Sinänsä laakereiden kannalta matalat kierrokset ja suuri vääntö on myrkkyä. Mutta missä se raja sitten oikein mahtaa mennä että mitkä lasketaan mataliksi kierroksiksi?
Factors affecting normal functioning of engine bearings:
Properties of engine bearing materials:
Fatigue strength (load capacity)
Seizure resistance (compatibility)
Wear resistance
Conformability
Embedability
Corrosion resistance
Cavitation resistance
Bearings dimensions:
Diameter
Length
Thickness
Oil clearance
Parameters of the internal combustion engine, which determines functioning conditions of the bearings:
The engine type (gasoline, diesel with direct fuel injection, diesel with indirect fuel injection).
Compression ratio.
Rotation speed.
Aspiration type (naturally aspirated, turbocharged, supercharged).
Combustion parameters.
Lubrication system:
Oil pressure and flow rate provided by the oil pump.
Oil supply through the oil filter, oil passages and the bearings oil holes.
Level of the oil contamination.
Geometry imperfections and misalignment:
Excessive or insufficient bearing crush.
Bearing back non-conformed to the round housing bore.
Improperly ground housing bore.
Improperly ground journal (taper shape, barrel shape, hour glass shape).
Excessive fillet of the journal.
Distorted connecting rod.
Distorted crankcase.
Distorted (bent) crankshaft.
Rough Crankshaft surface.
Engine work conditions:
Work under high torque at low rotation speed (climbing) for a long period .
Work at a rotation speed beyond the upper limit.
Non-authorized “improvements” of the engine for power increase.
Properties of engine bearing materials:
Fatigue strength (load capacity)
Seizure resistance (compatibility)
Wear resistance
Conformability
Embedability
Corrosion resistance
Cavitation resistance
Bearings dimensions:
Diameter
Length
Thickness
Oil clearance
Parameters of the internal combustion engine, which determines functioning conditions of the bearings:
The engine type (gasoline, diesel with direct fuel injection, diesel with indirect fuel injection).
Compression ratio.
Rotation speed.
Aspiration type (naturally aspirated, turbocharged, supercharged).
Combustion parameters.
Lubrication system:
Oil pressure and flow rate provided by the oil pump.
Oil supply through the oil filter, oil passages and the bearings oil holes.
Level of the oil contamination.
Geometry imperfections and misalignment:
Excessive or insufficient bearing crush.
Bearing back non-conformed to the round housing bore.
Improperly ground housing bore.
Improperly ground journal (taper shape, barrel shape, hour glass shape).
Excessive fillet of the journal.
Distorted connecting rod.
Distorted crankcase.
Distorted (bent) crankshaft.
Rough Crankshaft surface.
Engine work conditions:
Work under high torque at low rotation speed (climbing) for a long period .
Work at a rotation speed beyond the upper limit.
Non-authorized “improvements” of the engine for power increase.
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