Service Factor & Gearbox Selection
AGMA application factor, shock classification & required gearbox rating — AGMA 9002-B04
Required Power (P)
kW
Operating Speed
RPM
Daily Operating Hours
Prime Mover
Driven Machine
Start Frequency
Environment
AGMA Overload Factor K₀ Reference
| Prime Mover | Uniform | Mod. Shock | Heavy Shock |
|---|---|---|---|
| Electric (uniform) | 1.00 | 1.25 | 1.75 |
| Hydraulic / turbine | 1.10 | 1.35 | 1.85 |
| IC multi-cylinder | 1.25 | 1.50 | 2.00 |
| IC single-cylinder | 1.50 | 1.75 | 2.25 |
Factor Breakdown
Overload Factor (K₀)
—
Hours Factor (Kℋ)
—
Start Factor (Kₙ)
—
Environment Factor (Kₑ)
—
Service Factor & Required Rating
Total Service Factor (fₙ)
—
Nominal Power (P)
—kW
Required Gearbox Rating
—kW
Required Torque Rating
—N·m
Typical Service Factors by Application
| Application | fₙ range | Hours/day |
|---|---|---|
| Centrifugal pump | 1.0 – 1.25 | 8 – 24 |
| Belt conveyor | 1.25 – 1.5 | 8 – 24 |
| Screw conveyor | 1.5 – 2.0 | 8 – 16 |
| Reciprocating compressor | 1.75 – 2.0 | 8 – 24 |
| Crane / hoist | 1.5 – 2.0 | 4 – 12 |
| Ball / rod mill | 2.0 – 2.5 | 16 – 24 |
| Crusher | 2.0 – 2.5 | 8 – 24 |
| Agitator | 1.25 – 1.75 | 8 – 24 |
| Paper machinery | 1.5 – 2.0 | 16 – 24 |
| Machine tool | 1.25 – 1.5 | 8 – 16 |
Service Factor Formula
Service factorfₙ = K₀ × Kℋ × Kₙ × Kₑ
Required ratingPᵣₑℂ = P × fₙ
Required torqueT = 9549.3 × Pᵣₑℂ / n