Claims:CLAIMS:
We Claim:
1. A cooling system for electric long-tail boats, comprising:
a drive unit positioned in an enclosure configured to drive said electric long-tail boat;
a reservoir module positioned in contact with said drive unit in said enclosure, configured to store a coolant and configured with a pump unit to circulate said coolant to absorb heat from said drive unit;
plurality of conduits connected to said reservoir module configured to receive said coolant and to provide a channel for flow of said coolant along the length of a long-tail propulsion shaft of said electric long-tail boat; and
a cooling chamber positioned on rear end of said long-tail propulsion shaft,
wherein said cooling system discharges heat to surrounding water and provide efficient cooling for said drive unit of said electric long-tail boat.
2. The cooling system for electric long-tail boats as claimed in claim 1, wherein said enclosure comprises a controller configured to accelerate and navigate said electric long-tail boat in forward directions.
3. The cooling system for electric long-tail boats as claimed in claim 1, wherein said enclosure comprises a transmission module comprising of a plurality of pulleys, a power transmission shaft, and a bearing unit configured to maneuver said long-tail propulsion shaft.
4. The cooling system for electric long-tail boats as claimed in claim 1, wherein said drive unit drives said pump unit.
5. The cooling system for electric long-tail boats as claimed in claim 1, wherein said coolant comprises a fluid coolant comprising either a gas or a liquid or a nanofluid or combinations thereof to achieve required temperature change at said drive unit.
6. The cooling system for electric long-tail boats as claimed in claim 1, wherein said plurality of conduits forms a closed-loop cooling system to circulate said coolant between said reservoir module and said cooling chamber.
7. The cooling system for electric long-tail boats as claimed in claim 1, wherein said cooling chamber is further configured with a plurality of fins or any similar projections for effective dissipation of said absorbed heat from said coolant to the surrounding water.
8. The cooling system in an electric long-tail boats as claimed in claim 1, wherein length of said cooling chamber is sufficient enough to enable required temperature drop of said coolant from said drive unit.
9. The cooling system in an electric long-tail boats as claimed in claim 1, wherein said cooling chamber is placed on said long-tail whereby said cooling chamber is in contact with water to transfer heat from said drive unit.
10. The cooling system in an electric long-tail boats as claimed in claim 1, wherein said long-tail propulsion shaft connected to said transmission module and supported with a plurality of bushes configured to transfer power from said drive unit to a propeller. , Description:DESCRIPTION:
Field of the invention:
[0001] The present disclosure generally relates to the technical field of cooling systems for marine engines, and in specific relates to an electric long-tail boat drive with a liquid-cooling system designed to drive fishing or touring boats and to assist continuous removal of heat from a drive unit to function continuously for longer period of time.
Background of the invention:
[0002] Water transportation is an important means of transportation in many countries since ancient times. Many regions of the countries are seaside or have thousands of rivers and canals around the cities. People usually transport goods and passengers by rivers, canals and coasts. In the past, small to large boats have been developed with low cost, and are easy to build with local material and easy maintenance aspects. Such boats have been slowly improving over the past centuries.

[0003] Nowadays, the latest developments use modern materials such as aluminum, plastic, and fiber-reinforced plastic. Most of them, traditional or new designs, are equipped with an engine. Some of them use small general-purpose engines, the others use automotive diesel or gasoline engines. These boats emit polluted emissions and therefore have a bad impact on the environment.

[0004] The long-tail boat, is a type of watercraft which uses a common automotive internal combustion engine. In a long-tail boat using internal combustion engines without clutch may suffer from low starting engine torque. The propeller must be lifted out into the air before the engine can be started. While an electric motor has high starting torque, the propeller can be started in the water without any problem. Moreover, several advantages of electrical motors, such as high starting torque and regenerative braking, provide new functions that have never been possible with internal combustion engines.

[0005] Over the last few years, there is a spike in the development of electric boats (E-boat). It can mitigate noise and air pollutions along the rivers and canals during operations. However, continues operation of electric boats for a particular period generates heat in the driving unit or other component. If the heat is not discharged timely, the temperature of the driving unit or other element may increase, which may influence the performance. Overheating may cause permanent damage to the ship propulsion apparatus.

[0006] Conventionally, in the case of electric boats, it is often necessary to cool not only the drive unit but also the battery which provides the electrical supply for the electric drive unit. U.S. Pat. No. 8,535,104 B1 has disclosed a cooling system for a boat battery, wherein the battery is cooled by means of cooling air, which in turn is cooled by seawater. Cooling of the battery by convection, which is to say by means of air flowing past, necessitates relatively large cooling surfaces, which are generally not available in the boat.

[0007] Further, Outboard drives for boats are normally equipped with a cooling circuit. Water is drawn in by means of a pump and supplied to the motor via a coolant line. The coolant line is in thermal contact with the motor, such that the motor and the coolant exchange heat and the motor is cooled. However, the supply of the water into the interior of the boat to the battery often poses problems such as for example leaks, corrosion or electrolysis, and leads to increased maintenance outlay.

[0008] In existing technology, an electric long-tail boat is developed which is equipped with a complete electrical propulsion system. It comprises an electric motor, battery packs, transmission shaft, propeller, and an electric control unit. The motor is connected to the propeller via a long-tail shaft. It is mounted on a pivot engine stand, so the driver can rotate the propeller left-right and up-down. The Long tail drive unit cooled by an air cooling system aids in the continuous removal of heat, allowing the drive to function continuously for long periods of time. The drive unit is cooled by the natural wind while operating with the help of cooling fins perpendicular to the shaft. However, the coefficient of heat transfer of air is less, hence less efficient in cooling, which results in non-uniform cooling. Cooling fins under certain conditions may vibrate and amplify the noise level. Engines are subjected to high working temperature.

[0009] The traditional mode of cooling systems in marine crafts are air cooled, which requires relatively large cooling surfaces. Alternatively, the cooling systems comprise water cooling equipped with a cooling circuit wherein water is supplied into the interior of the boat to the battery often there is a chance of leaks, corrosion or electrolysis, and leads to increased maintenance outlay. Moreover, contamination in the external coolant supply and blockages because of the impurity of the external coolant supply results in improper function of cooling circuit.

[0010] Many fishing craft, sport-type boats and other marine vessels employ propulsion units of the internal combustion engine or electric engine utilizing water cooling of the engine. Water from the sea in which the ship is floating and then circulate round the engine by the use of pumps to contact the hot engine structure to cool it. The challenge with this system is subject to high rate of corrosion and erosion due to the nature of seawater. Furthermore, heat generation in the driving unit results in poor mobility, a short service life, high operating and maintenance costs, and irreversible damage to the ship's propulsion system.

[0011] All of the above conventional arrangements suffer from one or more of the same drawbacks. Therefore, there is a need of electric drive system composed of cost-effective equipment’s with sustainable and budget friendly operation and maintenance. The system designed needs to be economically viable and need to be a long-term drive associated with future technologies. Further, the system should be a one-of-a-kind shaft integrated liquid cooling system that will aid in the transition of conventional diesel-powered long tail boats to electrically powered drives. The system needs to mitigate noise and air pollutions along the rivers and canals during operations. Further there is a need for a system which can avoid usage of outside water there by avoiding corrosion etc. to the parts of the cooling system.
Objectives of the invention:
[0012] The primary objective of the invention is to provide an electric long-tail boat drive with a fluid-cooling system, which permit improved cooling of a drive unit or of other components situated in the boat.

[0013] Another objective of the invention is to provide with liquid-cooling system aids in the continuous removal of heat, to ensure that the temperature of an electric motor and a controller is kept within the acceptable limit for maximum performance during operations.

[0014] The other objective of the invention is to provide with a closed- loop cooling system which avert high rate of corrosion and erosion due to the nature of seawater.

[0015] Yet another objective of the invention is to provide a shaft is designed in such a way it eliminates the extra housing required to mount it on the drive unit.

[0016] Further objective of the invention is to provide a liquid cooling for electric long-tail boat drive to keep less noise of the drive unit as compared with air-cooled engines, as it has water for damping noise.

[0017] The other objective of the invention is to provide an electric liquid cooled motor with easily mounted and integrated with the existing boats.
Summary of the invention:
[0018] The present disclosure proposes a fluid cooling system for electric long-tail boats. The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0019] In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem to provide a cooling system for marine engines, and in specific relates to an electric long-tail boat with a fluid-cooling system designed to drive fishing or touring boats and to assist continuous removal of heat from a drive unit to function continuously for longer period of time.

[0020] According to an aspect, the invention provides a cooling system for electric long-tail boats. The cooling system comprises a drive unit, a reservoir module, a pump unit, a plurality of conduits and a cooling chamber. The drive unit positioned in an enclosure configured to drive the electric long-tail boat. The enclosure comprising a controller and a transmission module, the controller configured to accelerate and navigate the electric long-tail boat in forward direction. The transmission module comprising a plurality of pulleys, a power transmission shaft, and a bearing unit configured to maneuver the long-tail propulsion shaft. The long-tail propulsion shaft connected to the transmission module and supported with a plurality of bushes configured to transfer power from the drive unit to a propeller.

[0021] The reservoir module is positioned in contact with the drive unit and is configured to store a coolant. The reservoir module is configured with a pump unit to circulate the coolant to absorb heat from the drive unit. The drive unit drives the pump unit for circulation of the coolant. In specific, the coolant comprises a fluid coolant comprising either a gas or a liquid or a nanofluid or combinations thereof to achieve the required temperature change at the drive unit.

[0022] The plurality of conduits are connected between the cooling chamber and the reservoir module. The plurality of conduits is configured to receive the coolant and to provide a channel for flow of the coolant along the length of a long-tail propulsion shaft of the electric long-tail boat. The plurality of conduits form a closed-loop cooling system to circulate the coolant between the reservoir module and the cooling chamber.

[0023] The cooling chamber positioned on the rear end of the long-tail propulsion shaft. The cooling chamber is always in contact with water to transfer heat from the drive unit. The length of the cooling chamber is sufficient to enable the required temperature drop of the coolant from the drive unit. The cooling chamber is further configured with a plurality of fins or any similar projections or arrangement to enable effective dissipation of the absorbed heat from the coolant to the surrounding water.

[0024] Further, objects and advantages of the present invention will be apparent from a study of the following portion of the specification, the claims, and the attached drawings.
Detailed description of drawings:
[0025] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, explain the principles of the invention.

[0026] FIG. 1 illustrates an exemplary schematic view of a cooling system connected to an electric propulsion device of long-tail boat in accordance to an exemplary embodiment of the invention.

[0027] FIG. 2A illustrates an exemplary isometric propulsion view of an electric device of long-tail boat in accordance to an exemplary embodiment of the invention.

[0028] FIG. 2B illustrates an exemplary cross-sectional view of an electric propulsion device of long-tail boat in accordance to an exemplary embodiment of the invention.

[0029] FIG. 2C illustrates an exemplary isometric view of an electric propulsion device of long-tail boat in accordance to an exemplary embodiment of the invention.

[0030] FIG. 3 refers to an exemplary sectional view of a long-tail propulsion shaft assembly.

[0031] FIG. 4 illustrates an exemplary isometric view showing a cooling system connected to an electric propulsion device of long-tail boat in accordance to an exemplary embodiment of the invention.
Detailed invention disclosure:
[0032] Various embodiments of the present invention will be described in reference to the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps.

[0033] The present disclosure has been made with a view towards solving the problem with the prior art described above, and it is an object of the present invention to provide a cooling system for marine engines, and in specific relates to an electric long-tail boat with a fluid cooling system designed to drive fishing or touring boats and to assist continuous removal of heat from a drive unit to function continuously for longer period of time.

[0034] The driving unit is powered by rechargeable battery packs that are managed by a battery management system. The power received from the rechargeable battery packs is used to accelerate and steer the long-tail boats using a controller located near the drive unit. The drive unit is designed to be easily mounted on the rear/on one end of the boat and to provide the required thrust needed to drive the boat. The drive unit is configured with an electric drive unit has no moving parts such as piston cylinder as in diesel engine. The electric drive unit eliminates the loud noise and vibrations.

[0035] According to an exemplary embodiment of the invention, FIG. 1 refers to an exemplary schematic view of an electric propulsion device integrated with a cooling system 100 for a long-tail boat. The cooling system connected to an electric propulsion device includes the complete package of a drive unit enclosed in a robust enclosure 102, a long-tail propulsion shaft 104, a propeller 106, a cooling chamber 108, and a plurality of conduits 110. The drive unit enclosed in a robust enclosure 102 is capable of delivering the required power without interruption.

[0036] The long tail propulsion shaft 104 is designed in such a way that it eliminates the extra housing required to mount it on the drive unit. The plurality of conduits 110 help to circulate the coolant from the reservoir module to cooling chamber 108. The complete electric drive unit 100 with cooling chamber 108 is designed so that it can be easily mounted on the rear end of the long-tail boat and provide the required thrust needed to drive. The electric propulsion device 100 further includes a steering rod 112 for steering, trim adjustment, and tilt adjustment.

[0037] According to an exemplary embodiment of the invention, FIG. 2A, 2B and 2C refer to an exemplary isometric propulsion view of an electric device 200. The electric propulsion device 200 comprises a pump unit 202, a reservoir module 204, a controller 206, and a drive unit 208. Further, it comprises plurality of conduits 210, which pass through communication holes (212 and 214) and extend along the length of the long-tail propulsion shaft. The reservoir module 204 is positioned in contact with the drive unit 208 and the controller 206 and is configured to store a coolant.

[0038] The reservoir module 204 is further configured with the pump unit 202 to circulate the coolant to absorb heat from the drive unit 208 and the controller 206. The drive unit 208 drives the pump unit 202 for circulation of the coolant. In specific, the coolant comprises a fluid coolant comprising either a gas or a liquid or a nanofluid or combinations thereof to achieve the required temperature change at the electric device 200. The coolant in the reservoir module 204 circulates through the components needing to be cooled, to bring heat therefrom.

[0039] Further, the electric propulsion device 200 comprises a transmission module comprising a plurality of pulleys (216 and 220), a power transmission shaft 222, and a bearing unit 224 configured to maneuver the long-tail propulsion shaft. The plurality of pulleys comprises at least two pulleys, the first pulley 216 mounted to the drive unit 208 and the second pulley 220 attached with the power transmission shaft 222. The plurality of pulleys (216 and 220) are connected by a belt drive 218 is configured with suitable gear reduction to transfer power from the drive unit 208 to the power transmission shaft 222.

[0040] The power transmission shaft 222 positioned inside the robust enclosure beneath the drive unit 208. The bearing unit 224 is installed at either ends of the power transmission shaft 222 to seal the shaft to ensure the airtight and dust free enclosure. Further, the bearing unit 224 configured to bear loads produced by the belt drive 218 and the loads produced in rotation of power transmission shaft 222.

[0041] In another exemplary embodiment, FIG. 3 refers to an exemplary sectional view of a long-tail shaft assembly 300. The long tail shaft assembly 300 comprises a gear coupling 302, an outer tube 304, an inner shaft 306, a cooling chamber 308, and a propeller 310. One end of the inner shaft 306 consist of gear coupling 302 configured to connect the inner shaft 306 with the power transmission shaft, which is enclosed in a robust enclosure. The propeller 310 is mounted on the opposite end of the gear coupling 302 to the inner shaft 306. The inner shaft 306 supported by the outer tube 304 with plurality of nylon bushes 312 for free rotation of the inner shaft 306. The cooling chamber 308 is mounted on the rear end of the outer tube 304 to dissipate heat from the coolant.

[0042] In another exemplary embodiment, FIG. 4 refers to an exemplary isometric view showing a cooling system connected to an electric propulsion device 400. The long-tail boat is designed to run on the electric power. The battery packs provide the necessary input power to run the entire system, and the system's input is regulated via a throttle arrangement. The motor setup, which consists of the drive unit 408 and the controller 406, is contained in a robust enclosure capable of delivering the required power without interruption.

[0043] The coupling arrangement transfers power from the drive unit 408 to the long-tail propulsion shaft 414. The fluid cooling system aids in the continuous removal of heat, allows the drive to function continuously for long periods of time. The fluid cooling system comprises a cooling chamber 416 positioned on the rear end of the long-tail propulsion shaft 414 which is submersed inside the water. The coolant in the reservoir module 404 is driven by the pump unit 402 to circulate the coolant in a closed-loop. The pump unit 402 is driven by the drive unit 408.

[0044] Further, the reservoir module 404 is configured with the plurality of conduits to provide a channel for flow of the coolant along the length of the long-tail propulsion shaft 414 of the long-tail boat. The plurality of conduits includes at least an outflow conduit 412 and an inflow conduit 410. The outflow conduit 412 carries hot coolant from the reservoir module 404 to the cooling chamber 416. The inflow conduit 410 carries out the coolant which is cooled in the cooling chamber 416 to the reservoir module 404. The cooling chamber 416 is positioned on the rear end of the long-tail propulsion shaft 414 which is submersed inside the water. For the purpose illustration at least one outflow conduit and at least one inflow conduit are shown in the drawings and number of conduits can be varied based on heat transfer requirement.

[0045] The coolant in the reservoir module 404 absorbs heat from the drive unit 408 and the controller 406. The hot coolant flows through the outflow conduit 412 from the reservoir module 404 to the cooling chamber 416. The cooling chamber 416 which is submersed inside the water receives the hot coolant. The hot coolant in the cooling chamber 416 exchanges heat with its surrounding water, release significant amounts of absorbed heat from the coolant and thus lowering its temperature.

[0046] Further, the cooling chamber is configured with a plurality of fins or any similar projections or similar heat transfer enhancement means for effective dissipation of absorbed heat from the coolant to the surrounding water. The coolant which exchanges heat with its surrounding water returns to the reservoir module 404 through the inflow conduit 410. The circulation of the coolant is maintained by the pump unit 402 mounted in reservoir module 404.

[0047] Numerous advantages of the present disclosure may be apparent from the discussion above. In accordance with the present disclosure, an electric long-tail boat drive with a fluid cooling system is disclosed, which permits improved cooling of a drive unit or of other components situated in the boat. The cooling system aids in the continuous removal of heat, to ensure that the temperature of the drive unit and the controller is kept within the acceptable limit for maximum performance during operations.

[0048] The proposed cooling system is a closed-loop cooling system, which averts high rate of corrosion and erosion due to the nature of seawater. The system is to provide a liquid cooling for electric long-tail boat drive to keep less noise of the drive unit as compared with air-cooled engines, as it has water for damping noise.

[0049] The electric drive unit, which replaces the internal combustion engine, saves a significant amount of weight and is located outside the hull. This adds additional passenger or equipment volume inside the hull and eliminates the need for offsetting ballast. Some or all of the weight savings are offset by the weight of batteries, however the battery weight can be distributed throughout the hull as needed to optimize handling and stability.

[0050] In an alternative embodiment, the plurality of conduits may be spiral or helical or any other form whereby the design enables effective heat dissipation and fitted around the long-tail shaft. The cooling chamber may include a series of tubes for coolant circulation for the longest possible duration to achieve a high temperature drop from the coolant. The pump unit may be a gear pump or any other pumps to attain the required function. A stirring vane may be included in the cooling chamber to ensure that the inflow and outflow coolants are properly mixed.

[0051] It will readily be apparent that numerous modifications and alterations can be made to the processes described in the foregoing examples without departing from the principles underlying the invention, and all such modifications and alterations are intended to be embraced by this application.