Electric motor, any of a class of devices that convert electricity to mechanical energy, usually by employing electromagnetic phenomena.
What is a power motor?
How can you bring stuff in motion and maintain them moving without moving a muscle? While steam engines create mechanical energy using scorching steam or, more exactly, steam pressure, electric motors use electrical energy as their supply. For this reason, electric motors are also known as electromechanical transducers.
The counter piece to the electric electric motor is the generator, which has a similar structure. Generators transform mechanic motion into energy. The physical basis of both procedures may be the electromagnetic induction. In a generator, current is definitely induced and electricity is created when a conductor is at a shifting magnetic field. Meanwhile, within an electric electric motor a current-holding conductor induces magnetic areas. Their alternating forces of attraction and repulsion develop the foundation for generating motion.
How does a power motor work?
Motor housing with stator
Motor housing with stator
In general, the heart of an electric motor includes a stator and a rotor. The word “stator” is derived from the Latin verb “stare” = “to stand still”. The stator may be the immobile part of a power motor. It really is firmly attached to the equally immobile housing. The rotor on the contrary is installed to the electric motor shaft and will move (rotate).
In case of AC motors, the stator includes the so-called laminated core, which is wrapped in copper wires. The winding functions as a coil and generates a rotating magnetic field when current is certainly flowing through the wires. This magnetic field developed by the stator induces a current in the rotor. This current after that generates an electromagnetic field around the rotor. Consequently, the rotor (and the attached motor shaft) rotate to follow the rotating magnetic field of the stator.
The electric motor serves to apply the created rotary motion to be able to drive a equipment unit (as torque converter and speed variator) or even to directly drive a credit card applicatoin as line motor.
What forms of electric motors can be found?
All inventions began with the DC motor. Nowadays however, AC motors of various designs are the mostly used electrical motors in the market. They all possess a common result: The rotary motion of the motor axis. The function of AC motors is based on the electromagnetic operating principle of the DC engine.
As with most electrical motors, DC motors contain an immobile part, the stator, and a moving element, the rotor. The stator consists either of a power magnet used to induce the magnetic field, or of long lasting magnets that continually generate a magnetic field. Inside of the stator is where in fact the rotor is located, also known as armature, that is covered by a coil. If the coil is connected to a way to obtain direct current (a battery, accumulator, or DC voltage supply unit), it generates a magnetic field and the ferromagnetic core of the rotor becomes an electromagnet. The rotor is usually movable installed via bearings and may rotate so that it aligns with the attracting, i.electronic. opposing poles of the magnetic field – with the north pole of the armature opposite of the south pole of the stator, and the other method round.
In order to arranged the rotor in a continuing rotary motion, the magnetic alignment must be reversed over and over. This is attained by changing the current direction in the coil. The engine has a so-known as commutator for this function. Both supply contacts are connected to the commutator and it assumes the task of polarity reversal. The changing attraction and repulsion forces make sure that the armature/rotor continues to rotate.
DC motors are mainly utilized in applications with low power ratings. These include smaller tools, hoists, elevators or electric vehicles.
Asynchronous AC motors
Instead of immediate current, an AC motor requires three-phase alternating current. In asynchronous motors, the rotor is a so-called squirrel cage rotor. Turning results from electromagnetic induction of the rotor. The stator consists of windings (coils) offset by 120° (triangular) for every phase of the three-phase current. When linked to the three-phase current, these coils each build up a magnetic field which rotates in the rhythm of the temporally offset series frequency. The electromagnetically induced rotor is usually carried along by these magnetic fields and rotates. A commutator much like the DC engine is not required in this way.
Asynchronous motors are also called induction motors, as they function only via the electromagnetically induced voltage. They operate asynchronously since the circumferential quickness of the electromagnetically induced rotor by no means reaches the rotational quickness of the magnetic field (rotating field). Ac Induction Motor Because of this slip, the performance of asynchronous AC motors is lower than that of DC motors.
More on the framework of AC motors / asynchronous motors and on what we offer
AC synchronous motors
In synchronous motors, the rotor has permanent magnets instead of windings or conductor rods. In this manner the electromagnetic induction of the rotor can be omitted and the rotor rotates synchronously without slide at the same circumferential acceleration as that of the stator magnetic field. Performance, power density and the feasible speeds are thus considerably higher with synchronous motors than with asynchronous motors. However, the design of synchronous motors is also a lot more complex and time-consuming.
Additional information about synchronous motors and our portfolio
As well as the rotating machines that are mainly used in the industry, drives for actions on directly or curved tracks are also required. Such movement profiles occur mainly in machine tools as well as positioning and handling systems.
Rotating electric motors can also convert their rotary movement into a linear movement using a gear unit, we.e. they are able to cause it indirectly. Often, however, they do not have the required dynamics to realize especially demanding and fast “translational” movements or positioning.
This is where linear motors enter into play that generate the translational motion directly (direct drives). Their function could be produced from the rotating electric motors. To get this done, imagine a rotating engine “opened up”: The previously round stator becomes a set travel distance (track or rail) which is certainly protected. The magnetic field then forms along this route. In the linear electric motor, the rotor, which corresponds to the rotor in the three-phase engine and rotates in a circle there, is stopped the travel distance in a straight collection or in curves by the longitudinally shifting magnetic field of the stator as a so-called carriage or translator.
More information about linear motors and our drive solutions