Electric motor

Electric motor
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 factors in motion and maintain them moving without moving a muscle tissue? While steam engines create mechanical energy using incredibly hot steam or, more specifically, steam pressure, electric Ac Induction Motor motors use electrical energy as their source. For this reason, electric motors are also called electromechanical transducers.

The counter piece to the electric engine is the generator, that includes 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 certainly induced and electrical energy is created when a conductor is within a shifting magnetic field. Meanwhile, in an electric engine a current-holding conductor induces magnetic fields. 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 a power 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 component of a power motor. It really is firmly mounted on the equally immobile casing. The rotor on the contrary is installed to the engine shaft and can move (rotate).
In case of AC motors, the stator includes the so-called laminated core, which is wrapped in copper wires. The winding works as a coil and generates a rotating magnetic field when current is usually flowing through the wires. This magnetic field made 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 motor shaft) rotate to follow the rotating magnetic field of the stator.

The electric electric motor serves to apply the created rotary motion in order 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 started with the DC motor. Nowadays however, AC motors of varied designs are the mostly used electric motors in the industry. They all possess a common result: The rotary motion of the engine axis. The function of AC motors is founded on the electromagnetic working basic principle of the DC electric motor.

DC motors
As with most electric motors, DC motors consist of an immobile component, the stator, and a moving element, the rotor. The stator consists either of a power magnet utilized to induce the magnetic field, or of long term magnets that continually generate a magnetic field. Inside of the stator is where the rotor can be located, also known as armature, that is wrapped by a coil. If the coil is connected to a source of 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 movable installed via bearings and will 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 way round.

In order to arranged the rotor in a continuing rotary movement, the magnetic alignment must be reversed again and again. This is achieved by changing the current path in the coil. The motor has a so-called commutator for this purpose. Both supply contacts are connected to the commutator and it assumes the task of 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 rankings. These include smaller equipment, 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 certainly a so-called squirrel cage rotor. Turning outcomes from electromagnetic induction of this rotor. The stator contains windings (coils) offset by 120° (triangular) for each stage 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 range frequency. The electromagnetically induced rotor is definitely 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 run asynchronously since the circumferential swiftness of the electromagnetically induced rotor never reaches the rotational swiftness of the magnetic field (rotating field). For this reason slip, the performance of asynchronous AC motors is leaner than that of DC motors.

More on the structure of AC motors / asynchronous motors and upon what we offer

AC synchronous motors
In synchronous motors, the rotor has permanent magnets rather than windings or conductor rods. In this manner the electromagnetic induction of the rotor can be omitted and the rotor rotates synchronously without slip at the same circumferential rate 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.

More details about synchronous motors and our portfolio

Linear motors
As well as the rotating machines that are mainly used on the market, drives for motions on straight or curved tracks are also required. Such movement profiles occur primarily in machine tools along with positioning and managing systems.

Rotating electric motors may also convert their rotary motion into a linear movement with the aid of a gear unit, i.e. they are able to cause it indirectly. Frequently, however, they do not have the required 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 derived from the rotating electrical motors. To do this, imagine a rotating electric motor “exposed”: The previously circular stator becomes a set travel distance (monitor or rail) which is certainly protected. The magnetic field then forms along this path. In the linear electric motor, 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 range or in curves by the longitudinally moving magnetic field of the stator as a so-known as carriage or translator.

More information about linear motors and our drive solutions