Sealing device and drive apparatus including the same

A sealing device, comprising:

• a movable part which is fixed to a shaft penetrating a wall of a vessel and is movable with the shaft, the vessel being configured to include an interior space having a higher pressure or a lower pressure than an exterior space;
• a first bellows part which has a first end fixed to the vessel and a second end fixed to the movable part, for sealing a penetrated portion of the vessel by the shaft;
• a second bellows part which is disposed opposite to the first bellows part across the movable part, and has a first end disposed on a side of the first bellows part and fixed to the movable part, and a second end fixed to a stationary member;
• and
• a communication path for causing an interior space of the first bellows part and an interior space of the second bellows part to communicate with each other.

A sealing device, comprising:

• a movable part which is fixed to a shaft penetrating a wall of a vessel and is movable with the shaft, the vessel being configured to include an interior space having a higher pressure or a lower pressure than an exterior space;
• a first bellows part which has a stationary-side end fixed to the vessel and a movable-side end fixed to the movable part;
• and
• a second bellows part which is disposed in series with the first bellows part in an axial direction, and has a stationary-side end fixed to a stationary member and a movable-side end fixed to the movable part,
• wherein, among the stationary-side end and the movable-side end of the first bellows part and the stationary-side end and the movable-side end of the second bellows part, a distance in the axial direction between the stationary-side ends or between the movable-side ends located farthest from each other in the axial direction is constant regardless of a position of the shaft, and
• wherein an interior space of the first bellows part and an interior space of the second bellows part communicate with each other.