Free 173 Best Homemade Tools eBook:  
Results 1 to 6 of 6

Thread: AN UNUSUAL MOTOR

  1. #1

    Join Date
    Feb 2019
    Posts
    54
    Thanks
    4
    Thanked 70 Times in 32 Posts

    mariost's Tools

    AN UNUSUAL MOTOR

    CAN ANYBODY EXPLAIN HOW IT WORKS? I made it after following the instructions from a video in the net and actually it works. I cannot understand how it happens.
    In this motor there are no coils , magnetic fields, magnets, and brushes.There are only two bearings connected by a metal axis.
    The current flows through the first bearing, the axis and then the other bearing. The electrical power supply is connected to the outer rings of the bearings.

    MOTOR PROPERTIES:
    1. the engine must be first started. Cannot start alone with the current.
    2. the motor rotates in either direction.
    3. the engine is working both direct current and alternating current.The power is approximately 5 to 12 Volts with very strong current , about 20 or more Amps.(this is a short circuit and after a few seconds everything is too hot.)
    There are different explanation. One of them is :
    "In the ball bearing Motor" the current passes through inner race of one side ball bearing , then to the shaft , outer race of other ball bearing , then to inner race , causes a temporally expansion of each ball , deforms it to elliptical and adds pressure between inner & outer race then cause a moment of rotation , for that reason , it needs a prime movement to sustain rotation , by the way it doesn't matter whether the current is DC or AC , it just used to heat up the balls. WATCC THE VIDEO HERE:
    Attached Thumbnails Attached Thumbnails AN   UNUSUAL   MOTOR-7-10-2018-1-25-39-.jpg   AN   UNUSUAL   MOTOR-7-10-2018-1-28-02-.jpg   AN   UNUSUAL   MOTOR-7-10-2018-1-29-11-.jpg   AN   UNUSUAL   MOTOR-7-10-2018-1-31-13-.jpg  

  2. The Following 2 Users Say Thank You to mariost For This Useful Post:

    Gromet (04-21-2019), Seedtick (04-19-2019)

  3. #2
    JTG
    JTG is online now

    Join Date
    Dec 2018
    Posts
    35
    Thanks
    5
    Thanked 42 Times in 24 Posts
    Ah yes, the ball bearing motor -- a most unusual motor, and one that works purely through electromagnetic forces. The thermal expansion theory given by S. Marinov is wrong, but so were the first several attempts to explain it with electromagnetism. If the thermal mechanism were true, then simply passing electric current through a lone ball bearing (given an initial spin) should create a motor; I invite you to connect one lead to the inner race of a bearing, use a brush to make contact with the outer race, and see what happens.

    The actual mechanism is a rather complex interaction between the magnetic field of the axle (because you cannot pass a current through a conductor without creating a magnetic field) and the induced currents (via Lorentz forces) in the rolling elements of the bearing. Here's a pdf of a simplified version of the explanation, via Princeton. The full explanation gets into some very heavy math, but the calculations predict forces that closely match those observed experimentally, making it the most likely explanation of how this motor works.

  4. The Following 2 Users Say Thank You to JTG For This Useful Post:

    KustomsbyKent (04-21-2019), that_other_guy (04-24-2019)

  5. #3

    Join Date
    Feb 2019
    Posts
    54
    Thanks
    4
    Thanked 70 Times in 32 Posts

    mariost's Tools
    The strange thing of it all is that it works the same also with AC.

  6. #4
    [email protected] tonyfoale's Avatar
    Join Date
    Nov 2016
    Location
    Spain
    Posts
    743
    Thanks
    299
    Thanked 1,245 Times in 380 Posts

    tonyfoale's Tools
    Quote Originally Posted by mariost View Post
    The strange thing of it all is that it works the same also with AC.
    I don't think that it is strange. AC is just DC changing direction. So if with DC the direction of rotation is only dependent on the initial physically forced rotation, and not supply polarity then it follows that AC should work just as well. QED.

  7. #5
    [email protected] tonyfoale's Avatar
    Join Date
    Nov 2016
    Location
    Spain
    Posts
    743
    Thanks
    299
    Thanked 1,245 Times in 380 Posts

    tonyfoale's Tools
    A question.
    Does the speed of rotation depend on how fast you physically spin the disc at startup or is it only necessary to start it in a given direction and then it speeds up to some equilibrium RPM?

    Does the speed depend on voltage and hence current?

  8. #6
    JTG
    JTG is online now

    Join Date
    Dec 2018
    Posts
    35
    Thanks
    5
    Thanked 42 Times in 24 Posts
    This type of motor has no starting torque, so the initial push is just to get things going, and it will speed up until it draws the maximum current available from the power supply and/or it hits the frictional limit of the bearings. There's a roughly linear relation between speed and current, up until the motor seizes when the bearings overheat.

    Here's a pdf of a research article comparing AC and DC operation -- the speeds are fairly consistent for a given current, and slightly faster with DC, though DC killed the bearings faster. Their test motors could run for up to a minute before they overheated and seized, even in a kerosene bath, but some of them maxed out near 10k rpm (25A DC pumped through a motor with 1/2" bearings).


    Post your reply!
    Join 33,912 of us and get our 173 Must Read Homemade Tools eBook free.



    173 Must Read Homemade Tools

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •