Double Reduction Worm Gearbox
A double-reduction worm gearbox places two worm-and-wheel stages in series (or a worm stage following a worm or helical input stage) to reach very high reductions in a single, compact right-angle housing. By multiplying two stages, the unit delivers ratios far beyond what one worm stage can provide, while keeping the worm's strengths of quiet running, simple mounting and a self-locking tendency. Double-reduction worm units suit slow-speed conveyors, gates, agitators, hoists and positioners that need a large reduction and strong load-holding in a small footprint.
Where a single worm stage covers about 5:1 to 100:1, double-reduction units stack two stages to reach several hundred to one, with NMRV+NRV combinations a common way to build the train. Efficiency is the trade-off: because each worm stage carries its own sliding losses, overall efficiency is generally lower than a single stage, often well below 70 percent at high ratios. That same characteristic makes self-locking common at high ratios, useful for holding loads, though it should still be verified per duty. Enclosed-drive practice and gear quality follow AGMA 6034 / ISO 1328 where applicable.
Construction pairs hardened, ground alloy-steel worms with phosphor-bronze worm wheels in each stage. Housings are pressure die-cast aluminium on compact frames and cast iron on larger sizes, with SKF/FAG-equivalent bearings, shaft seals and ISO VG 220/320 lubrication, often synthetic PAO and lifetime-filled to handle the heat of two worm meshes.
The unit accepts an IEC motor adapter, a NEMA flange or a free input shaft, outputs a solid or hollow shaft, and mounts in foot, flange or shaft-mounted arrangements with selectable orientation. Service factor is selected per AGMA SF against thermal and shock duty.
Himalay's MSME partners manufacture double-reduction worm gearboxes with gear-rating to AGMA/ISO 6336 where applicable, ISO 9001 quality systems, load/efficiency test reports and traceability; CE (Machinery Directive), ATEX/IECEx for hazardous areas, and SABER (Saudi Arabia) coordinated as part of the standard order flow.
