Ram air turbine driveshaft gear and bearing arrangement

Patent metadata

Field	Value
Publication number	US-9828945-B2
Application number	US-201414280592-A
Country	US
Kind code	B2
Filing date	May 17, 2014
Priority date	May 17, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A ram air turbine is presented that includes a turbine having a blade and a turbine shaft, a strut removably coupled to the turbine, wherein the strut has a gearbox section and a drive section, a turbine shaft with a bevel gear oriented perpendicularly to the turbine shaft and positioned within the gearbox section of the strut, a driveshaft coupled to the generator and positioned within the drive section of the strut, and a pinion gear that engages with the bevel gear, wherein the pinion gear is secured to the driveshaft by a spanner nut, wherein the pinion gear utilizes a key configured to interact with the keyed joint of the driveshaft. The pinion gear is supported by a pinion bearing that may be press fit onto the pinion gear and by one of the generator bearings.

First claim

What is claimed:

1. A ram air turbine comprising:
a turbine comprising a blade and a turbine shaft;
a one-piece strut removably coupled to the turbine, wherein the one-piece strut comprises a gearbox section, a drive section, and a generator adapter section;
the turbine shaft comprising a bevel gear oriented perpendicularly to the turbine shaft and positioned within the gearbox section of the one-piece strut;
a driveshaft positioned within the drive section of the one-piece strut, wherein the driveshaft comprises a first end and a second end, the driveshaft comprising a keyed joint at the first end, and the driveshaft is removably coupled to a generator at the second end,
wherein the first end extends into the gearbox section and the second end extends into the generator adaptor section;
a pinion gear that engages with the bevel gear and is removably secured to the driveshaft by an interference fit, wherein the pinion gear includes a key configured to interact with the keyed joint of the driveshaft to maintain a position of pinion gear relative to the driveshaft;
a spanner nut coupled to the driveshaft and compressing the pinion gear against a shoulder on the driveshaft; and
a pinion bearing coupled to and surrounding the pinion gear,
wherein the driveshaft is supported at the first end by the pinion bearing and is supported at the second end by a generator bearing assembly located within the generator adapter section.

2. The ram air turbine of claim 1 , wherein the pinion bearing is press fit onto the pinion gear.

3. The ram air turbine of claim 1 , wherein the driveshaft comprises stainless steel.

4. The ram air turbine of claim 1 , wherein the pinion gear comprises an uncoated metal material.

5. The ram air turbine of claim 1 , further comprising a pinion bearing retainer having a seal, wherein the pinion bearing retainer maintains a position of the pinion bearing in a direction parallel to the driveshaft.

6. The ram air turbine of claim 5 , wherein the pinion bearing retainer is engaged with the strut assembly by a threaded engagement.

7. The ram air turbine of claim 1 , further comprising a cover configured to seal an end of the gearbox section opposite to the turbine.

8. A ram air turbine comprising:
a turbine comprising a blade;
a one-piece strut removably coupled to the turbine, wherein the one-piece strut comprises a gearbox section and a drive section;
a turbine shaft comprising a bevel gear oriented perpendicularly to the turbine shaft and positioned within the gearbox section of the one-piece strut;
a driveshaft positioned within the drive section and comprising a first end and a second end;
a pinion gear that engages with the bevel gear, wherein the pinion gear is coupled to the first end of the driveshaft; and
a generator having a bearing and a generator shaft, wherein the second end of the driveshaft is received into an end of the generator shaft, the second end comprising a spline that is complimentary to the end of the generator shaft.

9. The ram air turbine of claim 8 , wherein a shaft bending frequency of the driveshaft is greater than an operating range frequency of the turbine.

10. The ram air turbine of claim 8 , wherein a drivetrain comprises the turbine, the turbine shaft, the driveshaft, and the generator, and wherein a frequency of rotation of the drivetrain is greater than one revolution per revolution of the turbine.

11. The ram air turbine of claim 10 , wherein the driveshaft is hollow.

12. The ram air turbine of claim 11 , wherein an inner diameter of the driveshaft and an outer diameter of a driveshaft are chosen such that a torsional natural frequency of the drivetrain is less than one per revolution of the turbine.

13. The ram air turbine of claim 8 , wherein the driveshaft is solid.

14. The ram air turbine of claim 8 , wherein the gearbox section further comprises a pinion bearing retainer.

15. The ram air turbine of claim 8 , further comprising a cover configured to seal an end of the gearbox section opposite to the turbine.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Russ David
• Bortoli Stephen
• Schultz Richard

Classifications

• F05B2220/31

  in ram-air turbines ("RATS") · CPC title

• F05B2260/5032

  of the bevel or angled type · CPC title

• F05B2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title

• F05B2240/50

  Bearings · CPC title

• F05B2240/61

  hollow · CPC title