ROTATIONAL VIBRATION OF A HELICAL GEAR PAIR WITH MODIFIED TOOTH SURFACES - (VERIFICATION OF THE NEW THEORY BY EXPERIMENT AND A NEW DESIGN METHOD FOR DYNAMIC PERFORMANCE)

The dynamic increment-of-tooth load derived from the new theory is verified by experiment, which is expressed as a function of two variables, velocity and operating load, with the parameter of tooth surface modification, when the dimensions and the tooth-pair spring constant of the gear pair are given. This dynamic incremental load can be used as an index of the dynamic performance of a gear pair, such as noise, vibration and dynamic load. A gear design method to minimize the index is discussed theoretically, which clarifies that there are combinations of tooth surface modification, tooth-pair spring constant and static load which minimize the index and that, in the gear pair which realizes no dynamic incremental load (the index=0) under any load, the tooth surface is not modified and the equivalent tooth-pair spring constant does not vary. In other words, designing a gear pair to show good dynamic performance under any load means realizing an equivalent tooth-pair spring constant with variation as small as possible by choosing the optimal dimensions and realizing tooth suface modification as small as possible by choosing proper manufacturing processes.