OUTBOARD MOTOR

An outboard motor includes a first drive source, a drive shaft to transmit power from the first drive source, an upper case accommodating a drive shaft housing that accommodates a portion of the drive shaft, a propeller shaft rotationally drivable by power transmitted from the drive shaft, a shift actuator including a second drive source, and a forward-reverse switching mechanism to switch a rotation direction of the power transmitted from the drive shaft to the propeller shaft by an output from the shift actuator. The second drive source is located outside a cowl accommodating the first drive source, outside a lower case accommodating the forward-reverse switching mechanism, and outside the drive shaft housing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Japanese Patent Application No. 2023-102522, filed on Jun. 22, 2023, which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an outboard motor to be attached to a hull.

2. Description of the Related Art

In an outboard motor, generally, a propeller shaft is rotationally driven by power transmitted from a drive shaft. A rotation direction of the power transmitted from the drive shaft to the propeller shaft is switched by a forward-reverse switching mechanism. For example, a shift member in the forward-reverse switching mechanism is moved by a driving force from a shift actuator including a motor as a drive source, and a shift position is switched. The shift actuator is generally disposed in a casing of the outboard motor.

For example, the shift actuator described in U.S. Pat. No. 9,896,177 is disposed in an upper case. The shift actuator described in Japanese Laid-open Patent Publication (Kokai) No. 2010-63350 is disposed in a cowl. The shift actuator described in Japanese Laid-open Patent Publication (Kokai) No. 2004-1638 is disposed in a gear case (lower case).

However, in any of U.S. Pat. No. 9,896,177, Japanese Laid-open Patent Publication (Kokai) No. 2010-63350, and Japanese Laid-open Patent Publication (Kokai) No. 2004-1638, the shift actuator is disposed in the casing of the outboard motor, and therefore it is not easy for an operator to access the shift actuator from the outside. For example, when maintenance is performed on the motor or the like, it is necessary to remove the upper case, the cowl, the gear case, and the like such that maintenance is difficult.

In addition, a space in the casing is occupied by the shift actuator, which is disadvantageous for downsizing of the outboard motor, such as minimizing or reducing a dimension (in particular, a height) of the outboard motor.

SUMMARY OF THE INVENTION

Example embodiments of the present invention contribute to downsizing of outboard motors and provide outboard motors that are able to improve maintainability of a shift actuator.

According to an example embodiment of the present invention, an outboard motor includes a first drive source, a drive shaft to transmit power from the first drive source, an upper case accommodating a drive shaft housing that accommodates a portion of the drive shaft, a propeller shaft rotationally drivable by power transmitted from the drive shaft, a shift actuator including a second drive source, and a forward-reverse switching mechanism to switch a rotation direction of the power transmitted from the drive shaft to the propeller shaft by an output from the shift actuator, wherein the second drive source is location outside a cowl accommodating the first drive source, outside a lower case accommodating the forward-reverse switching mechanism, and outside the drive shaft housing.

According to this configuration, an upper case accommodates a drive shaft housing that accommodates a portion of the drive shaft. The power from a first drive source is transmitted from the drive shaft to rotationally drive a propeller shaft. A forward-reverse switching mechanism switches a rotation direction of the power transmitted from the drive shaft to the propeller shaft by an output from the shift actuator including a second drive source. The second drive source is located outside a cowl accommodating the first drive source, outside a lower case accommodating the forward-reverse switching mechanism, and outside the drive shaft housing.

DETAILED DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Hereinafter, example embodiments of the present invention will be described with reference to the drawings.

FIG.1is a schematic left side view of an outboard motor100according to a first example embodiment of the present invention. The outboard motor100includes an outboard motor main body101and a swivel bracket102. The outboard motor100is attached to a stern (not illustrated) of a hull via a suspension device (not illustrated). Hereinafter, an up-down direction and a front-rear direction of the outboard motor100are specified with reference to a posture of the outboard motor100during navigation illustrated inFIG.1. Namely, a +Y direction is upward, and a +Z direction is forward.

The swivel bracket102is rotatable with respect to a clamp bracket (not illustrated) of the suspension device about a tilt axis extending in a left-right direction. Therefore, the outboard motor main body101tilts with respect to the hull together with the swivel bracket102.

A steering shaft103is supported by the swivel bracket102so as to be rotatable about a steering axis line (a center line of the steering shaft103) extending in the up-down direction. The outboard motor main body101is coupled to an upper end portion of the steering shaft103via an upper mount11, and is coupled to a lower end portion of the steering shaft103via a lower mount12. Therefore, the outboard motor main body101is supported by the steering shaft103(that is, supported by the swivel bracket102) via the upper mount11and the lower mount12, and rotates about an axial center of the steering shaft103together with the steering shaft103.

The outboard motor main body101includes an upper portion and a lower portion. The upper portion includes a cowl104, an apron105, and an upper case30. The cowl104accommodates (covers) an engine15. The engine15is an example of a first drive source. The first drive source may be an electric motor. The apron105is fixed to the upper case30and covers a portion of the upper case30. The apron105may include a plurality of parts.

The lower portion includes a lower case20. The lower case20accommodates a forward-reverse switching mechanism26. The lower portion includes a propeller shaft21and a propeller22. The propeller shaft21extends in the front-rear direction. The propeller22is attached to a rear end portion of the propeller shaft21, and is rotatable about an axial center of the propeller shaft21together with the propeller shaft21. The propeller22rotates in a forward rotation direction to generate thrust in a direction to move the hull forward, and rotates in a reverse rotation direction to generate thrust in a direction to move the hull backward.

A drive shaft13to which power (rotation) of the engine15is transmitted extends in the up-down direction. The drive shaft13is rotatable around a center line of the drive shaft13. A lower end portion of the drive shaft13is coupled to the forward-reverse switching mechanism26. The propeller shaft21is rotationally driven by power transmitted from the drive shaft13. At that time, the forward-reverse switching mechanism26switches a rotation direction of the power transmitted from the drive shaft13to the propeller shaft21(details will be described with reference toFIGS.2and3).

The upper portion is provided with a shift actuator (hereinafter referred to as a shift ACT)40. In addition, the upper portion is provided with a cover50that covers at least a portion of the shift ACT40. A shift cam14that transmits an output from the shift ACT40to the forward-reverse switching mechanism26is disposed mainly in the lower case20. The shift cam14extends in the up-down direction. When the forward-reverse switching mechanism26is driven via the shift cam14by the output from the shift ACT40, the rotation direction of the power transmitted from the drive shaft13to the propeller shaft21is switched.

FIG.2is a block diagram of a main portion of the outboard motor100. The outboard motor100includes an engine control unit (ECU)17. A remote controller16is disposed on the hull. The shift ACT40includes a motor41(second drive source) and a shift position (SP) sensor42. The SP sensor42detects a shift position output by the shift ACT40and transmits the detection result to the ECU17. A rotation of the motor41rotates the shift cam14.

The ECU17controls driving of the engine15and driving of the shift ACT40based on a signal output due to an operation on the remote controller16. For example, the ECU17performs such controls, and changes a thrust of the outboard motor100(that is, a rotation speed of the propeller22) and switches a shift state (between a forward state, a backward state, and a neutral state) of the outboard motor100. As a result, movement, turning, and the like of the hull are controlled by a combination of an operation on the remote controller16and an operation on a steering wheel (not illustrated). Note that control such as the movement and the turning of the hull may be performed by operation on a joystick. When the shift ACT40is to be controlled, the signal of the shift position output from the SP sensor42is referred to.

As the forward-reverse switching mechanism26, a known configuration disclosed in Japanese Laid-open Patent Publication (Kokai) No. 2015-147541 or the like can be used. As an example, the forward-reverse switching mechanism26includes a slider24, a dog clutch25, and a gear portion23.

The gear portion23and the dog clutch25are disposed on the axial center of the propeller shaft21. The gear portion23includes a front gear and a rear gear, and the dog clutch25is disposed between the front gear and the rear gear. A position at which the dog clutch25meshes with the front gear is a forward rotation position. A position at which the dog clutch25meshes with the rear gear is a reverse rotation position. A position at which the dog clutch25meshes with neither the front gear nor the rear gear is a neutral position. The slider24is movable in the front-rear direction. Note that the configuration of the forward-reverse switching mechanism26is not limited to that illustrated.

FIG.3is an exploded perspective view of a main portion of the shift ACT40. The shift ACT40includes an output shaft43that outputs the rotation of the motor41as a rotational force. The “output from the shift ACT40” described above is, for example, the rotational force of the output shaft43. The rotation of the motor41is transmitted to the output shaft43via a transmission unit44including a plurality of gears or the like. The motor41is rotatable in both directions.

A spline portion14bis provided at an upper end portion of the shift cam14. Another spline portion corresponding to the spline portion14bis provided on an inner periphery of the output shaft43, and both spline portions are engaged with each other so that the shift cam14rotates in conjunction with the output shaft43(that is, the shift cam14is rotated by the rotational force of the output shaft43). The output shaft43and the shift cam14are relatively moved in the up-down direction to engage or disengage the spline portions with/from each other to allow the shift ACT40and the shift cam14to be assembled or disassembled.

A cam portion14ais provided at a lower end portion of the shift cam14. The cam portion14ais eccentric with respect to a center line of the shift cam14, and thus a position of the cam portion14ain the front-rear and left-right planes changes due to the rotation of the shift cam14.

The shift ACT40rotates the shift cam14by a driving force of the motor41. When the shift cam14rotates, the slider24(FIG.2) is driven forward or backward by the cam portion14ato move in the front-rear direction to move the dog clutch25(FIG.2) in the front-rear direction. As a result, the dog clutch25moves to one of the forward rotation position, the reverse rotation position, and the neutral position to switch the shift position. In this manner, the shift ACT40is a rotary type actuator.

Next, an arrangement of the shift ACT40and the cover50will be described.

FIG.4is a perspective view of the cover50and a periphery of the cover50.FIG.5is a top view of the shift ACT40, the lower mount12, and a periphery of the shift ACT40and the lower mount12.FIG.5illustrates a state in which the apron105and the cover50are removed.FIG.6is a schematic longitudinal sectional view of the upper case30, the shift ACT40, and a periphery of the upper case30and the shift ACT40. In each figure, illustration of a mount housing that covers the lower mount12is omitted.

The upper case30includes a splash plate32(FIGS.1and4to6). An opening33is provided in a side surface of the upper case30at a location lower than the splash plate32(FIGS.1and4). The opening33is provided in both a left portion and a right portion of the upper case30, however, only the opening33provided in the left portion of the upper case30is shown inFIGS.1and4. The shift ACT40is fixed to the upper case30(for example, to the splash plate32) by a screw or the like.

As illustrated inFIG.6, the upper case30includes (accommodates) a drive shaft housing31. A portion of the drive shaft13is accommodated in the drive shaft housing31. The entire shift ACT40is located outside the cowl104and outside the lower case20. Many portions of the shift ACT40are located outside the upper case30. The output shaft43of the shift ACT40extends from inside the upper case30to outside the upper case30. That is, at least a portion of the output shaft43is disposed inside the upper case30. The output shaft43is located outside the drive shaft housing31.

Focusing on the motor41, the motor41is located outside the cowl104, outside the lower case20, and outside the drive shaft housing31. As a result, an operator is able to easily access the motor41. Furthermore, the motor41is located outside the upper case30. As described above, the motor41is disposed outside a casing (the cowl104, the upper case30, and the lower case20) of the outboard motor, which makes it easier for the operator to access the motor41, and as a result, facilitate maintenance.

Assuming that the entire shift ACT40is disposed in the cowl, the upper case, or the lower case (gear case), it is not easy to access a motor or the like (as a drive source) to perform maintenance on the motor or the like. On the other hand, in the present example embodiment, the motor41is disposed outside the drive shaft housing31which makes access especially to the motor41is easy. This arrangement also contributes to downsizing of the outboard motor100.

As illustrated inFIG.6, the motor41is disposed forward of the drive shaft housing31in a front-rear direction of the outboard motor100. As a result, the operator is able to easily access the motor41from the front and thus from the hull so that maintenance is easy. Further, the motor41is disposed at a position closer to the lower mount12than to the upper mount11that are provided in the up-down direction to support the outboard motor main body101on the swivel bracket102(the steering shaft103). This arrangement is advantageous to shorten a distance between the shift ACT40and the forward-reverse switching mechanism26. Therefore, this arrangement is advantageous to provide a mechanism to transmit the output of the shift ACT40to the forward-reverse switching mechanism26compact, and is advantageous to use a rotary type actuator as the shift ACT40. Note that the shift ACT40is not limited to the rotary type, and may be a linear motion type using a link mechanism or the like.

The cover50is disposed forward of a foremost position E1of the apron105(FIGS.1and4). The foremost position E1is the foremost position of the apron105in a region in the up-down direction in which the cover50exists. The cover50covers the shift ACT40and also covers at least a portion of the lower mount12. As a result, not only protection of the shift ACT40and the lower mount12are improved, but also the appearance and design are improved.

The cover50is fixed to the upper case30by a screw, for example. As described above, the shift ACT40is also fixed to the upper case30. Therefore, with this arrangement, a relative positional accuracy between the shift ACT40and the cover50is high, and the shift ACT40is appropriately protected. A material of the cover50is not limited, and is made of, for example, a metal or a resin.

FIG.7is a perspective view of the cover50. Rear openings51and52are provided in a rear portion of the cover50. An upper opening53is provided in an upper portion of the cover50. The rear openings51and52are openings through which a wire harness18and an oil pipe19(FIG.5) pass through. The wire harness18and the oil pipe19are connected to the engine15. The swivel bracket102(FIG.1) and the steering shaft103(FIG.4) pass through the upper opening53.

In such a configuration, when maintenance of the shift ACT40is desired, the operator only has to remove the cover50to access the shift ACT40. In addition, the cover50and the apron105are separate bodies, and thus it is not necessary to remove the apron105having a large size at the time of maintenance, which makes the maintenance work easier.

In addition, the output shaft43of the shift ACT40and the shift cam14can be uncoupled and the entire shift ACT40can be removed so as to remove sand from the spline portion14b, clean the spline portion14b, and the like, which facilitates maintenance.

In addition, the operator can manually rotate the output shaft43of the shift ACT40through the opening33(FIGS.1and4) provided in the upper case30. For example, in a case where the output shaft43has a hexagonal outer diameter cross-sectional shape, the operator is able to rotate the shift cam14by rotating the output shaft43through the opening33using a spanner. Therefore, even in an emergency such as a case where the shift ACT40cannot move by electric power, the operator is able to manually switch the shift position.

According to the present example embodiment, the motor41of the shift ACT40is disposed at a location outside the cowl104, outside the lower case20, and outside the drive shaft housing31. The shift ACT40is not necessary to be disposed in the cowl104, which makes it possible to minimize or reduce a height of the outboard motor100. In addition, it is easy to avoid interference of the outboard motor100with a motor well (not illustrated) of the hull when the outboard motor100is tilted up. In addition, it is easy to perform maintenance of the shift ACT40without detaching the apron105. In particular, the motor41is disposed outside the casing of the outboard motor100, which makes it easier for the operator to access the motor41.

As a result, the present example embodiment contributes to downsizing of the outboard motor100and improve maintainability of the shift ACT40.

In addition, the motor41is disposed forward of the drive shaft housing31, and therefore, the operator is able to easily access the motor41from the front and from the hull, and increase maintainability.

In addition, the motor41is disposed at the position closer to the lower mount12than to the upper mount11, and therefore, it is advantageous to provide the mechanism to transmit the output of the shift ACT40to the forward-reverse switching mechanism26compact. For example, the rotary type actuator may be used for the shift ACT40, which contributes to downsizing and simplification of the configuration of the shift ACT40.

The output shaft43of the shift ACT40is disposed (extends) from inside the upper case30to outside the upper case30. The output shaft43is located outside the drive shaft housing31, and therefore, the shift position is able to be switched by the operator manually rotating the output shaft43. Moreover, the output shaft43is able to be rotated through the opening33of the upper case30so that the operator is able to manually switch the shift position with relatively easy work even in an emergency.

In addition, the cover50covers at least a portion of the shift ACT40. Further, the cover50also covers at least a portion of the lower mount12. Therefore, it is possible to protect the shift ACT40and the lower mount12and to enhance the design effect.

In addition, the cover50is fixed to the upper case30, which makes it possible to appropriately protect the shift ACT40.

FIG.8is a perspective view of a modification of the cover50in the present example embodiment. As illustrated inFIG.8, the cover50may include a plurality of (two or more) parts. For example, the cover50may include a left part and a right part, for example, a first member50-1and a second member50-2, wherein the cover50may be configured by the first member50-1and the second member50-2coupled to each other. Thus, the cover50can be easily manufactured and easily attached and detached from the upper case30. Note that the number and types of the parts defining the cover50are not limited to those illustrated.

Each of the first member50-1and the second member50-2is fixed to the upper case30. A method of coupling the first member50-1and the second member50-2is not limited. For example, the first member50-1and the second member50-2may be coupled by engagement between engaging portions and/or fastening using a fastener. The first member50-1and the second member50-2may be coupled to each other before being fixed to the upper case30, or may be coupled to each other when or after being fixed to the upper case30. Further, the first member50-1and the second member50-2may be configured to be individually detachable from the upper case30, which makes maintenance of the shift ACT40even easier.

FIG.9is a perspective view of a cover50B and a periphery of the cover50B according to a second example embodiment of the present invention. The outboard motor100of the second example embodiment is different from the outboard motor100of the first example embodiment in the shape of an apron and a cover. Other configurations in the second example embodiment are similar to those in the first example embodiment. In the present example embodiment, an apron105B and the cover50B are used.FIG.10is a perspective view of the cover50B.

The apron105B includes a mount covering portion105athat covers the lower mount12on the front portion thereof (FIG.9). The cover50B has a shape that prevents interference with the apron105B and does not cover the lower mount12. The cover50B has a fixing portion55at a left portion of the cover50B and a fixing portion55at a right portion of the cover50B. The cover50B is fixed to the upper case30, similarly to the cover50of the first example embodiment. In the present example embodiment, the cover50B is further fixed to the apron105B via the fixing portions55.

An opening105bthrough which the swivel bracket102(FIG.1) and the steering shaft103(FIG.4) pass is provided in the apron105B (FIG.9). An opening54through which the wire harness18and the oil pipe19(FIG.5) pass is provided in a rear portion of the cover50B (FIG.10).

The present example embodiment achieves downsizing of the outboard motor100and improvement of maintainability of the shift ACT40similar to that of the first example embodiment.

In addition, the apron105B covers the lower mount12, which improves the appearance. The apron105B may cover at least a portion of the lower mount12.

FIG.11is a perspective view of a cover50C and a periphery of the cover50C according to a third example embodiment of the present invention. The outboard motor100of the third example embodiment is different from the outboard motor100of the first example embodiment in the shape of the cover. Other configurations in the third example embodiment are similar to those in the first example embodiment. In the present example embodiment, the cover50C is used.FIG.12is a perspective view of the cover50C.

The cover50C includes a stepped surface56which has a height lower than an uppermost portion of the cover50C. The stepped surface56is a portion positioned below the lower mount12, and faces the lower mount12from below. The height of the stepped surface56is set so as not to interfere with the lower mount12. The shape of the apron105is similar to that of the first example embodiment, and the lower mount12is exposed. Note that illustration of the mount housing is omitted.

The cover50C covers at least a portion of the shift ACT40. Rear openings58and59are provided in a rear portion of the cover50C. The rear openings58and59are openings through which the wire harness18and the oil pipe19(FIG.5) pass, respectively.

The present example embodiment achieves downsizing of the outboard motor100and improvement of maintainability of the shift ACT40similar to that of the first example embodiment.

If it is desired to increase the height of the stepped surface56, a clearance portion57to avoid interference with the lower mount12may be provided on the stepped surface56(FIG.12). By increasing the height of the stepped surface56, a degree of freedom in designing the shift ACT40is increased. In addition, the structure including the clearance portion57is advantageous to downsize a mechanism around the cover50C in the up-down direction while avoiding interference with the lower mount12. The clearance portion57may be a hole or a recessed portion recessed downward.

FIG.13is a perspective view of a modification of the cover (cover50D) in the third example embodiment. The cover50D is different from the cover50C (FIG.12) in that the cover50D includes eave portions61and62. Other portions of the cover50D are similar to those of the cover50C. The eave portions61and62simply cover and hide at least a portion of the lower mount12from the left, right, and above. As a result, the design effect is enhanced. The eave portions61and62may be referred to as “airfoil-shaped portions” or “flange-shaped portions”.

The clearance portion57may also be used in the cover50D. The configuration in which the cover includes a plurality of parts may also be applied to the second and third example embodiments. In addition, some parts of the first to third example embodiments may be appropriately combined.