This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Gear Whine Improvements for an Automatic Transmission through Design Retargeting and Manufacturing Variability Reduction
Technical Paper
2001-01-1505
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Gear whine in 1st gear for an automatic transmission that has been in production for nearly thirty years was identified as an NVH issue. Due to advances in vehicle level refinement, and reduction of other masking noises, the automatic transmission gear whine became an issue with the customer. Since the transmission was already in production, the improvements had to be within the boundaries of manufacturing feasibility with existing equipment to avoid costly and time consuming investment in new machines. The approach used was one of identifying optimum values of existing gear parameters to provide a reduction in passenger compartment noise.
The problem was in a light truck application. Objective noise measurements were recorded for 10 transmissions from more than 50 driven in vehicles. The transmissions were disassembled and the gears inspected. Based on statistical analysis of the data, and using a CAE model with input from this measured data, a set of gear dimensions were identified for retargeting. This was not a complete redesign, but rather a fine-tuning of some gear dimensions with no changes to the manufacturing process. Parts made to this new specification showed a significant reduction in gear whine levels.
On analyzing the data that was collected for these gear dimensions, it was noted that the variability of these dimensions in high volume manufacturing was more than desired for optimum noise performance. Since the design retargeting was in the order of a few microns, there existed the probability there would be noisy gearboxes in the hands of the customer because of the variability. A statistical study was undertaken in the gear manufacturing line to identify the sources of variability and establish a way to control these critical dimensions in high volume production within the specified target range. The recommendations from this study are currently being implemented in the manufacturing plant.
Recommended Content
Technical Paper | Dynamic Modeling of Ratcheting Devices in Transmissions |
Technical Paper | Bending Fatigue Behavior of Carburized Gear Steels: Planetary Gear Test Development and Evaluation |
Ground Vehicle Standard | Passenger Car and Light Truck Axles |
Authors
Topic
Citation
Krishnaswami, R., DeFore, M., Hildebrand, D., Metcalf, J. et al., "Gear Whine Improvements for an Automatic Transmission through Design Retargeting and Manufacturing Variability Reduction," SAE Technical Paper 2001-01-1505, 2001, https://doi.org/10.4271/2001-01-1505.Also In
References
- Steyer G. C. Lim T.C. “System Dynamics in Quiet Gear Design” Proceedings of the 9 th International Modal Analysis Conference 999 1005 1991
- Campbell B. Stokes W. Steyer G. Clapper M. Krishnaswami R. Gagnon N. “Gear Noise Reduction of an Automatic Transmission through Finite Element Dynamic Simulation” SAE Noise and Vibration Conference 1997
- Houser D. Singh R. “Notes from Gear Noise Short Course” Ohio State University
- Chung C-H. Steyer G. Abe T. Clapper M. Shah C. “Gear Noise Reduction through Transmission Error Control and Gear Blank Dynamic Tuning Proceedings of the 1999 Noise and Vibration Conference SAE Technical Paper 1999-01-1766 1999
- Shetty R. Kinsella J. “Gear Noise Development Using Dr. Taguchi's Tolerance Design of Experiment Approach” Proceedings of Transmission and Driveline Symposium: Components, Gears, and CAE SAE Technical Paper 920763 1992
- Schildmeter E. F. “Gear Noise Reduction using Design of Experiments” Proceedings of International Congress and Exposition SAE Technical Paper 981194 1998
- Class notes from Consumer Driven Six Sigma Training Ford Motor Company
- Breyfogle F. W. “Implementing Six Sigma: Smarter Solutions Using Statistical Methods” John Wiley & Sons 374 393 1999