船用双级链式减速齿轮箱的英文

dual tandem reduction gear

• 船:    boat; ship; vessel ...
• 用:    40分钟跑完全程 run the c ...
• 双:    two; twin; both; d ...
• 级:    level; rank; grade
• 链式:    chain
• 减速齿轮箱:    drop-down gearbox; ...