The crankshaft bụ akụkụ dị mkpa nke engine. A na-eji ígwè arụ ọrụ carbon ma ọ bụ ihe nkedo nodular mee ihe ya. Ọ nwere akụkụ abụọ dị mkpa: akwụkwọ akụkọ bụ isi, akwụkwọ akụkọ mkpanaka njikọ (na ndị ọzọ). A na-etinye akwụkwọ akụkọ bụ isi na ngọngọ cylinder, a na-ejikọta olu olu na-ejikọta ya na nnukwu oghere isi nke njikọ njikọ, na obere oghere na-ejikọta ya na piston cylinder, nke bụ usoro ihe mmịfe crank na-ahụkarị.

A na-akpọkarị isi ihe nke crankshaft buru ibu. Dị ka mkpanaka na-ejikọta ya, ọ bụkwa ihe na-amị amị na-ekewa n'ime akụkụ abụọ, ya bụ isi ihe (n'elu na elu). A na-etinye oke ohia nke elu n'ime oghere oche oche nke ahụ; A na-etinye ihe mkpuchi ala na mkpuchi mkpuchi isi. A na-ejikọta isi ihe mgbochi na isi mkpuchi nke anụ ahụ site na isi ihe na-emepụta ihe. Ihe eji eme ihe, nhazi, ntinye na ntinye nke isi ihe bu ihe ndi ozo bu ihe eji eme ihe eji eme ihe. Iji bufee mmanụ na mkpanaka njikọ nnukwu isi ihe, a na-emeghe oghere mmanụ na oghere mmanụ na isi ihe na-emepụta ihe, na ebe dị ala nke isi ihe anaghị emeghe ya na oghere mmanụ na mmanụ mmanụ n'ihi ibu dị elu. . Mgbe ị na-etinye isi ihe nkedo nke crankshaft, ṅaa ntị na ọnọdụ na ntụziaka nke ibu ahụ.