Fig. 2,798.—View of armature in transit showing use of a wooden spreader as a protection. If a chain be used in place of the rope, a padding of cloth should be placed around the armature shaft and special care taken that the chain does not scratch the commutator.
Ques. If an armature cannot be placed at once in its final position what should be done?
Ans. It may be laid temporarily upon the floor, if a sheet of cardboard or cloth be placed underneath the armature as a protection for the windings; in case the armature is not to be used for some time, it is better practice to place it in a horizontal position on two wooden supports near the shaft ends.
Ques. What kind of base should be used with a belt driven generator or motor?
Ans. The base should be provided with V ways and adjusting screws for moving the machine horizontally to take up slack in the belt, as shown in [fig. 2,799].
Owing to the normal tension on the belt, there is a moment exerted equal in amount to the distance from the center of gravity of the machine to the center of the belt, multiplied by the effective pull on the belt. This force tends to turn the machine about its center of gravity. By placing the screws as shown, any turning moment, as just mentioned, is prevented.
