SHAFT ALIGNMENT Shaft alignment is the process to align two or more shafts shafts with with each other to within a tolerated margin. It is an absolute requirement requirement for machinery before the machinery is put in service. When a driver like an electric motor or a turbine is coupled to a pump, a generator, or any other piece of equipment, it is essential that the shafts sha fts of the two pieces are a re aligned. Any misalignment between the two increases the stress stress on on the shafts s hafts and will almost certainly result in excessive excessive wear and premature breakdown of the equipment. This can be very costly. When the equipment is down, production might be down. Also bearings or mechanical seals may be damaged and need to be replaced. A proper shaft alignment or the use of disc couplings can couplings can prevent this. Tools used to achieve alignment may be mechanical or optical, like the aser shaft alignment method, alignment method, or they are gyroscope based. The gyroscope based systems can be operated very time e!cient and can also be even used if the shafts have a large distance "e.g. on marine vessels#. $efore such a shaft alignment can be done, it is also essential that the foundations for the driver and the driven piece are designed and installed correctly corr ectly.. If that is the case, than shaft alignment can be started. The resulting fault if if alignment is not achieved within within the demanded speci%cations is shaft misalignment, which may be parallel, angular, or both. &isalignment can cause increased vibration and loads on the machine parts for which they have not been designed "i.e. improper operation#. Types Types of misalignment There are are two types of misalignment' misalignment' parallel and angular misalignment. misalignment. With parallel misalignment, the center lines of both shafts are parallel but they are o(set. With angular misalignment, the shafts are at an angle to each other. The parallel misalignment misalignment can be further divided up in hori)ontal hori)ontal and vertical misalignment. *ori)ontal misalignment misalignment is misalignment of the shafts s hafts in the hori)ontal plane and vertical misalignment is misalignment of the shafts in the vertical plane' •
+arallel +arall el hori)ontal misalignment is where the motor shaft is moved hori)ontally away from the pump shaft, but both shafts are still in the same hori)ontal plane and parallel.
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+arallel vertical misalignment is where the motor shaft is moved vertically away from the pump shaft, but both shafts are still in the same vertical plane and parallel.
imilar, angular misalignment can be divided up in hori)ontal and vertical misalignment' •
Angular hori)ontal misalignment is where the motor shaft is under an angle with the pump shaft but both shafts are still in the same hori)ontal plane.
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Angular vertical misalignment is where the motor shaft is under an angle with the pump shaft but both shafts are still in the same vertical plane.
-rrors of alignment can be caused by parallel misalignment, angular misalignment or a combination of the two.
