MAN B&W L28/32H, Руководство пользователя

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08028-0D/H5250/94.08.12
Mechanical Overspeed
01.01
L28/32H
1643414-2.1
Page 1 (1)
Mechanical Overspeed
The engine is protected against overspeeding in the
event of, for instance, governor failure by means of
an overspeed trip.
The engine is equipped with a stopping device which
starts to operate if the maximum permissible revo-
lution number is exceeded.
The overspeed tripping device is fitted to the end
cover of the lubricating oil pump and is driven through
this pump.
If the pre-set tripping speed is exceeded, the spring-
loaded fly weight (1), see fig 1, will move outwards
and press down the arm (2).
The arm is locked in its bottom position by the lock
pin (3) which is pressed in by the spring (4).
B 19 06 1
At the same time the arm (2) presses down the
spindle (5), and the pneumatic valve (6) opens,
whereby compressed air will be led to the stop
cylinder, (see also B 17 30 1) in which the piston is
pressed forward and, through the arm, turns the fuel
pump regulating shaft to STOP position. Thereby the
engine stops, the spring-loaded pull rod connection
to the governor being compressed.
The engine can be stopped manually by pressing
down the button (7), which will activate the spring-
loaded fly weight (1) through the lever (8).
If the overspeed has been activated, the overspeed
must be reset before the engine can be started.
Reset is done by means of the button (10).
Overspeed Alarm (SAH 81)
The overspeed alarm (SAH 81) is activated by
means of the micro switch (9).
Fig 1 Mechanical overspeed.