Dual-stage, separated gas/fluid shock strut servicing

Patent metadata

Field	Value
Publication number	US-10865848-B2
Application number	US-201715642081-A
Country	US
Kind code	B2
Filing date	Jul 5, 2017
Priority date	Jul 5, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A method for servicing a dual-stage, separated gas/fluid shock strut may comprise measuring a servicing temperature, charging a secondary gas chamber with compressed gas, wherein a secondary chamber pressure corresponds to the servicing temperature, pumping oil into the shock strut, and charging a primary gas chamber with compressed gas.

First claim

What is claimed is:

1. A method for servicing a dual-stage, separated gas/fluid shock strut, comprising:
measuring a servicing temperature;
charging a secondary gas chamber with a first quantity of compressed gas, wherein a secondary chamber pressure corresponds to the servicing temperature;
pumping an oil into an oil chamber of the dual-stage, separated gas/fluid shock strut subsequent to the secondary gas chamber being charged with the first quantity of compressed gas; and
charging a primary gas chamber with a second quantity of compressed gas,
wherein the primary gas chamber is fluidly separated from the oil chamber via a first separator piston and the secondary gas chamber is fluidly separated from the oil chamber via a second separator piston.

2. The method of claim 1 , wherein the secondary gas chamber is charged with the second quantity of compressed gas until the secondary chamber pressure corresponds to the servicing temperature as indicated by a secondary chamber servicing chart.

3. The method of claim 1 , further comprising extending the dual-stage, separated gas/fluid shock strut in response to the pumping, wherein the dual-stage, separated gas/fluid shock strut extends such that a shock strut extension and the secondary chamber pressure match an oil servicing reference curve.

4. The method of claim 1 , further comprising:
extending the dual-stage, separated gas/fluid shock strut to a shock strut extension corresponding to the secondary chamber pressure, in accordance with an oil servicing reference curve, wherein the oil is pumped into the dual-stage, separated gas/fluid shock strut to a pre-determined pressure.

5. The method of claim 3 , wherein the oil servicing reference curve is provided in the form of at least one of a series of curves or a series of tables for various servicing temperatures.

6. The method of claim 1 , wherein the primary gas chamber is charged with the second quantity of compressed gas until a primary chamber pressure and a shock strut extension correspond to a primary chamber servicing reference curve.

7. The method of claim 1 , further comprising releasing a gas from the primary gas chamber.

8. The method of claim 1 , further comprising releasing a gas from the secondary gas chamber.

9. The method of claim 4 , wherein the pre-determined pressure is about 75 psi (517.1 kPa).

10. A method for servicing a dual-stage, separated gas/fluid shock strut, comprising:
charging a secondary gas chamber with a first quantity of compressed gas, wherein a secondary chamber pressure corresponds to a servicing temperature;
pumping an oil into an oil chamber of the dual-stage, separated gas/fluid shock strut, wherein the dual-stage, separated gas/fluid shock strut extends until a first shock strut extension and the secondary chamber pressure match an oil servicing reference curve; and
charging a primary gas chamber with a second quantity of compressed gas until a second shock strut extension and a primary chamber pressure match a primary chamber servicing reference curve,
wherein the primary gas chamber is fluidly separated from the oil chamber via a first separator piston and the secondary gas chamber is fluidly separated from the oil chamber via a second separator piston.

11. The method of claim 10 , wherein at least one of the oil servicing reference curve and the primary chamber servicing reference curve correspond to the servicing temperature.

12. The method of claim 10 , further comprising measuring the servicing temperature.

13. The method of claim 10 , further comprising releasing a gas from the primary gas chamber.

14. The method of claim 10 , further comprising releasing a gas from the secondary gas chamber.

15. A method for servicing a dual-stage, separated gas/fluid shock strut, comprising:
charging a secondary gas chamber with a first quantity of compressed gas, wherein a secondary chamber pressure corresponds to a servicing temperature;
circulating an oil through an oil chamber of the dual-stage, separated gas/fluid shock strut via an oil charge port and an oil bleed port;
extending the dual-stage, separated gas/fluid shock strut to a shock strut extension corresponding to the secondary chamber pressure according to an oil servicing reference curve;
closing the oil bleed port;
pumping the oil into the oil chamber until an oil chamber pressure reaches a pre-determined pressure while maintaining the shock strut extension;
closing the oil charge port;
extending the dual-stage, separated gas/fluid shock strut to a fully extended position; and
charging a primary gas chamber with a second quantity of compressed gas until a shock strut extension and a primary chamber pressure match a primary chamber servicing reference curve.

16. The method of claim 15 , wherein at least one of the oil servicing reference curve and the primary chamber servicing reference curve correspond to the servicing temperature.

17. The method of claim 15 , further comprising measuring the servicing temperature.

18. The method of claim 15 , wherein the pre-determined pressure comprises about 75 psi (517.1 kPa).

19. The method of claim 15 , further comprising releasing a gas from the primary gas chamber.

20. The method of claim 15 , further comprising releasing a gas from the secondary gas chamber.

Assignees

• Goodrich Corp

Inventors

• Fazeli Amir
• Cepic Adnan
• Reber Susanne M

Classifications

• B64F5/40 Primary

  Maintaining or repairing aircraft · CPC title

• F16F9/063

  comprising a hollow piston rod · CPC title

• F16F2236/045

  the spring material being generally enclosed · CPC title

• F16F2230/46

  Maintenance · CPC title

• F16F15/022

  using dampers and springs in combination · CPC title