Software predicts how gears will mesh

The British gear-maker Holroyd has developed a computer program that it says will revolutionise the production of large centre-distance gears. Holroyd`s wormgear contact analysis program, which has taken the company four years to develop, can predict contact patterns between a worm and its wheel, and show how these patterns are affected by distortions or misalignments in the system.

Until now, manufacturers of large wormgears have relied on the expertise of their machine operators and on their familiarity with the individual characteristics of each gear-hobbing machine. Producing large gearsets has been a painstaking business, involving a complex series of machining processes, sometimes requiring re-grinding or re-cutting of the worm or wheel to achieve the desired contact.

According to Steve Whitehead, Holroyd`s gears sales director, the new software is allowing the company "to eliminate trial and error from the design and production process, using the contact prediction graphic and revised calculations to manufacture accurate and efficient gearsets first time around".

The accuracy between the predicted and actual contact patterns is said to be about 95%. The ability to predict the effects of distortions is allowing Holroyd to compensate for the inevitable distortion that the load will impose. The software has also led to dramatic reductions in leadtime and to "more competitive pricing". Holroyd says that the gears should also last longer because of their improved lubrication performance.