This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Influence of Micro-Geometry on Gear Scuffing
ISSN: 0148-7191, e-ISSN: 2688-3627
Published January 14, 2015 by SAE International in United States
Annotation ability available
Scuffing is an instantaneous failure which occurs when the meshed gear flanks undergo adhesive wear under extreme operating temperatures at medium- or high-speed conditions. It is one of the common failures in transmission gears, which tend to operate under long-duty cycle hours. The tip and the root regions often experience higher contact pressures because of the loading and surface curvature. These higher pressures, coupled with higher sliding velocities and heat generation, make the tip and root regions in the gear susceptible to scuffing.
Gear geometry, material composition and lubricant properties influence scuffing. A balanced gear tooth design with lower sliding velocities is often chosen as an approach to avoid scuffing. However, in the current scenarios of transmissions with high power density requirements, achieving a balanced gear tooth design is rare. Lubricants with higher viscosity avoid scuffing, but have adverse effects on the transmission efficiency. As per ISO 6336, there are no sufficient methods or techniques available to measure and prevent scuffing failures on gears. AGMA 925-A03 provides a method for determining the scuffing risk based on lubricant and gear macro-geometry properties through quantifying critical scuffing temperature. Higher quality gear materials, better manufacturing process and scuffing additives in lubricants avoid scuffing but involve significant costs.
In this study, we have used a statistical-based model to highlight the influence of gear mesh micro-geometries on the contact pressure and temperature distribution for an indication of scuffing risk in an automotive transmission. There is a discussion of the sensitivity of modifications on scuffing temperature and an optimal solution for a particular gear-mesh loading.
|Technical Paper||A Radiometric Method for Apex Seal Wear Measurements in Rotary Engines|
|Technical Paper||Development of Long Life Pulley-Supporting Bearing for Belt-CVT|
CitationGanti, V., Dewangan, Y., Arvariya, S., and Madhavan, S., "Influence of Micro-Geometry on Gear Scuffing," SAE Technical Paper 2015-26-0187, 2015, https://doi.org/10.4271/2015-26-0187.
- ISO/TR 13989-1 Calculation of Scuffing Load Capacity for Cylindrical Bevel and Hypoid Gears-Part 1
- AGMA 925-A03 Effect of Lubrication on Gear Surface Distress
- Gwidon , S. , Andrwe B. Engineering Tribology 4 th BH Publishers 2013
- Frazer , Shaw , Palmer , Fish Optimizing Gear Geometry for minimum transmission error, mesh friction losses and scuffing risk through computer aided engineering Gear Technology Magazine Aug. 2010
- Houser , D.R. and Harianto , J. Load Distribution Program Manual Gear Lab-The Ohio State University 2002
- Ciulli , E. , Bartilotta , I. , Polacco , A. , Manconi , S. , Vela , D. et al. A Model for Scuffing Prediction Journal of Mechanical Engineering 56 4 267 274 2010