一个 测功机 (commonly called a “dyno”) is a precision measurement instrument used to measure force, 扭矩, 力量, 和转速 in mechanical systems. In industrial testing, dynamometers form the core of test bench systems used to validate motors, 引擎, 变速箱, 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), 液压 (high power) and hysteresis/permanent magnet (small motors, full torque at zero speed).
- Select by torque range, 最大速度, accuracy class (typically ±0.2%–0.5% FS) and cooling method — not by price alone.
- EconoTest dynamometers span 0.1 纳米至 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, 效率, and performance characteristics across the full operating range. The fundamental equation: 力量 (KW) = Torque (纳米) × Speed (转速) ÷ 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. 优势: Fast response, no physical contact, wide speed range. Best for: 发动机测试, 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. 液压测力计
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 (纳米) — exceed peak DUT torque by 20-30%
- Maximum speed (转速) — cover full operating range including overspeed
- Power rating (KW) — continuous and peak absorption capacity
- 扭矩精度 — typically ±0.1% to ±0.5% full scale
- 速度精度 — typically ±0.01% using optical encoders
- 响应时间 — critical for transient and dynamic testing
Applications by Industry
汽车 & 电动汽车: Engine development, transmission testing, e-axle validation, end-of-line production testing. EV motor dynamometers measure efficiency maps, 峰值扭矩, and thermal limits across the full operating envelope.
航天: 飞机启动发电机测试, 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.
海洋 & Offshore: Ship propulsion motors, thruster systems, and diesel-electric generators under simulated sea load cycles.
Calibration Standards
- 国际标准化组织 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 千瓦至 5,000 kW and up to 50,000 转速. With 20+ years of experience 和 1,000+ systems delivered 在 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, 准确性, and automation. 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 转速, hysteresis models up to 30,000 RPM and AC dynamometers up to 18,000 转速. Dedicated high-speed motor test benches extend coverage to 100,000 转速.
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.
