Ball bearings hnathawh dan .

Ball bearings hian bearing-a raceway leh ball-te inkarah rolling friction hmangin hna a thawk a, chu chuan shaft leh bearing inkara friction a tih tlem theih nan a thawk a, chu chuan wheel-te avanga friction awm chu a ti tlem a, transmission efficiency a ti sang bawk. He rolling action hian shaft friction a tihchhiat loh nan a veng a, machine dam chhung a ti rei bawk.