# US 10,480,529 B2 · Induced draft fan and gas furnace comprising the same

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- Number: US 10,480,529 B2
- Document ID: US10480529B2
- Status: Granted
- Kind: B2
- Application number: 15/826,598
- Filed: 2017-11-29
- Published: 2019-03-21
- Granted: 2019-11-19
- Earliest claimed: 2017-09-20
- Assignees: Zhongshan Broad-Ocean Motor Co., Ltd.
- Applicants: Zhongshan Broad-Ocean Motor Co., Ltd.
- Inventors: Yanhu Lin; Wei Lei; Fengqi Wang
- Web page: https://patentgrep.com/patent/US10480529B2

## CPC

- F04D 29/4233: {with volutes extending mainly in axial or radially inward direction}
- F04D 13/06: the pump being electrically driven
- F04D 17/16: for displacing without appreciable compression
- F04D 29/422: {Discharge tongues (F04D17/04 takes precedence)}
- F04D 29/4226: {Fan casings}
- F04D 29/706: {Humidity separation}
- F24H 3/065: {using fluid fuel}
- F24H 9/0073: {Arrangement or mounting of means for forcing the circulation of air}
- F24H 9/16: Arrangements for water drainage
- F05D 2250/52: Outlet
- F05D 2260/602: Drainage
- F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02)
- F24H: FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL (steam generation F22)
- F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS

## Abstract

An induced draft fan, including a volute including a chamber and an air discharge pipe; and a wind wheel disposed in the chamber of the volute. The wind wheel is connected to and operationally driven by a rotation shaft of a motor. The air discharge pipe is disposed on one side of the volute, and includes an inner pipe and an outer pipe surrounding the inner pipe. The inner pipe of the air discharge pipe communicates with the chamber, to form an air discharge passage. An annular groove is disposed between the inner pipe and the outer pipe; and the outer end of the outer pipe is provided with a curved groove, the curved groove extends axially and circumferentially to divide the outer pipe into a fixed part and a flexible part.

## Claims

### Claim 1

An induced draft fan, comprising:
a volute comprising a chamber and an air discharge pipe; and
a wind wheel disposed in the chamber of the volute;
wherein
the wind wheel is connected to a rotation shaft of a motor;
the air discharge pipe is disposed on one side of the volute, and comprises an inner pipe and an outer pipe surrounding the inner pipe;
the inner pipe of the air discharge pipe communicates with the chamber to form an air discharge passage;
an annular groove is disposed between the inner pipe and the outer pipe; and
an outer end of the outer pipe is provided with a curved groove, the curved groove extends axially and circumferentially to divide the outer pipe into a fixed part and a flexible part.

### Claim 2 (depends on 1)

The induced draft fan of claim 1, wherein a first flange and a second flange protrude circumferentially from the outer end of the outer pipe, the first flange is located on an end face of the outer pipe, a locating slot is disposed between the first flange and the second flange, and the curved groove is located in the locating slot.

### Claim 3 (depends on 2)

The induced draft fan of claim 2, wherein the curved groove is arc-shaped or L-shaped.

### Claim 4 (depends on 3)

The induced draft fan of claim 3, wherein the curved groove is L-shaped and comprises an axial part and a circumferential part, and the circumferential part is close to one side of the second flange.

### Claim 5 (depends on 4)

The induced draft fan of claim 4, wherein the outer pipe comprises at least one drain hole at a bottom of the annular groove, and a drain pipe communicates with the at least one drain hole.

### Claim 6 (depends on 5)

The induced draft fan of claim 5, wherein the outer pipe comprises two drain holes, and the drain pipe is tangent to the outer pipe.

### Claim 7 (depends on 6)

The induced draft fan of claim 6, wherein a central angle formed by the axial part and the circumferential part of the curved groove is greater than or equal to 90 degrees and less than or equal to 270 degrees.

### Claim 8 (depends on 1)

The induced draft fan of claim 1, wherein the curved groove is L-shaped and comprises an axial part and a circumferential part; the fixed part comprises a lower lug in the vicinity of the axial part, and the flexible part comprises an upper lug in the vicinity of the axial part and corresponding to the lower lug; the upper lug and the lower lug each comprise mounting through holes, each mounting through hole comprises a bolt, and a nut is provided at a tail of the bolt, and the bolt and the nut cooperate to lock the fixed part and the flexible part.

### Claim 9 (depends on 8)

The induced draft fan of claim 8, wherein the outer pipe comprises at least one drain hole at a bottom of the annular groove, and a drain pipe communicates with the at least one drain hole.

### Claim 10 (depends on 9)

The induced draft fan of claim 9, wherein the outer pipe comprises two drain holes, and the drain pipe is tangent to the outer pipe.

### Claim 11 (depends on 10)

The induced draft fan of claim 10, wherein a central angle formed by the axial part and the circumferential part of the curved groove is greater than or equal to 90 degrees and less than or equal to 270 degrees.

### Claim 12 (depends on 1)

The induced draft fan of claim 1, wherein the outer pipe comprises at least one drain hole at a bottom of the annular groove, and a drain pipe communicates with the at least one drain hole.

### Claim 13 (depends on 12)

The induced draft fan of claim 12, wherein the outer pipe comprises two drain holes, and the drain pipe is tangent to the outer pipe.

### Claim 14 (depends on 13)

The induced draft fan of claim 13, wherein a central angle formed by the axial part and the circumferential part of the curved groove is greater than or equal to 90 degrees and less than or equal to 270 degrees.

### Claim 15 (depends on 1)

A gas furnace, comprising an induced draft fan of claim 1 and a conversion interface which is disposed on the air discharge pipe of the induced draft fan, wherein the conversion interface is embedded in the annular groove, a seal ring is disposed between the conversion interface and the outer pipe; the curved groove is located outside the seal ring, a hose clamp is disposed in the locating slot, a body of the hose clamp is located on the flexible part and the fixed part to close up the curved groove.

### Claim 16 (depends on 15)

The furnace of claim 15, wherein a first flange and a second flange protrude circumferentially from the outer end of the outer pipe, the first flange is located on an end face of the outer pipe, a locating slot is disposed between the first flange and the second flange, and the curved groove is located in the locating slot.

### Claim 17 (depends on 16)

The furnace of claim 16, wherein the curved groove is L-shaped and comprises an axial part and a circumferential part, and the circumferential part is close to one side of the second flange.

### Claim 18 (depends on 1)

A gas furnace, comprising an induced draft fan of claim 1 and a conversion interface which is disposed on the air discharge pipe of the induced draft fan, wherein the conversion interface is embedded in the annular groove, a seal ring is disposed between the conversion interface and the outer pipe; the curved groove is located outside the seal ring, and the bolt and the nut cooperate to lock the fixed part and the flexible part, and close up the axial part.

### Claim 19 (depends on 18)

The furnace of claim 18, wherein the curved groove is L-shaped and comprises an axial part and a circumferential part; the fixed part comprises a lower lug in the vicinity of the axial part, and the flexible part comprises an upper lug in the vicinity of the axial part and corresponding to the lower lug; the upper lug and the lower lug each comprise mounting through holes, each mounting through hole comprises a bolt, and a nut is provided at a tail of the bolt, and the bolt and the nut cooperate to lock the fixed part and the flexible part.

### Claim 20 (depends on 19)

The furnace of claim 19, wherein a central angle formed by the axial part and the circumferential part of the curved groove is greater than or equal to 90 degrees and less than or equal to 270 degrees.