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Gear Rolling for Production of High Gears Alireza Khodaee

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Gear Rolling for Production of High Gears Alireza Khodaee Gear Rolling for Production of High Gears Alireza Khodaee Gear Rolling for Production of High Gears Alireza Khodaee Licentiate Thesis, 2015 KTH Royal Institute of Technology Industrial Engineering and Management Department of Production Engineering SE-100 44 Stockholm, Sweden TRITA-IIP-15-06 ISSN: 1650-1888 ISBN: 978-91-7595-678-7 Abstract Gears are used to transmit mechanical work from one point to another. They are widely used in different mechanisms and they are the most important components of a transmission system. Thus, it is important that they are manufactured with high precision to deliver the work with highest possible efficiency. The dominant gear production method is metal cutting, like hobbing. The gear manufacturing industry aims to replace their traditional production lines with greener processes and thereby urge engineers to think about using metal forming methods instead of the traditional metal cutting solutions when possible. Gear rolling is an interesting metal forming method that can be an alternative method to fabricate gear wheels. Research on gear rolling firstly came into interest around 2000. Very few papers are published that covers the development of the method and its limitations and advantages. Almost all of these publications considered rolling of gear wheels with small modules. The focus of this study will be on application of gear rolling for gear wheels with large module (over 3 mm) where the amount of deformation is much larger than found in previous studies. In this thesis the Finite Element Method has been used to simulate and predict the results of rolling of high gears. In addition to that experiments were performed to validate the numerical results and develop the modelling technique for further investigations. The main topic of discussion is about the gear quality as a measure of the success for the process. Extra attention has been paid to the effects of friction and process planning in the result of process loads and also on the gear quality. The thesis structure is based on four published papers, and some additional results from the experiments which have not yet been published. According to the results of these papers, the effect of friction and process parameters are recognized in the final product quality. It is shown that FEM has a great potential in order to model and analyze the gear rolling process. A new approach to combine numerical methods with quality measurement to predict the process outcomes is also presented. The results show that gear wheels with a module of 4mm reach an ISO quality level between 11 and 12. This is substantially lower quality than can be obtained with metal cutting operations. The results of this thesis can be used as the starting point for future research to optimize the quality of gear rolling for high gears. i Sammanfattning Kugghjul är den viktigaste komponenten i transmissioner. De tillverkas med hög precision och hög effektivitet för att ge hög prestanda. Den dominerande tillverkningsmetoden är skärande bearbetning som hobbning Nya krav på miljövänlig tillverkning gör att man letar efter andra tillverkningsmetoder än de avverkande. Metoder baserade på plastisk formning är då intressanta. Kuggrullning är en sådan metod där material förflyttas och deformeras utan avverkning. Forskning kring kuggrullning tog fart under 2000-talet. Ett begränsat antal publikationer finns inom området. Nästan alla arbeten berör kugghjul med små moduler i storleksordningen 1mm. I denna studie fokuserar vi däremot på kugghjul med stora moduler som 4mm vilket är typiskt för tillämpningar i lastfordon. För dessa stora moduler fås större deformationer vid kuggrullning än vad som behandlats tidigare i litteraturen. I detta arbete används Finita Elementmetoden för att simulera och förutsäga resultat vid kuggrullning. Parallellt med detta arbete har experiment utförts på kuggrullning för att kunna verifiera simuleringsresultaten. Stor tyngd har lagts vid den kvalitet som fås efter kuggrullning. Effekter av processupplägg och faktorer som friktion har belysts. Avhandlingen bygger på fyra publikationer och på experiment som publiceras för första gången i denna avhandling. Resultaten visar att FEM har en stor potential för att analysera kuggrullning. Resultaten visar även hur FEM kan användas för att analysera kuggkvalitet. Den kvalitet som uppnåtts med FEM och experimentell ligger i intervallet ISO 11-12 för kuggmoduler av 4mm. Detta är väsentligt lägre kvaliter än de som idag kan uppnås med skärande bearbetning. De metoder som utvecklats i avhandlingen utgör startpunkter för framtida optimering av kuggrullningsprocessen för hjul med stora moduler. ii Acknowledgements My highest appreciation goes to Professor Arne Melander who supervised my research during past 3 years. Without his patience and insightful comments it was not possible to finish this thesis. Together we had fruitful discussions which always motivated me to go forward in my studies. In addition to my supervisor I would like to thank Doctor Sven Haglund from Swerea KIMAB, for his cooperation in my research and his time to discuss the technical details with me. I have to thank Doctor Niclas Stenberg, from Swerea KIMAB, who was the person bringing me into this project in first in 2012 and also helped me to edit this thesis as well. It would not be possible to do this project and write the thesis, without Swedish national research agency VINNOVA, who fund the FFI SMART project. Furthermore, I have to thank all industrial partners and their representatives in the project. Special thanks to Mr. Karl-Gustav Luren from VOLVO powertrain for his time and guidance when I need it. Also I would like to thank Mr. Ulf Bjarre from SCANIA, who always provide me his thoughts to develop new ideas to solve problems I had in project. I also have to thank all my colleagues at KTH, who made my days at KTH more interesting. You provide a good working environment and we had great discussions about the world problems with you. To my wife, Bahar, thanks for your love and support. You always encouraged me when I need it through my path toward my PhD. Stockholm, June 2015 Alireza Khodaee iii List of publications Paper A Khodaee, Alireza, and Arne Melander. "Finite Element Simulation as a Tool to Evaluate Gear Quality after Gear Rolling." In Key Engineering Materials, vol. 554, pp. 300-306. 2013. Paper B Khodaee, Alireza, and Arne Melander. "Finite Element Analysis on the Friction Effects in the Gear Rolling Process." Advanced Manufacturing Engineering and Technologies NEWTECH 2013 Stockholm, Sweden 27-30 October 2013 (2013): 93. Paper C Khodaee, Alireza, and Arne Melander. "A Study of the Effects of Reversal Cycles in the Gear Rolling Process by Using Finite Element Simulations." In Key Engineering Materials, vol. 611, pp. 134-141. 2014. Paper D Khodaee, Alireza, and Arne Melander. "Process Planning of Gear Rolling with the Finite Element Method." In Key Engineering Materials, vol. 622, pp. 986-992. 2014. iv List of abbreviations BC- Boundary conditions CMM- Coordinate measuring machine DIN- Deutsches institut für normung FE- Finite element FEM- Finite element method NC- Numerical controlled RQ- Research question 2D- Two dimensional 3D- Three dimensional v Contents Abstract ............................................................................................................................... i Sammanfattning ................................................................................................................. ii Acknowledgements ........................................................................................................... iii List of publications ............................................................................................................. iv List of abbreviations ........................................................................................................... v Chapter1: Introduction ...................................................................................................... 1 1.1 Industrial gear production background ................................................................... 1 1.2 Thesis outline ........................................................................................................... 2 1.3 Research questions .................................................................................................. 2 RQ #I: ......................................................................................................................... 2 RQ #II: ........................................................................................................................ 3 RQ #III: ....................................................................................................................... 3 1.4 Research methodology ............................................................................................ 4 1.5 Introduction to the papers ...................................................................................... 4 Chapter2: Theoretical Background .................................................................................... 8 2.1 History of gear rolling .............................................................................................. 8 2.2 Gear rolling process parameters ........................................................................... 20 2.2.1 Process ............................................................................................................ 21 2.2.2 Tools ...............................................................................................................
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