Almost all the mechanical movement that is done in the industries originates from the rotor of an electric motor. They put the assembly lines on the floor and bring the robotic arms and automation machines to life.
Mechanical and electrical problems can cause the engine to fail and cause downtime on the production line. In this sense, it is essential to know the main causes of failure and how to avoid them.
Electric motor: the heart of the factory
It is very difficult to find any factory in the world that does not use electric motors, and uses them extensively. They are responsible for getting the factories moving. They are the ones that drive the conveyor belts, trigger assembly lines and give movement to the robotic joints installed along the production line.
Because it is such an important part in the industries, it is essential that the electric motor has a good prevention and maintenance program in order to prevent the most common failures.
Problems can have different origins, most can be avoided with a good maintenance program and well-trained staff. Let’s learn about some of the most common faults in electric motors:
1 – Overload
Overload occurs when an electric motor is required in excess of its rated torque. This situation causes the operating electric current to be higher than normal, causing overheating.
With the engine running at a higher temperature, its service life is reduced and depending on the level of overload the protection device of the circuit that powers the electric motor will be activated, giving rise to an unexpected stop in the operation of that motor.
2 – Misalignment
Misalignment is a common cause of electrical motor failures. It happens when the motor drive shaft, the so-called rotor, or the coupling part are not correctly aligned with the load.
Misalignment results in the transfer of mechanical stresses that are harmful to the engine, increasing wear and apparent mechanical load. Another unwanted effect is the increase in vibration both in the load and in the engine itself.
3 – Sigma Chain
Sigma currents are eddy currents that circulate through an electrical circuit. They are generated by parasitic capacitances and inductances associated with electrical conductors. These currents are associated with loss of efficiency and a decrease in useful life.
Its prevention involves the use of well-dimensioned and quality conductors, in addition to avoiding improper soldering or conductor connections.
4 – Unbalanced phases
The electric motors in operation in the industry are mostly induction with squirrel cage. They are asynchronous motors powered by three-phase circuits. For the correct operation of the electric motor and generation of the rotating field, it is important that the three phases that supply the stator are balanced.
Unbalanced circuits can distort the electrical characteristics of the circuit and create stopping situations. In general, it also causes overheating and problems with the insulation of the motor windings.
5 – Smooth foot
This is a more common problem than you might think. It concerns cases in which the fixation of the motor feet or its driven component are not seated on the same surface.
This operating condition can cause, when tightening the fixing screws of each foot, new mechanical misalignment stresses are introduced in the set.
The main impact of the soft foot is the misalignment of the motor axles and the load. To avoid the problem, it is necessary to secure both the motor and the load so that the seating does not cause additional vibration or transfer of efforts to the motor.
These are some of the most common problems that cause electric motors to fail. Remembering that it is essential that an electric motor has electrical insulation with a quality material.
And Geartech BR is a national reference in electrical insulating products. To learn more about our products and services, contact us. It will be a great pleasure for us to be able to serve you!