Design quieter drives with accurate helical calculations fast. Validate ratios, diameters, and forces in minutes. Export results, compare scenarios, and share with teammates easily.
| Scenario | mn (mm) | β (°) | z1 | z2 | b (mm) | n1 (rpm) | Power (kW) | Key output |
|---|---|---|---|---|---|---|---|---|
| Conveyor drive | 3.0 | 15 | 20 | 60 | 35 | 900 | 7.5 | Center distance ~124 mm |
| Packaging line | 2.0 | 20 | 18 | 36 | 25 | 1500 | 4.0 | Ft typically near 600–900 N |
| High-speed stage | 1.5 | 25 | 24 | 48 | 20 | 3000 | 3.0 | Velocity ~5–7 m/s, check ε |
Helix angle increases overlap and perceived smoothness, yet it introduces axial thrust that bearings must support. In the 15°–25° range, overlap ratio rises with face width, while the transverse module grows because mt = mn/cosβ. That raises pitch diameters and center distance for a fixed tooth count. Use smaller β when packaging is tight, and higher β when noise and load sharing are priorities.
Normal module sets tooth size, bending stiffness, and manufacturing scale. Because pitch diameter is d = mt·z, diameters change linearly with teeth, while ratio is governed mainly by z2/z1. Center distance equals (d1+d2)/2, so even a two‑tooth change can move shafts several millimeters. Confirm root diameter remains positive after dedendum, and keep face width typically 8–14× mn for balanced load distribution.
Torque follows T = 9550·P/n for power P in kW and speed n in rpm. The calculator applies a sizing adjustment using Ks/η to reflect duty severity and efficiency losses, producing a conservative design torque. Pitch line velocity v = π·d1·n/60 indicates dynamic behavior; as velocity rises, surface finish, lubrication, and runout become more important. High speeds often justify tighter quality grades and better balancing.
Tangential force Ft transfers power and is computed from Ft = 2·Tdesign/d1. Radial force Fr = Ft·tanφt pushes shafts apart, increasing bearing radial loads and housing deflection risk. Axial force Fa = Ft·tanβ is characteristic of helical gearing and may dominate bearing selection at higher β. The normal force estimate helps compare contact loading across scenarios, especially when β and pressure angle change together.
Total contact ratio ε = εα + εβ estimates how many tooth pairs share load at any instant. Higher ε generally reduces vibration, improves load sharing, and tolerates minor errors better. If ε is low, increase face width, adjust helix angle, or revisit tooth counts while maintaining center distance constraints. Treat outputs as geometry and force baselines, then confirm rating factors, material limits, and life with ISO or AGMA strength calculations. Document assumptions and compare multiple runs to guide design decisions.
It uses common full‑depth proportions: addendum ≈ mn and dedendum ≈ 1.25·mn in the normal system. Outside and root diameters are therefore approximate and may differ with profile shift, tooling, or standards.
Helical teeth are angled, so spacing in the transverse plane stretches. The relationship mt = mn/cosβ increases mt as β increases, raising pitch diameters and center distance for the same tooth count.
Ft drives power transfer at the pitch circle. Fr pushes gears apart and loads bearings radially. Fa is axial thrust from the helix angle and can require dedicated thrust bearings or paired bearings.
Higher is usually smoother. Many designs target ε above about 1.4, but requirements vary with noise limits, quality grade, and load. Use ε as a comparative metric while confirming strength and durability separately.
Ks inflates load to reflect shocks and duty severity, while η accounts for losses. The combined adjustment provides a simple, conservative design torque for estimating mesh forces and comparing candidate geometries.
Use them as a baseline for geometry and load estimates. Final rating should include material properties, stress factors, reliability targets, and standard methods such as ISO or AGMA for bending and pitting resistance.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.