Splined muff

Patent metadata

Field	Value
Publication number	US-10124906-B2
Application number	US-201514877497-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 7, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A splined muff is provided for use with a ram air turbine (RAT). The splined muff includes a body formed of plastic material that acts as an insulator during a lightning strike. The body is formed to define an aperture and includes an interior facing spline for engagement with a complementary exterior facing spline; and an exterior facing spline for engagement with a complementary interior facing spline.

First claim

What is claimed is:

1. A splined muff for a ram air turbine (RAT), the splined muff comprising:
a body formed of plastic material having a compressive strength of about 30 ksi or higher,
the body being formed to define an aperture and comprising:
an interior facing spline for engagement with a complementary exterior facing spline;
an exterior facing spline for engagement with a complementary interior facing spline;
an interior flange extending radially inwardly from a first axial end of the body; and
an exterior flange extending radially outwardly from a second axial end of the body, which is opposite the first axial end of the body.

2. The splined muff according to claim 1 , wherein at least one or both of respective pitches and amplitudes of the interior and exterior facing splines are substantially similar.

3. The splined muff according to claim 1 , wherein the interior and exterior facing splines are off-phase or in-phase.

4. A ram air turbine (RAT) assembly, comprising:
a first driveshaft having a first spline;
a second driveshaft having a second spline; and
a splined muff formed of plastic material having a compressive strength of about 30 ksi or higher, which is interposed between the first and second driveshafts to transmit rotation from the first driveshaft to the second driveshaft,
the first and second splines being disposed to be axially overlapped along an axial dimension along respective aligned sections thereof and to be axially misaligned along respective misaligned sections thereof, the respective misaligned sections being non-overlapped along the axial dimension,
the splined muff having a length which traverses the respective aligned sections of the first and second splines and which traverses only respective portions of the respective misaligned sections thereof, and
the splined muff defining an aperture and comprising a third spline for engagement with the first spline and a fourth spline for engagement with the second spline.

5. The RAT assembly according to claim 4 , further comprising:
at least one electrical component to which the first driveshaft is connected;
a RAT; and
a gearbox to which the second driveshaft is connected, the gearbox being operably interposed between the RAT and the second driveshaft to transmit rotation from the RAT to the second driveshaft.

6. The RAT assembly according to claim 5 , wherein the at least one electrical component comprises a generator and a pump.

7. The RAT assembly according to claim 5 , wherein the gearbox comprises a gear set.

8. The RAT assembly according to claim 4 , wherein the splined muff has free play and ductility sufficient to absorb driveshaft flexion and relative driveshaft movement.

9. The RAT assembly according to claim 4 , further comprising a mechanical stopper disposed to impede translational movement of the second driveshaft relative to the first driveshaft beyond a predefined point.

10. The RAT assembly according to claim 4 , wherein respective pitches of the third and fourth splines are substantially similar.

11. The RAT assembly according to claim 4 , wherein respective amplitudes of the third and fourth splines are substantially similar.

12. The RAT assembly according to claim 4 , wherein the third and fourth splines are off-phase.

13. The RAT assembly according to claim 4 , wherein the third and fourth splines are in-phase.

14. The RAT assembly according to claim 4 , wherein the splined muff comprises:
a body;
an interior flange extending radially inwardly from a first axial end of the body to extend along a portion of a corresponding end of the first spline; and
an exterior flange extending radially outwardly from a second axial end of the body, which is opposite the first axial end of the body, to extend along a portion of a corresponding end of the second spline.

15. A ram air turbine (RAT) assembly, comprising:
a generator driveshaft, which is connected to a generator and which has a first spline;
a RAT strut driveshaft, which is connected to a gearbox of a RAT and which has a second spline; and
a splined muff formed of plastic material having a compressive strength of about 30 ksi or higher, which is interposed between the generator and RAT strut driveshafts to transmit RAT rotation from the gearbox and the RAT strut driveshaft to the generator driveshaft and the generator,
the first and second splines being disposed to extend in opposite directions from the generator driveshaft and the RAT strut driveshaft, respectively, to be axially overlapped along an axial dimension along respective aligned sections thereof and to be axially misaligned along respective misaligned sections thereof, the respective misaligned sections being non-overlapped along the axial dimension,
the splined muff having a length which traverses the respective aligned sections of the first and second splines and which traverses only respective portions of the respective misaligned sections thereof, and
the splined muff defining an aperture and comprising a third spline for engagement with the first spline and a fourth spline for engagement with the second spline.

16. The RAT assembly according to claim 15 , wherein:
the first and third splines are interior facing splines with the second and fourth splines being exterior facing splines, or
the first and third splines are exterior facing splines with the second and fourth splines being interior facing splines.

17. The RAT assembly according to claim 15 , wherein the splined muff is disposed to prevent electrical current from arcing between the RAT strut driveshaft and the generator driveshaft and comprises:
a body;
an interior flange extending radially inwardly from a first axial end of the body to extend along a portion of a corresponding end of the first spline; and
an exterior flange extending radially outwardly from a second axial end of the body, which is opposite the first axial end of the body, to extend along a portion of a corresponding end of the second spline.

Assignees

• Hamilton Sundstrand Corp
• Hamilton Sundstand Corp

Inventors

• Russ David Everett
• Chapman David Norman
• Marks Scott J

Classifications

• B64D41/007 Primary

  Ram air turbines · CPC title

• H02H1/04

  Arrangements for preventing response to transient abnormal conditions, e.g. to lightning {or to short duration over voltage or oscillations; Damping the influence of DC component by short circuits in AC networks} · CPC title

• F05D2300/43

  Synthetic polymers, e.g. plastics; Rubber · CPC title

• F05D2220/34

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

• F05D2240/24

  for turbines · CPC title