Kab rov tav geared motors ua haujlwm ntawm lub hauv paus ntsiab lus ntawm iav kis. Lub tshuab hluav taws xob muab siab- nrawm, qis- lub zog nkag lub zog, uas txo qis hauv kev nrawm los ntawm ntau- theem iav khub (xws li cylindrical gears, bevel gears, lossis planetary gears) nyob rau hauv lub reducer, yog li ua kom cov zis torque. Qhov kev txo qis yog txiav txim siab los ntawm cov iav hniav piv, nrog rau kev txo qis feem ntau ntawm 5: 1 txog 100: 1, xaiv tau raws li qhov xav tau tiag tiag.
Piv txwv li, thaum lub tshuab hluav taws xob ua haujlwm ntawm 1500 rpm, lub reducer nrog qhov txo qis ntawm 10: 1 txo cov zis ceev mus rau 150 rpm, thaum tib lub sijhawm nce cov zis torque los ntawm kwv yees li 10 zaug (tsis quav ntsej txog kev poob haujlwm). Cov yam ntxwv no ua rau kab rov tav geared motors haum rau cov ntawv thov uas xav tau qis- nrawm, siab- torque tsav.