Dismantling and explained a Starter motor

This video helps to identify the internal component of a starter motor. In this video a starter motor is dismantle and assembled back.Mechanical Engineering tutorials videos
A starter is a type of electrical machine which converts electrical energy into mechanical energy. Engineering tutorials
The electrical energy is obtained from the battery. When the starter switch is operated, current flows through the starter (the field coils and the armature conductors) and two magnetic fields are set up.

The interaction of these magnetic fields results in the production of turning movement, which is used for rotating the engine crankshaft, and hence starting the engine.
A considerable amount of mechanical power is required to start the engine (probably about 2 h.p.), and the starting current is usually in the region of 250 to 500A.
Starters are normally 4-pole machines with the field systems connected in series or series-parallel. It is a characteristic of this type of machine that the motor produces its maximum turning effort when its speed is at a minim urn. This makes it very suitable for starting engines. Hydraulic tutorials
Another characteristic of the series motor is that its speed varies inversely with the field strength. As the load on the series motor increases, the field strength also increases, and the armature speed is reduced. A series motor should not, therefore, be run without load, or it may reach dangerous speeds. When the series motor is properly loaded, however, its speed is practically constant.
The starter incorporates a drive to engage is with the engine when the switch is operated. An inertia- type drive is used on the majority engines. The pinion is mounted on a screwed sleeve and the shock of engagement is taken up by a coil spring.
The inertia of the pinion causes it to move along the screwed sleeve into engagement with the flywheel when the motor accelerates. The pinion also moves out of engagement when the starter switch is released, and the starter slows down.
Commercial vehicles with diesel engines employ pre-engaged starters. The main purpose of this type of starter is to prevent the pinion from being ejected prematurely from the engine. Further, full battery current is not supplied to the starter until the pinion is fully enmeshed with the flywheel. The drive is protected against over speeding by means of a clutch.
The starter requires very little attention in service, though the moving parts of the drive should be lubricated from time to time. Whenever starters are dismantled for periodical overhaul, the brush gear and the commutator surface should be checked.

More tutorial 

Tutorial videos

Hydraulic tutorials

Engineering tutorials 

Automobile Engineering tutorials

Mechanical Engineering tutorials videos