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Thread: Torque Calculations

  1. #1
    emisnug's Avatar
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    Robert Keyes
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    Been spending some of this evening looking on torque information for brushless motors: this is what I found. Is it right?

    KQ (Constant Torque) = 30/(piKV)

    From there

    Q (Torque) = KQ(I - io)
    With 'I' being current and 'io' being internal resistance in ohms

    Theoretically, this'll give you the torque produced (assuming 100% efficiency) at a given amperage input.

    However, I have no idea if this is right. Could anyone give me a hint? (I'm not great at math. I scraped past the GCSE.)

  2. #2
    TechAUmNu's Avatar
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    Euan Mutch
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    Is that torque in N/m?

    Why is there a piKV?

    There seems to be very little information on brushless motors around.
    Last edited by TechAUmNu; 30th January 2017 at 21:46.

  3. #3
    RobotExtreme's Avatar
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    Guilherme Ferreira
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    Hi,

    Since i started studying a little deeply Electrical motors, they seems to be more "complex" than we think when we look into a real machine, so i doubt that Q (Torque) = KQ(I - io) is a good aproximation even because, what is considerable as "Constant Torque"?

    Brushless motors (BLDC) is considered as a DC motor because we normally associate them to batteries and DC Sources, however they are more similar to normal AC motors than the "old" Brushed DC motor. The best designation is electronically commutated motors (ECM) and they are synchronous motors, this basically mean that the speed is fully proportional with the frequency.

    So they can be analized with almost all equations and relations as the AC synchronous motor easily found on internet.

    Guilherme

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