Direct Answer
How are motor torque-speed and efficiency tests performed?
Motor torque-speed and efficiency testing use a controlled loading workflow to run a motor at defined operating points. A complete test bench coordinates the loading unit, torque and speed measurement, electrical measurement, control, safety, data acquisition, and reporting. The exact sequence is selected around the motor, controller, application, and result the engineering team needs to evaluate.
For an integrated robot actuator, generate a torque-speed curve by mounting the complete motor-reducer-drive assembly, applying controlled output-side load at defined speeds and directions, and recording command, output torque, output speed, electrical input, temperature, controller state, and time on one synchronized time base. Report peak and continuous envelopes separately, with duration, cooling, electrical supply or bus condition, controller limits, invalid-run rules, and the exact measurement planes.
Measurement and Efficiency Boundary
Define the measurement boundary before calculating efficiency.
At a motoring operating point, complete-actuator efficiency is the synchronized mechanical output power measured at the joint flange divided by the synchronized electrical input power measured at the declared drive input, using the stated sign convention. Motor, drive, reducer, and complete-actuator efficiencies are different results and should not be mixed. Regenerative and backdrive conditions require separate power-flow and sign definitions.
| Reported result | Electrical measurement boundary | Mechanical measurement boundary | Required interpretation |
|---|---|---|---|
| Bare motor | Declared motor or drive electrical plane | Motor shaft | Motor-level result only |
| Motor plus drive | Declared DC or AC drive input | Motor shaft | Combined drive-motor result |
| Integrated actuator | Declared drive input | Joint output flange torque multiplied by angular speed | Complete-actuator result including the declared drive, motor, reducer, and mechanical losses |
| Regenerative or backdrive condition | Declare the electrical power destination, measurement plane, and sign convention | Declare mechanical power direction and the corresponding shaft or flange measurement plane | Do not mix this result with motoring efficiency |
For a Weiheng configuration review, provide the required output-side torque-speed-time envelope and the declared electrical measurement plane so the loading unit, sensors, coupling, cooling, safety limits, acquisition, and reporting workflow can be proposed. This is a configuration method, not a universal performance claim.
Retain the conditions behind every reported point.
| Record group | Required fields |
|---|---|
| Operating point | Speed, torque, direction or quadrant, and duration |
| Electrical and thermal state | Electrical supply or bus condition, cooling or ambient condition, and temperature channels |
| Control and validity | Controller limits, invalid-run rule, and retest rule |
Use the robot joint module test boundary guide to define which motor, drive, reducer, feedback, brake, housing, and output interface are included in an assembly-level result.
What the Test Can Show
From operating point to engineering decision.
Torque-speed curve
Shows motor output torque across the tested speed range under controlled loading conditions.
Mechanical and electrical power
Synchronized torque, speed, voltage, and current data provide the inputs needed to evaluate operating points.
Efficiency result
Efficiency evaluation depends on synchronized mechanical output and electrical input data, as well as the defined operating condition.
Thermal and endurance behavior
Where required, temperature channels and extended test sequences can add evidence beyond a single performance curve.
Repeatable report output
A defined sequence, measurement channels, data handling, and report fields help teams compare motors, revisions, or production results.
Weiheng Efficiency Method Passport v1.0
Map an integrated robot joint only after the power boundary and quadrant are declared.
An integrated robot-joint efficiency map is valid only when input and output power boundaries, motoring or generating quadrant, direction, speed, torque, thermal state, and synchronized electrical and mechanical channels are declared. Weiheng keeps motor, inverter, reducer, and complete-joint efficiency separate and does not turn unstable near-zero-power ratios into headline values.
| Passport control | Required evidence |
|---|---|
| Boundary | Keep reducer, motor, motor-drive, and complete-joint efficiencies separate; list every included or excluded auxiliary. |
| Power planes | Name electrical input and mechanical torque-speed planes, sign convention, direction, quadrant, ratio conversion, and fixture or load-device losses. |
| Map state | Record speed, torque, duty, dwell or stability, thermal and cooling state, voltage or bus condition, controller mode, point order, and alarms. |
| Validity | Use synchronized channels; predefine near-zero-power exclusion or alternate loss reporting; retain invalid points, repeats, retests, and uncertainty status. |
Every map point should link to measured input and output power, raw synchronized channels, calculation version, uncertainty status, valid-run rules, excluded points, repeats, and retests. A complete-joint loss cannot be assigned to the motor, inverter, reducer, bearings, or auxiliaries without independent measurement or an approved model.
Test-Bench Logic
Loading, measurement, and software should be one workflow.
A torque-speed curve is not only a mechanical loading question. It also depends on how torque and speed are measured, how electrical values are captured, how the controller is operated, how the motor is cooled, and how the data is synchronized. When the buyer needs efficiency, transient response, temperature rise, endurance, or traceable production output, the test procedure needs to make those conditions explicit.
Read the custom motor test bench overview for the full system architecture, or compare the system with its loading unit in Motor Test Bench vs Motor Dynamometer.
Before Quotation
Inputs that define a useful torque-speed or efficiency test system.
- Motor type, application, and target operating points
- Rated and peak torque, rated power, rated speed, and maximum speed
- Voltage platform, current range, controller or drive interface, and cooling method when relevant
- Required curve points, efficiency evaluation method, standards, or internal acceptance procedure
- Duty cycle, test duration, temperature channels, and any endurance requirement
- Shaft drawing, coupling, fixture requirement, guarding, and installation direction
- Required reports, data fields, language, traceability, and pass/fail workflow
For an RFQ-focused checklist, see Motor Test Bench RFQ Checklist. For broader configuration choices, use the Custom Motor Test Bench Configuration Guide.
FAQ
Torque-Speed and Efficiency Testing Questions
What does a motor torque-speed test measure?
A motor torque-speed test measures output torque at defined speed and loading conditions. A complete test workflow can synchronize torque and speed with electrical values so that the result can be evaluated and reported against the intended operating points.
Why is a dynamometer used for motor efficiency testing?
A dynamometer or loading unit creates controlled loading conditions. The test bench combines it with torque and speed measurement, electrical measurement, control, safety, and software so the required operating points can be tested repeatably.
Can a motor test bench create an efficiency map?
It can be discussed when the system is configured for the required torque-speed operating grid, synchronized electrical and mechanical measurements, data acquisition, and software workflow. The final method depends on the motor, controller, application, and the buyer's procedure.
What is needed before asking for a torque-speed test bench quotation?
Send the motor range, maximum speed, torque and power values, intended test items, controller and cooling information where relevant, mechanical drawing, duty cycle, reporting needs, and whether the project is for R&D, QC, EOL, or laboratory work.