ABSTRACT
The previous chapters have covered the selection and design of a gear set. If gear engineering were an exact science, information of this type would be all that the designer needed to know. But it is not an exact science; it is both an art and a science. Those who design gears are constantly surprised that some gears run better and last longer than would be expected from the design formulas, while others fail prematurely even when they are operated well within the design limits of the transmitted load. The gear designer needs to be able to evaluate the various causes of gear wear and failure. New gear designs must be based on both textbook logic and practical —eld experience if the best possible job is to be done.
