Worm Gear Selection

Discussion in 'Physics' started by ajitnayak, May 15, 2014.

  1. ajitnayak

    Thread Starter Member

    Feb 22, 2013
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    Dear all.

    I am trying to construct single and dual axis tracker using Worm gear box.I tried to Google but didn't find relevant relation i am looking for.
    1. How worm gear box selected for single or dual axis tracker?
    2. how gear ratio is choose??
    3. how output torque calculated on worm gear box
    4. how output/ input power are considered
    5. how axial load and radial load calculated???
    6. how speed is calculated??
    7. how to choose relevant motors??

    If any can share useful link also helpful to understand. I know these are too many silly question.But i really wanted to know answer.

    Link for worm gear box:
    http://www.sunflowerenergyinc.com/Slewing_Drive_-_032511_-_REV.03.pdf
     
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
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  3. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The most often reason for selecting a G.B. is for economics on the motor size and drive, so if the max output side rpm is known, the G.B. ratio would be to supply a G.B at a ratio that would enable a selected motor to operate at mid to upper rpm range.
    This is a rough generalization.
    The other things to consider is that the torque will increase by a ratio of the reduction.
    The first is to establish the output load and the desired RPM.
    Then work backwards.
    There are various was to establish load torque, if there is minimal accel/decel required, the breakaway torque can be obtained by simple means, one is the use of a torque wrench of suitable size.
    Max.
     
  4. ajitnayak

    Thread Starter Member

    Feb 22, 2013
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    @short bus

    for my application I need to with High torque motor with low speed.

    Since N1T1=N2T2
    If my output run @ torque of 1300nm and speed of 60 rpm
    my input from stepper motor run @ 300 rpm

    T1=N2*T2/N1=260 Nm efficient.
     
  5. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    WOW!! What are you moving? A stepper motor and gearbox won't do this. 1300 newton-meter is equal to 958.8 pound foot! This is multi-cylinder diesel engine type torque.
     
  6. ajitnayak

    Thread Starter Member

    Feb 22, 2013
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  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    But they don't run at 60 RPM! They run at one rev per DAY.

    That is more gearing than just one worm drive. :)
     
  8. ajitnayak

    Thread Starter Member

    Feb 22, 2013
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    Can you give us some guideline HEre.

    Even though it run particular time of the day turn on and turn off time will be approximately 3 minute.can you suggest me Or explain with Some formula so i can use it for calculation.

    Like How i should
    1)select output torque and speed of worm gear depend on load.
    2)How Motor Selected @ input side of Worm gear
    3)Is above calculation i made right or wrong . if Wrong How to consider point
     
  9. shortbus

    AAC Fanatic!

    Sep 30, 2009
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    Is this a 'homework' assignment? No offense meant here, but if this is a real project, shouldn't a qualified engineer be handling it? There is more to doing this than just the weight of the panels themselves. Wind and storm loading has to be figured in to this. Friction of the many 'gimbals' or rotation points and many more things are going to have to be figured in. And a stepper motor isn't going to do it, no matter how much gearing is used.
     
  10. MaxHeadRoom

    Expert

    Jul 18, 2013
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    The first thing to do as I mentioned is to obtain or measure the required breakaway torque, in the case shown, A suitable torque wrench could be used, If these panels are pivoted by some means, the effort should not be that great.
    If the incremental movement occurs every 3 minutes I would be looking as a motor with feedback to increment the desired angle and then use a brake in the off position as there is no need to have the motor active during this time.
    Max.
     
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