Cooling Tower Gearbox
A cooling-tower gearbox is a right-angle spiral-bevel (or bevel-helical) reducer that turns the horizontal drive from a motor or drive shaft through 90 degrees to spin a large, slow vertical-axis fan inside an induced- or forced-draught cooling tower. It works wet, in a high-humidity, often corrosive airstream, runs continuously, and must keep a heavy overhung fan stable, so it is built around case-hardened lapped spiral-bevel gears, robust bearings and a sealing and lubrication scheme that tolerates the environment. A three-point or unicase mounting and, on many designs, a pumpless splash-lubrication system keep installation and maintenance simple at height.
Cooling-tower drives reduce typical motor speeds to fan speeds in the low hundreds of rpm, in single- or two-stage right-angle layouts with ratios commonly from about 4:1 to 20:1, power up to several hundred kW (around 620 kW on large units), and efficiency near 96-98%. Gears are rated to AGMA 2101/ISO 6336 with bevel/enclosed-drive practice to AGMA 6010 and quality to ISO 1328 / AGMA 2015. The continuous, humid duty makes service factor, sealing and lubrication central design points.
Gears are case-hardened and lapped alloy steel in a corrosion-protected cast housing, on bearings sized for the fan's overhung and thrust load, with upgraded seals and surface treatments for the wet airstream.
Integration covers a drive-shaft or close-coupled motor input, a vertical output flange or shaft to the fan hub, vibration sensing provisions, and mineral or synthetic ISO VG 220/320 lubrication, with service factor set to continuous fan duty and ambient temperature.
Himalay's MSME partners manufacture cooling-tower gear drives with gear-rating to AGMA/ISO 6336, ISO 9001 quality systems, load and 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.
