Axial magnetic bearing centering device, axial magnetic bearing and assembling method

The invention relates to an axial magnetic bearing centering device, an axial magnetic bearing and an assembling method. The axial magnetic bearing centering device comprises a magnetic pole shell and an axial iron core (8) arranged in the magnetic pole shell and further comprises an axial iron core positioning ring (6). The radial outer circle face of the axial iron core positioning ring (6) abuts against the radial inner circle face of the magnetic pole shell. The radial inner circle face of the axial iron core positioning ring (6) abuts against the radial outer surface of the axial iron core (8), and accordingly radial positioning of the axial iron core (8) is achieved. The axial iron core positioning ring is added in an axial magnetic bearing structure, the assembling coaxiality between the axial iron core and a thrust disc is ensured through interference assembling between the axial iron core and the magnetic pole shell and between the axial iron core positioning ring and the magnetic pole shell, and accordingly the radial interference force of the axial magnetic bearing at the balance position is eliminated, and the radial positioning of the axial iron core is achieved.