WO2006019307A1

WO2006019307A1 - Subsea electronic assembly

Info

Publication number: WO2006019307A1
Application number: PCT/NO2005/000289
Authority: WO
Inventors: Espen Haagensen
Original assignee: Sicom As
Priority date: 2004-08-19
Filing date: 2005-08-15
Publication date: 2006-02-23
Also published as: NO20043451L; NO20043451D0; NO321919B1

Abstract

Subsea electronic assembly with cageforming elements (12, 13, 22, 23) for installation in a generally cylindrical receptacle (32) of a metallic or other thermal conducting material, in which the cageforming elements provide room for electronic equipment, including components releasing heat to the cageforming elements, for transfer to the cylindrical receptacle. The cageforming elements comprise at least one heat conducting wall element (22, 23) with an external face corresponding to a part of the internal wall of the cylindrical receptacle (32). The bolts (14 - 17) are provided to expand the heat conducting wall element or wall elements (22, 23) against the wall of the generally cylindrical receptacle (32) for achieving good thermal contact.

Description

Subsea electronic assembly

The invention relates to a subsea electronic assembly as stated in the introductory part of claim 1. More particularly, an electronic assembly able to be placed on carrying elements that function as a heat sink, where the assembly is enclosed in a receptacle particularly suited for subsea installation.

Background

When providing electronic units for deep sea deployment, the electronic assembly is enclosed in a pressure proof receptacle. Due to the requirements for mechanical strength, the unit has to withstand very severe environmental factors such as shock and vibration.

Additionally a good thermal contact to the external wall is important to conduct heat from the electronics to the sea water. Such equipment should be capable of use at depths down to 3000 meter.

Various installation equipment has been proposed for this purpose. It is known to provide mounting frames which have been fastened with bolts to the bottom of the pressure receptacle. This will provide an inferior heat conductance. The bolts extending through the bottom of the receptacle may cause leakage and reduced service life.

Objects

The main object of the invention is to provide an installation assembly for electronics, providing an efficient heat transfer to an outer metal receptacle, to provide efficient cooling. The equipment should be sturdy. Simplicity in components of manufacture and easy mounting and demounting is also an object.

Further it is important that the pressure receptacle is weakened as little as possible when mounting of the assembly.

The Invention

The invention is stated in claim 1. In claims 2 and 3, particularly favourable features of the invention are stated. The term "cageforming" is indicates that a cage or compartment is created inside the mounting device, which can accommodate electronics. Further advantageous features of the invention are described in claims 4 - 5. The invention can be realized with a minimum of elements. The expansion of one or more heat conducting carrying elements against the wall of the surrounding receptacle will provide good thermal contact. Bolts or other fastening elements, which can weaken the receptacle and make it leak, are not required to pierce the wall of the receptacle. The thermal conducting carrying elements may be symmetrically arranged to provide a balanced force against the wall of the receptacle. Together with the simple structure, this provides great resistance to shock and vibration. Mounting and demounting is simplified, in its most simplified form, by tightening one nut.

An assembly according to the invention is also suitable if multiple units, i. e. receptacles, are placed adjacent each other. The lack of external attachment enables the stacking of multiple receptacles, each containing an assembly, and locking them mutually.

Example The invention is described in more detail below, with reference to the drawings, wherein

Figure 1 shows a perspective view of an assembly according to the invention,

Figure 2 shows a plan view of Figure 1,

Figure 3 shows a section through a receptacle in which the assembly of claims 1 and 2 is mounted.

Figure 1 shows a construction unit 11 provided for accommodating various electronic components, including a power supply, amplifier circuits and other components releasing heat.

The construction unit 11 includes two end dishes 12 and 13 joined by four bolts 14, 15, 16, 17 arranged in a square at the edge of the end dishes. The end dish 12 is closed and forms a base, while end dish 13 has two opposing apertures 18, 19 arranged at the circular edge, for both both cable access cables and inspection.

The base dish 12 and the connection dish 13 both have two symmetrical side edges 20, 21 providing a stop for two side walls respectively. The side walls 22, 23 have a plane interior face 24 suited for the mounting of various components, and a circularly curved external face 25. As shown in Figure 3, the side edges 20, 21 have a bevelled edge 26 facing the side walls 22, 23, which each has a corresponding bevelled face 27 at its inner end edge. The bevelled edges 26, 27 will thus engage mutually in pairs.

The bolts 14 - 17 are inserted in threaded apertures in the base dish 12 and can be locked with a locking nut 28, as shown in Figure 1 , or can just be tightened by a nut at the bottom position as shown in Figure 3. The base dish 12 and the connection dish 13 are forced together with a locking nut 29 at the outer end of each bolt 14 - 17. The components of the electronic equipment can be conveniently mounted on the four inner faces of the base dish 12, the connection dish 13, and said two sidewalls. To these faces, mounting apertures 30 and 31 are arranged.

The elements of this assembly unit are preferably of metal. If manufactured of another material, good thermal conductivity is of importance.

Figures 2 and 3 show how the construction unit 11 is arranged in a bucket shaped, cylindrical receptacle 32 which is arranged bottom up. The receptacle 32 may be closed with a lid, which is not shown. Thus the equipment can be used in an environment with excess pressure, liquid and other external factorss.

During installation, the side walls 22, 23 are held together with a releasable strap during insertion of the assembly unit into the receptacle 32. Correspondingly, such a strap should be mounted such that it may be extracted from the receptacle.

Modifications

The device shown in the example may be modified in various ways. The number of side walls being with a circularly curved exterior, can be more or less than two, e.g. 1, 3, or 4. The side wall or the sidewalls may have an interior face different from the one shown.

The bevelled faces 26, 27 are an appropriate shape for the expanding means, but may be replaced by other means, e.g. double tightening screws with opposing threads. This device however, provides a less suitable means.

The receptacle with a generally cylindrical shape may be slightly conical, to push the side walls 22, 23 toward a sideward engagement, by introducing an axial displacement with a suitable tightening screw, or with a combination of axial and radial tightening.

Claims

Claims:

1. Subsea electronic assembly with cageforming elements (12, 13, 22, 23) for installation in a generally cylindrical receptacle (32) of a metallic or other thermal conducting material, in which the cageforming elements provide room for electronic equipment, including components releasing heat to the cageforming elements, for transfer to the cylindrical receptacle, characterized in

- that the cageforming elements comprise at least one heat conducting wall element (22, 23) with an external face corresponding to a part of the internal wall of the cylindrical receptacle (32), and - that bolts (14 - 17) are provided to expand the heat conducting wall element or wall elements (22, 23) against the wall of the generally cylindrical receptacle (32) for achieving good thermal contact.

2. Subsea electronic assembly according to claim 1, with a circular, cylindrical receptacle (32), characterized by including two symmetrically arranged wall elements (22, 23) with a circularly curved external face (25).

3. Subsea electronic assembly according to claim 2, characterized in that said two wall elements (22, 23) together with two end dishes (12, 13) are creating a cage for electronic components, said dishes are provided to be pressed axially together with at least one threaded element (14 - 17), the faces (26, 27) of engagement between the wall elements and the end dishes being bevelled.

4. Subsea electronic assembly according to any one of claims 2 or 3, characterized in that the wall elements (22, 23) are surrounded by a strap during insertion.

5. Subsea electronic assembly according to claim 3, characterized in that the bevelled faces (26, 27) are forming an angle of approximately 45^°to the longitudinal axis of the assembly.