Concentric reducer misalignment is widely considered to be the root cause of most reducer repairs and failures. It degrades machine performance and reduces the life of the reducer, motor and driven equipment.

　　Types and causes of misalignment of concentric reducers:

　　Correct alignment between the shaft of a concentric reducer and the shaft of a motor or equipment follower means that the shafts are collinear, that is, they lie in a straight line. Gearbox misalignment is often the result of installation and setup activities. But even if the alignment is within acceptable tolerances during installation, operating and environmental conditions can eventually cause the shaft to be out of alignment.

　　Signs of misaligned concentric reducers include damaged seals or couplings, shortened bearing life, reducer vibration, and damage to the gears themselves. If there is a severe angular misalignment, the first sign is usually a seal leak, as the shaft seal is deflected by a misaligned shaft.

　　Concentric reducer shafts are often connected to other equipment through flexible couplings that can compensate for small amounts of deflection, but good design practice does not rely on couplings to compensate for deflections. In some cases, proper alignment of the reducer can be achieved using a dial indicator, but laser alignment tools are more precise and less error-prone.