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gearbox
Sept 9, 2011 8:06:08 GMT -5
Post by turbochris on Sept 9, 2011 8:06:08 GMT -5
Here's the parts i made so far and the gears and bearings from the 7 inch grinder Here's what it looks like together. There will be shims between the bearing and gear to adjust the lash. Here's the stock Wren power turbine and original gears along with my modified pinion. I'll finish the output bearing holder today and start on the back cover which will support the smaller bearing. Then its time to put that big ring in the lathe and bore a hole in the side for the wren power turbine.
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wolfdragon
Senior Member
Joined: April 2011
Posts: 287
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gearbox
Sept 9, 2011 8:35:09 GMT -5
Post by wolfdragon on Sept 9, 2011 8:35:09 GMT -5
Actually, using shims and watching wear patterns is probably the best bet of making everything fit happy. Got any Dykem Blue?
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gearbox
Sept 11, 2011 8:40:59 GMT -5
Post by turbochris on Sept 11, 2011 8:40:59 GMT -5
Going to try to set the mesh today. I have the housing in my lathe sideways so I can machine a flat and hole in the side for the N2 shaft tunnel and pinion. I can assemble the gearbox while it's in the lathe so I plan on setting the pinion depth by machining away the housing a little at a time. I have about .030 inch of movement on the actual pinion shaft so I can fine tune the depth with shims after I get it close. The ring gear also has room for shims, I shimmed it where it was in the grinder for a starting point.
The problem is I need my lathe to make more shims but if I take the housing out I'll never get it back to where it was...... need another lathe.
Also, anyone have any ideas on how to put a load on this thing for testing? What can suck up about 8 horsepower at about 18,000 rpm?
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gearbox
Sept 11, 2011 13:19:56 GMT -5
Post by ernie wrenn on Sept 11, 2011 13:19:56 GMT -5
Chris
I have 7 lathes....
2nd question:I have a high pressure fan, not sure what the load factor but it is a strong unit. I also have 2 huffers on top of the conx box.
ernie
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gearbox
Sept 12, 2011 15:18:45 GMT -5
Post by turbochris on Sept 12, 2011 15:18:45 GMT -5
gearbox done. I did manage to get a pattern on the gears. It seems the faces of the gear teeth kind of bulge out as the contact patch is pretty small. Shims move the patch around but not that much. It seems these gears were designed to be able to run without critical setup of the gear mesh. i spun it up with the air hose and loaded the shaft a little with a rag in my hand, it sounds like a jet powered grinder. I have more work to do to this but the overall shape is done and now I can mock it up in the project. Then I think I have to modify the exhaust duct.
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gearbox
Sept 12, 2011 17:56:46 GMT -5
Post by pitciblackscotland on Sept 12, 2011 17:56:46 GMT -5
Hi Chris, nice work. Is the lubrication system going to be a sump type splash system?
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gearbox
Sept 12, 2011 19:32:38 GMT -5
Post by turbochris on Sept 12, 2011 19:32:38 GMT -5
the lube system- I copied the Wren turboprop setup. The hot N2 bearing is ceramic and gets a fuel/oil/compressor air mist. after the ceramic bearing there's a seal and then the second N2 bearing. The second N2 bearing along with all the gears and bearings with the exception of the output shaft bearing run in an automatic transmission fluid bath. I made my gearcase larger just to get some internal volume. Internal volume and oil control and rpm are a compromise in a splash system. The output shaft bearing is a sealed bearing. My gearbox uses the exact same setup. I used bearings from the grinder on the ring gear shaft, I'm going to spin them and the gears from the grinder about 2 or 3 times faster than they were meant to spin but only once in a while. I think about what I do to my 5 inch grinder and these gears are from a 7 inch grinder so I think they'll hold up fine. I'll run it a little and check the bearings and creep on on the power and make sure nothing is staring to give.
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jamiep
Veteran Member
Joined: November 2010
Posts: 102
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gearbox
Dec 3, 2013 11:59:35 GMT -5
Post by jamiep on Dec 3, 2013 11:59:35 GMT -5
nice! what is the reduction on the gearbox? what would it cost to machine something like that? Looking at all my options for my freepower turbine... jamie
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