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This study provides insights into the effectiveness of the genetic algorithm-based optimization process for long-short addendum helical gear pairs, aiming to balance the specific sliding ratio during approach and recess phases while concurrently increasing the load-carrying capacity to the pinion. The iterative process, undertaken with an appropriately chosen population size for the two variables ( x 1 and x 2 ) over the specified maximum number of generations, consistently yields reliable results, highlighting the algorithm’s efficiency and convergence. Visual representations highlight significant addendum modifications, showcasing the algorithm’s adaptability to meet specific design criteria for long-short addendum helical gear pairs. The study further explores the reduction in tooth root stress and contact stress of standard helical gears after optimization, determined through finite element analysis using ANSYS software. Additionally, the effects of addendum modification on helix angle and total volume of the gear are examined in detail. A numerical approach is established to calculate the cross-sectional area of the single helical gear tooth in the transverse plane and the total volume of the gear for both standard and optimized long-short addendum helical gears. This approach is validated using CAD models created in Solid Edge, confirming its accuracy by yielding identical values. In summary, the research underscores the effectiveness of the genetic algorithm-based optimization process for long-short addendum helical gear pairs, with a dual focus on balancing specific sliding ratios and increasing the load-carrying capacity to the pinion, offering valuable insights for advancing such gear configurations in engineering applications.

Based on the results obtained in the previous research, the values of meshing characteristics of profile shifted quasi-involute arc-tooth-trace gears is calculated. The influence of the values of profile shift coefficient and the angle of tooth trace on meshing characteristic distribution on the tooth flank surface along tooth trace is defined. The results can be used for design of profile shifted quasi-involute arc-tooth-trace gears, cut by Gleason-type cutters with different profile angle value.

A unique perspective in design optimization of helical gear pair has been emerged and presented in this article. Specific sliding needs to be balanced for enhancing wear and scuffing resistance of helical gears. Optimized modification in tooth profile has immense benefits in gear operations. Effect of profile shift and specific sliding on design optimization of helical gear pair have been studied and found to be beneficial of great importance. Preventing undercutting, balancing of wear and bending fatigue strength and centre distance adjustment are some of the advantages of profile tooth modifications. Real-coded genetic algorithm (RCGA) has been used to attain minimum volume of helical gear pair. Profile shift coefficients for gear and pinion have been included as design variables along with mostly used generic design variables, module, face width and number of teeth on pinion. Specific sliding, transverse contact ratio and face width constraint along with other strength requirements are the design constraints. The optimal design solutions obtained with and without profile shift are recorded and compared with commercially used software for validation. 3D computer-aided design (CAD) models have been developed by using the optimized results obtained from RCGA and commercially used software. These CAD models are used for performing finite element analysis (FEA) on the helical gear set for analyzing the stress developed in the gear pair. The developed stress in the helical gear pair is found to be well within the allowable stress limits for the gear pair.

This article presents a model of the geometry of teeth profiles based on the path of contact definition. The basic principles of the involute and convex–concave teeth profile generation are described. Due to the more difficult manufacturing of the convex–concave gear profile in comparison to the involute one, an application example was defined that suppressed this disadvantage, namely a planetary gearbox with plastic-injection-molded gears commonly used in vehicle back-view mirror positioners. The contact pressures and the slide ratios of the sun, planet, and ring gears with both teeth profile variants were observed and the differences between the calculated parameters are discussed.

Profile shift has an immense effect on the sliding, load capacity, and stability of involute cylindrical gears. Available standards such as ISO/DIS 6336 and BS 436 DIN/3990 currently give the recommendation for the selection of profile shift coefficients. It is, however, very approximate and usually given in the form of implicit graphs or charts. In this article, the optimal selection values of profile shift coefficients for cylindrical involute spur and helical gears are described, using a differential evolution algorithm. The optimization procedure is developed specifically for exact balancing specific sliding coefficients at extremes of contact path and account for gear design constraints. The obtained results are compared with those of standards and research of other authors. They demonstrate the effectiveness and robustness of the applied method. A substantial improvement in balancing specific sliding coefficients is found in this work.

In mechanical systems, helical gears are essential for transmitting power and motion between parallel shafts. Optimizing key parameters like addendum, center distance, tooth profile, and material selection is critical to improve performance and durability. Multi-objective optimization using genetic algorithm (MOO-GA) is employed in this research to optimize the design of innovative non-standard center distance helical gear pairs. The MOO-GA approach optimizes for three main objectives simultaneously: (i) balancing tooth root strength to maximize load-carrying capacity, (ii) optimizing the specific sliding ratio during tooth engagement and disengagement (approach and recess actions) for reduced noise and improved meshing efficiency, and (iii) maximizing the sum of the addendum modification coefficients. MOO-GA iteratively searches for optimal solutions by manipulating key design variables (x 1 and x 2 ), leading to consistent convergence and significant addendum modifications. Finite element analysis (FEA) with ANSYS software is used to evaluate how optimization reduces tooth stress. Experimental strain gauge technique involves strategically placing strain gauges on gear teeth identified by the FEA model. These strain gauges directly measure real-world strain under load, validating the predicted strains from FEA. Validation with a real-time CAD model confirms the optimized design exhibits reduced tooth root stress and contact stress compared to helical gear pairs with standard distance. The research demonstrates the effectiveness of MOO-GA in creating superior helical gear designs that meet performance requirements and potentially offer weight and space savings. Strain gauge validation strengthens confidence in FEA results and provides valuable data for further optimization refinement.

Methods used earlier for choosing profile shift coefficients were based on presumed advantages without physical proof justifying them. In this paper a new method is proposed which guaranties a positive influence on gear failures and on the operational conditions of gear pairs.

Methods used earlier for choosing profile shift coefficients were based on presumed advantages without physical proof justifying them. In this paper, a new method is proposed which guarantees a positive influence on gear failures and the operational conditions of gear pairs. The author proposes the introduction of a new concept: the cumulative effectiveness of profile shift coefficients.

Asymmetric gears have evolved from the rising demand for power transmission drives with high load-carrying capacity, surface durability, and service life. Direct design and S± profile shifted system are the most common approaches used for enhancing design features by geometry modification in asymmetric gears. This paper aims at establishing asymmetric gear geometry modification using tooth sum alteration for a family of gears running on a specified center distance as a feasible design approach. A complete mathematical treatment of the design approach is provided, and an in-house developed computer program is used for numerical simulation. The paper explores the influence of dynamic load factors, location factors for bending, specific sliding on load-bearing capacity, and surface durability on different tooth sum alterations. The study concludes that tooth sum altered asymmetric gear geometry can be employed as an effective design technique that offers designers flexibility in designing gears for surface wear, load-bearing, and tooth life.

Dealing with the risk of landslide-induced impulse waves is a significant challenge in the management of large reservoirs after impoundment. After the impoundment of the Baihetan Reservoir in Jinsha River, the WangJiaShan (WJS) landslide has been one of most active reservoir-induced landslides, and the Xiangbiling Community located on the opposite bank is at great risk of impulse waves. Based on the WJS landslide, five experiments in a physical model with dimensions of 30 m × 27 m × 1.5 m were conducted at a scale of 1:150. Measurements were performed with wave gauges and a particle image velocimetry system. The maximum potential sliding velocity of the natural WJS landslide was approximately 7.11 m/s, and the maximum amplitude of the generated impulse wave was 7.68 m at a water level of 825 m above sea level. The complex estuary topography of the Xiaojiang and Jinsha Rivers caused the generated waves to impact the Xiangbiling Community multiple times, with a maximum run-up of 11.75 m. This risk of impulse waves is significantly reduced when the sliding volume is decreased. As the landslide volume was reduced from 611 × 104 to 448 × 104 m3 by removing the upper part, the potential landslide velocity and the submerged sliding mass decreased, and the kinetic energy of the submerged sliding mass decreased from 2.69 × 1011 to 10.03 × 109 J, i.e., by approximately 96.3%. The maximum amplitude of the potential impulse wave decreased from 7.68 to 2.81 m, and the area with an amplitude larger than 1 m decreased by 75.4%. When removing 163 × 104 m3, the impulse wave would no longer impact the community, which is recommended as the main reduction scheme for the WJS landslide. If the factor of safety of the WJS landslide after removal is required to be greater than 1, the removed volume needs to be approximately larger than 303 × 104 m3, resulting in higher cost. This study provides a technical basis for the prevention and control of WJS landslide-induced impulse waves and a useful reference for their hazard reduction around the world.