Device for transmitting energy across a separating wall, where the wall includes a conductive element with a hole therein which passes through the wall

Abstract

A device for transmitting energy comprises: a wall separating two media; and at least one conductive element passing through the wall, the conductive element comprising an energetically conductive material extending in a longitudinal direction. The conductive element is joined to the wall and comprises a hole passing through the wall and extending in a direction substantially parallel to the longitudinal direction on either side of the surfaces of the wall, over respective lengths that are larger than or equal to the largest dimension of a cross section of the conductive element considered level with the wall, the maximum ratio of the area of the cross section of the conductive element with the hole to the area of the cross section of the conductive element without the hole level with the wall being higher than or equal to a threshold comprised between 0.85 and 0.95.

Claims

1. A device for transmitting energy, comprising: a wall separating two media; and at least one conductive element passing through the wall, the conductive element comprising an energetically conductive material extending in a longitudinal direction; wherein the at least one conductive element is joined to the wall and includes a hole passing through the wall and extending in a direction substantially parallel to the longitudinal direction on either side of surfaces of the wall over respective lengths that are greater than or equal to a largest dimension of a cross section of the at least one conductive element when the at least one conductive element is flush with the wall, and wherein a maximum ratio of an area of the cross section of the at least one conductive element when the hole is present in the at least one conductive element to an area of the cross section of the at least one conductive element without the hole, when the at least one conductive element is flush with the wall, is higher than or equal to a threshold lying between 0.85 and 0.95.

2. The device for transmitting energy according to claim 1, in which the threshold is higher than 0.9.

3. The device for transmitting energy according to claim 1, in which the cross section of the at least one conductive element lying within a thickness of the wall is circular and has a constant cross section having and a first diameter.

4. The device for transmitting energy according to claim 3, in which the first diameter is smaller than or equal to 3 mm.

5. The device for transmitting energy according to claim 1, in which a cross section of the hole considered flush with the wall is circular and constant.

6. The device for transmitting energy according to claim 1, in which a thickness of the wall in the longitudinal direction is smaller than or equal to 1 mm.

7. The device for transmitting energy according to claim 1, comprising a plurality of conductive elements including the at least one conductive element, each of said plurality of conductive elements arranged substantially parallel to the longitudinal direction, a distance between two successive conductive elements in the plurality of conductive elements being greater than or equal to 0.5 mm.

8. The device for transmitting energy according to claim 1, wherein said device is a microwave window.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood and other advantages will become apparent on reading the following nonlimiting description, and by virtue of the appended figures, in which:

(2) FIG. 1, described above, shows a first microwave window according to the prior art;

(3) FIG. 2 shows a device for transmitting energy from one medium to another, according to one aspect of the invention;

(4) FIG. 3 shows a multiple passage device for passing energy from one medium to another, according to another aspect of the invention;

(5) FIG. 4 illustrates the cross section (Sc) of the conductive element and the cross section (St) of a hole in the conductive element, according to an aspect of the invention.

DETAILED DESCRIPTION

(6) One embodiment of the invention is shown in FIG. 2.

(7) In the case in point, the device comprises a wall 2 comprising an electrically and thermally insulating material such as a ceramic, alumina being very particularly suitable. The wall 2 is joined to connector parts 7, for example using brazed joints 6.

(8) The transmitting device according to one aspect of the invention allows a conductive element 3 to be assembled with a thermally and/or electrically insulating wall 2.

(9) The wall 2 may be of any thickness e. However, the device described is particularly applicable to devices notably having a small wall 2 of thickness e, typically smaller than about 1 mm.

(10) This is because mechanical stresses due to temperature variations are, for this type of device, correspondingly more critical to the integrity of the energy transmitting device.

(11) The conductive element 3 extends in a longitudinal direction d.sub.Long and passes through the wall 2.

(12) The conductive element 3 comprises a material having good energy conduction properties, such as copper. The transmitted energy will possibly take the form of thermal energy, an electrical current or electromagnetic waves.

(13) The cross section Sc of the conductive element 3, shown in FIG. 4, considered level with the wall 2 may be of any size; the cross section Sc of the conductive element 3 is preferably circular and constant in the thickness e of the wall 2 and has a first diameter d1.

(14) The conductive element 3 is joined to the wall 2, for example hermetically, depending on the applications for which the energy transmitting device is intended. The conductive element 3 may, for example, be joined to the wall 2 by means of an adhesive, brazed joints or welded joints. In the case in point, the joint of the conductive element 3 to the wall 2 is achieved using brazed joints 6.

(15) The conductive element 3 furthermore comprises a hole 8 extending in a direction substantially parallel to the longitudinal direction d.sub.Long and protruding on either side of the surfaces of the wall 2 over lengths L that are greater than or equal to the largest dimension of the cross section Sc of the conductive element 3, the cross section Sc of the conductive element 3 being considered level or flush with the wall 2.

(16) In other words, if the cross section Sc of the conductive element 3 is circular and constant within the thickness e of the wall 2, the hole 8 extends on either side of the surfaces of the wall 2 or, in other words, protrudes on either side of the surfaces of the wall 2, over respective lengths that are greater than or equal to the first diameter d1 thus limiting expansionary and compressive mechanical stresses generated by temperature variations during the passage of the energy.

(17) The hole 8 may be located in any position, but advantageously the hole 8 is centered. The hole 8 may be closed or open onto one or other of the ends of the conductive element 3. Preferably, the hole 8 opens onto at least one of the ends of the conductive element 3. The hole 8 may have any cross section St (shown in FIG. 4); preferably the cross section St of the hole 8 is circular and constant within the thickness e of the wall 2, thereby allowing the hole 8 to be formed by drilling. The hole 8 has a second diameter d2.

(18) Advantageously, the ratio of the area of the cross section Sc of the conductive element 3 after the hole 8 has been drilled to the area of the cross section Sc of the conductive element 3 before the hole 8 has been drilled is comprised between 0.85 and 0.95, and is preferably higher than or equal to 0.9.

(19) In other words, the cross section Sc of the conductive element 3 after drilling is larger than 90% of the cross section Sc of the conductive element 3 before drilling. Thus, the loss of effective area allowing energy to be transferred is very small.

(20) Therefore, if the cross section Sc of the conductive element 3 and the cross section St of the hole 8 are circular in the thickness of the wall 2, the ratio of a diameter d2 of the hole 8 to a diameter d1 of the conductive element 3 is then 0.3 at least. The diameter d1 is referred to as the first diameter and the diameter d2 is referred to as the second diameter. The diameter of the drill hole may be the smallest producible, typically 0.2 mm.

(21) Another aspect of the invention includes placing a plurality of high-power energy transmission enabling microwave devices substantially parallel to the longitudinal direction d.sub.Long. This aspect of the invention is shown in FIG. 3.

(22) Advantageously, the distance d, shown in FIG. 3, between two successive devices for transmitting energy is larger than or equal to 0.5 mm. FIG. 3 further illustrates the conductive element 3 having the first diameter D1, the thickness e of the wall 2, the cladding 4 arranged coaxially around the wall 2, and the hole 8 having a second diameter d.sub.2.