Abstract: A regenerative blower is disclosed with a rotating impeller that includes a hub that includes a main body and a tapered outer periphery or volute that extends around the main body of the hub. The volute has a wide base that extends to a tapered volute tip. A plurality of vanes are spaced apart along the main body of the hub and intersect the volute. Each vane has a base coupled to or integral with the main body of the hub and a distal end extending radially away from the hub. Each vane has a downstream side and an upstream side. The downstream sides are concave and the upstream sides are convex. Each vane may also include a pair of side edges that are beveled inwardly towards the volute as the side edges extend from the downstream side of the vane to the upstream side of the vane.

Abstract: Rotary vane pumps include casings having asymmetrical cavities that accommodate a rotor. For a single pump chamber, one portion of the rotor abuts or nearly abuts the inner wall of the cavity at a single location while one portion of the rotor and the inner wall are not in contact with each other thereby defining a pump chamber. For a dual pump chamber embodiment, two diametrically opposed portions of the rotor abut or nearly abut the inner wall of the cavity while two portions of the rotor and inner wall are not in contact with each other thereby defining the two pump chambers. The two pump chambers are disposed on opposite sides of the minor axis of the cavity. The cavities of each pump are skewed so each pump chamber is larger in volume at the inlet end than at the outlet end.

Abstract: Rotary vane pumps include casings having asymmetrical cavities that accommodate a rotor. For a single pump chamber, one portion of the rotor abuts or nearly abuts the inner wall of the cavity at a single location while one portion of the rotor and the inner wall are not in contact with each other thereby defining a pump chamber. For a dual pump chamber embodiment, two diametrically opposed portions of the rotor abut or nearly abut the inner wall of the cavity while two portions of the rotor and inner wall are not in contact with each other thereby defining the two pump chambers. The two pump chambers are disposed on opposite sides of the minor axis of the cavity. The cavities of each pump are skewed so each pump chamber is larger in volume at the inlet end than at the outlet end.

Abstract: Piston assemblies for rocking piston compressors, diaphragm compressors and vacuum pumps wherein the overall mass of each piston assembly is identical to that of the other assembly despite having rod tops, retainers and diaphragms of different diameters and therefore different capacities. Each piston assembly includes a connecting rod connected to a rod top that supports a cup seal and a retainer or retainer plate. The mass of each rod is equal to that of the other rod despite the differing geometries. The mass of each retainer is the same as that of the other retainer despite the differing geometries. The overall length and stroke length of each piston assembly is the same. As a result, centers of gravity of the piston assemblies are continuously balanced on either side of the drive shaft in terms of distance from the drive shaft and in absolute value.