Rolling Machine Research Articles

MEANS, STANDS AND MACHINES FOR TESTING GEAR WHEELS AND GEAR TRAINS OF HELICOPTER REDUCTION TRAINS

The production and repair of such high-tech and important products as helicopters‟ reduction trains is impossible without comprehensive testing of these products, starting with the manufacture of their individual parts and assemblies and ending with the delivery of reduction trains to the customer.
 Various means for testing of gear wheels‟ rims and gear trains of helicopter‟s reduction trains, which have found application in testing equipment, are presented. Devices, testers, stands and machines for various tests are considered in order to control the characteristics of gear trains of aviation reduction trains after certain periods of their operation and repair, aimed at achieving better performance during further operation.
 The considered traditional metrological means of control of gear rims, gear measuring machines and complexes, some stands and machines for testing of reduction trains, pulse controllers and roll machines give an idea of various methods and means of control of gear wheels and gear trains of helicopters‟ reduction trains.
 The main method of experimental research of gear trains of reducers is stand tests both on movable gear wheels and on roll machines.
 Until recently, the most common method for monitoring and diagnosing gear trains has been vibrography, however, existing techniques do not give an accurate picture of the train condition, especially the contact surface of the teeth. During the operation of the gear train as a part of the helicopter‟s reduction train, signals from other sources (rotors, blades, shafts, bearings) are superimposed on the vibration signal generated by the gear train which significantly complicates the extraction and processing of the desired vibration signal.
 One of the most effective methods for monitoring and diagnosing the technical condition of kinematic chains of different complexity, which includes gear trains of helicopters„ reducers is kinematometry. The disadvantage of traditional kinematometry is the need to use high-precision sensors for the frequency and phase of the rotor rotation.
 Control of vibration from the early 1990s to the present time is the most advanced control, the means and methods of which are well developed in the aviation industry.

Chimerization of Monitor Flap in a Vascularized Ulnar Nerve Flap Is an Efficient Way for Vascularity Monitoring and the Reinnervation Checkup after Its Transplantation

Background Free vascularized ulnar nerve flaps (VUNF) are effective method for long nerve defects reconstruction. However, the monitorization of its microvascular circulation and the nerve regrowth can be challenging since it is usually designed as a buried flap. We designed a skin paddle based on a septocutaneous perforator from the ulnar artery that can be dissected and raised in conjunction with the vascularized ulnar nerve flap, which aims to improve postoperative monitorization to optimizing the clinical results.Methods We retrospectively reviewed 10 cases with long nerve defects who underwent reconstruction using VUNF between June 2018 and June 2019, including eight acute brachial plexus injuries, 1 multiple nerve injury due to a rolling machine accident, and 1 sequalae of nerve injury after arm replantation. All the demographic data, surgical details, outcomes, and perioperative complications were recorded.Results We evaluated 10 male patients, with a mean age of 34 ± 16 years. Cases included 5 antegrade, 4 retrograde, and 1 U-shaped VUNF. All chimeric skin paddles survived, and all of the underlying nerves presented with adequate circulation and functional improvement. There were no intraoperative or microvascular complications. One skin paddle had a transitory postoperative circulation compromise due to external compression (bandage) which resolved spontaneously after pressure release.Conclusion VUNF chimerization of a septocutaneous perforator skin flap is a relatively easy and efficient method for postoperative monitorization of the nerve's microvascular circulation as well as beneficial for postoperative Tinel's sign checkup to confirm the success of the nerve coaptation. The outcome is potentially improved.

Analysis of Platform Leveling Systems for Tracked Feller-Buncher Machines

The study was devoted to the analysis of feller buncher platform leveling systems. The widespread use of these systems in the design of modern feller-buncher machines makes the study relevant to assess operational efficiency. The analysis was conducted in five stages using analytical and stochastic mathematical modeling methods. In the first stage, the existing layouts of alignment systems were analyzed from the position of force on the hydraulic cylinder rods of the platform tilt drive. The three-cylinder layout scheme, where the force on the hydraulic cylinder rod was 50…60% less than that on the two-cylinder layout, appeared to be the most expedient. In the second stage, a mathematical model for determining changes in the position of the center of mass of the feller-buncher depending on the inclination angle of the platform was derived. In the third stage, a mathematical model was derived for determining the limiting angle of slope of the terrain when the feller buncher moved up the slope. For this purpose, two calculation schemes were considered when the machine moved up the slope without and with a tilted platform. Zero support reaction on the front roller was taken as the stability criterion. In the fourth stage, a mathematical model for determining the limiting angle of slope of the terrain during the roll of the feller-buncher machine was obtained. In the fifth stage, the efficiency of the application of leveling systems was evaluated. A graph of the dependence of changes in the terrain slope angle on the platform slope angle was plotted, and a regression dependence for an approximate estimate was obtained. A regression analysis was also carried out, and dependencies were obtained to determine the weight of a feller-buncher with a leveling system and the added pressure on the ground caused by the increase in the weight of the base machine. The analysis of platform leveling systems showed the effectiveness of their application in the designs of feller-buncher machines, as it allows the machines to work on slopes with an inclination of 50…60% more than without them.

Improvement of the Process of Mechanical Dehydration of Five-Layer Wet Leather Semi-finished Products

To improve the process of mechanical dehydration of semi-finished wet leather products, a multilayer dehydration using felt materials – monshons was experimentally investigated. The process is conducted by vertical feed of semi-finished wet leather products on a base plate between rotating squeezing rollers. The D-optimal method of mathematical planning of the experiment and the Kano design matrix were used for conducting experiments. The multi-layer package consists of five layers of semi-finished wet leather products and two layers of moistureremoving materials between each layer, folded over the base plate. The studies were carried out in laboratory conditions on an experimental bench, taking into account the production parameters of processing. As a result of the study, mathematical dependences of the amount of removed moisture for each of five layers of semifinished wet leather product on the feed speed and the pressure of the squeezing rollers were derived. The analysis of the results showed that, with the existing parameters of mechanical dehydration, it was possible to simultaneously squeeze out moisture from five layers of the semi-finished leather product with a minimum pressure of the squeezing rollers and an average feed speed. The productivity of the technological process was more than five times higher in comparison with the productivity of similar roller machines. In the near future, this research methodology will be used to determine the technological factors affecting the extraction of excess moisture from a package consisting of ten semi-finished wet leather products and moisture-removing materials.

Modelling and availability analysis of container manufacturing industry with Petri Nets

The present work deals with the modeling and availability analysis of Container Manufacturing industry by applying Petri Net (PN) technique and attains the various availability levels by varying various operating parameters that affects the overall availability of the system. This system consist of four subsystems/components namely Gas Cutting machine, Hydraulic Press, Rolling machine and Submerged arc welding (SAW) welding machine. For the mathematical recreation of the system pertaining to the real environment, a Petri module of GRIF 2021 software was used. The model of the system has been made with Generalized Stochastic Petri Net (GSPN) considering exponential distribution for the failure of the components. In the existing research, an attempt has been made to identify the most critical component of system and suggest the repair priorities of different components on the basis of effect of repair rate on overall system availability. Also an attempt has been to find out the optimum number of repairmen. In the present work Hydraulic Press is the critical subsystem having more effect on availability of the system as compared to other subsystems. The optimum no of repairmen required are four thereafter, no increase in system availability seen in the present case. The results of present research work are might be helpful for plant management to design a suitable maintenance strategy to meet one of the objectives i.e. economically maintenance with maximum availability of the system.

Development and process parameter optimization with an integrated test bench for rolling and forming strips of oolong tea

To solve the problems associated with the low rate of single‐use tea formation in oolong tea rolling equipment and the need for multiple rolling and formation processes, a new rolling and formation process is proposed. Based on the traditional rolling process, a heavy pressure holding process is added to keep the tea in a tight and curved state after the rolling is completed. Based on the traditional 25‐type rolling machine, the overall structure design of a test bench with integrated rolling and formation is described, and the control system of the test bench is established. In this article, a new orthogonal experiment using 12 factors and 3 levels for the rolling and formation of oolong tea strips is conducted, and the optimal process parameters are obtained. The experiment is carried out under the optimum process parameters, and the experimental results show that the strip formation rate of oolong tea is 77.37%, the tea breakage rate is 3.73%, and the time efficiency is 1.062 g s−1. Compared with the traditional rolling process, the formation rate and time efficiency of this process are significantly improved, and the comprehensive score is 1.613 times higher than that of the traditional rolling process. This shows that the new rolling and formation process improves the strip formation rate and efficiency of oolong tea production to ensure tea quality.Practical ApplicationsOolong tea is popular because of its high medicinal value and lasting fragrance. Efficient rolling and forming equipment can improve the efficiency of oolong tea production. The optimal parameters also provide a reference for rolling and forming equipment.

To the theory and practice of creating modern roller machines

The article describes the areas of application of roller machines, trends in the development of their designs, research work on the modernization and creation of new roller machines. Special attention given to the roller machines with a variable center distance of the working shafts. The descriptions of the gear-lever differential transmission mechanisms created by authors are given. In particular, the correct applications of the created mechanisms in roller machines of six types are shown; they are 1. One of the working shafts has the ability to rotate around its own axis, and the second working shaft, in addition to rotation around its own axis, moves relative to the first working shaft along the line, passing through the center of the axes of rotation of both working shafts; 2. Both working shafts have the ability to rotate around their own axes and move symmetrically along a line passing through the same axes of rotation relative to each other; 3. One of the working shafts has the ability to rotate around its own axis, and the second working shaft, in addition to rotation around its own axis, moves relative to the first working shaft along an arc with a certain radius of curvature; 4. Both working shafts can rotate around their own axes and move symmetrically relative to each other along an arc with some symmetrical centers of rotation; 5. One of the working shafts has the ability to rotate around its own axis, and the second working shaft, in addition to rotation around its own axis, moves relative to the first working shaft along a complex trajectory; 6. Both working shafts can rotate around their own axes and move symmetrically relative to each other along a complex trajectory.

Bending of sheets and profiles on a four-roll machine for rocket bodies, pipe and frame products. Part 7

The theory and calculation of the parameters of the strain-stress state at the stages of pre-bending, calibration, straightening, bending of a straightened section and bending of the subsequent sections, taking into account the hardening of the billet on a roller machine, is developed. Deformations, stresses and forces acting on the billet from the rolls were investigated by CAD/CAE-modeling. Criteria for the formation of cracks, low accuracy and excessive springback of the part after these stages of processing are determined. Recommendations for the elimination of these defects are given. Keywords: sheet stamping, billet, bending, roller machine, pre-bending, calibration, straightening, CAD/CAE modeling. dr_zharkov_v_a@mail.ru

Kinematics of the transmission gear mechanism for roller machines with different diameters of drive shaft

The article describes the arrangement, principle of operation and kinematic analysis of a ten-link gear-lever differential transmission mechanism with a parallelogram lever contour for roller machines with different diameters of the working shafts. The purpose of the kinematic analysis of the transmission mechanism is to determine the velocities and accelerations of the mechanism links, the gear ratio of the mechanism, and to show the constancy of the gear ratio of the transmission mechanism when the center distance of the driving and driven tooth gears changes. An important condition for the normal operation of roller machines with different diameters of the working shafts is the coincidence of the gear ratio of the working shafts and the gear ratio of the transmission mechanism between these shafts. Initially, the kinematics of the mechanism was performed using the analytical method. In the analytical study of the mechanism, the centroid method was used. Dependencies for determining the kinematic parameters of the ten-link gear-lever transmission mechanism are derived. The advantages and disadvantages of this method are shown. Further, to compare the results of the study, the kinematics of the mechanism is performed by the graphic-analytical method. The method developed by the authors was used in the graphic-analytical study.

Prediction of work-rolls failure in hot ring rolling process

The work-rolls of the hot ring rolling process are subjected to various damages due to the contact with hot metal. Thermo-mechanical fatigue is one of these damages. In order to predict failure due to the thermo-mechanical stress in the work-rolls, the developed code in ABAQUS has been used. The comparison between three- and two-dimensional models and, also, thermal and thermo-mechanical response of work-rolls with variable boundary conditions has been investigated. The results have shown that by applying mechanical and thermal loads separately or simultaneously, the response of work-rolls is completely different. In the mandrel, the location of the maximum equivalent stress is on the surface, while the location of equivalent maximum stress is in the subsurface of the main-roll. By making use of cumulative damage rules and the stress life method, the thermo-mechanical fatigue life was estimated. The cumulated damage in the mandrel’s surface was higher than subsurface regions. In contrast to the mandrel, the cumulated damage in the main-roll’s subsurface was higher than surface regions. In hot ring rolling machines, these locations are prone to crack initiation as a result of the thermo-mechanical fatigue in the work-rolls.

In-Line Measurement of the Surface Texture of Rolls Using Long Slender Piezoresistive Microprobes.

Long slender piezoresistive silicon microprobes are a new type of sensor for measurement of surface roughness. Their advantage is the ability to measure at speeds of up to 15 mm/s, which is much faster than conventional stylus probes. The drawbacks are their small measurement range and tendency to break easily when deflected by more than the allowed range of 1 mm. In this article, previously developed microprobes were tested in the laboratory to evaluate their metrological properties, then tested under industrial conditions. There are several industrial measurement applications in which microprobes are useful. Measurement of the roughness of paper machine rolls was selected for testing in this study. The integration of a microprobe into an existing roll measurement device is presented together with the measurement results. The results are promising, indicating that measurements using a microprobe can give useful data on the grinding process.

A Review on Application of Condition Indicators for Fault Detection in Rolling Machine Elements

Condition monitoring and fault detection of rolling machine elements is considered a key aspect as it ensures continuously decreased cost, unplanned downtime, and unexpected breakdown. The application of condition indicators is considered one of the most effective and popular methods for the detection of faults in machine elements. Condition indicators play a vital role in fault diagnosis because of their ability to quantify the changes in the vibration signals and thus provide key information about the state of various rolling machinery elements at subsequent levels of a fault i.e. from the initial level of a fault to its substantial level. However, the articles quoting condition indicators for the detection of faults in various rolling machinery elements are still less in number. So, there is a need for more work on the application of condition indicators for fault detection in machine elements. In this paper, various condition indicators are discussed domain-wise along with their mathematical expression & characteristics and then after the various application of the condition indictors to fault diagnosis are also briefed. The goal of the paper is to put forward a comprehensive review on the application of condition indicators for fault detection in machine elements to provide the researchers with a good and wide set of references for their future research works. This paper immensely reviews and classifies important papers and articles on conditional indicators on the basis of adopted methodologies. Finally, open problems are stated and future research prospects are also pointed out.

Rancang Bangun Mesin Pengerolan Pipa 1,5 Inci Menggunakan Motor Listrik Sebagai Penggerak dan Dongkrak 2 Ton Sebagai Penekan Pipa

The 1.5 inch pipe rolling machine utilizes an electric motor to drive the pipe holder and a 2ton jack as a pipe press. Although the roller machine is widely used in conventional workshops by using human power, it causes the pipe rolling time to be long and the machine user gets tired quickly. This is due to lack of resources to think about developing and improving the performance of these machines. Therefore, the focus of this research is the design of a 1.5 inch pipe rolling machine using an electric motor as a drive and a 2 ton jack as a pipe press. This research aims to produce a design and machine for 1.5 inch pipe rolling and to help accelerate the pipe rolling process and reduce worker fatigue. This pipe rolling machine consists of several components, namely, the engine frame, electric motor, gearbox reducer, chain-sprocket, shaft, pipe drive wheel, hydraulic pump and so on. The working process of this machine begins by preparing a 1.5 inch x 3 meter pipe then the pipe is positioned above the drive wheel, lowers the upper pressure wheel to the desired depth with a 2ton jack power, turn on the electric motor and press the button to roll the pipe back and forth and so on. up to pipe roll size as needed. The stages in making this machine are design, detailed drawing, manufacturing process, quality control, assembly and testing, data retrieval and data analysis. The research resulted in drawings of the design and manufacture of the machine, the calculation of the rotational speed of the machine for optimal rolling obtained 20.46 rpm and an average pipe rolling time of 6.80 minutes for one workpiece. This machine can still be optimized by adding a workpiece movement limiter when rolling.

Influence of rolling speed during hot forming using HDQT-R 30-12 machine on the properties of stainless steel 08Ch18N10T

Mechanical properties of austenitic stainless steels can be improved by a suitable combination of forming and heat treatment operations. In addition to rolling reduction and speed, the heat treatment parameters are very important as well. Heat treatment typically combines solution and stabilization annealing. In components of WWER nuclear reactors, most of which are made of these steels, it is necessary to achieve the prescribed hot mechanical properties. Bars of 30 mm diameter made of titanium stabilized 08Ch18N10T steel were rolled in an incremental rolling machine. After induction heating to 950°C, different roll speeds were used, from 200 rpm to 25 rpm. The rolled bars were cooled in water and stabilization annealed at 720°C for 10 hours or at 800°C for 1 hour. Mechanical properties were determined by tensile testing at room temperature and at 350°C. Slower rolling speeds led to lower elongation (40%) than the faster ones (50%). Metallographic evaluation focused on the effect of forming on the grain size.

The selection of the main axis and the forming plane in automatic profiling and stamping lines

The article defines the main axis and the profiling plane in automatic profiling and stamping lines. Specific recommendations are given for choosing the position of the main axis and the profiling plane, depending on the configuration of the manufactured parts of the roll-formed section. Under the general name of profiling in the practice of stamping works, it is meant to obtain rigid and light profiles of large length and various configurations from sheet blanks. Profiling is carried out in four ways: in dies on crank presses, in dies on special bending presses, on universal bending machines (edging machines), on profiling roller machines. The first method, profiling on crank presses, is used for complex semi-closed and open profiles of relatively small length, if there are no special bending presses or profiling machines. The second method, profiling on special bending presses, is used for open and semiclosed profiles up to 5 mm long. The advantage of such presses is the possibility of using simple, and therefore cheap, tools in the manufacture. The third method, profiling on universal bending machines (edging machines), is used for bending parts (profiles of a simple shape in straight lines with different coupling radii determined by the radius of the machine ruler, for which the latter has a set of rulers). Bending machines allow bending materials of small thickness. Low productivity and the need for physical labor costs limit the use of these machines. The fourth method, profiling on roller machines, is used for open, semi-closed and closed profiles. The essence of the profiling process is to gradually change the profile drawing of a flat belt to a given profile when it is moved sequentially through several pairs of shaped rollers arranged sequentially one after the other in the same plane and rotating at the same speed. The article describes in detail the fourth method; the advantages and disadvantages are noted.

Production and Mechanical Properties of Cu-Al-Ni-Be Shape Memory Alloy Thin Ribbons Using a Cold Co-Rolled Process

The use of shape memory alloys for micro-actuators constitutes a field of application in which copper–aluminum-based alloys find their usefulness because they can reach higher activation temperatures and are easier to produce than titanium-based alloys, particularly by the method proposed in this work. SMA tapes are a two-dimensional structure that offers many design options such as stamping, punching, and deep drawing, but they are also suitable for laser cutting, engraving, stamping, and EDM machining. This work has been made to study the manufacture of copper-based shape memory alloys (SMAs) using the cold co-rolling process also called the cold-roll bonding (CRB) process. In this process, a thin metal sandwich can be produced with a rolling machine. This sandwich consists of layers of CuNiBe master alloy and Al. During the rolling phase, the sandwich has no shape memory effect (SME) or superelastic effect (SE), so thin strips can be easily produced. After the rolling phase, the sandwich is subjected to a complex heat treatment to gain the SME. To validate this process to produce Cu-based SMAs, several alloys with different CuAlNiBe compositions have been tested. The SMAs obtained were characterized by optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The martensitic transformation was studied by Differential Scanning Calorimetry (DSC) and SME and SE were studied by three-point bending tests. This work shows that the CRB is a good process for making a wide variety of Cu-based SMA ribbons.

Preliminary rolling noise measurements toward the design of a standard rolling noise device

The tapping machine has long existed as the primary standard method for measuring the performance of floors in buildings in response to structure-borne noise. However, other sources of structure-borne noise exist. One of these is rolling noise: such as a trolley rolling across the floor in an indoor building environment. Because the sound profile of indoor rolling noise is substantially different than that of impact noise, the techniques developed to reduce the latter may not necessarily be effective at reducing the former. To this end, a means of repeatably measuring indoor rolling noise is needed. Here the results of a study on indoor rolling noise are presented, identifying the various characteristics of this type of excitation which until now have been left unexplored. The proposal for a standard rolling device is also put forth: a machine which may be capable of characterizing a floor’s performance with regards to indoor rolling noise. A series of indoor rolling noise tests were conducted in order to characterize the range of sound profiles that various indoor rolling items are capable of producing, as well as identify how the different characteristics govern the shape of the sound profile produced. Just as the standard tapping machine assesses a floor’s performance in response to impact noise, a standard rolling machine may assess a floor’s performance in response to rolling noise.

Bending of sheets and profiles on a four-roll machine for rocket bodies, tubular and frame products. Part 6

The theory and calculation of the parameters of the strain-stress state at the stages of pre-bending, calibration, straightening, bending of a straightened section and bending of the next section, taking into account the hardening of the workpiece on a roller machine, is developed. Deformations, stresses and forces acting on the workpiece from the rolls were investigated by CAD/CAE-modeling. Criteria for the formation of cracks, low accuracy and excessive springback of the workpiece after these stages of processing are determined. Recommendations for eliminating these defects are given. Keywords: sheet stamping, billet, bending, roller machine, pre-bending, calibration, straightening, CAD/CAEmodeling. dr_zharkov_v_a@mail.ru

МАТЕМАТИЧНЕ МОДЕЛЮВАННЯ ТЕХНОЛОГІЧНОГО ПРОЦЕСУ ВІДВАРЮВАННЯ КОТОНІНОВМІСНОЇ ТКАНИНИ

Flax is a very valuable raw material for making fabric. The processes of preparation of flax-containing textile material are multi-stage and energy-intensive. Therefore, the development of effective methods of preparation of flax-containing textile material is relevant. In this work, the method of mathematical planning of the experiment conducted a study of the dependence of the breaking load, capillarity and the degree of whiteness of cotton-containing textile material on the concentration of components of the boiling bath. The research was carried out on a mixed polyester-cotton-linen fabric TPK-11 produced by the private joint-stock company “Edelvika” (Lutsk). Technological process of boiling was carried out periodic method on a painting- roller machine. After boiling, the tissue samples were bleached according to the recipe based on hydrogen peroxide under the same conditions. Evaluation of the quality of boiled fabric was performed on such indicators as capillarity, breaking load and degree of whiteness. Processing of research results was carried out in the program “MathCAD 15”. At the result regression equations and response surfaces was received. The analysis of the obtained results shows that the quality of preparation of mixed flax-containing fabric depends on the concentration of the components of the boiling bath, and these models allow to establish the optimal recipe regimes of the boiling process. The obtained data can be used to justify further research.

Investigation of cavity filling in profile ring rolling process for T-shape ring

In this paper, key parameters affecting the cavity filling in single and double T-shape profile rings are comprehensively investigated via numerical and experimental analysis. A three-dimensional finite element model was developed in Abaqus\Explicit to assess the influence of crucial ring rolling process parameters, including feed speed, main roll rotational velocity, the existence and the absence of axial rolls on the cavity filling of single and T-shape rings and the main roll torque. Besides, a ring rolling machine was built to conduct practical experiments and validate the numerical evaluation, while for the first time, the role of the axial roll and the main roll torque on the quality of the cavity filling is experimentally evaluated. Power requirements and the final ring profile geometry were obtained by the simulation method, and the results were confirmed by the experiments. The results showed that axial rollers significantly reduced the cavity filling rate, and in contrast, the effect of mandrel feed speed and the main roll rotational velocity was much lower. Also, the axial forces were considerably less than the radial forces. However, the rolling operation was done in both radial and axial directions. The existence of axial rolls had an intensive effect on the process’ required power, as a result the main roll torque increased more than three times in case of applying axial rolls, compared with not considering them. Severe effects of axial rollers on increasing force and decreasing cavity filling rate can be attributed to frictional forces between the ring and axial rolls, restricted ring motion, which has to be compensated by a higher torque of the main roll. When the axial rolls are used, the material flow in the ring’s height direction is restricted. Therefore, the material cannot move easily to form the profile. All experimental and simulation results, including mandrel force, cavity filling, and ring profile geometry, were in good agreement, and in all cases, the simulation error was less than 10%.