Wednesday, December 16, 2009

驴How are radial plane engines lubricated?. Doesn't the oil acumulate in the lower cylinders?

Doesn't the oil acumulate in the lower cylinders?


Where is the oil kept? Is there any kind or ';Carter';?驴How are radial plane engines lubricated?. Doesn't the oil acumulate in the lower cylinders?
this is a great question..in some of the old motors the crank did not turn ..the block and cylinders rotated around it.


in many of that type oil was a total loss system..oil was feed from a tank to the bearings ..from there centrifugal force pushed it out to the piston past the rings and it was burned..





the oil tank was filled each time the gas tank was filled驴How are radial plane engines lubricated?. Doesn't the oil acumulate in the lower cylinders?
They have a pressurized oil system which insures proper lubrication to all cylinders.
oil does accumulate when it isn't running, that is why they rotate the propeller through by hand first to assure you don't liquid lock the bottom cylinders.


The engine is lubricated by a dry sump system.
Additional info. for the bad seed.


Referring to the Gnome Rotary engine I quote the following.


The fuel air mixture entered the combustion chamber via valves installed in the top of the piston.





';Since the mixture of gas and oil filled the crankcase, normal lubrication methods would have failed because the oil would have been washed away by the fuel. The Gnome used the simpler method of inducing a steady stream of oil along with the gas and the air mixture. This ment that oil reached the combustion chambers, where it was partially burned, What didn't burn passed out with the exhaust, and since the only oil that would stand up to the heat and pressure was Castor oil, the exhaust was both aromatic and , in is own way, therapeutic.';


The above taken from ';Aircraft Piston Engines'; ';The Engine That Was Built Backwards';.
They use a dry sump oil system. The oil is drawn from a remote tank by a pressure pump to the main bearings, con rods, cam gears, pushrods, rockerarms, valves, and accessories. It is splashed from the bearings onto the pistons and cylinder walls. It is then scavenged by scavenge pumps back up to the oil tank.





When radial engines are sitting, a common occurrence is the bottom cylinders fill with oil due to gravity. This is why radial must be turned over by hand (usually between 5-10 times) before the first start of the day. This is to let the oil out through the exhaust valves so it doesn't hydraulic lock and bend a con rod or blow a cylinder.





There is an old saying about radials. If it ain't leaking oil, it doesn't have any.
yes and no. yes, oil will collect in the lower cylinders while the engine is not running. that is why, when a plane sits very long before it is started, they turn the prop by hand until it turns easily. if that is not done, you can blow tho top off the cylinder. ww2 aircraft mechanic.
centrifugal pump does the work of circulatin the flow
no
The radial engine is suseptable to hydro lock which means that fluid(in this case oil) accumulates in the lower cylinders and will not allow the engine to turn. The process of cleaning out the cylinder is to hand turn the engine backwards with the propeller. Then fire the engine before the oil leaches back into the cylinder. If you did not reverse the engine, you could bend the connecting rod, valves or blow holes in the piston or even possibly blow the jug off the motor.
they have a dual lubrication system: one brings the oil from reservoir to the various systems and the other scavenges the used oil back to tank by the oil coolers. this is only a systematic explanation and every engine has its own designed system


have a nice day
PRESSURE is a magical thing, it will make the oil go where we want it to go.

No comments:

Post a Comment