Fluid-cushion sealing device

Patent metadata

Field	Value
Publication number	US-10890258-B2
Application number	US-201916287632-A
Country	US
Kind code	B2
Filing date	Feb 27, 2019
Priority date	Jan 30, 2015
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

The fluid-cushion sealing device ( 100 ) for a piston ( 101 ) moving in a cylinder ( 102 ) and defining with the latter a chamber to be sealed ( 104 ) includes: a continuous perforated ring ( 105 ) through the radial thickness of which passes a calibrated opening ( 111 ) and which is sealingly accommodated in a ring groove ( 109 ) provided in the piston ( 101 ) so as to define, with said groove ( 109 ), a pressure distribution chamber ( 119 ) connected to a pressurized fluid source ( 112 ), while an axially blind counter-pressure recess ( 115 ) is provided recessed on an external cylindrical ring surface ( 107 ) which faces the cylinder ( 102 ) and which the continuous perforated ring ( 105 ) comprises, the calibrated opening ( 111 ) leading into said recess ( 115 ).

First claim

The invention claimed is:

1. A fluid-cushion sealing device for a piston, wherein:
said sealing device is configured to move in longitudinal translation in a cylinder, along an axis of the cylinder, said piston and said cylinder defining, with at least one cylinder head, a chamber to be sealed, wherein the sealing device comprises:
at least one continuous perforated ring which comprises an internal cylindrical ring surface, an external cylindrical ring surface, and two axial ring surfaces, said ring being configured to be accommodated in at least one ring groove provided in the piston or in the cylinder, while said ring is capable of moving radially in the ring groove without being able to leave the ring groove, said continuous perforated ring being sufficiently flexible to allow a diameter of the continuous perforated ring to increase or decrease relative to said groove under an effect of a pressure of a source of pressurized fluid;
a ring seal that produces a seal between each axial ring surface and the ring groove, so that the ring groove defines, with the continuous perforated ring, a pressure distribution chamber connected by a transfer circuit to a pressurized fluid source;
at least one calibrated opening which passes right through the continuous perforated ring in its radial thickness;
at least one fluid-cushion carrying surface which the continuous perforated ring comprises, said carrying surface being arranged on an opposite side from the pressure distribution chamber.

2. The fluid-cushion sealing device according to claim 1 , wherein the ring groove is provided in the piston, further comprising an axially blind counter-pressure recess provided recessed on the external cylindrical ring surface, so that the surface that is not occupied by the counter-pressure recess of the external cylindrical ring surface which receives said recess constitutes the fluid-cushion carrying surface.

3. The fluid-cushion sealing device according to claim 1 , wherein the ring groove is provided in the cylinder, further comprising an axially blind counter-pressure recess provided recessed on the internal cylindrical ring surface, so that the surface that is not occupied by the counter-pressure recess of the internal cylindrical ring surface which receives said recess constitutes the fluid-cushion carrying surface.

4. The fluid-cushion sealing device according to claim 1 , further comprising a counter-pressure recess that consists of a counter-pressure groove of small depth that is approximately centered on an axial length of the external cylindrical ring surface or of the internal cylindrical ring surface which receives said recess, said counter-pressure groove being produced over the entire circumference of said external cylindrical ring surface or of said internal cylindrical ring surface.

5. The fluid-cushion sealing device according to claim 3 , wherein the calibrated opening opens into the counter-pressure recess.

6. The fluid-cushion sealing device according to claim 2 , wherein the calibrated opening opens into the counter-pressure recess via a pressure distribution recess provided recessed at the bottom of said counter-pressure recess.

7. The fluid-cushion sealing device according to claim 6 , wherein the pressure distribution recess consists of a pressure distribution groove which is more or less centered on the axial length of the external cylindrical ring surface or of the internal cylindrical ring surface which receives the counter-pressure recess, said pressure distribution groove being produced over the entire circumference of said external cylindrical ring surface or of said internal cylindrical ring surface.

8. The fluid-cushion sealing device according to claim 1 , wherein the ring seal consists of a thinned axial portion provided in a vicinity of at least one of the axial ends of the continuous perforated ring, said thinned axial portion being sealingly secured to the ring groove and sufficiently flexible to allow the diameter of the continuous perforated ring to increase or decrease relative to said groove.

9. The fluid-cushion sealing device according to claim 1 , wherein the continuous perforated ring consists of a flexible material and includes at least one circumferential ring spring which tends to reduce the diameter of said ring if the ring groove is provided in the piston or which tends to increase the diameter of said ring if the ring groove is provided in the cylinder.

10. The fluid-cushion sealing device according to claim 1 , wherein the pressure distribution chamber accommodates a ring fluid disperser which forces ring fluid originating from the pressure transfer circuit to sweep the largest possible area of the internal cylindrical ring surface in the case in which the ring groove is provided in the piston or the largest possible area of the external cylindrical ring surface in the case in which the ring groove is provided in the cylinder, before escaping through the calibrated opening.

11. The fluid-cushion sealing device according to claim 1 , wherein the ring groove accommodates an expanding spring which bears against said groove in order to exert a radial force on the internal cylindrical ring surface in the case in which the ring groove is provided in the piston or on the external cylindrical ring surface in the case in which the ring groove is provided in the cylinder.

12. The fluid-cushion sealing device according to claim 11 , wherein the expanding spring produces by contact a seal between the ring groove and the continuous perforated ring.

13. The fluid-cushion sealing device according to claim 11 , wherein the pressure distribution chamber accommodates a ring fluid disperser which forces ring fluid originating from the pressure transfer circuit to sweep the largest possible area of the internal cylindrical ring surface in the case in which the ring groove is provided in the piston or the largest possible area of the external cylindrical ring surface in the case in which the ring groove is provided in the cylinder, before escaping through the calibrated opening, and the expanding spring is provided with at least one fluid dispersion opening and/or with at least one fluid dispersion groove so as to constitute, with said opening and/or said groove, the ring fluid disperser.

Assignees

• Rabhi Vianney

Inventors

• Rabhi Vianney

Classifications

• F16J15/441

  with floating ring · CPC title

• F16J9/12

  Details · CPC title

• F04B53/143

  Sealing provided on the piston · CPC title

• F16J15/40 Primary

  by means of fluid · CPC title

• F16J15/406

  by at least one pump · CPC title