A method for the preliminary design of gears using a reduced number of American Gear Manufacturers Association (AGMA) correction factors

ABSTRACT

Typically, the preliminary design of mechanical components such as gears is carried out using standardized design processes such as those developed by the American Gear Manufacturers Association (AGMA). These design standards include a large number of ‘correction factors’ to account for various uncertainties. As the knowledge about these uncertainties increases, it becomes possible to include them systematically in the design procedure, thereby reducing the number of empirical correction factors. Robust design provides a way to design in the presence of various uncertainties. In this article, a design method is proposed to eliminate empirical correction factors and is demonstrated by eliminating two correction factors from the AGMA design standards for a spur gear, namely, the factor of safety in contact and the reliability factor by the formal introduction of uncertainty in the magnitude of load and material properties. The proposed method is illustrated with the design of an automotive gear with desired reliability, cost and robustness.

KEYWORDS:

• Robust design
• uncertainty
• correction factors
• gear design

Acknowledgement

The authors acknowledge the support and encouragement given by the management of Tata Consultancy Services Ltd, India.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

F. Mistree and J.K. Allen gratefully acknowledge support from the NSF [grant CMMI 1258439] and the L.A. Comp and John and Mary Moore Chairs at the University of Oklahoma, respectively.