汽(qi)(qi)車(che)要(yao)跑得(de)快，就必須(xu)要(yao)有(you)強勁的(de)(de)(de)動(dong)(dong)力。目(mu)前汽(qi)(qi)車(che)的(de)(de)(de)動(dong)(dong)力系(xi)(xi)(xi)統(tong)可(ke)粗分為(wei)自(zi)然(ran)進(jin)(jin)氣(qi)系(xi)(xi)(xi)統(tong)及(ji)增(zeng)壓(ya)進(jin)(jin)氣(qi)系(xi)(xi)(xi)統(tong)兩大類。在歐(ou)洲跑車(che)中(zhong)，除(chu)了(le)寶(bao)馬汽(qi)(qi)車(che)公(gong)司(si)依然(ran)堅持(chi)使(shi)用(yong)自(zi)然(ran)進(jin)(jin)氣(qi)發動(dong)(dong)機外，其他各汽(qi)(qi)車(che)公(gong)司(si)為(wei)了(le)提升車(che)輛的(de)(de)(de)動(dong)(dong)力性能，紛紛采用(yong)增(zeng)壓(ya)系(xi)(xi)(xi)統(tong)，例如：奔馳跑車(che)使(shi)用(yong)機械(xie)增(zeng)壓(ya)系(xi)(xi)(xi)統(tong)，紳寶(bao)汽(qi)(qi)車(che)則為(wei)渦輪(lun)增(zeng)壓(ya)的(de)(de)(de)開(kai)山鼻祖。近年日系(xi)(xi)(xi)汽(qi)(qi)車(che)也開(kai)始(shi)大量(liang)采用(yong)渦輪(lun)增(zeng)壓(ya)技術。自(zi)然(ran)進(jin)(jin)氣(qi)系(xi)(xi)(xi)統(tong)沒有(you)安裝任何形(xing)式(shi)的(de)(de)(de)增(zeng)壓(ya)器，只是利(li)用(yong)活塞下(xia)行所產(chan)生的(de)(de)(de)負壓(ya)來(lai)吸進(jin)(jin)混合氣(qi)。雖然(ran)自(zi)然(ran)進(jin)(jin)氣(qi)系(xi)(xi)(xi)統(tong)通過(guo)可(ke)變氣(qi)門正時系(xi)(xi)(xi)統(tong)能夠得(de)到較(jiao)大的(de)(de)(de)馬力輸出(chu)，但動(dong)(dong)力的(de)(de)(de)提升很有(you)限。為(wei)了(le)有(you)效增(zeng)加發動(dong)(dong)機的(de)(de)(de)輸出(chu)功率(lv)，采用(yong)增(zeng)壓(ya)系(xi)(xi)(xi)統(tong)可(ke)說是最有(you)效的(de)(de)(de)方(fang)式(shi)。

最常(chang)見(jian)的發動機(ji)增(zeng)壓系(xi)統有機(ji)械(xie)增(zeng)壓與廢氣渦輪增(zeng)壓兩(liang)種(zhong)。

機械增壓

發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)以(yi)機(ji)(ji)(ji)(ji)械(xie)方(fang)式(shi)驅(qu)動(dong)機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器進行增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)，稱為機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)。當發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)采用(yong)機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)時，通常由發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)曲軸通過齒輪(lun)驅(qu)動(dong)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器。增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器一般采用(yong)離心式(shi)或羅茨壓(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)，個別的(de)(de)采用(yong)螺桿式(shi)壓(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)。近年來(lai)，在(zai)國(guo)外也開始采用(yong)新型(xing)的(de)(de)機(ji)(ji)(ji)(ji)械(xie)渦旋(xuan)式(shi)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器。因(yin)為驅(qu)動(dong)壓(ya)(ya)(ya)(ya)(ya)氣(qi)機(ji)(ji)(ji)(ji)消耗(hao)了發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)一定(ding)的(de)(de)輸出(chu)功(gong)率(lv)(lv)，所以(yi)機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)的(de)(de)熱(re)效(xiao)率(lv)(lv)不一定(ding)得到(dao)改(gai)善，有(you)時反而比非增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)內燃機(ji)(ji)(ji)(ji)還低些。選擇增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力時，首先(xian)要保(bao)證能達到(dao)所要求的(de)(de)平(ping)均(jun)有(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)力，其次要獲得盡可(ke)能低的(de)(de)燃油(you)(you)消耗(hao)率(lv)(lv)。擔這兩個要求對于機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)來(lai)說常常是(shi)相互矛盾的(de)(de)。如果追求平(ping)均(jun)有(you)效(xiao)壓(ya)(ya)(ya)(ya)(ya)力，則必然導致(zhi)機(ji)(ji)(ji)(ji)械(xie)效(xiao)率(lv)(lv)降(jiang)低，燃油(you)(you)消耗(hao)率(lv)(lv)升高。因(yin)此，增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力值的(de)(de)選取應在(zai)功(gong)率(lv)(lv)和(he)燃油(you)(you)消耗(hao)率(lv)(lv)兩者之間尋求最佳的(de)(de)妥協方(fang)案。機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)系(xi)統目前在(zai)歐洲(zhou)車上用(yong)得較普遍。由于機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)機(ji)(ji)(ji)(ji)是(shi)在(zai)曲軸的(de)(de)帶動(dong)下持續(xu)地運轉，因(yin)此不動(dong)產生像渦輪(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)渦輪(lun)遲滯現象。機(ji)(ji)(ji)(ji)械(xie)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)雖然只能提升約(yue)10%20%的(de)(de)動(dong)力輸出(chu)，但平(ping)順連續(xu)性是(shi)渦輪(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)發(fa)(fa)動(dong)機(ji)(ji)(ji)(ji)所不及的(de)(de)。

廢氣(qi)渦輪增壓

利(li)用發(fa)(fa)動(dong)(dong)機(ji)廢(fei)氣(qi)(qi)(qi)(qi)(qi)能量驅動(dong)(dong)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)器，稱(cheng)為(wei)(wei)廢(fei)氣(qi)(qi)(qi)(qi)(qi)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)（簡(jian)稱(cheng)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)），如圖所示是(shi)(shi)廢(fei)氣(qi)(qi)(qi)(qi)(qi)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)系統。廢(fei)氣(qi)(qi)(qi)(qi)(qi)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)的(de)(de)(de)特(te)點是(shi)(shi)在渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)器和發(fa)(fa)動(dong)(dong)機(ji)之間(jian)沒有機(ji)械連接。它(ta)們之間(jian)靠(kao)氣(qi)(qi)(qi)(qi)(qi)路相通。因為(wei)(wei)壓(ya)(ya)氣(qi)(qi)(qi)(qi)(qi)機(ji)消耗的(de)(de)(de)功(gong)是(shi)(shi)渦(wo)(wo)(wo)輪(lun)(lun)從(cong)廢(fei)氣(qi)(qi)(qi)(qi)(qi)中回收的(de)(de)(de)一部(bu)分能量，所以渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)發(fa)(fa)動(dong)(dong)機(ji)不僅(jin)可以增(zeng)(zeng)(zeng)(zeng)加發(fa)(fa)動(dong)(dong)機(ji)的(de)(de)(de)功(gong)率(lv)(lv)，而且可以提高其熱效率(lv)(lv)，降低燃(ran)油(you)消耗率(lv)(lv)。如果在轎車尾部(bu)看到Turbo或者(zhe)T的(de)(de)(de)標識，即表(biao)明該車采用的(de)(de)(de)發(fa)(fa)動(dong)(dong)機(ji)是(shi)(shi)渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)的(de)(de)(de)。渦(wo)(wo)(wo)輪(lun)(lun)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)器實際(ji)上是(shi)(shi)臺空氣(qi)(qi)(qi)(qi)(qi)壓(ya)(ya)縮(suo)(suo)機(ji)，它(ta)是(shi)(shi)利(li)用發(fa)(fa)動(dong)(dong)機(ji)排(pai)出的(de)(de)(de)廢(fei)氣(qi)(qi)(qi)(qi)(qi)慣性推動(dong)(dong)渦(wo)(wo)(wo)輪(lun)(lun)，渦(wo)(wo)(wo)輪(lun)(lun)又帶(dai)動(dong)(dong)同(tong)軸的(de)(de)(de)葉輪(lun)(lun)壓(ya)(ya)縮(suo)(suo)由(you)空氣(qi)(qi)(qi)(qi)(qi)濾清器管道(dao)送來的(de)(de)(de)空氣(qi)(qi)(qi)(qi)(qi)，使空氣(qi)(qi)(qi)(qi)(qi)增(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)后進入(ru)氣(qi)(qi)(qi)(qi)(qi)缸(gang)。當發(fa)(fa)動(dong)(dong)機(ji)轉(zhuan)速提高，廢(fei)氣(qi)(qi)(qi)(qi)(qi)排(pai)出速度與(yu)渦(wo)(wo)(wo)輪(lun)(lun)轉(zhuan)速也同(tong)步(bu)提高，葉輪(lun)(lun)就壓(ya)(ya)縮(suo)(suo)更多的(de)(de)(de)空氣(qi)(qi)(qi)(qi)(qi)進入(ru)氣(qi)(qi)(qi)(qi)(qi)缸(gang)，空氣(qi)(qi)(qi)(qi)(qi)的(de)(de)(de)壓(ya)(ya)力和密度增(zeng)(zeng)(zeng)(zeng)大可以燃(ran)燒更多的(de)(de)(de)燃(ran)油(you)，相應增(zeng)(zeng)(zeng)(zeng)加油(you)量和調整一下發(fa)(fa)動(dong)(dong)機(ji)的(de)(de)(de)轉(zhuan)速，就可以增(zeng)(zeng)(zeng)(zeng)加發(fa)(fa)動(dong)(dong)機(ji)的(de)(de)(de)輸出功(gong)率(lv)(lv)。