As part of the development process for its flagship large outboard motor, the BF250, Honda has developed a gear case for large outboard motors in order to realize increased reliability and power performance against existing models.Enhanced tooth contact has been achieved through redesign of the structure of the bearing mountings, and pitting resistance has been increased by modifying the gear materials and heat treatment. In addition, gear specifications making it possible to realize high durability under high loads have been employed, and the optimization of tooth contact via finite element model (FEM) analysis with consideration of stiffness and manufacturing variations has assisted in the realization of a tooth grinding process that reduces manufacturing variations.These innovations have resulted in the realization of a gear case that achieves class-topping power performance while satisfying targets for durability performance.
Article of Honda R&D Technical Review Vol.25 No.1 (58 - 62)