ARM ASSEM. 2S9008 - Caterpillar

Alternators (7T2095 And 7T2096)
7T2095 And 7T2096 Alternators
(1) Slip rings. (2) Fan. (3) Stator assembly. (4) Rotor assembly. (5) Brush and holder assembly.The alternator is a three phase, self-rectifying charging unit that is driven by V-belts. The only part of the alternator that has movement is the rotor assembly. Rotor assembly (4) is held in position by a ball bearing at each end of the rotor shaft.The alternator is made up of a front frame at the drive end, rotor assembly (4) stator assembly (3), rectifier assembly, brushes and holder assembly (5), slip rings (1) and rear end frame. Fan (2) provides heat removal by the movement of air through the alternator.Rotor assembly (4) has field windings (wires around an iron core) that make magnetic lines of force when direct current (DC) flows through them. As the rotor assembly turns, the magnetic lines of force are broken by stator assembly (3). This makes alternating current (AC) in the stator. The rectifier assembly diodes that change the alternating current (AC) from the stator to direct current (DC). Most of the DC current goes to charge the battery and make a supply for the low amperage circuit. The remainder of the DC current is sent to the field windings through the brushes.The voltage regulator is not fastened to the alternator, but is mounted separately and is connected to the alternator with wires. The regulator is a solid state (transistor, stationary parts) electronic switch. It feels the voltage in the system and switches on and off many times a second to control the field current (DC current to the field windings) for the alternator to make the needed voltage output. There is a voltage adjustment for this regulator to change the alternator output.Alternator (9G4574, 8T9700 And 100-5045)
9G4574, 8T9700 And 100-5045) Alternator Components
(1) Fan. (2) Front frame assembly. (3) Stator assembly. (4) Rotor assembly. (5) Field winding (coil) assembly. (6) Regulator assembly. (7) Condenser (suppression capacitor). (8) Rectifier assembly. (9) Rear frame assembly.The alternator has three-phase, full-wave rectified output. It is brushless. The rotor and bearings are the only moving parts.When the engine is started and the rotor turns inside the stator windings, three-phase alternating current (AC) and rapidly rising voltage is generated.A small amount of alternating current (AC) is changed (rectified) to pulsating direct current (DC) by the exciter diodes on the rectifier assembly. Output current from these diodes adds to the initial current which flows through the rotor field windings from residual magnetism. This will make the rotor a stronger magnet and cause the alternator to become activated automatically. As rotor speed, current and voltages increase, the rotor field current increases enough until the alternator becomes fully activated.The main battery charging current is charged (rectified) from AC to DC by the other positive and negative diodes in the rectifier and pack (main output diodes) which operate in a full wave linkage rectifier circuit.The voltage regulator is a solid state electronic switch. It feels the voltage in the system and gives the