DC motor rotor + stator : torque by attraction ?

In summary, the concept of torque by attraction in a DC motor is based on the force created by the interaction of two magnetic fields, one from the rotor and one from the stator. The direction of the magnetic fields determines the direction of rotation, and the force is strongest when the fields are aligned. This may seem contradictory, but it is due to the fact that the flux vector only points in the direction of the flux at a specific location. By understanding this, it becomes clear why both images presented are correct and the confusion is solved.
  • #1
An1MuS
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DC motor rotor + stator : torque by attraction ? [Solved]

So on that image there's a very simple dc motor.

Knowing that F = B*I, the force acting on the wire can be represented as on the image.
Also the current passing through the rotor will create a magnetic field, represented by Brotor, pointing downards.
Acording to the first image, it will rotate as if the magnetic fields align, because of the F = BI equation, so both magnetic fields would point in the same direction.

TlaMt.gif



On the other hand, here we just have that the opposite poles attract, so the force is for the magnetic fields to point in opposite directions.

Uaml2.jpg


I'm having some difficulty understanding this, because these concepts seem to contradict each other.

1Plpe.png


So where am i thinking wrong here?
 
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  • #2
Could it be because on the outside the flux of the rotor points upward ?

http://imageshack.us/f/14/asdadfq.jpg/
 
  • #3
Ok i think I've come to grips to what's causing the confusion.

Since i saw the magnet flux from north to south, i assumed wrongly that South is where the flux vector always points.

But it seems it only points in the direction of the flux on that specific location. So both images are correct and this problem is solved.

magpart3a.gif
 

1. What is a DC motor rotor and stator?

A DC motor rotor and stator are two essential components of a DC motor. The rotor is the rotating part of the motor, while the stator is the stationary part. The stator contains the permanent magnets, and the rotor contains the electromagnets. When an electric current is passed through the electromagnets, it interacts with the permanent magnets, causing the rotor to rotate and produce torque.

2. How does torque by attraction work in a DC motor?

Torque by attraction is the principle by which a DC motor generates motion. When an electric current is passed through the electromagnets on the rotor, they create a magnetic field. This magnetic field interacts with the permanent magnets on the stator, causing a force of attraction between them. This force of attraction produces torque, which causes the rotor to rotate.

3. What factors affect the torque by attraction in a DC motor?

The torque by attraction in a DC motor is affected by several factors, including the strength of the permanent magnets, the number of turns in the electromagnets, and the current passing through the electromagnets. Additionally, the distance between the rotor and stator, known as the air gap, also plays a role in determining the torque by attraction.

4. How is torque by attraction measured in a DC motor?

Torque by attraction is typically measured in units of force multiplied by distance, such as newton-meters or pound-feet. To measure the torque by attraction in a DC motor, a torque sensor is typically used. This sensor measures the force exerted by the rotor and converts it into a measurable unit of torque.

5. Can the torque by attraction in a DC motor be changed?

Yes, the torque by attraction in a DC motor can be changed by altering the strength of the permanent magnets, the number of turns in the electromagnets, or the current passing through the electromagnets. Additionally, the air gap between the rotor and stator can also be adjusted to change the torque by attraction. However, these changes may also affect other aspects of the motor's performance, such as speed and efficiency.

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