Rotor structure of superspeed PMSM

The utility model relates to a rotor structure of a superspeed PMSM; the rotor structure comprises a rotation shaft and a rotor yoke arranged on the rotation shaft; the rotor yoke is provided with a plurality of permanent magnets arranged in a circumferential of the rotor yoke; the rotor structure is characterized by also comprising a round-shaped dynamic balancing disc extending from the rotation shaft in a radial direction; at least one side surface of the dynamic balancing disc is provided with an annular balancing groove in a recessed manner and used for mounting a balancing block; the balancing groove comprises at least two flaring portions and arc-shaped closing segments connected between the flaring portions; the whole body of the balancing groove is rotatably and symmetrically arranged around an axis of the rotation shaft; a section shape of the closing segment is in an inner closing shape; and a minimum width of a section of the flaring portion is bigger than or equal to a maximum width of the sectio