Abstract: An apparatus comprising includes a conduit portion having a conduit inner surface and a conduit outer surface, and a plurality of chambers in fluid communication with the conduit portion. The chambers include a first chamber defined, at least in part, by a first outer housing and a first chamber volume. The first chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the first chamber through a first flow area. The chambers also include a second chamber defined, at least in part, by a second outer housing and a second chamber volume. The second chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the second chamber through a second flow area. The first chamber volume is generally equal to the second chamber volume and the first flow area is greater than the second flow area.

Abstract: An apparatus comprising includes a conduit portion having a conduit inner surface and a conduit outer surface, and a plurality of chambers in fluid communication with the conduit portion. The chambers include a first chamber defined, at least in part, by a first outer housing and a first chamber volume. The first chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the first chamber through a first flow area. The chambers also include a second chamber defined, at least in part, by a second outer housing and a second chamber volume. The second chamber is in fluid communication with the conduit portion. A fluid is permitted to flow between the conduit portion and the second chamber through a second flow area. The first chamber volume is generally equal to the second chamber volume and the first flow area is greater than the second flow area.

Abstract: A rotary blower (26) including a pair of shafts (70,56) on which are mounted a pair of rotors (28,29), input to the first shaft (70) being by way of an input pulley (76;108;201). The first shaft (70) has a forward terminal portion (72) extending forwardly of a first timing gear (60) to a location disposed within the input pulley. A torsion damping means is associated with the input pulley (76;108;201) and includes a resilient means (94;124;213) which resists relative rotation between the input pulley and the terminal portion (72) of the first shaft. The torsion damper also includes means (88,90,92;118,122;207,211) for limiting the relative rotation of the input pulley and the first shaft. The disclosed arrangement provides a more compact, less expensive input portion of the blower which eliminates the need for the conventional "third shaft" and its associated bearings.