Alternator Nomenclature; Regulator Components (Lamar); Brush Installation Diagram - Piper Navajo Chieftain PA-31-350 Service Manual

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ALTERNATOR
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VIEW SIDE VIEW
Figure 1 1-16. Brush Installation
Figure 11-17. Internal Wiring
Diagram
11-17. ALTERNATOR
NOMENCLATURE.
a. Bearings: These units have a sealed ball bearing at the drive end and a two-piece roller bearing at
the slip ring end. The inner race is pressed onto the rotor shaft and the rest of the bearing is in the slip ring
end head. When the unit is assembled, the inner race aligns with the bearing. When the bearing is replaced.
PIN
END VIEW
SIDE VIEW
Figure 11-16. Brush Installation
Figure 11-17. Internal Wiring shaft.
Diagram
11-17. ALTERNATOR NOMENCLATURE.
a. Bearings: These units have a sealed ball bearing at the drive end and a two-piece roller bearing at
the slip ring end. The inner race is pressed onto the rotor shaft and the rest of the bearing is in the slip ring
end head. When the unit is assembled, the inner race aligns with the bearing. When the bearing is replaced.
the new inner race must be installed on the rotor shaft.
b. Lubrication: The slip ring end bearing should be lubricated whenever the alternator is
disassembled. The bearing should be thoroughly cleaned and repacked with Shell Alvania No. 2 or an
equivalent bearing lubricant. The cavity behind the bearing should be packed one-third to one-half full with
the same lubricant.
c. Brushes: These units have a separate brush holder assembly that is installed after the alternator
has been assembled. The brush holder has a small hole that intersects the brush cavities. Use a pin or a piece
of wire. as shown in Figure 11-16, to hold the brushes in the holder during assembly. Remove the pin after
the brush holder retaining screws have been tightened. Make a continuity check to be sure the brushes are
seated against the slip rings.
d. Drive Pulley: Torque the drive pulley retaining nut to 35 foot-pounds.
e. Ventilation: These units use a slip ring end cover that has a hose type connection for air pressure
ventilation. Remove this cover when bench testing the alternator.
11-18. REGULATOR.
11-19. REGULATOR COMPONENTS (Lamar). Alternator output voltage can, within the limits of the
design capability of the alternator, be controlled by properly varying the average level of current flow in the
rotor winding. The LAMAR solid state electronic regulator is well suited for this purpose. The alternator.
due to its design, has self-limiting current characteristics and therefore needs no current-limiting element in
the regulator.
a. Transistor: The transistor (Symbol "Q") is an electronic device which can control the flow of
current in an electrical circuit. It has no mechanical or moving parts to wear out.
b. Rectifier Diode: The rectifier diode (Symbol "D") will pass current in only one direction
(forward direction); and in this respect it may be compared to a check valve.
c. Zener Diode: The zener diode (Symbol "Z") in addition to passing current in the forward
Reissued: 9/23/80
ELECTRICAL SYSTEM
NAVAJO CHIEFTAIN SERVICE MANUAL
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