Gear coupling

A gear coupling for a railway vehicle comprising:

• a first inner cylinder provided at a shaft end of a driving shaft, which is a rotating shaft of an electric motor, and including an external tooth gear;
• a first outer cylinder including an internal tooth gear meshing with the external tooth gear;
• a second inner cylinder provided at a shaft end of a driven shaft, which is a small gear shaft of a transmission gear, and including an external tooth gear;
• a second outer cylinder including an internal tooth gear meshing with the external tooth gear;
• a first closing plate interposed between the first inner cylinder and the second inner cylinder and closing an end face of the first outer cylinder in a direction in which the first outer cylinder and the second outer cylinder are opposed to each other;
• and
• a second closing plate interposed between the first inner cylinder and the second inner cylinder and closing an end face of the second outer cylinder in the direction, wherein
• in the first closing plate, one or a plurality of reversible through-holes communicating with a device outer side of the first closing plate from a first space surrounded by the first inner cylinder, the first outer cylinder, and the first closing plate are formed,
• in the second closing plate, one or a plurality of reversible through-holes communicating with a device outer side of the second closing plate from a second space surrounded by the second inner cylinder, the second outer cylinder, and the second closing plate are formed,
• a plugging member screwed into a surface on which the first closing plate and the second closing plate are opposed to each other and closing the through-holes is fitted to the through-holes formed in the first closing plate,
• a plugging member screwed into a surface on which the first closing plate and the second closing plate are opposed to each other and closing the through-holes is fitted to the through-holes formed in the second closing plate,
• a tip of a screw section of the plugging member fitted to the first closing plate is located on the first closing plate side with respect to a boundary between the first closing plate and the first space, and
• a tip of a screw section of the plugging member fitted to the second closing plate is located on the second closing plate side with respect to a boundary between the second closing plate and the second space.