| 摘要 |
PURPOSE:To average pressure pulsations and reduce noises by providing a cavity section with a specific shape guiding the compressed gas discharged through a discharge port and a block section blocking the flow on a valve cover fitted to a main bearing having the discharge port. CONSTITUTION:One end face of a cavity section R is provided at an average tansfer length L' determined by a specific equation apart from a discharge port 10 and the other end face is provided at a distance integral times L' from this end face in the counter-transfer direction on a valve cover 20 fitted to a main bearing 8 having the discharge port 10, and the remaining portions are made a block section S. That is, L' is determined to satisfy an equation D'-do/2<=L'<= piD/2[3.3-1.2(do/D)], where D is the inner diameter size of a closed container, D' is the outer diameter size of the main bearing 8, do is the outer diameter size of a boss section of the main bearing 8. Accordingly, the compressed gas guided into the cavity section R of the valve cover 20 hits both end faces of the block section S, pressure pulsations are attenuated, and since the transfer path is short, pressure pulsations are quickly averaged and noises are reduced. |
