Crankshaft ndi gawo lofunikira la injini. Zinthu zake zimapangidwa ndi chitsulo chopanga kaboni kapena chitsulo cha nodular cast. Ili ndi magawo awiri ofunikira: magazini yayikulu, magazini yolumikizira ndodo (ndi ena). Magazini yayikulu imayikidwa pa cylinder block, khosi la ndodo yolumikizira limalumikizidwa ndi dzenje lalikulu la mutu wa ndodo yolumikizira, ndipo dzenje laling'ono lolumikizira limalumikizidwa ndi silinda pisitoni, yomwe ndi njira yolowera.

Choyimira chachikulu cha crankshaft nthawi zambiri chimatchedwa lalikulu. Mofanana ndi ndodo yolumikizira, imakhalanso yotsetsereka yomwe imagawidwa m'magawo awiri, yomwe ndi yaikulu (zonyamulira zapamwamba ndi zapansi). Chapamwamba chitsamba chitsamba chimayikidwa mu dzenje lalikulu la mpando wa thupi; kubereka m'munsi kumayikidwa pachivundikiro chachikulu chonyamula. Chophimba chachikulu ndi chivundikiro chachikulu cha thupi chimagwirizanitsidwa pamodzi ndi mabawuti akuluakulu onyamula. Zida, kapangidwe, kuyika ndi kuyika kwa chotengera chachikulu ndizofanana ndi zomwe zingwe zolumikizira ndodo. Kuti apereke mafuta ku ndodo yolumikizira mutu waukulu, mabowo amafuta ndi ma groove amafuta nthawi zambiri amatsegulidwa pa chonyamulira chachikulu, ndipo kumunsi kwa chotengera chachikulu nthawi zambiri sikumatseguka ndi mabowo amafuta ndi ma groove amafuta chifukwa cha katundu wapamwamba. . Mukayika choyimira chachikulu cha crankshaft, samalani ndi malo ndi komwe akuchokera.