Patent ID: 6068459
Filing Date: 2000-05-30
Classification: F04C

Abstract:
Vacuum pumping apparatus comprising:a scroll blade set having an inlet and an outlet, said scroll blade set comprising a first scroll blade and a second scroll blade that are nested together to define one or more interblade pockets, at least one of said first and second scroll blades having a seal groove along an edge thereof;an eccentric drive operatively coupled to said scroll blade set for producing orbiting movement of said first scroll blade relative to said second scroll blade so as to cause said one or more interblade pockets to move toward said outlet; anda tip seal positioned in said seal groove between said first and second scroll blades, said tip seal comprising a seal element and an energizer element affixed to said seal element, said energizer element comprising a resilient material having multiple compressible voids, wherein said energizer element having compressible voids is more compressible than said resilient material alone, when confined by said seal groove, wherein said energizer element comprises a low porosity urethane foam.