation as well as application of relevant sensor has been discussed in this paper in detail.

Optimization of Tension Control System for Cold Rolling Exit Section

Through theoretical analysis of the working condition of the tension roller and stress, user can discuss the main reasons of tension roller slip, and put forward the preventive measures to eliminate tension roller slip by using Euler formula and the research on the tension roller slip phenomenon of cold rolling. This technology has significant practical meaning for improving both the quality and efficiency of product.

Electromechanical Hybrid Transmission Control System of Tension Leveler

For tension roller skidding and motor alarm phenomenon often appeared in the process of straightening. This paper take electromechanical hybrid drive system of tension leveler as example, analysis the control system, focusing on the dynamic tension load distribution, points out that the above situation can be avoid effectively by setting the parameter of tension reasonably. And the same time, speed control and torque control are analyzed in this paper, and it provides a reference for the further study of electromechanical hybrid transmission control system.

Sensors connection for yield determination on round balers with variable chamber

The main aim of this article is to present a technical solution for straw and forage yield mapping when using round balers with variable chamber for harvest. The yield measurement is based on monitoring of instantaneous position of a tension roller mechanism for press chamber circular belt. Wheat straw was harvested – baled, during our trial measurements. The acreage of the trial field was 12 ha. Calibration of the measuring system showed a strong dependence of the tension roller position on the amount of pressed straw (R<sup>2</sup> = 0.99). Geostatistical evaluation confirms a spatial relationship of measured data sets with a moderate spatial dependence. Finally, yield map of straw was created

Design of the Pinch Machine for Battery Grid Continuous Casting Machine Based on Link and Floating Gear Mechanism

In order to realize pinch during the production of the continuous casting battery grid, using the link and floating mechanism a pinch machine is designed which can automatically adjust the roll gap and pinch tension. First the structure of the grid pinch machine is introduced ,in which adopts the dual drive roller to achieve the upper and lower pinch roll and pinch roll to rotate in accordance with the same speed, but in the opposite direction. The pinch force generates by the fiction force between the grid plate and the upper and lower pinch roller. By means of the shifting bearing and spring the position of the upper pinch roller is controlled and the roll gap adjustment mechanism adopts the link and floating gear mechanism which results in structure simplification , high reliability, Low cost, stable, long life and low noise. Finally, according to the design principle of the pinch machine, using the theoretical mechanics and the Euler formula the pinch roller tension, tension roller tension and pinch pressure are calculated. The pinch machine has made it possible to achieve the manufacturing system of continuous casting battery grid.

Optimum Temper Rolling Degree: Pre‐Set and Influencing Effects of Bending Deformations

The present article describes a research project concerning the influence of bending deformations on strip mechanical properties imparted by temper rolling and a strategy for mill pre‐set to achieve the selected temper rolling degree in as short a time as possible. Research results show that, during strip temper rolling, rolls involved in the process, for example deflector rolls and anti‐sticking rolls, introduce plastic bending deformations into the strip which can amount to more than 30% of the temper rolling reduction, depending on the effective bending radii.Bending tests involving strips made of low‐carbon steel in a tension roller system with an integrated bending unit demonstrate that bending deformations influence the mechanical properties of the strip in a manner similar to the temper rolling process itself. It appears necessary to take account of the bending effects when selecting the optimum temper rolling degree.The most accurate roll force pre‐calculation possible and its application at the mill stand are of major importance for pre‐setting the required temper rolling degree. Existing analytical methods have been unable to yield the necessary calculation accuracy. Combination of an optimised analytical approach with a data‐based model to create a hybrid model has led to significant improvements. The accuracy achieved in the pre‐calculation of the required roll force has helped to improve mill pre‐set of the investigated temper mill and to reduce strip head‐end scrap on average by around 6 m per strip. Based on the annual outputs stated by the plant operator, this makes it possible to achieve a cost saving of more than 200,000 € per year.

Study on Belt Skew (3rd Report, Out-of-Plane Roller Misalignment Case)

We simulated skew phenomena of a flat belt running between cylindrical rollers with out-of-plane angular misalignment by means of the FEM software MARC. We investigated the effects of roller misalignment angle, belt initial tension, coefficient of friction, and an added tension roller on the belt skew. The results indicate that the skew transient state disappears very quickly and the skew rate is proportional to the roller misalignment angle and is about 60% in magnitude comparing with the inplane misalignment case. The tension roller greatly reduces the belt skew due to the out-of-plane misalignment, when it is placed in a suitable position with a certain in-plane angular misalignment. Both skew generating mechanism and skew reducing mechanism are also discussed.

The outlook for the use of frequency-controlled electric drives for high-speed centrifuges

High-speed tubular centrifuges are designed for clarifying suspensions containing small quantities of highly disperse solid impurities (lacquers, enamels, vaccines, otis, waste water from the production of motion picture films, etc.), and for separating stable emulsions (separation of water from transformer oils, various fats, etc.). In the first case OTR centrifuges are used (with clarifying rotors), while in the second case use is made of RTR centrifuges (with separating rotors). For separating emulsions the centrifuges operate continuously, while for separating suspensions they operate batchwise, since it is necessary from time to time to dump the solids accumulating in the rotor. In the standard supercentrifuge models RTR-100 and OTR-123 with rates of rotation of the rotor up to 15,000 rain ! the drive is accomplished from an asynchronous electric motor through a flat-bek transmission with tensioning rollers. During a direct startup of the motor there is slippage of the belt on the pulleys because of the considerable moment of inertia of the rotor, which leads to rapid wear of the belt and the buildup of static electrical charges. Operating tests have confirmed the short lives of the flat belts and the timited durability of the bearings of the tension rollers and upper supports of fhe centrifuge, and also of their unsuitability for operation in plants where there is a danger of fires caused by sparking. Tests carried out at working speed for a fully loaded OTR-123 centrifuge showed that the power drawn by the electric motor was only 50-60 % of the nomknal power. The rest of the power is required only for starting up the centrifuge. The use for directly driving a supercentrifuge of a high-speed explosion-proof electric motor with a frequency transformer would make it possible to avoid the use of a flat-belt transmission with tensioning rollers. At present there are no such electric drives for industrial centrifuges in our country. tn designing a high-speed electric drive it is necessary to satisfy constructional requirements for installation of a centrifuge with respect to the energy requirements and reliability during use. Such an electrical drive (type ASTs 10-504 of power 10 kW for the direct drive of an industrial centrifuge) was developed more than 25 years ago in the All-Union Scientific Research and Construction Institute for Chemical Equipment Construction (Nllk.himmash). The results of tests in the Frtmze Scientific Production Unit (NPO) of one of the prototypes of this drive, which was built in the Order of the Red Star All-Union Scientific Research Institute for Electromechanics (VNII61ektromekhaniki), for 326 h as the drive for a SGS-150 centrifuge showed reliability in use of the bearing subassembly of the electric drive and supercentrifuge at rates of rotation of the order of 15,000 min-1. However, at this stage operations were discontinued because of the lack of reliable static frequency transformers. Prolonged tests under load under industrial conditions to determine the service life of the bearings of the electric motor and supercentrifuge, the insulation strength of the motor windings, and other operating characteristics were not carried out. Due to the appearance of domestically produced frequency converters, in recent years the possibility has again arisen to develop and introduce the production of a fixed direct electric drive for centrifuges built as an integral unit. In the course of the development of the high-speed electric drive it was necessary to solve several important problems, the most important of which was to provide the required mechanical properties of the rotor taking into account the occurrence of critical frequencies in it during acceleration, and ensuring the strength of the rotor at high rates of rotation (up to 20,000 rain-l); the choice of the cooling system and rotation support were also important. In addition to these main requirements, there were also secondary problems: selection of the technology, for manufacturing the motor parts, providing the controls for the electric drive durhag the acceleration process and under the specified conditions in order to achieve satisfactory energy parameters, and finding the most suitable layout of the electric drive and centrifuge.

Thick and Thin Places in Fabrics during Weaving

The purpose of this article is to develop a utilized device for preventing the thick and thin places in fabrics with the aid of the theoretical and experimental results obtained in previous reports.The ability of the developed device has been looked into with the following results:(1) The warp tensioning device comprising a whirl spring has a higher ability than that of the coiled spring system.(2) The following two kinds of preventive devices against “set mark” have neen manufactured. One is of (i) the restraint type which restrains the tension roller only when the loom starts or stops; and or which does not restrain it only when the loom starts or stops. The other is of (ii) the contsraint type which pulls the easing roller positively only when the loom starts or stops.(3) The devices showed a high degree of ability to prevent the “set mark” on the loom in which the shedding time is at top center or front dead center.(4) The “set mark” on the water jet loom is not only caused by the difference in tension curve between the stop and start and the stationary running state, but also by the difference in the bending of the race. The latter has a greater influence.(5) The device on the water jet loom is in principle based on the restraint type which is usable on the automatic cotton loom. It can satisfactorily eliminate the “set mark” caused by the difference in tension curves between the stop and start and the stationary running state.(6) The compensating device for the pick spacing by pushing the pedal is useful for relieving the “set mark” caused by the difference in the values of the bending of the race.