WATERCRAFT WITH ADJUSTABLE CENTER OF GRAVITY

Abstract

A watercraft comprising a hull, an electric drive, a battery electrically coupled to the electric drive, and an actuation assembly coupled to the battery. The battery is movable with respect to the hull by the actuation assembly between a first position and a second position.

Description

TECHNICAL FIELD

This disclosure relates to ballast systems in watercraft (e.g., boats) and methods of using the same.

BACKGROUND

Recreational sport boats are often used to tow water sports participants (e.g., water skiers, wakeboarders, wake surfers, etc.). The optimal wake depends on the sport, and the participant's preferences and skill. For example, wake surfers generally prefer a large wake that is shaped like ocean waves. To make such wakes with a conventional recreational sport boat, large amounts of ballast in the form of water is loaded onto the boat to pitch the boat, and/or roll it to one side, such that it throws a larger wake.

Conventional ballast configurations, however, are slow and cumbersome, particularly when water is used as the ballast. For example, it can take several minutes to fill ballast tanks and the pumps and filters involved often require maintenance because they interact with contaminated or briny water. Furthermore, water ballast reduces performance efficiency because adding water to the boat adds additional “dead” weight that would not otherwise be on the boat, thereby increasing the overall drag the boat has to overcome above and beyond the effects of the change in pitch or roll itself.

SUMMARY

The disclosure provides, in one aspect, a watercraft including a hull, an electric drive, a battery electrically coupled to the electric drive, and an actuation assembly coupled to the battery. The battery is movable with respect to the hull by the actuation assembly between a first position and a second position.

In some embodiments, moving the battery between the first position and the second position adjusts a center of gravity of the watercraft.

In some embodiments, the battery is movable with respect to the electric drive.

In some embodiments, the battery is movable with respect to the hull by the actuation assembly to a plurality of intermediate positions between the first position and the second position.

In some embodiments, the battery moves between the first position and the second position along a translation axis.

In some embodiments, the translation axis is parallel to a center bow-stern axis of the watercraft.

In some embodiments, the translation axis is transverse to a center bow-stern axis of the watercraft.

In some embodiments, the actuation assembly includes a carriage coupled to the battery, a pinion driven by an actuator, and a rack with a plurality of teeth configured to engage the pinion, wherein the carriage is configured to slide along the rack.

In some embodiments, the watercraft further includes a lock assembly configured to lock the position of the battery with respect to the hull.

In some embodiments, the watercraft further includes an electrical cable extending between the battery and the electric drive, and wherein the electrical cable has a length that is sufficient to permit travel of the battery between the first position and the second position.

In some embodiments, the watercraft further includes a coolant line extending between the battery and the electric drive, and wherein the coolant line has a length that is sufficient to permit travel of the battery between the first position and the second position.

In some embodiments, the battery is a first battery, and the watercraft further includes a second battery electrically coupled to the electric drive.

In some embodiments, the second battery is movable with respect to the hull by the actuation assembly between a third position and a fourth position.

In some embodiments, the first battery moves between the first position and the second position along a first translation axis, and the second battery moves between the third position and the fourth position along a second translation axis.

In some embodiments, the first translation axis is orthogonal to the second translation axis.

In some embodiments, the first translation axis is parallel to the second translation axis.

In some embodiments, the electric drive includes an electric motor and an inverter, and wherein the battery includes a housing and a plurality of battery cells positioned within the housing.

In some embodiments, the watercraft further includes a sensor that detects the position of the battery.

In some embodiments, the watercraft further includes a controller configured to energize the actuation assembly in response to a detected position of the battery by the sensor and a position of the watercraft in water.

In some embodiments, the actuation assembly is configured to move the battery at a first speed and at a second speed, wherein the second speed is larger than the first speed.

Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present technology will become better understood with regards to the following drawings. The accompanying figures and examples are provided by way of illustration and not by way of limitation.

FIG. 1 is top view of a boat illustrating an electric drive, a first movable battery in a neutral position, and a second movable battery in a neutral position.

FIG. 2A is a side view of the boat of FIG. 1, illustrating the first movable battery in the neutral position.

FIG. 2B is a side view of the boat of FIG. 1, illustrating the first movable battery in a stern position.

FIG. 3A is a rear view of the boat of FIG. 1, illustrating the second movable battery in the neutral position.

FIG. 3B is a rear view of the boat of FIG. 1, illustrating the second movable battery in a starboard position.

FIG. 4 is a top view of the boat of FIG. 1, illustrating a heeled configuration with the first movable battery in a stern position and the second movable battery in a port position.

FIG. 5 is an enlarged partial side tear-away view of the boat of FIG. 1, illustrating an actuation assembly coupled to the first movable battery.

Before any embodiments are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways.

DETAILED DESCRIPTION

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of” and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.

For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the number 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are explicitly contemplated.

The term “coupled,” as used herein, is defined as “connected,” although not necessarily directly, and not necessarily mechanically. The term coupled is to be understood to mean physically, magnetically, chemically, fluidly, electrically, or otherwise coupled, connected or linked and does not exclude the presence of intermediate elements between the coupled elements absent specific contrary language.

To facilitate the understanding of this disclosure, a number of marine terms are defined below. Terms defined herein have meanings as commonly understood by a person of ordinary skill in the areas relevant to the present disclosure. “Starboard” refers to the right-hand, or driver's, side of the watercraft. “Port” refers to the left-hand, or passenger's, side of the watercraft. “Bow” refers to the front of the watercraft. “Transom” and “stern” refer to the rear of the watercraft. The starboard 2, port 4, bow 6, and stern 8 directions are illustrated in FIG. 1 for reference.

With reference to FIG. 1, a watercraft 10 includes a hull 14, a front windshield 18, a deck region 22, and a transom 26. The hull 14 defines a center bow-stern axis 28. The watercraft 10 is propelled through the water by a propeller 30 (FIG. 2A) that is rotationally driven by an electric drive 34. In some embodiments, the electric drive 34 includes an electric motor (e.g., an induction motor, a synchronous motor, a brushless DC motor, a permanent magnet rotor, an interior permanent magnet motor, a surface permanent magnet motor, a reluctance motor, etc.) and a power converter (e.g., an inverter, a converter, etc.). The watercraft 10 is steered through the water with adjustment of a rudder 38 by an operator input 42 (e.g., steering wheel).

The watercraft 10 includes at least one battery (e.g., the first battery 46, the second battery 50) that is movable with respect to the hull 14. The term “battery” as used herein, refers to one or more cells electrically coupled in parallel or series (e.g., a battery pack). In some embodiments, each battery includes a battery pack housing with a plurality of battery cells positioned within the battery pack housing. In some embodiments, the moveable battery is positioned within the transom 26. In some embodiments, the movable battery is positioned underneath the floor of the deck region 22. In the illustrated embodiment, the electric drive 34 is fixed relative to the hull 14, and the first battery 46 and the second battery 50 are movable with respect to the electric drive 34 as well as the hull 14.

The watercraft 10 further includes an actuation assembly (e.g., actuation assembly 90, FIG. 5) coupled to the battery, and the battery is movable with respect to the hull 14 by the actuation assembly between a first position (e.g., a neutral position, a starting position, etc.) and a second position (e.g., a starboard position, a port position, a stern position, an offset position, and adjusted position, etc.). In some embodiments, the battery is movable with respect to the hull by the actuation assembly to a plurality of intermediate positions between the first position and the second position. In other words, the first position and the second position may be the positions at the ends of travel with a plurality of intermediate positions between the two end positions.

Moving the battery with respect to the hull between a first position and a second position, adjusts a center of gravity of the watercraft relative to a center of pressure of the watercraft, thereby changing its pitch or roll. In other words, the center of gravity is adjusted relative to the center of pressure, where the difference between the two centers causes the watercraft to pitch or roll. Advantageously, an operator of the watercraft can easily adjust the center of gravity of the watercraft as needed or desired. For example, the amount of or shape of wake created by the watercraft can be adjusted by adjusting the center of gravity of the watercraft as the center of pressure does not change. Unlike conventional ballasts that take on water and add “dead” weight to the watercraft in order to change the center of gravity, the center of gravity adjustment disclosed is achieved by adjusting the relative positioning of batteries that have additional functionality (e.g., powering the electric drive) and are already part of the overall weight of the watercraft. In other words, the disclosure herein achieves additional functionality (e.g., center of gravity adjustment) with components already included in the watercraft.

With continued reference to FIG. 1, in the illustrated embodiment, the watercraft 10 includes a first battery 46 and a second battery 50 electrically coupled to the electric drive 34. As detailed further herein, the first battery 46 and the second battery 50 are movable with respect to the hull 14. In other embodiments, the watercraft 10 includes any number of movable batteries (e.g., 1, 2, 3, 4, 5, etc.). In the illustrated embodiment, movement of the first battery 46 is independent of movement of the second battery 50. In other embodiments, movement of one battery is dependent upon the movement of another battery.

With reference to FIGS. 2A and 2B, the first battery 46 moves with respect to the hull 14 between a first position (FIG. 2A, a neutral position) and second position (FIG. 2B, a stern position) along a first translation axis 54. In some embodiments, the first translation axis 54 is parallel to the center bow-stern axis 28 of the watercraft 10. In the illustrated embodiment, the first translation axis 54 co-axial with the center bow-stern axis 28 of the watercraft 10. The first battery 46 has a first range of motion 58 that extends along the first translation axis 54. As used herein, the terms “first position,” “second position,” etc. may refer to any position of the first battery 46 within the first range of motion 58.

With reference to FIGS. 3A and 3B, the second battery 50 moves with respect to the hull 14 between a third position (FIG. 3A, a neutral position) and a fourth position (FIG. 3B, a starboard position) along a second translation axis 62. In some embodiments, the second translation axis 62 is transverse to the center bow-stern axis 28 of the watercraft 10. In the illustrated embodiment, the second translation axis 62 is perpendicular to the center bow-stern axis 28. In the illustrated embodiment, the first translation axis 54 (of the first battery 46) is orthogonal to the second translation axis 62 (of the second battery 50). In other embodiments, the first translation axis 54 is parallel to the second translation axis 62. For example, in one embodiment, both translation axes 54, 62 are spaced apart and parallel to the center bow-stern axis 28). The second battery 50 has a second range of motion 66 that extends along the second translation axis 62. As used herein, the terms “third position,” “fourth position,” etc. may refer to any position of the second battery 50 within the second range of motion 66 and are used to distinguish from the positions of the first battery 46.

Advantageously, the combination of the two movable batteries permits weight adjustment for the watercraft in at least two dimensions (e.g., a bow-stern direction and a port-starboard direction). In some embodiments, at least one movable battery provides weight adjustment for the watercraft in three dimensions (e.g., a bow-stern direction, a port-starboard direction, and a vertical up-down direction). As such, the movable batteries provide multiple degree-of-freedom weight adjustment for the watercraft. A center of gravity 70 for the watercraft 10 is shown in FIGS. 1-4 to illustrate the adjustment of the center of gravity based on movement and positioning of the batteries 46, 50. For example, with reference to FIG. 4, the first battery 46 is in a stern position and the second battery 50 is a port position such that combined effect is to the move the center of gravity 70 of the watercraft 10 in two directions toward the stern/port corner (e.g., bottom left corner as viewed from FIG. 4). Advantageously, the arrangement of batteries shown in FIG. 4 can be used to “heel” a rear corner of the watercraft 10 into the water to create the desired wake.

With reference to FIG. 1, a first electrical cable 74 extends between the first battery 46 and the electric drive 34, and a second electrical cable 78 extends between the second battery 50 and the electric drive 34. In other words, the first electrical cable 74 electrically connects the first battery 46 to the electric drive 34, and the second electrical cable 78 electrically connects the second battery 50 to the electric drive 34. The first electrical cable 74 has a total length that is sufficient to permit travel of the first battery 46 anywhere in the first range of motion 58. In other words, the total length of the first electrical cable 74 is at least half of the distance of the first range of motion 58. Likewise, the second electrical cable 78 has a total length that is sufficient to permit travel of the second battery 50 anywhere in the second range of motion 58. In other words, the total length of the second electrical cable 78 is at least half of the distance of the second range of motion 66. As such, the electrical connections are maintained by the electrical cables 74, 78 regardless of the positioning of the movable batteries 46, 50.

With continued reference to FIG. 1, a first coolant line 82 extends between the first battery 46 and the electric drive 34, and a second coolant line 86 extends between the second battery 50 and the electric drive 34. In other words, the first coolant line 82 is fluidly coupled to the first battery 46 and the second coolant line 86 is fluidly coupled to the second battery 50. In some embodiments, the coolant lines 82, 86 are configured to cycle a coolant (e.g., a refrigerant) to and from the respective batteries 46, 50. In some embodiments, the coolant lines are coupled to a heat exchanger positioned separated from the electric drive. In some embodiments, the heat exchanger is integrated within the electric drive. The first coolant line 82 has a total length that is sufficient to permit travel of the first battery 46 anywhere in the first range of motion 58. In other words, the total length of the first coolant line 82 is at least half of the distance of the first range of motion 58. Likewise, the second coolant line 86 has a total length that is sufficient to permit travel of the second battery 50 anywhere in the second range of motion 58. In other words, the total length of the second coolant line 86 is at least half of the distance of the second range of motion 66. As such, the fluid connections are maintained by the coolant lines 82, 86 regardless of the positioning of the movable batteries 46, 50.

In some embodiments, a coolant lines includes a bellow or a telescoping tube such that the coolant line has an adjustable length. As such, the coolant line would expand in length or retract in length depending on the positioning of the corresponding movable battery.

With reference to FIG. 5, an actuation assembly 90 is illustrated coupled to the first battery 46. In the illustrated embodiment, the actuation assembly 90 includes a carriage 94 supporting the battery 46, a pinion 98 driven by an actuator 102 (e.g., an electric motor), and at least one rack 106. The rack 106 includes a plurality of teeth 108 configured to engage and enmesh with the pinion 98. The carriage 94 is configured to slide along the rack 106 in the first range of motion 58 along the first translation axis 54. In some embodiments, the actuation assembly 90 includes two or more racks 106 to form rails along which the carriage 94 and the battery 46 slide along. A similar actuation assembly may be coupled to each movable battery in the watercraft. In other embodiments, the actuation assembly includes a ball screw mechanism, a lead screw mechanism, a linkage, a roller, or any other suitable actuation mechanism to adjust the position of the battery.

With continued reference to FIG. 5, the watercraft 10 further includes a lock assembly 110 configured to lock the position of the first battery 46 with respect to the hull 14. In other words, the lock assembly 110 is in a locked configuration to maintain the first battery 46 at the desired location, and the lock assembly 110 is in an unlocked configured to permit movement of the first battery 46 when position adjustment is desired. In some embodiments, the lock assembly includes a friction pad positioned on the carriage 94 and movable to selectively engage a portion (e.g., a side) the rack 106.

With continued reference to FIG. 5, the watercraft 10 further includes a sensor 114 that detects the position of the first battery 46. In some embodiments, the sensor is a position sensor (e.g., an encoder) coupled to the actuator 102 of the actuation assembly 90. In the illustrated embodiment, the sensor 114 is positioned on the carriage 94 and detects a location along the rack 106. In some embodiments, the sensor is based on optical detection, magnetic detection, or tactile detection.

In some embodiments, the detected position of the battery is utilized in an active feedback control system to actively control and maintain the battery at a desired position. In some embodiments, the active feedback control system maintains the desired position of the battery without a lock assembly. In some embodiments, a controller is configured to energize the actuation assembly 90 in response to a detected position of the first battery 46 by the sensor 114. In some embodiments, the watercraft 10 includes a sensor to detect the relative position of the watercraft 10 in the water (e.g., roll and pitch). In some embodiments, the controller is further configured to energize the actuation assembly 90 in response to the detected relative position of the watercraft in the water (e.g., roll and pitch). In some embodiments, a controller is configured to energize the actuation assembly 90 in response to an operator input (e.g., a user selected option on a touch screen, etc.). As such, an operator may select a desired positioning of the batteries and/or of the watercraft in the water, which is then actively controlled by adjustment of the movable batteries based on detected feedback.

The systems and methods described herein can be implemented in hardware, software, firmware, or combinations of hardware, software and/or firmware. In some examples, the systems and methods described in this specification may be implemented using a non-transitory computer readable medium storing computer executable instructions that when executed by one or more processors of a computer cause the computer to perform operations. Computer readable media suitable for implementing the systems and methods described in this specification include non-transitory computer-readable media, such as disk memory devices, chip memory devices, programmable logic devices, random access memory (RAM), read only memory (ROM), optical read/write memory, cache memory, magnetic read/write memory, flash memory, and application-specific integrated circuits. In addition, a computer readable medium that implements a system or method described in this specification may be located on a single device or computing platform or may be distributed across multiple devices or computing platforms.

In some embodiments, the actuation assembly 90 is configured to move the battery 46 at more than one speed. In one embodiment, the actuation assembly 90 is configured to move the battery 46 at a first speed and at a second speed larger than the first speed. In some embodiments, the first speed is within a range of approximately 0.01 meters/second and approximately 0.5 meters/second, and the second speed is within a range of approximately 1.0 meters/second to approximately 3.0 meters/second. In some embodiments, the actuation assembly 90 is configured to move the battery 46 at any number of variable speeds. In one embodiment, slowly moving the batteries at a first speed is used to adjust the center of gravity and provide the desired wake shape; and quickly moving the batteries at a second speed is used to provide a counterbalancing effect for dampening the rocking motion of the watercraft in waves.

In the illustrated embodiment, the watercraft 10 is a boat. In other embodiments, the watercraft is a fishing boat, a dingy boat, a deck boat, a bowrider boat, a catamaran boat, a cuddy cabin boat, a center console boat, a houseboat, a trawler boat, a cruiser boat, a game boat, a yacht, a personal watercraft boat, a water scooter, a jet-ski, a runabout boat, a jet boat, a wakeboard, a ski boat, a life boat, a pontoon boat, or any suitable motor boat, vessel, craft, or ship.

Although an example is illustrated with respect to an all-electric watercraft, the movable battery and actuation assembly described herein can also be used in a conventional motorboat application (e.g., with a gasoline or diesel-powered engine), where a battery is positioned in the watercraft to power auxiliary functions (e.g., controls, lights, speakers, etc.).

Various features and advantages are set forth in the following claims.

Claims

1. A watercraft comprising: a hull;an electric drive;a battery electrically coupled to the electric drive;an actuation assembly coupled to the battery; wherein the battery is movable with respect to the hull by the actuation assembly between a first position and a second position.

2. The watercraft of claim 1, wherein moving the battery between the first position and the second position adjusts a center of gravity of the watercraft.

3. The watercraft of claim 1, wherein the battery is movable with respect to the electric drive.

4. The watercraft of claim 1, wherein the battery is movable with respect to the hull by the actuation assembly to a plurality of intermediate positions between the first position and the second position.

5. The watercraft of claim 1, wherein the battery moves between the first position and the second position along a translation axis.

6. The watercraft of claim 5, wherein the translation axis is parallel to a center bow-stern axis of the watercraft.

7. The watercraft of claim 5, wherein the translation axis is transverse to a center bow-stern axis of the watercraft.

8. The watercraft of claim 1, wherein the actuation assembly includes a carriage coupled to the battery, a pinion driven by an actuator, and a rack with a plurality of teeth configured to engage the pinion, wherein the carriage is configured to slide along the rack.

9. The watercraft of claim 1, further comprising a lock assembly configured to lock the position of the battery with respect to the hull.

10. The watercraft of claim 1, further comprising an electrical cable extending between the battery and the electric drive, and wherein the electrical cable has a length that is sufficient to permit travel of the battery between the first position and the second position.

11. The watercraft of claim 1, further comprising a coolant line extending between the battery and the electric drive, and wherein the coolant line has a length that is sufficient to permit travel of the battery between the first position and the second position.

12. The watercraft of claim 1, wherein the battery is a first battery, and the watercraft further includes a second battery electrically coupled to the electric drive.

13. The watercraft of claim 12, wherein the second battery is movable with respect to the hull by the actuation assembly between a third position and a fourth position.

14. The watercraft of claim 13, wherein the first battery moves between the first position and the second position along a first translation axis, and the second battery moves between the third position and the fourth position along a second translation axis.

15. The watercraft of claim 14, wherein the first translation axis is orthogonal to the second translation axis.

16. The watercraft of claim 14, wherein the first translation axis is parallel to the second translation axis.

17. The watercraft of claim 1, wherein the electric drive includes an electric motor and an inverter, and wherein the battery includes a housing and a plurality of battery cells positioned within the housing.

18. The watercraft of claim 1, further comprising a sensor that detects the position of the battery.

19. The watercraft of claim 18, further comprising a controller configured to energize the actuation assembly in response to a detected position of the battery by the sensor and a position of the watercraft in water.

20. The watercraft of claim 1, wherein the actuation assembly is configured to move the battery at a first speed and at a second speed, wherein the second speed is larger than the first speed.