VuckoH
Član
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- 11 Svi 2015
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S vremenom tlak ulja pada radi većih zazora, a ne obratno
Na nekim motorima to nije slučaj,ali svakako sam se krivo izrazio,mislio sam na "izbacivanje ulja ispod ležaja"
Evo nešto što bi moglo objasnit problem na traktorima koji troše više ulja, naravno uz potrošene karike.
Worn or Damaged Main Bearings
Worn or damaged main bearings throw off an excessive amount of oil
which flows along the crankshaft and is thrown up into the cylinders. The
amount of oil throw off increases rapidly when bearing wear increases.
For instance, if the bearing is designed to have .0015” clearance for
proper lubrication and cooling, the throw off of oil will be normal as long
as this clearance is maintained and the bearing is not damaged in any
way. However, when the bearing clearance increases to .003”, the throw
off will be five times normal. If the clearance is increased to .006”, the
throw off will be twenty-five times normal. When the main bearings throw
off too much oil, the cylinders are usually flooded with more oil than can
be controlled by the pistons and rings. This causes burning of the oil in the combustion chamber and
carboning of pistons and rings.
In a conventional, full-pressure lubricated engine a large loss of oil at the main bearings may starve the
downstream connecting rod bearings of lubrication to such an extent that sometimes, especially at low speeds,
insufficient oil may be thrown on the cylinder walls. This will cause the pistons and rings to wear to such an
extent that they will not be able to control the oil at high speeds. The effect of main bearing wear will be high
oil consumption.
Worn or Damaged Connecting Rod Bearings
Clearances on connecting rod bearings affect the throw off of oil in the same proportions as mentioned for main
bearings. In addition to this, the oil is thrown more directly into the cylinders. Worn or damaged connecting
rod bearings flood the cylinders with such a large volume of oil that the pistons and rings, which are designed
to control a normal amount of oil or a reasonable increase in the normal amount, are overloaded to such an
extent that some oil escapes past them to the combustion chamber and causes high oil consumption.
CAUTION - Insufficient bearing clearance can also produce piston, ring and cylinder damage as well as
damage to the bearing itself.
https://www.amsoil.com/techservicesbulletin/MotorOil/TSB MO-2004-04-03 Oil Consumption.pdf