Patent Application
20240343371
This application claims the benefit of priority to Japanese Patent Application No. 2023-066309 filed on Apr. 14, 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 has a drive source, a propeller, and a transmission that has a propeller shaft and transmits the drive power of the drive source to the propeller.
There has been disclosed an outboard motor including an engine having a crankshaft, a propeller, a propeller shaft mechanically connected to the propeller, and a drive shaft transmitting the power of the engine to the propeller shaft. The upper end of the drive shaft is mechanically connected to the crankshaft and the lower end of the drive shaft is mechanically connected to the propeller shaft (see, for example, JP 2018-071446 A).
In the outboard motor of the above conventional technology, the drive shaft, which constitutes the transmission, extends in a straight line from the drive source to the propeller shaft which means that there was little flexibility in changing the layout of the outboard motor.
Example embodiments of the present invention disclose technologies that are able to solve the above-mentioned problems.
An outboard motor according to an example embodiment of the present invention includes a drive source, a propeller, and a transmission to transmit a drive power of the drive source to the propeller. The transmission includes a propeller shaft extending in a first direction and rotatable together with the propeller, an input shaft connected to the drive source and rotatable by the drive power of the drive source, a first output shaft connected to the propeller shaft, spaced apart from the input shaft, to transmit power to the propeller shaft, and a first winding transmission to transmit rotation of the input shaft to the first output shaft.
According to this outboard motor, since the input shaft and the first output shaft are spaced apart from each other and the first winding transmission transmits the power of the input shaft to the first output shaft, the location of the first output shaft can be easily changed by changing the configuration of the first winding transmission, thus increasing the degree of freedom in changing the layout of the outboard motor.
An outboard motor according to another example embodiment of the present invention includes a drive source, a propeller, and a transmission to transmit a drive power of the drive source to the propeller. The transmission includes a propeller shaft extending in a first direction and rotatable together with the propeller, an input shaft connected to the drive source and rotatable by the drive power of the drive source, a first output shaft connected to the propeller shaft, spaced apart from the input shaft, to transmit power to the propeller shaft, and a first transmission to transmit rotation of the input shaft to the first output shaft.
According to this outboard motor, since the input shaft and the first output shaft are spaced apart a distance from each other and the first transmission transmits the power of the input shaft to the first output shaft, the location of the first output shaft can be easily changed by changing the configuration of the first transmission, thus increasing the degree of freedom in changing the layout of the outboard motor.
The technologies disclosed herein can be implemented in various aspects, including, e.g., outboard motors, boats provided with outboard motors and hulls, etc.
According to the example embodiments disclosed herein, since the input shaft and the first output shaft are spaced apart from each other and the first transmission transmits the power of the input shaft to the first output shaft, the location of the first output shaft can be easily changed by changing the configuration of the first transmission, thus increasing the degree of freedom in changing the layout 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 this 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 installed in the living space 204, and an operating device 250 installed 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 an engine assembly 120, a transmission 130, a propeller 112, a cowl 114, a casing 116, a water pump 140, and a pump shaft 134.
The cowl 114 is a housing disposed on top of the outboard motor main body 110. The cowl 114 includes an upper cowl 114a defining an upper portion of the cowl 114 and a lower cowl 114b defining a lower portion of the cowl 114. The upper cowl 114a is detachably attached to the lower cowl 114b.
The casing 116 is a housing disposed below the cowl 114 and provided in the lower portion of the outboard motor main body 110. The casing 116 includes a lower case 116b and an upper case 116a. The lower case 116b accommodates at least a portion of an output shaft 133 and the propeller shaft 137 described below. The lower case 116b is connected to the upper case 116aso as to be pivotable around the output shaft 133. The upper case 116a is disposed above the lower case 116b and accommodates a transmission shifter 300. The lower case 116b is an example of a first case, and the upper case 116a is an example of a second case.
An engine assembly 120 is accommodated within the cowl 114. The engine assembly 120 includes an engine body 122 and a flywheel magnet generator 127.
The engine body 122 is a prime mover that generates power. The engine body 122 includes, e.g., an internal combustion engine. The engine body 122 includes a crankshaft 124 that converts the reciprocating motion of a piston, not shown, into rotational motion. The crankshaft 124 is arranged in an attitude in which its rotation axis Ac extends in the upper-lower direction. The engine body 122 is an example of a drive source. It should be noted that although the outboard motor 100 of this example embodiment includes the engine body 122, which is an internal combustion engine, as an example of a drive source, the outboard motor 100 may include an electric motor as a drive source or both an internal combustion engine and an electric motor.
The flywheel magnet generator 127 is an alternator as an auxiliary generator for the engine body 122 and is accommodated above the engine body 122 in the cowl 114. The flywheel magnet generator 127 includes a flywheel rotor 128 and a stator 129. The flywheel rotor 128 is connected to the upper end of the crankshaft 124 and rotates along with the rotation of the crankshaft 124.
The transmission 130 transmits the driving force of the engine body 122 to the propeller 112. At least a portion of the transmission 130 is accommodated in the casing 116. The transmission 130 includes the transmission shifter 300 and a propeller shaft 137.
The propeller shaft 137 is a rod-shaped member extending in the front-rear direction and located below the outboard motor main body 110. The propeller shaft 137 rotates along with the propeller 112. The front end of the propeller shaft 137 is accommodated in the lower case 116b, and the rear end of the propeller shaft 137 protrudes rearward from the lower case 116b. The front end of the propeller shaft 137 includes a gear 138.
The transmission shifter 300 transmits the driving force of the engine body 122 to the propeller shaft 137. The transmission shifter 300 is disposed above the output shaft 133. The operation of the transmission shifter 300, which will be described in detail below, switches the boat 10 between the forward and backward movement states by switching the rotating direction of the propeller shaft 137 to change the rotating direction of the propeller 112.
The propeller 112 is a rotor including a plurality of blades and is attached to the rear end of the propeller shaft 137. The propeller 112 rotates along with the rotation of the propeller shaft 137 around the rotation axis Ap. The propeller 112 generates thrust by rotating. As mentioned above, since the lower case 116b is pivotable, the propeller 112 pivots about the output shaft 133 along with the lower case 116b. Therefore, the boat 10 is steered by pivoting the lower case 116b.
The water pump 140 pumps water from outside the outboard motor 100 to, e.g., cool the engine body 122. The pump shaft 134 extends in an upper-lower direction. The pump shaft 134 is driven by the drive power of the engine body 122 and transmits power to the water pump 140. The water pump 140 is driven by the driving force of the engine body 122 transmitted by the pump shaft 134. The water pump 140 is an example of a driven device. The pump shaft 134 is an example of a second output shaft.
The suspension device 150 connects 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 160, 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. Each clamp bracket 152 has a cylindrical supporting portion 152a provided with a through-hole extending in the left-right direction.
The tilt shaft 160 is a rod-shaped member and is rotatably supported within the through-hole in the supporting portion 152a of the clamp bracket 152. The tilt axis At, which is the centerline of the tilt shaft 160, defines a horizontal (left-right) axis in the tilting operation of the outboard motor 100.
The swivel bracket 156 is sandwiched between the pair of clamp brackets 152 and is supported by the supporting portion 152a of the clamp brackets 152 via the tilt shaft 160 so as to be rotatable around 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 tilt device (not shown) that includes 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 around the tilt axis At in the range from the tilt-down state in which the propeller 112 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 112 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 around the tilt axis At of the outboard motor main body 110.
The controller 180 includes, e.g., a CPU, a multi-core CPU, and a programmable device (field programmable gate array (FPGA), programmable logic device (PLD), and the like).
The switch 190 is included in the transmission shifter 300 and mechanically controls the configuration of various components of the outboard motor 100, such as a first clutch 331 and a second clutch 332 described below, e.g., by hydraulic pressure.
The controller 180 controls the operation of the switch 190 based on the operation of the shift/throttle lever 254 by a crew on the boat 10. The switch 190 operates the first clutch 331 and the second clutch 332 to turn on and off the power transmission of a first winding transmission 310 described below and the gear transmission 320 described below to control the shifting of the boat 10.
The transmission shifter 300 in the first example embodiment includes a housing 304, a first assembly 301, a second assembly 302, the first winding transmission 310, a gear transmission 320, and the switch 190 described above.
The housing 304 is a case that accommodates at least some of the components of the transmission shifter 300.
The first assembly 301 is a collection of components disposed around a first virtual axis VA1 that is parallel to the upper-lower direction. The first assembly 301 includes an input shaft 132, a first clutch 331, a first piston 335, and a first rotor 341. At least some of the components of the first assembly 301 are in a first flow path 351 that supplies oil, e.g., hydraulic oil, to operate the first piston 335.
The input shaft 132 is a rod-shaped member extending in the upper-lower direction. The upper end of the input shaft 132 is mechanically connected to the lower end of the crankshaft 124 in the engine body 122 and extends downward from a connecting portion with the engine body 122. The input shaft 132 rotates along with the crankshaft 124 under the driving force of the engine body 122.
The first rotor 341 is disposed around the input shaft 132 and rotates around the first virtual axis VA1.
The first clutch 331 and the first piston 335 are disposed around the input shaft 132. The first piston 335 is actuated by hydraulic pressure of the oil supplied through the first flow path 351 to switch the first clutch 331 between engaged and disengaged states. In other words, the first clutch 331 is a hydraulic clutch. When the first clutch 331 is engaged, the first input side sprocket 311 described below and the first rotor 341 are connected.
The second assembly 302 is a collection of components disposed around a second virtual axis VA2 that is rearward of the first virtual axis VA1 and parallel to the upper-lower direction. The second assembly 302 includes an output shaft 133, a second clutch 332, and a second piston 336. At least some of the components of the second assembly 302 are provided in a second flow path 352 which is a channel that supplies oil to operate the second piston 336.
The output shaft 133 is a rod-shaped member to transmit power to the propeller shaft 137. The lower portion of the output shaft 133 protrudes from the housing 304. The lower end of the output shaft 133 includes a gear 135. The output shaft 133 is mechanically connected to the propeller shaft 137 by meshing the gear 135 of the output shaft 133 with the gear 138 of the propeller shaft 137. The output shaft 133 extends upward from the connecting portion with the propeller shaft 137. The output shaft 133 is disposed rearwardly of the input shaft 132 and is spaced apart from the input shaft 132. In this case, “spaced apart” does not simply mean that the input shaft 132 and the output shaft 133 are not disposed on the same axis, but rather that in the transmission of power from the input shaft 132 to the output shaft 133, the input shaft 132 or the members provided around the input shaft 132 and the output shaft 133 or the members provided around the output shaft 133 are not directly engaged. This means that the first input side sprocket 311, described below, provided around the input shaft 132 and the first output side sprocket 312, described below, provided around the output shaft 133 are not directly engaged and are spaced apart. When the output shaft 133 is disposed rearwardly of the input shaft 132, as shown in this example embodiment, the load on the transom 210 can be reduced because the layout can be changed while the relatively heavy engine body 122 is disposed forward. Also, because the output shaft 133 is disposed rearwardly of the input shaft 132, interference between the lower portion of the outboard motor main body 110 and the hull main body 202 can be prevented when the lower case 116b is pivoted. Although the output shaft 133 is disposed more rearwardly than the input shaft 132, it is sufficient if at least a portion of the output shaft 133 is disposed more rearwardly than the rear end of the input shaft 132, and a portion of the output shaft 133 may be disposed more forwardly than a portion of the input shaft 132, or the output shaft 133 and the input shaft 132 may be completely separated from each other in the front-rear direction. The output shaft 133 is an example of a first output shaft.
The second clutch 332 and the second piston 336 are disposed around the output shaft 133. Engaging the second clutch 332 will connect the first output side sprocket 312 and the output shaft 133 as described below. The second piston 336 is actuated by the hydraulic pressure of the oil supplied through the second flow path 352 to switch the second clutch 332 between engaging state and disengaging state. In other words, the second clutch 332 is a hydraulic clutch.
The gear transmission 320 transmits power between the first assembly 301 and the second assembly 302. The gear transmission 320 includes a first gear 321 and a second gear 322. The first gear 321 and the second gear 322 may be helical gears, for example.
The first gear 321 is attached to the outer circumference of the first rotor 341 and rotates around the first virtual axis VA1 together with the first rotor 341. The second gear 322 is attached to the outer circumference of the output shaft 133, meshes with the first gear 321, and rotates around the second virtual axis VA2 together with the output shaft 133. Since the first gear 321 and the second gear 322 mesh with each other, the rotation of one of the first gear 321 and the second gear 322 causes the rotation of the other of the first gear 321 and the second gear 322. The transmission of power by the gear transmission 320 causes the first assembly 301 and the second assembly 302 to rotate in mutually opposite directions.
The first winding transmission 310 is disposed above the gear transmission 320 and transmits power between the first assembly 301 and the second assembly 302. The first winding transmission 310 includes a first input side sprocket 311, a first output side sprocket 312, and a first chain 314.
The first input side sprocket 311 is provided around the input shaft 132. The first input side sprocket 311 rotates around the first virtual axis VA1 together with the input shaft 132. The first output side sprocket 312 is provided around the output shaft 133. The first output side sprocket 312 rotates around the second virtual axis VA2 together with the output shaft 133. The first chain 314 meshes with both the first input side sprocket 311 and the first output side sprocket 312. Because the first chain 314 meshes with both the first input side sprocket 311 and the first output side sprocket 312, the rotation of one of the first input side sprocket 311 and the first output side sprocket 312 causes the rotation of the other of the first input side sprocket 311 and the first output side sprocket 312. The transmission of power by the first winding transmission 310 causes the first assembly 301 and the second assembly 302 to rotate in the same direction as each other. With reference to
the transmission shifter 300 during the forward movement of the boat 10 will be explained. The arrows in
First, the switch 190 causes the first clutch 331 to be engaged by supplying oil to the first piston 335 via the first flow path 351. By engaging the first clutch 331, the first input side sprocket 311 and the first rotor 341 are connected. The first input side sprocket 311 rotates along with the rotation of the input shaft 132. The rotation of the input shaft 132 is transmitted to the first rotor 341 via the first input side sprocket 311, and the first rotor 341 rotates around the first virtual axis VA1. The rotation of the first rotor 341 causes the first gear 321 to rotate. The rotation of the first gear 321 causes the second gear 322 to rotate, and the rotation of the second gear 322 causes the output shaft 133 to rotate (i.e., the transmission of power from the first assembly 301 to the second assembly 302 by the gear transmission 320 occurs). The rotation of the output shaft 133 is transmitted to the propeller shaft 137 to generate thrust to move the boat 10 forward.
In the forward movement, the switch 190 disengages the second clutch 332. Thus, the first output side sprocket 312 and the output shaft 133 are disconnected. As a result, even if the first input side sprocket 311 rotates along with the rotation of the input shaft 132 and the first output side sprocket 312 is rotated by the first chain 314, the rotation of the first output side sprocket 312 is not transmitted to the output shaft 133. Therefore, transmission of power from the first assembly 301 to the second assembly 302 by the first winding transmission 310 does not occur.
With reference to
First, the switch 190 causes the second clutch 332 to be engaged by supplying oil to the second piston 336 via the second flow path 352. By engaging the second clutch 332, the first output side sprocket 312 and the output shaft 133 are connected. The first input side sprocket 311 rotates along with the rotation of the input shaft 132. When the rotation of the input shaft 132 is transmitted to the first input side sprocket 311, the first output side sprocket 312 is rotated by the first chain 314, and the rotation of the first output side sprocket 312 causes the output shaft 133 to rotate around the second virtual axis VA2 (i.e., the transmission of power from the first assembly 301 to the second assembly 302 by the first winding transmission 310 occurs). The rotation of the output shaft 133 is transmitted to the propeller shaft 137 to generate thrust to move the boat 10 backward.
In the backward movement, the switch 190 disengages the first clutch 331. That is, the first input side sprocket 311 and the first rotor 341 are disconnected. As a result, even if the first input side sprocket 311 rotates along with the rotation of the input shaft 132, the rotation of the first input side sprocket 311 is not transmitted to the first rotor 341. Therefore, the transmission of power from the first assembly 301 to the second assembly 302 by the gear transmission 320 does not occur.
With reference to
First, the switch 190 stops supplying oil to the first piston 335 and the second piston 336 and disengages the first clutch 331 clutch and the second clutch 332. By disengaging the first clutch 331, the first input side sprocket 311 and the first rotor 341 are disconnected. As a result, even if the first input side sprocket 311 rotates along with the rotation of the input shaft 132, the rotation of the first input side sprocket 311 is not transmitted to the first rotor 341. Therefore, the transmission of power from the first assembly 301 to the second assembly 302 by the gear transmission 320 does not occur. In addition, by disengaging the second clutch 332, the first output side sprocket 312 and the output shaft 133 are disconnected. As a result, even if the first input side sprocket 311 rotates along with the rotation of the input shaft 132 and the first output side sprocket 312 is rotated by the first chain 314, the rotation of the first output side sprocket 312 is not transmitted to the output shaft 133. Therefore, the transmission of power from the first assembly 301 to the second assembly 302 by the first winding transmission 310 does not occur. Thus, the rotation of the input shaft 132 is not transmitted to the output shaft 133 by either the first winding transmission 310 or the gear transmission 320, so that the rotation of the input shaft 132 is not transmitted to the propeller shaft 137.
As explained above, during forward movement of the boat 10, the switch 190 transmits the rotation of the input shaft 132 to the output shaft 133 via the gear transmission 320, which is one of the first winding transmission 310 and the gear transmission 320, (i.e., the input shaft 132 and output shaft 133 rotate in mutually opposite directions). In addition, during backward movement of the boat 10, the switch 190 transmits the rotation of the input shaft 132 to the output shaft 133 via the first winding transmission 310, which is the other of the first winding transmission 310 and the gear transmission 320 (i.e., the input shaft 132 and the output shaft 133 rotate in the same direction as each other). Furthermore, in neutral state of the boat 10, the switch 190 does not transmit the rotation of the input shaft 132 to the output shaft 133. This switches the forward, backward, and neutral states of the boat 10 thus achieving shift control of the boat 10.
In the first example embodiment, the pump shaft 134 is disposed on the first virtual axis VA1. The pump shaft 134 is connected to the input shaft 132 below the input shaft 132 and rotates along with the input shaft 132. The water pump 140 is disposed below the input shaft 132 and in front of the output shaft 133 (see
The outboard motor 100a of the second example embodiment further includes a second winding transmission 315a. The second winding transmission 315a includes a second input side sprocket 316a, a second output side sprocket 317a, and a second chain 318a. It should be noted that the pump shaft 134 in the first example embodiment is disposed below the input shaft 132, but the pump shaft 134a in the second example embodiment is disposed parallel to the input shaft 132a in front of the input shaft 132a.
The second input side sprocket 316a is disposed around the input shaft 132a. The second input side sprocket 316a rotates around the first virtual axis VA1 along with the input shaft 132. The second output side sprocket 317a is disposed around the pump shaft 134a. The second output side sprocket 317a rotates along with the pump shaft 134a. The second chain 318a meshes with both the second input side sprocket 316a and the second output side sprocket 317a. Since the second chain 318a meshes with both the second input side sprocket 316a and the second output side sprocket 317a, the rotation of the second input side sprocket 316a is transmitted to the second output side sprocket 317a. That is, the second winding transmission 315a transmits the power of the input shaft 132a to the pump shaft 134a. In this way, the transmission can also be used to extract power for equipment not directly involved in the propulsion of the boat 10.
The techniques disclosed herein are not limited to the above-described example embodiments and may be modified in various forms without departing from the gist of the present invention, including the following modifications.
The configuration of the boat 10 and the outboard motor 100 of the example embodiments is only an example and is variously changeable. For example, in the above example embodiments, the output shaft 133 is disposed rearward of the input shaft 132, but the output shaft 133 may be disposed forward of the input shaft 132.
In the above example embodiments, the outboard motor 100 includes the gear transmission 320, but it is not necessary to include the gear transmission 320. Furthermore, it is not necessary to include the first winding transmission 310, and another transmission, such as a gear transmission, may be provided in place of the first winding transmission 310.
In the above example embodiments, the first winding transmission 310 is disposed above the gear transmission 320, but the first winding transmission 310 may be disposed below the gear transmission 320.
In the above example embodiments, a transmission shifter that performs forward/reverse movement switching to control the forward movement state, backward movement state, and neutral state of the boat 10 is shown, but the transmission shifter may be one that performs speed switching during forward/reverse movements, or may be one that performs both forward/reverse movement switching and speed switching during forward/reverse movements.
In the above example embodiments, the lower case 116b is connected to the upper case 116a in the casing 116 so that the lower case 116b is freely rotatable, but the lower case 116b need not necessarily be rotatable. Furthermore, the casing 116 need not include the upper case 116a and the lower case 116b, but may be a single member.
In the above example embodiments, the first winding transmission 310 includes two sprockets (first input side sprocket 311 and first output side sprocket 312) and a first chain 314, but pulleys or the like may be used instead of the sprockets, and a belt or the like may be used instead of the first chain 314.
In the above example embodiments, the outboard motor 100 is provided with the water pump 140 as a driven device, but it may not be provided with the water pump 140 or may be provided with another driven device instead of the water pump 140.
In the above example embodiments, the pump shaft 134a and the second winding transmission 315a are disposed outside the housing 304, but the pump shaft 134a and the second winding transmission 315a may be housed inside the housing 304.
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 |
|---|---|---|---|
| 2023-066309 | Apr 2023 | JP | national |
