Starlight Power will share the overhaul and treatment method of crankshaft of diesel generator set. if you are interested, please continue to read.
Crankshaft is the most
important part of diesel generator set. Due to the complex stress and working
conditions of crankshaft, the sliding speed of each friction surface is very
high, and the heat dissipation condition is poor. Therefore crankshaft journals
is easily wear, bent and distorted, even cracks or breaks, etc. Once crankshaft
has fault, it will affect the working efficiency of diesel generators. So
overhaul is a very important maintenance step.
Overhaul
and treatment method of crankshaft crack
The cracks on the
crankshaft are very fine, which can not be easily seen by the naked eye. The
magnetic flaw detector can be used for inspection.
When conditions are not
available, the simple way is:
First immerse the
crankshaft in kerosene for a moment, take it out and wipe it, then sprinkle it
with white powder. Then knock on the crankshaft arm in sections with a hammer.
Due to the vibration, the kerosene in the crack seeps out, making the white
powder show the yellow oil stains. The crack position and length can be
determined.
Overhaul
and treatment of crankshaft deformation
The obvious part of
crankshaft bending deformation is the middle main journal. If the crankshaft
continues to be used after bending and deformation, it will cause crankshaft
connecting rod structure fast wear and tear, even make crankshaft cracked and
broken. Therefore in the repair process of diesel engine, inspection must be
done.
When inspecting, both
ends of the crankshaft shall be supported on the V-shaped frame on the
platform, and the contact of the dial indicator shall be put against the middle
main journal to avoid the oil hole. Slowly turn round the crankshaft for one
revolution, observe the maximum and minimum values indicated on the dial
indicator. One half of the difference between the two values is the
straightness of the crankshaft. If the crankshaft has partial wear, the amount
of partial wear should be subtracted. When the straightness is within the range
of 0.05 ~ 0.10mm, we can combine with journal grinding to make corrections.
The
test method of crankshaft angle of torsion
Support the crankshaft
horizontally on the platform, make the two journals of the same connecting rod
at the top dead center. Then use a dial indicator to measure the height
difference between the front and rear connecting rod journals at their highest
points. The greater the difference, the greater the torsional angle.
The main journal and
connecting rod journal of crankshaft will inevitably produce wear and tear in
work, and the wear is uneven. Its main performance is the roundness of the
journal, cylindricity exceeding the standard value and strain. The most worn
part of connecting rod journal is generally on the inner side of each journal,
that is, the side close to the crankshaft centerline. However, the parts that
are worn into a cone are generally on the side where impurities are attached to
the lubricating oil passage and on the parts with large stress. The worn parts
of crankshaft main journal are different according to the strengthening degree
of engine, the number of cylinders, the length of crankshaft and the balance
weight. And wear is more uniform relative to the connecting rod journal. The
practice shows that the wear of connecting rod journal is faster than that of
main journal. However, consequences of journal wear is more serious than that
of connecting rod journal.
Inspection and treatment
methods: find out the worn parts according to the wear law of each journal.
Roundness and cylindricity can be measured by external micrometer to determine
the repair level and grinding dimension of crankshaft.
Hope this article is
helpful to you. Starlight Power is a manufacturer of diesel generators and has
focused on high quality product for more than 43 years. We have a very
professional sales team and after-sales service team. If you are interested,
please contact us by email sales@dieselgeneratortech.com, we will work with
you.
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