MEC-41

Lewis gear bending

Spur-tooth bending with form factor Y.

Reading speed

MachinesLewis gear bending

Governing equation

\sigma=F_t/(b m Y)

where

F_t: Tangential (N)
b: Face (mm)
m: Module (mm)
Y: Lewis Y (—)
\sigma: Stress (MPa)

Lecture brief

Historical brief

Machine design grew from Coulomb torsion and Hertz contact (1881) through Soderberg fatigue and the heat-engine cycle. The lab writes shaft, bearing, contact and thermodynamic limits in SI. This sheet (MEC-41 — Lewis gear bending) is the form associated with Lewis gear bending. Working symbols: $F_t$ , $b$ , $m$ , $Y$ $\rightarrow$ $\sigma$ . Spur-tooth bending with form factor Y. Pedagogical SI sheet with a live model and a swept parameter.

Purpose

Purpose: compute

\sigma

from

F_t

b

m

Y

in Mechanical via

\sigma=F_t/(b m Y)

Spur-tooth bending with form factor Y. Use it when a real mechanical question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

F_t = 1200.000\,\mathrm{N}

b = 20.000\,\mathrm{mm}

m = 3.000\,\mathrm{mm}

Y = 0.300\,\mathrm{—}

, the governing relation

\sigma=F_t/(b m Y)

yields

\sigma = 66.67\,\mathrm{MPa}

. One governing identity, SI units, a single sweep on the sheet. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Tangential F_t1200 NFace b20 mmModule m3 mmLewis Y Y0.3 —

Outputs

Stress \sigma66.67 MPa

Reading speed

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Narration of this film

One governing identity, SI units, a single sweep on the sheet.

Spur-tooth bending with form factor Y. Pedagogical SI sheet with a live model and a swept parameter.

Reading speed

Watch on YouTube