Input Parameters

Gear type - according to the position of root and head cone

Gear ratio and tooth numbers

Pressure angle (the angle of tool profile) α t

Helix angle β m

Axis angle Σ

Tangential module on outer cone met (for metric calculation)

Tangential Diametral Pitch on outer cone Pet (for English units)

Unit addendum height ha *

Unit clearance c *

Unit dedendum fillet r f *

Facewidths b 1 , b 2

Unit correction x = x 1 = - x 2

Unit change of tooth thickness x t = x t1 = - x t2

Auxiliary Geometric Calculations

Distribution of Unit Corrections for Single Gears

Design According to the Strength Calculation

Design of Face Width

Calculation of Maximum Dedendum Filleting

Calculated parameters

Normal Pressure Angle in Middle Plane

tg α nm = tg α t cos β m

Pitch angle

Outside pitch diameter

d e1,2 = m et z 1,2

Outside length of surface line on pitch cone

Length of surface line on the mean cone

R m = R e - 0.5 b

Relative face width

Tangential module on the mean cone

Normal module on the mean cone

m mn = m mt cos β m

Mean pitch diameter

d m1,2 = m mt z 1,2

Equivalent number of teeth

Ekvivalent pitch diameter

Ekvivalent base diameter

d vb1,2 = d v1,2 cos α t

Ekvivalent outside diameter

d va1,2 = d v1,2 + 2 h ae1,2 m mt / m et

Ekvivalent center distance

a v = 0.5 (d v1 + d v2 )

Virtual gear ratio

Virtual number of teeth

Virtual pitch diameter

Virtual base diameter

d bn1,2 = d n1,2 cos α t

Virtual outside diameter

d an1,2 = d n1,2 + 2 h ae1,2 m mt / m et

Virtual helix angle at the base cylinder

sin β b = sin β m cos α nm

Virtual center distance

a n = 0.5 (d n1 + d n2 )

Dedendum reduction

k 1,2 = 0.02 (17 - z n1,2 ) for k > 0 the dedendum shortening is done

Addendum

h ae1,2 = m et (h a * + x 1,2 - k 1,2 )

Dedendum

hf e1,2 = m et (h a * + c * - x 1,2 )

Outside diameter

d ae1,2 = d e1,2 + 2ha e1,2 cos δ 1,2

Root diameter

d fe1,2 = d e1,2 - 2 hfe1,2 cos δ 1,2 )

Outside diameter at small end

d ai1,2 = d ae1,2 (1 - ψ R )

Vertex distance

A 1,2 = R e cos δ 1,2 - h ae1,2 sin δ 1,2

Outside bevel angle

Cutting angle

Tooth thickness (measured normally on the pitch diameter)

Chordal facewidth (normal)

s ke1,2 = s e1,2 cos 2 α t

Addendum height above the chord

Unit addendum width (measured normally)

	where:

Operating width of gears

b w = b

Factor of mesh duration

ε γ = ε α + ε β

Minimum correction without tapering

	where:
		h a0 * = h a * + c * - r f * (1 - sin α t )

Minimum correction without undercut

Minimum correction without undercut

Helix angle at end

sinβ e = sinβ m R m /R e

Normal pressure angle at end

tanα ne = tanα t cosβe