3022521 - 5520B starter motor and components
COMPOSITION
The starting system consists of the ignition switch operated by the key and the starter motor which is connected directly to the battery.In addition to tried and tested starter motors which are energized in series and in series/parallel, for some time now starter motors are being developed which are energized by ceramic, ferrite type permanent magnets.CIRCULAR SECTOR MAGNET WITH MAGNETICALLY PRE-ORIENTATED CRYSTALS
The rough components are formed into the desired shape by pressing and extrusion. Finally, after a thorough baking process, the material produces the mangets which are black in colour with a ceramic structure. The magnetizing treatment takes place during the manufacturing process.The magnets have a circular section and replace the polar section and winding.1 - Radial orientation
2 - Parallel orientation
STATOR-INDUCTOR
The positioning of the magnets cannot take place using strong compression or riveting, also because the magnets are fairly fragile: they are secured by flexible fastenings and springs and, in some cases, they are stuck to the casing. The casing can be compared to a simple mechanical component without wires and is fitted using two stay bolts; it is equipped with 6 magnetic poles.1 - N-S permanent magnets
ROTOR-ARMATURE
The diagram below shows the rotor-armature assembly.1 - Shaft
2 - Ring gear
3 - Satellite/planet gears
4 - Pinion/sun gear
5 - Armature
6 - Manifold/switchGiven that the magnetic field
is created by permanent magnets, the energizing is the same in all
motor operating conditions; in addition, as there are no energizing
windings, there is neither an energizing current nor ohmic resistance:
the total resistance depends solely on the armature circuit. The
rotation speed is only affected by the current which passes through
the blades and reaches the rotor depending on the voltage. Since
the motor is equipped with permanent magnets, i.e. with fixed polarity,
the direction of rotation depends on how the current is sent to
the blades.When the rotor rotates it transmits movement
to the three satellite gears on special supports which transmit
their torque to the ring gear on the output shaft where the pinion
which rotates the flywheel can be found. The optimum reduction ratio 1:4.26
is 4.26 revolutions of the rotor for each revolution of the ring
gear and the presence of the permanent magnets makes it possible
to construct motors of equal power from a simple design which are
small in size compared with motors which have windings.STARTER MOTOR DIAM 74.5 1.1/12V
1 - Pinion with free wheel
2 - Epicyclic reduction gear
3 - Rotor permanent mangets
4 - Complete polar casing
5 - Armature or rotor
6 - Blades
7 - Manifold
8 - Manifold side support
9 - Engagment relay
10 - Lever
11 - Control side support
TECHNICAL DATA
Starter motor: AM 74.5 1.1 12VNominal voltage: 12VRated power: 1.1 kwPinion side rotation: clockwiseEnergizing: 6 permanent magnet polesElectro-magnetic operation with pull in and hold in windingReduction ratio 1:4.26Blades 2+2Free wheel engagementWIRING DIAGRAM
The starter motor wiring diagram is illustrated below.1 - Control unit on battery
2 - Starter motor
3 - Alternator
4 - Body computer
5 - Ignition switch
6 - Engine compartment control unit (CVM)
7- Control unit under dashboard (CPL)