Electric motor
Electric motor, any of a class of devices that convert electrical energy to mechanical energy, usually by employing electromagnetic phenomena.
What is an electric motor?
How do you bring issues in motion and maintain them moving without moving a muscle mass? While steam engines create mechanical energy using hot steam or, more specifically, 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 motor is the generator, that includes a similar structure. Generators transform mechanic motion into energy. The physical basis of both processes is the electromagnetic induction. In a generator, current is induced and electrical energy is created when a conductor is at a moving magnetic field. Meanwhile, within an electric engine a current-holding conductor induces magnetic areas. Their alternating forces of attraction and repulsion produce the foundation for generating motion.
How does a power motor work?
Motor housing with stator
Motor housing with stator
Generally, the heart of an electric motor consists of a stator and a rotor. The word “stator” comes from the Latin verb “stare” = “to stand still”. The stator is the immobile component of a power motor. It really is firmly mounted on the equally immobile housing. The rotor on the other hand is installed to the engine shaft and may move (rotate).
In case of AC motors, the stator includes the so-called laminated core, which is wrapped in copper wires. The winding acts as a coil and generates a rotating magnetic field when current is usually flowing through the cables. This magnetic field created by the stator induces a current in the rotor. This current then generates an electromagnetic field around the rotor. Consequently, the rotor (and the attached engine shaft) rotate to check out the rotating magnetic field of the stator.
The electric engine serves to use the created rotary motion in order to drive a equipment unit (as torque converter and speed variator) or to directly drive an application as line motor.
What forms of electric motors are available?
All inventions began with the DC electric motor. Nowadays nevertheless, AC motors of various designs are the mostly used electric motors in the industry. They all possess a common result: The rotary movement of the electric motor axis. The function of AC motors is founded on the electromagnetic working theory of the DC electric motor.
DC motors
As with most electric motors, DC motors contain an immobile part, the stator, and a moving element, the rotor. The stator consists either of an electric magnet utilized to induce the magnetic field, or of long term magnets that consistently generate a magnetic field. Within the stator is where in fact the rotor is certainly located, also known as armature, that is wrapped by a coil. If the coil is connected to a way to obtain direct current (a electric battery, accumulator, or DC voltage supply device), it 
generates a magnetic field and the ferromagnetic core of the rotor turns into an electromagnet. The rotor is certainly movable installed via bearings and may rotate to ensure that it aligns with the attracting, i.e. 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 movement, the magnetic alignment should be reversed again and again. This is achieved by changing the current path in the coil. The electric motor has a so-called commutator for this purpose. Both supply contacts are linked to the commutator and it assumes the duty of Ac Induction Motor polarity reversal. The changing attraction and repulsion forces ensure that the armature/rotor proceeds to rotate.
DC motors are mainly used in applications with low power ratings. These include smaller tools, hoists, elevators or electrical vehicles.
Asynchronous AC motors
Instead of direct current, an AC motor requires three-phase alternating electric current. In asynchronous motors, the rotor can be a so-called squirrel cage rotor. Turning outcomes 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 areas and rotates. A commutator as with the DC engine is not needed in this way.
Asynchronous motors are also called induction motors, because they function only via the electromagnetically induced voltage. They operate asynchronously since the circumferential velocity of the electromagnetically induced rotor by no means reaches the rotational speed of the magnetic field (rotating field). Due to this slip, the efficiency of asynchronous AC motors is lower than that of DC motors.
More on the framework of AC motors / asynchronous motors and upon 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 quickness as that of the stator magnetic field. Efficiency, power density and the feasible speeds are thus significantly higher with synchronous motors than with asynchronous motors. However, the design of synchronous motors can be much 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 on the market, drives for motions on directly or curved tracks are also required. Such movement profiles occur primarily in machine tools in addition to positioning and handling systems.
Rotating electric motors may also convert their rotary movement into a linear movement using a gear unit, i.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.
That’s where linear motors enter into play that generate the translational motion directly (direct drives). Their function can be derived from the rotating electrical motors. To get this done, imagine a rotating electric motor “opened up”: The previously circular stator becomes a flat travel distance (monitor or rail) which is certainly protected. The magnetic field after that forms along this route. In the linear electric motor, the rotor, which corresponds to the rotor in the three-phase motor and rotates in a circle there, is stopped the travel range in a straight series or in curves by the longitudinally moving magnetic field of the stator as a so-called carriage or translator.
More details about linear motors and our drive solutions