Spur and helical gear generator: ISO 21771 geometry, 3D model and STEP export

Input

Gear pair

Teeth z₁ Teeth z₂ Normal module m_nmm Facewidth bmm Helix angle β° Pinion hand Basic rack, ISO 53

Backlash: DIN 3967 tooth thickness fits and the DIN 3964 housing field. The model and the STEP are built at the tooth thickness chosen below - the thinnest by default; the limits and j_t, j_n are on the Inspection tab.

Pinion deviation series Pinion tolerance series Wheel deviation series Wheel tolerance series Housing field, DIN 3964 Model at Tip diameter tolerance

Profile shift

Given as Pinion x₁ Wheel x₂ Pinion tip alteration k₁ Wheel tip alteration k₂

Chamfer and bore

ISO 21771 Figure 24 gives a tip chamfer by two dimensions, the radial height h_K and the top land left, s_aK. The standard gives no value; 0 means none. A chamfer lowers the tip form circle, d_Fa = d_a − 2h_K, and with it the contact ratio.

Pinion chamfer h_K1mm Pinion top land s_aK1mm Wheel chamfer h_K2mm Wheel top land s_aK2mm Pinion boremm Wheel boremm

Measuring balls

Pinion ball D_M1mm Wheel ball D_M2mm

Inspection

The ISO 1328-1 flank classes are on the Load tab: the rating reads them too.

Not part of the design file. The class and grade default to 7, DIN 3967 5's milled wheel (quality 7 to DIN 3961).

Pinion radial grade Wheel radial grade Pinion f_is(design)µm Wheel f_is(design)µm

Load

Pinion torque T₁N·m Pinion speed n₁1/min Required lifeh Driving machine Driven machine

Rating (ISO 6336)

Pinion flank class Wheel flank class Material Material quality Surface hardness

Core hardness wheel in the same material

The face load factor K_Hβ (ISO 6336-1 7.5, Method C) needs the pinion’s shaft. The standards give no default, so the rating waits until the three are filled in.

Arrangement K′ with stiffening Shaft diameter d_shmm Bearing span lmm Pinion offset smm Oil viscosity ν₄₀mm²/s Flank roughness R_zµm Root roughness R_zµm

Advanced

Dynamic factor method Flank modification (helical) Helix modification Mesh misalignment f_ma Position of contact pattern limited pitting acceptable optimum material and manufacture Minimum safety, pitting S_H,min Minimum safety, root S_F,min Mesh load factor K_γ Tip relief, pinion C_aµm Tip relief, wheel C_aµm Root relief, pinion C_fµm Root relief, wheel C_fµm Density, pinionkg/dm³ Density, wheelkg/dm³

Show axes

Press Generate view to see the pair here.

Both gears are built whole: under a second for a spur pair, a few seconds for a helical one. No STEP is written.

pinionwheel

Transverse section in mesh, pinion below. Drawn at the tooth thickness chosen under Model at, as the 3D model and the STEP. drag to pan · wheel to zoom · double-click to fitdrag to pan · two fingers to zoom · double-tap to fit

Axial section through both axes: the root d_fE hidden, the reference cylinder dash-dot. drag to pan · wheel to zoom · double-click to fitdrag to pan · two fingers to zoom · double-tap to fit

Reference diameters

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Centre distance

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Pitting S_H

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Bending S_F

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Results

Filter the dimensions

Dimension	Pinion	Wheel

Quantity	Pinion	Wheel

Enter a pinion torque in the Load tab to rate this pair to ISO 6336.

Inspection	Pinion	Wheel

Spur and helical gear generator: ISO 21771 geometry, 3D model and STEP export

Generated files