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
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Normal Pressure Angle in Middle Plane
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tg α nm = tg α t cos β m |
Pitch angle
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Outside pitch diameter
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d e1,2 = m et z 1,2 |
Outside length of surface line on pitch cone
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Length of surface line on the mean cone
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R m = R e - 0.5 b |
Relative face width
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Tangential module on the mean cone
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Normal module on the mean cone
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m mn = m mt cos β m |
Mean pitch diameter
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d m1,2 = m mt z 1,2 |
Equivalent number of teeth
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Ekvivalent pitch diameter
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Ekvivalent base diameter
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d vb1,2 = d v1,2 cos α t |
Ekvivalent outside diameter
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d va1,2 = d v1,2 + 2 h ae1,2 m mt / m et |
Ekvivalent center distance
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a v = 0.5 (d v1 + d v2 ) |
Virtual gear ratio
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Virtual number of teeth
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Virtual pitch diameter
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Virtual base diameter
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d bn1,2 = d n1,2 cos α t |
Virtual outside diameter
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d an1,2 = d n1,2 + 2 h ae1,2 m mt / m et |
Virtual helix angle at the base cylinder
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sin β b = sin β m cos α nm |
Virtual center distance
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a n = 0.5 (d n1 + d n2 ) |
Dedendum reduction
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k 1,2 = 0.02 (17 - z n1,2 ) for k > 0 the dedendum shortening is done |
Addendum
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h ae1,2 = m et (h a * + x 1,2 - k 1,2 ) |
Dedendum
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hf e1,2 = m et (h a * + c * - x 1,2 ) |
Outside diameter
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d ae1,2 = d e1,2 + 2ha e1,2 cos δ 1,2 |
Root diameter
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d fe1,2 = d e1,2 - 2 hfe1,2 cos δ 1,2 ) |
Outside diameter at small end
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d ai1,2 = d ae1,2 (1 - φ R ) |
Vertex distance
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A 1,2 = R e cos δ 1,2 - h ae1,2 sin δ 1,2 |
Outside bevel angle
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Cutting angle
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Tooth thickness (measured normally on the pitch diameter)
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Chordal facewidth (normal)
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s ke1,2 = s e1,2 cos 2 α t |
Addendum height above the chord
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Unit addendum width (measured normally)
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where: |
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Operating width of gears
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b w = b |
Factor of mesh duration
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ε γ = ε α + ε β
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Minimum correction without tapering
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where: |
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h a0 * = h a * + c * - r f * (1 - sin α t ) |
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Minimum correction without undercut
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Minimum correction without undercut
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Helix angle at end
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sinβ e = sinβ m R m /R e |
Normal pressure angle at end
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tanα ne = tanα t cosβe |