Simple Gear Selection Procedure

Simple Gear Selection Procedure

The Lewis formula, in the form given by   can be used in a provisional spur gear selection procedure for a given transmission power, input, and output speeds. The procedure is outlined as follows:

  1. Select the number of teeth for the pinion and the gear to give the required gear ratio. Note that the minimum number of teeth permissible when using a pressure angle of 20° is 18.
  2. Use either the standard teeth numbers or as listed in a stock gear catalog.
  3. Select a material. This will be limited to those listed in the stock gear catalogs.
  4. Select a module, m from standard or as listed in a stock gear catalog
  5. Calculate the pitch diameter, d = mN.
  6. Calculate the pitch line velocity, 
  7. Calculate the dynamic factor, 
  8. Calculate the transmitted load, Wt = Power/V.
  9. Calculate an acceptable face width using the Lewis formula in the form 

References:

CHILDS, PETER R. N. MECHANICAL DESIGN ENGINEERING HANDBOOK. BUTTERWORTH-HEINEMANN LTD, 2014.

 

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