Draft inducer having single piece metal impeller and improved housing
View Patent ↗A furnace blower assembly having a single piece impeller formed from a stamped metal material. The impeller of the blower assembly is formed from a single piece of metal material and includes a plurality of individual impeller blades each having a blade portion bent at a 90° angle relative to the back wall of the impeller. Each of the impeller blades is backward inclined and forward curved to increase the efficiency of the impeller.
1. A blower assembly for use in expelling gases from a furnace through an exhaust pipe comprising:
a blower housing having an internal impeller cavity defined by an outer wall and a top wall, the blower housing having an inlet opening for receiving exhaust gases from the furnace;
a drive motor mounted to the blower housing, the drive motor including a drive shaft extending through the blower housing and into the impeller cavity; and
an impeller mounted to the motor shaft and contained within the impeller cavity, the impeller being formed from a single sheet of metal and having a plurality of impeller blades, wherein each of the impeller blades are backward inclined and forward curved;
wherein each of the impeller blades includes a blade portion extending from a leading edge to a trailing edge, each of the blade portions being bent perpendicular to an impeller back wall to an operating condition, each impeller blade including a back wall trailing edge, wherein the leading edge of each impeller blade portion is directly adjacent the back wall trailing edge of an adjacent impeller blade prior to the impeller blade portion being bent 90° into its operating position.
2. The blower assembly of claim 1 wherein the impeller is formed from a single piece of stamped steel.
3. The blower assembly of claim 1 wherein each of the impeller blades is backward inclined and forward curved with an inlet angle of between 15° and 25°.
4. The blower assembly of claim 1 wherein a generally planar back wall has a plurality of reinforcing ribs each aligned with one of the impeller blades.
5. The blower assembly of claim 1 further comprising a raised plenum extending from the top wall of the blower housing to define a plenum cavity, the plenum cavity being in fluid communication with the impeller cavity.
6. The blower assembly of claim 5 wherein the blower housing and raised plenum are formed from a single piece of stamped steel.
7. The blower assembly of claim 5 wherein the raised plenum includes a plenum top wall separated from the top wall of the blower housing by an angled sidewall, wherein the angled sidewall and the plenum top wall are integrally formed with the blower housing top wall and define the plenum cavity.
8. The blower assembly of claim 5 wherein the drive shaft of the drive motor extends through an opening formed in the raised plenum, wherein rotation of the impeller in the impeller cavity draws a flow of air into the plenum cavity through the opening surrounding the drive shaft.
9. The blower assembly of claim 8 wherein a back wall of the impeller is closely spaced from the top wall of the blower housing and overlies the plenum cavity, wherein the back wall of the impeller restricts the flow of exhaust gases from the impeller cavity into the plenum cavity.