Ship propulsion machine

Abstract

To enhance cooling efficiencies for a motor and an inverter and enable cooling capacities for cooling the motor and the inverter to be easily optimized according to amounts of heat generation of the motor and the inverter.SOLUTION: An outboard engine includes a motor 2, an inverter 11, and a cooling mechanism which cools these components with a coolant. The cooling mechanism includes: a motor water jacket 42 configured to cool the motor 2; an inverter water jacket 46 configured to cool the inverter 11; a coolant supply passage 35 configured to allow the coolant to flow toward the motor water jacket 42 and the inverter water jacket 46; and a branch passage 36 connecting the motor water jacket 42 and the inverter water jacket 46 in parallel to the coolant supply passage 35 and configured to supply the coolant flowing in the coolant supply passage 35 to the motor water jacket 42 and the inverter water jacket 46 in a distributed manner.SELECTED DRAWING: Figure 6

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 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] When cooling the motor and the inverter with cooling water, in order to improve the cooling efficiency, it is desirable to smoothly circulate the cooling water in the cooling water passage, in the water jacket of the motor, and in the water jacket of the inverter.

[0006] In this regard, in the ship propulsion machine described in Japanese Patent Application Laid-Open No. 2022-34677, the water jacket of the inverter and the water jacket of the motor are connected in series to the cooling water passage, and the cooling water first flows through the passage formed in the water jacket of the inverter, and then flows through the passage formed in the water jacket of the motor. Therefore, the flow path of the cooling water from the inflow position of the cooling water in the water jacket of the inverter to the outflow position of the cooling water in the water jacket of the motor is long, and the pressure loss of the cooling water is large. Therefore, in order to smoothly circulate the cooling water, a pump with a high discharge capacity must be used, which leads to an increase in the size of the pump or an increase in power consumption.

[0007] Further, when the water jacket of the inverter and the water jacket of the motor 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.

[0008] The present invention has been made in view of problems such as those described above, and an object of the present invention is to provide a ship propulsion machine that can improve the cooling efficiency of a motor and an inverter, and can easily optimize the cooling capacity for cooling each of the motor and the inverter according to the heat generation amount of each of the motor and the inverter.

Means for Solving the Problems

[0009] In order to solve the above problems, the present invention provides a marine propulsion unit including a motor, an inverter that generates a drive current for driving and controlling the motor, a propeller, a power transmission mechanism that transmits the power of the motor to the propeller, and a cooling mechanism that cools the motor and the inverter. The cooling mechanism includes a motor water jacket provided in the motor and cooling the motor by circulating cooling water inside, an inverter water jacket provided in the inverter and cooling the inverter by circulating cooling water inside, a first cooling water passage that circulates cooling water toward the motor water jacket and the inverter water jacket, and a branch passage that connects the motor water jacket and the 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 motor water jacket and the inverter water jacket.

Advantages of the Invention

[0010] According to the present invention, the cooling efficiency of the motor and the inverter can be improved, and the cooling capacity for cooling the motor and the inverter respectively can be easily optimized according to the heat generation amounts of the motor and the inverter.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0012] The marine propulsion unit according to the embodiment of the present invention includes a motor, an inverter that generates a drive current for driving and controlling the motor, a propeller, a power transmission mechanism that transmits the power of the motor to the propeller, and a cooling mechanism that cools the motor and the inverter.

[0013] Further, in the marine propulsion unit according to the embodiment of the present invention, the cooling mechanism includes a motor water jacket provided in the motor and cooling the motor by circulating cooling water inside, an inverter water jacket provided in the inverter and cooling the inverter by circulating cooling water inside, a first cooling water passage for circulating cooling water toward the motor water jacket and the inverter water jacket, and a branch passage that connects the motor water jacket and the 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 motor water jacket and the inverter water jacket.

[0014] In the cooling mechanism of the marine propulsion device according to the embodiment of the present invention, the motor water jacket and the inverter water jacket are connected in parallel to the first cooling water passage via a branch passage. As a result, compared with the case where the motor water jacket and the 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, even when a small pump with a low discharge capacity is used, the cooling efficiency of the cooling water by the cooling mechanism can be enhanced.

[0015] Further, in the cooling mechanism of the present embodiment, since the motor water jacket and the inverter water jacket are connected in parallel to the first cooling water passage via a branch passage, according to the respective heat generation amounts of the motor and the inverter, it becomes easy to individually set the flow rate of the cooling water flowing through the motor water jacket and the flow rate of the cooling water flowing through the inverter water jacket. Therefore, the cooling capacity for cooling the motor and the cooling capacity for cooling the inverter can be easily optimized respectively.

Example

[0016] An example of the marine propulsion device of the present invention will be described with reference to the drawings. In the description of this example, when referring to the directions of up (Ud), down (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd), follow the arrows drawn at the lower right in each figure except FIG. 5.

[0017] (Outboard motor) FIG. 1 shows the whole of an outboard motor 1 which is an example of the marine propulsion device of the present invention. In FIG. 1, the outboard motor 1 includes a motor 2, an inverter 11, a propeller 15, a drive shaft 16, a propeller shaft 17, and a gear mechanism 18. Further, the outboard motor 1 includes a cooling mechanism 31 shown in FIG. 5.

[0018] The motor 2 is an alternating current motor and generates the power to propel the ship. The motor 2 is attached to the motor holder 10. The inverter 11 is a device that generates a drive current for controlling the drive of the motor 2 and is attached to the motor 2. The motor 2, the inverter 11, and the motor holder 10 are arranged at the upper part of the outboard motor 1 and covered by the motor cover 21.

[0019] The propeller 15 converts the power of the motor 2 into the propulsive force of the ship. The drive shaft 16, the propeller shaft 17, and the gear mechanism 18 are power transmission mechanisms that transmit the power of the motor 2 to the propeller 15. The propeller 15, the propeller shaft 17, and the gear mechanism 18 are arranged at the lower part of the outboard motor 1. The drive shaft 16 extends vertically between the upper and lower parts of the outboard motor 1.

[0020] The upper end of the drive shaft 16 is connected to the motor 2. The gear mechanism 18 has a drive gear 19 and a driven gear 20. The drive gear 19 is fixed to the lower end of the drive shaft 16, and the driven gear 20 is fixed to the front end of the propeller shaft 17. Both the drive gear 19 and the driven gear 20 are bevel gears and mesh with each other. Also, the propeller 15 is fixed to the rear end of the propeller shaft 17. Also, the drive shaft 16 is housed in the drive shaft case 22. Also, the propeller shaft 17 and the gear mechanism 18 are housed in the gear case 23.

[0021] Also, the outboard motor 1 is provided with a clamp mechanism 24 for attaching the outboard motor 1 to the transom of the ship. In the 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 22 and the gear case 23 are located below the water surface.

[0022] Figure 2 shows a state of a unit formed by attaching motor 2 to motor holder 10 and attaching inverter 11 to motor 2, as viewed from the upper left in the front. Figure 3 shows a state of the unit as viewed from the left, and Figure 4 shows a state of the unit as viewed from above.

[0023] As shown in Figure 2, motor holder 10 is a robust structure having a three-dimensional shape serving as a base for motor 2, and is formed of, for example, a metal material. Motor 2 is placed on the upper surface of the front portion of motor holder 10 and is firmly fixed to motor holder 10 using fixing members such as bolts.

[0024] As shown in Figure 3, motor 2 has a motor shaft 3, a rotor 4 provided on the outer peripheral side of motor shaft 3, a stator 5 provided on the outer peripheral side of rotor 4, a cylindrical motor housing 6 provided on the outer peripheral side of stator 5, and two motor brackets 7, 8 respectively provided on one end side and the other end side (upper end side and lower end side) in the axial direction of motor housing 6.

[0025] Inverter 11 has an inverter main body 12 and a rectangular parallelepiped-shaped inverter housing 13 that houses inverter main body 12. Inverter main body 12 generates a drive current for driving and controlling motor 2 by converting the current supplied from the battery from direct current to alternating current. Inverter main body 12 includes components such as a power semiconductor that generate a large amount of heat.

[0026] The motor 2 is disposed on the motor holder 10 such that the extending direction of the motor shaft 3, that is, the extending direction of the rotation axis A of the motor 2 is in the vertical direction. Further, the motor 2 and the inverter 11 are arranged side by side in the front-rear direction above the motor holder 10. The inverter 11 is disposed behind the motor 2 and is attached and fixed to the motor 2 via inverter attachment portions 9 provided at the rear portions of two motor brackets 7 and 8, respectively. In the present embodiment, the vertical direction corresponds to the "X direction" in the description of the claims, and the front-rear direction corresponds to the "Y direction" in the description of the claims.

[0027] (Configuration of the cooling mechanism) FIG. 5 shows the configuration of a cooling mechanism 31 provided in the outboard motor 1. FIG. 6 shows a state in which a cross-section of the motor 2, the inverter 11, the motor holder 10, etc., cut along the cutting line VI-VI in FIG. 4, is viewed from the left (lower in FIG. 4). FIG. 7 shows a state in which a cross-section of the motor 2, the inverter 11, the motor holder 10, etc., cut along the cutting line VII-VII in FIG. 6, is viewed from above. FIG. 8 shows a state in which a cross-section of the motor 2, the inverter 11, the motor holder 10, etc., cut along the cutting line VIII-VIII in FIG. 4, is viewed from the right (upper in FIG. 4).

[0028] The cooling mechanism 31 is a mechanism that uses the water around the outboard motor 1 as cooling water to cool the motor 2 and the inverter 11. As shown in FIG. 5, the cooling mechanism 31 has a water intake 32, a water intake passage 33, a pump 34, a cooling water supply passage 35, a branch passage 36, a motor water jacket 42, an inverter water jacket 46, a confluence passage 50, a cooling water discharge passage 54, a drain port 55, and a control valve 56.

[0029] As shown in FIG. 1, the water intake 32 is an opening for taking in the water around the outboard motor 1 into the cooling mechanism 31, and is provided in the gear case 23. A strainer for preventing dust, algae, etc. in the water around the outboard motor 1 from entering the cooling mechanism 31 is attached to the water intake 32.

[0030] The water intake passage 33 connects between the water intake port 32 and the suction port of the pump 34, and is a passage for sending the water flowing into the water intake port 32 to the pump 34.

[0031] The pump 34 is a device that sucks up the water flowing into the water intake port 32 and discharges the water into the cooling water supply passage 35 as cooling water, thereby circulating the cooling water in the cooling mechanism 31. As the pump 34, various pumps such as a Yabsco pump can be used. In this embodiment, the pump 34 is driven by utilizing the rotation of the drive shaft 16.

[0032] The cooling water supply passage 35 is a passage for circulating the cooling water toward the motor water jacket 42 and the inverter water jacket 46. The cooling water supply passage 35 is formed by, for example, a hose. The lower end portion of the cooling water supply passage 35 is connected to the discharge port of the pump 34, and the upper end portion of the cooling water supply passage 35 is connected to the branch passage 36 as shown in FIG. 6. Note that the cooling water supply passage 35 is a specific example of the "first cooling water passage".

[0033] As shown in FIG. 5, the branch path 36 is a path that connects the motor water jacket 42 and the inverter water jacket 46 in parallel to the cooling water supply path 35, and distributes and supplies the cooling water flowing in the cooling water supply path 35 to the motor water jacket 42 and the inverter water jacket 46. As shown in FIG. 6, the branch path 36 is formed by the main line passage hole 37, the branch line passage holes 38 and 39 formed in the motor holder 10, the connecting pipe 40 shown in FIG. 6, and the connecting pipe 41 shown in FIG. 3. As shown in FIG. 6, the upper end portion of the cooling water supply path 35 is connected to the lower end portion of the main line passage hole 37. After extending upward in the motor holder 10, the main line passage hole 37 branches into two branch line passage holes 38 and 39. The lower end portion of the connecting pipe 40 disposed in the motor holder 10 is connected to the upper end portion of one of the branch line passage holes 38, and the upper end portion of the connecting pipe 40 is connected to the inlet 43 of the motor water jacket 42. As shown in FIG. 3, the lower end portion of the connecting pipe 41 disposed outside the motor holder 10 is connected to the upper end portion of the other branch line passage hole 39, and the upper end portion of the connecting pipe 41 is connected to the inlet 47 of the inverter water jacket 46.

[0034] The motor water jacket 42 is a mechanism provided in the motor 2 and cools the motor 2 by circulating cooling water inside. As shown in FIG. 7, the motor water jacket 42 is provided so as to surround the motor 2 on the outer peripheral side of the motor 2. Specifically, the motor water jacket 42 is disposed between the stator 5 and the motor housing 6 and surrounds the stator 5. Further, an internal passage 44 for circulating cooling water is formed inside the motor water jacket 42. The internal passage 44 surrounds the stator 5. Further, as shown in FIG. 6, the motor water jacket 42 covers the stator 5 over a wide range from the lower end side portion to the upper end side portion of the stator 5. Further, the internal passage 44 is formed from the lower end side portion to the upper end side portion of the stator 5.

[0035] Further, the motor water jacket 42 has an inlet 43 through which the cooling water supplied via the branch passage 36 flows into the internal passage 44 of the motor water jacket 42. The inlet 43 communicates with the inside of the internal passage 44. As shown in FIGS. 4 and 7, the inlet 43 is disposed at the left rear portion of the motor 2. Also, as shown in FIG. 6, the inlet 43 is disposed at the lower portion of the motor 2. Further, the upper end portion of the connecting pipe 40 of the branch passage 36 is connected to the inlet 43.

[0036] Further, the motor water jacket 42 has an outlet 45 through which the cooling water that has flowed through the internal passage 44 of the motor water jacket 42 flows out of the motor water jacket 42. The outlet 45 communicates with the inside of the internal passage 44. As shown in FIGS. 4 and 7, the outlet 45 is disposed at the right front portion of the motor 2. Also, as shown in FIG. 8, the outlet 45 is disposed at the upper portion of the motor 2. The internal passage 44 communicates with the inside of the confluence chamber 52 through the outlet 45.

[0037] The inverter water jacket 46 is a mechanism provided in the inverter 11 for cooling the inverter main body 12 by circulating cooling water inside. As shown in FIGS. 6 and 7, the inverter water jacket 46 is provided inside the inverter housing 13 and is disposed in front of the inverter main body 12. The inverter water jacket 46 widely covers the front surface of the inverter main body 12 from its left end to its right end and from its lower end to its upper end. Also, an internal passage 48 for circulating cooling water is formed inside the inverter water jacket 46. The internal passage 48 is formed so as to widely cover the front surface of the inverter main body 12 from its left end to its right end and from its lower end to its upper end.

[0038] Further, the inverter water jacket 46 has an inlet 47 for allowing the cooling water supplied through the branch passage 36 to flow into the internal passage 48 of the inverter water jacket 46. The inlet 47 communicates with the inside of the internal passage 48. As shown in FIG. 7, the inlet 47 is disposed on the left side of the inverter 11. Also, as shown in FIG. 6, the inlet 47 is disposed below the inverter 11. Further, the upper end of the connecting pipe 41 of the branch passage 36 is connected to the inlet 47.

[0039] Further, the inverter water jacket 46 has an outlet 49 for allowing the cooling water that has flowed through the internal passage 48 of the inverter water jacket 46 to flow out of the inverter water jacket 46. The outlet 49 communicates with the internal passage 48. As shown in FIG. 7, the outlet 49 is disposed on the right side of the inverter 11. Also, as shown in FIG. 8, the outlet 49 is disposed above the inverter 11. Further, the rear end of the connecting pipe 53 is connected to the outlet 49. Also, the outlet 49 of the inverter water jacket 46 is disposed at a position equal in the left - right direction to the outlet 45 of the motor water jacket 42, as shown in FIG. 4. In this embodiment, the left - right direction corresponds to the "Z direction" in the description of the claims.

[0040] The confluence passage 50 is connected to the outlet 45 of the motor water jacket 42, the outlet 49 of the inverter water jacket 46, and the cooling water discharge passage 54, and is a passage for combining the cooling water flowing out from the outlet 45 of the motor water jacket 42 and the cooling water flowing out from the outlet 49 of the inverter water jacket 46 and allowing them to flow into the cooling water discharge passage 54. As shown in FIG. 8, the confluence passage 50 is formed by a confluence chamber 52 and a connecting pipe 53. As shown in FIG. 2, a confluence chamber forming portion 51 protruding upward is formed at the right front portion of the motor bracket 7. As shown in FIG. 8, a confluence chamber 52 is formed in the confluence chamber forming portion 51. The outlet 45 of the motor water jacket 42 is connected to the bottom of the confluence chamber forming portion 51, and the internal passage 44 of the motor water jacket 42 communicates with the inside of the confluence chamber 52 through the outlet 45. Further, the front end portion of the connecting pipe 53 is connected to the rear portion of the peripheral portion of the confluence chamber forming portion 51, and the internal passage 48 of the inverter water jacket 46 communicates with the inside of the confluence chamber 52 through the outlet 49 and the connecting pipe 53. Further, the upper end portion of the cooling water discharge passage 54 is connected to the upper portion of the confluence chamber forming portion 51, and the confluence chamber 52 communicates with the inside of the cooling water discharge passage 54.

[0041] The cooling water discharge passage 54 is a passage for allowing the cooling water that has flowed out from the inside of the motor water jacket 42 and the inverter water jacket 46 to flow through. The lower end side of the cooling water discharge passage 54 is connected to a drain port 55 (see FIG. 5). Note that the drain port 55 is provided, for example, at the rear portion of the lower part of the outboard motor 1. Further, the cooling water discharge passage 54 is a specific example of the "second cooling water passage".

[0042] The control valve 56 is a valve that controls the flow rate of the cooling water after it has merged in the confluence passage 50. As shown in FIG. 8, the control valve 56 is disposed above the confluence chamber 52, between the confluence position P where the cooling water flowing out from the outlet 45 of the motor water jacket 42 and the cooling water flowing out from the outlet 49 of the inverter water jacket 46 merge, and the connection position Q of the cooling water discharge passage 54. The control valve 56 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 56 increases the valve opening degree according to the rise in the temperature of the cooling water after confluence. Thereby, when the temperature of the cooling water rises, the flow rate of the cooling water flowing through the motor water jacket 42 and the inverter water jacket 46 respectively can be increased, and the temperature of the cooling water can be lowered. For example, the control valve 56 has a sensor for detecting the temperature of the cooling water in the confluence chamber 52. As the control valve 56, a thermostat can be used, for example.

[0043] In addition, a bypass passage may be added to directly connect between the cooling water supply passage 35 and the drain port 55, and a relief valve for communicating and blocking the bypass passage may be provided in the bypass passage. The relief valve closes when the pressure in the cooling water supply passage 35 is below a predetermined pressure, and opens when the pressure in the cooling water supply passage 35 exceeds the predetermined pressure.

[0044] (Operation of the cooling mechanism) The operation of the cooling mechanism 31 is as follows. As the drive shaft 16 rotates due to the drive of the motor 2, the pump 34 is driven. By driving the pump 34, the water flowing into the water intake 32 is sucked up, flows through the water intake passage 33, flows into the suction port of the pump 34, and then flows into the cooling water supply passage 35 as cooling water from the discharge port of the pump 34. The cooling water flows through the cooling water supply passage 35, moves to the upper part of the outboard motor 1, and flows into the main line passage hole 37 of the branch passage 36. In the branch passage 36, the cooling water flowing into the main line passage hole 37 is divided into the cooling water flowing through the branch line passage hole 38 and the connecting pipe 40, and the cooling water flowing through the branch line passage hole 39 and the connecting pipe 41.

[0045] The cooling water flowing through the branch passage hole 38 and the connecting pipe 40 flows into the internal passage 44 of the motor water jacket 42 through the inlet 43 of the motor water jacket 42. The cooling water flowing into the internal passage 44 flows through the internal passage 44, receives the heat of the motor 2 during that time, and flows into the confluence chamber 52 through the outlet 45 of the motor water jacket 42.

[0046] On the other hand, the cooling water flowing through the branch passage hole 39 and the connecting pipe 41 flows into the internal passage 48 of the inverter water jacket 46 through the inlet 47 of the inverter water jacket 46. The cooling water flowing into the internal passage 48 flows through the internal passage 48, receives the heat of the inverter main body 12 during that time, and flows into the connecting pipe 53 through the outlet 49 of the inverter water jacket 46. Subsequently, the cooling water flows through the connecting pipe 53 and flows into the confluence chamber 52.

[0047] The cooling water that flows into the confluence chamber 52 through the outlet 45 of the motor water jacket 42 and the cooling water that flows into the confluence chamber 52 through the connecting pipe 53 after flowing through the outlet 49 of the inverter water jacket 46 merge in the confluence chamber 52. The merged cooling water flows into the cooling water discharge passage 54 from the confluence chamber 52, flows through the cooling water discharge passage 54, and is discharged outside the outboard motor 1 from the drain port 55.

[0048] Also, the flow rate of the cooling water flowing through the motor water jacket 42 and the inverter water jacket 46 is adjusted according to the valve opening of the control valve 56. Thereby, the temperature of the cooling water can be adjusted. When the valve opening of the control valve 56 increases, the flow rate of the cooling water flowing through the motor water jacket 42 and the inverter water jacket 46 increases, the temperature of the cooling water becomes lower, and the cooling capacity for cooling the motor 2 and the inverter main body 12 by the cooling water increases. On the other hand, when the valve opening of the control valve 56 decreases, the flow rate of the cooling water flowing through the motor water jacket 42 and the inverter water jacket 46 decreases.

[0049] (Main features and effects of the cooling mechanism) (1) In the cooling mechanism 31 in the embodiment of the present invention, the motor water jacket 42 and the inverter water jacket 46 are connected in parallel to the cooling water supply path 35 via the branch path 36. Here, Fig. 9(A) shows a configuration in which the motor water jacket 71 and the inverter water jacket 72 are connected in parallel between the starting point B and the ending point E of the cooling water path. Fig. 9(B) shows a configuration in which the motor water jacket 71 and the inverter water jacket 72 are connected in series between the starting point B and the ending point E of the cooling water path. In each of Fig. 9(A) and 9(B), the cooling water flows from the starting point B to the ending point E as indicated by the arrows in the respective figures.

[0050] As can be seen by comparing the configuration of Fig. 9(A) with that of Fig. 9(B), the length of the cooling water flow path from the starting point B through the motor water jacket 71 to the ending point E in the configuration of Fig. 9(A), and the length of the cooling water flow path from the starting point B through the inverter water jacket 72 to the ending point E in the configuration of Fig. 9(A) are both shorter than the length of the cooling water flow path from the starting point B through the motor water jacket 71 and the inverter water jacket 72 in sequence to the ending point E in the configuration of Fig. 9(B). Therefore, the configuration of Fig. 9(A) can reduce the pressure loss between the starting point B and the ending point E of the cooling water path more than the configuration of Fig. 9(B), and the cooling water can flow smoothly from the starting point B to the ending point E.

[0051] Thus, according to the outboard motor 1 of the embodiment of the present invention provided with the cooling mechanism 31 in which the motor water jacket 42 and the inverter water jacket 46 are connected in parallel via the branch path 36 to the cooling water supply path 35, for example, compared with a conventional outboard motor provided with a cooling mechanism in which the water jacket of the motor and the water jacket of the inverter are connected in series as described in Japanese Patent Application Laid-Open No. 2022-34677, the cooling water can be smoothly circulated in the cooling mechanism. Therefore, even when a small pump with a low discharge capacity is used, the cooling efficiency of the motor 2 and the inverter 11 by the cooling mechanism 31 can be enhanced.

[0052] Further, according to the cooling mechanism 31, since the motor water jacket 42 and the inverter water jacket 46 are connected in parallel via the branch path 36 to the cooling water supply path 35, the flow rate of the cooling water flowing in the motor water jacket 42 and the flow rate of the cooling water flowing in the inverter water jacket 46 can be easily set individually according to the respective heat generation amounts of the motor 2 and the inverter main body 12. Therefore, the cooling capacity for cooling the motor 2 and the cooling capacity for cooling the inverter main body 12 can be easily optimized individually. For example, when the heat generation amount of the motor 2 is larger than the heat generation amount of the inverter 11, by making the diameters of the branch passage holes 38 and the connecting pipes 40 of the branch path 36 larger than the diameters of the branch passage holes 39 and the connecting pipes 41, the flow rate of the cooling water flowing from the main line passage hole 37 through the branch passage holes 38 and the connecting pipes 40 and flowing into the motor water jacket 42 can be made larger than the flow rate of the cooling water flowing from the main line passage hole 37 through the branch passage holes 39 and the connecting pipes 41 and flowing into the inverter water jacket 46. Thereby, the cooling capacity for cooling the motor 2 can be more easily made higher than the cooling capacity for cooling the inverter main body 12.

[0053] (2) In the cooling mechanism 31 in the embodiment of the present invention, the inlet 43 of the motor water jacket 42 and the inlet 47 of the inverter water jacket 46 are respectively arranged at the lower parts of the motor 2 and the inverter 11, and the outlet 45 of the motor water jacket 42 and the outlet 49 of the inverter water jacket 46 are respectively arranged at the upper parts of the motor 2 and the inverter 11. Here, FIG. 9(C) shows a configuration in which the motor water jacket 81 and the inverter water jacket 82 are connected in parallel between the starting point B and the ending point E of the cooling water passage, the position of the inlet of the motor water jacket 81 and the position of the outlet of the motor water jacket 81 are on opposite sides in the motor 61, the position of the inlet of the inverter water jacket 82 and the position of the outlet of the inverter water jacket 82 are on opposite sides in the inverter 62, when the motor 61 and the inverter 62 are arranged in the motor case of the outboard motor, the position of the inlet of the motor water jacket 81 and the position of the inlet of the inverter water jacket 82 are on the same side in the motor 61 and the inverter 62 respectively, and when the motor 61 and the inverter 62 are arranged in the motor case of the outboard motor, the position of the outlet of the motor water jacket 81 and the position of the outlet of the inverter water jacket 82 are on the same side in the motor 61 and the inverter 62 respectively, the positions of the inlet and the outlet of the motor water jacket 81, and the positions of the inlet and the outlet of the inverter water jacket 82 are set.Fig. 9(D) shows a configuration in which the motor water jacket 91 and the inverter water jacket 92 are connected in parallel between the starting point B and the ending point E of the cooling water passage. The position of the inlet of the motor water jacket 91 and the position of the outlet of the motor water jacket 91 are on the same side of the motor 61, and the position of the inlet of the inverter water jacket 92 and the position of the outlet of the inverter water jacket 92 are on the same side of the inverter 62. When the motor 61 and the inverter 62 are arranged in the motor case of the outboard motor, the positions of the inlet and the outlet of the motor water jacket 91, and the positions of the inlet and the outlet of the inverter water jacket 92 are on the same side of the motor 61 and the inverter 62 respectively. The positions of the inlet and the outlet of the motor water jacket 91, and the positions of the inlet and the outlet of the inverter water jacket 92 are set. In Figs. 9(C) and 9(D), the cooling water flows from the starting point B to the ending point E as indicated by the arrows in each figure.

[0054] In the configuration of Fig. 9(C), the position of the inlet of the motor water jacket 81 and the position of the inlet of the inverter water jacket 82 are on the same side of the motor 61 and the inverter 62 respectively. Thereby, the length of the cooling water passage from the starting point B to the inlet of the motor water jacket 81 and the length of the cooling water passage from the starting point B to the inlet of the inverter water jacket 82 can be shortened respectively. Also, in the configuration of Fig. 9(D), the position of the inlet of the motor water jacket 91 and the position of the inlet of the inverter water jacket 92 are on the same side of the motor 61 and the inverter 62 respectively. Thereby, the length of the cooling water passage from the starting point B to the inlet of the motor water jacket 91 and the length of the cooling water passage from the starting point B to the inlet of the inverter water jacket 92 can be shortened respectively.

[0055] Further, in the configuration of FIG. 9(C), the positions of the outlets of the motor water jacket 81 and the inverter water jacket 82 are on the same side with respect to the motor 61 and the inverter 62, respectively. As a result, the lengths of the cooling water paths from the outlets of the motor water jacket 81 to the end point E and from the outlets of the inverter water jacket 82 to the end point E can be shortened respectively. Also, in the configuration of FIG. 9(D), the positions of the outlets of the motor water jacket 91 and the inverter water jacket 92 are on the same side with respect to the motor 61 and the inverter 62, respectively. As a result, the lengths of the cooling water paths from the outlets of the motor water jacket 91 to the end point E and from the outlets of the inverter water jacket 92 to the end point E can be shortened respectively.

[0056] Also, as can be seen by comparing the configuration of FIG. 9(C) with the configuration of FIG. 9(D), in the configuration of FIG. 9(C), the direction of the internal passage of the motor water jacket 81 is not reversed. On the other hand, in the configuration of FIG. 9(D), the direction of the internal passage of the motor water jacket 91 is reversed. That is, in the configuration of FIG. 9(C), since the position of the inlet of the motor water jacket 81 and the position of the outlet of the motor water jacket 81 are on opposite sides of the motor 61, even without reversing the direction of the internal passage of the motor water jacket 81, the cooling water can be circulated everywhere around the motor 61 to efficiently cool the motor 61. On the other hand, in the configuration of FIG. 9(D), since the position of the inlet of the motor water jacket 91 and the position of the outlet of the motor water jacket 91 are on the same side of the motor 61, it is difficult to circulate the cooling water everywhere around the motor 61 to efficiently cool the motor 61 without reversing the direction of the internal passage of the motor water jacket 91. Also, an internal passage having no structure with a reversed direction can be more easily simplified in structure than an internal passage having a structure with a reversed direction. Therefore, the structure shown in FIG. 9(C) can more easily simplify the internal passage of the motor water jacket than the structure shown in FIG. 9(D). Also, for the same reason, the structure of FIG. 9(C) in which the direction of the internal passage of the inverter water jacket 82 is not reversed can more easily simplify the internal passage of the inverter water jacket than the structure of FIG. 9(D) in which the direction of the internal passage of the inverter water jacket 92 is reversed.

[0057] Thus, according to the cooling mechanism 31 in the embodiment of the present invention, the inlet 43 of the motor water jacket 42 and the inlet 47 of the inverter water jacket 46 are respectively arranged at the lower parts of the motor 2 and the inverter 11, and the outlet 45 of the motor water jacket 42 and the outlet 49 of the inverter water jacket 46 are respectively arranged at the upper parts of the motor 2 and the inverter 11. Therefore, the cooling water supply path 35 or the branch path 36, and the confluence path 50 or the cooling water discharge path 54 can be shortened respectively, and while realizing good cooling efficiency of the motor 2, the internal passage 44 of the motor water jacket 42 and the internal passage 48 of the inverter water jacket 46 can be easily simplified respectively.

[0058] (3) In the cooling mechanism 31 in the embodiment of the present invention, as shown in FIG. 4 or FIG. 7, when the motor 2 and the motor water jacket 42 are viewed from above, the outlet 45 of the motor water jacket 42 is arranged on the substantially opposite side of the inlet 43 of the motor water jacket 42 across the rotation center C of the motor 2. Here, FIG. 9(E) shows a configuration in which when the motor 61 and the motor water jacket 101 are viewed from above, the outlet of the motor water jacket 101 is arranged on the substantially opposite side of the inlet of the motor water jacket 101 across the rotation center D of the motor 61. FIG. 9(F) shows a configuration in which when the motor 61 and the motor water jacket 111 are viewed from above, the outlet of the motor water jacket 111 is not arranged on the substantially opposite side of the inlet of the motor water jacket 111 across the rotation center D of the motor 61, and the inlet and the outlet of the motor water jacket 111 are arranged close to each other on a part of the outer periphery of the motor 61. In each of FIGS. 9(E) and 9(F), the cooling water flows from the starting point B to the ending point E as indicated by the arrows in the respective figures.

[0059] As can be seen by comparing the configuration of Fig. 9(E) with the configuration of Fig. 9(F), in the internal passage of the motor water jacket 101 of the configuration of Fig. 9(E), the counterclockwise passage length from the inlet to the outlet is substantially equal to the clockwise passage length from the inlet to the outlet. On the other hand, in the internal passage of the motor water jacket 111 of the configuration of Fig. 9(F), the counterclockwise passage length from the inlet to the outlet is significantly longer than the clockwise passage length from the inlet to the outlet. Therefore, the configuration of Fig. 9(E) can more easily flow the cooling water uniformly over the entire circumference of the motor 61 than the configuration of Fig. 9(F), and the cooling efficiency of the motor 61 can be increased. That is, in the configuration of Fig. 9(E), the flow rate of the cooling water flowing counterclockwise from the inlet to the outlet in the internal passage of the motor water jacket 101 is substantially equal to the flow rate of the cooling water flowing clockwise from the inlet to the outlet in the internal passage of the motor water jacket 101. As a result, the entire circumference of the motor 61 can be cooled uniformly. In contrast, in the configuration of Fig. 9(F), most of the cooling water flows clockwise from the inlet to the outlet in the internal passage of the motor water jacket 111. As a result, the amount of cooling water flowing counterclockwise from the inlet to the outlet in the internal passage of the motor water jacket 111 decreases, and therefore, there is a possibility that a part of the motor 61 cannot be sufficiently cooled.

[0060] Thus, according to the cooling mechanism 31 in the embodiment of the present invention, when the motor 2 and the motor water jacket 42 are viewed from above, the outlet 45 of the motor water jacket 42 is arranged substantially on the opposite side of the inlet 43 of the motor water jacket 42 with the rotation center C of the motor 2 interposed therebetween. Therefore, the cooling water can be uniformly flowed over the entire circumference of the motor 2, and the cooling efficiency of the motor 2 can be increased.

[0061] (4) In the cooling mechanism 31 in the embodiment of the present invention, as shown in FIGS. 6 to 8, the inlet 47 of the inverter water jacket 46 is disposed at the lower left portion of the inverter 11, and the outlet 49 of the inverter water jacket 46 is disposed at the upper right portion of the inverter 11. As can be seen from FIG. 2, when the inverter 11 is viewed from the front, the shape of the inverter 11 is a quadrilateral, and the inlet 47 and the outlet 49 are respectively disposed at the diagonal portions of the inverter 11. Here, FIG. 9(G) shows a configuration in which the inlet and the outlet of the inverter water jacket 102 are respectively disposed at the diagonal portions of the inverter 62 having a quadrilateral shape when viewed from the front. FIG. 9(H) shows a configuration in which the inlet and the outlet of the inverter water jacket 112 are not disposed at the diagonal portions of the inverter 62, but are respectively disposed on the same side in the left-right direction of the inverter 62. In each of FIGS. 9(G) and 9(H), the cooling water flows from the starting point B to the ending point E as indicated by the arrows in each figure.

[0062] As can be seen by comparing the configuration of FIG. 9(G) with the configuration of FIG. 9(H), in the configuration of FIG. 9(G), the direction of the internal passage of the inverter water jacket 102 is not reversed. On the other hand, in the configuration of FIG. 9(H), the direction of the internal passage of the inverter water jacket 112 is reversed. That is, in the configuration of FIG. 9(G), since the inlet and outlet of the inverter water jacket 102 are respectively arranged at the diagonal portions of the inverter 62, even without reversing the direction of the internal passage of the inverter water jacket 102, the cooling water can be circulated to all parts of the surface of the inverter body where the inverter water jacket 102 is in contact or close proximity, and the inverter body can be efficiently cooled. On the other hand, in the configuration of FIG. 9(H), since the positions of the inlet and outlet of the inverter water jacket 112 are on the same side of each other in the inverter 62, it is difficult to circulate the cooling water to all parts of the surface of the inverter body where the inverter water jacket 112 is in contact or close proximity and efficiently cool the inverter body without reversing the direction of the internal passage of the inverter water jacket 112. In addition, an internal passage having a structure whose direction is not reversed can be more easily simplified in structure than an internal passage having a structure whose direction is reversed. Therefore, the structure shown in FIG. 9(G) can more easily simplify the internal passage of the inverter water jacket than the structure shown in FIG. 9(H).

[0063] Thus, according to the cooling mechanism 31 in the embodiment of the present invention, the inlet 47 of the inverter water jacket 46 is arranged at the lower left part of the inverter 11, and the outlet 49 of the inverter water jacket 46 is arranged at the upper right part of the inverter 11. That is, when the inverter 11 is viewed from the front, the inlet 47 and the outlet 49 are respectively arranged at the diagonal portions of the inverter 11 formed in a rectangular shape. Therefore, while realizing good cooling efficiency of the inverter body 12, the internal passage 48 of the inverter water jacket 46 can be easily simplified.

[0064] (5) In the cooling mechanism 31 according to the embodiment of the present invention, the outlet 49 of the inverter water jacket 46 is arranged at the same position in the left - right direction as the outlet 45 of the motor water jacket 42, as shown in FIG. 4. Thereby, the confluence path 50, specifically, the connection pipe 53 can be shortened. Therefore, the pressure loss of the cooling water flowing through the connection pipe 53 from the outlet 49 of the inverter water jacket 46 toward the confluence chamber 52 can be reduced.

[0065] (6) The cooling mechanism 31 according to the embodiment of the present invention includes a control valve 56 for controlling the flow rate of the cooling water after confluence in the confluence path 50. By adopting a configuration for controlling the flow rate of the cooling water after confluence, the temperature of the cooling water can be adjusted by a single control valve 56, and the structure of the cooling mechanism 31 can be simplified.

[0066] In addition, in the cooling mechanism 31 in the above - mentioned embodiment, the respective arrangements of the branch path 36, the inlet 43 and the outlet 45 of the motor water jacket 42, the inlet 47 and the outlet 49 of the inverter water jacket 46, and the confluence path 50, etc. may be entirely reversed left - right.

[0067] Also, in the cooling mechanism 31 in the above embodiment, the inlet 43 of the motor water jacket 42 and the inlet 47 of the inverter water jacket 46 are respectively arranged at the lower parts of the motor 2 and the inverter 11, and the outlet 45 of the motor water jacket 42 and the outlet 49 of the inverter water jacket 46 are respectively arranged at the upper parts of the motor 2 and the inverter 11. However, the present invention is not limited to this. For example, as shown in Fig. 10(A), the inlet of the motor water jacket 42 and the inlet of the inverter water jacket 46 can be respectively arranged at the upper parts of the motor 2 and the inverter 11, and the outlet of the motor water jacket 42 and the outlet of the inverter water jacket 46 can be respectively arranged at the lower parts of the motor 2 and the inverter 11. Also, as shown in Fig. 10(B), the inlet of the motor water jacket 42 and the inlet of the inverter water jacket 46 can be respectively arranged at the front parts of the motor 2 and the inverter 11, and the outlet of the motor water jacket 42 and the outlet of the inverter water jacket 46 can be respectively arranged at the rear parts of the motor 2 and the inverter 11.

[0068] Also, in the above embodiment, the inverter water jacket 46 is arranged in front of the inverter main body 12, but the inverter water jacket 46 can be arranged behind the inverter main body 12, or in front of and behind the inverter main body 12.

[0069] Also, in the above embodiment, the inverter 11 is arranged behind the motor 2, but the inverter 11 can be arranged in front of the motor 2, or on the left or right side of the motor 2.

[0070] In the above-described embodiment, the water around the outboard motor 1 is taken into the cooling mechanism 31 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.

[0071] In addition, the present invention can also be applied to marine propulsion devices other than outboard motors.

[0072] In addition, the present invention can be appropriately modified within the scope 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 a modification is also included in the technical idea of the present invention.

Explanation of Reference Numerals

[0073] 1 Outboard motor (marine propulsion device) 2 Motor 3 Motor shaft 11 Inverter 15 Propeller 16 Drive shaft (power transmission mechanism) 17 Propeller shaft (power transmission mechanism) 18 Gear mechanism (power transmission mechanism) 31 Cooling mechanism 35 Cooling water supply path (first cooling water path) 36 Branch path 42 Motor water jacket 43 Inlet 45 Outlet 46 Inverter water jacket 47 Inlet 49 Outlet 50 Confluence path 54 Cooling water discharge path (second cooling water path) 55 Drain port 56 Control valve (valve)

Claims

1. A marine propulsion machine comprising a motor, an inverter that generates a drive current for controlling the drive of the motor, a propeller, a power transmission mechanism that transmits the power of the motor to the propeller, and a cooling mechanism that cools the motor and the inverter, wherein the cooling mechanism includes a motor water jacket provided in the motor and cooling the motor by circulating cooling water therein, an inverter water jacket provided in the inverter and cooling the inverter by circulating cooling water therein, a first cooling water passage for circulating cooling water toward the motor water jacket and the inverter water jacket, a branch passage that connects the motor water jacket and the 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 motor water jacket and the inverter water jacket. The marine propulsion machine is characterized by this.

2. When the extending direction of the rotation shaft of the motor is defined as the X direction and the direction orthogonal to the extending direction of the rotation shaft of the motor is defined as the Y direction, the motor and the inverter are arranged side by side in the Y direction, the motor water jacket has an inlet through which the cooling water supplied through the branch passage flows into the motor water jacket and an outlet through which the cooling water that has circulated in the motor water jacket flows out of the motor water jacket, the inverter water jacket has an inlet through which the cooling water supplied through the branch passage flows into the inverter water jacket and an outlet through which the cooling water that has circulated in the inverter water jacket flows out of the inverter water jacket, the inlets of the motor water jacket and the inverter water jacket are respectively arranged at one side portion in the X direction of the motor and the inverter, the outlets of the motor water jacket and the inverter water jacket are respectively arranged at the other side portion in the X direction of the motor and the inverter. The marine propulsion machine according to Claim 1 is characterized by this.

3. the motor water jacket is provided so as to surround the motor on the outer peripheral side of the motor, When the motor and the motor water jacket are viewed from one side in the X direction, the outlet of the motor water jacket is arranged substantially on the opposite side of the inlet of the motor water jacket with the rotation center of the motor therebetween. 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 inverter water jacket is arranged at a portion on one side of the inverter in the Z direction, and the outlet of the inverter water jacket is arranged at a portion on the other side of the inverter in the Z direction. 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 motor water jacket and the inverter water jacket respectively; a confluence path that is connected to the outlet of the motor water jacket, the outlet of the inverter water jacket, and the second cooling water passage, and that combines the cooling water flowing out from the outlet of the motor water jacket and the cooling water flowing out from the outlet of the inverter water jacket and allows them to flow into the second cooling water passage. When the direction orthogonal to the X direction and the Y direction is defined as the Z direction, the outlet of the motor water jacket and the outlet of the inverter water jacket are arranged at the same position in the Z direction. The marine propulsion device according to claim 2, characterized in that.

6. The cooling mechanism includes a valve for controlling the flow rate of the cooling water after confluence in the confluence path. The marine propulsion device according to claim 5, characterized in that.

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