Abstract: A volumetric assembly includes: a roots-type supercharger device; a roots-type expander device; a first duct extending from the supercharger fluid inlet, the first duct supplying fluid to the roots-type supercharger device; and a second duct extending from the expander fluid outlet, the second duct directing fluid away from the roots-type expander device, wherein the first duct is positioned adjacent to the second duct, and wherein the first duct defines a first aperture and the second duct defines a second aperture, the first and second apertures being generally aligned; and a flexible membrane positioned between the first and second ducts in the first and second apertures, the flexible membrane sealing the first duct from the second duct, and the flexible membrane flexing as fluid flows within the first and second ducts to attenuate noise associated with the fluid flows.

Abstract: A positive displacement pump (8) comprises a cylindrical input shaft (13) comprising a first area (A1) with a first diameter (D1), a second area (A2) with a second diameter (D2), and a third area (A3) with a third diameter (D3), where the second diameter is greater than the first diameter and the third diameter. A stator (19) is press fit to a portion of the third area. A cylindrical bushing (15) is press fit around the second area. When the input shaft (13) rotates, the torsional vibration damping bushing (15) resists the rotation. The pump also comprises a clutch assembly (21). A clutch armature (29) of the assembly comprises a cylindrical, hollow passageway (290) and radially extending arms (39). Each arm comprises an opening (293), at least one slot (295) passing through the arm, and at least one void (297) abutting the slot, the void passing through the arm. When the clutch assembly engages, the armature damps vibrations.