抄録
As a part of the research program probing into the cause of failures in the nose suspension type traction gears, measurements of fillet stresses occurring in both sides of gear tooth surfaces of a running electric locomotive were carried out using wire resistance strain gauges with the following results;
1. Nose suspension type traction gears are not free from occurrence of uneven contact at the sides; actually the whole width of tooth surface does not share the load uniformly.
2. Maximum fillet stress of gear develops at the side nearer to the motor when the motor is preceding the wheel in the running direction.
3. The proportion of the fillet stress at the side nearer to the motor to the calculated fillet stress on the assumption of uniform tooth contact is 3.9 maximum for EF 58 locomotive and 11 maximum for DF 50. Maximum measured stress caused by uneven contact, even when the actual output torque was small, turned out often larger than the calculated value assuming uniform tooth contact under maximum load.
4. When the wheel precedes the motor in the running direction, it is clearly observed in the DF 50 locomotive having less weight of motor that the movement of tooth contact from the wheel side to the motor side takes place.
5. In the quill drive transmission mechanism, uneven contact was observed by measuring the fillet stresses of gear at both sides of the tooth surface when the shafts of pinion and gear were misaligned.
