Marine propulsion

Abstract

The motor is used as a power source to rotate the propeller, and the rotation direction of the motor's output shaft is switched, while preventing the lifespan of the water pump impeller from being shortened. [Solution] The cooling device provided in the marine propulsion unit 1 includes a cooling mechanism that cools equipment requiring cooling, such as the motor 3, and a water pump 51 that sends water from outside the marine propulsion unit 1 to the cooling mechanism. The impeller 52 of the water pump 51 is connected to the output shaft 4 of the motor 3 via a one-way clutch 84 and a transmission shaft 81, and the impeller 52 rotates only when the output shaft 4 of the motor 3 rotates in a direction that moves the marine vessel forward.

Description

[Technical Field]

[0001] The present invention relates to a boat propulsion device that propels a boat. [Background technology]

[0002] A conventional marine propulsion unit includes an engine, which is a power source that rotates a propeller, a drive shaft connected to the engine crankshaft, a propeller shaft, a gear mechanism that transmits the rotation of the drive shaft to the propeller shaft, and a propeller attached to the propeller shaft.

[0003] The engine is located above the water surface at the top of the marine propulsion unit, and the propeller shaft and propeller are located below the water surface at the bottom of the marine propulsion unit. The drive shaft extends vertically between the engine and the propeller shaft. The propeller shaft also extends longitudinally, with the propeller attached to the rear of the propeller shaft. The lower end of the drive shaft and the front of the propeller shaft are connected to each other via a gear mechanism, thereby transmitting rotation of the drive shaft to the propeller shaft.

[0004] Conventional marine propulsion units also include a shift mechanism that switches the rotation direction of the propeller to switch the marine vessel between forward and reverse. The shift mechanism basically includes a dog clutch provided in the gear mechanism and a shift rod that transmits external shift operations to the dog clutch to move the dog clutch. Specifically, the gear mechanism includes a drive bevel gear connected to the lower end of the drive shaft, and a forward bevel gear and a reverse bevel gear that mesh with the drive bevel gear, respectively. The forward bevel gear and the reverse bevel gear are arranged in front of and behind the drive bevel gear so that they sandwich the drive bevel gear. As a result, the forward bevel gear and the reverse bevel gear rotate in opposite directions in response to the rotation of the drive bevel gear. The dog clutch is arranged between the forward bevel gear and the reverse bevel gear. The dog clutch is attached to the propeller shaft so that it rotates integrally with the propeller shaft but can move forward and backward relative to the propeller shaft. When the dog clutch is moved forward by external shift operation, the dog clutch engages with the forward gear, and the rotation of the forward gear is transmitted to the propeller shaft. This causes the propeller shaft and propeller to rotate forward, and the propeller generates thrust to move the boat forward. On the other hand, when the dog clutch is moved rearward by external shift operation, the dog clutch engages with the reverse gear, and the rotation of the reverse gear is transmitted to the propeller shaft. This causes the propeller shaft and propeller to rotate in the reverse direction, and the propeller generates thrust to move the boat backward.

[0005] Conventional marine propulsion units are also equipped with a water-cooled cooling system that primarily cools the engine. The cooling system includes a water intake, a water pump, and a water jacket. The water intake is an opening that draws water from outside the marine propulsion unit into the marine propulsion unit and is located in a submerged portion at the bottom of the marine propulsion unit. The water pump is a pump that pumps water taken into the marine propulsion unit through the water intake into the engine. The water jacket is a mechanism located on the engine that cools the engine by circulating water pumped by the water pump around or inside the engine. Many conventional marine propulsion units use a rotary variable-displacement water pump with a rubber impeller as the water pump. The water pump impeller is fixed to the drive shaft and rotates integrally with the drive shaft.

[0006] Japanese Patent Laid-Open Publication No. 2004-211619 (Patent Document 1) describes the above-mentioned conventional boat propulsion device. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-211619 Summary of the Invention [Problem to be solved by the invention]

[0008] Recently, development of marine propulsion devices that use a motor (electric motor) as a power source for rotating a propeller has been progressing.

[0009] It is difficult to reverse the rotation direction of the crankshaft in an engine. Therefore, when a marine propulsion device uses an engine as the power source for rotating the propeller, the marine propulsion device usually needs to be provided with a shift mechanism as described above to enable the marine vessel to switch between forward and reverse travel.

[0010] In contrast, a motor can switch the rotation direction of the rotor through electrical control. Therefore, when a motor is used as a power source to rotate a propeller in a marine propulsion unit, the rotation direction of the motor's output shaft can be switched through electrical control, thereby switching the rotation directions of the drive shaft and the propeller shaft, and thereby switching the rotation direction of the propeller. Therefore, when a motor is used as a power source to rotate a propeller in a marine propulsion unit, there is no need to provide a shift mechanism in the marine propulsion unit. By not providing a shift mechanism in the marine propulsion unit, the structure of the marine propulsion unit can be simplified, the marine propulsion unit can be made smaller, and the manufacturing costs of the marine propulsion unit can be reduced.

[0011] However, in a marine propulsion device, when a motor is used as a power source for rotating a propeller and the rotation direction of the motor's output shaft is switched by electrical control, the following problems arise.

[0012] In rotary variable displacement water pumps with rubber impellers, which are used as water pumps for many conventional marine propulsion systems, the life of the impeller is significantly shortened when the rotation direction of the impeller changes. When a motor is used as the power source to rotate the propeller and the rotation direction of the motor's output shaft is switched by electrical control, reversing the rotation direction of the motor's output shaft reverses the rotation direction of the drive shaft. This changes the rotation direction of the impeller fixed to the drive shaft. As a result, the life of the impeller is significantly shortened.

[0013] The present invention has been made in consideration of problems such as those described above, and an object of the present invention is to provide a marine propulsion device that uses a motor as a power source to rotate a propeller, has a configuration that switches the direction of rotation of the motor's output shaft, and yet can prevent the lifespan of the water pump impeller from being shortened. [Means for solving the problem]

[0014] In order to solve the above problem, the present invention provides a marine propulsion device for propelling a marine vessel, comprising: a motor having an output shaft; a drive shaft that rotates when rotation of the output shaft is transmitted; a propeller shaft that is provided with a propeller and rotates when rotation of the drive shaft is transmitted; and a cooling device, wherein the cooling device comprises a cooling mechanism that cools the motor, and a water pump that sends water outside the marine propulsion device to the cooling mechanism, and the impeller of the water pump is connected via a one-way clutch to a rotation transmission member other than the output shaft, the drive shaft, or the drive shaft that is provided in the marine propulsion device and rotates when rotation of the output shaft is transmitted. [Effects of the Invention]

[0015] According to the present invention, a motor is used as a power source for rotating a propeller, and the rotation direction of the output shaft of the motor is switched, while still being able to prevent the life of the water pump impeller from being shortened. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an explanatory diagram showing a marine vessel propulsion device according to a first embodiment of the present invention as viewed from the left. FIG. [Figure 2] 1 is an explanatory diagram showing a state in which a marine vessel propulsion device according to a first embodiment of the present invention is viewed from behind. [Figure 3] 3 is a cross-sectional view of the marine vessel propulsion device taken along the line AA in FIG. 2 as viewed from the left. [Figure 4] 1 is a block diagram showing the configuration of a cooling device in a marine propulsion device according to a first embodiment of the present invention. [Figure 5] 4 is an enlarged cross-sectional view showing a portion of the marine vessel propulsion device in FIG. 3 where a water pump is disposed. [Figure 6] 3 is a cross-sectional view of a marine vessel propulsion device according to a second embodiment of the present invention taken along the same line as line AA in FIG. 2, as viewed from the left. [Figure 7]7 is an enlarged cross-sectional view showing a portion of the marine vessel propulsion device in FIG. 6 where a water pump is disposed. [Figure 8] 10 is an explanatory diagram showing another embodiment of the water pump connection structure of the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] A marine propulsion device according to an embodiment of the present invention includes a motor having an output shaft, a drive shaft that rotates when rotation of the output shaft is transmitted, a propeller shaft that is provided with a propeller and rotates when rotation of the drive shaft is transmitted, and a cooling device. The cooling device for the marine propulsion device according to this embodiment includes a cooling mechanism that cools the motor, and a water pump that sends water from outside the marine propulsion device to the cooling mechanism. The impeller of the water pump is connected via a one-way clutch to the output shaft, the drive shaft, or a rotation transmission member other than the drive shaft that is provided in the marine propulsion device and rotates when rotation of the output shaft is transmitted.

[0018] For ease of explanation, the output shaft, drive shaft, and rotation transmission member are each referred to as a "rotating body." Furthermore, the rotation of the motor rotor in one direction and the rotation of the rotating body when the motor rotor rotates in that one direction are each referred to as a "forward rotation." Furthermore, the rotation of the motor rotor in the other direction and the rotation of the rotating body when the motor rotor rotates in that other direction are each referred to as a "reverse rotation."

[0019] In the marine propulsion device of this embodiment, the impeller of the water pump is connected to one of the rotating bodies via a one-way clutch, which is a clutch that transmits rotation in only one direction.

[0020] For example, when the rotor of the motor is rotated in the forward direction by electrical control and the rotating body connected to the impeller via the one-way clutch rotates in the forward direction accordingly, the rotation of the rotating body is transmitted to the impeller via the one-way clutch, causing the impeller to rotate.On the other hand, when the rotor of the motor is rotated in the reverse direction by electrical control and the rotating body connected to the impeller via the one-way clutch rotates in the reverse direction accordingly, the rotation of the rotating body is not transmitted to the impeller via the one-way clutch, and therefore the impeller does not rotate.

[0021] By connecting the water pump impeller to one of the rotors via a one-way clutch, it is possible to prevent the rotation direction of the water pump impeller from changing when the rotation direction of the motor output shaft changes, thereby preventing the impeller from becoming shorter in life.

[0022] Because the impeller's lifespan can be prevented from being shortened, it is possible to realize a small, simple-structured, or inexpensive marine propulsion unit that does not have a shift mechanism, while still employing a water pump similar to that used in conventional marine propulsion units (for example, a rotary volume-changing water pump with a rubber impeller). [Example]

[0023] Several embodiments of the present invention will be described with reference to the drawings. In describing each embodiment, the directions of up (Ud), down (Dd), front (Fd), back (Bd), left (Ld), and right (Rd) are indicated by the arrows at the bottom left of Figures 1 to 3 and 5 to 7.

[0024] (Ship propulsion system) Fig. 1 shows a marine vessel propulsion device 1 according to a first embodiment of the present invention as viewed from the left. Fig. 2 shows the marine vessel propulsion device 1 as viewed from the rear. Fig. 3 shows a cross section of the marine vessel propulsion device 1 taken along section line AA in Fig. 2 as viewed from the left.

[0025] The boat propulsion device 1 is a device for propelling a boat. As shown in Fig. 1, the boat propulsion device 1 of this embodiment is an outboard motor that is attached to a boat. The boat propulsion device 1 of this embodiment is an electric outboard motor that uses a motor 3 as a power source to rotate a propeller 19.

[0026] As shown in FIG. 3, the marine vessel propulsion device 1 includes a motor 3, an inverter 6, a reduction gear 11, a drive shaft 14, a propeller shaft 18, a propeller 19, and a rotation transmission mechanism 15.

[0027] The motor 3 is a power source that rotates the propeller 19. The motor 3 is, for example, an AC motor, and includes an output shaft 4, a rotor, a stator, and a motor case 5. The output shaft 4, excluding the end that extracts rotor rotation, the rotor, and the stator, are housed within the motor case 5. The motor 3 is disposed on top of the marine vessel propulsion unit 1. When the marine vessel propulsion unit 1 is attached to the marine vessel, the motor 3 is located above the water surface. The motor 3 is also disposed on the marine vessel propulsion unit 1 so that the extension direction of the output shaft 4 is vertical.

[0028] The inverter 6 is a device that controls the driving of the motor 3. As shown in FIG. 3 , the inverter 6 includes an inverter main body 7 that is provided with circuits and the like that control the driving of the motor 3, and an inverter case 8 that houses the inverter main body 7. The inverter 6 is disposed above the motor 3. The inverter 6 is attached to the motor 3 via an inverter mounting member 10.

[0029] The reduction gear 11 is a device that reduces the rotation of the output shaft 4 of the motor 3 and transmits it to the drive shaft 14. The reduction gear 11 is disposed below the motor 3. The reduction gear 11 includes a drive gear 12 and a driven gear 13. The drive gear 12 is connected to the lower end of the output shaft 4 of the motor 3 and rotates integrally with the output shaft 4. The driven gear 13 is disposed in front of the drive gear 12, connected to the upper end of the drive shaft 14, and meshes with the drive gear 12. The drive gear 12 is a specific example of a "gear." The drive gear 12 is also a specific example of a "rotation transmission member."

[0030] The drive shaft 14 is located forward of the output shaft 4 of the motor 3, and extends in the vertical direction from the reduction gear 11 to the rotation transmission mechanism 15. The drive shaft 14 rotates when the rotation of the output shaft 4 is transmitted to it via the reduction gear 11. Specifically, the driven gear 13 is coupled to the upper end of the drive shaft 14 as described above, and the drive shaft 14 rotates integrally with the driven gear 13.

[0031] The rotation transmission mechanism 15 is a mechanism that transmits the rotation of the drive shaft 14 to the propeller shaft 18. The rotation transmission mechanism 15 includes two bevel gears 16 and 17 that mesh with each other. One of the bevel gears, 16, is coupled to the lower end of the drive shaft 14 and rotates integrally with the drive shaft 14. The other bevel gear, 17, is coupled to the front end of the propeller shaft 18.

[0032] The propeller shaft 18 extends in the front-to-rear direction and is disposed below the motor 3. The propeller shaft 18 rotates when rotation of the drive shaft 14 is transmitted to it via the rotation transmission mechanism 15. Specifically, as described above, the bevel gear 17 of the rotation transmission mechanism 15 is coupled to the front end of the propeller shaft 18, and the propeller shaft 18 rotates integrally with the bevel gear 17. The propeller 19 is coupled to the rear end of the propeller shaft 18 and rotates integrally with the propeller shaft 18. The propeller shaft 18 and the propeller 19 are disposed at the bottom of the marine vessel propulsion device 1 and are located below the water surface when the marine vessel propulsion device 1 is attached to the marine vessel.

[0033] The motor 3 is driven under the control of the inverter 6, causing the output shaft 4 to rotate. The rotation of the output shaft 4 is transmitted to the drive shaft 14 while being reduced in speed by the reduction gear 11, causing the drive shaft 14 to rotate. The rotation of the drive shaft 14 is transmitted to the propeller shaft 18 by the rotation transmission mechanism 15, causing the propeller shaft 18 and the propeller 19 to rotate. The rotation of the propeller 19 generates propulsion force for the vessel.

[0034] As shown in Figure 3, the marine propulsion unit 1 also includes a middle case 25 that houses the reduction gear 11 and the upper part of the drive shaft 14. The middle case 25 is disposed below the motor 3 and attached to the motor 3. The marine propulsion unit 1 also includes a lower case 27 that houses the lower part of the drive shaft 14, the front part of the propeller shaft 18, and the rotation transmission mechanism 15. The lower case 27 is disposed below the middle case 25 and attached to the middle case 25. The lower case 27 also includes an anti-cavitation plate 28.

[0035] 1, the marine vessel propulsion unit 1 is equipped with an attachment mechanism 30 that attaches the marine vessel propulsion unit 1 to the marine vessel. The attachment mechanism 30 includes a clamp bracket 31 that secures the marine vessel propulsion unit 1 to the transom of the marine vessel, a swivel bracket 33 that is connected to the clamp bracket 31 via a tilt shaft 32, a pilot shaft 34 that extends in the vertical direction and is rotatably supported by the swivel bracket 33, and mounts 35, 36 that connect the upper and lower ends of the pilot shaft 34 to the marine vessel propulsion unit 1.

[0036] (cooling device) The marine vessel propulsion unit 1 is equipped with a liquid-cooling type cooling device 41 that cools equipment that needs to be cooled and is provided in the marine vessel propulsion unit 1. Specifically, the equipment that needs to be cooled and is provided in the marine vessel propulsion unit 1 is the motor 3 and the inverter 6.

[0037] Fig. 4 shows the configuration of the cooling device 41. As shown in Fig. 4, the cooling device 41 includes a water intake 42, a supply passage, a water pump 51, a cooling mechanism 61, a discharge passage 55, a discharge chamber 57, and a drain port 58. The supply passage includes a lower internal supply passage 44, an upper internal supply passage 45, and an external supply passage 46.

[0038] The water intake 42 is an opening for taking water from outside the marine vessel propulsion device 1 into the marine vessel propulsion device 1. The water intake 42 is provided in a submerged portion of the marine vessel propulsion device 1. Specifically, the water intake 42 is provided in the front portion of the lower part of the lower case 27, as shown in FIGS.

[0039] The supply passage connects the water intake 42 and the heat exchanger 62 that constitutes part of the cooling mechanism 61, and supplies water outside the marine vessel propulsion device 1 that is taken into the marine vessel propulsion device 1 through the water intake 42 to the heat exchanger 62 as cooling water. The thick arrows in Figure 3 indicate the flow direction of the cooling water within the supply passage. As described above, the supply passage has the lower internal supply passage 44, the upper internal supply passage 45, and the external supply passage 46.

[0040] A water pump 51 is provided in the supply passage. The portion of the supply passage from the water intake 42 to the suction port 54A of the water pump 51 (see FIG. 5) is the lower internal supply passage 44. The lower internal supply passage 44 is formed, for example, by a hole provided inside the lower case 27 and a hole provided inside the middle case 25. The supply passage also passes through a connection port 47 that opens on the rear surface of the middle case 25. The portion of the supply passage from the discharge port 54B of the water pump 51 (see FIG. 5) to the connection port 47 is the upper internal supply passage 45. The upper internal supply passage 45 is formed, for example, by a hole provided inside the middle case 25. The portion of the supply passage from the connection port 47 to the heat exchanger 62 is the external supply passage 46. The external supply passage 46 is formed, for example, by a hose or a pipe. The outlet end of the external supply passage 46 is connected to the inlet of the internal coolant flow path of the heat exchanger 62.

[0041] The water pump 51 sends water from outside the marine propulsion unit 1, i.e., cooling water, to the heat exchanger 62 via a supply passage. The water pump 51 is a rotary variable-displacement water pump equipped with a rubber impeller. The water pump 51 has an impeller 52 and a pump case 54 that houses the impeller 52. As shown in FIG. 3 , the water pump 51 is disposed in the lower part of the middle case 25. The water pump 51 is disposed below the motor 3, and overlaps the motor 3 when the marine propulsion unit 1 is viewed from above. The water pump 51 is disposed so that the rotation axis of the impeller 52 is coaxial with the output shaft 4 of the motor 3. The pump case 54 is attached to the bottom of the middle case 25. The pump case 54 may also be attached to the upper surface of the lower case 27. As will be described in detail later, the impeller 52 of the water pump 51 is connected to the output shaft 4 of the motor 3 via the drive gear 12 of the reduction gear 11, the one-way clutch 84, and the transmission shaft 81. When the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward, the rotation of the output shaft 4 is transmitted to the impeller 52, causing it to rotate.

[0042] The cooling mechanism 61 is a mechanism that cools devices that require cooling and are provided in the marine vessel propulsion device 1, namely the motor 3 and the inverter 6. The cooling mechanism 61 cools a refrigerant using cooling water in a heat exchanger 62, and cools the motor 3 and the inverter 6 by causing the refrigerant to flow through a motor cooling jacket 63 and an inverter cooling jacket 64. Details of the cooling mechanism 61 will be described later.

[0043] The discharge passage 55 is a passage that carries the coolant that has flowed through the internal coolant flow path of the heat exchanger 62 to a drain port 58. As shown in FIGS. 1 and 2 , the discharge passage 55 is formed, for example, by a hose or a pipe. The inlet end of the discharge passage 55 is connected to an outlet of the internal coolant flow path that is provided in the lower part of the heat exchanger 62. As shown in FIG. 3 , a discharge chamber 57 is provided from the rear part of the lower part of the middle case 25 to the rear part of the lower case 27. As shown in FIG. 1 , a connection port 56 that communicates with the inside of the discharge chamber 57 opens on the left side of the middle case 25. The outlet end of the discharge passage 55 is connected to the connection port 56 and communicates with the inside of the discharge chamber 57 via the connection port 56.

[0044] The drain port 58 is an opening for discharging the cooling water after it has flowed through the heat exchanger 62 to the outside of the marine vessel propulsion device 1. As shown in Fig. 3, the drain port 58 is formed, for example, inside the hub of the propeller 19. The drain port 58 is in communication with the inside of the discharge chamber 57.

[0045] In Fig. 3, when the motor 3 is driven and the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward, the impeller 52 of the water pump 51 rotates. As a result, water outside the boat propulsion device 1 that is taken into the boat propulsion device 1 through the water intake 42 flows as cooling water through the lower internal supply passage 44, the water pump 51, the upper internal supply passage 45, and the external supply passage 46 in this order, before flowing into the internal cooling water flow path of the heat exchanger 62 and flowing through the internal cooling water flow path. The cooling water flowing through the internal cooling water flow path of the heat exchanger 62 cools the refrigerant circulating through the circulation passage of the cooling mechanism 61. After flowing through the internal cooling water flow path of the heat exchanger 62, the cooling water flows through the discharge passage 55 (see Fig. 1), then through the discharge chamber 57 (see Fig. 3), and then is discharged outside the boat propulsion device 1 through the discharge port 58.

[0046] (cooling mechanism) 4, the cooling mechanism 61 includes a heat exchanger 62, a motor cooling jacket 63, an inverter cooling jacket 64, a circulation passage, a refrigerant pump 65, and a degassing tank 66. The circulation passage has refrigerant passages 71-75.

[0047] The heat exchanger 62 is a device that cools the refrigerant by exchanging heat between water outside the marine propulsion device 1, i.e., cooling water, and the refrigerant circulating in a circulation passage. The refrigerant is, for example, a coolant such as LLC. The heat exchanger 62 is provided with an internal cooling water passage through which the cooling water flows and an internal refrigerant passage through which the refrigerant flows. The internal cooling water passage and the internal refrigerant passage are arranged so that heat exchange is possible between the cooling water flowing in the internal cooling water passage and the refrigerant flowing in the internal refrigerant passage. As shown in FIG. 1, the heat exchanger 62 is arranged behind the motor 3.

[0048] The motor cooling jacket 63 is a mechanism that cools the motor 3 using the refrigerant cooled by the heat exchanger 62. As shown in FIG. 3, the motor cooling jacket 63 is provided on the motor 3. For example, the motor cooling jacket 63 is composed of flow paths formed in the motor case 5 of the motor 3. The flow paths that make up the motor cooling jacket 63 are formed over a wide area of ​​the motor case 5. For example, the flow paths are formed around the entire circumference of the motor case 5, and are formed from one end portion to the other end portion of the motor case 5 in the axial direction.

[0049] The inverter cooling jacket 64 is a mechanism that cools the inverter 6 using the refrigerant cooled by the heat exchanger 62. The inverter cooling jacket 64 is provided on the inverter 6. For example, the inverter cooling jacket 64 is disposed in the lower rear part of the inverter 6, and is located below the rear part of the inverter main body 7. Specifically, the inverter cooling jacket 64 is configured by a flow path formed in the lower rear part of the inverter case 8. The flow path extends from the left end to the right end of the inverter case 8.

[0050] The refrigerant pump 65 is a pump that circulates the refrigerant in the circulation passage. The refrigerant pump 65 is an electric pump, and is driven, for example, by a motor dedicated to the refrigerant pump 65, separate from the motor 3. As shown in FIG. 1 , the refrigerant pump 65 is disposed above the heat exchanger 62. The refrigerant pump 65 is also disposed behind the inverter 6. The refrigerant pump 65 is also attached to the rear of the inverter 6.

[0051] The degassing tank 66 has the function of releasing bubbles generated in the refrigerant due to heat, etc., and the function of acting as a reserve tank to absorb increases or decreases in the amount of refrigerant due to thermal expansion or aging of the refrigerant. The degassing tank 66 is located above the inverter 6 and attached to the inverter 6.

[0052] The circulation passage is a passage that circulates the refrigerant between the heat exchanger 62 and the motor cooling jacket 63 and the inverter cooling jacket 64. As shown in Fig. 4, the circulation passage connects these devices so that the refrigerant flows through the heat exchanger 62, the motor cooling jacket 63, the inverter cooling jacket 64, and the refrigerant pump 65 in this order before returning to the heat exchanger 62. The circulation passage includes a refrigerant passage 71 that connects the heat exchanger 62 and the motor cooling jacket 63, a refrigerant passage 72 that connects the motor cooling jacket 63 and the inverter cooling jacket 64, a refrigerant passage 73 that connects the inverter cooling jacket 64 and a passage connection part 77, a refrigerant passage 74 that connects the passage connection part 77 and the refrigerant pump 65, a refrigerant passage 75 that connects the refrigerant pump 65 and the heat exchanger 62, and a refrigerant passage 76 that connects the passage connection part 77 and the degassing tank 66.

[0053] 1 and 2, the refrigerant passage 71 extends from the upper left side of the heat exchanger 62 to the lower rear side of the motor 3. The refrigerant passage 71 is formed, for example, by a hose or a pipe. The inlet end of the refrigerant passage 71 is connected to an outlet of the internal refrigerant flow path that opens on the upper left surface of the heat exchanger 62. The outlet end of the refrigerant passage 71 is connected to an inlet 63A (see FIG. 3) of the motor cooling jacket 63 that opens on the lower rear part of the motor case 5.

[0054] 1 , the refrigerant passage 72 is provided in a section extending from the upper left rear of the motor case 5 to the lower left rear of the inverter case 8. The refrigerant passage 72 is formed by a hole provided inside this section and extending in the vertical direction. The inlet end of the refrigerant passage 72 is connected to the outlet of the motor cooling jacket 63 provided in the upper left rear of the motor case 5, and the outlet end of the refrigerant passage 72 is connected to the inlet of the inverter cooling jacket 64 provided in the lower left rear of the inverter case 8.

[0055] As shown in FIG. 2, the refrigerant passage 73 is disposed to the rear right of the inverter 6. The refrigerant passage 73 is formed, for example, by a hose or a pipe. The inlet end of the refrigerant passage 73 is connected to an outlet of the inverter cooling jacket 64, which opens on the right surface of the lower rear part of the inverter case 8. The outlet end of the refrigerant passage 73 is connected to a passage connection part 77. The passage connection part 77 is a part that connects the outlet end of the refrigerant passage 73, the inlet end of the refrigerant passage 74, and the lower end of the refrigerant passage 76 to each other, and is formed, for example, by a T-joint.

[0056] The refrigerant passage 74 is disposed to the right of the refrigerant pump 65. The refrigerant passage 74 is formed, for example, by a pipe. An inflow end of the refrigerant passage 74 is connected to a passage connection part 77. An outflow end of the refrigerant passage 74 is connected to a suction port of the refrigerant pump 65 provided on the right surface of the refrigerant pump 65.

[0057] The refrigerant passage 75 extends from the lower right side of the refrigerant pump 65 to the lower right side of the heat exchanger 62. The refrigerant passage 75 is formed, for example, by a hose or a pipe. An inflow end of the refrigerant passage 75 is connected to a discharge port of the refrigerant pump 65 provided at the lower right side of the refrigerant pump 65. An outflow end of the refrigerant passage 75 is connected to an inflow port of an internal refrigerant flow path that opens to the right face of the lower part of the heat exchanger 62.

[0058] The refrigerant passage 76 is disposed above the right rear portion of the inverter 6 and behind the right portion of the degassing tank 66. The refrigerant passage 76 is formed, for example, by a hose or a pipe. The lower end of the refrigerant passage 76 is connected to a passage connection portion 77. The upper end of the refrigerant passage 76 is connected to the right rear portion of the degassing tank 66.

[0059] When the refrigerant pump 65 is driven, the refrigerant cooled by the heat exchanger 62 flows out from the outlet of the internal refrigerant flow path of the heat exchanger 62, flows through the refrigerant passage 71, and then flows through the motor cooling jacket 63. The refrigerant flows through the motor cooling jacket 63, thereby cooling the motor 3. After flowing through the motor cooling jacket 63, the refrigerant flows through the refrigerant passage 72 and then flows through the inverter cooling jacket 64. The refrigerant flows through the inverter cooling jacket 64, thereby cooling the inverter main body 7. After flowing through the inverter cooling jacket 64, the refrigerant flows sequentially through the refrigerant passage 73, the passage connection portion 77, the refrigerant passage 74, the refrigerant pump 65, and the refrigerant passage 75, before flowing into the internal refrigerant flow path of the heat exchanger 62 from the inlet of the internal refrigerant flow path. The refrigerant, which has been heated by the heat of the motor 3 and the inverter 6, is cooled in the heat exchanger 62 by cooling water taken in from outside the marine propulsion device 1.

[0060] A refrigerant is stored in the degassing tank 66. Air bubbles in the refrigerant move into the degassing tank 66 through the refrigerant passage 76 and are released into the atmosphere, for example, through a gas vent passage formed in the degassing tank 66. When the amount of refrigerant flowing through the circulation passage becomes low, the cap of the degassing tank 66 can be removed and refrigerant can be injected into the degassing tank 66 to replenish the refrigerant.

[0061] (Water pump connection structure) Fig. 5 is an enlarged view of the portion of the marine vessel propulsion device 1 in Fig. 3 where the water pump 51 is disposed. As shown in Fig. 5, the impeller 52 of the water pump 51 is connected to the output shaft 4 of the motor 3 via the drive gear 12 of the reduction gear 11, the one-way clutch 84, and the transmission shaft 81.

[0062] The drive gear 12 has a tooth portion 12A, an upper boss portion 12B, and a lower boss portion 12C. The drive gear 12 is attached to the lower end of the output shaft 4 of the motor 3. Specifically, the upper boss portion 12B of the drive gear 12 is connected to the lower end of the output shaft 4 of the motor 3 via a spline. The outer periphery of the lower boss portion 12C of the drive gear 12 is rotatably supported by a part of the middle case 25 via a bearing 85. The outer diameter of the lower boss portion 12C is larger than the outer diameter of the upper boss portion 12B, and the inner diameter of the lower boss portion 12C is larger than the inner diameter of the upper boss portion 12B.

[0063] The marine vessel propulsion unit 1 also includes a transmission shaft 81. The transmission shaft 81 extends in the vertical direction and is disposed coaxially with the output shaft 4 of the motor 3. The transmission shaft 81 has an upper shaft portion 82 and a lower shaft portion 83. The upper end portion of the lower shaft portion 83 is coupled to the lower end portion of the upper shaft portion 82 via a spline, for example, so that the upper shaft portion 82 and the lower shaft portion 83 rotate integrally. Therefore, the transmission shaft 81 can be seen as a single shaft formed by coupling the upper shaft portion 82 and the lower shaft portion 83 so that they cannot rotate with each other.

[0064] The transmission shaft 81 is attached to the drive gear 12 and extends downward from the drive gear 12. Specifically, the upper end of the transmission shaft 81 is inserted into the lower boss portion 12C of the drive gear 12. The upper end of the transmission shaft 81 is coupled to the lower boss portion 12C by a bearing 86 provided between the upper end of the transmission shaft 81 and the lower boss portion 12C so as to be rotatable relative to the lower boss portion 12C. The transmission shaft 81 is also rotatably supported by a portion of the middle case 25 via bearings 87 and 88.

[0065] Furthermore, the transmission shaft 81 is attached to the drive gear 12 via a one-way clutch 84. Specifically, the one-way clutch 84 is provided between the upper end of the transmission shaft 81 and the lower boss portion 12C, and the upper end of the transmission shaft 81 is connected to the lower boss portion 12C via the one-way clutch 84. The one-way clutch 84 is a clutch that transmits rotation in only one direction. In this embodiment, the one-way clutch 84 is configured so that the rotation of the output shaft 4 of the motor 3 is transmitted to the transmission shaft 81 via the drive gear 12 only when the output shaft 4 of the motor 3 rotates in a direction that rotates the propeller 19 forward. In other words, the one-way clutch 84 transmits the rotation of the output shaft 4 to the transmission shaft 81 when the output shaft 4 of the motor 3 rotates in a direction that rotates the propeller 19 forward, and does not transmit the rotation of the output shaft 4 to the transmission shaft 81 when the output shaft 4 of the motor 3 rotates in a direction that rotates the propeller 19 reversely. The propeller 19 generates a propulsive force that moves the vessel forward by rotating forward. The one-way clutch 84 transmits the rotation of the output shaft 4 of the motor 3 to the transmission shaft 81 only when the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward.

[0066] The impeller 52 of the water pump 51 is attached to the outer periphery of the transmission shaft 81. Specifically, the lower end of the transmission shaft 81 is inserted into an insertion hole 53A of the shaft portion 53 provided in the center of the impeller 52. The impeller 52 is non-rotatably coupled to the lower end of the transmission shaft 81 via, for example, a key or a spline. Therefore, the impeller 52 rotates integrally with the transmission shaft 81. As described above, the one-way clutch 84 transmits the rotation of the output shaft 4 of the motor 3 to the transmission shaft 81, and the transmission shaft 81 rotates only when the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward. Therefore, the impeller 52 rotates only when the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward.

[0067] As described above, the impeller 52 of the water pump 51 is connected to the output shaft 4 of the motor 3 via the one-way clutch 84 and rotates only when the output shaft 4 of the motor 3 rotates in a direction that moves the boat forward. Therefore, when the boat is moving forward, water from outside the boat propulsion unit 1, i.e., cooling water, is sent to the heat exchanger 62 by the water pump 51. In the heat exchanger 62, the cooling water cools the refrigerant circulating through the circulation passage of the cooling mechanism 61. On the other hand, when the boat is moving backward, the water pump 51 does not send cooling water to the heat exchanger 62, so the refrigerant is not cooled in the heat exchanger 62. However, boats only move backward for extremely short periods of time, such as when docking. As long as this is the case, the heat generated by the motor 3 and inverter 6 when the boat is moving backward can be sufficiently absorbed by the thermal capacity of the refrigerant. If the boat continues to move backward for a long period of time and there is a concern that the motor 3 or inverter 6 may overheat, overheating of the motor 3 or inverter 6 can be prevented by, for example, issuing a warning to the boat operator or controlling the motor 3 to reduce its rotation speed.

[0068] As described above, in the marine vessel propulsion device 1 according to the embodiment of the present invention, the impeller 52 of the water pump 51 is connected to the output shaft 4 of the motor 3 via the one-way clutch 84. This configuration ensures that the rotation direction of the impeller 52 is always constant. This prevents the rotation direction of the impeller 52 from changing when the rotation direction of the output shaft 4 of the motor 3 changes. This prevents the life of the impeller 52 from being shortened.

[0069] Since the lifespan of the impeller 52 can be prevented from being shortened, it is possible to realize a small-sized or inexpensive marine propulsion unit 1 that does not have a shift mechanism, has a simple structure, or is inexpensive, while employing a rotary variable volume water pump with a rubber impeller, similar to conventional marine propulsion units.

[0070] Furthermore, in the marine propulsion device 1 of this embodiment, the motor 3 is disposed so that the extension direction of the output shaft 4 is the vertical direction, and a transmission shaft 81, which is disposed coaxially below the output shaft 4 and extends in the vertical direction, is connected to the output shaft 4 via a one-way clutch 84, and the impeller 52 of the water pump 51 is attached to the transmission shaft 81. With this configuration, a structure is constructed in which rotation of the output shaft 4 is transmitted to the impeller 52 only in a fixed direction, while the water pump 51 can be disposed below the motor 3.

[0071] Furthermore, in the marine propulsion device 1 of this embodiment, a drive gear 12 of a reduction gear device 11 is attached to the output shaft 4 of the motor 3, and a transmission shaft 81 that is disposed coaxially with the output shaft 4 and extends downward from the drive gear 12 is attached to the drive gear 12 via a one-way clutch 84, and the impeller 52 of the water pump 51 is attached to the transmission shaft 81. In this way, by using the drive gear 12 as a member that connects the output shaft 4 and the transmission shaft 81 via the one-way clutch 84, there is no need to provide a separate member that connects the output shaft 4 and the transmission shaft 81 via the one-way clutch 84, and the number of parts in the marine propulsion device 1 can be reduced.

[0072] In addition, in the marine vessel propulsion device 1 of this embodiment, the impeller 52 of the water pump 51 is made of rubber. This increases the self-priming and discharge capabilities of the water pump 51, eliminating the need for priming water at start-up.

[0073] Furthermore, in the cooling device 41 provided in the marine propulsion unit 1 of this embodiment, the cooling mechanism 61 includes a heat exchanger 62 that cools a refrigerant using water outside the marine propulsion unit 1, cooling jackets (a motor cooling jacket 63 and an inverter cooling jacket 64) that cool the equipment requiring cooling using the refrigerant, and a circulation passage that circulates the refrigerant between the heat exchanger 62 and the cooling jackets. That is, in the cooling device 41 provided in the marine propulsion unit 1 of this embodiment, the equipment requiring cooling is cooled not by flowing cooling water through the cooling jacket, but by flowing the refrigerant cooled by the cooling water in the heat exchanger 62 through the cooling jacket. With this configuration, by increasing the heat capacity of the refrigerant, the equipment requiring cooling can be sufficiently cooled even while the impeller 52 of the water pump 51 is stopped from rotating. Possible methods for increasing the heat capacity of the refrigerant include selecting a refrigerant with a large heat capacity for use in the cooling mechanism 61, increasing the flow rate of the refrigerant flowing through the circulation passage by increasing the flow path area of ​​the circulation passage, and connecting a storage section for storing the refrigerant midway through the circulation passage so that the refrigerant passes through the storage section as it circulates through the circulation passage, thereby increasing the flow rate of the refrigerant.

[0074] Furthermore, in the marine vessel propulsion device 1 of this embodiment, the water pump 51 is disposed so that it overlaps with the motor 3 when the marine vessel propulsion device 1 is viewed from above. That is, the positions of the motor 3 and the water pump 51 are substantially aligned with each other in the fore-aft and aft directions and the left-right directions. This configuration allows the marine vessel propulsion device 1 to be made more compact and to be placed closer to the marine vessel than in a configuration in which the positions of the motor 3 and the water pump 51 are significantly misaligned in the fore-aft or aft directions or the left-right directions. Furthermore, the cooling device 41 can be made more compact, and the supply passages, discharge passages, and circulation passages connecting the components in the cooling device 41 can be shortened. [Example]

[0075] Fig. 6 shows a cross section of a marine vessel propulsion device 91 according to a second embodiment of the present invention, taken at the same position as the cutting line AA in Fig. 2, as viewed from the left. Fig. 7 shows an enlarged view of the portion of the marine vessel propulsion device 91 in Fig. 6 where the water pump 96 is disposed. Note that in the marine vessel propulsion device 91 according to the second embodiment of the present invention, the same components as those in the marine vessel propulsion device 1 according to the first embodiment of the present invention are designated by the same reference numerals, and their description will be omitted or simplified.

[0076] As shown in FIG. 6 , the cooling device provided in the marine propulsion device 91 according to the second embodiment of the present invention includes a water pump 96 that sends water from outside the marine propulsion device 1, i.e., cooling water, to the heat exchanger 62 via a supply passage. The water pump 96 is a rotary variable-displacement water pump equipped with a rubber impeller. The water pump 96 includes an impeller 97 and a pump case 99. The water pump 96 is disposed in the front portion of the lower part of the middle case 25. The water pump 96 is disposed so that the rotation axis of the impeller 97 is coaxial with the drive shaft 14. The pump case 99 is attached to the upper surface of the lower case 27. In addition, to accommodate the arrangement of the water pump 51, the shapes or arrangement of the lower internal supply passage 94 and the upper internal supply passage 45 according to the first embodiment are partially different.

[0077] The impeller 97 of the water pump 96 is connected to the drive shaft 14 via a one-way clutch 102 and a cylindrical transmission shaft 101. Specifically, as shown in FIG. 7, the cylindrical transmission shaft 101 is provided coaxially with the drive shaft 14 on the outer circumferential side of the drive shaft 14. The inner diameter of the transmission shaft 101 is larger than the outer diameter of the drive shaft 14. The drive shaft 14 is inserted inside the transmission shaft 81 with a space therebetween. The transmission shaft 101 is supported by the drive shaft 14 via bearings 103 and 104 so as to be rotatable relative to the drive shaft 14. The transmission shaft 101 is rotatably supported by a portion of the middle case 25 via bearings 105 and 106. A seal member 107 is provided between the drive shaft 14 and the upper end of the transmission shaft 101. In this embodiment, since no transmission shaft is attached to the drive gear 93 of the reduction gear 92, the shape of the drive gear 93 is partially different from the shape of the drive gear 12 according to the first embodiment.

[0078] Furthermore, the transmission shaft 101 is attached to the outer periphery of the drive shaft 14 via a one-way clutch 102. Specifically, the one-way clutch 102 is provided between the transmission shaft 101 and the drive shaft 14, and the transmission shaft 101 is connected to the drive shaft 14 via the one-way clutch 102. The one-way clutch 102 transmits the rotation of the drive shaft 14 to the transmission shaft 101 only when the drive shaft 14 rotates in a direction that moves the boat forward.

[0079] Furthermore, the impeller 97 of the water pump 96 is attached to the outer periphery of a transmission shaft 101. Specifically, the transmission shaft 101 is inserted into a mounting hole 98A in a shaft portion 98 of the impeller 97, and the impeller 97 is non-rotatably coupled to the transmission shaft 101. Due to the operation of the one-way clutch 102, the rotation of the drive shaft 14 is transmitted to the transmission shaft 101, and the transmission shaft 101 rotates only when the drive shaft 14 rotates in a direction that moves the boat forward. Therefore, the impeller 97 rotates only when the drive shaft 14 rotates in a direction that moves the boat forward.

[0080] The vessel propulsion device 91 of the second embodiment of the present invention having such a configuration can prevent the rotation direction of the impeller 97 from changing when the rotation direction of the output shaft 4 of the motor 3 is switched, as in the vessel propulsion device 1 of the first embodiment of the present invention, and can prevent the life of the impeller 97 from being shortened.

[0081] Furthermore, in the marine vessel propulsion device 91 according to the second embodiment of the present invention, the water pump 96 can be disposed in approximately the same location as in conventional marine vessel propulsion devices. Therefore, new marine vessel propulsion devices can be manufactured efficiently and at low cost using parts from conventional marine vessel propulsion devices.

[0082] In the first embodiment, the transmission shaft 81 is attached to the drive gear 12 via a one-way clutch 84, and the impeller 52 of the water pump 51 is attached directly to the transmission shaft 81. Also in the second embodiment, the transmission shaft 101 is attached to the drive shaft 14 via a one-way clutch 102, and the impeller 97 of the water pump 96 is attached directly to the transmission shaft 101. However, in the present invention, the method of attaching the water pump impeller is not limited to this. For example, as shown in FIG. 8(A), the impeller 124 of the water pump 123 may be attached to the output shaft 122 of the motor 121 via a one-way clutch 125. Furthermore, as shown in FIG. 8(B), the impeller 134 of the water pump 133 may be attached to the drive shaft 131 via a one-way clutch 135. 8(C), an extension shaft 143 may be non-rotatably coupled to an output shaft 142 of a motor 141, and an impeller 145 of a water pump 144 may be attached to the extension shaft 143 via a one-way clutch 146. The extension shaft 143 is a specific example of a "rotation transmission member."

[0083] Furthermore, in each of the above embodiments, a rotary variable volume water pump equipped with a rubber impeller was used as the water pump 51 (96), but other types of water pumps equipped with a rubber impeller may also be used as the water pump in the cooling device equipped in the marine propulsion unit of the present invention.

[0084] Furthermore, in each of the above embodiments, the cooling mechanism 61 is used to cool the motor 3 and the inverter 6, but the present invention is not limited to this, and the cooling mechanism may be used to cool only the motor, or may be used to cool other devices in addition to the motor and inverter.

[0085] Furthermore, the configuration of the cooling mechanism of the cooling device of the present invention is not limited to that described in the embodiment. For example, the direction of the refrigerant flowing through the circulation passage of the cooling mechanism may be reversed.

[0086] Furthermore, the present invention is not limited to being applied to outboard motors, but can also be applied to other types of marine propulsion devices, such as inboard / outboard motors.

[0087] Furthermore, the present invention can be modified as appropriate within the scope of the claims and the spirit or concept of the invention that can be read from the entire specification, and a marine propulsion device with such modifications is also included in the technical concept of the present invention. [Explanation of symbols]

[0088] 1, 91 Ship propulsion equipment 3, 121, 141 motors 4, 122, 142 output shaft 12 Drive gear (rotation transmission member, gear) 14, 131 Drive shaft 18 Propeller shaft 19 Propeller 41 Cooling device 51, 96, 123, 133, 144 Water pump 52, 97, 124, 134, 145 Impeller 61 Cooling mechanism 62 Heat exchanger 63 Motor cooling jacket 71 Refrigerant passage (circulation passage) 72 Refrigerant passage (circulation passage) 73 Refrigerant passage (circulation passage) 74 Refrigerant passage (circulation passage) 75 Refrigerant passage (circulation passage) 81, 101 Transmission shaft (rotation transmission member, shaft) 84, 102, 125, 135, 147 One-way clutch 143 Extension shaft (rotation transmission member)

Claims

1. A marine vessel propulsion device for propelling a marine vessel, a motor having an output shaft; a drive shaft that rotates when the rotation of the output shaft is transmitted to the drive shaft; a propeller shaft provided with a propeller and rotated by the rotation of the drive shaft; a cooling device; The cooling device is a cooling mechanism that cools the motor; a water pump that sends water outside the marine propulsion machine to the cooling mechanism, a water pump impeller connected via a one-way clutch to a rotation transmission member other than the drive shaft that is provided on the output shaft, the drive shaft, or the marine propulsion device and rotates as a result of the rotation of the output shaft being transmitted thereto.

2. 2. A marine propulsion device according to claim 1, wherein the impeller is attached to the output shaft, the drive shaft, or a shaft that is attached to the rotation transmission member via the one-way clutch.

3. 2. A marine propulsion device according to claim 1, wherein the impeller is attached to the output shaft, the drive shaft, or the rotation transmission member via the one-way clutch.

4. The motor is disposed so that the extension direction of the output shaft is in the vertical direction, a transmission shaft that is disposed below the output shaft and is coaxial with the output shaft and extends in the vertical direction is connected to the output shaft via the one-way clutch; 2. A marine propulsion device according to claim 1, wherein the impeller is attached to the transmission shaft.

5. The motor is disposed so that the extension direction of the output shaft is in the vertical direction, a gear is attached to the output shaft to transmit the rotation of the output shaft to the drive shaft; a transmission shaft that is disposed coaxially with the output shaft and extends downward from the gear is attached to the gear via the one-way clutch; 2. A marine propulsion device according to claim 1, wherein the impeller is attached to the transmission shaft.

6. a cylindrical transmission shaft coaxial with the drive shaft is provided on the outer circumferential side of the drive shaft; the transmission shaft is attached to the outer peripheral side of the drive shaft via the one-way clutch, 2. A marine propulsion device according to claim 1, wherein the impeller is attached to the transmission shaft.

7. 2. A marine propulsion device according to claim 1, wherein the impeller is made of rubber.

8. The cooling mechanism includes: a heat exchanger that uses water outside the marine propulsion device as cooling water to cool a refrigerant; a motor cooling jacket provided on the motor and configured to cool the motor using the refrigerant; 2. A marine propulsion device according to claim 1, further comprising a circulation passage for circulating the coolant between the heat exchanger and the motor cooling jacket.

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