Mechanical Transmission Research Articles

The transient concept of bearings: a novel strategy for RUL prediction

Abstract Bearings serve as integral components in mechanical devices, providing stability during mechanical transmission and reducing friction coefficients. Hence, the precise prediction of bearing remaining useful life (RUL) is paramount for the health monitoring of mechanical systems. However, traditional techniques which utilize linear degradation processes for constructing health index models often fail to adequately portray the complex relationship between degradation and time. To rectify this, we introduce The Transient Concept of Bearings and determine the degradation rate predicated on this novel concept. We construct a degradation rate model for bearings using a K-means-transformer network and leverage transfer learning methodologies to predict the RUL of bearings. Validation of the proposed concepts and demonstration of their accuracy are achieved using the PHM2012 challenge dataset, even amidst incomplete data scenarios. When compared to existing RUL prediction models, our approach not only significantly improves prediction accuracy but also sheds valuable insights into the bearing degradation process.

Design, Load Analysis and Optimization of Epicyclic Gear Trains

Abstract: Mechanical power transmission systems rely heavily on Epicyclic gear trains, as their failure can compromise the entire system. Consequently, identifying and mitigating the causes of gear failure is crucial. Various gear failure modes, including bending pitting (contact stresses), failure (load failure), abrasive wear, and scoring, are discussed in literature by J.R. Davis(2005) [24], Khurmi & Gupta (2006) [23], and P. Kannaiah (2006) [21][22]. These failures are often linked to the loads acting on the gears. This research focuses on optimizing gear design to reduce gear load failure. Table 1 summarizes various research efforts on Epicyclic gear trains conducted by different authors. This study delves into the optimization of epicyclic gear trains in India to minimize load failure. The analysis focuses on optimizing the gear train through load analysis of the pinions, gears, and annulus, including the sun and planet gears. The goal is to determine the optimal load conditions for the gear train to function effectively without succumbing to load failure. Epicyclic Gear Trains are widely used in industry due to their numerous advantages, including high torque capacity, improved efficiency, relatively smaller size, lower weight, and a highly compact package. However, there has been no comprehensive study of their load-bearing performance with respect to various parameters such as rotational speed, material, and power. This research paper aims to fill this gap by investigating the load performance of epicyclic gear trains under different parameters such as loading conditions and rotational speeds. This process helps in identifying the optimized design of epicyclic gear trains, ensuring optimal performance and minimizing gear loads and choosing correct rotational speed. The primary objective of this research investigation is to optimize epicyclic gear trains through load analysis to prevent future load failures.

A mechatronic seed metering control system for improving sowing uniformity of planters

One of the most crucial aspect of a planter's performance lies in its ability to distribute the seeds at uniform spacing within the row. Conventional planters experience non-uniformity in seed spacing due to ground wheel skidding and high vibration prevalent with their ground wheel-driven mechanical transmission units. In addition, the seed spacing adjustment process in these machines is also very tedious and time-consuming. In this study, an embedded mechatronic seed metering control system that uses an electric motor instead of a ground-engaging wheel to drive the seed metering units was developed to address the challenges associated with conventional planters. This system was mainly comprised of an electric motor, motor controller, relay switches, microcontroller board, radar sensor, and 12 V battery. The developed system was incorporated with a conventional inclined plate planter, and the test planter's performance was evaluated in electric motor-driven (EMD) and ground wheel-driven (GWD) modes. The field-testing results demonstrated a significant improvement in the seed spacing uniformity with the EMD mode compared to the GWD mode, through an increase of 8.12–21.32% in the quality of feed index and a reduction of 11.82–19.73% in the precision across a speed range of 1.6–4.8 km/h. These findings confirm the effectiveness of the newly developed control system in addressing the problem of non-uniform seed spacing in conventional planters.

The Phylogenetic Characterization of Cockroaches (Insecta: Blattaria) in Türkiye and Determination of Their Vector Potential for Medically Important Parasites

This study was performed to investigate the phylogenetic characters of the cockroaches in XXX region for mitochondrial cytochrome c oxidase subunit I (mt-COI), mt-COII, and internal transcribed spacer-2 (ITS-2) gene regions, and to determine their mechanical transmission of medically important parasites. PCR-restriction fragment length polymorphism (RFLP) was performed using mt-COI, mt-COII, and ITS-2 DNA gene regions to identify cockroach species (n=220) collected from different regions. Differentiation of cockroach species was based on RFLP models using two restriction enzymes: AvaI and EciI. For phylogenetic analysis, mt-COI, mt-COII, and ITS-2 DNA barcode regions were amplified with standard primers. The amplicons obtained were purified and sequenced with PCR primers. According to PCR-RFLP, cockroach species were identified as Blattella germanica (n =105), Blatta orientalis (n = 86), and Periplaneta americana (n = 29). A total of 13 haplotypes were detected and Maximum likelihood (ML) analyses revealed that the sequences of all three species for the three gene regions showed monophyletic structuring. The cockroaches were examined for the presence of parasites. It was determined that of the 58 parasitic forms identified belonged to helminth species 46 (79.3%) and protozoan species and 12 (20.7%). The results showed that B. germanica (58.6%) had the highest prevalence, followed by Bl. orientalis (32.8%) and P. americana (8.6%). The study findings not only contribute to the molecular epidemiology of cockroaches but also confirm that they play an important role as mechanical vectors of protozoan and helminth parasites.

Robust data-driven design of a jamming detection filter for airborne electromechanical actuators

The electrification of the actuations on aircraft is a technological trend towards a greener aviation. Electromechanical Actuators (EMAs) are a key item in the more electric aircraft concept. However, EMAs are still prone to the jamming of their mechanical transmission, leading to possible incidents when flight surfaces can no longer be controlled. Jamming detection algorithms are thus envisaged. In this paper, we conduct a large experimental campaign on a 1:1 scale airborne EMA and design a robust data-driven jamming detection algorithm. The designed algorithm is compared with a traditional non-robust model-based jamming detection algorithm design. The benefits of robust data-driven approach are experimentally evaluated on real faulty data with several performance indexes.

Characterization of a Putative New Member of the Genus Potyvirus from Kudzu (Pueraria montana var. lobata) in Mississippi.

Kudzu (Pueraria montana var. lobata), a plant native to Southeastern Asia, has become a major noxious weed covering millions of hectares in the Southern United States. A kudzu patch displaying virus-like symptoms located in Ackerman, northeastern Mississippi (MS), was used as a source for virus isolation and characterization involving mechanical and vector transmission, ultrastructural observation, surveys, Sanger and high-throughput genome sequencing, and sequence analyses. The results revealed the presence of a new potyvirus in infected kudzu, closely related to wisteria vein mosaic virus (WVMV) and provisionally named kudzu chlorotic ring blotch virus (KudCRBV). Genome features and pairwise comparison with six WVMV genomes currently available in GenBank and three additional isolates from MS sequenced in this work suggest that KudCRBV is likely a member of a new species in the genus Potyvirus. Furthermore, under experimental conditions, KudCRBV was successfully transmitted by cotton and potato aphids and mechanically to soybean and beans. A state-wide survey revealed several kudzu patches infected by the virus in northern MS.

Design and characterization of a novel motion conversion element: curved groove ball bearing without retainer

An unconventional and innovative mechanical transmission component, the curved groove ball bearing without retainer (CGBBR), is introduced in this article to facilitate the conversion between rotational and reciprocating motion. The CGBBR boasts several advantages over conventional motion conversion mechanisms, including a streamlined and compact structure, as well as the mitigation of high-order vibrations. This article delves into the design methodology, structural attributes, kinematic principles, and dynamic response properties of the CGBBR. A novel design method named closed curve envelopment theory is proposed to generate the distinctive spatial surface structure of the CGBBR. Moreover, a design scheme is presented that employs the concept of diameter-stroke ratio for CGBBR implementation. A calculation methodology is also introduced for determining the number of rolling elements within the CGBBR, which serves as the foundation for subsequent optimization design. This article deeply analyzes the kinematics principle of CGBBR and provides a new insight of motion conversion in mechanism.

The Effectiveness of Using Continuous Variable Transmission (CVT) in 2WD Buggy Vehicles

Continuous Variable Transmission (CVT) is a transmission system that does not have gears like in manual transmission cars or conventional automatic transmission cars. CVT has the advantage of being able to maintain the proper rotational speed at any time in terms of engine efficiency by changing the speed ratio flexibly and continuously. A continuously variable transmission (CVT) is a transmission that can change steplessly through an infinite effective gear ratio between maximum and minimum. This is in contrast to other mechanical transmissions which only allow a few different gear ratios to choose. The flexibility of the CVT allows the drive shaft to maintain a constant angular speed over the output speed range. Torque is transmitted from the drive to the pulley which is driven by friction acting between the belt and pulley surfaces. Tests were carried out using a dynotest to obtain wheel rotation data and the resulting torque. The loading is given from 3 kg, 5 kg, 7 kg and 8 kg, the engine rpm used is 5500 rpm, 6000 rpm, 6500 rpm, 7000 rpm and 8000 rpm. Rear wheel rotation is inversely proportional to the load, the greater the load the rotation will decrease. Load is directly proportional to torque, the greater the load given the torque will increase. The CVT system is still effective for use as a power successor. The power that can be transmitted is still greater than 50%, namely 68%.

Modelling and Analysis of Dynamic Servo Error of Heavy Vertical Machining Centre Considering Nonlinear Factors

The dynamic servo error of heavy-duty vertical machining centres is one of the decisive factors affecting the machining accuracy of large and complex parts. Due to the characteristics of large mass, large load, and the large travel distance of the machine tool, non-linear factors such as friction, backlash, and lateral shift are more likely to cause unstable behaviours such as stick-slip and oscillation of the servo feed system of the machine tool, and reduce the performance and servo accuracy of the motion axis. In this paper, to consider the influence of non-linear factors such as friction, backlash, and lateral shift, an appropriately simplified representation of the mechanical transmission system of the ball screw has been used. According to the control structure of the Siemens 840D numerical control system, a theoretical model of the servo feed system for the heavy-duty vertical machining centre was established based on three-loop control. Then, the single-axis and double-axis closed-loop simulation models of the servo feed system were built in Simulink, and the influence pattern of control parameters and nonlinear factors on the dynamic servo error was obtained through simulation analysis. Finally, the validity of the theoretical model for the servo feed system was verified through a comprehensive comparison of simulation and experimental outcomes. This encompasses an analysis of the control system Bode plots, critical stick-slip velocity, and tracking errors in the X-axis with linear motion. The validation provides theoretical guidance for parameter design and mechanical adjustments of the servo feed system in heavy-duty vertical machining centres.

Optimization Analysis on the Transmission Characteristics of Multipurpose Power Transmission Devices

Particularly crucial throughout the mode transition procedure is the transmission properties of hydro–mechanical composite transmission devices. This paper describes a multipurpose power transmission device that integrates hydrostatic, hydro-mechanical, and mechanical transmission and mainly discusses the transmission characteristic optimization problem from the perspective of speed regulation characteristics, shift strategy, and efficiency characteristics. The kinematic and dynamic analysis of the transmission system, the assembly scheme, and relevant parameters of the power transmission device are analyzed, and the speed regulation characteristic curve is obtained. The shift strategy of power transmission devices involving clutches and brakes during the whole speed regulation process and the best switch time of each component are found. The efficiency expression of the static pressure system is obtained from the efficiency model of the pump-control-motor system, and the efficiency of the multi-purpose power transmission device is obtained using the efficiency definition method. The fitting curves of hydrostatic system efficiency are determined using experimental data, and the efficiency of the hydro–mechanical composite power transmission system is obtained using the conversion mechanism method. The results show that the shift quality of power transmission devices can be improved greatly by controlling the switch sequence of clutches and brakes reasonably.

Motion, Static Force, and Efficiency Analysis of Planetary Gear Transmission Based on Graph Theory

This paper employs graph theory to analyze kinematic relationships, static force, and power flow for planetary gear systems. We start from the graphs of these trains to determine all the structurally distinct kinematic inversions. We then obtain all the constructive solutions resulting from every possible combination of gear configuration. Based on the kinematic and static force analysis model, related matrices are acquired. Hence, a kinematic and static force analysis of the planetary gear mechanism is achieved. The link power can be determined by the link speed and torque. Power flow diagrams of each gear are acquired. The efficiency is calculated by the transmission ratio method. This analysis is useful in the design of power transmission applications. A planetary gear system of a 6HP26 automatic transmission is further illustrated for the motion, static force, and efficiency calculations by using graph theory technique and matrix equations. This paper provides a guide for engineers in gear transmission fields to easily finish mechanical transmission design.

Comparative tribological performance of a-C:H, ta-C and AlCrSiN coatings on 20CrMnTi gear steel under dry sliding condition

PurposeThis study aims to investigate the surface modification on 20CrMnTi gear steel individually treated by diamond-like carbon films and nitride coatings.Design/methodology/approachFor this purpose, the mechanical properties of a-C:H, ta-C and AlCrSiN coatings are characterized by nano-indentation and scratch tests. The friction and wear behaviors of these three coatings are evaluated by ball-on-disc tribological experiments under dry contact conditions.FindingsThe results show that the a-C:H coating has the highest coating-substrate adhesion strength (495 mN) and the smoothest surface (Ra is about 0.045 µm) compared with the other two coatings. The AlCrSiN coating shows the highest mean coefficient of friction (COF), whereas the ta-C coating exhibits the lowest one (steady at about 0.16). The carbon-based coatings possess excellent self-lubricating properties compared with nitride ceramic ones, which effectively reduce the COF by about 64%. The major failure mode of carbon-based coatings in dry contact is slight abrasive wear. The damage of AlCrSiN coating is mainly adhesive wear and abrasive wear.Originality/valueIt is suggested that the carbon-based film can effectively improve the friction-reducing and wear resistance performance of the gear steel surface, which has a promising application prospect in the mechanical transmission field.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0129/

Digital and analysis of alarm clock design based on Multisim

With the development of technology and the times, virtual simulation technology represented by Multisim has been widely used, and simulation technology is also an indispensable part of industrial design. This article uses Multisim simulation technology to design and complete a digital electronic clock based on a 74ls160 counter, composed of a decoder, a display, a numerical comparator, and an alarm clock. In this design, digital circuits are used to display and adjust "time", "minute", and "second". By using various integrated digital chips to build circuits to achieve corresponding functions. It successfully realizes the functions of calibrating the time, reporting the time on the hour, and alarming the clock. Compared with traditional electronic clocks, it has the characteristics of accurate travel, intuitive display, and no mechanical transmission, The research in this paper will contribute to the further application of virtual simulation software in the design of small devices, and will not lay a foundation for the future industrial design process.

Analysis of the principle of mechanical transmissions and their advantages and disadvantages

As the proportion of cars in our lives gradually increases, the proportion of cars in the market also gradually increases. How to make it an efficient transportation is the problem we need to consider as well as solve. In order to study the improvement direction of the three transmissions (MT, AT, CVT) which are more common in the market, this paper uses the internet to collect and integrate the information, from the structure and principles of the transmission as the research direction, to analyze the advantages and disadvantages of the transmission so as to find out the areas that can be improved. It was found that MT gearboxes offer a higher degree of freedom than AT gearboxes, but the more complex driving conditions in the city can lead to frequent gear changes in MT gearboxes, thus affecting the driver's attention to a certain extent.

Epidemiology and Transmission of Theileria orientalis in Australasia.

Oriental theileriosis, a disease primarily impacting cattle is caused by an apicomplexan hemoprotozoan parasite, Theileria orientalis. It has now become established in the Australasia region. The organism was long considered a benign cause of persistent infections; however, an increase in clinical outbreaks since 2006 in the eastern Australian states and New Zealand was associated with the identification of the pathogenic Ikeda (Type 2) and Chitose (Type 1) genotypes. Unlike the pathogenic T. parva and T. annulate, which target leucocytes, clinical manifestation with T. orientalis is due to its effects on erythrocytes, with the infection sometimes designated as Theileria associated bovine anemia (TABA). In Australia and New Zealand, the tick Haemaphysalis longicornis is the principal vector, though other Haemaphysalis species are also likely vectors. The endemic status of infection with pathogenic genotypes in areas with low or absent tick populations is an apparent paradox that may be attributable to alternative modes of transmission, such as mechanical transmission by hematophagous insects (lice, mosquitoes, and biting flies), vertical transmission, and transmission via iatrogenic means. This review addresses the evidence for the different modes of transmission of T. orientalis with particular focus on the reported and potential vectors in Australasia.

A new fault feature extraction method of rolling bearings based on the improved self-selection ICEEMDAN-permutation entropy

The vibration signals of rolling bearings are complex and changeable, and extracting meaningful features is difficult. Currently, the commonly used empirical mode decomposition (EMD) algorithms have the problem of mode aliasing. In this paper, a new feature extraction method based on the improved complete ensemble empirical mode decomposition with adapted noise (ICEEMDAN) and permutation entropy is proposed. In this method, the ICEEMDAN algorithm is first improved and optimized to enable a self-selection function The vibration signal is then decomposed into several intrinsic modal functions using this algorithm, and the permutation entropy is extracted as the fault feature of rolling bearings, which improves the accuracy of fault classification and realizes the intelligent feature extraction of different fault states. Then, the Case Western Reserve University dataset is used for verification, and the results show that this scheme can effectively separate the vibration signal characteristics of bearings in different states, and can be used to characterize the characteristics of different bearing signals. Finally, based on the mechanical transmission system bearing experimental platform independently developed by our school, the experimental results show that compared with the unimproved ICEEMDAN algorithm, the diagnostic accuracy rate of the proposed method is 99.5%, which is increased by 6.4%, and it can be effectively used for feature extraction of rolling bearings.

Diversity of Anaplasma and novel Bartonella species in Lipoptena fortisetosa collected from captive Eld's deer in Thailand.

Lipoptena insects are important ectoparasites of cervids and may affect humans that are incidentally bitten. The presence of zoonotic pathogen DNA, such as Anaplasma, and Bartonella, raises the importance of Lipoptena insects in veterinary and human medicine. Eld's deer (Rucervus eldii thamin), an endangered wild ruminant in Thailand, are bred and raised in the open zoo. The semi-wild zoo environment suggests ectoparasite infestation and potential risk for mechanical transmission of pathogens to visitors, zoo workers, or other animals. However, epidemiology knowledge of pathogens related to endangered wild ruminants in Thailand is limited. This study aims to determine the prevalence and diversity of Anaplasma and Bartonella in the L. fortisetosa collected from captive Eld's deer in Chon Buri, Thailand. Of the 91 Lipoptena DNA samples obtained, 42 (46.15%) and 25 (27.47%) were positive for Anaplasma and Bartonella by molecular detection, respectively. Further, 42 sequences of Anaplasma (4 nucleotide sequence types) showed 100% identity to those detected in other ruminants and blood-sucking ectoparasites. Twenty-five sequences of Bartonella (8 nucleotide sequence types) showed 97.35-99.11% identity to the novel Bartonella species from sika deer and keds in Japan. Phylogenetic trees revealed Anaplasma sequences were grouped with the clusters of A. bovis and other ruminant-related Anaplasma, while Bartonella sequences were clustered with the novel Bartonella species lineages C, D, and E, which originated from Japan. Interestingly, a new independent lineage of novel Bartonella species was found in obtained specimens. We report the first molecular detection of Anaplasma and Bartonella on L. fortisetosa, which could represent infectious status of captive Eld's deer in the zoo. Wild animals act as reservoirs for many pathogens, thus preventive measures in surrounding areas should be considered to prevent pathogen infection among animals or potential zoonotic infection among humans.

Dynamic modelling of locomotive with direct drive traction system considering electromechanical coupling effect

Permanent magnet synchronous motors (PMSMs) have been employed in the direct drive traction system of locomotives as the traction motor. Due to the unique traction structure of the direct drive system, complicated excitations such as track irregularity and harmonic torque have a direct effect on the dynamic performance of the motor and other key components of the locomotive. However, the dynamic characteristics under this effect and influencing law have not been revealed completely. This paper develops a dynamics model of a locomotive with direct drive traction system which enables considering the electromechanical coupling effect between the vehicle subsystem and the PMSM control subsystem. The nonlinearity of the wheel–rail contact and flexible transmission coupling are taken into account in this model. By using this model, the dynamic responses of the locomotive are analysed under electrical and mechanical excitations. The results indicate that the harmonic components in the electrical subsystem have considerable effects on the key components of the locomotive, such as the wheelsets and the motors. It can also cause resonance in the mechanical transmission system when the locomotive is operating at a specific speed. This resonance can be eliminated by adopting the harmonic suppression algorithm.

Cell Activities on Viscoelastic Substrates Show an Elastic Energy Threshold and Correlate with the Linear Elastic Energy Loss in the Strain‐Softening Region

Energy‐sensing in viscoelastic substrates has recently been shown to be an important regulator of cellular activities, modulating mechanical transmission and transduction processes. Here, this study fine‐tunes the elastic energy of viscoelastic hydrogels with different physical and chemical compositions and shows that this has an impact on cell response in 2D cell cultures. This study shows that there is a threshold value for elastic energy (≈0.15 J m−3) above which cell adhesion is impaired. When hydrogels leave the linear stress–strain range, they show softening (plastic) behavior typical of soft tissues. This study identifies a correlation between the theoretical linear elastic energy loss in the strain‐softening region and the number of cells adhering to the substrate. This also has implications for the formation of vinculin‐rich anchorage points and the ability of cells to remodel the substrate through traction forces. Overall, the results reported in this study support that the relationship between cell activities and energy‐sensing in viscoelastic substrates is an important aspect to consider in the development of reliable ex vivo models of human tissues that mimic both normal and pathological conditions.

First Report of Passiflora latent virus in Passion fruit (Passiflora edulis) in China.

Passion fruit (Passilora edulis, family Passifloraceae.) is an economically important fruit crop in many tropical and subtropical regions worldwide. It is widely planting in southern China, and in greenhouses throughout the country. In Mar 2022, symptoms of a viral-like infection were observed on the leaves of passion fruit plants in a 3-hectare greenhouse complex in Hohhot, China. Chlorotic lesions were observed on leaves of two vines of passion fruit and symptomatic leaves developed chlorotic spots, followed by systemic leaf chlorosis and necrosis. Dark ringed spots emerged on the surface of matured fruits (Figure 1). To confirm infectivity, mechanical transmission of the virus was performed by grinding leaves from two symptomatic passion fruit vines in 0.1M phosphate buffer pH 7, and the resulting two samples were each used to rub-inoculate carborundum-dusted leaves of three healthy passion fruit seedlings. Newly emerging leaves of inoculated plants developed mild mosaic symptoms 30-days after inoculation. Three samples from each of the two original symptomatic plants and two samples from each inoculated seedling tested positive using a Passiflora latent virus (PLV) ELISA Kit (Creative Diagnostics, USA). To further confirm the virus identity, total RNA from leaf samples from one of the original greenhouse symptomatic plants and one of the inoculated seedlings were extracted using an TaKaRa MiniBEST Viral RNA Extraction Kit (Takara, Japan). The two RNA samples were subjected to reverse transcription-polymerase chain reaction (RT-PCR) tests with virus specific primers PLV-F (5'-ACACAAAACTGCGTGTTGGA-3') and PLV-R (5'-CAAGACCCACCTACCTCAGTGTG-3') (Cho et al., 2020). RT-PCR products of the expected 571 bp were obtained from both the original greenhouse sample and inoculated seedling. Amplicons were cloned into the pGEM-T Easy Vector, and two clones per sample were Sanger sequenced bidirectionally (Sangon Biotech, China), and the sequence of one clone from one of the original symptomatic sample was uploaded to NCBI (GenBank OP320922.1). This accession had 98% nucleotide sequence identity with a PLV isolate from Korea (GenBank: LC556232.1). RNA extracts from two asymptomatic samples tested negative for PLV with both ELISA and RT-PCR tests. We also tested the original symptomatic sample for common occurring passion fruit viruses, including passion fruit woodiness virus (PWV), cucumber mosaic virus (CMV), east asian passiflora virus (EAPV), telosma mosaic virus (TeMV), papaya leaf curl Guangdong virus (PaLCuGdV), and the RT-PCR results were negative for those viruses. However, based on the systemic leaf chlorosis and necrosis symptoms, we cannot preclude a mixed infestation of other viruses. PLV affects fruit quality and has high potential to reduce market value. To our knowledge, this is the first report of PLV in China, which could provide a reference basis to PLV identification, prevention and control. Acknowledgments This research was carried out with the support of Inner Mongolia Normal University High-level Talents Scientific Research Startup Project (Grant no. 2020YJRC010). Supplementary material Figure 1. Mottle, leaf distortion, puckering symptoms on old leaf (A), mild puckering symptom on young leaf (B), and ring-striped spots symptoms on fruit (C) of the PLV infected passion fruit plant in China.