Patent ID: 12187398

FIG.1shows an embodiment of the outboard propulsion system1comprising a first portion2and second portion5. The first portion2comprises an engine3including a crankshaft4. The engine3is configured to produce and transfer motive power to the crankshaft4. In some embodiments, the engine3may be a traditional four-stroke compression ignition diesel engine. However, any internal combustion engine may be used. In some embodiments, the engine is diesel, whereas in other embodiments the engine is petrol. In some embodiments, the engine is a hybrid and comprises at least one battery and at least one electric motor. In some embodiments, not shown, the outboard propulsion system is electric and comprises at least one electric motor and an output shaft instead of an engine and crankshaft.

The longitudinal axis9of the crankshaft4is parallel to the steering axis8. The steering axis8and the longitudinal axis of the crankshaft9intersect a longitudinal axis of the boat40at an acute angle α of approximately 60 degrees. In some embodiments, not shown, the longitudinal axis of the crankshaft may intersect the longitudinal axis of the boat at an acute angle α between 0-90 degrees, 20-85 degrees, 40-80 degrees, 50-70 degrees, 55-55 degrees or at approximately 60 degrees. Furthermore, the second portion5comprises an outer propeller shaft6and an inner propeller shaft106having a longitudinal axis7along the elongate length of the shaft.

The crankshaft4is operably connected to a first intermediate shaft12via a spline joint. The first intermediate shaft12is operably connected to a transmission assembly30. The transmission assembly30is operably connected to a second intermediate shaft14which is operably connected to a drop shaft13via a bevel gear15. The first12and second14intermediate shafts are substantially parallel to the crankshaft4. The drop shaft13is operably connected to the outer propeller shaft6via a first 90 degree bevel gear17, hence completing the transfer of motive power between the crankshaft4and the outer propeller shaft6. Furthermore, the drop shaft13is operably connected to the inner propeller shaft106via a second 90 degree bevel gear117, hence completing the transfer of motive power between the crankshaft4and the inner propeller shaft106.

Alternatively, in some embodiments (not shown), the first intermediate shaft12or second intermediate shaft14may be directly connected to the outer propeller shaft6via a first bevel gear configured to transmit motive power therebetween. The first intermediate shaft12or second intermediate shaft14may also be directly connected to the inner propeller shaft106via a second bevel gear configured to transmit motive power therebetween.

In some embodiments, not shown, there may be a single propeller shaft and the first intermediate shaft12or second intermediate shaft14may be directly connected to the propeller shaft via a bevel gear configured to transmit motive power therebetween.

Alternatively, in some embodiments (not shown), the crankshaft4may be directly connected to the at least one propeller shaft via a bevel gear configured to transmit motive power therebetween. For example, the crankshaft4may extend out of the engine3, through the first portion2, into the second portion5and connect to the at least one propeller shaft via at least one bevel gear.

As shown inFIG.1, the plurality of drive shafts comprises a drop shaft13, a first intermediate shaft12and a second intermediate shaft14. The drop shaft13is substantially perpendicular to the outer6and inner116propeller shafts and is configured to transmit motive power from the crankshaft4to the inner106and outer6propeller shafts.

The second intermediate shaft14is operably connected between the first intermediate shaft12and the drop shaft13. The second intermediate shaft14is substantially parallel to a longitudinal axis of the crankshaft9and is operably connected to the drop shaft13via a bevel gear15.

The second portion5is configured to pivot relative to the first portion2about the steering axis8. The steering axis8extends substantially parallel to the longitudinal axis of the crankshaft9and intersects the longitudinal axis of the propeller shafts7at an obtuse angle β between 100 degrees and 140 degrees. The axis8′ is parallel to and offset from the steering axis inFIG.1and has been used to demonstrate the obtuse angle β for clarity. Preferably, the steering axis8(and offset axis8′) intersect the longitudinal axis of the propeller shafts7at an angle β of about 120 degrees.

Furthermore, the outer propeller shaft6comprises a first propeller16configured to receive motive force from the outer propeller shaft6and generate thrust to drive the boat through a fluid, such as water, in use. The inner propeller shaft106comprises a second propeller116configured to receive motive force from the inner propeller shaft106and generate thrust to drive the boat through a fluid, such as water, in use.

In some embodiments, not shown, the inner and/or outer propeller shaft comprise a plurality of propellers.

The outboard propulsion system further comprises a transmission assembly30configured to control the motive power provided to the propeller shafts.

FIG.2shows a transmission assembly of the present invention. The transmission assembly30comprises a forward gear set34and a reversing gear32configured to control the speed and/or direction of motive power transferred to the propeller shafts. The transmission assembly also comprises a forward clutch37configured to enable the forward gear set34and a reversing clutch36configured to enable the reversing gears to be engaged interchangeably. The transmission assembly30is located in the first portion2. However, in some embodiments (not shown), the transmission assembly may be located in the second portion5.

Furthermore, the transmission assembly comprises an offset pair of offset gears38configured to move the second portion closer to the stern of the boat by a distance X. The distance X is approximately 105-110 mm, for example 107 mm. In some embodiments, not shown, X may be 0-1000 mm, 20-500 mm, 50-300 mm, 70-200 mm, 80-150 mm or 100-120 mm.

FIG.3shows a section through the fixing mechanism11, wherein the section is taken through a plane parallel to the longitudinal axis of the boat40and approximately 5 to 250 mm from a side elevation of the fixing mechanism. The fixing mechanism11is configured to attach the first portion of the outboard propulsion system to the transom of a boat. Furthermore, the fixing mechanism is configured to tilt the first portion2and second portion5together about a single axis of rotation10substantially parallel to the stern of the boat.

The fixing mechanism11comprises a cradle21for attachment to the first portion2and a transom bracket22for attachment to the transom of the boat. The cradle21is fixed to the first portion2via a plurality of bolts configured to prevent relative movement therebetween. The cradle is bolted to the housing of the transmission assembly30. The first portion is therefore fixed about a substantially vertical axis42. In some embodiments, not shown, the first portion may be fixed about a substantially vertical plane.

The transom bracket22is configured to attach to the stern of the boat via a plurality of bolts, screws and/or clamps configured to pass through the transom bracket and the transom of the boat to couple the two components together. The cradle21and transom bracket22are operably connected via a rotatable joint25configured to permit the single axis of rotation10substantially parallel to the stern of the boat.

The rotatable joint25shown in theFIG.3section comprises a single rotatable joint. In some embodiments (not shown), the full fixing mechanism11may comprise at least two separate coaxial rotatable joints. Each rotatable joint comprises a spindle less than 500 mm long. More preferably, the spindle may be less than 400 mm, 300 mm or 200 mm long and most preferably the spindle is less than 100 mm long, for example 65 mm.

The fixing mechanism11, as shown in theFIG.3section, further comprises a hydraulic arm28operably connected between the cradle21and transom bracket22. The hydraulic arm28is configured to rotate the cradle relative to the transom bracket, hence rotating the outboard propulsion system1relative to the transom of the boat about the axis of rotation10. This rotation may be used to trim and/or tilt the outboard propulsion system. In some embodiments (not shown), the full fixing mechanism may comprise a second hydraulic arm located on the opposing side of the fixing mechanism such that the fixing mechanism is symmetrical about a vertical axis. The second hydraulic arm may assist with trimming and/or tilting a heavy marine propulsion system and/or enabling two smaller hydraulic arms to replace one larger component. Furthermore, in some embodiments (not shown, the fixing mechanism may comprise a plurality of hydraulic arms, comprising up to, 2, 3, 4, 5, 8, 10 or more than 10 hydraulic arms.

The hydraulic arm(s)28is operably connected to an electronic control unit configured to expand and contract the hydraulic arm to control the movement of the cradle relative to the transom bracket. The control unit may be operated by a user, such as a captain, driver and/or crew member of the boat.

FIG.4shows the outboard propulsion system1including an engine3having a crankcase60comprising the crankshaft4. The outboard propulsion system1further comprises an oil pan65and an oil reservoir70. The engine3is configured to receive oil from the oil reservoir70. In use, an oil transfer pump80pumps oil from the oil pan65into the oil reservoir70via at least one conduit. In addition, an oil supply pump, not shown in the accompanying drawings, pumps oil from the oil reservoir70into the engine3via at least one conduit. The oil supply pump is powered via a chain or belt operably connected to the crankshaft4. Therefore, as the rotational speed of the crankshaft4increases, the oil supply pump receives more rotational energy, thus increasing the volume of oil supplied to the engine per unit of time. Alternatively, in some embodiments, the oil supply pump is operably connected to a pump shaft82, thus receiving power therefrom.

Excess oil within the engine3is collected in the oil pan65. The oil pan65is located substantially below the engine3, in use. More specifically, the oil pan65is located substantially below the crankcase60, in use. Consequently, oil within the engine and/or crankcase flows towards to oil pan under gravity. Oil within the oil pan65is then transferred into the oil reservoir70via the oil transfer pump80, in use.

In some embodiments, the outboard propulsion system1further comprises an oil filter. The oil filter is positioned such that oil flowing from the oil reservoir70to the engine3passes through the filter. The filter is configured to remove contaminants, such as metal particles, from with the oil. This again increases the efficiency with which the engine can generate power. The outboard propulsion system1further comprises an oil cooler. The oil cooler is located between the oil reservoir70and the oil filter. More specifically, the oil cooler is located between the oil supply pump and the oil filter. Consequently, oil flowing from the reservoir70to the engine3is cooled and then filtered.

The oil reservoir70comprises an oil pick-up configured to receive oil and transfer it into the engine. The oil pick-up is in fluid communication with the engine3via at least one conduit. More specifically, the oil pick-up is in fluid communication with the engine3via the oil supply pump. Preferably, the oil pick-up is located towards the bottom of the oil reservoir70. Locating the oil pick-up towards the bottom of the oil reservoir, in use, ensures that it remains submerged in oil, in use. This is particularly advantageous when the outboard propulsion system is rotated away from a horizontal plane, such as when turning a corner.

The oil reservoir70is located fore of the engine, as shown inFIG.4. Therefore, in use, the oil reservoir70is located between the engine3and the boat. Alternatively, in some embodiments, the oil reservoir is located behind the engine or above the engine. Accordingly, the oil reservoir70may be located in any desirable position.

More specifically, the oil reservoir is located directly adjacent to the engine, as shown inFIG.4. For example, the oil reservoir may be positioned in order to optimise the weight distribution of the outboard propulsion system and/or to improve the overall packaging of the system.

In some embodiments, the engine3comprises an internal wall72configured to separate the crankcase60from the oil reservoir70. Consequently, a boundary of each of the crankcase60and the oil reservoir70is defined by the internal wall72. The internal wall72further comprises an aperture74configured to balance pressure between the crankcase60and the oil reservoir70. The aperture74is located towards the top of the oil reservoir70, in use. Consequently, the aperture72and the oil pick-up are located at opposing ends of the oil reservoir70.

FIG.5shows an outboard transmission assembly30comprising an oil transfer pump80. The oil transfer pump80is configured to receive motive power, in the form of rotational energy, directly from the transmission assembly30. More specifically, the engine3causes the crankshaft4to rotate about its longitudinal axis, which, in turn, causes the first intermediate shaft12and/or input shaft12to rotate. The oil transfer pump80comprises a pump shaft82which is coupled to the first intermediate shaft12and/or the input shaft. More specifically, the first intermediate shaft12and/or the input shaft is directly coupled to the reverse gear32and the reverse clutch36, and the pump shaft82is directly coupled to the forward gear34and the forward clutch37. Alternatively, in some embodiments, the pump shaft82is directly coupled to the first intermediate shaft12and/or the input shaft. However, in some embodiments, the pump shaft82is coupled to the first intermediate shaft12and/or the input shaft via at least one additional shaft.

The pump shaft82is configured to rotate constantly, in use. For example, the pump shaft is configured to rotate constantly when the engine3is turned on. More specifically, the pump shaft82is operably coupled to the crankshaft4. Consequently, as the rotational speed of the crankshaft increases, the rotational speed of the pump shaft increases. However, there may be at least one gear configured to increases and/or decrease the rotational speed of the pump shaft82with respect to the crankshaft4. Nevertheless, as the rotational speed of the crankshaft4increases, the pump shaft rotational speed increases, thus increasing the rate at which of oil is transferred from the oil pan65to the oil reservoir70.

The engine, crankcase, oil pan, oil reservoir, turbocharger and conduits therebetween may comprise between 3 and 20 litres of oil in total. More specifically, the engine, crankcase, oil pan, oil reservoir, turbocharger and conduits therebetween may comprise between 5-15 litres of oil in total. Most specifically, the engine, crankcase, oil pan, oil reservoir, turbocharger and conduits therebetween may comprise between 7 and 11 litres of oil in total. For example, in some embodiments, the engine, crankcase, oil pan, oil reservoir, turbocharger and conduits therebetween comprises between 8 and 10 litres of oil in total.

In some embodiments, in use, the engine receives between 30 and 150 litres of oil per minute. More specifically, the engine receives between 35 and 60 litres of oil per minute. Most specifically, the engine receives between 40 and 45 litres of oil per minute. The oil supply pump is configured to deliver the aforementioned oil flow rates to the engine via a conduit. Alternatively, in some embodiments, the oil transfer pump80may pump up to 1,000 litres of fluid per minute from the oil pan to the oil reservoir. The fluid may comprise air and oil.

Alternatively, or in addition, the oil transfer pump80is configured to pump between 100 and 140 litres of oil per minute from the oil pan65to the oil reservoir70. More specifically, the oil transfer pump80is configured to pump between 110 and 130 litres of oil per minute from the oil pan65to the oil reservoir70. Most specifically, the oil transfer pump80is configured to pump between 115 and 125 litres of oil per minute from the oil pan65to the oil reservoir70. Consequently, the oil transfer pump80may pull air from within the engine and deliver it to the oil reservoir70. Consequently, the oil transfer pump80may be configured to generate a partial vacuum within the engine3.

In some embodiments, the oil transfer pump80is configured to generate a partial vacuum within the crankcase60. This ensures that substantially all of the oil within the crankcase is emptied into the oil reservoir70when engine3is turned off. The air pressure within the crankcase may be less than 1 bar, in use. More specifically, the air pressure within the crankcase may be less than 0.75 bar, in use. Most specifically, the air pressure within the crankcase may be less than 0.5 bar, in use. However, in some embodiments, the air pressure within the crankcase is less than 0.4 bar, in use.

The partial vacuum within the engine and/or crankcase reduces the air resistance on the crankshaft as it rotates, in use. Moreover, the partial vacuum within the crankcase also prevents excess oil within the crankcase from coming into contact with the crankshaft, in use. This may improve the efficiency of the engine by up to 3%.

FIG.6Ashows the oil transfer pump80when viewed from above;FIG.6Bshows the top and side view of the oil transfer pump80; andFIG.6Cshows the bottom and side view of the oil transfer pump80.

More specifically, the oil transfer pump80comprises a rotor84configured to transfers the oil from an inlet port to an outlet port within the transfer pump80. The rotor84is a dual filled rotor. Consequently, the oil transfer pump80comprises a first inlet86configured to receive oil from the oil pan65. The first inlet86is located at a first end of the oil transfer pump80. More specifically, the first inlet86is located at a first end of the rotor84. For example, the first inlet86is located towards the top of the oil transfer pump80, in use. The oil transfer pump80further comprises a second inlet88configured to receive oil from the turbocharger. The second inlet88is located at a second end of the oil transfer pump80. More specifically, the second inlet88is located at a second end of the rotor84. For example, the second inlet88is located towards the bottom of the oil transfer pump80, in use. Accordingly, the first and second end of the oil transfer pump are opposing ends. More specifically, the first inlet86is positioned at the top on the oil transfer pump and the second inlet88is positioned at the bottom of the oil transfer pump. The oil transfer pump80further comprises an outlet position between the first inlet and the second inlet. The outlet is in fluid communication with the oil reservoir70. Consequently, the turbocharger drain, oil pump inlet, oil pump outlet and corresponding oil conduits can be sized in order to optimise the engine performance.

The outboard propulsions system further comprises a seal87configured to provide a substantially fluid-tight seal between the transmission assembly and the engine. More specifically, the outboard propulsions system further comprises a seal87configured to provide a substantially fluid-tight seal between the transmission assembly and the engine3. Most specifically, the outboard propulsions system further comprises a seal87configured to provide a substantially fluid-tight seal between the transmission assembly and the crankcase60. The seal87is a lip seal. However, any suitable seal may be used.

Various further aspects and embodiments of the present invention will be apparent to those skilled in the art in view of the present disclosure.

“and/or” where used herein is to be taken as specific disclosure of each of the two specified features or components with or without the other. For example, “A and/or B” is to be taken as specific disclosure of each of (i) A, (ii) B and (iii) A and B, just as if each is set out individually herein.

Unless the context dictates otherwise, the descriptions and definitions of the features set out above are not limited to any particular aspect or embodiment of the invention and apply equally to all aspects and embodiments that are described.

It will further be appreciated by those skilled in the art that, although the invention has been described by way of example with reference to several embodiments, the invention is not limited to the disclosed embodiments and that alternative embodiments could be constructed without departing from the scope of the invention as defined in the appended claims.