12V直流減速正反轉電機屬于小功率減速電機，主要傳動結構由直流電機作為傳動源、齒輪箱（減速器）集成組裝而成，由電機斷路器、接觸器控制直流電機的正反轉，下面詳細介紹12V直流減速正反轉電機規格、參數、技術原理。

正反轉電機傳動原理：

? 直(zhi)流電(dian)(dian)(dian)(dian)(dian)機正反(fan)轉(zhuan)，代表的是(shi)電(dian)(dian)(dian)(dian)(dian)機順(shun)時針轉(zhuan)動(dong)(dong)和逆時針轉(zhuan)動(dong)(dong)。電(dian)(dian)(dian)(dian)(dian)機順(shun)時針轉(zhuan)動(dong)(dong)是(shi)電(dian)(dian)(dian)(dian)(dian)機正轉(zhuan)，電(dian)(dian)(dian)(dian)(dian)機逆時針轉(zhuan)動(dong)(dong)是(shi)電(dian)(dian)(dian)(dian)(dian)機反(fan)轉(zhuan)。正反(fan)轉(zhuan)控制電(dian)(dian)(dian)(dian)(dian)路圖及(ji)其原(yuan)理分(fen)析要實現(xian)電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機的正反(fan)轉(zhuan)只(zhi)要將接至電(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機三相(xiang)電(dian)(dian)(dian)(dian)(dian)源進線中的任意兩相(xiang)對調接線即(ji)可達到反(fan)轉(zhuan)的目的。

線路技術原理分析：

  一、正向啟動：　
  1、合上空氣開關QF接通三相電源　
  2、按下正向啟動按鈕SB3，KM1通電吸合并自鎖，主觸頭閉合接通電動機，電動機這時的相序是L1、L2、L3，即正向運行。

  二、反向啟動：　
  1、合上空氣開關QF接通三相電源　
  2、按下反向啟動按鈕SB2，KM2通電吸合并通過輔助觸點自鎖，常開主觸頭閉合換接了電動機三相的電源相序，這時電動機的相序是L3、L2、L1，即反向運行。

  三、互鎖環節：具有禁止功能在線路中起安全保護作用　
  1、接觸器互鎖：KM1線圈回路串入KM2的常閉輔助觸點，KM2線圈回路串入KM1的常閉觸點。當正轉接觸器KM1線圈通電動作后，KM1的輔助常閉觸點斷開了KM2線圈回路，若使KM1得電吸合，必須先使KM2斷電釋放，其輔助常閉觸頭復位，這就防止了KM1、KM2同時吸合造成相間短路，這一線路環節稱為互鎖環節。　

  2、按(an)(an)鈕(niu)互(hu)鎖：在電(dian)路(lu)中采用了(le)控(kong)制按(an)(an)鈕(niu)操作的(de)(de)正反傳控(kong)制電(dian)路(lu)，按(an)(an)鈕(niu)SB2、SB3都具有(you)(you)一對常(chang)開(kai)觸(chu)(chu)(chu)(chu)點(dian)，一對常(chang)閉(bi)觸(chu)(chu)(chu)(chu)點(dian)，這兩(liang)個觸(chu)(chu)(chu)(chu)點(dian)分別與(yu)KM1、KM2線圈(quan)回路(lu)連(lian)接(jie)。例如按(an)(an)鈕(niu)SB2的(de)(de)常(chang)開(kai)觸(chu)(chu)(chu)(chu)點(dian)與(yu)接(jie)觸(chu)(chu)(chu)(chu)器(qi)KM2線圈(quan)串(chuan)聯(lian)(lian)(lian)，而(er)(er)常(chang)閉(bi)觸(chu)(chu)(chu)(chu)點(dian)與(yu)接(jie)觸(chu)(chu)(chu)(chu)器(qi)KM1線圈(quan)回路(lu)串(chuan)聯(lian)(lian)(lian)。按(an)(an)鈕(niu)SB3的(de)(de)常(chang)開(kai)觸(chu)(chu)(chu)(chu)點(dian)與(yu)接(jie)觸(chu)(chu)(chu)(chu)器(qi)KM1線圈(quan)串(chuan)聯(lian)(lian)(lian)，而(er)(er)常(chang)閉(bi)觸(chu)(chu)(chu)(chu)點(dian)壓KM2線圈(quan)回路(lu)串(chuan)聯(lian)(lian)(lian)。這樣(yang)當按(an)(an)下(xia)(xia)SB2時只(zhi)能(neng)有(you)(you)接(jie)觸(chu)(chu)(chu)(chu)器(qi)KM2的(de)(de)線圈(quan)可以通(tong)電(dian)而(er)(er)KM1斷電(dian)，按(an)(an)下(xia)(xia)SB3時只(zhi)能(neng)有(you)(you)接(jie)觸(chu)(chu)(chu)(chu)器(qi)KM1的(de)(de)線圈(quan)可以通(tong)電(dian)而(er)(er)KM2斷電(dian)，如果同時按(an)(an)下(xia)(xia)SB2和SB3則兩(liang)只(zhi)接(jie)觸(chu)(chu)(chu)(chu)器(qi)線圈(quan)都不能(neng)通(tong)電(dian)。這樣(yang)就起到了(le)互(hu)鎖的(de)(de)作用。

  四(si)、電(dian)動(dong)機正向(xiang)(xiang)（或反(fan)向(xiang)(xiang)）啟動(dong)運轉后(hou)，不必先按(an)停(ting)止按(an)鈕使電(dian)動(dong)機停(ting)止，可以直接按(an)反(fan)向(xiang)(xiang)（或正向(xiang)(xiang)）啟動(dong)按(an)鈕，使電(dian)動(dong)機變為反(fan)方向(xiang)(xiang)運行。

  五、電動(dong)機的(de)過載保護由熱繼電器(qi)FR完成。