11-5. ALTERNATOR AND COMPONENTS
a. The brush and holder assembly contains two brushes, two brush springs, a brush holder and insulator. One
brush is connected to a terminal stud and is insulated from ground. The other brush is connected to ground thru
the brush holder. The brush and holder assembly can easily be removed for inspection or brush replacement
purposes.
b. The slip ring end head provides the mounting for the rectifiers and rectifier mounting plate, output and
auxiliary terminal studs, and the brush and holder assembly. The slip ring end head contains a roller bearing and
outer race assembly and a grease seal.
c. The rectifiers used in these units are rated at 150 peak inverse voltage (PIV) minimum for transient voltage
protection. Three positive rectifiers are mounted in the rectifier mounting plate while the three negative rectifiers
are mounted in the slip ring end head. Each pair of rectifiers is connected to a stator lead with high temperature
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 connected to the center of the three phase windings. The stator
has been treated with a special epoxy varnish for high temperature resistance.
e. The rotor contains the slip ring end bearing inner race and spacer on the slip ring end of the shaft. The
rotor winding and winding leads have been specially treated with a high temperature epoxy cement to provide
vibration and temperature resistance characteristics. High temperature solder is used to secure the winding leads
to the slip rings.
f. The drive end head supports a sealed, prelubricated ball bearing in which the drive end of the rotor shaft
rotates
1240
1. BRUSH HOLDER
2. SLIP RING END HEAD
3. RECTIFIERS
4. STATOR
5. ROTOR
6. DRIVE END HEAD
.Figure 11-3 Exploded View of Alternator
PIPER AIRCRAFT
PA-28-161 CADET
AIRPLANE MAINTENANCE MANUAL
Issued: FEBRUARY. 28, 1989
ELECTRICAL SYSTEM
2C24