ʻO nā bearings pōleʻa hohonu e lawe i ka ukana radial a me ka lawe ʻana i ka ukana axial haʻahaʻa. Me ka liʻiliʻi liʻiliʻi o ka friction, ka wikiwiki palena kiʻekiʻe, ka laulā nui a me ka hui pū ʻana o ka hale; kūpono lākou no ka tractor, nā kaʻa, nā kaʻa, nā kaʻa, a me nā mīkini maʻamau, e like me ke ʻano o nā bearings i hoʻohana nui ʻia i ka ʻoihana mīkini.