| 摘要 |
<p>The column-mounted crane has the jib slewed by compressed air, the column being preferably tubular with a closing plate at the top on which a gear ring for the slewing mechanism pinion is mounted. A central bore in the plate has bearings for the jib slewing boss, which is situated centrally on a motor support plate on the underside of the jib. The slewing pinion is mounted on a gearbox with automatic brake, and preceded by an overload protection device. Its driving motor runs on compressed air, and a coupling is provided between motor and gearbox. The latter can be of the non-reversing worm type, or have straight teeth, together with an automatic brake.</p> |
