Marine outboard motor with transmission lubrication system and lubricant filter

Abstract

A marine outboard motor 2 for a marine vessel 1 is provided. The marine outboard motor includes an internal combustion engine 100, a drive shaft 27 configured to transmit drive power from the internal combustion engine, a propeller shaft 29, and a drive transmission configured to transmit drive power from the drive shaft to the propeller shaft. The marine outboard motor also includes a lubrication system configured to deliver lubricant along a lubricant flow path for lubricating one or both of the drive transmission and the drive shaft, and a lubricant filter 83 disposed along the lubricant flow path and configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path. The lubricant filter is configured to be driven by the drive shaft.

Description

[Technical Field]

[0001] The present invention relates to a marine outboard motor with a lubricant filter. Although the present application relates to a marine outboard motor, the teachings of the present application are applicable to any other internal combustion engine. [Background technology]

[0002] Currently, the marine outboard motor market is dominated by gasoline engines, which are typically lighter than diesel engines. However, due to the improved safety of diesel fuel due to its lower volatility and fuel compatibility with motherships, a variety of users, from military operators to superyacht owners, are beginning to prefer diesel outboard motors. Additionally, diesel is a more economical fuel source with more readily accessible infrastructure for marine applications.

[0003] In outboard motors, lubrication of the drive shaft and transmission gear housing, to which the propeller shaft is attached, is required to extend the life of the outboard motor. Typically, oil is used as the lubricant in outboard motors. As the outboard motor components continue to be lubricated, solid contaminants that are washed off the components begin to accumulate in the oil. A problem with known outboard motors is that outboard motor components, such as the gear transmission, can have a relatively short service life due, at least in part, to the accumulation of solid contaminants or debris in the lubricant. In particular, U.S. Patent Application Publication No. 2006 / 0160441 discloses an outboard motor with an oil pump for circulating oil from an oil reservoir upwardly along a conduit to the drive shaft and bearings, the oil pump extending over the conduit to remove contaminants. Japanese Patent Application Laid-Open No. 61-205597 discloses an outboard motor equipped with an oil pump driven by the propeller shaft to pump oil from an oil tank in the lower landing gear to the engine. Also, U.S. Patent No. 6,261,455 discloses a centrifugal oil filter for removing soot from oil in a vehicle engine, which includes a centrifugal cartridge held within a filter housing and rotated by the flow of oil into the filter. Additionally, U.S. Patent Application Publication No. 2008 / 0009207 discloses an outboard motor with a lubricant circulation system that circulates lubricant through a propeller shaft along a lubricant passageway between a bevel gear mechanism and the vicinity of a bearing that supports the propeller shaft journal. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION The present invention seeks to provide an improved marine outboard motor that overcomes or mitigates one or more problems associated with the prior art. [Means for solving the problem]

[0005] According to a first aspect of the present invention, there is provided an outboard motor for a marine vessel, comprising: an engine assembly including an internal combustion engine; a drive shaft configured to transmit drive power from the internal combustion engine; a drive transmission device configured to transmit drive power from the drive shaft to a propeller shaft; a lubrication system configured to deliver lubricant along a lubricant flow path to lubricate one or both of the drive transmission device and the drive shaft; and a lubricant filter provided along the lubricant flow path, the lubricant filter configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path, the lubricant filter configured to be driven by the drive shaft.

[0006] This configuration advantageously utilizes drive shaft motion to actively filter debris from the lubricant (e.g., oil) as it flows along the lubricant flow path, thereby improving the service life of transmission and marine outboard motor components by actively reducing contaminants in the lubricant.

[0007] The lubricant filter may be configured to be indirectly driven by the drive shaft via a drive mechanism coupled to the drive shaft.

[0008] This configuration provides compact packaging for the filter system that is more easily packaged within a marine outboard motor, as the filter can be offset from the drive shaft and placed in a more convenient location, rather than requiring the filter to be mounted directly on the drive shaft.

[0009] The drive mechanism may have a gear ratio greater than 1:1.

[0010] By using the "step-up" drive described above, the centrifugal force generated within the filter can be increased at a given rotational speed of the drive shaft, which may improve the efficiency with which smaller contaminants are removed from the lubricant by the filter.

[0011] The lubrication system may be configured to deliver lubricant along the lubricant flow path to lubricate the drive mechanism.

[0012] The marine outboard motor may include a cooling system for cooling the internal combustion engine, the cooling system may include a water pump configured to propel water drawn in along a coolant flow path to cool the internal combustion engine, the water pump may be configured to be driven by the drive shaft via a drive mechanism, and the lubricant filter is configured to be driven by the water pump.

[0013] With this configuration, the water pump and lubricant filter are driven by the same drive mechanism, thereby avoiding the need for separate drive mechanisms and therefore advantageously reducing transmission losses and improving the efficiency of the marine outboard motor.

[0014] The water pump comprises a centrifugal water pump.

[0015] The water pump may include a water pump output shaft, and the lubricant filter may include a filter drive shaft configured to be driven by the water pump output shaft.

[0016] This configuration advantageously further reduces losses in the transmission, thereby improving the efficiency of the marine outboard motor.

[0017] The filter drive shaft may be coaxial with the water pump output shaft and directly connected to the water pump output shaft.

[0018] The drive mechanism may include a water pump drive shaft coaxial with and directly connected to the water pump output shaft.

[0019] The water pump drive shaft, the water pump output shaft and the filter drive shaft may all be defined by a single shaft.

[0020] The lubricant filter may be connected to the water pump via a mechanical fuse.

[0021] Connecting the lubricant filter to the water pump via a mechanical fuse ensures that the connection is set to break if a predetermined level of torque is exceeded, ensuring that the connection between the water pump drive shaft and the filter drive shaft breaks if the filter becomes clogged to prevent damage to the water pump and pump drive transmission.

[0022] The drive mechanism may include a drive gear concentrically mounted on the drive shaft and a driven gear concentrically mounted on the water pump drive shaft. The drive gear and the driven gear may be in meshing engagement.

[0023] By providing a drive gear rotatably fixed to the drive shaft, it is ensured that the motive power transmitted by the drive shaft can be used to drive the cooling system.

[0024] The lubricant filter may be a centrifugal lubricant filter configured to be driven by the drive shaft.

[0025] The marine outboard motor may include a transmission casing that at least partially houses the propeller shaft and the transmission drive. The transmission casing may define a lubricant reservoir for the lubrication system.

[0026] The lubrication system may include a lubricant pump configured, during use, to draw lubricant from the fluid reservoir and pump the drawn lubricant along a lubricant flow path to at least one rotating component located above the fluid reservoir.

[0027] In the case where the marine outboard motor is vertical, the drive shaft may extend vertically.

[0028] The engine block may comprise a single cylinder, but preferably the engine block comprises multiple cylinders.

[0029] As used herein, the term "engine block" refers to a solid structure in which at least one cylinder of an engine is located. The term may refer to the combination of a cylinder block with a cylinder head and crankcase, or to the cylinder block alone. An engine block may be formed from a single engine block casting. An engine block may be formed from multiple separate engine block castings connected together, for example, with bolts.

[0030] The engine block may include a single cylinder bank.

[0031] The engine block may include a first cylinder bank and a second cylinder bank, which may be arranged in a V-configuration.

[0032] The engine block may have three cylinder banks. The three cylinder banks may be arranged in a sector configuration. The engine block may have four cylinder banks. The four cylinder banks may be arranged in a W configuration or two V configurations.

[0033] The internal combustion engine may be arranged in any suitable orientation. Preferably, the internal combustion engine is a vertical axis internal combustion engine, in which the internal combustion engine has a crankshaft mounted vertically within the engine.

[0034] The internal combustion engine may be a gasoline engine. Preferably, the internal combustion engine is a diesel engine. The internal combustion engine may be a turbocharged diesel engine.

[0035] According to a second aspect of the present invention, there is provided a marine vessel equipped with the marine outboard motor of the first aspect.

[0036] Within the scope of this application, the various aspects, embodiments, examples, and alternatives set forth in the preceding paragraphs, in the claims and / or the following description and drawings, and in particular their individual features, are expressly intended to be understood independently or in any combination. That is, all embodiments and / or features of any embodiment may be combined in any manner and / or combination, provided that the combined features are not incompatible. The applicant reserves the right to modify the originally filed claims or to file new claims, including the right to amend the originally filed claims to rely on and / or incorporate any features of other claims, even if not originally claimed.

[0037] Further features and advantages of the present invention will be further described hereinafter, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is a schematic side view of a small boat equipped with an outboard motor for boats. [Figure 2a] FIG. 2a is a schematic diagram of an outboard motor for a marine vessel in a tilted position. [Figure 2b] FIG. 2b illustrates various aligned positions of the marine outboard motor and the corresponding orientation of the watercraft within the body of water. [Figure 2c] FIG. 2c illustrates various aligned positions of the marine outboard motor and the corresponding orientation of the watercraft within the body of water. [Figure 2d] FIG. 2d illustrates various aligned positions of the marine outboard motor and the corresponding orientation of the watercraft within the body of water. [Figure 3] FIG. 3 is a schematic cross-sectional view of an outboard motor for a marine vessel according to one embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view of the middle and lower portions of the outboard motor for marine use shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0039] Referring initially to FIG. 1 , a schematic side view of a boat 1 equipped with a marine outboard motor 2 is shown. The boat 1 may be any type of vessel suitable for use with a marine outboard motor, such as a ferry or a scuba diving boat. The marine outboard motor 2 shown in FIG. 1 is mounted on the stern of the boat 1. The marine outboard motor 2 is typically connected to a fuel tank 3 received within the hull of the boat 1. Fuel from a reservoir or fuel tank 3 is supplied to the marine outboard motor 2 via a fuel line 4. The fuel line 4 may collectively include one or more filters, a low-pressure pump, and a separator tank (to prevent water from entering the marine outboard motor 2) located between the fuel tank 3 and the marine outboard motor 2.

[0040] As will be explained in more detail below, the marine outboard motor 2 is generally divided into three sections: an upper section 21, a middle section 22, and a lower section 23. The middle section 22 and the lower section 23 are often collectively known as the leg, and the leg houses the exhaust system. The propeller 8 is rotatably disposed on a propeller shaft in the lower section 23, also referred to as the gearbox of the marine outboard motor 2. Of course, during operation, the propeller 8 is at least partially submerged in water and can be operated at various rotational speeds to propel the marine vessel 1.

[0041] Typically, the marine outboard motor 2 is pivotally connected to the stern of the boat 1 by a pivot pin. Rotation about the pivot pin allows an operator to tilt and position the marine outboard motor 2 about a horizontal axis in a known manner. Furthermore, as is well known in the art, the marine outboard motor 2 is pivotally mounted to the stern of the boat 1, thereby allowing it to rotate about a generally upright axis to steer the boat 1.

[0042] Tilting refers to the movement of the marine outboard motor 2 sufficiently raising the entire outboard motor 2 so that it can rise completely out of the water. Tilting of the marine outboard motor 2 can be performed with the outboard motor 2 turned off or in neutral. However, in some examples, the marine outboard motor 2 may be configured to allow limited operation of the outboard motor 2 in a tilting range to enable operation in shallow waters. Therefore, the marine engine assembly is primarily operated with the longitudinal axis of the legs substantially vertical. The engine crankshaft of the marine outboard motor 2, which is substantially parallel to the longitudinal axis of the legs of the outboard motor 2, will be oriented generally vertically during normal operation of the outboard motor 2, but may be oriented non-vertically under certain operating conditions, particularly when the outboard motor is operated on a marine vessel in shallow water. A crankshaft of the marine outboard motor 2 oriented substantially parallel to the longitudinal axis of the engine assembly legs may also be referred to as a vertical crankshaft configuration. Additionally, the crankshaft of the marine outboard motor 2 being oriented substantially perpendicular to the longitudinal axis of the engine assembly legs may be referred to as a horizontal crankshaft arrangement.

[0043] As previously mentioned, the lower section 23 of the marine outboard motor 2 must extend into the water to operate properly. However, in very shallow waters, or when launching a boat from a trailer, if the lower section 23 of the marine outboard motor 2 is in a tilted-down position, it may drag on the seabed or cause the boat to heel. By tilting the marine outboard motor 2 to a tilted-up position, such as the position shown in Figure 2a, damage to the lower section 23 and propeller 8 is prevented.

[0044] In contrast, alignment is a mechanism for moving the marine outboard motor 2 over a relatively small range, upward by a few degrees from a fully lowered position, as shown in the three examples in Figures 2b-2d. Alignment helps direct the thrust of the propeller 8 in a direction that provides the best combination of fuel economy, acceleration, and high-speed operation for the marine vessel 1.

[0045] When the vessel 1 is on a plane (when the weight of the vessel 1 is supported primarily by hydrodynamic lift rather than hydrostatic lift), the bow-up configuration provides relatively little drag and relatively greater stability and efficiency. This is typically the case when the centerline of the boat or vessel 1 is angled upward at approximately 3 to 5 degrees, as shown in Figure 2b, for example.

[0046] Too much tilt will result in the bow of vessel 1 being too high in the water, such as the position shown in Figure 2c. In this configuration, the hull of vessel 1 pushes through the water, resulting in more air resistance and reducing performance and economy. Too much upward tilt can also cause the propeller to vent, further reducing performance. In more severe cases, vessel 1 may splash through the water, potentially throwing the operator and passengers overboard.

[0047] A downward tilt lowers the bow of vessel 1, helping it accelerate from a standing start. Too much downward tilt, as shown in Figure 2d, causes vessel 1 to "plow" through the water, reducing fuel economy and slowing speed. At high speeds, a downward tilt can even make vessel 1 unstable.

[0048] 3, there is shown a schematic cross-section of a marine outboard motor 2 according to one embodiment of the present invention. The marine outboard motor 2 is equipped with a tilt and position adjustment mechanism 10 for performing the tilt and position adjustment operation described above. In this embodiment, the tilt and position adjustment mechanism 10 has a fluid pressure actuator 11 that can be operated via an electrical control system to tilt and position the marine outboard motor 2. Alternatively, it is also possible to provide a manual tilt and position adjustment mechanism in which an operator rotates the marine outboard motor 2 by hand rather than using a hydraulic actuator.

[0049] As described above, the marine outboard motor 2 is generally divided into three sections. The upper section 21, also known as the engine, contains the internal combustion engine 100 for powering the marine vessel 1. A cowling section 25 is disposed around the internal combustion engine 100. The middle section 22 and the lower section 23 form an exhaust system that defines an exhaust gas flow path for transporting exhaust gases from the internal combustion engine 100 and from the marine outboard motor 2.

[0050] The outboard motor 2 includes an intermediate section 22 and a lower section 23 extending downward adjacent to the upper section 21 or engine. The lower section 23 extends downward adjacent to the intermediate section 22 and connects the upper section 21 to the lower section 23. Together, the intermediate section 22 and the lower section 23 form the legs of the outboard motor 2 for marine use. The intermediate section 22 houses a drive shaft 27 extending vertically between the internal combustion engine 100 and a propeller shaft 29 and connected to a crankshaft 31 of the internal combustion engine via a floating connector 33 (e.g., a splined connection). In this manner, the drive shaft 27 is configured to transmit driving power from the internal combustion engine 100. A gearbox or transmission (transmission) is provided at the lower end of the drive shaft 27, which horizontally supplies the rotational energy of the drive shaft 27 to the propeller 8. The gearbox or drive transmission has a transmission casing 61 that houses at least a portion of the propeller shaft 29. The gearbox or drive transmission is configured to transmit drive power from the drive shaft 27 to the propeller shaft 29. More specifically, the bottom end of the drive shaft 27 may have a bevel gear 35 connected to a pair of bevel gears 37, 39 that are rotatably connected to the propeller shaft 29 of the propeller 8.

[0051] As shown schematically in Figure 3, the marine outboard motor 2 includes a cooling system that transports water drawn from the body of water in which the marine outboard motor operates during use along a coolant flow path 43 that extends through the housing 6 to the internal combustion engine 100. The water is propelled around the coolant flow path 43 by at least one water pump (see Figures 4 and 5) for cooling the internal combustion engine 100.

[0052] The housing 6 of the marine outboard motor 2 has one or more openings that are intended to be submerged in use in the body of water in which the marine outboard motor 2 operates. In other words, in use, water from the body of water in which the marine outboard motor 2 operates enters the housing 6 through one or more openings in the housing 6 that are located below the waterline of the body of water in which the marine vessel 1 is stationary. In the illustrated configuration, the one or more openings are provided on the lower portion 23, as will be described below.

[0053] In the illustrated embodiment, the housing 6 has a first inlet 45 in the lower portion 23. Although not shown, the housing 6 is provided with a second inlet, a third inlet, and a fourth inlet, two inlets on each opposite side of the housing 6. In alternative configurations, the coolant flow passage 43 can have any suitable number of inlets (e.g., one, two, five, etc.) and / or one or more of these inlets can be provided in the middle portion 22.

[0054] The opening located below the waterline allows, during use, water in which the marine outboard motor 2 is operating to be drawn into the chamber 52 within the housing 6. In this way, the chamber 52 within the housing 6 is continuously supplied with water drawn from the body of water in which the marine outboard motor 2 is operating.

[0055] Referring now to FIG. 4, the middle portion 22 and the lower portion 23 are shown.

[0056] The cooling system includes a centrifugal water pump 49 located within the foot 21 of the marine outboard motor 2. In use, water from the body of water in which the marine outboard motor 2 is used enters the chamber 52 of the housing 6 via the first inlet 45. Like other types of centrifugal pumps, the centrifugal water pump 49 includes a bladed circular disk or impeller 75 that is concentrically mounted on a water pump drive shaft 71 and is configured to rotate within a pump housing 77 about its central axis.

[0057] The rotating impeller 75 accelerates the drawn water as it moves across the impeller 75, creating a pressure differential across the centrifugal water pump 49. This causes a pressurized flow of the drawn water to be directed through the centrifugal water pump 49 and along the coolant flow path 43 to the internal combustion engine 100. To absorb heat from the internal combustion engine 100, the drawn water flows along at least one coolant passage (not shown) within the internal combustion engine 100 before returning to the body of water via one or more drains (not shown). In this manner, the cooling system is configured to draw water into the housing 6 and propel the drawn water along the coolant flow path 43 to the internal combustion engine 100.

[0058] In the illustrated embodiment, the centrifugal water pump 49 is a centrifugal pump that is located remote from (i.e., not directly attached to) the drive shaft 27 and configured to be driven by the drive shaft 27. That is, the impeller 75 of the centrifugal water pump 49 is indirectly driven by rotation of the drive shaft 27. It will be appreciated that alternative types of water pumps, such as flexible impeller pumps, may be used in the marine outboard motor 2. It will also be appreciated that in alternative configurations, the centrifugal water pump 49 may be mounted directly to the drive shaft 27 or to a sleeve around the drive shaft 27, as will be described in more detail below.

[0059] To drive the centrifugal water pump 49, the marine outboard motor 2 has a drive mechanism 63 connected to the drive shaft 27. The drive mechanism 63 is configured to supply rotational energy of the drive shaft 27 to the centrifugal water pump 49 to drive the impeller 75. The drive mechanism 63 is disposed within a drive mechanism housing 73.

[0060] In this example, the centrifugal water pump 49 is connected to the drive shaft 27 by a drive mechanism and is configured to transmit driving force from the drive shaft 27 to the centrifugal water pump 49. The drive mechanism 63 has a drive gear 65 attached concentrically to the drive shaft 27 and a driven gear 66 attached concentrically to the water pump drive shaft 71, and the drive gear 65 and the driven gear 66 are in meshing engagement.

[0061] In some embodiments, the centrifugal water pump 49 is coupled to the drive shaft 27 by a drive mechanism 63 having a gear ratio greater than 1:1. The "step-up drive" described above can be advantageous when the typical rotational speed of the drive shaft 27 cannot provide sufficient flow rate through the centrifugal water pump 49, for example, when the diameter of the centrifugal water pump 49 is limited by available space.

[0062] In use, water from the body of water in which the marine outboard motor is used is supplied to a central region of the pump's impeller 75 through pump inlet 79, while impeller 75 is rotated by drive shaft 27 via drive gear 65. The rotating impeller 75 accelerates the water as it moves radially across impeller 75, creating a pressure differential across centrifugal water pump 49 and directing a flow of pressurized water into the coolant passages of internal combustion engine 100. As the cooling water flows around the coolant passages of internal combustion engine 100, it absorbs heat from internal combustion engine 100 before being discharged back into the body of water through a coolant outlet (not shown).

[0063] The marine outboard motor 2 is provided with a lubrication system for lubricating the drive transmission. The lubrication system is configured to deliver a lubricant (e.g., oil) along a lubricant flow path to lubricate the drive transmission and / or the drive shaft 27. The lubrication system includes a lubricant filter 83 along the lubricant flow path to remove solid contaminants from the lubricant in situ.

[0064] During operation of the marine outboard motor 2, the lubricant flows along the lubricant flow passages to flow across the different components housed within the transmission casing 61. In addition to lubricating the components within the transmission casing 61, such as the bevel gears 35, 37, and 39, the lubricant also cleans the components by flushing away solid contaminants or debris. In this manner, the lubricant can both lubricate and clean the components housed within the transmission casing 61.

[0065] Over time, this process results in the buildup of solid contaminants within the lubricant. To mitigate this, the lubrication system includes a lubricant filter 83 located along the lubricant flow path. The lubricant filter 83 is configured to filter the lubricant as it flows along the lubricant flow path to remove solid contaminants suspended within the lubricant.

[0066] In the illustrated configuration, the filter is provided in the form of a centrifugal lubricant filter 83. In order to utilize the motive power of the drive shaft 27, the centrifugal lubricant filter 83 is configured to be indirectly driven by the drive shaft 27. In the illustrated configuration, the centrifugal lubricant filter 83 is configured to be indirectly driven by the drive shaft 27 via a drive mechanism coupled to the drive shaft 27. This configuration eliminates the need for a separate drive device for the lubricant filter 83.

[0067] In the illustrated embodiment, the centrifugal lubricant filter 83 is configured to be driven by the centrifugal water pump 49. This configuration provides a single connection to the drive shaft 27 for both the centrifugal lubricant filter 83 and the centrifugal water pump 49, reducing losses in the transmission.

[0068] As described above, centrifugal water pump 49 has impeller 75 concentrically attached to water pump drive shaft 71. Water pump drive shaft 71 is separate from drive shaft 27 and is configured to be driven by drive shaft 27. In the illustrated configuration, centrifugal lubricant filter 83 is configured to be driven by water pump drive shaft 71.

[0069] The centrifugal lubricant filter 83 includes a filter drive shaft 93 configured to be driven by the water pump drive shaft 71. In the illustrated configuration, the centrifugal water pump 49 includes a water pump output shaft, and the lubricant filter 83 includes a filter drive shaft 93 configured to be driven by the water pump output shaft.

[0070] The filter drive shaft 89 is substantially centrally disposed within the filter housing 94 and is configured to be driven by the water pump drive shaft 71. The filter drive shaft 89 is axially aligned with and rotationally fixed to the water pump drive shaft 71. The filter housing 94 acts as a lubricant reservoir, allowing the lubricant to flow into the reservoir so that solid contaminants can be filtered from the lubricant.

[0071] To prevent damage to the centrifugal water pump 49, for example, when the lubricant filter 83 becomes clogged, the filter drive shaft 89 may be attached to the water pump drive shaft 71 via a mechanical fuse (not shown). Ensure that the mechanically fused connection between the water pump drive shaft 71 and the filter drive shaft 89 is configured to break above a predetermined level of torque (i.e., when one of the shafts becomes clogged).

[0072] The centrifugal lubricant filter 83 has a rotor 95 mounted on a filter drive shaft 89 such that the rotor 95 rotates within a filter housing 94 to drive the centrifugal lubricant filter 83. The centrifugal lubricant filter 83 also includes a separator disc 96 configured to filter solid contaminants from the lubricant. The separator disc 96 is configured in the form of a cone extending outward from the filter drive shaft 89 and is angled upward (i.e., toward the centrifugal water pump 49). An upper surface of the separator disc 96 is spaced from the transmission casing 61 to define an outlet 97 for the centrifugal lubricant filter 83.

[0073] Here, the movement of the lubricant along the lubricant flow path will be described.

[0074] Of course, a variety of different flow paths for the lubricant may be provided.

[0075] In the illustrated configuration, the lubricant travels along the drive shaft 27 (e.g., away from the propeller shaft 29) and this travel is driven by an Archimedes screw pump 81 on the radially outer surface of the input shaft 27.

[0076] Through the continued operation of this Archimedes screw pump 81, lubricant is driven upward along the outer surface of the drive shaft 27 toward the drive mechanism housing 73. In this manner, lubricant may flow into the drive mechanism housing 73 to lubricate the drive gear 65 and driven gear 66 of the drive mechanism 63.

[0077] As the lubricant continues to flow into the drive mechanism housing 73, the volume of lubricant within the drive mechanism housing 73 builds up.

[0078] The water pump drive shaft 71 is provided with a shaft bore 74 that extends from the outer surface of the water pump drive shaft 71 to a central bore 72 that extends axially along the water pump drive shaft 71. As the lubricant level increases within the drive mechanism housing 73, it will reach a predetermined level and flow into the shaft bore 74.

[0079] In this manner, lubricant can enter central bore 72 of water pump drive shaft 71 such that the lubricant flows through filter housing 94. In the illustrated configuration, filter drive shaft 89 is axially aligned and rotationally fixed to water pump drive shaft 71, and lubricant flows from central bore 72 to and along bores 76 extending through filter drive shaft 89 and into filter housing 94.

[0080] It will be appreciated that in an alternative configuration, the lubricant flow path may bypass the drive mechanism housing 73. In such a configuration, as described above, the lubricant may travel along the drive shaft 27 driven by the Archimedes screw pump 81 on the radially outer surface of the input shaft 27. An inlet passage may be provided to allow the lubricant to flow directly from the drive shaft 27 to the lubricant filter 83.

[0081] The rotation of the rotor 95 acts to separate the relatively heavy solid contaminants from the relatively light lubricant. Through the centrifugal force exerted by the rotation of the rotor 95, the relatively dense solid contaminants are forced radially outward. Furthermore, the solid contaminants settle to the bottom surface of the filter housing 94 due to their weight. In this manner, the solid contaminants are retained within the lubricant filter 83. The lubricant filter 83 has a separation disk 96 that redirects the separated (or filtered) lubricant radially outward before exiting the centrifugal lubricant filter 83 via an outlet 97. In this manner, the solid contaminants separated from the lubricant are retained within the lubricant filter 83, and the filtered lubricant can exit the centrifugal lubricant filter 83 via the outlet 97 and proceed toward the propeller shaft 29.

[0082] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications can be made without departing from the scope of the invention, as defined in the appended claims. The present disclosure also includes the following inventions. The first aspect is An outboard motor for a marine vessel, the outboard motor for a marine vessel comprising: an engine assembly comprising an internal combustion engine; a drive shaft configured to transmit driving power from the internal combustion engine; A propeller shaft, a drive transmission device configured to transmit the drive force from the drive shaft to a propeller shaft; a lubrication system configured to deliver lubricant along a lubricant flow path to lubricate one or both of the drive transmission and the drive shaft; a lubricant filter disposed along the lubricant flow path, the lubricant filter configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path; The lubricant filter is an outboard motor for a marine vessel that is configured to be driven by the drive shaft. The second aspect is In a first aspect of the marine outboard motor, the lubricant filter is configured to be indirectly driven by the drive shaft via a drive mechanism connected to the drive shaft. The third aspect is The drive mechanism is an outboard motor for a marine vehicle according to a second aspect, having a gear ratio greater than 1:1. The fourth aspect is In the marine outboard motor of the second or third aspect, the lubrication system is configured to transport lubricant along a lubricant flow path to lubricate the drive mechanism. The fifth aspect is the marine outboard motor includes a cooling system that cools the internal combustion engine, the cooling system including a water pump configured to propel water drawn along a coolant flow path to cool the internal combustion engine; the water pump is configured to be driven by the drive shaft via the drive mechanism, In the outboard motor for a marine vessel according to any one of the second to fourth aspects, the lubricant filter is configured to be driven by the water pump. The sixth aspect is In a fifth aspect of the present invention, the water pump is a centrifugal water pump. A seventh aspect is the water pump includes a water pump output shaft; In the marine outboard motor according to the fifth or sixth aspect, the lubricant filter includes a filter drive shaft configured to be driven by the water pump output shaft. The eighth aspect is In a seventh aspect of the present invention, in the outboard motor for a marine vessel, the filter drive shaft is coaxial with the water pump output shaft and is directly connected to the water pump output shaft. A ninth aspect is In an eighth aspect of the present invention, there is provided an outboard motor for a marine vessel, wherein the drive mechanism includes a water pump drive shaft that is coaxial with the water pump output shaft and is directly connected to the water pump output shaft. A tenth aspect is In a ninth aspect, in the outboard motor for a marine vessel, the water pump drive shaft, the water pump output shaft, and the filter drive shaft are all defined by a single shaft. An eleventh aspect is In the outboard motor for a marine vessel according to any one of the fifth to tenth aspects, the lubricant filter is connected to the water pump via a mechanical fuse. A twelfth aspect is In any one of the fifth to eleventh aspects of the outboard motor for a marine vessel, the drive mechanism comprises a drive gear concentrically attached to the drive shaft and a driven gear concentrically attached to the water pump drive shaft, and the drive gear and the driven gear are engaged with each other. A thirteenth aspect is In the marine outboard motor according to any one of the first to twelfth aspects, the lubricant filter is a centrifugal lubricant filter configured to be driven by the drive shaft. A fourteenth aspect is The marine outboard motor is an outboard motor for marine use in any of the first to thirteenth aspects, further comprising a transmission casing in which the propeller shaft and the transmission drive unit are at least partially housed, the transmission casing defining a lubricant reservoir for the lubrication system. A fifteenth aspect is In a fourteenth aspect of the present invention, the lubrication system further includes a lubrication pump configured to draw lubricant from a fluid reservoir during use and pump the drawn-in lubricant along the lubricant flow path to at least one rotating component located above the fluid reservoir. A sixteenth aspect is In the outboard motor for a marine vessel according to any one of the first to fifteenth aspects, the drive shaft extends vertically when the outboard motor for a marine vessel is in a vertical position. A seventeenth aspect is In the outboard motor for a marine vessel according to any one of the first to sixteenth aspects, the internal combustion engine is a diesel engine. An eighteenth aspect is A boat equipped with the outboard motor for a boat according to any one of the first to seventeenth aspects.

Claims

1. An outboard motor for a marine vessel, the outboard motor for a marine vessel comprising: an engine assembly comprising an internal combustion engine; a drive shaft configured to transmit driving power from the internal combustion engine; A propeller shaft, a drive transmission device configured to transmit the drive force from the drive shaft to a propeller shaft; a cooling system for cooling the internal combustion engine, the cooling system including a water pump configured to propel water drawn along a coolant flow path to cool the internal combustion engine; a lubrication system configured to deliver lubricant along a lubricant flow path to lubricate one or both of the drive transmission and the drive shaft; a lubricant filter disposed along the lubricant flow path, the lubricant filter configured to remove solid contaminants from the lubricant as it flows along the lubricant flow path; the water pump includes a water pump drive shaft configured to be driven by the drive shaft via a drive mechanism coupled to the drive shaft; the lubricant filter is configured to be driven by the water pump drive shaft.

2. 2. The marine outboard motor according to claim 1, wherein the drive mechanism has a gear ratio, the number of teeth on the drive side divided by the number of teeth on the driven side, that is greater than 1:

1.

3. 3. The marine outboard motor of claim 1, wherein the lubrication system is configured to deliver lubricant along a lubricant flow path to lubricate the drive mechanism.

4. 4. The marine outboard motor according to claim 1, wherein the water pump is a centrifugal water pump.

5. the water pump includes a water pump output shaft; 5. The marine outboard motor according to claim 1, wherein the lubricant filter includes a filter drive shaft configured to be driven by the water pump output shaft.

6. 6. The marine outboard motor according to claim 5, wherein the filter drive shaft is coaxial with the water pump output shaft and is directly connected to the water pump output shaft.

7. 7. The marine outboard motor according to claim 6, wherein the water pump drive shaft is coaxial with the water pump output shaft and is directly connected to the water pump output shaft.

8. 8. The marine outboard motor of claim 7, wherein the water pump drive shaft, the water pump output shaft, and the filter drive shaft are all defined by a single shaft.

9. 9. The marine outboard motor according to claim 1, wherein the lubricant filter is connected to the water pump drive shaft via a mechanical fuse.

10. 9. The marine outboard motor according to claim 7, wherein the drive mechanism includes a drive gear concentrically attached to the drive shaft, and a driven gear concentrically attached to the water pump drive shaft.

11. 11. The marine outboard motor according to claim 1, wherein the lubricant filter is a centrifugal lubricant filter.

12. 12. The marine outboard motor according to claim 1, further comprising a transmission casing in which the propeller shaft and the transmission drive are at least partially housed, the transmission casing defining a lubricant reservoir for the lubrication system.

13. 13. The marine outboard motor of claim 12, wherein the lubrication system further comprises a lubrication pump configured, during use, to draw lubricant from a fluid reservoir and pump the drawn lubricant along the lubricant flow path to at least one rotating component located above the fluid reservoir.

14. 14. The marine outboard motor according to claim 1, wherein the drive shaft extends parallel to the marine outboard motor.

15. 15. An outboard motor for a marine vessel according to any one of claims 1 to 14, wherein the internal combustion engine is a diesel engine.

16. A boat equipped with the outboard motor for a boat according to any one of claims 1 to 15.

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