Manufacturing the Stator Laminations

The nitrile stator laminations begin as thin sheets of silicon steel, typically around 0.35-0.5mm thick. This silicon steel has excellent magnetic properties that make it ideal for transforming electrical energy into rotational motion in motors and vice versa in generators. During manufacturing, large reels of silicon steel sheet are blanked or punched to produce the exact shape and slots needed for the individual laminations.

For efficient motor operation, it's important that the laminations are precisely-shaped to very tight tolerances. Modern punching machines can produce thousands of identical laminations per hour. Any burrs or imperfections left on the cut edges would decrease the magnetic efficiency of the stacked core. Thus, the laminations undergo additional polishing and cleaning steps after punching.

Preparing the Lamination Pack

With hundreds or even thousands of identical laminations produced, they must then be prepared and aligned for stacking. The individual sheets are first treated with a binding agent like resin or varnish on one side. This acts as an electrical insulator betweenadjacent sheets once stacked. It also helps bind the packed core together for additional mechanical strength.

The laminations are then sorted and arranged into a neatly organized "pack" that will form the foundation for stacking. Proper orientation and alignment is key, so that the punched slots and profiles line up precisely when compressed together. Spacers may be inserted periodically to maintain separation and airflow between sheets during stacking.

Performing the Stacking Operation

With the laminations prepared, the stacking process can begin. It involves using a specialized stacking machine or jig to gradually compress the stack upward from the base. Lamination by lamination, the machine gently lifts and aligns each new sheet on top with the help of dowel pins, guide rails or other positioning aids.

As the stack grows in height, it's important to maintain even compression across the entire surface. Machines provide very precise control over the stacking pressure and speed. Technicians routinely inspect that the sheets remain flush and properly seated together without skewing or jamming. Any issues require dismantling a portion of the stack to fix before resuming the stacking process.

Final Steps Before Winding

Once fully stacked to the required axial height, the lamination pack still requires some final processing before winding can begin. It's common for the outer laminations or entire pack surfaces to receive additional coats of insulating varnish. This helps seal and protect the iron core from moisture and corrosion.

The stacked assembly also needs to be heat cured or baked to fully set the binding resins. This final hardening step strengthens the mechanical bond between laminations before any further handling or winding stresses are applied. Careful quality checks ensure the lamination stack met all dimensional and inspection criteria to become the foundation for the rest of motor assembly.

And with that, the stacked stator core is then ready for the next stage of motor manufacturing - winding the coils into its slots to complete the bulk of the stator assembly! Let me know if any part of the stator lamination stacking process needs more explanation.