Gear Technology Research Articles

A Review of Energy use and Carbon Footprint in Fishing with special reference to Life Cycle Assessment (LCA)

With over 4.1 million vessels operating worldwide the global fishing industry is critical for ensuring food security and supporting livelihoods. Asia leads in the total number of vessels globally with 2.68 million vessels which are operational, while India has about 0.166 million vessels (FAO, 2024). The fishing industry heavily depends on fossil fuels for fishing operations, which contributes significantly to greenhouse gas emissions. In 2011 alone, global fisheries consumed 40 billion litres of fuel, resulting in 179 million tonnes of CO2 emissions, which is about 4% of total emission from global food production (Parker et al., 2018). In Indian scenario fuel consumption and thus CO2 emissions per tonne of fish landed, have increased from 0.50 tonnes in 1961 to 1.52 tonnes in 2024. Mechanized and motorized vessels contributed the most to emissions, with trawlers emitting up to 1.43 tonnes of CO2 per tonne of fish. The economic challenges posed by rising fuel prices and inefficiencies in operations are highlighted in many fisheries, including India, where high fuel consumption and associated costs limits capacity utilization by up to 55% in many cases. This review examines strategies used for reducing energy use and emissions in fisheries and explores best strategies to minimize emissions from fishing fleet. Innovations in vessel design, fuel-efficient engines, and advanced gear technologies can be effective solutions for reducing energy use and emissions. Additionally, practices such as conducting energy audits, optimizing routes, and transitioning to alternative fuels like LNG and biogas can significantly improve sustainability. While traditional approaches based on fuel consumption provide a comparative understanding of energy use, Life Cycle Assessment (LCA) frameworks offer deeper insights into environmental impacts, making them valuable for shaping policies and practices that promote both economic and environmental sustainability in the fisheries sector.

Electromagnetic performance analysis of a novel radial compound differential field-modulated magnetic gears

PurposeThe purpose of this study is to propose a new magnetic gearing device and the proposed transmission model can be applied in the field of wind power and wave energy generation gearboxes.Design/methodology/approachA novel radial differential field-modulated two-stage magnetic gear is introduced, using a unique radial differential linkage to integrate two single-stage magnetic gears. This design incorporates a magnetic isolation ring to enhance transmission efficiency by minimizing magnetic interference and preventing power circulation. The two-stage modulating ring rotor operates synchronously via a connecting bridge, ensuring system stability and efficiency. This configuration not only boosts the gear ratio but also maintains a compact structure, improving power density and efficiency. Leveraging the magnetic field modulation and differential transmission, a finite element model of this gear is developed and its electromagnetic performance is analyzed.FindingsThe torque density of the new radial differential field-modulated two-stage magnetic gear has increased by 44.97% compared to the traditional tandem two-stage magnetic gear. It achieves a high transmission ratio of 64 and maintains comparable power density, indicating strong torque transfer capabilities suitable for low-speed, high-torque applications. During steady-state operation, the torque pulsation difference between the two stages is minimal, ensuring stable working torque.Social implicationsThis research not only propels the forefront of magnetic gear technology through heightened efficiency and streamlined design but also bears profound societal significance in fostering sustainable energy paradigms. By facilitating superior energy conversion efficiencies in wind turbines and wave energy converters, it plays a pivotal role in mitigating carbon emissions and accelerating the global pivot towards cleaner, renewable energy landscapes.Originality/valueA magnetic gear transmission device is proposed, which can achieve high power density and large transmission ratio at the same time, and this study provides a useful reference for the design optimization of new high-performance multistage magnetic gears.

The Concept of Technological Support of Operational Properties Based on Stabilization of Mechanical Properties of Gear Materials in a Gas Turbine Engine Drive System

Modern production of gears for gas turbine engines for aviation, marine and land use is inherently related to the calculation of the stress state of the working surfaces of the mating teeth. To create conditions for the operability of the gear train and the drive system as a whole, an engineering analysis of the contact endurance of the mating surfaces is a necessary criterion. The contact strength determines the life of the gear mechanism. The value of the contact strength, taking into account its distribution in the contact zone of the working mating surfaces of the gears, is determined by the processing technology and operation, but the mechanical properties and texture of the material have the greatest influence. This determines the requirements for the stability of the mechanical properties of the materials used for the manufacture of gears, making a topical question on their study. The technology of manufacturing the gears in the gas turbine engine drives forms the layer structure of the toothed crown because of the use of chemical-thermal treatment. The surface hardened layer of the gear tooth after chemical-thermal treatment is saturated with carbon and nitrogen, and as a result of thermal action acquires mechanical properties and structure different from the material in the supply. The paper presents the results of practical research of evolution of mechanical properties of structural steels 20H3MVF-Sh, 18H2N4MA, 16H3NVFM-Sh and 12H2N4A-Sh based on various types of chemical-thermal treatment, as well as microstructure of toughened layer and core of the part. The steel mechanical properties stabilization evaluation in the process of gear technology was performed. The presented results of experimental studies of mechanical properties of the material prove stabilization of mechanical and structural indicators, which are responsible for the contact strength of the mating surfaces of toothed gears.

Optimizing Structural Steel Spur Gear Design for Reduced Stress Concentrations in Industry 4.0 Using Finite Element Analysis

Abstract: The advent of Industry 4.0 has highlighted the importance of spur gears in power transmission across the automotive, aerospace, and marine industries. However, these gears are susceptible to failure due to bending and contact stresses from fatigue. Designing an involute gear profile presents challenges, particularly in managing tooth root stresses and avoiding interference. This study tackles these issues through comprehensive stress analysis, using modeling and FEM assessment. The focus is on evaluating bending stresses at critical locations and identifying strategies to reduce stress concentrations at the gear tooth root. By enhancing gear robustness, this research could contribute to potential patents in gear technology. Background: Spur gears are crucial for power transmission but often fail due to fatigue-induced stresses and design challenges at the tooth root. Objective: This study aims to address spur gear design challenges through comprehensive stress analysis, using modeling and FEM to assess bending stresses and explore strategies to reduce stress concentrations at the tooth root. Methods: The research uses SolidWorks and ANSYS for FEM analysis, focusing on bending stresses and exploring modifications in gear design using various materials for optimization. Results: The analysis shows strategic modifications to the gear's fillet radius and addendum can reduce stress at the tooth root by 38.26%, with stainless steel being the optimal material for enhanced gear strength. Conclusion: The study emphasizes strategic adjustments in fillet radius and addendum to reduce stress in spur gears, highlighting stainless steel's superior performance for optimized design and enhanced strength.

Research on Anti-Rollover Adaptive Landing Gear Technology Based on Impedance Control

During the Vertical Take-Off and Landing (VTOL) of a rotorcraft, there is a high risk of instability and safety incidents due to the possibility of one side of the landing gear making initial contact with the ground, particularly under extreme environmental conditions and maneuvers. Furthermore, the varied performance of adaptive landing gear necessitates a landing control approach that specifically targets both sides of the adaptive landing gear. This study proposes a method that regulates the landing gear first touchdown side through an impedance controller to guarantee the stability of the rotorcraft and then tilts the landing gear toward the rear landing leg side, followed by a soft and smooth landing through the rear landing leg. This approach accomplishes steady adaptive VTOL of the rotorcraft. The fall vibration test results demonstrate that the adaptive landing gear system with impedance control has excellent adaptive landing functionality, which can handle not only landing on uneven ground at various points but also cope with different ascent rates and ground friction during stable takeoff/landing.

3D Numerical Simulation for Thermal Protection of Phase Change Material-Integrated Firefighters' Turnout Gear.

This work aims to investigate and develop a novel phase change material (PCM)-integrated firefighters' turnout gear technology that would significantly enhance the thermal protection of firefighters' bodies from thermal burn injuries under high-heat conditions (such as in fire scenes). This work established a 3D human thermal simulation to explore the thermal protection improvements of firefighters' turnout gear by using PCM segments under flashover and hazardous conditions. This simulation study will guide future experimental design and testing effectively and save time and effort. The study found that the 3.0-mm-thick PCM segments with a melting temperature of 60°C could extend the thermal protection time for skin surface to reach second-degree burn injury (60°C) by one to three times under flashover conditions compared to the turnout gear without PCM. Moreover, thinner PCM segments, i.e., 1.0-3.0 mm thickness, could also significantly mitigate the skin surface temperature increase while avoiding the added weight on the turnout gear. The 3D modelling results can be used to develop a next-generation firefighter turnout gear technology.

A Review of Magnetic Gear Technologies Used in Mechanical Power Transmission

This paper presents a literature review on magnetic gears, highlighting the advantages of using these technologies for mechanical power transmission applications in wind energy conversion systems and transportation, such as in electric vehicles. Magnetic gear technologies have important advantages over their mechanical counterparts. They can perform the speed change and torque transmission between input and output shafts by a contactless mechanism with a quiet operation and overload protection without the issues associated with conventional mechanical gears. The paper describes the fundamentals and operating principle of the field-modulated magnetic gear topologies and investigates the magnetic torque transmission mechanism. However, despite all the advantages highlighted in different research and development reports, there is still no convincing evidence to show that magnetic gear technologies are an acceptable alternative for industrial applications. The aim of this paper is to summarize previous work on magnetic gears to identify the topologies most suited for mechanical power transmission systems in wind energy conversion systems and electric vehicle applications. These applications will show that research and development of magnetic gear technologies contribute significantly to solutions for sustainable systems, a subject to which our current civilization must pay a lot of attention.

Gear metrology – An update

Twenty years after the publication of a first CIRP Keynote Paper about gear metrology [32], this paper reviews again the state of the art in this area. Gear technology has changed and improved significantly during the past decades, which initiated substantial improvements in gear metrology, too. On the other hand, for up to 50% of gear inspection technologies used today, only minor changes are observed. Consequently, this update focuses on new or significantly improved techniques, such that only the combination of both this publication and [32] gives a comprehensive review of the state of the art in gear metrology. Gear technology in emerging markets, e.g., electric cars, large gears for energy systems, and micro gear drives, extends the scope of inspection tasks and requires new measuring methods and instruments, including optical sensors. Measured data, covering the entire gear flank of all teeth, need areal flank descriptions, areal evaluation methods, and areal deviation parameters. New calibration methods and artifacts will improve measurement uncertainties.

Design, Analysis and Weight Optimization Lathe Machine Gear by Using Composite Material

Abstract: To design the spur gear to study the weight reduction and stress distribution for cast steel and composite materials. Gearing is one of the most critical components in a mechanical power transmission system, and in most industrial rotating machinery. It is possible that gears will predominate as the most effective means of transmitting power in future machines due to their high degree of reliability and compactness. In addition, the rapid shift in the industry from heavy industries such as shipbuilding to industries such as automobile manufacture and office automation tools will necessitate a refined application of gear technology. To design the spur gear model using designs software. To study the impact analysis for cast steel and composite materials. To study the torque loading for cast steel and composite materials. Finally, comparing and analysing of the composite gear with existing cast steel gear is to be done

Phylogeny explains capture mortality of sharks and rays in pelagic longline fisheries: a global meta-analytic synthesis

Apex and mesopredators such as elasmobranchs are important for maintaining ocean health and are the focus of conservation efforts to mitigate exposure to fishing and other anthropogenic hazards. Quantifying fishing mortality components such as at-vessel mortality (AVM) is necessary for effective bycatch management. We assembled a database for 61 elasmobranch species and conducted a global meta-synthesis to estimate pelagic longline AVM rates. Evolutionary history was a significant predictor of AVM, accounting for up to 13% of variance in Bayesian phylogenetic meta-regression models for Lamniformes and Carcharhiniformes clades. Phylogenetically related species may have a high degree of shared traits that explain AVM. Model-estimated posterior mean AVM rates ranged from 5% (95% HDI 0.1%–16%) for pelagic stingrays and 76% (95% HDI 49%–90%) for salmon sharks. Measures that reduce catch, and hence AVM levels, such as input controls, bycatch quotas and gear technology to increase selectivity are appropriate for species with higher AVM rates. In addition to reducing catchability, handling-and-release practices and interventions such as retention bans in shark sanctuaries and bans on shark finning and trade hold promise for species with lower AVM rates. Robust, and where applicable, phylogenetically-adjusted elasmobranch AVM rates are essential for evidence-informed bycatch policy.

COVID-19 and Thai marine capture fishery in the Gulf of Thailand: A case of small-scale fishery versus industrial fishery

By the end of 2020, Thailand had low number of COVID-19 cases in comparison to other countries; however, the socio-economic well-being of the country was also severely affected, including the fisheries sector. The objectives of this research were to identify the impacts of COVID-19 on fishers in small-scale fishery (SSF) and industrial fishery (IDF) and to distinguish the support received as well as additional government support requested by fishers in SSF and IDF. This research also aimed at discussing fishing technology extension to correspond with the additional government support. Data were collected from 171 Thai fishers (97 in SSF and 74 in IDF) through interviews in five coastal provinces along the Gulf of Thailand from July to November 2020. Most of fishers in SSF and IDF experienced similar impacts of COVID-19, i.e., decreased number of market channels, price of fish, and revenue from catch. They received support from the national government (i.e., financial assistance and fishing gear), the local government and private sector (i.e., financial donations and subsistence supplies), and the government banks (i.e., low-interest bank loan). However, 67.0 % of fishers in SSF and 74.3 % of fishers in IDF requested additional government support, i.e., 1) fishing vessel and gear technology, 2) workers onboard recruitment system, 3) regulations, policies, and measures, 4) marine environment and fishery resources, 5) investment and marketing system, 6) infrastructures, and 7) other support. The extension of fishing technology and other support were discussed to address the additional government support and sustain the marine capture fishery. It is crucial to continue supporting fishers in both SSF and IDF during the persistence of COVID-19 pandemic and consider the prevention or mitigation measures for other pandemics or disasters in the future.

Ten lessons on the resilience of the EU common fisheries policy towards climate change and fuel efficiency - A call for adaptive, flexible and well-informed fisheries management

To effectively future-proof the management of the European Union fishing fleets we have explored a suite of case studies encompassing the northeast and tropical Atlantic, the Mediterranean, Baltic and Black Seas. This study shows that European Union (EU) fisheries are likely resilient to climate-driven short-term stresses, but may be negatively impacted by long-term trends in climate change. However, fisheries’ long-term stock resilience can be improved (and therefore be more resilient to increasing changes in climate) by adopting robust and adaptive fisheries management, provided such measures are based on sound scientific advice which includes uncertainty. Such management requires regular updates of biological reference points. Such updates will delineate safe biological limits for exploitation, providing both high long-term yields with reduced risk of stock collapse when affected by short-term stresses, and enhanced compliance with advice to avoid higher than intended fishing mortality. However, high resilience of the exploited ecosystem does not necessarily lead to the resilience of the economy of EU fisheries from suffering shocks associated with reduced yields, neither to a reduced carbon footprint if fuel use increases from lower stock abundances. Fuel consumption is impacted by stock development, but also by changes in vessel and gear technologies, as well as fishing techniques. In this respect, energy-efficient fishing technologies already exist within the EU, though implementing them would require improving the uptake of innovations and demonstrating to stakeholders the potential for both reduced fuel costs and increased catch rates. A transition towards reducing fuel consumption and costs would need to be supported by the setup of EU regulatory instruments. Overall, to effectively manage EU fisheries within a changing climate, flexible, adaptive, well-informed and well-enforced management is needed, with incentives provided for innovations and ocean literacy to cope with the changing conditions, while also reducing the dependency of the capture fishing industry on fossil fuels. To support such management, we provide 10 lessons to characterize ‘win-win’ fishing strategies for the European Union, which develop leverages in which fishing effort deployed corresponds to Maximum Sustainable Yield targets and Common Fisheries Policy minimal effects objectives. In these strategies, higher catch is obtained in the long run, less fuel is spent to attain the catch, and the fisheries have a higher resistance and resilience to shock and long-term factors to face climate-induced stresses.

Contact stress analysis of a spur gear using Lewis and Hertz theory

The rapid development of the automobile and aircraft industries has made applying gear technology necessary. Gears offer the benefits of efficiency, reliability, simplicity and a higher speed ratio with power transmission. However, they cannot transmit power over a long period, are more expensive when compared to belts and chain drives and requires continuous lubrication. They are used for transmitting high load in gear tools. The gear teeth fail when subjected to a high load beyond a certain limit. A deciding factor in gear design is the amount of stress developed on the contact surface of the mating gears. This paper deals with contact stress analysis of spur gear. The theoretical analysis presented in this paper aims to analyse rolling bearing contacts based on the principles of the Hertz and Lewis equations. A 3D domain-based finite element method was used to calculate the stresses between the contact surfaces of the structure. Contact analysis was performed using ANSYS Workbench software to figure out the deformation and optimum stress developed on the teeth of the gear. The simulation results indicated that the stress distribution on the gear contact surface has a maximum value of 144.82 MPa, while the deformation is at a maximum value of 0.01676 mm. The safety factor indicates the maximum level of 15, indicating the safety of the design.

Technological creep masks continued decline in a lobster (Homarus gammarus) fishery over a century

Fishery-dependent data are frequently used to inform management decisions. However, inferences about stock development based on commercial data such as Catch-Per-Unit-Effort (CPUE) can be severely biased due to a phenomenon known as technological creep, where fishing technology improves over time. Here we show how trap improvement over nine decades has driven technological creep in a European lobster (Homarus gammarus) fishery. We combined fishing data, experimental fishing with contemporary and older trap types, and information on depletion effects during fishing seasons. The resulting standardized CPUE time series indicates a 92% decline in lobster abundance between 1928 and 2019 compared to 70% if technological creep is not corrected for. Differences are most pronounced within the last 40 years when the most substantial shift in gear technology occurred: an uncorrected CPUE index suggests an 8% increase in lobster abundance during this period, while the corrected CPUE index declined by 57%. We conclude that technological creep has masked a continuous stock decline, particularly in recent decades and largely driven by the shift from one- to two-chambered traps, as well as the ability of newer trap designs to capture larger lobsters. Our study confirms the importance of adequate standardization, including technological development, when using fishery dependent CPUE for monitoring and management of data-limited fisheries.

Theoretical model analysis and case simulation of spherical involute surface

The theoretical model of a spherical involute surface is the premise and foundation of the 3D modelling design technology of spiral bevel gear. The forming process of the surface is also the forming process of its mathematical model. Based on the generating principle of spherical involute on cone and surface analysis, the system model is gradually divided into blocks from curve to surface, and the surface of the bevel gear is obtained by parameter coupling. The modelling process of curve, surface or initial spiral can be independently referenced. It can realise the precise modelling of complex spiral profile surfaces such as variable spiral angles. In this paper, the mathematical model of spiral bevel gear was simulated and analysed on the MATLAB2019b platform. The simulation results verified the correctness of the algorithm of the spiral bevel gear model and the practicability of design optimisation.

History of Gleason Works Spiral Bevel Gear Technology

The paper deals with the history of Gleason Works history in regard for their bevel gear manufacturing technology. In spiral bevel gear technology Gleason is a leading company, with many patterns and research studies in this field. The focus of this paper is to show the development of the technology provided by Gleason over the past more than 100 years.

Health Promotion System for the Elderly’s Daily Body Functions Based on Nanoprotective Technology

With the acceleration of China’s aging trend, the physical health of the elderly needs more attention and research from us. In particular, many elderly people are prone to accidental injuries during exercise, so how to protect the health of the elderly through high‐tech is worthy of more in‐depth research. This measure can promote the establishment of a health system for the elderly. This article is mainly based on the research on the health promotion system of the elderly’s daily body functions based on nanoprotective gear technology. It uses the literature method to read a lot of literature to understand the current research status of the elderly’s daily body function and health and the application status of nanotechnology, through the questionnaire and survey method for testing the blood pressure, heart rate, pulse wave velocity, bone density, and other physical indicators of the surveyed elderly population, and organize and analyze the relevant data. In this survey, 28.8% of the elderly who regularly participate in physical exercise have high systolic blood pressure, 33.3% of the elderly who do not participate in exercise regularly have high systolic blood pressure, and most of them are in the low bone density stage. Therefore, nanocare technology can effectively protect the health of the elderly and provide protection during exercise. The research in this article is aimed at illustrating the establishment and improvement of the physical function and health promotion system of the elderly through the impact data on physical indicators and providing a factual basis for the elderly to better participate in physical exercise and improve the health quality of the elderly.

Adoption and impacts of fishing gear innovations: Insights from a small-scale fishery in Chile

Small-scale fisheries contribute to food security and employ millions around the world. Overexploitation, however, threatens the suite of benefits that they can provide. Adopting innovations in gear technology can help to solve problems in fisheries (e.g. by-catch) but can also fuel overexploitation, with detrimental social, ecological, and economic impacts. Early assessments of the impacts of fishing gear innovations are crucial to preventing these innovations' adverse consequences. Using diverse methodologies, we assessed the impacts of a trammel net innovation in the cusk-eel small-scale fishery in central Chile. We show that the trammel net's adoption followed the path predicted by the diffusion of innovations theory and led to significant increases in landings. We also show, using a data-poor stock assessment methodology, that the red cusk-eel stock is overexploited. Next, we identified fishersperception of the ecological and economic impacts of the trammel net innovation. Finally, we used bidding games to assess fishers willingness to accept potential management measures to reduce the gear innovation impacts. Together, our results provide a comprehensive assessment of the trammel net innovation's diverse impacts in the cusk-eel small-scale fishery in central Chile and help identify potential ways forward. Timely and holistic assessments of the impacts of fishing gear innovations are essential to sustain fish stocks, promote responsible fishing and support the livelihoods of those who depend on fisheries worldwide.

New technologies to improve bycatch mitigation in industrial tuna fisheries

AbstractFor many years, tremendous effort has been dedicated to developing new industrial tuna fisheries, while their adverse impacts on threatened marine species have received relatively little attention. In tuna fisheries, bycatch is the major anthropogenic threat to marine megafauna in general, particularly sharks. Research on the development of gear technology for bycatch reduction and potential mitigation measures helped tuna Regional Fisheries Management Organizations adopt bycatch reduction management measures. After reviewing past research on the development of mitigation measures for pelagic longline and tropical purse seine fisheries based on pelagic species' behaviours, we describe promising new approaches integrating recent technological breakthroughs. New innovations include autonomous underwater vehicles carrying cameras along with miniaturized sensors, aerial drones, computer simulation of fishing gear geometry, environmental DNA assays, computer visualizations and deep learning. The successful application of such tools and methods promises to improve our understanding of factors that influence capture, escape and stress of caught species. Moreover, results emerging from recent ethological research explaining the power of social connection and learning in the “fish world” such as social learning from congeners, habituation to deterrents, and how past fishery interactions affect responses to fishing gear should be taken into account when developing technical mitigation measures.

Vibration Analysis of Gearbox Fault Diagnosis using DWT and Statistical Features

The gearbox is one of the critical subsystems in any rotating machinery, which plays a significant role in machine-driven power transmission in terms of change in speed and torque. It plays a vital role in patching different industrial functionalities. The advent of developing different gear technologies and the requirement to fulfil the desired mechanical benefits lead to add more importance to the gearbox health condition monitoring from various types of fault occurrences at an earlier stage. This study presents the vibration analysis of gearbox fault diagnosis using discrete wavelet transform (DWT) and statistical features. It is observed that, using wavelet reconstruction in the fault diagnosis better fault classification is achieved. The fault diagnosis has presented with an emphasis in time-domain followed by two different approaches. The approach-1 is illustrated as windowing of raw signal, feature extraction and feature classification using support vector machine (SVM). In the approach-2, after windowing the raw signal - each window of original vibration signal has converted into wavelet coefficients reconstructed signals (without leaving the time domain) using discrete wavelet transform (DWT) at different levels of decomposition followed by approach-1. The fault diagnostic accuracy of SVM is presented with 100 Monte-Carlo -runs to validate the consistency in the accomplished result. By observing the success rates in two approaches, it is clear that approach-2 with wavelet coefficient’s reconstructed signal is providing better classification accuracy, which can be practically deployed to diagnose the gearbox fault.