ADAPTER-EXHAUST 2909931 - Caterpillar

Charging System Components
Alternator
The alternator is driven by a belt from the crankshaft pulley. This alternator is a three-phase, self-rectifying charging unit, and the regulator is part of the alternator. The alternator design has no need for slip rings or brushes, and the only part that has movement is the rotor assembly. All conductors that carry current are stationary. The following conductors are in the circuit:
Field winding
Stator windings
Six rectifying diodes
Regulator circuit componentsThe rotor assembly has many magnetic poles that look like fingers with air space between each of the opposite poles. The poles have residual magnetism. The residual magnetism produces a small magnetic field between the poles. As the rotor assembly begins to turn between the field winding and the stator windings, a small amount of alternating current (AC) is produced. The AC current is produced in the stator windings from the small magnetic field. The AC current is changed to direct current (DC) when the AC current passes through the diodes of the rectifier bridge. The current is used for the following applications:
Charging the battery
Supplying the low amperage circuit
Strengthening the magnetic fieldThe first two applications use the majority of the current. As the DC current increases through the field windings, the strength of the magnetic field is increased. As the magnetic field becomes stronger, more AC current is produced in the stator windings. The increased speed of the rotor assembly also increases the current and voltage output of the alternator. The voltage regulator is a solid-state electronic switch. The voltage regulator senses the voltage in the system. The voltage regulator switches ON and OFF many times per second in order to control the field current for the alternator. The alternator uses the field current in order to generate the required voltage output.
Never operate the alternator without the battery in the circuit. Making or breaking an alternator connection with heavy load on the circuit can cause damage to the regulator.
Illustration 1 g00425518
Typical alternator components (1) Regulator (2) Roller bearing (3) Stator winding (4) Ball bearing (5) Rectifier bridge (6) Field winding (7) Rotor assembly (8) FanStarting System Components
Starting Solenoid
Illustration 2 g00317613
Typical starting solenoidThe starting solenoid is an electromagnetic switch that performs the following basic operations:
The starting solenoid closes the high current starting motor circuit with a low current start switch circuit.
The starting solenoid engages the starter motor pinion with the ring gear.The solenoid has windings (one or two sets) around a hollow cylinder. A spring loaded plunger (core) is inside of the cylinder. The plunger can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is made. The magnetic field pulls the plunger forward in the cylinder. This moves the shift lever in order to engage the pinion drive gear with the ring gear. The front end of the plunger then makes contact across the battery and motor terminals of the solenoid. Next, the starting motor begins to turn the flywheel of the engine. When the start switch is opened,