液(ye)壓(ya)(ya)缸工作(zuo)過(guo)程(cheng)：降(jiang)低風機(ji)流量(liang)及全(quan)壓(ya)(ya)時(shi),電動(dong)(dong)(dong)(dong)頭(tou)驅動(dong)(dong)(dong)(dong)控制盤(7)逆時(shi)針旋轉(zhuan),帶動(dong)(dong)(dong)(dong)滑塊(12)向(xiang)右移(yi)動(dong)(dong)(dong)(dong)。此時(shi)液(ye)壓(ya)(ya)缸只隨葉(xie)輪作(zuo)旋轉(zhuan)運動(dong)(dong)(dong)(dong),定位軸(zhou)(1)及與(yu)之相連(lian)(lian)的(de)(de)(de)雙(shuang)面齒(chi)條(8)靜止不動(dong)(dong)(dong)(dong)。于是(shi)大齒(chi)輪(10)只能推動(dong)(dong)(dong)(dong)與(yu)之嚙合的(de)(de)(de)單(dan)面小齒(chi)條(13)往右移(yi)動(dong)(dong)(dong)(dong)。壓(ya)(ya)力(li)油口(kou)與(yu)藍(lan)色油道相通,紅色油道與(yu)回油口(kou)接通,壓(ya)(ya)力(li)油從藍(lan)色油道不斷(duan)進入活(huo)塞(sai)(3)右側的(de)(de)(de)液(ye)壓(ya)(ya)油缸內(nei),使液(ye)壓(ya)(ya)油缸不斷(duan)向(xiang)右移(yi)動(dong)(dong)(dong)(dong)。活(huo)塞(sai)左側液(ye)壓(ya)(ya)油缸內(nei)的(de)(de)(de)工作(zuo)油從紅色油道通過(guo)回油孔返(fan)回油箱。液(ye)壓(ya)(ya)油缸與(yu)葉(xie)輪上(shang)的(de)(de)(de)每個動(dong)(dong)(dong)(dong)葉(xie)片(pian)的(de)(de)(de)調節桿(gan)(調節桿(gan)連(lian)(lian)接葉(xie)柄，葉(xie)柄上(shang)有葉(xie)片(pian))相連(lian)(lian),當液(ye)壓(ya)(ya)油缸向(xiang)右移(yi)動(dong)(dong)(dong)(dong)時(shi),動(dong)(dong)(dong)(dong)葉(xie)片(pian)的(de)(de)(de)角度減小,風機(ji)輸送流量(liang)與(yu)全(quan)壓(ya)(ya)隨即降(jiang)低。

　　液(ye)壓(ya)缸(gang)反饋過程：當液(ye)壓(ya)缸(gang)向右(you)移(yi)動時,定(ding)位軸(1)被帶(dai)動同時向右(you)移(yi)動。但由于滑塊不動,所以雙(shuang)面齒(chi)條(tiao)(8)向右(you)移(yi)動帶(dai)動大(da)小(xiao)齒(chi)輪(10、11)使單(dan)面齒(chi)條(tiao)(13)向左移(yi)動。這(zhe)樣又使伺服閥將(jiang)油道(dao)藍色與紅色油道(dao)的(de)油孔關(guan)閉,液(ye)壓(ya)油缸(gang)隨之處(chu)在新的(de)平衡位置不再移(yi)動。而動葉片(pian)亦在關(guan)小(xiao)的(de)狀態下工作,這(zhe)就是(shi)反饋過程。在反饋時指示(shi)齒(chi)輪帶(dai)動指示(shi)軸(指示(shi)盤(pan))旋轉,將(jiang)動葉片(pian)關(guan)小(xiao)的(de)角度顯示(shi)出來。