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Design of High Speed Engine's Cam Profile Using B-Spline Functions for Controlled Dynamics
Technical Paper
2012-28-0006
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Recent trends towards design of High Performance Diesel engines creating more challenges in the area of design, durability and NVH aspects of components and systems. In particular, Valvetrain system of High Speed application engines is one of the most critical and complicated dynamic system in terms of precise control of events, max. Lift, control over accelerations and vibration related issues. This can be tackled by designing the cam profile for better valve train dynamics. High frequency components and/or excessive jerks in a cam profile are important sources of cam-follower vibrations. There are various techniques of designing cam profile to achieve controlled valve train dynamic behavior at high speed operations.
Present paper discuss the impact of various cam profile options designed using Polydyne, N-Harmonic and B-Spline methodologies on a field problem of cam wear for high speed engine application. Conventional Polydyne method for designing the cam profile has certain limitations in controlling the cam accelerations for valve train system operating at high speed. The cam profile designed using N-harmonic algorithm showed better dynamics and improved cam lobe wear. However, this method also has certain limitations in controlling the cam profile curve for the existing pushrod operated valve train system. Cam profile design technique using B-Spline Curves has ability in controlling curve by defining the boundary conditions for higher derivatives. Therefore, B-spline curve algorithm is adopted for cam profile design of High Speed engines in order to control excessive jerks which were the major cause of the vibrations.
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Citation
Jamkhande, A., Tikar, S., Ramdasi, S., and Marathe, N., "Design of High Speed Engine's Cam Profile Using B-Spline Functions for Controlled Dynamics," SAE Technical Paper 2012-28-0006, 2012, https://doi.org/10.4271/2012-28-0006.Also In
References
- Wang, Yushu “Introductions to Engine Valvetrains: SAE R-339” SAE USA 2007 978-0-7680-1079-4
- Stoddart, David A. “Polydyne CAM design” Machine design 25 2 121 135 Jan 1953
- Thoren, T. R. Engemann, H. H. Stoddart, D. A. “CAM design as Related to Valve train dynamics” 6 Jan 1952
- Wenzhi, Gao Jingqi, Feng Zhaoxin, He “A design approach of asymmetrical CAM profile and its effect on performance of High speed engine” 2004-01-0610 SAE 2004
- Zeid, Ibrahim “CAD/CAM: Theory and Practice” Mc Graw-Hill Inc New York 1991 0-07-072857-7
- Tsay, D. M. Huey, C. O. Jr. “Spline Functions Applied to the synthesis and analysis of non-rigid Cam-follower systems” Journal of Mechanisms, transmissions and automation in design 111/561 Dec 1989
- Norton, Robert L. “CAM Design and Manufacturing Handbook” Industrial Press Inc USA 2002 0-8311-3122-5
- Nguyen, VU-Thinh Kim, Dojoong “CAM profile smoothening by modified spline curves” IFToMM World Congress Besancon 2007
- Chen, Fan Y. “Mechanics and Design of Cam Mechanisms” Pergamon Press New York 1982 0-08-028049-8
- Rothbart, Harold A. “CAM Design Handbook” Mc Graw-Hill USA 2004 0-07-137757-3
- Rothbart, Harold A. “CAMS: Design, Dynamics and Accuracy” John-Wiley & Sons USA 1965