Heavy object supporting device

A heavy object supporting device comprising:

• a mounting table on which a supported object is mounted;
• a base which is arranged to face the mounting table to form a gap between the mounting table and the base;
• at least one elastic annular sealing member having elasticity and an annular shape which is arranged between the mounting table and the base;
• and
• a separation preventing structure which prevents separation between the mounting table and the base,
• the base and the mounting table respectively having facing surfaces facing each other,
• the mounting table having a separate annular arrangement groove for each of the at least one sealing member, wherein each groove is opened toward the base,
• the facing surface of the base including a seal region configured to be in contact with the each of the at least one sealing member, an inner pressure-receiving region arranged inside the seal region, and an outer slide region arranged outside the seal region, and having the seal region, the inner pressure-receiving region, and the outer slide region formed to expand on the same plane,
• the at least one sealing member being held in close contact with an inner surface of the arrangement groove and the facing surface of the base, with the at least one sealing member arranged in the arrangement groove,
• a space, which is formed between the mounting table and the base and surrounded by the at least one sealing member, being formed as a fluid-filled space sealed off from an outside of the mounting table and the base in a state of being filled with fluid,
• the at least one sealing member being formed to support the mounting table against the base so as to form the gap, and being formed to be able to be compressed to reduce the gap,
• the mounting table having an outer peripheral edge entirely located outward of an outer peripheral edge of the base,
• the separation preventing structure being configured to permit relative movement between the base and the mounting table in a direction such that the mutually facing surfaces of the base and the mounting table come close to each other and away from each other, and relative sliding movement between the base and the mounting table in the direction orthogonal to the direction in which the mutually facing surfaces of the base and the mounting table come close to each other and away from each other, within a range to keep the close contact between the at least one sealing member and the mounting table,
• the separation preventing structure comprising a plurality of abutment stop sections extending downward from the outer peripheral edge of the mounting table and arranged to face a side of the base, and a plurality of holding sections each extending from each of the plurality of abutment stop sections and abutting the base from below,
• the fluid-filled space being configured to increase a pressure of the fluid with the supported object mounted on the mounting table, so that the mounting table is supported on the base in such a manner as to be slidable in the orthogonal direction with respect to the base by means of the pressure of the fluid,
• the heavy object supporting device further comprising a pressure control structure which controls the pressure of the fluid in the fluid-filled space, and
• the pressure control structure having:
• a storage space formed inside the mounting table, the storage space being filled with fluid and sealed with a fixed amount of fluid, a communication passage formed inside the mounting table and communicating the storage space with the fluid-filled space, the communication passage being filled with fluid and sealed with a fixed amount of fluid, a movable wall section arranged in the storage space, a sealing member located for sealing between an entire circumference of the movable wall section and an inner surface of the mounting table forming the storage space, and an operation section mounted on the mounting table and configured to move the movable wall section in the storage space.