In the present paper the authors have carried out a study on the stress on root fillet of non-metallic gear tooth in meshing by use of the gear running test machine and the measuring equipment of dynamic load designed by the authors.
In consequence we got following results.
(1) The dynamic load is increased according to the increase of the circumference speed and yet it shows the maximum value when the meshing period of gear teeth coincides with the period at natural frequency of gear tooth, then dynamic load is decreased as the speed is increased still more.
(2) The rate of increase of dynamic load shows smaller value as static load of gear tooth becomes larger.
(3) The fillet stress is larger in the case of speed up gears than in the case of reduction gears.
(4) The tendency of dynamic load coincides with the tendency of wear and noise properties.