Actual Gear Research Articles

A multi-layer predictive energy management strategy for intelligent hybrid electric trucks collaborated with eco-driving control

Nowadays, hybrid electric trucks (HETs) are also urgently expected to further enhance energy efficiency with the development of intelligent driving system. A multi-layer predictive energy management strategy is designed for intelligent parallel HET to enhance fuel economy and computational efficiency. Depending on intelligently implementation of traffic prediction with navigation data, an online smart battery SOC generation is proposed to obtain an approximately global optimal SOC reference trajectory in the upper layer. In the bottom controller, a novel method, the tolerant sequential model predictive control (MPC) collaborated with sampling strategy, could achieve eco-driving in consideration of both driving comfort and safety with less computation time in autonomous driving scenario. Moreover, to simultaneously accomplish fuel economy and decrease computational burden, the integrated equivalent consumption minimization strategy with dynamic programming (ECMS-DP) solver for MPC scheme is presented to frozen SOC state and jointly control torque distribution and gear action. Numerical simulations demonstrate that the proposed multi-layer strategy has improved over 20 % fuel economy and decreased almost 50 % computational burden relative to traditional MPC benchmark strategy, which could exhibit great effectiveness and potential for practical implementation in real driving routes.

A Novel Multi-Objective Dynamic Reliability Optimization Approach for a Planetary Gear Transmission Mechanism

Planetary gear transmission mechanisms (PGTMs) are widely used in mechanical transmission systems due to their compact structure and high transmission efficiency. To implement the reliability design and optimization of a PGTM, a novel multi-objective dynamic reliability optimization approach is proposed. First, a multi-objective reliability optimization model is established. Furthermore, considering the strength degradation of gears during service, a dynamic reliability analysis is conducted based on the theory of nonlinear fatigue damage accumulation. In addition, to improve computing efficiency, a random forest surrogate model based on the particle swarm optimization algorithm is proposed. Finally, an adaptive multi-objective evolutionary algorithm based on decomposition (AMOEA/D) is designed to optimize the mechanism, along with an adaptive neighborhood updating strategy and a hybrid crossover operator. The feasibility and superiority of the proposed approach are verified through an NGW planetary gear reducer. The results show that the proposed surrogate model can reduce the calculation cost and has high accuracy. The AMOEA/D algorithm can improve transmission efficiency, reduce gear volume and ensure reliability at the same time. It can provide guidance for actual gear production.

Compensation method of the spiral bevel gear tooth surface error based on eight tooth-surface fitting

Abstract The misalignment error between the gear theoretical coordinate system and actual gear coordinate system is illustrated, as well as its influence on the measurement of tooth surface deviation is discussed. On the analysis of the tooth convex and concave surface error measurement process, the measured points in the theoretical coordinate system are transformed from the actual measured points in the actual coordinate system. Then, an eight tooth-surface fitting method is utilized to calculate the misalignment error and the compensation method is given. Finally, actual measurements of three different spiral bevel gears are analyzed, and the misalignment error are calculated. Using the proposed compensation method, both the eccentricity and tilt are compensated to some extent. And the machining suggestions of each spiral bevel gear are also given according to its compensated tooth surface error distribution.

Mathematical Complexities in Modelling Damage in Spur Gears

Analytical modelling is an effective approach to obtaining a gear dynamic response or vibration pattern for health monitoring and useful life prediction. Many researchers have modelled this response with various fault conditions commonly observed in gears. The outcome of such models provides a good idea about the changes in the dynamic response available between different gear health states. Hence, a catalogue of the responses is currently available, which ought to aid predictions of the health of actual gears by their vibration patterns. However, these analytical models are limited in providing solutions to useful life prediction. This may be because a majority of these models used single fault conditions for modelling and are not valid to predict the remaining life of gears undergoing more than one fault condition. Existing reviews related to gear faults and dynamic modelling can provide an overview of fault modes, methods for modelling and health prediction. However, these reviews are unable to provide the critical similarities and differences in the single-fault dynamic models to ascertain the possibility of developing models under combined fault modes. In this paper, existing analytical models of spur gears are reviewed with their associated challenges to predict the gear health state. Recommendations for establishing more realistic models are made especially in the context of modelling combined faults and their possible impact on gear dynamic response and health prediction.

MICROSTRUCTURAL AND CORROSION ANALYSIS OF CROWN PINION WITH VARIOUS COMPOSITIONS OF HIGH CARBON STEEL AND SILICON CARBIDE MATERIALS

The pinion and crown are key components in an automobile’s transmission system. The surface characteristics of high-carbon steel have a major effect on differential gear action. As a result, gear damages and increased downtime for repairs are experienced over time. To address this issue, manufacturers have started using alternative materials such as aluminium alloys and composites to improve the durability and efficiency of the transmission system. Engineers can now adjust the design of crown and pinion gears for best performance thanks to developments in computer-aided design and simulation tools. This has led to the development of more compact and lightweight transmission systems that offer better fuel efficiency and acceleration. However, these innovations come at a cost, as they require specialized manufacturing processes and materials that can be expensive. Nevertheless, the benefits of improved transmission systems are clear, as they can significantly enhance the driving experience while reducing maintenance costs over time. As technology continues to evolve, we can expect further improvements in material design that will further enhance crown pinion performance and reliability. To overcome these failures and increase the material’s life, high-carbon steel is preferred. In this study, high-carbon steel composites with various material proportions (100% to 0%, 99% to 1%, and 97.5% to 2.5% of high-carbon steel, and silicon carbide, respectively) are experimentally investigated and evaluated for better structural strength and surface behavior of the crown pinion. The crown pinion is thoroughly analyzed using salt spray corrosion testing and X-ray diffraction analysis. According to the results, the proportion of 97.5% high carbon steel with 2.5% silicon carbide has better surface properties than the other proportions, and it is also recommended to make the crown pinion for future uses.

Postrelease Mortality of Angled Tarpon in Puerto Rico

AbstractTarpon Megalops atlanticus is a popular and economically important inshore sport fish in Puerto Rico, and the pursuit of this species by local anglers and tourists contributes to the economy. This species is managed as a no‐take fishery, which aims to preserve populations by catching and releasing fish that would otherwise be subjected to harvest and removal from the population. The approach assumes minimal mortality and/or reduced fitness of released fish, yet the process of angling can produce many sublethal side effects or direct mortality. In this study, charter angling for Tarpon in the San Juan lagoon system in Puerto Rico was examined to determine postrelease mortality. Angled fish were externally tagged with acoustic transmitters and relocated periodically to determine the fate after release. Postrelease mortality was at least 4.5% (two fish observed dead) and at most 18.2% (observed dead plus classified dead based on lack of movement; confidence interval [CI] = 7.5–28.9%). Some tag loss was observed, which could have artificially elevated classified mortality estimates. Potential factors that contribute to mortality are discussed and compared to the literature. Hook type, gear action, landing procedures, and air exposure were key areas of possible improvement. Recommendations to minimize fish harm during angling include the use of heavier action gear to reduce fight time, a circle hook requirement for live bait to reduce deep hooking, maintaining fish in the water during landing and photography, and limiting air exposure to 2 min or less if fish are removed from the water.

Research on the composite fault diagnosis of gearbox based on local mean decomposition and Hilbert demodulation

For the sake of deriving the signature frequencies of the composite malfunctions of broken and worn teeth of gearbox, the essay raised a method on account of local mean decomposition and Hilbert demodulation to diagnose gearbox composite fault. The local mean decomposition translates a complicated multi-component AM-FM signal into several PF elements with certain physical significance. Every PF component can be approximately regarded as a simplex component AM-FM signal. Using correlation coefficient method, the Hilbert envelope demodulation spectrum is analyzed by selecting the PF component which is strongly relevant to the incipient composite malfunction signal, and the malfunction signature frequency is identified from the demodulation spectrum. Through analyzing the emulation signal and the vibration signal of the actual gear box broken-wear complex fault, and compared with EMD, it is shown that the means can effectually discern the malfunction characteristic frequency in the composite fault signal.

Finite Element Analysis of Mg Alloy Based Gear Set Using ANSYS

Now magnesium alloy is the lightest metal materials of in engineering application, it has a wide application in automobile sector, aerospace, biomedical and other fields. Magnesium alloy gear is utilized in the present research, and a gear-pinon cad model is utilized by utilizing finite element software ANSYS, under loads. Here the model is designed in ANSYS SpaceClaim then imported to ANSYS commercial software and determine the contact stress of mating gears for other different materials and results comparing with Mg alloy gear. Gears a major component utilized in the field of engineering and technology, these fears have played a major role in transmit of puissance. Contact stress is generally the deciding factor for kenning the requisite dimensions of gears. Research on gear action has substantiated fact that adjacent to. In the gears contact stress is main parameter, the contact stress is dependent on involution of the model and material properties, as the material property transmutes the contact stress will withal change. The modal analysis and harmonic replication are required for analysis of gear systems. The aim of this project is to determine the contact stress and frequency replication of gear for sundry materials. The modal analysis is carried out token the mode shapes & natural frequency, and the harmonic analysis is withal done for different materials like Mg alloy, Cast iron and Al alloy.

МОДЕЛИРОВАНИЕ ПЕРЕКЛЮЧЕНИЯ ПЕРЕДАЧ АВТОМОБИЛЬНОЙ ТРАНСМИССИИ С ДВОЙНЫМ СЦЕПЛЕНИЕМ

A computer dynamic model of an automobile transmission with a double dry clutch, created using the "Universal Mechanism" software package, is presented. Work objective is to analyze the possibility of improving double dry clutch efficiency at various controls of compressive forces of clutch plates. The computer model contains 7 bodies: an engine crankshaft, two clutch plates, two gearbox input shafts for odd and even gears, an output shaft, a fly wheel. The simulation of gear shifting shows that pressing a clutch pedal or letting out the clutch simultaneously, cutoff time increment increases the rotational speed justification of the engine shaft and the input shaft of the actual gear, the total work of the friction forces of both clutches and does not affect the maximum value of clutch plates rotary sliding resistance. Frictional energy of the clutch when shifting gears from lower to higher is greater than when shifting gears from higher to lower. Sequential clutch on-off reduces the total frictional energy of both clutches by 1.17...1.31 times compared to simultaneous one. The model allows looking into different gearshift modes with uniform velocity or accelerated vehicle motion, optimize the gearshift strategy.

Vibration modelling and fault evolution symptom analysis of a planetary gear train for sun gear wear status assessment

The diagnosis and monitoring of surface wear are very critical for the prevention of shutdown and even catastrophic destruction of a geared transmission system. However, the detection for the evolutionary status of surface wear in a planetary gear train is quite challengeable due to the complicated and weak characteristics buried in the vibration signals. To assess the wear status of gears in a planetary gear train, a sophisticated vibration signal analysis based methodology is proposed. First, an analytical dynamic model of single-stage planetary gear train is established, which incorporates the effects of distributed surface wear of mating gears. With the analytical dynamic model, a resultant vibration signal model is further established after considering the influences of transfer path, direction variation of gear action lines and background noise. This vibration signal model is used to represent the actual vibration signals collected by transducers installed on the housing of planetary gearbox. Based on the constructed resultant vibration signals, two novel fault indicators are defined to reveal the evolution law of fault symptom. The fault evolution symptom analysis is used to identify healthy status and wear status of mating gears in the planetary transmission system. The effectiveness of the proposed model as well as the fault indicators are validated by both simulated signals and experimental signals.

A novel estimation method of friction coefficient for evaluating gear pitting fault

In present, the model-based gear dynamics is the main method for gear pitting fault diagnosis. However, most of gear dynamic models use a constant friction coefficient or friction coefficient obtained by calculation method that contains many simplifications and assumptions. Especially when a gear has fault, previous studies lack calculation of friction coefficient. In this paper, a new method is proposed to estimate the friction coefficient of gear pairs with different pitting. Based on the strain signal of actual gear pitting damage, the proposed method combines the finite element method and optimization method to obtain the friction coefficient at the different gear pitting level. Furthermore, by using calculated friction coefficient to obtain dynamic responses of different gear pitting states, the effects in dynamic responses of different types of friction coefficient are compared and analyzed.

Optimal analysis of gear modification fitting in alternating time domain aiming at minimizing meshing-in impact of teeth-pair contact interface

In a pair of actual gears alternating meshing process, the transmission system errors and thermal elastic deformation of the gear teeth can cause gears in the meshing zone to form high contact pairs inconsistently mesh-in and mesh-out points to deviate from the theoretical line, which will lead to sudden changes in meshing velocity and an instantaneous meshing effect. Offline meshing impact generates large additional loads, and it increases the vibration and noise of gear transmission system. Further, the gear teeth mesh-in impact is significantly greater than that of gear teeth mesh out. Therefore, to analyze the impact with the minimum value of gear teeth mesh in, the initial mesh-in points need to be determined, and the meshing impact velocity and impact force of teeth meshing-out need to be calculated. The optimized meshing tooth-pair contact interface (CI) anti-impact numerical calculation mode is validated using the loaded teeth contact analysis method.

Gear tooth action in a plane synthesis based on the criterion of constant curvature

The relevance of the problem of the gear tooth action in a plane synthesis based on the criterion of tooth profile wheel group curvature is justified. Based on a mathematical model of gear tooth action in a plane with a constant angular speed ratio, an algorithm for solving the problem with a given constant curvature is given. The obtained solutions allow us to perform an analysis of the general type of lantern gear in a plane.

From helmets to face masks: how collective emotions sustain diaspora mobilization from homeland uprising to global pandemic among the Hong Kongers

Purpose Diasporic mobilization studies often incorporate collective emotions into the discussion of movement strategies, less we knew about how emotion becomes the language by which they communicate collective responsibility after the protests. The purpose of this paper is to draw from participant observation research to explore how diasporas construct the language of collective emotions to sustain their commitment to the transnational mobilization project during and after the homeland protests. Design/methodology/approach Drawing on ten months of participant observations in the USA, the author observed how members in a Hong Kong diaspora group, Black Bauhinia Society (BBS), transform their project from a transnational protective gear sourcing action during the Hong Kong Anti-Extradition Bill Movement into a global medical personal protective equipment (PPE) sourcing action during the COVID-19 pandemic. Findings During homeland uprising, BBS recruits participants using a set of compassion language that encompasses the suffering stories of homeland dissidents and the members’ expression of guiltiness for staying afar. The compassion talk reinforces the transnational ties between BBS members and Hong Kong dissidents over the process of resource mobilization. When the homeland movement ceased during the pandemic, BBS transformed their compassion talk to politicize charitable actions and recruit volunteers and donors to source PPE for Hong Kong. Originality/value This paper contributes to the emerging discussion on how diaspora mobilizes after the protest by showing how the language of collective emotion cultivates commitments and sustain collective identity after the protests.

Gear Root Bending Strength: A New Multiaxial Approach to Translate the Results of Single Tooth Bending Fatigue Tests to Meshing Gears

Developing accurate design data to enable the effective use of new materials is undoubtedly an essential goal in the gear industry. To speed up this process, Single Tooth Bending Fatigue (STBF) tests can be conducted. However, STBF tests tend to overestimate the material properties with respect to tests conducted on Running Gears (RG). Therefore, it is common practice to use a constant correction factor fkorr, of value 0.9 to exploit STBF results to design actual gears, e.g., through ISO 6336. In this paper, the assumption that this coefficient can be considered independent from the gear material, geometry, and loading condition was questioned, and through the combination of numerical simulations with a multiaxial fatigue criterion, a method for the calculation of fkorr was proposed. The implementation of this method using different gear geometries and material properties shows that fkorr varies with the gears geometrical characteristics, the material fatigue strength, and the load ratio (R) set in STBF tests. In particular, by applying the Findley criterion, it was found that, for the same gear geometry, fkorr depends on the material as well. Specifically, fkorr increases with the ratio between the bending and torsional fatigue limits. Moreover, through this method it was shown that the characteristics related to the material and the geometry have a relevant effect in determining the critical point (at the tooth root) where the fracture nucleates.

MACHINE LEARNING FOR DECISION-MAKING IN THE REMANUFACTURING OF WORN-OUT GEARS AND BEARINGS

Mechanical industries use rotating mechanical equipment in their day to day operations. The equipment suffers from wear and tear, and is usually discarded as scrap. But is there a way to recover some of this equipment and reuse it? This paper uses machine learning to capture and analyse the wearing damage of bearings and gears to determine whether they can be redeemed. Finite element analysis is conducted on worn-out spur gears and pillow bearings in order to facilitate feature extraction in image processing algorithms. This converts the actual gears, bearings, and seals into CAD files. The decision-making system is designed, and it uses these CAD files to decide on the optimum manufacturing process to restore redeemable components. The mechanical components of the system are designed using SOLIDWORKS. MATLAB, Proteus software, and the Arduino micro-controller are used for the system application design and simulation. The results from tests conducted on a worn-out gear and bearing show that the gear is 4% non-redeemable, while the bearing is 60.2% non-redeemable. The decision taken by the system is to redeem the gear and to discard the bearing.

Fatigue Life Simulation of Tractor Spiral Bevel Gear According to Major Agricultural Operations

The spiral bevel gear in a tractor, unlike the other gears in the transmission, is one of the most vulnerable gears in terms of fatigue life, as it is consistently driven throughout the operations of the tractor. Conventional fatigue life tests of transmission gears require expensive equipment and repeated tests, and do not reflect dynamic field loads. The aim of this study is to develop a simulation model which can replace conventional fatigue life tests for actual gears, in order to evaluate the fatigue life of a tractor using dynamic field load data. A transmission simulation model including a spiral bevel gear was developed using commercial software. In order to measure the dynamic load of the tractor according to various field operations, an axle torque measurement system was developed, and field experiments were performed for major agricultural operations occurring in the field. Fatigue life was calculated using Rainflow cycle counting (RFC), the Smith–Watson–Topper (SWT) model, and S–N curves based on torque data measured in the field. The fatigue life under moldboard plow tillage, subsoiler tillage, rotary tillage, and baler operation were 13,599, 285, 278,884, and 525,977 h, respectively. The fatigue life of the tractor, according to subsoiler tillage and baler operation, was 0.104 and 192 times the service life, respectively, where the difference between these two operations was about 1846 times. The fatigue life of the tractor, according to the attached implement type, was significantly different. Therefore, it can be seen that the fatigue life of a tractor can be significantly different, depending on agricultural operation type which the farmer uses most often; this can be used as basic data for tractor design and evaluation. In addition, it is considered that the developed simulation model can be applied to fatigue life evaluation using dynamic field load data.

Adaptive data-driven modular control approach to computer aided process planning for manufacturing spiral bevel and hypoid gears

Machine setting modification has been an increasingly important access to the accurate flank manufacturing geometric accuracy control for spiral bevel and hypoid gears. More recently, machine setting driven integration of the theoretical design and the actual gear manufacturing is gaining more and more attention. In this paper, the traditional machine setting modification is extended to the case when higher-order component of the prescribed ease-off flank topography is investigated in form of high-order polynomial expression. Moreover, the actual gear manufacturing and general measurement are integrated into an adaptive data-driven high-order machine setting modification. In particular, this modification method is used to perform adaptive modular control for computer aided process planning (CAPP). Here, a data-driven operation and optimization is developed for adaptive high-order modification. It mainly includes: (i) Polynomial fitting and its optimization by using overall interpolation based on energy method, (ii) Data-driven ease-off flank parametrization based on the fastest descent Newton iteration method, (iii) adaptive control strategy by considering the sensitivity analysis, and (iv) Levenberg-Marquardt (L-M) based approximation for high-order machine setting modification. Given numerical test can verify the proposed method.

State-Degradation-Oriented Fault Diagnosis for High-Speed Train Running Gears System.

As one of the critical components of high-speed trains, the running gears system directly affects the operation performance of the train. This paper proposes a state-degradation-oriented method for fault diagnosis of an actual running gears system based on the Wiener state degradation process and multi-sensor filtering. First of all, for the given measurements of the high-speed train, this paper considers the information acquisition and transfer characteristics of composite sensors, which establish a distributed topology for axle box bearing. Secondly, a distributed filtering is built based on the bilinear system model, and the gain parameters of the filter are designed to minimize the mean square error. For a better presentation of the degradation characteristics in actual operation, this paper constructs an improved nonlinear model. Finally, threshold is determined based on the Chebyshev’s inequality for a reliable fault diagnosis. Open datasets of rotating machinery bearings and the real measurements are utilized in the case studies to demonstrate the effectiveness of the proposed method. Results obtained in this paper are consistent with the actual situation, which validate the proposed methods.

Design and Development of Semi-Automatic Gear Changing Module by using Pneumatic Drives

This is the research work regarding the development of pneumatic gear changing module which helps to reduce the gear changing time and increases driver's feasibility on changing gears. The gear changing action is actuated by the pressurized air from the compressor via a pneumatic cylinder to the mechanism. When the driver actuates the push button manually, the gear changing module is actuated by a solenoid valve and the gear is shifted in a shorter time. Additionally, a load device is used to control the speeds of input and output shafts of the gearbox. This method also eliminates the clash due to misplacement of gears, in case of mesh type gearboxes, since; the gears are changed manually by push buttons.