the brush cover will be installed; when cooling air is required to enter
through the brush access windows, a cover will be installed on the anti-drive
end to prevent the loss of cooling air. The starter-generator will be
furnished with the Air Inlet Cover on the anti-drive end and the Brush Cover
installed. See Figure 3.
3.4.10 Shaft deflection. The starter-generator shall be designed to
operate with the driveshaft misaligned to the maximum allowable limits
defined by the tolerances of the mating engine accessory drive, AND20002,
3.4.11 Operating attitude. The starter-generator shall be designed to
operate in any installed position.
3.4.12 Rotation. The direction of rotation of the splined drive shall be
as specified on Figure 3.
The overhung moment shall not exceed 200 inch-
3.4.13 Overhung moment.
3.5 Reliability. The starter-generator shall be designed and constructed
to provide an inherent reliability of 1,000 hours maintenance-free operation
under the conditions required herein except for one change of brushes. To meet
this requirement, careful attention shall be given to selection of materials,
treatment of materials, finishes, securing of all electrical conductors, and
the assembly of each and every part.
3.6 Maintainability. The starter-generator shall have a minimum number of
parts consistent with reliability.
Its designs shall permit easy assembly,
disassembly, location of trouble sources, and maintenance with tools and equip-
ment normally available commercially.
3.6.1 Armature. The starter-generator shall be so constructed that the
armature is readily removable for maintenance with minimum disassembly. In no
case shall it be necessary to disconnect soldered or brazed connections.
3.6.2 Commutator. A turned down section (step) shall be provided at the
outboard end of the commutator, the diameter of which shall be the minimum
diameter to which the commutator can be safely reduced during its maintenance
life. The minimum diameter shall be consistent with brush stability.
3.7.1 Environmental conditions. The starter-generator shall be capable of
satisfactory operation under the following environmental conditions:
Ambient temperatures ranging from -54° Centigrade (C) to
b. Relative humidity up to 100 per cent, including conditions wherein
condensation takes place in the form of both water and frost.
Vibration incident to service use.
Fungus growth as encountered in tropical climates.
Operation in an explosive vapor within or surrounding the equipment.