APP 01

FERTILISER
SPREADER

Worm gear specification: M2–M5, ratio 10:1–20:1, PB2 bronze wheel, C45 worm shaft (zinc-passivated), epoxy-coated aluminium or 316L stainless housing, double-lip shaft seal, NSF-compatible lubricant for incidental fertiliser contact. The fertiliser spreader disc drive worm gearbox converts the electric motor shaft to the spinning fertiliser disc (typically 200–600 RPM disc speed from 1,400 RPM motor, via ratio 2.5:1–7:1 — sometimes a single gear stage rather than a worm). The housing is directly in the fertiliser flow path when the spreader lid is open for refilling — ammonium nitrate, potash, and urea granules fall onto the housing and dissolve in morning dew to form highly corrosive solutions. Epoxy powder coat rated for pH 4–12 resistance is the minimum housing protection. After each spreading season, flush the housing exterior with clean water and apply corrosion inhibitor spray before storage. Korea Ever-Power supplies fertiliser spreader worm gearboxes with corrosion-resistant coating as standard for the Australian, Dutch, and UK markets where ammonium nitrate use is highest.

APP 02

CENTRE-PIVOT
IRRIGATION DRIVE

Worm gear specification: M4–M8, ratio 40:1–80:1, PB2 or AB2 bronze wheel, self-locking (lead angle <5°), IP67 sealed housing (constant rain and irrigation water exposure), food-grade or water-tolerant lubricant. The centre-pivot irrigation system rotates a long (100–500 m) lateral pipeline around a central pivot point, powered by electric motors at each tower wheel. The tower wheel drive worm gearbox provides the 40:1–80:1 reduction from the electric motor to the large pneumatic drive wheel, at very slow rotation (typically 0.01–0.05 RPM at the wheel). The self-locking property of the worm gear is important in irrigation pivot drives — when the pivot is stationary during a field obstruction stop or timed pause, the pipeline must hold position without back-driving under the weight of the water-filled pipeline. Korea Ever-Power pivot tower drive worm gearboxes are rated for continuous outdoor exposure with IP67 sealing and UV-stable housing coating — including the Brazilian and Colombian markets where pivot irrigation is expanding rapidly.

APP 03

GRAIN AUGER
& ELEVATOR

Worm gear specification: M3–M6, ratio 15:1–30:1, PB2 bronze wheel, C45 or 42CrMo4 worm shaft, sealed housing (grain dust exclusion), continuous duty rated. Grain auger worm gearboxes drive the helical auger screw at 300–600 RPM (from a 1,400 RPM electric motor at ratio 2.5:1–5:1), transferring grain vertically or at an angle between storage bins, drying equipment, and transport hoppers. The grain auger worm gear operates in a highly abrasive environment — grain dust, chaff, and husk particles can enter a poorly sealed housing and contaminate the gear oil rapidly, causing abrasive wear of the worm thread and wheel surface. Korea Ever-Power grain auger worm gearboxes use pressed-in labyrinth seals at both shaft entries in addition to the rubber lip seal — the labyrinth prevents grain dust from reaching the lip seal contact surface, extending the effective seal life in dust-contaminated field conditions from typically 500 hours to 2,000+ hours.

APP 04

FEED MIXER
& BLENDER

Worm gear specification: M4–M8, ratio 20:1–40:1, AB2 aluminium bronze wheel (for higher continuous duty at elevated temperature), 42CrMo4 worm shaft, stainless housing option for dairy farm feed mixer, self-locking property allows mixer drum to hold position when motor stops. Livestock feed mixer worm gearboxes operate in a high-acid environment — silage and fermented feed products have pH 3.5–4.5, which attacks standard gear oil additives and corrodes aluminium housing rapidly if the housing is not sealed. Total mixed ration (TMR) mixers for dairy farms use continuous duty worm gearboxes (the mixer runs for 30–60 minutes per feed event, multiple times per day) with self-locking capability to prevent mixer drum coast-down when the motor trips or is switched off. Korea Ever-Power TMR feed mixer worm gearboxes include a silage acid-resistant external housing coating and a food-grade gear oil option for application compliance in dairy farm feed preparation areas.

My fertiliser spreader worm gearbox is rusting through the housing every two seasons. What is the correct long-term solution?

Cast iron or standard aluminium worm gearbox housings in fertiliser spreader applications typically fail by external corrosion (housing wall perforation or joint face corrosion causing oil leakage) rather than by gear wear, because ammonium nitrate and other fertiliser salts are highly aggressive to iron and aluminium. The permanent solution is to upgrade to a 316L stainless steel housing — stainless is immune to ammonium nitrate, urea, and MAP/DAP corrosion at the concentrations encountered in field spreading conditions. Korea Ever-Power supplies agricultural worm gearboxes in 316L stainless housing as a direct replacement for the standard cast iron or aluminium housing models, retaining the same gear geometry, shaft dimensions, and mounting pattern. First cost is approximately 60–80% higher than the standard aluminium housing variant, but eliminates the two-season replacement cycle, reducing the total lifetime cost of ownership by 50–70% over ten years of spreader operation. Specify 316L stainless housing with PTFE-coated shaft seals (standard nitrile rubber seals are degraded by fertiliser solvents) and synthetic food-grade PAO gear oil resistant to contamination by agricultural chemicals.

What worm gear ratio is correct for a centre-pivot irrigation system with a 1.5 kW electric motor per tower and a 0.8 m diameter drive wheel requiring 1.5 RPM output speed?

Ratio calculation for the irrigation pivot tower drive: Motor speed = 1,400 RPM (standard 4-pole 50 Hz motor). Required output = 1.5 RPM at drive wheel. Required ratio = 1,400 ÷ 1.5 = 933:1 total. This total ratio is achieved in two stages in a standard irrigation pivot tower drive: (1) a chain-and-sprocket reduction of approximately 13:1 between the worm gearbox output shaft and the drive wheel axle, and (2) the worm gearbox providing the remaining ratio = 933 ÷ 13 = approximately 71:1. Specify a worm gearbox with ratio 70:1–80:1 (standard NMRV 090 or 110 size at 1.5 kW input, ratio 75:1 is a common catalogue size). Self-locking is confirmed at ratio 70:1+ (lead angle well below 5°). At 1.5 kW input and ratio 75:1, output torque at the worm gearbox = 1,500 W × 0.62 (efficiency at ratio 75:1) ÷ (2π × 18.7 RPM output) = 795 Nm. Confirm this is within the gearbox’s rated output torque for the applicable thermal power limit at the pivot’s operating ambient temperature. Korea Ever-Power can confirm the correct gearbox size and ratio for your specific pivot system — provide motor kW, motor RPM, chain-sprocket ratio, and required pivot rotation speed.

How should I store agricultural worm gearboxes during the off-season to prevent internal corrosion and seal degradation?

Agricultural worm gearbox off-season storage protocol: (1) Drain and flush after the last use of the season: drain the contaminated gear oil (which will contain fertiliser salt, grain dust, or silage acid residue depending on the application), flush with clean mineral oil run for 5 minutes under no-load to flush residual contaminants, drain the flush oil, and refill with fresh gear oil of the correct specification. (2) Seal all shaft openings: any shaft that was disconnected at the end of the season should be sealed with a plastic cap or tape to prevent moisture and rodents entering through the unsealed shaft opening. (3) External corrosion inhibitor: apply a light rust-inhibiting oil or wax to all unpainted external surfaces — particularly the mounting flange face, shaft extensions, and any bare steel components. (4) Dry storage location: store agricultural gearboxes in a dry shed, not in a field implement left outdoors — condensation cycles inside an outdoor-stored gearbox progressively corrode the housing interior and emulsify the gear oil even with the gearbox completely sealed. (5) Inspection before next season: before reinstalling the gearbox at the start of the next season, check the oil colour (milky white indicates water emulsification — drain and refill), the shaft seal condition (replace if the lip seal shows hardening or cracking after storage), and the backlash at the output shaft (should feel firm with minimal free play).

Spur Gears

Tractor · combine · 20CrMnTi · seeder

Helical Gears

Agricultural machinery · low noise · gearbox

Engrenages coniques

PTO right-angle · mower · tiller drive

Worm Gears

Spreader · pivot · auger · mixer

Ring Gears

Tractor flywheel · planetary · final drive

Planetary Gears

Hub reduction · tractor · compact

Plastic Gears

POM · Nylon · corrosion-free · seeder