Over the past week I had begun to notice a rumble coming from the Powerspout rear end and last night it became a more unhappy noise. As the turbine came to rest after shutting down, there was a clearly audible clicking as the shaft came to a standstill. On inspection this morning, there was palpable free play in the shaft, - not much, but after so short a time, it was not worthwhile continuing the trial and risking a major bearing failure with damage to the Smart Drive rotor and core.
Michael Lawley commented when I told him about it that he had always had concerns about ceramic bearings, - "the only people who seem to use them are skate-boarders who would be lucky to do 100 hours".
So this morning was spent putting in a new bearing block, this time with SKF E2 Energy Efficient bearings. I plan to run these with just their factory fill of grease, not adding any extra grease via the grease nipple.
Here are a few pics of doing the replacement to illustrate:
- how tightening the runner retaining bolt can be a one-man job
- a homemade tool for accurately aligning the runner to the jets:
|Home-made tool to lock S-D rotor|
|Tapping lugs into place in the holes in the rotor|
|Tightening to 38 ft lbs with the shaft locked|
|Piece of pipe which is a tight sliding fit in the nozzle holder, |
with two wood inserts each end, bored dead centre
to take a 4 mm knitting needle
|Device in place in bottom nozzle holder after removing nozzle|
|Close up of needle point on splitter ridge with just the|
right number of packing washers behind the runner
to have the jet divided equally in two by the