PROBLEM TO BE SOLVED: To provide a railroad vehicle eddy current decelerator which can solve the problems of a conventional ECB brake.
SOLUTION: A disc 12 is attached to an axle 1 with a boss 11 therebetween. Bearing units 16a and 16b are attached to the axle 1 on both the sides of the boss 11. A semi-circular stator assembly 17 is detachably attached to the bearing units 16a and 16b so as to cover the disc 12 partially. The stator assembly 17 has pole pieces 17a which are fixed on both the sides of the stator assembly 17 so as to face both the sides of the disc 12 and to be arranged on the respective same circles with predetermined intervals, a row of inside permanent magnets 17b which are fixed to positions facing the inner circumferential parts of the pole pieces 17a on the opposite side of the disc 12 so as to have their N-poles and S-poles arranged alternately, a row of outside permanent magnets 17c which are fixed to positions facing the outer circumferential parts of the pole pieces 17a so as to have their N-poles and S-poles arranged alternately and to have them able to be turned by one pitch of the pole pieces 17a, and a hydraulic cylinder 17k which turns the row of the outside permanent magnets 17c.