Outboard machine

Abstract

To reduce the size of a shift device, and improve the degree of freedom of the part layout of the shift device.SOLUTION: An outboard machine includes a power transmission mechanism (30), and a shift device (50). The power transmission mechanism is provided with an upper side gear (31) fixed to an upper shaft (22), a lower side gear (32) relatively rotatable to a lower shaft (23), and intermediate gears (33 and 34) which are engaged with the upper side gear and the lower side gear. The shift device is provided with a cam mechanism (54) for converting the rotation of the shift shaft (52) into a vertical motion of an operation part (57), a shift slider (61) which is slid in a vertical direction by the operation part, a dog clutch (66) which is connectable to the upper side gear or the lower side gear, and a connector pin (63) for connecting the shift slider and the dog clutch. The dog clutch is integrally and rotatably connected to the lower shaft, and the shift slider is positioned below the lower side gear.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an outboard motor. [Background technology]

[0002] Outboard motors are provided with a shift device in which the shift position is changed by an actuator (see, for example, Patent Document 1). In the outboard motor described in Patent Document 1, an upper shaft extends downward from the engine, and an upper bevel gear is fixed to the lower end of the upper shaft. The upper bevel gear is connected to a lower bevel gear via a middle bevel gear, and the lower shaft is inserted into the lower bevel gear so as to be able to rotate relative to the upper shaft. The upper end of the lower shaft protrudes from the lower bevel gear, and a dog clutch fixed to the upper end of the lower shaft is positioned in the opposing space between the upper bevel gear and the lower bevel gear.

[0003] In the shift device, the dog clutch is moved up and down between the upper bevel gear and the lower bevel gear by an actuator. When the dog clutch is moved up and connected to the upper bevel gear, the shift position changes to forward and the engine power is transmitted directly from the upper shaft to the lower shaft. When the dog clutch is moved down and connected to the lower bevel gear, the shift position changes to reverse and the lower bevel gear and lower shaft are connected via the dog clutch. The engine power is transmitted in reverse from the upper shaft through the upper bevel gear, middle bevel gear, and lower bevel gear to the lower shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-202849 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, since the dog clutch is located between the upper bevel gear and the lower bevel gear, the components of the shift device are installed at approximately the same height as the upper bevel gear and the lower bevel gear. Therefore, each component of the shift device is positioned forward of the upper bevel gear and the lower bevel gear, making the shift device larger. In addition, the layout of the components of the shift device is limited to approximately the same height as the upper bevel gear and the lower bevel gear, reducing the degree of freedom in the layout of the components.

[0006] The present invention has been made in consideration of the above-mentioned points, and has an object to provide an outboard motor that enables a shift device to be made smaller and that increases the degree of freedom in the layout of parts of the shift device. [Means for solving the problem]

[0007] An outboard motor according to one aspect of the present invention is an outboard motor including an upper shaft and a lower shaft extending from an engine side to a propeller side, a power transmission mechanism interposed between the upper shaft and the lower shaft, and a shift device that operates the power transmission mechanism to rotate the propeller in reverse, the power transmission mechanism having an upper gear fixed to a lower end of the upper shaft, a lower gear facing the upper gear from below, and an intermediate gear that meshes with the upper gear and the lower gear, the lower gear being supported by the lower shaft for relative rotation, and the shift device being configured to shift the propeller in reverse by a shift lever that is movable from an actuator side to an actuator side. The above problem is solved by having a shift shaft extending downward, a cam mechanism that converts rotation of the shift shaft into up and down movement of an operating unit, a shift slider connected to the operating unit and slidable in the up and down direction, a dog clutch installed between the upper gear and the lower gear, and a connector pin that connects the shift slider and the dog clutch, wherein the dog clutch can be connected to the upper gear or the lower gear, the dog clutch is connected to the lower shaft so as to rotate integrally, and the shift slider is positioned above the upper gear or below the lower gear. Effect of the Invention

[0008] According to an outboard motor of one aspect of the present invention, when the actuator rotates the shift shaft, the shift slider is slid up and down by the cam mechanism. A dog clutch is connected to the shift slider via a connector pin, so that the dog clutch is moved up and down between the upper gear and the lower gear. When the dog clutch is connected to the upper gear, the upper shaft is connected to the lower shaft so as to be rotatable together with the lower shaft, and engine power is directly transmitted from the upper shaft to the lower shaft. When the dog clutch is connected to the lower gear, the lower gear is connected to the lower shaft so as to be rotatable together with the lower shaft via the dog clutch. Engine power is transmitted in reverse to the lower shaft via the upper gear, intermediate gear, and lower gear. The rotation direction of the lower shaft is reversed, so that the rotation direction of the propeller is switched. In addition, since the shift slider is offset in height from the upper gear and the lower gear, the shift shaft and the dog clutch can be brought closer to each other in the horizontal direction, and the shift device can be made smaller and the degree of freedom in the layout of the components of the shift device can be improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a side view of the outboard motor of the present embodiment. [Diagram 2] FIG. 2 is a front view of the outboard motor of the present embodiment. [Diagram 3] FIG. 2 is a perspective view of a first gear mechanism and a shift device according to the embodiment. [Figure 4] FIG. 2 is a side view of the first gear mechanism and the shift device of the embodiment. [Diagram 5] 5A to 5C are explanatory diagrams of a shift position switching operation in the present embodiment. [Figure 6] FIG. 2 is an explanatory diagram of a component layout of the shift device and the first gear mechanism of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] In an outboard motor according to one aspect of the present invention, an upper shaft and a lower shaft extend from the engine side to the propeller side, and a power transmission mechanism is interposed between the upper shaft and the lower shaft. The propeller is rotated in the reverse direction by operating the power transmission mechanism by a shift device. In the power transmission mechanism, a lower gear faces an upper gear from below, and an intermediate gear meshes with the upper gear and the lower gear. The upper gear is fixed to a lower end of the upper shaft, and the lower gear is supported by the lower shaft so as to be relatively rotatable. In the shift device, a shift shaft extends downward from the actuator side, and a cam mechanism converts the rotation of the shift shaft into vertical movement of an operating unit. A shift slider that can slide in the vertical direction is connected to the operating unit, and a dog clutch is connected to the shift slider via a connector pin. The dog clutch is supported by the lower shaft so as to be rotatable together with the upper gear. The dog clutch is installed between the upper gear and the lower gear, and the dog clutch is connected to the upper gear or the lower gear by the vertical movement of the dog clutch. When the actuator rotates the shift shaft, the cam mechanism moves the shift slider in the vertical direction. The dog clutch is connected to the shift slider via a connector pin, so that the dog clutch is moved in the vertical direction between the upper gear and the lower gear. When the dog clutch is connected to the upper gear, the upper shaft is connected to the lower shaft so as to be rotatable together with the upper shaft, and the engine power is directly transmitted from the upper shaft to the lower shaft. When the dog clutch is connected to the lower gear, the lower gear is connected to the lower shaft so as to be rotatable together with the lower shaft via the dog clutch. The engine power is transmitted in the reverse direction to the lower shaft via the upper gear, intermediate gear, and lower gear. The propeller rotation direction is switched by reversing the rotation direction of the lower shaft. In addition, the shift slider of the shift device is located above the upper gear or below the lower gear. Since the shift slider is offset in height from the upper gear and the lower gear, the shift shaft and the dog clutch can be brought closer to each other in the horizontal direction, and the shift device can be made smaller and the degree of freedom in the layout of the parts of the shift device can be improved. EXAMPLES

[0011] Hereinafter, an outboard motor according to this embodiment will be described with reference to the accompanying drawings. Fig. 1 is a side view of the outboard motor according to this embodiment. Fig. 2 is a front view of the outboard motor according to this embodiment. In the following drawings, the arrow FR indicates the front of the vehicle, the arrow RE indicates the rear of the vehicle, the arrow L indicates the left side of the vehicle, and the arrow R indicates the right side of the vehicle.

[0012] 1 and 2, the outboard motor 1 transmits driving force from an engine 20 to counter-rotating propellers 27, 28 to generate propulsion for the boat. The engine 20 and other components are housed inside a top cowl 11 and a bottom cowl 12 at the upper part of the outboard motor 1. An upper housing 13 is provided below the bottom cowl 12, and a lower housing 14 is provided below the upper housing 13. A drive shaft 21 is housed vertically in the upper housing 13 and the lower housing 14, and a propeller shaft 24 connected to the drive shaft 21 is housed horizontally in the lower housing 14.

[0013] The drive shaft 21 has an upper drive shaft (upper shaft) 22 and a lower drive shaft (lower shaft) 23 that extend from the engine 20 side to the propellers 27, 28 side (lower side). The upper drive shaft 22 and the lower drive shaft 23 are spaced apart in the vertical direction, and a first gear mechanism (power transmission mechanism) 30 is interposed between the upper drive shaft 22 and the lower drive shaft 23. Although described in detail below, the first gear mechanism 30 is connected to a shift device 50, and the shift device 50 operates the first gear mechanism 30 to transmit or cut off the power of the engine 20 and to reversely rotate the propellers 27, 28.

[0014] The propeller shaft 24 is perpendicular to the drive shaft 21, and a second gear mechanism 40 is interposed between the propeller shaft 24 and the drive shaft 21. The propeller shaft 24 has a double-tube structure in which an inner propeller shaft 26 is inserted inside a hollow outer propeller shaft 25. The inner propeller shaft 26 protrudes in the front-to-rear direction from the front and rear ends of the outer propeller shaft 25. A front propeller 27 is fixed to the rear end of the outer propeller shaft 25, and a rear propeller 28 is fixed to the rear end of the inner propeller shaft 26.

[0015] The second gear mechanism 40 has a lower drive gear 41, a rear driven gear 42, and a front driven gear 43. The lower drive gear 41 is fixed to a lower end of the lower drive shaft 23, the rear driven gear 42 is fixed to a front end of the outer propeller shaft 25, and the front driven gear 43 is fixed to a front end of the inner propeller shaft 26. The lower drive gear 41, the rear driven gear 42, and the front driven gear 43 are bevel gears, and the rear driven gear 42 and the front driven gear 43 mesh with the lower drive gear 41. Rotation of the lower drive shaft 23 causes the outer propeller shaft 25 and the inner propeller shaft 26 to rotate in opposite directions.

[0016] The front propeller 27 fixed to the outer propeller shaft 25 is provided with three propeller blades, and the rear propeller 28 fixed to the inner propeller shaft 26 is also provided with three propeller blades. The outer propeller shaft 25 and the inner propeller shaft 26 rotate in opposite directions, causing the front propeller 27 and the rear propeller 28 to rotate in opposite directions. The swirling flow generated by the rotation of the front propeller 27 is collected by the reverse rotation of the rear propeller 28, improving propulsion efficiency, and counter torque generated by the rotation of the front propeller 27 and the rear propeller 28 is offset.

[0017] Meanwhile, an anti-cavitation plate 15 is formed above the propellers 27, 28 of the lower housing 14 to suppress air being drawn into the propellers 27, 28. The part of the lower housing 14 above the anti-cavitation plate 15 is a wide section 16, and the part of the lower housing 14 below the anti-cavitation plate 15 is a narrow section 17. Below the narrow section 17 is a housing section 18 for the propeller shaft 24 that bulges out like a bullet. Because the lower housing 14 is located below the water surface, if the frontal projection area of ​​the lower housing 14 is small, running resistance is reduced and acceleration is improved.

[0018] The lower housing 14 houses a first gear mechanism 30. A shift device 50 is connected to the first gear mechanism 30, but when the shift device 50 is housed in the lower housing 14, the propeller shaft 24 may move downward, increasing the frontal projection area of ​​the lower housing 14. In addition, a water pump 70 for cooling the engine 20 is installed on the upper surface of the lower housing 14, and the distance from the water surface near the anti-cavitation plate 15 to the water pump 70 becomes long during planing. For this reason, a large water pump must be provided to pump water from the water surface.

[0019] Therefore, the outboard motor 1 of this embodiment employs a smaller pinion gear of the first gear mechanism 30, a gear transmission structure of the shift device 50, and a layout of the shift device 50 that utilizes the space below the first gear mechanism 30. The first gear mechanism 30 and the shift device 50 are made smaller, and the shift device 50 is compactly installed within the lower housing 14, preventing an increase in the frontal projection area of ​​the lower housing 14. In addition, an increase in the distance from the water surface to the water pump 70 is prevented even when the boat is planing, making it possible to use a small water pump 70 for the outboard motor 1.

[0020] The first gear mechanism and the shift device will be described with reference to Figures 3 to 5. Figure 3 is a perspective view of the first gear mechanism and the shift device of this embodiment. Figure 4 is a side view of the first gear mechanism and the shift device of this embodiment. Figure 5 is an explanatory diagram of the shift position switching operation of this embodiment.

[0021] 3 and 4, the first gear mechanism 30 has an upper drive gear (upper gear) 31, a lower driven gear (lower gear) 32, and a pair of pinion gears (other intermediate gears, intermediate gears) 33, 34. The upper drive gear 31 is fixed to the lower end of the upper drive shaft 22, and the lower driven gear 32 is inserted into the lower drive shaft 23 and faces the upper drive gear 31 from below. The upper drive gear 31, the lower driven gear 32, and the pair of pinion gears 33, 34 are bevel gears, and the pair of pinion gears 33, 34 mesh with the upper drive gear 31 and the lower driven gear 32.

[0022] When rotation is transmitted from the upper drive gear 31 to the lower driven gear 32, the lower driven gear 32 rotates in the opposite direction to the upper drive gear 31. The lower driven gear 32 is supported by the lower drive shaft 23 so as to be rotatable relative to the lower drive shaft 23, and is configured so that the lower driven gear 32 and the lower drive shaft 23 can be connected by a dog clutch 66 of the shift device 50. When the lower driven gear 32 and the lower drive shaft 23 are not connected, the power transmission from the lower driven gear 32 to the lower drive shaft 23 is cut off, and when the lower driven gear 32 and the lower drive shaft 23 are connected, the lower driven gear 32 and the lower drive shaft 23 rotate integrally.

[0023] The shift device 50 uses power from the actuator 51 to operate a dog clutch 66 via a shift shaft 52, a cam mechanism 54, a shift slider 61, and a connector pin 63. The shift shaft 52 extends downward from the actuator 51 side, and a sector gear 53 having teeth formed in a predetermined area on its outer periphery is fixed to the middle part of the shift shaft 52 in the height direction. The cam mechanism 54 is configured by slidably attaching a shift fork (operating part) 57 to the outer periphery of a cylindrical cam 55. A sector gear 59 having teeth formed in a predetermined area on its outer periphery is fixed to the upper end side of the cylindrical cam 55, and the sector gear 59 meshes with the sector gear 53 of the shift shaft 52.

[0024] A spiral cam groove is formed on the outer circumferential surface of the cylindrical cam 55, and a follower 58 (see FIG. 5) inside the cylinder of the shift fork 57 fits into the cam groove of the cylindrical cam 55. The rotation of the shift shaft 52 is transmitted to the cylindrical cam 55 via sector gears 53, 59, and the cylindrical cam 55 rotates to move the follower 58 of the shift fork 57 along the cam groove. In this way, the rotation of the shift shaft 52 is converted into the up and down movement of the shift fork 57 by the cam mechanism 54. The tip side of the shift fork 57 is forked, and the fork portion of the shift fork 57 is connected to a shift slider 61 that is movably installed on the outer circumferential surface of the lower drive shaft 23.

[0025] The shift slider 61 is formed in a cylindrical shape, and is slidably installed on the outer circumferential surface of the lower drive shaft 23. Two annular grooves, one above and one below, are formed on the outer circumferential surface of the shift slider 61. The fork portion of the shift fork 57 fits into the upper annular groove of the shift slider 61, and the shift slider 61 slides up and down along the lower drive shaft 23 as the shift fork 57 moves up and down. A retaining spring 62 is attached to the lower annular groove of the shift slider 61, and the retaining spring 62 prevents a through pin 64 of a connector pin 63, which will be described later, from falling out.

[0026] A connector pin 63 is housed inside the lower drive shaft 23 and protrudes from the upper end of the lower drive shaft 23. A through pin 64 is inserted horizontally into the lower end of the connector pin 63, and the through pin 64 protruding from an elongated hole extending vertically in the lower drive shaft 23 is inserted into the shift slider 61. A through pin 65 is inserted horizontally into the upper end of the connector pin 63, and the through pin 65 is inserted into a dog clutch 66 above the lower drive shaft 23. The shift slider 61 and dog clutch 66 are connected via the connector pin 63.

[0027] The dog clutch 66 is disposed in the opposing space between the upper drive gear 31 and the lower driven gear 32. The dog clutch 66 is formed in a cylindrical shape, and an annular groove is formed on the outer circumferential surface of the dog clutch 66. A retaining spring 67 is attached to the annular groove of the dog clutch 66, and the through pin 65 of the connector pin 63 is prevented from falling off by the retaining spring 67. The upper surface of the dog clutch 66 faces the lower surface of the upper drive gear 31, and the lower surface of the dog clutch 66 faces the upper surface of the lower driven gear 32. A plurality of claws are formed on the opposing surfaces of the dog clutch 66 and the upper drive gear 31, and on the opposing surfaces of the dog clutch 66 and the lower driven gear 32.

[0028] Since the dog clutch 66 is connected to the shift slider 61 via the connector pin 63, the dog clutch 66 is moved up and down so as to be able to come into contact with and separate from the upper drive gear 31 and the lower driven gear 32. The dog clutch 66 is connected to the upper drive gear 31 by hooking the claw portions of the dog clutch 66 and the upper drive gear 31 together, and the dog clutch 66 is connected to the lower driven gear 32 by hooking the claw portions of the dog clutch 66 and the lower driven gear 32 together. In addition, the dog clutch 66 is fixed to the lower drive shaft 23 via a through pin 65, and is connected to the lower drive shaft 23 so as to be able to rotate integrally therewith.

[0029] As shown in Fig. 5(A), when the shift position is in the neutral position, the dog clutch 66 is located at a neutral position between the upper drive gear 31 and the lower driven gear 32. The dog clutch 66 is not connected to either the upper drive gear 31 or the lower driven gear 32. The power of the engine 20 (see Fig. 1) is transmitted to the lower driven gear 32 via the upper drive gear 31 and the pair of pinion gears 33, 34, but the lower driven gear 32 rotates idly relative to the lower drive shaft 23. Therefore, the power of the engine 20 is not transmitted from the upper drive shaft 22 to the lower drive shaft 23.

[0030] 5(B), when actuator 51 rotates shift shaft 52 in one direction, cam mechanism 54 converts the rotation of shift shaft 52 into upward movement of shift fork 57. Shift fork 57 causes shift slider 61 to slide upward along lower drive shaft 23. As shift slider 61 slides, dog clutch 66 moves upward from the neutral position, and the claws of dog clutch 66 are hooked onto the claws of upper drive gear 31. Dog clutch 66 is connected to upper drive gear 31, and the shift position is switched from the neutral position to the forward position.

[0031] The upper drive shaft 22 is fixed to the upper drive gear 31, and the dog clutch 66 is connected to the lower drive shaft 23 via a connector pin 63, so that the upper drive shaft 22 is connected to the lower drive shaft 23. The power of the engine 20 is transmitted from the upper drive shaft 22 to the lower drive shaft 23, causing the propellers 27, 28 (see FIG. 1) to rotate and generating thrust in the forward direction. Note that even in the forward position, the power of the engine 20 is transmitted to the lower driven gear 32 via the upper drive gear 31 and a pair of pinion gears 33, 34, but the lower driven gear 32 is rotating idly relative to the lower drive shaft 23.

[0032] 5(C), when actuator 51 rotates shift shaft 52 in the other direction, cam mechanism 54 converts the rotation of shift shaft 52 into downward movement of shift fork 57. Shift fork 57 causes shift slider 61 to slide downward along lower drive shaft 23. As shift slider 61 slides, dog clutch 66 moves downward from the neutral position, and the claws of dog clutch 66 are hooked onto the claws of lower driven gear 32. Dog clutch 66 is connected to lower driven gear 32, and the shift position is switched from the neutral position to the reverse position.

[0033] The lower driven gear 32 is connected to the lower drive shaft 23 via a dog clutch 66. The power of the engine 20 is transmitted from the upper drive shaft 22 to the lower drive shaft 23 via the upper drive gear 31, the pair of pinion gears 33, 34, and the lower driven gear 32, causing the propellers 27, 28 (see FIG. 1) to rotate in the reverse direction, generating thrust in the backward direction. In this way, the dog clutch 66 moves vertically to operate the first gear mechanism 30, thereby changing the transmission path from the upper drive shaft 22 to the lower drive shaft 23, and switching the rotation direction of the propellers 27, 28.

[0034] The layout of parts in the shift device and the first gear mechanism will be described with reference to Fig. 6. Fig. 6 is an explanatory diagram of the layout of parts in the shift device and the first gear mechanism of this embodiment.

[0035] 6, the first gear mechanism 30 is positioned between the upper drive shaft 22 and the lower drive shaft 23, and the shift device 50 is positioned in front of the upper drive shaft 22 and the lower drive shaft 23. The first gear mechanism 30 is accommodated in the wide portion 16 of the lower housing 14, and the shift device 50 is accommodated across the wide portion 16 and the narrow portion 17 of the lower housing 14. More specifically, the shift shaft 52, the cam mechanism 54, the upper halves of the connector pin 63 (see FIG. 5), and the dog clutch 66 are accommodated in the wide portion 16, and the shift shaft 52, the cam mechanism 54, the lower halves of the connector pin 63, and the shift slider 61 are accommodated in the narrow portion 17.

[0036] By installing the shift slider 61 and the like of the shift device 50 in the narrow width portion 17, the height dimension of the wide width portion 16 of the lower housing 14 is reduced. By reducing the height dimension of the wide width portion 16, the frontal projected area of ​​the lower housing 14 is reduced, thereby reducing running resistance. Also, the shift slider 61 is located below the lower driven gear 32. Unlike a configuration in which the dog clutch 66 is directly operated by the shift fork 57, there is no need to place the shift fork 57 or the shift shaft 52 far away from the dog clutch 66. The shift shaft 52 and the dog clutch 66 are brought closer together in the front-to-rear direction, making the shift device 50 more compact.

[0037] In the first gear mechanism 30, a pair of pinion gears 33, 34 mesh with the upper drive gear 31 and the lower driven gear 32. The pair of pinion gears 33, 34 face each other in the front and rear with a dog clutch 66 in between. Since the torque of the upper drive shaft 22 is distributed and transmitted to the pair of pinion gears 33, 34, the strength of the pair of pinion gears 33, 34 can be reduced to achieve a reduction in the size of the gears. The reduction in the size of the pinion gears 33, 34 reduces the height of the wide portion 16 in which the first gear mechanism 30 is housed. The outboard motor 1 is made more compact, and the frontal projected area of ​​the lower housing 14 is reduced, reducing running resistance.

[0038] The pinion gear 34 is installed between the shift shaft 52 and the dog clutch 66. Even if the pinion gear 34 is installed on the shift shaft 52 side, the pinion gear 34 does not interfere with the shift device 50, and the pinion gear 34 and the shift device 50 are installed compactly in the wide portion 16 of the lower housing 14. A cam mechanism 54 is installed below the pinion gear 34. The cam mechanism 54 is installed in the space below the pinion gear 34, thereby making the shift device 50 more compact. In this case, the pinion gears 33, 34 and the cylindrical cam 55 are rotatably supported by a single bearing housing 69 (see FIG. 5).

[0039] As described above, power is transmitted from the shift shaft 52 to the cam mechanism 54 via gears. The amount of rotation of the shift shaft 52, the stroke of the dog clutch 66, and the shift load are adjusted by changing the gear ratio. With a small amount of rotation of the shift shaft 52, the stroke of the dog clutch 66 is increased, and the shift device 50 is made smaller and can be installed compactly in the lower housing 14. In this embodiment, the sector gear 59 of the cylindrical cam 55 is smaller than the sector gear 53 of the shift shaft 52, the number of teeth of the sector gear 53 of the shift shaft 52 is set to "10," and the number of teeth of the sector gear 59 of the cylindrical cam 55 is set to "9."

[0040] A water pump 70 is installed on the upper drive shaft 22 on the top surface of the lower housing 14. A water intake port 71 is formed in the accommodation portion 18 on the lower side of the lower housing 14, and water enters the lower housing 14 from the water intake port 71 up to the water surface level. Because the height dimension of the wide portion 16 above the anti-cavitation plate 15 of the lower housing 14 is reduced, the distance from the water surface near the anti-cavitation plate 15 to the water pump 70 is short. Therefore, even a small water pump 70 can pump water up from the water surface and send it to the engine 20.

[0041] As described above, according to the outboard motor 1 of this embodiment, when the dog clutch 66 is connected to the upper drive gear 31, the upper drive shaft 22 is connected to the lower drive shaft 23 so as to be rotatable together with the upper drive shaft 22, and the power of the engine 20 is directly transmitted from the upper drive shaft 22 to the lower drive shaft 23. When the dog clutch 66 is connected to the lower driven gear 32, the lower driven gear 32 is connected to the lower drive shaft 23 so as to be rotatable together with the lower drive shaft 23 via the dog clutch 66. The power of the engine 20 is transmitted in the reverse direction to the lower drive shaft 23 via the upper drive gear 31, the pair of pinion gears 33, 34, and the lower driven gear 32. The rotation direction of the propellers 27, 28 is switched by reversing the rotation direction of the lower drive shaft 23. In addition, since the shift slider 61 is located below the lower driven gear 32, the shift shaft 52 and the dog clutch 66 are brought closer to each other in the horizontal direction, and the shift device 50 is made smaller and the degree of freedom in the layout of the components of the shift device 50 is improved.

[0042] In this embodiment, the shift slider is located below the lower driven gear, but the shift slider may be located above the upper driven gear. In this case, the cam mechanism is installed above the pair of pinion gears. Even with this layout, the shift shaft and the dog clutch are brought closer to each other in the horizontal direction, making the shift device more compact.

[0043] Also, in this embodiment, the outboard motor is equipped with contra-rotating propellers, but the outboard motor may be equipped with a single propeller.

[0044] Also, in this embodiment, power is transmitted from the upper drive gear to the lower driven gear via a pair of pinion gears, but power may be transmitted from the upper drive gear to the lower driven gear via a single pinion gear.

[0045] In addition, in this embodiment, power is transmitted from the shift shaft to the cam mechanism by gears, but the power transmission mechanism from the shift shaft to the cam mechanism is not particularly limited.

[0046] As described above, the first aspect is an outboard motor (1) including an upper shaft (upper drive shaft 22) and a lower shaft (lower drive shaft 23) extending from the engine (20) side to the propellers (27, 28) side, a power transmission mechanism (first gear mechanism 30) interposed between the upper shaft and the lower shaft, and a shift device (50) that operates the power transmission mechanism to rotate the propeller in the reverse direction, in which the power transmission mechanism has an upper gear (upper drive gear 31) fixed to the lower end of the upper shaft, a lower gear (lower driven gear 32) facing the upper gear from below, and an intermediate gear (pinion gear 34) that meshes with the upper gear and the lower gear, and the lower gear has a gear teeth (upper drive gear 31) and a lower gear teeth (lower driven gear 32) that face the upper gear from below. The vehicle is supported by the lower shaft so as to be rotatable relative to the vehicle, and the shift device includes a shift shaft (52) extending downward from the actuator side, a cam mechanism (54) that converts the rotation of the shift shaft into vertical movement of an operating part (shift fork 57), a shift slider (61) that is connected to the operating part and can slide vertically, a dog clutch (66) installed between an upper gear and a lower gear, and a connector pin (63) that connects the shift slider and the dog clutch, the dog clutch being connectable to the upper gear or the lower gear, the dog clutch being connected to the lower shaft so as to be rotatable together with the lower shaft, and the shift slider being located above the upper gear or below the lower gear. According to this configuration, when the actuator rotates the shift shaft, the shift slider is slid vertically by the cam mechanism. Since the dog clutch is connected to the shift slider via the connector pin, the dog clutch is moved vertically between the upper gear and the lower gear. When the dog clutch is connected to the upper gear, the upper shaft is connected to the lower shaft so that they can rotate together, and engine power is transmitted directly from the upper shaft to the lower shaft. When the dog clutch is connected to the lower gear, the lower gear is connected to the lower shaft via the dog clutch so that they can rotate together. Engine power is transmitted in the reverse direction to the lower shaft via the upper gear, intermediate gear, and lower gear. Reversing the rotation direction of the lower shaft switches the rotation direction of the propeller.In addition, since the shift slider is vertically offset from the upper gear and the lower gear, the shift shaft and the dog clutch can be brought closer together horizontally, making the shift device more compact and improving the freedom of component layout of the shift device.

[0047] In the second aspect, in the first aspect, the shift slider is movably installed on the outer circumferential surface of the lower shaft, and the connector pin is accommodated inside the lower shaft. With this configuration, the connector pin can be installed by utilizing the inner space of the lower shaft.

[0048] In the third aspect, in the first or second aspect, the intermediate gear is installed between the rotation axis of the shift shaft and the dog clutch. With this configuration, even if the intermediate gear is installed on the shift shaft side, it does not interfere with the shift device, and the intermediate gear and the shift device can be installed compactly.

[0049] In the fourth aspect, the power transmission mechanism of the third aspect has another intermediate gear (pinion gear 33) that meshes with the upper gear and the lower gear, and the other intermediate gear faces one of the intermediate gears across a dog clutch. With this configuration, the torque of the upper shaft is dispersed, so that the strength of the intermediate gear and the other intermediate gear can be reduced and the outboard motor can be made smaller. Reducing the size of the intermediate gear and the other intermediate gear allows the outboard motor to be made smaller.

[0050] In a fifth aspect, in any one of the first to fourth aspects, a cam mechanism is provided above or below the intermediate gear. With this configuration, the cam mechanism can be provided in the space above or below the intermediate gear, thereby making it possible to reduce the size of the shift device.

[0051] A sixth aspect is any one of the first to fifth aspects, in which power is transmitted from the shift shaft to the cam mechanism by gears. With this configuration, the rotation amount of the shift shaft, the stroke of the dog clutch, and the shift load are adjusted by changing the gear ratio. The stroke of the dog clutch can be increased with a small rotation amount of the shift shaft, making it possible to reduce the size of the shift device.

[0052] Although the present embodiment has been described, other embodiments may be made by combining the above-described embodiments and modifications in whole or in part.

[0053] In addition, the technology of the present invention is not limited to the above examples, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea. Furthermore, if the technical idea can be realized in a different way due to the progress of technology or a different technology derived therefrom, the invention may be implemented using that method. Therefore, the claims cover all embodiments that may be included within the scope of the technical idea. [Explanation of symbols]

[0054] 1: Outboard motor 20: Engine 22: Upper drive shaft (upper shaft) 23: Lower drive shaft (lower shaft) 27: Front propeller (propeller) 28: Rear propeller (propeller) 30: First gear mechanism (power transmission mechanism) 31: Upper drive gear 32: Lower driven gear 33: Pinion gear (other intermediate gear) 34: Pinion gear (intermediate gear) 50: Shift device 51: Actuator 52: Shift shaft 54: Cam mechanism 57: Shift fork (operating part) 61: Shift slider 63: Connector pin 66: Dog clutch

Claims

1. an upper shaft and a lower shaft extending from the engine side to the propeller side; a power transmission mechanism interposed between the upper shaft and the lower shaft; a shift device that operates the power transmission mechanism to rotate the propeller in reverse, The power transmission mechanism includes: An upper gear fixed to a lower end of the upper shaft; a lower gear facing the upper gear from below; an intermediate gear that meshes with the upper gear and the lower gear, The lower gear is supported by the lower shaft so as to be rotatable relative to the lower gear, The shift device is A shift shaft extending downward from the actuator side; a cam mechanism that converts rotation of the shift shaft into vertical movement of an operating part; a shift slider connected to the operation unit and slidable in an up and down direction; a dog clutch disposed between the upper gear and the lower gear; a connector pin that connects the shift slider and the dog clutch, the dog clutch is connectable to the upper gear or the lower gear; The dog clutch is connected to the lower shaft so as to be integrally rotatable with the lower shaft, 2. An outboard motor according to claim 1, wherein the shift slider is located above the upper gear or below the lower gear.

2. The shift slider is movably installed on an outer circumferential surface of the lower shaft, 2. The outboard motor according to claim 1, wherein the connector pin is accommodated inside the lower shaft.

3. 3. An outboard motor according to claim 1, wherein the intermediate gear is disposed between a rotation axis of the shift shaft and the dog clutch.

4. The power transmission mechanism includes: another intermediate gear that meshes with the upper gear and the lower gear, 4. An outboard motor according to claim 3, wherein the other intermediate gear faces the one intermediate gear across the dog clutch.

5. 4. An outboard motor according to claim 3, wherein the cam mechanism is disposed above or below the intermediate gear.

6. 3. An outboard motor according to claim 1, wherein power is transmitted from the shift shaft to the cam mechanism by means of gears.

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