| 摘要 |
PURPOSE:To enable a piston sliding part to be accurately lubricated without causing any trouble for assembly of a pump to an engine, by providing a lubricating mechanism, which can sufficiently supply lubricating oil to the piston sliding part by effectively utilizing driving power of the vacuum pump, in the inside of a housing main unit. CONSTITUTION:Oil in an oil reservoir R3 forces a valve body 29b of a check valve 29 to be pressed by repeating the vertical motion of an operating piston 20, being allowed to successively flow into the first commnication path P1 formed in a piston rod 22 and flow upward, and the oil is supplied almost equally to the whole periphery of a piston 1 from many notched grooves 28e in a piston band 25 via the second communication path P2 and the third communication path P3. While a part of the oil supplied to the whole periphery of the piston 21 is also accumulated staying in many notched grooves 28f provided in an upper end of the piston band 25 and successively supplied to the whole periphery of the piston 21. In this way, the whole periphery of a sliding part of the piston 21 can be accurately lubricated. |
