Alternator Description - Piper PA-24 Comanche Service Manual

PIPER COMANCHE SERVICE MANUAL
9-61a. Alternator And Alte,"otor Components (Prestolito).
9-6tb. Oescription Of Alternotor. (Refer to Figure 9-27a.) The principal components of the
alternator are the brush bolder assembly (1), tbe slip rinl end b.ad (2), the rectifiers (3), the
stator (4), the rotor
($)
and tbe drive end head (6).
a. The brush and holder assembly contains two brushes, two br1lSh springs. a brush holder
and insulators. Each brushis connected to a separate terminal stud and is insulated from around.
The brus h holder assembly can eu ily be removed for inapeetion or brush replacement pUfl'Oses.
b. The slip rina end head provides the lI10untinl for the rectifiers and rectifier mounting
plate, outout and au:ciliary terminal studs, and the brush and holder assembly.
7he
slip ring end
head contains a roller bearing and outer race assembly
.nd •
lrea•• s.al.
c. The rectifiers used in these units
.~
rated at 150 peak inv.,.e voltal' (PIV) minimum for
transient voltage prot.cUon. Three positive rectifiers are lDQllftted in the rectifier mountiDI plate
while
~he
three negative rectifiers are mounted
in
the slip rinl end head. Each pair of rectifiers
is connected to a stator lead with hilh temperatUle solder. The stator leads are anchored to the
rectifier mounting plate with epoxy cement for vibration protection.
d. The stator contains a special lead which
is
COlln8eted to the center of the three phase
',vindings and is used to activate low voltace warninc systema or relays. The stator has been
treated with a special epoxy varnish for hieh temperature resistanc.. .
e. The
rotOt
contains the slip rinc end beannl inner race and spacer on the slip ring end of
the shaft. The rotor windinc and winding leads have been specially treated with
Q
high tempera·
ture epoxy cemerit to prOVide vibration and temperature resistance characteristics. High
te~.
perature solder is used to secure the windinl leads to the sl ip rinas.
1260
•
•
,
2.~
':;'lI.~."
-.
....:.,.. ;!5I1:'].';-a
••
~f.,
- .
11 ::: CO
-"'-
c.
4
6
FIGURE 9·270. EXPLODED VIEW OF ALTERHATOR
ELECTRICAL SYSTEM
I~UED: 8/18172
3
820
•