A Review of Gear optimization Methods

Lightening vehicles is one of the great challenges to reduce fuel consumption and thus dioxide carbon emissions. Many researchers are studying engine designs leading to less fuel consumption. Gearbox selection plays a key role in an engine design. Achieving better operational gear train characteristics, and a lower mass are basic objectives when designing a gearbox. This paper offers a comprehensive and original approach to optimize a gear trains with spur gears. The proposed approach is based on two level optimizations. A first optimization is performed to find the optimal dimeters, width and module while the second optimization is focused on gear body structure. In this second optimization, topology optimization technique is used to determine the ideal repartition of material with respect to the strength requirements. The application of the proposed approach on a case study shows a meaningful reduction in gearbox weight.

Mechanism and Machine Theory, 1984

An efficient method for analyzing multi-speed gear trains is presented and used in this paper. This new technique obtains equations for the diameters of all the gears used in the transmission based on information contained in the speed diagram. The form of the equations is such that they can be generated by the computer automatically. Further, the equations are applicable to the general arrangement, the single composite arrangements, and the double composite arrangements. As a result, all of the promising kinematic arrangements possible for a given number of speeds can be easily studied. By promoting different constraints and objective functions, trace-offs between different parameters can easily be examined. The technique is illustrated using a case study of a 9 speed gear train. A multi-parameter optimization technique is used to solve 19 different arrangements for a weighted ebjective function minimizing volume and maximizing stiffness.

Gears are used to transmit motion from on shaft to another and it has wide variety of applications. One of the applications of gear is in automobile gear box. Gears generally fail when the working stress exceeds the maximum permissible stress. These stresses are proportional to the amount of power transmitted by the gears. This project intends to identify the magnitude of the stresses for a given configuration of a two wheeler gears transmitting power while trying to find ways for reducing weight of the gear. The philosophy for driving this work is the lightness of the gear for a given purpose while keeping intact its functionality thus reducing the material cost of the gear. Ease of incorporating the new feature for weight reduction over the existing process of manufacturing and the magnitude of volume of weight reduced could be considered as the key parameters for assessment for this work.

Science & Technology Development Journal - Engineering and Technology, 2021

Gear is one of the most common and important components in machinery. Evaluation on durability of gears plays crucial role in the assessment of the whole system reliability and service life. For other parts like shafts, the gears also act as loads. Therefore, dimensions and weight of the gears should be reduced as much as possible, contributing the size and weight reduction of the whole systems, which is essential to be cost-effectiveness. The current research focuses on optimal weight design problem of spur gears, such that the weight is minimized under the constraints taken from working conditions. The weight is a function of six variables, i.e. face width, shaft diameter of pinion, shaft diameter of gear, number of teeth on pinion, module and hardness. Constraints are derived based on AGMA standard and engineering handbooks, including the bending strength, the surface fatigue strength, the interference condition, the condition for uniform load distribution, the torsional strength...

Journal of Modern Processes in Manufacturing and Production, 2018

A powerful optimization method is proposed in this study for the minimal dimensional design problem of gearbox. It is a general model that is suitable to use for any series of gear drives system and can extract both dimensional and layout of components-limited optimization design together. The objective function in this study has many local extremes so for avoiding this situation, various constraints have been determined Then, Particle swarm optimization algorithm has been implemented to speed up the convergence of optimization and elitist particles searched in problem space to find optimum value of goal function until all of them converge to the similar set of values. At the end, Results have been presented in the utilitarian diagrams to obtain optimal parameters from useful diagrams. The results display that the proposed method in this study is better than other reported in last works and it shows optimum volume of gearbox being related to a decrease of not just space but costs, m...

Review , 2024

Nowadays, several machinery and vehicles utilize mechanical elements which transmit power ranges from low, middle, and high levels depending on the type of equipment needed. Gears are the most influential design elements on any process during the running of a specific application, moreover engineers tried to obtain the optimality of a gear design which is a more compact, reliable-long service with simply operating features by following a systematic calculation of the mathematical model from standards and handbooks, however this process doesn't give the optimal design of the gears. Optimization techniques have been added to the design process for a more robustness of the gear pair design as well as improvements of the performance of the whole machine with better operational characteristics included. In this review paper, a concentration on macro geometry (such as module, facewidth, profile shift coefficients and helix angle) optimization process of cylindrical gears with distinct stages which includes objective function selection, decision variable selection and constraints handling formulation reported in the literature. This paper also provides some details about naturally inspired algorithms presented in the literature and this is what differentiates it from other review articles. Findings deduced by other authors are summarized where they are divided into two sections; based on the parameters of the technique itself while the other section considers the basic geometric parameters.

Journal of Optimization, 2014

Gears not only transmit the motion and power satisfactorily but also can do so with uniform motion. The design of gears requires an iterative approach to optimize the design parameters that take care of kinematics aspects as well as strength aspects. Moreover, the choice of materials available for gears is limited. Owing to the complex combinations of the above facts, manual design of gears is complicated and time consuming. In this paper, the volume and load carrying capacity are optimized. Three different methodologies (i) MATLAB optimization toolbox, (ii) genetic algorithm (GA), and (iii) multiobjective optimization (NSGA-II) technique are used to solve the problem. In the first two methods, volume is minimized in the first step and then the load carrying capacities of both shafts are calculated. In the third method, the problem is treated as a multiobjective problem. For the optimization purpose, face width, module, and number of teeth are taken as design variables. Constraints ...

Journal of Computational Design and Engineering, 2021

A reliable method of optimization of polymer gears remains, to date, an open challenge, due to the lack of specific material characterization of polymers and to the complex nonlinear relations between different geometric and operating parameters. For spur and helical gears, the authors herein have developed the optimization algorithm, which primarily enables variation of geometry according to various criteria: the number of teeth (z1, z2), face width (b), helix angle (β), and normal module (mn). The method enables a better insight into how design parameters influence the target criteria. The main paper contribution is a newly developed multicriteria function that enables a simultaneous consideration of different criteria such as root/flank stress, gear bulk/flank temperature, wear, deformation, quality, cost, and volume.

Lecture notes on data engineering and communications technologies, 2022

Gearing is one of the most efficient methods of transmitting power from a source to its application with or without change of speed or direction. In this paper, a spur gear model is optimized aiming to maximize its transmission power and minimize its weight. Several design variables named as transmitted power, number of pinion teeth, modules, and thickness of gears have been considered during optimization process. For the sake of optimization, two developed metaheuristics named as water cycle and neural network algorithms have been examined using MATLAB programming language platform. Besides, obtained optimization results have been validated and analyzed using well-known commercial computer aided engineering software ANSYS. Based on the obtained optimization results, optimum design has been found using optimizers and in terms of engineering analysis good agreement has been observed between the applied finite element approach.

This paper presents a global optimization method focused on gear vibration reduction by means of profile modifications. A nonlinear dynamic model is used to study the vibration behavior; such model is validated using data available in literature. The optimization method considers different regimes and torque levels; the objective function can be the static transmission error or the maximum amplitude of the gear vibration in terms of dynamic transmission error. The procedure finds the optimal profile modification that reduces the vibrations over a wide range of operating conditions. In order to reduce the computational cost, a Random-Simplex optimization algorithm is developed; the optimum reliability is estimated using a Monte Carlo simulation. The approach shows good performances for the computational efficiency as well as the reliability of results. Finally, an application to High Contact Ratio (HCR) gears is presented and an extremely good performance is obtained by combining optimization procedures and HCR properties.