Car Self Starter Motor 3f2y4n

CAR SELF STARTER MOTOR

CRANKING CIRCUIT  

For any engine to start, it must first be rotated, using an external power source. It is the purpose and function of the cranking circuit to create the necessary power and transfer it from the battery to the starter motor that rotates the engine.

Cranking Circuit 

Modern cranking circuits include the following: 1. Starter motor. 2. Battery. 3. Starter solenoid or

relay. 4. Starter drive. 5. Ignition switch.

CRANKING CIRCUIT Control Circuit 

Many automobile manufacturers use an electric switch called a neutral safety switch that opens the circuit between the ignition switch and the starter to prevent starter motor operation unless the gear selector is in neutral or park.

Circuit Diagram

HOW THE STARTER MOTOR WORKS 

A starter consists of the main structural of a starter called the main field housing, one end of which is called a commutator-end (or brushend) housing and the other end a drive-end housing.

HOW THE STARTER MOTOR WORKS 

The starter uses four brushes—two brushes to transfer the current from the field coils to the armature, and two brushes to provide the ground return path for the current that flows through the armature.

HOW THE STARTER MOTOR WORKS 

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The magnetic field of the starter motor is provided by two or more pole shoes and field windings. The pole shoes are made of iron and are attached to the frame with large screws.

HOW THE STARTER MOTOR WORKS 

The field windings are usually made of a heavy copper ribbon to increase their current-carrying capacity and electromagnetic field strength.

SOLENOID-OPERATED STARTERS 

A starter solenoid is an electromagnetic switch containing two separate, but connected, electromagnetic windings Wiring diagram of a typical starter solenoid. Notice that both the pull-in winding and the hold-in winding are energized when the ignition switch is first turned to the “start” position. As soon as the solenoid disk makes electrical with both the B and M terminals, the battery current is conducted to the starter motor and electrically neutralizes the pull-in winding.

STARTER DRIVES A starter drive includes a small pinion gear that meshes with and rotates the larger gear on the engine for starting.  The ends of the starter pinion gear are tapered to help the teeth mesh more easily without damaging the flywheel ring gear teeth. 

STARTER DRIVE 

If the engine starts and is accelerated to 2000 RPM (normal cold engine speed), the starter will be destroyed by the high speed (36,000 RPM) if the starter was not disengaged from the engine.

Components  

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Pinion Gear : attached to the flywheel. Used to transfer the power to the engine crankshaft. Engaging System : consists of a electromagnet attached to a lever. Main purpose is to bring forward the pinion gear to meet with the flywheel. Field coils : when current is supplied to these coils they become powerful magnets producing a spinning motion in the armature. Armature : the rotating part of the starter motor. Contain windings and metal core laminations that produce magnetic field when voltage is applied. Carbon Brushes : used to supply voltage to the armature.

SUMMARY All starter motors use the principle of magnetic interaction between the field coils attached to the housing and the magnetic field of the armature. 2. The control circuit includes the ignition switch, neutral safety (clutch) switch, and solenoid. 3. The power circuit includes the battery, battery cables, solenoid, and starter motor. 4. The parts of a typical starter include the main field housing, commutator-end (or brush-end) housing, drive-end housing, brushes, armature, and starter drive. 1.