EDDY CURRENT-TYPE SPEED REDUCER

An eddy current deceleration device (100) includes a rotor (10) and a stator (20). The rotor (10) includes a hub (12), a rotor body (11), and a spoke (13). The spoke (13) has neutral axes (N1, N2). The neutral axis (N1) is a neutral axis when the spoke (13) is bent in a circumferential direction of the rotor body (11). The neutral axis (N1) is positioned forward in a rotating direction (R) of the rotor (10) with respect to a center line (C1) of the spoke (13) in the circumferential direction. The neutral axis (N2) is a neutral axis when the spoke (13) is bent in an axial direction of the rotor body (11). The neutral axis (N2) is positioned on a rotor body (11) side with respect to a center line (C2) of the spoke (13) in the axial direction.