ʻO ka hoʻouna pololei ʻana i ka mian shaft e pili ana i ka axis rotating mua i loko o kahi mea mīkini. He kuleana koʻikoʻi ia i ke kākoʻo ʻana a me ka wili ʻana i nā mea ʻē aʻe e like me nā gears, fan, turbines, a me nā mea hou aku. Kūkulu ʻia nā kumu nui mai nā mea ikaika kiʻekiʻe e hiki ke kū i ka torque a me nā ukana. Loaʻa iā lākou ka hoʻohana ākea ma waena o nā lako like ʻole a me nā mīkini me nā mīkini kaʻa, nā mīkini ʻenehana, nā ʻenekini aerospace, a ma waho aʻe. ʻO ka hoʻolālā a me ka maikaʻi o ka hana ʻana o nā shafts nui ka hopena i ka hana a me ke kūpaʻa o nā ʻōnaehana mechanical