Multilevel-redundancy main shaft sealing method

The invention discloses a multilevel-redundancy main shaft sealing method and belongs to the technical field of motor equipment. The multilevel-redundancy main shaft sealing method is characterized in by comprising the following steps: arranging a sealing seat in contact with an external medium cavity on a main shaft, forming an axial hole in the sealing seat and communicating the axial hole with an internal oil cavity; mounting a one-way valve in the axial hole and embedding a seal ring into the sealing seat to form an annular transition cavity; communicating the annular transition cavity with the axial hole, and adjusting pressure difference between the annular transition cavity and the internal oil cavity through axial movement of the one-way valve in the axial hole. Through the multilevel-redundancy main shaft sealing method, at least two-level redundancy sealing is matched with one-way oil permeability and mobility of the one-way valve, so that the pressure difference applied to the seal ring can be reduced; the sealing reliability is improved; the multilevel-redundancy main shaft sealing method is capable of preventing the dilute oil leakage in the motor and the external multiphase liquid from entering the motor, thereby guaranteeing long-term stable operation of the motor.