Iishafu zeemoto zensimbi ezingenasici ezisetyenziswa kwiimoto zeemoto ngamacandelo enziwe ngobunjineli obuchanekileyo enzelwe ukubonelela ukuhanjiswa kwamandla okuthembekileyo kunye nokuqina kwiindawo ezibango.Ezi shafts zenziwa ngentsimbi ekumgangatho ophezulu, enika ukuxhathisa okugqwesileyo kunye nokomelela.
Kwizicelo zeemoto, iishafti zensimbi ezingenasici zidlala indima ebalulekileyo ekudluliseleni intshukumo ejikelezayo ukusuka kwimoto ukuya kwizinto ezahlukeneyo ezinje ngabalandeli, iimpompo kunye negiya.Ziyilelwe ukumelana nezantya eziphezulu, imithwalo, kunye namaqondo obushushu axhaphakileyo adibana nawo kwiinkqubo zeemoto.
Enye yeenzuzo eziphambili zensimbi engenasici ye-motor shafts kukuchasana nokubola, okunceda ukuqinisekisa ukusebenza kwexesha elide kunye nokuthembeka kwiindawo ezinzima zeemoto.Ukongeza, i-shafts yensimbi engenasici inokwenziwa ngoomatshini ukuba inyamezeleke kakhulu, ivumela ulungelelwaniso oluchanekileyo kunye nokusebenza kakuhle.