POWER TRAIN AND CONSTRUCTION MACHINE

A first planetary gear set includes a first sun gear to which power is input from a hydraulic motor. The first planetary gear set includes a first carrier and a first ring gear. The first carrier and the first ring gear are able to rotate in conjunction with rotation of the first sun gear. A second planetary gear set includes a second sun gear configured so as to rotate integrally with the first carrier. A hydraulic clutch mechanism allows or prohibits the rotation of the first ring gear.