Hot Staking Measurement

The Hot Staking measurement is a central procedure for verifying the contact resistance between winding wire and commutator or terminal. It ensures consistently high quality of the welding process in motor manufacturing. A low contact resistance is crucial for reducing the risk of failure and for the reliable operation of electrical machines.

Measurement method for armatures

For armatures, the Hot Staking measurement is performed by contacting the commutator using the four-wire method (Kelvin measurement). A special compensation procedure eliminates the parallel current flow within the ring-shaped interconnection of the coils. This enables precise and direct measurement of the contact resistance across multiple commutator segments.

The optimal measurement parameters for each test piece are automatically determined and stored through a one-time sample run. This ensures fast and reproducible testing in series production.

Measurement method for stators

For stators, contacting is usually performed at the terminals or at a connection plate. Additionally, the winding wire is contacted directly with a blade in close proximity to the welding point. This approach allows for accurate detection of the contact resistance at the critical connection.

Temperature compensation

Since the contact resistance is temperature-dependent, the measurement results are temperature-compensated. This ensures high accuracy and comparability of the results – regardless of environmental influences. (more information)

Evaluation and monitoring

The evaluation of the contact resistance is typically based on the maximum value. Additionally, the following monitoring strategies can be implemented:

• Absolute or relative deviation: Defining limits for permissible deviations.
• Range monitoring: Defining an allowable measurement range.
• Spread: Monitoring the difference between the minimum and maximum contact resistance.

These flexible evaluation options enable application-specific quality control and seamless monitoring of the welding process.

Advantages of the Hot Staking measurement

• Fast and automated testing for high volumes in series production
• High precision through compensation procedures and temperature-corrected measurements
• Early detection of process deviations to prevent failures
• Flexible evaluation and adaptation to different types of test pieces

Conclusion

The Hot Staking measurement is an indispensable testing procedure for ensuring connection quality in electrical machines. It enables fast, precise, and automated monitoring of contact resistance and makes a significant contribution to quality assurance in the manufacturing process.