| 摘要 |
<p>PURPOSE: To provide a foreign matter infiltration preventing device of a tank, capable of completely preventing foreign matters from infiltrating into the tank, immediately finding the damage of the tank, and avoiding variation of components of operating fluid. CONSTITUTION: The upper part of a tank 12 for storing operating oil to be supplied to a hydraulic device 10 is sealed by a block plate 16. A bellows-like air accumulator 44 in which air is enclosed is connected to this block plate 16, and the air accumulator 44 and the upper part of the tank 12 are airtightly communicated with each other. Air is moved between the air accumulator 44 and the tank 12 according to the fluctuation of the quantity of operating oil in the tank 12, and the air accumulator 44 is expanded or contracted.</p> |
