General information
The only task of the engine starting system is to ensure that the engine rotates at a speed sufficient to start it.
The starting system consists of a starter, battery, ignition switch, traction relay and connecting wiring.
The starter is a mixed-excitation DC motor with an externally mounted electromagnetic traction relay. The starter consists of a housing or a stator with excitation windings, an armature with an overrunning clutch, a cover with brush holders and a traction relay.
When the starter is turned on, current from the battery begins to flow through the winding of the traction relay. The relay armature is pulled in and the contacts are closed. At the same time, the relay armature through the drive lever ensures the extension of the gear with the overrunning clutch, while the clutch hub rotates on the screw splines of the starter armature shaft and also turns the gear, which facilitates the engagement of the latter with the flywheel ring gear. A current passes through the closed contacts of the traction relay, which feeds the stator and armature windings, and the starter armature begins to rotate together with the hub and freewheel.
After starting the engine, the speed of the gear exceeds the speed of the starter armature. In this case, the overrunning clutch turns freely, and torque is not transmitted from the engine flywheel to the starter armature shaft. After releasing the ignition key, the power circuit of the windings of the traction relay opens through the ignition switch, the armature of the traction relay is pressed back to its original position by a spring, the relay contacts open and the drive gear disengages from the flywheel ring gear.
The starter with a retractor relay is located parallel to the engine crankshaft and is fixed to the power unit.
Precautionary measures
When carrying out any work on the engine starting system, observe the following requirements:
- To avoid failure of the e / motor as a result of overheating, do not turn on the starter for more than 15 seconds - wait at least 1 minute before turning it on again. Prolonged cranking of a non-starting engine with a starter leads to the accumulation of unburned fuel in the catalytic converter, which is fraught with failure of the latter as a result of ignition during starting;
- The starter is connected directly to the battery and careless handling may cause a fire due to a short circuit;
- Always disconnect the negative cable from the battery before servicing the starter.