Crane Drives Keep Moving with New PB Gear Units from Renold
Modified PB70 and PB80 bevel helical units eradicate costly downtime for busy dockside cranes.
On any dockside where container cargo is loaded on and off ships, large rail mounted gantries are used to lift and move the heavy cargo containers. These cranes (some in excess of 200 feet high) move along the dockside on rails and can have up to 8 large steel wheels - 4 on either side. Each wheel is driven individually by shaft mounted gearboxes.
London Thamesport (LTP) one of the UK's busiest container ports was experiencing problems with the gearboxes driving the wheels of their cranes. The helical worm arrangements, originally supplied by other gearbox manufacturers, were proving unreliable in this application due to the large back driving inertias involved as the cranes come to a standstill. As a result they were experiencing premature failures. These failures were manifesting in unnecessary downtime and hefty repair costs.
The port consequently approached Renold to help them find a solution to their costly problem. The solution offered by Renold was the PM Series, PB70 and PB80 bevel helical units - standard products but modified with special bores and torque brackets to enable them to fit into the existing mountings.
Rob Stanley, Renold Gears' Southern Area Sales Engineer, comments: "To date Renold have supplied over 100 units to this and other sites. Tony Sloat of Thamesport was happy that the all helical design was the ideal solution as it is flexible, yet strong enough to drive the cranes forward and decelerate without any problems."
A further feature of the PM Series design is the motor connection which allows the customer to 'plug-in' their own motor once the units are fitted to the cranes.