Marine propulsion device

Abstract

To miniaturize a hybrid type ship propulsion machine.SOLUTION: The marine vessel propulsion device 1 includes an engine 4 and a motor 17 as a power source for rotating the propeller 2, an inverter 19 for controlling the motor 17, and a power switching mechanism 24 for switching a power source for rotating the propeller 2, the engine 4 is disposed in a vertical posture, the oil pan 15 extends downward from the engine main body 5, the engine drive shaft 21 is disposed so as to extend in the up-down direction in front of the oil pan 15, and the motor 17 is disposed below the rear portion of the engine main body 5 so that the extending direction of the output shaft 18 is in the front-rear direction. The motor drive shaft 22 is disposed below the oil pan 15 so as to extend in the front-rear direction, the power switcher mechanism 24 is disposed below the engine drive shaft 21 and in front of the motor drive shaft 22, and the inverter 19 is disposed behind the oil pan 15 and between the rear portion of the engine body 5 and the motor 17.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a marine propulsion device equipped with an engine and a motor as power sources for rotating a propeller. [Background technology]

[0002] Hybrid marine propulsion devices that use the power of an engine (internal combustion engine) and the power of a motor (electric motor) to rotate a propeller are known. Japanese Patent Laid-Open Publication No. 2020-189556 (Patent Document 1) describes a hybrid outboard motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-189556 Summary of the Invention [Problem to be solved by the invention]

[0004] A hybrid marine propulsion unit includes an engine as a first power source that rotates the propeller, a motor as a second power source that rotates the propeller, an inverter that controls the drive of the motor, and a power switching mechanism that switches the power source that rotates the propeller between the engine and the motor. The engine, motor, inverter, and power switching mechanism are all large devices with large volumes.

[0005] As such, hybrid marine propulsion units have many larger devices than non-hybrid marine propulsion units, i.e., marine propulsion units that use only an engine or only a motor as the power source for rotating the propeller, and therefore have the problem of being larger than non-hybrid marine propulsion units.

[0006] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to reduce the size of a hybrid marine propulsion device. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a marine propulsion device for propelling a marine vessel, the marine propulsion device comprising: a propeller; an engine as a first power source for rotating the propeller; a motor as a second power source for rotating the propeller; an inverter for controlling the drive of the motor; an engine drive shaft connected to a crankshaft of the engine; a motor drive shaft connected to an output shaft of the motor; a transmission shaft connected to a propeller shaft on which the propeller is mounted; and a power switching mechanism for switching the connection state of the engine drive shaft, the motor drive shaft, and the transmission shaft to switch the power source for rotating the propeller between the engine and the motor, the engine being configured such that the extension direction of the rotation axis of the crankshaft is in the vertical direction. the engine, when positioned longitudinally, has a downward extension portion extending downward from a front portion or a middle portion of the engine body in the longitudinal direction of the engine, the engine drive shaft is positioned to extend in the vertical direction in front of the downward extension portion, the motor is positioned below the rear portion of the engine body such that the extension direction of the output shaft is in the longitudinal direction and the position of the output shaft is lower than the downward extension portion, the motor drive shaft is positioned to extend in the longitudinal direction below the downward extension portion, the power switching mechanism is positioned below the lower end of the engine drive shaft and in front of the front end of the motor drive shaft, and the inverter is positioned behind the downward extension portion and between the rear portion of the engine body and the motor. [Effects of the Invention]

[0008] According to the present invention, it is possible to reduce the size of a hybrid marine propulsion device. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram showing a marine propulsion device according to an embodiment of the present invention; [Figure 2] 1 is an explanatory diagram showing the arrangement of components of a marine propulsion device according to an embodiment of the present invention; [Figure 3] 1 is an explanatory diagram showing an engine of a marine propulsion device according to an embodiment of the present invention; [Figure 4] 1 is an explanatory diagram showing a cooling structure for a marine propulsion device according to an embodiment of the present invention; [Figure 5] 2 is an external view showing a part of the engine, the motor, the inverter, the heat exchanger, the inverter bracket, etc. of the marine propulsion device in FIG. 1 as viewed from the left. FIG. [Figure 6] 1 is an external view showing a motor, an inverter, a heat exchanger, an inverter bracket, and the like in a marine propulsion device according to an embodiment of the present invention, as viewed from behind. FIG. [Figure 7] 1 is an external view showing a state in which a part of an engine, a motor, an inverter, a heat exchanger, an inverter bracket, and the like are separated from each other in a marine propulsion device according to an embodiment of the present invention. [Figure 8] (A) is an external view showing the inverter bracket in a marine propulsion device according to an embodiment of the present invention as viewed from the left, (B) is an external view showing the inverter bracket as viewed from above, and (C) is an external view showing the inverter bracket as viewed from the front. [Figure 9] 9(A) is an external view showing the inverter bracket and inverter in a marine propulsion device according to an embodiment of the present invention as viewed from the left, and FIG. 9(B) is a cross-sectional view showing the inverter bracket and inverter as viewed from the front, taken along the cutting line AA in FIG. 9(A). DETAILED DESCRIPTION OF THE INVENTION

[0010] A marine propulsion device according to an embodiment of the present invention is a hybrid marine propulsion device for propelling a marine vessel, and includes a propeller, an engine as a first power source for rotating the propeller, a motor as a second power source for rotating the propeller, an inverter for controlling the drive of the motor, an engine drive shaft connected to the crankshaft of the engine, a motor drive shaft connected to the output shaft of the motor, a transmission shaft connected to the propeller shaft on which the propeller is mounted, and a power switching mechanism for switching the power source for rotating the propeller between the engine and the motor by switching the connection mode of the engine drive shaft, the motor drive shaft, and the transmission shaft.

[0011] In the marine propulsion device of this embodiment, the engine is disposed longitudinally so that the extension direction of the rotation axis of the crankshaft is in the vertical direction. Furthermore, when disposed longitudinally, the engine has a downward extension portion that extends downward from a front portion or a middle portion of the engine body in the longitudinal direction. The engine drive shaft is disposed so as to extend in the vertical direction in front of the downward extension portion of the engine. The motor is disposed below the rear portion of the engine body so that the extension direction of the output shaft is in the longitudinal direction and the output shaft is positioned below the downward extension portion of the engine. The motor drive shaft is disposed so as to extend in the longitudinal direction below the downward extension portion of the engine. The power switching mechanism is disposed below the lower end of the engine drive shaft and in front of the front end of the motor drive shaft. The inverter is disposed behind the downward extension portion of the engine and between the rear portion of the engine body and the motor.

[0012] By positioning the engine vertically so that the extension direction of the rotation axis of the crankshaft is vertical, and by positioning the engine drive shaft so that it extends vertically in front of the downward extension portion of the engine, the engine drive shaft can be positioned along the front surface of the downward extension portion of the engine, and the engine drive shaft can be brought close to the front surface of the downward extension portion of the engine.

[0013] In addition, by positioning the motor below the rear of the engine body so that the extension direction of the output shaft is in the fore-and-aft direction and the position of the output shaft is lower than the downward extension portion of the engine, and by positioning the motor drive shaft so that it extends in the fore-and-aft direction and passes below the downward extension portion of the engine, the motor drive shaft can be positioned so that it follows the underside of the downward extension portion of the engine and can be brought close to the underside of the downward extension portion of the engine.

[0014] Furthermore, by positioning the power switching mechanism below the lower end of the engine drive shaft and in front of the front end of the motor drive shaft, the power switching mechanism can be positioned close to the front lower corner of the downward extension of the engine.

[0015] Furthermore, because the downward extension portion extends downward from the front or longitudinally intermediate portion of the engine body when the engine is disposed longitudinally, the rear surface of the engine body is located rearward of the rear surface of the downward extension portion of the engine. In other words, the rear portion of the engine body protrudes further rearward than the downward extension portion of the engine. Therefore, when the motor is disposed below the rear portion of the engine body, a space is formed between the rear portion of the engine body and the motor behind the downward extension portion. By disposing the inverter behind the downward extension portion of the engine and between the rear portion of the engine body and the motor, i.e., within the space, the inverter can be located close to each of the downward extension portion of the engine, the rear portion of the engine body, and the motor.

[0016] As described above, in the marine propulsion device of this embodiment, the engine drive shaft can be arranged along the front surface of the engine downward extension portion and in a position close to the front surface of the engine downward extension portion, the motor drive shaft can be arranged along the underside of the engine downward extension portion and in a position close to the underside of the engine downward extension portion, the power switching mechanism can be arranged in a position close to a lower front corner of the engine downward extension portion, and the inverter can be arranged in positions close to the engine downward extension portion, the rear of the engine main body, and the motor. In other words, the marine propulsion device of this embodiment allows the engine, motor, inverter, engine drive shaft, motor drive shaft, and power transmission mechanism to be arranged together so that the gaps between them are small. This allows the hybrid marine propulsion device to be made smaller. [Example]

[0017] Hereinafter, an embodiment of a marine vessel propulsion device 1 according to the present invention will be described with reference to the drawings. In describing the embodiment, when describing the directions of up (Ud), down (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd), for the sake of convenience, the arrows drawn at the bottom right of each figure will be used.

[0018] (Ship propulsion system) Fig. 1 shows a boat propulsion device 1. Fig. 2 shows the arrangement of components of the boat propulsion device 1. Fig. 3 shows an engine 4 of the boat propulsion device 1.

[0019] The marine vessel propulsion unit 1 is a device for propelling a marine vessel. In this embodiment, the marine vessel propulsion unit 1 is an outboard motor that is attached to a marine vessel. As shown in Figures 1 and 2, the marine vessel propulsion unit 1 includes a propeller 2, a propeller shaft 3 to which the propeller 2 is fixed, an engine 4 that is a first power source for rotating the propeller 2, a motor 17 that is a second power source for rotating the propeller 2, and an inverter 19 that controls the drive of the motor 17.

[0020] The propeller 2 and the propeller shaft 3 are disposed at the bottom of the vessel propulsion device 1 and are located below the water surface when the vessel propulsion device 1 is attached to the vessel. The engine 4, the motor 17, and the inverter 19 are disposed in a section from the top to the middle in the vertical direction of the vessel propulsion device 1 and are located above the water surface when the vessel propulsion device 1 is attached to the vessel.

[0021] 3, the engine body 5 of the engine 4 includes a crankcase 7 in which a crankshaft 6 is provided, a cylinder block 9 in which pistons 8 are provided, a cylinder head 13 in which intake valves 10, exhaust valves 11 and a camshaft 12 are provided, and an intake manifold 14 that supplies air to the combustion chamber. The engine body 5 also includes an oil pan 15 that stores engine oil.

[0022] As shown in FIG. 3, the engine 4 is disposed vertically so that the extension direction of the rotational axis of the crankshaft 6 is the up-down direction. The engine 4 is disposed so that the crankcase 7 is at the front and the intake manifold 14 is at the rear. With the engine 4 disposed vertically in this manner, the oil pan 15 extends downward from the front or middle portion of the engine body 5 in the fore-and-aft direction. The rear portion of the underside of the oil pan 15 is provided with an upwardly recessed recess 16. The rear portion 5A of the engine body 5 (the portion of the engine 4 above the oil pan 15) protrudes rearward beyond the oil pan 15, and the rear surface of the rear portion 5A of the engine body 5 is located rearward beyond the rear surface of the oil pan 15. The oil pan 15 is a specific example of a "downwardly extending portion."

[0023] 2, motor 17 is disposed below rear portion 5A of engine body 5 such that output shaft 18 extends in the front-rear direction and is positioned below oil pan 15. An upper portion of the front portion of motor 17 is disposed within recess 16 of oil pan 15.

[0024] The inverter 19 is disposed behind the oil pan 15, between the rear section 5A of the engine body 5 and the motor 17. As will be described later, the marine vessel propulsion device 1 also includes a heat exchanger 43 that cools the cooling medium that cools the motor 17 and the inverter 19. The heat exchanger 43 is disposed behind the oil pan 15, between the rear section 5A of the engine body 5 and the inverter 19.

[0025] Furthermore, the marine vessel propulsion device 1 includes an engine drive shaft 21, a motor drive shaft 22, a transmission shaft 23, a power switching mechanism 24, and a rotation transmission mechanism 25.

[0026] The engine drive shaft 21 is disposed so as to extend in the vertical direction in front of the oil pan 15. The engine drive shaft 21 is connected to the crankshaft 6 of the engine 4 via a gear, and is rotated by the rotation of the crankshaft 6.

[0027] The motor drive shaft 22 is disposed below the oil pan 15 so as to extend in the front-rear direction. The motor drive shaft 22 is connected to the output shaft 18 of the motor 17 and rotates integrally with the output shaft 18.

[0028] The transmission shaft 23 is disposed below the engine drive shaft 21 so as to extend in the vertical direction. The transmission shaft 23 is connected to the propeller shaft 3 via a rotation transmission mechanism 25.

[0029] The power switching mechanism 24 is disposed below the lower end of the engine drive shaft 21 and forward of the front end of the motor drive shaft 22. The power switching mechanism 24 switches the power source that rotates the propeller 2 between the engine 4 and the motor 17 by switching the connection modes of the engine drive shaft 21, the motor drive shaft 22, and the transmission shaft 23. The power switching mechanism 24 has a clutch that switches the connection modes of the engine drive shaft 21, the motor drive shaft 22, and the transmission shaft 23. When the engine drive shaft 21 and the transmission shaft 23 are connected to each other by the clutch, the rotation of the engine drive shaft 21 is transmitted to the transmission shaft 23, and as a result, the propeller 2 rotates by the power of the engine 4. When the motor drive shaft 22 and the transmission shaft 23 are connected to each other by the clutch, the rotation of the motor drive shaft 22 is transmitted to the transmission shaft 23, and as a result, the propeller 2 rotates by the power of the motor 17. In addition, when both the engine drive shaft 21 and the motor drive shaft 22 are connected to the transmission shaft 23 by the clutch, the rotation of the engine drive shaft 21 and the motor drive shaft 22 is transmitted to the transmission shaft 23, and as a result, the propeller 2 rotates due to the power of the engine 4 and the motor 17.

[0030] The rotation transmission mechanism 25 is disposed at the front of the lower part of the marine vessel propulsion unit 1. The rotation transmission mechanism 25 is a mechanism that transmits the rotation of the transmission shaft 23 to the propeller shaft 3. The rotation transmission mechanism 25 has a first gear mechanism 26 that switches the rotation direction of the propeller shaft 3. The marine vessel propulsion unit 1 of this embodiment also employs contra-rotating propellers, and is equipped with two propellers 2 and two propeller shafts 3 to which these propellers 2 are respectively fixed. The rotation transmission mechanism 25 has a second gear mechanism 27 that transmits the rotation of the transmission shaft 23 to the two propeller shafts 3 so that the rotation directions of these propeller shafts 3 are opposite to each other.

[0031] (cooling structure) 4 shows the cooling structure of the marine vessel propulsion unit 1. As shown in FIG. 4, the marine vessel propulsion unit 1 has a liquid-cooling type cooling structure 31 that cools the engine 4, the motor 17, and the inverter 19.

[0032] The cooling structure 31 includes a water intake 32, a first cooling water supply passage 33, a water pump 34, an engine cooling mechanism 35, a first cooling water discharge passage 36, a drain port 37, and a cooling water temperature control valve 38.

[0033] The water intake 32 is an inlet that takes in water outside the marine propulsion device 1 (e.g., seawater) into the marine propulsion device 1 as cooling water. The water intake 32 is provided in a lower portion of the marine propulsion device 1 that is submerged underwater. The first cooling water supply passage 33 connects the water intake 32 to the engine cooling mechanism 35 and is a passage through which the cooling water taken in from the water intake 32 flows toward the engine cooling mechanism 35. The water pump 34 is a pump that sends cooling water that flows into the first cooling water supply passage 33 from outside the marine propulsion device 1 via the water intake 32 toward the engine cooling mechanism 35. The engine cooling mechanism 35 is, for example, a cooling jacket or a water jacket, and is composed of cooling passages formed inside or around the engine 4. The first cooling water discharge passage 36 connects the engine cooling mechanism 35 to a drain outlet 37 and is a passage through which the cooling water that has flowed through the engine cooling mechanism 35 flows toward the drain outlet 37. The drain port 37 is an opening for discharging the cooling water after flowing through the engine cooling mechanism 35 and the cooling water after flowing through the heat exchanger 43 to the outside of the marine propulsion device 1. The cooling water temperature control valve 38 is a valve that controls the flow rate of the cooling water in the first cooling water supply passage 33 based on the temperature of the cooling water after flowing through the engine cooling mechanism 35. The cooling water temperature control valve 38 controls the flow rate of the cooling water in the first cooling water supply passage 33 so that the flow rate of the cooling water in the first cooling water supply passage 33 increases as the temperature of the cooling water after flowing through the engine cooling mechanism 35 increases. The cooling water temperature control valve 38 is, for example, a thermostat.

[0034] Furthermore, the cooling structure 31 includes a cooling medium circulation passage 39 , a cooling medium pump 40 , a motor cooling mechanism 41 , an inverter cooling mechanism 42 , a heat exchanger 43 , and a degassing tank 44 .

[0035] The cooling medium circulation passage 39 is a passage for circulating a cooling medium such as a coolant liquid between the motor cooling mechanism 41, the inverter cooling mechanism 42, and the heat exchanger 43. The cooling medium pump 40 is a pump for circulating the cooling medium. The motor cooling mechanism 41 is, for example, a cooling jacket and is composed of cooling passages formed inside or around the motor 17. The motor cooling mechanism 41 is connected to the cooling medium circulation passage 39. The inverter cooling mechanism 42 is, for example, a cooling jacket and is composed of cooling passages formed inside or around the inverter 19. The inverter cooling mechanism 42 is connected to the cooling medium circulation passage 39. The heat exchanger 43 is a device for cooling the cooling medium circulating in the cooling medium circulation passage 39 by exchanging heat between the cooling medium circulating in the cooling medium circulation passage 39 and the cooling water taken in from the water intake 32. The heat exchanger 43 has a cooling medium flow path and a cooling water flow path. The cooling medium flow path is connected to the cooling medium circulation passage 39. The cooling water flow path is connected to the first cooling water supply passage 33 via a second cooling water supply passage 45 branching off from the first cooling water supply passage 33. The degassing tank 44 has a function of separating gas in the cooling medium circulating in the cooling medium circulation passage 39 from the cooling medium, and is connected to the cooling medium circulation passage 39.

[0036] Furthermore, the cooling structure 31 includes a second cooling water supply passage 45 , a second cooling water discharge passage 46 , and an inflow control valve 47 .

[0037] The second coolant supply passage 45 branches off from the first coolant supply passage 33 and connects the first coolant supply passage 33 to the coolant flow path of the heat exchanger 43. The second coolant discharge passage 46 connects the coolant flow path of the heat exchanger 43 to the drain port 37. The inflow control valve 47 controls the inflow of coolant from the first coolant supply passage 33 to the second coolant supply passage 45. Specifically, the inflow control valve 47 controls the amount of coolant flowing from the first coolant supply passage 33 to the second coolant supply passage 45 so that the amount of coolant flowing from the first coolant supply passage 33 to the second coolant supply passage 45 decreases as the pressure of the coolant in the first coolant supply passage 33 increases.

[0038] When the marine vessel propulsion device 1 is operating, the rotation of the engine 4 or the motor 17 is transmitted to the transmission shaft 23, causing the transmission shaft 23 to rotate. For example, the water pump 34 is driven by the rotation of the transmission shaft 23. The coolant pump 40 is, for example, an electric pump (a pump that has a pump drive motor dedicated to driving the pump and is driven by the pump drive motor). When the marine vessel propulsion device 1 is operating, power is supplied to the pump drive motor of the coolant pump 40, causing the coolant pump 40 to be driven.

[0039] When the water pump 34 is driven, water outside the marine vessel propulsion device 1 flows as cooling water through the water intake port 32 into the first cooling water supply passage 33, then flows through the first cooling water supply passage 33, the engine cooling mechanism 35, and the first cooling water discharge passage 36, and is then discharged from the discharge port 37 to the outside of the marine vessel propulsion device 1. In this process, the cooling water flows through the engine cooling mechanism 35, thereby cooling the engine 4.

[0040] Furthermore, the coolant pump 40 is driven to circulate the coolant through the coolant circulation passage 39. As a result, the coolant flows sequentially through the motor cooling mechanism 41, the inverter cooling mechanism 42, and the coolant flow path of the heat exchanger 43. The coolant flows through the motor cooling mechanism 41 to cool the motor 17. The coolant flows through the inverter cooling mechanism 42 to cool the inverter 19.

[0041] Furthermore, when the water pump 34 is driven, a portion of the cooling water flowing through the first cooling water supply passage 33 flows through the second cooling water supply passage 45, the cooling water flow path of the heat exchanger 43, and the second cooling water discharge passage 46, and is then discharged from the discharge port 37 to the outside of the marine propulsion device 1. In this process, the cooling water flows through the cooling water flow path of the heat exchanger 43, thereby cooling the cooling medium flowing through the cooling medium flow path of the heat exchanger 43.

[0042] (Mounting structure for motors, inverters, etc.) Fig. 5 shows part of the engine 4, the motor 17, the inverter 19, the heat exchanger 43, the inverter bracket 61, etc., as viewed from the left in the marine propulsion device 1 in Fig. 1. Fig. 6 shows the motor 17, the inverter 19, the heat exchanger 43, the inverter bracket 61, etc., as viewed from the rear in Fig. 5. Fig. 7 shows part of the engine 4, the motor 17, the inverter 19, the heat exchanger 43, the inverter bracket 61, etc., separated from each other.

[0043] As shown in FIG. 7, two inverter bracket mounting portions 51, 52 are provided on the left rear portion of the oil pan 15 of the engine 4. One inverter bracket mounting portion 51 is located in the vertically central portion of the rear left portion of the oil pan 15. The other inverter bracket mounting portion 52 is located in the lower portion of the rear left portion of the oil pan 15. Although not shown, two inverter bracket mounting portions are also provided on the right rear portion of the oil pan 15, located in the vertically central portion of the rear right portion of the oil pan 15 and in the lower portion of the rear right portion of the oil pan 15, respectively. In addition, a motor mounting portion 54 is provided on the left rear portion of the oil pan 15 of the engine 4. In addition, although not shown, a motor mounting portion is also provided on the right rear portion of the oil pan 15 of the engine 4. In addition, an upwardly recessed recess 16 is provided in the rear portion of the underside of the oil pan 15 of the engine 4 (see also FIG. 3).

[0044] The marine vessel propulsion device 1 is also provided with a base 20 that supports the engine 4 and the motor 17 (see also FIG. 1). A motor mounting portion 55 is provided on the left rear portion of the base 20. Although not shown, another motor mounting portion is also provided on the right rear portion of the base 20.

[0045] 6 and 7, the outer peripheral surface of the motor case of motor 17 is provided with four coupling protrusions 56 for attaching motor 17 to motor attachment parts 54, 55. An inverter bracket attachment part 53 is provided on the upper left part of the motor case of motor 17. Although not shown, an inverter bracket attachment part is also provided on the upper right part of the motor case of motor 17.

[0046] As shown in FIG. 5, motor 17 is disposed below rear portion 5A of engine main body 5. Motor 17 is also located behind base 20. The upper front portion of motor 17 is inserted into recess 16 provided in the underside of oil pan 15. Motor 17 is attached and fixed to engine 4 and base 20 by connecting four connecting protrusions 56 provided on motor 17 to two left and right motor mounting portions 54 provided on oil pan 15 and two left and right motor mounting portions 55 provided on base 20 using connecting members such as bolts.

[0047] The inverter 19 and the heat exchanger 43 are attached to the inverter bracket 61. The inverter bracket 61, to which the inverter 19 and the heat exchanger 43 are attached, is disposed behind the oil pan 15, between the rear part 5A of the engine main body 5 and the motor 17. The inverter bracket 61 is attached and fixed to the engine 4 (oil pan 15) and the motor 17 by respectively connecting parts 71, 72, and 73 (described below) provided on the inverter bracket 61 to two left and right inverter bracket mounting parts 51 provided on the oil pan 15, two left and right inverter bracket mounting parts 52 provided on the oil pan 15, and two left and right inverter bracket mounting parts 53 provided on the motor 17 using connecting members such as bolts. By attaching the inverter bracket 61 to which the inverter 19 and heat exchanger 43 are attached to the engine 4 and motor 17, the inverter 19 is positioned behind the oil pan 15 and between the rear 5A of the engine body 5 and the motor 17, and the heat exchanger 43 is positioned behind the oil pan 15 and between the rear 5A of the engine body 5 and the inverter 19.

[0048] (Inverter bracket) Fig. 8(A) shows the inverter bracket 61 as seen from the left. Fig. 8(B) shows the inverter bracket 61 as seen from above. Fig. 8(C) shows the inverter bracket 61 as seen from the front. Fig. 9(A) shows the inverter bracket 61 with the inverter 19 attached as seen from the left. Fig. 9(B) shows a cross section of the inverter bracket 61 and the inverter 19 cut along cutting line AA in Fig. 9(A) as seen from the front (left in Fig. 9(A)).

[0049] The inverter bracket 61 is a member that attaches the inverter 19 and the heat exchanger 43 to the engine 4 and the motor 17. As shown in Figures 8(A) and 8(B), the inverter bracket 61 has an inverter fixing portion 62, two legs 66, two arms 67, and four bosses 68. The inverter fixing portion 62, the legs 66, the arms 67, and the bosses 68 are formed of a high-strength material such as metal.

[0050] The inverter fixing portion 62 is a portion that fixes the inverter 19 to the inverter bracket 61. The inverter fixing portion 62 has a left support portion 63 that supports the left portion of the inverter 19 from the left side of the inverter 19, a right support portion 64 that supports the right portion of the inverter 19 from the right side of the inverter 19, and a rear support portion 65 that supports the rear portion of the inverter 19 from the rear of the inverter 19. When viewed from above as shown in FIG. 8(B), the inverter fixing portion 62 is generally formed in a U-shape. The inverter 19 is disposed inside the inverter fixing portion 62 as shown in FIGS. 9(A) and 9(B).

[0051] An annular support member 69 is attached to the inner periphery of the inverter fixing portion 62. The annular support member 69 is formed into an annular shape from, for example, resin or hard rubber. As shown in FIG. 9(B) , when the inverter 19 is placed inside the inverter fixing portion 62, the annular support member 69 is disposed between the inverter fixing portion 62 and the inverter 19. The inverter 19 is supported by the inverter fixing portion 62 via the annular support member 69. The annular support member 69 has the functions of supporting the inverter 19 on the inverter fixing portion 62, suppressing the transmission of vibration from the engine 4 and motor 17 to the inverter 19, and suppressing the conduction of heat from the engine 4 and motor 17 to the inverter 19.

[0052] The legs 66 function to connect the inverter fixing part 62 to the engine 4 and the motor 17, respectively. As shown in Figures 8(A) to 8(C), one of the two legs 66 extends downward from the left part of the inverter fixing part 62, specifically from the left support part 63. The other leg 66 extends downward from the right part of the inverter fixing part 62, specifically from the right support part 64.

[0053] The arm 67 has the function of connecting the inverter fixing part 62 to the engine 4. Of the two arms 67, one arm 67 extends forward from the left front part of the inverter fixing part 62, specifically from the front end part of the left support part 63 (strictly speaking, from the front end part of the upper end part of the left leg 66 that is connected to the left support part 63). The other arm 67 extends forward from the right front part of the inverter fixing part 62, specifically from the front end part of the right support part 64 (strictly speaking, from the front end part of the upper end part of the right leg 66 that is connected to the right support part 64).

[0054] Furthermore, a coupling portion 71 is provided at the front end of each arm portion 67 for attaching the inverter bracket 61 to the inverter bracket attachment portion 51 provided on the oil pan 15. Furthermore, a coupling portion 72 is provided at the front of the lower end portion of each leg portion 66 for attaching the inverter bracket 61 to the inverter bracket attachment portion 52 provided on the oil pan 15. Furthermore, a coupling portion 73 is provided at the lower end portion of each leg portion 66 rearward of the coupling portion 72 for attaching the inverter bracket 61 to the inverter bracket attachment portion 53 provided on the motor 17.

[0055] The bosses 68 also function to attach the heat exchanger 43 to the inverter bracket 61. Of the four bosses 68, two bosses 68 protrude upward from the upper surface of the left support portion 63 of the inverter fixing portion 62. The remaining two bosses 68 protrude upward from the upper surface of the right support portion 64 of the inverter fixing portion 62. As shown in FIGS. 5 and 6 , the heat exchanger 43 is attached and fixed to the four bosses 68 via two heat exchanger brackets 75. That is, the left portion of the heat exchanger 43 is fixed to the two bosses 68 provided on the left support portion 63 via one heat exchanger bracket 75, and the right portion of the heat exchanger 43 is fixed to the two bosses 68 provided on the right support portion 64 via the other heat exchanger bracket 75. By attaching the heat exchanger 43 to the inverter bracket 61 in this manner, the heat exchanger 43 is positioned above the inverter 19 so as not to come into contact with the inverter 19.

[0056] In the marine propulsion device 1 according to the embodiment of the present invention described above, as shown in FIG. 2, the engine 4 is arranged vertically so that the extension direction of the rotational axis of the crankshaft 6 is vertical, and the engine drive shaft 21 is arranged to extend vertically in front of the oil pan 15 of the engine 4. This allows the engine drive shaft 21 to be arranged along the front surface of the oil pan 15 and to be brought close to the front surface of the oil pan 15.

[0057] Furthermore, by positioning the motor 17 below the rear 5A of the engine body 5 so that the extension direction of the output shaft 18 is in the fore-and-aft direction and the position of the output shaft 18 is lower than the oil pan 15 of the engine 4, and by positioning the motor drive shaft 22 so that it passes below the oil pan 15 and extends in the fore-and-aft direction, the motor drive shaft 22 can be positioned along the underside of the oil pan 15 and can be brought close to the underside of the oil pan 15.

[0058] Furthermore, by positioning the power switching mechanism 24 below the lower end of the engine drive shaft 21 and in front of the front end of the motor drive shaft 22, the power switching mechanism 24 can be positioned close to the front lower corner of the oil pan 15 of the engine 4.

[0059] Furthermore, when the engine 4 is disposed longitudinally, the oil pan 15 extends downward from the front or the middle portion in the fore-and-aft direction of the engine body 5. Therefore, when the engine 4 is disposed longitudinally, the rear surface of the rear portion 5A of the engine body 5 is located rearward of the rear surface of the oil pan 15. In other words, the rear portion 5A of the engine body 5 protrudes rearward beyond the oil pan 15. Therefore, when the motor 17 is disposed below the rear portion 5A of the engine body 5, a space is formed behind the oil pan 15 between the rear portion 5A of the engine body 5 and the motor 17. By disposing the inverter 19 behind the oil pan 15 between the rear portion 5A of the engine body 5 and the motor 17, i.e., within the space, the inverter 19 can be brought close to the oil pan 15, the rear portion 5A of the engine body 5, and the motor 17.

[0060] As described above, in the marine vessel propulsion device 1 of this embodiment, the engine drive shaft 21 can be positioned along the front surface of the oil pan 15 and close to the front surface of the oil pan 15, the motor drive shaft 22 can be positioned along the underside of the oil pan 15 and close to the underside of the oil pan 15, the power switching mechanism 24 can be positioned close to a lower front corner of the oil pan 15, and the inverter 19 can be positioned close to the oil pan 15, the rear portion 5A of the engine body 5, and the motor 17. In other words, with the marine vessel propulsion device 1 of this embodiment, the engine 4, motor 17, inverter 19, engine drive shaft 21, motor drive shaft 22, and power switching mechanism 24 can be positioned close to each other so that the gaps between them are small. This allows the hybrid marine vessel propulsion device 1 to be made smaller.

[0061] Furthermore, in the marine vessel propulsion device 1 of this embodiment, by arranging the heat exchanger 43 behind the oil pan 15 and between the rear section 5A of the engine body 5 and the inverter 19, the heat exchanger 43 can be arranged in close proximity to the oil pan 15, the rear section 5A of the engine body 5, and the inverter 19. Therefore, with the marine vessel propulsion device 1 of this embodiment, it is possible to reduce the size of the hybrid marine vessel propulsion device 1 equipped with the heat exchanger 43.

[0062] Furthermore, in the marine vessel propulsion unit 1 of this embodiment, an upwardly recessed recess 16 is provided in the rear portion of the underside of the oil pan 15, and the upper portion of the front portion of the motor 17 is disposed within the recess 16. As a result, in the marine vessel propulsion unit 1, when the position of the engine 4 is used as the reference position, the motor 17 can be disposed above by the depth of the recess 16. Therefore, the vertical dimension of the marine vessel propulsion unit 1 can be shortened, and the marine vessel propulsion unit 1 can be made more compact.

[0063] The marine vessel propulsion device 1 of this embodiment also includes an inverter bracket 61. The inverter bracket 61 has an inverter fixing portion 62 that fixes the inverter 19 to the inverter bracket 61, legs 66 that extend downward from the inverter fixing portion 62, and arms 67 that extend forward from the inverter fixing portion 62 or the legs 66. The inverter bracket 61 is supported by both the engine 4 and the motor 17 with the legs 66 connected to the engine 4 and the arms 67 connected to the engine 4. By supporting the inverter bracket 61 on both the engine 4 and the motor 17 in this manner, the support strength and support stability of the inverter 19 and heat exchanger 43 attached to the inverter bracket 61 can be increased. Furthermore, by supporting the inverter bracket 61 on the motor 17, which is formed in a cylindrical shape and therefore has high rigidity, the support strength and support stability of the inverter 19 and heat exchanger 43 can be increased.

[0064] Furthermore, in the marine vessel propulsion device 1 of this embodiment, the inverter fixing portion 62 of the inverter bracket 61 has a left support portion 63 that supports the left portion of the inverter 19 from the left side of the inverter 19, a right support portion 64 that supports the right portion of the inverter 19 from the right side of the inverter 19, and a rear support portion 65 that supports the rear portion of the inverter 19 from the rear of the inverter 19. With this configuration, the inverter 19 can be supported so as to be surrounded by the inverter fixing portion 62, and the inverter 19 and the inverter fixing portion 62 can be integrated. Therefore, the inverter 19 can be firmly fixed to the inverter bracket 61. Furthermore, by configuring the inverter fixing portion 62 to surround the inverter 19 from the left, right, and rear, the inverter 19 can be brought closer to the motor 17 by at least the thickness of the plate-shaped inverter fixing portion, compared to when the inverter 19 is placed on the top surface of the plate-shaped inverter fixing portion. Furthermore, by configuring the inverter fixing portion 62 to surround the inverter 19 from the left, right, and rear, the legs 66 can be made shorter compared to when the inverter 19 is attached to the underside of the plate-shaped inverter fixing portion, thereby increasing the support strength and stability of the inverter 19.

[0065] Furthermore, in the marine vessel propulsion device 1 of this embodiment, the inverter fixing portion 62 is provided with a boss 68 that protrudes upward, and the heat exchanger 43 is fixed to the boss 68. This allows the inverter 19 and the heat exchanger 43 to be attached to the engine 4 and the motor 17 using a single inverter bracket 61. This reduces the number of parts required to attach the inverter 19 and the heat exchanger 43 to the engine 4 and the motor 17, and simplifies the installation work for attaching the inverter 19 and the heat exchanger 43 to the engine 4 and the motor 17.

[0066] The present invention can also be applied to a boat propulsion unit that does not include the heat exchanger 43. The present invention can also be applied to other types of boat propulsion units other than outboard motors.

[0067] Furthermore, the present invention can be modified as appropriate within the scope of the claims and the spirit or concept of the invention that can be read from the entire specification, and a marine propulsion device with such modifications is also included in the technical concept of the present invention. [Explanation of symbols]

[0068] 1 Ship propulsion machine 2 propellers 3 Propeller shaft 4 Engine 5 Engine body 5A rear 6 crankshaft 15 Oil pan (lower extension) 16 Recess 17 Motor 18 Output shaft 19 Inverter 21 Engine drive shaft 22 Motor drive shaft 23 Transmission shaft 24 Power switching mechanism 43 Heat exchanger 61 Inverter bracket 62 Inverter fixing part 63 Left side support part 64 Right side support part 65 Rear support 66 Legs 67 Arm 68 Boss

Claims

1. A marine vessel propulsion device for propelling a marine vessel, Propeller and an engine as a first power source that rotates the propeller; a motor as a second power source that rotates the propeller; an inverter for controlling the driving of the motor; an engine drive shaft connected to a crankshaft of the engine; a motor drive shaft connected to an output shaft of the motor; a transmission shaft connected to a propeller shaft on which the propeller is provided; a power switching mechanism that switches the power source that rotates the propeller between the engine and the motor by switching the connection modes of the engine drive shaft, the motor drive shaft, and the transmission shaft, the engine is disposed vertically so that the extension direction of the rotation axis of the crankshaft is vertical; the engine has a downward extension portion that extends downward from a front portion or a middle portion in the front-rear direction of an engine body of the engine when the engine is disposed vertically, the engine drive shaft is disposed in front of the lower extension portion so as to extend in the vertical direction, the motor is disposed below a rear portion of the engine body such that an extension direction of the output shaft is in a front-rear direction and the position of the output shaft is lower than the downward extension portion, the motor drive shaft is disposed below the downward extension portion so as to extend in the front-to-rear direction; the power switching mechanism is disposed below a lower end of the engine drive shaft and in front of a front end of the motor drive shaft, The marine propulsion device according to claim 1, wherein the inverter is disposed rearward of the downward extension portion and between a rear portion of the engine body and the motor.

2. 2. A marine propulsion device according to claim 1, wherein the downward extension is an oil pan.

3. a heat exchanger that cools a cooling medium and supplies the cooled cooling medium to the motor and the inverter; 2. The marine propulsion device according to claim 1, wherein the heat exchanger is disposed rearward of the downward extension portion and between a rear portion of the engine body and the inverter.

4. 2. The marine vessel propulsion device according to claim 1, wherein a recess recessed upward is provided in a rear portion of the lower surface of the downward extension portion, and at least a portion of the motor is disposed within the recess.

5. an inverter bracket for attaching the inverter to the engine and the motor; 2. The marine propulsion device according to claim 1, wherein the inverter bracket has an inverter fixing portion that fixes the inverter to the inverter bracket, a leg portion that extends downward from the inverter fixing portion, and an arm portion that extends forward from the inverter fixing portion or the leg portion, and the inverter bracket is supported by both the motor and the engine by connecting the leg portion to the motor and the arm portion to the engine.

6. 6. The marine vessel propulsion device according to claim 5, wherein the inverter fixing portion includes a left support portion that supports a left portion of the inverter from the left side of the inverter, a right support portion that supports a right portion of the inverter from the right side of the inverter, and a rear support portion that supports a rear portion of the inverter from behind the inverter.

7. 6. A marine propulsion device according to claim 5, wherein the inverter fixing portion is provided with a boss that protrudes upward, and a heat exchanger is fixed to the boss.

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