Patent Application
20250153825
This application claims the benefit of priority to Japanese Patent Application No. 2023-191230 filed on Nov. 9, 2023. The entire contents of this application are hereby incorporated herein by reference.
The technologies disclosed herein relate to outboard motors and boats.
A boat is provided with a hull and an outboard motor mounted to a rear portion of the hull. The outboard motor is a device that generates thrust to propel the boat.
The outboard motor includes a drive source, a drive shaft that extends in an upper-lower direction and rotates by the driving force of the drive source, a hollow tubular steering shaft arranged to surround the outer circumference of the drive shaft, and a case that is located lower than the drive source. The case is provided with an oil chamber in which oil is stored, and at least a portion of the steering shaft is housed in the oil chamber.
An outboard motor has been disclosed that includes an outboard motor main body and a steering mechanism that rotates the outboard motor main body about a steering axis. The steering mechanism includes a pinion that is fixed around the steering axis and rotates together with the outboard motor main body, a rack that moves linearly to rotate the pinion, and a rack position detection unit (angle detection sensor) that detects the position of the rack (e.g. see JP 2023-102979 A).
When the angle detection sensor is provided in an oil chamber in the case, at least a portion of the wiring connected to the angle detection sensor should also be provided in the oil chamber such that the layout of the wiring of the angle detection sensor becomes complex, which might complicate the configuration of the outboard motor.
Example embodiments of the present invention disclose technologies that can solve one or more of the above-mentioned problems.
The technologies disclosed herein can be implemented in the following example embodiments.
An outboard motor includes a drive source, a drive shaft, a steering shaft, a case, and an angle detection sensor. The drive shaft extends in an upper-lower direction and is rotatable by the driving force of the drive source. The steering shaft surrounds an outer circumference of the drive shaft. The case is located lower than the drive source, and includes an oil chamber to store oil, and at least a portion of the steering shaft is housed in the oil chamber. The angle detection sensor is located higher than the oil chamber and detects the rotation angle of the steering shaft.
The technologies disclosed herein can be implemented in various example embodiments, including, e.g., outboard motors, boats provided with outboard motors and hulls, among other implementations, applications, or example embodiments.
According to example embodiments of the present outboard motor, the angle detection sensor is surrounded by air, which simplifies the layout of the wiring connected to the angle detection sensor and thus the configuration of the outboard motor.
The above and other elements, features, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of the example embodiments with reference to the attached drawings.
The boat 10 includes a hull 200 and an outboard motor 100. In an example embodiment, the boat 10 includes only one outboard motor 100, but the boat 10 may include a plurality of outboard motors 100.
The hull 200 is a portion of the boat 10 for occupants to ride. The hull 200 includes a hull main body 202 including a living space 204, a pilot seat 240 in the living space 204, and an operating device 250 near the pilot seat 240. The operating device 250 steers the boat and includes, e.g., a steering wheel 252, a shift/throttle lever 254, a joystick 255, a monitor 256, and an input device 258. The hull 200 includes a partition wall 220 to partition the rear end of the living space 204 and a transom 210 disposed at the rear end of the hull 200. In the front-rear direction, a space 206 is provided between the transom 210 and the partition wall 220.
The outboard motor 100 generates thrust to propel the boat 10. The outboard motor 100 is attached to the transom 210 at a rear portion of the hull 200. The outboard motor 100 includes an outboard motor main body 110 and a suspension device 150.
The outboard motor main body 110 includes a waterproof case 112, a middle case 116, a lower case 118, a motor assembly 120, a control assembly 500, a transmission 130, a propeller 111, and a steering mechanism 140.
The waterproof case 112 is a housing located at an upper portion of the outboard motor main body 110. The waterproof case 112 houses an electric motor 122 described below and other electrical components to protect the electric motor 122 and other electrical components from being exposed to seawater. The waterproof case 112 includes an upper cover 113 defining an upper portion of the waterproof case 112 and a lower box 114 defining a lower portion of the waterproof case 112. The lower box 114 has a box-shaped configuration with an open top. The upper cover 113 is removably attached to the lower box 114 so as to cover the open top of the lower box 114.
The middle case 116 is a housing located below the waterproof case 112 and near the center of the outboard motor main body 110 in the upper-lower direction. The upper portion of the middle case 116 is connected to the lower box 114 of the waterproof case 112. The middle case 116 is an example of the case.
The lower case 118 is a housing located below the middle case 116 and at the bottom of the outboard motor main body 110.
The motor assembly 120 is housed inside the waterproof case 112. The motor assembly 120 includes an electric motor 122 as a driving source. The electric motor 122 is a prime mover that generates power. The electric motor 122 includes an output shaft 123 that outputs the driving force generated by the electric motor 122. The output shaft 123 is arranged in an attitude in which its rotation axis Ac extends in the upper-lower direction. The electric motor 122 is an example of the drive source.
The control assembly 500 is housed inside the waterproof case 112 and is located higher than the motor assembly 120. The control assembly 500 controls the rotation of the electric motor 122 and the like. The control assembly 500 includes a control case 502, a motor control unit (MCU) 510, and a power supply line 520 (see
The transmission 130 transmits the driving force of the electric motor 122 to the propeller 111. The transmission 130 includes a primary reduction gear 300, a drive shaft 133, and a propeller shaft 135.
The primary reduction gear 300 is housed inside the waterproof case 112 and is located lower than the motor assembly 120. The primary reduction gear 300 is connected to the output shaft 123 of the electric motor 122 and the drive shaft 133. The primary reduction gear 300 reduces the driving force of the electric motor 122 and transmits it to the drive shaft 133. This allows the propeller 111 to rotate at a desired torque.
The drive shaft 133 is a rod-shaped member that transmits power to the propeller shaft 135 and is arranged in an attitude extending in the upper-lower direction. The drive shaft 133 is housed so that it spans the inside of the waterproof case 112, the inside of the middle case 116, and the inside of the lower case 118.
The propeller shaft 135 is a rod-shaped member and extends in the front-rear direction at a height relatively lower than the outboard motor main body 110. The propeller shaft 135 rotates along with the propeller 111. The front end of the propeller shaft 135 is accommodated in the lower case 118, and the rear end of the propeller shaft 135 protrudes rearward from the lower case 118.
A gear is provided at the lower end of the drive shaft 133 and at the front end of the propeller shaft 135, respectively. The rotation of the drive shaft 133 is transmitted to the propeller shaft 135 by meshing the gears of the drive shaft 133 and the propeller shaft 135.
The propeller 111 is a rotatable body with a plurality of blades and is attached to the rear end of the propeller shaft 135. The propeller 111 rotates along with the rotation of the propeller shaft 135 about the rotation axis Ap. The propeller 111 generates thrust to propel the boat 10 by rotating.
The steering mechanism 140 controls changes in the traveling direction of the boat 10. The steering mechanism 140 includes a steering shaft 141. Details of the steering mechanism 140 will be described below.
The suspension device 150 attaches the outboard motor main body 110 to the hull 200. The suspension device 150 includes a pair of left and right clamp brackets 152, a tilt shaft 154, and a swivel bracket 156.
The pair of left and right clamp brackets 152 are disposed behind the hull 200 in a state separated from each other in the left-right direction and are fixed to the transom 210 of the hull 200 by using, e.g., bolts.
The tilt shaft 154 is a rod-shaped member and is rotatably supported by the clamp brackets 152. The tilt axis At, which is the center line of the tilt shaft 154, defines the horizontal (left-right) axis of the outboard motor 100 during tilting.
The swivel bracket 156 is sandwiched between the pair of clamp brackets 152 and is supported by the clamp brackets 152 via the tilt shaft 154 so as to be rotatable about the tilt axis At. The swivel bracket 156 is driven to rotate about the tilt axis At with respect to the clamp bracket 152 by a tilting device (not shown) including an actuator, such as a hydraulic cylinder, for example.
When the swivel bracket 156 rotates about the tilt axis At with respect to the clamp bracket 152, the outboard motor main body 110 supported by the swivel bracket 156 also rotates about the tilt axis At. This achieves the tilting operation of rotating the outboard motor main body 110 in the upper-lower direction with respect to the hull 200. By this tilting operation, the outboard motor 100 can change the angle of the outboard motor main body 110 about the tilt axis At in the range from the tilt-down state in which the propeller 111 is disposed under the water (the state in which the outboard motor 100 is in the reference attitude) to the tilt-up state in which the propeller 111 is disposed above the water surface. Trimming operation to adjust the attitude of the boat 10 during travel can also be performed by adjusting the angle about the tilt axis At of the outboard motor main body 110.
The steering shaft 141 rotates about the rotation axis As, e.g., by the driving force of a driving motor (not shown) housed in the middle case 116. When the steering shaft 141 rotates, the lower case 118 connected to the steering shaft 141 also rotates, and the direction of the propeller 111 is changed. This changes the direction of the thrust generated by the propeller 111 to enable the steering of the boat 10.
As shown in
The offset shaft 164 is arranged in parallel with the drive shaft 133 and the steering shaft 141. At least a portion of the offset shaft 164 is located higher than the oil chamber 117 and inside the waterproof case 112. The offset shaft 164 rotates in conjunction with the rotation of the steering shaft 141, as will be described in more detail below. The offset shaft 164 is an example of the rotatable body.
The transmission 163 transmits the rotation of the steering shaft 141 to the offset shaft 164. The transmission 163 is located higher than the oil chamber 117 and inside the waterproof case 112. More specifically, the transmission 163 includes a first gear 161 and a second gear 162. The first gear 161 is attached to the outer circumference of a portion of the steering shaft 141 located inside the waterproof case 112. The second gear 162 is attached to the outer circumference of a portion of the offset shaft 164 located inside the waterproof case 112. The first gear 161 and the second gear 162 are arranged to mesh with each other. In an example embodiment, the gear ratio between the first gear 161 and the second gear 162 is, for example, 1:1.
The rotation of the steering shaft 141 is transmitted to the offset shaft 164 at a location higher than the oil chamber 117 and inside the waterproof case 112 by the action of the transmission 163. Specifically, when the steering shaft 141 rotates by the driving force of the drive motor housed in the middle case 116, the rotation of the steering shaft 141 is transmitted to the first gear 161, the rotation of the first gear 161 is transmitted to the second gear 162, and the rotation of the second gear 162 is transmitted to the offset shaft 164. As a result, the offset shaft 164 rotates in conjunction with the rotation of the steering shaft 141. In an example embodiment, since the gear ratio between the first gear 161 and the second gear 162 is 1:1, the number of rotations of the steering shaft 141 and the number of rotations of the offset shaft 164 are the same.
As will be explained in more detail below, the potentiometer 168 is a sensor that detects the rotation angle of the steering shaft 141 by measuring the rotation angle of the offset shaft 164. The potentiometer 168 is located higher than the oil chamber 117 and is therefore not positioned in the oil. In other words, the potentiometer 168 is surrounded by air. More specifically, the potentiometer 168 is housed inside the waterproof case 112 below the primary reduction gear 300. In other words, the potentiometer 168 is located between the electric motor 122 and the oil chamber 117 in the upper-lower direction, and between the primary reduction gear 300 and the oil chamber 117. Although not shown in the cross-section in
As shown in
As explained above, the outboard motor 100 of an example embodiment includes the drive source, the drive shaft 133, the steering shaft 141, the middle case 116, and the potentiometer 168. The drive shaft 133 extends in an upper-lower direction and rotates by the driving force of the drive source. The hollow tubular steering shaft 141 surrounds the outer circumference of the drive shaft 133. The middle case 116 is located lower than the drive source and provided with the oil chamber 117 to store oil, and at least a portion of the steering shaft 141 is housed in the oil chamber 117. The potentiometer 168 is located higher than the oil chamber 117 and detects the rotation angle of the steering shaft 141.
According to an example embodiment of the outboard motor 100, the potentiometer 168 is arranged outside the oil chamber 117 in the middle case 116. In other words, the potentiometer 168 is surrounded by air, which simplifies the layout of the wiring connected to the potentiometer 168 and thus the configuration of the outboard motor 100.
In addition, in the outboard motor 100 of an example embodiment, the potentiometer 168 is located between the drive source and the oil chamber 117 in the upper-lower direction. According to the outboard motor 100 of an example embodiment, when a dead space is provided between the drive source and the oil chamber 117 in the upper-lower direction, the potentiometer 168 can be arranged in the dead space, which simplifies the configuration of the outboard motor 100.
In addition, the outboard motor 100 of an example embodiment further includes the primary reduction gear 300 located lower than the drive source and higher than the oil chamber 117, and the potentiometer 168 is located between the primary reduction gear 300 and the oil chamber 117 in the upper-lower direction. According to the outboard motor 100 of an example embodiment, when a dead space is provided between the primary reduction gear 300 and the oil chamber 117 in the upper-lower direction, the potentiometer 168 can be arranged in the dead space, which simplifies the configuration of the outboard motor 100.
In addition, the outboard motor 100 of an example embodiment further includes the rotatable body that rotates in conjunction with the rotation of the steering shaft 141 and at least a portion of which is located above the oil chamber 117, and the potentiometer 168 detects the rotation angle of the steering shaft 141 by measuring the rotation angle of the rotatable body. According to the outboard motor 100 of an example embodiment, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located higher than the oil chamber 117. This simplifies the layout of the wiring connected to the potentiometer 168 and the configuration of the outboard motor 100.
In addition, according to the outboard motor 100 of an example embodiment, the potentiometer 168, which indirectly detects the rotation angle of the steering shaft 141 by measuring the rotation angle of the rotatable body, can be selected according to the size of the rotatable body regardless of the size of the steering shaft 141. Therefore, by using a rotatable body that is smaller than the steering shaft 141, the size of which is difficult to change due to the structure of the outboard motor 100, the potentiometer 168 can be made smaller, which in turn reduces the size of the outboard motor 100.
In addition, in the outboard motor 100 of an example embodiment, a portion of the steering shaft 141 is located higher than the oil chamber 117, and the rotation of the steering shaft 141 is transmitted to the rotatable body at a location higher than the oil chamber 117. According to the outboard motor 100 of an example embodiment, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located higher than the oil chamber 117. This simplifies the layout of the wiring connected to the potentiometer 168 and thus the configuration of the outboard motor 100.
In addition, in the outboard motor 100 of an example embodiment, the rotatable body is the offset shaft 164 that is parallel to the steering shaft 141, and the outboard motor 100 further includes the transmission 163 that is located higher than the oil chamber 117 and transmits the rotation of the steering shaft 141 to the offset shaft 164. According to an example embodiment of the outboard motor 100, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located higher than the oil chamber 117. This simplifies the layout of the wiring connected to the potentiometer 168 and thus the configuration of the outboard motor 100.
In addition, in the outboard motor 100 of an example embodiment, the drive source includes the electric motor 122, and the outboard motor 100 further includes a waterproof case 112 located higher than the oil chamber 117 and housing the electric motor 122 and the potentiometer 168. According to an example embodiment of the outboard motor 100, the potentiometer 168 is housed in the waterproof case 112 located higher than the oil chamber 117, which simplifies the layout of the wiring connected to the potentiometer 168, thus simplifying the configuration of the outboard motor 100 and reducing or preventing the potentiometer 168 from getting wet by water.
In addition, the outboard motor 100 of an example embodiment includes the rotatable body that rotates in conjunction with the rotation of the steering shaft 141 and at least a portion of which is located inside the waterproof case 112, and the potentiometer 168 detects the rotation angle of the steering shaft 141 by measuring the rotation angle of the rotatable body. According to the outboard motor 100 of an example embodiment, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located inside the waterproof case 112. This simplifies the layout of the wiring connected to the potentiometer 168, simplifies the configuration of the outboard motor 100, and reduces or prevents the potentiometer 168 from getting wet by water.
In addition, according to the outboard motor 100 of an example embodiment, the potentiometer 168, which indirectly detects the rotation angle of the steering shaft 141 by measuring the rotation angle of the rotatable body, can be selected according to the size of the rotatable body regardless of the size of the steering shaft 141. Therefore, by using the rotatable body smaller than the steering shaft 141, the size of which is difficult to change due to the structure of the outboard motor 100, the potentiometer 168 can be made smaller, which in turn reduces the size of the outboard motor 100.
In addition, in the outboard motor 100 of an example embodiment, a portion of the steering shaft 141 is located inside the waterproof case 112, and the rotation of the steering shaft 141 is transmitted to the rotatable body inside the waterproof case 112. According to an example embodiment of the outboard motor 100, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located inside the waterproof case 112. This simplifies the layout of the wiring connected to the potentiometer 168, simplifies the configuration of the outboard motor 100, and reduces or prevents the potentiometer 168 from getting wet by water.
In addition, in the outboard motor 100 of an example embodiment, the rotatable body is the offset shaft 164 that is parallel to the steering shaft 141, and the outboard motor 100 further includes a transmission 163 inside the waterproof case 112 and transmits the rotation of the steering shaft 141 to the offset shaft 164. According to an example embodiment of the outboard motor 100, it is possible to detect the rotation angle of the steering shaft 141 even when the potentiometer 168 is located inside the waterproof case 112. This simplifies the layout of the wiring connected to the potentiometer 168, simplifies the configuration of the outboard motor 100, and reduces or prevents the potentiometer 168 from getting wet by water.
The technologies disclosed herein are not limited to the above-described preferred example embodiments and may be modified in various ways without departing from the gist of the present invention, including the following modifications.
The configurations of the boat 10 and the outboard motor 100 of the example embodiments are only examples and may be variously modified. For example, the drive source of the above example embodiments only includes the electric motor 122, but the drive source may include both the electric motor and an engine such as an internal combustion engine or may consist only of an internal combustion engine.
In the above example embodiments, the outboard motor 100 is provided with a primary reduction gear 300, but it is not necessarily required to be provided with a primary reduction gear.
In the above example embodiments, the rotation of the steering shaft 141 is transmitted to the offset shaft 164 at a location higher than the oil chamber 117, but the rotation of the steering shaft may be transmitted to the rotatable body inside the oil chamber.
The above example embodiments are provided with the offset shaft 164 as the rotatable body, but the rotatable body is not limited to this.
In the above example embodiments, the outboard motor 100 is provided with the waterproof case 112, but the outboard motor does not necessarily have to be provided with a waterproof case.
In the above example embodiments, the transmission 163 includes the first gear 161 and the second gear 162, but the configuration of the transmission is not limited to this. For example, the transmission may include a first sprocket attached to the steering shaft, a second sprocket attached to the rotatable body, and a chain that meshes with the first and second sprockets.
In the above example embodiments, the gear ratio between the first gear 161 and the second gear 162 is 1:1, but the gear ratio between the first gear and the second gear is not limited to this.
In the above example embodiments, the potentiometer 168 is used as an angle detection sensor, but other angle detection sensors such as a rotary sensor or rotary encoder may be used.
While example embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-191230 | Nov 2023 | JP | national |
