摘要 |
<p>Pneumatic valve spring members (10) provide replacement for mechanical springs used to seat engine valves in internal-combustion engines. A valve guide (16) sits atop the engine head (40), allowing the valve stem (12) of valve (14) to pass and reciprocate therethrough. At the distal end of the valve stem (12), a valve retainer (30) is attached to the valve stem (12). The valve retainer (30) is spaced apart from the valve guide (16). A bellows seal flexibly interconnects the valve retainer (30) with the valve guide (16). Upper and lower isolators (52, 50) serve to hold an air cushion about the valve stem (12) adjacent the bellows seal (42). The air cushion (60) serves to maintain and store pressure, lifting the distal end of the valve stem (12) toward the rocker arm (36).</p> |