An increase in power of the electric motors is due to the development of enameled conductors, papers or synthetic insulation films, magnetic plates, aluminum alloys and plastic materials have notably contributed to the reduction of the weight ratio by the power of these machines. Observing the weight of an electric motor of the same power over time, we can see that the current engine is only 8% of its predecessor’s weight in 1891.
Examples are the tiny motors that drive computer hard drives, the wide variety of motors that power appliances, and the giant motors that drive pumps, compressors, fans, mills, extruders and many other applications. https://www.mrosupply.com/motors/ac-motors/commercial-motors/26825_chm344a_baldor/ Comparing the data of catalogs of different manufacturers from different times, we can verify that there was a reduction of weight and, consequently, reduction of the constructive size of the engine for the same power, of approximately 20% every 10 years, except the last two, in which the reduction was less pronounced.
It is clear that there is a need for periodic revision of the standards to adapt the relationship between powers and carcasses to the sizes achieved through technological development. This technological evolution is mainly differentiated by the development of new insulation materials that support higher temperatures. Today electric motors are present in virtually every industrial, commercial and residential facility.
We use the left hand rule on electric motors to determine the direction of rotation of the armature conductors. This rule consists of: with the thumb, forefinger and middle of the left hand perpendicular to each other, point the indicator towards the magnetic field flow lines and the middle finger in the direction of the current passing through the conductor RAB STL200W-LED , thus the thumb direction of the driver.
Two forces act to produce a torque by turning the coil clockwise, so the electric motor of a single coil is impractical because it has dead centers and the torque that will be produced is pulsating. Switching is fundamental for a DC motor as it reverts to current in a conductor as it moves under a pole of opposite polarity. In a rectangular coil formed by a single loop parallel to a magnetic field, the direction of current in the left conductor is outward while in the right side conductor is inward. As a result, the driver on the left moves upward with a force F1, and the driver on the right hand side moves down with a force equal to F2
Three-phase alternating current electric motors are widely used in industry because in most cases the distribution of electric power is done in alternating current and also in function of simplicity, robustness and low cost, being suitable for almost all types of machines found, so this type of engine is widely found in the industry. It has constant speed and can vary depending on some factors as loads applied to its axis.https://www.mrosupply.com/hydraulics-and-pneumatics/hose-reels/2517404_112-3-100_coxreels/
The three-phase induction motor generally operates at constant speed provided by the rotating magnetic field, so the speed of the field is called the synchronous speed, and is a function of two factors, which are: Magnetic poles generated as a function of their physical construction and Frequency the electrical network on which it is installed.
We can thus say that the speed of the electric induction motor is directly proportional to frequency and inversely proportional to the number of magnetic poles. Its working principle is based on the rotating magnetic field, which appears when a three-phase alternating current system is applied to physically out of phase poles of 120º. In this way, a magnetic field appears in this set of motor coils, these magnetic fields.