SHIP PROPULSION MACHINE

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2023-194306 filed on Nov. 15, 2023, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a ship propulsion machine using a motor (electric motor) as a power source for generating a propulsive force of a ship.

BACKGROUND ART

JP2005-153727A describes an outboard motor that uses a motor as a power source for generating a propulsive force for a ship. In the outboard motor, the motor is provided in an upper portion of the outboard motor, and a propeller shaft to which a propeller is fixed is provided in a lower portion of the outboard motor. In addition, a drive shaft extending vertically is provided between the motor and the propeller shaft, and power of the motor is transmitted to the propeller shaft via the drive shaft.

SUMMARY OF INVENTION

Incidentally, by using two motors as a power source for generating a propulsive force for a ship and switching a propeller rotation mode between at least two modes of the following modes: a mode in which a propeller is rotated by a force obtained by combining powers of the two motors, a mode in which the propeller is rotated only by power of one of the two motors, and a mode in which the propeller is rotated only by power of the other of the two motors, the performance of the ship propulsion machine can be improved.

However, when the ship propulsion machine is provided with two motors and a mechanism that switches the propeller rotation mode, there is a concern that the ship propulsion machine will become significantly larger compared to a ship propulsion machine in which only one motor is provided as a power source for generating a propulsive force for a ship.

The present disclosure has been made in view of the circumstances as described above, for example, and an object of the present disclosure is to prevent a ship propulsion machine from becoming significantly larger even when the ship propulsion machine is provided with two motors and a mechanism that switches a propeller rotation mode.

The present disclosure provides a ship propulsion machine including: a power unit configured to generate power; a propeller shaft to which a propeller is fixed; and a drive shaft provided between the power unit and the propeller shaft and configured to transmit the power generated by the power unit to the propeller shaft. The power unit includes: a first motor including a first motor shaft extending vertically; a second motor arranged above the first motor and including a second motor shaft extending vertically; a connecting member arranged to be movable vertically between the first motor and the second motor, the connecting member including: a lower end portion provided with a first connecting portion configured to connect the connecting member to an upper end portion of the first motor shaft; and an upper end portion provided with a second connecting portion configured to connect the connecting member to a lower end portion of the second motor shaft; and a switching mechanism arranged between the first motor and the second motor and configured to switch a connection mode of the first motor shaft, the second motor shaft, and the drive shaft by moving the connecting member upward or downward, so as to be selectable from at least two modes of a mode (a) in which both the first motor shaft and the second motor shaft are connected to the drive shaft, a mode (b) in which the first motor shaft is connected to the drive shaft and the second motor shaft is not connected to the drive shaft, and a mode (c) in which the second motor shaft is connected to the drive shaft and the first motor shaft is not connected to the drive shaft.

According to the present disclosure, it is possible to prevent a ship propulsion machine from becoming significantly larger even when the ship propulsion machine is provided with two motors and a mechanism that switches a propeller rotation mode.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure will be described in detail based on the following without being limited thereto, wherein:

FIG. 1 is an overall view showing an outboard motor according to an embodiment of the present disclosure;

FIG. 2 is an external perspective view showing a power unit and the like in the outboard motor according to the embodiment of the present disclosure;

FIG. 3 is an external view showing the power unit in FIG. 2, as viewed from the left;

FIG. 4 is an external view showing the power unit in FIG. 2, as viewed from the front;

FIG. 5 is a cross-sectional view taken along cutting line V-V in FIG. 4, showing the power unit as viewed from the left;

FIG. 6 is a cross-sectional view taken along cutting line VI-VI in FIG. 3, showing a power switching device and the like, as viewed from above;

FIG. 7 is an explanatory view showing a space between a lower motor and an upper motor in the power unit of the outboard motor according to the embodiment of the present disclosure, as viewed from the left;

FIG. 8A is a perspective view showing a dog clutch in the power unit of the outboard motor according to the embodiment of the present disclosure, FIG. 8B is a perspective view showing a lower fitted member in the power unit of the outboard motor according to the embodiment of the present disclosure, and FIG. 8C is an exploded perspective view showing a switching mechanism in the power switching device of the power unit of the outboard motor according to the embodiment of the present disclosure; and

FIGS. 9A to 9C are explanatory views showing operations of the power switching device in the power unit of the outboard motor according to the embodiment of the present disclosure;

FIGS. 10A to 10F are explanatory views showing examples of a structure, in which a connection mode of a first motor shaft, a second motor shaft, and a drive shaft is switched by movement of a connecting member, in the ship propulsion machine according to the embodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

A ship propulsion machine according to an embodiment of the present disclosure includes a power unit that generates power, a propeller shaft to which a propeller is fixed, and a drive shaft that is provided between the power unit and the propeller shaft and transmits power generated by the power unit to the propeller shaft. In addition, the power unit includes a first motor, a second motor, a connecting member, and a switching mechanism.

The first motor includes a first motor shaft extending vertically.

The second motor is arranged above the first motor. Additionally, the second motor includes a second motor shaft extending vertically.

The connecting member is arranged so as to be movable vertically between the first motor and the second motor. Additionally, a lower end portion of the connecting member is provided with a first connecting portion for connecting the connecting member to an upper end portion of the first motor shaft. Additionally, an upper end portion of the connecting member is provided with a second connecting portion for connecting the connecting member to a lower end portion of the second motor shaft.

The switching mechanism is arranged between the first motor and the second motor. Additionally, the switching mechanism switches a connection mode of the first motor shaft, the second motor shaft, and the drive shaft by moving the connecting member upward or downward, between at least two of the three modes as follows:

- (a) A mode in which both the first motor shaft and the second motor shaft are connected to the drive shaft;
- (b) A mode in which the first motor shaft is connected to the drive shaft and the second motor shaft is not connected to the drive shaft; and
- (c) A mode in which the second motor shaft is connected to the drive shaft and the first motor shaft is not connected to the drive shaft.

In the mode (a), both the power of the first motor and the power of the second motor are transmitted to the drive shaft. With this, the propeller is rotated by a force obtained by combining the power of the first motor and the power of the second motor. In the mode (b), the power of the first motor is transmitted to the drive shaft, while the power of the second motor is not transmitted to the drive shaft. With this, the propeller is rotated only by the power of the first motor of the two motors of the power unit. In the mode (c), the power of the second motor is transmitted to the drive shaft, while the power of the first motor is not transmitted to the drive shaft. With this, the propeller is rotated only by the power of the second motor of the two motors of the power unit. According to the switching mechanism, it is possible to switch a propeller rotation mode between at least two modes of the following modes: a mode in which a propeller is rotated by a force obtained by combining powers of the two motors, a mode in which the propeller is rotated only by power of one of the two motors, and a mode in which the propeller is rotated only by power of the other of the two motors.

Here, several specific examples of a structure, in which a connection mode of a first motor shaft, a second motor shaft, and a drive shaft is switched by movement of a connecting member, will be described.

First Example

FIG. 10A shows a first example of a structure in which the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched by movement of the connecting member. FIG. 10B shows a state in which the connecting member is moved downward in the first example, and FIG. 10C shows a state in which the connecting member is moved upward in the first example.

In the first example, the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched among the modes (a), (b), and (c) by the movement of the connecting member.

In FIG. 10A, a first motor 111 includes a motor shaft 112 (first motor shaft) extending vertically. A second motor 121 is arranged above the first motor 111. Additionally, the second motor 121 includes a motor shaft 122 (second motor shaft) extending vertically. The motor shaft 112 of the first motor 111 is formed in a cylindrical shape, and an upper portion of a drive shaft 131 passes through an inner periphery side of the motor shaft 112 and reaches between the first motor 111 and the second motor 121. An outer peripheral surface of the drive shaft 131 is spaced apart from an inner peripheral surface of the motor shaft 112 of the first motor 111, allowing the drive shaft 131 to rotate independently of the motor shaft 112. A connecting member 141 is arranged between the first motor 111 and the second motor 121. The connecting member 141 is attached to an outer periphery side of the upper portion of the drive shaft 131 so as to be non-rotatable with respect to the drive shaft 131 and movable vertically with respect to the drive shaft 131. In addition, a lower end portion of the connecting member 141 is provided with a first connecting portion 145, and an upper end portion of the motor shaft 112 of the first motor 111 is provided with a connected portion 113. The first connecting portion 145 and the connected portion 113 have shapes that can fit with each other, for example, respectively. In addition, an upper end portion of the connecting member 141 is provided with a second connecting portion 146, and a lower end portion of the motor shaft 122 of the second motor 121 is provided with a connected portion 123. The second connecting portion 146 and the connected portion 123 have shapes that can fit with each other, for example, respectively.

In FIG. 10A, the connecting member 141 is positioned at a vertically middle portion between the upper end portion of the motor shaft 112 of the first motor 111 and the lower end portion of the motor shaft 122 of the second motor 121. In this state, the first connecting portion 145 of the connecting member 141 is connected to the connected portion 113 of the motor shaft 112 of the first motor 111, and at the same time, the second connecting portion 146 of the connecting member 141 is connected to the connected portion 123 of the motor shaft 122 of the second motor 121. As a result, both the motor shaft 112 of the first motor 111 and the motor shaft 122 of the second motor 121 are connected to the drive shaft 131 via the connecting member 141.

As can be seen by comparing FIG. 10B and FIG. 10A, in FIG. 10B, the connecting member 141 is moved downward. With this, the first connecting portion 145 of the connecting member 141 is connected to the connected portion 113 of the motor shaft 112 of the first motor 111, while the connection between the second connecting portion 146 of the connecting member 141 and the connected portion 123 of the motor shaft 122 of the second motor 121 is released. As a result, the motor shaft 112 of the first motor 111 is connected to the drive shaft 131 via the connecting member 141, while the motor shaft 122 of the second motor 121 is not connected to the drive shaft 131.

As can be seen by comparing FIG. 10C and FIG. 10A, in FIG. 10C, the connecting member 141 is moved upward. With this, the second connecting portion 146 of the connecting member 141 is connected to the connected portion 123 of the motor shaft 122 of the second motor 121, while the connection between the first connecting portion 145 of the connecting member 141 and the connected portion 113 of the motor shaft 112 of the first motor 111 is released. As a result, the motor shaft 122 of the second motor 121 is connected to the drive shaft 131 via the connecting member 141, while the motor shaft 112 of the first motor 111 is not connected to the drive shaft 131.

Second Example

FIG. 10D shows a second example of the structure in which the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched by movement of the connecting member. FIG. 10E shows a state in which the connecting member is moved upward in the second example.

In the second example, the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched between the modes (a) and (b) by movement of the connecting member.

In FIG. 10D, a first motor 211 includes a motor shaft 212 (first motor shaft) extending vertically. A drive shaft 231 is connected to a lower end portion of the motor shaft 212 of the first motor 211, and the motor shaft 212 of the first motor 211 rotates together with the drive shaft 231. A second motor 221 is arranged above the first motor 211. Additionally, the second motor 221 includes a motor shaft 222 (second motor shaft) extending vertically. A connecting member 241 is arranged between the first motor 211 and the second motor 221. In addition, a lower end portion of the connecting member 241 is provided with a first connecting portion 245, and an upper end portion of the motor shaft 212 of the first motor 211 is provided with a connected portion 213. The first connecting portion 245 and the connected portion 213 have shapes that can fit with each other, for example, respectively. In addition, an upper end portion of the connecting member 241 is provided with a second connecting portion 246, and a lower end portion of the motor shaft 222 of the second motor 221 is provided with a connected portion 223. The second connecting portion 246 and the connected portion 223 have shapes that can fit with each other, for example, respectively.

In FIG. 10D, the connecting member 241 is positioned at a vertically middle portion between the upper end portion of the motor shaft 212 of the first motor 211 and the lower end portion of the motor shaft 222 of the second motor 221. In this state, the first connecting portion 245 of the connecting member 241 is connected to the connected portion 213 of the motor shaft 212 of the first motor 211, and at the same time, the second connecting portion 246 of the connecting member 241 is connected to the connected portion 223 of the motor shaft 222 of the second motor 221. With this, the motor shaft 212 of the first motor 211 and the motor shaft 222 of the second motor 221 are connected to each other via the connecting member 241. As a result, the motor shaft 212 of the first motor 211 is directly connected to the drive shaft 231, and at the same time, the motor shaft 222 of the second motor 221 is connected to the drive shaft 231 via the connecting member 241 and the motor shaft 212 of the first motor 211. That is, both the motor shaft 212 of the first motor 211 and the motor shaft 222 of the second motor 221 are connected to the drive shaft 231.

As can be seen by comparing FIG. 10D and FIG. 10E, in FIG. 10E, the connecting member 241 is moved upward. With this, the second connecting portion 246 of the connecting member 241 is connected to the connected portion 223 of the motor shaft 222 of the second motor 221, while the connection between the first connecting portion 245 of the connecting member 241 and the connected portion 213 of the motor shaft 212 of the first motor 211 is released. With this, the motor shaft 212 of the first motor 211 and the motor shaft 222 of the second motor 221 are separated from each other. As a result, the motor shaft 212 of the first motor 211 is connected to the drive shaft 231, while the motor shaft 222 of the second motor 221 is not connected to the drive shaft 231.

In FIG. 10D, downward movement of the connecting member 241 can connect the first connecting portion 245 of the connecting member 241 and the connected portion 213 of the motor shaft 212 of the first motor 211, and release the connection between the second connecting portion 246 of the connecting member 241 and the connected portion 223 of the motor shaft 222 of the second motor 221. With this, a state can be made in which the motor shaft 212 of the first motor 211 is connected to the drive shaft 231, while the motor shaft 222 of the second motor 221 is not connected to the drive shaft 231.

Third Example

FIG. 10F shows a third example of the structure in which the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched by movement of the connecting member.

In the third example, as with the second example, the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched between the modes (a) and (b) by movement of the connecting member. However, the third example differs from the second example in that the connecting member is arranged non-coaxially with each motor shaft.

In FIG. 10F, a first motor 311 includes a motor shaft 312 (first motor shaft) extending vertically. A drive shaft 331 is connected to a lower end portion of the motor shaft 312 of the first motor 311, and the motor shaft 312 of the first motor 311 rotates together with the drive shaft 331. A second motor 321 is arranged above the first motor 311. Additionally, the second motor 321 includes a motor shaft 322 (second motor shaft) extending vertically. A connecting member 341 is arranged between the first motor 311 and the second motor 321. Additionally, in the second example, the motor shaft 212 of the first motor 211, the motor shaft 222 of the second motor 221, and the connecting member 241 are arranged coaxially with each other, while in the third example, the motor shaft 312 of the first motor 311 and the motor shaft 322 of the second motor 321 are arranged coaxially with each other, but the connecting member 341 is arranged non-coaxially with the motor shafts 312 and 322. A shaft 347 that is not coaxial with the motor shafts 312 and 322 and extends vertically parallel to the motor shafts 312 and 322 is provided between the first motor 311 and the second motor 321, and the connecting member 341 is attached to the shaft 347 so as to be rotatable and movable vertically. In addition, a lower end portion of the connecting member 341 is provided with a first connecting portion 345, and an upper end portion of the motor shaft 312 of the first motor 311 is provided with a connected portion 313. Outer peripheral surfaces of the first connecting portion 345 and the connected portion 313 are provided with a plurality of teeth that can mesh with each other, for example, respectively. In addition, an upper end portion of the connecting member 341 is provided with a second connecting portion 346, and a lower end portion of the motor shaft 322 of the second motor 321 is provided with a connected portion 323. Outer peripheral surfaces of the second connecting portion 346 and the connected portion 323 are provided with a plurality of teeth that can mesh with each other, for example, respectively.

In FIG. 10F, the first connecting portion 345 of the connecting member 341 is connected to the connected portion 313 of the motor shaft 312, and at the same time, the second connecting portion 346 of the connecting member 341 is connected to the connected portion 323 of the motor shaft 322, thereby connecting the motor shaft 312 and the motor shaft 322 to each other via the connecting member 341. As a result, both the motor shaft 312 of the first motor 311 and the motor shaft 322 of the second motor 321 are connected to the drive shaft 331.

When the connecting member 341 is moved upward or downward from the state shown in FIG. 10F, the connection between the first connecting portion 345 of the connecting member 341 and the connected portion 313 of the motor shaft 312 and the connection between the second connecting portion 346 of the connecting member 341 and the connected portion 323 of the motor shaft 322 can be released, respectively, and the motor shaft 312 and the motor shaft 322 can be separated from each other. As the motor shaft 312 and the motor shaft 322 are separated from each other, the connection between the motor shaft 322 and the drive shaft 331 is disconnected.

The ship propulsion machine of the present embodiment can adopt any of the three examples described above, as the structure in which the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched by movement of the connecting member. In the ship propulsion machine of the present embodiment, the structure in which the connection mode of the first motor shaft, the second motor shaft, and the drive shaft is switched by the movement of the connecting member is not limited to the three examples described above.

According to the ship propulsion machine of the present embodiment, it is possible to prevent a ship propulsion machine from becoming significantly larger even when the ship propulsion machine is provided with two motors and a mechanism that switches a propeller rotation mode. Specifically, by arranging the first motor and the second motor in a vertically parallel manner so that each motor shaft extends vertically, the upper end portion of the first motor shaft and the lower end portion of the second motor shaft can be brought close to each other within the space between the first motor and the second motor. By arranging the connecting member and the switching mechanism between the first motor and the second motor, the upper end portion of the first motor shaft, the lower end portion of the second motor shaft, the connecting member, and the switching mechanism can be concentratedly arranged between the first motor and the second motor. In addition, by arranging the upper end portion of the first motor shaft, the lower end portion of the second motor shaft, the connecting member, and the switching mechanism in the concentrated manner, the connecting member and the switching mechanism can be made compact. As a result, it is possible to prevent the ship propulsion machine from becoming significantly larger compared to a ship propulsion machine with only one motor.

Embodiment

Hereinafter, a case in which the present disclosure is applied to an outboard motor, which is a type of ship propulsion machine, will be described as an embodiment of the present disclosure. In the description of the present embodiment, when referring to upper (Ud), lower (Dd), front (Fd), rear (Bd), left (Ld), and right (Rd) directions, they follow arrows drawn at the lower right in each drawing.

(Outboard Motor)

FIG. 1 shows an outboard motor 1 according to an embodiment of the present disclosure. In FIG. 1, the outboard motor 1 includes a power unit 2, a propeller 3, a drive shaft 4, a propeller shaft 5, and a gear mechanism 6.

The power unit 2 generates power to propel a ship. The power unit 2 is arranged in an upper portion of the outboard motor 1 so that it is positioned above a water surface in a state in which the outboard motor 1 is attached to the ship. Additionally, the power unit 2 is fixed to a motor holder 9 provided in the upper portion of the outboard motor 1.

The propeller 3 converts the power generated by the power unit 2 into a propulsive force. The propeller 3 is arranged at a lower portion of the outboard motor 1 so that it is positioned below the water surface in a state in which the outboard motor 1 is attached to the ship.

The drive shaft 4, the propeller shaft 5, and the gear mechanism 6 transmit the power generated by power unit 2 to the propeller 3. The drive shaft 4 extends vertically from the upper portion to the lower portion of the outboard motor 1. An upper portion of the drive shaft 4 is introduced inside the power unit 2. The propeller shaft 5 is arranged in the lower portion of the outboard motor 1 and extends in the front-rear direction. The propeller 3 is fixed to a rear portion of the propeller shaft 5. The gear mechanism 6 is arranged in a lower front portion of the outboard motor 1. The gear mechanism 6 includes a drive gear 7 and a driven gear 8, the drive gear 7 being fixed to a lower end portion of the drive shaft 4 and the driven gear 8 being fixed to a front end portion of the propeller shaft 5. Both the drive gear 7 and the driven gear 8 are bevel gears, and the meshing of these gears converts rotation of the drive shaft 4 around a vertical axis into rotation of the propeller shaft 5 around a horizontal axis. The drive shaft 4 rotates by receiving the power from the power unit 2, and the rotation of the drive shaft 4 is transmitted to the propeller shaft 5 via the gear mechanism 6, thereby rotating the propeller 3 together with the propeller shaft 5.

Additionally, the upper portion of the outboard motor 1 is provided with a motor cover 10 that covers the power unit 2 and the motor holder 9. The motor cover 10 is divided into a bottom cover 11 that covers a lower portion of the power unit 2 and the motor holder 9, and a top cover 12 that covers an upper portion of the power unit 2. In addition, a vertically middle portion of the outboard motor 1 is provided with a drive shaft case 13 that covers an outer periphery side of the drive shaft 4. Additionally, the lower portion of the outboard motor 1 is provided with a gear case 14 that covers a front side portion of the gear mechanism 6 and the propeller shaft 5. Additionally, the outboard motor 1 is provided with a clamp mechanism 15 for detachably fixing the outboard motor 1 to a ship hull.

(Power Unit)

FIG. 2 shows the power unit 2 and the motor holder 9 as viewed from the upper left front. FIG. 3 shows the power unit 2 as seen from the left. FIG. 4 shows the power unit 2 as seen from the front. FIG. 5 is a cross-sectional view of the power unit 2 taken along cutting line V-V in FIG. 4, as viewed from the left (right in FIG. 4).

As shown in FIG. 2, the power unit 2 includes a lower motor 21, a lower inverter 35, an upper motor 41, an upper inverter 55, and a power switching device 61.

The lower motor 21 is an AC electric motor, i.e., an AC motor. As shown in FIG. 5, the lower motor 21 includes a motor shaft 22, a rotor 23 provided on an outer periphery side of the motor shaft 22, a stator 24 provided on an outer periphery side of the rotor 23, and a cylindrical motor case 25 provided on an outer periphery side of the stator 24. The rotor 23 rotates together with the motor shaft 22, and the stator 24 is fixed to the motor case 25. Additionally, the motor shaft 22 is formed in a cylindrical shape. In other words, a central portion of the motor shaft 22 is formed with a through hole penetrating axially.

Additionally, the lower motor 21 includes a bottom motor bracket 26 and a top motor bracket 27, as shown in FIG. 2. The bottom motor bracket 26 is formed in a polygonal or circular plate shape and is arranged below the motor case 25 so as to substantially block a lower portion of the motor case 25. The lower portion of the motor case 25 is fixed to the bottom motor bracket 26. For example, the lower portion of the motor case 25 is provided with a plurality of motor fixing portions 25A protruding outward, and these motor fixing portions 25A are fixed to the bottom motor bracket 26. In addition, as shown in FIG. 5, a central portion of the bottom motor bracket 26 is formed with a motor shaft insertion hole 26A. A lower end portion of the motor shaft 22 is rotatably supported by a bearing 31 inside the motor shaft insertion hole 26A. In addition, as shown in FIG. 2, the bottom motor bracket 26 is provided on an upper surface of a front portion of the motor holder 9 and is fixed to the motor holder 9.

As shown in FIG. 2, the top motor bracket 27 is formed in a polygonal or circular plate shape and is arranged above the motor case 25 so as to substantially block an upper portion of the motor case 25. The upper portion of the motor case 25 is fixed to the top motor bracket 27. For example, the upper portion of the motor case 25 is provided with a plurality of motor fixing portions 25B protruding outward, and these motor fixing portions 25B are fixed to the top motor bracket 27. In addition, a central portion of the top motor bracket 27 is formed with a motor shaft insertion hole 27A, as shown in FIG. 5. An upper end portion of the motor shaft 22 is rotatably supported by a bearing 32 inside the motor shaft insertion hole 27A.

The lower inverter 35 is a device that converts current supplied from a battery from direct current to alternating current to drive the lower motor 21. Inverter attachment portions 30 are provided on left and right rear portions of the bottom motor bracket 26 and on left and right rear portions of the top motor bracket 27. The lower inverter 35 is fixed to a rear portion of the lower motor 21 by being attached to the inverter attachment portions 30.

The upper motor 41 is an AC motor. In the present embodiment, the upper motor 41 is the same as the lower motor 21 in terms of the basic configuration as an AC motor and the performance related to power generation, such as output and torque. The upper motor 41 includes a motor shaft 42, a rotor 43, a stator 44, and a cylindrical motor case 45, substantially similarly to the lower motor 21. First of all, the motor shaft 42 of the upper motor 41, unlike the motor shaft 22 of the lower motor 21, is not cylindrical. That is, the motor shaft 42 is not formed with a through hole penetrating axially through a central portion thereof. For the purpose of reducing the weight of the motor shaft 42, and the like, the motor shaft 42 may be formed into a cylindrical shape.

Additionally, the upper motor 41 includes a bottom motor bracket 46 and a top motor bracket 49. The bottom motor bracket 46 is formed in a polygonal or circular plate shape and is arranged below the motor case 45 so as to substantially block a lower portion of the motor case 45. The lower portion of the motor case 45 is fixed to the bottom motor bracket 46 via, for example, a plurality of motor fixing portions 45A protruding outward from the lower portion of the motor case 45. Additionally, a central portion of the bottom motor bracket 46 is formed with a motor shaft insertion hole 46A. A lower end portion of the motor shaft 42 is rotatably supported by a bearing 51 inside the motor shaft insertion hole 46A.

The top motor bracket 49 is formed in a polygonal or circular plate shape and is arranged above the motor case 45 so as to substantially block an upper portion of the motor case 45. The upper portion of the motor case 45 is fixed to the top motor bracket 49 via, for example, a plurality of motor fixing portions 45B protruding outward from the upper portion of the motor case 45. Additionally, a central portion of the top motor bracket 49 is formed with a motor shaft insertion hole 49A. An upper end portion of the motor shaft 42 is rotatably supported by a bearing 52 inside the motor shaft insertion hole 49A.

The upper inverter 55 is a device that converts current supplied from the battery from direct current to alternating current to drive the upper motor 41. The upper inverter 55 is fixed to a rear portion of the upper motor 41 by being attached to inverter attachment portions 50 provided on left and right rear portions of the bottom motor bracket 46 and on left and right rear portions of the top motor bracket 49.

The upper motor 41 is arranged above the lower motor 21. The lower motor 21 and the upper motor 41 are arranged so that the motor shafts 22 and 42 extend vertically, respectively. The lower motor 21 and the upper motor 41 are arranged so that the motor shafts 22 and 42 are coaxial.

As shown in FIGS. 2 to 5, the power unit 2 is provided with a plurality of support members 85 fixing the upper motor 41 to the lower motor 21. The upper motor 41 is supported by the support members 85 at a position above and spaced from the lower motor 21. Each support member 85 is formed into a column shape extending vertically, for example, using a metal material or the like. Each support member 85 is arranged between the top motor bracket 27 of the lower motor 21 and the bottom motor bracket 46 of the upper motor 41. A lower portion of each support member 85 is fixed to the top motor bracket 27 of the lower motor 21, and an upper portion of each support member 85 is fixed to the bottom motor bracket 46 of the upper motor 41. In the present embodiment, a central portion of each support member 85 is formed with a through hole penetrating axially. In addition, through holes penetrating vertically are formed in portions of the top motor bracket 27 of the lower motor 21 and the bottom motor bracket 46 of the upper motor 41 where each support member 85 is arranged. Each support member 85 is fixed between the top motor bracket 27 and the bottom motor bracket 46 by inserting a bolt 86 into each of the through holes of the support member 85, the top motor bracket 27 of the lower motor 21, and the bottom motor bracket 46 of the upper motor 41, and fastening a nut 87 onto an end portion of the bolt 86. With this, the upper motor 41 is supported by the lower motor 21.

The plurality of support members 85 are arranged on an outer periphery side portion of each of the top motor bracket 27 and the bottom motor bracket 46. FIG. 6 is a cross-sectional view of the power unit 2 taken along cutting line VI-VI in FIG. 3, as viewed from above. As shown in FIG. 6, in the present embodiment, two of the seven support members 85 are arranged on the left portion of the top motor bracket 27 and the bottom motor bracket 46, the other two support members 85 are arranged on the right portion of the top motor bracket 27 and the bottom motor bracket 46, and the remaining three support members 85 are arranged on the rear portion of the top motor bracket 27 and the bottom motor bracket 46.

A space is formed between the lower motor 21 and the upper motor 41 by the plurality of support members 85. In the space between the lower motor 21 and the upper motor 41, as shown in FIG. 5, the upper end portion of the motor shaft 22 of the lower motor 21 and the lower end portion of the motor shaft 42 of the upper motor 41 are arranged to face each other and to be close to each other.

Additionally, the upper portion of the drive shaft 4 is inserted into the inner periphery side of the motor shaft 22 of the lower motor 21. The upper portion of the drive shaft 4 passes through the motor holder 9, passes through the inner periphery side of the motor shaft 22 of the lower motor 21, and reaches the space between the lower motor 21 and the upper motor 41. The upper end portion of the drive shaft 4 is close to the upper end portion of the motor shaft 22 of the lower motor 21 and the lower end portion of the motor shaft 42 of the upper motor 41, respectively.

Additionally, an inner diameter of the motor shaft 22 of the lower motor 21 is set to a larger value than an outer diameter of the upper portion of the drive shaft 4. The upper portion of the drive shaft 4 is inserted into the motor shaft 22 in a state in which an outer peripheral surface thereof is spaced apart from an inner peripheral surface of the motor shaft 22 of the lower motor 21. Therefore, the drive shaft 4 can rotate independently of the motor shaft 22 of the lower motor 21.

The lower motor 21 serves as an example of a “first motor”, the motor shaft 22 of the lower motor 21 serves as an example of a “first motor shaft”, and the top motor bracket 27 of the lower motor 21 serves as an example of a “first motor bracket.” In addition, the upper motor 41 serves as an example of a “second motor,” the motor shaft 42 of the upper motor 41 serves as an example of a “second motor shaft,” and the bottom motor bracket 46 of the upper motor 41 serves as an example of a “second motor bracket.” Additionally, the support member 85 serves as an example of a “fixing member.”

(Power Switching Device)

The power unit 2 includes a power switching device 61 that transmits both or either of the power of the lower motor 21 and the power of the upper motor 41 to the drive shaft 4. By means of the power switching device 61, it is possible to switch a mode of rotating the propeller 3 among a mode in which the propeller 3 is rotated by a force obtained by combining the power of the lower motor 21 and the power of the upper motor 41, a mode in which the propeller 3 is rotated only by the power of the lower motor 21 of the two motors of the power unit 2, and a mode in which the propeller 3 is rotated only by the power of the upper motor 41 of the two motors of the power unit 2.

FIG. 7 shows the space between the lower motor 21 and the upper motor 41 in the power unit 2, as viewed from the left. In FIG. 7, each support member 85 is not shown. As shown in FIG. 7, the power switching device 61 is arranged between the lower motor 21 and the upper motor 41. The power switching device 61 includes a dog clutch 62, a lower fitted member 66, an upper fitted member 68, and a switching mechanism 71.

FIG. 8A shows the dog clutch 62. The dog clutch 62 is a member that connects both or either of the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 to the drive shaft 4. As shown in FIG. 8A, the dog clutch 62 is formed in a cylindrical shape. As shown in FIG. 5, the dog clutch 62 is arranged between the upper end portion of the motor shaft 22 of the lower motor 21 and the lower end portion of the motor shaft 42 of the upper motor 41. Additionally, the dog clutch 62 is attached to an outer periphery side of the upper end portion of the drive shaft 4 so as to be non-rotatable with respect to the drive shaft 4 and movable vertically with respect to the drive shaft 4.

As shown in FIG. 8A, an upper portion of the dog clutch 62 is formed with an upper fitting portion 64. An outer periphery side of the upper fitting portion 64 is formed with an unevenness. Additionally, a lower portion of the dog clutch 62 is formed with a lower fitting portion 63. An outer periphery side of the lower fitting portion 63 is formed with an unevenness similar to that formed on the outer periphery side of the upper fitting portion 64. Additionally, an outer peripheral surface of a vertically middle portion of the dog clutch 62 is formed with a clutch groove 65. The clutch groove 65 extends over an entire periphery of the dog clutch 62. The dog clutch 62 serves as an example of a “connecting member”, the lower fitting portion 63 serves as an example of a “first connecting portion”, and the upper fitting portion 64 serves as an example of a “second connecting portion”.

FIG. 8B shows the lower fitted member 66. The lower fitted member 66 is formed in a cylindrical shape, as shown in FIG. 8B. In addition, as shown in FIG. 5, the lower fitted member 66 is fixed to the upper end portion of the motor shaft 22 of the lower motor 21 so as to be non-rotatable with respect to the motor shaft 22. Specifically, the upper end portion of the motor shaft 22 of the lower motor 21 is formed with a fitted member insertion portion 22A where the inner diameter of the motor shaft 22 is made larger than the inner diameter of the other portion of the motor shaft 22. A lower portion of the lower fitted member 66 is inserted into the fitted member insertion portion 22A and is fixed inside the fitted member insertion portion 22A by a method such as spline coupling.

As shown in FIG. 8B, an upper portion of the lower fitted member 66 is formed with a fitted portion 67. An inner periphery side of the fitted portion 67 is formed with an unevenness. A shape of the unevenness of the lower fitting portion 63 of the dog clutch 62 and a shape of the unevenness of the fitted portion 67 of the lower fitted member 66 are set so that the lower fitting portion 63 can be fitted with the fitted portion 67.

The upper fitted member 68 is formed in a cylindrical shape, and as shown in FIG. 5, is fixed to the lower end portion of the motor shaft 42 of the upper motor 41 so as to be non-rotatable with respect to the motor shaft 42. Specifically, the lower end portion of the motor shaft 42 of the upper motor 41 is formed with a fitted member insertion portion 42A. The fitted member insertion portion 42A is a hole formed at a central portion of a lower end surface of the motor shaft 42. An upper portion of the upper fitted member 68 is inserted into the fitted member insertion portion 42A and is fixed inside the fitted member insertion portion 42A by a method such as spline coupling.

A lower portion of the upper fitted member 68 is formed with a fitted portion 69 (see FIG. 9A). An inner periphery side of the fitted portion 69 is formed with an unevenness. A shape of the unevenness of the upper fitting portion 64 of the dog clutch 62 and a shape of the unevenness of the fitted portion 69 of the upper fitted member 68 are set so that the upper fitting portion 64 can be fitted with the fitted portion 69.

Two common fitted members may be used as the lower fitted member 66 and the upper fitted member 68. That is, one of the two common fitted members may be used as the lower fitted member 66 by fixing the one fitted member within the fitted member insertion portion 22A of the motor shaft 22 of the lower motor 21 so that the fitted member faces upward, and the other of the two common fitted members may be used as the upper fitted member 68 by fixing the other fitted member within the fitted member insertion portion 42A of the motor shaft 42 of the upper motor 41 so that the fitted member faces downward.

FIGS. 9A to 9C show operations of the dog clutch 62. In the present embodiment, the dog clutch 62 can move vertically within a movement range from a position where the lower fitting portion 63 of the dog clutch 62 is deeply fitted with the fitted portion 67 of the lower fitted member 66, as shown in FIG. 9B, to a position where the upper fitting portion 64 of the dog clutch 62 is deeply fitted with the fitted portion 69 of the upper fitted member 68, as shown in FIG. 9C.

As shown in FIG. 9A, when the dog clutch 62 moves to a middle position within the movement range, the lower fitting portion 63 of the dog clutch 62 is fitted with the fitted portion 67 of the lower fitted member 66, and the upper fitting portion 64 of the dog clutch 62 is fitted with the fitted portion 69 of the upper fitted member 68. With this, the motor shaft 22 of the lower motor 21 and the drive shaft 4 are interconnected via the dog clutch 62, and at the same time, the motor shaft 42 of the upper motor 41 and the drive shaft 4 are interconnected via the dog clutch 62. As a result, both the power of the lower motor 21 and the power of the upper motor 41 are transmitted to the drive shaft 4, and the propeller 3 is rotated by a force obtained by combining the power of the lower motor 21 and the power of the upper motor 41.

As shown in FIG. 9B, when the dog clutch 62 moves to a lower position within the movement range, the lower fitting portion 63 of the dog clutch 62 is fitted with the fitted portion 67 of the lower fitted member 66, and the fitting between the upper fitting portion 64 of the dog clutch 62 and the fitted portion 69 of the upper fitted member 68 is released. With this, the motor shaft 22 of the lower motor 21 and the drive shaft 4 are interconnected via the dog clutch 62, and at the same time, the motor shaft 42 of the upper motor 41 and the drive shaft 4 are disconnected. As a result, only the power of the lower motor 21 of the two motors of the power unit 2 is transmitted to the drive shaft 4, and the propeller 3 is rotated only by the power of the lower motor 21.

As shown in FIG. 9C, when the dog clutch 62 moves to an upper portion of the movement range, the upper fitting portion 64 of the dog clutch 62 is fitted with the fitted portion 69 of the upper fitted member 68, and the fitting between the lower fitting portion 63 of the dog clutch 62 and the fitted portion 67 of the lower fitted member 66 is released. With this, the motor shaft 42 of the lower motor 41 and the drive shaft 4 are interconnected via the dog clutch 62, and at the same time, the motor shaft 22 of the upper motor 21 and the drive shaft 4 are disconnected. As a result, only the power of the upper motor 41 of the two motors of the power unit 2 is transmitted to the drive shaft 4, and the propeller 3 is rotated only by the power of the upper motor 41.

(Switching Mechanism)

The power switching device 61 includes the switching mechanism 71 that switches the connection mode of the motor shaft 22 of the lower motor 21, the motor shaft 42 of the upper motor 41, and the drive shaft 4 by moving the dog clutch 62 vertically based on an operation input from an outside, among (a) a mode in which both the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are connected to the drive shaft 4, (b) a mode in which the motor shaft 22 of the lower motor 21 is connected to the drive shaft 4 and the motor shaft 42 of the upper motor 41 is not connected to the drive shaft 4, and (c) a mode in which the motor shaft 42 of the upper motor 41 is connected to the drive shaft 4 and the motor shaft 22 of the lower motor 21 is not connected to the drive shaft 4. By the mode (a), the propeller 3 can be rotated by a force obtained by combining the power of the lower motor 21 and the power of the upper motor 41. In addition, by the mode (b), the propeller 3 can be rotated only by the power of the lower motor 21 of the two motors of the power unit 2. In addition, by the mode (c), the propeller 3 can be rotated only by the power of the upper motor 41 of the two motors of the power unit 2.

As shown in FIG. 7, the switching mechanism 71 is arranged in the front portion of the space between the lower motor 21 and the upper motor 41.

FIG. 8C shows the disassembled switching mechanism 71. As shown in FIG. 8C, the switching mechanism 71 includes a clutch camshaft 72, a fork unit 74, a clutch rod 80, and a link mechanism 81.

The clutch camshaft 72 is a shaft extending vertically. The clutch camshaft 72 has a cylindrical cam structure. An outer peripheral surface of a vertically middle portion of the clutch camshaft 72 is formed with a cam groove 73 for converting rotation of the clutch camshaft 72 into vertical movement of the fork unit 74.

The fork unit 74 is attached to the outer periphery side of the clutch camshaft 72 so as to be movable vertically with respect to the clutch camshaft 72. The fork unit 74 has a tubular portion 75 and a driven pin 76, and the vertically middle portion of the clutch camshaft 72 is inserted into an inner periphery side of the tubular portion 75. Additionally, the driven pin 76 is inserted into a pin hole 75A formed in the tubular portion 75. The driven pin 76 passes through the pin hole 75A, and a tip end portion of the driven pin 76 is inserted into the cam groove 73 within the tubular portion 75. The driven pin 76 inserted in the pin hole 75A is locked to the tubular portion 75 by a stopper member 78, with a coil spring 77 interposed. With this configuration, the fork unit 74 moves vertically along with rotation of the clutch camshaft 72. In addition, the fork unit 74 has a fork 79. The fork 79 is formed integrally with the tubular portion 75. The fork 79 protrudes radially outward from an outer peripheral surface of the tubular portion 75. The fork 79 has a two-pronged tip end portion.

As shown in FIG. 7, the clutch camshaft 72 with the fork unit 74 attached is rotatably supported between an outer periphery-side portion of the lower motor 21 and an outer periphery-side portion of the upper motor 41. Specifically, a cam shaft support portion 29 is provided on the left front side of the top motor bracket 27 of the lower motor 21. A lower end portion of the clutch camshaft 72 is rotatably supported by the cam shaft support portion 29, for example, via a bearing. Additionally, a cam shaft support portion 48 is provided on the left front side of the bottom motor bracket 46 of the upper motor 41. An upper end portion of the clutch camshaft 72 is rotatably supported by the cam shaft support portion 48, for example, via a bearing.

In addition, the fork 79 of the fork unit 74 sandwiches and grips the outer peripheral portion of the dog clutch 62 by the two-pronged tip end portion. Specifically, the tip end portion of the fork 79 of the fork unit 74 is inserted into the clutch groove 65 of the dog clutch 62, as shown in FIGS. 6 and 7. The tip end portion of the fork 79 is inserted into the clutch groove 65 with a gap. With this, the dog clutch 62 can rotate along with the rotation of the drive shaft 4 with the tip end portion of the fork 79 inserted into the clutch groove 65.

As shown in FIG. 8C, the clutch rod 80 is a rod extending vertically. As shown in FIG. 4, the clutch rod 80 is rotatably supported between the outer periphery-side portion of the lower motor 21 and the outer periphery-side portion of the upper motor 41. Specifically, a rod support portion 28 is provided on the right front side of the top motor bracket 27 of the lower motor 21. A lower end portion of the clutch rod 80 is rotatably supported by the rod support portion 28, for example, via a bearing. Additionally, a rod support portion 47 is provided on the right front side of the bottom motor bracket 46 of the upper motor 41. An upper end portion of the clutch rod 80 is rotatably supported by the rod support portion 47, for example, via a bearing.

As shown in FIG. 6, the link mechanism 81 is a mechanism that interconnects the clutch camshaft 72 and the clutch rod 80 and transmits rotation of the clutch rod 80 to the clutch camshaft 72. As shown in FIG. 8C, the link mechanism 81 includes a first link member 81A, a second link member 81B, and a third link member 81C. The first link member 81A includes a first one end portion and a first another end portion, the second link member 81B includes a second one end portion and a second another end portion, and the third link member 81C includes a third one end portion and a third another end portion. The first one end portion of the first link member 81A is connected to the clutch rod 80 so as to be non-rotatable with respect to the clutch rod 80. The second one end portion of the second link member 81B is connected to the clutch camshaft 72 so as to be non-rotatable with respect to the clutch camshaft 72. The third one end portion of the third link member 81C is connected to the first another end portion of the first link member 81A so as to be rotatable with respect to the first link member 81A. The third another end portion of the third link member 81C is connected to the second another end portion of the second link member 81B so as to be rotatable with respect to the second link member 81B.

In FIG. 8C, when the clutch rod 80 rotates in the direction of arrow A, the rotation is transmitted to the clutch camshaft 72 via the link mechanism 81, and the clutch camshaft 72 rotates in the direction of arrow C. The rotation of the clutch camshaft 72 moves the fork unit 74 upward, for example. On the other hand, when the clutch rod 80 rotates in the direction of arrow B, the rotation is transmitted to the clutch camshaft 72 via the link mechanism 81, and the clutch camshaft 72 rotates in the direction of arrow D. The rotation of the clutch camshaft 72 moves the fork unit 74 downward, for example. The relationship between the rotation direction of the clutch rod 80 and the movement direction of the fork unit 74 in the vertical direction, and the relationship between the rotation amount of the clutch rod 80 and the movement amount of the fork unit 74 in the vertical direction can be set by the shape of the cam groove 73 formed on the clutch camshaft 72.

Since the outer peripheral portion of the dog clutch 62 is gripped by the fork 79 of the fork unit 74, the dog clutch 62 moves upward as the fork unit 74 moves upward. Additionally, the dog clutch 62 moves downward as the fork unit 74 moves downward.

Additionally, the clutch rod 80 rotates by receiving switching power to switch the connection mode of the motor shaft 22, the motor shaft 42, and the drive shaft 4. Although not shown, the upper portion of the outboard motor 1 is provided with an actuator (e.g., a DC motor), and an output shaft of the actuator is connected to the clutch rod 80. The operation input from the outside is input to the actuator. Based on the operation input from the outside, the actuator operates, the clutch rod 80 rotates by receiving rotational power output from the output shaft of the actuator, and the dog clutch 62 moves vertically in response to the rotation of the clutch rod 80.

The clutch camshaft 72 serves as an example of a “switching shaft”, and the cam groove 73 serves as an example of a “cam.” In addition, the fork unit 74 serves as an example of a “driven member”, and the fork 79 serves as an example of a “gripping portion.” Additionally, the clutch rod 80 serves as an example of an “input rod.”

As described above, in the power unit 2 of the outboard motor 1 of the embodiment of the present disclosure, the lower motor 21 and the upper motor 41 are arranged vertically so that the respective motor shafts 22 and 42 extend vertically. In addition, the dog clutch 62 that connects both or either of the upper end portion of the motor shaft 22 of the lower motor 21 and the lower end portion of the motor shaft 42 of the upper motor 41 to the drive shaft 4 is arranged between the lower motor 21 and the upper motor 41. Additionally, the switching mechanism 71 that switches the connection mode of the motor shaft 22, the motor shaft 42, and the drive shaft 4 by moving the dog clutch 62 is arranged between the lower motor 21 and the upper motor 41. With the above configuration, it is possible to prevent an outboard motor from becoming significantly larger even when the outboard motor is provided with two motors and a mechanism that switches a propeller rotation mode. Specifically, the lower motor 21 and the upper motor 41 are arranged vertically so that the respective motor shafts 22 and 42 extend vertically, so the upper end portion of the motor shaft 22 of the lower motor 21 and the lower end portion of the motor shaft 42 of the upper motor 41 can be brought close to each other. By arranging the dog clutch 62 and the switching mechanism 71 between the lower motor 21 and the upper motor 41, the upper end portion of the motor shaft 22 of the lower motor 21, the lower end portion of the motor shaft 42 of the upper motor 41, the dog clutch 62, and the switching mechanism 71 can be concentratedly arranged between the lower motor 21 and the upper motor 41. In addition, by arranging the upper end portion of the motor shaft 22, the lower end portion of the motor shaft 42, the dog clutch 62, and the switching mechanism 71 in the concentrated manner, the dog clutch 62 and the switching mechanism 71 can be made compact. As a result, the small power unit 2 with two motors can be made, and thus, the outboard motor 1 can be prevented from becoming significantly larger compared to an outboard motor with only one motor.

According to the outboard motor 1 of the present embodiment, it is possible to switch the mode of rotating the propeller 3 among the mode in which the propeller 3 is rotated by the force obtained by combining the power of the lower motor 21 and the power of the upper motor 41, the mode in which the propeller 3 is rotated only by the power of the lower motor 21 of the two motors of the power unit 2, and the mode in which the propeller 3 is rotated only by the power of the upper motor 41 of the two motors of the power unit 2. Therefore, the performance of the outboard motor can be enhanced. Specifically, the output of the power unit 2 can be significantly changed in response to the sailing conditions of the ship, and the power consumption of the power unit 2 can also be adjusted. For example, by switching the mode of rotating the propeller 3 from the mode in which the propeller 3 is rotated only by the power of one motor of the lower motor 21 and the upper motor 41 to the mode in which the propeller 3 is rotated by the force obtained by combining the power of the lower motor 21 and the power of the upper motor 41, the output of the power unit 2 can be significantly increased. In addition, by switching the mode from the mode in which the propeller 3 is rotated by the force obtained by combining the power of the lower motor 21 and the power of the upper motor 41 to the mode in which the propeller 3 is rotated only by the power of one motor of the lower motor 21 and the upper motor 41, the power consumption of the power unit 2 can be reduced. In addition, for example, when one of the lower motor 21 and the upper motor 41 fails during sailing, the failed motor is disconnected from the drive shaft 4 and the non-failed motor is connected to the drive shaft 4. With this, it is possible to cause the propeller 25 to rotate only by the power of the non-failed motor, thereby moving the ship.

In addition, in the outboard motor 1 of the present embodiment, the switching mechanism 71 includes the clutch camshaft 72 rotatably supported between the outer periphery-side portion of the lower motor 21 and the outer periphery-side portion of the upper motor 41, the fork unit 74 that moves vertically in response to the rotation of the clutch camshaft 72, and the cam groove 73 that converts the rotation of the clutch camshaft 72 into the vertical movement of the fork unit 74, and the fork unit 74 is provided with the fork 79 that grips the outer peripheral portion of the dog clutch 62. With this, it is possible to implement the switching mechanism 71 for moving the dog clutch 62 vertically by a simple mechanism.

In addition, in the outboard motor 1 of the present embodiment, the upper motor 41 is firmly fixed to the lower motor 21 by the plurality of support members 85. The lower end portion of the clutch camshaft 72 is rotatably supported by the top motor bracket 27 of the lower motor 21, and the upper end portion of the clutch camshaft 72 is rotatably supported by the bottom motor bracket 46 of the upper motor 41. In this way, by supporting both end portions of the clutch camshaft 72 between the lower motor 21 and the upper motor 41, which are firmly fixed to each other, the structure for rotatably supporting the clutch camshaft 72 can be made robust, the positional misalignment, inclination, or the like of the clutch camshaft 72 can be suppressed, and the durability of the clutch camshaft 72 can be enhanced. In addition, by using the top motor bracket 27 and the bottom motor bracket 46 to support the clutch camshaft 72, the support structure of the clutch camshaft 72 can be made compact, and the number of components constituting the support structure of the clutch camshaft 72 can be reduced.

In addition, in the outboard motor 1 of the present embodiment, the switching mechanism 71 includes the clutch rod 80 to which the output shaft of the actuator is connected and which rotates by receiving the rotational power output from the output shaft of the actuator, and the link mechanism 81 that transmits the rotation of the clutch rod 80 to the clutch camshaft 72 to cause the clutch camshaft 72 to rotate. The link mechanism 81 includes the first link member 81A, the second link member 81B, and the third link member 81C. With this configuration, the rotation amount of the clutch camshaft 72 with respect to the rotation amount of the output shaft of the actuator can be set by a ratio of a length of the first link member 81A and a length of the second link member 81B, so the degree of freedom of the setting is increased. In addition, when the first link member 81A is made long with respect to the second link member 81B, the output torque of the actuator for rotating the clutch camshaft 72 can be lowered. With this, it becomes possible to adopt a small, low-power actuator as the actuator that rotates the clutch camshaft 72. Therefore, miniaturization and weight reduction of the power unit 2 can be promoted.

In addition, according to the outboard motor 1 of the present embodiment, since the configuration is such that the upper motor 41 is fixed to the lower motor 21 fixed to the motor holder 9, the number of components for fixing the two motors to the outboard motor 1 can be reduced, which enables the miniaturization and weight reduction of the outboard motor 1.

In addition, in the outboard motor 1 of the present embodiment, the switching mechanism 71 is arranged in the front portion of the space between the lower motor 21 and the upper motor 41. With this configuration, when performing maintenance or repair on the switching mechanism 71, the top cover 12 can be separated, and maintenance or repair on the switching mechanism 71 can be easily performed from the ship side.

In the above embodiment, the example has been described in which the switching mechanism 71 switches the connection mode of the motor shaft 22 of the lower motor 21, the motor shaft 42 of the upper motor 41, and the drive shaft 4 among the mode (a) in which both the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are connected to the drive shaft 4, the mode (b) in which the motor shaft 22 of the lower motor 21 is connected to the drive shaft 4 and the motor shaft 42 of the upper motor 41 is not connected to the drive shaft 4, and the mode (c) in which the motor shaft 42 of the upper motor 41 is connected to the drive shaft 4 and the motor shaft 22 of the lower motor 21 is not connected to the drive shaft 4, but the present disclosure is not limited thereto. The switching of the connection mode of the motor shaft 22, the motor shaft 42, and the drive shaft 4 by the switching mechanism 71 may be performed only between the modes (a) and (b), only between the modes (a) and (c), or only between the modes (b) and (c).

In addition, in the above embodiment, the lower motor 21 and the upper motor 41, which have the same performances in terms of power generation, such as output and torque, are provided in the power unit 2. However, the performances in terms of power generation, such as output and torque, may be made different between the lower motor 21 and the upper motor 41.

In addition, in the above embodiment, the case has been exemplified in which the upper portion of the motor shaft 22 is provided with the fitted portion that is fitted with the fitting portion of the dog clutch by fixing the lower fitted member 66 to the upper end portion of the motor shaft 22 of the lower motor 21. However, the present disclosure is not limited thereto. For example, the fitted portion that is fitted with the fitting portion of the dog clutch may be formed integrally with the upper end portion of the motor shaft 22. Similarly, for the motor shaft 42 of the upper motor 41, the fitted portion that is fitted with the fitting portion of the dog clutch may be formed integrally with the lower end portion of the motor shaft 42.

In addition, the type of motor that is used in the power unit in the present disclosure is not limited, and for example, a direct current motor may also be used. In addition, the present disclosure can be applied to a ship propulsion machine other than the outboard motor.

In addition, the present disclosure can be changed as appropriate without departing from the scope or spirit of the disclosure which can be read from the claims and the entire specification, and the ship propulsion machine to which such a change is applied is also included in the technical spirit of the present disclosure.

SHIP PROPULSION MACHINE

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CPC

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Abstract

Description

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Priority Claims (1)