Drain holes in ram air fan housing

Patent metadata

Field	Value
Publication number	US-9909594-B2
Application number	US-201414584469-A
Country	US
Kind code	B2
Filing date	Dec 29, 2014
Priority date	Dec 29, 2014
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A ram air fan housing includes an outer cylindrical housing portion centered on a central axis, with a first end and a second end positioned axially away from the first end. The ram air fan housing also includes an inner cylindrical housing portion centered on a central axis, with a first end and a second end positioned axially away from the first end. The first end of the outer cylindrical housing portion is connected to the first end of the inner cylindrical housing portion with a disk portion. The ram air fan housing also includes a first drain hole in the outer cylindrical housing portion adjacent to the second end of the outer cylindrical housing portion.

First claim

The invention claimed is:

1. A ram air fan housing comprising:
an outer cylindrical housing portion centered on a central axis, with a first end and a second end positioned axially away from the first end;
an inner cylindrical housing portion centered on a central axis, with a first end and a second end positioned axially away from the first end, wherein the first end of the outer cylindrical housing portion and the first end of the inner cylindrical housing portion are axially aligned;
a disk portion connecting the first end of the outer cylindrical housing portion to the first end of the inner cylindrical housing portion, wherein the outer cylindrical housing portion is connected to a radially outer edge of the disk portion and the inner cylindrical housing portion is connected to a radially inner edge of the disk portion; and
a first drain hole in the outer cylindrical housing portion adjacent to the second end of the outer cylindrical housing portion.

2. The ram air fan housing of claim 1 , and further comprising:
a cylindrical ring positioned around the outer cylindrical housing portion;
a plurality of struts extending between the outer cylindrical housing portion and the cylindrical ring; and
a mounting flange on a radially outer surface of the cylindrical ring.

3. The ram air fan housing of claim 2 , wherein a diameter D is a diameter of the first drain hole, and a length L extends from the mounting flange to a center of the first drain hole.

4. The ram air fan housing of claim 3 , wherein a ratio of the diameter D to the length L is between 0.02247 and 0.02389.

5. The ram air fan housing of claim 3 , wherein the diameter D is between 0.1510 inches (0.3835 centimeters) and 0.1610 inches (0.4089 centimeters).

6. The ram air fan housing of claim 3 , wherein the length L is between 6.7200 inches (17.0688 centimeters) and 6.74 inches (17.1196 centimeters).

7. The ram air fan housing of claim 1 , and further comprising:
a second drain hole in the outer cylindrical housing portion adjacent to the second end of the outer cylindrical housing portion and 180 degrees away from the first drain hole.

8. A ram air fan comprising:
a tie rod with a first end and a second end;
a motor including a rotor that rotates with the tie rod and a stator positioned radially around the rotor;
a fan housing positioned around the tie rod with an outer housing portion with a first end and a second end positioned axially away from the first end, and an inner housing portion with a first end and a second end positioned axially away from the first end, wherein the first end of the outer housing portion and the first end of the inner housing portion are axially aligned and connected with a disk portion, wherein the outer housing portion is connected to a radially outer edge of the disk portion and the inner housing portion is connected to a radially inner edge of the disk portion, and wherein there is a first drain hole in the outer housing portion adjacent to the second end of the outer housing portion; and
journal bearings positioned between the fan housing and the tie rod.

9. The ram air fan of claim 8 , wherein the fan housing further comprises:
a cylindrical ring positioned around the outer housing portion;
a plurality of struts extending between the outer housing portion and the cylindrical ring; and
a mounting flange on a radially outer surface of the cylindrical ring.

10. The ram air fan of claim 9 , wherein a diameter D is the diameter of the first drain hole, and wherein a length L extends from the mounting flange to a center of the first drain hole.

11. The ram air fan of claim 10 , wherein a ratio of the diameter D to the length L is between 0.02247 and 0.02389.

12. The ram air fan of claim 10 , wherein the diameter D is between 0.1510 inches (0.3835centimeters) and 0.1610 inches (0.4089 centimeters).

13. The ram air fan of claim 10 , wherein the length L is between 6.7200 inches (17.0688centimeters) and 6.74 inches (17.1196 centimeters).

14. The ram air fan of claim 9 , and further comprising:
a second drain hole in the outer housing portion of the fan housing positioned 180degrees away from the first drain hole.

15. The ram air fan of claim 9 , and further comprising:
a thrust shaft positioned radially around the first end of the tie rod, wherein a first journal bearing is positioned between the thrust shaft and the inner housing portion of the fan housing;
a bearing housing adjacent the second end of the tie rod;
a journal bearing shaft adjacent the second end of the tie rod, wherein a second journal bearing is positioned between the bearing housing and the journal bearing shaft;
a fan rotor attached to the first end of the tie rod;
an inlet housing surrounding the fan rotor and connected to the mounting flange of the fan housing; and
an outer housing surrounding the fan housing and connected to the mounting flange of the fan housing.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Chrabascz Eric
• Beers Craig M

Classifications

• F04D29/5806 Primary

  Cooling the drive system · CPC title

• F04D29/542

  Bladed diffusers (fixing blades to stators F01D9/042) · CPC title

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title

• F04D19/00

  Axial-flow pumps (F04D21/00 takes precedence; {pump comprising axial flow and radial flow stages F04D17/025}) · CPC title

• B64D13/08

  the air being heated or cooled · CPC title