Outboard motor

An outboard motor includes an outboard motor body, a mount mounted on a boat body, and a support member that supports the outboard motor body so as to be steerable with respect to the mount. The support member includes an upper support that surrounds a drive shaft and supports the outboard motor body, a lower support that is spaced below the upper support, surrounds the drive shaft, and supports the outboard motor body, and a coupler that couples the upper support to the lower support.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Patent Application No. 2016-132756 filed in Japan on Jul. 4, 2016, the entire contents of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an outboard motor.

2. Description of the Related Art

An outboard motor is known in general. Such an outboard motor is disclosed in Japanese Patent Laid-Open No. 2014-024501, for example.

Japanese Patent Laid-Open No. 2014-024501 discloses an outboard motor including an outboard motor body including an engine and a drive shaft that is coupled to the engine and transmits power, and a bracket that is mounted on a boat body and supports the outboard motor body such that the outboard motor body is steerable about a steering shaft. In the outboard motor disclosed in Japanese Patent Laid-Open No. 2014-024501, the steering shaft is arranged at a position spaced forward of the drive shaft.

In the conventional outboard motor disclosed in Japanese Patent Laid-Open No. 2014-024501, the steering shaft is arranged at the position spaced forward of the drive shaft, and hence the entire length of a boat including the outboard motor is increased. Furthermore, the center of gravity of the outboard motor is spaced rearward from the boat body, and hence it is necessary to increase the flotation or buoyancy of the boat body such that a rear portion of the boat body does not sink. Thus, the boat body is increased in size. Therefore, an outboard motor that significantly reduces or prevents an increase in the size of a boat body on which the outboard motor is mounted while significantly reducing or preventing an increase in the entire length of a boat including the outboard motor is desired.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide an outboard motor that significantly reduces or prevents an increase in the size of a boat body on which the outboard motor is mounted while significantly reducing or preventing an increase in the entire length of a boat including the outboard motor.

An outboard motor according to a preferred embodiment of the present invention includes an outboard motor body including an engine and a drive shaft that is coupled to the engine and transmits power, a mount mounted on a boat body, and a support member that supports the outboard motor body so as to be steerable with respect to the mount, and the support member includes an upper support that surrounds the drive shaft and supports the outboard motor body, a lower support that is spaced below the upper support, surrounds the drive shaft, and supports the outboard motor body, and a coupler that couples the upper support to the lower support.

In an outboard motor according to a preferred embodiment of the present invention, the support member that steerably supports the outboard motor body includes the upper support that surrounds the drive shaft and supports the outboard motor body, the lower support that is spaced below the upper support, surrounds the drive shaft, and supports the outboard motor body, and the coupler that couples the upper support to the lower support. Thus, a steering axis and the drive shaft are close to each other, and hence an increase in the entire length of a boat including the outboard motor is significantly reduced or prevented. Furthermore, the steering axis and the drive shaft are close to each other, and hence the center of gravity of the outboard motor is close to the boat body. Thus, it is not necessary to increase the amount of float of the boat body. Consequently, an increase in the size of the boat body is significantly reduced or prevented. In addition, the upper support and the lower support steerably support the outboard motor body, and hence friction (frictional resistance) generated during steering is reduced as compared with the case where the outboard motor is supported by an entire steering shaft. Moreover, the upper support and the lower support are coupled to each other by the coupler, and hence relative displacement of positions of support of the upper support and the lower support is significantly reduced or prevented.

In an outboard motor according to a preferred embodiment of the present invention, the outboard motor body preferably includes a cover that covers the drive shaft, and the coupler preferably couples the upper support to the lower support at a position outside of the cover. Accordingly, at a position spaced from the steering axis and outside of the cover, the upper support and the lower support are coupled to each other by the coupler, and hence relative displacement of the positions of support of the upper support and the lower support is significantly reduced or prevented as compared with the case where the upper support and the lower support are coupled to each other near the steering axis.

In an outboard motor according to a preferred embodiment of the present invention, the coupler preferably includes a pair of couplers. Accordingly, relative displacement of the positions of support of the upper support and the lower support is effectively significantly reduced or prevented by the pair of couplers.

In an outboard motor according to a preferred embodiment of the present invention, the support member preferably supports the outboard motor body at a position forward of an exhaust passage through which exhaust air from the engine flows. Accordingly, the exhaust passage that is a space is located in a rear portion of the outboard motor body, and hence the center of gravity of the outboard motor body is located forward. Consequently, the center of gravity of the outboard motor is close to the boat body.

In an outboard motor according to a preferred embodiment of the present invention, the outboard motor body preferably includes a cover that covers the drive shaft and a housing provided with a through-hole in which the drive shaft is located, and the support member preferably surrounds the through-hole and supports the housing. Accordingly, the support member supports the housing including the through-hole, and hence the support member surrounds the drive shaft and easily supports the outboard motor body.

In this case, a shift shaft that changes a shift state is preferably located in the through-hole of the housing. Accordingly, the shift shaft is easily positioned using the through-hole through which the drive shaft passes.

In the structure in which the outboard motor body includes the housing, the housing is preferably provided with a flow passage through which at least one of exhaust air from the engine, engine oil, and cooling water flows. Accordingly, the flow passage is integrally provided in the housing supported by the support member, and hence an increase in the number of components is significantly reduced or prevented.

In an outboard motor according to a preferred embodiment of the present invention, the outboard motor body preferably includes a cover that covers the drive shaft, and the support member preferably includes a support that supports the outboard motor body, and supports the outboard motor body by the support inside the cover. Accordingly, as compared with the case where the outboard motor body is supported by a support outside the cover, the steering axis and the drive shaft are closer to each other, and hence an increase in the size of the boat body on which the outboard motor is mounted is further significantly reduced or prevented while an increase in the entire length of the boat including the outboard motor is further significantly reduced or prevented.

In this case, the cover preferably includes a first cover and a second cover below the first cover, the upper support preferably includes an upper support that supports the outboard motor body, and supports the outboard motor body by the upper support inside the first cover, and the lower support preferably includes a lower support that supports the outboard motor body, and supports the outboard motor body by the lower support inside the second cover. Accordingly, the outboard motor body is supported by the upper support inside the first cover while the outboard motor body is supported by the lower support inside the second cover, and hence the outboard motor body is supported in a balanced manner at positions vertically spaced apart while the steering axis and the drive shaft are close to each other.

In an outboard motor according to a preferred embodiment of the present invention, the support member preferably supports the outboard motor body through a damper. Accordingly, transfer of vibrations of the outboard motor body to the boat body is significantly reduced or prevented.

In this case, the damper is preferably annular, and preferably has an inner diameter larger than the drive shaft and an outer diameter smaller than or equal to an inner diameter of a support hole that supports the outboard motor body. Accordingly, transfer of vibrations of the outboard motor body to the boat body is effectively significantly reduced or prevented by the damper having the inner diameter larger than the drive shaft and the outer diameter smaller than or equal to the inner diameter of the support hole.

In the structure in which the support member supports the outboard motor body through the damper, the outboard motor body preferably includes a housing including a boss that protrudes in an axial direction of the drive shaft, and the support member preferably supports the outboard motor body by fitting or inserting the boss into the support hole through the damper. Accordingly, the support member supports the outboard motor body by inserting the boss provided on the housing of the outboard motor body into the support hole, and hence the outboard motor body is easily rotated about the steering axis.

In this case, the support member preferably supports the outboard motor body by inserting the boss into the support hole through a collar that is annular and facilitates rotation of the outboard motor body and the damper. Accordingly, rotation of the outboard motor body is facilitated by the collar while transfer of vibrations of the outboard motor body is significantly reduced or prevented by the damper, and hence the outboard motor body is more easily rotated about the steering axis.

In an outboard motor according to a preferred embodiment of the present invention, the support member preferably rotatably supports the outboard motor body about a steering axis, and the steering axis preferably overlaps with the drive shaft as viewed in an axial direction of the drive shaft. Accordingly, the steering axis and the drive shaft are reliably close to each other, and hence an increase in the size of the boat body on which the outboard motor is mounted is more effectively significantly reduced or prevented while an increase in the entire length of the boat including the outboard motor is more effectively significantly reduced or prevented.

An outboard motor according to a preferred embodiment of the present invention preferably further includes a trim-tilt mechanism that couples the lower support of the support member to the mount and rotates the outboard motor body in a vertical direction. Accordingly, a coupling position of the trim-tilt mechanism with respect to the boat body is elevated, and hence the drive amount of the trim-tilt mechanism is reduced when the outboard motor is fully tilted up. Furthermore, when the outboard motor is fully tilted up, the coupling position where the trim-tilt mechanism is attached to the boat body is prevented from being under water.

An outboard motor according to a preferred embodiment of the present invention preferably further includes a trim-tilt mechanism that couples the coupler of the support member to the mount and rotates the outboard motor body in a vertical direction. Accordingly, the coupling position of the trim-tilt mechanism with respect to the boat body is elevated, and hence the drive amount of the trim-tilt mechanism is reduced when the outboard motor is fully tilted up. Furthermore, when the outboard motor is fully tilted up, the coupling position where the trim-tilt mechanism is attached to the boat body is prevented from being under water.

In this case, a coupling position of the trim-tilt mechanism with respect to the coupler of the support member is preferably adjustable. Accordingly, the coupling position of the trim-tilt mechanism is adjusted according to the size of the boat body and the size of the outboard motor such that the trim of the outboard motor is properly adjusted, and the outboard motor is properly tilted up.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention are hereinafter described with reference to the drawings.

First Preferred Embodiment

The structure of a boat10including an outboard motor100according to a first preferred embodiment of the present invention is now described with reference toFIG. 1. In the figures, arrow FWD represents the forward movement direction of the boat10, and arrow BWD represents the reverse movement direction of the boat10. In the figures, arrow R represents the starboard direction of the boat10, and arrow L represents the portside direction of the boat10.

The boat10includes a boat body11, a steering wheel12, and remote controller13, as shown inFIG. 1. The outboard motor100is mounted on the boat10.

The steering wheel12steers the boat body11(turns the outboard motor100). Specifically, the steering wheel12is connected to a steering device of the outboard motor100. The steering device rotates the outboard motor100in a horizontal direction based on operation of the steering wheel12.

The remote controller13manipulates the shift and output (throttle position) of the outboard motor100. Specifically, the remote controller13is connected to the outboard motor100. The output and the shift (forward movement, reverse movement, or neutral) of an engine1of the outboard motor100are controlled based on operation of the remote controller13.

The outboard motor100is mounted on a rear portion of the boat body11, as shown inFIG. 1. The outboard motor100includes an outboard motor body100a, as shown inFIG. 2. The outboard motor body100aincludes the engine1, a power transmission2, a propeller3, a shift actuator4, an engine cover5a, an apron5b, an upper cover5c, a lower cover5d, an upper housing6, and a lower housing7. The outboard motor100includes an outboard motor mount8and a trim-tilt mechanism9. The outboard motor body100ais mounted on the boat body11to be rotatable about a vertical axis and a horizontal axis by the outboard motor mount8. The apron5bis an example of a “cover” or a “first cover,” and the upper cover5cis an example of a “cover” or a “second cover.”

The power transmission2includes a drive shaft21, a gearing22, and a propeller shaft23. The shift actuator4is connected to the gearing22through a shift shaft41. The upper housing6includes a boss61and a flow passage62, as shown inFIG. 3. The lower housing7includes a boss71and a flow passage72, as shown inFIG. 5. The flow passages62and72are examples of an “exhaust passage.”

The outboard motor mount8includes a pair of clamp brackets81, an upper support82, a trim-tilt shaft83, a pair of couplers84, and a lower support85, as shown inFIG. 2. The outboard motor mount8includes a support member8aincluding the upper support82, the couplers84, and the lower support85. The trim-tilt mechanism9includes a cylinder91, an upper mount92, and a lower mount93. The clamp brackets81are examples of a “mount.”

The engine1is located in an upper portion of the outboard motor100, and includes an internal combustion driven by explosive combustion of gasoline, light oil, or the like. The engine1is covered by the engine cover5a.

The drive shaft21is coupled to a crankshaft of the engine1so as to transmit the power of the engine1. The drive shaft21extends in a vertical direction. The drive shaft21is rotatably coupled to the engine1. The drive shaft21is covered by the apron5b, the upper cover5c, and the lower cover5d. In other words, an upper portion of the drive shaft21is covered by the apron5b, an intermediate portion of the drive shaft21is covered by the upper cover5c, and a lower portion of the drive shaft21is covered by the lower cover5d.

The gearing22is located in a lower portion of the outboard motor100. The gearing22decreases the rotational speed of the drive shaft21and transmits the decreased rotational speed to the propeller shaft23. In other words, the gearing22transmits the drive force of the drive shaft21that rotates about a rotation axis extending in the vertical direction to the propeller shaft23that rotates about a rotation axis extending in a front to back direction. Specifically, the gearing22includes a pinion gear, a forward movement bevel gear, a reverse movement bevel gear, and a dog clutch. The pinion gear is mounted on a lower end of the drive shaft21. The forward movement bevel gear and the reverse movement bevel gear are provided on the propeller shaft23to hold the pinion gear therebetween. The pinion gear meshes with the forward movement bevel gear and the reverse movement bevel gear. The gearing22switches between a state where the dog clutch that rotates integrally with the propeller shaft23engages with the forward movement bevel gear and a state where the dog clutch engages with the reverse movement bevel gear so as to switch the shift position (the rotation direction (the forward movement direction and the reverse movement direction) of the propeller shaft23). The gearing22switches to a state where the dog clutch engages with neither the forward movement bevel gear nor the reverse movement bevel gear so as to change the shift position to neutral. The gearing22and the propeller shaft23are covered by the lower cover5d.

The propeller3is connected to the propeller shaft23. The propeller3is driven to rotate about the rotation axis extending in the front to back direction. The propeller3rotates in water to generate thrust force in an axial direction. The propeller3moves the boat body11forward or reversely according to the rotation direction.

The shift actuator4switches the shift state of the outboard motor100based on the user's operation. Specifically, the shift actuator4changes the shift position to any of forward movement, reverse movement, and neutral. More specifically, the shift actuator4changes the meshing of the gearing22through the shift shaft41to switch the shift state.

On a front portion of the engine cover5a, a bar101is mounted. The bar101steers the outboard motor body100a. In other words, the bar101is moved right and left by the steering device such that the outboard motor body100ais rotated about a steering axis A (seeFIGS. 3 and 5).

The apron5bis located below the engine cover5a. In other words, the apron5bis located below the engine1. The upper cover5cis located below the apron5b. The lower cover5dis located below the upper cover5c.

The upper housing6is located below the engine1and supports the engine1, as shown inFIG. 2. The upper housing6is covered by the engine cover5aand the apron5b. The upper housing6is supported by the upper support82. Specifically, the upper housing6is supported by the upper support82so as to be rotatable about the steering axis A, as shown inFIG. 3. The boss61of the upper housing6protrudes in the axial direction of the drive shaft21. The boss61is located in a front portion of the upper housing6. The boss61is annular. A through-hole611is provided inside the boss61. The drive shaft21is located in the through-hole611. The shift shaft41is located in the through-hole611. The shift shaft41is forward of the drive shaft21. The flow passage62is located in a rear portion of the upper housing6. At least one of exhaust air from the engine1, engine oil, and cooling water flows through the flow passage62. The flow passage62may be provided with an oil pan in which the engine oil is accumulated.

The lower housing7is located below the upper housing6, as shown inFIG. 2. The lower housing7is covered by the upper cover5c. The lower housing7is supported by the lower support85. Specifically, the lower housing7is supported by the lower support85so as to be rotatable about the steering axis A, as shown inFIG. 5. The boss71of the lower housing7protrudes in the axial direction of the drive shaft21. The boss71is located in a front portion of the lower housing7. The boss71is annular. A through-hole711is provided inside the boss71. The drive shaft21is located in the through-hole711. The shift shaft41is located in the through-hole711. The shift shaft41is located forward of the drive shaft21. The flow passage72is located in a rear portion of the lower housing7. At least one of exhaust air from the engine1, engine oil, and cooling water flows through the flow passage72. The flow passage72may be provided with an oil pan in which the engine oil accumulates.

The outboard motor mount8is mounted on the boat body11so as to support the outboard motor body100a. Specifically, the pair of clamp brackets81is fixed to the rear portion of the boat body11. The outboard motor body100ais supported by the support member8aso as to be steerable with respect to the clamp brackets81. More specifically, the support member8ais supported by the clamp brackets81so as to be rotatable about the trim-tilt shaft83. The upper support82of the support member8ais rotatably coupled to the clamp brackets81through the trim-tilt shaft83. The upper support82is coupled to the lower support85through the couplers84. The outboard motor body100ais supported by the upper support82and the lower support85so as to be steerable about the steering axis A and rotatable about the trim-tilt shaft83.

According to the first preferred embodiment of the present invention, the support member8asurrounds the drive shaft21and supports the outboard motor body100a, as shown inFIGS. 3 and 5. In other words, the upper support82surrounds the drive shaft21and supports the outboard motor body100a. The lower support85spaced below the upper support82surrounds the drive shaft21and supports the outboard motor body100a. Thus, the support member8asupports the outboard motor body100asuch that the outboard motor body100ais rotatable about the steering axis A. The steering axis A overlaps with the drive shaft21as viewed in the axial direction of the drive shaft21. According to the first preferred embodiment of the present invention, the steering axis A coincides with a portion of the drive shaft21forward of the center of the drive shaft21. The support member8asupports the outboard motor body100aat a position forward of the flow passages62and72through which exhaust air from the engine1flows.

According to the first preferred embodiment of the present invention, the upper support82includes an upper support82a, as shown inFIG. 3. The upper support82asupports the outboard motor body100a. Specifically, the upper support82aincludes a circular support hole821. The upper support82supports the upper housing6(outboard motor body100a) by inserting the boss61of the upper housing6into the support hole821. The upper support82supports the outboard motor body100aby the upper support82ainside the apron5b.

The upper support82surrounds the through-hole611of the boss61and supports the upper housing6. The upper support82supports the outboard motor body100athrough an annular damper822. Specifically, the upper support82supports the outboard motor body100aby inserting the boss61into the support hole821of the upper support82athrough an annular collar823and the annular damper822, as shown inFIG. 4. As shown inFIG. 3, the inner diameters of the annular damper822and the annular collar823are larger than the outer diameter of the drive shaft21. The outer diameters of the annular damper822and the annular collar823are smaller than the inner width of the apron5b. The outer diameters of the annular damper822and the annular collar823are smaller than or equal to the inner diameter of the support hole821. The damper822is located outside the collar823. The boss61is located inside the collar823. The collar823facilitates rotation of the outboard motor body100a. In other words, the collar823and the boss61easily slide over each other, and hence the upper housing6(outboard motor body100a) easily rotates with respect to the upper support82(support member8a). InFIGS. 3 and 4, the upper support82and the upper housing6are shown in a simplified manner in order to make it easy to understand the structure.

The trim-tilt shaft83supports the support member8asuch that the support member8ais rotatable in the vertical direction. The trim-tilt shaft83is supported by the pair of clamp brackets81, as shown inFIG. 6. Specifically, the trim-tilt shaft83is held between the pair of clamp brackets81through a pair of dampers831and is supported by the pair of clamp brackets81, as shown inFIG. 3.

The couplers84couple the upper support82to the lower support85, as shown inFIG. 6. The pair of couplers84are spaced apart at a predetermined interval in a right to left direction. The couplers84couple the upper support82to the lower support85at locations spaced outward from the apron5band the upper cover5c. Specifically, the couplers84couple the upper support82to the lower support85at locations spaced forward of the apron5band the upper cover5c. The couplers84are preferably made of a material containing carbon fiber, for example.

According to the first preferred embodiment of the present invention, the lower support85includes a lower support85a, as shown inFIG. 5. The lower support85asupports the outboard motor body100a. Specifically, the lower support85aincludes a circular support hole851. The lower support85supports the lower housing7(outboard motor body100a) by inserting the boss71of the lower housing7into the support hole851. The lower support85supports the outboard motor body100aby the lower support85ainside the upper cover5c.

The lower support85surrounds the through-hole711of the boss71and supports the lower housing7. The lower support85supports the outboard motor body100athrough an annular damper852. Specifically, the lower support85supports the outboard motor body100aby inserting the boss71into the support hole851of the lower support85athrough an annular collar853and the annular damper852, as shown inFIG. 4. As shown inFIG. 5, the inner diameters of the annular damper852and the annular collar853are larger than the outer diameter of the drive shaft21. The outer diameters of the annular damper852and the annular collar853are smaller than the inner width of the upper cover5c. The outer diameters of the annular damper852and the annular collar853are smaller than or equal to the inner diameter of the support hole851. The damper852is located outside the collar853. The boss71is located inside the collar853. The collar853facilitates rotation of the outboard motor body100a. In other words, the collar853and the boss71easily slide over each other, and hence the lower housing7(outboard motor body100a) easily rotates with respect to the lower support85(support member8a). InFIGS. 4 and 5, the lower support85and the lower housing7are shown in a simplified manner in order to make it easy to understand the structure.

The trim-tilt mechanism9changes the angle of the outboard motor body100awith respect to the boat body11, as shown inFIG. 2. Specifically, the trim-tilt mechanism9rotates the outboard motor body100aabout the trim-tilt shaft83. The upper mount92of the trim-tilt mechanism9is coupled to the clamp brackets81. Specifically, the upper mount92is connected to a connector921held between the pair of clamp brackets81and coupled to the pair of clamp brackets81, as shown inFIG. 6. The upper mount92is rotatably connected to the connector921. The lower mount93of the trim-tilt mechanism9is coupled to the lower support85. Specifically, the lower mount93is connected to a connector931coupled to the lower support85. The lower mount93is rotatably connected to the connector931.

The trim-tilt mechanism9adjusts the angle of the outboard motor body100aby extension and retraction of the cylinder91. Specifically, the cylinder91retracts such that the outboard motor body100ais rotated clockwise when the outboard motor body100ais viewed from the left. The cylinder91extends such that the outboard motor body100ais rotated counterclockwise when the outboard motor body100ais viewed from the left. The cylinder91is hydraulically driven, for example.

According to the first preferred embodiment of the present invention, the following advantageous effects are obtained.

According to the first preferred embodiment of the present invention, the support member8athat steerably supports the outboard motor body100aincludes the upper support82that surrounds the drive shaft21and supports the outboard motor body100a, the lower support85that is spaced below the upper support82, surrounds the drive shaft21, and supports the outboard motor body100a, and the couplers84that couple the upper support82to the lower support85. Thus, the steering axis A and the drive shaft21are close to each other, and hence an increase in the entire length of the boat10including the outboard motor100is significantly reduced or prevented. Furthermore, the steering axis A and the drive shaft21are close to each other, and hence the center of gravity of the outboard motor100is close to the boat body11. Thus, it is not necessary to increase the flotation of the boat body11. Consequently, an increase in the size of the boat body11is significantly reduced or prevented. In addition, the upper support82and the lower support85steerably support the outboard motor body100a, and hence friction (frictional resistance) generated during steering is reduced as compared with the case where the outboard motor is supported by an entire steering shaft. Moreover, the upper support82and the lower support85are coupled to each other by the couplers84, and hence relative displacement of the support positions of the upper support82and the lower support85is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the couplers84couple the upper support82to the lower support85at locations spaced outward from the apron5band the upper cover5c. Thus, at the locations spaced from the steering axis A outward from the apron5band the upper cover5c, the upper support82and the lower support85are coupled to each other by the couplers84, and hence relative displacement of the support positions of the upper support82and the lower support85is significantly reduced or prevented as compared with the case where the upper support82and the lower support85are coupled to each other near the steering axis A.

According to the first preferred embodiment of the present invention, the pair of couplers84is provided. Thus, relative displacement of the support positions of the upper support82and the lower support85is effectively significantly reduced or prevented by the pair of couplers84.

According to the first preferred embodiment of the present invention, the support member8asupports the outboard motor body100aat the position forward of the flow passages62and72through which exhaust air from the engine1flows. Thus, spaces for the flow passages62and72are located in a rear portion of the outboard motor body100a, and hence the center of gravity of the outboard motor body100ais located farther forward. Consequently, the center of gravity of the outboard motor100is close to the boat body11.

According to the first preferred embodiment of the present invention, the outboard motor body100aincludes the apron5band the upper cover5cthat cover the drive shaft21, and the housing6(7) inside the apron5band the upper cover5cthat are provided with the through-hole611(711) accommodating the drive shaft21, and the support member8asurrounds the through-hole611(711) and supports the housing6(7). Thus, the support member8asupports the housing6(7) including the through-hole611(711), and hence the support member8asurrounds the drive shaft21and easily supports the outboard motor body100a.

According to the first preferred embodiment of the present invention, the shift shaft41that changes the shift state (changes the meshing of the gearing22) is located in the through-hole611(711) of the housing6(7). Thus, the shift shaft41is easily positioned using the through-hole611(711) through which the drive shaft21passes.

According to the first preferred embodiment of the present invention, the flow passage62(72) through which at least one of exhaust air from the engine1, engine oil, and cooling water flows is provided in the housing6(7). Thus, the flow passage62(72) is integrally provided in the housing6(7) supported by the support member8a, and hence an increase in the number of components is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the support member8asupports the outboard motor body100aby the upper support82aand the lower support85ainside the apron5band the upper cover5c. Thus, as compared with the case where the outboard motor body100ais supported by support structures outside the apron5band the upper cover5c, the steering axis A and the drive shaft21are closer to each other, and hence an increase in the size of the boat body11on which the outboard motor100is mounted is further significantly reduced or prevented while an increase in the entire length of the boat10including the outboard motor100is further significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the upper support82supports the outboard motor body100aby the upper support82ainside the apron5b, and the lower support85supports the outboard motor body100aby the lower support85ainside the upper cover5c. Thus, the outboard motor body100ais supported by the upper support82ainside the apron5bwhile the outboard motor body100ais supported by the lower support85ainside the upper cover5c, and hence the outboard motor body100ais supported in a balanced manner at positions vertically spaced apart while the steering axis A and the drive shaft21are close to each other.

According to the first preferred embodiment of the present invention, the support member8asupports the outboard motor body100athrough the damper822(852). Thus, the transfer of vibrations of the outboard motor body100ato the boat body11is significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the damper822(852) is annular, and has an inner diameter larger than the drive shaft21and an outer diameter smaller than or equal to the inner diameter of the support hole821(851) as the upper support82a(lower support85a) that supports the outboard motor body100a. Thus, the transfer of vibrations of the outboard motor body100ato the boat body11is effectively significantly reduced or prevented by the damper822(852) with the inner diameter larger than the drive shaft21and the outer diameter smaller than or equal to the inner diameter of the support hole821(851).

According to the first preferred embodiment of the present invention, the support member8asupports the outboard motor body100aby inserting the boss61(71) of the housing6(7) into the support hole821(851) through the damper822(852). Thus, the support member8asupports the outboard motor body100aby inserting the boss61(71) provided on the housing6(7) of the outboard motor body100ainto the support hole821(851), and hence the outboard motor body100ais easily rotated about the steering axis A.

According to the first preferred embodiment of the present invention, the support member8asupports the outboard motor body100aby inserting the boss61(71) into the support hole821(851) through the collar823(853) that is annular and facilitates rotation of the outboard motor body100aand the damper822(852). Thus, rotation of the outboard motor body100ais facilitated by the collar823(853) while the transfer of vibrations of the outboard motor body100ais significantly reduced or prevented by the damper822(852), and hence the outboard motor body100ais more easily rotated about the steering axis A.

According to the first preferred embodiment of the present invention, the steering axis A overlaps with the drive shaft21as viewed in the axial direction of the drive shaft21. Thus, the steering axis A and the drive shaft21are reliably close to each other, and hence an increase in the size of the boat body11on which the outboard motor100is mounted is more effectively significantly reduced or prevented while an increase in the entire length of the boat10including the outboard motor100is more effectively significantly reduced or prevented.

According to the first preferred embodiment of the present invention, the outboard motor100includes the trim-tilt mechanism9that couples the lower support85aof the support member8ato the clamp brackets81and rotates the outboard motor body100ain the vertical direction. Thus, the coupling position of the trim-tilt mechanism9with respect to the boat body11is elevated, and hence the drive amount of the trim-tilt mechanism9(the amount of extension of the cylinder91) is reduced when the outboard motor100is fully tilted up. Furthermore, when the outboard motor100is fully tilted up, the coupling position where the trim-tilt mechanism9is attached to the boat body11is prevented from being under water.

Second Preferred Embodiment

A second preferred embodiment of the present invention is now described with reference toFIG. 7. In the second preferred embodiment, a trim-tilt mechanism9ais coupled to couplers84and a pair of clamp brackets81, unlike the first preferred embodiment in which the trim-tilt mechanism9is coupled to the lower support85aof the support member8aand the clamp brackets81.

An outboard motor200according to the second preferred embodiment of the present invention is mounted on a rear portion of a boat body11, as shown inFIG. 1. The outboard motor200includes an outboard motor body100a, as shown inFIG. 7. The outboard motor body100aincludes an engine1, a power transmission2, a propeller3, a shift actuator4, an engine cover5a, an apron5b, an upper cover5c, a lower cover5d, an upper housing6, and a lower housing7. The outboard motor200includes an outboard motor mount8and the trim-tilt mechanism9a. The outboard motor body100ais mounted on the boat body11to be rotatable about a vertical axis and a horizontal axis by the outboard motor mount8. The apron5bis an example of a “cover” or a “first cover,” and the upper cover5cis an example of a “cover” or a “second cover.”

According to the second preferred embodiment of the present invention, a support member8asurrounds a drive shaft21and supports the outboard motor body100a, as shown inFIG. 7. In other words, an upper support82surrounds the drive shaft21and supports the outboard motor body100a. A lower support85spaced below the upper support82surrounds the drive shaft21and supports the outboard motor body100a. Thus, the support member8asupports the outboard motor body100asuch that the outboard motor body100ais rotatable about a steering axis A.

According to the second preferred embodiment of the present invention, the trim-tilt mechanism9achanges the angle of the outboard motor body100awith respect to the boat body11. Specifically, the trim-tilt mechanism9arotates the outboard motor body100aabout a trim-tilt shaft83. An upper mount92of the trim-tilt mechanism9ais coupled to the clamp brackets81. Specifically, the upper mount92is connected to a connector921held between the pair of clamp brackets81and coupled to the pair of clamp brackets81. The upper mount92is rotatably connected to the connector921. A lower mount94of the trim-tilt mechanism9ais coupled to the couplers84. Specifically, the lower mount94is connected to a connector941coupled to the couplers84. The lower mount94is rotatably connected to the connector941.

The trim-tilt mechanism9ais connected to the couplers84of the support member8asuch that its coupling position with respect to the couplers84is adjustable. Specifically, the lower mount94of the trim-tilt mechanism9ais fixed such that its coupling position is adjustable in a vertical direction with respect to the couplers84. As shown inFIG. 8, the lower mount94is fastened with, for example, threaded fasteners942and is fixed to the couplers84. In other words, the fastener members942are loosened such that the lower mount94is slidable with respect to the couplers84.

The remaining structure of the second preferred embodiment is preferably similar to that of the above first preferred embodiment.

According to the second preferred embodiment of the present invention, the following advantageous effects are obtained.

According to the second preferred embodiment of the present invention, the support member8athat steerably supports the outboard motor body100aincludes the upper support82that surrounds the drive shaft21and supports the outboard motor body100a, the lower support85that is spaced below the upper support82, surrounds the drive shaft21, and supports the outboard motor body100a, and the couplers84that couple the upper support82to the lower support85, similarly to the first preferred embodiment. Thus, an increase in the entire length of a boat10including the outboard motor200is significantly reduced or prevented, and an increase in the size of the boat body11is significantly reduced or prevented.

According to the second preferred embodiment of the present invention, the outboard motor200includes the trim-tilt mechanism9athat couples the couplers84of the support member8ato the clamp brackets81and rotates the outboard motor body100ain the vertical direction. Thus, the coupling position of the trim-tilt mechanism9awith respect to the boat body11is elevated, and hence the drive amount of the trim-tilt mechanism9a(the amount of extension of a cylinder91) is reduced when the outboard motor200is fully tilted up. Furthermore, when the outboard motor200is fully tilted up, the coupling position where the trim-tilt mechanism9ais attached to the boat body11is prevented from being under water.

According to the second preferred embodiment of the present invention, the coupling position of the trim-tilt mechanism9awith respect to the couplers84of the support member8ais adjustable. Thus, the coupling position of the trim-tilt mechanism9ais adjusted according to the size of the boat body11and the size of the outboard motor200such that the trim of the outboard motor200is properly adjusted, and the outboard motor200is properly tilted up.

The remaining advantageous effects of the second preferred embodiment are similar to those of the above first preferred embodiment.

The preferred embodiments of the present invention described above are illustrative in all points and not restrictive. The extent of the present invention is not defined by the above description of the preferred embodiments but by the scope of claims, and all modifications within the meaning and range equivalent to the scope of claims are further included.

For example, while a single outboard motor is preferably provided in the boat in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, multiple outboard motors may alternatively be provided in the boat.

While the steering axis preferably overlaps with the drive shaft as viewed in the axial direction of the drive shaft in each of the first and second preferred embodiments described above, the present invention is not restricted to this. The steering axis may not overlap with the drive shaft as viewed in the axial direction of the drive shaft. For example, the steering axis and the drive shaft may be close to each other inside the support.

While the pair of couplers is preferably provided in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, one coupler may alternatively be provided, or three or more couplers may alternatively be provided.

While the couplers are preferably made of a material containing carbon fiber in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the couplers may alternatively be made of metal. For example, the couplers may be made of a material containing metal such as aluminum or iron.

While the collar is preferably provided inside the damper in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the collar may alternatively be provided outside the damper. Furthermore, the damper and the collar may alternatively be integral and unitary with each other.

While the shift shaft is preferably located in the through-hole of the housing in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the shift shaft may alternatively be located outside the through-hole of the housing. For example, the shift shaft may be located outside the cover.

While the apron is preferably used as the cover or the first cover in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the cover or the first cover may alternatively be a cover other than the apron. For example, the cover or the first cover may be a housing that covers the drive shaft.

While the upper cover is preferably used as the cover or the second cover in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the cover or the second cover may alternatively be a cover other than the upper cover. For example, the cover or the second cover may be a housing that covers the drive shaft.

While the trim-tilt mechanism preferably couples the boat body to the outboard motor body in a state where the couplers of the boat body are above and the coupler(s) of the outboard motor body is below in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the trim-tilt mechanism may alternatively couple the boat body to the outboard motor body in a state where the couplers of the boat body are below and the coupler(s) of the outboard motor body is above.

While the trim-tilt mechanism is preferably hydraulically driven in each of the first and second preferred embodiments described above, the present invention is not restricted to this. According to a preferred embodiment of the present invention, the trim-tilt mechanism may alternatively be driven other than hydraulically. The trim-tilt mechanism may be electrically driven, for example.