ABSTRACT
The alignment of rotating machinery shafts, as discussed in the previous chapters, concen-
trates on measuring the centerline of rotation of one shaft with respect to another shaft. These
shafts are usually solid cylinders of various lengths supported by a bearing at each end. The
position of the two bearings that support each shaft dictates the location of that shaft’s
centerline of rotation. If we are aligning two shafts, each of which is supported in two
bearings, then the goal is to align the centers of all four bearings in the two shafts. Therefore,
shaft alignment and bearing alignment both really mean the same thing.
