US20240208629A1 - Outboard motor and boat propulsion device - Google Patents
Outboard motor and boat propulsion device Download PDFInfo
- Publication number
- US20240208629A1 US20240208629A1 US18/383,047 US202318383047A US2024208629A1 US 20240208629 A1 US20240208629 A1 US 20240208629A1 US 202318383047 A US202318383047 A US 202318383047A US 2024208629 A1 US2024208629 A1 US 2024208629A1
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- United States
- Prior art keywords
- cooling water
- pump
- outboard motor
- shaft
- filter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- 239000000498 cooling water Substances 0.000 claims abstract description 90
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 52
- 239000011347 resin Substances 0.000 claims description 14
- 229920005989 resin Polymers 0.000 claims description 14
- 229910052751 metal Inorganic materials 0.000 claims description 12
- 239000002184 metal Substances 0.000 claims description 12
- 239000011152 fibreglass Substances 0.000 claims description 5
- 230000007246 mechanism Effects 0.000 description 18
- 239000000463 material Substances 0.000 description 6
- 238000005192 partition Methods 0.000 description 6
- 230000007797 corrosion Effects 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 230000009471 action Effects 0.000 description 4
- 238000004873 anchoring Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 241000195493 Cryptophyta Species 0.000 description 2
- 239000004677 Nylon Substances 0.000 description 2
- 229930182556 Polyacetal Natural products 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000003365 glass fiber Substances 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 229920001778 nylon Polymers 0.000 description 2
- 229920006324 polyoxymethylene Polymers 0.000 description 2
- 230000001141 propulsive effect Effects 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 238000009966 trimming Methods 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H20/00—Outboard propulsion units, e.g. outboard motors or Z-drives; Arrangements thereof on vessels
- B63H20/28—Arrangements, apparatus and methods for handling cooling-water in outboard drives, e.g. cooling-water intakes
- B63H20/285—Cooling-water intakes
Definitions
- the technologies disclosed herein relate to an outboard motor and a boat propulsion device.
- outboard motors are equipped with a water pump to pump cooling water to cool the engine.
- the water pump includes an impeller or the like attached to a drive shaft. When the engine is driven, the impeller rotates together with the rotation of the drive shaft, and cooling water is pumped into the engine (see JP 2015-145137 A).
- An outboard motor includes a cooling water flow path including an intake port to take in cooling water from outside the outboard motor and through which cooling water flows, and a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path, wherein an inlet channel of the cooling water flow path from the intake port to the water pump extends along a rotation axis of the pump shaft in front of the water pump, and a filter to allow passage of the cooling water and prevent entry of foreign objects is located inside the inlet channel.
- the cooling water taken in from the outside flows from the front of the water pump to the impeller attached to the pump shaft so that the cooling water is pumped efficiently.
- This configuration also reduces or prevents damage to the water pump caused by foreign objects colliding with the water pump.
- the outboard motor may further include a drive unit, a drive shaft to be rotationally driven by the drive unit, a propeller, and a propeller shaft to rotate together with the propeller, the drive shaft may be rotatable in both a forward direction and a reverse direction opposite to the forward direction, and the water pump may be a non-volumetric pump.
- the drive shaft which is able to rotate in the both forward and reverse directions, eliminates the need for a clutch such as a dog clutch thus providing a relatively large space around the propeller shaft.
- This space can be used to accommodate the water pump eliminating the need for a larger outboard motor and optimizing the arrangement of the components necessary to transport the cooling water.
- the non-volumetric pump since the non-volumetric pump has no restriction on the direction of rotation, it is suitable as a pump connected to a drive shaft that is able to rotate in both the forward and reverse directions.
- the drive unit may be an electric motor driven by electricity supplied from a power source.
- the water pump may be a centrifugal pump.
- the water pump may be located on the rotation axis of the propeller shaft.
- This configuration allows the water pump to be positioned without protruding sideways from the rotation axis of the propeller shaft thus avoiding a reduction in the propulsive force of the hull.
- the filter may be made of resin.
- the filter may be made of glass fiber reinforced plastic.
- the filter is stronger, and thus the filter can be prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- the filter may include a holder including a through hole and fixed inside the inlet channel, and a filter body held inside the through hole to allow the passage of the cooling water and prevent entry of foreign objects, and the holder may be made of resin, and the filter body may be made of metal.
- the holder of the filter that is in contact with the inlet channel is made of resin, it is possible to prevent the filter from corroding and adhering to the inlet channel.
- the filter body is made of metal, a filter portion is stronger compared to the case where the entire the filter is made of resin, and thus the filter portion is prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- a boat propulsion device includes a cooling water flow path including an intake port to take in cooling water from outside the boat propulsion device and through which cooling water flows, and a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path, wherein a filter to allow passage of the cooling water and prevent entry of foreign objects is located at the intake port, and the filter is located on a rotation axis of the pump shaft in front of the water pump.
- cooling water taken in from the outside flows in from the front of the water pump to the impeller attached to the pump shaft, thus enabling efficient pumping of the cooling water.
- This configuration also reduces or prevents damage to the water pump caused by foreign objects colliding with the water pump.
- FIG. 1 is a perspective view schematically illustrating a configuration of a boat according to a first preferred embodiment of the present invention.
- FIG. 2 is a side view schematically illustrating a configuration of an outboard motor according to the first preferred embodiment.
- FIG. 3 is a partially enlarged cross-sectional view of the outboard motor according to the first preferred embodiment, showing a partially enlarged cross-section cut at the position indicated by line III-III in FIG. 1 .
- FIG. 4 is an enlarged cross-sectional view of the portion indicated by frame F 1 in FIG. 3 .
- FIG. 5 is an enlarged cross-sectional view of the portion indicated by frame F 2 in FIG. 3 .
- FIG. 6 is a front view of an inlet according to the first preferred embodiment.
- FIG. 7 is a partially enlarged cross-sectional view of an outboard motor according to a second preferred embodiment of the present invention, showing the same area as in FIG. 5 enlarged.
- FIG. 8 is a front view of an inlet according to the second preferred embodiment.
- FIG. 9 is a partially enlarged cross-sectional view of an outboard motor according to a third preferred embodiment of the present invention, showing the same area as in FIG. 5 enlarged.
- FIG. 10 is a front view of an inlet according to the third preferred embodiment.
- a boat 1 according to the first preferred embodiment includes a hull 10 and an outboard motor 100 (an example of the boat propulsion device), as shown in FIG. 1 .
- FIG. 1 and other figures described below show arrows representing each direction with respect to the position of the boat 1 . More specifically, each figure shows arrows representing front (FRONT), rear (REAR), left (LEFT), right (RIGHT), upper (UPPER), and lower (LOWER) directions, respectively.
- the front-rear direction, left-right direction, and upper-lower direction are orthogonal to each other.
- the hull 10 is a portion of the boat 1 for occupants to ride.
- the hull 10 includes a hull body 12 including a living space 11 , a pilot seat 16 installed in the living space 11 , and an operating device 17 installed near the pilot seat 16 .
- the operating device 17 maneuvers the boat and includes, e.g., a steering wheel, a shift throttle lever, a joystick, a monitor, and an input device.
- the hull 10 also includes a partition wall 13 that partitions the rear end of the living space 11 and a transom 14 positioned at the rear end of the hull 10 . In the front-rear direction, there is a space 15 between the transom 14 and the partition wall 13 .
- the outboard motor 100 generates thrust to propel the boat 1 .
- the outboard motor 100 in the present preferred embodiment is an electric outboard motor driven by an electric motor 120 (an example of a drive unit).
- the outboard motor 100 in the reference attitude will be described below unless otherwise specified.
- the reference attitude is the attitude of the outboard motor 100 when the boat 1 is cruising (attitude shown in FIG. 1 ), in which the rotation axis Ad of the drive shaft 130 (described below) extends in the upper-lower direction and the rotation axis Apr of the propeller shaft 140 extends in the front-rear direction.
- the front-rear direction, the left-right direction, and the upper-lower direction are defined based on the outboard motor 100 in the reference attitude.
- the outboard motor 100 is attached to the transom 14 located at the rear (stern) of the hull 10 .
- the outboard motor 100 includes an outboard motor main body 110 and a suspension device 150 .
- the outboard motor main body 110 includes a cowl 114 , a casing 116 , an electric motor 120 , a drive shaft 130 , a propeller 141 , a propeller shaft 140 , a cooling water flow path 200 , a water pump 210 , a first gear mechanism 180 , a second gear mechanism 190 , and an inlet 310 (an example of the filter).
- the cowl 114 is a housing located on top of the outboard motor main body 110 .
- the casing 116 includes an upper case 116 a and a lower case 116 b , as shown in FIG. 2 .
- the upper case 116 a is a housing located below the cowl 114 .
- the lower case 116 b is a housing located below the upper case 116 a.
- the lower case 116 b includes a gear chamber 118 that stores oil therein and houses the first gear mechanism 180 and the second gear mechanism 190 , as shown in FIG. 4 .
- the electric motor 120 is driven by electric power supplied from a battery (power source).
- the electric motor 120 includes a rotor including a permanent magnet, a stator including a coil to which the battery power is supplied, and a motor housing that houses the rotor and stator.
- the electric motor 120 is located inside the cowl 114 .
- the battery may be located inside the cowl 114 or inside the hull 10 .
- the drive shaft 130 is a rod-shaped member extending downward from the electric motor 120 and housed within the casing 116 , as shown in FIG. 2 .
- the drive shaft 130 is arranged in an attitude in which its rotation axis Ad extends in the upper-lower direction.
- the drive shaft 130 includes a rod-shaped main shaft 131 and an extension shaft 132 extending from the tip of the main shaft 131 opposite to the electric motor 120 (lower end in FIG. 4 ).
- the main shaft 131 includes a constant-diameter shaft 131 A extending from the electric motor 120 , which is a round rod of constant thickness, and a reduced-diameter shaft 131 B connecting the constant-diameter shaft 131 A and the extension shaft 132 .
- the extension shaft 132 extends coaxially with the main shaft 131 and has a round rod shape with a smaller diameter than the constant-diameter shaft 131 A.
- the constant-diameter shaft 131 A, the reduced-diameter shaft 131 B, and the extension shaft 132 are coaxial.
- the drive shaft 130 rotates around the rotation axis Ad due to the rotational driving force of the electric motor 120 . Since the electric motor 120 is able to rotate in both the forward and reverse directions, the drive shaft 130 is also able to rotate around the rotation axis line Ad in both forward direction to move the boat 1 forward and the reverse direction to move the boat 1 backward opposite to the forward direction, according to the rotational driving direction of the electric motor 120 .
- the propeller 141 is a rotating body including a plurality of blades.
- the propeller 141 generates thrust by rotation.
- the propeller shaft 140 is a rod-shaped member and extends in the front-rear direction inside the lower case 116 b , as shown in FIGS. 2 , 3 , and 4 .
- the propeller shaft 140 is rotatably supported by the lower case 116 b via a bearing 142 .
- the rear end of the propeller shaft 140 protrudes rearwardly from the lower case 116 b , and the propeller 141 is attached to this rear end. As the propeller shaft 140 rotates around the rotation axis Apr, the propeller 141 also rotates.
- the cooling water flow path 200 is located inside the outboard motor main body 110 .
- the cooling water flow path 200 includes a channel through which cooling water (seawater, lake water, and river water, among others) taken in from outside the outboard motor 100 flows.
- the cooling water flow path 200 includes an intake port 201 that opens on the outer surface of the lower case 116 b to take in cooling water into the interior and a drain port 202 that also opens on the outer surface of the lower case 116 b to discharge cooling water to the exterior.
- the cooling water flow path 200 extends from the intake port 201 through the periphery of the electric motor 120 to the drain port 202 .
- the intake port 201 is located below the waterline when the boat 1 is cruising, i.e., when the outboard motor 100 is in the reference attitude.
- the intake port 201 is open at the front end of the lower case 116 b.
- a portion of the cooling water flow path 200 includes a pump chamber 203 .
- the pump chamber 203 is located in front of the gear chamber 118 in the lower case 116 b and is separated from the gear chamber 118 by a partition 220 .
- the partition 220 includes a shaft hole 221 that is connected to the pump chamber 203 and the gear chamber 118 .
- the water pump 210 is a non-volumetric pump including an impeller 211 and a pump shaft 212 that rotates together with the impeller 211 , as shown in FIG. 4 .
- a centrifugal pump is exemplified as the water pump 210 .
- the impeller 211 is a rotating body including a plurality of blades and is located inside the pump chamber 203 .
- the pump shaft 212 is a rod-shaped member and extends in a front-rear direction.
- the pump shaft 212 is inserted into the shaft hole 221 and is supported by the partition 220 in a rotatable manner via a bearing 213 .
- the rotation axis Apn of the pump shaft 212 coincides with the rotation axis Apr of the propeller shaft 140 .
- the front end of the pump shaft 212 is located inside the pump chamber 203 , where the impeller 211 is mounted.
- the water pump 210 (specifically, the pump shaft 212 and impeller 211 ) is located on the rotation axis Apr of the propeller shaft 140 .
- the impeller 211 also rotates.
- the rear end of the pump shaft 212 is located inside the gear chamber 118 .
- a plurality of seals 230 are arranged on the outer surface of the pump shaft 212 to fill the gap between the inner surface of the shaft hole 221 and the pump shaft 212 .
- Each seal 230 is circular in shape, is made of a material such as rubber having elasticity, and encircles the pump shaft 212 all the way around.
- the plurality of seals 230 are arranged in line along the rotation axis Apn of the pump shaft 212 . These seals 230 prevent cooling water flowing into the pump chamber 203 from entering the gear chamber 118 through the gap between the inner circumferential surface of the shaft hole 221 and the pump shaft 212 .
- the portion of the cooling water flow path 200 from the intake port 201 to the water pump 210 i.e., the portion located between the intake port 201 and the pump chamber 203 (inlet channel 204 ), is located in front of the water pump 210 and extends along the rotation axis Apn of the pump shaft 212 , as shown in FIG. 4 .
- one portion of the inlet channel 204 adjacent to the intake port 201 has a larger inner diameter than the remaining portion adjacent to the pump chamber 203 (constant-diameter channel 206 ).
- a member e.g., a pipe
- a first stepped surface 207 is provided, which connects the inner surface of the enlarged-diameter channel 205 to the inner surface of the constant-diameter channel 206 .
- the first stepped surface 207 is arranged to face toward the intake port 201 and is perpendicular or substantially perpendicular to the rotation axis Apn of the pump shaft 212 .
- a threaded groove to fix the inlet 310 is provided on the inner surface of the constant-diameter channel 206 .
- the first gear mechanism 180 transmits the rotation of the drive shaft 130 to the propeller shaft 140
- the second gear mechanism 190 transmits the rotation of the drive shaft 130 to the pump shaft 212 .
- the first gear mechanism 180 and the second gear mechanism 190 have different gear ratios.
- the first gear mechanism 180 includes a first gear 181 and a second gear 182 , as shown in FIG. 4 .
- the first gear 181 is coaxially mounted to the main shaft 131 of the drive shaft 130 (more specifically, the reduced-diameter shaft 131 B) and rotates together with the drive shaft 130 .
- the second gear 182 is coaxially mounted to the propeller shaft 140 and rotates together with the propeller shaft 140 .
- the second gear 182 meshes with the first gear 181 .
- the first gear 181 and the second gear 182 are, e.g., bevel gears.
- the second gear mechanism 190 includes a third gear 191 and a fourth gear 192 , as shown in FIG. 4 .
- the third gear 191 is coaxially mounted to the extension shaft 132 of the drive shaft 130 and rotates together with the drive shaft 130 .
- the third gear 191 has a smaller outer diameter than the first gear 181 and is located farther from the electric motor 120 than the first gear 181 .
- the fourth gear 192 is coaxially mounted to the pump shaft 212 and rotates together with the pump shaft 212 .
- the fourth gear 192 meshes with the third gear 191 .
- the third gear 191 and the fourth gear 192 are, e.g., bevel gears.
- the first gear mechanism 180 and the second gear mechanism 190 are located inside the gear chamber 118 .
- the four gears 181 , 182 , 191 , and 192 are lubricated by oil provided inside the gear chamber 118 .
- the inlet 310 is located inside the inlet channel 204 and prevents foreign objects contained in the cooling water taken in from the intake port 201 from entering the cooling water flow path 200 and includes a filter plate 311 and a mounting cylinder 315 , as shown in FIGS. 5 and 6 .
- the filter plate 311 is disc-shaped and includes a number of passage holes 312 .
- the passage holes 312 penetrate from one side to the other and allow the passage of cooling water.
- the size of each passage hole 312 is sufficient to allow the cooling water to pass smoothly but to prevent the entering of foreign objects of a size that could clog the cooling water flow path 200 , such as algae or pebbles, e.g., a hole having an inner diameter of about 2.5 mm, for example.
- the mounting cylinder 315 is a cylindrical portion extending from one side of the filter plate 311 (right side of FIG. 5 ) and has an outer diameter smaller than the outer diameter of the filter plate 311 .
- the outer surface of the mounting cylinder 315 has threads corresponding to the grooves threaded on the inner surface of the constant-diameter channel 206 .
- the recess defined by the attachment/detachment ring 313 and filter plate 311 has a hexagonal inner circumferential edge and is an attachment/detachment recess 314 that fits a hexagonal wrench.
- the filter plate 311 When the inlet 310 is located within the inlet channel 204 , the filter plate 311 is disposed near the intake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of the pump shaft 212 to separate the interior space of the inlet channel 204 from the exterior space. The outer circumferential edge of the filter plate 311 abuts the first stepped surface 207 to position the inlet 310 .
- the mounting cylinder 315 is located on the rotation axis Apn of the pump shaft 212 . Cooling water flows into the pump chamber 203 through the passage hole 312 and the interior of the mounting cylinder 315 .
- the inlet 310 of the present preferred embodiment is made of resin, adhesion of the inlet 310 to the pipe defining the inlet channel 204 due to corrosion is prevented compared to the case where the inlet 310 is made of metal.
- the material for the inlet 310 may include nylon and polyacetal.
- the suspension device 150 suspends the outboard motor main body 110 on the hull 10 .
- the suspension device 150 includes a pair of left and right clamp brackets 152 , a tilt shaft 160 , and a connection bracket 156 , as shown in FIG. 2 .
- the pair of left and right clamp brackets 152 are disposed behind the hull 10 in a state separated from each other in the left-right direction and are fixed to the transom 14 of the hull 10 by using, e.g., bolts.
- Each clamp bracket 152 includes a cylindrical supporting portion 152 a provided with a through-hole extending in the left-right directions.
- the tilt shaft 160 is a rod-shaped member.
- the tilt shaft 160 is rotatably supported in the through-hole of the supporting portion 152 a of the clamp bracket 152 .
- the tilt axis At which is the center line of the tilt shaft 160 , defines an axis extending in the horizontal direction (left-right direction) during the tilting action of the outboard motor 100 .
- connection bracket 156 is sandwiched between the pair of clamp brackets 152 and is supported by the supporting portion 152 a of the clamp bracket 152 via the tilt shaft 160 in such a manner that the connection bracket 156 is able to rotate around the tilt axis At.
- the connection bracket 156 is fixed to the outboard motor main body 110 .
- the connection bracket 156 is rotationally driven around the tilt axis At with respect to the clamp bracket 152 by a tilt device (not shown) including an actuator such as, e.g., a hydraulic cylinder.
- the outboard motor main body 110 fixed to the connection bracket 156 also rotates about the tilt axis At. This achieves the tilting action of rotating the outboard motor main body 110 in the upper-lower direction with respect to the hull 10 . Due to this tilting action, the outboard motor 100 can change the angle around the tilt axis At of the outboard motor main body 110 in the range from the tilt-down state in which the propeller 141 is located under the waterline (the state in which the outboard motor 100 is in the reference attitude: the state shown in FIG. 1 ) to the tilt-up state in which the propeller 141 is above the waterline. Trimming action to adjust the attitude of the boat 1 during cruising can also be performed by adjusting the angle around the tilt axis At of the outboard motor main body 110 .
- the outboard motor 100 When the boat 1 is cruising, the outboard motor 100 is placed in the tilt-down state, and the lower case 116 b and the propeller 141 are positioned below the waterline.
- the intake port 201 , inlet channel 204 , pump chamber 203 , and water pump 210 located inside the lower case 116 b are also below the waterline, and cooling water flows into the pump chamber 203 from outside through the intake port 201 and inlet channel 204 .
- the inlet 310 which is located in the inlet channel 204 , prevents the entry of foreign objects of a size that could clog the cooling water flow path 200 , such as algae and pebbles.
- the drive shaft 130 rotates around the rotation axis Ad due to the rotational driving force of the electric motor 120 .
- the rotation of the drive shaft 130 is transmitted to the propeller shaft 140 via the first gear mechanism 180 .
- the first gear mechanism 180 transmits the forward rotation of the drive shaft 130 to the propeller shaft 140
- the propeller 141 rotating together with the propeller shaft 140 generates thrust in the forward direction.
- the first gear mechanism 180 transmits the reverse rotation of the drive shaft 130 to the propeller shaft 140
- the propeller 141 rotating together with the propeller shaft 140 generates thrust in the rearward direction.
- the rotation of the drive shaft 130 is transmitted to the pump shaft 212 via the second gear mechanism 190 , and the impeller 211 rotates together with the pump shaft 212 .
- Cooling water taken in from the intake port 201 is pumped through the cooling water flow path 200 by centrifugal force generated by the rotation of the impeller 211 , and is supplied around the electric motor 120 to cool the electric motor 120 .
- the cooling water may also cool the battery, inverter, and reduction gears, among others, located inside the outboard motor main body 110 . After being used for cooling, the cooling water is discharged to the outside through the drain port 202 .
- the intake port 201 and the inlet channel 204 are located on the rotation axis Apn of the pump shaft 212 and in front (bow side) of the water pump 210 , so that when the boat 1 moves forward, the cooling water flows through the intake port 201 and the inlet channel 204 from the front to the impeller 211 .
- This allows the cooling water to be pumped efficiently, especially when the boat 1 is moving forward.
- the inlet 310 is arranged in the inlet channel 204 in this configuration. The inlet 310 prevents foreign objects from entering the cooling water flow path 200 and prevents damage to the impeller 211 .
- the pump shaft 212 also rotates around the rotation axis Apn in both the direction of rotation associated with the forward direction of the drive shaft 130 and the direction of rotation associated with the reverse direction of the drive shaft 130 .
- the water pump 210 which is a non-volumetric pump with no restriction on the direction of rotation, operates normally no matter which direction the drive shaft 130 rotates.
- the outboard motor 100 of the present preferred embodiment is mounted on the hull 10 and includes a cooling water flow path 200 including an intake port 201 to take in cooling water from the outside and through which cooling water flows, and a water pump 210 including an impeller 211 and a pump shaft 212 to rotate together with the impeller 211 to pump the cooling water into the cooling water flow path 200 , wherein the inlet channel 204 of the cooling water flow path 200 from the intake port 201 to the water pump 210 is located in front of the water pump 210 and extends along the rotation axis Apn of the pump shaft 212 , and the inlet 310 that allows the passage of the cooling water and prevents entry of foreign objects is located inside the inlet channel 204 .
- the cooling water taken in from the outside flows from the front of the water pump 210 to the impeller 211 attached to the pump shaft 212 so that the cooling water is pumped efficiently.
- This configuration also prevents damage to the water pump 210 caused by foreign objects colliding with the water pump 210 .
- the outboard motor 100 further includes the electric motor 120 , the drive shaft 130 to be rotationally driven by the electric motor 120 , the propeller 141 , and the propeller shaft 140 to rotate together with the propeller 141 .
- the drive shaft 130 is able to rotate in both the forward direction and the reverse direction opposite to the forward direction, and the water pump 210 is a non-volumetric pump.
- the drive shaft 130 which is able to rotate in both the forward and reverse directions, eliminates the need for a clutch mechanism such as a dog clutch thus providing a relatively large space around the propeller shaft 140 .
- This space can be used to accommodate the water pump 210 , avoiding an increase in the size of the outboard motor 100 and optimizing the arrangement of the components necessary to transport the cooling water.
- the non-volumetric water pump 210 since the non-volumetric water pump 210 has no restrictions on the direction of rotation, it is suitable as a pump, the rotation of which is transmitted from the drive shaft 130 that is able to rotate in both the forward and reverse directions.
- the water pump 210 is located on the rotation axis Apr of the propeller shaft 140 .
- This configuration allows the water pump 210 to be positioned without protruding sideways from the rotation axis Apr of the propeller shaft 140 , thus avoiding a reduction in the propulsive force of the hull 10 .
- the inlet 310 is made of resin, compared to the case where the inlet 310 is made of metal, adhesion of the inlet 310 to the member defining the inlet channel 204 due to corrosion is prevented.
- FIGS. 7 and 8 A second preferred embodiment of the present invention will now be explained with reference to FIGS. 7 and 8 .
- the material and shape of the inlet 320 are different from those of the first preferred embodiment.
- the same configuration as in the first preferred embodiment will be indicated by the same reference characters, and explanation thereof will be omitted.
- the inlet 320 is located inside the inlet channel 204 and prevents foreign objects contained in the cooling water taken in from the intake port 201 from entering the cooling water flow path 200 , as in the first preferred embodiment.
- the inlet 320 includes a filter plate 321 and a mounting cylinder 315 .
- the filter plate 321 is disc-shaped with an outer diameter larger than that of the mounting cylinder 315 and includes a number of passage holes 322 .
- the passage holes 322 penetrate from one side of the filter plate 321 to the other side and allow the passage of cooling water.
- At the center position of the filter plate 311 there is an attachment/detachment hole 323 with a hexagonal inner circumferential edge that fits a hexagonal wrench.
- the mounting cylinder 315 is a cylindrical portion extending from one side of the filter plate 311 (right side in FIG. 7 ) and having threads on the outer surface.
- the filter plate 321 is disposed near the intake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of the pump shaft 212 to separate the interior space of the inlet channel 204 from the exterior space.
- the outer circumferential edge of the filter plate 321 abuts the first stepped surface 207 to position the inlet 320 .
- the cooling water can flow into the interior of the pump chamber 203 through the passage hole 322 and the mounting cylinder 315 .
- the mounting cylinder 315 is located on the rotation axis Apn of the pump shaft 212 .
- the inlet 320 of the present preferred embodiment is made of glass fiber reinforced plastic, adhesion of the inlet 320 to the pipe defining the inlet channel 204 due to corrosion is prevented compared to the case where the inlet 320 is made of metal.
- the glass fiber reinforced plastic is stronger than resin that does not contain glass fibers, the inlet 320 is prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- inlet 330 an example of the filter
- filter body 340 includes two members, a filter body 340 and a holder 350 .
- the same configuration as in the first preferred embodiment will be indicated by the same reference characters, and explanation thereof will be omitted.
- the inlet 330 is located inside the inlet channel 204 and prevents foreign objects contained in the cooling water taken in from the intake port 201 from entering the cooling water flow path 200 , as in the first preferred embodiment.
- the inlet 330 includes a filter body 340 and a holder 350 that holds the filter body 340 and is fixed to the interior of the inlet channel 204 .
- the filter body 340 is a metal plate having a hexagonal outline and a curved shape that matches the curved shape of the front end surface of the lower case 116 b .
- the filter body 340 includes a number of passage holes 341 .
- the passage holes 341 penetrate the filter body 340 from one surface to the other surface and allow the passage of cooling water.
- Two parallel sides of the six sides defining the outer circumference of the filter body 340 respectively have a locking projection 343 projecting therefrom.
- the two attachment/detachment grooves 342 are arranged to face each other.
- the holder 350 is made of resin, is cylindrical in shape as a whole, and includes through holes 351 open at both ends. At one end of the holder 350 , an outwardly protruding flange 352 is provided.
- the outer surface of the holder 350 has threads corresponding to the grooves threaded on the inner surface of the constant-diameter channel 206 , except for the portion where the flange 352 is provided.
- a portion of the through hole 351 on the flange 352 side has a hexagonal inner circumferential edge and is a filter receiving hole 351 A to receive the filter body 340 .
- Two parallel sides of the six sides defining the inner circumferential edge of the filter receiving hole 351 A are respectively provided with a locking groove 353 which is recessed outwardly to receive the locking projection 343 .
- the holder 350 When the inlet 330 is attached to the inside of the inlet channel 204 , the holder 350 is disposed on the rotation axis Apn of the pump shaft 212 .
- the filter body 340 is disposed near the intake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of the pump shaft 212 to separate the interior space of the inlet channel 204 from the exterior space.
- the flange 352 abuts the first stepped surface 207 to position the inlet 330 .
- the cooling water can flow into the interior of the pump chamber 203 through the passage holes 341 and the through hole 351 .
- the inlet 330 is attached to the interior of the inlet channel 204 by first inserting a hexagonal wrench into the filter receiving hole 351 A to rotate the holder 350 around the rotation axis Apn, thus screwing the holder 350 to the pipe defining the inlet channel 204 .
- the filter body 340 is fitted into the interior of the filter receiving hole 351 A.
- the filter body 340 is secured to the interior of the filter receiving hole 351 A by the locking projection 343 inserted into the locking groove 353 .
- the inlet 330 is detached from the inlet channel 204 by first inserting a removal jig into the interior of the attachment/detachment groove 342 , hooking the jig onto the filter body 340 , and then pulling the jig to pull the filter body 340 out of the filter receiving hole 351 A.
- the holder 350 is removed from the pipe defining the inlet channel 204 by inserting a hexagonal wrench inside the filter receiving hole 351 A and rotating the holder 350 around the rotation axis Apn.
- the holder 350 of the inlet 330 that contacts the pipe defining the inlet channel 204 is made of resin, adhesion of the holder 350 to the pipe due to corrosion is prevented compared to the case where the holder 350 is made of metal.
- the material for the holder 350 may include nylon and polyacetal.
- the filter body 340 is made of metal, the filter body 340 is stronger compared to the case where the entire inlet is made of resin, and thus the filter body 340 is reduced or prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- the material of the filter body 340 is preferably a metal that is resistant to corrosion, e.g., aluminum, which forms an oxide film on its surface, is suitable.
- the electric outboard motor 100 is driven by the electric motor 120 , but the drive unit of the outboard motor does not have to be an electric motor and may be, e.g., an internal combustion engine.
- the drive shaft 130 is rotatable in both forward and reverse directions according to the rotational drive direction of the electric motor 120 , but the outboard motor may include an internal combustion engine as a drive unit and a shift mechanism to switch the rotational direction of the drive shaft.
- circular holes are illustrated as the passage holes 312 , 322 , and 341 , but the shape of the passage holes is freely selectable, e.g., the shape may be polygonal.
- the inlets 310 , 320 , and 330 have threads and are screwed to the pipe defining the inlet channel 204 , but the method of mounting the filter inside the inlet channel is freely selectable and may be, e.g., by a bolt and nut.
- the inlets 310 and 320 are made of resin and glass fiber reinforced plastic, respectively, but the material of the filter is freely selectable and may be, e.g., metal.
Abstract
An outboard motor includes a cooling water flow path including an intake port to take in cooling water from outside the outboard motor and through which cooling water flows, and a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path. An inlet channel of the cooling water flow path from the intake port to the water pump is located in front of the water pump and extends along a rotation axis of the pump shaft, and an inlet that allows the passage of the cooling water and prevents entry of foreign objects is located inside the inlet channel.
Description
- This application claims the benefit of priority to Japanese Patent Application No. 2022-206223 filed on Dec. 23, 2022. The entire contents of this application are hereby incorporated herein by reference.
- The technologies disclosed herein relate to an outboard motor and a boat propulsion device.
- Generally, outboard motors are equipped with a water pump to pump cooling water to cool the engine. The water pump includes an impeller or the like attached to a drive shaft. When the engine is driven, the impeller rotates together with the rotation of the drive shaft, and cooling water is pumped into the engine (see JP 2015-145137 A).
- In the water pump of the above configuration, because the impeller is directly attached to the drive shaft, the rotational speed of the impeller depends on the rotational speed of the drive shaft. Therefore, it is difficult to adjust the rotational speed of the impeller according to the required amount of cooling water to be transported, which may hinder efficient cooling water transport.
- An outboard motor according to a preferred embodiment of the present invention includes a cooling water flow path including an intake port to take in cooling water from outside the outboard motor and through which cooling water flows, and a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path, wherein an inlet channel of the cooling water flow path from the intake port to the water pump extends along a rotation axis of the pump shaft in front of the water pump, and a filter to allow passage of the cooling water and prevent entry of foreign objects is located inside the inlet channel.
- According to the above configuration, the cooling water taken in from the outside flows from the front of the water pump to the impeller attached to the pump shaft so that the cooling water is pumped efficiently. This configuration also reduces or prevents damage to the water pump caused by foreign objects colliding with the water pump.
- The outboard motor may further include a drive unit, a drive shaft to be rotationally driven by the drive unit, a propeller, and a propeller shaft to rotate together with the propeller, the drive shaft may be rotatable in both a forward direction and a reverse direction opposite to the forward direction, and the water pump may be a non-volumetric pump.
- The drive shaft, which is able to rotate in the both forward and reverse directions, eliminates the need for a clutch such as a dog clutch thus providing a relatively large space around the propeller shaft. This space can be used to accommodate the water pump eliminating the need for a larger outboard motor and optimizing the arrangement of the components necessary to transport the cooling water. In addition, since the non-volumetric pump has no restriction on the direction of rotation, it is suitable as a pump connected to a drive shaft that is able to rotate in both the forward and reverse directions.
- In the outboard motor, the drive unit may be an electric motor driven by electricity supplied from a power source.
- In the outboard motor, the water pump may be a centrifugal pump.
- In the outboard motor, the water pump may be located on the rotation axis of the propeller shaft.
- This configuration allows the water pump to be positioned without protruding sideways from the rotation axis of the propeller shaft thus avoiding a reduction in the propulsive force of the hull.
- In the outboard motor, the filter may be made of resin.
- According to this configuration, compared to the case where the filter is made of metal, it is possible to prevent the filter from corroding and adhering to the inlet channel.
- In the outboard motor, the filter may be made of glass fiber reinforced plastic.
- According to this configuration, compared to the case where the filter is made of resin that does not contain glass fibers, the filter is stronger, and thus the filter can be prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- In the outboard motor, the filter may include a holder including a through hole and fixed inside the inlet channel, and a filter body held inside the through hole to allow the passage of the cooling water and prevent entry of foreign objects, and the holder may be made of resin, and the filter body may be made of metal.
- According to this configuration, since the holder of the filter that is in contact with the inlet channel is made of resin, it is possible to prevent the filter from corroding and adhering to the inlet channel. In addition, since the filter body is made of metal, a filter portion is stronger compared to the case where the entire the filter is made of resin, and thus the filter portion is prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like.
- A boat propulsion device according to a preferred embodiment of the present invention includes a cooling water flow path including an intake port to take in cooling water from outside the boat propulsion device and through which cooling water flows, and a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path, wherein a filter to allow passage of the cooling water and prevent entry of foreign objects is located at the intake port, and the filter is located on a rotation axis of the pump shaft in front of the water pump.
- In this configuration, cooling water taken in from the outside flows in from the front of the water pump to the impeller attached to the pump shaft, thus enabling efficient pumping of the cooling water. This configuration also reduces or prevents damage to the water pump caused by foreign objects colliding with the water pump.
- According to the technologies disclosed herein, it is possible to provide outboard motors or boat propulsion devices that are each able to efficiently transport cooling water.
- 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 preferred embodiments with reference to the attached drawings.
-
FIG. 1 is a perspective view schematically illustrating a configuration of a boat according to a first preferred embodiment of the present invention. -
FIG. 2 is a side view schematically illustrating a configuration of an outboard motor according to the first preferred embodiment. -
FIG. 3 is a partially enlarged cross-sectional view of the outboard motor according to the first preferred embodiment, showing a partially enlarged cross-section cut at the position indicated by line III-III inFIG. 1 . -
FIG. 4 is an enlarged cross-sectional view of the portion indicated by frame F1 inFIG. 3 . -
FIG. 5 is an enlarged cross-sectional view of the portion indicated by frame F2 inFIG. 3 . -
FIG. 6 is a front view of an inlet according to the first preferred embodiment. -
FIG. 7 is a partially enlarged cross-sectional view of an outboard motor according to a second preferred embodiment of the present invention, showing the same area as inFIG. 5 enlarged. -
FIG. 8 is a front view of an inlet according to the second preferred embodiment. -
FIG. 9 is a partially enlarged cross-sectional view of an outboard motor according to a third preferred embodiment of the present invention, showing the same area as inFIG. 5 enlarged. -
FIG. 10 is a front view of an inlet according to the third preferred embodiment. - Specific preferred embodiments of the technologies disclosed by this specification are described below with reference to the drawings. The present invention is not limited to these preferred embodiments but is indicated by the claims, which are intended to include all modifications within the meaning and scope equivalent to the claims.
- A first preferred embodiment of the present invention will be described with reference to
FIGS. 1 to 4 . Aboat 1 according to the first preferred embodiment includes ahull 10 and an outboard motor 100 (an example of the boat propulsion device), as shown inFIG. 1 .FIG. 1 and other figures described below show arrows representing each direction with respect to the position of theboat 1. More specifically, each figure shows arrows representing front (FRONT), rear (REAR), left (LEFT), right (RIGHT), upper (UPPER), and lower (LOWER) directions, respectively. The front-rear direction, left-right direction, and upper-lower direction (vertical direction) are orthogonal to each other. - The
hull 10 is a portion of theboat 1 for occupants to ride. As shown inFIG. 1 , thehull 10 includes ahull body 12 including aliving space 11, apilot seat 16 installed in theliving space 11, and anoperating device 17 installed near thepilot seat 16. Theoperating device 17 maneuvers the boat and includes, e.g., a steering wheel, a shift throttle lever, a joystick, a monitor, and an input device. Thehull 10 also includes apartition wall 13 that partitions the rear end of theliving space 11 and atransom 14 positioned at the rear end of thehull 10. In the front-rear direction, there is aspace 15 between thetransom 14 and thepartition wall 13. - The
outboard motor 100 generates thrust to propel theboat 1. Theoutboard motor 100 in the present preferred embodiment is an electric outboard motor driven by an electric motor 120 (an example of a drive unit). Theoutboard motor 100 in the reference attitude will be described below unless otherwise specified. The reference attitude is the attitude of theoutboard motor 100 when theboat 1 is cruising (attitude shown inFIG. 1 ), in which the rotation axis Ad of the drive shaft 130 (described below) extends in the upper-lower direction and the rotation axis Apr of thepropeller shaft 140 extends in the front-rear direction. The front-rear direction, the left-right direction, and the upper-lower direction are defined based on theoutboard motor 100 in the reference attitude. - As shown in
FIG. 1 , theoutboard motor 100 is attached to thetransom 14 located at the rear (stern) of thehull 10. Theoutboard motor 100 includes an outboard motormain body 110 and a suspension device 150. - As shown in
FIGS. 2 and 3 , the outboard motormain body 110 includes acowl 114, acasing 116, anelectric motor 120, adrive shaft 130, apropeller 141, apropeller shaft 140, a coolingwater flow path 200, awater pump 210, afirst gear mechanism 180, asecond gear mechanism 190, and an inlet 310 (an example of the filter). - As shown in
FIG. 2 , thecowl 114 is a housing located on top of the outboard motormain body 110. Thecasing 116 includes anupper case 116 a and alower case 116 b, as shown inFIG. 2 . Theupper case 116 a is a housing located below thecowl 114. Thelower case 116 b is a housing located below theupper case 116 a. - The
lower case 116 b includes agear chamber 118 that stores oil therein and houses thefirst gear mechanism 180 and thesecond gear mechanism 190, as shown inFIG. 4 . - The
electric motor 120 is driven by electric power supplied from a battery (power source). Theelectric motor 120 includes a rotor including a permanent magnet, a stator including a coil to which the battery power is supplied, and a motor housing that houses the rotor and stator. Theelectric motor 120 is located inside thecowl 114. The battery may be located inside thecowl 114 or inside thehull 10. - The
drive shaft 130 is a rod-shaped member extending downward from theelectric motor 120 and housed within thecasing 116, as shown inFIG. 2 . Thedrive shaft 130 is arranged in an attitude in which its rotation axis Ad extends in the upper-lower direction. - As shown in
FIG. 4 , thedrive shaft 130 includes a rod-shapedmain shaft 131 and anextension shaft 132 extending from the tip of themain shaft 131 opposite to the electric motor 120 (lower end inFIG. 4 ). Themain shaft 131 includes a constant-diameter shaft 131A extending from theelectric motor 120, which is a round rod of constant thickness, and a reduced-diameter shaft 131B connecting the constant-diameter shaft 131A and theextension shaft 132. Theextension shaft 132 extends coaxially with themain shaft 131 and has a round rod shape with a smaller diameter than the constant-diameter shaft 131A. The constant-diameter shaft 131A, the reduced-diameter shaft 131B, and theextension shaft 132 are coaxial. - The
drive shaft 130 rotates around the rotation axis Ad due to the rotational driving force of theelectric motor 120. Since theelectric motor 120 is able to rotate in both the forward and reverse directions, thedrive shaft 130 is also able to rotate around the rotation axis line Ad in both forward direction to move theboat 1 forward and the reverse direction to move theboat 1 backward opposite to the forward direction, according to the rotational driving direction of theelectric motor 120. - The
propeller 141 is a rotating body including a plurality of blades. Thepropeller 141 generates thrust by rotation. - The
propeller shaft 140 is a rod-shaped member and extends in the front-rear direction inside thelower case 116 b, as shown inFIGS. 2, 3, and 4 . Thepropeller shaft 140 is rotatably supported by thelower case 116 b via abearing 142. The rear end of thepropeller shaft 140 protrudes rearwardly from thelower case 116 b, and thepropeller 141 is attached to this rear end. As thepropeller shaft 140 rotates around the rotation axis Apr, thepropeller 141 also rotates. - The cooling
water flow path 200 is located inside the outboard motormain body 110. The coolingwater flow path 200 includes a channel through which cooling water (seawater, lake water, and river water, among others) taken in from outside theoutboard motor 100 flows. The coolingwater flow path 200 includes anintake port 201 that opens on the outer surface of thelower case 116 b to take in cooling water into the interior and adrain port 202 that also opens on the outer surface of thelower case 116 b to discharge cooling water to the exterior. The coolingwater flow path 200 extends from theintake port 201 through the periphery of theelectric motor 120 to thedrain port 202. Theintake port 201 is located below the waterline when theboat 1 is cruising, i.e., when theoutboard motor 100 is in the reference attitude. Theintake port 201 is open at the front end of thelower case 116 b. - As shown in
FIG. 4 , a portion of the coolingwater flow path 200 includes apump chamber 203. Thepump chamber 203 is located in front of thegear chamber 118 in thelower case 116 b and is separated from thegear chamber 118 by apartition 220. Thepartition 220 includes ashaft hole 221 that is connected to thepump chamber 203 and thegear chamber 118. - The
water pump 210 is a non-volumetric pump including animpeller 211 and apump shaft 212 that rotates together with theimpeller 211, as shown inFIG. 4 . In the present preferred embodiment, a centrifugal pump is exemplified as thewater pump 210. - The
impeller 211 is a rotating body including a plurality of blades and is located inside thepump chamber 203. Thepump shaft 212 is a rod-shaped member and extends in a front-rear direction. Thepump shaft 212 is inserted into theshaft hole 221 and is supported by thepartition 220 in a rotatable manner via abearing 213. The rotation axis Apn of thepump shaft 212 coincides with the rotation axis Apr of thepropeller shaft 140. The front end of thepump shaft 212 is located inside thepump chamber 203, where theimpeller 211 is mounted. In other words, the water pump 210 (specifically, thepump shaft 212 and impeller 211) is located on the rotation axis Apr of thepropeller shaft 140. As thepump shaft 212 rotates around the rotation axis Apn, theimpeller 211 also rotates. The rear end of thepump shaft 212 is located inside thegear chamber 118. - Inside the
shaft hole 221, as shown inFIG. 4 , a plurality ofseals 230 are arranged on the outer surface of thepump shaft 212 to fill the gap between the inner surface of theshaft hole 221 and thepump shaft 212. Eachseal 230 is circular in shape, is made of a material such as rubber having elasticity, and encircles thepump shaft 212 all the way around. The plurality ofseals 230 are arranged in line along the rotation axis Apn of thepump shaft 212. Theseseals 230 prevent cooling water flowing into thepump chamber 203 from entering thegear chamber 118 through the gap between the inner circumferential surface of theshaft hole 221 and thepump shaft 212. - The portion of the cooling
water flow path 200 from theintake port 201 to thewater pump 210, i.e., the portion located between theintake port 201 and the pump chamber 203 (inlet channel 204), is located in front of thewater pump 210 and extends along the rotation axis Apn of thepump shaft 212, as shown inFIG. 4 . - As shown in
FIG. 5 , one portion of theinlet channel 204 adjacent to the intake port 201 (enlarged-diameter channel 205) has a larger inner diameter than the remaining portion adjacent to the pump chamber 203 (constant-diameter channel 206). On the inner surface of a member (e.g., a pipe) defining theinlet channel 204, a first steppedsurface 207 is provided, which connects the inner surface of the enlarged-diameter channel 205 to the inner surface of the constant-diameter channel 206. The first steppedsurface 207 is arranged to face toward theintake port 201 and is perpendicular or substantially perpendicular to the rotation axis Apn of thepump shaft 212. A threaded groove to fix theinlet 310 is provided on the inner surface of the constant-diameter channel 206. - The
first gear mechanism 180 transmits the rotation of thedrive shaft 130 to thepropeller shaft 140, and thesecond gear mechanism 190 transmits the rotation of thedrive shaft 130 to thepump shaft 212. Thefirst gear mechanism 180 and thesecond gear mechanism 190 have different gear ratios. - The
first gear mechanism 180 includes afirst gear 181 and asecond gear 182, as shown inFIG. 4 . Thefirst gear 181 is coaxially mounted to themain shaft 131 of the drive shaft 130 (more specifically, the reduced-diameter shaft 131B) and rotates together with thedrive shaft 130. Thesecond gear 182 is coaxially mounted to thepropeller shaft 140 and rotates together with thepropeller shaft 140. Thesecond gear 182 meshes with thefirst gear 181. Thefirst gear 181 and thesecond gear 182 are, e.g., bevel gears. - The
second gear mechanism 190 includes athird gear 191 and afourth gear 192, as shown inFIG. 4 . Thethird gear 191 is coaxially mounted to theextension shaft 132 of thedrive shaft 130 and rotates together with thedrive shaft 130. Thethird gear 191 has a smaller outer diameter than thefirst gear 181 and is located farther from theelectric motor 120 than thefirst gear 181. Thefourth gear 192 is coaxially mounted to thepump shaft 212 and rotates together with thepump shaft 212. Thefourth gear 192 meshes with thethird gear 191. Thethird gear 191 and thefourth gear 192 are, e.g., bevel gears. - The
first gear mechanism 180 and thesecond gear mechanism 190 are located inside thegear chamber 118. The four gears 181, 182, 191, and 192 are lubricated by oil provided inside thegear chamber 118. - The
inlet 310 is located inside theinlet channel 204 and prevents foreign objects contained in the cooling water taken in from theintake port 201 from entering the coolingwater flow path 200 and includes afilter plate 311 and a mountingcylinder 315, as shown inFIGS. 5 and 6 . - The
filter plate 311 is disc-shaped and includes a number of passage holes 312. The passage holes 312 penetrate from one side to the other and allow the passage of cooling water. The size of eachpassage hole 312 is sufficient to allow the cooling water to pass smoothly but to prevent the entering of foreign objects of a size that could clog the coolingwater flow path 200, such as algae or pebbles, e.g., a hole having an inner diameter of about 2.5 mm, for example. - The mounting
cylinder 315 is a cylindrical portion extending from one side of the filter plate 311 (right side ofFIG. 5 ) and has an outer diameter smaller than the outer diameter of thefilter plate 311. The outer surface of the mountingcylinder 315 has threads corresponding to the grooves threaded on the inner surface of the constant-diameter channel 206. - A circular attachment/
detachment ring 313 arranged along the outer circumferential edge protrudes from the other side of the filter plate 311 (left side ofFIG. 5 ). The recess defined by the attachment/detachment ring 313 andfilter plate 311 has a hexagonal inner circumferential edge and is an attachment/detachment recess 314 that fits a hexagonal wrench. - When the
inlet 310 is located within theinlet channel 204, thefilter plate 311 is disposed near theintake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of thepump shaft 212 to separate the interior space of theinlet channel 204 from the exterior space. The outer circumferential edge of thefilter plate 311 abuts the first steppedsurface 207 to position theinlet 310. The mountingcylinder 315 is located on the rotation axis Apn of thepump shaft 212. Cooling water flows into thepump chamber 203 through thepassage hole 312 and the interior of the mountingcylinder 315. By turning theinlet 310 around the rotation axis Apn using a hexagonal wrench, theinlet 310 can be attached to or removed from the pipe defining theinlet channel 204. - Since the
inlet 310 of the present preferred embodiment is made of resin, adhesion of theinlet 310 to the pipe defining theinlet channel 204 due to corrosion is prevented compared to the case where theinlet 310 is made of metal. Examples of the material for theinlet 310 may include nylon and polyacetal. - The suspension device 150 suspends the outboard motor
main body 110 on thehull 10. The suspension device 150 includes a pair of left and right clamp brackets 152, atilt shaft 160, and aconnection bracket 156, as shown inFIG. 2 . - The pair of left and right clamp brackets 152 are disposed behind the
hull 10 in a state separated from each other in the left-right direction and are fixed to thetransom 14 of thehull 10 by using, e.g., bolts. Each clamp bracket 152 includes a cylindrical supportingportion 152 a provided with a through-hole extending in the left-right directions. - The
tilt shaft 160 is a rod-shaped member. Thetilt shaft 160 is rotatably supported in the through-hole of the supportingportion 152 a of the clamp bracket 152. The tilt axis At, which is the center line of thetilt shaft 160, defines an axis extending in the horizontal direction (left-right direction) during the tilting action of theoutboard motor 100. - The
connection bracket 156 is sandwiched between the pair of clamp brackets 152 and is supported by the supportingportion 152 a of the clamp bracket 152 via thetilt shaft 160 in such a manner that theconnection bracket 156 is able to rotate around the tilt axis At. Theconnection bracket 156 is fixed to the outboard motormain body 110. Theconnection bracket 156 is rotationally driven around the tilt axis At with respect to the clamp bracket 152 by a tilt device (not shown) including an actuator such as, e.g., a hydraulic cylinder. - When the
connection bracket 156 rotates about the tilt axis At with respect to the clamp bracket 152, the outboard motormain body 110 fixed to theconnection bracket 156 also rotates about the tilt axis At. This achieves the tilting action of rotating the outboard motormain body 110 in the upper-lower direction with respect to thehull 10. Due to this tilting action, theoutboard motor 100 can change the angle around the tilt axis At of the outboard motormain body 110 in the range from the tilt-down state in which thepropeller 141 is located under the waterline (the state in which theoutboard motor 100 is in the reference attitude: the state shown inFIG. 1 ) to the tilt-up state in which thepropeller 141 is above the waterline. Trimming action to adjust the attitude of theboat 1 during cruising can also be performed by adjusting the angle around the tilt axis At of the outboard motormain body 110. - When the
boat 1 is cruising, theoutboard motor 100 is placed in the tilt-down state, and thelower case 116 b and thepropeller 141 are positioned below the waterline. Theintake port 201,inlet channel 204,pump chamber 203, andwater pump 210 located inside thelower case 116 b are also below the waterline, and cooling water flows into thepump chamber 203 from outside through theintake port 201 andinlet channel 204. At this time, theinlet 310, which is located in theinlet channel 204, prevents the entry of foreign objects of a size that could clog the coolingwater flow path 200, such as algae and pebbles. - When the
electric motor 120 is driven, thedrive shaft 130 rotates around the rotation axis Ad due to the rotational driving force of theelectric motor 120. - The rotation of the
drive shaft 130 is transmitted to thepropeller shaft 140 via thefirst gear mechanism 180. When thefirst gear mechanism 180 transmits the forward rotation of thedrive shaft 130 to thepropeller shaft 140, thepropeller 141 rotating together with thepropeller shaft 140 generates thrust in the forward direction. When thefirst gear mechanism 180 transmits the reverse rotation of thedrive shaft 130 to thepropeller shaft 140, thepropeller 141 rotating together with thepropeller shaft 140 generates thrust in the rearward direction. - The rotation of the
drive shaft 130 is transmitted to thepump shaft 212 via thesecond gear mechanism 190, and theimpeller 211 rotates together with thepump shaft 212. Cooling water taken in from theintake port 201 is pumped through the coolingwater flow path 200 by centrifugal force generated by the rotation of theimpeller 211, and is supplied around theelectric motor 120 to cool theelectric motor 120. In addition to theelectric motor 120, the cooling water may also cool the battery, inverter, and reduction gears, among others, located inside the outboard motormain body 110. After being used for cooling, the cooling water is discharged to the outside through thedrain port 202. - The
intake port 201 and theinlet channel 204 are located on the rotation axis Apn of thepump shaft 212 and in front (bow side) of thewater pump 210, so that when theboat 1 moves forward, the cooling water flows through theintake port 201 and theinlet channel 204 from the front to theimpeller 211. This allows the cooling water to be pumped efficiently, especially when theboat 1 is moving forward. In this configuration, there is a concern that foreign objects contained in the cooling water may also flow in with great force and collide with theimpeller 211. To prevent this, theinlet 310 is arranged in theinlet channel 204 in this configuration. Theinlet 310 prevents foreign objects from entering the coolingwater flow path 200 and prevents damage to theimpeller 211. - As the
drive shaft 130 rotates in both the forward and reverse directions, thepump shaft 212 also rotates around the rotation axis Apn in both the direction of rotation associated with the forward direction of thedrive shaft 130 and the direction of rotation associated with the reverse direction of thedrive shaft 130. Thewater pump 210, which is a non-volumetric pump with no restriction on the direction of rotation, operates normally no matter which direction thedrive shaft 130 rotates. - As described above, the
outboard motor 100 of the present preferred embodiment is mounted on thehull 10 and includes a coolingwater flow path 200 including anintake port 201 to take in cooling water from the outside and through which cooling water flows, and awater pump 210 including animpeller 211 and apump shaft 212 to rotate together with theimpeller 211 to pump the cooling water into the coolingwater flow path 200, wherein theinlet channel 204 of the coolingwater flow path 200 from theintake port 201 to thewater pump 210 is located in front of thewater pump 210 and extends along the rotation axis Apn of thepump shaft 212, and theinlet 310 that allows the passage of the cooling water and prevents entry of foreign objects is located inside theinlet channel 204. - According to the above configuration, the cooling water taken in from the outside flows from the front of the
water pump 210 to theimpeller 211 attached to thepump shaft 212 so that the cooling water is pumped efficiently. This configuration also prevents damage to thewater pump 210 caused by foreign objects colliding with thewater pump 210. - The
outboard motor 100 further includes theelectric motor 120, thedrive shaft 130 to be rotationally driven by theelectric motor 120, thepropeller 141, and thepropeller shaft 140 to rotate together with thepropeller 141. Thedrive shaft 130 is able to rotate in both the forward direction and the reverse direction opposite to the forward direction, and thewater pump 210 is a non-volumetric pump. - According to this configuration, the
drive shaft 130, which is able to rotate in both the forward and reverse directions, eliminates the need for a clutch mechanism such as a dog clutch thus providing a relatively large space around thepropeller shaft 140. This space can be used to accommodate thewater pump 210, avoiding an increase in the size of theoutboard motor 100 and optimizing the arrangement of the components necessary to transport the cooling water. In addition, since thenon-volumetric water pump 210 has no restrictions on the direction of rotation, it is suitable as a pump, the rotation of which is transmitted from thedrive shaft 130 that is able to rotate in both the forward and reverse directions. - In addition, the
water pump 210 is located on the rotation axis Apr of thepropeller shaft 140. - This configuration allows the
water pump 210 to be positioned without protruding sideways from the rotation axis Apr of thepropeller shaft 140, thus avoiding a reduction in the propulsive force of thehull 10. - In addition, since the
inlet 310 is made of resin, compared to the case where theinlet 310 is made of metal, adhesion of theinlet 310 to the member defining theinlet channel 204 due to corrosion is prevented. - A second preferred embodiment of the present invention will now be explained with reference to
FIGS. 7 and 8 . In this preferred embodiment, the material and shape of the inlet 320 (an example of the filter) are different from those of the first preferred embodiment. In this preferred embodiment, the same configuration as in the first preferred embodiment will be indicated by the same reference characters, and explanation thereof will be omitted. - The
inlet 320 is located inside theinlet channel 204 and prevents foreign objects contained in the cooling water taken in from theintake port 201 from entering the coolingwater flow path 200, as in the first preferred embodiment. Theinlet 320 includes afilter plate 321 and a mountingcylinder 315. - The
filter plate 321 is disc-shaped with an outer diameter larger than that of the mountingcylinder 315 and includes a number of passage holes 322. The passage holes 322 penetrate from one side of thefilter plate 321 to the other side and allow the passage of cooling water. At the center position of thefilter plate 311, there is an attachment/detachment hole 323 with a hexagonal inner circumferential edge that fits a hexagonal wrench. As in the first preferred embodiment, the mountingcylinder 315 is a cylindrical portion extending from one side of the filter plate 311 (right side inFIG. 7 ) and having threads on the outer surface. - When the
inlet 320 is attached to the inside of theinlet channel 204, as in the first preferred embodiment, thefilter plate 321 is disposed near theintake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of thepump shaft 212 to separate the interior space of theinlet channel 204 from the exterior space. The outer circumferential edge of thefilter plate 321 abuts the first steppedsurface 207 to position theinlet 320. The cooling water can flow into the interior of thepump chamber 203 through thepassage hole 322 and the mountingcylinder 315. The mountingcylinder 315 is located on the rotation axis Apn of thepump shaft 212. By turning theinlet 320 around the rotation axis Apn using a hexagonal wrench, theinlet 320 can be attached to or removed from the pipe defining theinlet channel 204. - Since the
inlet 320 of the present preferred embodiment is made of glass fiber reinforced plastic, adhesion of theinlet 320 to the pipe defining theinlet channel 204 due to corrosion is prevented compared to the case where theinlet 320 is made of metal. In addition, since the glass fiber reinforced plastic is stronger than resin that does not contain glass fibers, theinlet 320 is prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like. - Next, a third preferred embodiment of the present invention will be described with reference to
FIGS. 9 and 10 . This preferred embodiment differs from the first preferred embodiment in that inlet 330 (an example of the filter) includes two members, afilter body 340 and aholder 350. In this preferred embodiment, the same configuration as in the first preferred embodiment will be indicated by the same reference characters, and explanation thereof will be omitted. - The
inlet 330 is located inside theinlet channel 204 and prevents foreign objects contained in the cooling water taken in from theintake port 201 from entering the coolingwater flow path 200, as in the first preferred embodiment. Theinlet 330 includes afilter body 340 and aholder 350 that holds thefilter body 340 and is fixed to the interior of theinlet channel 204. - The
filter body 340 is a metal plate having a hexagonal outline and a curved shape that matches the curved shape of the front end surface of thelower case 116 b. Thefilter body 340 includes a number of passage holes 341. The passage holes 341 penetrate thefilter body 340 from one surface to the other surface and allow the passage of cooling water. Two parallel sides of the six sides defining the outer circumference of thefilter body 340 respectively have a lockingprojection 343 projecting therefrom. On the inner surface of onepassage hole 341A located at the center of thefilter body 340, two attachment/detachment grooves 342 are provided, which are recessed outwardly. The two attachment/detachment grooves 342 are arranged to face each other. - The
holder 350 is made of resin, is cylindrical in shape as a whole, and includes throughholes 351 open at both ends. At one end of theholder 350, an outwardlyprotruding flange 352 is provided. The outer surface of theholder 350 has threads corresponding to the grooves threaded on the inner surface of the constant-diameter channel 206, except for the portion where theflange 352 is provided. - A portion of the through
hole 351 on theflange 352 side has a hexagonal inner circumferential edge and is afilter receiving hole 351A to receive thefilter body 340. Two parallel sides of the six sides defining the inner circumferential edge of thefilter receiving hole 351A are respectively provided with a lockinggroove 353 which is recessed outwardly to receive the lockingprojection 343. - When the
inlet 330 is attached to the inside of theinlet channel 204, theholder 350 is disposed on the rotation axis Apn of thepump shaft 212. Thefilter body 340 is disposed near theintake port 201 and perpendicular or substantially perpendicular to the rotation axis Apn of thepump shaft 212 to separate the interior space of theinlet channel 204 from the exterior space. Theflange 352 abuts the first steppedsurface 207 to position theinlet 330. The cooling water can flow into the interior of thepump chamber 203 through the passage holes 341 and the throughhole 351. - The
inlet 330 is attached to the interior of theinlet channel 204 by first inserting a hexagonal wrench into thefilter receiving hole 351A to rotate theholder 350 around the rotation axis Apn, thus screwing theholder 350 to the pipe defining theinlet channel 204. Next, thefilter body 340 is fitted into the interior of thefilter receiving hole 351A. Thefilter body 340 is secured to the interior of thefilter receiving hole 351A by the lockingprojection 343 inserted into the lockinggroove 353. - The
inlet 330 is detached from theinlet channel 204 by first inserting a removal jig into the interior of the attachment/detachment groove 342, hooking the jig onto thefilter body 340, and then pulling the jig to pull thefilter body 340 out of thefilter receiving hole 351A. Next, theholder 350 is removed from the pipe defining theinlet channel 204 by inserting a hexagonal wrench inside thefilter receiving hole 351A and rotating theholder 350 around the rotation axis Apn. - Since the
holder 350 of theinlet 330 that contacts the pipe defining theinlet channel 204 is made of resin, adhesion of theholder 350 to the pipe due to corrosion is prevented compared to the case where theholder 350 is made of metal. Examples of the material for theholder 350 may include nylon and polyacetal. In addition, since thefilter body 340 is made of metal, thefilter body 340 is stronger compared to the case where the entire inlet is made of resin, and thus thefilter body 340 is reduced or prevented from being damaged by collisions with foreign objects while cruising, collisions with a shore while anchoring, and the like. The material of thefilter body 340 is preferably a metal that is resistant to corrosion, e.g., aluminum, which forms an oxide film on its surface, is suitable. - In the above preferred embodiments, as an example, the electric
outboard motor 100 is driven by theelectric motor 120, but the drive unit of the outboard motor does not have to be an electric motor and may be, e.g., an internal combustion engine. - In the above preferred embodiments, the
drive shaft 130 is rotatable in both forward and reverse directions according to the rotational drive direction of theelectric motor 120, but the outboard motor may include an internal combustion engine as a drive unit and a shift mechanism to switch the rotational direction of the drive shaft. - In the above preferred embodiments, circular holes are illustrated as the passage holes 312, 322, and 341, but the shape of the passage holes is freely selectable, e.g., the shape may be polygonal.
- In the above preferred embodiments, the
inlets inlet channel 204, but the method of mounting the filter inside the inlet channel is freely selectable and may be, e.g., by a bolt and nut. - In the above preferred embodiments, the
inlets - While preferred 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.
Claims (11)
1. An outboard motor to be mounted on a hull, the outboard motor comprising:
a cooling water flow path including an intake port to take in cooling water from outside the outboard motor and through which cooling water flows; and
a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path; wherein
an inlet channel of the cooling water flow path from the intake port to the water pump extends along a rotation axis of the pump shaft in front of the water pump; and
a filter to allow passage of the cooling water and prevent entry of foreign objects is located inside the inlet channel.
2. The outboard motor according to claim 1 , further comprising:
a drive unit;
a drive shaft to be rotationally driven by the drive unit;
a propeller; and
a propeller shaft to rotate together with the propeller; wherein
the drive shaft is rotatable in both a forward direction and a reverse direction opposite to the forward direction; and
the water pump is a non-volumetric pump.
3. The outboard motor according to claim 2 , wherein the drive unit is an electric motor to be driven by electric power supplied from a power source.
4. The outboard motor according to claim 2 , wherein the water pump is a centrifugal pump.
5. The outboard motor according to claim 2 , wherein the water pump is located on the rotation axis of the propeller shaft.
6. The outboard motor according to claim 1 , wherein the filter is made of resin.
7. The outboard motor according to claim 1 , wherein the filter is made of glass fiber reinforced plastic.
8. The outboard motor according to claim 1 , wherein the filter includes:
a holder including a through hole and fixed inside the inlet channel; and
a filter body inside the through hole to allow the passage of the cooling water and prevent entry of foreign objects; wherein
the holder is made of resin; and
the filter body is made of metal.
9. A boat propulsion device provided on a hull, the boat propulsion device comprising:
a cooling water flow path including an intake port to take in cooling water from outside the boat propulsion device and through which cooling water flows; and
a water pump including an impeller and a pump shaft to rotate together with the impeller to pump the cooling water into the cooling water flow path; wherein
a filter to allow passage of the cooling water and prevent entry of foreign objects is located at the intake port; and
the filter is located on a rotation axis of the pump shaft in front of the water pump.
10. A boat comprising:
a hull; and
the outboard motor according to claim 1 attached to a transom at a rear end of the hull.
11. A boat comprising:
a hull; and
the boat propulsion device according to claim 9 attached to a transom at a rear end of the hull.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2022-206223 | 2022-12-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
US20240208629A1 true US20240208629A1 (en) | 2024-06-27 |
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