Ship propulsion machine

Abstract

To enhance cooling efficiencies for two motors and two inverters and enable cooling capacities for cooling the two motors and two inverters to be easily optimized according to amounts of heat generation of the two motors and the two inverters.SOLUTION: An outboard engine includes: a first motor 11; a second motor 21; a first inverter 31; a second inverter 35; and a cooling mechanism which cools these components. The cooling mechanism includes: a first motor water jacket 81 configured to cool the first motor 11; a second motor water jacket 86 configured to cool the second motor 21; a first inverter water jacket 91 configured to cool the first inverter 31; and a second inverter water jacket 96 configured to cool the second inverter 35. The two motor water jackets 81, 86 connected to each other and the two inverter water jackets 91, 96 connected to each other are connected in parallel to a coolant supply passage 65.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a ship propulsion machine using a motor (electric motor) as a power source for propelling a ship.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2022-34677 (Patent Document 1) describes an electric ship propulsion machine. In an electric ship propulsion machine, an AC motor is often used as a motor serving as a power source for propelling a ship. When an AC motor is used, an inverter for converting a DC current from a battery into an AC current is used to drive the AC motor.

[0003] The motor and the inverter generate heat during operation. An electric ship propulsion machine is provided with a mechanism for cooling the motor and the inverter. For example, the ship propulsion machine described in Japanese Unexamined Patent Application Publication No. 2022-34677 is provided with a cooling water passage through which cooling water flows, and each of the inverter and the motor is provided with a water jacket. A pump, the water jacket of the inverter, and the water jacket of the motor are connected in series to the cooling water passage, and a heat sink for cooling the cooling water flowing through the cooling water passage is attached to a part of the cooling water passage.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, if two motors are provided in a ship propulsion machine and the propeller is rotated by the combined force of the power output from the two motors respectively to generate the propulsion force of the ship, the output of the ship propulsion machine can be increased. Further, by providing a power switching device in the ship propulsion machine that switches between a method of rotating the propeller by the combined force of the power of two motors and a method of rotating the propeller by the power of one motor, for example, it becomes easier to significantly increase or decrease the output of the ship propulsion machine or adjust the electricity cost, and the performance of the ship propulsion machine can be improved.

[0006] When two motors are provided in a ship propulsion machine, it is necessary to provide two inverters in the ship propulsion machine to drive the two motors respectively, and it is also necessary to provide a mechanism for cooling the two motors and the two inverters in the ship propulsion machine.

[0007] As a configuration of the mechanism for cooling the two motors and the two inverters respectively, applying the configuration of the cooling mechanism provided in the ship propulsion machine described in Japanese Patent Application Laid-Open No. 2022-34677, a water jacket is provided for each of the two motors and the two inverters, and a configuration in which a total of four water jackets are connected in series to the cooling water passage is conceivable.

[0008] However, when four water jackets are connected in series to the cooling water passage, the cooling water will flow sequentially through the four water jackets. In that case, the flow path of the cooling water becomes long, the pressure loss becomes large, and there is a risk that the cooling efficiency will decrease.

[0009] Also, when the water jacket of the motor and the water jacket of the inverter are connected in series to the cooling water passage, it is difficult to individually set the flow rate of the cooling water flowing through the water jacket of the motor and the flow rate of the cooling water flowing through the water jacket of the inverter according to the heat generation amount of each of the motor and the inverter. Therefore, it is difficult to individually optimize the cooling capacity for cooling the motor and the cooling capacity for cooling the inverter.

[0010] The present invention has been made in view of the problems as described above, for example. The object of the present invention is, when having two motors and two inverters, to increase the cooling efficiency of the two motors and the two inverters, and also to easily optimize the cooling capacity for cooling each of the two motors and the two inverters according to the amount of heat generated by each of the two motors and the two inverters, and to provide a ship propulsion machine capable of doing so.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention provides a marine propulsion device comprising a first motor, a second motor, a first inverter that generates a drive current for driving and controlling the first motor, a second inverter that generates a drive current for driving and controlling the second motor, a propeller, a power transmission mechanism that transmits the power of each of the first motor and the second motor to the propeller, and a cooling mechanism that cools the first motor, the second motor, the first inverter, and the second inverter. The cooling mechanism includes a first motor water jacket provided in the first motor and cooling the first motor by circulating cooling water therein, a second motor water jacket provided in the second motor and cooling the second motor by circulating cooling water therein, a first inverter water jacket provided in the first inverter and cooling the first inverter by circulating cooling water therein, a second inverter water jacket provided in the second inverter and cooling the second inverter by circulating cooling water therein, a first cooling water passage that circulates cooling water toward the first motor water jacket and the first inverter water jacket, a branch passage that connects the first motor water jacket and the first inverter water jacket in parallel to the first cooling water passage and distributes and supplies the cooling water flowing in the first cooling water passage to the first motor water jacket and the first inverter water jacket, a first connection passage that connects the second motor water jacket to the downstream side of the first motor water jacket and sends the cooling water that has flowed through the first motor water jacket to the second motor water jacket, and a second connection passage that connects the second inverter water jacket to the downstream side of the first inverter water jacket and sends the cooling water that has flowed through the first inverter water jacket to the second inverter water jacket.

Advantages of the Invention

[0012] According to the present invention, when having two motors and two inverters, the cooling efficiency of the two motors and the two inverters can be enhanced, and the cooling capacity for cooling each of the two motors and the two inverters according to the heat generation amount of each of the two motors and the two inverters can be easily optimized.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

DETAILED DESCRIPTION OF THE INVENTION

[0014] The ship propulsion machine according to the embodiment of the present invention includes a first motor, a second motor, a first inverter that generates a drive current for driving and controlling the first motor, a second inverter that generates a drive current for driving and controlling the second motor, a propeller, a power transmission mechanism that transmits the power of each of the first motor and the second motor to the propeller, and a cooling mechanism that cools the first motor, the second motor, the first inverter, and the second inverter.

[0015] In the ship propulsion machine of the present embodiment, the cooling mechanism includes a first motor water jacket provided in the first motor and cooling the first motor by circulating cooling water inside, a second motor water jacket provided in the second motor and cooling the second motor by circulating cooling water inside, a first inverter water jacket provided in the first inverter and cooling the first inverter by circulating cooling water inside, and a second inverter water jacket provided in the second inverter and cooling the second inverter by circulating cooling water inside.

[0016] Furthermore, the cooling mechanism includes a first cooling water passage for circulating cooling water toward the first motor water jacket and the first inverter water jacket, a branch passage that connects the first motor water jacket and the first inverter water jacket in parallel to the first cooling water passage and distributes and supplies the cooling water flowing in the first cooling water passage to the first motor water jacket and the first inverter water jacket, a first connection passage that connects a second motor water jacket to the downstream side of the first motor water jacket and sends the cooling water that has flowed through the first motor water jacket to the second motor water jacket, and a second connection passage that connects a second inverter water jacket to the downstream side of the first inverter water jacket and sends the cooling water that has flowed through the first inverter water jacket to the second inverter water jacket.

[0017] In the cooling mechanism of the outboard motor of the present embodiment, the first motor water jacket and the second motor water jacket connected to each other by the first connection passage, and the first inverter water jacket and the second inverter water jacket connected to each other by the second connection passage are connected in parallel to the first cooling water passage via the branch passage. As a result, compared with the case where the first motor water jacket, the second motor water jacket, the first inverter water jacket, and the second inverter water jacket are connected in series to the first cooling water passage, the flow path of the cooling water in the cooling mechanism can be shortened. Thereby, the pressure loss of the cooling water flowing through the flow path can be reduced, and the circulation of the cooling water can be made smooth. Therefore, the cooling efficiency of the first motor, the second motor, the first inverter, and the second inverter can be improved.

[0018] In addition, in the cooling mechanism of the present embodiment, the first motor water jacket and the second motor water jacket connected to each other, and the first inverter water jacket and the second inverter water jacket connected to each other are connected in parallel via a branch path to the first cooling water path. Therefore, according to the heat generation amounts of the first motor and the second motor, and the heat generation amounts of the first inverter and the second inverter, it becomes easy to individually set the flow rate of the cooling water flowing through the first motor water jacket and the second motor water jacket, and the flow rate of the cooling water flowing through the first inverter water jacket and the second inverter water jacket. Therefore, the cooling capacity for cooling the first motor and the second motor, and the cooling capacity for cooling the first inverter and the second inverter can be easily optimized respectively.

Example

[0019] An example of a marine propulsion device of the present invention will be described with reference to the drawings. In the description of this example, when describing the directions of up (Ud), down (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd), follow the arrows drawn in the lower right of each figure except for FIG. 6.

[0020] (Outboard motor) FIG. 1 shows the entirety of an outboard motor 1 which is an example of a marine propulsion device of the present invention. In FIG. 1, the outboard motor 1 includes a first motor 11, a second motor 21, a first inverter 31, a second inverter 35, a propeller 41, a drive shaft 42, a propeller shaft 43, a gear mechanism 44, and a power switching mechanism 51. The outboard motor 1 also includes a cooling mechanism 61 shown in FIG. 6.

[0021] The first motor 11 and the second motor 21 are each an alternating current motor, and generate power for propelling the ship. The first motor 11 is attached to the motor holder 10. The second motor 21 is attached to the first motor 11. The first inverter 31 is a device that generates a drive current for driving and controlling the first motor 11, and is attached to the first motor 11. The second inverter 35 is a device that generates a drive current for driving and controlling the second motor 21, and is attached to the second motor 21. The first motor 11, the second motor 21, the first inverter 31, the second inverter 35, and the motor holder 10 are arranged at the upper part of the outboard motor 1 and are covered by the motor cover 2.

[0022] The propeller 41 converts the power of the first motor 11 and the power of the second motor 21 into the propulsive force of the ship. The drive shaft 42, the propeller shaft 43, and the gear mechanism 44 are power transmission mechanisms that transmit the power of the first motor 11 and the power of the second motor 21 to the propeller 41. The propeller 41, the propeller shaft 43, and the gear mechanism 44 are arranged at the lower part of the outboard motor 1. The drive shaft 42 extends vertically between the upper and lower parts of the outboard motor 1.

[0023] The upper end of the drive shaft 42 is connected to the first motor 11 and the second motor 21 via the power switching mechanism 51. The gear mechanism 44 has a drive gear 45 and a driven gear 46. The drive gear 45 is fixed to the lower end of the drive shaft 42, and the driven gear 46 is fixed to the front end of the propeller shaft 43. Both the drive gear 45 and the driven gear 46 are bevel gears and mesh with each other. Also, the propeller 41 is fixed to the rear end of the propeller shaft 43. Also, the drive shaft 42 is housed in the drive shaft case 3. Also, the propeller shaft 43 and the gear mechanism 44 are housed in the gear case 4.

[0024] The power switching mechanism 51 is a mechanism that switches the connection modes of the first motor 11, the second motor 21, and the drive shaft 42, and is disposed between the first motor 11 and the second motor 21.

[0025] In addition, the outboard motor 1 is provided with a clamp mechanism 48 for attaching the outboard motor 1 to the transom of the ship. In a state where the outboard motor 1 is attached to the transom of the ship, the lower part of the outboard motor 1, specifically, the lower part of the drive shaft case 3 and the gear case 4 are located below the water surface.

[0026] FIG. 2 shows a state of a unit formed by the first motor 11, the second motor 21, the first inverter 31, the second inverter 35, the motor holder 10, etc. as viewed from the upper left in the front. FIG. 3 shows a state of the unit as viewed from the left. FIG. 4(A) shows a state of the unit as viewed from the rear, and FIG. 4(B) shows a state of the unit as viewed from above. FIG. 5(A) shows a state of a cross-section of the unit cut along the cutting line V-V in FIG. 3 as viewed from above. FIG. 5(B) shows the power switching mechanism 51.

[0027] As shown in FIG. 2, the motor holder 10 is a robust structure having a three-dimensional shape serving as a base for the first motor 11 and the second motor 21, and is formed of, for example, a metal material. The first motor 11 is placed on the upper surface of the front part of the motor holder 10 and is firmly fixed to the motor holder 10 using a fixing member such as a bolt.

[0028] As shown in FIG. 3, the first motor 11 has a motor shaft 12, a rotor 13 provided on the outer peripheral side of the motor shaft 12, a stator 14 provided on the outer peripheral side of the rotor 13, a cylindrical motor housing 15 provided on the outer peripheral side of the stator 14, and two motor brackets 16, 17 provided on one side and the other side (upper side and lower side) in the axial direction of the motor housing 15, respectively.

[0029] The basic structure of the second motor 21 is the same as that of the first motor 11. The second motor 21 has a motor shaft 22, a rotor 23, a stator 24, a motor housing 25, and two motor brackets 26, 27. However, as will be described later, the motor shaft 12 of the first motor 11 is formed in a cylindrical shape and has a structure in which the upper part of the drive shaft 42 is inserted therein, while the motor shaft 22 of the second motor 21 does not have such a structure and is simply formed in a cylindrical shape.

[0030] The first inverter 31 has an inverter main body 32 and a rectangular parallelepiped-shaped inverter housing 33 that houses the inverter main body 32. The inverter main body 32 generates a drive current for driving and controlling the first motor 11 by converting the current supplied from the battery from direct current to alternating current. The inverter main body 32 includes components such as power semiconductors that generate a large amount of heat.

[0031] The basic structure of the second inverter 35 is the same as that of the first inverter 31. The second inverter 35 has an inverter main body 36 and a rectangular parallelepiped-shaped inverter housing 37.

[0032] The first motor 11 is arranged on the motor holder 10 such that the extending direction of the motor shaft 12, that is, the extending direction of the rotation axis E of the first motor 11, is in the vertical direction. The second motor 21 is arranged above the first motor 11 such that the extending direction of the motor shaft 22, that is, the extending direction of the rotation axis F of the second motor 21, is in the vertical direction. Also, the first motor 11 and the second motor 21 are arranged such that their respective rotation axes E, F are coaxial.

[0033] Further, the second motor 21 is attached to and fixed to the first motor 11 via a plurality of support members 29. That is, a plurality of support members 29 extending in the vertical direction are provided between the upper motor bracket 17 of the first motor 11 and the lower motor bracket 26 of the second motor 21. As shown in FIG. 5(A), the plurality of support members 29 are arranged on the outer peripheral side of the motor brackets 17 and 26. For example, each support member 29 is formed with a bolt hole penetrating in the axial direction thereof, bolt holes are also formed at the locations on the outer peripheral side of the motor bracket 17 where the support members 29 are arranged, and bolt holes are also formed at the locations on the outer peripheral side of the motor bracket 26 where the support members 29 are arranged. Each support member 29 is fixed between the motor bracket 17 and the motor bracket 26 by inserting a long bolt into the bolt hole of the motor bracket 26, the bolt hole of the support member 29, and the bolt hole of the motor bracket 17 and fastening a nut to the end of the bolt. Thereby, the second motor 21 is fixed above the first motor 11. Further, by interposing a plurality of support members 29 between the first motor 11 and the second motor 21, a space is formed between the first motor 11 and the second motor 21.

[0034] Further, the first inverter 31 is disposed behind the first motor 11. The first inverter 31 is attached and fixed to the first motor 11 via inverter attachment portions 18 provided at the rear portions of two motor brackets 16 and 17 of the first motor 11, respectively. Also, the second inverter 35 is disposed behind the second motor 21 and above the first inverter 31. The second inverter 35 is attached and fixed to the second motor 21 via inverter attachment portions 28 provided at the rear portions of two motor brackets 26 and 27 of the second motor 21, respectively. Further, as shown in FIGS. 3 and 4(A), the first inverter 31 and the second inverter 35 have the same positions in their front-rear direction and left-right direction. That is, the second inverter 35 is disposed directly above the first inverter 31. In the present embodiment, the front-rear direction corresponds to the "Y direction" in the description of the claims, the upper side or the upper portion corresponds to the "one side in the X direction" in the description of the claims, and the rear side or the rear portion corresponds to the "one side in the Y direction" in the description of the claims.

[0035] (Power switching mechanism) Here, the power switching mechanism 51 will be described. The power switching mechanism 51 is a mechanism that switches the connection modes of the first motor 11, the second motor 21, and the drive shaft 42 among a connection mode A in which the first motor 11 and the second motor 21 are connected to the drive shaft 42, a connection mode B in which only the first motor 11 is connected to the drive shaft 42, and a connection mode C in which only the second motor 21 is connected to the drive shaft 42. In the connection mode A, the power of both the first motor 11 and the second motor 21 is transmitted to the drive shaft 42, and the propeller 41 rotates by the combined force of the power of both the first motor 11 and the second motor 21. In the connection mode B, only the power of the first motor 11 is transmitted to the drive shaft 42, and the propeller 41 rotates by only the power of the first motor 11 among the first motor 11 and the second motor 21. In the connection mode C, only the power of the second motor 21 is transmitted to the drive shaft 42, and the propeller 41 rotates by only the power of the second motor 21 among the first motor 11 and the second motor 21.

[0036] As shown in FIG. 5(B), the upper end portion of the motor shaft 12 of the first motor 11 and the lower end portion of the motor shaft 22 of the second motor 21 face each other within the space formed between the first motor 11 and the second motor 21. Also, the upper portion of the drive shaft 42 is located within the space formed between the first motor 11 and the second motor 21 through the inner peripheral side of the cylindrical motor shaft 12 of the first motor 11. Although the upper portion of the drive shaft 42 is inserted into the inner peripheral side of the motor shaft 12, the outer peripheral surface of the drive shaft 42 and the inner peripheral surface of the motor shaft 12 do not contact each other. Therefore, the drive shaft 42 and the motor shaft 12 can rotate independently of each other.

[0037] Further, a dog clutch 52 formed in a cylindrical shape is provided at the upper end of the drive shaft 42. The dog clutch 52 is attached to the outer peripheral side of the upper end of the drive shaft 42 so as not to be rotatable with respect to the drive shaft 42 and to be movable in the vertical direction with respect to the drive shaft 42. Further, a fitting member 53 is attached and fixed to the upper end of the motor shaft 12 of the first motor 11. Further, a fitting member 54 is attached and fixed to the lower end of the motor shaft 22 of the second motor 21. The dog clutch 52 is positioned between the fitting member 53 and the fitting member 54. Further, teeth are formed on each of the lower end and the upper end of the dog clutch 52. Further, teeth that can be engaged with the teeth at the lower end of the dog clutch 52 are formed on the fitting member 53, and teeth that can be engaged with the teeth at the upper end of the dog clutch 52 are formed on the fitting member 54.

[0038] Further, a clutch control device 55 for switching and controlling the dog clutch 52 is provided in the vicinity of the dog clutch 52 within the space between the first motor 11 and the second motor 21. The clutch control device 55 is disposed on the left front side of the first motor 11 and the second motor 21. The clutch control device 55 includes a clutch cam shaft 56, a cam groove 57, and a fork unit 58.

[0039] The clutch camshaft 56 extends in the vertical direction, with its lower end rotatably supported by the motor bracket 17 above the first motor 11 and its upper end rotatably supported by the motor bracket 26 below the second motor 21. The cam groove 57 is formed on the outer peripheral surface of the clutch camshaft 56. The fork unit 58 is attached to the clutch camshaft 56. The fork unit 58 has a cylindrical base 58A, a driven pin 58B provided on the base 58A, and a fork portion 58C extending from the base 58A toward the dog clutch 52. The base 58A is disposed on the outer peripheral side of the clutch camshaft 56, and the tip of the driven pin 58B is inserted into the cam groove 57 of the clutch camshaft 56. Also, as shown in Fig. 5(A), the tip of the fork portion 58C is bifurcated and grips the dog clutch 52. The gripping of the dog clutch 52 by the fork portion 58C is not firm, and therefore, the dog clutch 52 can rotate while being gripped by the fork portion 58C.

[0040] The clutch camshaft 56 and the fork unit 58 constitute a cylindrical cam. For example, when the clutch camshaft 56 rotates in one direction, the fork unit 58 moves upward, and accordingly, the dog clutch 52 moves upward. On the other hand, when the clutch camshaft 56 rotates in the other direction, the fork unit 58 moves downward, and accordingly, the dog clutch 52 moves downward.

[0041] When the dog clutch 52 is located at the intermediate portion between the fitted member 53 and the fitted member 54, the teeth at the lower end of the dog clutch 52 engage with the teeth of the fitted member 53, and at the same time, the teeth at the upper end of the dog clutch 52 engage with the teeth of the fitted member 54. As a result, both the motor shaft 12 of the first motor 11 and the motor shaft 22 of the second motor 21 are connected to the drive shaft 42, and the connection mode of the first motor 11, the second motor 21, and the drive shaft 42 becomes connection mode A.

[0042] Also, when the dog clutch 52 moves to the lower part between the fitted member 53 and the fitted member 54, the teeth at the lower end of the dog clutch 52 and the teeth of the fitted member 53 are engaged with each other, and the engagement between the teeth at the upper end of the dog clutch 52 and the teeth of the fitted member 54 is released. As a result, only the motor shaft 12 of the first motor 11 is connected to the drive shaft 42, and the connection mode of the first motor 11, the second motor 21, and the drive shaft 42 becomes the connection mode B.

[0043] Also, when the dog clutch 52 moves to the upper part between the fitted member 53 and the fitted member 54, the teeth at the upper end of the dog clutch 52 and the teeth of the fitted member 54 are engaged with each other, and the engagement between the teeth at the lower end of the dog clutch 52 and the teeth of the fitted member 53 is released. As a result, only the motor shaft 22 of the second motor 21 is connected to the drive shaft 42, and the connection mode of the first motor 11, the second motor 21, and the drive shaft 42 becomes the connection mode C.

[0044] Although not shown in the figure, the outboard motor 1 is provided with an actuator (for example, a DC motor) that rotates the clutch cam shaft 56 based on an operation signal input from the outside, and the connection mode of the first motor 11, the second motor 21, and the drive shaft 42 can be switched based on the operation signal.

[0045] The outboard motor 1 has the first motor 11 and the second motor 21, and since the connection mode of the first motor 11, the second motor 21, and the drive shaft 42 can be switched, the performance of the outboard motor 1 can be improved. Specifically, the output or torque of the outboard motor 1 can be significantly changed according to the navigation status of the ship, etc., and the electricity cost of the outboard motor 1 can be adjusted. Also, for example, when one of the first motor 11 and the second motor 21 fails during navigation, the failed motor can be disconnected from the drive shaft 42, and the non-failed motor can be connected to the drive shaft 42, so that the propeller 41 can be rotated only by the power of the non-failed motor to move the ship.

[0046] (Configuration of the Cooling Mechanism) FIG. 6 shows the configuration of a cooling mechanism 61 provided in the outboard motor 1. FIG. 7 shows a state in which a unit formed by the first motor 11, the second motor 21, the first inverter 31, the second inverter 35, the motor holder 10, etc. is cut along the cutting line VII-VII in FIG. 4(B), and the cross section thereof is viewed from the left (lower in FIG. 4(B)). FIG. 8 shows a state in which the cross section of the above unit cut along the cutting line VIII-VIII in FIG. 4(B) is viewed from the right (upper in FIG. 4(B)). FIG. 9 shows a state in which the cross section of the above unit cut along the cutting line IX-IX in FIG. 7 is viewed from above.

[0047] The cooling mechanism 61 is a mechanism that uses the water around the outboard motor 1 as cooling water to cool the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35. As shown in FIG. 6, the cooling mechanism 61 includes a water intake 62, a water intake passage 63, a pump 64, a cooling water supply passage 65, a branch passage 66, a first motor water jacket 81, a motor water jacket connecting pipe 85, a second motor water jacket 86, a first inverter water jacket 91, an inverter water jacket connecting pipe 95, a second inverter water jacket 96, a confluence passage 101, a cooling water discharge passage 105, a drain port 106, and a control valve 107.

[0048] As shown in FIG. 1, the water intake 62 is an opening for taking the water around the outboard motor 1 into the cooling mechanism 61, and is provided in the gear case 4. A strainer for preventing dust, algae, etc. in the water around the outboard motor 1 from entering the cooling mechanism 61 is attached to the water intake 62.

[0049] The water intake passage 63 is a passage that connects between the water intake 62 and the suction port of the pump 64 and sends the water flowing into the water intake 62 to the pump 64.

[0050] The pump 64 is a device that sucks up the water flowing into the water intake 62 and discharges the water into the cooling water supply path 65 as cooling water, thereby circulating the cooling water in the cooling mechanism 61. As the pump 64, various pumps such as a Yabuko pump can be used. In this embodiment, the pump 64 is driven by utilizing the rotation of the drive shaft 42.

[0051] The cooling water supply path 65 is a passage for circulating the cooling water toward the first motor water jacket 81 and the first inverter water jacket 91. The cooling water supply path 65 is formed by, for example, a hose. The lower end of the cooling water supply path 65 is connected to the discharge port of the pump 64, and the upper end of the cooling water supply path 65 is connected to the branch path 66 as shown in FIG. 7. Note that the cooling water supply path is a specific example of the "first cooling water path".

[0052] As shown in FIG. 6, the branch path 66 connects the first motor water jacket 81 and the first inverter water jacket 91 in parallel to the cooling water supply path 65, and distributes and supplies the cooling water flowing in the cooling water supply path 65 to the first motor water jacket 81 and the first inverter water jacket 91. The branch path 66 is formed by the main line passage hole 67, the branch line passage holes 68 and 69 formed in the motor holder 10 as shown in FIG. 7, the connecting pipe 70 shown in FIG. 7, and the connecting pipe 71 shown in FIG. 3. As shown in FIG. 7, the upper end of the lower end of the main line passage hole 67 is connected to the cooling water supply path 65. The main line passage hole 67 branches into two branch line passage holes 68 and 69 after extending upward in the motor holder 10. The lower end of the connecting pipe 70 disposed in the motor holder 10 is connected to the upper end of one of the branch line passage holes 68, and the upper end of the connecting pipe 70 is connected to the inlet 82 of the first motor water jacket 81. As shown in FIG. 3, the lower end of the connecting pipe 71 disposed outside the motor holder 10 is connected to the upper end of the other branch line passage hole 69, and the upper end of the connecting pipe 71 is connected to the inlet 92 of the first inverter water jacket 91.

[0053] The first motor water jacket 81 is provided on the first motor 11 and is a mechanism for cooling the first motor 11 by circulating cooling water inside. As shown in FIG. 9, the first motor water jacket 81 is provided so as to surround the first motor 11 on the outer peripheral side of the first motor 11. Specifically, the first motor water jacket 81 is disposed between the stator 14 and the motor housing 15 of the first motor 11 and surrounds the stator 14. Further, an internal passage 83 for circulating cooling water is formed inside the first motor water jacket 81. The internal passage 83 surrounds the stator 14. Also, as shown in FIG. 7, the first motor water jacket 81 covers the stator 14 over a wide range from the lower end side portion to the upper end side portion of the stator 14. Further, the internal passage 83 is formed from the lower end side portion to the upper end side portion of the stator 14.

[0054] The first motor water jacket 81 also has an inlet 82 through which the cooling water supplied via the branch passage 66 flows into the internal passage 83 inside the first motor water jacket 81. The inlet 82 communicates with the inside of the internal passage 83. As shown in FIGS. 7 and 9, the inlet 82 is disposed at the lower left rear portion of the first motor 11. Also, the inlet 82 opens downward toward the outside of the first motor water jacket 81. The upper end portion of the connecting pipe 70 of the branch passage 66 is connected to the inlet 82.

[0055] The first motor water jacket 81 also has an outlet 84 through which the cooling water that has circulated inside the internal passage 83 of the first motor water jacket 81 flows out of the first motor water jacket 81. The outlet 84 communicates with the inside of the internal passage 83. As shown in FIGS. 8 and 9, the outlet 84 is disposed at the upper right front portion of the first motor 11. Also, the outlet 84 opens upward toward the outside of the first motor water jacket 81. The lower end portion of the motor water jacket connecting pipe 85 is connected to the outlet 84.

[0056] The motor water jacket connecting pipe 85 is a pipe such as a pipe or a hose that connects the second motor water jacket 86 to the downstream side of the first motor water jacket 81 and forms a passage for sending the cooling water after flowing through the first motor water jacket 81 to the second motor water jacket 86. As shown in FIG. 8, the motor water jacket connecting pipe 85 extends linearly in the vertical direction, the lower end is connected to the outlet 84 of the first motor water jacket 81, and the upper end is connected to the inlet 87 of the second motor water jacket 86. Further, as shown in FIG. 5(A), the motor water jacket connecting pipe 85 is disposed at the right front portion between the first motor 11 and the second motor 21. Note that the motor water jacket connecting pipe 85 is a specific example of the "first connecting path".

[0057] The second motor water jacket 86 is a mechanism provided in the second motor 21 for cooling the second motor 21 by circulating cooling water inside. As shown in FIGS. 3, 4, 7, and 8, the second motor water jacket 86 is provided so as to surround the second motor 21 on the outer peripheral side of the second motor 21. Specifically, the second motor water jacket 86 is disposed between the stator 24 and the motor housing 25 of the second motor 21 and surrounds the stator 24. The basic structure of the second motor water jacket 86 is the same as that of the first motor water jacket 81. The internal passage 88 formed inside the second motor water jacket 86 surrounds the stator 24 of the second motor 21. Further, the internal passage 88 is formed from the lower end side portion to the upper end side portion of the stator 24. Further, the second motor water jacket 86 has an inlet 87 through which the cooling water flowing out from the outlet 84 of the first motor water jacket 81 and sent through the motor water jacket connecting pipe 85 flows into the internal passage 88 of the second motor water jacket 86. Further, the second motor water jacket 86 has an outlet 89 through which the cooling water flowing through the internal passage 88 of the second motor water jacket 86 flows out of the second motor water jacket 86.

[0058] However, the arrangement of the inlet 87 of the second motor water jacket 86 is different from the arrangement of the inlet 82 of the first motor water jacket 81. The inlet 82 of the first motor water jacket 81 is arranged at the lower left rear part of the first motor 11, while the inlet 87 of the second motor water jacket 86 is arranged at the lower right front part of the second motor 21 as shown in FIG. 8. Further, the inlet 87 of the second motor water jacket 86 is arranged directly above the outlet 84 of the first motor water jacket 81. That is, the front-rear direction and the left-right direction positions of the outlet 84 of the first motor water jacket 81 and the inlet 87 of the second motor water jacket 86 are the same as each other. Also, the inlet 87 opens downward toward the outside of the second motor water jacket 86. Further, the upper end portion of the motor water jacket connecting pipe 85 is connected to the inlet 87 of the second motor water jacket 86. Since the front-rear direction and the left-right direction positions of the outlet 84 of the first motor water jacket 81 and the inlet 87 of the second motor water jacket 86 are the same as each other and they open so as to face each other, the motor water jacket connecting pipe 85 connecting the outlet 84 of the first motor water jacket 81 and the inlet 87 of the second motor water jacket 86 extends linearly.

[0059] Also, the arrangement of the outlet 89 of the second motor water jacket 86 is different from the arrangement of the outlet 84 of the first motor water jacket 81. The outlet 84 of the first motor water jacket 81 is arranged at the upper right front part of the first motor 11, while the outlet 89 of the second motor water jacket 86 is arranged at the upper left rear part of the second motor 21 as shown in FIG. 7. Further, the outlet 89 opens upward toward the outside of the second motor water jacket 86. The internal passage 88 of the second motor water jacket 86 communicates with the inside of the confluence chamber 103 through the outlet 89.

[0060] The first inverter water jacket 91 is provided in the first inverter 31 and is a mechanism for cooling the inverter body 32 of the first inverter 31 by circulating cooling water inside. As shown in FIGS. 7 and 9, the first inverter water jacket 91 is provided inside the inverter housing 33 of the first inverter 31 and is arranged in front of the inverter body 32. The first inverter water jacket 91 widely covers the front surface of the inverter body 32 from its left end to its right end and from its lower end to its upper end. Further, an internal passage 93 for circulating cooling water is formed inside the first inverter water jacket 91. The internal passage 93 is formed so as to widely cover the front surface of the inverter body 32 from its left end to its right end and from its lower end to its upper end.

[0061] The first inverter water jacket 91 also has an inlet 92 through which the cooling water supplied via the branch passage 66 flows into the internal passage 93 of the first inverter water jacket 91. The inlet 92 communicates with the inside of the internal passage 93. As shown in FIG. 9, the inlet 92 is arranged at the lower left part of the first inverter 31. Further, the inlet 92 opens leftward toward the outside of the first inverter water jacket 91. The upper end of the connecting pipe 71 of the branch passage 66 is connected to the inlet 92.

[0062] The first inverter water jacket 91 also has an outlet 94 through which the cooling water flowing through the internal passage 93 of the first inverter water jacket 91 flows out of the first inverter water jacket 91. The outlet 94 communicates with the internal passage 93. As shown in FIG. 8, the outlet 94 is arranged at the upper right part of the first inverter 31. Further, the outlet 94 opens upward toward the outside of the first inverter water jacket 91. The lower end of the inverter water jacket connecting pipe 95 is connected to the outlet 94.

[0063] The inverter water jacket connecting pipe 95 is a pipe such as a pipe or a hose that connects the second inverter water jacket 96 to the downstream side of the first inverter water jacket 91 and forms a passage for sending the cooling water after flowing through the first inverter water jacket 91 to the second inverter water jacket 96. As shown in FIGS. 4 and 8, the inverter water jacket connecting pipe 95 is disposed between the right part of the first inverter 31 and the right part of the second inverter 35. Further, the inverter water jacket connecting pipe 95 extends linearly in the vertical direction, the lower end is connected to the outlet 94 of the first inverter water jacket 91, and the upper end is connected to the inlet 97 of the second inverter water jacket 96. Note that the inverter water jacket connecting pipe 95 is a specific example of the "second connecting path".

[0064] The second inverter water jacket 96 is a mechanism provided in the second inverter 35 and cools the second inverter 35 by circulating cooling water inside. The second inverter water jacket 96 is provided in the inverter housing 37 of the second inverter 35 and is disposed in front of the inverter body 36. The basic structure of the second inverter water jacket 96 is the same as that of the first inverter water jacket 91. The internal passage 98 formed inside the second inverter water jacket 96 widely covers the front surface of the inverter body 36 from its left end to its right end and from its lower end to its upper end. Further, the second inverter water jacket 96 has an inlet 97 for allowing the cooling water flowing out from the outlet 94 of the first inverter water jacket 91 and sent through the inverter water jacket connecting pipe 95 to flow into the internal passage 98 of the second inverter water jacket 96. Also, the second inverter water jacket 96 has an outlet 99 for allowing the cooling water flowing through the internal passage 98 of the second inverter water jacket 96 to flow out of the second inverter water jacket 96.

[0065] However, the arrangement of the inlet 97 of the second inverter water jacket 96 is different from that of the inlet 92 of the first inverter water jacket 91. The inlet 92 of the first inverter water jacket 91 is arranged at the lower left part of the first inverter 31, while the inlet 97 of the second inverter water jacket 96 is arranged at the lower right part of the second inverter 35 as shown in FIG. 8. Also, the inlet 97 of the second inverter water jacket 96 is arranged directly above the outlet 94 of the first inverter water jacket 91. That is, the front-rear direction and the left-right direction positions of the outlet 94 of the first inverter water jacket 91 and the inlet 97 of the second inverter water jacket 96 are the same as each other. Further, the inlet 97 opens downward toward the outside of the second inverter water jacket 96. Also, the upper end portion of the inverter water jacket connecting pipe 95 is connected to the inlet 97 of the second inverter water jacket 96. Since the front-rear direction and the left-right direction positions of the outlet 94 of the first inverter water jacket 91 and the inlet 97 of the second inverter water jacket 96 are the same as each other and they open so as to face each other, the inverter water jacket connecting pipe 95 connecting the outlet 94 of the first inverter water jacket 91 and the inlet 97 of the second inverter water jacket 96 extends linearly.

[0066] Also, the arrangement of the outlet 99 of the second inverter water jacket 96 is different from the arrangement of the outlet 94 of the first inverter water jacket 91. The outlet 94 of the first inverter water jacket 91 is arranged at the upper right part of the first inverter 31, while the outlet 99 of the second inverter water jacket 96 is arranged at the upper left part of the second inverter 35 as shown in FIG. 7. Further, the outlet 99 opens upward toward the outside of the second inverter water jacket 96. Also, the lower end of the connecting pipe 104 is connected to the outlet 99. Also, as shown in FIG. 4(B), in the left-right direction, the position of the outlet 99 of the second inverter water jacket 96 is substantially the same as the position of the outlet 89 of the second motor water jacket 86. In this embodiment, the left-right direction corresponds to the "Z direction" in the description of the claims, the left side corresponds to the "one side in the Z direction" in the description of the claims, and the right side corresponds to the "other side in the Z direction" in the description of the claims.

[0067] The confluence passage 101 is connected to the outlet 89 of the second motor water jacket 86, the outlet 99 of the second inverter water jacket 96, and the cooling water discharge passage 105, and is a passage for combining the cooling water flowing out from the outlet 89 of the second motor water jacket 86 and the cooling water flowing out from the outlet 99 of the second inverter water jacket 96 and allowing them to flow into the cooling water discharge passage 105. As shown in FIG. 7, the confluence passage 101 is formed by a confluence chamber 103 and a connecting pipe 104. As shown in FIG. 2, a confluence chamber forming portion 102 protruding upward is formed at the left rear portion of the upper motor bracket 27 of the second motor 21. As shown in FIG. 7, a confluence chamber 103 is formed in the confluence chamber forming portion 102. The outlet 89 of the second motor water jacket 86 is connected to the bottom of the confluence chamber forming portion 102, and the internal passage 88 of the second motor water jacket 86 communicates with the inside of the confluence chamber 103 through the outlet 89. Further, the front end portion of the connecting pipe 104 is connected to the rear portion of the peripheral portion of the confluence chamber forming portion 102, and the internal passage 98 of the second inverter water jacket 96 communicates with the inside of the confluence chamber 103 through the outlet 99 and the connecting pipe 104. Further, the upper end portion of the cooling water discharge passage 105 is connected to the upper portion of the confluence chamber forming portion 102, and the confluence chamber 103 communicates with the inside of the cooling water discharge passage 105.

[0068] The cooling water discharge passage 105 is a passage for allowing the cooling water that has flowed out from the inside of the second motor water jacket 86 and the second inverter water jacket 96 to flow through. The lower end side of the cooling water discharge passage 105 is connected to a drain port 106 (see FIG. 6). The drain port 106 is provided, for example, at the rear portion of the lower part of the outboard motor 1. Further, the cooling water discharge passage 105 is a specific example of the "second cooling water passage".

[0069] The control valve 107 is a valve that controls the flow rate of the cooling water after it has merged in the confluence path 101. As shown in FIG. 7, the control valve 107 is located above the confluence chamber 103, between the confluence position P where the cooling water flowing out from the outlet 89 of the second motor water jacket 86 and the cooling water flowing out from the outlet 99 of the second inverter water jacket 96 merge, and the connection position Q of the cooling water discharge path 105. The control valve 107 changes the valve opening degree according to the temperature of the cooling water after confluence, and adjusts the temperature of the cooling water. Specifically, the control valve 107 increases the valve opening degree in response to an increase in the temperature of the cooling water after confluence. Thereby, when the temperature of the cooling water rises, the flow rates of the cooling water flowing through the first motor water jacket 81, the second motor water jacket 86, the first inverter water jacket 91, and the second inverter water jacket 96 can be increased, and the temperature of the cooling water can be lowered. For example, the control valve 107 has a sensor for detecting the temperature of the cooling water in the confluence chamber 103. For example, a thermostat can be used as the control valve 107.

[0070] In addition, a bypass passage may be added to directly connect between the cooling water supply path 65 and the drain port 106, and a relief valve for communicating and shutting off the bypass passage may be provided in the bypass passage. The relief valve closes when the pressure in the cooling water supply path 65 is below a predetermined pressure, and opens when the pressure in the cooling water supply path 65 exceeds the predetermined pressure.

[0071] (Operation of the cooling mechanism) The operation of the cooling mechanism 61 is as follows. As the drive shaft 42 rotates due to the driving of the first motor 11 and the second motor 21, the pump 64 is driven. By driving the pump 64, the water flowing into the water intake 62 is sucked up, flows through the water intake passage 63, and flows into the suction port of the pump 64. Subsequently, it flows into the cooling water supply passage 65 as cooling water from the discharge port of the pump 64. The cooling water flows through the cooling water supply passage 65, moves to the upper part of the outboard motor 1, and flows into the main passage hole 67 of the branch passage 66. In the branch passage 66, the cooling water flowing into the main passage hole 67 is divided into the cooling water flowing through the branch passage hole 68 and the connecting pipe 70 and the cooling water flowing through the branch passage hole 69 and the connecting pipe 71.

[0072] The cooling water flowing through the branch passage hole 68 and the connecting pipe 70 flows into the internal passage 83 of the first motor water jacket 81 through the inlet 82 of the first motor water jacket 81. The cooling water flowing into the internal passage 83 flows through the internal passage 83, receives the heat of the first motor 11 during that time, and flows into the motor water jacket connecting pipe 85 through the outlet 84 of the first motor water jacket 81.

[0073] The cooling water flowing into the motor water jacket connecting pipe 85 flows through the motor water jacket connecting pipe 85 and flows into the internal passage 88 of the second motor water jacket 86 through the inlet 87 of the second motor water jacket 86. The cooling water flowing into the internal passage 88 flows through the internal passage 88, receives the heat of the second motor 21 during that time, and flows into the confluence chamber 103 through the outlet 89 of the second motor water jacket 86.

[0074] On one hand, the cooling water flowing through the branch passage hole 69 and the connecting pipe 71 enters the internal passage 93 of the first inverter water jacket 91 through the inlet 92 of the first inverter water jacket 91. The cooling water that has entered the internal passage 93 flows through the internal passage 93, receives the heat of the inverter body 32 of the first inverter 31 during this process, and then enters the inverter water jacket connecting pipe 95 through the outlet 94 of the first inverter water jacket 91.

[0075] The cooling water that has entered the inverter water jacket connecting pipe 95 flows through the inverter water jacket connecting pipe 95 and enters the internal passage 98 of the second inverter water jacket 96 through the inlet 97 of the second inverter water jacket 96. The cooling water that has entered the internal passage 98 flows through the internal passage 98, receives the heat of the inverter body 36 of the second inverter 35 during this process, and then enters the connecting pipe 104 through the outlet 99 of the second inverter water jacket 96. Subsequently, the cooling water flows through the connecting pipe 104 and enters the confluence chamber 103.

[0076] The cooling water that has entered the confluence chamber 103 through the outlet 89 of the second motor water jacket 86 and the cooling water that has flowed through the connecting pipe 104 after passing through the outlet 99 of the second inverter water jacket 96 and then entered the confluence chamber 103 merge in the confluence chamber 103. The merged cooling water flows from the confluence chamber 103 into the cooling water discharge path 105, flows through the cooling water discharge path 105, and is discharged outside the outboard motor 1 from the drain port 106.

[0077] Also, the flow rate of the cooling water flowing through the first motor water jacket 81, the second motor water jacket 86, the first inverter water jacket 91, and the second inverter water jacket 96 is adjusted by the valve opening degree of the control valve 107. Thereby, the temperature of the cooling water can be adjusted. When the valve opening degree of the control valve 107 increases, the flow rate of the cooling water flowing through each of the water jackets 81, 86, 91, 96 increases, the temperature of the cooling water decreases, and the cooling capacity for cooling the first motor 11, the second motor 21, the inverter body 32 of the first inverter, and the inverter body 36 of the second inverter 35 by the cooling water increases. On the other hand, when the valve opening degree of the control valve 107 decreases, the flow rate of the cooling water flowing through each of the water jackets 81, 86, 91, 96 decreases.

[0078] (Main features and effects of the cooling mechanism) (1) In the cooling mechanism 61 of the outboard motor 1 according to an embodiment of the present invention, as shown in FIG. 6, a first motor water jacket 81 and a second motor water jacket 86 connected to each other by a motor water jacket connecting pipe 85, and a first inverter water jacket 91 and a second inverter water jacket 96 connected to each other by an inverter water jacket connecting pipe 95 are connected in parallel between a cooling water supply passage 65 and a cooling water discharge passage 105. In this configuration, the length of the flow path of the cooling water that sequentially flows through the inside of the first motor water jacket 81 and the second motor water jacket 86 from the cooling water supply passage 65 until it reaches the cooling water discharge passage 105, and the length of the flow path of the cooling water that sequentially flows through the inside of the first inverter water jacket 91 and the second inverter water jacket 96 from the cooling water supply passage 65 until it reaches the cooling water discharge passage 105 are both shorter than the length of the flow path of the cooling water that sequentially flows through the four water jackets 81, 86, 91, 96 from the cooling water supply passage 65 until it reaches the cooling water discharge passage 105 when the four water jackets 81, 86, 91, 96 are connected in series between the cooling water supply passage 65 and the cooling water discharge passage 105. Therefore, according to the cooling mechanism 61 in the present embodiment, compared with the case where the four water jackets 81, 86, 91, 96 are connected in series between the cooling water supply passage 65 and the cooling water discharge passage 105, the pressure loss of the cooling water flowing through the cooling mechanism 61 can be reduced, and thus the flow of the cooling water in the cooling mechanism 61 can be smoothed. Therefore, the cooling efficiency of the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35 can be increased.

[0079] Also, in the cooling mechanism 61 of the present embodiment, the first motor water jacket 81 and the second motor water jacket 86 connected to each other, and the first inverter water jacket 91 and the second inverter water jacket 96 connected to each other are connected in parallel between the cooling water supply passage 65 and the cooling water discharge passage 105. Therefore, according to the calorific value of the first motor 11 and the second motor 21 and the calorific value of the first inverter 31 and the second inverter 35, the flow rate of the cooling water flowing through the first motor water jacket 81 and the second motor water jacket 86, and the flow rate of the cooling water flowing through the first inverter water jacket 91 and the second inverter water jacket 96 can be individually set. Thus, the cooling capacity for cooling the first motor 11 and the second motor 21 and the cooling capacity for cooling the first inverter 31 and the second inverter 35 can be easily optimized individually. For example, when the calorific value of the first motor 11 and the second motor 21 is larger than the calorific value of the first inverter 31 and the second inverter 35, by making the diameters of the branch passage holes 68 and the connecting pipes 70 in the branch passage 66 larger than the diameters of the branch passage holes 69 and the connecting pipes 71, the flow rate of the cooling water flowing from the main passage hole 67 through the branch passage holes 68 and the connecting pipes 70 and flowing into the first motor water jacket 81 can be made larger than the flow rate of the cooling water flowing from the main passage hole 67 through the branch passage holes 69 and the connecting pipes 71 and flowing into the first inverter water jacket 91. Thereby, the cooling capacity for cooling the first motor 11 and the second motor 21 can be easily made higher than the cooling capacity for cooling the first inverter 31 and the second inverter 35.

[0080] (2) In the cooling mechanism 61 of the outboard motor 1 of this embodiment, in addition to the first motor water jacket 81 and the second motor water jacket 86 being connected to each other, and the first inverter water jacket 91 and the second inverter water jacket 96 being connected to each other and being connected in parallel between the cooling water supply passage 65 and the cooling water discharge passage 105, as shown in FIGS. 7 and 8, the first motor 11 and the second motor 21 are arranged such that the extending directions of their rotation shafts E and F are in the vertical direction, the second motor 21 is arranged above the first motor 11, the first inverter 31 is arranged behind the first motor 11, the second inverter 35 is arranged behind the second motor 21 and above the first inverter 31, the inlet 82 of the first motor water jacket 81, the inlet 87 of the second motor water jacket 86, the inlet 92 of the first inverter water jacket 91, and the inlet 97 of the second inverter water jacket 96 are respectively arranged at the lower parts of the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35, and the outlet 84 of the first motor water jacket 81, the outlet 89 of the second motor water jacket 86, the outlet 94 of the first inverter water jacket 91, and the outlet 99 of the second inverter water jacket 96 are respectively arranged at the upper parts of the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35. With this configuration, the branch passage 66, the motor water jacket connecting pipe 85, the inverter water jacket connecting pipe 95, and the confluence passage 101 can be shortened respectively. Therefore, the pressure loss of the cooling water flowing through the cooling mechanism 61 can be reduced, and thus the flow of the cooling water in the cooling mechanism 61 can be smoothed. Therefore, the cooling efficiency of the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35 can be enhanced.

[0081] That is, in the first motor water jacket 81 and the first inverter water jacket 91 arranged at the lower stage, by arranging the inlet 82 and the inlet 92 at the lower parts of the first motor 11 and the first inverter 31 respectively, the inlet 82 and the inlet 92 can be brought closer to each other. Therefore, the branch path 66 connected to the inlet 82 and the inlet 92 can be shortened.

[0082] Also, by arranging the outlet 84 of the first motor water jacket 81 arranged at the lower stage at the upper part of the first motor 11 and arranging the inlet 87 of the second motor water jacket 86 arranged at the upper stage at the lower part of the second motor 21, the outlet 84 and the inlet 87 can be brought closer to each other. Therefore, the motor water jacket connecting pipe 85 connecting between the outlet 84 and the inlet 87 can be shortened.

[0083] Also, by arranging the outlet 94 of the first inverter water jacket 91 arranged at the lower stage at the upper part of the first inverter 31 and arranging the inlet 97 of the second inverter water jacket 96 arranged at the upper stage at the lower part of the second inverter 35. The outlet 94 and the inlet 97 can be brought closer to each other. Therefore, the inverter water jacket connecting pipe 95 connecting between the outlet 94 and the inlet 97 can be shortened.

[0084] Also, in the second motor water jacket 86 and the second inverter water jacket 96 arranged at the upper stage, by arranging the outlet 89 and the outlet 99 at the upper parts of the second motor 21 and the second inverter 35 respectively, the outlet 89 and the outlet 99 can be brought closer to each other. Therefore, the confluence path 101 connected to the outlet 89 and the outlet 99 can be shortened.

[0085] (3) Fig. 10(A) schematically shows a state of the first motor water jacket 81 and the second motor water jacket 86 arranged vertically as viewed from the upper left. Fig. 10(B) schematically shows states of cross-sections of the first motor water jacket 81 and the second motor water jacket 86 cut along the cutting lines S-S and T-T in Fig. 10(A) as viewed from above.

[0086] As shown in FIGS. 10(A) and 10(B), in the cooling mechanism 61 of the outboard motor 1 of this embodiment, the first motor water jacket 81 is provided so as to surround the first motor 11 on the outer peripheral side of the first motor 11. When the first motor water jacket 81 is viewed from above, the outlet 84 of the first motor water jacket 81 is disposed substantially on the opposite side of the inlet 82 of the first motor water jacket 81 with respect to the rotation axis E (rotation center) of the first motor 11. Specifically, in the first motor water jacket 81, the inlet 82 is disposed at the lower left rear portion of the first motor 11, and the outlet 84 is disposed at the upper right front portion of the first motor 11. Further, the second motor water jacket 86 is provided so as to surround the second motor 21 on the outer peripheral side of the second motor 21. When the second motor water jacket 86 is viewed from above, the outlet 89 of the second motor water jacket 86 is disposed substantially on the opposite side of the inlet 87 of the second motor water jacket 86 with respect to the rotation axis F (rotation center) of the second motor 21. Specifically, in the second motor water jacket 86, the inlet 87 is disposed at the lower right front portion of the second motor 21, and the outlet 89 is disposed at the upper left rear portion of the second motor 21. Further, the first motor 11 and the second motor 21 are respectively arranged such that the outlet 84 of the first motor water jacket 81 and the inlet 87 of the second motor water jacket 86 face each other in the vertical direction. With this configuration, without complicating the structure of the internal passage 83 of the first motor water jacket 81, the first motor water jacket 81 can uniformly cool the entire circumference of the first motor 11. Also, without complicating the structure of the internal passage 88 of the second motor water jacket 86, the second motor water jacket 86 can uniformly cool the entire circumference of the second motor 21. Further, cooling water can be smoothly sent from the first motor water jacket 81 to the second motor water jacket 86. Overall, with the simple-structured motor water jackets 81 and 86, the cooling efficiency of each of the first motor 11 and the second motor 21 can be increased.

[0087] That is, the first motor water jacket 81 is provided so as to surround the first motor 11 on the outer peripheral side of the first motor 11. When the first motor water jacket 81 is viewed from above, the outlet 84 of the first motor water jacket 81 is arranged on the substantially opposite side of the inlet 82 of the first motor water jacket 81 with the rotation axis E (rotation center) of the first motor 11 interposed therebetween. As shown in FIG. 10(B), in the internal passage 83 of the first motor water jacket 81, the counterclockwise passage length from the inlet 82 to the outlet 84 and the clockwise passage length from the inlet 82 to the outlet 84 can be made substantially equal. Thereby, the cooling water can be uniformly flowed over the entire circumference of the first motor 11, and the entire circumference of the first motor 11 can be uniformly cooled. Further, in order to uniformly flow the cooling water over the entire circumference of the first motor 11, it is not necessary to make the internal passage 83 have a complicated structure such that the direction of the passage is reversed at a plurality of locations, for example.

[0088] Similarly, the second motor water jacket 86 is provided so as to surround the second motor 21 on the outer peripheral side of the second motor 21. When the second motor water jacket 86 is viewed from above, the outlet 89 of the second motor water jacket 86 is arranged on the substantially opposite side of the inlet 87 of the second motor water jacket 86 with the rotation axis F (rotation center) of the second motor 21 interposed therebetween. Thereby, in the internal passage 88 of the second motor water jacket 86, the counterclockwise passage length from the inlet 87 to the outlet 89 and the clockwise passage length from the inlet 87 to the outlet 89 can be made substantially equal. Thereby, the cooling water can be uniformly flowed over the entire circumference of the second motor 21, and the entire circumference of the second motor 21 can be uniformly cooled. Further, in order to uniformly flow the cooling water over the entire circumference of the second motor 21, it is not necessary to make the internal passage 88 have a complicated structure such that the direction of the passage is reversed at a plurality of locations, for example.

[0089] In addition, since the first motor 11 and the second motor 21 are arranged such that the outlet 84 of the first motor water jacket 81 and the inlet 87 of the second motor water jacket 86 face each other in the vertical direction, the motor water jacket connecting pipe 85 can be made short and straight. Thereby, the pressure loss of the cooling water flowing through the motor water jacket connecting pipe 85 can be reduced.

[0090] (4) Fig. 10(C) schematically shows a state of viewing the first inverter water jacket 91 and the second inverter water jacket 96 from behind. As shown in Fig. 10(C), the second inverter water jacket 96 is disposed above the first inverter water jacket 91. In the first inverter water jacket 91, the inlet 92 is disposed at the lower left part of the first inverter 31, and the outlet 94 is disposed at the upper right part of the first inverter 31. In the second inverter water jacket 96, the inlet 97 is disposed at the lower right part of the second inverter 35, and the outlet 99 is disposed at the upper left part of the second inverter 35. With this configuration, without complicating the structure of the internal passage 93 of the first inverter water jacket 91, the first inverter water jacket 91 can uniformly cool the inverter body 32 of the first inverter 31 over a wide range. Also, without complicating the structure of the internal passage 98 of the second inverter water jacket 96, the second motor water jacket 86 can uniformly cool the inverter body 36 of the second inverter 35 over a wide range. Further, cooling water can be smoothly sent from the first inverter water jacket 91 to the second inverter water jacket 96. Overall, with the simply configured inverter water jackets 91 and 96, the cooling efficiency of each of the first inverter 31 and the second inverter 35 can be enhanced.

[0091] That is, in the first inverter water jacket 91, the inlet 92 is arranged at the lower left part of the first inverter 31, and the outlet 94 is arranged at the upper right part of the first inverter 31. Thus, the inlet 92 and the outlet 94 are respectively arranged at the diagonal parts of the first inverter 31. As a result, as shown in Fig. 10(C), the cooling water flowing into the internal passage 93 from the inlet 92 can be easily spread over the entire area within the internal passage 93. Also, the cooling water spread over the entire area within the internal passage 93 can be smoothly discharged from the outlet 94, and the retention of the cooling water within the internal passage 93 can be suppressed. Thereby, the cooling water can be uniformly flowed over a wide range in front of the inverter main body 32, and the inverter main body 32 can be uniformly cooled. Also, in order to uniformly flow the cooling water over a wide range in front of the inverter main body 32, it is not necessary to make the internal passage 93 into a complicated structure such that the direction of the passage is reversed at a plurality of locations, for example.

[0092] Also, in the second inverter water jacket 96, the inlet 97 is arranged at the lower right part of the second inverter 35, and the outlet 99 is arranged at the upper left part of the second inverter 35. Thus, the inlet 97 and the outlet 99 are respectively arranged at the diagonal parts of the second inverter 35. As a result, as shown in Fig. 10(C), the cooling water flowing into the internal passage 98 from the inlet 97 can be easily spread over the entire area within the internal passage 98. Also, the cooling water spread over the entire area within the internal passage 98 can be smoothly discharged from the outlet 99, and the retention of the cooling water within the internal passage 98 can be suppressed. Thereby, the cooling water can be uniformly flowed over a wide range in front of the inverter main body 36, and the inverter main body 36 can be uniformly cooled. Also, in order to uniformly flow the cooling water over a wide range in front of the inverter main body 36, it is not necessary to make the internal passage 98 into a complicated structure such that the direction of the passage is reversed at a plurality of locations, for example.

[0093] Also, the second inverter water jacket 96 is disposed above the first inverter water jacket 91, the outlet 94 of the first inverter water jacket 91 is disposed at the upper right part of the first inverter 31, and the inlet 97 of the second inverter water jacket 96 is disposed at the lower right part of the second inverter 35. Thus, the outlet 94 and the inlet 97 can be brought closer to each other, and the inverter water jacket connecting pipe 95 connecting between the outlet 94 and the inlet 97 can be shortened. Further, as shown in FIG. 10(C), by disposing the outlet 94 and the inlet 97 to face each other, the inverter water jacket connecting pipe 95 can be made straight. Thereby, the pressure loss of the cooling water flowing through the inverter water jacket connecting pipe 95 can be reduced.

[0094] (5) In the outboard motor 1 of the present embodiment, the first inverter 31 is disposed behind the first motor 11. In the cooling mechanism 61, the inlet 82 of the first motor water jacket 81 is disposed at the lower left rear part of the first motor 11, and the inlet 92 of the first inverter water jacket 91 is disposed at the lower left part of the first inverter 31. Thus, the branch path 66 can be shortened.

[0095] (6) In the outboard motor 1 of the present embodiment, the second inverter 35 is disposed behind the second motor 21. In the cooling mechanism 61, the outlet 89 of the second motor water jacket 86 is disposed at the upper left rear part of the second motor 21, and the outlet 99 of the second inverter water jacket 96 is disposed at the upper left part of the second inverter 35. Thus, the confluence path 101 (connection pipe 104) can be shortened.

[0096] (7) In the outboard motor 1 of this embodiment, the clutch control device 55 is disposed on the left front side between the first motor 11 and the second motor 21. In the cooling mechanism 61, the outlet 84 of the first motor water jacket 81 is disposed at the upper right front portion of the first motor 11, the inlet 87 of the second motor water jacket 86 is disposed at the lower right front portion of the second motor 21, and the motor water jacket connecting pipe 85 is disposed on the right front side between the first motor 11 and the second motor 21. With this configuration, the clutch control device 55 and the motor water jacket connecting pipe 85 can be disposed separately from each other at different positions in the space between the first motor 11 and the second motor 21, and the assemblability or maintainability of the outboard motor 1 can be improved.

[0097] (8) The cooling mechanism 61 in this embodiment includes a control valve 107 that controls the flow rate of the cooling water after it has merged in the merging passage 101. By adopting a configuration that controls the flow rate of the cooling water after it has merged, the temperature of the cooling water can be adjusted by a single control valve 107, and the structure of the cooling mechanism 61 can be simplified.

[0098] (9) In the cooling mechanism 61 of this embodiment, cooling water is first supplied to the first motor water jacket 81, and the cooling water after flowing through the first motor water jacket 81 is supplied to the second motor water jacket 86. Due to this structure, the cooling water flowing through the first motor water jacket 81 has a lower temperature than the cooling water flowing through the second motor water jacket 86. Therefore, the cooling capacity of the first motor water jacket 81 is higher than that of the second motor water jacket 86. Thus, the cooling efficiency of the first motor 11 is higher than that of the second motor 21. Similarly, since the cooling capacity of the first inverter water jacket 91 is higher than that of the second inverter water jacket 96, the cooling efficiency of the first inverter 31 is higher than that of the second inverter 35. Therefore, when using the outboard motor 1, if there is a difference between the operating rates of the first motor 11 and the first inverter 31 and the operating rates of the second motor 21 and the second inverter 35, it is preferable that the operating rates of the first motor 11 and the first inverter 31 be higher than those of the second motor 21 and the second inverter 35. Thereby, the first motor 11 and the first inverter 31, which have a high operating rate and thus a large heat generation amount, are cooled more efficiently than the second motor 21 and the second inverter 35, which have a low operating rate and thus a small heat generation amount. Overall, the cooling efficiency of the first motor 11, the second motor 21, the first inverter 31, and the second inverter 35 can be increased.

[0099] In addition, in the cooling mechanism 61 in the above embodiment, the respective arrangements of the branch path 66, the inlet 82 and the outlet 84 of the first motor water jacket 81, the inlet 87 and the outlet 89 of the second motor water jacket 86, the inlet 92 and the outlet 94 of the first inverter water jacket 91, the inlet 97 and the outlet 99 of the second inverter water jacket 96, the confluence path 101, the clutch control device 55, etc. may be entirely reversed left and right.

[0100] Also, in the cooling mechanism 61 in the above-described embodiment, the inlets 82, 87, 92, 97 of the four water jackets 81, 86, 91, 96 are respectively arranged below the two motors 11, 21 and the two inverters 31, 35, and the outlets 84, 89, 94, 99 of the four water jackets 81, 86, 91, 96 are respectively arranged above the two motors 11, 21 and the two inverters 31, 35, and the cooling water flows upward from bottom to top in each of the water jackets 81, 86, 91, 96. However, the present invention is not limited to this, and the inlets 82, 87, 92, 97 of the four water jackets 81, 86, 91, 96 may be respectively arranged above the two motors 11, 21 and the two inverters 31, 35, and the outlets 84, 89, 94, 99 of the four water jackets 81, 86, 91, 96 may be respectively arranged below the two motors 11, 21 and the two inverters 31, 35, and the cooling water may flow downward from top to bottom in each of the water jackets 81, 86, 91, 96.

[0101] Also, in the above-described embodiment, each inverter water jacket 91, 96 is arranged in front of the inverter body, but each inverter water jacket 91, 96 may be arranged behind the inverter body, or in front of and behind the inverter body.

[0102] Also, in the above-described embodiment, the water around the outboard motor 1 is taken into the cooling mechanism 61 and used as cooling water, and the cooled cooling water is discharged outside the outboard motor 1. However, the present invention is not limited to this, and the cooling water may be circulated inside the outboard motor, and a heat dissipation mechanism such as a heat sink for dissipating the heat of the cooling water may be provided in the middle of the circulation path of the cooling water.

[0103] Also, in the present invention, the power switching mechanism is not limited to that described in the above embodiment. For example, the upper end of the drive shaft 42 may be constantly connected to the lower end of the motor shaft 12 of the first motor 11, and a power switching mechanism for switching the connection and separation between the upper end of the motor shaft 12 of the first motor 11 and the lower end of the motor shaft 22 of the second motor 21 may be provided between these two motor shafts. Further, the present invention includes those in which there is no power switching mechanism and both the motor shaft of the first motor and the motor shaft of the second motor are constantly connected to the drive shaft.

[0104] Also, the present invention may be configured to have three or more motors and three or more inverters. Further, the present invention can also be applied to marine propulsion devices other than outboard motors.

[0105] Also, the present invention can be appropriately modified within a range not contrary to the gist or idea of the invention that can be read from the claims and the entire specification, and a marine propulsion device with such modifications is also included in the technical idea of the present invention.

Explanation of Reference Numerals

[0106] 1 Outboard motor 11 First motor 21 Second motor 31 First inverter 35 Second inverter 41 Propeller 42 Drive shaft (power transmission mechanism) 43 Propeller shaft (power transmission mechanism) 44 Gear mechanism (power transmission mechanism) 61 Cooling mechanism 65 Cooling water supply path (first cooling water path) 66 Branch path 81 First motor water jacket 82 Inlet 84 Outlet 85 Motor water jacket connecting pipe (first connecting path) 86 Second motor water jacket 87 Inlet 89 Outlet 91 First Inverter Water Jacket 92 Inlet 94 Outlet 95 Inverter Water Jacket Connecting Pipe (Second Connecting Path) 96 Second Inverter Water Jacket 97 Inlet 99 Outlet 101 Confluence Path 103 Confluence Chamber 104 Connecting Pipe 105 Cooling Water Discharge Path (Second Cooling Water Path) 107 Control Valve

Claims

1. A ship propulsion machine comprising a first motor, a second motor, a first inverter that generates a drive current for controlling the drive of the first motor, a second inverter that generates a drive current for controlling the drive of the second motor, a propeller, a power transmission mechanism that transmits the power of each of the first motor and the second motor to the propeller, and a cooling mechanism that cools the first motor, the second motor, the first inverter, and the second inverter, wherein the cooling mechanism includes a first motor water jacket provided in the first motor and cooling the first motor by circulating cooling water therein, a second motor water jacket provided in the second motor and cooling the second motor by circulating cooling water therein, a first inverter water jacket provided in the first inverter and cooling the first inverter by circulating cooling water therein, a second inverter water jacket provided in the second inverter and cooling the second inverter by circulating cooling water therein, a first cooling water passage for circulating cooling water toward the first motor water jacket and the first inverter water jacket, a branch passage that connects the first motor water jacket and the first inverter water jacket in parallel to the first cooling water passage and distributes and supplies the cooling water flowing in the first cooling water passage to the first motor water jacket and the first inverter water jacket, a first connection passage that connects the second motor water jacket to the downstream side of the first motor water jacket and sends the cooling water that has flowed through the first motor water jacket to the second motor water jacket, and a second connection passage that connects the second inverter water jacket to the downstream side of the first inverter water jacket and sends the cooling water that has flowed through the first inverter water jacket to the second inverter water jacket. The ship propulsion machine is characterized by this.

2. When the vertical direction of the ship propulsion machine is defined as the X direction and the direction orthogonal to the X direction is defined as the Y direction, the first motor is arranged such that the extending direction of its rotation axis is the X direction, the second motor is arranged on the X-direction side of the first motor such that the extending direction of its rotation axis is the X direction, the first inverter is arranged on the Y-direction side of the first motor, and the second inverter is arranged on the Y-direction side of the second motor and on the X-direction side of the first inverter. The first motor water jacket has an inlet through which the cooling water supplied through the branch passage flows into the first motor water jacket, and an outlet through which the cooling water that has flowed through the first motor water jacket flows out of the first motor water jacket. The second motor water jacket has an inlet through which the cooling water flowing out from the outlet of the first motor water jacket and sent through the first connection passage flows into the second motor water jacket, and an outlet through which the cooling water that has flowed through the second motor water jacket flows out of the second motor water jacket. The first inverter water jacket has an inlet through which the cooling water supplied through the branch passage flows into the first inverter water jacket, and an outlet through which the cooling water that has flowed through the first inverter water jacket flows out of the first inverter water jacket. The second inverter water jacket has an inlet through which the cooling water flowing out from the outlet of the first inverter water jacket and sent through the second connection passage flows into the second inverter water jacket, and an outlet through which the cooling water that has flowed through the second inverter water jacket flows out of the second inverter water jacket. The inlets of the first motor water jacket, the second motor water jacket, the first inverter water jacket, and the second inverter water jacket are respectively arranged at the portions on the other side in the X direction of the first motor, the second motor, the first inverter, and the second inverter. The outlet of the first motor water jacket, the outlet of the second motor water jacket, the outlet of the first inverter water jacket, and the outlet of the second inverter water jacket are respectively arranged at the portions on one side in the X direction of the first motor, the second motor, the first inverter, and the second inverter. The marine propulsion device according to claim 1, characterized in that.

3. The first motor water jacket is provided so as to surround the first motor on the outer peripheral side of the first motor. When the first motor and the first motor water jacket are viewed from one side in the X direction, the outlet of the first motor water jacket is arranged on the substantially opposite side of the inlet of the first motor water jacket with the rotation center of the first motor interposed therebetween. The second motor water jacket is provided so as to surround the second motor on the outer peripheral side of the second motor. When the second motor and the second motor water jacket are viewed from one side in the X direction, the outlet of the second motor water jacket is arranged on the substantially opposite side of the inlet of the second motor water jacket with the rotation center of the second motor interposed therebetween. The first motor and the second motor are respectively arranged such that the outlet of the first motor water jacket and the inlet of the second motor water jacket face each other in the X direction. The marine propulsion device according to claim 2, characterized in that.

4. When the direction orthogonal to the X direction and the Y direction is defined as the Z direction, The inlet of the first inverter water jacket is arranged at a portion on one side in the Z direction of the first inverter, and the outlet of the first inverter water jacket is arranged at a portion on the other side in the Z direction of the first inverter. The inlet of the second inverter water jacket is arranged at a portion on the other side in the Z direction of the second inverter, and the outlet of the second inverter water jacket is arranged at a portion on one side in the Z direction of the second inverter. The marine propulsion device according to claim 2, characterized in that.

5. The cooling mechanism is A second cooling water passage for circulating the cooling water after flowing out from the second motor water jacket and the second inverter water jacket respectively. An outlet of the second motor water jacket, an outlet of the second inverter water jacket, and a confluence path that is connected to the second cooling water passage and that merges the cooling water flowing out from the outlet of the second motor water jacket and the cooling water flowing out from the outlet of the second inverter water jacket and causes the merged cooling water to flow into the second cooling water passage; The marine propulsion device according to claim 2, further comprising a valve that controls the flow rate of the cooling water after the cooling water has merged in the confluence path.

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