Makina opangira nyimbo za crank, omwe amadziwikanso kuti bokosi la nyimbo la crankshaft kapena bokosi la nyimbo, ndi chipangizo chachikhalidwe chomwe chimagwiritsidwa ntchito popanga nyimbo ndi nyimbo zokongola. Makinawa nthawi zambiri amakhala ndi shaft yokhomeredwa pamanja yomwe, ikatembenuzidwa, imayendetsa magiya ndi mapini angapo, zomwe zimapangitsa kuti chisa chachitsulo chizule mano a silinda kapena disk.
Pamene mano a cylinder kapena disk akudulidwa, amatulutsa zolemba za nyimbo, zomwe zimapangitsa kuti pakhale nyimbo zabwino kwambiri zomwe zimagwirizanitsidwa ndi mabokosi a nyimbo.
Kusintha kwa bokosi la nyimbo ndikuwona momwe makinawo amagwirira ntchito kungathe kubweretsa chisangalalo ndi kudabwa kwa ana ndi akulu omwe.Mabokosi a bokosi la nyimbo amapezeka m'mabokosi osiyanasiyana a nyimbo, kuphatikizapo mabokosi a nyimbo zamatabwa, mabokosi anyimbo zachilendo, ndi mabokosi okongoletsa nyimbo ophatikizidwa. Mapangidwe awo osatha komanso osatha akupitilizabe kukopa okonda nyimbo ndi osonkhanitsa padziko lonse lapansi, zomwe zimawapangitsa kukhala okondedwa kwa mibadwomibadwo.