Outboard motors and ships

Abstract

The transmission of steering force from the steering system to the steering shaft is improved. [Solution] The outboard motor includes a main body case, a drive source, a propeller, a drive shaft, a bracket attached to the hull, and a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side. The steering device supports the main body case so that it can rotate around the steering shaft relative to the bracket, and a steering device positioned on the third end side of the steering shaft that outputs a steering force to rotate the main body case. The steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft and the distance from the fourth end to the drive shaft are different from each other. The steering device is located on the opposite side of the steering shaft from the fourth end to the third end, when viewed in the direction along the drive shaft.

Description

Technical Field

[0006] , , ,

[0001] The technology disclosed in this specification relates to outboard motors and ships.

Background Art

[0002] A ship includes a hull and an outboard motor attached to the rear part of the hull. The outboard motor is a device that generates thrust to propel the ship.

[0003] The outboard motor includes a main body case, a drive source, a propeller, a drive shaft, and a bracket. The drive source has an output shaft and is housed in the upper part of the main body case. The propeller is rotatably provided in the lower part of the main body case. The drive shaft is provided in the main body case so as to extend in the vertical direction. The upper end of the drive shaft is connected to the output shaft of the drive source so as to be torque-transmittable, and the lower end of the drive shaft is connected to the propeller so as to be torque-transmittable. The bracket is attached to the hull. The bracket includes a steering shaft and supports the main body case so as to be rotatable about the steering shaft.

[0004] Among outboard motors, there are not only outboard motors having a configuration in which the steering shaft is parallel to the drive shaft, but also outboard motors having a configuration in which the steering shaft is inclined with respect to the drive shaft are known.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] Outboard motors are sometimes equipped with a steering actuator that outputs steering force to rotate the main body case around the steering shaft. In conventional outboard motors, the arrangement relationship between the steering shaft and the steering actuator has not been sufficiently considered in configurations where the steering shaft is inclined relative to the drive shaft, and there is room for improvement. This issue is common not only to steering actuators but also to outboard motors equipped with manual steering devices.

[0007] This specification discloses a technology capable of solving the above-mentioned problems. [Means for solving the problem]

[0008] The technologies disclosed herein can be implemented, for example, in the following forms:

[0009] (1) An outboard motor disclosed herein is an outboard motor comprising: a main body case; a drive source housed in the main body case and having an output shaft; a propeller rotatably mounted on the main body case; a drive shaft provided on the main body case and having a first end connected to the output shaft of the drive source and a second end connected to the propeller; a bracket attached to the hull; and a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side, wherein the steering shaft is rotatably supported on the bracket by the steering shaft; and a steering device positioned on the third end side of the steering shaft and outputting a steering force to rotate the main body case, wherein the steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft and the distance from the fourth end to the drive shaft are different from each other, and the steering device is located on the opposite side of the steering shaft from the third end to the fourth end in a view along the drive shaft.

[0010] In this configuration, for example, compared to a configuration where the steering device is located on the same side as the fourth end of the steering shaft relative to the third end of the steering shaft when viewed in the direction along the drive shaft, the distance between the steering device and the third end of the steering shaft is reduced, thus improving the transmission of steering force from the steering device to the steering shaft.

[0011] (2) In the above outboard motor, the central axis is a straight line parallel to the drive shaft and passing through the center of gravity of the outboard motor, the drive shaft is located between the steering shaft and the central axis, and the distance from the fourth end of the steering shaft to the drive shaft may be shorter than the distance from the third end to the drive shaft. In this configuration, because the distance between the fourth end of the steering shaft and the central axis is relatively short, the steering torque generated on the steering shaft by the force exerted by water pressure on the propeller side of the outboard motor, which is located in the water, can be reduced.

[0012] (3) In the above outboard motor, the propeller may have a propeller shaft and blades fixed to the propeller shaft, and the first intersection point between the first extension line extending from the steering shaft and the propeller shaft may be located on the opposite side from the blades to the second intersection point between the second extension line extending from the drive shaft and the propeller shaft. This configuration can reduce the steering torque burden required to steer the main body case against the force received by the water pressure on the propeller side portion located in the water.

[0013] (4) In the above outboard motor, the central axis is a straight line parallel to the drive shaft and passing through the center of gravity of the outboard motor, and the propeller has a propeller shaft and blades fixed to the propeller shaft, and the first intersection point of the first extension line extending from the steering shaft and the propeller shaft is located on the opposite side from the blades with respect to the third intersection point of the central axis and the propeller shaft. This configuration can reduce the steering torque burden required to steer the main body case against the force received by the water pressure on the propeller side portion located in the water.

[0014] (5) The outboard motor further comprises a first mounting member extending from the third end of the steering shaft toward the main body case and joined to the main body case, and a second mounting member extending from the fourth end of the steering shaft toward the main body case and joined to the main body case, wherein the degree of parallelism of the imaginary straight line connecting the joint point between the first mounting member and the main body case and the joint point between the second mounting member and the main body case with respect to the drive shaft is higher than the degree of parallelism of the steering shaft with respect to the drive shaft. In this configuration, the two positions to which force is transmitted from the steering shaft to the main body case are located on a straight line with a high degree of parallelism to the drive shaft. Therefore, vibrations caused by differences between the two positions to which force is transmitted from the steering shaft to the main body case can be suppressed.

[0015] (6) In the above outboard motor, at least a part of the steering device may be configured to overlap the steering shaft when viewed in a direction along the rotation axis of the propeller. This configuration can suppress an increase in the size of the portion including the steering device and the steering shaft in a direction parallel to the drive shaft.

[0016] (7) In the above outboard motor, the bracket may have a tilt axis perpendicular to the drive shaft and constituting the tilt axis in the tilt operation of the main body case, and the steering device may be arranged on the tilt axis. This configuration can suppress the increase in size of the outboard motor compared to, for example, a configuration in which the steering device is not arranged on the tilt axis.

[0017] (8) The outboard motor may further be equipped with a tilt actuator that outputs a rotational force to perform a tilting motion relative to the main body case, and the tilt actuator may be configured to overlap with the steering device when viewed in the direction along the drive shaft. This configuration can suppress the increase in size of the outboard motor.

[0018] (9) The outboard motor may further include a shift device for switching the operating state of the propeller and a shift actuator for controlling the switching operation of the shift device, wherein the shift actuator is located in the space between the shift device and the fourth end of the steering shaft. Compared to a configuration in which the steering shaft is arranged parallel to the drive shaft, for example, this configuration provides more space below the steering shaft and improves the freedom of placement of the shift actuator.

[0019] (10) In the above outboard motor, the propeller has a propeller shaft and blades fixed to the propeller shaft, and the shift device has a shift shaft extending from the shift actuator to the end of the propeller shaft opposite to the blades, and the first extension straight line extending from the steering shaft may pass between the first end of the drive shaft and the shift shaft. This configuration can reduce the steering torque burden required to steer the main body case against the force received by the water pressure on the propeller side portion located in water.

[0020] (11) In the above outboard motor, at least a portion of the steering shaft may overlap with the shift shaft when viewed in the direction along the drive shaft. This configuration can suppress the increase in size of the outboard motor.

[0021] (12) In the above outboard motor, the shift actuator may be electrically powered. This configuration allows the electrically powered shift actuator to be placed near the shift device, thereby reducing the torque load on the electric motor.

[0022] (13) In the above outboard motor, the steering device may be electrically operated. This configuration allows the electrically operated steering device to be placed near the steering device, thereby reducing the torque load on the electric motor.

[0023] (14) The outboard motor disclosed in this specification is an outboard motor, comprising a main body case, a drive source housed in the main body case and having an output shaft, a propeller rotatably provided on the main body case, a drive shaft provided on the main body case and having a first end connected to the output shaft of the drive source and a second end connected to the propeller, and a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side. The main body case is supported by a steering device so as to be rotatable about the steering shaft. The steering device includes a steering device that is arranged on the third end side of the steering shaft and outputs a steering force for rotating the main body case. The steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft is different from the distance from the fourth end to the drive shaft. The steering device is located closer to the fourth end of the steering shaft than the third end of the steering shaft when viewed in the direction along the drive shaft. According to this outboard motor, the transmission performance of the steering force from the steering device to the steering shaft is improved.

[0024] Note that the technology disclosed in this specification can be realized in various forms. For example, it can be realized in the form of an outboard motor, a ship equipped with an outboard motor and a hull, etc.

Effects of the Invention

[0025] According to the outboard motor disclosed in this specification, the transmission performance of the steering force from the steering device to the steering shaft is improved.

Brief Description of the Drawings

[0026] [Figure 1] Perspective view schematically showing the configuration of a ship in an embodiment [Figure 2] Side view schematically showing the configuration of an outboard motor [Figure 3] Side view schematically showing a part of the configuration of an outboard motor [Figure 4]Diagram illustrating the relationship between the steering shaft and steering torque of the outboard motor in the comparative example. [Figure 5] This diagram illustrates the relationship between the steering shaft and steering torque of the outboard motor in this embodiment. [Modes for carrying out the invention]

[0027] Figure 1 is a schematic perspective view showing the configuration of the vessel 10 of this embodiment. Figure 1 and other drawings described later show arrows representing each direction relative to the position of the vessel 10. More specifically, each figure shows arrows representing the front, rear, left, right, up, and down directions. The front-to-back, left-to-right, and up-to-down (vertical) directions are all perpendicular to each other.

[0028] The vessel 10 comprises a hull 200 and an outboard motor 100.

[0029] The hull 200 is the part of the vessel 10 where the crew is seated. The hull 200 has a main hull section 202 having a living space 204, a cockpit 240 installed in the living space 204, and a control system 250 installed near the cockpit 240. The control system 250 includes, for example, a steering wheel 252, a shift / throttle lever 254, a monitor 256, and an input device 258. The hull 200 also has a partition wall 220 that demarcates the aft end of the living space 204, and a transom 210 located at the aft end of the hull 200. In the longitudinal direction, there is a space (hereinafter referred to as the "aft upper space 206") between the transom 210 and the partition wall 220.

[0030] Figure 2 is a schematic side view showing the configuration of the outboard motor 100. Figure 3 is a schematic side view showing a part of the configuration of the outboard motor 100. Figure 3 shows an enlarged view of the configuration of the part enclosed by frame line III in Figure 2. In the following, unless otherwise specified, the outboard motor 100 in the standard position will be described. The standard position is the position in which the rotation axis Ac of the crankshaft 124, which will be described later, extends in the vertical direction, and the rotation axis Ap of the propeller shaft 112b extends in the longitudinal direction (horizontal direction). The longitudinal direction, the left-right direction, and the vertical direction are each determined based on the outboard motor 100 in the standard position.

[0031] The outboard motor 100 is a device that generates thrust to propel the vessel 10. The outboard motor 100 is mounted on the transom 210 at the rear of the hull 200. The outboard motor 100 includes an outboard motor body 110, a suspension system 150, a steering support 157, a steering actuator 170, and a tilt actuator 180. The steering actuator 170 is an example of a steering device.

[0032] (Outboard motor body 110 configuration) The outboard motor body 110 comprises an engine assembly 120, a propeller 112, a power transmission mechanism 130, a cowl 114, and a casing 116. The cowl 114 and casing 116 are examples of the main body case.

[0033] The engine assembly 120 is a collection of multiple parts centered around the engine body 122. In addition to the engine body 122, the engine assembly 120 includes electrical components 128 (e.g., fuse box, ECU, steering CU, etc.). The engine assembly 120 is located in a relatively high position in the outboard motor 100.

[0034] At least a portion of the engine assembly 120 is housed within the cowl 114. The cowl 114 has a lower cowl 114b that forms the lower part of the cowl 114 and an upper cowl 114a that forms the upper part of the cowl 114. The upper cowl 114a is removablely attached to the lower cowl 114b.

[0035] The engine body 122 is a prime mover that generates power. The engine body 122 is composed of, for example, an internal combustion engine. The engine body 122 has a crankshaft 124 that converts the reciprocating motion of a piston (not shown) into rotational motion. The crankshaft 124 is positioned so that its axis of rotation Ac extends in the vertical direction. The crankshaft 124 has journals 124a that support the crankshaft 124 itself at the bearing portion of a crankcase (not shown), and splines 124b where multiple longitudinal grooves are formed for connection to a drive shaft 132, which will be described later. The engine body 122 is an example of a drive source, and the splines 124b is an example of an output shaft.

[0036] The propeller 112 is a rotating body having multiple blades 112a. The propeller 112 is positioned relatively low on the outboard motor 100. The propeller 112 generates thrust by rotating.

[0037] Specifically, the propeller 112 has multiple blades 112a and a propeller shaft 112b. The propeller shaft 112b is a rod-shaped member and is positioned relatively low on the outboard motor 100, extending in the front-rear direction. The rear end of the propeller shaft 112b protrudes outside the casing 116, and multiple blades 112a are attached to this rear end. As the propeller shaft 112b rotates around the rotation axis Ap, the multiple blades 112a also rotate.

[0038] The power transmission mechanism 130 is a mechanism that transmits power generated in the engine assembly 120 to the propeller 112 (propeller shaft 112b). At least a part of the power transmission mechanism 130 is housed in the casing 116. The power transmission mechanism 130 includes a drive shaft 132, a shift device 134, and a shift actuator 190.

[0039] The drive shaft 132 is a rod-shaped member positioned below the crankshaft 124 of the engine body 122, extending vertically. The upper end 132U of the drive shaft 132 is directly or indirectly connected to a spline 124b provided at the lower end of the crankshaft 124, enabling torque transmission. Therefore, the drive shaft 132 rotates around the drive axis Ad as the crankshaft 124 rotates. The upper end 132U of the drive shaft 132 is an example of a first end.

[0040] The shift device 134 is connected to the lower end 132L of the drive shaft 132 and is also directly or indirectly connected to the front end of the propeller shaft 112b in a manner that allows torque transmission. The shift device 134 includes, for example, a plurality of gears, a clutch for switching the meshing of the gears, and a shift shaft 133, and transmits the rotation of the drive shaft 132 to the propeller shaft 112b in a manner that allows the direction of rotation to be switched.

[0041] The shift shaft 133 is a rod-shaped member positioned in front of the drive shaft 132, extending vertically. The upper end of the shift shaft 133 extends to the space 163 directly below the steering shaft 158. The lower end of the shift shaft 133 is connected to the front end of the propeller shaft 112b. The rotation of the shift shaft 133 causes the clutch of the shift device 134 to switch between rotating the drive shaft 132 in the forward direction and rotating the drive shaft 132 in the reverse direction. When the shift device 134 transmits the rotation of the drive shaft 132 as forward rotation to the propeller shaft 112b, the propeller 112, which rotates in the forward direction together with the propeller shaft 112b, generates thrust in the forward direction. Conversely, when the shift device 134 transmits the rotation of the drive shaft 132 to the propeller shaft 112b as rotation in the reverse direction, the propeller 112, which rotates in the reverse direction together with the propeller shaft 112b, generates thrust in the reverse direction. The lower end 132L of the drive shaft 132 is an example of a second end.

[0042] The shift actuator 190 controls the switching operation of the shift device 134. The shift actuator 190 is located in the space 163. The shift actuator 190 is connected to the upper end of the shift shaft 133 and controls the switching operation of the shift device 134 by controlling the rotation of the shift shaft 133. The shift actuator 190 is an electrically operated actuator having an electric motor (not shown) that rotates the shift shaft 133.

[0043] (Configuration of suspension system 150) The suspension system 150 is a device for suspending the outboard motor body 110 from the hull 200. The suspension system 150 includes a pair of left and right clamp brackets 152, a tilt shaft 160, and a swivel bracket 156. The clamp brackets 152 and swivel bracket 156 are examples of brackets.

[0044] A pair of left and right clamp brackets 152 are positioned at the rear of the hull 200, spaced apart from each other in the left-right direction, and are fixed to the transom 210 of the hull 200, for example, by bolts. Each clamp bracket 152 has a cylindrical support portion 152a with a through hole extending in the left-right direction.

[0045] The tilt shaft 160 is a rod-shaped member. At least a portion of the tilt shaft 160 is rotatably supported within a through-hole in the support portion 152a of the clamp bracket 152. The tilt axis line At, which is the center line of the tilt shaft 160, constitutes the horizontal (left-right) axis in the tilt operation of the outboard motor 100.

[0046] The swivel bracket 156 is positioned between a pair of clamp brackets 152 and is supported by the support portion 152a of the clamp brackets 152 via a tilt shaft 160 so as to be rotatable around the tilt axis At. The swivel bracket 156 is rotationally driven around the tilt axis At relative to the clamp brackets 152 by a tilt actuator 180, such as a hydraulic cylinder 185. The tilt actuator 180 is positioned, for example, below the tilt shaft 160 in the space between the pair of clamp brackets 152.

[0047] The steering support 157 includes a steering shaft 158. The steering shaft 158 ​​is a rod-shaped member. The steering shaft 158 ​​is supported by a swivel bracket 156 so as to be rotatable about the steering axis As, which is the centerline of the steering shaft 158, in a position extending in a direction inclined with respect to the vertical direction (drive shaft 132).

[0048] The steering actuator 170 is located on the upper end 158U side of the steering shaft 158. The steering actuator 170 is electrically powered and includes an electric motor (not shown) that outputs a steering force to rotate the steering shaft 158, and a pair of arms 172 (only one shown in Figure 3) connected to the steering shaft 158. The steering shaft 158 ​​is rotationally driven around the steering axis As relative to the swivel bracket 156 via the arms 172 of the steering actuator 170. The steering actuator 170 is located, for example, coaxially with the tilt shaft 160 in the space sandwiched between the support portions 152a of a pair of clamp brackets 152.

[0049] The outboard motor body 110 is fixed to the steering shaft 158. Therefore, when the steering shaft 158 ​​rotates around the steering axis As relative to the swivel bracket 156, the outboard motor body 110, which is fixed to the steering shaft 158, also rotates around the steering axis As. This changes the direction of the thrust generated by the propeller 112 relative to the orientation of the hull 200, thereby enabling the steering of the vessel 10.

[0050] Furthermore, when the swivel bracket 156 rotates around the tilt axis At relative to the clamp bracket 152, the steering shaft 158 ​​supported by the swivel bracket 156 and the outboard motor body 110 fixed to the steering shaft 158 ​​also rotate around the tilt axis At. This enables a tilt operation that rotates the outboard motor body 110 vertically relative to the hull 200. The tilt operation of the outboard motor 100 allows the angle of the outboard motor body 110 around the tilt axis At to be changed within a range from a tilt-down state where the propeller 112 is underwater (the state in which the outboard motor 100 is in its standard position) to a tilt-up state where the propeller 112 is above the water surface. In addition, the tilt actuator 180 can be used to perform a trim operation to adjust the attitude of the vessel 10 while it is running by adjusting the angle of the outboard motor body 110 around the tilt axis At.

[0051] The outboard motor body 110 is equipped with steer-by-wire (SBW). The SBW transmits operations from the control device 250 to the steering actuator 170 and the shift actuator 190 via electrical control. For example, the control device 250 has sensors that detect various operations, and the SBW receives output signals from these sensors and controls the steering actuator 170 and the shift actuator 190 in accordance with the operations from the control device 250 based on these output signals.

[0052] As shown in Figures 2 and 3, the steering shaft 158 ​​(steering axis line As) is inclined with respect to the drive shaft 132. Specifically, the shortest distance (straight line distance in the direction along the propeller shaft 112b) from the lower end 158L of the steering shaft 158 ​​to the drive shaft 132 (drive axis line Ad) is shorter than the shortest distance from the upper end 158U of the steering shaft 158 ​​to the drive shaft 132. The steering actuator 170 is located on the opposite side of the lower end 158L of the steering shaft 158 ​​from the upper end 158U when viewed in the vertical direction (direction along the drive shaft 132). That is, the steering actuator 170 is located in front of the upper end 158U of the steering shaft 158. The upper end 158U of the steering shaft 158 ​​is an example of a third end, and the lower end 158L of the steering shaft 158 ​​is an example of a fourth end. The inclination angle of the steering axis 158 (steering axis As) relative to the drive axis 132 (drive axis Ad) may be, for example, 2 degrees or more and 20 degrees or less, or 3 degrees or more and 10 degrees or less.

[0053] The upper end 158U of the steering shaft 158 ​​is fixed to the outboard motor body 110 via a first mounting member 159U. The first mounting member 159U extends in the longitudinal direction from the upper end 158U toward the outboard motor body 110. The lower end 158L of the steering shaft 158 ​​is fixed to the outboard motor body 110 via a second mounting member 159L. The second mounting member 159L extends in the longitudinal direction from the lower end 158L toward the outboard motor body 110.

[0054] The positional relationship between the steering shaft 158 ​​(steering axis As), the drive shaft 132 (drive axis Ad), and the central axis Ag is as follows: The central axis Ag is parallel to the drive shaft 132 and is a virtual straight line passing through the center of gravity G of the outboard motor body 110. In this embodiment, the center of gravity G of the outboard motor body 110 is the centroid of the lower portion of the casing 116 that is located underwater. The drive shaft 132 is located between the steering shaft 158 ​​and the central axis Ag in the longitudinal direction. The shortest distance from the lower end 158L of the steering shaft 158 ​​to the central axis Ag (straight-line distance along the propeller shaft 112b) is shorter than the shortest distance from the upper end 158U of the steering shaft 158 ​​to the central axis Ag. In this specification, "parallel" is not limited to the angle between line A and line B being 180 degrees (perfect parallelism), but also includes cases where there is an inclination of approximately ±5 degrees.

[0055] The positional relationship between the steering shaft 158 ​​(steering axis As), the drive shaft 132 (drive axis Ad), and the propeller shaft 112b (rotation axis Ap) is as follows: The intersection of the steering axis As and the rotation axis Ap is designated as the first intersection point Ps, and the intersection of the drive axis Ad and the rotation axis Ap is designated as the second intersection point Pd. The first intersection point Ps is located in front of the second intersection point Pd (on the opposite side from the blade 112a). The steering axis As is an example of the first extended straight line, and the drive axis Ad is an example of the second extended straight line.

[0056] The positional relationship between the steering axis 158 (steering axis As), the central axis Ag, and the propeller axis 112b (rotation axis Ap) is as follows. The intersection point of the central axis Ag and the rotation axis Ap is defined as the third intersection point Pg. The first intersection point Ps is located in front of the third intersection point Pg (on the opposite side from the blade 112a). The central axis Ag is an example of a third extended straight line.

[0057] The positional relationship between the steering shaft 158 ​​(steering axis line As), the drive shaft 132 (drive axis line Ad), and the shift shaft 133 is as follows: The steering axis line As passes between the upper end 132U of the drive shaft 132 and the upper end of the shift shaft 133. In a vertical view, at least a portion of the steering shaft 158 ​​overlaps with the shift shaft 133.

[0058] The steering actuator 170 is positioned as follows: The steering actuator 170 is positioned in space 163 as described above. Space 163 is the space secured in the vertical direction between the lower end 158L of the steering shaft 158 ​​and the shift device 134 (shift shaft 133).

[0059] At least a portion of the steering actuator 170 is located at the same position as the steering shaft 158 ​​in the vertical direction (parallel to the drive shaft 132). Specifically, in a view in the front-rear direction, a portion of the steering actuator 170 (the lower portion) overlaps with the upper end 158U of the steering shaft 158.

[0060] Figure 4 is an explanatory diagram showing the relationship between the steering shaft 158A and steering torque of the comparative example outboard motor 100A. Figure 4 schematically shows the configuration of the comparative example outboard motor 100A. The comparative example outboard motor 100A differs from the outboard motor 100 of this embodiment mainly in that the steering shaft 158A is parallel to the drive axis Ad. The shortest distance L1 between the steering axis As and the center of gravity G is relatively long. Therefore, the steering torque load (=F × L1) generated on the steering shaft 158A by the force received by the water pressure on the lower part (propeller side) of the casing 116 which is placed in the water is relatively large. Also, because the steering shaft 158A extends along the vertical direction, the distance H1 between the lower end of the steering shaft 158A and the upper surface of the casing 116 is relatively short. As a result, the degree of freedom in the placement of the shift actuator 190 is restricted.

[0061] Figure 5 is an explanatory diagram showing the relationship between the steering shaft 158 ​​and steering torque of the outboard motor 100 of this embodiment. Figure 5 schematically shows the configuration of the outboard motor 100. The steering shaft 158 ​​is inclined with respect to the drive axis Ad. The shortest distance L2 between the steering axis As and the center of gravity G is relatively short. Therefore, the steering torque load (=F × L2) generated on the steering shaft 158 ​​by the force received by the water pressure on the lower part (propeller side) of the casing 116 which is placed in the water is relatively small. Accordingly, in this embodiment, compared to the comparative example, the required strength of the components of the steering support 157 and steering actuator 170 is lower, which allows for miniaturization and weight reduction of the steering support 157 and steering actuator 170.

[0062] In this embodiment, the steering actuator 170 is located on the opposite side of the lower end 158L of the steering shaft 158 ​​from the upper end 158U when viewed in the vertical direction. Therefore, compared to a configuration in which, for example, the steering actuator 170 is located on the same side as the lower end 158L when viewed in the vertical direction from the upper end 158U, the distance between the steering actuator 170 and the upper end 158U of the steering shaft 158 ​​is reduced, thus improving the transmission of steering force from the steering actuator 170 to the steering shaft 158.

[0063] In this embodiment, the upper end 158U of the steering shaft 158 ​​is located at the same height as the upper end of the steering shaft 158A in the comparative example. The lower end 158L of the steering shaft 158 ​​is located at a higher position than the lower end of the steering shaft 158A in the comparative example. The distance H2 between the lower end of the steering shaft 158A and the upper surface of the casing 116 is relatively long. As a result, the space 163 is increased, improving the degree of freedom in the placement of the shift actuator 190.

[0064] In this embodiment, the virtual straight line Lt connecting the joint point between the first mounting member 159U and the outboard motor body 110, and the joint point between the second mounting member 159L and the outboard motor body 110, is parallel to the drive axis Ad. That is, although the steering shaft 158 ​​is inclined with respect to the drive axis Ad, the joint point of the first mounting member 159U and the joint point of the second mounting member 159L that support the steering shaft 158 ​​are located on a straight line parallel to the drive axis Ad. Therefore, vibrations (forward and backward vibrations) caused by the difference in the two positions to which the force transmitted from the steering shaft 158 ​​to the outboard motor body 110 is applied can be suppressed. Note that the virtual straight line Lt does not have to be parallel to the drive axis Ad; it is sufficient that the degree of parallelism of the virtual straight line Lt with respect to the drive axis Ad is higher than the degree of parallelism of the steering shaft As with respect to the drive axis Ad.

[0065] The technologies disclosed herein are not limited to the embodiments described above and can be modified in various forms without departing from their essence, for example, the following modifications are possible.

[0066] The configuration of the vessel 10 in the above embodiment is merely an example and can be modified in various ways. For example, in the above embodiment, the drive source was the engine body 122, but it is not limited to this and could be an electric motor, for example. When the drive source is an electric motor, the rotating shaft of the electric motor is an example of an output shaft.

[0067] In the above embodiment, the steering actuator 170 and the shift actuator 190 were electrically operated, but they may also be hydraulic, such as having a hydraulic cylinder. In the above embodiment, the actuator device was a steering actuator that converts energy such as electricity, pneumatics, or hydraulics into mechanical movement, but it is not limited to this, and may also be a manual steering device that has a lever to rotate the steering shaft, and the steering shaft is rotated by a person operating the lever. In the above embodiment, the tilt actuator 180 was hydraulic, but it may also be electric, such as having a hydraulic system.

[0068] In the above embodiment, the shortest distance from the lower end 158L of the steering shaft 158 ​​to the drive shaft 132 may be longer than the shortest distance from the upper end 158U of the steering shaft 158 ​​to the drive shaft 132. Also, the shortest distance from the lower end 158L of the steering shaft 158 ​​to the central axis Ag may be longer than the shortest distance from the upper end 158U of the steering shaft 158 ​​to the central axis Ag. Even in these cases, the tilt of the steering shaft 158 ​​can ensure a wide space 163. The steering actuator 170 is not limited to space 163, but may be housed, for example, in the cowl 114. In the above embodiment, the steering actuator 170 does not have to overlap with the upper end 158U of the steering shaft 158 ​​when viewed in the front-rear direction.

[0069] The steering actuator 170 may be positioned at a location different from the tilt axis At. For example, the steering actuator 170 may be positioned above the upper end 158U of the steering shaft 158, or behind the upper end 158U.

[0070] In the above embodiment, the first intersection Ps may coincide with the second intersection Pd, or it may be located behind the second intersection Pd (on the side of the wing 112a). In the above embodiment, the first intersection Ps may be located at the third intersection Pg, or it may be located behind the third intersection Pg (on the side of the wing 112a). In the above embodiment, the steering axis As may pass behind the upper end 132U of the drive axis 132 or in front of the upper end of the shift axis 133. In the above embodiment, the steering axis 158 does not have to overlap with the shift axis 133 when viewed in the vertical direction.

[0071] In the above embodiment, the joint point of the first mounting member 159U supporting the steering shaft 158 ​​and the joint point of the second mounting member 159L may be located on a straight line inclined with respect to the drive axis Ad.

[0072] In this embodiment, the steering actuator 170 may be located on the same side as the lower end 158L of the steering shaft 158 ​​with respect to the upper end 158U when viewed in the vertical direction. In this embodiment, the tilt actuator 180 overlapped the steering actuator 170 when viewed in the vertical direction, but it does not have to overlap the steering actuator 170.

[0073] The inventions disclosed herein may also be as follows: "It is an outboard motor, The main case and A drive source housed in the aforementioned main case and having an output shaft, A propeller is rotatably mounted on the main body case, A drive shaft provided in the main body case, having a first end connected to the output shaft of the drive source and a second end connected to the propeller, A bracket that attaches to the hull, A steering device that includes a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side, and supports the main body case so as to be rotatable about the steering shaft with respect to the bracket, A steering device is positioned on the third end side of the steering shaft and outputs a steering force that rotates the main body case, Equipped with, The steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft and the distance from the fourth end to the drive shaft are different from each other. Furthermore, a shift device for switching the operating state of the propeller, The system includes a shift actuator that controls the switching operation of the shift device, The shift actuator is located in the space between the shift device and the fourth end of the steering shaft of the outboard motor. [Explanation of Symbols]

[0074] 10: Ship 100,100A: Outboard motor 110: Outboard motor body 112: Propeller 112a: Blade 112b: Propeller shaft 116: Casing 120: Engine assembly 122: Engine body 124: Crankshaft 124a: Journal 124b: Spline 130: Power transmission mechanism 132: Drive shaft 133: Shift shaft 134: Shift device 150: Suspension device 152: Clamp bracket 156: Swivel bracket 157: Steering support 158,158A: Steering shaft 159L: Second mounting member 159U: First mounting member 160: Tilt shaft 163: Space 170: Steering actuator 180: Tilt actuator 190: Shift actuator 200: Hull 202: Hull body 250: Control system Ac: Rotation axis Ad: Drive axis Ag: Center axis Ap: Rotation axis As: Steering axis At: Tilt axis CU: Steering G: Center of gravity Pd: Second intersection Pg: Third intersection Ps: First intersection

Claims

1. It is an outboard motor, The main case and A drive source housed in the aforementioned main case and having an output shaft, A propeller is rotatably mounted on the main body case, A drive shaft provided in the main body case, having a first end connected to the output shaft of the drive source and a second end connected to the propeller, A bracket that attaches to the hull, A steering device that includes a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side, and supports the main body case so as to be rotatable about the steering shaft with respect to the bracket, A steering device is positioned on the third end side of the steering shaft and outputs a steering force that rotates the main body case, Equipped with, The steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft and the distance from the fourth end to the drive shaft are different from each other. The steering device is located, in a view along the drive shaft, on the opposite side of the fourth end from the third end of the steering shaft. Outboard motor.

2. An outboard motor according to claim 1, The central axis is defined as a straight line parallel to the drive shaft and passing through the center of gravity of the outboard motor. The drive shaft is located between the steering shaft and the central axis. An outboard motor in which the distance from the fourth end of the steering shaft to the drive shaft is shorter than the distance from the third end to the drive shaft.

3. An outboard motor according to claim 1 or claim 2, The propeller has a propeller shaft and blades fixed to the propeller shaft. An outboard motor in which the first intersection point between a first extension line extending from the steering shaft and the propeller shaft is located on the opposite side from the blades to the second intersection point between a second extension line extending from the drive shaft and the propeller shaft.

4. An outboard motor according to any one of claims 1 to 3, The central axis is defined as a straight line parallel to the drive shaft and passing through the center of gravity of the outboard motor. The propeller has a propeller shaft and blades fixed to the propeller shaft. An outboard motor in which the first intersection point between the first extension line extending from the steering shaft and the propeller shaft is located on the opposite side from the blades with respect to the third intersection point between the central axis and the propeller shaft.

5. An outboard motor according to any one of claims 1 to 4, Furthermore, a first mounting member extends from the third end of the steering shaft toward the main body case and is joined to the main body case, The steering shaft comprises a second mounting member that extends from the fourth end toward the main body case and is joined to the main body case, An outboard motor in which, with respect to the drive shaft, the degree of parallelism of the imaginary straight line connecting the joint point between the first mounting member and the main body case and the joint point between the second mounting member and the main body case is higher than the degree of parallelism of the steering shaft with respect to the drive shaft.

6. An outboard motor according to any one of claims 1 to 5, An outboard motor in which, when viewed in a direction along the rotation axis of the propeller, at least a portion of the steering device overlaps the steering shaft.

7. An outboard motor according to any one of claims 1 to 6, The bracket has a tilt axis that is perpendicular to the drive axis and constitutes the tilt axis in the tilt operation of the main body case, The steering device is an outboard motor positioned on the tilt axis.

8. An outboard motor according to claim 7, Furthermore, it is equipped with a tilt actuator that outputs a rotational force to perform a tilting motion relative to the main body case. An outboard motor in which the tilt actuator overlaps with the steering device when viewed in a direction along the drive axis.

9. An outboard motor according to any one of claims 1 to 8, Furthermore, a shift device for switching the operating state of the propeller, The system includes a shift actuator that controls the switching operation of the shift device, An outboard motor in which the shift actuator is located in the space between the shift device and the fourth end of the steering shaft.

10. An outboard motor according to claim 9, The propeller has a propeller shaft and blades fixed to the propeller shaft. The shift device has a shift shaft that extends from the shift actuator to the end of the propeller shaft opposite to the blade, An outboard motor in which a first extension line extending from the steering shaft passes between the first end of the drive shaft and the shift shaft.

11. An outboard motor according to claim 10, An outboard motor in which, when viewed in a direction along the drive shaft, at least a portion of the steering shaft overlaps with the shift shaft.

12. An outboard motor according to any one of claims 9 to 11, The aforementioned shift actuator is an electric outboard motor.

13. An outboard motor according to any one of claims 1 to 12, The steering device is an electric outboard motor.

14. The hull and, An outboard motor according to any one of claims 1 to 13, attached to the rear of the hull, A ship equipped with these features.

15. It is an outboard motor, The main case and A drive source housed in the aforementioned main case and having an output shaft, A propeller is rotatably mounted on the main body case, A drive shaft provided in the main body case, having a first end connected to the output shaft of the drive source and a second end connected to the propeller, A steering device that includes a steering shaft having a third end located on the drive source side and a fourth end located on the propeller side, and supports the main body case so as to be rotatable about the steering shaft, A steering device is positioned on the third end side of the steering shaft and outputs a steering force that rotates the main body case, Equipped with, The steering shaft is inclined with respect to the drive shaft such that the distance from the third end to the drive shaft and the distance from the fourth end to the drive shaft are different from each other. The steering device is positioned such that, when viewed in the direction along the drive shaft, it is closer to the fourth end of the steering shaft than to the third end. Outboard motor.

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