Lewis Gear Strength Calculator

Enter value and click on calculate. Result will be displayed.

Gear Pitch:
Face Width (inches):
Tensile Strength of Material (PSI):
Number of Teeth:
RPM:
Maximum Safe Tooth Load:
Pounds
Maximum Safe Tooth Load:
Kilograms

To make the Lewis Gear Strength Calculator more interactive, here’s a simple guide to input your values and get the calculated bending stress. If you'd like, I can provide this as a tool, or you can calculate it manually by following the steps outlined below.

Lewis Gear Strength Formula Recap

The bending stress (σb) in a gear tooth is calculated using the following formula:

Where:

  • σb = Bending stress (Pa or MPa)
  • Ft= Tangential load (N)
  • P = Circular pitch (m)
  • b = Face width of the gear (m)
  • Y = Lewis form factor (dimensionless)

Steps for Calculation:

  1. Calculate Tangential Load (Ft): The tangential load is calculated from the torque using the formula:

    Where:

    • T = Transmitted torque (Nm)
    • d = Pitch diameter (m)

  2. Calculate Circular Pitch (P): Circular pitch is calculated as:

    Where:

    • d = Pitch diameter (m)
    • N = Number of teeth

  3. Calculate the Lewis Form Factor (Y): The Lewis form factor depends on the number of teeth and the pressure angle. It is calculated as:

    Where:

    • N = Number of teeth
    • β = Pressure angle (typically 20° or 25°)

  4. Calculate Bending Stress (σb): Use the formula:

Now, Input the Following Values:

  • Number of teeth (N):
  • Pitch diameter (d) [m]:
  • Transmitted torque (T) [Nm]:
  • Face width (b) [m]:
  • Pressure angle (β) [°]: