DOOR GP-CAB 2763440 - Caterpillar

4 Generators With 580 And 680 Series Frame NumbersDescription of Change: The main rotor for SR 4 Generators with 580 and 680 Series frame numbers is modified to allow the exciter rotor to contact the shoulder of the main rotor shaft. The exciter rotor is assembled using small socket head bolts which do not contact the smaller diameter shoulder on the main rotor. This prevents loosening of the bolts that connect the exciter rotor and retainer plate to the main rotor. The former hex head bolts came in contact with the shoulder of the former rotor shaft and prevented a solid fit for the exciter rotor. The illustration shows the changes that were made to the rotor shaft and the relative positions of the new bolts to the rotor shaft shoulder.
Adaptable To: Chart A shows the beginning serial numbers for this change. The former main rotors cannot be used on later generators without also replacing the exciter rotor. Also, the "hex bolt" exciter rotors are not compatible with the redesigned main rotors. Chart B contains a list of new part numbers available for the main rotors and exciter rotor heat sink assemblies. More rotor part numbers will be available later.
Comparison of former and new main rotor shafts.