SAFE GROOVING OF COLLECTOR RINGS

Lost your groove? Funny as it may sound, loss of a functional groove on your collector rings can create real problems. The loss of a spiral groove can only be solved in one of two ways -- ring replacement or recutting of the groove. If possible, regrooving of your ring is clearly the best choice for extending the life of your collector ring.

With our patent pending grooving process we have greatly reduced the necessary downtime usually required for regrooving. Typically the old process can exceed ours by at least two to three times because of our simplified set-up process. We can return your groove to its optimal condition in a fraction of the time. (See testimonials)

Spiral grooving is necessary on high speed turbines in order to prevent problems of selective action, where the current attempts to pass through one brush. There are two main ways the spiral groove accomplishes this. The first is to break up the boundary layer of the air that attaches to a spinning surface. This lifts the brushes, increasing the brush-to-ring contact resistance. The second and more important function is that it forces the points of contact to move around the face of the brush, stopping most of the selective action. This groove has been commonly referred to as the cooling groove, which is incorrect. It actually stops the action that would cause the rings to overheat.

Spiral grooving can be performed at the end of an outage just prior to installing the brush holders, while the rotor is rotated on turning gear. Final polishing is done when the turbine is spinning back up to speed and coming on-line. If the work has to be performed between outages, the rotor is stopped only long enough to remove the holders, and then again for short periods to install and remove our guide system.