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Gearing Down A High Speed Input (>10K RPM)

  1. Jun 29, 2015 #1
    Hello All,

    I am trying to find a combination of gearing technologies to satisfy the below design challenge. I don't see a commercially available solution; I am hoping you might be able to help me understand what physical effects make this design problem hard, and propose solutions worth looking into.
    • They system must provide 129 oz in of peak torque.
    • The system must be less than 50mm in diameter, preferably less than 42mm.
    • The system's input will be one of two motors, both of which are in the 200-300 watt power range
      • Motor A provides peak torque of 6.212 oz in. Motor A 's no load speed is 37.7k RPM.
      • Motor B has similar peak torque but a 50k RPM no load speed.
    • The system should attain the highest top speed possible while also meeting all the above specs.
    • If possible, the gearing system will introduce a 45-90 degree turn away from the motor axis.
    This implies a ~24:1 reduction. This system is only run for a few minutes at a time if that helps.

    So far it seems to me that the physical size, power level, gear ratio and peak torque are all reasonable given what is commercially available. There are many two stage planetary gearboxes that would meet all the requirements, except the very high input speed. So far the highest input speed I have seen on a gearbox is 10K RPM.
  2. jcsd
  3. Jun 29, 2015 #2
    Pittman seems to reference a G10 and G12 gearbox for very high speed motors in this chart: http://www.pittman-motors.com/Portals/0/pittman_dc_motor_configuration_options.pdf but those gearboxes don't appear to be listed in any of their catalogs/website and they are likely unable to handle the torque levels I require.

    Also as an anecdote, RC cars use motors very similar (perhaps even identical) to the ones I must use. RC cars get away with a pinion and spur arrangement. How do they get away with that? Is my solution as simple as adding a pinion/spur before some sort of off the shelf planetary gearbox.
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