positive speed gearboxreducer casingreduction boxreduction gear boxreduction gearboxspeed reducer gearboxtransmission case减速: moderate; reduce the speed; ...箱: chest; box; case; trunk齿轮减速箱: gear reducer; speed reduction gear box电梯减速箱: elevator gear reducer box减速箱盖: gear box cover下载手机词典可随时随地查词查翻译