| 摘要 |
PURPOSE:To provide compatibleness of both lubricity and sealing performance by disposing a lubricating oil absorbing member between an oil sealing member and a bearing face which is formed at a part of a cylinder internal face and surrounds a reciprocating shaft supported by the bearing face. CONSTITUTION:A gas cut-off mechanism 5 which prevents gas entry is mounted in a housing 1 in which a power piston cylinder 2 is formed at the upper part thereof and a cylinder 4 containing a cross head 3 is formed at the lower part thereof. A large-diameter internal face 4a and a small-diameter bearing face 4b are formed on the cylinder 4. The marginal part of both the internal faces 4a and 4b is holed at specified intervals and porous substances 6 are put in the holes. The internal end part of the porous substances 6 is made in intimate contact with the external periphery of the cross head 3 and the external end part thereof faces to an oil reservoir 7. The cross head 3 is shaped in the cylindrical form and has oil sealings 9a, 9b and 9c on the upper external periphery thereof. |
