2 txheej ntawm 4 txheej reciprocating siv tshuab ziab khaub ncaws tau raug xa mus.

2 txheej ntawm 4 txheej reciprocating siv tshuab ziab khaub ncaws tau raug xa mus.

Covband tshuab ziab khaub ncaws, raws li tus neeg sawv cev tsis tu ncua kom qhuav apparatus, muaj npe nrov rau nws cov peev xwm tuav tau ntau heev. Nws tuaj yeem raug teeb tsa nrog qhov dav tshaj 4m, thiab ntau theem, los ntawm 4 txog 9, nrog rau kev ncua mus txog kaum ob metres, tso cai rau nws tuav ntau pua tons ntawm cov khoom txhua hnub.