A starter (also self-starter, cranking motor, or starter motor) is a device used to rotate (crank) an
internal-combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combust ...
so as to initiate the engine's operation under its own power. Starters can be
electric
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described ...
,
pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases. A centrally located and ele ...
, or
hydraulic
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counter ...
. The starter can also be another internal-combustion engine in the case, for instance, of very large engines, or
diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-cal ...
s in agricultural or excavation applications.
Internal combustion engines are feedback systems, which, once started, rely on the inertia from each cycle to initiate the next cycle. In a
four-stroke engine
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directio ...
, the third stroke releases energy from the fuel, powering the fourth (exhaust) stroke and also the first two (intake, compression) strokes of the next cycle, as well as powering the engine's external load. To start the first cycle at the beginning of any particular session, the first two strokes must be powered in some other way than from the engine itself. The starter motor is used for this purpose and it is not required once the engine starts running and its feedback loop becomes self-sustaining.
_on_its_flywheel">Starter_ring_gear_on_its_
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__History_
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__History_
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__History_
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Crank_may_refer_to:
_Mechanisms
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*_Crankset,_the_componen_...
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__History_
Before_the_advent_of_the_starter_motor,_engines_were_started_by_various_methods_including_wind-up_springs,_Coffman_engine_starter">gunpowder_cylinders,_and_human-powered_techniques_such_as_a_removable_Crank_(mechanism)">crank_
Crank_may_refer_to:
_Mechanisms
*_Crank_(mechanism),_in_mechanical_engineering,_a_bent_portion_of_an_axle_or_shaft,_or_an_arm_keyed_at_right_angles_to_the_end_of_a_shaft,_by_which_motion_is_imparted_to_or_received_from_it
*_Crankset,_the_componen_...
_handle_which_engaged_the_front_of_the_crankshaft,_pulling_on_an_airplane_propeller,_or_pulling_a_cord_that_was_wound_around_an_open-face_pulley.
The_hand-crank_method_was_commonly_used_to_start_engines,_but_it_was_inconvenient,_difficult,_and_dangerous._The_behavior_of_an_engine_during_starting_is_not_always_predictable._The_engine_can_kick_back,_causing_sudden_reverse_rotation._Many_manual_starters_included_a_Freewheel">one-directional_slip_or_release_provision_so_that_once_engine_rotation_began,_the_starter_would_disengage_from_the_engine._In_the_event_of_a_kickback,_the_reverse_rotation_of_the_engine_could_suddenly_engage_the_starter,_causing_the_crank_to_unexpectedly_and_violently_jerk,_possibly_injuring_the_operator._For_cord-wound_starters,_a_kickback_could_pull_the_operator_towards_the_engine_or_machine,_or_swing_the_starter_cord_and_handle_at_high_speed_around_the_starter_pulley._Even_though_cranks_had_an_