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Oversized Pulley Bore Hole

  1. Dec 5, 2013 #1
    What would happen if the bore hole of a pulley in a conveyor was significantly larger than the shaft like in the figure below:


    I would imagine if the RPM was high, the whole system would shake violently. However, what if the RPM was around 30 RPM. Would the conveyor still function properly? At such low speeds I feel like it would still work, however, I have never seen something like this in the industrial world which is why I am curious.

    The shaft diameter is approximately 1 inch and the bore is approximately 2 inches.
    Last edited: Dec 5, 2013
  2. jcsd
  3. Dec 5, 2013 #2


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    Staff: Mentor

    Can you provide more context? Is this from an existing conveyor system? How wide is it, what is the pulley spacing, what is the belt material, what is being moved by the conveyor?
  4. Dec 5, 2013 #3


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    Science Advisor
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    That would act like an off center load, making the shaft assembly vibrate violently. You need a bearing to keep the shaft well behaved.
  5. Dec 5, 2013 #4


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    Is the white space air? If it was an idler then the bearing should be replaced. The eccentric roller - shaft would wear very quickly since the shaft would be in direct contact with the inside of the roller. It would be noisy and cost more power to operate.
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