UN dinamometro (commonly called a “dyno”) is a precision measurement instrument used to measure force, coppia, energia, e velocità di rotazione in mechanical systems. In industrial testing, dynamometers form the core of test bench systems used to validate motors, motori, cambi, and drivetrain components before they enter service.
Key Takeaways
- A dynamometer measures torque and rotational speed to determine the true mechanical power of motors, engines and powertrains.
- Four main families: eddy current (high speed), AC regenerative (four-quadrant with energy recovery), idraulico (high power) and hysteresis/permanent magnet (small motors, full torque at zero speed).
- Select by torque range, velocità massima, accuracy class (typically ±0.2%–0.5% FS) and cooling method — not by price alone.
- EconoTest dynamometers span 0.1 Nm a 2,000 Nm with speeds up to 50,000 RPM across hysteresis, eddy current, magnetic powder and AC series.
What Is a Dynamometer?
A dynamometer test bench creates a controlled load against which the device under test (DUT) must work. By precisely measuring the torque and speed, engineers calculate power output, efficienza, and performance characteristics across the full operating range. The fundamental equation: Energia (KW) = Torque (Nm) × Speed (giri al minuto) ÷ 9550
Types of Dynamometers
1. Eddy Current Dynamometer
Eddy current dynamometers use electromagnetic induction to create braking torque. A rotating conductive disc passes through a magnetic field, inducing eddy currents that oppose rotation. Vantaggi: Fast response, no physical contact, wide speed range. Best for: Prova del motore, high-speed motors, aerospace components.
2. AC Motor Dynamometer (Regenerative)
AC motor dynamometers use a variable-frequency-driven AC motor as the load. The motor absorbs power and returns energy to the grid — highly energy-efficient. Best for: Electric motor testing, e-axle testing, long-duration endurance tests.
3. Dinamometro idraulico
Hydraulic dynamometers use fluid friction to absorb power. Simple, robust, very high power capacity. Best for: Marine engine testing, high-power industrial machinery.
4. Permanent Magnet Dynamometer
PM dynamometers offer excellent torque density and precise control at low speeds — ideal for testing small, high-precision motors and servo systems.
Key Parameters for Dynamometer Selection
- Maximum torque (Nm) — exceed peak DUT torque by 20-30%
- Maximum speed (giri al minuto) — cover full operating range including overspeed
- Power rating (KW) — continuous and peak absorption capacity
- Precisione della coppia — typically ±0.1% to ±0.5% full scale
- Precisione della velocità — typically ±0.01% using optical encoders
- Tempo di risposta — critical for transient and dynamic testing
Applications by Industry
Automobilistico & EV: Engine development, transmission testing, e-axle validation, end-of-line production testing. EV motor dynamometers measure efficiency maps, coppia di picco, and thermal limits across the full operating envelope.
Aerospaziale: Aircraft starter generator testing, APU validation, electric actuation system testing. Compliance with MIL-STD-704 and DO-160 required.
Industrial Motor Testing: Type testing and routine production QC to IEC 60034-2-1 standards for IE3/IE5 efficiency classification.
Marino & Offshore: Ship propulsion motors, thruster systems, and diesel-electric generators under simulated sea load cycles.
Calibration Standards
- Iso 6789 — Torque measurement calibration
- IEC 60034-2-1 — Motor efficiency testing methods
- IEEE 112 — Polyphase induction motor test procedure
- SAE J1349 — Automotive engine power testing
EconoTest Dynamometer Solutions
EconoTest offers eddy current, AC regenerative, permanent magnet, and hydraulic dynamometer test benches from 0.5 kW a 5,000 kW and up to 50,000 giri al minuto. With 20+ years of experience E 1,000+ systems delivered In 50+ countries, we are your trusted dynamometer manufacturer. Contact us for a technical proposal.
FAQ
What is the difference between a dynamometer and a load bank?
A load bank absorbs electrical power; a dynamometer absorbs mechanical power (torque × speed) and measures it precisely for rotating machinery testing.
How much does a dynamometer test bench cost?
Costs range from USD 20,000 for small motor test stations to several million USD for large aerospace facilities, depending on power rating, precisione, e automazione. Contact EconoTest for a project quote.
Which dynamometer type is best for testing small electric motors?
Hysteresis dynamometers are ideal for fractional and low-power motors: 0.1–30 Nm torque range, full braking torque available even at zero speed, and ±0.2%–0.5% accuracy. They suit AC, DC, BLDC and stepper motors.
What speed range can dynamometers cover?
Eddy current dynamometers reach up to 50,000 giri al minuto, hysteresis models up to 30,000 RPM and AC dynamometers up to 18,000 giri al minuto. Dedicated high-speed motor test benches extend coverage to 100,000 giri al minuto.
How accurate are industrial dynamometers?
Typical torque accuracy is ±0.2%–0.5% of full scale depending on series and size. Precision AC dynamometer systems achieve ±0.2%, while aerospace-grade starter generator benches reach 0.05–0.1% FS.
