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(11) | EP 0 787 903 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Regenerative pump having vanes and side channels particularly shaped to direct fluid flow |
| (57) A regenerative or toric pump adds energy to a fluid using an impeller having an axis
of rotation and axially spaced, radially extending first and second surfaces. A casing
encloses the impeller and has a fluid inlet and a fluid outlet separated by a stripper.
The casing has axially spaced, radially extending first and second sidewalls facing
the first and second surfaces of the impeller respectively. Axially and radially extending
blades or vanes are formed on an outer radial periphery of the impeller for driving
fluid from the inlet toward the outlet as the impeller rotates about the axis of rotation.
A fixed surface is formed in at least one sidewall of the casing for directing fluid
back toward the impeller. Improved operating characteristics and extended range are
accomplished through modification to the vane configuration of the impeller and/or
by modification of the side channel configuration of the pump chamber in an asymmetrical
fashion. The vanes can be modified to include a radially inward based portion extending
in a generally trailing direction with respect to rotation of the impeller and a radially
outward tip portion extending in a generally leading direction. The blades may also
include a chamfered surface on the trailing edge of the base portion. The impeller
chamber can be modified separately by expanding a side channel in the casing, or by
insertion of a spacer between the side channel and the remaining portion of the casing
defining the impeller chamber. |