|
Post by enginewhisperer on Mar 6, 2015 0:23:17 GMT -5
yeah it looks pretty nice! I've never seen it before, but it came up while looking for speed sensors The 36psi pressure sensor is a bit limiting, but you can probably run a different sensor on it and adjust the calibration.
|
|
|
Post by frankenhealey on Mar 6, 2015 8:13:35 GMT -5
Anders,
Can I ask what is the max. rpm and power your bevel gearbox is designed to take please?
Cheers,
Ian
|
|
|
Post by Johansson on Mar 6, 2015 8:45:29 GMT -5
yeah it looks pretty nice! I've never seen it before, but it came up while looking for speed sensors The 36psi pressure sensor is a bit limiting, but you can probably run a different sensor on it and adjust the calibration. It had a decent price tag on it as well, too bad that the logging function can´t handle more sensors than the three ones used for the display. Anders, Can I ask what is the max. rpm and power your bevel gearbox is designed to take please? Cheers, Ian The gearbox max pinion revs are 3000rpm, so I am planning to overrev it 11 times... Luckily the ceramic bearings and oil jet lubrication helps out a bit, seems to hold together just fine so far.
|
|
|
Post by frankenhealey on Mar 6, 2015 9:02:20 GMT -5
I have the same problem obviously and have found a 6:1 reduction gearbox using hardened helical gears for £330. Maximum input is also 3000 rpm and max power is 16HP. For the cost of me designing and producing a 150HP @ 47k rpm gearbox I could just be like the drag racing guys and use them as 2-3 runs disposable items. I was very impressed with the lack of wear on your bevel box!
|
|
|
Post by racket on Mar 6, 2015 15:18:11 GMT -5
Hi Frankenhealey With gearboxes its about torque loading of the teeth , your 16HP at 3,000 rpm equates to 28 ft lbs of torque , 28 ft lbs of torque at 47,000 rpm equates to 250 HP , your gearbox is plenty strong enough , now assuming you have 150 hp at 47,000 rpm, the torque will be only ~17 ft lbs, but with a stalled freepower turbine with a 2:1 torque multiplication , the gearbox will experience ~34 ft lbs , only a 20% overload , thats nothing , the gearbox probably has at least a 100% safety margin as standard . The transmission I made up for jetandturbineowners.proboards.com/thread/34/motorcycle-project uses 6.125:1 helical David Brown gears from a Textron MO812 Model electric motor gearbox( single reduction) rated at 18 hp at 2,900 rpm , this has an ~200 hp capacity at our 32,000 rpm freepower max , ............just right :-) I know its more complicated than this , but the teeth will be strong enough , its just a matter of solid oil jet lubrication to the gear mesh otherwise they'll run dry at high rpm if in just an oil bath, there's also the matter of pinion shaft bearings , 47,000 rpm is getting pretty high so you'll need positive jet lubrication to the inner raceway of some high quality bearings . Cheers John
|
|
|
Post by Johansson on Mar 6, 2015 16:56:57 GMT -5
I disassembled the gearbox today and have taken a couple of more pictures of the gears for inspection. The wear on the pinion is even and very shallow, it is difficult to take pictures of shiny surfaces but I can´t see that the teeths are worn more in any certain location. The larger sprocket has also a very even wear pattern, the darker radius on the left on the teeths isn´t visibly worn more but only a difference in colour. You can see the original surface between the teeths where there are stains of rust, higher up the teeths are evenly worn all along their lengths. For a novice such as I the wear looks pretty acceptable, but please comment if you have an opinion. I figured out a better way to lock the freepower turbine centrum bolt in place, earlier there was a hole drilled through the bolt head but it was a pain in the arse to get all four holes to align so I grinded a slot in the bolt head instead. Finally I have found a reason for the massive oil leakage during running, earlier this winter I ruptured the tank during a run thanks to an overly restrictive oil tank ventilation hose. I must have overlooked one crack because while pressure testing the tank I found a >10cm long crack in a weld on the side of the tank. I had pretty much filled the tank with oil before the race, and when the oil was being forced rearwards during acceleration the oil must have sprayed out through the crack. I have never had a leak during static running and if the leak was internal as I believed up until now the engine should have smoked like mad, everything points towards an external leak and I think I just found it! Cheers! /Anders
|
|
|
Post by racket on Mar 6, 2015 17:21:26 GMT -5
Hi Anders
Gears look OK , turbine wheel seems fine , no "funny" colouration.
Ah , split tank , now that looks promising , you might find that you'll need to leave plenty of "air space" in the tank for any frothing of the oil, otherwise frothed up oil will be trying to force out your tank breather, frothy oil won't pass through the breather as easily as just air so there could be some repressurisation of the tank exacerbating the leak from the split . ...............LOL, that was a quick fix of your "engine" oil leak :-)
All looking good .
Cheers John
|
|
|
Post by frankenhealey on Mar 6, 2015 17:40:57 GMT -5
Hi Frankenhealey With gearboxes its about torque loading of the teeth , your 16HP at 3,000 rpm equates to 28 ft lbs of torque , 28 ft lbs of torque at 47,000 rpm equates to 250 HP , your gearbox is plenty strong enough , now assuming you have 150 hp at 47,000 rpm, the torque will be only ~17 ft lbs, but with a stalled freepower turbine with a 2:1 torque multiplication , the gearbox will experience ~34 ft lbs , only a 20% overload , thats nothing , the gearbox probably has at least a 100% safety margin as standard . The transmission I made up for jetandturbineowners.proboards.com/thread/34/motorcycle-project uses 6.125:1 helical David Brown gears from a Textron MO812 Model electric motor gearbox( single reduction) rated at 18 hp at 2,900 rpm , this has an ~200 hp capacity at our 32,000 rpm freepower max , ............just right :-) I know its more complicated than this , but the teeth will be strong enough , its just a matter of solid oil jet lubrication to the gear mesh otherwise they'll run dry at high rpm if in just an oil bath, there's also the matter of pinion shaft bearings , 47,000 rpm is getting pretty high so you'll need positive jet lubrication to the inner raceway of some high quality bearings . Cheers John John, Thanks for the confirmation. I'm pretty excited about not having to build my own 'box. Cheers, Ian
|
|
|
Post by Johansson on Mar 6, 2015 17:59:48 GMT -5
Hi Anders Gears look OK , turbine wheel seems fine , no "funny" colouration. Ah , split tank , now that looks promising , you might find that you'll need to leave plenty of "air space" in the tank for any frothing of the oil, otherwise frothed up oil will be trying to force out your tank breather, frothy oil won't pass through the breather as easily as just air so there could be some repressurisation of the tank exacerbating the leak from the split . ...............LOL, that was a quick fix of your "engine" oil leak :-) All looking good . Cheers John Hi John, Yup, promising indeed. It made me wonder a bit since oil has ended up all the way up front over the gas producer and fuel tank, but I guess there is no telling how the winds move around inside a motorcycle frame at 200km/h. I´ll skip the bleed valve modification for now, first I want to confirm that this was the only cause for the leak. It can be made later without having to remove the engine from the frame if I need to. The turbine wheel, NGV and everything else for that matter look fine, can´t believe I can assemble the engine again without having to redesign something. I am very tempted to buy the Road Rage Gages SBT+1 kit that Enginewisperer linked to, I get RPM, TOT and P2 plus a second pressure sensor on a small screen that logs to a microSD card and can easily be read in Excel. 500 euros for the SBT+1 kit and a BorgWarner Turbo speed sensor, not bad at all considering thats probably what a 4 channel data logger would cost me without the dashboard or tacho sensor. www.roadragegages.com/SBTp1.htmlCheers! /Anders
|
|
|
Post by racket on Mar 6, 2015 19:15:46 GMT -5
Hi Anders
LOL, yeh , there can be some strange air movements behind a fairing at that speed.
Nothing broke .................heh heh , you weren't trying hard enough , more fuel more fuel ;-)
Electronics ...............I just don't understand them , my mind goes blank once I start reading the specs sheet , I have trouble retuning my TV set , but 500 euros does sound pretty good :-)
Cheers John
|
|
mitch
Senior Member
Joined: August 2014
Posts: 285
|
Post by mitch on Mar 7, 2015 9:50:26 GMT -5
Anders, you may want to adjust your pinion depth to get a slightly lower contact on your ring gear teeth. Just my opinion, as I have taken a class that dealt with manual drive lines and differentials.
Everything else looks good though!!
|
|
|
Post by Johansson on Mar 7, 2015 9:52:44 GMT -5
Hi Mitch,
So I need to tighten up the play so to speak? During assembly I had an idea that I needed a bit larger play than normal since the pinion shaft gets lots of heat from the turbine wheel and might grow a bit thus tightening up the play during running.
/Anders
|
|
mitch
Senior Member
Joined: August 2014
Posts: 285
|
Post by mitch on Mar 7, 2015 10:20:51 GMT -5
Gear toward pinion It isn't so much "play" in the pinion I think, I would say try moving the gear a bit closer to the pinion. It may take a bit of tweaking to get it right, but based on a few pictures I have seen regarding pinion/ ring gear depth and wear patterns, your best bet would be to start off by moving the gear toward the pinion. Hope that helps, I'm glad to help where I can!
|
|
|
Post by Johansson on Mar 7, 2015 10:23:11 GMT -5
Hi Anders LOL, yeh , there can be some strange air movements behind a fairing at that speed. Nothing broke .................heh heh , you weren't trying hard enough , more fuel more fuel ;-) Electronics ...............I just don't understand them , my mind goes blank once I start reading the specs sheet , I have trouble retuning my TV set , but 500 euros does sound pretty good :-) Cheers John Hi John, Hopefully the summer track is a bit less bumpy, with a tachometer fitted I can run the engine to 100% and still be able to keep both wheels on the ground during the run. I have actually started to appreciate electronics a bit, perhaps the idea of a data logger broke the ice so to speak... Cheers! /Anders
|
|
|
Post by Johansson on Mar 7, 2015 10:42:16 GMT -5
Gear toward pinion It isn't so much "play" in the pinion I think, I would say try moving the gear a bit closer to the pinion. It may take a bit of tweaking to get it right, but based on a few pictures I have seen regarding pinion/ ring gear depth and wear patterns, your best bet would be to start off by moving the gear toward the pinion. Hope that helps, I'm glad to help where I can! Thanks for the suggestion Mitch, I´ll play around with the gearbox a bit to get a feeling on how much there is to adjust.
|
|