Generac Power Systems 941-2 - Manual (Page 14)

Section 1.2
MAJOR GENERATOR COMPONENTS
ROTOR HUB
See Figure 2 on previous page. The Rotor Hub is bal-
anced with the Rotor and must be replaced with the
Rotor as an assembly. Part of the engine ignition sys-
tem is pressed onto the Hub and can be replaced
only as part of the Rotor and Hub assembly.
STATOR RETAINING RING
The Stator Retaining Ring is made of die-cast alu-
minum. Four hex head capscrews with lockwashers
pass through holes in the Retaining Ring, to retain
the Stator Assembly to the Stator Adapter (Item 7,
Figure 1).
STATOR ASSEMBLY
The 2-phase Stator is made up of six (6) windings,
with leads brought out as shown in figure 4. Figure 5
is a schematic representation of each stator winding.
Note that there are two (2) power phase windings
(Leads AC1, AC2, SL1 and SL2 ); a timing winding
(Leads TIM1 and TIM2); a power supply winding
(Leads PSI, PS2); and a dual battery charge winding
(Leads 55, 66, 77).
STATOR ADAPTER
The Adapter is retained to the engine by means of
four hex head capscrews. The Stator is retained to
the Stator Adapter and is "sandwiched" between the
Adapter and the Stator Retaining Ring.
LOWER FAN & FLYWHEEL
The Lower Fan and Flywheel are retained to the
engine PTO shaft by means of a conical washer and
an M16-1.50 hex nut. When assembling, tighten the
flywheel nut to 75 foot-pounds.
ENGINE
The engine is a single cylinder, 220 cc, overhead
valve type manufactured by Generac® Power
Systems, Inc.
STEPPER MOTOR
The Stepper Motor (Figure 3) consists of a stepper
motor along with a gear and cam arrangement which
allows motor movement to change the engine carbu-
retor throttle setting. The Motor is controlled by output
signals from the Computer Control Circuit Board,
which calculates the number of steps the stepper
needs to take and generates the required signals to
the Motor. The circuit board signals the Motor to actu-
ate in response to changes in AC output voltage.
Thus, in response to decreasing AC output voltages,
the Motor will increase the throttle setting and engine
speed will increase. Conversely, Increasing AC out-
put voltages will cause the Motor to decrease throttle
setting and engine speed will decrease.
Figure 3. The Stepper Motor
Figure 4. Stator Pictorial View
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