Gearbox Comparison Guide — Planetary vs Helical vs Worm

Gearbox Type Comparison Guide

Selecting the right gearbox type is one of the most important engineering decisions in industrial drive design. This guide compares the three most common reducer types: planetary, helical, and worm gearboxes.

Quick Comparison

Parameter	Planetary	Helical	Worm
Efficiency	90-97%	95-98%	60-90%
Torque Density	Highest	High	Medium
Ratio Range	1:5 - 1:500+	1:2.5 - 1:40	1:5 - 1:100
Noise Level	Low	Very Low	Low
Self-Locking	No	No	Yes
Cost	Medium	Low	Lowest
Best For	High torque, compact space	General industrial, continuous duty	Light duty, position holding

When to Choose Planetary Gearboxes

Choose planetary when you need:

Maximum torque in the smallest footprint
High reduction ratios in a compact multi-stage design
Heavy continuous duty in mining, cement, or steel applications
High starting torque capability
Compact mounting in space-constrained equipment

Typical applications: Mining conveyor drives, cement mill drives, crane hoist systems, heavy-duty mixers

Avoid planetary when: Cost is the primary constraint, or the application does not require high torque density. Helical reducers offer similar performance at lower cost for moderate-duty applications.

When to Choose Helical Gearboxes

Choose helical when you need:

Highest efficiency (up to 98%) for energy-sensitive applications
Quiet, smooth operation for continuous-duty environments
Wide torque range at competitive cost
Flexible mounting positions (B3, B5, B6, B7, B8)
General industrial applications across multiple sectors

Typical applications: Conveyor systems, mixer drives, fan and blower drives, pump drives, packaging machinery

Avoid helical when: You need self-locking capability (worm is better), or extreme torque density in a very compact space (planetary is better).

When to Choose Worm Gearboxes

Choose worm when you need:

Self-locking feature to hold position without a brake
90-degree right-angle drive in a compact package
Single-stage high reduction ratios
Cost-sensitive projects where efficiency is secondary

Typical applications: Bucket elevators, light-duty conveyors, packaging machinery, positioning systems, small mixers

Avoid worm when: Energy efficiency is critical (worm loses 10-40% to friction), or you need high torque density. Planetary or helical are better choices for demanding applications.

Still Unsure?

Our engineering team provides free gearbox selection consultation. Send us your application details and we will recommend the optimal gearbox type and series.