Frameless torque motors are increasingly used in servo systems, precision motion platforms, robotic joints, and radar gimbals, thanks to their defining advantages:

compact stator–rotor structure, direct drive coupling, low inertia, and high torque density.

To fully unlock their performance, high-precision and application-specific testing becomes essential.

This article introduces the core testing features required for frameless torque motors and how AIP’s customized testers ensure accuracy, stability, and real-world performance verification.

Ⅰ.Customized Test Fixtures for Frameless Torque Motors

Because frameless torque motors consist only of a stator and rotor without housings, endcaps, or bearings, traditional motor test benches cannot be used directly. Their bare, integrated design requires testing fixtures that replicate real installation conditions.

1.AIP’s Customized High-Precision Support Fixtures

AIP designs specialized fixtures that include:

· Bearing-supported adapter housings precisely matched to the motor’s inner and outer diameters

· Precision alignment structures to maintain strict coaxiality

· Locating jigs to secure the stator and stabilize the rotor movement

· Anti-eccentricity designs that eliminate mechanical error and signal distortion

These fixtures ensure accurate, repeatable measurements and fully reproduce real application loads—especially critical in high-precision industries such as robotics, aerospace, metrology, and advanced servo systems.

Ⅱ. Targeted Frameless Torque Motor Testing Items

Frameless motors deliver value through precise torque output and fast dynamic response. AIP’s testing architecture covers both dimensions extensively.

1. Torque Performance Testing: Ensuring Accurate Output Power

1.1 Static Torque Measurement

Using torque sensors with accuracy ≥ ±0.1% FS, AIP’s system evaluates:

· Holding torque at multiple rotor positions

· Torque consistency and uniformity

· Anti-vibration stability under static load

This ensures smooth operation without oscillation or jitter.

1.2 Cogging Torque Measurement

AIP employs fine-step positioning + high-resolution torque sampling to:

· Quantify cogging torque precisely

· Reduce cogging torque to <0.5% of rated torque

· Eliminate low-speed creeping and improve positioning accuracy

This is crucial for applications where ultra-smooth motion is required.

1.3 Dynamic Torque Response

The system measures torque rise time under step current excitation, evaluating:

· Motor responsiveness to command signals

· Control-loop compatibility in servo systems

· Dynamic tracking performance

This ensures the motor meets the real-time demands of high-performance robotics and automation.

2. Dynamic Electrical Performance Under Load

2.1 Back-EMF Testing

· The system uses high-precision DAQ modules to record:

· Back-EMF amplitude at various speeds

· Waveform distortion and harmonic content

· Speed–EMF characteristic curves

Built-in FFT spectral analysis ensures compliance with sinusoidal standards, improving servo stability and reducing torque ripple.

2.2 Temperature Rise & Insulation Testing

A multi-channel temperature module monitors:

· Stator core temperature

· Winding end temperature

· Magnet surface temperature

The system automatically generates thermal-rise curves and integrates:

· Insulation resistance testing

· High-voltage withstand testing

This helps detect insulation aging or leakage risks early.

2.3 Dynamic Current & Power Analysis

Under-rated load, stall, and acceleration conditions, the system captures:

· DC and three-phase current curves

· Voltage waveforms

· Instantaneous power behavior

High-sampling-rate analysis provides essential references for optimizing servo driver design.

Ⅲ.Why Precise Testing Matters

The outstanding performance of a frameless torque motor depends on meticulous design, manufacturing, and validation.

AIP’s dedicated test systems ensure:

· Precise measurement accuracy

· Stability under real operating conditions

· Deep insight into both mechanical and electrical behavior

This guarantees that every motor meets the demands of advanced applications.

Ⅳ.AIP: Your Partner in Global Motor Testing Solutions

AIP specializes in global motor testing, providing complete testers and customized motor test solutions for robotics frameless torque motors and other high-precision applications.

Ready to Improve Your Frameless Torque Motor Testing?

Contact AIP today to get customized robot motor test solutions for your motor R&D, production, or laboratory needs.