Gaining the edge
A new high-speed compressor neatly combines the best features of rotary and reciprocating machines in a simple basic unit
How do you compress air efficiently at speed, without the need for seals or very elaborate valves? The answer would seem to be by having an eccentric cylindrical rotor within a chamber, rotating with an edge velocity that is supersonic.
While the edge may be moving faster than sound, the air is moving much more slowly and in a manner that avoids unnecessary changes of direction, so it’s expected to run more quietly and efficiently than conventional designs. The first intended application is in engine supercharging, but the design is suitable for any kind of air or gas compression task.
The man behind the concept is John Hammerbeck, who invented the SCRAM compliant variable ratio coiled spring drive (Eureka, September 2000) and the hypocycloidal reducer (October 2003). This latest idea is a hypocycloidal air compressor.
A longer version of this appears in the July 2008 issue of Eureka.
