Seal member for reductant delivery unit

Abstract

A reductant delivery unit includes a fluid injector having a fluid inlet for receiving a reductant, and a fluid outlet disposed for discharging the reductant, the fluid injector defining a fluid path from the fluid inlet to the fluid outlet. The fluid injector further includes a tube having an end disposed at the fluid inlet of the fluid injector, the tube configured to pass reductant along the fluid path. A cup covers the end of the tube, including a sidewall and an axial end portion. A compressible seal member is disposed within the cup between the end of the tube and the axial end portion of the cup, the seal member occupying a volume so as to reduce an amount of space for reductant between the tube and the cup.

1 . A reductant delivery unit, comprising:
 a fluid injector having a fluid inlet disposed at a first end of the fluid injector for receiving a reductant, and a fluid outlet disposed at a second end of the fluid injector for discharging the reductant, the fluid injector defining a fluid path from the fluid inlet to the fluid outlet, the fluid injector further including a tube member having an end disposed at the fluid inlet of the fluid injector, the tube member configured to pass reductant along the fluid path; and   a cup covering the end of the tube member and comprising a sidewall and an end wall extending radially inwardly from the sidewall; and   a seal member disposed within the cup and contacting an inner surface of the sidewall of the cup and an inner surface of the end wall of the cup, the seal member occupying a volume so as to reduce an amount of space for reductant between the tube member and the cup,   wherein the fluid injector further comprises an injector component disposed in the tube member of the fluid injector, and the seal member contacts the injector component, and   wherein the seal member is constructed from compressible material, and the seal member is under compression in the reductant delivery unit when assembled so that the amount of space in the reductant delivery unit for reductant does not increase over an operating temperature range of the reductant delivery unit.   
     
     
         2 . (canceled) 
     
     
         3 . The reductant delivery unit of  claim 1 , wherein the fluid injector comprises a filter disposed in the tube member, and the injector component comprises a cap member in which the filter is disposed. 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The reductant delivery unit of  claim 1 , wherein the seal member extends radially outwardly such that an outer sidewall of the seal member contacts the sidewall of the cup. 
     
     
         7 . The reductant delivery unit of  claim 6 , wherein the seal member comprises a top surface, a bottom surface and a protrusion which extends from the bottom surface and is disposed within the end of the tube member, the protrusion having an outer diameter which is smaller than a diameter of the outer sidewall of the seal member. 
     
     
         8 . The reductant delivery unit of  claim 1 , wherein the seal member includes a bore defined therethrough, the bore in fluid communication with the fluid path through the reductant delivery unit. 
     
     
         9 . The reductant delivery unit of  claim 1 , wherein the seal member includes a protrusion which extends into the end of the tube member. 
     
     
         10 . A reductant delivery unit, comprising:
 a fluid injector comprising a fluid inlet disposed at a first end of the fluid injector and configured for receiving a reductant, a fluid outlet disposed at a second end of the fluid injector and configured for discharging the reductant, and a tube member having an end disposed at the fluid inlet of the fluid injector;   a cup covering the end of the tube member, comprising a sidewall and an end wall extending radially inwardly from the sidewall; and   a seal member disposed within the cup between and contacting each of the end of the tube member and the end wall of the cup, the seal member occupying a volume in the cup so as to reduce a volume for reductant in the reductant delivery unit between the cup and the tube member,   wherein the seal member is formed from compressible material and the seal member is under compression in the reductant delivery unit upon completion of assembly of the reductant delivery unit so that the volume for the reductant in the reductant delivery unit does not increase over an operating temperature range of the reductant delivery unit.   
     
     
         11 . The reductant delivery unit of  claim 10 , wherein the fluid injector further comprises an injector component disposed in the tube member of the fluid injector, and the seal member contacts the injector component. 
     
     
         12 . The reductant delivery unit of  claim 11 , wherein the fluid injector comprises a filter disposed in the tube member, and the injector component comprises a support member in which the filter is disposed. 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The reductant delivery unit of  claim 10 , wherein the seal member extends radially outwardly such that an outer radial surface of the seal member contacts the sidewall of the cup. 
     
     
         16 . The reductant delivery unit of  claim 15 , wherein the seal member further comprises a protrusion disposed at least partly within the end of the tube member, the protrusion having an outer diameter which is smaller than the outer radial surface of the seal member. 
     
     
         17 . The reductant delivery unit of  claim 10 , wherein the seal member includes a bore defined therethrough, the bore in fluid communication with the fluid path through the reductant delivery unit. 
     
     
         18 . The reductant delivery unit of  claim 10 , wherein a portion of the seal member extends into the end of the tube member.