Effects of Rotational Conditions on Performance of Gear Unit Pinion Bearing

Tapered roller bearings are mainly used in rotating parts of gear units on railway vehicles. In order to prevent bearing seizure and to improve gear unit reliability, it is important to ensure appropriate clearance between bearings. Bearing clearance changes from its initial value as vehicles travel due to atmospheric temperatures and variation in the initial values in the gear unit assembly, which affects bearing perfor mance. In this research, an actual gear unit was subjected to bench rotation tests under various bearing clearances and various atmospheric temperatures. Bearing temperature and torque were measured, and changes in bearing clearance were estimated. was limited to that of a conventional DMU. For this paper, using passenger areas was not necessary, because downsized FC and power converters were installed under the vehicle floor. Furthermore, we improved tractive performance to reach that of a standard EMU, by increasing the power capacity of each FC and Bat.