The Challenge: refurbishing large winches within tight schedule
Brevini Australia was requested 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 1200 kW to one drum with a peak power of 2600 kW.
The motors were back to back with a rear non-drive end shaft extension with and electromagnetic clutch that could combine the power. The winch drums were running parallel to the motors and 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, hence the input and output shafts we parallel.
The solution: PIV helical reducers with extended centre distance
The centre distance between shafts was in excess of 2.7 m between the motor output shaft and the driven winch shaft. So, we not only considered using a single stage bevel and bevel helical reducer on a base frame but also an “N” series helical reducer with extended centre distance.
The Helical unit could offer a lot of advantages over the old method including having only half of the shafts exposed, no base frame would be required, alignment would be easier and if we were to use our contactless oil seals they would never have the need to be concerned with oil leaks as in the past.
Brevini PIV Germany were able to design a helical reducer that would not only meet the technical requirements but that also was able to provide the exact ratio and the required centre distance down to 1 mm. Delivery was also required on a very tight delivery schedule. Note that he mass of each reducer is over 13 tonnes. These are the largest “N” series helical units ever sold in the world.