Electric motor

Electric motor
Electric motor, some of a class of devices that convert electrical energy to mechanical energy, usually by employing electromagnetic phenomena.

What is a power motor?
How can you bring stuff in motion and keep them moving without moving a muscles? While steam engines create mechanical energy using popular steam or, more specifically, steam pressure, electric motors use electrical energy as their resource. For this reason, electrical 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 electricity is created when a conductor is within a shifting magnetic field. Meanwhile, in an electric engine a current-carrying conductor induces magnetic fields. Their alternating forces of appeal and repulsion generate the basis for generating motion.
How does an electric motor work?
Motor housing with stator
Motor housing with stator
Generally, the heart of a power motor includes a stator and a rotor. The word “stator” comes from the Latin verb “stare” = “to stand still”. The stator may be the immobile part of an electric motor. It is firmly mounted on the equally immobile housing. The rotor on the contrary is installed to the motor shaft and may move (rotate).
In the event of AC motors, the stator includes the so-called laminated core, which is wrapped in copper wires. The winding functions as a coil and Ac Induction Motor generates a rotating magnetic field when current can be flowing through the cables. This magnetic field created 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 electric motor shaft) rotate to check out the rotating magnetic field of the stator.

The electric electric motor serves to apply the created rotary movement in order to drive a gear unit (as torque converter and speed variator) or even to directly drive a credit card applicatoin as line motor.
What forms of electric motors are available?
All inventions began with the DC motor. Nowadays however, AC motors of various designs are the most commonly used electrical motors in the industry. They all possess a common result: The rotary movement of the electric motor axis. The function of AC motors is based on the electromagnetic operating principle of the DC motor.

DC motors
As with most electrical motors, DC motors contain an immobile component, the stator, and a moving component, the rotor. The stator consists either of an electric magnet used to induce the magnetic field, or of long term magnets that continuously generate a magnetic field. Inside of the stator is where the rotor can be located, also called armature, that is wrapped by a coil. If the coil is connected to a way to obtain direct current (a battery, accumulator, or DC voltage supply device), it creates a magnetic field and the ferromagnetic core of the rotor becomes an electromagnet. The rotor is usually movable mounted via bearings and can 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 motion, the magnetic alignment should be reversed over and over. This is attained by changing the current path in the coil. The motor has a so-called commutator for this function. Both supply contacts are linked 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 utilized in applications with low power ratings. These include smaller equipment, 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 is definitely a so-known as squirrel cage rotor. Turning outcomes from electromagnetic induction of the rotor. The stator includes windings (coils) offset by 120° (triangular) for each 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 range frequency. The electromagnetically induced rotor is definitely carried along by these magnetic areas and rotates. A commutator as with the DC electric motor is not required in this way.

Asynchronous motors are also known as induction motors, because they function only via the electromagnetically induced voltage. They operate asynchronously since the circumferential rate of the electromagnetically induced rotor by no means reaches the rotational swiftness of the magnetic field (rotating field). For this reason 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 has permanent magnets rather than 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. Efficiency, power density and the possible speeds are thus considerably 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 on the market, drives for actions on directly 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 motion into a linear movement 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 particularly 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 could be produced from the rotating electrical motors. To do this, imagine a rotating engine “exposed”: The previously round stator becomes a set travel distance (monitor or rail) which is certainly protected. The magnetic field after that forms along this route. In the linear motor, the rotor, which corresponds to the rotor in the three-phase engine and rotates in a circle there, is pulled over the travel distance in a straight series or in curves by the longitudinally shifting magnetic field of the stator as a so-known as carriage or translator.

More information regarding linear motors and our drive solutions