PUMP GP-PISTON 3349990 - Caterpillar

Regulator
Illustration 2 g00360155The voltage regulator is located inside the alternator. The voltage regulator limits the voltage that is produced by the alternator at the output terminal. This is done by controlling the magnetic field that is present in the stationary field coil. The regulator allows current to flow. The current satisfies the electrical loads that are placed on the electrical system and the current charges the batteries.Starting System Components
Solenoid
A solenoid is an electromagnetic switch that performs two basic functions:
The solenoid closes the high current starter motor circuit with a low current start switch circuit.
The solenoid engages the starter motor pinion with the ring gear.
Illustration 3 g00292316
Typical solenoid schematic
The solenoid has windings (one set or two sets) around a hollow housing. A spring loaded plunger assembly is inside of the solenoid housing. The spring loaded plunger can move forward and backward. When the start switch is closed and electricity is sent through the windings, a magnetic field is created. The magnetic field pulls the spring loaded plunger forward in the housing. This moves the shift lever in order for the pinion drive gear to engage with the ring gear. The front end of the plunger then makes contact across the battery and across the motor terminals of the solenoid. The starter motor then begins to turn the flywheel of the engine.When the start switch is opened, current no longer flows through the windings. The spring now returns the spring loaded plunger to the original position. At the same time, the spring moves the pinion gear away from the flywheel.When two sets of windings in the solenoid are used, the windings are called the hold-in winding and the pull-in winding. Both of the windings wind around the cylinder for an equal amount of times. The pull-in winding uses a wire with a larger diameter in order to produce a stronger magnetic field. When the start switch is closed, part of the current flows from the battery through the hold-in winding. The remainder of the current flows through the pull-in windings, to the motor terminal, and then to the ground. When the solenoid is fully activated, the current is shut off through the pull-in windings. Only the smaller hold-in windings are in operation for the extended period of time that is necessary for the engine to be started. The solenoid will now take a smaller amount of current from the battery. Heat that is created by the solenoid will be kept at an acceptable level.Starter Motor
Illustration 4 g00292330
Starter motor cross section
(1) Field
(2) Solenoid
(3) Clutch
(4) Starter pinion
(5) Commutator
(6) Brush assembly
(7) Armature The starter motor rotates the engine flywheel at a rate that is fast enough to start the engine.The starter motor contains a solenoid (2). When the start switch is activated, the solenoid (2) will move the starter pinion (4). Then, this starter pinion (4) engages the ring gear on the flywheel of the engine. The starter pinion (4) engages with the ring gear before the electric contacts in the solenoid (2) close the circuit