démarreur

Démarreur is a French word that translates to "starter" in English, most commonly referring to the device used to start an internal combustion engine. In the context of vehicles, the starter motor is an electric motor that engages with the engine's flywheel to initiate the crankshaft's rotation. This initial rotation provides the necessary momentum for the engine's cylinders to draw in fuel and air, compress the mixture, and ignite it, thereby starting the engine's own power cycle.

The starter motor typically receives a significant surge of electrical power from the vehicle's battery. This high current allows the motor to generate the torque needed to overcome the engine's internal resistance and inertia. When the ignition key is turned to the start position, a solenoid acts as a switch, connecting the battery to the starter motor and simultaneously pushing a small gear (the pinion gear) into mesh with the larger ring gear on the flywheel. Once the engine starts, the ignition switch is released, the solenoid disengages the pinion gear, and the starter motor stops.

In a broader sense, "démarreur" can also refer to any device that initiates a process or action. For example, in a business context, a "démarreur d'entreprise" might be an entrepreneur or a startup incubator that helps launch new ventures. However, in common technical usage, it almost exclusively refers to the engine starter motor.