One of the UK’s largest import/export ports needed four spare DC travel motors for their 50T rubber-tyred gantry cranes. The spares had to be identical to the existing units, as modifications to the housing were not an option. Designing and manufacturing brand new motors would have been expensive.
We identified mechanically-identical DC motors fitted to a decommissioned gantry crane; however they did not meet the required electrical output. After a full survey of the motors at our Bristol workshop, we concluded that the most efficient route would be to upgrade them from 11kW to the required 15 kW.
The non-machined surfaces were sandblasted back to the original casting, and the fields, interpoles and armature stripped and rewound. The commutator was replaced, skimmed, and undercut, and the armature laminations were replaced, allowing the units to meet the required output and speed. The units were insulated to the correct specification, then tested, painted and despatched.
This extremely satisfactory solution was reached thanks to Mawdsley’s extensive knowledge of DC motors. And as ever, the work was carried out on time and on budget.