Monthly Archives: julho 2017

Heat Transfer

When the electric motor is in full operation, its temperature increases and can reach an external temperature of 80º to 90º, but even then they work perfectly, without their characteristics being affected, as this heat is dissipated to the external area.

The ambient heating where the engine is installed is related to the heat dissipation and not to the temperature of the casings. This temperature will also depend on the number of motors that are installed and working in the same environment.

An electric motor with cold housing may have greater losses or greater heating of the windings than a hot engine.

Irregular surfaces cause poor contact and inefficient thermal conduction. When the coils, stator and housing are in contact with each other without void spaces, there is good heat transfer. This heat generated by them will be dissipated out in the best possible way, and this will depend on the thickness of the carcass and various other factors.

When there is air accumulation, direct contact between the engine parts is prevented, we will have a poor heat transfer. The engine casing may be cold on the outside, but inside it will be so high that it could damage the engine.

Electric Drive – Definition

Rotary electric motors are the most common, they make the movement available as a rotation around an axis. Linear motors are the ones that produce a linear sense of motion.

From the structural point of view the electric motor T3533111S can be divided into two parts, the stator which is fixed, and the rotor, a moving part.

The moving parts of an engine will interact by the electromagnetic field produced by the engine power and this interaction results in a torque supplied to the rotor shaft or an electromagnetic force.

The motor is the element that transforms with high performance, the electrical energy that comes from the static converter, in mechanical energy that is necessary to transmit the mechanical movement to rotate the machine. Most engines work by the interaction between these electromagnetic fields, but there are engines driven by other electromechanical phenomena such as electrostatic forces

The structure of the electromagnetic part will depend on the type of motor. As for the functional is represented by circuit examples of the stator and rotor windings, and the structure of the mechanical part will be independent of the type of electric motor.

The Brake Coil Supply

The supply of the rectifier bridge by alternating current can be obtained from an independent source or also through the terminals of the electric motor. The power supply can be in 110 V, 220 V, 440 V or 575 V depending on the characteristics of the brake coil assembly and bridge rectifier. The coil can also be given at 24 Vdc, but it is important to remember that in this case, the power must be supplied through a direct current, an independent source, not requiring the use of a bridge rectifier.

For motors of different voltages, the terminals of the rectifier bridge must be connected to the 220 V independent source, considering the simultaneous interruption with the motor supply. With the power supply, in this case independent, it is feasible to electrically realize the brake unlocking.

Baldor L1405T-50

A smoother stoppage of the engine may be possible by reducing the value of the braking torque by withdrawing the brake pressure springs. It is important to remember that the springs have to be taken in a way, that the rest remain symmetrically arranged, to avoid that it continues having a friction even after starting the motor, causing the uneven wear of the pads.