External pressure adjusting type magnetic liquid sealing device

The invention discloses an external pressure adjusting type magnetic liquid sealing device. The magnetic liquid sealing device comprises a magnetic liquid sealing core device arranged on a spindle ina sleeving mode for sealing; the magnetic liquid sealing core device comprises a sealing permanent magnet movably arranged on the spindle in a sleeving mode; pole teeth are arranged in a gap, betweenthe sealing permanent magnet and the spindle, of the sealing permanent magnet; and the magnetic liquid sealing device further comprises a driving device for driving the magnetic liquid sealing core device to move in the axial direction of the spindle. According to the external pressure adjusting type magnetic liquid sealing device of the structure, the magnetic liquid sealing device is pushed by the driving device to move towards the high-pressure side, so that the upper limit pressure value of magnetic liquid sealing is increased, the size of a radial magnetic pole sealing gap is changed, andthe pressure value of the