The motor manufacturing industry faces a persistent challenge: reliable, cost-effective electrical grounding of stator assemblies. Conventional approaches – welded terminals, conductive brackets and rigid pin systems – often compromise either manufacturing efficiency or long-term reliability. Ground Pin technology is a fundamental breakthrough: a press-fit connector system that combines an innovative star geometry with a precision-engineered pin, delivering superior grounding performance while significantly simplifying assembly.
Ground Pin: star geometry
The breakthrough is a star-shaped guide hole drilled in the stator core laminations – it transforms both insertion and grounding performance.
• Round guide hole with radial protrusions forming a star pattern
• Typical configuration: Ø0.83–0.87 mm round hole, Ø0.96–0.97 mm star points
• Controlled deformation zone during pin insertion
• Multiple electrical contact points around the pin
How Ground Pin Technology Works
The Ground Pin is inserted into a specially designed hole in the stator core. During insertion, the pin engages with the star-shaped geometry, creating controlled deformation and multiple contact zones. The resulting mechanical interference secures the pin while establishing an electrical grounding connection.
The solder-free process eliminates the need for heat during pin installation and is suitable for integration into automated manufacturing processes.
Advantages of Press-Fit Grounding
Solder-free assembly: No soldering or welding is required for pin installation.
Controlled insertion force: Supports process monitoring and repeatable production.
Mechanical retention: Interference between the pin and stator laminations provides mechanical locking.
Multiple contact points: The star-shaped geometry establishes several electrical contact zones.
Automation compatibility: Designed for integration into automated pin insertion processes.
Reduced maintenance requirements: The controlled insertion process can help reduce tooling wear and maintenance needs.
Engineering and Process Validation
SM Contact evaluates pin insertion and mechanical retention through laboratory testing. Insertion force and pull-out force measurements help assess connection performance and establish suitable process parameters for the intended application.
