Polymer Compressor Wheel with Co-Molded Bore Insert

Abstract

A centrifugal compressor wheel assembly that can be employed in devices such as turbochargers or as a component for mechanisms requiring a compressor wheel assembly that includes a tubular insert with a compressor wheel member connected thereto which engages a shaft and a turbocharger including the compressor wheel assembly. The tubular insert has a wall member defining a shaft bore that extends from an inlet end to an opposed outlet end. The wall member has an outer circumferential surface and an opposed inner circumferential surface. At least one engagement member may be defined on the inner circumferential surface. An engagement member may be defined on the outer circumferential surface. The tubular insert can be composed of a suitable metal.

What is claimed is: 
     
         1 . A compressor wheel assembly comprising:
 a metal tubular insert having a shaft bore extending from an inlet end to an outlet end opposed to the inlet end, and a wall member, the wall member having an outer circumferential surface and an inner circumferential surface opposed to the outer circumferential surface defining the tubular insert shaft bore, wherein the at least one of the outer circumferential surface or inner circumferential surface includes at least one engagement member defined thereon;   a compressor wheel member composed of a polymeric material, the compressor wheel having an axially extending center portion molded on to the tubular insert, the center portion having an inlet end and an outlet end opposed to the inlet end, the compressor wheel member further having a blade array projecting outward from the center portion, the blade array having an outer surface and an inner region and a plurality of circumferentially-spaced, radially and axially extending blades disposed thereon; and   a shaft having an outer surface, the shaft extending through the tubular insert wherein the at least one contoured surface region on the opposed inner surface of the tubular insert engages the outer surface of the shaft.   
     
     
         2 . The compressor wheel assembly of  claim 1  wherein the polymeric material of the compressor wheel member comprises at least one of epoxy compounds, phenolic polymers, polyimide polymers, polyamide polymers, polypropylene polymers, or polyether ether ketone polymers. 
     
     
         3 . The compressor wheel assembly of  claim 2  wherein the polymeric material further comprises a reinforcement material, the reinforcement material comprising at least one of metal fibers, glass fibers, carbon fibers, metal particles, glass particles, carbon particles. 
     
     
         4 . The compressor wheel assembly of  claim 1  wherein the metal of the tubular insert comprises at least one of bronze, leaded bronze, copper iron, iron, leaded iron, aluminum, titanium, steel. 
     
     
         5 . The compressor wheel assembly of  claim 4  wherein the tubular insert comprises at least two engagement members tangentially disposed on and projecting axially outward from the outer circumferential surface of the tubular insert, and wherein the at least two engagement members project into and are surrounded by the polymeric material present in the center portion of the compressor wheel member. 
     
     
         6 . The compressor wheel assembly of  claim 5  wherein the at least two engagement members each extend from the inlet end to the outlet end of the tubular insert, each of the at least two engagement members having a torque transfer face. 
     
     
         7 . The compressor wheel assembly of  claim 5  wherein the inner circumferential surface of the tubular insert has a non-circular cross section. 
     
     
         8 . The compressor wheel assembly of  claim 1  wherein the center portion of the compressor wheel has a compressor wheel inlet end and an opposed compressor wheel outlet end having a length wherein the length of the center portion of the compressor wheel is less than or equal to a length defined by the tubular insert. 
     
     
         9 . The compressor wheel assembly of  claim 1  wherein the at least one engagement member of the tubular insert includes a plurality of apertures defined in the wall member of the tubular insert, the apertures extending from the outer circumferential surface to the inner circumferential surface, wherein the polymeric material of the compressor member extends through the plurality of apertures and overlays at least a portion of the inner circumferential surface. 
     
     
         10 . The compressor wheel assembly of  claim 9  wherein the polymeric material overlaying at least a portion of the inner circumferential surface defines a central bore coaxially disposed interior to the inner circumferential surface of the tubular insert, wherein the contoured surface region of the opposed inner surface of the tubular insert is in abutting contact with the outer surface of the shaft. 
     
     
         11 . The compressor wheel assembly of  claim 1  wherein the tubular insert is composed of at least one of bronze, leaded bronze, copper iron, iron, leaded iron, aluminum, titanium, steel and wherein the tubular insert comprises at least two engagement members tangentially disposed on and projecting axially outward from the outer circumferential surface of the tubular insert, the at least two engagement members projecting into and surrounded by the polymeric material of the center portion of the compressor wheel member and wherein the polymeric material of the compressor wheel member comprises at least one of epoxy resin, phenolic polymers, polyimide polymers, polyamide polymers, polypropylene polymers, polyether ether ketone polymers. 
     
     
         12 . The compressor wheel assembly of  claim 11  wherein the at least two engagement members of the tubular insert are configured as arcuate members defining a continuous spiroid configured relative to the rotational direction of the compressor wheel assembly when in the use position. 
     
     
         13 . A compressor wheel assembly comprising:
 a metal tubular insert having a shaft bore extending from an inlet end to an outlet end opposed to the inlet end, and a wall member, the wall member having an outer circumferential surface and an inner circumferential surface opposed to the outer circumferential surface defining the tubular insert shaft bore, wherein at least one of the outer circumferential surface or inner circumferential surface defines at least one engagement member defined thereon, wherein the metal of the tubular insert comprises at least one of bronze, leaded bronze, copper iron, iron, leaded iron, aluminum, titanium, steel;   a compressor wheel member composed of a polymeric material, the compressor wheel having an axially extending center portion molded on to the tubular insert, the center portion having an inlet end and an outlet end, the compressor wheel member further having a blade array projecting outward from the center portion, the blade array having an outer surface and an inner region and a plurality of circumferentially-spaced, radially and axially extending blades disposed thereon, wherein the polymeric material of the compressor wheel member comprises at least one of epoxy compounds, phenolic polymers, polyimide polymers, polyamide polymers, polypropylene polymers, or polyether ether ketone polymers and the polymeric material optionally contains at least one of metal fibers, glass fibers, carbon fibers, metal particles, glass particles, carbon particles, wherein the center portion of the compressor wheel has a compressor wheel inlet end and an opposed compressor wheel outlet end having a length wherein the length of the center portion of the compressor wheel is less than or equal to a length defined by the tubular insert; and   a shaft having an outer surface, the shaft extending through the tubular insert wherein the at least one contoured surface region on the opposed inner surface of the tubular insert engages the outer surface of the shaft.   
     
     
         14 . The compressor wheel assembly of  claim 13  tubular insert comprises at least two engagement members tangentially disposed on and projecting axially outward from the outer circumferential surface of the tubular insert, the at least two engagement members projecting into and surrounded by the polymeric material of the center portion of the compressor wheel member, the at least two engagement members each extending from the inlet end to the outlet end of the tubular insert and defining a torque engagement face and wherein the inner circumferential surface of the at least two engagement members has a non-circular cross section. 
     
     
         15 . The compressor wheel assembly of  claim 14  wherein the at least one engagement member of the tubular insert includes a plurality of apertures defined in the wall member of the tubular insert, the apertures extending from the outer circumferential surface to the inner circumferential surface, wherein the polymeric material of the compressor member extends through the plurality of apertures and overlays at least a portion of the inner circumferential surface and wherein the polymeric material overlaying at least a portion of the inner circumferential surface defines a central bore coaxially disposed interior to the inner circumferential surface of the tubular insert, wherein the contoured surface region of the opposed inner surface of the tubular insert is in abutting contact with the outer surface of the shaft. 
     
     
         16 . The compressor wheel assembly of  claim 15  wherein the at least two support ribs are configured as arcuate members defining a continuous spiroid configured relative to the rotational direction of the compressor wheel assembly when in the use position. 
     
     
         17 . A turbocharger comprising the compressor wheel of  claim 1  operatively mounted therein. 
     
     
         18 . The turbocharger of  claim 17  wherein the polymeric material of the blade array is a thermosetting polymer comprising at least one of epoxy resin, phenolic resin, polyimide resin, polyamide resin, polypropylene resin, or polyether ether ketone resin and the metal of the axially extending hub comprises at least one of bronze, leaded bronze, copper iron, iron, leaded iron, aluminum, titanium, steel.