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 do you bring stuff in motion and keep them moving without moving a muscle tissue? While steam engines create mechanical energy using sizzling steam or, more precisely, steam pressure, electric motors use electrical energy as their source. For this reason, electric motors are also called electromechanical transducers.
The counter piece to the electric motor is the generator, that includes a similar structure. Generators transform mechanic movement into energy. The physical basis of both procedures may be the electromagnetic induction. In a generator, current is definitely induced and electricity is created whenever a conductor is within a shifting magnetic field. Meanwhile, within an electric electric motor a current-having conductor induces magnetic areas. Their alternating forces of appeal and repulsion produce the foundation for generating motion.
How does an electric motor work?
Motor Ac Induction Motor housing with stator
Motor housing with stator
In general, the heart of a power motor contains a stator and a rotor. The term “stator” comes from the Latin verb “stare” = “to stand still”. The stator may be the immobile part of an electric motor. It really 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 acts 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 then generates an electromagnetic field around the rotor. Because of this, the rotor (and the attached electric motor shaft) rotate to check out the rotating magnetic field of the stator.
The electric motor serves to use the created rotary motion to be able 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 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 industry. They all possess a common result: The rotary motion of the motor axis. The function of AC motors is based on the electromagnetic working theory of the DC motor.
As with most electrical motors, DC motors contain an immobile component, the stator, and a moving component, the rotor. The stator consists either of a power magnet utilized to induce the magnetic field, or of permanent magnets that constantly generate a magnetic field. Within the stator is where in fact the rotor is located, also known as armature, that is wrapped by a coil. If the coil is linked to a source of direct current (a electric 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 mounted via bearings and will rotate so 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 established the rotor in a continuous rotary motion, the magnetic alignment should be reversed again and again. This is attained by changing the current direction in the coil. The electric motor has a so-called commutator for this purpose. The two supply contacts are linked 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 ratings. These include smaller equipment, hoists, elevators or electrical vehicles.
Asynchronous AC motors
Instead of immediate current, an AC motor requires three-phase alternating electric current. In asynchronous motors, the rotor is a so-called squirrel cage rotor. Turning outcomes from electromagnetic induction of the rotor. The stator includes 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 series frequency. The electromagnetically induced rotor is certainly carried along by these magnetic areas and rotates. A commutator as with the DC motor is not required in this way.
Asynchronous motors are also known as induction motors, as they function only via the electromagnetically induced voltage. They operate asynchronously because the circumferential acceleration of the electromagnetically induced rotor never reaches the rotational quickness 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 structure of AC motors / asynchronous motors and upon what we offer
AC synchronous motors
In synchronous motors, the rotor is equipped with permanent magnets rather than windings or conductor rods. In this way the electromagnetic induction of the rotor can be omitted and the rotor rotates synchronously without slip at the same circumferential acceleration as that of the stator magnetic field. Effectiveness, power density and the possible speeds are thus significantly higher with synchronous motors than with asynchronous motors. However, the look of synchronous motors is also much more complex and time-consuming.
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As well as the rotating machines that are mainly utilized in the industry, drives for movements on directly or curved tracks are also required. Such motion profiles occur primarily in machine tools as well as positioning and managing systems.
Rotating electric motors can also convert their rotary motion into a linear motion using a gear unit, i.e. they are able to cause it indirectly. Often, however, they don’t have the required dynamics to realize especially demanding 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 electric motors. To do this, imagine a rotating motor “exposed”: The previously round stator becomes a flat travel distance (monitor or rail) which is covered. The magnetic field after that forms along this path. In the linear engine, the rotor, which corresponds to the rotor in the three-phase engine and rotates in a circle there, is stopped the travel range in a straight collection or in curves by the longitudinally moving magnetic field of the stator as a so-called carriage or translator.
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