Patent ID: 8875841

Claim:
A transmission comprising: a case; a plurality of gears rotatably supported in the case; lubrication oil contained in the case; a lubrication oil storage region in a bottom portion of the case, storing the lubrication oil, and enabling the stored lubrication oil to be scooped up by rotation of a first gear of the plurality of gears above the first gear; a receiver for flowing the lubrication oil scooped up upward by the rotation of the first gear to sliding parts of the gears; and a lubrication oil retention section having a U-letter shape that surrounds a circumferential surface and both side surfaces of a circumferential part of the first gear, the lubrication oil retention section extending from the lubrication oil storage region to an outside of the lubrication oil storage region at a portion on the circumferential part where the lubrication oil is splashed towards the receiver, and the lubrication oil retention section retaining the lubrication oil scooped up by the rotation of the first gear between itself and the first gear at the outside of the lubrication oil storage region and enabling the first gear to splash toward the receiver the lubrication oil retained at the outside of the lubrication oil storage region.