PULLEY AS-IDLER 2644441 - Caterpillar

Illustration 1 g00670044
21-SI Sectional viewComponents (1) Brush holder (2) Rotor (3) Slip rings (4) Fan (5) Rear frame (6) Rectifier (7) Stator (8) Drive end frame
Illustration 2 g00670055
21-SI inside view of rear frameComponents (1) Brush holder (5) Rear frame (6) Rectifier (7) Stator (9) Capacitor (10) Regulator (11) Diode assemblyRotor
Illustration 3 g00670083
(2) Rotor (3) Slip ringsThe rotor (2) consists of a core, a field winding, and a shaft. The rotor provides the magnetic field between the rotor field winding and the stator. The slip rings (3) provide the surfaces for the brushes (12) to contact.Stator
Illustration 4 g00670090
(7) StatorThe stator (7) consists of a stator core and windings. As the rotor turns, a varying magnetic field causes the stator coil to produce three-phase AC voltage.Brush Holder
Illustration 5 g00670098
(1) Brush holder (12) BrushesThe brush holder (1) contains two brushes (12). The two brushes contact the two slip rings that are located on the rotor shaft. Current flows to the rotor coil through the contact between the brushes (12) and the slip rings (3). One brush is positive, and one brush is negative. The brush material is graphite.Rectifier
Illustration 6 g00670102
(6) RectifierThe rectifier (6) contains three positive diodes and three negative diodes. The six diodes form the three-phase full wave rectifier that is connected to the stator. The rectifier (6) changes the AC voltage that is produced by the stator to DC voltage.Capacitor
Illustration 7 g00670112
(9) CapacitorThe capacitor (9) performs the following tasks:
The capacitor protects the rectifier from high transient voltages.
The capacitor protects the diode assembly from high transient voltages.
The capacitor smooths the output of the rectifier.
The capacitor reduces electrical noise.The capacitor (9) is mounted in the back of the alternator on the rectifier.Diode Assembly
Illustration 8 g00670114
(11) Diode AssemblyThe diode assembly (11) contains three diodes. The diode assembly rectifies the output of the stator. The rectified output of the stator is used to energize the field coil. The diode assembly (11) is located on the rectifier.Regulator
Illustration 9 g00670115
(10) RegulatorThe regulator (10) limits the output of the alternator to a preset value by controlling the current through the field coil. The regulator electronically switches the connection between the field coil and ground. The switching occurs at rates between 10 hertz and 7000 hertz.