Repairing Chain and Sprocket Wear | Cogmatic Gear Machining

Smoothing Out a Tooth Form

Cogmatic Helps Customer Solve Early Chain and Sprocket Wear

CASE STUDY #7

Customer:

A major manufacturer in the stationary concrete mixing plant industry.

Challenge:

Cogmatic was asked by an existing customer to quote on a sprocket that had been in use for many years on one of the division’s basic machines. The machine is a real breadwinner, solid old design, but with periodic modernization was still a consistent seller. The only issue with it had been early chain and sprocket wear. When they came to Cogmatic, they were facing continued manufacturing in-house on old equipment or farming out manufacturing to us as an existing vendor, and hopefully, creating some needed space in their plant for new manufacturing equipment. If we could make it more durable and last longer, then so much the better.

Cogmatic Solution:

Since Cogmatic had a solid relationship with the customer, the customer came to Cogmatic for assistance each time a new model was being developed.

Because we had never made this part before, Cogmatic had to design a profiled cam to Flame Machine the tooth form to the proper shape. In working on a study of the tooth form detail, our team discovered that the drawing, if it was faithfully reproduced in the metal, resulted in a subtle bump near the pitch line. Basically, two radii didn’t quite meet where they were supposed to.

When we shared this finding with the customer, we also presented an alternate design that smoothed the transition from tooth flank to tooth tip. Our customer examined our detail drawings and had that “ahaa!” moment where they realized this bump (or hook), was the source of the excess wear and the rough operation.

The customer quickly approved our alternate design proposal and our quote. Since Cogmatic has been making the part, they are enjoying smoother operation and seeing longer life with reduced wear.

Sometimes it is a very subtle but simple thing, as you can see from the detail of the before and after tooth form, but that can make the difference between just working and working really well. Cogmatic will do the detail analysis to make sure that we understand our customer’s custom design requirements. We usually don’t find bumps where the customer didn’t want them to be, but it’s good to know that we are a vendor that will assume nothing and check everything.