Free Engineering Tool #084
Coupling Torque Calculator
Calculate shaft torque from power and speed using T = P×9549/n. Includes service factors for coupling selection and direct force application T = F×r.
Results
Torque from Power & Speed
The constant 9549 = 60000 / (2π), converting kW and RPM to N·m.
Design Torque with Service Factor
Torque from Force & Radius
Where F is tangential force in N and r is the lever arm in meters.
Service Factors Table
| KA | Load Type | Driven Machine Examples |
|---|---|---|
| 1.0 | Uniform | Fans, centrifugal pumps, generators |
| 1.25 | Light shocks | Belt conveyors, blowers, light mixers |
| 1.5 | Moderate shocks | Reciprocating compressors, screw conveyors, positive displacement pumps |
| 1.75 | Heavy shocks | Ball mills, rubber mills, heavy mixers |
| 2.0 | Very heavy shocks | Crushers, sugar mills, steel rolling mills |
| 2.5 | Severe reversing | Reversing rolling mills, vibrating screens |
| 3.0 | Extreme | Presses, shears, hammer mills |
Tip: When the driving machine (motor) also has pulsating output (e.g., single-cylinder engine), multiply KA by an additional motor factor (typically 1.25–2.0).
Given: P = 15 kW, n = 1500 RPM, KA = 1.5
Tn = 9549 × 15 / 1500 = 95.5 N·m
Tdesign = 1.5 × 95.5 = 143.2 N·m
Professional field balancing instruments and software. Used in 50+ countries.
Nikolai Shelkovenko
Nikolai Shelkovenko is a vibration analysis engineer and the founder and CEO of Vibromera. For more than 15 years he has balanced rotating equipment in the field rather than on a test bench: mulchers, industrial fans, crushers, centrifuges, shafts and spindles. That work is what the Balanset instruments grew out of — they were designed as a tool a specialist can carry to the machine and use alone, on site, not as laboratory equipment. Vibromera was founded in 2017 and has been based in Porto, Portugal, since 2023. Development, assembly and support of the Balanset line all happen here. The flagship instrument is the Balanset-1A, a portable analyser for single- and two-plane balancing and for vibration diagnostics. Nikolai is personally involved in customer support, in working through difficult balancing cases and in the development of the software. He works with customers worldwide, in any language.
