SUSPENSION OF SENSOR COMPONENTS IN HIGH SHOCK APPLICATIONS

Description

Field of the Invention

[0001] This application relates generally to sensors and sensitive instruments and more particularly, but not by way of limitation, to a suspension system for supporting sensor components that resists shock and vibration.

Background

[0002] From US 2009/0308618 A1 a device for supporting a power cable is known. The power cable is inserted into a length of a tubing disposed in a wellbore. The device comprises a suspension support mounted onto the cable in frictional sliding contact with a tubing inner surface.

[0003] Further, from GB 2 238 390 A describes a liquid sensing apparatus. The sensing apparatus includes a central and a sleeve electrode, and an insulator means. The insulator means and the central electrode are attached firmly and rigidly to each other and form a sub-assembly. The sleeve electrode is mountable upon, and separable from, the sub-assembly. The sub-assembly is designed such that the central electrode and the insulator means remain attached rigidly together even when the sleeve electrode is separated from the sub-assembly.

[0004] Sensors are often susceptible to damage or performance degradation when exposed to mechanical shock and vibration. In downhole applications, sensor components must be made to withstand inhospitable conditions that include elevated temperatures, pressures and mechanical shock. Fragile sensor components must be suspended in a manner that will protect them from damage or performance failures when exposed to shock or vibration.

[0005] In the past designers have suspended sensor components with leaf springs and wave springs to dampen shock and vibration. Although generally accepted, the use of leaf springs and wave springs complicates the manufacturing process and may produce inconsistent results. Accordingly, there is a need for an improved mechanism for suspending sensor components in a downhole environment. It is to this and other needs that the preferred embodiments are directed.

Summary of the Invention

[0006] Disclosed is a suspension assembly for securing a sensitive component within a shock-resistant housing as set forth in independent claim 1.

[0007] Preferred embodiments of the present invention include a suspension assembly for supporting a shock-sensitive component includes an outer housing and one or more radial canted coil springs that surround and support the shock-sensitive component. Each of the plurality of radial canted coil springs is preferably a toroid. The exterior of each of the plurality of radial canted coil springs is in contact with the outer housing and the interior of each of the plurality of canted radial canted coil springs is in contact with the exterior of the shock-sensitive component. The radial canted coil springs dampen mechanical shock and vibration applied in a lateral direction. The suspension assembly optionally includes an axial canted coil spring that dampens mechanical shock in the axial direction. The outer housing may include grooves that locate the radial canted coil springs within the suspension assembly. The scope of the protection is defined by appended claims 1-12.

Brief Description of the Drawings

[0008] 

FIG. 1 is an elevational view of a downhole instrument constructed in accordance with a preferred embodiment.

FIG. 2 is cross-sectional elevational view of the suspension assembly of the downhole instrument of FIG. 1.

FIG. 3 is cross-sectional top view of the suspension assembly of the downhole instrument of FIG. 2.

FIG. 4 is a perspective view of a toroidal canted coil spring of the suspension assembly of FIGS. 2 and 3.

Detailed Description of the Preferred Embodiment

[0009] In an illustrative example, FIG. 1 shows an elevational view of a downhole instrument 100 attached to a deployment cable 102. The downhole instrument 100 and deployment cable 102 are disposed in a wellbore 104, which is drilled for the production of a fluid such as water or petroleum. As used herein, the term "petroleum" refers broadly to all mineral hydrocarbons, such as crude oil, gas and combinations of oil and gas.

[0010] The downhole instrument 100 includes a sensor module 106. The sensor module 106 may include sensors, analyzers, control systems, power systems, data processors and communication systems, all of which are well-known in the art. The deployment cable 102 connects the downhole instrument to surface-based facilities and provides power and communication to and from the downhole instrument 100. It will be appreciated that the downhole instrument 100 may alternatively be configured as part of a larger downhole assembly. For example, the downhole instrument 100 is attached to a submersible pumping system or as part of a measurement while drilling system. If the downhole instrument 100 is incorporated within a measurement while drilling system, the instrument 100 may be powered by one or more batteries rather than through an umbilical extending to surface-based power supplies. Although demonstrated in a vertical wellbore 104, it will be appreciated that downhole instrument 100 may also be implemented in horizontal and non-vertical wellbores. Further illustrative examples may also find utility in surface pumping applications and in other applications in which a sensor or other sensitive component is exposed to the potential of shock and vibration.

[0011] Turning to FIGS. 2 and 3, shown therein are elevational and top cross-sectional views, respectively, of a suspension assembly 108 constructed in accordance with a preferred embodiment. In the presently preferred embodiment, the suspension assembly 108 is incorporated within the sensor module 106. The suspension assembly 108 preferably includes an outer housing 110, one or more radial coiled springs 112, one or more axial coiled springs 114, a sealed cap 116, a locking ring 118 and a shock and vibration sensitive component 120. The space between the interior of the outer housing 110 and the exterior of the component 120 defines an annulus 122. The outer housing 110 preferably provides an access port 124 for making connections to the component 120.

[0012] The component 120 is preferably selected from the group of sensitive components that includes scintillators, gamma ray detectors, x-ray detectors, accelerometers, photomultipliers, and other shock-sensitive components. It will be appreciated, however, that the component 120 could alternatively be selected from other mechanical, electrical or electro-mechanical devices and that the component 120 and suspension assembly 108 could be positioned outside the sensor module 106.

[0013] The radial coiled springs 112 are sized and configured to occupy the annular space between the interior of the outer housing 110 and the exterior of the component 120. The axial coiled springs 114 are sized and configured to occupy the space between the end of the component 120 and the sealed cap 116. The radial and axial coiled springs 112, 114 are preferably toroidal and canted coiled springs that are constructed from a resilient metal. The canted coiled springs preferably exhibit a resilient and substantially uniform force that increases less than conventional springs during deflection. The exterior of each of the radial canted coil springs 112 is in contact with the outer housing 110 and the interior of each of the plurality of canted radial canted coil springs 112 is in contact with the exterior of the component 120. The suspension assembly 108 optionally includes a force distribution plate 130 positioned between the component 120 and the axial spring 114. The force distribution plate 130 more evenly distributes the application of forces between the axial spring 114 and the component 120.

[0014] Turning to FIG. 4, shown therein is a front perspective view of a particularly preferred embodiment of the radial and axial coiled springs 112, 114. In the particularly preferred embodiment depicted in FIGS. 3 and 4, the radial and axial coiled springs 112, 114 include a polymer envelope 126 that entirely or partially encompasses the radial and axial coiled springs 112, 114. In highly preferred embodiments, the envelope is constructed from polytetrafluoroethylene (PTFE), which is available from a number of commercial sources. The envelope 126 protects the component 120 from direct contact with the radial and axial coiled springs 112, 114.

[0015] The outer housing 110 preferably includes one or more grooves 128 at selected locations along the interior of the outer housing 110. The machined grooves 128 are preferably machined in the outer housing 110 and sized and configured to accept the one or more radial coiled springs 112. In the particularly preferred embodiment depicted in FIG. 2, the suspension assembly 108 includes three radial coiled springs 112, each disposed in a separate groove 128. The combined use of the radial coiled springs 112 and the grooves 128 facilitates the manufacturing process because the radial coiled springs 112 can more easily be located in the appropriate place within the suspension assembly 108.

[0016] During use, the radial coiled springs 112 reduce mechanical shock applied from a lateral direction by absorbing a portion of the kinetic energy imparted on the suspension assembly 108. Similarly, when a shock is applied in the longitudinal direction, the axial coiled spring 114 absorbs a portion of the kinetic energy to reduce the shock applied to the component 120. The outer housing 110, the radial coiled springs 112 and the axial coiled springs 114 are preferably sized to permit the component 120 to deflect up to a predetermined threshold amount. Together, the outer housing 110, radial coiled springs 112 and axial coiled springs 114 provide a durable and resilient suspension system that is cost-effective and easy to manufacture.

Claims

1. A suspension assembly (108) for securing a sensitive component (120) within a shock-resistant housing, the suspension assembly (108) comprising:

an outer housing (110) that contains the component (120), wherein the outer housing (110) has an interior surface;

an annulus (122) between the interior surface of the outer housing (110) and the sensitive component (120); and

one or more radial coiled springs (112), wherein each of the one or more radial coiled springs (112) comprises a toroidal coiled spring that is positioned within the annulus (122) between the outer housing (110) and the component (120),

characterized in that, the suspension assembly (108) further comprises:

a cap (116) enclosing a first end of the outer housing (110); and

an axial coiled spring (114), wherein the axial coiled spring (114) is captured between the cap (116) and the component (120).

2. The suspension assembly (108) of claim 1, wherein the outer housing (110) comprises one or more grooves (128) along the interior surface and wherein each of the one or more radial coiled springs (112) being secured within a corresponding one of the one or more grooves (128).

3. The suspension assembly (108) of claim 2, further comprising three radial coiled springs (112) positioned in the annulus (122) between the outer housing (110) and the component (120), wherein each of the three radial coiled springs (112) is a toroidal and canted coiled spring.

4. The suspension assembly (108) of claim 3, wherein each of the three radial coiled springs (112) further comprises a polymer envelope (126) that at least partially surrounds the radial coiled spring (112).

5. The suspension assembly (108) of claim 4, wherein the polymer envelope (126) comprises a polytetrafluoroethylene envelope.

6. The suspension assembly (108) of claim 1, wherein the axial coiled spring (114) comprises a toroidal and canted coiled spring.

7. The suspension assembly (108) of claim 6, wherein the axial coiled spring (114) further comprises an envelope.

8. The suspension assembly (108) of claim 7, wherein the axial coiled spring (114) further comprises a polymer envelope (126).

9. The suspension assembly (108) of claim 1, comprising:
a plurality of radial canted coil springs (112), wherein each of the plurality of radial canted coil springs (112) is a toroid and wherein an exterior of each of the plurality of radial canted coil springs (112) is in contact with the outer housing (110) and an interior of each of the plurality of radial canted coil springs (112) is in contact with an exterior of the sensitive component (120).

10. The suspension assembly (108) of claim 9, wherein each of the plurality of radial canted coil springs (112) further includes a polymer envelope (126).

11. The suspension assembly (108) of claim 10, wherein the outer housing (110) further comprises a plurality of grooves (128) extending along the interior surface and wherein each of the plurality of radial canted coil springs is secured within a corresponding one of the plurality of grooves (128).

12. A sensor module (106) incorporating the suspension assembly (108) according to any preceding claim.

Ansprüche

1. Aufhängungsanordnung (108) zum Sichern einer empfindlichen Komponente (120) innerhalb eines stoßfesten Gehäuses, wobei die Aufhängungsanordnung (108) Folgendes umfasst:

ein äußeres Gehäuse (110), das die Komponente (120) enthält, wobei das äußere Gehäuse (110) eine innere Oberfläche aufweist;

einen Ringraum (122) zwischen der inneren Oberfläche des äußeren Gehäuses (110) und der empfindlichen Komponente (120); und

eine oder mehrere radiale Schraubenfedern (112), wobei jede der einen oder mehreren radialen Schraubenfedern (112) eine toroidale Schraubenfeder umfasst, die innerhalb des Ringraums (122) zwischen dem äußeren Gehäuse (110) und der Komponente (120) angeordnet ist,

dadurch gekennzeichnet, dass die Aufhängungsanordnung (108) ferner Folgendes umfasst:

eine Kappe (116), die ein erstes Ende des äußeren Gehäuses (110) umschließt; und

eine axiale Schraubenfeder (114), wobei die axiale Schraubenfeder (114) zwischen der Kappe (116) und der Komponente (120) eingeschlossen ist.

2. Aufhängungsanordnung (108) nach Anspruch 1, wobei das äußere Gehäuse (110) eine oder mehrere Nuten (128) entlang der innere Oberfläche umfasst und wobei jede der einen oder mehreren radialen Schraubenfedern (112) in einer entsprechenden der einen oder mehreren Nuten (128) befestigt ist.

3. Aufhängungsanordnung (108) nach Anspruch 2, die ferner drei radiale Schraubenfedern (112) umfasst, die in dem Ringraum (122) zwischen dem äußeren Gehäuse (110) und der Komponente (120) angeordnet sind, wobei jede der drei radialen Schraubenfedern (112) eine toroidale und geneigte Schraubenfeder ist.

4. Aufhängungsanordnung (108) nach Anspruch 3, wobei jede der drei radialen Schraubenfedern (112) ferner eine Polymerhülle (126) umfasst, welche die radiale Schraubenfeder (112) mindestens teilweise umgibt.

5. Aufhängungsanordnung (108) nach Anspruch 4, wobei die Polymerhülle (126) eine Polytetrafluorethylenhülle umfasst.

6. Aufhängungsanordnung (108) nach Anspruch 1, wobei die axiale Schraubenfeder (114) eine toroidale und geneigte Schraubenfeder umfasst.

7. Aufhängungsanordnung (108) nach Anspruch 6, wobei die axiale Schraubenfeder (114) ferner eine Hülle umfasst.

8. Aufhängungsanordnung (108) nach Anspruch 7, wobei die axiale Schraubenfeder (114) ferner eine Polymerhülle (126) umfasst.

9. Aufhängungsanordnung (108) nach Anspruch 1, umfassend:
eine Vielzahl von radial geneigten Schraubenfedern (112), wobei jede der Vielzahl von radial geneigten Schraubenfedern (112) ein Toroid ist und wobei ein Äußeres von jeder der Vielzahl von radial geneigten Schraubenfedern (112) in Kontakt mit dem äußeren Gehäuse (110) ist und ein Inneres von jeder der Vielzahl von radial geneigten Schraubenfedern (112) in Kontakt mit einem Äußeren der empfindlichen Komponente (120) ist.

10. Aufhängungsanordnung (108) nach Anspruch 9, wobei jede der mehreren radial geneigten Schraubenfedern (112) ferner eine Polymerhülle (126) einschließt.

11. Aufhängungsanordnung (108) nach Anspruch 10, wobei das äußere Gehäuse (110) ferner eine Vielzahl von Nuten (128) umfasst, die sich entlang der inneren Oberfläche erstrecken, und wobei jede der Vielzahl von radial geneigten Schraubenfedern in einer entsprechenden der Vielzahl von Nuten (128) gesichert ist.

12. Sensormodul (106), das die Aufhängungsanordnung (108) nach einem der vorstehenden Ansprüche aufnimmt.

Revendications

1. Ensemble de suspension (108) pour fixer un composant sensible (120) au sein d'un logement résistant aux chocs, l'ensemble de suspension (108) comprenant :

un logement externe (110) qui contient le composant (120), dans lequel le logement externe (110) a une surface intérieure ;

un espace annulaire (122) entre la surface intérieure du logement externe (110) et le composant sensible (120) ; et

un ou plusieurs ressorts hélicoïdaux radiaux (112), dans lequel chacun parmi le ou les ressorts hélicoïdaux radiaux (112) comprend un ressort hélicoïdal toroïdal qui est positionné au sein de l'espace annulaire (122) entre le logement externe (110) et le composant (120),

caractérisé en ce que, l'ensemble de suspension (108) comprend en outre :

une coiffe (116) enfermant une première extrémité du logement externe (110) ; et

un ressort hélicoïdal axial (114), dans lequel le ressort hélicoïdal axial (114) est capturé entre la coiffe (116) et le composant (120).

2. Ensemble de suspension (108) selon la revendication 1, dans lequel le logement externe (110) comprend une ou plusieurs rainures (128) le long de la surface intérieure et dans lequel chacun parmi le ou les ressorts hélicoïdaux radiaux (112) est fixé au sein d'une correspondante parmi la ou les rainures (128).

3. Ensemble de suspension (108) selon la revendication 2, comprenant en outre trois ressorts hélicoïdaux radiaux (112) positionnés dans l'espace annulaire (122) entre le logement externe (110) et le composant (120), dans lequel chacun des trois ressorts hélicoïdaux radiaux (112) est un ressort hélicoïdal toroïdal et oblique.

4. Ensemble de suspension (108) selon la revendication 3, dans lequel chacun des trois ressorts hélicoïdaux radiaux (112) comprend en outre une enveloppe polymère (126) qui entoure au moins partiellement le ressort hélicoïdal radial (112).

5. Ensemble de suspension (108) selon la revendication 4, dans lequel l'enveloppe polymère (126) comprend une enveloppe de polytétrafluoréthylène.

6. Ensemble de suspension (108) selon la revendication 1, dans lequel le ressort hélicoïdal axial (114) comprend un ressort hélicoïdal toroïdal et oblique.

7. Ensemble de suspension (108) selon la revendication 6, dans lequel le ressort hélicoïdal axial (114) comprend en outre une enveloppe.

8. Ensemble de suspension (108) selon la revendication 7, dans lequel le ressort hélicoïdal axial (114) comprend en outre une enveloppe polymère (126).

9. Ensemble de suspension (108) selon la revendication 1, comprenant :
une pluralité de ressorts hélicoïdaux obliques radiaux (112), dans lequel chacun parmi la pluralité de ressorts hélicoïdaux obliques radiaux (112) est un tore et dans lequel un extérieur de chacun parmi la pluralité de ressorts hélicoïdaux obliques radiaux (112) est en contact avec le logement externe (110) et un intérieur de chacun parmi la pluralité de ressorts hélicoïdaux obliques radiaux (112) est en contact avec un extérieur du composant sensible (120).

10. Ensemble de suspension (108) selon la revendication 9, dans lequel chacun parmi la pluralité de ressorts hélicoïdaux obliques radiaux (112) inclut en outre une enveloppe polymère (126).

11. Ensemble de suspension (108) selon la revendication 10, dans lequel le logement externe (110) comprend en outre une pluralité de rainures (128) s'étendant le long de la surface intérieure et dans lequel chacun parmi la pluralité de ressorts hélicoïdaux obliques radiaux est fixé au sein d'une correspondante parmi la pluralité de rainures (128).

12. Module capteur (106) incorporant l'ensemble de suspension (108) selon une quelconque revendication précédente.

Drawing