Monthly Archives: October 2017

Distorted Field

Distorted field motors, which can also be called shaded pole motors, are considered to be one of the simplest and most cost-effective types of single-phase induction motors. From the constructive life point there are several types, one of the most common forms being that of protruding poles. Each of these poles should have a part, on average from 25% to 35% of the pole, is embraced by a shorted copper loop. The current induced in this loop will cause the flow through it to suffer a delay in relation to the flow of the part not embraced by it.

The result of this process, similar to a rotating field that can move in the direction of the uncaged part to the embraced part of the pole, causing the torque to dye the nominal rotation, which will allow the motor to split the direction of rotation, depending on the side in which is

the embraced part of the pole. In this way the distorted field motor may have a single direction of rotation. This sense can even be reversed by changing the position of the rotor shaft tip relative to the stator.

Grease in electric machines

On grease engines, at the precise moment of relubrication of their bearings with the machine in complete rest, it is necessary to carry out a thorough cleaning of the vicinity of the grease entry holes. It is extremely important that approximately half of the recommended total grease is placed on the nameplate of the electric motor, and thus cause the motor to rotate for about one minute at the rated speed. It is necessary to switch off the engine so that the remaining grease is put in and afterwards, put the grease inlet protection again.

For the process of relubrication of the bearings at the moment the engine is in operation, it is important that the person responsible for the action be careful to clean the vicinity of the grease entry hole and, as in electric motors 9003-2040 B40 without grease, under no circumstances should you forget to put the recommended total amount of grease on the motor nameplate and then replace the grease entry guard. In greaseless electric motors, lubrication must be performed as described in the existing preventive maintenance plan. Disassembly and assembly of this type of motor must be made in accordance with the specifications described by the manufacturer.