減速(su)(su)機是(shi)一種(zhong)相(xiang)對(dui)精密的機械，使用它的目的是(shi)降低轉(zhuan)(zhuan)速(su)(su)，增加轉(zhuan)(zhuan)矩。它的種(zhong)類(lei)繁多，型號各(ge)異(yi)，不同種(zhong)類(lei)有不同的用途。
減速器的種(zhong)類繁(fan)多，按照傳(chuan)動類型可分為齒輪減速(su)(su)(su)器、蝸(gua)桿減速(su)(su)(su)器和(he)行星(xing)齒輪減速(su)(su)(su)器；
按照傳動級數不同可分為單級和多級減速器；
按(an)照齒(chi)輪形狀可分為圓(yuan)柱齒(chi)輪減速器(qi)、圓(yuan)錐齒(chi)輪減速器(qi)和圓(yuan)錐－圓(yuan)柱齒(chi)輪減速器(qi)；
按照傳動的布置(zhi)形(xing)式又(you)可分(fen)(fen)為(wei)展(zhan)開式、分(fen)(fen)流(liu)式和同(tong)軸式減速器。
蝸(gua)輪蝸(gua)桿減(jian)(jian)(jian)速機(ji)(ji)(ji)的(de)(de)主要特點是具有(you)(you)反向自鎖功能(neng)，可(ke)以有(you)(you)較大的(de)(de)減(jian)(jian)(jian)速比(bi)(bi)，輸(shu)入軸(zhou)(zhou)和(he)輸(shu)出軸(zhou)(zhou)不(bu)在同(tong)(tong)一軸(zhou)(zhou)線上，也不(bu)在同(tong)(tong)一平面上。但(dan)(dan)是一般(ban)體(ti)積較大，傳動(dong)(dong)(dong)(dong)效(xiao)(xiao)率不(bu)高(gao)，精度(du)(du)(du)不(bu)高(gao)。諧波減(jian)(jian)(jian)速機(ji)(ji)(ji)的(de)(de)諧波傳動(dong)(dong)(dong)(dong)是利用(yong)柔性(xing)元件(jian)可(ke)控的(de)(de)彈性(xing)變形(xing)來(lai)傳遞運(yun)(yun)動(dong)(dong)(dong)(dong)和(he)動(dong)(dong)(dong)(dong)力的(de)(de)，體(ti)積不(bu)大、精度(du)(du)(du)很(hen)高(gao)，但(dan)(dan)缺點是柔輪壽命有(you)(you)限、不(bu)耐沖擊(ji)，剛(gang)性(xing)與金屬件(jian)相(xiang)比(bi)(bi)較差。輸(shu)入轉(zhuan)速不(bu)能(neng)太高(gao)。行(xing)星(xing)(xing)減(jian)(jian)(jian)速機(ji)(ji)(ji)其優(you)點是結構比(bi)(bi)較緊湊，回程(cheng)間(jian)隙小、精度(du)(du)(du)較高(gao)，使(shi)用(yong)壽命很(hen)長，額定輸(shu)出扭矩可(ke)以做的(de)(de)很(hen)大。但(dan)(dan)價格略貴。齒輪減(jian)(jian)(jian)速機(ji)(ji)(ji)具有(you)(you)體(ti)積小，傳遞扭矩大的(de)(de)特點。齒輪減(jian)(jian)(jian)速機(ji)(ji)(ji)在模塊組合體(ti)系基礎上設計制造，有(you)(you)極多(duo)的(de)(de)電(dian)機(ji)(ji)(ji)組合、安裝形(xing)式和(he)結構方案，傳動(dong)(dong)(dong)(dong)比(bi)(bi)分級細密，滿(man)足(zu)不(bu)同(tong)(tong)的(de)(de)使(shi)用(yong)工況，實現機(ji)(ji)(ji)電(dian)一體(ti)化。齒輪減(jian)(jian)(jian)速機(ji)(ji)(ji)傳動(dong)(dong)(dong)(dong)效(xiao)(xiao)率高(gao)，耗(hao)能(neng)低，性(xing)能(neng)優(you)越。擺線針輪減(jian)(jian)(jian)速機(ji)(ji)(ji)是一種采用(yong)擺線針齒嚙合行(xing)星(xing)(xing)傳動(dong)(dong)(dong)(dong)原理(li)的(de)(de)傳動(dong)(dong)(dong)(dong)機(ji)(ji)(ji)型，是一種理(li)想的(de)(de)傳動(dong)(dong)(dong)(dong)裝置，具有(you)(you)許(xu)多(duo)優(you)點，用(yong)途廣泛，并可(ke)正反運(yun)(yun)轉(zhuan)。