​​​​​​​​​​​​April 2018, Vol. 3, No. 4, pp 83-89. 

​​Estimation and Validation of Highest Point Single Tooth Contact in Spur Gears using Spreadsheet Application

K. M. Abubacker*, V. Suresh Babu
Department of Mechanical and Industrial Engineering, Caledonian College of Engineering, Seeb, Sultanate of Oman.
​​*Corresponding author’s e-mail: abubacker@caledonian.edu.om


Gear is one of the most critical components widely used in the transmission of motion and power between two shafts.  During motion, the gears are instantaneously loaded which develops bending stress at the root of the gear.  The loading point is termed to be Highest Point Single Tooth Contact (HPSTC) and Lowest Point Single Tooth Contact (LPSTC).  HPSTC is the most critical loading point in any gear. While a designer analyses a gear, it is essential to determine this instantaneous loading point (HPSTC, LPSTC) for the purpose of finding out the induced stress on the gear tooth.  Moreover, this point is so important that it determines the bending stress at the root fillet portion of the gear.  It is known fact that identification of these points involves many steps with huge ream of calculations.  The present research work involves estimation of radius for Highest Point Single Tooth Contact using Spreadsheet application.  This works for different range of input parameters like module, number of teeth, pressure angle etc., For this purpose, a customized spreadsheet is developed involving gear formula and all calculation steps. Two typical case studies were conducted using few specific parameters. The calculated outputs from the spreadsheets were compared with the available results of existing studies. It was noted that there were no variations notified in the calculated results, which indicates the validation of the current work. With addition of few formula and steps, this work can be extended to carryout bending stress analysis based on Lewis approach with AGMA standards. Further the study can be incorporated in ANSYS mechanical APDL.

Keywords: Highest Point Single Tooth Contact; Lowest Point Single Tooth Contact; Base root critical tooth thickness; Bending stress.


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