Centrifugal compressor impeller with nonlinear backwall
AssigneeIngersoll-Rand Industrial U.S., Inc.
InventorNoel Blair
Life of this patent
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Abstract
A centrifugal compressor impeller includes a plurality of blades on a front side that extend from a first axial side to an outer radial end of the impeller. The centrifugal impeller includes a back side having a nonlinear backwall. The backwall can include a flat area hear a bore of impeller, a flat area near a tip of the impeller, and a convex surface between the flat areas of the bore and the tip. In some forms the impeller further includes a concave surface between the convex surface and the tip to form an s-shape. A transition or inflection point can denote the change from convex to concave. The convex and/or concave surfaces can take any variety of forms such as constant radius sections and/or compound curves.
Claims19
An apparatus comprising:
- a centrifugal impeller having a blade side and a backwall side, the backwall side having a backwall and a hub region configured with a bore to be affixed to a rotatable shaft, the blade side including a plurality of impeller blades that extend from a first axial end to a first radial end of the centrifugal impeller, the plurality of impeller blades configured to receive a working fluid in the first axial end, compress the working, and discharge the working fluid through the first radial end when the centrifugal impeller is being operated, the backwall of the centrifugal impeller defined by:
- a flat area that extends inward from an outermost radial extent of the centrifugal impeller to a first location;
- a flat area in the hub region that extends outward from an outer diameter of the bore to a second location;
- and
- a compound curve located between the first location and the second location,
- wherein the compound curve includes a concave curve at a location radially outward of a convex curve.
An apparatus comprising:
- a centrifugal impeller having a plurality of blades on a first side and a backwall on a second side, the centrifugal impeller defining an intake on a first axial end of the first side and an outlet on an outer radial end of the first side, the centrifugal impeller having a bore hole and a bore hole flat area on the second side surrounding the bore hole, the backwall defined by a tip region flat area near the outer radial end, the backwall defining a convex region;
- wherein the backwall defines a compound curve, the compound curve including a concave region located radially outward of the convex region.
An apparatus comprising:
- a centrifugal compressor impeller having a plurality of blades disposed on a front side and a backwall disposed on a back side, the backwall having a central flat area surrounding a bore of the centrifugal compressor impeller and a curvilinear extension extending from the central flat area toward a tip of the centrifugal compressor impeller, wherein the curvilinear extension extends radially outward and axially towards the front side, the central flat area and the curvilinear extension defining a convex shape;
- wherein the backwall defines a compound curve, the compound curve including a concave region located radially outward of the convex region.
Dependencies are inferred from the claim text.