Alternators

Rotors

Rotor is a rotating part of alternator. It consist of the magnetically conducting mantle shell in the form of " U". The mantle is symmetric riveted on the nave of rotor (carrier of the rotor). Inside on the mantle circumference are fixed the permanent magnets. On the rotors with the external sensing is on the mantle circumference forced or fixed the pole shoe , further only "mark". It means the magnetically conducting stump around 2 mm over the mantle circumference. The mark on the rotor has according to the purpose diverse shape and legth. The nave of rotor has in its axis a conical opening, through which is the whole rotor drived on the crank of motor.

Function of rotor

It is concerned the rotors of alternators with permanent excitation, where the magnetically flow is not excited of the battery, but it is excited through the permanent magnets. The magnetical flow is closed from the magnets through the stator core and rotor mantle. At the rotation of the rotor is induced the electric current in the windings of the stator of alternator. The types of the windings are described in part STATORS. The mark is only on the rotors with "external sensing ", in the sets, where is the synchronizing electric impuls obtained through position sensor. At the rotation of rotor pass the mark at close quarters position sensor, in which induces the electric impuls for ignition control. Angular position of the mark is exactly defined compared to skewing of the crankshaft. Generally is the position of rotor and thereby also of the mark fixed through the key over the groove in the rotor nave and crankshaft.

Disposal of rotors:

1. According to the diameter
   • Ø 112 mm
   • Ø 103 mm
2. According to the synchronizing principle:
   • for external sensing, has the rotor on the circumference 1 to 2 marks, depending if it is for 1 cylinder or 2 cylinder engine. For the direct control of the electronic ignition switches it concerns about angular short marks, eventually marks with gradual incidence over the reverse running of motor.
     The marks for the control of the digital control unit have a longer mark, around 28°.
   • for internal sensing are the rotors modified so, that always one magnet is not magnetized
3. According to the type and length of rotor nave, according to the coning angle and input diameter of conus opening.
4. Disposal according to the electric output of alternator is described in part STATORS.

Important warning!
At the manipulation it is non-permissible the mechanical straining of the mantel circumference of the rotor or fall of rotor on the cant of mantel circumference. Also is non-permissible the direct mechanical straining of the magnets. At that manipulation it could come to the damage of magnets.

Stators

Stator is a static part of alternator. It consist of a magnetically conducting core starform, at what are cyclic fixed the winding coils. By rotation of the external rotor with the permanent magnets is induced into the winding the electric current for the power supply of the ignition and the electric appliances in the board net.

According to the purpose we differ on the stators three types of electric winding:

1. Source winding for the power supply of the electric appliances of the voltage rating 12V or 6V.
   The winding is wound with a isolated wire of a bigger diameter.
2. Charging winding for power supply of the ignition.
   Output voltage is pulse. The value depends on the turning speed of the rotor and it variates from 80V to 400V. The electric resistance is approximately about 550 to 630 ohm. Winding is wound on a bigger black plastic coil frame. For the two-cylinder engines are two coil like this placed together after 180°.
3. 
   
4. Synchronizing winding is used at stators in sets, which do not use for the control of ignition the position sensor. In the winding are induced the voltage impulses, whose frequence is identical with the frequence of the crank movement of the engine. For 1 crank revolution 1 impuls. The electric impulses are used for the control of the ignition. Either directly to the control of the el. switch, or for the control of the digital control units at the sets with the regulation of preignition charakteristic of ignition.
   The winding is wound on the two small black coils, whose el. resistance is 70 to 75 ohm.

 Disposal of stators:

1. According to the type of synchronizing of ignition (external or internal sensing).
   • in the set is used the external sensor of rotor position:
     The stator has not a synchronizing winding. It contains only charging and source winding. For the two cylinder engines are the charging winding two. (on two big black coils).
   • in the set is not used the external sensor of rotor position:
     The stator has a synchronizing winding (it is wound on two small black coils). Further it contains the charging coil and source winding.
2. According to the sense of rotation of rotor / running direction
   • "righthanded" stators
   • "lefthanded" stators
3. According to the electric output [W].
   1. Standard type according to the combination with the rotor
      • with rotor Ø 112 mm, without the synchronizing coils 185 W
      • with rotor Ø 112 mm, with the synchronizing coils 140 W
      • with rotor Ø 103 mm, without the synchronizing coils 140 W
      • with rotor Ø 103 mm, with the synchronizing coils 100 W
   2. The special design has a combined source winding. A part of the winding supplies after rectification only the battery and some appliances, e.g. stop light, direction indicator etc. The second part of winding with major el. output supplies the bulbs for the lighting with alternating current.