The revolving parts have now been completed with the exception of the shaft. From the previous drawings all data is available for making the shaft drawing as shown in Plate G. The center lines of bearings, the center line of the armature, and the center line of the shaft itself will give the starting points. The size of the main section of the shaft and of the bearings has been determined. Note that the bearing at the coupling end is larger than the other one since the strains there are greater. The total length of bearing between oil deflectors is made slightly greater than the length of bearing to allow for end play of the armature when running.

Oil Rings

If the shaft were extended in smooth lines toward the center, the oil would gradually creep along the shaft until it reached the spider or commutator shell where it would be thrown out into the machine. Rings are therefore formed on the shaft which will throw off the oil inside the bearing housing. These deflectors are shown on a larger scale so that the details can be given more clearly. Sections through the shaft for the purpose of showing the keyways are also given. Note how the finish is given according to whether it is for a fit with some other part or is a polished journal finish.


The coupling is also shown on this plate, since it forms a part of the shaft. The dimensions are given in decimals where they affect the other half coupling which will be furnished by the manufacturer of the prime mover to which the machine is to be coupled.

The keys are called for in the title table by dimensions, no other information being necessary.

It will be noted that only enough of the sections of armature spider and commutator shell are shown to give their location on the shaft and furnish needed dimensions.