Brevini Australia was commissioned to provide a solution for a large double drum shaft sink kibble winch. The winch had two drums, each powered by 600kW motors that could be ‘clutched-in’ together to provide 1200kW to one drum with a peak power of 2600kW.
The challenge was to refurbish the large winches within a tight schedule.
The motors were back-to-back with a rear non-drive end shaft extension and an electromagnetic clutch that could combine the power. The winch drums were running parallel to the motors. The method used to reduce the speed and increase the torque was to employ a single stage spiral bevel reducer providing a right angle arrangement and then driving into a bevel helical reducer, also providing a right angle arrangement with both gear reducers mounted onto a base frame, making the input and output shafts parallel.
PIV helical reducers with extended centre distance were identified as the solution.
The centre distance between shafts was in excess of 2.7m between the motor output shaft and the driven winch shaft. A single stage bevel and bevel helical reducer on a base frame was considered in addition to an ‘N’ series helical reducer with extended centre distance.
The helical unit offered a number of advantages over the old method including having only half of the shafts exposed, no requirement for base frame, easier alignment and no concerns about oil leaks with contactless oil seals.
Brevini PIV Germany designed a helical reducer featuring a mass of over 13 tonnes that would not only meet the technical requirements but was also able to provide the exact ratio and the required centre distance down to 1mm.