Generac Power Systems OHVI GSH 190, Руководство по обслуживанию

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SeCTIoN 4: MeCHANICAl GoverNor
GoverNor oPerATIoN
. The GOVERNOR SPRING tends to pull the LEVER and GOV-
ERNOR ROD toward the "INCREASE RPM" direction.
2. As engine speed increases, centripetal force acts on the
FLYWEIGHT. When FLYWEIGHT centripetal force exceeds
SPRING force, the governor SPOOL is moved axially by
FLYWEIGHT force. This causes the GOVERNOR ARM to
rotate, which then moves the LEVER and GOVERNOR ROD
toward a "DECREASE RPM" direction.
. As engine speed decreases, a point is reached where gov-
ernor SPRING force is greater than FLYWEIGHT centripetal
force. SPRING force then moves the LEVER and GOVER-
NOR ROD toward "INCREASE RPM."
. Governor action consists of a series of small rpm over-
shoots and undershoots, as SPRING force increases rpm
and FLYWEIGHT centripetal force decreases rpm.
5. The point at which SPRING tension and FLYWEIGHT force
are equal is the governed speed of the engine.
SPOOL
FLYWEIGHT
CRANKSHAFT
(PTO END)
CRANKSHAFT
GEAR
GOVERNOR
GEAR
TO THROTTLE LINK
DECREASE RPM
INCREASE RPM
CENTRIPETAL
FORCE
SHAFT
SPRING
SPEED
ADJUST
Figure 4-1. Governor Operating Diagram
GoverNor INTerNAl PArTS
See Figure -2. A governor gear shaft is pressed into a bore
in the engine crankcase cover. Internal governor components
include (a) a THRUST WASHER, (b) GOVERNOR GEAR ASSEM-
BLY, (c) SNAP RING, (d) GOVERNOR SPOOL, and (e) GOVERNOR
ARM. A lock pin and washer retain the governor arm in the
crankcase cover.
The governor gear assembly houses the governor fly-
weights.
Flyweight movement causes the spool to move axially. In
turn, axial movement of the spool results in rotation of the
governor arm.
GOVERNOR
GEAR SHAFT
THRUST
WASHER
GOVERNOR
GEAR ASSEMBLY
GOVERNOR SPOOL
GOVERNOR ARM
SNAP RING
WASHER
LOCK PIN
Figure 4-2. Internal Governor Parts
GoverNor eXTerNAl PArTS
WITHOUT AUTOMATIC IDLE CONTROL:
External governor parts for units without automatic idle
control are shown in Figure -. Parts include (a) a GOVER-
NOR LEVER, (b) a GOVERNOR ROD, (c) ANTI-LASH SPRING,
(d) a SPEED ADJUST BOLT, (e) a SPEED ADJUST NUT, and (f) a
GOVERNOR SPRING.
The governor lever is clamped to the governor arm, so that
arm rotation is imparted to the lever. The governor rod con-
nects to the governor lever at one end and to the carburetor
throttle arm at it's other end. Governor spring tension is adjust-
able by means of the speed adjust bolt and nut.
Engine speed can be adjusted by changing the tension of
the governor spring. Governor spring
tension can be changed
by turning a locknut on the governor adjusting bolt.
SPEED
ADJUST
NUT
SPEED
ADJUST
SCREW
GOVERNOR
SPRING
GOVERNOR
LEVER
GOVERNOR
LEVER CLAMP
BOLT
GOVERNOR
ARM
GOVERNOR
ROD
ANTI-LASH
SPRING
Figure 4-3. External Governor Parts
(Units without Idle Control)
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