Optimizing involute gear design for maximum bending strength and equivalent pitting resistance

2007 ◽  
Vol 221 (4) ◽  
pp. 479-488 ◽  
Author(s):  
V Spitas ◽  
C Spitas
Keyword(s):  
Bending Strength ◽  
Power Transmission ◽  
Optimization Procedure ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Design ◽  
Involute Gear ◽  
Involute Gears ◽  
High Power Transmission ◽  
Complex Algorithm

Standard involute gear designs dominate high-power transmission applications because they combine sufficient bending strength with high pitting resistance, while retaining an adequate contact ratio. In this paper, a non-standard, optimal alternative involute gear design has been presented, which has the same pitting resistance as the standard involute gears but exhibits maximum resistance to bending. The optimization procedure is based on the complex algorithm, where the root stress, as calculated through tabulated boundary element analysis values, is the objective function and the active constraints include all of the kinematical, manufacturing and geometrical conditions, which must be satisfied by the optimal design, including the pitting resistance. The results indicate that optimal designs can achieve up to 8.5 per cent reduction of the fillet stress. Two-dimensional photoelasticity was used to verify the optimization results.

Performance enhancement of normal contact ratio gearing system through correction factor

2019 ◽  
Vol 13 (3) ◽  
pp. 5242-5258
Author(s):  
R. Ravivarman ◽  
K. Palaniradja ◽  
R. Prabhu Sekar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Correction Factor ◽  
Bending Strength ◽  
Performance Enhancement ◽  
Transmission Ratio ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact ◽  
Root Region

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.

The Equal Bending Strength Design of Space Curve Meshing Wheel

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Yang-zhi Chen ◽  
Shun-ke Liang ◽  
Jiang Ding
Keyword(s):  
Finite Element Analysis ◽  
Cross Section ◽  
Mechanical Model ◽  
Bending Strength ◽  
Power Transmission ◽  
Space Curve ◽  
Element Analysis ◽  
Small Power ◽  
Theoretical Design ◽  
The Finite Element Analysis

The space curve meshing wheel (SCMW) has been studied previously for small power transmission. To extend its application in conventional power transmission, the bending strength of the SCMW needs to be studied. In this paper, the tine's section of the SCMW is optimized, the mechanical model of the bending strength is deduced according to the equations for a couple of given contact curves of the SCMW, and the design formulas of the tines are newly deduced based on the equal bending strength principle. Finally, one design example of a SCMW with elliptical torus cross-section tines is provided. The result shows that the theoretical design attained from the presented formulas coincides with that from the finite element analysis. It dedicates that the SCMW possesses enough equal bending strength to be used to in conventional industrial gearing device design.

Can non-standard involute gears of different modules mesh?

2006 ◽  
Vol 220 (8) ◽  
pp. 1305-1313 ◽  
Author(s):  
C Spitas ◽  
V Spitas
Keyword(s):  
Bending Strength ◽  
Gear Tooth ◽  
Sliding Velocity ◽  
Initial Investigation ◽  
Involute Gear ◽  
Involute Gears ◽  
Gear Systems ◽  
Standard Designs

Under the current standardized involute gear systems, meshing of gears of different modules is a practical impossibility. However, by performing a fresh reinterpretation of the well-established fundamental meshing principles, a more insightful form for the compatibility equations that govern involute gear tooth generation and meshing can be obtained. This article reports some first non-standard designs based on this analysis that allows gears of different modules to mesh. By the same token, standard gears can be manufactured with non-standard hobs and vice versa. Initial investigation suggests that practical benefits such as increasing the root bending strength without affecting the pitting resistance and the sliding velocity can be achieved that may justify such deviation from standard designs.

Generating standard 20° involute pinions with increased fillet strength by using 25° rack cutters with non-standard module

2006 ◽  
Vol 220 (8) ◽  
pp. 1297-1304 ◽  
Author(s):  
C Spitas ◽  
V Spitas
Keyword(s):  
Finite Element Analysis ◽  
Geometrical Parameters ◽  
Gear Pair ◽  
Element Analysis ◽  
Gear Design ◽  
Strict Guideline ◽  
Involute Gears ◽  
Standard Module ◽  
Increased Strength ◽  
The Individual

According to all prevailing standards for gear design, a strict guideline is that the individual gears of a gear pair must be of the same module and pressure angle in order to mesh properly and the compatibility of the remaining geometrical parameters is determined under this assumption. However, in this article, the fundamental meshing principles of a generating rack and pinion are reinterpreted, and a more insightful form of the compatibility equations for involute gears is presented. In this context, stronger tooth forms with thicker root fillets can be produced using 25° rack cutters and still be able to mesh with standard 20° involute gears indiscriminately. The increased strength of pinions of the proposed design versus their standard counterparts is verified with finite element analysis.

Optimization of fillet stress to enhance the bending strength through non-standard high contact ratio spur gears

2015 ◽  
Vol 230 (7-8) ◽  
pp. 1139-1148 ◽  
Author(s):  
P Marimuthu ◽  
G Muthuveerappan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Parametric Study ◽  
Bending Strength ◽  
Spur Gear ◽  
Gear Ratio ◽  
Spur Gears ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Drives

The present study aims to determine the improvement in the bending strength of the non-standard high contact ratio spur gears based on the balanced (optimum) fillet stress of the pinion and gear. The average number teeth in contact is more than two for high contact ratio gear drives. In the non-standard high contact ratio spur gears, the rack cutter tooth thickness factor is more than 0.5, whereas the standard rack cutter tooth thickness factor is 0.5. The maximum fillet stresses of the pinion and gear is not equal for non-standard high contact ratio spur gear drives when the gear ratio increases. In order to avoid the fatigue failure of the gear, the fillet stresses of the pinion and gear should be balanced. This balanced stress is predicted as the optimum fillet stress. Hence, the present study focuses to optimize the fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear through finite element analysis. Also, a parametric study is carried out to obtain the influence of some gear parameters, such as gear ratio, teeth number in the pinion, pressure angle, addendum height and corrected gear drives (S+, S− and So) on the optimum fillet stress with respect to the rack cutter tooth thickness factor of the pinion and gear.

Effect of Adjacent Teeth Load on Bending Strength of High Contact Ratio Asymmetrical Spur Gear Drive

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
R. Thirumurugan ◽  
C.C.C. Deepak ◽  
K. Karthieeban
Keyword(s):  
Computer Aided Design ◽  
Bending Strength ◽  
Gear Tooth ◽  
Spur Gear ◽  
Design Tool ◽  
Bending Stress ◽  
Contact Ratio ◽  
Element Analysis ◽  
Gear Drive ◽  
Pressure Angle

This paper describes methodology for predicting the bending stress of the spur gear accurately by including the load on the adjacent teeth for high contact ratio asymmetric spur gear drive. Higher contact ratio is obtained by enlarging the addendum from the standard addendum value where as the asymmetric is achieved by keeping various pressure angles (170, 200 and 220) at non drive side while the drive side pressure angle was kept as 200. The bending stress developed for the given load according to the load sharing calculated by using stiffness based method along with the effect of adjacent teeth loads are explored in this work. Computer aided design tool is used for generating the gear tooth profile and ANSYS is used to carry out the finite element analysis. The result shows that the maximum bending stress level in a mesh cycle is increased when the load on adjacent teeth are taken into account. The higher pressure angle at the non-drive side yields lesser stress at the fillet region when compared to the lower pressure angle.

Geometry and contact characteristics of torus involute gears

2016 ◽  
Vol 231 (2) ◽  
pp. 250-270 ◽  
Author(s):  
Lei Liu ◽  
Jingwen Tan ◽  
Meijuan Fang
Keyword(s):  
Mathematical Models ◽  
High Sensitivity ◽  
Spur Gear ◽  
Tooth Contact Analysis ◽  
Element Analysis ◽  
Tooth Contact ◽  
Involute Gear ◽  
Involute Gears ◽  
Conjugate Surfaces ◽  
Tooth Flank

Aimed at overcoming high sensitivity to machining or mounting error of line-contact conjugate surfaces, a novel torus involute gear drive is proposed which can compensate large axial misalignments and possess good meshing characteristics without lead correction. The torus involute gear is essentially a special spur gear with continuous shifting in the second order. Based on the processing principle of the torus involute gears, their mathematical models are established according to the corresponding imaginary rack cutter. In order to provide the approach to choose proper designing parameters, geometry characteristics of the torus involute gear are investigated: condition equations of tooth undercutting for a convex torus involute gear and tooth pointing for a concave torus involute gear are formulated utilizing the developed mathematical models, and the approach to checking tooth flank interference is provided. Contact characteristics of the gear set is studied through tooth contact analysis and finite element analysis. The simulated results produce useful information about tooth contact pattern, stress distribution, and transmission errors of the gear set.

scholarly journals Shear cutting induced residual stresses in involute gears and resulting tooth root bending strength of a fineblanked gear

2021 ◽  
Author(s):  
Daniel Müller ◽  
Jens Stahl ◽  
Anian Nürnberger ◽  
Roland Golle ◽  
Thomas Tobie ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Residual Stresses ◽  
Carrying Capacity ◽  
Bending Strength ◽  
Tooth Root ◽  
Load Carrying Capacity ◽  
Near Surface ◽  
Load Carrying ◽  
Involute Gears ◽  
Cut Surface

AbstractThe manufacturing of case-hardened gears usually consists of several complex and expensive steps to ensure high load carrying capacity. The load carrying capacity for the main fatigue failure modes pitting and tooth root breakage can be increased significantly by increasing the near surface compressive residual stresses. In earlier publications, different shear cutting techniques, the near-net-shape-blanking processes (NNSBP’s), were investigated regarding a favorable residual stress state. The influence of the process parameters on the amount of clean cut, surface roughness, hardness and residual stresses was investigated. Furthermore, fatigue bending tests were carried out using C-shaped specimens. This paper reports about involute gears that are manufactured by fineblanking. This NNSBP was identified as suitable based on the previous research, because it led to a high amount of clean cut and favorable residual stresses. For the fineblanked gears of S355MC (1.0976), the die edge radii were varied and the effects on the cut surface geometry, hardness distribution, surface roughness and residual stresses are investigated. The accuracy of blanking the gear geometry is measured, and the tooth root bending strength is determined in a pulsating test rig according to standardized testing methods. It is shown that it is possible to manufacture gears by fineblanking with a high precision comparable to gear hobbing. Additionally, the cut surface properties lead to an increased tooth root bending strength.

scholarly journals Global experience of HVDC composite insulators in outdoor and indoor environment

2020 ◽  
Vol 59 (1) ◽  
pp. 606-618
Author(s):  
Mohammad Akbar ◽  
Basharat Mehmood
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Transmission Lines ◽  
Power Transmission ◽  
Green Energy ◽  
Attractive Alternative ◽  
Hvdc Transmission ◽  
Ceramic Insulators ◽  
High Power Transmission ◽  
Aging Performance

AbstractHigh-voltage direct current (HVDC) transmission is known as green-energy transfer technology and has recently become an attractive alternative of high-voltage alternating current (HVAC) due to its high-power transmission capability and lower power loss. Use of composite insulators on direct current (DC) transmission lines experienced rapid growth in recent years due to their high hydrophobicity and better performance in contaminated environment than conventional ceramic insulators. During their service operation on DC lines, insulators are prone to more accumulation of contaminants due to unidirectional electric field. The contaminants under wet conditions allow leakage current to flow on the insulator surface. Being organic in nature, polymeric insulators have a tendency to age under the combined effects of electrical and environmental stresses. To fully understand the long-term aging performance of DC composite insulators, a detailed survey was considered necessary. Towards that end, this paper critically summarizes worldwide experience of aging performance of composite insulators in the field as well as in laboratory conditions.

Multimodal pizza-shaped piezoelectric vibration-based energy harvesters

2021 ◽  
pp. 1045389X2110069
Author(s):  
Virgilio J Caetano ◽  
Marcelo A Savi
Keyword(s):  
Energy Harvesting ◽  
Frequency Spectrum ◽  
Optimization Procedure ◽  
Single Mode ◽  
Ambient Vibration ◽  
Vibration Source ◽  
Element Analysis ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Harvesting Systems

Energy harvesting from ambient vibration through piezoelectric devices has received a lot of attention in recent years from both academia and industry. One of the main challenges is to develop devices capable of adapting to diverse sources of environmental excitation, being able to efficiently operate over a broadband frequency spectrum. This work proposes a novel multimodal design of a piezoelectric energy harvesting system to harness energy from a wideband ambient vibration source. Circular-shaped and pizza-shaped designs are employed as candidates for the device, comparing their performance with classical beam-shaped devices. Finite element analysis is employed to model system dynamics using ANSYS Workbench. An optimization procedure is applied to the system aiming to seek a configuration that can extract energy from a broader frequency spectrum and maximize its output power. A comparative analysis with conventional energy harvesting systems is performed. Numerical simulations are carried out to investigate the harvester performances under harmonic and random excitations. Results show that the proposed multimodal harvester has potential to harness energy from broadband ambient vibration sources presenting performance advantages in comparison to conventional single-mode energy harvesters.

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