Electric motor
Electric motor, some of a class of devices that convert electrical energy to mechanical energy, usually by employing electromagnetic phenomena.
What is an electric motor?
How can you bring points in motion and maintain them moving without moving a muscle tissue? While steam engines create mechanical energy using warm steam or, more exactly, steam pressure, electrical motors use electric energy as their resource. 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 movement into electric power. The physical basis of both processes is the electromagnetic induction. In a generator, current is induced and electricity is created when a conductor is within a shifting magnetic field. Meanwhile, in an electric electric motor a current-carrying conductor induces magnetic fields. Their alternating forces of attraction and repulsion generate the foundation for generating motion.
How does an electric motor work?
Motor housing with stator
Motor housing with stator
In general, the heart of a power motor includes a stator and a rotor. The term “stator” is derived from the Latin verb “stare” = “to stand still”. The stator may be the immobile component of a power motor. It is firmly attached to the equally immobile housing. The rotor on the contrary is mounted to the electric motor shaft and can move (rotate).
In case of AC motors, the stator includes the Ac Induction Motor 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 flowing through the wires. This magnetic field produced by the stator induces a current in the rotor. This current then generates an electromagnetic field around the rotor. As a result, the rotor (and 
the attached motor shaft) rotate to check out the rotating magnetic field of the stator.
The electric motor serves to use the created rotary movement in order to drive a gear unit (as torque converter and speed variator) or to directly drive an application as line motor.
What types of electric motors are available?
All inventions started with the DC motor. Nowadays however, AC motors of various designs are the most commonly used electrical motors in the market. They all have got a common result: The rotary motion of the electric motor axis. The function of AC motors is based on the electromagnetic working principle of the DC engine.
DC motors
As with most electric motors, DC motors consist of an immobile part, the stator, and a moving component, the rotor. The stator consists either of an electric magnet utilized to induce the magnetic field, or of long term magnets that continually generate a magnetic field. Within the stator is where in fact the rotor is located, also called armature, that is wrapped by a coil. If the coil is linked to a way to obtain direct current (a electric battery, accumulator, or DC voltage supply unit), it generates a magnetic field and the ferromagnetic primary of the rotor becomes an electromagnet. The rotor is definitely movable installed via bearings and can rotate so that it aligns with the attracting, i.e. opposing poles of the magnetic field – with the north pole of the armature reverse of the southern 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 again and again. This is attained by changing the current direction in the coil. The motor has a so-called commutator for this function. Both supply contacts are connected to the commutator and it assumes the duty of polarity reversal. The changing attraction and repulsion forces ensure that the armature/rotor continues to rotate.
DC motors are mainly utilized in applications with low power rankings. These include smaller tools, hoists, elevators or electrical vehicles.
Asynchronous AC motors
Instead of immediate current, an AC motor requires three-phase alternating current. In asynchronous motors, the rotor can be a so-known as squirrel cage rotor. Turning outcomes from electromagnetic induction of the rotor. The stator consists of windings (coils) offset by 120° (triangular) for each stage of the three-phase current. When connected to the three-stage current, these coils each build up a magnetic field which rotates in the rhythm of the temporally offset range frequency. The electromagnetically induced rotor is usually carried along by these magnetic fields and rotates. A commutator much like the DC engine is not needed in this way.
Asynchronous motors are also known as induction motors, because they function just via the electromagnetically induced voltage. They run asynchronously since the circumferential speed of the electromagnetically induced rotor never reaches the rotational speed of the magnetic field (rotating field). Due to this slip, the effectiveness of asynchronous AC motors is leaner than that of DC motors.
More on the structure of AC motors / asynchronous motors and on what we offer
AC synchronous motors
In synchronous motors, the rotor is equipped with permanent magnets instead of windings or conductor rods. In this way the electromagnetic induction of the rotor could be omitted and the rotor rotates synchronously without slip at the same circumferential acceleration as that of the stator magnetic field. Performance, power density and the possible speeds are thus significantly higher with synchronous motors than with asynchronous motors. However, the design of synchronous motors can be a lot more complex and time-consuming.
Additional information about synchronous motors and our portfolio
Linear motors
As well as the rotating devices that are mainly utilized in the industry, drives for motions on straight or curved tracks are also required. Such motion profiles occur primarily in machine tools in addition to positioning and managing systems.
Rotating electric motors may also convert their rotary movement into a linear motion with the aid of a gear unit, i.e. they can cause it indirectly. Frequently, however, they don’t have the necessary dynamics to realize especially challenging and fast “translational” movements or positioning.
This is where linear motors come into play that generate the translational motion directly (direct drives). Their function could be produced from the rotating electrical motors. To do this, imagine a rotating electric motor “opened up”: The previously round stator becomes a set travel distance (monitor or rail) which is certainly protected. The magnetic field after that forms along this path. In the linear engine, the rotor, which corresponds to the rotor in the three-phase electric motor and rotates in a circle there, is stopped the travel distance in a straight line or in curves by the longitudinally moving magnetic field of the stator as a so-known as carriage or translator.
More details about linear motors and our drive solutions