| 摘要 |
<p>PURPOSE:To absorb pressure fluctuation in a closed space in an oil tank and to prevent dust from entering the oil tank by providing such a vessel as its outer enclosing part deforms softly or moves in one direction so as to vary the capacity of the vessel. CONSTITUTION:An oil tank 10 storing oil 7 is provided with a vessel 1, which is communicated with a closed space 2 above an oil surface level, and disconnects the tank from the atmosphere, and whose outer enclosing part corresponds softly to the variation so that the fluctuation of pressure within the closed space 2, which is caused by the variation in the oil surface level, is absorbed. In this case, the vessel 1 is designed in such a way that its content volume sufficiently covers the change of volume of the closed space 2 of the oil tank 10, which is caused by the variation of the oil surface level. In addition, the outer enclosing part of the vessel 1 should be such that either it is formed of such a member as is easily deformed by the pressure of about several tenth of the open air pressure (one atmospheric pressure) or at least it can move in one direction, keeping the air tightness, even if it is not deformed. With this contrivance, a hydraulic driving device can always work stably and smoothly.</p> |
