TRANSOM BRACKET WITH WATER PICK-UP FUNCTION

Abstract

A transom bracket for mounting a marine drive unit to the hull of a marine vessel is provided The transom bracket extends in a plane spanned by a first axis and by a second axis, where a third axis is normal to the plane, and where a center line of the transom bracket extends in the plane and parallel to the first axis. The transom bracket includes at least one drive unit support for holding the drive unit in position. The transom bracket includes a first water conduit and a second water conduit integrated in the transom bracket, where the first water conduit and the second water conduit extend from respective upper apertures formed in an upper part of the bracket to respective lower apertures formed in a lower part of the bracket, where the lower apertures are separated from each other by the center line.

Claims

1. A transom bracket for mounting a marine drive unit to the hull of a marine vessel, the transom bracket extending in a plane spanned by a first axis and by a second axis, where a third axis is normal to the plane, and where a center line of the transom bracket extends in the plane and parallel to the first axis, the transom bracket comprising at least one drive unit support for holding the drive unit in position, the transom bracket comprising a first water conduit and a second water conduit integrated in the transom bracket, where the first water conduit and the second water conduit extend from respective upper apertures formed in an upper part of the bracket to respective lower apertures formed in a lower part of the bracket, where the lower apertures are separated from each other by the center line.

2. The transom bracket according to claim 1, where the center line is a symmetry line of the lower apertures about the first axis.

3. The transom bracket according to claim 1, where the first water conduit and the second water conduit extend symmetrically about the center line.

4. The transom bracket according to claim 1, where the first water conduit and/or the second water conduit comprises an adjustable length portion arranged in connection to the respective lower aperture.

5. The transom bracket according to claim 4, where the adjustable length portion is a telescopic member or a portion that extend out from the bracket and that can be cut to a desired length measured along the first axis.

6. The transom bracket according to claim 1, where at least one drive unit support encloses an aperture facing transversal to the plane.

7. The transom bracket according to claim 1, where the upper apertures of the first and second water conduits are arranged facing transversal to the plane.

8. The transom bracket according to claim 1, where the lower apertures of the water conduits are arranged facing in direction of the first axis.

9. The marine drive unit assembly according to claim 1, where at least one of the first and second water conduits has an at least partly non-circular cross section.

10. A marine drive unit assembly comprising a transom bracket according to claim 1, a drive unit supported by the transom bracket, and a water pump, where the drive unit is arranged to be tilted from a nominal position where at least part of the drive unit is submerged in water to an up-tilted position where at least a propeller arrangement of the drive unit is above water, where the first water conduit, the second water conduit, and the water pump forms part of a cooling circuit operable to transfer water via at least one of the first and second water conduits when the drive unit is in the nominal position and also when the drive unit is in the up-tilted position.

11. The marine drive unit assembly according to claim 10, where the water pump and the drive unit are separated by the plane.

12. The marine drive unit assembly according to claim 10, where the cooling circuit comprises a first sub-circuit extending via an electrical energy storage comprised in the marine drive unit assembly.

13. The marine drive unit assembly according to claim 12, where the electrical energy storage and the drive unit are separated by the plane.

14. The marine drive unit assembly according to claim 10, where a second sub-circuit of the cooling circuit passes via an electric machine comprised in the drive unit.

15. The marine drive unit assembly according to claim 14, where the cooling circuit comprises a valve arrangement configurable to exclude the electric machine from the cooling circuit when the drive unit is in the up-tilted position.

16. A marine vessel comprising a marine drive unit assembly according to claim 1.

17. A marine drive unit assembly comprising a drive unit, a transom bracket for mounting the drive unit to a hull of a marine vessel, and a water pump, the transom bracket extending in a plane spanned by a first axis and by a second axis, the transom bracket comprising a first water conduit and a second water conduit integrated in the transom bracket, where the first water conduit and the second water conduit extend from respective upper apertures formed in an upper part of the bracket to respective lower apertures formed in a lower part of the bracket, where the drive unit is arranged to be tilted from a nominal position where at least part of the drive unit is submerged in water to an up-tilted position where the drive unit is above water, where the first water conduit, the second water conduit, and the water pump forms part of a cooling circuit operable to transfer water via the first and second water conduits when the drive unit is in the nominal position and also when the drive unit is in the up-tilted position.

18. A marine vessel comprising a marine drive unit assembly according to claim 17.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Examples are described in more detail below with reference to the appended drawings.

[0017] FIG. 1 illustrates an example transom-mounted marine drive unit;

[0018] FIG. 2 shows an example marine drive unit in nominal position;

[0019] FIG. 3 shows an example marine drive unit in up-tilted position;

[0020] FIGS. 4A-B show an example transom bracket with dual water conduits;

[0021] FIG. 5 schematically illustrates water conduits integrated in a transom bracket;

[0022] FIG. 6 illustrates details of a water conduit in an example transom bracket;

[0023] FIG. 7 illustrates an example single drive unit mounting example;

[0024] FIG. 8 illustrates an example twin drive unit mounting example;

[0025] FIGS. 9A-B illustrate example fastening option arrays formed in a transom bracket;

[0026] FIG. 10 schematically illustrate geometrical aspects of a transom bracket sealing region;

[0027] FIG. 11 shows an example cutout geometry associated with a transom bracket;

[0028] FIG. 12 shows a first transom bracket adjustment example;

[0029] FIG. 13 shows a second transom bracket adjustment example; and

[0030] FIG. 14 illustrates details of a transom bracket sealing arrangement.

DETAILED DESCRIPTION

[0031] The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practice the disclosure.

[0032] FIG. 1 shows a marine vessel 100 with a drive unit 110 mounted to the transom of a hull 120. A transom bracket 130, sometimes referred to as a transom shield, holds the drive unit 110 in position on the hull 120. The drive unit 110 comprises a propeller arrangement 140 which provides thrust that propels and often also steers the vessel 100. The thrust generated by the propeller arrangement 140 is transferred to the hull 120 via the transom bracket 130. Hence, it is important that the transom bracket has sufficient mechanical strength in order to withstand the forces involved. A marine vessel may generally comprise one or more drive units, that comprise one or more propeller arrangements. The drive unit 110 comprises a main power source, such as an electric machine 150, which powers the propeller arrangement 140.

[0033] A set of reference axes x, y, z will be used herein to describe various geometrical relationships. The x-axis is a longitudinal axis extending in the forward direction of the hull. The y-axis is a lateral axis perpendicular to the x-axis. The z-axis is a vertical axis normal to a plane spanned by the x and y axes.

[0034] The drive unit 110 forms part of a drive unit assembly 101 which normally also comprises a cooling system to control temperatures of the various components of the drive unit assembly 101. The cooling system comprises a water pump 160 configured to pump water through a cooling circuit. The cooling circuit normally comprises one or more cooling media sub-circuits that exchange heat with the sea or lake water pumped by the water pump 160. The sub-circuits can be configured to cool the main power source 150 and optionally also an electric energy storage 170 of the vessel 100. Both the water pump 160 and the electric energy storage 170 of the vessel 100 are schematically illustrated in FIG. 1. The electrical energy storage 170 and the drive unit 110 are normally located on separate sides of the transom, i.e., separated by the plane P shown in FIG. 1, although some drive units also support an integrated electrical energy storage. Water pumps are well known and will therefore not be discussed in more detail herein. Electrical energy storage systems, such as battery banks, are also well known in the art and will therefore not be discussed in more detail herein.

[0035] More than one electric machine 150 is of course an option, as well as more than one water pump 160 and/or more than one electrical energy storage 170.

[0036] FIG. 2 illustrates an example drive unit 110 in a nominal operating position 200 where the propeller arrangement 140 is positioned under the water surface and operable to propel the vessel 100.

[0037] The drive unit 110 is pivotably supported by a first support member 230 and by a second support member 240, which are attached to respective drive unit supports on the transom bracket 130. These drive unit interfaces may, e.g., comprise bolt holes or the like. The first support member 230 and/or the second support member 240 may also be integrally formed with the transom bracket 130.

[0038] This particular drive unit 110 is pivotable about a first pivot axis y.sub.1 and also about a second pivot axis y.sub.2 that is spatially offset from the first pivot axis y.sub.1 along the z-axis. Pivoting by the drive unit 110 about the second pivot axis y.sub.2 may be used for trim of the thrust elevation angle of the propeller arrangement 140, while pivoting about the first pivot axis y.sub.1 can be used for tilting the drive unit 110 into an up-tilted position. Pivoting about both the first pivot axis y.sub.1 and about the second pivot axis y.sub.2 may be used to reduce the draught of the drive unit 110, i.e., to position the propeller arrangement 140 close to the water surface. To operate the drive unit 110 at reduced draught, it is pivoted counter-clockwise about the first pivot axis y.sub.1 in FIG. 2 and clockwise above the second pivot axis y.sub.2 in FIG. 2. This moves the propeller arrangement 140 rearwards and upwards to the position of reduced draught, while maintaining the horizontal propeller axle 210 at least approximately horizontal. It is an advantage that the transom bracket supports operation at reduced draught.

[0039] FIG. 3 illustrates an example drive unit 110 in up-tilted position 300, where the drive unit 110 has been moved 310 to a position above water. This position is commonly used as storage position since no biofouling occurs when the drive unit is up-tilted and above water.

[0040] Conventional marine drive units normally comprise water conduits for cooling that are integrated in the drive unit, and that open up in lower apertures in vicinity of the propeller arrangement, such as on the propeller side of the cavitation plate 220. These lower apertures are submerged in the nominal position but will be above water in the up-tilted position. This is a problem in case of an electric drive line which comprises an electrical energy storage 170 in need of cooling also when the drive unit 110 is in the up-tilted position 300. Cooling of the electrical energy storage system 170 may, e.g., be required during charging, and in case of high ambient temperatures. A functional sea-water intake may also be required by other auxiliary equipment on the vessel 100, during periods when the drive unit 110 is in the up-tilted position 300. Some of the transom brackets discussed herein solve this issue by integrating the water intake in the transom bracket, where it is operable also when the drive unit 110 is in the up-tilted position 300.

[0041] FIGS. 4A and 4B illustrate an example transom bracket 130 for mounting a marine drive unit 110 to the transom part of a hull 120 of a marine vessel 100, such as the marine vessel illustrated in FIGS. 1-3. The various aspects of the transom brackets disclosed herein will be illustrated using a single example. It is, however, appreciated that the different transom bracket features disclosed herein can be applied more generally to different types of transom brackets arranged to support diverse types of drive units.

[0042] The transom bracket 130 extends in a plane P, as illustrated in FIG. 1 and in FIG. 2. The plane P is spanned by a first axis a.sub.1 and by a second axis a.sub.2. A third axis a.sub.3 is normal to the plane P, and a center line 440 of the transom bracket 130 extends in the plane P and parallel to the first axis a.sub.1.

[0043] The first axis a.sub.1 and the second axis a.sub.2 are generally pivoted relative to the reference axes z, y in FIG. 1, but are often at least approximately vertical and horizontal, respectively, depending on the geometry of the hull transom. The first axis a.sub.1 is directed upwards on the transom when the transom bracket 130 is mounted, and the second axis a.sub.2 is directed laterally across the transom from the starboard side to the port side when the transom bracket 130 is mounted.

[0044] The transom bracket 130 comprises at least one drive unit support 450, 460 for holding the drive unit 110 in position. In the illustrated examples this drive unit support has an upper part 450 and a lower part 460. The lower part may be used to support a tilt actuator as illustrated in FIG. 2, while the upper part 450 may be used to pivotably support the drive unit 110. It is noted that the upper drive unit supports 450 enclose apertures 470, 471 that extend through the transom bracket 130, across the plane P. These apertures can be used to route media from inside the hull to the drive unit 110. The media can then pass via a pivot axle of the drive unit.

[0045] According to a more general teaching, one or more apertures 470, 471 of the transom bracket 130 can be arranged facing transversal to the plane P, in direction of the third axis a.sub.3 or angled relative to the third axis a.sub.3, and formed inside at least one of the drive unit supports 450, 460. This aperture or apertures allow a harness, such as an electrical harness or part of a hydraulic connection to pass from inside the hull to the drive unit through the transom bracket in an efficient manner. The upper apertures 411, 421 of the first and second water conduits 410, 420 in this example are arranged facing in direction of a third axis a.sub.3 transversal to the plane P. i.e., towards the interior of the vessel 100 but not necessarily in parallel with the third axis a.sub.3, and the lower apertures are arranged facing in direction of the first axis a.sub.1. i.e., towards the water. At least one of the first and second water conduits 410, 420 optionally has a non-circular cross section. The non-circular cross section allows for a larger cross section area in cases where the thickness of the transom bracket (direction of a third axis a.sub.3) is limited.

[0046] The transom bracket 130 comprises a first water conduit 410 and a second water conduit 420 integrated in the transom bracket 130. The first water conduit 410 and the second water conduit 420 extend from respective upper apertures 411, 421 formed in an upper part 401 of the bracket 130 to respective lower apertures 412, 422 formed in a lower part 402 of the bracket 130. The upper apertures 411, 421 are here angled to face in direction of the third axis a.sub.3 while the lower apertures face downwards along the first axis a.sub.1. This simplifies installation and improves the capability of the water conduit to take in water. However, both the upper apertures and the lower apertures can be angled differently compared to the example in FIG. 4A. Both water conduits 410, 420 here extend downwards along straight parallel lines. This is also not necessary, both water conduit can have different extension paths, not necessarily symmetric.

[0047] Herein, upper and lower refer to relative positions with respect to the first axis a.sub.1. Hence, the lower part 402 of the bracket 130 is closer to the water in use compared to the upper part 401 of the bracket. The lower apertures 412, 422 are separated from each other by a center line 440 indicated in FIG. 4B. The center line 440 is a line that lies in the extension plane P of the transom bracket, and which divides the transom bracket into two parts in direction of the first axis a.sub.1. These two parts may be of equal extension length along the second axis a.sub.2. i.e., the center line 440 may divide the transom bracket into two halves a port side and a starboard side. The two halves need not be exactly equal in size, although the center line 440 in the illustrated examples is a symmetry line of the transom bracket 130. The center line 440 is preferably a symmetry line of at least the lower apertures 412, 422 about the first axis a.sub.1. The first water conduit 410 and the second water conduit 420 may extend symmetrically about the center line 440, although this is not necessary for the sea water intake functions discussed herein.

[0048] According to preferred aspects, the first water conduit 410 and the second water conduit 420 are intersected by the plane P. and a symmetry line 440 of the first and second water conduits 410, 420 extends in the plane P in parallel with the first axis a.sub.1 at the center of the transom bracket, as illustrated in FIG. 4B and more schematically in FIG. 5. Any of the first water conduit 410 and the second water conduit 420 can be arranged as intake channel for the cooling circuit, and the other is then arranged as discharge channel. This is primarily advantageous in installations comprising more than one drive unit, such as in twin drive unit installations or quad drive unit installations. Since the water channel located closest to the water in use can be selected as the water intake in a convenient manner, without changes to the transom bracket. The same transom bracket can also be used on the starboard side and on the port side which is an advantage. Installations comprising three or more drive units also benefit from this feature of having integrated water conduits with lower apertures separated by the transom bracket center line 440. A twin drive unit installation will be discussed below in connection to FIG. 8.

[0049] At least one out of the first water conduit 410 and the second water conduit 420 can be configured with an adjustable length portion 430 arranged in connection to the respective lower aperture 412, 422 of the water conduit as illustrated in FIG. 6. The adjustable length portion 430 may, e.g., be a telescopic member or a portion that can be cut to a desired length in a convenient manner by the boat builder. The adjustable length portion may be extendible 600 in direction of the first axis a.sub.1, as illustrated in FIG. 6, or in some other downwards direction. The adjustable length portion can be used with advantage to match a water intake location to the hull shape as the transom bracket is adjusted along the first axis a.sub.1 as will be discussed in more detail below.

[0050] FIG. 7 illustrates a mounting example 700 where a single drive unit is to be mounted to the transom of the marine vessel. In this case the transom bracket 130 is centered on the transom, and the lower apertures 412, 422 are at equal distances from the water level W in use (which will follow the lower contour of the hull when the vessel is planing). Any of the first and second water channels can be selected as water intake 710 and water discharge 720. The selection may, e.g., be made based on other design considerations, such as the geometry of the cooling circuit inboard (on the other side of the plane P).

[0051] FIG. 8 illustrates a twin drive mounting example 800 where two drive units are to be mounted to the transom of the marine vessel 100. In this case the lower apertures 412, 422 of the first and second water conduits 410, 420 at the two brackets 130a, 130b are at different distances from the water level W in use. The port bracket has its left water conduit lower aperture closer to the water surface while the starboard bracket has its right water conduit lower aperture closer to the water surface. It is therefore advantageous to choose different water conduits as water intake 710 and discharge 720 at the two brackets, where the water conduit with lower aperture closest to the water level W in use is selected as water intake and the other as water discharge.

[0052] There is also disclosed herein a marine drive unit assembly 101 that is based on the transom bracket 130 discussed above. The marine drive unit assembly comprises a drive unit 110 supported by the transom bracket 130, and a water pump 160. The drive unit 110 is arranged to be tilted from a nominal position 200 where at least part of the drive unit 110 is submerged in water as shown in FIG. 2 to an up-tilted position 300 where at least a propeller arrangement 140 of the drive unit 110 is above water, as illustrated in FIG. 3. The first water conduit 410, the second water conduit 420, and the water pump 160 forms part of a cooling circuit operable to transfer water via at least one of the first and second water conduits 410, 420 when the drive unit 110 is in the nominal position 200 and also when the drive unit 110 is in the up-tilted position 300. One out of the first water conduit 410 and the second water conduit 420 can be arranged as water intake and the other arranged as water discharge. The water intake aperture will remain submerged regardless of tilt position of the drive unit which is an advantage compared to drive unit assemblies that integrate water conduits in the drive unit lower part that is raised above the water line in the up-tilted position 300. Hence, the cooling function of the cooling circuit is not lost when moving the drive unit 110 into the up-tilted position 300, which is an advantage. For instance, the electrical energy storage component 170 can receive cooling during charging even though the drive unit 110 is in the up-tilted position when charging.

[0053] The cooling circuit optionally comprises a first sub-circuit extending via the electrical energy storage 170 comprised in the marine drive unit assembly 101 such that the temperature of the electrical energy storage 170 can be regulated. A second sub-circuit of the cooling circuit may pass via the electric machine 150 comprised in the drive unit 110 in order to cool the electric machine in use. The cooling circuit may also comprise a valve arrangement configurable to exclude the electric machine 150 from the cooling circuit when the drive unit 110 is in the up-tilted position 300. This way the cooling pump 160 does not need to pump cooling media via the electric machine 150 in case the electric machine is up-tilted and not in use. It is noted that at least some aspects of the transom brackets discussed herein are applicable also together with more conventional combustion engine based drive units, and also with hybrid drive units that comprise both combustion engine and electric machine power sources.

[0054] The water pump 160 and the drive unit 110 can in some case be separated by the plane P. i.e., the water pump 160 can be arranged inboard while the drive unit 110 is outboard. In other examples the water pump 160 is integrated in the drive unit 110, i.e., separated from the vessel hull by the plane P. The electrical energy storage 170 and the drive unit 110 are normally separated by the plane P. i.e., the electrical energy storage 170 is normally located inboards while the drive unit is located outboards.

[0055] A boat builder often desires to adjust the position of the drive unit 110 along the z-axis, i.e., the vertical position of the drive unit 110. It may be challenging to optimize the position of the drive unit from computer simulations alone, even if the hull shape is known. Hence, some adjustment is often necessary after field trials. The optimal location of the drive unit or units may also depend on the boat configuration, i.e., its weight distribution and selected equipment options. To allow adjustment of the drive unit position on the transom in a convenient manner, there is disclosed herein a transom bracket 130 for supporting a marine drive unit 110 on a hull 120 of a marine vessel 100 that can be offset vertically by means of one or more fastening option arrays. A fastening option array is a selection of fastening options that the boat builder can choose from in order to position the transom bracket 130 at least vertically on the transom. FIG. 9A illustrates an example transom bracket 130 with fastening option arrays in the form of bolt-hole arrays that extend over a translation distance d.sub.T measured along the first axis a.sub.1. The example bracket in FIG. 9B has two apertures (indicated as checkered regions). The boatbuilder can offset the transom bracket 130 vertically 930 by selecting one of the fastening options in the arrays, i.e., in this case one of the bolt holes in the line of bolt holes. FIG. 9B schematically illustrates another example 950 where vertical slots have been formed in the transom bracket, with clamping devices 960 that are operable to lock the transom bracket in a desired vertical position. The slots may be complemented by matching surface shapes on the transom bracket and on the transom, such as a saw-tooth pattern on the like in order to better hold the transom bracket in position. A fastening option array 480 can be realized in many different ways. It is, generally, configured to allow offset of the transom bracket 130 relative to the hull 120 along the first axis a.sub.1 by the translation distance d.sub.T. The transom brackets 130 discussed herein preferably comprise at least one such fastening option array 480 extending over the translation distance d.sub.T measured along the first axis a.sub.1. The fastening option array geometries are preferably identical to each other, which means that a boat builder or other technician wishing to adjust the location of the drive unit on the transom can select an alternative fastening option in the fastening option array. The fastening option arrays may in some cases extend along both the first axis a.sub.1 and the second axis a.sub.2, although the examples in the Figures only show extension along a straight line parallel to the first axis a.sub.1. An array of bolt holes is a fastening option array, so is an array of bolts fixed to the transom bracket. The array of fastening options may also comprise a slot extending along the first axis as exemplified in FIG. 9B, possibly with some form of structure to provide friction in the vertical direction, such as a saw-tooth structure.

[0056] The transom bracket 130 comprises one or more apertures 411, 421, 470, 471 as discussed above, facing transversal to the plane P, and configured to route media such as electrical harness, hydraulic connections, and control signal interface cables (both mechanical and electrical), past the plane P to and from the marine drive unit 110, via a routing area R in the plane P. The routing area R extends over a routing area distance d.sub.R measured along the first axis a.sub.1. The routing area distance d.sub.R is illustrated schematically in FIG. 10, top, 1010. The routing area R is basically the required area in the plane P to pass all the necessary connections and conduits to and from the drive unit 110. A cutout geometry, i.e., a hole, is formed in the transom to pass the routing media. This cutout geometry extends over a cutout distance d.sub.C measured along the first axis a.sub.1. FIG. 11 shows an example hole formed in the transom that extends over the cutout distance d.sub.C. A seal has to extend by at least d.sub.C+d.sub.T on the transom bracket, measured along the first axis, in order to cover the cutout geometry extending over the cutout distance d.sub.C.

[0057] The transom bracket 130 comprises a sealing arrangement 920 that is exemplified in FIG. 9A. This sealing arrangement 920 is configured to seal against the hull 120 in direction of the third axis a.sub.3. The sealing arrangement 920 extends along the periphery of a sealing region S in the plane P. The sealing region S is arranged to define a region in the plane at least as large as to maintain the seal against the hull during translation of the transom bracket 130 along the first axis a.sub.1 by the translation distance d.sub.T.

[0058] The upper apertures 411, 421 of the first and second water conduits formed in the upper part 401 of the bracket 130 are preferably comprised in the sealing region S and the lower apertures 412, 422 formed in the lower part 402 of the transom bracket 130 are external to the sealing region S, as exemplified in FIG. 9A.

[0059] It is desired to be able to move the transom bracket 130 vertically on the transom by selecting a fastening option in the array or arrays, without reconfiguring the cutout geometry in the transom, i.e., without changing the position and dimension of the hole cut in the transom to route media to and from the drive unit 110.

[0060] According to a first option, lateral offset is made possible if the transom bracket 130 has apertures that span over a large enough distance along the first axis a.sub.1 to allow vertical offset of the transom bracket 130 without changing media position relative to the transom, as illustrated in FIG. 10 middle left 1020. The one or more apertures 411, 421, 470, 471 here define an aperture area A that extends over an aperture distance d.sub.A measured along the first axis a.sub.1, which aperture distance d.sub.A is larger than or equal to a sum of the routing area distance d.sub.R and the translation distance d.sub.T. i.e., d.sub.A>d.sub.R+d.sub.T. For all installations on all transoms, the transom bracket 130 is arranged offsetable over the routing area R along the first axis a.sub.1 by the difference between the aperture distance d.sub.T and the routing area distance d.sub.R, regardless of the cutout geometry in the transom. As the transom bracket is repositioned vertically, the routing media can in this case stay in place relative to the transom, since the apertures formed in the transom are large enough in the vertical dimension to support the repositioning off the transom bracket. This can be understood from FIG. 10 middle left 1020, where the dashed region A moves relative to the checkered regions as the transom bracket is offset vertically. In this case the sealing region S extends over a sealing distance d.sub.S measured along the first axis a.sub.1 that is at least as large as the sum of the routing area distance d.sub.R and the translation distance d.sub.T. Thus, regardless of the selection of fastening option in the fastening option array or arrays, the seal will seal the cutout geometry formed in the transom as well as the apertures of the transom bracket.

[0061] Vertical displacement of the transom bracket 130 over the translation distance d.sub.T with maintained sealing function by the sealing arrangement 920 can be achieved also if d.sub.A<d.sub.R+d.sub.T as long as the cutout geometry in the transom is adapted to allow vertical displacement, as illustrated in FIG. 10, middle right 1030. In this case the one or more apertures 411, 421, 470, 471 in the transom bracket 130 define an aperture area A that extends over an aperture distance d.sub.A measured along the first axis a.sub.1 that is smaller than a sum of the routing area distance d.sub.R and the translation distance d.sub.T. The transom bracket 130 is again arranged offsetable over the routing area R along the first axis a.sub.1 by the difference between the aperture distance d.sub.A and the routing area distance d.sub.R. A difference =d.sub.R+d.sub.Td.sub.A is what is missing to allow the vertical displacement, and this remainder has to be cut out from the transom, i.e., added to the cutout geometry formed in the transom to increase the cutout distance d.sub.C.

[0062] In other words, the cutout region in the transom needs a vertical extension length along the first axis of at least d.sub.C=d.sub.R+. This can be understood from the illustration in FIG. 10, middle right 1030. As the transom bracket 130 is offset vertically, the routing area R will first move vertically within the transom apertures (and not relative to the transom), but not all of the required translation distance d.sub.T. The routing are R will therefore have to be displaced relative to the transom, which means that it needs to move within the transom cutout also. The distance it needs to move inside the transom cutout is . In this case the sealing region S extends over a sealing distance d.sub.S measured along the first axis a.sub.1 that is at least as large as the difference between twice the sum of the routing area distance d.sub.R and the translation distance d.sub.T and the aperture distance d.sub.A, i.e., d.sub.S=2d.sub.R+2d.sub.Td.sub.A. This simplifies to d.sub.S=d.sub.R+2d.sub.T in case d.sub.R=d.sub.A.

[0063] The transom bracket 130 preferably comprises one or more fastening option arrays 480 arranged extending over a lateral fastening option array distance measured along the second axis a.sub.2. Although a single fastening option array could be possible, having more than one array improves the mechanical strength of the connection between transom bracket and drive unit. The sealing region S is arranged to define a region in the plane P at least as large as to maintain seal against the hull during translation of the transom bracket 130 along the second axis a.sub.2 by the lateral fastening option array distance.

[0064] At least one fastening option array 480 may extend along a straight line parallel to the first axis a.sub.1, as illustrated in FIG. 9A. The at least one fastening option array 480 may also comprise at least two bolt holes, and preferably five bolt holes. The bolt holes in the at least one fastening option array 480 are preferably separated by between 10-20 mm, and preferably 16 mm. At least four fastening option arrays 480, and preferably six fastening option arrays 480 hold the transom bracket in position relative to the transom.

[0065] At least one of the fastening option arrays 480 is preferably enclosed by the sealing region S, although one or more fastening option arrays 480 can also be located external to the sealing region S, as illustrated in FIG. 9A. At least one of the apertures 470, 471 may be elongated in direction of the first axis a.sub.1.

[0066] The sealing arrangement 920 may comprise a groove arranged to receive a replaceable sealing member. This is an advantage since a fresh seal can easily be mounted when the position of the bracket on the transom is changed. Thus, when changing the position of the drive unit on the transom, the bolts in the fastening option arrays are loosened and removed, whereupon the sealing member can be replaced and the transom mounted at another location, i.e., using another set of holes in the fastening option arrays 480.

[0067] FIG. 11 shows a view 1100 from inside the vessel 100, looking out at the transom bracket 130 in position on the transom of the hull 120. A cutout geometry 1110 has been formed in the transom in order to accommodate the routing media that passes to and from the drive unit 110. Bolt holes 1120 are schematically indicated in FIG. 11. The bolt holes are used to hold the transom bracket 130 securely in position relative to the transom.

[0068] FIG. 12 shows a view 1200 illustrating the example transom bracket 130, seen through the transom of the vessel 100. The transom bracket 130 is here offset vertically 930 upwards as far as it can go. Any further displacement of the transom bracket will cover one or more apertures by the transom, i.e., any further vertical offset will be resisted by the routing media that requires an opening at least as large as the routing area R.

[0069] FIG. 13 shows a view 1300 where the transom bracket 130 has instead been offset vertically 930 downwards as far as it can go.

[0070] Note that the sealing region S seals the interface between transom bracket and transom in both vertical positions.

[0071] FIG. 14 illustrates some geometrical considerations that are generally applicable to transom brackets according to the teachings herein.

[0072] According to some aspects, a distance 1410, 1420 from the sealing arrangement 920 to the closest aperture upwards and/or downwards on the transom bracket in use, measured along the first axis a.sub.1, is at least as large as the translation distance d.sub.T.

[0073] According to some aspects, the shortest distance 1410, 1420 measured along the first axis a.sub.1 from an aperture in the transom bracket 130 to the sealing arrangement 920 is at least 50 mm, and preferably more than 60 mm.

[0074] According to some aspects, the distance 1430 measured along the first axis a.sub.1 and upwards from the upper apertures of the water conduits 411, 421 to the sealing arrangement 920 is at least as large as the translation distance d.sub.T.

[0075] According to some aspects, at least a part of a contour of the cutout in the transom is arranged to match a peripheral contour of at least one aperture in the transom bracket 130. This can be seen from, e.g., FIG. 13, where the oval apertures have radii that match the contour of the cutout.

[0076] It is of course understood that the sealing region should be made as small as possible, while satisfying the above geometry constrains, in order to not cause an inflation of the size of the transom bracket beyond what is necessary to maintain the seal for all possible vertical offsets of the drive unit. Hence, according to some aspects, a distance 1410, 1420 from the sealing arrangement 920 to the closest aperture upwards and/or downwards on the transom bracket in use, measured along the first axis a.sub.1, is at most as large as twice the translation distance d.sub.T. According to some aspects, the shortest distance 1410, 1420 measured along the first axis a.sub.1 from an aperture in the transom bracket 130 to the sealing arrangement 920 is at most 150 mm. The distance 1430 measured along the first axis a.sub.1 and upwards from the upper apertures of the water conduits 411, 421 to the sealing arrangement 920 is at most as large as twice the translation distance d.sub.T.

[0077] The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms comprises, comprising, includes, and/or including when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and/or groups thereof.

[0078] It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.

[0079] Relative terms such as below or above or upper or lower or horizontal or vertical may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being connected or coupled to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being directly connected or directly coupled to another element, there are no intervening elements present.

[0080] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0081] It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the disclosure being set forth in the following claims.