Description of the starter (VW Golf 4)

The starter is a DC electric motor with mixed excitation with an electromagnetic traction relay. The starter consists of a housing or stator with excitation windings, an anchor 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 starter traction relay. The relay anchor is pulled in and the relay contacts close. At the same time, the relay anchor moves the overrunning clutch with the gear through the lever. The hub of the overrunning clutch rotates on the helical splines of the starter anchor shaft and also rotates the gear, which facilitates its engagement with the flywheel ring gear. Current flows through the closed contacts of the traction relay, feeding the stator and anchor windings, and the starter anchor begins to rotate together with the hub and overrunning clutch.

After the engine is started, the rotation speed of the pinion exceeds the rotation speed of the starter anchor. In this case, the overrunning clutch rotates freely and the torque is not transmitted from the engine flywheel to the starter anchor shaft. After the ignition key is released, the power supply circuit of the traction relay windings through the ignition switch is opened, the anchor of the traction relay is pressed back to its original position by the spring, the relay contacts are opened and the drive pinion disengages from the flywheel ring gear.