Coaxial Helical Gearbox
A coaxial helical gearbox is an inline reducer in which the helical gear stages share a common axis, so input and output shafts lie on the same line. The straight-through path makes the unit axially compact and mechanically efficient, and the angled helical teeth engage progressively for smooth, quiet meshing with good load sharing. Coaxial units are a default reducer for pumps, fans, conveyors, mixers and general drives where the machine layout suits an in-line input and output.
The unit is built as a single-, two- or three-stage train. A single stage typically covers about 1.25:1 to 8:1; two- and three-stage versions reach roughly 200:1 and higher. Per-stage efficiency is generally high, commonly cited near 96-98 percent, so even three-stage coaxial units usually stay well above 90 percent overall. Power and torque scale with frame size, from fractional-kW gearmotors to several hundred kW. Load rating follows AGMA 2001/2101 or ISO 6336, with enclosed-drive practice per AGMA 6010 and gear quality to ISO 1328 / AGMA 2015.
Gears are case-hardened alloy steel (20MnCr5 or 18CrNiMo7-6) with ground or lapped profiles for accuracy and low noise. Housings are cast iron on industrial frames and aluminium on compact gearmotors, with SKF/FAG-equivalent bearings, shaft seals and ISO VG 220/320 mineral or synthetic PAO lubrication, frequently lifetime-filled on smaller units.
The unit accepts an IEC/NEMA motor adapter, a servo flange or a free input shaft, and outputs a solid keyed shaft or, where offered, a flange. Foot and B5/B14 flange positions are standard. Service factor is selected per AGMA SF against the duty profile, and ATEX/IECEx and ingress options are available where the application requires them.
Himalay's MSME partners manufacture coaxial helical gearboxes and gearmotors with gear-rating to AGMA/ISO 6336, 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.
