| 摘要 |
PROBLEM TO BE SOLVED: To prevent infiltration of water and dust into the inside of an electric motor. SOLUTION: In this vacuum pump, the air discharged from a pump portion P is discharged from a respiration hole 64 of the electric motor 50 after passing through the inside of the electric motor 50. This vacuum pump is provided with a check valve 60 which opens the respiration hole 64 when an inner pressure of the electric motor 50 is higher than an outer pressure of the electric motor 50. Thus, the check valve 60 closes the respiration hole 64 during non- operation of the pump, thereby preventing infiltration of water and dust into the inside of the motor 50 from the respiration hole 64.
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