Fluid delivery system for exhaust aftertreatment system
A fluid delivery system for an exhaust aftertreatment system may include an outer housing, a pump, a filter assembly, an electric heating blanket, and a heater retention plate. The heater retention plate is shaped to correspond to the shapes of the pump and filter assembly. A lid of the outer housing contacts the heater retention plate and clamps the heating blanket between the heater retention plate and the pump and filter assembly so that the heating blanket takes the shapes of portions of the pump and filter assembly. The outer housing includes mounting flanges and reinforcement members extending from corresponding mounting flanges to corresponding sidewalls of the outer housing and forming a hollow space therebetween. The filter assembly includes compensation elements that contract in response to expansion of fluid within a pump housing due to freezing and expand in response to thawing of the fluid.
1. A fluid delivery system for an exhaust aftertreatment system, the fluid delivery system comprising:
an outer housing including a base and a lid;
a pump disposed within the outer housing;
a filter assembly disposed within the outer housing and in fluid communication with the pump;
an electric heating blanket disposed within the outer housing and covering at least a portion of the pump and at least a portion of the filter assembly, the heating blanket is disposed between the lid and the portion of the pump and the portion of the filter assembly; and
a heater retention plate disposed within the outer housing between the lid and the heating blanket, the heater retention plate having a body portion and a flange, the body portion shaped to correspond to the shapes of the portion of the pump and the portion of the filter assembly, the flange extending from the body portion and contacting an interior surface of the lid such that the lid urges the heater retention plate and the heating blanket toward the portions of the pump and filter assembly so that the heating blanket takes the shapes of the portions of the pump and filter assembly.
2. The fluid delivery system of claim 1 , wherein the body of the heater retention plate includes a concave side and a convex side, the concave side contacting the heating blanket.
3. The fluid delivery system of claim 2 , wherein the flange extends from an edge of the body and extends around at least a portion of a periphery of the body.
4. The fluid delivery system of claim 3 , wherein the body of the heater retention plate includes a recessed portion receiving a thermostat of the heating blanket.
5. The fluid delivery system of claim 4 , wherein the heating blanket is in contact with housings of the pump and filter assembly.
6. The fluid delivery system of claim 5 , wherein the body of the heater retention plate includes a plurality of reinforcement ribs.
7. The fluid delivery system of claim 6 , wherein first and second portions of the body of the heater retention plate cooperate to form a V shape.
8. The fluid delivery system of claim 7 , wherein the first portion of the body includes alignment apertures receiving posts extending from the filter assembly.
9. The fluid delivery system of claim 8 , wherein the second portion of the body includes an L-shaped tab extending therefrom, the L-shaped tab receiving a mounting fastener.
10. The fluid delivery system of claim 9 , wherein the base of the outer housing includes sidewalls defining a cavity in which the pump, filter assembly, heating blanket and heater retention plate are disposed, the base including a pair of mounting flanges extending from respective sidewalls away from the cavity, the mounting flanges including mounting apertures and reinforcement members, each reinforcement member extending from a corresponding mounting flange to a corresponding sidewall, each reinforcement member cooperating with the corresponding sidewall to form a hollow space therebetween that is outside of the cavity.
11. The fluid delivery system of claim 10 , wherein the filter assembly comprises:
a tubular filter medium;
an elongated first compensation element disposed within an elongated aperture of the filter medium;
a support ring disposed at an axial end of the filter medium and including a plurality of flexible arms defining a central aperture and an annular recess surrounding the central aperture;
an annular second compensation element disposed within the annular recess of the support ring;
a cap including a body and a post axially from the body, the post engaging the flexible arms of the support ring; and
a third compensation element extending circumferentially around the post and disposed axially between the body and the second compensation element,
wherein the first, second and third compensation elements are formed from a material that contracts in response to expansion of fluid within the pump housing due to freezing and expands in response to thawing of the fluid.