BOSCH starter — design description (Scorpio 2)

To start an internal combustion engine, a small electric motor called a starter is used. In order for the car engine to start, the starter must spin the engine crankshaft to a frequency of at least 300 1/min. This can only be done if the starter is working perfectly and the battery is sufficiently charged.

The starter consists of a drive housing, a pole housing, and a collector housing. The pole housing contains the anchor, and the collector housing contains the collector and brush holder. The brush holder contains brushes that wear out slowly but constantly. If the brushes are heavily worn, the starter cannot operate flawlessly.

The pinion drive is located in the front part of the drive housing. When the starter is switched on and voltage is supplied to it from the storage battery, the traction relay located on the starter housing, through the drive engagement lever, extends the pinion along the helical splines on the armature shaft to the toothed ring of the flywheel. As soon as the pinion reaches the stop at the end of the armature shaft, it enters into force engagement with the toothed ring of the flywheel. In this case, the traction relay switches on the electric circuit of the starter, and now it can turn the crankshaft of the engine to the starting speed. As soon as the engine starts, the flywheel ring will begin to rotate the pinion faster than the starter shaft rotates, and it, having disengaged from the flywheel ring, will move along the helical splines of the shaft to its original position.



Since the starter consumes a large current when starting the engine, it is necessary to pay attention to the perfect connection of the wires as part of engine maintenance. Remove corrosion at the wire connections and lubricate with acid-resistant protective grease.

Engines are equipped with starters of different power, manufactured by different companies (BOSCH, MAGNETIMARELLI, NIPPON-DENSO). This must be kept in mind when replacing the starter.

Note: Depending on the type, the starter is an exchange unit. This means that the faulty starter is accepted by the manufacturer as payment when buying a used or new starter, and therefore the old starter should be taken with you to the store.