Hybrid ship propulsion system

Abstract

To prevent complication of an internal structure of a hybrid ship propeller and inhibit deterioration of cruising performance of a ship during planing.SOLUTION: A hybrid outboard engine 1 includes: an internal combustion drive propulsion unit 11 which generates propulsion power of a ship by an internal combustion engine; and an electric propulsion unit 30 which generates propulsion power of the ship by an electric motor. The electric propulsion unit 30 is detachably attached to a portion, ranging from a rear part of a middle case 21 to an upper rear part of a gear case 22 in the internal combustion drive propulsion unit 11, and arranged at a position higher than an anti-cavitation plate 23 so that propellers 34, 54 of the electric propulsion unit 30 sink below a surface of water during low speed traveling, which is not in a planing state of the ship and the propellers 34, 54 of the electric propulsion unit 30 get out from under the surface of the water during planing of the ship.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a hybrid ship propulsion machine including an internal combustion propulsion unit powered by an internal combustion engine and an electric propulsion unit powered by an electric motor.

Background Art

[0002] Conventionally, ship propulsion machines powered by internal combustion engines are common. Recently, however, ship propulsion machines powered by electric motors have also become widespread.

[0003] Comparing an internal combustion engine with an electric motor, it can be said that the internal combustion engine is superior to the electric motor in terms of the ability to navigate a ship at high speed for a long time. Considering that a large-capacity battery is required to rotate an electric motor at high speed for a long time, the internal combustion engine is more practical at present. On the other hand, regarding the ability to move a ship at an extremely low speed, it can be said that an electric motor that can generate high torque from a low rotation range is superior to an internal combustion engine. Also, regarding quietness during low-speed navigation, it can be said that an electric motor is superior to an internal combustion engine. In an internal combustion engine, a large driving noise during low-speed navigation may be annoying.

[0004] Also, as a power source for a ship propulsion machine, there is a method of using both an internal combustion engine and an electric motor. According to this method, while taking advantage of the high capabilities of the internal combustion engine in the high-speed range, the lack of capabilities of the internal combustion engine in the low-speed range can be compensated for by an electric motor. Also, according to this method, the noise during low-speed navigation can be suppressed.

[0005] Specifically, there are the following two methods for using both an internal combustion engine and an electric motor as a power source for a ship propulsion machine.

[0006] The first method involves separately preparing an internal combustion-driven ship propulsion system powered solely by an internal combustion engine and an electric ship propulsion system powered solely by an electric motor, and installing these two types of ship propulsion systems on the ship. For example, this would involve installing multiple internal combustion-driven and electric outboard motors on a single ship. The second method involves installing a hybrid ship propulsion system on the ship that uses both an internal combustion engine and an electric motor as power sources.

[0007] Patent Document 1, described below, describes an outboard motor equipped with both an internal combustion engine and an electric motor as power sources. This outboard motor incorporates both an internal combustion engine and an electric motor, and has a structure in which the power from the internal combustion engine and the power from the electric motor are transmitted to a common propeller via a common main drive shaft and a common propeller shaft. Figure 2 of Patent Document 1 shows a mechanism for transmitting the power from the internal combustion engine and the power from the electric motor to the main drive shaft, and this mechanism is equipped with an automatic centrifugal clutch and a number of gears. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2007-8329 [Overview of the project] [Problems that the invention aims to solve]

[0009] By using both an internal combustion engine and an electric motor as the power source for a ship's propulsion system, as described above, it is possible to take advantage of the internal combustion engine's strengths while compensating for its weaknesses with the electric motor, thereby improving the ship's cruising performance over a wide range of speeds.

[0010] However, there are the following problems with the method of equipping a ship with both an internal combustion-driven ship propulsion system powered solely by an internal combustion engine and an electric ship propulsion system powered solely by an electric motor.

[0011] Installing both internal combustion and electric ship propulsion systems requires a certain amount of space. Therefore, it is difficult to install both internal combustion and electric ship propulsion systems on small vessels with limited space in the stern. Furthermore, even on medium-sized vessels, if, for example, multiple internal combustion outboard motors are already installed, it may be difficult to add an electric outboard motor to that vessel.

[0012] Furthermore, regarding the method of installing a hybrid ship propulsion system, as with the outboard motor described in Patent Document 1 above, the mechanism for transmitting the power of the internal combustion engine and the power of the electric motor to a common drive shaft is complex, which leads to high manufacturing costs.

[0013] Therefore, the inventor of this application devised a method of externally attaching an electric propulsion system, which comprises an electric motor and a propeller connected to the output shaft of the electric motor, to an internal combustion-driven ship propulsion engine that uses only an internal combustion engine as its power source. According to this method, an internal combustion-driven ship propulsion engine with an externally attached electric propulsion system is installed on the ship, so the only ship propulsion engine directly installed on the ship is the internal combustion-driven ship propulsion engine. Therefore, even in small ships with limited space in the stern section, and even in ships that already have multiple internal combustion-driven outboard motors, an internal combustion-driven ship propulsion engine with an externally attached electric propulsion system can be easily installed, and both internal combustion-driven and electric propulsion forces can be obtained. Furthermore, according to this method, since the electric propulsion system is externally attached to the internal combustion-driven ship propulsion engine, the propeller that rotates with the power of the internal combustion engine and the propeller that rotates with the power of the electric motor are separate, and the mechanism that transmits power from the internal combustion engine to the propeller and the mechanism that transmits power from the electric motor to the propeller are separate. Therefore, when obtaining propulsion from both an internal combustion engine and an electric motor, it is not necessary to provide a complex mechanism in the ship's propulsion system to transmit the power of the internal combustion engine and the power of the electric motor to a common drive shaft.

[0014] However, there are the following problems with attaching an electric propulsion system to an internal combustion engine-driven ship's propulsion system. An electric propulsion system attached to an internal combustion engine-driven ship's propulsion system is submerged below the waterline. Therefore, when the ship moves, water hits the electric propulsion system, creating resistance to the ship's movement. This resistance increases when the ship is planing, which may reduce the ship's cruising performance during planing.

[0015] The present invention has been made in view of the problems described above, for example, and the object of the present invention is to provide a hybrid ship propulsion system that can prevent the internal structure from becoming complicated and can suppress the deterioration of the ship's navigation performance during planing. [Means for solving the problem]

[0016] To solve the above problems, the present invention The first hybrid ship propulsion systemThis is a hybrid ship propulsion system comprising an internal combustion drive propulsion unit that generates thrust for a ship and an electric propulsion unit that generates thrust for the ship, wherein the internal combustion drive propulsion unit comprises an internal combustion engine, an internal combustion drive propeller shaft that extends in the longitudinal direction and rotates by power output from the internal combustion engine, a power transmission mechanism that transmits power output from the internal combustion engine to the internal combustion drive propeller shaft, a case for the internal combustion drive propulsion unit that houses the power transmission mechanism and the internal combustion drive propeller shaft, an internal combustion drive propeller attached to the internal combustion drive propeller shaft, and an anti-cavitation plate provided in the case for the internal combustion drive propulsion unit and positioned above the internal combustion drive propeller, and the electric propulsion unit is a unit that combines a first electric propulsion unit and a second electric propulsion unit, wherein the first electric propulsion unit comprises a first electric motor and the internal combustion drive propeller shaft The first electric propulsion unit comprises a first electric propeller shaft extending parallel to the first electric propeller shaft and rotating by power output from the first electric motor, and a first electric propeller attached to the first electric propeller shaft, the second electric propulsion unit comprises a second electric motor, a second electric propeller shaft extending in a direction perpendicular to the first electric propeller shaft and rotating by power output from the second electric motor, and a second electric propeller attached to the second electric propeller shaft, the electric propulsion unit is detachably attached to the case for the internal combustion drive propulsion unit, and is positioned higher than the anti-cavitation plate so that the first electric propeller and the second electric propeller are submerged below the water surface when the vessel is moving at low speed and not planing, and the first electric propeller and the second electric propeller are above the water surface when the vessel is planing. In the electric propulsion unit, the second electric propeller is positioned behind the first electric propeller, and when the electric propulsion unit is viewed from the rear, a portion of the second electric propeller overlaps with the first electric propeller. It is characterized by the following: Furthermore, the second hybrid ship propulsion system of the present invention is a hybrid ship propulsion system comprising an internal combustion drive propulsion unit that generates propulsion force for a ship and an electric propulsion unit that generates propulsion force for the ship, wherein the internal combustion drive propulsion unit comprises an internal combustion engine, an internal combustion drive propeller shaft that extends in the longitudinal direction and rotates by power output from the internal combustion engine, a power transmission mechanism that transmits power output from the internal combustion engine to the internal combustion drive propeller shaft, a case for the internal combustion drive propulsion unit that houses the power transmission mechanism and the internal combustion drive propeller shaft, an internal combustion drive propeller attached to the internal combustion drive propeller shaft, and an anti-cavitation plate provided in the case for the internal combustion drive propulsion unit and positioned above the internal combustion drive propeller, wherein the electric propulsion unit is a unit that combines the first electric propulsion unit and the second electric propulsion unit, wherein the first electric propulsion unit comprises a first electric motor and a power transmission mechanism that extends parallel to the internal combustion drive propeller shaft and generates power output from the first electric motor The electric propulsion unit comprises a first electric propeller shaft that rotates by a motor and a first electric propeller attached to the first electric propeller shaft, the second electric propulsion unit comprises a second electric motor, a second electric propeller shaft that extends in a direction perpendicular to the first electric propeller shaft and rotates by power output from the second electric motor, and a second electric propeller attached to the second electric propeller shaft, the electric propulsion unit is detachably attached to the case for the internal combustion drive propulsion unit, and is positioned higher than the anti-cavitation plate so that the first electric propeller and the second electric propeller are submerged below the water surface when the vessel is moving at low speed and not in a planing state, and the first electric propeller and the second electric propeller are above the water surface when the vessel is planing, and when the electric propulsion unit is viewed from above, the second electric propeller is positioned between the first electric motor and the first electric propeller. [Effects of the Invention]

[0017] According to the present invention, it is possible to prevent the internal structure of a hybrid ship propulsion system from becoming complicated, and to suppress the deterioration of the ship's navigation performance during planing. [Brief explanation of the drawing]

[0018] [Figure 1] It is an explanatory view showing a state of a hybrid outboard motor, which is an embodiment of the hybrid ship propulsion machine of the present invention, as viewed from its left side. [Figure 2] It is a perspective view showing a state of the lower part of the hybrid outboard motor of the embodiment of the present invention as viewed from the upper left rear side thereof. [Figure 3] In the hybrid outboard motor of the embodiment of the present invention, it is an explanatory view showing a state of a middle case, an anti-cavitation plate, an electric propulsion unit, etc. as viewed from their upper sides. [Figure 4] In the hybrid outboard motor of the embodiment of the present invention, it is an explanatory view showing a state of a middle case, a gear case, an anti-cavitation plate, an electric propulsion unit, etc. as viewed from their rear sides. [Figure 5] It is an explanatory view showing a state of the electric propulsion unit in the hybrid outboard motor of the embodiment of the present invention as viewed from its right side. [Figure 6] It is an explanatory view showing the positional relationship between the hybrid outboard motor of the embodiment of the present invention and the water surface. In the figure, (A) shows the positional relationship between the hybrid outboard motor and the water surface during low-speed movement, and (B) in the figure shows the positional relationship between the hybrid outboard motor and the water surface during planning. [Figure 7] In the hybrid outboard motor of the embodiment of the present invention, it is an explanatory view showing a structure in which an electric propulsion unit is attached to an internal combustion engine-driven propulsion part. [Figure 8] It is an explanatory view showing the electrical configuration of the hybrid outboard motor of the embodiment of the present invention. [Figure 9] It is an explanatory view showing the movement control of a ship by the hybrid outboard motor of the embodiment of the present invention. [Figure 10] It is an explanatory view showing some modified examples and application examples of the hybrid outboard motor of the embodiment of the present invention.

Modes for Carrying Out the Invention

[0019] The hybrid ship propulsion system according to an embodiment of the present invention comprises an internal combustion drive propulsion unit that generates propulsion force for the ship using an internal combustion engine, and an electric propulsion unit that generates propulsion force for the ship using an electric motor.

[0020] The internal combustion drive propulsion unit comprises an internal combustion engine, a first propeller shaft that rotates by power output from the internal combustion engine, a power transmission mechanism that transmits power output from the internal combustion engine to the first propeller shaft, a first housing that houses the power transmission mechanism and the first propeller shaft, a first propeller attached to the first propeller shaft, and an anti-cavitation plate provided in the first housing and positioned above the first propeller.

[0021] The electric propulsion unit comprises an electric motor, a second propeller shaft which is provided separately from the first propeller shaft and rotates by power output from the electric motor, a second housing which accommodates the electric motor and the second propeller shaft, and a second propeller which is provided separately from the first propeller and attached to the second propeller shaft.

[0022] Furthermore, the electric propulsion unit is mounted in the first housing and is positioned higher than the anti-cavitation plate so that the second propeller is submerged underwater when the vessel is moving at low speeds and not planing, and the second propeller is above water when the vessel is planing.

[0023] By setting the mounting position of the electric propulsion unit in this manner, the resistance caused by water hitting the electric propulsion unit when the ship is planing can be reduced, thereby suppressing the decrease in the ship's cruising performance due to this resistance during planing.

[0024] Furthermore, the first propeller of the internal combustion engine drive unit and the second propeller of the electric propulsion unit are provided separately. In addition, the mechanism for transmitting power from the internal combustion engine to the first propeller in the internal combustion engine drive unit (power transmission mechanism and first propeller shaft) and the second propeller shaft of the electric propulsion unit are provided separately. This makes it possible to generate thrust from both the internal combustion engine and the electric motor without using a complex mechanism to transmit power from both the internal combustion engine and the electric motor to a common drive shaft. Therefore, it is possible to prevent the internal structure of the hybrid marine propulsion system from becoming overly complex. [Examples]

[0025] The following describes a hybrid outboard motor, which is an embodiment of the hybrid ship propulsion system of the present invention, with reference to the drawings. In the embodiment, when describing the directions of forward (Fd), aft (Bd), left (Ld), right (Rd), up (Ud), and down (Dd), refer to the arrows drawn in the lower right of Figures 1-7 and 9.

[0026] (Hybrid outboard motor) Figure 1 shows a hybrid outboard motor 1, an embodiment of the present invention, viewed from its left side. Figure 2 shows the lower part of the hybrid outboard motor 1, viewed from its upper left rear side.

[0027] The hybrid outboard motor 1 is an outboard motor that uses both an internal combustion engine and an electric motor as power sources. As shown in Figure 1, the hybrid outboard motor 1 comprises an internal combustion drive propulsion unit 11 and an electric propulsion unit 30. The internal combustion drive propulsion unit 11 is the part that generates the propulsion force of the ship using an internal combustion engine. On the other hand, the electric propulsion unit 30 is a unit formed by combining two electric propulsion units 31 and 51. Each electric propulsion unit 31 and 51 is the part that generates the propulsion force of the ship using an electric motor. As shown in Figure 2, the electric propulsion unit 30 is attached to the outside of the internal combustion drive propulsion unit 11, in the part located above the anti-cavitation plate 23. Hereinafter, the hybrid outboard motor 1 will simply be referred to as "outboard motor 1".

[0028] (Internal combustion drive propulsion unit) The internal combustion drive propulsion unit 11 comprises an internal combustion engine 12 located on the upper part of the outboard motor 1, a drive shaft 13 extending vertically through the middle section of the outboard motor 1, a gear mechanism 14 located on the lower part of the outboard motor 1, a propeller shaft 15 located on the lower part of the outboard motor 1 and extending in the front-rear direction, and a propeller 16 attached to the rear end portion of the propeller shaft 15.

[0029] The internal combustion engine 12 is, for example, a four-stroke engine that uses gasoline as fuel. Power output from the internal combustion engine 12 is transmitted to the propeller shaft 15 via the drive shaft 13 and the gear mechanism 14. As a result, the propeller shaft 15 rotates based on the power of the internal combustion engine 12. The propeller 16 rotates together with the propeller shaft 15, generating the thrust of the ship. The gear mechanism 14 is also equipped with a clutch (not shown), which allows switching whether or not power from the internal combustion engine 12 is transmitted to the propeller shaft 15, and also allows switching the direction of rotation of the propeller shaft 15.

[0030] Furthermore, the internal combustion drive propulsion unit 11 includes a top cowl 18, a bottom cowl 19, an upper case 20, a middle case 21, and a gear case 22 (lower case). For ease of understanding, the parts of the middle case 21 exposed to the outside in Figures 1 and 6 are marked with a dot pattern.

[0031] The top cowl 18 and bottom cowl 19 cover the internal combustion engine 12. The drive shaft 13 is housed in the upper case 20 and the middle case 21. The gear case 22 houses the gear mechanism 14 and the front end portion of the propeller shaft 15. An anti-cavitation plate 23 is provided on the upper rear portion of the gear case 22, above the propeller 16, to suppress air intake to the propeller 16. A clamp bracket 24 is provided in front of the upper case 20 for mounting and securing the outboard motor 1 to the transom of the vessel. A swivel bracket 25 is attached to the clamp bracket 24, and the outboard motor 1 is rotatably supported on the swivel bracket 25 via a steering shaft 26 so that its orientation can be changed from side to side.

[0032] Furthermore, the propeller shaft 15 is " Internal combustion drive This is a specific example of a "propeller shaft". Also, the drive shaft 13 and gear mechanism 14 are specific examples of a "power transmission mechanism". Furthermore, the propeller 16 is " Internal combustion drive This is a specific example of a "propeller". Also, the upper case 20, middle case 21 and gear case 22 are " Case for internal combustion engine propulsion unit This is a concrete example of "[...]."

[0033] (Electric propulsion unit) Figure 3 shows the middle case 21, anti-cavitation plate 23, and electric propulsion unit 30, etc., viewed from above. Figure 4 shows the middle case 21, gear case 22, anti-cavitation plate 23, and electric propulsion unit 30, etc., viewed from the rear. Figure 5 shows the electric propulsion unit 30 viewed from its right side.

[0034] The electric propulsion unit 30 includes a first electric propulsion unit 31 that generates a propulsion force in the same direction as the propulsion force generated by the internal combustion drive propulsion unit 11, and a second electric propulsion unit 51 that generates a propulsion force in a direction perpendicular to the direction of the propulsion force generated by the internal combustion drive propulsion unit 11.

[0035] As shown in Figure 5, the first electric propulsion unit 31 includes an electric motor 32, a propeller shaft 33, a propeller 34, an inverter 35, a housing case 36, and a propeller guard 37.

[0036] The electric motor 32 is, for example, a brushless motor. The propeller shaft 33 extends in the front-rear direction, and its front end is connected to the output shaft of the electric motor 32. The propeller shaft 33 rotates together with the output shaft of the electric motor 32, transmitting the rotation of the electric motor 32 to the propeller 34. Furthermore, the axis B of the propeller shaft 33 is parallel to the axis A of the propeller shaft 15 of the internal combustion drive propulsion unit 11, as shown in Figure 1.

[0037] As shown in Figure 5, the propeller 34 is attached to the rear end portion of the propeller shaft 33. The propeller 34 rotates together with the propeller shaft 33 and generates thrust in the same direction (forward and backward direction) as the thrust generated by the internal combustion drive propulsion unit 11.

[0038] The inverter 35 is a circuit that controls the drive of the electric motor 32. The electric motor 32, the front end portion of the propeller shaft 33, and the inverter 35 are housed in a housing case 36. The housing case 36 has a completely waterproof structure to prevent water from entering its interior.

[0039] The propeller guard 37 is a component that protects the propeller 34 by preventing contact between the propeller 34 and objects present in or on the water surface. The propeller guard 37 is formed in a cylindrical shape with a generally conical outer shape and covers the periphery of the propeller 34. The propeller guard 37 is attached to the lower rear portion of the housing case 36. A front cover 38 with numerous holes 39 is provided at the front of the propeller guard 37, as shown in Figure 2. In addition, as shown in Figure 5, multiple holes 40 are formed in the portion of the propeller guard 37 located behind the propeller 34. When the propeller 34 rotates, water flows smoothly through the holes 39 and 40 within the propeller guard 37 in a forward or backward direction.

[0040] As shown in Figure 3, the second electric propulsion unit 51 includes an electric motor 52, a propeller shaft 53, a propeller 54, an inverter 55, a motor case 56, and a propeller guard 57.

[0041] The electric motor 52 is, for example, a brushless motor. As shown in Figure 5, the electric motor 52 is housed in a motor case 56 having a complete protection structure and is positioned within the propeller guard 57. The motor case 56 is supported by the propeller guard 57 via a motor case support 58.

[0042] As shown in Figure 3, the propeller shaft 53 extends in the left-right direction, and its right end is connected to the output shaft of the electric motor 52. The propeller shaft 53 rotates together with the output shaft of the electric motor 52, transmitting the rotation of the electric motor 52 to the propeller 54. Furthermore, the axis C of the propeller shaft 53 is perpendicular to the axis B of the propeller shaft 33 of the first electric propulsion unit 31. In other words, when the outboard motor 1 is viewed from above, the first electric propulsion unit 31 and the second electric propulsion unit 51 are arranged such that the axis B of the propeller shaft 33 and the axis C of the propeller shaft 53 are perpendicular to each other.

[0043] The propeller 54 is attached to the left end of the propeller shaft 53. The propeller 54 rotates together with the propeller shaft 53 and generates thrust in a direction perpendicular to the direction of thrust generated by the first electric propulsion unit 31 (left-right direction). Furthermore, the direction of thrust generated by the propeller 54 is perpendicular to the direction of thrust generated by the internal combustion drive propulsion unit 11.

[0044] The inverter 55 is a circuit that controls the drive of the electric motor 52. The inverter 55 is housed in a housing case 36, as shown in Figure 5.

[0045] The propeller guard 57 is a component that protects the propeller 54 by preventing contact between the propeller 54 and objects mainly present in or on the water surface. As shown in Figure 2, the propeller guard 57 is formed in a cylindrical shape and covers the outer circumference of the propeller 54. The propeller guard 57 is also attached to the upper rear portion of the housing case 36. Furthermore, a protective member 59 is provided on the left side of the propeller guard 57 to protect the propeller 54 by preventing objects mainly present in or on the water surface from entering the propeller guard 57. When the propeller 54 rotates, water flows smoothly to the left or right within the cylindrical propeller guard 57. The protective member 59 hardly obstructs this water flow.

[0046] In addition, Propeller shaft 33 is a specific example of the "first electric propeller shaft," and propeller shaft 53 is a specific example of the "second electric propeller shaft." Furthermore, propeller 34 is a specific example of the "first electric propeller," and propeller 54 is a specific example of the "second electric propeller." Furthermore, since the housing case 36 houses the electric motor 32 and inverter 35 of the first electric propulsion unit 31, as well as the inverter 55 of the second electric propulsion unit 51, the housing case 36 is a component of both the first electric propulsion unit 31 and the second electric propulsion unit 51.

[0047] (Arrangement of electric propulsion units) As shown in Figure 1, the electric propulsion unit 30 is positioned at the rear of the lower part of the internal combustion drive propulsion unit 11 and is attached to the portion extending from the rear of the middle case 21 to the upper rear of the gear case 22. The electric propulsion unit 30 is also located above and behind the propeller 16 of the internal combustion drive propulsion unit 11.

[0048] Furthermore, the electric propulsion unit 30 is positioned higher than the anti-cavitation plate 23. Also, the electric propulsion unit 30 is positioned lower than the upper case 20. However, the mounting position changing structure 66, which will be described later, can raise the position of the electric propulsion unit 30 to the same height as the lower end of the upper case 20.

[0049] Furthermore, as shown in Figure 6, the electric propulsion unit 30 is positioned so that when the ship is moving at low speed and not planing, the propellers 34 and 54 are submerged below the water surface, and when the ship is planing, the propellers 34 and 54 are above the water surface.

[0050] In other words, the dashed line S1 in Figure 6(A) indicates the water level when the vessel is moving at a low speed and is not planing. When the vessel is moving at a low speed and is not planing, most of the portion of the middle case 21 that is exposed to the outside (the portion with a dotted pattern in the figure), and the entire gear case 22 are submerged below the water surface, and the anti-cavitation plate 23 is also submerged below the water surface. Furthermore, when the vessel is moving at a low speed and is not planing, most of the electric propulsion unit 30, including the propellers 34 and 54, are submerged below the water surface.

[0051] When the vessel is moving at a low speed and is not planing, either or both of the electric motors 32 and 52 are driven according to the user's steering of the vessel, causing either or both of the propellers 34 and 54 to rotate. When the vessel is moving at a low speed and is not planing, the propellers 34 and 54 of the electric propulsion unit 30 are submerged below the water surface, so propulsion can be provided to the vessel by rotating either or both of the propellers 34 and 54.

[0052] On the other hand, the dashed line S2 in Figure 6(B) indicates the position of the water surface when the vessel is planing. When the vessel is planing, compared to when the vessel is moving at low speed and not planing, the vessel and outboard motor 1 float, and their position relative to the water surface becomes higher. When the vessel is planing, the water surface becomes equal to the position of the anti-cavitation plate 23, and the entire middle case 21 and the upper part of the gear case 22 (the part above the anti-cavitation plate 23) are above the water surface. Also, when the vessel is planing, most of the electric propulsion unit 30, including the propellers 34 and 54, are above the water surface.

[0053] When the ship is planing, the driving of both electric motor 32 and electric motor 52 is stopped, and the rotation of both propeller 34 and propeller 54 is stopped. When the ship is planing, most of the electric propulsion unit 30, including propellers 34 and 54, is above the water surface, so the resistance to the ship's movement can be suppressed. In other words, if most of the electric propulsion unit 30, including propellers 34 and 54, is submerged when the ship is planing, the resistance generated by water hitting the electric propulsion unit 30 will hinder the ship's movement. In this embodiment, when the ship is planing, most of the electric propulsion unit 30 is above the water surface, so the generation of such resistance can be suppressed.

[0054] Furthermore, as shown in Figure 4, the electric propulsion unit 30 is positioned in the center of the outboard motor 1 in the left-right direction. Also, the electric propulsion unit 30 is contained within the width of the middle case 21. That is, when the outboard motor 1 is viewed from the rear, the electric propulsion unit 30 is positioned so that it does not extend to the left from the leftmost part on the left side of the middle case 21, and does not extend to the right from the rightmost part on the right side of the middle case 21. This reduces the amount of water that hits the electric propulsion unit 30 when it is submerged underwater during low-speed movement when the vessel is not planing, thereby reducing the resistance caused by water hitting the electric propulsion unit 30.

[0055] (Installation of electric propulsion unit) Figure 7 shows the structure for attaching the electric propulsion unit 30 to the internal combustion drive propulsion unit 11. As shown in Figure 7, an upper mounting bracket 61 and a lower mounting bracket 62 are provided on the upper and lower front parts of the housing case 36 of the electric propulsion unit 30, respectively. On the other hand, an upper mounting plate 63 and a lower mounting plate 64 are provided on the rear of the middle case 21 and the upper rear of the gear case 22 of the internal combustion drive propulsion unit 11, respectively. The electric propulsion unit 30 is attached to the portion from the rear of the middle case 21 to the upper rear of the gear case 22 by fixing the upper mounting bracket 61 to the upper mounting plate 63 with a fixing member 65 (e.g., a bolt), and fixing the lower mounting bracket 62 to the lower mounting plate 64 with a fixing member 65. With this mounting structure, the electric propulsion unit 30 can be easily attached to the internal combustion drive propulsion unit 11. Furthermore, with this mounting structure, the electric propulsion unit 30 can be easily attached to and detached from the internal combustion drive propulsion unit 11. The upper mounting bracket 61 and the lower mounting bracket 62 are specific examples of "mounting parts".

[0056] Furthermore, the upper mounting plate 63 and the lower mounting plate 64 are provided with a mounting position changing structure 66 that allows the mounting position of the electric propulsion unit 30 relative to the internal combustion drive propulsion unit 11 in the vertical direction to be changed. Specifically, each of the upper mounting plate 63 and the lower mounting plate 64 has multiple holes 67 (for example, threaded bolt holes) arranged vertically for fixing (fastening) a fixing member 65. By selecting a hole for fixing the fixing member 65 from among the multiple holes 67, the mounting position of the electric propulsion unit 30 in the vertical direction can be selected. Note that such a mounting position changing structure may also be provided on the upper mounting bracket 61 and the lower mounting bracket 62 instead of the upper mounting plate 63 and the lower mounting plate 64.

[0057] (Control of ship movement) Figure 8 shows the electrical configuration of the outboard motor 1. For example, a control unit 71 is provided on the top of the outboard motor 1. The control unit 71 is equipped with a microcomputer and the like. As shown in Figure 8, a remote controller 72 and a GPS (Global Positioning System) receiver 74 are connected to the input side of the control unit 71. The internal combustion drive propulsion unit 11, the inverter 35 of the first electric propulsion unit 31, the inverter 55 of the second electric propulsion unit 51, and the steering device 75 are connected to the output side of the control unit 71. The remote controller 72, GPS receiver 74, and steering device 75 are installed on the ship. The control unit 71 is a specific example of a "mobile control unit".

[0058] The operator of the vessel can operate the clutch by tilting the lever 73 of the remote controller 72 in the F or R direction in Figure 8, thereby switching whether or not power from the internal combustion engine 12 is transmitted to the propeller shaft 15, and switching the direction of rotation of the propeller shaft 15. The operator can also increase or decrease the rotational speed of the internal combustion engine 12 by tilting the lever 73 of the remote controller 72 in the F or R direction. Furthermore, the operator can switch the operation of the electric motors 32 and 52 on and off, and increase or decrease their rotational speed by tilting the lever 73 of the remote controller 72 in the F or R direction.

[0059] Specifically, when the operator places the lever 73 of the remote controller 72 in the neutral position (not tilted in either the F or R direction), the control unit 71 stops the internal combustion engine 12 (or puts the internal combustion engine 12 into an idling state where power is not transmitted to the propeller shaft 15), and also stops the electric motor 32 of the first electric propulsion unit 31 and the electric motor 52 of the second electric propulsion unit 51.

[0060] Furthermore, if the operator tilts the lever 73 of the remote controller 72 slightly in the F direction to move the vessel forward at an extremely slow speed, the control unit 71 drives the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward direction while maintaining the internal combustion engine 12 in a stopped state (or idling state). As a result, the vessel moves forward at an extremely slow speed using the thrust from the first electric propulsion unit 31.

[0061] Furthermore, if the operator tilts the lever 73 of the remote controller 72 to the F direction to a moderate degree in order to move the vessel forward at a speed that is not extremely slow but not slow enough to reach a planing state, the control unit 71 operates the internal combustion engine 12 at a low rotation speed, transmits its rotation to the propeller shaft 15 to rotate the propeller 16 in the forward direction, and also drives the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward direction. As a result, the vessel moves forward at a low speed using the thrust from the internal combustion drive propulsion unit 11 and the thrust from the first electric propulsion unit 31.

[0062] Furthermore, when the operator tilts the lever 73 of the remote controller 72 sharply in the F direction to move the vessel forward in a planing state, the control unit 71 first operates the internal combustion engine 12 at high speed to rotate the propeller 16 in the forward direction at high speed, and also drives the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward direction. As a result, the vessel accelerates with the thrust from the internal combustion drive propulsion unit 11 and the thrust from the first electric propulsion unit 31. When the vessel reaches a planing state, the control unit 71 recognizes that the vessel has reached a planing state based on the vessel's speed and stops the electric motor 32 while maintaining the operation of the internal combustion engine 12. As a result, the vessel slides using only the thrust from the internal combustion drive propulsion unit 11.

[0063] Furthermore, the operator can control the steering device 75 by operating the steering handle 76 connected to the steering device 75, thereby changing the left-right direction of the outboard motor 1 and turning the vessel.

[0064] Furthermore, the control unit 71 can perform automatic movement control (automatic movement control) to move the vessel at a slow speed to a position set by the operator, and control to keep the vessel at its current position against waves and currents, based on the vessel's position information received by the GPS receiver 74.

[0065] Specifically, the control unit 71 controls the drive of the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward or reverse direction, thereby allowing the vessel 121 to move forward or backward at a slow speed, as shown in Figure 9(A). Furthermore, as shown in Figure 9(B), the control unit 71 controls the drive of the electric motor 52 of the second electric propulsion unit 51 to rotate the propeller 54 in the reverse or forward direction, thereby allowing the vessel 121 to turn left or right. Additionally, as shown in Figure 9(C), the control unit 71 controls the drive of the steering device 75 to change the orientation of the outboard motor 1 so that the propeller 16 of the internal combustion drive propulsion unit 11 faces to the right rear, controls the drive of the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward direction, and controls the drive of the electric motor 52 of the second electric propulsion unit 51 to rotate the propeller 54 in the forward direction, thereby allowing the vessel 121 to move to the left. Furthermore, as shown in Figure 9(D), the control unit 71 controls the drive of the steering device 75 to change the direction of the outboard motor 1 so that the propeller 16 of the internal combustion drive propulsion unit 11 faces left rear, controls the drive of the electric motor 32 of the first electric propulsion unit 31 to rotate the propeller 34 in the forward direction, and controls the drive of the electric motor 52 of the second electric propulsion unit 51 to rotate the propeller 54 in the reverse direction, thereby moving the ship 121 to the right.

[0066] The control unit 71 recognizes the current position of the vessel based on the vessel's position information received by the GPS receiver 74, determines the direction of movement of the vessel based on the vessel's current position and the position set by the operator, and controls the drive of the electric motors 32 and 52 and the steering gear 75 to automatically move the vessel in that direction. Furthermore, the control unit 71 recognizes the current position of the vessel based on the vessel's position information received by the GPS receiver 74, and if the vessel's current position deviates from a certain position due to waves or currents, it can control the drive of the electric motors 32 and 52 and the steering gear 75 to automatically move the vessel back to that certain position and keep the vessel in that certain position.

[0067] As described above, in the outboard motor 1 of the embodiment of the present invention, the electric propulsion unit 30 is mounted on the portion of the internal combustion drive propulsion unit 11 from the rear of the middle case 21 to the upper rear of the gear case 22. The electric propulsion unit 30 is positioned higher than the anti-cavitation plate 23 so that when the vessel is moving at low speed and not planing, the propellers 34 and 54 of the electric propulsion unit 30 are submerged below the water surface, and when the vessel is planing, the propellers 34 and 54 are above the water surface. By setting the mounting position of the electric propulsion unit 30 in this way, the resistance caused by water hitting the electric propulsion unit 30 when the vessel is planing can be reduced, and the decrease in the vessel's cruising performance due to this resistance during planing can be suppressed. Furthermore, by making it more difficult for water to hit the propeller 34 or propeller 54 when the vessel is planing, the effect of reducing resistance can be enhanced, and the decrease in the vessel's cruising performance during planing can be effectively suppressed.

[0068] Furthermore, in the outboard motor 1 of this embodiment, the propeller 16 of the internal combustion drive propulsion unit 11 and the propeller 34 of the first electric propulsion unit 31 are provided separately and are independent of each other. Also, the mechanism (drive shaft 13, gear mechanism 14 and propeller shaft 15) that transmits power from the internal combustion engine 12 to the propeller 16 in the internal combustion drive propulsion unit 11 and the propeller shaft 33 of the first electric propulsion unit 31 are provided separately and are independent of each other. Also, the propeller 16 of the internal combustion drive propulsion unit 11 and the propeller 54 of the second electric propulsion unit 51 are provided separately and are independent of each other. Also, the mechanism that transmits power from the internal combustion engine 12 to the propeller 16 in the internal combustion drive propulsion unit 11 and the propeller shaft 53 of the second electric propulsion unit 51 are provided separately and are independent of each other. Therefore, according to the outboard motor 1 of this embodiment, it is possible to generate thrust from both the internal combustion engine and the electric motor without using a complex mechanism (for example, an automatic centrifugal clutch or a mechanism with multiple gears as described in Patent Document 1) that transmits the power of the internal combustion engine and the power of the electric motor to a common drive shaft. Thus, it is possible to prevent the internal structure of the outboard motor 1 from becoming complicated.

[0069] Furthermore, in the outboard motor 1 of this embodiment, the electric propulsion unit 30 is provided with an upper mounting bracket 61 and a lower mounting bracket 62, and the internal combustion drive propulsion unit 11 is provided with an upper mounting plate 63 and a lower mounting plate 64. The electric propulsion unit 30 is detachably attached to the internal combustion drive propulsion unit 11 via the upper mounting bracket 61, the lower mounting bracket 62, the upper mounting plate 63, and the lower mounting plate 64. Therefore, users can easily attach or detach the electric propulsion unit 30 to the internal combustion drive propulsion unit 11 depending on the application of the outboard motor 1, providing high convenience. In addition, according to the outboard motor 1 of this embodiment, the electric propulsion unit 30 can be easily attached to an existing internal combustion drive outboard motor, making it easy to hybridize an existing internal combustion drive outboard motor.

[0070] Furthermore, the outboard motor 1 of this embodiment is equipped with a mounting position changing structure 66 that allows the mounting position of the electric propulsion unit 30 relative to the internal combustion drive propulsion unit 11 in the vertical direction to be changed. This makes it possible to easily adjust the mounting position of the electric propulsion unit 30 according to the size of the outboard motor, the number of crew members or the weight of the cargo on board, or the draft.

[0071] Furthermore, in the outboard motor 1 of this embodiment, inverters 35 and 55, which control the driving of electric motors 32 and 52, respectively, are provided within the housing case 36 of the electric propulsion unit 30. By unitizing the electric motors and inverters in this way, the electric propulsion unit 30 can be easily attached externally to the internal combustion drive propulsion unit 11.

[0072] Furthermore, in the electric propulsion unit 30 of this embodiment, the two electric propulsion units 31 and 51 are arranged such that the axis B of the propeller shaft 33 and the axis C of the propeller shaft 53 are perpendicular to each other. This makes it easy to move the ship forward, backward, and turn, as well as move the ship laterally (moving the ship to the left or right without changing the direction of the bow). In addition, the second electric propulsion unit 51 can function as a thruster. Therefore, it is easy to automatically move the ship, hold it in a fixed position, or dock and undock the ship. Moreover, the control unit 71 of this embodiment can easily perform automatic movement or hold the ship in a fixed position using GPS.

[0073] Furthermore, according to the outboard motor 1 of this embodiment, since the power source and propeller etc. are electric propulsion units 31 and 51 which are independent of the internal combustion drive propulsion unit 11, for example, even if the internal combustion drive propulsion unit 11 malfunctions and stops working while sailing, the electric propulsion units 31 and 51 can be used to bring the ship closer to the shore.

[0074] Furthermore, with the outboard motor 1, since the electric propulsion unit 30 is attached to the internal combustion-driven propulsion unit 11, both propulsion from the internal combustion engine and propulsion from the electric motor can be obtained by attaching the outboard motor 1 to the vessel. Therefore, in order to obtain both propulsion from the internal combustion engine and propulsion from the electric motor, it is not necessary to attach an internal combustion-driven outboard motor and an electric outboard motor to the vessel separately. Consequently, even if the vessel is small, or if multiple internal combustion-driven outboard motors are already installed on the vessel, both propulsion from the internal combustion engine and propulsion from the electric motor can be obtained.

[0075] Furthermore, with the outboard motor 1, the low-speed torque before planing can be easily compensated for by the first electric propulsion unit 31. This makes it possible to ensure high cruising performance or good acceleration performance of the vessel at low speeds, even when employing an internal combustion engine with enhanced torque performance in the high-speed range. Also, since the low-speed movement of the vessel can be compensated for by the first electric propulsion unit 31, by employing a propeller for high-speed cruising as the propeller 16 of the internal combustion drive propulsion unit 11, it is possible to improve high-speed cruising performance without reducing low-speed cruising performance. In addition, when the vessel is moving at low speed, the operation of the internal combustion engine 12 can be stopped, and the vessel can be moved solely by the thrust of the first electric propulsion unit 31, allowing the vessel to move at low speeds without generating noise. Furthermore, fuel efficiency can be improved by using the internal combustion engine and electric motor in combination.

[0076] Furthermore, in Figure 8, the transmission and reception of control signals, etc., between the control unit 71 and the inverter 35, and between the control unit 71 and the inverter 55 may be performed wirelessly. This eliminates the need for wiring cables for transmitting and receiving control signals, etc., between the control unit 71 and the inverters 35 and 55, making it even easier to attach and detach the electric propulsion unit 30 to the internal combustion drive propulsion unit 11.

[0077] In the above embodiment, the electric propulsion unit 30 was shown as being attached to the portion of the internal combustion drive propulsion unit 11 from the rear of the middle case 21 to the upper rear of the gear case 22. However, the position where the electric propulsion unit 30 is attached is not limited to the portion from the rear of the middle case 21 to the upper rear of the gear case 22, and is located in any part of the middle case 21, gear case 22, or upper case 20, at a position higher than the anti-cavitation plate, and where the propellers 34 and 54 of the electric propulsion unit 30 are submerged underwater when the vessel is moving at low speed and not planing, and where the propellers 34 and 54 are above water when the vessel is planing. Furthermore, the present invention also includes a configuration in which the electric propulsion unit 30 is attached to the frame or bracket portion that supports the middle case 21, etc., in the outboard motor 1.

[0078] Furthermore, the present invention is not limited to outboard motors but can also be applied to inboard and outboard motors. Specifically, as shown in Figure 10(A), an electric propulsion unit 30 may be attached to an internal combustion-driven inboard and outboard motor 82. This allows for the construction of a hybrid inboard and outboard motor 81.

[0079] Furthermore, as shown in Figure 10(B), an electric outboard motor 85 can be constructed by attaching the electric propulsion unit 30 to a frame 88 on which a handlebar 86 and a clamp bracket 87 are provided.

[0080] Alternatively, as shown in Figure 10(C), the two electric propulsion units 92 and 93 may be arranged parallel to each other. Specifically, the hybrid outboard motor 91 comprises two electric propulsion units 92 and 93, each of which comprises an electric motor 94, a propeller shaft 95, a propeller 96, and a housing case 97. Each electric propulsion unit 92 and 93 is detachably attached to the internal combustion drive propulsion unit 11 via a mounting bracket 98 and is positioned above the anti-cavitation plate 23. When the hybrid outboard motor 91 is viewed from above, the two electric propulsion units 92 and 93 are arranged such that their propeller shafts 95 are parallel to each other. Alternatively, as shown in Figure 10(D), the hybrid outboard motor 101 may be arranged such that its propeller shafts 95 form a V-shape when viewed from above. Furthermore, the left and right orientations of the two electric propulsion units 92 and 93 may be changed.

[0081] Furthermore, the internal combustion engine drive propulsion unit 11 may be fitted with a single electric propulsion unit, or three or more electric propulsion units.

[0082] Furthermore, the present invention may be modified as appropriate, provided that it does not contradict the gist or idea of ​​the invention as can be read from the claims and the specification as a whole, and hybrid ship propulsion systems with such modifications are also included in the technical concept of the present invention. [Explanation of Symbols]

[0083] 1 Ha Hybrid outboard motor (hybrid marine propulsion system) 11 Internal combustion drive propulsion unit 12 Internal Combustion Engines 13. Drive shaft (power transmission mechanism) 14. Gear mechanism (power transmission mechanism) 15 Propeller shaft ( Internal combustion drive (Propeller shaft) 16 propellers ( Internal combustion drive propeller) 20 Upper case (case for internal combustion engine propulsion unit) 21 Middle case (case for internal combustion engine propulsion unit) 22 Gear case (case for internal combustion engine propulsion unit) 23 Anti-cavitation plate 30 Electric propulsion unit 31, 5 1 electric dynamic propulsion section (First electric propulsion unit, second electric propulsion unit) 32, 5 2 electric Motor (First electric motor, second electric motor) 33, 5 3 P Lopera shaft (First electric propeller shaft, second electric propeller shaft) 34, 5 4 P Lopera (First electric propeller, second electric propeller) 3 6. Capacity vinegar 61 Upper mounting bracket (mounting part) 62 Lower mounting bracket (mounting part) 63 Upper mounting plate 64 Lower mounting plate 66. Mounting position change structure 71 Control Unit (Movement Control Unit) 81 Hybrid Inboard / Outboard Motor (Hybrid Marine Propulsion System) )

Claims

1. A hybrid ship propulsion system comprising an internal combustion drive propulsion unit that generates propulsion force for a ship, and an electric propulsion unit that generates propulsion force for the ship, The internal combustion drive propulsion unit is Internal combustion engines and An internal combustion drive propeller shaft that extends in the front-rear direction and rotates due to power output from the internal combustion engine, A power transmission mechanism that transmits power output from the internal combustion engine to the internal combustion drive propeller shaft, A case for an internal combustion drive propulsion unit that houses the power transmission mechanism and the internal combustion drive propeller shaft, An internal combustion drive propeller attached to the aforementioned internal combustion drive propeller shaft, The case for the internal combustion drive propulsion unit is provided with an anti-cavitation plate positioned above the internal combustion drive propeller, The aforementioned electric propulsion unit is a unit formed by combining a first electric propulsion unit and a second electric propulsion unit. The first electric propulsion unit is, The first electric motor and A first electric propeller shaft extends parallel to the internal combustion drive propeller shaft and rotates by power output from the first electric motor, The system comprises a first electric propeller attached to the first electric propeller shaft, The second electric propulsion unit is, A second electric motor, A second electric propeller shaft extends in a direction perpendicular to the first electric propeller shaft and rotates by power output from the second electric motor, The system comprises a second electric propeller attached to the second electric propeller shaft, The electric propulsion unit is detachably mounted to the case for the internal combustion drive propulsion unit, and is positioned higher than the anti-cavitation plate such that the first electric propeller and the second electric propeller are submerged below the water surface when the vessel is moving at low speed and not planing, and the first electric propeller and the second electric propeller are above the water surface when the vessel is planing. A hybrid marine propulsion system characterized in that, in the electric propulsion unit, the second electric propeller is positioned behind the first electric propeller, and when the electric propulsion unit is viewed from the rear, a portion of the second electric propeller overlaps with the first electric propeller.

2. A hybrid ship propulsion system comprising an internal combustion drive propulsion unit that generates propulsion force for a ship and an electric propulsion unit that generates propulsion force for the ship, The internal combustion drive propulsion unit is Internal combustion engines and An internal combustion drive propeller shaft that extends in the front-rear direction and rotates due to power output from the internal combustion engine, A power transmission mechanism that transmits power output from the internal combustion engine to the internal combustion drive propeller shaft, A case for an internal combustion drive propulsion unit that houses the power transmission mechanism and the internal combustion drive propeller shaft, An internal combustion drive propeller attached to the aforementioned internal combustion drive propeller shaft, The case for the internal combustion drive propulsion unit is provided with an anti-cavitation plate positioned above the internal combustion drive propeller, The aforementioned electric propulsion unit is a unit formed by combining a first electric propulsion unit and a second electric propulsion unit. The first electric propulsion unit is, The first electric motor and A first electric propeller shaft extends parallel to the internal combustion drive propeller shaft and rotates by power output from the first electric motor, The system comprises a first electric propeller attached to the first electric propeller shaft, The second electric propulsion unit is, A second electric motor, A second electric propeller shaft extends in a direction perpendicular to the first electric propeller shaft and rotates by power output from the second electric motor, The system comprises a second electric propeller attached to the second electric propeller shaft, The electric propulsion unit is detachably mounted to the case for the internal combustion drive propulsion unit, and is positioned higher than the anti-cavitation plate such that the first electric propeller and the second electric propeller are submerged below the water surface when the vessel is moving at low speed and not planing, and the first electric propeller and the second electric propeller are above the water surface when the vessel is planing. A hybrid marine propulsion system characterized in that, when the electric propulsion unit is viewed from above, the second electric propeller is positioned between the first electric motor and the first electric propeller.

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