Metallic sealing assembly for sealing between a rotating shaft and a fixed frame

Patent metadata

Field	Value
Publication number	US-11933403-B2
Application number	US-201917043799-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 4, 2018
Publication date	Mar 19, 2024
Grant date	Mar 19, 2024

Abstract

A metallic sealing assembly between a rotating shaft and a fixed frame comprises: a flexible metallic seal having two tori, inner and outer, that are concentric and of different average diameters, comprising a metal envelope which encases and holds the inner and outer tori; a shaft rotating about an axis of rotation, comprising an annular shoulder against which the seal comes to press; a counter-face, comprising a contact face against which the seal comes to press; a wedge block positioned around the rotating shaft such that the seal is held between the wedge block and the contact face, the wedge block mounted to slide on the rotating shaft; a metal part which forms a cap through which the rotating shaft passes and which is secured to the frame and/or to the counter-face, the rotating shaft being free to rotate with respect to the cap and axially secured to the cap.

First claim

What is claimed is:

1. Metallic sealing assembly for sealing between a rotating shaft and a fixed frame of a receiving machine, comprising:
a flexible metallic sealing joint with two concentric tori having different average diameters, comprising:
a first metallic helical spring with touching turns closed onto itself and having, at rest, the shape of a torus, called inner torus,
a second metallic helical spring with touching turns closed onto itself and having, at rest, the shape of a torus, called outer torus, the outer torus having an average diameter greater than the average diameter of the inner torus, one of the inner and outer tori being positioned between a rotating part and a non-rotating part and thus being called “dynamic torus”, and the other of the inner and outer tori being positioned between two parts not rotating with respect to one another and thus being called “static torus”,
a metallic envelope in which the inner torus and the outer torus are embedded and maintained, having, at rest, the shape of a hollow torus comprising an inner housing and an outer housing, respectively for the embedding of the inner torus and of the outer torus, the surface of the envelope comprising an annular opening between the inner and outer housings, said envelope comprising:
an inner covering portion defining the inner housing and allowing the partial covering of the inner torus,
an outer covering portion defining the outer housing and allowing the partial covering of the outer torus,
an intermediate portion, called inter-tori, connecting the inner covering portion and the outer covering portion, formed facing the annular opening,

a shaft rotating about an axis of rotation, comprising an annular shoulder against which the metallic sealing joint bears at the static torus, the metallic sealing joint positioned around the rotating shaft being centred via its inner diameter,
a part called back, comprising a contact face, flat, against which the metallic sealing joint bears at the dynamic torus,
a spacer, positioned around the rotating shaft so that the metallic sealing joint is blocked between on the one hand the spacer and on the other hand the contact face of the back, the spacer being mounted on the rotating shaft in a sliding way along the axis of rotation of the rotating shaft,
a metallic part forming a bonnet covering the assembly comprising the metallic sealing joint and at least the contact face of the back, the bonnet being passed through by the rotating shaft and being fastened onto the frame and/or onto the back, on the exterior of the contact face, the rotating shaft being free in rotation with respect to the bonnet and axially rigidly connected to the bonnet.

2. Assembly according to claim 1 , wherein the back is a non-rotating part, intended to be fastened to the fixed frame.

3. Assembly according to claim 1 , wherein the contact face of the back is rough.

4. Assembly according to claim 1 , wherein the spacer is blocked in rotation on the rotating shaft via a pinned and/or keyed link.

5. Assembly according to claim 1 , further comprising a nut for clamping the spacer positioned so that the spacer is located between the clamping nut and the metallic sealing joint, the rotating shaft including a threaded portion onto which the clamping nut is screwed.

6. Assembly according to claim 1 , wherein the bonnet includes a plurality of first smooth holes extending along the axis of rotation and axially passing through the bonnet, intended to be positioned facing second threaded holes formed axially in the back and/or third threaded holes formed axially in the fixed frame, or intended to be positioned facing second smooth holes formed axially in the back and third threaded holes formed axially in the fixed frame, and wherein the assembly includes a plurality of threaded rods, each threaded rod being capable of being inserted into a first smooth hole as well as into a second smooth or threaded hole and/or a third threaded hole, the bonnet being fastened onto the frame and/or onto the back by screwing of nuts onto the threaded rods in the top part of the bonnet.

7. Assembly according to claim 1 , wherein the bonnet comprises, in the top part, a plurality of radial holes having the same diameter, extending perpendicularly to the axis of rotation and opening onto the inner diameter of the bonnet so as to pass through it radially, wherein pins, having the same diameter as the radial holes, are inserted into the radial holes, and wherein the rotating shaft includes a groove into which the pins penetrate to block the axial movement of the rotating shaft, a blocking element being positioned around the bonnet to prevent sliding of the pins towards the outside.

8. Assembly according to claim 1 , wherein the bonnet includes on its inner diameter, at the centring of the rotating shaft, an inner thread, and wherein the rotating shaft includes, at the inner thread, a portion having a reduced diameter so as to create a blocking shoulder on the rotating shaft, the assembly including a locking nut capable of being housed between the rotating shaft and the bonnet at the inner thread and the portion having a reduced diameter and of bearing against the blocking shoulder so as to axially block the movement of the rotating shaft.

9. Assembly according to any one of the previous claim 1 , wherein the spacer is made in at least two parts, comprising a first part called inner spacer bearing on the inner torus, having a smooth inner diameter intended to slide on the rotating shaft and a threaded outer diameter, and a second part called outer spacer bearing on the outer torus, having a threaded inner diameter intended to be screwed onto the inner spacer.

10. Assembly according to claim 1 , wherein the spacer surface of the spacer, in contact with the outer covering portion, has a roughness greater than that of the contact face of the back.

11. Assembly according to claim 1 , wherein the spacer includes a fold on its outer diameter allowing to cover the outer torus on its outer diameter.

12. Assembly according to claim 1 , wherein the contact face of the back has a female conical shape.

13. Assembly according to claim 1 , wherein the metallic sealing joint includes, on its surface, a deposit of added material, gold and/or silver.

14. Assembly according to claim 1 , wherein the metallic envelope is a first metallic envelope consisting of a material with a high mechanical strength, and wherein the metallic sealing joint includes a second metallic envelope wound onto the first metallic envelope and consisting of a material more ductile than that of the first metallic envelope, being intended to be plastically deformed during the crushing of the metallic sealing joint.

15. Assembly according to claim 1 , wherein the back consists of at least three parts rigidly connected together, comprising an inner block provided with the contact face against which the metallic sealing joint bears at the outer torus, a bellows and an outer flange, the bellows conferring a degree of axial liberty onto the assembly to not block possible differential expansions, the bellows connecting the inner block and the outer flange, the outer flange being fastened to the fixed frame.

16. Assembly according to claim 1 , wherein the bonnet consists of at least two parts, comprising an outer bonnet fastened onto the fixed frame and an inner bonnet rigidly connected to the outer bonnet via a screwed link.

17. Assembly according to claim 1 , wherein the back is a rotating part, rigidly connected to the rotating shaft at the shoulder.

Assignees

• Commissariat Energie Atomique
• Technetics Group France Sas

Inventors

• Guimet Laurent
• Juliaa Jean-François
• Lefrancois Michel
• Darles Christophe
• Constant Olivier

Classifications

• F16J15/32 Primary

  with elastic sealings, e.g. O-rings · CPC title

• F16J15/3212

  with metal springs · CPC title

• F16J15/3248

  provided with casings or supports · CPC title

• F16J15/3276

  with additional static sealing between the sealing, or its casing or support, and the surface on which it is mounted · CPC title

• F16J15/0893 Primary

  the packing having a hollow profile · CPC title