This content is not included in your SAE MOBILUS subscription, or you are not logged in.
A Direct Comparison between Numerical and Experimental Results for Airborne Noise Levels in Automotive Transmission Rattle
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 01, 2014 by SAE International in United States
Annotation ability available
In this paper, a direct correlation between transmission gear rattle experiments and numerical models is presented, particularly focusing on the noise levels (dB) measured from a single gear pair test rig. The rig is placed in a semi-anechoic chamber environment to aid the noise measurements and instrumented with laser vibrometers, accelerometers and free field microphones. The input torsional velocity is provided by an electric motor, which is controlled by a signal generator, aiming to introduce an alternating component onto the otherwise nominal speed; thus, emulating the engine orders found in an internal combustion engine. These harmonic irregularities are conceived to be the triggering factor for gear rattle to occur. Hence, the rig is capable of running under rattling and non-rattling conditions.
The numerical model used accounts for the gear pair's torsional dynamics, lubricated impacts between meshing teeth and bearing friction.
The results show that rattle is indeed triggered by the governing engine orders present in the transmission's primary input shaft. This is seen in the increase of 3-4 dB compared to the same running conditions when a 13 Hz excitation is introduced onto the rig. In addition, the comparison between experimental and numerical data also reveals that gear rattling is an airborne noise phenomenon.
CitationDe la Cruz, M. and Theodossiades, S., "A Direct Comparison between Numerical and Experimental Results for Airborne Noise Levels in Automotive Transmission Rattle," SAE Technical Paper 2014-01-1756, 2014, https://doi.org/10.4271/2014-01-1756.
- Russo , R. , Brancati , R. and Rocca E. Experimental investigations about the influence of oil lubricant between teeth on the gear rattle phenomenon Journal of Sound and Vibration 321 2009 647 661
- Ottewill , J., R. , Neild , S. A. and Wilson , R. E. An investigation into the effect of tooth profile errors on gear rattle Journal of Sound and Vibration 329 2010 3495 3506
- De la Cruz M , Theodossiades S , Rahnejat H. An investigation of manual transmission rattle Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 2010 224 167 81
- Steinel , K. and Tebbe , G. New Torsional Damper Concept to Reduce Idle Rattle in Truck Transmissions SAE Technical Paper 2004-01-2722 2004 10.4271/2004-01-2722
- Theodossiades , S. , Gnanakumarr , M. , Rahnejat , H. and Kelly , P. Effect of a dual-mass flywheel on the impact- induced noise in vehicular powertrain systems Proc. IMechE - part D, J. Auto. Engr. 220 2006 747 761 Bellomo , P. , De Vito , N. , Lang , C. , and Scamardi , L. In Depth Study of Vehicle Powertrains to Identify Causes of Loose Components Rattle in Transmissions SAE Technical Paper 2002-01-0702 2002 10.4271/2002- 01-0702
- Fietkau , P. , Baumann , A. and Bertsche , B. Simulation of passenger car synchronizer ring movement during rattling Proceedings of the Institution of Mechanical Engineers, Part K: Journal of Multi-body Dynamics 226 3 2012
- Fietkau , P. and Bertsche , B. Influence of tribological and geometrical parameters on lubrication conditions and noise of gear transmissions Mechanism and Machine Theory 69 2013
- Chen , Z. , Shao , Y. M. and Lim , T. C. Non-linear dynamic simulation of gear response under the idling condition International Journal of Automotive Technology 13 4 2012 541 552
- Lu , J. W. , Chen , H. , Zeng , F. , Vakakis , A. and Bergman , L. Influence of system parameters on dynamic behavior of gear pair with stochastic backlash Meccanica 10.1007/s11012-013-9803
- Forcelli , A. , Grasso , C. , and Pappalardo , T. The Transmission Gear Rattle Noise:Parametric Sensitivity Study SAE Technical Paper 2004-01-1225 2004 10.4271/2004-01-1225
- Dogan , S. N. , Ryborz , J. and Bertsche , B. Desing of low noise manual automotive transmission Proc. IMechE Part K: Journal of Multi-Body dynamics 220 19 95 2006
- Gohar , Elastohydrodynamics R. 2001 Imperial College Press London Gohar, Elastohydrodynamics 2001
- De la Cruz , M. , Theodossiades , S. , King , P. and Rahnejat , H. Transmission drive rattle with thermo- elastohydrodynamic impacts: numerical and experimental Investigations International Journal of Powertrains 1 2 2011 137 161