Abstract: This machine includes: a rotor; sliprings that are placed on an outer circumferential surface of an end portion of a shaft located on one end side thereof and projecting from the rotor; a brush assembly that has a cylindrical shape with an open end located near a head of the shaft, to thereby surround the sliprings; and brushes that penetrate in the brush assembly toward the sliprings from their radially outer sides and make contact with the sliprings, for supplying a current to the sliprings; wherein, on an inner circumferential surface of the brush assembly near the open end, a first wall that extends in a circumferential direction and a second wall that forms, between it and the first wall, a flow passage that leads in the circumferential direction from a region corresponding to a penetrating region of the brush, to an outside thereof, are formed.