Lower bearing part structure of the output shaft of the reduction gear

摘要

PROBLEM TO BE SOLVED: To prevent a pressure rise due to a lubricating oil inside a bearing rack by automatically discharging an excessive lubricating oil from the bearing rack out of a lubricating agent sealed for lubricating a lower bearing which causes a leak, and to prevent the excessive deformation and the like of an oil seal.;SOLUTION: A lower bearing part structure includes: a lower bearing 128, which supports an output shaft 130 extended downward; a bearing rack part 138, which supports the lower bearing 128; and the oil seal 132 provided between the output shaft 130 and the bearing rack 138. In this structure, a stopper ring 148 is provided through a gap 151 from the output shaft 130 on the top surface 140 of the bearing rack 138. The stopper ring 148 has a thermal expansion coefficient, by which the gap 151 is contracted to the size Go that shuts off the upward leak of the lubricating agent from the top surface 140 when the lubricating oil is supplied at the time of stop of the output shaft 130 and the gap 151 is expanded to the size G1 that permits the upward leak of the lubricating oil from the top surface 140 when the output shaft 130 is rotated.;COPYRIGHT: (C)2010,JPO&INPIT