汽(qi)車要跑得(de)快，就必須要有強勁的(de)動力(li)。目前汽(qi)車的(de)動力(li)系(xi)(xi)統可粗分為自然進(jin)氣(qi)(qi)系(xi)(xi)統及增(zeng)(zeng)壓(ya)進(jin)氣(qi)(qi)系(xi)(xi)統兩(liang)大類(lei)。在歐洲跑車中，除(chu)了(le)寶馬汽(qi)車公司(si)依(yi)然堅持(chi)使用(yong)(yong)(yong)自然進(jin)氣(qi)(qi)發動機(ji)(ji)外，其(qi)他各汽(qi)車公司(si)為了(le)提(ti)升車輛的(de)動力(li)性能(neng)，紛(fen)紛(fen)采用(yong)(yong)(yong)增(zeng)(zeng)壓(ya)系(xi)(xi)統，例如：奔馳跑車使用(yong)(yong)(yong)機(ji)(ji)械(xie)增(zeng)(zeng)壓(ya)系(xi)(xi)統，紳寶汽(qi)車則為渦輪增(zeng)(zeng)壓(ya)的(de)開(kai)山(shan)鼻祖。近(jin)年日系(xi)(xi)汽(qi)車也開(kai)始大量采用(yong)(yong)(yong)渦輪增(zeng)(zeng)壓(ya)技(ji)術。自然進(jin)氣(qi)(qi)系(xi)(xi)統沒有安裝任(ren)何形(xing)式的(de)增(zeng)(zeng)壓(ya)器(qi)，只是利用(yong)(yong)(yong)活塞下行所產生的(de)負壓(ya)來吸(xi)進(jin)混合氣(qi)(qi)。雖然自然進(jin)氣(qi)(qi)系(xi)(xi)統通過(guo)可變氣(qi)(qi)門正時系(xi)(xi)統能(neng)夠(gou)得(de)到較大的(de)馬力(li)輸出，但(dan)動力(li)的(de)提(ti)升很有限(xian)。為了(le)有效增(zeng)(zeng)加(jia)發動機(ji)(ji)的(de)輸出功率，采用(yong)(yong)(yong)增(zeng)(zeng)壓(ya)系(xi)(xi)統可說是最有效的(de)方式。

最常見的發動機(ji)增壓(ya)(ya)系統有機(ji)械增壓(ya)(ya)與廢氣渦輪增壓(ya)(ya)兩種。

機械增壓

發(fa)動(dong)機(ji)(ji)以機(ji)(ji)械(xie)(xie)方式驅(qu)動(dong)機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器(qi)進(jin)行(xing)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)，稱為機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)。當(dang)發(fa)動(dong)機(ji)(ji)采(cai)用(yong)(yong)機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)時(shi)，通(tong)常(chang)由(you)發(fa)動(dong)機(ji)(ji)曲(qu)軸通(tong)過齒輪(lun)驅(qu)動(dong)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器(qi)。增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器(qi)一(yi)(yi)般(ban)采(cai)用(yong)(yong)離心式或羅(luo)茨(ci)壓(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)，個別的(de)(de)采(cai)用(yong)(yong)螺桿式壓(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)。近年(nian)來，在國(guo)外也開始采(cai)用(yong)(yong)新型的(de)(de)機(ji)(ji)械(xie)(xie)渦旋式增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)器(qi)。因(yin)(yin)為驅(qu)動(dong)壓(ya)(ya)(ya)(ya)(ya)氣機(ji)(ji)消耗(hao)(hao)(hao)了發(fa)動(dong)機(ji)(ji)一(yi)(yi)定(ding)的(de)(de)輸出功率(lv)(lv)，所以機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)發(fa)動(dong)機(ji)(ji)的(de)(de)熱效率(lv)(lv)不一(yi)(yi)定(ding)得到改善，有(you)時(shi)反而(er)比非(fei)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)內燃機(ji)(ji)還低(di)些。選(xuan)(xuan)擇增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力時(shi)，首先(xian)要(yao)保證能達到所要(yao)求的(de)(de)平(ping)均(jun)有(you)效壓(ya)(ya)(ya)(ya)(ya)力，其次(ci)要(yao)獲得盡可(ke)能低(di)的(de)(de)燃油(you)消耗(hao)(hao)(hao)率(lv)(lv)。擔這兩(liang)個要(yao)求對于機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)來說常(chang)常(chang)是相互矛盾的(de)(de)。如果追(zhui)求平(ping)均(jun)有(you)效壓(ya)(ya)(ya)(ya)(ya)力，則必然(ran)導(dao)致機(ji)(ji)械(xie)(xie)效率(lv)(lv)降低(di)，燃油(you)消耗(hao)(hao)(hao)率(lv)(lv)升高。因(yin)(yin)此(ci)，增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)壓(ya)(ya)(ya)(ya)(ya)力值的(de)(de)選(xuan)(xuan)取應在功率(lv)(lv)和(he)燃油(you)消耗(hao)(hao)(hao)率(lv)(lv)兩(liang)者之間尋求最佳(jia)的(de)(de)妥(tuo)協(xie)方案。機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)系統目前在歐洲車(che)上用(yong)(yong)得較普遍。由(you)于機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)機(ji)(ji)是在曲(qu)軸的(de)(de)帶(dai)動(dong)下持續地運(yun)轉，因(yin)(yin)此(ci)不動(dong)產生像渦輪(lun)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)的(de)(de)渦輪(lun)遲滯(zhi)現象。機(ji)(ji)械(xie)(xie)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)雖然(ran)只能提升約10%20%的(de)(de)動(dong)力輸出，但(dan)平(ping)順連續性是渦輪(lun)增(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)(zeng)壓(ya)(ya)(ya)(ya)(ya)發(fa)動(dong)機(ji)(ji)所不及的(de)(de)。

廢(fei)氣渦(wo)輪增壓

利(li)(li)用(yong)發(fa)(fa)動(dong)(dong)(dong)機(ji)廢(fei)(fei)氣(qi)(qi)能量(liang)驅動(dong)(dong)(dong)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)器，稱(cheng)為廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)（簡稱(cheng)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)），如圖所示是(shi)廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)系(xi)統。廢(fei)(fei)氣(qi)(qi)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)的(de)(de)(de)(de)特點(dian)是(shi)在渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)器和(he)發(fa)(fa)動(dong)(dong)(dong)機(ji)之間沒有機(ji)械連接(jie)。它們之間靠氣(qi)(qi)路相通。因為壓(ya)氣(qi)(qi)機(ji)消耗的(de)(de)(de)(de)功(gong)(gong)是(shi)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)從(cong)廢(fei)(fei)氣(qi)(qi)中(zhong)回收的(de)(de)(de)(de)一(yi)部分能量(liang)，所以渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)發(fa)(fa)動(dong)(dong)(dong)機(ji)不僅可(ke)(ke)以增(zeng)(zeng)(zeng)加發(fa)(fa)動(dong)(dong)(dong)機(ji)的(de)(de)(de)(de)功(gong)(gong)率(lv)，而且可(ke)(ke)以提(ti)高(gao)其熱效(xiao)率(lv)，降低燃油消耗率(lv)。如果(guo)在轎車(che)尾(wei)部看到Turbo或者T的(de)(de)(de)(de)標識(shi)，即表明(ming)該車(che)采用(yong)的(de)(de)(de)(de)發(fa)(fa)動(dong)(dong)(dong)機(ji)是(shi)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)的(de)(de)(de)(de)。渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)增(zeng)(zeng)(zeng)壓(ya)器實(shi)際上是(shi)臺空(kong)(kong)(kong)氣(qi)(qi)壓(ya)縮(suo)機(ji)，它是(shi)利(li)(li)用(yong)發(fa)(fa)動(dong)(dong)(dong)機(ji)排出的(de)(de)(de)(de)廢(fei)(fei)氣(qi)(qi)慣性推(tui)動(dong)(dong)(dong)渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)，渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)又帶動(dong)(dong)(dong)同軸的(de)(de)(de)(de)葉輪(lun)(lun)(lun)壓(ya)縮(suo)由空(kong)(kong)(kong)氣(qi)(qi)濾清器管道送來的(de)(de)(de)(de)空(kong)(kong)(kong)氣(qi)(qi)，使空(kong)(kong)(kong)氣(qi)(qi)增(zeng)(zeng)(zeng)壓(ya)后(hou)進(jin)入氣(qi)(qi)缸。當(dang)發(fa)(fa)動(dong)(dong)(dong)機(ji)轉(zhuan)速提(ti)高(gao)，廢(fei)(fei)氣(qi)(qi)排出速度與渦(wo)(wo)(wo)(wo)輪(lun)(lun)(lun)轉(zhuan)速也同步(bu)提(ti)高(gao)，葉輪(lun)(lun)(lun)就(jiu)壓(ya)縮(suo)更(geng)多的(de)(de)(de)(de)空(kong)(kong)(kong)氣(qi)(qi)進(jin)入氣(qi)(qi)缸，空(kong)(kong)(kong)氣(qi)(qi)的(de)(de)(de)(de)壓(ya)力和(he)密度增(zeng)(zeng)(zeng)大可(ke)(ke)以燃燒更(geng)多的(de)(de)(de)(de)燃油，相應增(zeng)(zeng)(zeng)加油量(liang)和(he)調整一(yi)下發(fa)(fa)動(dong)(dong)(dong)機(ji)的(de)(de)(de)(de)轉(zhuan)速，就(jiu)可(ke)(ke)以增(zeng)(zeng)(zeng)加發(fa)(fa)動(dong)(dong)(dong)機(ji)的(de)(de)(de)(de)輸出功(gong)(gong)率(lv)。