Abstract: The present invention provides a pump for generating an Electroosmotic Flow (EOF) in a solution in a canal, guide, pipe or equivalent. Electroosmotic flow is generated by application of an electric field through a solution in a canal defined by insulating walls. The phenomenon depends on ionisation of sites on the surface so that for electroneutrality there is an excess mobile charge in the solution. The electric field acts on the excess charge in the solution causing the fluid to flow. The quantity and distribution of excess charge in the solution depends on the solution and the surface materials and is related to a parameter, the zeta (z) potential characterising material/solution combinations.

Abstract: A diaphragm unit includes a diaphragm and a diaphragm case. The diaphragm has a center point and an outer peripheral portion. The diaphragm case includes a fixing surface and a regulating surface. The fixing surface supports the diaphragm at the outer peripheral portion thereof, thereby defining a fluid chamber in the diaphragm case. The regulating surface forms an inner surface of the fluid chamber, thereby providing a limit of deformation of the diaphragm. The regulating surface has a convex surface region and a concave surface region. The convex surface region is formed continuously with the fixing surface for supporting the diaphragm at a portion thereof adjacent to the outer peripheral portion. The concave surface region is formed continuously with the convex surface region for supporting the diaphragm at a portion thereof adjacent to the center point. Curvatures of the convex and concave surface regions are the same.

Abstract: A pump (10) includes an impeller (12) positioned in a housing (11). A valve assembly (13) is positioned within a valve sleeve (25) which is carried by the impeller (12). The impeller (12) is carried by an armature (27), and a pocket (28) is formed between the impeller (12) and the armature (27) adjacent to the valve sleeve (25). One or more elastomeric members (29) are positioned in the pocket (28) to surround the impeller (12) at the area of the valve sleeve (25) to provide a retaining force on the valve sleeve (25).

Abstract: Valve guide and spring retainer assemblies are described for use in plunger pump housings that incorporate structural features for stress-relief. These pump housing structural features accommodate correspondingly-shaped valve guides and/or spring retainers that are internally fixed in place using one or more non-threaded spacers. Plunger pumps so constructed are relatively resistant to fatigue failure because of stress reductions, and they may incorporate a variety of valve styles, including top and lower stem-guided valves and crow-foot-guided valves, in easily-maintained configurations. Besides securing valve guides and/or spring retainers, non-threaded spacers may be shaped and dimensioned to aid in further reducing stress and to improve volumetric efficiency of the pumps in which they are used.