When Kranbau Köthen, a European manufacturer of overhead cranes, was commissioned to develop a new series of cranes for use in the scrap yard of a global steel producer’s mill in Luxembourg, it turned to gear motor specialist, Bauer, part of Altra Industrial Motion.
Scrap yard cranes have always needed to be able to operate at high speed while lifting heavy loads. With ever-greater emphasis being put on recycling, scrap yard operations are being pushed to new levels of productivity. Simultaneously improving safety systems, energy efficiency and automation are also informing the design of new cranes.
Looking at all the issues of the Kranbau project, engineers at Bauer developed a solution, based on modified versions of their BK series of bevel gear motors. BK80 models were identified as the best choice for the cranes’ travel drives and BK90s for the trolley drives.
The housings of the BK motors are made from spheroidal graphite cast iron, a robust and corrosion resistant material that can withstand harsh environmental conditions. High IP protection and a corrosion-resistant coating, also help them stand up to the rigours of scrap yard operations.
Bauer engineers suggested modifying the BK motors to include specially reinforced torque arms and heavy-duty encoders, to better suit the specific needs of the application.
Alexander Dölger, Bauer’s global account manager for crane technologies, said: “Advanced drives engineering often requires bespoke solutions for demanding applications. Our 75 years of experience across virtually all sectors means that very few problems are new to us and we are able to rapidly identify the best possible solution for each application.”
The BK series is available in power ratings up to 45kW; it produces output torque from 80Nm to 18,500Nm and speeds from 0.2 to 280rpm. The design is completely enclosed and sealed against dust and water spray to IP65 as standard (IP66 optional). Corrosion protection is to CORO1, CORO2, CORO3, as required, and the lubrication does not need to be changed until after 15,000 hours of operation.
The BK motor is inverter friendly, a critical characteristic for crane applications. Also, there is total flexibility in mounting options including shaft, base, face and flange solutions; horizontal, vertical and suspended orientation. The terminal box can be mounted in multiple positions.
Generously dimensioned ball or roller bearings, case-hardened forged and ground gears, and internally and externally reinforced gearboxes ensure a long, low maintenance life. A hardened wear sleeve and spray ring at the rotor seal allow for reduced sump capacity, reliable lubrication and leak-free performance. Hollow shaft options are available throughout the BK series.
Dölger continues: “With energy conservation high on the agenda these days, the BK series’ efficiency is often a key factor in its selection. A high level of parts interchangeability or modularity reduces costs and aids maintenance, while compliance with NEMA, IEC, CSA, CE, etc. makes the BK series acceptable around the world.”