This invention relates to an apparatus and method for aligning shafts. Particularly, this invention is useful in the new construction or maintenance fields in cases of setting and aligning the working or drive shafts of motors so that they can be coupled to the driven shafts of equipment, such as agitators, pumps, drive shafts, compressors and the like.
Whenever a motor is attached to a piece of equipment to be operated the motor working or drive shaft must be attached to the equipment or driven shaft so that both are in perfect or near perfect alignment. If alignment is unsatisfactory, when the drive and driven shafts are coupled together by known conventional methods, the stresses resulting from operation in coupled misalignment will cause premature bearing failure in the motor or equipment or both. Often such failure will occur before operating speeds are attained in high speed electric motors or soon thereafter in lower speed motors. For these reasons engineering specifications often require alignment both horizontally and vertically of the drive and driven shafts within on thousandth (1/1000) of an inch.
Shaft alignment can be satisfactorily accomplished using a conventional alignment indicator which is fixed to one shaft and rides the other with a spring loaded stem capable of registering differences up to 200,000ths over two full turns on the indicator dial. When the shaft to which the indicator is attached is rotated through 360.degree., the variation in alignment is read at 90.degree., 180.degree., 270.degree. and 360.degree. or 0.degree.. A skilled man can then adjust one of the shafts until alignment indicator readings throughout the 360.degree. rotation are identical or within the specified tolerance. However, in order to have accurate readings, the indicator must be rigidly fixed to one of the shafts. Thus, one of the objects of the present invention is to provide an apparatus which can be rigidly fixed to a shaft to which the alignment indicator can be secured. Another object is to provide an alignment indicator clamp apparatus with more than one shaft engaging member. A further object of this invention is to provide an alignment indicator clamp apparatus which is easily attached and removed from the shaft without special tools. Another object of this invention is to provide an alignment indicator clamp apparatus which can handle shafts of widely varying diameter. A still further object of this invention is to provide an alignment indicator clamp apparatus which can be rigidly fixed to a shaft but is not cumbersome or bulky in size. These and other objects of the invention are accomplished by means of the apparatus of this invention.