KR> Reading related to Cranks and flywheels
Seems to me that all of the ?solutions? just transfers the problem away from the crankshaft, dosen?t make it go away. Whatever the propeller is connected to just has to be strong enough to never break. So the ultimate solution seems to be a stronger crankshaft to withstand the propeller vibrations. Can the Corvair crankcase bearing be bored out for a bigger journal? And can the crankshaft be modified to a larger journal? I know they can rebuild them by building up the journal with an electric welder and regrinding it.
KR> Reading related to Cranks and flywheels
Spose its too common sense for most but 'if its not broken dont fix it" thinking applies in a lot of cases! flywheels are needed (as are harmonic balancers). The suggestion from Phil re belted reduction drives is partly correct as to allowing engines to produce the designed rpm/power, but belted reductions impose side thrust on the rear main bearing. Neil Hintz (www.autoflight.co.nz) produces a PSRU that uses a flexible coupling to isolate the engine fom the reduction gears which seems to be a sound engineering approach. (the PSRU would provide some measure of flywheel inertia effect I would think). Just more fuel for the fire of debate! Vaughan Thomas Hamilton New Zealand - Original Message - From: "Glenn Martin" To: "KRnet" Sent: Wednesday, December 28, 2011 9:24 AM Subject: KR> Reading related to Cranks and flywheels Might be helpful: http://www.flat6innovations.com/broken-crank -- Glenn Martin, KR2 N1333A, Biloxi, MS ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.454 / Virus Database: 271.1.1/4105 - Release Date: 12/26/11 19:34:00
KR> Reading related to Cranks and flywheels
Running a type 4 VW with a direct drive prop at the 'right' end (from a car perspective) is considered by many (and proven by some) to be a recipe for disaster, however that's considered the correct end for a PSRU. So to answer the question, the aircraft equivalent of the auto transmission (in terms of its effect on dampening pulses) probably is the PSRU. Cheers, Tony King Queensland Australia On 28 December 2011 06:48, Barrett wrote: > Good article. The L-98 Corvette engine (and LT-1) when coupled to the > 6-speed tranny also use a dual mass flywheel, for exactly that same reason. > When switched to an aluminum flywheel- same results. Another thing too- > when > the clutch disc with spring dampeners are changed to one without the > springs, same thing happens, just takes a bit longer. The Corvettes with > auto tranny's don't have this problem as the transmission acts as the > buffer > (shock & harmonics absorber). > In our case, I'm sure the problem can be fixed by finding and fixing the > dynamics of the problem rather than the use of just brute strength (heavier > crankshaft). > > With all else being equal, do planes with constant speed props have the > same > problem? > (grasping at straws here- what would our equivalence be to the auto tranny > vs. manual gearbox) > Rubber mounted prop huh?? > Self balancing prop huh?? > More mass in the prop hub?? > 2-blade vs. 3-blade prop?? > > -Barrett > > -Original Message- > From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf > Of Glenn Martin > Sent: Tuesday, December 27, 2011 1:25 PM > To: KRnet > Subject: KR> Reading related to Cranks and flywheels > > Might be helpful: > > http://www.flat6innovations.com/broken-crank > -- > Glenn Martin, > KR2 N1333A, > Biloxi, MS > > ___ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > > > ___ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
KR> Reading related to Cranks and flywheels
Good article. The L-98 Corvette engine (and LT-1) when coupled to the 6-speed tranny also use a dual mass flywheel, for exactly that same reason. When switched to an aluminum flywheel- same results. Another thing too- when the clutch disc with spring dampeners are changed to one without the springs, same thing happens, just takes a bit longer. The Corvettes with auto tranny's don't have this problem as the transmission acts as the buffer (shock & harmonics absorber). In our case, I'm sure the problem can be fixed by finding and fixing the dynamics of the problem rather than the use of just brute strength (heavier crankshaft). With all else being equal, do planes with constant speed props have the same problem? (grasping at straws here- what would our equivalence be to the auto tranny vs. manual gearbox) Rubber mounted prop huh?? Self balancing prop huh?? More mass in the prop hub?? 2-blade vs. 3-blade prop?? -Barrett -Original Message- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of Glenn Martin Sent: Tuesday, December 27, 2011 1:25 PM To: KRnet Subject: KR> Reading related to Cranks and flywheels Might be helpful: http://www.flat6innovations.com/broken-crank -- Glenn Martin, KR2 N1333A, Biloxi, MS ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> Reading related to Cranks and flywheels
Might be helpful: http://www.flat6innovations.com/broken-crank -- Glenn Martin, KR2 N1333A, Biloxi, MS