This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Low-Height Differential Concepts for EVs
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 03, 2018 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
Compared to the internal-combustion-engine (ICE) vehicles on the road today, Electric Vehicles (EV) deliver more torque to vehicle wheels, and require smaller driveline packaging envelopes. Current differentials use asymmetrical ring gears with differential housings that are roughly a third of the tire outside diameter. New differential architecture concepts are shown here to deliver more torque to the wheels, while decreasing the height of the differential as much as fourfold. Most EV’s are driven by one or more torsion motors, delivering torque to the left side and the right side of the EV’s at different speeds during a vehicle turn, or a wheel “spinout.” At low speeds, the EV motors deliver more torque to the wheels than comparably sized ICE vehicles, so EV differentials must be built stronger and stiffer to manage the distribution of available drive torque. But, less space is available within EV’s as battery space is added while passenger and cabin space is expanded, leaving a smaller envelope for the driveline in competitive models. New concepts that reduce the vertical envelope by seventy-five percent are depicted here, with analysis of the methods of higher torque in a smaller package. Novel methods with smaller ring gears, internal cases, reduction of residual loading, and redistribution of components are depicted, explained, and justified for size, torque, shape, and mass. The open space necessary for additional componentry such as limited slip or lock-up are shown, so the EV driveline can be optimized for cabin space, road clearance, aerodynamics, and energy efficiency. Although these architectures focus on EV applications, they can be used for retrofit into ICE pass-car, light truck, and heavy truck vehicles.
CitationFritz, P., "Low-Height Differential Concepts for EVs," SAE Technical Paper 2018-01-1294, 2018, https://doi.org/10.4271/2018-01-1294.
Data Sets - Support Documents
|[Unnamed Dataset 1]|
|[Unnamed Dataset 2]|
|[Unnamed Dataset 3]|
|[Unnamed Dataset 4]|
- Anand, A., and Konka, H., and Fritz, P., "Light Weight Structures - Structural Analysis for Weight Optimization and Joining Techniques of Dissimilar Materials," SAE Technical Paper 2016-01-1394, 2016, April 12, 2016, 10.4271/2016-01-1394.
- Fritz, P., Mapkar, J., and Williams, K., “Metal-To-Composite Structural Joining for Drivetrain Applications,” http://www.nasampe.org/page/searchengine#home/technicalpaperdetails/57aa64407d12ebee580e8aad SAMPE 2016 - Long Beach CA - May 23-26/2016, LB15-0108, May 23, 2016.
- Fritz, P., Cloud, G. Patterson, E., and Backman, D., Joining Technologies for Composites and Dissimilar Materials, Volume 10: Proceedings of the 2016 Annual Conference on Experimental and Applied Mechanics, Society for Experimental Mechanics Series), Springer, ISBN-13: 978-33194242551st ed. 2017 Edition, pp. 107-114.
- Fritz, P., “On Improvements in Differential Power Flow Architectures for Increased Efficiency,” CTI Symposium-16th International Congress, http://www.transmission-symposium.com/usa/on-improvements-in-differential-power-flow-architectures-for-increased-efficiency May 19, 2017.
- Fritz, P., “A System Evaluation of Rotational Inertia for Lightweighting in Driveline Components,” http://www.euroforum.de/veranstaltung/pdf/p2300447en.pdf CTI Symposium-16th International Congress, May 19, 2017.
- Cole, J., and Loveday, E., “Monthly Plug-In EVs Scorecard.” Inside EVs, https://insideevs.com/monthly-plug-in-sales-scorecard, September 26, 2017.
- Brown, D., “Next EV Revolution-think Trucks and Buses,” Energy Post Weekly, http://energypost.eu/next-ev-revolution-think-trucks-buses Feb. 1, 2017.
- Masson, L., “The Pros and Cons of Using In-Wheel Motors in Electric Cars, “Plug-In Cars, http://www.plugincars.com/pros-and-cons-wheel-motors-127174.html, May 8, 2013
- Al Emran Hasan, M.M., Motamed Ektesabi, M., and Kapoor, A., “An Investigation into Differential Torque Based Strategies for Electronic Stability Control in an In-Wheel Electric Vehicle,” ISSN: 2277-3754 ISO 9001:2008 Certified,” International Journal of Engineering and Innovative Technology (IJEIT) 2(7), January 2013.
- Learn More about DC Motors, IEEE GlobalSpec Engineering 360, http://www.globalspec.com/learnmore/motion_controls/motors/dc_motors pr. 15-20 2012-2017.