标 准 编 号:DIN 3990-21-1989简体中文标题:圆柱齿轮承载能力计算.快速齿轮和类似要求齿轮的应用标准繁体中文标题:圆柱齿轮承载能力计算.快速齿轮和类似要求齿轮的应用标准English Name:Calculation of load capacity of cylindrical gears; application standard for high speed gears and gears of similar requirement