As part of a customer project for Widap AG, the engineering team at Antrimon Group AG investigated the mechanical behaviour of an automatic star-delta motor protection switch. The challenge: an unexpected delay in the Y-Δ switchover, which had a negative impact on the switching speed and thus the reliability of the electrical contacts.

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Problem analysis using the finite element method (FEM)

The affected tooth segment in the gearbox was simulated in detail using the finite element method (FEM). The aim of the simulation was to represent realistic loads and understand their effects on the dynamic behaviour of the component. The FEM analysis clearly showed that the damper used in the gearbox was the main cause of the delayed switching – the closing speed was too low, resulting in increased wear on the contact points.
 

The Antrimon solution: targeted optimisation of the damping concept

Based on the FEM results, Antrimon developed a technical solution that addresses the problem in a sustainable manner:

• Adjustment of the damper: A stronger damper was selected, but one that only acts over half the distance.
• Spring mechanism for re-meshing: A spring-loaded tooth segment allows the gearbox to re-engage securely after decoupling.
• Improved switching performance: This combination ensures a significantly higher closing speed of the gearbox while significantly reducing the contact wear rate.

Thanks to this data- and simulation-based adjustment, the functionality of the Y-Δ switch has been sustainably improved – with positive effects on the service life, reliability and overall performance of the mechanics.
 

Project structure: Interdisciplinary development from concept to implementation

The project covered several areas of expertise:

• Project management: Definition and prioritisation of customer-specific requirements as well as project planning and coordination
• Mechanical development: Search for innovative concept ideas for deceleration reduction, CAD design and FEM design of the spring-loaded tooth segment as well as prototype procurement and adaptation
• Testing and validation: Verification of simulation results in the test laboratory and selection of the optimal damper based on real shift times
• Production: Construction of initial prototypes and fine-tuning of manufacturing tools and series production readiness

This structured approach – from analysis to simulation to validation – reflects Antrimon's interdisciplinary engineering expertise.
 

Result: Reliable, high-performance transmission control

Through the targeted application of the finite element method in conjunction with mechanical innovation, Antrimon was able to achieve the following for the customer:

• Significant improvement in shift speed
• Increased mechanical reliability
• Optimised service life of the shift contacts

A solution that is not only technically convincing, but also economically viable – a typical example of practical engineering excellence.