The plant’s high speed gas turbine sets, fitted with main speed reduction units and other associated equipment, were housed inside an acoustic compartment making routine maintenance difficult. With operational hours on some of the generator sets approaching the point where main speed reduction idler bearings were due for service, it was important to find the right solution and the right service partner to reduce downtime.
David Brown Santasalo came up with a unique procedure to raise the lid of the acoustic compartment rather than use the traditional dismantling solution. This made the maintenance less expensive to perform and even more importantly, the shorter downtime meant the cost to the customer in terms of lost production was significantly reduced.
In brief, the procedure involves inserting four high tensile screwed bars into the M20 jacking holes in the gearbox lid and gradually raising the cover, little by little at each corner ensuring that the cover remains level at all times.
At an appropriate height, support tubes are positioned between the joints by removing each of the four corner bars in turn and refitting them through the tubes. Additional safety measures are then taken and in the space now available the idler gear can be supported by a sling and the cartridge removed to allow the bearing change to be effected.
Health and safety considerations were paramount and the diligence shown by David Brown Santasalo was matched by exceptional technical proficiency. The work carried out by the David Brown Santasalo team to develop the procedure is now paying off and the in-situ bearing change method is being applied to all the customer’s service contracts.