ZLY是(shi)硬(ying)齒面圓(yuan)柱齒輪減速機，N是(shi)帶逆(ni)止器，125是(shi)中心距，20是(shi)速比(bi)，1是(shi)裝配形式。

減速機(ji)在原動機(ji)和工作機(ji)或執行機(ji)構之(zhi)間起匹(pi)配轉速和傳遞轉矩的作用(yong)，是一種相對精密(mi)的機(ji)械(xie)。

使用它(ta)的(de)目的(de)是降低轉速(su)，增加轉矩(ju)。它(ta)的(de)種類繁多，型號各異，不(bu)同種類有不(bu)同的(de)用途。

減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)的種(zhong)類繁多，按(an)照(zhao)傳(chuan)(chuan)動類型可(ke)(ke)分(fen)(fen)為(wei)齒(chi)輪減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)、蝸桿減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)和(he)行星齒(chi)輪減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)；按(an)照(zhao)傳(chuan)(chuan)動級(ji)數不同(tong)可(ke)(ke)分(fen)(fen)為(wei)單級(ji)和(he)多級(ji)減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)；按(an)照(zhao)齒(chi)輪形狀可(ke)(ke)分(fen)(fen)為(wei)圓柱(zhu)齒(chi)輪減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)、圓錐齒(chi)輪減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)和(he)圓錐－圓柱(zhu)齒(chi)輪減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)；按(an)照(zhao)傳(chuan)(chuan)動的布置形式又可(ke)(ke)分(fen)(fen)為(wei)展開式、分(fen)(fen)流式和(he)同(tong)軸(zhou)式減(jian)(jian)(jian)(jian)速器(qi)(qi)(qi)。