Noriteru Nishida

Term of life and wear of plastic intermediate gears.

The plastic gears used for driving paper-drying drums in paper-making machines and others are used at a gear ratio of 1:1 by putting several gears in a row. Accordingly, the intermediate gears undergo loading on both tooth surfaces, but at present, the operational characteristics of the plastic gears being used in this way have not been elucidated at all. Therefore, in this study, the operation test applying alternating loads was carried out using MC nylon gears and such things as the operational term of life, the wear of teeth, and the state of change of tooth profile were examined.

Extraction of average component of gear vibrations and gear noises. (2nd report). The influence of the fluctuation of the number of revolution of gears.

Vibrations and noises of gears consist of the average component and the fluctuating one. The former is the component which always appears in each tooth meshing. The latter is the component which fluctuates about the average component. In the first report, it was described that the moving average method was very effective for extracting the average component. In that report, a steady rotation of gears was assumed. However, the number of revolution of gears always fluctuates more or less in actual gear equipments. In this report, the generation of the side band waves due to the fluctuation is explained and the allowable value of the fluctuation ratio is given to extract the average component.

Extraction of average component of gear vibrations and gear noises.

Vibrations and noises of gears consist of the average component and the fluctuant one. The former is the component which always appears in each tooth meshing. In general, this component consists of the meshing frequency and its harmonics. The latter is the component which fluctuates about the average component and is caused by the error of gears, torque fluctuation, and so on. In this report, the extraction of this average component by using a method of moving averages is described. This method is very effective for extracting the average component of gear noises or gear vibrations. The effectiveness of this method is shown theoretically and experimentally.