GB2583711A

GB2583711A - Subsea electronic apparatus

Info

Publication number: GB2583711A
Application number: GB1905860.1A
Authority: GB
Inventors: Moen Stig; Låg Ørjan
Original assignee: Aker Solutions IP Ltd
Current assignee: Aker Solutions IP Ltd
Priority date: 2019-04-26
Filing date: 2019-04-26
Publication date: 2020-11-11
Anticipated expiration: 2039-04-26
Also published as: GB2583711B; GB201905860D0

Abstract

A subsea electronic apparatus comprising a housing 12; a chassis 16 for insertion in a longitudinal direction through an insertion opening defined in the housing 12, the chassis 16 having at least one electronic component 18 mounted thereto; and a heat transfer portion 20 configured to be in thermal contact with the at least one electronic component 28 to transfer, in use, heat away from the at least one electronic component 28 via the heat transfer portion 20. The heat transfer portion 20 is configured to be caused to move relative to the chassis 16, by insertion of the chassis 16 into the housing 12, from a disengaged position fig 3 spaced from the housing to an engaged position fig 2 in contact with the housing. When the heat transfer portion 20 is in the engaged position, a thermal conduction pathway is provided from the at least one electronic component 18 to the housing 12 via the heat transfer portion 20.

Description

Subsea Electronic Apparatus [0001] This invention relates to a subsea electronic apparatus, and a subsea electronic device assembled from the subsea electronic apparatus.

BACKGROUND

[0002] Typically, an electronic device or module for use in a well, such as a hydrocarbon well, must be protected from the extreme conditions of the local environment by a housing. The extreme conditions can include high pressure and damaging contaminants. Generally, during manufacture of the electronic device, electronic components of the electronic device are assembled within a chassis and the chassis inserted within a housing and sealed within the housing by sealing an insertion opening defined in the housing with an endplate or similar. Once sealed, the internal components, such as the electronic components, of the electronic apparatus are isolated from the high pressure and damaging contaminants which can be encountered when the electronic device is positioned in the local environment of the well.

[0003] Nevertheless, some electronic components can generate heat which should be dissipated out of the electric device. It is known to dissipate the heat from the electronic components by thermal transfer from the electronic components to the chassis, onwards to the housing of the electronic device and from there to the local environment of the well.

[0004] It is in this context that the present invention has been devised.

BRIEF SUMMARY OF THE DISCLOSURE

[0005] In accordance with the present disclosure there is provided a subsea electronic apparatus comprising: a housing; a chassis for insertion in a longitudinal direction through an insertion opening defined in the housing, the chassis having at least one electronic component mounted thereto; and a heat transfer portion configured to be in thermal contact with the at least one electronic component to transfer, in use, heat away from the at least one electronic component via the heat transfer portion. The heat transfer portion is configured to be caused to move relative to the chassis, by insertion of the chassis into the housing, from a disengaged position spaced from the housing to an engaged position in contact with the housing. When the heat transfer portion is in the engaged position, a thermal conduction pathway is provided from the at least one electronic component to the housing via the heat transfer portion.

[0006] Thus, insertion of the chassis within the insertion opening defined in the housing causes the heat transfer portion to move into an engaged position in contact with the housing. In other words, the chassis and heat transfer portion can be sized so as to fit easily within the insertion opening of the housing initially when the heat transfer portion is in the disengaged position, and, by insertion of the chassis into the housing, subsequently move such that the heat transfer portion is in the engaged position on insertion of the chassis into the housing. In this way, the subsea electronic apparatus can be easily and simply assembled.

[0007] It will be understood that in the disengaged position, the heat transfer portion is typically not in contact with the housing, and therefore can be considered to be spaced therefrom. Nevertheless, in the disengaged position, the heat transfer portion may be in contact with other components of the subsea electronic apparatus, for example the chassis. In the engaged position, the heat transfer portion should typically have sufficient contact with the housing to ensure that thermal heat conduction can occur directly between the heat transfer portion and the housing.

[0008] The subsea electronic apparatus may further comprise at least one resiliently deformable member configured to bias the heat transfer portion towards the disengaged position. Thus, the resiliently deformable member is configured to ensure that the heat transfer portion remains spaced from the housing during at least a portion of the insertion of the chassis into the housing through the insertion opening defined in the housing. It will be understood that the at least one resiliently deformable member can be any component configured to urge the heat transfer portion towards the disengaged position. For example, the at least one resiliently deformable member may comprise a spring, such as a compression spring arranged to urge the heat transfer portion towards the disengaged position by expansion of the compression spring towards an equilibrium position of the compression spring. Alternatively or additionally, the at least one resiliently deformable member may be arranged to provide redundancy in the system such that the chassis and heat transfer portion will work acceptably with a range of differently sized housings. In this way, at least small manufacturing variances on one or more of the housing, the chassis and the heat transfer portion will not unacceptably affect the ability to assemble the subsea electronic apparatus, or the ability of the heat transfer portion to adequately transfer thermal energy from the at least one electronic component to the housing. In embodiments, the at least one resiliently deformable member may comprise a plurality of resiliently deformable members, including one or more resiliently deformable members configured to bias the heat transfer portion towards the disengaged position and one or more other resiliently deformable members arranged to provide redundancy in the system such that the chassis and heat transfer portion will work acceptably with a range of differently sized housings.

[0009] The heat transfer portion may be configured to be in thermal contact with the at least one electronic component via the chassis. Thus, the thermal pathway for excess heat generated by the at least one electronic component, in use, may pass through one or more other components of the subsea electronic apparatus before the heat transfer portion, for example the chassis. The chassis and optionally the one or more other components of the subsea electronic apparatus through which the excess heat may pass are typically formed from a relatively thermally conductive material, for example sufficiently thermally conductive for excess heat from the at least one electronic component to be transferred therethrough to the heat transfer portion. At least a portion of the chassis and the one or more other components of the subsea electronic apparatus may be formed from metal.

[0010] The heat transfer portion may be configured to be secured relative to the chassis before the chassis is inserted into the housing. Thus, the heat transfer portion and the chassis may be inserted into the housing as a single component, which can increase the ease of assembly of the subsea electronic apparatus. In other words, the heat transfer portion may be affixed relative to the chassis during at least an initial stage of insertion of the chassis into the housing to prevent separation of the heat transfer portion from the chassis. Even though the heat transfer portion may be secured relative to the chassis, it can be moveably secured thereto, for example to restrict some of, such as most of, but not all of, the relative movement therebetween.

[0011] The housing may define an engagement region configured to be engaged during insertion of the chassis within the housing to cause movement of the heat transfer portion from the disengaged position to the engaged position. The engagement region may be formed to define an engagement surface. The engagement region may comprise a protrusion. The engagement region may be provided by a shoulder of an inner wall of the housing. Thus, the heat transfer portion may be caused to move into the engaged position by engagement with the engagement region once the chassis is inserted beyond a predetermined distance into the housing. In this way, any contact between the heat transfer portion and the housing can be avoided and/or reduced, at least until the chassis is partially, or almost fully inserted into the housing.

[0012] The at least one of the heat transfer portion and the chassis may define at least one inclined surface to cause movement of the heat transfer portion towards the housing during insertion of the chassis within the housing in the longitudinal direction. The movement of the heat transfer portion may be in a direction other than the longitudinal direction, for example in a radially outward direction, substantially transverse to the longitudinal direction. Thus, movement of the chassis in a longitudinal direction only, can cause movement of the heat transfer portion in a non-longitudinal direction towards the housing. The chassis can be inserted into the housing in response to a force applied to the chassis in the longitudinal direction. The heat transfer portion may be moved into the engaged position as a result of force applied to the housing in a longitudinal direction. It will be understood that the term inclined surface can include any surface shaped so as to cause movement of a further component, in sliding contact therewith, in a direction other than the longitudinal direction, such as having at least a component transverse to the longitudinal direction, and towards an inner surface of the housing.

[0013] The movement of the heat transfer portion towards the housing may be caused by movement between the at least one inclined surface and at least one of the heat transfer portion and the chassis. Thus, the heat transfer portion may be moved into the engaged position by movement between the at least one inclined surface and at least one of the heat transfer portion and the chassis. In other words, the at least one inclined surface can act as a ramp and/or a wedge to move the heat transfer portion towards the housing.

[0014] The at least one inclined surface may comprise a plurality of inclined surfaces.

The heat transfer portion may define a first inclined surface of the plurality of inclined surfaces. The chassis may define a second inclined surface of the plurality of inclined surfaces, configured to be in mutual contact with the first inclined surface, such that movement of the heat transfer portion relative to the chassis causes movement of the heat transfer portion towards the housing during insertion of the chassis within the housing.

Thus, movement of the heat transfer portion towards the housing and/or movement of the heat transfer portion into the engaged position may result from an interaction between the first and second inclined surfaces. The first and second inclined surfaces may be in slidable mutual contact such that they can change their position relative to one another without being separated. The first and second inclined surfaces may be configured such that they slope in opposing directions, that is, they taper in opposing directions.

[0015] The subsea electronic apparatus may further comprise an engagement member configured to engage the engagement region during insertion of the chassis within the housing. The engagement member may be configured to engage with the heat transfer portion to cause movement of the heat transfer portion towards the housing during insertion of the chassis within the housing. The engagement member may comprise an engagement pin and/or an engagement rod. Thus, engagement between the engagement member and the engagement region can cause movement of the heat transfer portion to cause the heat transfer portion to be moved into the engaged position. The engagement member may thus operate to move the heat transfer portion into the engaged position automatically during insertion of the chassis within the housing. As used herein, it will be understood that the term "automatically" means that no further operator action is required beyond insertion of the chassis within the housing to cause movement of the heat transfer portion into the engaged position. Typically, it will not be possible to fully insert the chassis into the housing without the heat transfer portion being moved into the engaged position.

[0016] As described previously, the at least one inclined surface may comprise a further plurality of inclined surfaces. The engagement member may define a first further inclined surface of the further plurality of inclined surfaces. The heat transfer portion may define a second further inclined surface of the further plurality of inclined surfaces, configured to be in mutual contact with the first further inclined surface, such that movement of the heat transfer portion relative to the engagement member causes movement of the heat transfer portion towards the housing during insertion of the chassis within the housing. Thus, the heat transfer portion may be moved towards the housing and/or moved into the engaged position as a result of movement of the engagement member. Furthermore, each of the plurality of inclined surfaces and the further plurality of inclined surfaces may be formed to have a substantially complementary shape such that any overlapping portions of the inclined surfaces remain substantially in contact during mutual sliding movement of the inclined surfaces. Thus, the inclined surfaces can move easily past each other. Furthermore, a high quality thermal coupling can be achieved between the two components having the mutually contacting inclined surfaces, such as the engagement member and the heat transfer portion in this example.

[0017] The engagement member may comprise a first resiliently deformable member of the at least one resiliently deformable member. The first resiliently deformable member may be configured to urge the engagement member in a substantially longitudinal direction with respect to the housing, The first resiliently deformable member may be arranged to resiliently deform along an axis parallel to a longitudinal axis of the housing. The first resiliently deformable member may be provided by a first spring. The first resiliently deformable member may be arranged to urge the engagement member outwardly towards the engagement region during insertion of the chassis within the housing. The first spring may be provided in a partially-compressed configuration. Thus, any movement of the engagement member against the urging of the first spring may be met with a greater immediate restoring force than if the first spring was provided in an equilibrium position instead of the partially-compressed configuration.

[0018] In this way, the first resiliently deformable member can be used to allow for manufacturing tolerances in one or more of the chassis, the heat transfer portion, the housing and the engagement member. In other words, if a first housing is formed such that a radial gap between the housing and the chassis in a direction transverse to the longitudinal direction in the vicinity of the heat transfer portion when the chassis is fully inserted into the housing is slightly smaller than for a second housing, the same chassis and heat transfer portion can be fully inserted into the housing in both instances, with a different amount of resilient deformation of the first resiliently deformable member being needed for each of the first housing and the second housing.

[0019] Furthermore, the engagement member may be biased outwardly in the longitudinal direction, away from the heat transfer portion, by the first spring during insertion of the chassis within the housing, which can help to ensure that when a sufficient force is exerted on the engagement member when the engagement member engages the engagement region, the engagement member can be moved in the longitudinal direction towards the heat transfer portion to move the heat transfer portion transverse to the longitudinal direction, towards the housing.

[0020] A second resiliently deformable member of the at least one resiliently deformable member may be arranged to urge the engagement member away from the heat transfer portion in a direction parallel to the longitudinal direction. The second resiliently deformable member may be provided between the engagement member and the heat transfer portion.

A third resiliently deformable member of the at least one resiliently deformable member may be arranged to urge the heat transfer portion away from the chassis in a direction parallel to the longitudinal direction. The third resiliently deformable member may be provided between the heat transfer portion and the chassis. The third resiliently deformable member may be provided on an opposite side of the heat transfer portion to the second resiliently deformable member. Thus, the heat transfer portion may be stabilised relative to the chassis and/or the engagement member. In other words, the heat transfer portion can remain centralised between the engagement member and the housing adjacent the heat transfer portion. Furthermore, the heat transfer portion can be arranged to move in a translational manner, substantially without any rotation of the heat transfer portion relative to the chassis during movement between the disengaged position and the engaged position.

[0021] Furthermore, one or both of the second resiliently deformable member and the third resiliently deformable member may urge relative movement of the heat transfer portion and at least one of the engagement member and the chassis. Thus, movement is permitted of the heat transfer portion into the disengaged position when the engagement member is not pressed into contact with the engagement region of the housing. In examples, the heat transfer portion may be biased into the disengaged position.

[0022] The chassis may be provided with a disengagement member configured to cause the further inclined surface of the heat transfer portion to be moved at least partially away from the further inclined surface of the engagement member during a first portion of removal of the chassis from the housing. Thus, the further inclined surfaces can be taken out of mutual contact, to allow the heat transfer portion to be removed easily from the housing along with the chassis. Without initial separation of the further inclined surfaces, any initial movement of the engagement member could cause the further inclined surfaces to become more engaged, urging the heat transfer portion outwardly against the housing.

In other words, the force required to remove the chassis from the housing can be reduced compared to if the further inclined surfaces of the heat transfer portion and the engagement member are not initially taken out of mutual contact prior to attempted removal of the chassis from the housing. The disengagement member may be configured to cause the further inclined surface of the heat transfer portion to be moved away from the further inclined surface of the engagement member by contact between the disengagement member and the heat transfer portion.

[0023] The disengagement member may be spaced from the heat transfer portion when the heat transfer portion is in the engaged position. Thus, when the disengagement member contacts the heat transfer portion, the inclined surfaces defined on the chassis and the heat transfer portion are already moved out of mutual contact by a preliminary portion of movement of the chassis out of the housing before the first portion of removal of the chassis from the housing. In this way, the heat transfer portion is moved at least partially out of the engaged position in contact with the housing, increasing the ease of removal of the chassis from the housing.

[0024] The chassis may be further provided with a further disengagement member configured to cause the engagement member to be moved away from the engagement region during a second portion of removal of the chassis from the housing, subsequent to the first portion of removal of the chassis from the housing. Thus, the engagement member can also be removed easily from the housing by removal of the chassis from the housing.

Viewed another way, a first distance between the disengagement member and a region of the heat transfer portion to be contacted by the disengagement member is less than a second distance between the further disengagement member and a region of the engagement member to be contacted by the further disengagement member.

[0025] The at least one electronic component may comprise at least one processor. The at least one electronic component may be a processing module, for example for processing data provided by one or more sensors electrically connected to the subsea electronic apparatus. The one or more sensors may be mechanically connected to the housing. In one example, the one or more sensors are located within the housing.

[0026] The subsea electronic apparatus may further comprise an endplate configured to be secured to the housing to cover the insertion opening and to secure the chassis within the housing. Thus, the chassis may be sealed inside the housing. The subsea electronic apparatus preferably defines exactly one insertion opening for insertion of the chassis into the housing therethrough. The subsea electronic apparatus may comprise exactly one endplate. In this way, external contaminants cannot penetrate within the housing of the subsea electronic apparatus when the endplate is secured to the housing to cover the insertion opening.

[0027] A subsea electronic device may be assembled from the subsea electronic apparatus, wherein the chassis is inserted within the housing.

[0028] It will be understood that the subsea electronic device may be a subsea electronic module (SEM).

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which: Figure 1 is a sectional side-view of a subsea electronic apparatus according to an embodiment of the present invention; Figure 2 is a detail view of the area bounded by rectangular box 'A' in Fig. 1, which shows a heat transfer apparatus in the engaged position; Figure 3 is a detail view of a heat transfer apparatus in the disengaged position; and Figure 4 is a sectional view of a subsea electronic apparatus according to the present disclosure, viewed as a section through the heat transfer portion of Figure 2, taken along a horizontal orientation.

DETAILED DESCRIPTION

[0030] Subsea equipment is often controlled by Subsea Electronic Modules (SEMs) that typically include printed wiring boards with multiple integrated circuits provided within a housing. These integrated circuits will typically generate a significant amount of waste heat during operation. Failure to manage this waste heat and prevent the build-up of excessive temperatures can result in reduced product lifetimes and component failures, leading to expensive interventions.

[0031] Fig. 1 shows a subsea electronic apparatus 10 comprising a housing 12 and a chassis 16. In this example, the apparatus 10, when assembled, is an SEM 10, and the chassis 16 is sealed inside the housing 12 by a removable endplate 14, sometimes referred to as a penetrator 14 at an insertion opening 15 defined in the housing 12. The chassis 16 has at least one electronic component 18 mounted thereto. in this example a plurality of electronic components (e.g. processor(s)) are mounted on one or a series of circuit boards, forming an electronics assembly 18, which is in turn mounted on the chassis 16. The subsea electronic apparatus 10 further comprises a heat transfer portion 20, which in this example is formed as a heat sink 20. The heat transfer portion 20 is provided between the outside of the chassis 16 and an inner surface of a wall 13 of the housing 12.

A more detailed description of the shape of the wall 13 of the housing in the vicinity of the heat transfer portion 20 is provided with reference to Figure 2 hereinafter.

[0032] In this example, an outer shape of the housing 12 is substantially cylindrical in form, though it will be appreciated that the present disclosure can apply to a housing 12 having substantially any external shape. Although not shown, the chassis 16 is typically formed from two substantially semi-cylindrical portions. It will be appreciated that the present disclosure can apply to a chassis 16 having substantially any external shape. That said, the chassis 16 is typically formed such that its external shape substantially matches the internal shape of the housing 12. The heat sink 20 has an inner surface configured to be contactable with at least a portion of the outer surface of the chassis 16, and an outer surface configured to be contactable with at least a portion of the inner surface of the wall 13 of the housing 12.

[0033] As shown in Figure 1, when the chassis 16 is fully inserted into the housing 12, the heat sink 20 is configured to be in thermal contact with the at least one electronics 18 assembly, for example via the chassis 16. In this way, the heat sink 20 can transfer, in use, heat away from the at least one electronics assembly 18 via the heat sink 20 to the housing 12. The heat sink 20 is configured to be caused to move relative to the chassis 16, by insertion of the chassis 16 into the housing 12 in a longitudinal direction. In particular, no subsequent operation by the chassis 16 or the heat sink 20 is required beyond insertion of the chassis 16 into the housing 12 to cause movement of the heat sink 20 relative to the chassis 16 to come into contact with the housing 20. The heat sink 20 is caused to move from a disengaged position (as see in Fig. 3) in which the heat sink 20 is spaced from the housing 12, to an engaged position (as seen in Figs. 1 and 2) in which the heat sink 20 is in contact with the housing 12. Typically, the movement of the chassis 16 is along a longitudinal axis 50 of the housing 12.

[0034] When the heat sink 20 is in the engaged position, a thermal conduction pathway is provided from the electronics assembly 18 to the housing 12 via heat sink 20, and in this example, via the chassis 16 too. Together, these elements may form a heat transfer arrangement 22.

[0035] The heat transfer potion 20 may be formed from a heat-conductive material, such as a metal and/or a material comprising one or more metallic elements. The housing 12 may be formed from a heat-conductive material, such as a metal and/or a material comprising one or more metallic elements. Accordingly, the thermal conduction pathway may be a direct metal-to-metal conductive thermal path. Importantly, the components of the subsea electronic apparatus 10 along the thermal conduction pathway between the at least one electronic component 18 and an external surface of the housing 12 must be sufficiently thermally conductive to allow enough excess heat to pass from the at least one electronic component 18 to the external surface of the housing 12 and out to the external environment to substantially prevent, or reduce the likelihood of damage to the at least one electronic component 18 caused by the excess heat.

[0036] An advantage of such embodiments is that the heat sink 20 automatically moves into the engaged position, where the thermal conduction pathway is provided, by insertion of the chassis 16 into the housing 12. Whilst the heat sink 20 is spaced from the housing 12 in the disengaged position, the chassis 16 can be easily inserted into the housing 12 with reduced or substantially eliminated chances of undesirably contacting edges of the heat sink 20 with the housing 12.

[0037] Fig. 1 includes detail 'A', which is bounded by a rectangular box, and which is shown on a greater scale in Fig. 2. Fig. 2 shows part of the subsea electronic apparatus 10, such that the heat transfer arrangement 22 can be viewed in more detail.

[0038] The chassis 16 comprises a engagement member 30 in this example. The heat 20 sink 20 is shown to be adjacent the engagement member 30. The engagement member 30 is configured to be slidable in the longitudinal direction relative to a portion of the chassis 16 between the at least one electronic component 18 and the heat sink 20.

[0039] In this example, the engagement member 30 comprises a first resiliently deformable member 34, in the form of a first spring 34, such as a die-spring 34. The engagement member 30 further comprises a stopper member 36, in the form of a set screw 36, formed as an M12 set screw 36 and an engagement protrusion 40, in the form of an engagement pin 40, having a transverse flange 41. Here, the set screw 36 is positionally secured within the engagement member 30, whilst the engagement pin 40 is moveable relative thereto.

[0040] The first spring 34 extends between the transverse flange 41 of the engagement pin 40, and the set screw 36. In this example, the first spring 34 is pre-compressed. In other words, an equilibrium length of the first spring 34 is greater than a distance between the set screw 36 and the transverse flange 41, such that the first spring 34 exerts an outward longitudinal force on the set screw 36 and on the transverse flange 41. During assembly, the position of the set screw 36 can be varied to control an amount of force applied by the first spring 34 to the transverse flange 41 of the engagement pin 40.

[0041] The first spring 34 is configured to bias the engagement pin 40 outwards with respect to the engagement member 30. Thus, the engagement pin 40 may be referred to as spring-loaded in this example.

[0042] Also provided in the presently described example is a second resiliently deformable member, in the form of a second spring 38, and a third resiliently deformable member 19, in the form of a third spring 19 (shown in Fig. 1). The second spring 38 is provided between the heat sink 20 and the engagement member 30, in particular between the heat sink 20 and the set screw 36 of the engagement member 30. The third spring 19 is provided between the heat sink 20 and a portion of the chassis 16 adjacent the heat sink 20 and opposite the second spring 38. Together, the second spring 38 and the third spring 19 can help to stabilise the heat sink 20 with respect to the chassis 16 and/or the engagement member 30, such that the heat transfer portion can remain substantially aligned with a longitudinal axis of the housing 12 when it is moved relative to the housing 12 between the engaged position and the disengaged position. Furthermore, one or both of the second spring 38 and the third spring 19 can urge separation between the heat sink and one or both of the engagement member 30 and the portion of the chassis 16 adjacent the heat sink 20 and opposite the engagement member 30 in the longitudinal direction. In this way, the heat sink 20 can be free to move away from the engaged position to facilitate insertion of the chassis 16 into the housing 12 when the heat sink 20 is in the disengaged position.

[0043] The engagement member 30 and the heat sink 20 each define an inclined surface in this example, formed as a wedge face 32. Here, the wedge faces 32 are configured to be in mutual contact, such that movement of the engagement member 30 relative to the heat sink 20 in the longitudinal direction, for example during insertion of the chassis 16 into the housing 12, causes movement of the heat sink 20 towards the housing 12 in a direction transverse to the longitudinal direction.

[0044] The housing 12 defines an internal engagement region 11, formed as a shoulder of the inner wall 13 of the housing 12. An abutment face 42 of the engagement pin 40 is configured to abut the engagement region 11 when the heat sink 20 is to move from the disengaged position to the engaged position (as shown in Fig. 2) during insertion of the chassis 16 into the housing 12. Thus, in this example, the housing 12 is wider in a region from the internal engagement region 11 towards the insertion opening 15 compared to a region of the housing inward from the internal engagement region 11, away from the insertion opening 15.

[0045] In this example, the heat sink 20 is secured relative to the chassis 16 before the chassis 16 is inserted into the housing 12. This prevents separation of the heat sink 20 from the chassis 16 during and immediately prior to insertion of the chassis 16 into the housing 12.

[0046] An exemplary use of the aforedescribed apparatus will now be discussed. Immediately before the chassis 16 is inserted longitudinally into the housing 12, the heat sink 20 is initially in the disengaged position, as shown in Fig. 3. The heat sink 20 is not in contact with the housing 12 in the disengaged position, and does not extend outwardly from the chassis 16 a sufficient distance to contact the housing if inserted substantially centrally within the housing 12. The transverse flange 41 of the engagement pin 40 is in contact with the end of the engagement member 30. The abutment face 42 of the engagement pin 40 is initially spaced away from the engagement region 11 of the housing 12.

[0047] As the chassis 16 is inserted into the housing 12, the abutment face 42 of the engagement pin 40 comes into contact with the engagement region 11 of the housing 12, as shown in Fig. 2. Depending on the relative resistances in the system, the transverse flange 41 is pushed away from the end of the engagement member 30, and/or the engagement member 30 is moved longitudinally along the chassis 16 towards the heat sink 20.

[0048] Movement of the transverse flange 41 away from the end of the engagement member 30 causes the first spring 34 to undergo further compression and exert a corresponding force against the set screw 36. This force acts to move (or further move) the engagement member 30 longitudinally with respect to the chassis 16 towards the heat sink 20. The wedge face 32 of the engagement member 30 slides with respect to that of the heat sink 20. This moves the heat sink 20 towards the housing 12, and away from the engagement member 30, forcing the heat sink 20 into contact with the housing 12. The second and third resilient members 38 and 19 stabilise the heat sink 20 with respect to the chassis 16, such that the heat sink 20 remains substantially aligned with the longitudinal axis 50 of the housing 12 when it is moved towards the housing 12, as described hereinbefore. The second and third resilient members 38, 19 may also help to ensure evenly-distributed contact between the outer surface of the heat sink 20, and the housing 12. In this way, it can be understood that the heat sink 20 is moved from the disengaged position to the engaged position on insertion of the chassis 16 into the housing 12.

[0049] The arrangement of the subsea electronic apparatus 10 in the form of the SEM 10 as described hereinbefore takes advantage of the environment that SEMs are operated in, that is to say within a liquid environment (such as seawater or dielectric oil) to effectively transfer heat away from the at least one electronic component provided in the SEM. The excess heat is subsequently transferred from the housing 12 to the surrounding environment.

[0050] A further advantage of at least some of the hereinbefore described examples is a reduced need for having access to the housing from both sides. Consequently, this reduces the number of parts and/or seals required. It is henceforth suitable for 'seawater washed' Subsea Electronic Modules (SEMs) where more than one lid is not typically permitted.

[0051] A further advantage of at least some of the hereinbefore described examples is that a large cross-section of the thermal conductive path is provided, capable of a relatively high rates of thermal conductivity.

[0052] A further advantage of at least some of the hereinbefore described examples includes that there is a relatively low variation in radial forces exerted on the heat sink 20 when the subsea electronics apparatus 10 is assembled. This helps to ensure a good degree of thermal conduction, even when the dimensions of the various interfaces vary (e.g. engagement pin length, housing diameter, concentricity of the chassis with the housing etc). The manufacturing tolerances can therefore be more lenient, lowering manufacturing costs. In particular, the longitudinal dimensions can vary to a greater extent whilst still retaining the engagement pin 40 in place in the engagement member 30, and ultimately ensuring thermal contact between the heat sink 20 and the housing 12 in the engaged position.

[0053] Fig. 4 shows a sectional view of the subsea electronic apparatus 10 in the disengaged position. In at least some of the hereinbefore described examples, the chassis 16 is provided with at least one disengagement member 61, which is typically configured to cause the heat sink 20 to be moved away from the engagement member 30 during removal of the chassis 16 from the housing 12. A second disengagement member 62 may also be provided, which is typically configured to cause the engagement member 30 to move with the chassis 16 out of the housing 12 during removal of the chassis 16 from the housing 12.

[0054] In this example, the first and second disengagement members comprise first and second disengagement surfaces 61, 62 for contacting with the heat sink 20 and the engagement member 30 respectively. The first and second disengagement surfaces 61, 62 are typically longitudinally separated. Here, longitudinally separated is used to mean that the respective components are typically spaced away from each other along a longitudinal axis such as the primary longitudinal axis 50. Furthermore, the first disengagement surface 61 is typically spaced from the heat sink 20 when the chassis 16 is fully inserted into the housing 12 and the heat sink 20 is provided in the engaged position.

Yet further, in this example, in the engaged position of the heat sink 20, the first disengagement surface 61 is spaced from a region of the heat sink 20 to be contacted by the first disengagement surface 61 by a first distance less than a second distance by which the second disengagement surface 62 is spaced from a region of the engagement member 30 to be contacted by the second disengagement surface 62.

[0055] An exemplary use of the aforedescribed apparatus will now be discussed. The first disengagement surface 61 of the chassis 16 is initially longitudinally separated from a proximal end of heatsink 20, closest to the engagement member 30. A distal end of the heat sink 20, furthest from the engagement member 30, is initially in contact with the chassis 16. During disassembly of the subsea electronic apparatus 10, the chassis 16 is to be removed from the housing 12. At first, the chassis 16 moves with respect to the engagement member 30 and the heat sink 20, and the heat sink 20 remains in the engaged position, e.g. in contact (for example pressed) against the housing 12.

[0056] As the chassis 16 begins to move out of the housing 12, the chassis 16 moves away from the distal end of the heat sink 20, until the first disengagement surface 61 engages with the proximal end of the heat sink 20. Continued removal of the chassis 16 from the housing 12 causes the heat sink 20 to start to move with the chassis 16. Thus, the heat sink 20 is separated from the engagement member 30, such that the respective inclined surfaces defined on the heat sink 20 and the engagement member 30 move away from each other, and the heat sink 20 is able to disengage with the inner wall of the housing 12. Thereafter, the heat sink 20 continues to move out of the housing 12 together with the chassis 16.

[0057] After the chassis 16 has moved yet further out of the housing 12, the second disengagement surface 62 engages the engagement member 30, causing the engagement member 30 to start to move out of the housing 12. Therefore, the engagement member 30 moves towards the outside of the housing 12 together with the chassis 16 and the heat sink 20. Thus, the chassis 16, the heat sink 20 and the engagement member 30 are removed from the housing 12.

[0058] Advantageously, the first disengagement region 61 may be configured to relieve the radial pressure exerted between the heat sink 20 and the housing when the heat sink is provided in the engaged position. This can avoid the need to apply substantial force to the engagement member 30 to remove the heat sink 20, which would typically act to increase the radial pressure on the heat sink 20. In this way, the force required to remove the chassis 16 from the housing 12 can be reduced, therefore improving the ease of disassembly of the apparatus 10.

[0059] At least one second or further heat transfer portion 20' may also be provided in embodiments, disposed elsewhere between the chassis 16 and the housing, such as on an opposite side of the chassis 16 to the first heat transfer portion 20, as part of a second or further heat transfer assembly 22' (shown in Fig. 1). Any further heat transfer assemblies are constructed in a similar manner to the first heat transfer assembly 22 described hereinbefore, and will not be described further to omit repetition. The provision of one or more further heat transfer assemblies can help to increase the rate of heat transfer from the electronics assembly 18 to the outside of the housing 12.

[0060] In some examples, the engagement pin 40 is biased by the first spring 34 to move outwardly with respect thereto. The action of the force of the spring-loaded engagement member 40 may increase the ease of removal of the chassis 16 from the housing 12, due to a degree of automatic ejection upon release of the endplate 14 allow the heat sink 20 to move away from the engaged position.

[0061] In at least some of the hereinbefore described examples, when the heat transfer portion 20 is moved relative to the chassis 16 into the engaged position, it is moved into a press fit, for example an interference fit, with the housing 12 and/or it is urged against the housing 12. The resulting radial force outwards to the housing 12 from the chassis 16 via the heat sink 20 can be used to substantially strengthen the assembly of the chassis 16 in the housing. In particular, this arrangement has been found to constrain the chassis 16 from twisting inside the housing 12, and can reduce or even prevent bending of the chassis 16 when assembled in the housing 12. In this way, shock and/or vibrational force applied to the subsea electronic apparatus 10 does not result in excessive shock and/or vibrations of the chassis 16. In the disengaged position, the heat transfer portion 20 may not interfere with the housing 12 and/or may not be urged against the housing 12.

Advantageously, this frictional force may be difficult to overcome, which assists in binding together and/or maintaining thermal contact between the heat transfer portion 20 and the housing 12.

[0062] In summary, there is provided a subsea electronic apparatus (10) comprising a housing (12); a chassis (16) for insertion in a longitudinal direction through an insertion opening (15) defined in the housing (12), the chassis (16) having at least one electronic component (18) mounted thereto; and a heat transfer portion (20) configured to be in thermal contact with the at least one electronic component (18) to transfer, in use, heat away from the at least one electronic component (18) via the heat transfer portion (20). The heat transfer portion (20) is configured to be caused to move relative to the chassis (16), by insertion of the chassis (16) into the housing (12), from a disengaged position spaced from the housing (12) to an engaged position in contact with the housing (12).

When the heat transfer portion (20) is in the engaged position, a thermal conduction pathway is provided from the at least one electronic component (18) to the housing (12) via the heat transfer portion (20).

[0063] Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of them mean "including but not limited to", and they are not intended to (and do not) exclude other components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[0064] Features, integers, characteristics, or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

CLAIMSA subsea electronic apparatus comprising: a housing; a chassis for insertion in a longitudinal direction through an insertion opening defined in the housing, the chassis having at least one electronic component mounted thereto; and a heat transfer portion configured to be in thermal contact with the at least one electronic component to transfer, in use, heat away from the at least one electronic component via the heat transfer portion, wherein the heat transfer portion is configured to be caused to move relative to the chassis, by insertion of the chassis into the housing, from a disengaged position spaced from the housing to an engaged position in contact with the housing, and wherein when the heat transfer portion is in the engaged position, a thermal conduction pathway is provided from the at least one electronic component to the housing via the heat transfer portion.
2. The subsea electronic apparatus of claim 1, further comprising at least one resiliently deformable member configured to bias the heat transfer portion towards the disengaged position.
3. The subsea electronic apparatus of claim 1 or claim 2, wherein the heat transfer portion is configured to be in thermal contact with the at least one electronic component via the chassis.
4. The subsea electronic apparatus of any preceding claim, wherein the heat transfer portion is configured to be secured relative to the chassis before the chassis is inserted into the housing.
5. The subsea electronic apparatus of any preceding claim, wherein the housing defines an engagement region configured to be engaged during insertion of the chassis within the housing to cause movement of the heat transfer portion from the disengaged position to the engaged position.
6. The subsea electronic apparatus of any preceding claim, wherein at least one of the heat transfer portion and the chassis define at least one inclined surface to cause movement of the heat transfer portion towards the housing during insertion of the chassis within the housing in the longitudinal direction.
7. The subsea electronic apparatus of claim 6, wherein the movement of the heat transfer portion towards the housing is caused by movement between the at least one inclined surface and at least one of the heat transfer portion and the chassis.
8. The subsea electronic apparatus of claim 6 or claim 7, wherein the heat transfer portion and the chassis each define an inclined surface of the at least one inclined surface, configured to be in mutual contact, such that movement of the heat transfer portion relative to the chassis causes movement of the heat transfer portion towards the housing during insertion of the chassis within the housing.
9. The subsea electronic apparatus of any of claims 6 to 8, when dependent on claim 5, further comprising an engagement member configured to engage the engagement region during insertion of the chassis within the housing, and to engage with the heat transfer portion to cause movement of the heat transfer portion towards the housing during insertion of the chassis within the housing.
10. The subsea electronic apparatus of claim 9, wherein the engagement member and the heat transfer portion each define a further inclined surface of the at least one inclined surface, configured to be in mutual contact, such that movement of the heat transfer portion relative to the engagement member causes movement of the heat transfer portion towards the housing during insertion of the chassis within the housing.
11. The subsea electronic apparatus of claim 10, wherein the chassis is provided with a disengagement member configured to cause the further inclined surface of the heat transfer portion to be moved at least partially away from the further inclined surface of the engagement member during a first portion of removal of the chassis from the housing.
12. The subsea electronic apparatus of claim 11, wherein the disengagement member is spaced from the heat transfer portion when the heat transfer portion is in the engaged 25 position.
13. The subsea electronic apparatus of claim 11 or claim 12, wherein the chassis is further provided with a further disengagement member configured to cause the engagement member to be moved away from the engagement region during a second portion of removal of the chassis from the housing, subsequent to the first portion of removal of the chassis from the housing.
14. The subsea electronic apparatus of any of claims 9 to 13, when dependent on claim 2, wherein the engagement member comprises a first resiliently deformable member of the at least one resiliently deformable member.
15. The subsea electronic apparatus of claim 14, wherein the first resiliently deformable member is provided by a first spring and is configured to be provided in a partially-compressed configuration in the engagement member, and to urge an engagement pin of the engagement member outwardly towards the engagement region during insertion of the chassis within the housing.
16. The subsea electronic apparatus of claim 15, comprising a second resiliently deformable member arranged to urge the engagement member away from the heat transfer portion in a direction parallel to the longitudinal direction and a third resiliently deformable member arranged to urge the heat transfer portion away from the chassis in the direction parallel to the longitudinal direction.
17. The subsea electronic apparatus of any preceding claim, wherein the at least one electronic component comprises at least one processor.
18. The subsea electronic apparatus of any preceding claim, further comprising an endplate configured to be secured to the housing to cover the insertion opening and to secure the chassis within the housing.
19. A subsea electronic device assembled from a subsea electronic apparatus of any preceding claim, wherein the chassis is inserted within the housing.