LIGHTWEIGHT HIGH PRESSURE REPAIRABLE PISTON COMPOSITE ACCUMULATOR WITH SLIP FLANGE

• US 20090126815A1
• Filed: 11/10/2008
• Published: 05/21/2009
• Est. Priority Date: 11/08/2007
• Status: Active Grant

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: Parker-Hannifin Corporation
• Inventors: Rajabi, Bahram S., Hansen, Allen R.
• Granted Patent: US 8,695,643 B2
• Time in Patent Office: Days
• US Class Current: 138/31
• CPC Class Codes: F15B 1/24 with rigid separating means, e.g. pistons
• CPC Class Codes: F15B 2201/205 using gas
• CPC Class Codes: F15B 2201/31 having rigid separating means, e.g. pistons
• CPC Class Codes: F15B 2201/4053 characterised by the material
• CPC Class Codes: F15B 2201/4056 characterised by the attachment of housing components
• CPC Class Codes: F15B 2201/605 Assembling or methods for making housings therefor
• CPC Class Codes: Y10T 29/49394 Accumulator making

Abstract

A reduced weight and repairable piston accumulator. The accumulator includes a load bearing metallic cylinder with removable end caps secured thereto with slip flanges for allowing repairability and for achieving the required cycle life. The cylinder serves as the surface on which the piston slides and is designed such that it sustains the axial stress induced by pressurization of the accumulator. A composite over wrapping is designed such that it sustains the stress in the hoop (radial) direction. A stress transitioning bushing can be provided for transitioning hoop stresses between the overwrap and the slip flange. When combined with the cylinder, the fibers of the composite wrap will not be placed in shear and thus will not fatigue in the same manner as some prior art designs.

Claims

1. An accumulator comprising:

a liner having an open end and a radially outwardly extending shoulder at the open end;

a composite overwrap wrapped around the liner for carrying hoop stress applied to the liner;

a cap for closing the open end of the liner; and

a slip flange for connection to the cap with the shoulder of the liner trapped between the cap and the slip flange.

2. An accumulator as set forth in claim 1, further including a stress transition bushing in an area of transition between the overwrap and the slip flange for transitioning hoop stress between the overwrap and the slip flange.

3. An accumulator as set forth in claim 2, wherein the bushing is tapered.

4. An accumulator as set forth in claim 3, wherein the bushing is tapered along its axial length such that it has a greater radial dimension at an end nearest the shoulder of the liner the slip flange.

5. An accumulator as set forth in claim 2, wherein the slip flange includes a counterbore, and the bushing is received at least partially within the counterbore.

6. An accumulator as set forth in claim 5, wherein the counterbore is tapered along its axial length so as to have a greater radius at an end nearest the overwrap.

7. An accumulator as set forth in claim 2, wherein the bushing is at least partially overwrapped with the composite liner.

8. An accumulator as set forth in claim 1, wherein an inner diameter of the slip flange engages an outer diameter of the liner.

9. An accumulator as set forth in claim 1, wherein the inner diameter of the slip flange that engages the outer diameter of the liner is tapered along its axial length.

10. An accumulator as set forth in claim 1, having an operating pressure between about 3000 Psi and 10000 Psi, and a liner thickness of no more than 0.375 inches.

11. An accumulator as set forth in claim 2, wherein the bushing is a carbon composite bushing.

12. An accumulator as set forth in claim 1, further comprising a pressure balanced liner located interior to the liner.

13. An accumulator as set forth in claim 1, further comprising a piston supported for sliding axial movement within the accumulator and forming separate chambers within the accumulator.

14. An accumulator as set forth in claim 1, wherein the slip flange is in the form of a ring that can be telescoped over the liner.

15. A method of making an accumulator comprising:

forming a liner with an open end and with a radially outwardly extending shoulder at the open end thereof;

positioning a slip flange over the liner axially inwardly of the radially outwardly extending shoulder;

and closing the open end by securing a cap to the slip flange such that the shoulder of the cylindrical liner is trapped between the slip flange and the cap.

16. A method as set forth in claim 15, wherein the forming the liner includes machining the liner from a tubular blank such as a conventional metal liner.