1 of 5 - Steel Shrink Ring Commutators
Here we have received the comm assembled to the armature. We then tear it down to collect interior and exterior dimensions. This comm will be rebuilt on the armature shaft, as opposed to most commutators which are assembled to a hub with caps then installed on the armature shaft back at the motor shop.
2 of 5 - Steel Shrink Ring Commutator
This is the segment pack that has been compressed under significant tonnage, banded and cured. The copper and mica are so tight as a result of this process, that the segment pack behaves like a single piece of metal (picture a collector ring). It will grow symmetrically when heated, which then allows ICC to install the segment pack to the mica wrapped armature, with significant retained fit to the shaft.
3 of 5 - Shrink Ring Progress – this compressed segment pack has been installed to the armature shaft. Designed with complex tapers on the bore of the segment pack and the OD of the shaft, the unit retains all the required fit and is ready for the next steps. Of interest, GE and Westinghouse Steel Shrink Ring designs are very different, and require a whole different set of process steps and expertise.
4 of 5 - Cont. Shrink Ring Progress – Can you guess what RPM this 15” diameter commutator operates at? Like glassbound commutators, external steel shrink ring comm segment packs are retained on the OD (unlike v-ring comms which are held together internally). Forged steel rings need to be fully insulated from the copper, as well as installed with significant retained fit to ensure tightness which hold up under instantaneous acceleration and high rpm. This process is one of the most finicky of all, and requires years of experience to master.
5 of 5 - Finished
Isn’t she beautiful? This careful crafted steel shrink ring commutator will run at 6000 RPM, and our customer can be confident that it will be fully electrically and mechanically sound, thanks to the expertise of our talented people.