渐开线正齿轮 meaning in English

involute spur gear

Tolerances for single - start hobs for involute spur gears
渐开线正齿轮用单头滚铣刀的公差
Design dimensions and errors of hobs for involute spur gears ; fundamental terms
渐开线正齿轮加工用滚铣刀的设计尺寸与误差.基本术语
Fundamental rating factors and calculation methods for involute spur and helical gear teeth
渐开线正齿轮齿和斜齿轮螺旋齿的基本额定因子和计算方法