| 摘要 |
PURPOSE:To enhance shock resistance of a dedendum and prevent low cycle fatigue, by applying plastic deformation to the bottom surface of a spece including a corner angular part of the space so as to form a hardened layer while forming a quenching hardened layer in a gear in the upper from the corner angular part of the space. CONSTITUTION:A shaves gear 1, applying high frequency quching to a tooth surface 4 in the upper from the corner angular part of a space 2, forms quenching hardened layer 5. Next the gear 1, being fitted to a work supporting shaft 11, positions one of the spaces in the gear 1 along the center line of a tool head 12 by indexing this supporting shaft 11 to be rotated in a pitch of each tooth of the gear 1. And a tool bed 16 is lowered both forcing a steel ball 8 to be brought into pressure contact with inside the space 2 and moving the steel ball 8 along the space 2. In this way, a space bottom surface 9 containing the corner angular part of each space 2 forms a hardened layer 10. Then the hardened layer 10, being connected with an end part of the quenching hardened layer 5 in the tooth surface, enables the whole tooth surface containing the bottom surface 9 of the space 2 to be strengthened. |
