自動車分野でのフェースギヤの設計・工法開発状況と今後の課題について

抄録

In recent years, hybrid and electric vehicles have gained attention due to increased environmental consciousness. This trend towards electrification has resulted in a demand for actuators in automotive products that are compact, lightweight, and energy-efficient. To meet these needs, combining a small, high-speed motor with a high gear reduction ratio and efficient power transmission through a reduction mechanism is considered effective. Among them, "face gears" are widely used in the reduction section of actuators that require relatively high gear reduction. Face gears allow for high gear reduction ratio, compactness, and excellent positioning accuracy, making them user-friendly. However, their meshing contact is dominated by sliding friction, resulting in decreased transmission efficiency due to frictional losses. This characteristic hinders the low-power operation of actuators. Therefore, development efforts have been made to replace worm gears with orthogonally meshed gear mechanisms, such as face gears, which have high transmission efficiency when combined with the number of teeth gears. However, addressing design and manufacturing challenges is necessary for practical implementation. This paper reports on the relationship between design parameters and efficiency on the design front, as well as the development status of form rolling techniques for small gears and the manufacturing process of face gears.