MIMにより製造したSUS製モジュール0.07mm超小型歯車の精度評価

抄録

A micro-planetary gears made of stainless steel has been developed by micro metal powder injection molding (μ-MIM) process. In this study, the accuracy and the quality of ultra-compact planet gear (module: m=0.07 mm, number of teeth: z=24) was evaluated. Cross-sections of the gear teeth were observed with a digital microscope and dimensions of the teeth were measured with a digital image processing. The variations in dimensions and shape of gear teeth were systematically investigated for mold, green and sintered parts, and heat treated ones. The accuracy classes of the ultra-compact planet gear were defined from four shape variations of gear teeth, i.e. total runout, single pitch deviation, accumulated pitch deviation and tooth profile deviation. The accuracy class was concluded as JIS N class seven which is a comparatively high precise level for practical applications.