{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T09:53:27Z","timestamp":1769507607544,"version":"3.49.0"},"reference-count":53,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,24]],"date-time":"2022-01-24T00:00:00Z","timestamp":1642982400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Machines"],"abstract":"<jats:p>This paper aims to present the design of a new 3D-printed continuously variable transmission (CVT) developed for an electric vehicle prototype competing in Shell Eco-marathon electric battery category, a world-wide energy efficiency competition sponsored by Shell. The proposed system is composed of a polymeric conic geared friction wheel assembled in the motor axle and directly coupled to the rear tire of the vehicle. The conical shape allows to implement a continuous variation of the geared friction wheel diameter in contact with the tire. The motor with the geared friction wheel was mounted over a board with linear bearings, allowing the speed ratio to change by moving the board laterally. A computational simulation model of a prototype electric vehicle with the proposed 3D-printed CVT was created in Matlab\/Simulink environment to obtain the traction force in the geared friction wheel and also to analyze the vehicle performance. The simulation results demonstrated possibilities of increasing vehicle speed range output and available torque in the rear traction wheel. Also, it is shown with the simulated model that the designed CVT consumes 10.46% less energy than a fixed transmission ratio, demonstrating the CVT concept\u2019s potential for battery consumption reduction. Lastly, a 3D-printing slicing software with an optimization algorithm plug-in was used to determine the best printing parameters for the conic geared friction wheel based on the tangential force, maximum displacement and safety factor. When compared to the original part with a 100% infill density, the optimized solution reduced the component mass by about 12% while maintaining safe mechanical resistance and stiffness.<\/jats:p>","DOI":"10.3390\/machines10020084","type":"journal-article","created":{"date-parts":[[2022,1,25]],"date-time":"2022-01-25T20:40:18Z","timestamp":1643143218000},"page":"84","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["A 3D-Printed Continuously Variable Transmission for an Electric Vehicle Prototype"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8086-5340","authenticated-orcid":false,"given":"Marcos R. C.","family":"Coimbra","sequence":"first","affiliation":[{"name":"Alto Paraopeba Campus, Federal University of S\u00e3o Jo\u00e3o del-Rei, Rodovia MG 443, Ouro Branco-MG 36420-00, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2951-8730","authenticated-orcid":false,"given":"T\u00e1rsis P.","family":"Barbosa","sequence":"additional","affiliation":[{"name":"Alto Paraopeba Campus, Federal University of S\u00e3o Jo\u00e3o del-Rei, Rodovia MG 443, Ouro Branco-MG 36420-00, Brazil"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1926-7250","authenticated-orcid":false,"given":"C\u00e9sar M. A.","family":"Vasques","sequence":"additional","affiliation":[{"name":"proMetheus, Escola Superior de Tecnologia e Gest\u00e3o, Instituto Polit\u00e9cnico de Viana do Castelo, Rua Escola Industrial e Comercial de Nun\u2019\u00c1lvares, 4900-347 Viana do Castelo, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"17387","DOI":"10.1016\/j.ijhydene.2018.07.076","article-title":"Energy sources and multi-input DC-DC converters used in hybrid electric vehicle applications\u2014A review","volume":"43","author":"Reddy","year":"2018","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1331","DOI":"10.1016\/j.enpol.2019.02.053","article-title":"Climate agreement and technology diffusion: Impact of the Kyoto Protocol on international patent applications for renewable energy technologies","volume":"129","author":"Miyamoto","year":"2019","journal-title":"Energy Policy"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Alnunu, N., Said, S., Al-Sharman, S., Al-Ibrahimi, A., AbdulAziz, A., Hellabi, M.A., Touati, F., Ghani, S., Mahdi, E.S., and Benammar, M. (2012, January 26\u201328). Design of Qatar University\u2019s first solar car for Shell Eco-Marathon competition. Proceedings of the 2012 First International Conference on Renewable Energies and Vehicular Technology, Nabeul, TN, USA.","DOI":"10.1109\/REVET.2012.6195247"},{"key":"ref_4","unstructured":"Baldissera, P., and Delprete, C. (2014, January 25\u201327). Human powered vehicle design: A challenge for engineering Education. Proceedings of the ASME 2014 12th Biennial Conference on Engineering Systems Design and Analysis, Copenhagen, Denmark. ASME ESDA2014-20549."},{"key":"ref_5","unstructured":"Buck, L., Mclening, C., and Burgess, J. (2014, January 4\u20135). Eco-car: A perfect vehicle for technical design teaching?. Proceedings of the 16th International Conference on Engineering and Product Design Education (E&PDE14), Design Education and Human Technology Relations, University of Twente, Enschede, The Netherlands."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Abdulwahed, M., Ahmad, S., Hasna, M.O., Ghani, S., and Benammar, M. (2014, January 3\u20136). Contribution of Shell Eco-Marathon engineering design experience to soft skills development: A qualitative analysis in the Asian context. Proceedings of the 2014 International Conference on Interactive Collaborative Learning (ICL), Dubai, United Arab Emirates.","DOI":"10.1109\/ICL.2014.7017810"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"von Solms, S., and Nel, H. (2017, January 10\u201313). Reflective learning in engineering education: A case study of shell Eco-Marathon. Proceedings of the 2017 IEEE International Conference on Industrial Engineering and Engineering Management (IEEM), Singapore.","DOI":"10.1109\/IEEM.2017.8289895"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Verma, A.R., Chaurasia, A., Jaiswal, S.S., Bhonde, L., Guha, R., Sahu, H., Patel, S., Banthiya, S., Maddeshiya, S., and Mirzapure, S. (2021). Team AVERERA\u2019s Alterno V4.0\u2013A Hyper Energy-Efficient Electric Prototype Vehicle for Shell Eco-Marathon, SAE International. SAE Technical Paper 2021-01-0792.","DOI":"10.4271\/2021-01-0792"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"413","DOI":"10.1016\/j.advengsoft.2017.10.006","article-title":"Design of experimental vehicle specified for competition Shell Eco-marathon 2017 according to principles of car body digitisation based on views in 2D using the intuitive tool Imagine&Shape CATIA V5","volume":"115","author":"Fabian","year":"2018","journal-title":"Adv. Eng. Softw."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"012072","DOI":"10.1088\/1742-6596\/1700\/1\/012072","article-title":"Designing Shell Eco-Marathon car bodies with SolidWorks","volume":"1700","author":"Gunadi","year":"2020","journal-title":"J. Physics Conf. Ser."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1515\/cls-2021-0016","article-title":"Numerical estimation of the torsional stiffness characteristics on urban Shell Eco-Marathon (SEM) vehicle design","volume":"8","author":"Ary","year":"2021","journal-title":"Curved Layer. Struct."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"160","DOI":"10.3390\/wevj3010160","article-title":"New technologies demonstrated at Formula Electric and Hybrid Italy 2008","volume":"3","author":"Brusaglino","year":"2009","journal-title":"World Electr. Veh. J."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Carello, M., Bertipaglia, A., Messana, A., Airale, A.G., and Sisca, L. (2019). Modeling and Optimization of the Consumption of a Three-Wheeled Vehicle, SAE International. SAE Technical Pape 2019-01-0164.","DOI":"10.4271\/2019-01-0164"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"012018","DOI":"10.1088\/1757-899X\/1002\/1\/012018","article-title":"Driving strategy for minimal energy consumption of an ultra-energy-efficient vehicle in Shell Eco-Marathon competition","volume":"1002","author":"Gechev","year":"2020","journal-title":"IOP Conf. Ser. Mater. Sci. Eng."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"20291","DOI":"10.1016\/j.ijhydene.2020.09.059","article-title":"Energy management of a fuel cell hybrid ultra-energy efficient vehicle","volume":"46","author":"Punov","year":"2021","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Stabile, P., Ballo, F., Mastinu, G., and Gobbi, M. (2021). An ultra-efficient lightweight electric vehicle\u2014Power demand analysis to enable lightweight construction. Energies, 14.","DOI":"10.3390\/en14030766"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1016\/j.energy.2011.11.022","article-title":"Design and testing of a fuel cell powertrain with energy constraints","volume":"38","author":"Wasselynck","year":"2012","journal-title":"Energy"},{"key":"ref_18","first-page":"65","article-title":"The comparative study of drivetrain of high-performance electric vehicle","volume":"15","author":"Skarka","year":"2014","journal-title":"Diagnostyka"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"21722","DOI":"10.1016\/j.ijhydene.2020.05.138","article-title":"Impact of powertrain hybridization on the performance and costs of a fuel cell electric vehicle","volume":"45","author":"Nassif","year":"2020","journal-title":"Int. J. Hydrogen Energy"},{"key":"ref_20","unstructured":"Carello, M., Pinheiro, H.C., Longega, L., and Di Napoli, L. (2021). Design and Modelling of the Powertrain of a Hybrid Fuel Cell Electric Vehicle, SAE International. SAE Technical Pape 2021-01-0734."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Messana, A., Sisca, L., Ferraris, A., Airale, A., de Carvalho Pinheiro, H., Sanfilippo, P., and Carello, M. (2019). From Design to Manufacture of a Carbon Fiber Monocoque for a Three-Wheeler Vehicle Prototype. Materials, 12.","DOI":"10.3390\/ma12030332"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Sethi, N., Chauhan, P., Bansal, S., and Singari, R.M. (2021). Robust vehicle development for student competitions using fiber-reinforced composites. Lecture Notes in Mechanical Engineering, Springer.","DOI":"10.1007\/978-981-15-8542-5_6"},{"key":"ref_23","first-page":"91","article-title":"Steering System of a Low-Consumption Vehicle: From the Dynamics Analysis to the Design of the Wheel Assembly","volume":"Volume 68","author":"Carbone","year":"2018","journal-title":"Advances in Italian Mechanism Science. IFToMM ITALY 2018. Mechanisms and Machine Science"},{"key":"ref_24","first-page":"1","article-title":"Study on the Optimization Model of a Flexible Transmission","volume":"2019","author":"Zhai","year":"2019","journal-title":"Math. Probl. Eng."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Iliev, S., Gunev, D., and Mitev, E. (2019, January 23\u201326). Design and Development of a Steering Wheel for an Energy Efficient Vehicle. Proceedings of the International Symposium on Intelligent Manufacturing and Automation, Vienna, Austria.","DOI":"10.2507\/30th.daaam.proceedings.055"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"232","DOI":"10.1515\/eng-2020-0032","article-title":"Design and development of ultra-light front and rear axle of experimental vehicle","volume":"10","author":"Kral","year":"2020","journal-title":"Open Eng."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"012056","DOI":"10.1088\/1742-6596\/1736\/1\/012056","article-title":"Strength analysis of the drive wheel hub of a hydrogen-powered prototype hyper-light vehicle","volume":"1736","author":"Gilewski","year":"2021","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_28","unstructured":"Soto, P.A., Collet, M., Bauduin, S., Fernandez Sanchez, E.F., Aguilera, A.M., and Duysinx, P. (2017, January 5\u20139). Topology optimization of mechanical components fabricated by additive manufacturing for a Shell Eco-Marathon vehicle. Proceedings of the 12th World Congress of Structural and Multidisciplinary Optimisation, Braunschweig, Germany."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Hands, C.H., du Plessis, A., Minnaar, N., Blakey-Milner, B.A., and Burger, E. (2018). Can Additive Manufacturing Help Win the Race?. Preprints, 2018110040.","DOI":"10.20944\/preprints201811.0040.v1"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Sosnowski, M., and Skarka, W. (2018). Optimization of a Composite Beam-Based Load Bearing Structure, for an Ultra-Efficient Electric Vehicle. EngOpt 2018 Proceedings of the 6th International Conference on Engineering Optimization, Springer.","DOI":"10.1007\/978-3-319-97773-7_93"},{"key":"ref_31","first-page":"51","article-title":"Optimal Build Inclination in 3d Printing\u2013Shell Eco\u2013Marathon Rapid Prototyping Car Parts Case7","volume":"58","author":"Yankov","year":"2019","journal-title":"Proc. Univ. Ruse"},{"key":"ref_32","unstructured":"Scholz, S.G., Howlett, R.J., and Setchi, R. (2020). Additive Manufacturing of Continuous Carbon Fiber-Reinforced Plastic Components. Sustainable Design and Manufacturing 2020, Springer."},{"key":"ref_33","unstructured":"K\u0131l\u0131\u00e7, A.E. (2020). Redesign of Drivetrain Component of a Shell Eco-Marathon Vehicle for Additive Manufacturing via Topology Optimization. [Master\u2019s Thesis, Piri Reis \u00dcniversitesi]."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Pagerit, S., Sharer, P., and Rousseau, A. (2006). Fuel Economy Sensitivity to Vehicle Mass for Advanced Vehicle Powertrains, SAE International. SAE Technical Paper 2006-01-0665.","DOI":"10.4271\/2006-01-0665"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Merschak, S., Hehenberger, P., Schmidt, S., and Kirchberger, R. (2020). Considerations of Life Cycle Assessment and the Estimate of Carbon Footprint of Powertrains, SAE International. SAE Technical Paper 2020-32-2314.","DOI":"10.4271\/2020-32-2314"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Crolla, D., Foster, D., Kobayashi, T., and Vaughan, N. (2014). Transmission and Driveline: Introduction. Encyclopedia of Automotive Engineering, Wiley.","DOI":"10.1002\/9781118354179"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.mechmachtheory.2008.06.007","article-title":"A review on belt and chain continuously variable transmissions (CVT): Dynamics and control","volume":"44","author":"Srivastava","year":"2009","journal-title":"Mech. Mach. Theory"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Crolla, D., Foster, D., Kobayashi, T., and Vaughan, N. (2014). The Variable Pulley CVT. Encyclopedia of Automotive Engineering, Wiley.","DOI":"10.1002\/9781118354179"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Crolla, D., Foster, D., Kobayashi, T., and Vaughan, N. (2014). Traction Drive CVT. Encyclopedia of Automotive Engineering, Wiley.","DOI":"10.1002\/9781118354179"},{"key":"ref_40","unstructured":"Wikipedia (2021, August 03). Continuously Variable Transmission\u2014Wikipedia, The Free Encyclopedia. Available online: http:\/\/en.wikipedia.org\/w\/index.php?title=Continuously%20variable%20transmission&oldid=1035194623."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1109\/TCST.2002.806434","article-title":"Nonlinear control of a continuously variable transmission (CVT)","volume":"11","author":"Setlur","year":"2003","journal-title":"IEEE Trans. Control. Syst. Technol."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Crolla, D., Foster, D., Kobayashi, T., and Vaughan, N. (2014). CVT Control\u2013System Integration, Ratio Choice, Shift Strategy and Dynamics, Adaptive Features, Engine Calibration, Electric Motor Assist. Encyclopedia of Automotive Engineering, Wiley.","DOI":"10.1002\/9781118354179"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"7611","DOI":"10.1016\/j.jfranklin.2018.11.011","article-title":"Design and modeling of the CVT for adjustable inerter","volume":"356","author":"Lazarek","year":"2019","journal-title":"J. Frankl. Inst."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.mechmachtheory.2019.02.014","article-title":"Integrated optimal control of transmission ratio and power split ratio for a CVT-based plug-in hybrid electric vehicle","volume":"136","author":"Yao","year":"2019","journal-title":"Mech. Mach. Theory"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Nihari, Y., Gonzalez, V.L., Rodrigues, G.S., and Lopes, E.D.R. (2021). Performance Comparison between Passenger\u2019s Vehicles Using Manual Transmission and CVT Systems, SAE International. SAE Technical Pape 2020-36-0171.","DOI":"10.4271\/2020-36-0171"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"677","DOI":"10.1016\/j.bushor.2017.05.011","article-title":"The rise of 3-D printing: The advantages of additive manufacturing over traditional manufacturing","volume":"60","author":"Attaran","year":"2017","journal-title":"Bus. Hor."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"335","DOI":"10.5539\/mas.v9n4p335","article-title":"Production technology of the internal combustion engine crankcase using additive technologies","volume":"9","author":"Agapovichev","year":"2015","journal-title":"Mod. Appl. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"617","DOI":"10.4271\/03-13-05-0039","article-title":"Review of additive manufacturing for internal combustion engine components","volume":"13","author":"Gray","year":"2020","journal-title":"SAE Int. J. Engines"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Ehsani, M., Gao, Y., Longo, S., and Ebrahimi, K.M. (2018). Modern Electric, Hybrid Electric, and Fuel Cell Vehicles, CRC Press. [3rd ed.].","DOI":"10.1201\/9781420054002"},{"key":"ref_50","unstructured":"Minaker, B.P. (2019). Fundamentals of Vehicle Dynamics and Modelling: A Textbook for Engineers With Illustrations and Examples, John Wiley & Sons."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Gillespie, T.D. (1992). Fundamentals of Vehicle Dynamics, Society of Automotive Engineers.","DOI":"10.4271\/R-114"},{"key":"ref_52","first-page":"1","article-title":"Modelagem Computacional de um Ve\u00edculo El\u00e9trico para Competi\u00e7\u00e3o de Efici\u00eancia Energ\u00e9tica. Anais do XXIII Congresso Brasileiro de Autom\u00e1tica","volume":"2","author":"Faria","year":"2020","journal-title":"Soc. Bras. Autom."},{"key":"ref_53","doi-asserted-by":"crossref","unstructured":"Barbosa, T.P., da Silva, L.A.R., Pujatti, F.J.P., and Guti\u00e9rrez, J.C.H. (2020). Hydraulic hybrid passenger vehicle: Fuel savings possibilities. Mech. Based Des. Struct. 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