Start the engine
When the driver turns the ignition key or presses the start button, the starter motor connects the circuit via an electromagnetic switch, driving the gear to mesh with the engine flywheel, causing the crankshaft to rotate at high speed (usually 200-400 rpm), thus allowing the engine to complete the initial intake, compression, and ignition cycles, ultimately achieving self-sustaining operation.
Provide instantaneous high torque
When starting the engine, internal resistance (such as piston friction and cylinder compression) must be overcome. The starter motor needs to output high torque (typically 100-300 Nm) in a short time to ensure smooth engine starting.