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. 2023-194308 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

An outboard motor is known in which a motor is provided in a portion located below a water surface in a state in which the outboard motor is attached to a hull, i.e., a lower portion of the outboard motor, and a propeller is attached to a rear end portion of a shaft extending rearward from the motor. This type of outboard motor has the motor arranged in the lower portion of the outboard motor. Therefore, when a large motor is adopted, the lower portion of the outboard motor becomes larger, which may increase water resistance during sailing. This makes it difficult to adopt a large motor to increase the output of the outboard machine for this type of outboard motor.

JP2005-153727A describes an outboard motor in which a motor is provided in a portion located above a water surface in a state in which the outboard motor is attached to a hull, i.e., an upper portion of the outboard motor. This type of outboard motor includes a drive shaft extending vertically between the motor and a propeller shaft provided at a lower portion of the outboard motor, and is configured to transmit an output of the motor to the propeller shaft by the drive shaft. In this type of outboard motor, the motor is provided in the upper portion of the outboard motor. Therefore, even when a large motor is adopted, the size of the lower portion of the outboard motor can be suppressed from increasing. Therefore, it is easy to adopt a large motor, and the output of the outboard motor can be increased by adopting a large motor.

SUMMARY OF INVENTION

Incidentally, when the ship propulsion machine is provided with two motors and a propulsive force for a ship is generated by rotating a propeller with a force obtained by combining powers output from the two motors, an output of the ship propulsion machine can be increased. In addition, when the ship propulsion machine is provided with a power switching device that switches between a mode in which the propeller is rotated by a force obtained by combining powers of the two motors and a mode in which the propeller is rotated by power of one motor, it becomes easy to, for example, significantly increase or decrease the output of the ship propulsion machine or adjust the power consumption, thereby enhancing performance of the ship propulsion machine.

However, when the ship propulsion machine is provided with two motors and a power switching device, 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. For example, when the two motors and the power switching device are provided in the lower portion of the outboard motor, the lower portion of the outboard motor becomes significantly larger, which may increase the water resistance during sailing. In addition, even when the two motors and the power switching device are provided in the upper portion of the outboard motor, the upper portion of the outboard motor becomes significantly larger, which may increase air resistance during sailing, reduce the attachment stability of the outboard motor to the hull, or deteriorate the appearance of the outboard motor.

The present disclosure has been made in view of the problems as described above, for example, and an object of the present disclosure is to provide a ship propulsion machine that enables switching between a mode in which a propeller is rotated by a force obtained by combining powers of two motors and a mode in which the propeller is rotated by power of one motor, while preventing the ship propulsion machine from becoming significantly larger.

The present disclosure provides a ship propulsion machine including: a power unit configured to generate power; a propeller; and a drive shaft configured to transmit the power generated by the power unit to the propeller. The power unit includes: a first motor including a first motor shaft; a second motor including a second motor shaft; and a power switching device configured to disconnectably connect the first motor shaft and the second motor shaft to each other and to switch a mode between a mode in which the first motor shaft and the second motor shaft are connected to each other and a mode in which the first motor shaft and the second motor shaft are disconnected from each other. The first motor and the second motor are arranged in an upper portion of the ship propulsion machine. Each of the first motor shaft, the second motor shaft, and the drive shaft extends vertically. The second motor is arranged above the first motor. An upper portion of the drive shaft is connected to the first motor shaft. The power switching device is arranged between the first motor and the second motor.

According to the present disclosure, it is possible to provide a ship propulsion machine with a function that enables switching the mode between a mode in which a propeller is rotated by a force obtained by combining powers of two motors and a mode in which the propeller is rotated by power of one motor, while preventing the ship propulsion machine from becoming significantly larger.

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 and the like in FIG. 2, as viewed from the left;

FIG. 4 is an external view showing the power unit and the like 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 connecting shaft in the power unit of the outboard motor according to the embodiment of the present disclosure, FIG. 8B is a perspective view showing an upper end portion of a motor shaft of the lower motor 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 unit of the outboard motor according to the embodiment of the present disclosure;

FIGS. 9A and 9B 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; and

FIG. 10 is a cross-sectional view showing a variation of the power unit of the outboard motor of 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, and a drive shaft that transmits power generated by the power unit to the propeller. For example, the drive shaft is connected to a propeller shaft, to which the propeller is fixed, via a gear mechanism.

In the ship propulsion machine according to the present embodiment, the power unit includes a first motor having a first motor shaft, a second motor having a second motor shaft, and a power switching device. The power switching device disconnectably connects the first motor shaft and the second motor shaft to each other. In addition, the power switching device switches a mode between a mode in which the first motor shaft and the second motor shaft are connected to each other and a mode in which the first motor shaft and the second motor shaft are disconnected from each other.

In the ship propulsion machine according to the present embodiment, the first motor and the second motor are arranged in an upper portion of the ship propulsion machine. Additionally, the first motor shaft, the second motor shaft, and the drive shaft each extend vertically. Additionally, the second motor is arranged above the first motor. Additionally, an upper portion of the drive shaft is connected to the first motor shaft. Additionally, the power switching device is arranged between the first motor and the second motor.

According to the ship propulsion machine of the present embodiment, it is possible to provide a ship propulsion machine with a function that enables switching a mode between a mode in which a propeller is rotated by a force obtained by combining powers of two motors and a mode in which the propeller is rotated by power of one motor. Specifically, the ship propulsion machine of the present embodiment includes the power switching device that switches between the mode in which the first motor shaft and the second motor shaft are connected to each other and the mode in which the first motor shaft and the second motor shaft are disconnected from each other, and the upper portion of the drive shaft is connected to the first motor shaft. When the mode is switched to the mode in which the first motor shaft and the second motor shaft are connected to each other by the power switching device, the first motor shaft is directly connected to the drive shaft, and the second motor shaft is connected to the drive shaft via the first motor shaft. With this, the propeller can be rotated by a force obtained by combining the power of the first motor and the power of the second motor. On the other hand, when the mode is switched to the mode in which the first motor shaft and the second motor shaft are disconnected from each other by the power switching device, the first motor shaft is connected to the drive shaft and the second motor shaft is no longer connected to the drive shaft. With this, the propeller can be rotated only by the power of the first motor.

In addition, according to the ship propulsion machine of the present embodiment, the ship propulsion machine can be prevented from becoming significantly larger due to the two motors and the power switching device being provided in the ship propulsion machine. Specifically, the first motor and the second motor are arranged vertically side by side such that each motor shaft thereof extends vertically, and the power switching device is arranged between the first motor and the second motor, allowing the power switching device to be made compact. That is, the first motor and the second motor are arranged in the upper portion of the ship propulsion machine such that each of the first motor shaft and the second motor shaft extends vertically, and the second motor is arranged above the first motor, allowing an upper end portion of the first motor shaft and a lower end portion of the second motor shaft to be brought close to each other within a space between the first motor and the second motor. The power switching device is arranged between the first motor and the second motor and is configured to disconnectably connect the upper end portion of the first motor shaft and the lower end portion of the second motor shaft, which are brought close to each other within the space between the first motor and the second motor, resulting in a compact power switching device. Therefore, according to the ship propulsion machine of the present embodiment, the degree of size increase of the ship propulsion machine can be reduced compared to a ship propulsion machine with only one motor.

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. 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 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 and motor holder 9 as viewed from the left. FIG. 4 shows the power unit 2 and the motor holder 9 as viewed 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 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. 3, 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.

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. Additionally, the lower motor 21 and the upper motor 41 are arranged so that the motor shafts 22 and 42 are coaxial.

The lower motor 21 and the upper motor 41 are connected to each other using a plurality of support members 85, as shown in FIGS. 2 to 5. Each support member 85 is formed of, for example, a metal material and extends vertically. 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 lower motor 21 and the upper motor 41 are connected.

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, each of the motor shafts 22 and 42 is arranged coaxially with the drive shaft 4. Additionally, an upper end portion of the drive shaft 4 is connected to the lower end portion of the motor shaft 22 of the lower motor 21. The motor shaft 22 and the drive shaft 4 are coupled such that one cannot rotate with respect to the other, for example by means of spline coupling.

The lower motor 21 serves as an example of a “first motor”, and the motor shaft 22 of the lower motor 21 serves as an example of a “first motor shaft”. Additionally, the upper motor 41 serves as an example of a “second motor,” and the motor shaft 42 of the upper motor 41 serves as an example of a “second motor shaft.”

(Power Switching Device)

The power unit 2 includes a power switching device 61 that disconnectably connects the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 to each other. The power switching device 61 has a function of switching a mode between a mode in which the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are connected to each other and a mode in which the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are disconnected from each other.

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 connecting shaft 62 and a switching mechanism 71.

The connecting shaft 62 is a shaft with a circular cross-section, formed of, for example, a metal material. As shown in FIG. 5, the connecting shaft 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. In addition, the connecting shaft 62 is arranged so that its axis line extends vertically, and is also arranged coaxially with each of the motor shafts 22 and 42. The connecting shaft 62 serves as an example of a “connecting member.”

FIG. 8A shows the connecting shaft 62 as viewed obliquely from below. As shown in FIG. 8A, a coupling portion 63 is formed at an upper end portion of the connecting shaft 62. A spline is formed on an outer peripheral surface of the coupling portion 63. Additionally, a fitting portion 65 is formed above a lower end portion 64 at the lower portion of the connecting shaft 62. A lower surface of the fitting portion 65 is formed with an unevenness. In addition, at an axially middle portion of the connecting shaft 62, a lower collar portion 66 and an upper collar portion 67 are arranged vertically side by side with a gap. The lower collar portion 66 and the upper collar portion 67 each protrude radially outward from an outer peripheral surface of the connecting shaft 62. Additionally, a space between the lower collar portion 66 and the upper collar portion 67 is formed as a fork insertion portion 68.

As shown in FIG. 5, a lower end surface of the motor shaft 42 of the upper motor 41 is formed with a connecting shaft coupling hole 53. An inner peripheral surface of the connecting shaft coupling hole 53 has a spline formed. The coupling portion 63 of the connecting shaft 62 is inserted in the connecting shaft coupling hole 53. With this, the upper end portion of the connecting shaft 62 is spline-coupled with the motor shaft 42 of the upper motor 41. Above all, the connecting shaft 62 cannot rotate with respect to the motor shaft 42 of the upper motor 41, but can move vertically with respect to the motor shaft 42. A shape of the spline formed on the coupling portion 63 of the connecting shaft 62 and a shape of the spline formed in the connecting shaft coupling hole 53 are set such that the connecting shaft 62 can move vertically with respect to the motor shaft 42 while being non-rotatably coupled with the motor shaft 42.

Additionally, an upper surface of the motor shaft 22 of the lower motor 21 is formed with a connecting shaft insertion hole 33. The lower end portion 64 of the connecting shaft 62 is inserted in the connecting shaft insertion hole 33. A diameter of the connecting shaft insertion hole 33 is set to a value slightly larger than a diameter of the lower end portion 64 of the connecting shaft 62. Neither the outer peripheral surface of the lower end portion 64 of the connecting shaft 62 nor the inner peripheral surface of the connecting shaft insertion hole 33 is formed with splines. The outer peripheral surface of the lower end portion 64 of the connecting shaft 62 is not in contact with the inner peripheral surface of the connecting shaft insertion hole 33.

In addition, a distance between a bottom surface of the connecting shaft coupling hole 53 and a bottom surface of the connecting shaft insertion hole 33 is set to a value greater than an axial length of the connecting shaft 62. The connecting shaft 62 can move vertically while the connecting portion 63 remains inserted in the connecting shaft connecting hole 53 and the lower end portion 64 remains inserted in the connecting shaft insertion hole 33.

FIG. 8B shows the upper end portion of the motor shaft 22 of the lower motor 21, as viewed obliquely from above. As shown in FIG. 8B, a fitted portion 34 is formed on an outer peripheral portion of an upper end surface of the motor shaft 22 of the lower motor 21, i.e., on an outer periphery side of an opening portion of the connecting shaft insertion hole 33. An upper surface of the fitted portion 34 is formed with an unevenness. A shape of the unevenness formed on the fitting portion 65 of the connecting shaft 62 and a shape of the unevenness formed on the fitted portion 34 of the motor shaft 22 of the lower motor 21 are each set such that the fitting portion 65 and the fitted portion 34 can fit with each other.

FIGS. 9A and 9B show operations of the power switching device 61. As shown in FIG. 9A, when the connecting shaft 62 moves downward, the fitting portion 65 of the connecting shaft 62 fits with the fitted portion 34 of the motor shaft 22 of the lower motor 21. At this time, the coupling portion 63 of the connecting shaft 62 is inserted into the connecting shaft coupling hole 53 of the motor shaft 42 of the upper motor 41, so that the spline-coupled state with the motor shaft 42 is maintained. As a result, the motor shaft 42 of the upper motor 41 is connected to the motor shaft 22 of the lower motor 21. In this state, the motor shaft 22 of the lower motor 21 is directly connected to the drive shaft 4, and the motor shaft 42 of the upper motor 41 is connected to the drive shaft 4 via the motor shaft 22 of the lower motor 21, so both the power of the lower motor 21 and the power of the upper motor 41 are transmitted to the drive shaft 4. As a result, 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.

On the other hand, as shown in FIG. 9B, when the connecting shaft 62 moves upward, the fitting between the fitting portion 65 of the connecting shaft 62 and the fitted portion 34 of the motor shaft 22 of the lower motor 21 is released. As a result, the motor shaft 42 of the upper motor 41 is separated from the motor shaft 22 of the lower motor 21. In this state, 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 no longer connected to the drive shaft 4, so the power of the lower motor 21 is transmitted to the drive shaft 4, but the power of the upper motor 41 is not transmitted to the drive shaft 4. As a result, the propeller 3 is rotated only by the power of the lower motor 21 of the two motors of the power unit 2.

(Switching Mechanism)

The power switching device 61 includes a switching mechanism 71 that switches a mode between a mode in which the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are connected to each other and a mode in which the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are disconnected from each other by moving the connecting shaft 62 based on an operation input from the outside. FIG. 8C shows disassembled components of the switching mechanism 71. As shown in FIG. 8C, the switching mechanism 71 includes a clutch rod 72, a first joint member 73, a clutch link 74, a second joint member 75, a clutch camshaft 76, and a fork unit 78.

One end portion of the first joint member 73 is connected to the clutch rod 72 so as to be non-rotatable with respect to the clutch rod 72. One end portion of the clutch link 74 is connected to the other end portion of the first joint member 73 so as to be rotatable with respect to the first joint member 73. One end portion of the second joint member 75 is connected to the other end portion of the clutch link 74 so as to be rotatable with respect to the clutch link 74. The other end portion of the second joint member 75 is connected to an upper portion of the clutch camshaft 76 so as to be non-rotatable with respect to the clutch camshaft 76. The clutch camshaft 76 has a cylindrical cam structure, and a cam groove 77 is formed on an outer peripheral surface of a vertically middle portion of the clutch camshaft 76. The vertically middle portion of the clutch camshaft 76 is inserted into the inner periphery side of a tubular portion 79 of the fork unit 78. A driven pin 81 is inserted into a pin hole 79A formed in the tubular portion 79 of the fork unit 78. The driven pin 81 passes through the pin hole 79A, and a tip end portion of the driven pin 81 is inserted into the cam groove 77 within the tubular portion 79. The driven pin 81 inserted in the pin hole 79A is locked to the tubular portion 79 of the fork unit 78 by a stopper member 83, with a coil spring 82 interposed. The tubular portion 79 of the fork unit 78 is formed with a fork 80. The fork 80 protrudes radially outward from the tubular portion 79. A tip end portion of the fork 80 is inserted into the fork insertion portion 68 of the connecting shaft 62, as shown in FIGS. 5 to 7. The tip end portion of the fork 80 is inserted into the fork insertion portion 68 with a gap interposed so that the connecting shaft 62 can rotate along with the rotation of the motor shaft 42 while the tip end portion of the fork 80 remains inserted in the fork insertion portion 68.

In FIG. 8C, when the clutch rod 72 rotates in the direction of arrow A, the rotation is transmitted to the clutch camshaft 76 via the first joint member 73, the clutch link 74, and the second joint member 75, and the clutch camshaft 76 is rotated in the direction of arrow C. The rotation of the clutch camshaft 76 moves the fork unit 78 upward, for example. The upward movement of the fork unit 78 moves the connecting shaft 62 upward. On the other hand, when the clutch rod 72 rotates in the direction of arrow B, the rotation is transmitted to the clutch camshaft 76 via the first joint member 73, the clutch link 74, and the second joint member 75, and the clutch camshaft 76 is rotated in the direction of arrow D. The rotation of the clutch camshaft 76 moves the fork unit 78 downward, for example. The downward movement of the fork unit 78 moves the connecting shaft 62 downward. The relationship between the rotation direction of the clutch rod 72 and the movement direction of the fork unit 78 in the vertical direction, and the relationship between the rotation amount of the clutch rod 72 and the movement amount of the fork unit 78 in the vertical direction can be set by the shape of the cam groove 77 formed on the clutch camshaft 76.

In addition, as shown in FIG. 2, the clutch rod 72 is rotatably supported between a rod support portion 28 provided on a right front side of the top motor bracket 27 of the lower motor 21 and a rod support portion 47 provided on a right front side of the bottom motor bracket 46 of the upper motor 41. In addition, the clutch camshaft 76 is rotatably supported between a camshaft support portion 29 provided on a left front side of the top motor bracket 27 of the lower motor 21 and a camshaft support portion 48 provided on a left front side of the bottom motor bracket 46 of the upper motor 41.

Although not shown, the upper portion of the outboard motor 1 is provided with an actuator (e.g., a DC motor) for rotating the clutch rod 72, and an output shaft of the actuator is connected to the clutch rod 72. In addition, an operation input from the outside for moving the connecting shaft 62 is input to the actuator. Based on the operation input from the outside, the actuator operates, the clutch rod 72 rotates, and the connecting shaft 62 moves.

As described above, the power unit 2 of the outboard motor 1 of the embodiment of the present disclosure includes the lower motor 21, the upper motor 41, and the power switching device 61, and the drive shaft 4 is connected to the motor shaft 22 of the lower motor 21. The power switching device 61 disconnectably connects the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41, and switches a mode between the mode in which the motor shaft 22 and the motor shaft 42 are connected to each other and the mode in which the motor shaft 22 and the motor shaft 42 are disconnected from each other. With this configuration, it is possible to provide the outboard motor 1 with a function of switching a mode between the mode in which the propeller 3 is rotated by a force obtained by combining the powers of both the lower motor 21 and the upper motor 41 and the mode in which the propeller 3 is rotated only by the power of the lower motor 21.

According to this function, the output of power unit 2 can be significantly changed in response to the sailing conditions of the ship, and the like. For example, by switching a mode the mode of rotating the propeller 3 from the mode in which the propeller 3 is rotated only by the power of the lower motor 21 to the mode in which the propeller 3 is rotated by the force obtained by combining the powers of both the lower motor 21 and the upper motor 41, the output of the power unit 2, and consequently the propulsive force for the ship generated by the outboard motor 1 can be significantly increased. In addition, the power consumption of the power unit 2 can be adjusted by the function. For example, by switching a mode the mode of rotating the propeller 3 from the mode in which the propeller 3 is rotated by the force obtained by combining the powers of both the lower motor 21 and the upper motor 41 to the mode in which the propeller 3 is rotated only by the power of the lower motor 21, the power consumption of the power unit 2 can be reduced. In addition, according to the function, if the upper motor 41 fails during sailing, the ship can continue sailing by switching the mode of rotating the propeller 3 to the mode in which the propeller 3 is rotated only by the power of the lower motor 21.

In addition, according to the outboard motor 1 of the embodiment of the present disclosure, when applying the regenerative braking by using the rotational power of the propeller 3 after stopping the motor drive, the motor shaft 42 of the upper motor 41 is separated from the motor shaft 22 of the lower motor 21, thereby reducing the internal resistance of the outboard motor 1, which reduces the rotational force of the propeller 3, compared to a case where the motor shaft 42 of the upper motor 41 is connected to the motor shaft 22 of the lower motor 21. Therefore, after stopping the motor drive, it is possible to sustain the rotation of the propeller 3 up to a low-speed range, thereby extending the time for which the regenerative braking can be used.

In addition, in the outboard motor 1 of the present embodiment, the lower motor 21 and the upper motor 41 are arranged in the upper portion of the outboard motor 1, the motor shaft 22 of the lower motor 21, the motor shaft 42 of the upper motor 41, and the drive shaft 4 extend vertically, respectively, the upper motor 41 is arranged above the lower motor 21, the upper portion of the drive shaft 4 is connected to the motor shaft 22 of the lower motor 21, and the power switching device 61 is arranged between the lower motor 21 and the upper motor 41. With this configuration, the outboard motor can be prevented from becoming significantly larger due to the two motors 21 and 41 and the power switching device 61 being provided in the outboard motor. Specifically, the lower motor 21 and the upper motor 41 are arranged vertically side by side such that each of the motor shafts 22 and 42 extends vertically, allowing 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 be brought close to each other within the space between the lower motor 21 and the upper motor 41. The power switching device 61 is arranged between the lower motor 21 and the upper motor 41 and is configured to disconnectably connect the upper end portion of the motor shaft 22 and the lower end portion of the motor shaft 42, which are brought close to each other within the space between the lower motor 21 and the upper motor 41, resulting in a compact power switching device 61. That is, since the upper end portion of the motor shaft 22 and the lower end portion of the motor shaft 42 of the upper motor 41 are close to each other, a means for connecting the upper end portion of the motor shaft 22 and the lower end portion of the motor shaft 42 to each other can be formed by the connecting shaft 62, which is a short shaft arranged between the upper end portion of the motor shaft 22 and the lower end portion of the motor shaft 42. In addition, the switching mechanism 71, which moves the connecting shaft 62, is arranged between the lower motor 21 and the upper motor 41, allowing the connecting shaft 62 and the switching mechanism 71 to be concentratedly arranged between the lower motor 21 and the upper motor 41.

According to the outboard motor 1 of the present embodiment, since the upper portion of the outboard motor 1 can be prevented from becoming significantly larger, it is possible to suppress air resistance while sailing, prevent the reduction of attachment stability of the outboard motor 1 to the hull, and additionally, prevent the deterioration of the appearance of the outboard motor 1. In addition, in the outboard motor 1 of the present embodiment, the lower motor 21, the upper motor 41, and the power switching device 61 are all arranged in the upper portion of the outboard motor 1, so the lower portion of the outboard motor 1 can be suppressed from becoming larger, and the water resistance during sailing of the ship can be prevented from increasing.

In addition, in the outboard motor 1 of the present embodiment, the power switching device 61 includes the connecting shaft 62 provided to be movable vertically between the lower motor 21 and the upper motor 41, and the connecting shaft 62, when moved downward, connects 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 each other, and when moved upward, disconnects 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 from each other. With this configuration, the connection and disconnection of the motor shaft 22 and the motor shaft 42 can be realized by a simple configuration, leading to the compact power switching device 61.

In addition, in the outboard motor 1 of the present embodiment, the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are arranged coaxially with each other, the connecting shaft 62 is provided 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 so as to be coaxial with each of the motor shafts 22 and 42 and movable vertically, the upper end portion of the connecting shaft 62 is provided with the coupling portion 63 for connecting the connecting shaft 62 to the lower end portion of the motor shaft 42 so that the connecting shaft 62 cannot rotate with respect to the motor shaft 42 of the upper motor 41 but can move vertically with respect to the motor shaft 42, and the lower end portion of the connecting shaft 62 is provided with the fitting portion 65 that fits with the fitted portion 34 provided at the upper end portion of the motor shaft 22 of the lower motor 21. The connecting shaft 62, when moved downward, connects 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 each other by allowing the fitting portion 65 to fit with the fitted portion 34 while the coupling portion 63 remains coupled with the lower end portion of the motor shaft 42 of the upper motor 41, and when moved upward, disconnects 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 from each other by releasing the fitting between the fitting portion 65 and the fitted portion 34. With this configuration, a mechanism for disconnectably connecting the motor shaft 22 and the motor shaft 42 to each other can be configured by one short connecting shaft 62 that can move vertically. Accordingly, the mechanism for disconnectably connecting the motor shaft 22 and the motor shaft 42 to each other can be simplified, the number of components related to the mechanism can be reduced, and the weight of the mechanism can be reduced. In addition, while allowing the motor shaft 22 and the motor shaft 42 to be disconnectable from each other, the two shafts can still be firmly connected to each other. Accordingly, the transmission of the power of the upper motor 41 to the drive shaft 4 can be stabilized in the state in which the motor shaft 22 and the motor shaft 42 are connected to each other.

In addition, according to the outboard motor 1 of the present embodiment, the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 are connected to each other by the connecting shaft 62 without using gears (teeth). Therefore, the rotational speed of the lower motor 21 and the rotational speed of the upper motor 41 can be easily synchronized without considering gear configurations (e.g., gear ratio, etc.), allowing for a simple configuration that enables both the power of the lower motor 21 and the power of the upper motor 41 to be input to the drive shaft 4.

In the power switching device of the power unit 2 of the outboard motor 1, the structure that allows the motor shaft 22 of the lower motor 21 and the motor shaft 42 of the upper motor 41 to be disconnectably connected by the connecting shaft can be reversed vertically. That is, as in a power switching device 101 shown in FIG. 10, an upper end surface of the motor shaft 22 of the lower motor 21 is formed with a connecting shaft coupling hole 91, a lower end portion of a connecting shaft 102 is provided with a coupling portion 103, the coupling portion 103 is inserted into the connecting shaft coupling hole 91, and the connecting shaft 102 and the motor shaft 22 of the lower motor 21 are coupled such that the connecting shaft 102 cannot rotate with respect to the motor shaft 22 of the lower motor 21 but can move vertically with respect to the motor shaft 22. In addition, a lower end surface of the motor shaft 42 of the upper motor 41 is provided with a connecting shaft insertion hole 92, and an upper end portion 104 of the connecting shaft 102 is inserted into the connecting shaft insertion hole 92 so that the upper end portion 104 of the connecting shaft 102 remains out of contact with an inner peripheral surface of the connecting shaft insertion hole 92. In addition, an outer peripheral portion of the lower end surface of the motor shaft 42 of the upper motor 41 is provided with a fitted portion 93, and an upper portion of the connecting shaft 102 is provided with a fitting portion 105 that fits with the fitted portion 93. In addition, a vertically middle portion of the connecting shaft 102 is provided with a lower collar portion 106 and an upper collar portion 107, and the fork 80 of the fork unit 78 in the switching mechanism 71 is inserted into a fork insertion portion 108 between the lower collar portion 106 and the upper collar portion 107. In the power switching device 101, when the connecting shaft 102 moves upward, the fitting portion 105 fits with the fitted portion 93 while the coupling portion 103 remains coupled with the upper end portion of the motor shaft 22 of the lower motor 21. With this, 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 connected to each other. On the other hand, when the connecting shaft 102 moves downward, the fitting between the fitting portion 105 and the fitted portion 93 is released. With this, 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 disconnected from each other.

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, 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

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

International Classifications

Abstract

Description

Claims

Priority Claims (1)