Geared Motors & Speed Reducers

Q: What is the Service Factor (SF) on a gearbox?

The service factor is a multiplier representing the gearbox’s mechanical safety margin above the motor’s rated power. For uniform conveyor loads, SF = 1.2 is adequate; for heavy shock loads (crushers, mixers), SF ≥ 1.8 is required to prevent tooth fatigue.

Precision speed reduction, high torque multiplication, and rugged mechanical power transmission systems

Geared Motors & Speed Reducers — engineering concept

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Geared Motors & Industrial Gearboxes

Mechanical drive systems in manufacturing, processing, and material handling require precise output speeds and multiplied shaft torque to drive heavy conveyors, mixers, crushers, and elevators. Nairobi Power Engineers supplies premium European-engineered Geared Motors and Industrial Gearboxes.

Our inventory includes Inline Helical Geared Motors (high efficiency, up to 98%), Worm Geared Speed Reducers (NMRV series, compact right-angle torque), and Heavy Bevel-Helical Gear Units engineered with case-hardened alloy steel gears, synthetic lubricants, and high service factors (SF ≥ 1.5).

Equipment & Range Highlights

Helical Geared Motors — engineering concept

High Efficiency • Inline / Foot / Flange

Conceptual helical geared motors scene; exact specifications vary.

Coaxial Inline Helical Geared Motors

High-efficiency inline helical gear units delivering up to 98% mechanical efficiency per gear stage with torque ratings up to 18,000 Nm.

EfficiencyUp to 98% per Stage

Torque50 Nm to 18,000 Nm

Ratiosi = 1.3 to 300:1

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Worm Geared Motors (NMRV) — engineering concept

Right-Angle • NMRV / NRV

Conceptual worm geared motors (nmrv) scene; exact specifications vary.

Worm Geared Motors & Speed Reducers

Compact right-angle worm gearboxes featuring die-cast aluminium/cast iron housings, phosphor bronze worm wheels, and self-locking capabilities.

SizesNMRV 025 to NMRV 150

Ratiosi = 5:1 to 100:1

Hollow Shaft14 mm to 50 mm Keyed

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Bevel-Helical Geared Motors — engineering concept

Heavy Industrial • High Torque

Conceptual bevel-helical geared motors scene; exact specifications vary.

Bevel-Helical Right-Angle Gearboxes

Heavy-duty right-angle bevel-helical units combining spiral bevel and helical gear stages for severe shock loads and high thermal capacities.

TorqueUp to 50,000 Nm

ExecutionSolid / Hollow Splined Shaft

Service FactorSF ≥ 1.8 Heavy Duty

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Geared Motor Family Comparison

Gearbox Technology	Efficiency Rating	Torque Range	Orientation & Shaft
Coaxial Helical (RC Series)	96% – 98% (Ultra High)	50 Nm – 18,000 Nm	Coaxial Inline (Solid Output Shaft)
Worm Gear (NMRV Series)	55% – 85% (Compact Right-Angle)	20 Nm – 2,500 Nm	90° Right Angle (Hollow Keyed Shaft)
Bevel-Helical (K / B Series)	94% – 96% (Heavy Industrial)	200 Nm – 50,000 Nm	90° Right Angle (Solid / Hollow / Shrink Disc)
Parallel Shaft (F Series)	95% – 97% (Slim Profile)	150 Nm – 20,000 Nm	Offset Parallel (Ideal for Conveyors & Cranes)

Engineering & Build Highlights

Case-hardened (58–62 HRC) and precision ground alloy steel gears (20CrMnTi) for silent operation and minimum friction
Factory pre-filled with premium synthetic gear lubricant (ISO VG 220 / VG 320) for maintenance-free long life
Standard IEC normalized motor input flanges (B5 / B14) allow coupling with any standard electric motor
Double-lip synthetic rubber oil seals (FKM / Viton) prevent lubricant leakage and ingress of dust
Modular universal mounting: foot, flange, or torque arm mounting with hollow output shaft
Comprehensive stock of gearboxes, spare gear wheels, seals, and torque arms maintained in Nairobi

Target Applications & Sectors

Belt conveyors, bucket elevators & screw augersWater treatment aerators, clarifiers & chemical agitatorsTea sorting machines, CTC rollers & withering troughsPackaging bottling plants & conveyor accumulating tablesMining vibratory feeders & stone crushing linesOverhead gantry crane travel & hoist mechanisms

Worm gearboxes are economical and compact for right-angle drives with moderate power (< 7.5 kW). Helical gearboxes have much higher efficiency (96-98% vs 65-80%), saving significant electrical energy on continuous heavy-duty industrial machinery.

The service factor is a multiplier representing the gearbox’s mechanical safety margin above the motor’s rated power. For uniform conveyor loads, SF = 1.2 is adequate; for heavy shock loads (crushers, mixers), SF ≥ 1.8 is required to prevent tooth fatigue.

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Conceptual engineering scenes illustrate applications. Manufacturer reference photos are identified separately. Confirm exact models, dimensions and ratings before ordering.