Download or read book A Study on the Long Cycle Micro pitting Behavior of Spur Gear Pairs written by Suhas Ashok Kedilaya and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Contact fatigue behavior of a gear pair is typically gauged by size of macro-pits formed during the operation of the gear pair. It is common that very small pits form in certain tooth contact locations first. Macro-pits typically initiate from the boundaries of these micro-pitted zones. As most macro-pitting evaluations were performed at high- stress, medium-life conditions, micro-pit formation has often been overlooked. In this study, a set of spur gear experiments are performed under typical automotive speed, temperature and operating conditions with a modest torque transmitted, to investigate micro-pitting performance during ultra-long cycle operation up to 400 million cycles. Evolution of contact surfaces throughout each test are documented through interim inspections, including surface geometries, roughnesses and micro-pitted area. Digital imaging techniques are employed to automate the quantification of micro-pitted regions for each tooth image. The micro-pitting experiments are simulated by using an existing spur gear micro-pit life prediction methodology. Based on comparisons between predictions and measurements, an assessment on the accuracy and effectiveness of this methodology is made along with the potential areas of improvement.
Download or read book An Investigation of the Influence of Micropitting on the Progression of Gear Surface Pitting written by Eunsung Kim and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the progression of micropitting and its effect on the fatigue life of a spur gear is investigated through an experimental study. Standard contact durability testing is performed on two test gears and an inspection is done throughout the gear's life cycle. Operating conditions for the test are closely controlled to minimize the effect of applied load, lubrication conditions, shaft rotation speed, and temperature on the micropitting behavior. Gear tooth topography is captured using a gear specific CMM and roughness measurement is obtained using a profilometer. Macroscopic images are also taken to have a record of the physical appearance of the gear flank. Using the experimental data, the severity of surface degradation due to micropitting is quantified by measuring the maximum profile deviation from the initial state. Gear tooth surface topography is used in a load distribution prediction. The change in contact stress distribution and maximum contact stress location are compared to the gear tooth surface topography over the life of the gear to study the effect of micropitting. Contact stress data is then applied to a multi-axial fatigue damage model using the critical plane approach to calculate the fatigue damage parameter. The critical plane is determined by testing which candidate plane produces the maximum shear strain amplitude. Stress and strain components on this critical plane are then applied to the fatigue damage model to calculate the predicted number of cycles to failure, and a damage accumulation rule is employed to predict crack initiation. The maximum accumulated damage location closely aligned with the maximum contact stress location as well as the maximum critical-plane shear strain location. Most importantly, these locations corresponded to the pitting location. Based on the experimental and modelled results, micropitting significantly influences the contact stress distribution that leads to stress concentration, potentially leading to contact fatigue failure such as pitting. The fatigue damage prediction model is somewhat validated through the minimal experimental data further experimental data is needed to develop a method of predicting pitting initiation accurately.
Download or read book An Experimental Study of the Impact of Various Tooth Surface Treatments on Spur Gear Pitting Life written by Jeremy Micah Bluestein and published by . This book was released on 2007 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this study, the influence of various engineered surface treatments on the contact fatigue behavior of spur gear pairs was investigated, focusing on pitting life. A number of standard gear durability test machines were furbished and sets of specially designed spur gear test specimens were procured to execute a test matrix that includes gears having various surface treatments. Typical hobbed-shaved surfaces were considered to represent the baseline surface treatment and their pitting lives were compared to lives of gears having (i) chemically polished, (ii) shot-peened and plastic honed, and (iii) chemically polished and CrN coated surfaces. Pitting life of each variation was quantified at several stress levels by using a set of predetermined failure criteria, and test and inspection procedures. The data for each variation was processed statistically and compared to data from other surface variations. The results indicate that chemically polishing increases the pitting life of spur gears nearly three times over the life of the baseline hobbed-shaved gears. It was also observed that the shot-peened and plastic honed gears did not deliver any tangible pitting life improvements over the baseline conditions. Finally, a slight increase in pitting life was observed over chemically polished gears with the application of the CrN coating.
Download or read book A Study on the Relationship Between the Dynamic Factor and the Dynamic Transmission Error of Spur Gear Pairs written by Venkata Krishna Tamminana and published by . This book was released on 2005 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Power Transmission systems are widely used in automotive and aerospace industries. These systems are often operated under relatively high rotational speeds and hence their dynamic behavior, especially its impact on the gears, becomes a relevant issue. Dynamic behavior of gear systems is important for two main reasons: durability and noise. In this study, two different dynamic models, a finite elements-based deformable-body model and a simplified discrete model, are developed to predict dynamic behavior of spur gear pairs. The deformable-body model will have the ability to predict both DTE and DF based on mesh and tooth forces as well as dynamic gear tooth bending stresses. The discrete model will rely on the deformable-body model for computation of gear mesh parameters under quasi-static conditions and will predict both DTE and DF based on mesh and tooth forces. Dynamic transmission error (DTE) and dynamic factors (DF) defined based on the gear mesh loads, tooth loads and bending stresses are computed for a number of unmodified and modified spur gears within a wide range of rotational speed for different involute contact ratios and torques. Both models are validated by comparing their DTE predictions with experimental data obtained from a set of tests using spur gear having unmodified and modified tooth profiles. The predicted Dc DF and DTE values are related to each other through simplified formulas. Impact of nonlinear behavior such as tooth separations and jump discontinuities on DF is also quantified.
Download or read book An Experimental Investigation of the Effect of Spacing Errors on the Loaded Transmission Error of Spur Gear Pairs written by Brian Anichowski (Jr.) and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper complements recent investigations [Handschuh et al. (2014), Talbot et al. (2016)] of the influences of tooth indexing errors on dynamic factors of spur gears by presenting data on changes to the dynamic transmission error. An experimental study is performed using an accelerometer-based dynamic transmission error measurement system incorporated into a high-speed gear tester to establish baseline dynamic behavior of gears having negligible indexing errors, and to characterize changes to this baseline due to application of tightly-controlled intentional indexing errors. Spur gears having different forms of indexing errors are paired with a gear having negligible indexing error. Dynamic transmission error of gear pairs under these error conditions is measured and examined in both time and frequency domains to quantify the transient effects induced by these indexing errors. These measurements are then compared against the baseline, no error condition, as a means to quantify the dynamic vibratory behavior induced due to the tooth indexing errors. These comparisons between measurements indicate clearly that the baseline dynamic response, dominated by well-defined resonance peaks and mesh harmonics, are complemented by non-mesh orders of transmission error due the transient behavior induced by indexing errors. In addition, the tooth (or teeth) having indexing error imparts transient effects which dominate the vibratory response of the system for significantly more mesh cycles than the teeth having errors are in contact. For this reason, along with the results presented in Talbot et al. (2016), it was concluded that spur gears containing indexing errors exhibit significant deviations from nominal behavior, at both a system and time-domain level.
Download or read book Tribology and Surface Engineering written by Aleksander Lisiecki and published by MDPI. This book was released on 2020-01-15 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book covers very important issues, not only scientific in nature but, ultimately, for industry and the economy. Wear and deterioration of surface properties during operation is a natural and unavoidable phenomenon. However, minimizing the degree of wear is of great importance for the entire economy, as illustrated by the example of the US economy, for which the loss of natural resources as a direct cause of friction and wear exceeds 6% of the Gross National Product. This book showcases the valuable knowledge revealed from both theoretical and practical research results in the field of advanced technologies of coatings and surface modification, as well as wear and tribological characteristics of advanced materials and surface layers. Therefore, it is hoped that this book will be a valuable resource and helpful tool for scientists, engineers, and students in the field of surface engineering, materials science, and manufacturing engineering.
Download or read book Encyclopedia of Tribology written by Q. Jane Wang and published by Springer. This book was released on 2013-09-26 with total page 4139 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRIBOLOGY – the study of friction, wear and lubrication – impacts almost every aspect of our daily lives. The Springer Encyclopedia of Tribology is an authoritative and comprehensive reference covering all major aspects of the science and engineering of tribology that are relevant to researchers across all engineering industries and related scientific disciplines. This is the first major reference that brings together the science, engineering and technological aspects of tribology of this breadth and scope in a single work. Developed and written by leading experts in the field, the Springer Encyclopedia of Tribology covers the fundamentals as well as advanced applications across material types, different length and time scales, and encompassing various engineering applications and technologies. Exciting new areas such as nanotribology, tribochemistry and biotribology have also been included. As a six-volume set, the Springer Encyclopedia of Tribology comprises 1630 entries written by authoritative experts in each subject area, under the guidance of an international panel of key researchers from academia, national laboratories and industry. With alphabetically-arranged entries, concept diagrams and cross-linking features, this comprehensive work provides easy access to essential information for both researchers and practicing engineers in the fields of engineering (aerospace, automotive, biomedical, chemical, electrical, and mechanical) as well as materials science, physics, and chemistry.
Download or read book Atlas of Fatigue Curves written by Howard E. Boyer and published by ASM International. This book was released on 1985-12-31 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains more than 500 fatigue curves for industrial ferrous and nonferrous alloys. Also includes an explanation of fatigue testing and interpretation of test results. Each curve is presented independently and includes an explanation of its particular importance.
Download or read book Gear Materials Properties and Manufacture written by Joseph R. Davis and published by ASM International. This book was released on 2005 with total page 349 pages. Available in PDF, EPUB and Kindle. Book excerpt: All of the critical technical aspects of gear materials technology are addressed in this new reference work. Gear Materials, Properties, and Manufacture is intended for gear metallurgists and materials specialists, manufacturing engineers, lubrication technologists, and analysts concerned with gear failures who seek a better understanding of gear performance and gear life. This volume complements other gear texts that emphasize the design, geometry, and theory of gears. The coverage begins with an overview of the various types of gears used, important gear terminology, applied stresses and strength requirements associated with gears, and lubrication and wear. This is followed by in-depth treatment of metallic (ferrous and nonferrous alloys) and plastic gear materials. Emphasis is on the properties of carburized steels, the material of choice for high-performance power transmission gearing.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1993 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1997 with total page 1060 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finishing of Conical Gears by Pulsed Electrochemical Honing written by Neelesh K Jain and published by Cambridge Scholars Publishing. This book was released on 2019-06-04 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book sheds light on the development of Pulsed-Electrochemical Honing (PECH), a unique hybrid finishing process, which has capabilities of finishing intricate shaped components (especially gears). The text covers the fundamentals of the process, and details all parameters of PECH in the finishing of straight bevel gears. It discusses all important aspects of electrochemical honing, and details recent developments in tools, technologies, controls and operations.
Download or read book Direct Gear Design written by Alexander L. Kapelevich and published by CRC Press. This book was released on 2013-03-22 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the last several decades, gearing development has focused on improvements in materials, manufacturing technology and tooling, thermal treatment, and coatings and lubricants. In contrast, gear design methods have remained frozen in time, as the vast majority of gears are designed with standard tooth proportions. This over-standardization significantly limits the potential performance of custom gear drives, especially in demanding aerospace or automotive applications. Direct Gear Design introduces an alternate gear design approach to maximize gear drive performance in custom gear applications. Developed by the author, the Direct Gear Design® method has been successfully implemented in a wide variety of custom gear transmissions over the past 30 years. The results are maximized gear drive performance, increased transmission load capacity and efficiency, and reduced size and weight. This book explains the method clearly, making it easy to apply to actual gear design. Describes the origin and theoretical foundations of the Direct Gear Design approach as well as some of its applications—and its limits Details the optimization techniques and the specifics of Direct Gear Design Discusses how this approach can be used with asymmetric gears to further improve performance Describes tolerance selection, manufacturing technologies, and measurement methods of custom gears Compares Direct Gear Design with traditional gear design from both an analytical and an experimental perspective Illustrates the applicability and benefits of this gear design approach with implementation examples Written by an engineer for engineers, this book presents a unique alternative to traditional gear design. It inspires readers to explore ways of improving gear transmission performance in custom gear applications, from higher transmission load capacity, efficiency, and reliability to lower size, weight, and cost.
Download or read book High Conformal Gearing written by Stephen P. Radzevich and published by CRC Press. This book was released on 2016-01-05 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a Concept That Makes Gear Transmissions Noiseless, Smaller, and Lighter in WeightHigh-conformal gearing is a new gear system inspired by the human skeleton. Unlike conventional external involute gearing, which features convex-to-convex contact, high-conformal gearing features a convex-to-concave type of contact between the tooth fla
Download or read book Fatigue Design written by Eliahu Zahavi and published by CRC Press. This book was released on 2019-01-22 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern analytical theories of fatigue coupled with a knowledge of processing effects on metals make up the sound basis for designing machine parts that are free from unexpected failure. Fatigue Design: Life Expectancy of Machine Parts provides the information and the tools needed for optimal design. It highlights practical approaches for effectively solving fatigue problems, including minimizing the risk of hidden perils that may arise during production processes or from exposure to the environment.The material is presented with a dual approach: the excellent coverage of the theoretical aspects is accented by practical illustrations of the behavior of machine parts. The theoretical approach combines the fundamentals of solid mechanics, fatigue analysis, and crack propagation. The chapters covering fatigue theories are given special emphasis, starting with the basics and progressing to complicated multiaxial nonlinear problems.The practical approach concentrates on the effects of surface processing on fatigue life and it illustrates many faceted fatigue problems taken from case studies. The solutions demonstrate the authors' detailed analyses of failure and are intended to be used as preventive guidelines. The cases are a unique feature of the book. The numerical method used is the finite element method, and is presented with clear explanations and illustrations.Fatigue Design: Life Expectancy of Machine Parts is an extremely valuable tool for both practicing design engineers and engineering students.
Download or read book Systematic Analysis of Gear Failures written by Lester E. Alban and published by ASM International. This book was released on 1985-01-01 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explores the detailed steps necessary to determine the causes of failure. First, the physical characteristics of a gear are studied: where the stress points are, from what directions the forces are applied, where the movement of material progresses, and where strain patterns exist. Second, all external conditions and forces are considered. With this background information, a systematic examination is described from beginning to end, the end being a conclusion about the mode and cause of failure.
Download or read book Paper written by and published by . This book was released on 1990 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
