Patent attributes
Provided is a joint structure for a robot which can prevent leakage of a lubricant which is charged to the interior of the joint structure while improving a drip-proof property. The joint structure for the robot includes: a first arm which is hollow; a second arm which is rotatably mounted to the first arm; a power transmission mechanism which is provided adjacent to the outside of the first arm, the power transmission mechanism including a gear and an inner space which houses the gear and is charged with a lubricant; a booster section which increases a pressure in an interior of the first arm to be higher than an outside pressure; and a one-way communication section which allows the interior of the first arm and the inner space to communicate with each other and a gas in the interior of the first arm to flow into the inner space, while preventing the lubricant in the inner space from flowing out to the interior of the first arm.