REDUCTION GEAR

摘要

PROBLEM TO BE SOLVED: To obtain a reduction gear capable of detecting failure of an oil seal.SOLUTION: A reduction gear GM1 includes: a speed reducer G1 having an input shaft 30; and a motor M1 serving as a pre-stage device disposed at the pre-stage of the speed reducer. A casing 58 of the speed reducer includes: an air injection port 89 from which air may be injected; and an input side casing body (an input side cover) 58B which is disposed facing the motor. The input shaft 30 is provided penetrating through the input side casing body. An input side oil seal 84 is disposed between the input side casing body and the input shaft. A space SP1 is formed between the input side casing body and the motor so that air circulates between the space and the exterior of the reduction gear.