Machine Components Research Articles

Machine Learning-Driven RUL Prediction and Uncertainty Quantification for Ball Screw Drives in a Cloud-Ready Maintenance Framework

In today's rapidly evolving industrial landscape, efficient predictive maintenance solutions are essential for minimizing downtime and enhancing productivity. This research introduces an adaptive cloud-based model pipeline for predicting the Remaining Useful Life (RUL) of machine components, specifically ball screws. The pipeline integrates local preprocessing, edge computing, and cloud-based adaptive model training, ensuring data privacy and reducing data transmission volumes. The system classifies wear states using various machine learning mod-els and predicts RUL through regression analysis, incorporating uncertainty quantification for robust maintenance scheduling. The experimental setup includes accelerated degradation of ball screws, with data collected via a three-dimensional accelerometer. Feature extraction and data augmentation techniques are employed to enhance prediction accuracy. Random Forest and Gradient Boosting models demonstrate superior performance, with Random Forest selected for its robustness and uncertainty quantification capabilities. Empirical results indicate high prediction accuracy, with Random Forest achieving up to 91% accuracy in Phase 2. This cloud-ready predictive maintenance framework leverages scalable cloud infrastructure for efficient data processing and real-time updates, offering a practical solution for industrial applications. The proposed approach significantly advances the adoption of digital business models within the manufacturing industry, providing a reliable and efficient tool for predictive maintenance.

Preventive Maintenance Planning for Machines Computer Numerical Control (CNC) Type Hurco Vmx24 to Improve Reliability Using the Reability Centered Maintenance (RCM) Method (Case Study)

Abstract: This paper presents the results of the analysis of Computer Numerical Control (CNC) machine components that result in decreased machine efficiency in the production system with the Reliability Centered Maintenance (RCM) approach. Utilized to improve the performance of machine components. The machine has not been maintained regularly so that at any time the machine can experience damage which results in losses to the company's income. so that an analysis is designed for maintenance planning management activities with the methodology of identifying and analyzing failure factors using the Failure Mode Effect Analysis (FMECA) worksheet, Logic Tree Analysis (LTA), and finally the Action Road Map. The results of the analysis carried out are divided into three categories of maintenance actions, namely, Condition Direction (CD) maintenance, Time Directed (TD) maintenance, Finding Failure (FF) maintenance with a periodic checking interval of 2 times within a period of 12 days.

Assessment of Hydraulic Oil Properties during Operation of a Mini Loader

This study employs a rigorous methodology to assess the condition of the hydraulic oil in a recently introduced mini skid-steer loader. The assessment is conducted through laboratory analysis, which adheres to a range of international standards. The objective is to provide accurate insights into the viscosity, particle count, and characterisation of the oil, along with thermographic data. The friction of oil is evaluated at specific time points: 0, 10, 100, 125, and 150 h of operation. This examination offers a comprehensive insight into the alterations in oil characteristics during a pivotal period when machine components are undergoing initial consolidation and abrasion to attain the factory-defined performance thresholds. The principal aim of this research is to provide valuable insights into the wear of oil and hydraulic system components through an in-depth analysis of a range of variables. Moreover, the investigation aims to ascertain the impact of this factor on the temperature elevation of system components and accessories to formulate enhanced technical guidelines for implementation. The main results indicate the presence of particles in the oil, resulting in a cleanliness code of 23/21/13, which exceeds the permissible threshold of 20/18/15 specified in ISO 11171. In addition, hydraulic oil shows a viscosity instability of more than 10% due to moisture absorption, leading to wear of mechanical components composed of iron, nickel, copper, zinc, and silicon. This deterioration is corroborated by thermographic evaluations, which reveal a considerable temperature increase in components such as cylinders and system accessories.

Backlash size identification for servomechanisms with gear transmission devices

Backlash refers to the spaces between the gear teeth in a transmission device for the purpose of lubrication and accommodating thermal expansion of the gears. This space gets wider with time due to wear on machine components, leading to tracking errors on the load side as well as vibration within the system. If the backlash size can be identified by known information, it can not only be used as an index of a maintenance strategy, but also used in a control scheme to compensate for the effects of the backlash. As a result, this paper proposes an approach for identifying the backlash size using actuator-side information only. In the proposed approach, the timing of a backlash event is determined by a Hilbert-Huang Transform-based method to find the instant in time wherein the actuator side and the load side disengage, while the inertia and friction are identified by a 2-step method. Backlash size can be estimated by integrating the velocity difference between the actuator side and the load side. Experimental results verify the effectiveness of the proposed backlash size estimation method.

Experimental investigation of stick-slip behaviors in dry sliding friction

Friction-induced vibration, particularly the bothersome stick-slip behavior, is a significant contributor to machine damage and component failure. In this study, the vibrational displacement, sound pressure, and coefficient of friction (COF) of several metal or alloy samples in dry conditions are tested using a reciprocating friction force test apparatus. It is found that the stick-slip behavior is more likely to occur at low sliding speeds and high normal loads. Furthermore, under the same working conditions, increasing the surface roughness of the sample or enhancing the hardness difference between the sample and the counterpart can mitigate the stick-slip behavior during the friction process. By analyzing the characteristic parameters of the stick-slip behavior, it is found that the temporal period and the stick-time decrease significantly with an increase in relative sliding speed. Additionally, the amplitude and intensity of the friction-induced noise increases with the increase of the relative sliding speed and normal load. The frequencies of the sound pressure are primarily concentrated around the natural frequency of the frictional system. Finally, we extract the COF and find that the average COF as well as the maximum and minimum COF first decreases sharply, and then becomes stable with the increase of the relative sliding speed due to the transition of friction state from stick-slip behavior to smooth sliding.

Image of the solid-state rotary motion encoded in the dielectric response

The future development of advanced molecular systems with controlled rotation requires the development of an effective methodology for assessing the rotational performance of artificial machine components. We identified two patterns of the dielectric behavior for polar rotators in a static non-polar framework of sizable crystal showing relations between the spectral and molecular-level features of solid-state rotary motion. Various functionalization of phenylene rotors with a fluorine atom(s) changed rotational performance from high to low with rotational barriers ranging from 6.06 to 11.84 kcal mol-1. The meta-F-substitution favored rotator-rotator contacts allowing for the implementation of fast rotary motion. Contrary, the presence of rotator-stator contacts inhibited independent rotator dynamics leading to opposite spectral behavior in terms of temperature evolution of loss peak amplitude. Our observations, supported by an analysis based on an asymmetric double well-potential model, show that easily noticeable spectral differences encoded some molecular-level information important for the implementation of rotary motion.

Real time detection of fatigue cracks on steel structures by applying square wave induction

For years the Eddy currents principle together with inductive thermography have been applied to detect cracks or defects in metallic machine components. In case a component has a crack, by inducing Eddy currents within a coil, it is possible to cause a temperature increase in the edges of the crack. This temperature variation can be observed by using an infrared camera. Thus, the crack is registered and observed in the infrared images, which are later analyzed. However, currently used systems require an enormous amount of power and a long time for image processing. For this reason, applying this method to large steel structures such as bridges, cranes, wind power towers, pipe lines or offshore oil stations has been much more complex. To overcome these limitations, a light portable system that optimally recreates the Eddy currents principle has been developed and used in this research. This system generates a square wave AC voltage, it uses considerably less power and it is capable of detecting cracks in real time. This paper presents the simulations and experiments carried out on two different structural steel specimens to demonstrate the efficiency of the system and its potential in the field of nondestructive testing.

Standardization in Tribology

This paper presents an analysis of standards applied in tribology, especially concerning materials, test methods and failures of machine components, related to exploitation under load and motion. By the help of their own research and based on open literature, the authors justify the use of standards in tribology, but also the researchers’ initiative to develop new and more particular test methods and materials with application in tribology, starting from the already standardized ones. The market asks for products that could be rapidly and efficiently assessed by standards, but laboratory work ask for standards in order to compare old and new, original solutions. Thus, using standards does not block the researchers’ work, but helps to point out the new solution and even to develop new materials and test methods that accelerates the introduction of these new solution in actual applications. There are given examples of applying standards in tribology laboratories and how they are used or extend in order to point out a beneficial aspect of the tribological behavior.

Computational Fluid Dynamics Analysis of Erosion in Active Components of Abrasive Water Jet Machine

This study presents a comprehensive three-dimensional computational fluid dynamics (CFD) analysis of abrasive fluid flow and its erosive effects on the active components of the WUXI YCWJ-380-1520 water jet cutting machine. The research investigates the behavior and impact of abrasive particles within the fluid, determining the erosion rates for particles with diameters of 0.19 mm, 0.285 mm, and 0.38 mm (dimensions resulting from the granulometry of the experimentally established sand), considering various abrasive flow rates. The methodology includes a detailed granulometric analysis of the abrasive material, identifying critical particle sizes and distributions, with a focus on M50 granulation (average particle size of 0.285 mm). Additionally, the study employs the Wadell method to determine the shape factor (Ψi = 0.622) of the abrasive particles, which plays a significant role in the erosion process. Experimental determination of the abrasive flow rate is conducted, leading to the development of a second-order parabolic model that accurately predicts flow variations based on the control settings of the AWJ machine. The maximum erosion occurs at the entry surface of the mixing tube’s truncated zone, with a higher intensity as the particle size increases. For the 0.19 mm particles, the erosion rates range from 1.090 × 10−6 kg/m2·s to 2.022 × 10−6 kg/m2·s and follow a parabolic distribution. The particles of 0.285 mm show erosion rates ranging from 2.450 × 10−6 kg/m2·s to 6.119 × 10−6 kg/m2·s, also fitting the second-order parabolic model. The largest particles (0.38 mm) exhibit erosion rates ranging from 3.646 × 10−6 kg/m2·s to 7.123 × 10−6 kg/m2·s, described by a third-order polynomial. The study concludes that larger particle sizes result in higher erosion rates due to their increased mass and kinetic energy. Therefore, the present investigation demonstrates a significant relationship between particle size, abrasive flow rate, and erosion rate, highlighting critical wear points in the machine’s components. The findings contribute to optimizing the design and operational parameters of water jet cutting machines, thereby enhancing their efficiency and lifespan.

Representation of Vending Device using Finite State Automata

Automata theory predominates in a number of applications derived using the technique of a finite state machine . In the paper, we study the representation of a vending machine (VM) that enhances the academic institution’s book delivery service using the concepts of the computation theories. The effectiveness regarding the virtual machine(VM) is viewed as a problem. Automata theory relies on the finite state machine (FSM) design to increase efficiency. The different components of a vending machine are examined at, and it is determined how they can be modelled as finite state machines. We go over the architectural considerations for vending machines, such as the selection of components, the layout of the machine, and the selection of input and output approaches. We use the theory of computation to examine the constraints and difficulties in vending machine design. The paper will design an FSM with fewer states in the end. As a result, we will learn how to increase the VM’s design effectiveness and cost.

Electrical insulation properties in a cold plasma of alumina coating for the in-vessel stabilizing shell of the RFX-mod2 fusion device

This paper presents the results of experimental tests on samples made of copper coated with alumina layer, performed to assess the reliability of its dielectric properties for applications in the low temperature plasma at the edge of a fusion device. The cue of the study was related to the plasma facing components of the RFX-mod2 fusion device (Marrelli et al., 2019, Peruzzo et al., 2023, Peruzzo et al., 2019), devoted to the experimental study of the magnetic confinement of fusion plasmas in a variety of configurations, including the reversed-field pinch and the tokamak. In RFX-mod2 an in-vacuum copper shell for the passive stabilization of MHD modes will surround the plasma. To avoid potentially harmful electrical discharges, which could be induced by rapid transients of the plasma current, this structure must be covered with an electrically insulating layer. For RFX-mod2 an alumina coating was chosen, whose dielectric properties have been tested both in air and in the presence of weakly ionized plasma. Electrical tests, conducted on copper samples with alumina deposits of about 100μm thickness, revealed that the ceramic layer has a high electrical resistance value in air (>1GΩ), but electrical discharges can occur in presence of a weakly ionized plasma, depending on compactness and porosity of the alumina layer, causing local melting of the alumina and expulsion of copper droplets from the substrate. Scanning Electron Microscope (SEM) analyses revealed that in the failed samples the ceramic layer was irregular and rough, with interconnected cavities and cracks, which could reduce its effective thickness and explain the dielectric breakdown at relatively low voltages (<400V). The analyses also showed that samples with a more compact layer present a higher dielectric strength in the presence of the plasma, highlighting that compactness and porosity play crucial roles in ensuring good insulation for materials in a plasma. This study led the definition of the requirements for the insulating coating of the plasma facing components of the RFX-mod2 fusion machine, however the results can be useful for other fusion and non-fusion plasma applications requiring electrical insulation, which can span from industrial devices to spacecrafts.

Experimental Determination of Tensile Stress Concentration Factors of 3D-Printed PLA Polymers: Fillet Radius, Hole Diameter, and Infill Density

3D-printing technology is being used as a regular approach in prototyping and the production of machine components. However, despite their metallic counterparts, there are many issues including infill pattern, density, and stress concentration coefficient in 3D printing that are not well-defined. The infill density plays a significant role in the printing time and mechanical properties of the printed objects. On the other hand, like metallic materials, changing geometry, such as fillet radius and hole alters the strength of the printed elements. In this work, experimental works have been conducted to determine the effect of infill density on the tensile strength of 3D printed elements. Furthermore, various standard specimens for tensile testing have been prepared to investigate the effects of fillet radius and in-plane hole diameters on the tensile strength of PLA 3D-printed elements with different infill density. Using the experimental results, the tensile stress concentration coefficients as a function of fillet radius, hole diameters, and infill density have been determined. The results of the present work can be used as a guideline for analytical design and manufacturing 3D printing objects.

Gels/Hydrogels in Different Devices/Instruments-A Review.

Owing to their physical and chemical properties and stimuli-responsive nature, gels and hydrogels play vital roles in diverse application fields. The three-dimensional polymeric network structure of hydrogels is considered an alternative to many materials, such as conductors, ordinary films, constituent components of machines and robots, etc. The most recent applications of gels are in different devices like sensors, actuators, flexible screens, touch panels, flexible storage, solar cells, batteries, and electronic skin. This review article addresses the devices where gels are used, the progress of research, the working mechanisms of hydrogels in those devices, and future prospects. Preparation methods are also important for obtaining a suitable hydrogel. This review discusses different methods of hydrogel preparation from the respective raw materials. Moreover, the mechanism by which gels act as a part of electronic devices is described.

Effects of TiAlN Coating Thickness on Machined Surface Roughness, Surface Residual Stresses, and Fatigue Life in Turning Inconel 718

The surface roughness and surface residual stresses are affected by the coating thickness of physical vapor deposition (PVD) TiAlN tools, which could alter the service performance of machined components. However, the relationships among the tool coating thickness, the machined surface roughness, the surface residual stress, and the fatigue life are still not sufficiently illustrated. In this research, PVD TiAlN coatings with several thicknesses of 1.6 μm, 2 μm, 2.5 μm, and 3 μm were deposited on carbide tools. Turning experiments using Inconel 718 were conducted with uncoated and various TiAlN tools under flood cooling conditions. The surface roughness could be improved with the selection of thin PVD TiAlN coating thicknesses of 1.6 μm and 2 μm compared to that of uncoated tools. The tensile residual stresses at the machined surface in the directions of cutting speed and feed rate linearly decreased by 148.67% and exponentially decreased by 92.24% when the TiAlN coating thickness was increased from 0 μm to 3 μm. The values of the low-cycle fatigue life of machined Inconel 718 linearly increased by 15.60% with the increase in TiAlN coating thickness from 0 μm to 3 μm, which was mainly due to the improvement of surface residual stresses. The results could provide guidance for the selection of suitable TiAlN coating thicknesses for wet machining Inconel 718 based on the part service conditions.

Bio-Inspired Strategies Are Adaptable to Sensors Manufactured on the Moon.

Bio-inspired strategies for robotic sensing are essential for in situ manufactured sensors on the Moon. Sensors are one crucial component of robots that should be manufactured from lunar resources to industrialize the Moon at low cost. We are concerned with two classes of sensor: (a) position sensors and derivatives thereof are the most elementary of measurements; and (b) light sensing arrays provide for distance measurement within the visible waveband. Terrestrial approaches to sensor design cannot be accommodated within the severe limitations imposed by the material resources and expected manufacturing competences on the Moon. Displacement and strain sensors may be constructed as potentiometers with aluminium extracted from anorthite. Anorthite is also a source of silica from which quartz may be manufactured. Thus, piezoelectric sensors may be constructed. Silicone plastic (siloxane) is an elastomer that may be derived from lunar volatiles. This offers the prospect for tactile sensing arrays. All components of photomultiplier tubes may be constructed from lunar resources. However, the spatial resolution of photomultiplier tubes is limited so only modest array sizes can be constructed. This requires us to exploit biomimetic strategies: (i) optical flow provides the visual navigation competences of insects implemented through modest circuitry, and (ii) foveated vision trades the visual resolution deficiencies with higher resolution of pan-tilt motors enabled by micro-stepping. Thus, basic sensors may be manufactured from lunar resources. They are elementary components of robotic machines that are crucial for constructing a sustainable lunar infrastructure. Constraints imposed by the Moon may be compensated for using biomimetic strategies which are adaptable to non-Earth environments.

Collimator challenges at SuperKEKB and their countermeasures using nonlinear collimator

In SuperKEKB, movable collimators reduce the beam background noise in the Belle II particle detector and protect crucial machine components, such as final focusing superconducting quadrupole magnets (QCS), from abnormal beam losses. The challenges related to the collimator, which were not properly considered at the time of SuperKEKB design, have surfaced through experience with its operation. In this paper, we report the collimator operation strategy in SuperKEKB. In addition, a significant challenge of beam collimation due to the future increase in the beam background is highlighted. We also discuss another issue caused by unexpected and sudden beam losses in the machine that damage collimators, leading to weaker beam collimation performance and an increase in transverse impedance. Furthermore, we introduce a novel collimation approach called the nonlinear collimator (NLC) to address these challenges. We detail the concept of NLC and evaluate their effectiveness by assessing the collimator impedance, beam background reduction, and impact on the dynamic aperture. The possibility of using NLCs as absorber collimators to counteract events that damage the collimator is also shown to be helpful. Published by the American Physical Society 2024

The Impact of an Electric Machine Body on EM Wave Propagation in RTMS

The metallic components of an electric machine exert a notable impact on the electromagnetic transmission between an external recipient and an internal shaft sensor. The RTMS (rotor temperature monitoring system) is aimed at boosting power transfer in the machine, regardless of the considerable impact of its components. This research assesses the influence of the components of an electric machine on shaft sensor transmission and specifically addresses the packaging needs of the receiver antenna. The study includes a comparative analysis of two antennas. HFSS (high frequency structure simulator) simulation was utilized to identify the antenna with a superior propagation factor. The principal contribution of this paper is the assessment of how the electrical machine body affects the transmission and propagation of rotor sensor signals, establishing a connection between these effects and the packaging criteria for the receiver antenna. Moreover, the paper presents an antenna design that capitalizes on the electrical machine body to enhance the power transmission effectiveness. The final section of this paper encompasses the experimental results obtained from the implementation of the RN171 antenna on the electrical machine, provides valuable insights into the propagation characteristics, and contributes to a comprehensive understanding of the electromagnetic dynamics within the system.

Process Parameter Effects on Powder Mixed EDM Machining Characteristics Using Biocompatible Ti-6Al-4V Alloy

This study examines how various process parameters affect the machining properties of a bio-compatible Ti-6Al-4V alloy using PMEDM with silicon carbide (SiC) powder. The parameters investigated include peak current, pulse on/off time, powder concentration, and voltage gap. The study analyzed their effects on material removal rate (MRR), tool wear rate (TWR), surface roughness (SR), and surface morphology. A central composite design was used in the tests to make empirical models that use response surface methods to link the process parameters to the machining results. It is found that the Pulse current and Ton influence the material removal rate and the surface roughness significantly. The powder concentration also impacts PMEDM's machining performance. The Scanning electron microscopic images reveal the effect of powder seen in the machined components. The crater, micro cracks and machining marks can be seen in the SEM images. The surface integrity is correlated with the output parameters of surface roughness. The developed mathematical models effectively predict and optimize the machining properties of Ti-6Al-4V alloy using PMEDM with SiC powder. This research offers valuable insights for applying PMEDM in the fabrication of biomedical implants and devices made from Ti-6Al-4V alloy.

Wear Mechanism of an AlCrN-Coated Solid Carbide Endmill Cutter and Machined Surface Quality under Eco-Friendly Settings during Open Slot Milling of Tempered JIS SKD11 Steel

In the die and mold industry, tempered JIS SKD11 steel is selected to manufacture cold-forming dies that require an optimum balance of toughness, strength, and wear resistance. Therefore, the machinability of tempered JIS SKD11 in the milling machining process is challenging. The use of eco-friendly machining settings is intended to diminish tool wear and enhance the quality of the machined surface as well as the accuracy of the machined components. Adapting to the aforementioned factors for cold-forming dies is a pivotal issue. In this study, the machinability of tempered JIS SKD11 steel was analyzed under dry, MQL, cryogenic cooling with liquid nitrogen (LN2), and liquid carbon dioxide (LCO2) machining settings during open slot milling operations with varying input parameters, including cutting speeds and cutting feeds. An in-depth evaluation of output responses, including tool wear, surface roughness, cutting temperature in the cutting zone, and microhardness of the machined surface, was also conducted. The findings unveiled that the flank wear of the cutters and surface roughness of the machined surfaces obtained minimum values of 0.22 mm and 0.197 µm, respectively, during open slot milling operations at a cutting speed of 100 m/min and a cutting feed of 204 mm/min under cryogenic cooling with liquid carbon dioxide (LCO2). The findings from this study suggest that employing cryogenic cooling with LCO2 could serve as a viable substitute for dry, MQL, and cryogenic cooling with LN2 methods to enhance the machinability of hardened JIS SKD11 steel.

Preliminary architecture design for human-in-the-loop control of robotic equipment in remote handling tasks: Case study on the NEFERTARI project

In this work, we present a general control architecture for robotic systems dedicated to the remote handling of in-vessel components in fusion machines. This control architecture will be tested for the inspection and maintenance of the first wall components of the RFX-mod2 experiment, in the scope of the New Equipment For the Experimental Research and Technological Advancement for the Rfx Infrastructure (NEFERTARI) project. The architecture is split into low-level and high-level layers. The former is used for the low-level control of the robotics systems and to manage safety; the latter is used for the high-level planning and implements several sub-modules, such as a Virtual Reality (VR) environment for the visualisation of the robot’s digital twin. Moreover, an Application Programming Interface (API) is intended to connect the two layers, and the communication between modules and layers is provided by the ROS2 framework. A typical usage of such a framework involves a human operator who is teleoperating the real robot, data from motor encoders are used as inputs for the dynamic model module. This module is used to compute the forward dynamics in real-time, providing an accurate simulation of the robot (digital twin) in the virtual environment.