| 摘要 |
<p>The pump has a piston which provides compression and exhaust. The pump provides a small flow, normally working at about 25Hz, typically being used in EXPRESSO (RTM) machines. The pump is designed to be easily dismantled to allow cleaning without calling in specialised staff and also to minimise noise occuring when the synthetic rubber ring sealing the end of the pump to the piston deteriorates. The pump has a magnetic piston working, against a spring during the output cycle, and driven by a surrounding coil. This is housed within a shell keyed to the piston chamber wall. This is in turn screwed into the upper chamber containing two spring valves which are accessible from either end of the chamber. The movement of the piston rod within this chamber is sealed by an '0' ring.</p> |
