船用齿轮方向控制阀
marine gear directional control valve
船用齿轮控制阀
marine gear control valve
船用齿轮选择器阀
marine gear selector valve
齿轮轮齿接触印痕
gear tooth contact pattern
复合轮齿齿轮副
complex wheel teeth gear set
小齿轮轮齿啮合
pinion gear tooth contact
小齿轮轮齿啮合型式
pinion tooth contact pattern