Optimisation of gear geometrical parameters using KISSsoft

  • 1 Yildiz Technical University, Science Institute, Yildiz, Istanbul, Turkey
  • 2 Yildiz Technical University, Mechanical Engineering Faculty, Yildiz, ─░stanbul, Turkey


In this study, optimisation of speed gears for a tractor transmission was performed with KISSsoft software. Optimisation was carried out under three constraints. These constraints are input power-torque, volume for system in transmission and gear ratio for each speed. The purpose of this study was to optimize the module, face width, gear quality, centre distance, number of teeth, helix angle, addendum modification coefficient and pressure angle for each speed considering the constraints. Tooth bending stress, tooth contact stress, contact ratio and specific sliding were considered for evaluation during optimisation. Strength calculation of gear pairs which were optimized and defined all geometrical parameters with KISSsoft were also calculated with mathematical model indicated in ISO 6336. Then, the results were compared.



  1. ISO 6336-1: calculation of load capacity os spur and helical gears, part: basic principle, introduction and general influence factors.
  2. ISO 6336-2: calculation of load capacity of spur and helical gears, part2: calculation of surface durability (pitting).
  3. ISO 6336-3: calculation of load capacity of spur and helical gears, part 3: calculation of tooth bending strength.
  4. ISO 6336-5: calculation of load capacity of spur and helical gears, part 5: strength and quality of materials.
  5. Mehmet Bozca, Optimisation of the geometrical design parameters of a five speed gearbox for an automotive transmission, The Latest Methods of Construction Design, Springer International Publishing, Switzerland, 2016, pp. 313-318.
  6. Mehmet Bozca, Optimisation of effective design parameters for an automotive transmission gearbox to reduce tooth bending stress, Modern Mechanical Engineering, 2017, vol. 7, pp. 35-36.

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