WO2024010546A2

WO2024010546A2 - An in-propeller, in-line, coaxial electric motor group and drive system for vessels

Info

Publication number: WO2024010546A2
Application number: PCT/TR2022/051420
Authority: WO
Inventors: Bülent ORAN
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-07-03
Filing date: 2022-12-06
Publication date: 2024-01-11
Anticipated expiration: 2025-01-03
Also published as: WO2024010546A3; TR2022010974A2

Abstract

The invention relates to motor groups comprising electric motors for use in electric marine vessels and the propulsion system that propels and manages them. Each electric motor with an axial flux or a radial flux has a propeller on the outside, and a rotor and a stator integrated with the propeller are located inside the propeller. For this reason, the motors are called "in-propeller motors". Motor groups are formed by coaxially positioning a plurality of impeller motors on a non-rotating hollow axial shaft. Since the number of motors can be increased as desired, this motor group is named "endless motor", or "worm motor" due to its compact structure and shape. Each of the motors is driven by its own driver, and the rotational speeds and directions of the propellers change simultaneously according to the algorithm.

Description

AN IN-PROPELLER, IN-LINE, COAXIAL ELECTRIC MOTOR GROUP AND DRIVE SYSTEM FOR VESSELS

TECHNICAL FIELD

The invention relates to motor groups comprising electric motors for use in electric marine vessels and the propulsion system that propels and manages them. A propeller is located at the outermost part of each electric motor. A rotor and a stator are integrated with the propeller are located inside the propeller. For this reason, the motors are called "in-propeller motors". Motor groups are formed by coaxially positioning a plurality of impeller motors on a non-rotating hollow axial shaft. Since the number of motors can be increased as desired, this motor group is named "endless motor", or "worm motor" due to its compact structure and shape. Each of the motors is driven by its own driver. In addition, the rotational speeds and directions of the propellers change simultaneously according to the algorithm. (Figure 1).

BRIEF DESCRIPTION OF THE INVENTION

The invention relates to coaxial electric motor assemblies for use in electric marine vessels and the propulsion system that manages them. This assembly, comprising a large number of stators and rotors in series, is arranged on a common, hollow and non-rotating axis shaft. There is a space between the stators and rotors that allows rotation. All stators are fixed to this shaft at certain intervals, while rotors are not fixed. All rotors are integrated with the propeller blades and rotate in the opposite direction relative to each other without contact in the hydrodynamic bearing or ball bearing. The rotors and stators of each motor are inside its propeller. The power cables and sensor cables of the electric motors pass through the hollow axis shaft and reach the driver and microprocessor.

Since there is no casing outside of these motors, water easily enters between the motor parts, cools the heated parts, and therefore there is no need for a cooling apparatus. Electric motors show axial flux or radial flux, DC or AC, single or polyphase, brushless, synchronous or asynchronous winding characteristics. Each of the motors is driven by its own driver. Thus, the rotational speeds and directions of the propellers can be changed simultaneously. PRIOR ART

The counter-rotating propeller pair has long been used in fossil fuel-powered and electric motors. These designs include two propellers arranged coaxially one behind the other and rotating in the opposite direction (one clockwise and the other counter-clockwise). Two separate propellers rotate back to back coaxially in opposite directions. However, it is not mechanically possible to rotate more than two propellers together on the same axis (e.g., 4, 6, 8 ...). For this reason, the number of propellers rotating on the co-axis could not be more than two for years. When considered from this point of view, the coaxial multiple propeller design idea constitutes the main theme of the inventive step.

BRIEF DESCRIPTION OF THE INVENTION

An in-propeller motor is an axial or radial flux electric motor that is positioned inside a propeller and drives it directly. Since the motor of each propeller is contained within itself, a plurality of serial stators and rotors are arranged on a hollow and nonrotating axial shaft. The number of counter-rotating propeller pairs can be increased as desired without any change in their mechanical design. The motor group, which is formed by arranging the motors one after the other, is called a “worm motor” as it resembles a worm in rings (Figure 1).

There is a space between the stators and rotors that allows rotation. All stators are fixed to this axis shaft at certain intervals, while rotors are not fixed. All rotors are integrated with the propeller blades and rotate in a ball bearing or hydrodynamic bearing without contact.

The fixed part of the hydrodynamic bearing is located between the motors. This part is made of a composite material such as carbon, Teflon, ceramic, or at least one of a metal or alloy suitable for bearing such as bronze, and there are many water channels on it. There are radial water channels also on the hydrodynamic bearing surfaces of the propellers.

While the propeller rotates in the hydrodynamic bearing, the electromagnetic flux formed in the stator pulls the propeller into the stator, so it rotates in a stable equilibrium. If necessary, ball bearings can also be used for bearing the propellers. The propellers are designed either with fixed-pitch or variable-pitch. Due to its modular and compact design, the number of motors can be increased as desired according to the wishes of the user or the characteristics of the marine vessel, which undoubtedly brings with it many new advantages.

Main advantages of our invention

• Powerful motor groups can be created as desired by increasing the number of propeller pairs since it is possible to obtain greater power with counter-rotating propeller pairs of the same diameter. (Figure 3-6).

• The rotational speed of each propeller can be easily optimized individually until optimum performance is achieved.

• Propulsion efficiency is increased as the helical flow of each propeller is corrected by the counter-rotating propeller following it..

• Motor groups can be easily mounted to the back, front, or sides of the marine vessel. It is a very suitable design for hydrofoil-type flying watercraft (Figure 3- 6).

• The overturning torque that will occur especially for torpedoes is prevented by the counter-rotating propellers.

• It is easier to design and simpler to manufacture them, and their maintenance cost will be much lower.

• Energy consumption will be much lower since there is no energy loss due to friction due to the use of "Direct Drive" technology.

• It can be easily installed on vessels of different segments, from small to large, and furthermore, fossil-fuel vessels can be hybridized (Figure 3-6).

• The effect of cavitation is minimal as the propellers are not allowed to rotate at high speed.

• High technologies will not be required in their production since it does not contain complex, heavy, and sensitive parts.

• It is lighter than its counterparts since it does not contain complex, heavy, and fragile parts such as gearboxes, reducers, shafts, etc.

• The desired number of counter-rotating propeller pairs can be designed in a modular manner.

• The propellers operate very quietly and do not cause much vibration as they rotate in a hydrodynamic bearing, and are not allowed to rotate at high speed. • There is no need for a cooling unit, as the heat that will arise during operation will be cooled by the water flow.

• They are lighter as there is no casing on the outside of the motors.

• Using clean and renewable energy, i.e., “zero emission” will be one of its most important advantages.

There are permanent magnets in the rotors of the in-propeller motors to form at least two magnetic pole pairs. The shape and number of these permanent magnets vary in accordance with the selected motor winding type. The number of blades in the propellers of each of the electric motors (1) is at least two or in the form of a single helical blade. Although the stator comprises a lamination prepared by cutting s sheets or similar materials, it can also be non-ferrous (ironless). The water insulation of the copper wires on the stator is ensured with varnish-like materials.

In-propeller motors form motor groups by assembling at least two of them in a row on a hollow circular tube or polygonal hollow axial shaft (Fig. 1).

The axis shaft is linear and rigid. However, optionally, flexible axis shaft is also used in some special cases such as underwater drones. In this structuring, there is a joint in the axis shaft between each motor and the axis shaft can be tilted thanks to these joints. When applied to the front of the underwater drone, it moves it left-right and up-down like a worm (Figure 2).

The electrical cables of each motor enter into the shaft through the appropriate hole in the hollow axial shaft. The cables thus reach the battery and the driver inside the marine vessel (Figure 1).

Motor groups can be mounted on the front, rear, underside, or both sides of the marine vessel from one, two, or more points. It includes connection apparatus prepared for this purpose (Figure 3-6).

There is an alarm system that activates and gives a warning in case of jamming, failure, or breakdown of any motor among the motor groups. For safety, there are protection grilles or protection cages around the motor groups. For safety reasons, there are protection grilles or protection cages around the motor groups, which are designed not to interfere with the water flow of the rotating propellers.

The motors are driven with the help of suitable driver circuits. The direction of rotation (clockwise or counterclockwise) and rotational speed (rpm) of the propeller of each of the in-propeller motors can be determined independently of each other. The rotation direction and rotational speed for each of the motors in the system are controlled by the driver circuit, microprocessor, and special software, and the most ideal torque values and pitch angle (attack angle) are determined and applied simultaneously.

There are driver algorithms, in the software within the processor, that are programmed separately or together for each of the electric motors and enable them to operate in different rotational modulations. These algorithms simultaneously compare the instantaneous torque value of the motors and the pitch angles (attack angles) of the propeller blades and allow them to rotate at the most ideal rotational speed.

The battery selection varies according to the motor type and winding technique to be used. The type and power of the batteries also vary according to the total energy consumption of the electric motors and the range of the vessel.

The in-propeller motor propulsion system is a very suitable design, especially for "flying" hydrofoil boats. It can easily be positioned between the front and rear wings (blades) navigating underwater (Fig. 2).

Today, "avionics" systems are used in hydrofoil boats that sail on the sea surface and without contacting the sea. The in-propeller motor propulsion system has features that can be easily integrated and compatible with "avionics" systems and flight control electronics.

If we give some examples that will not limit the scope of protection regarding the usage area of our invention;

Advantages in "flying" hydrofoil boats: In-propeller motor propulsion system is a very suitable design especially for "flying" hydrofoil boats and catamaran-type watercraft. As it is known, these vessels go on their wings (blades) without touching the water. In this case, the drive of the watercraft must be done well below the hull. Outboard motors are far from serving this purpose. In-line motor groups, which are our invention, provide perfect and safe driving comfort in such flying watercraft. It can be applied to all types of electric watercraft in small, medium, and large segments. Due to the small diameter of the motors, the resistance of the water is less in the motors arranged in a row. Low water resistance combined with high torque values provides a distinct advantage compared to its counterparts (Figure 3-6).

Advantages in underwater drones: Underwater drones have superior mobility when in-line motor groups are positioned horizontally, vertically, and obliquely. One end of a motor group with a flexible axis shaft can be fixed to the front of the underwater drone. By moving its other free end like a worm, it can propel the underwater drone left and right, up and down like a fish. This is a very suitable design for manned or unmanned underwater drones (Figure 2).

Advantages in the defense industry: In-line motor groups can also be used in many areas for underwater and surface military purposes, especially in torpedoes.

Advantages in floating toys: Children's interest in floating toys has been known for a long time; such as toy boats, toy speedboats, and different kinds of boats. Today, simple motors of varying power and size are widely sold in hobby shops. Now, hobby motors have become a separate sector on their own. Model marine motors, propellers, drivers, remote control apparatus, mounting parts, and batteries are sold together as a set. It is an obvious fact that hobby-sized "mini motor groups" and "mini worm motors", in which the in-propeller motor propulsion system is used, will soon enter this sector. Examples of such vehicles include flying “jet-skis”, hover boards, flying yachts, flying boats, flying water taxis, and other flying watercraft carrying people or cargo.

In brief, our invention, the coaxial, in-propeller, in-line motor group, which we call the "worm motor", has superior features with its modular design using direct drive technology when compared to its counterparts such that it has the desired power, high efficiency, lower production and maintenance costs, lighter weight, lower energy consumption, longer battery life, longer warranty periods, using renewable energy, being quieter and more environmentally friendly.

This system comprises the following components;

• Radial flux or axial flux in-line electric motors

• Rotor and stator arrays positioned inside the propeller

• Impeller with permanent magnet pole pairs integrated with the rotor Fixed and rotating elements of the hydrodynamic bearing containing channels

• Hollow axial shaft that can be linear, rigid, or flexible

• Driver circuit

• Microprocessor

• Special software

• Avionics

• Battery LIST OF FIGURES

Figure 1. View of the Worm-like Appearance of the In-Propeller Motor Group

Figure 2. View of the Articulated Structure of the In-Propeller Motor Group

Figure 3. View of the Invention Applied in Marine Vessels

Figure 4. View of the Invention Applied in Marine Vessels

Figure 5. View of the Invention Applied in Marine Vessels

Figure 6. Cross Section of Radial Flux Motor

Figure 7. Cross Section of Axial Flux Motor

Figure 8. Exploded View

Figure 9. Detail View of Radial Flux Motor

Figure 9.1. Detail View of the Radial Flux Motor

Figure 9.2. Detail View of the Radial Flux Motor

Figure 10. Detail View of the Axial Flux Motor

Figure 10.1. Detail View of the Axial Flux Motor

Figure 10.2. Detail View of the Axial Flux Motor

The corresponding part numbers in the figures are given below

1 . Electric Motors

1.1. Stator

1.2. Rotor

1.3. Propeller

1.4. Axial Shaft

1.5. Hydrodynamic Bearing

1.6. Ball Bearing

1.7. Permanent Magnet

1 .8. Motor Connection Cables

THE DETAILED DESCRIPTION OF THE INVENTION

The invention comprises two main parts, i.e., at least two electric motors (1) and a motor power unit. The first part, which is the electric motors (1), comprises a stator (1.1), a rotor (1.2), a propeller (1.3), an axis shaft (1.4), a hydrodynamic bearing (1.5), a ball bearing (1.6), a permanent magnet (1.7), a propeller protection safety cage and their relevant parts. The second part, i.e., the motor power unit comprises motor connection cables (1 .8), a microprocessor, a motor driver circuit, a software, a battery and their relevant parts.

The invention comprises the electric motors (1) further comprising the stator (1.1) and the rotors (1.2) arranged in a row on the hollow axial shaft (1.4). There are permanent magnets (1.7) in the rotors (1.2) of the in-propeller motors to form at least two magnetic poles. The shape and number of these permanent magnets (1.7) vary in accordance with the selected motor winding type. The number of blades in the propellers of each of the electric motors (1) is at least two or in the form of a single helical blade. Parameters such as the number of blades, blade lengths, and attack angles of the blades are similar to each other but may have different values for each electric motor (1). The stator (1.1) comprises a lamination prepared from iron-silicium alloy or similar materials. In addition, non-iron (ironless) axial (Fig. 10, 10.1 , 10.2) and radial flux motors (Fig. 9, 9.1, 9.2) are also preferred because they are light in forming motor groups. The stators (1.1) comprises copper wire windings.

The in-propeller electric motors (1) form motor groups by assembling at least two of them in a row on a linear hollow support profile axis (1.4) with a around pipe or polygonal cross-section (triangular, rectangular, square, pentagonal and similar). The stators (1.1) of the electric motors (1) are fixed from their centers to the axis shaft (1 .4). The rotors (1 .2) are mounted in a manner to rotate in one of the ball bearings (1.6) and hydrodynamic bearings (1.5). Thus, when the power is turned on, the stators (1.1) remain stationary and the rotors (1.2) rotate. The motor connection cables (1.8) of the each stator (1.1) enter an empty space inside the axial shaft through a hole suitable for the axial shaft (1 .4), and reach a motor driver circuit by running separately inside the axis shaft (1.4). The each electric motor (1) can be driven together or separately.

When the hydrodynamic bearings (1.5) and the ball bearings (1.6) are used in the bearing of the propellers (1.3) integrated with the rotors (1.2), the rotors (1.2) and the stators (1.1) rotate without contacting each other. There is a rigid part of the hydrodynamic bearing (1.5) between the two stators (1.1). This part is made of a composite material such as carbon, Teflon, ceramic, or a metal or alloy suitable for bearing such as bronze, and there are many water channels on it. On the other hand, there are radial air channels also on the hydrodynamic bearing (1.5) surfaces of the propellers. One end of the axis shaft (1.4) on which the electric motors (1) are fixed is closed. While the propeller (1.3) rotates in the hydrodynamic bearing (1.5), the electromagnetic flux created in the stator (1.1) pulls the rotor (1.2) into the stator (1.1). Thus, the propellers (1.3) rotate in stable equilibrium on a liquid cushion formed.

In one embodiment of the invention, the axial shaft (1.4) is rigid and does not flex. In another embodiment, the axis shaft (1.4) has a flexible structure. In this embodiment, there is a joint between the each motor (1 ) on the axial shaft (1 .4). Thus, the axial shaft (1 .4) can be moved right-left and up-down (Figure 2).

The electric motor (1) groups can be mounted on the front, rear, underside, or both sides of the vehicle, in a horizontal or vertical position, from one, two, or more points, depending on the characteristics of the marine vessel (Figure 3-6).

There is an audible and illuminated alarm system that activates and gives a warning in case of jamming, failure, or breakdown of the any electric motor (1) among the motor groups. The location of the fault is shown on the screen to the operator. The alarm system detects the malfunction occurring in the motor (1) by means of constant monitoring of the rotational speeds of the motors by the processor. The processor activates the alarm system at the point where it detects that the speed the one of the motors (1), which has been commanded to run, is zero.

For safety, there is a safety cage around the propellers (1 .3).

The rotation direction (clockwise or counter clockwise) and rotational speed (rpm) of the propeller (1.3) of each of the in-propeller electric motors (1) can be determined independently of each other. The driving of the electric motors (1) is provided by the motor driver circuit and the algorithms developed with the help of the software on it. The windings in the stator (1.1) are controlled by the driver algorithm in the software on the motor driver circuit and the magnetic flux generated rotates the rotor (1 .2) and the propeller (1.3) integrated with the rotor.

The choice of battery varies depending on the type of electric motor (1) to be used and the winding technique. The type and power of the battery also varies according to the total energy consumption of the electric motors (1) and the type and range of the marine vessels.

Claims

CLAIMS An in-line coaxial motor propulsion system for electric watercraft and is characterized by comprising at least two in-propeller electric motors (1), a microprocessor that enables the direction of rotation (clockwise or counterclockwise), and the rotational speed (rpm) of the propeller of each electric motor to be determined independently of each other, a motor driver circuit, a software, and a motor power unit comprising batteries. The electric motor (1) according to Claim 1 characterized comprising a propeller (1.3) located at the outermost part, a rotor integrated with a propeller (1.2), and a stator (1 .1) in the inner part. The electric motor (1) according to Claim 2, characterized by being an axial flux or a radial flux electric motor. The rotor (1.2) according to Claim 2, characterized by comprising a multiple of permanent magnets (1 .7) that create magnetic pole pairs inside. The electric motor (1) according to Claim 3 characterized by comprising at least one of the types of a hydrodynamic bearing (1.5), a aball bearing (1.6), and a magnetic bearing enabling the rotor (1 .2) to rotate. The in-line coaxial motor propulsion system for the electric marine vessels according to Claim 1, characterized by comprising a linear, a rigid, or a flexible non-rotating hollow axial shaft (1 .4) having a circular pipe or a polygon crosssection, on which the electric motors (1) can be mounted to form a motor group. The power unit according to Claim 1 , characterized by comprising a connection apparatus and motor connection cables (1 .8) enabling the motor groups to be mounted on the front, rear, bottom, or both sides of the marine vessels, from one, two or more points in a vertical position, horizontal position or at different angles. The propeller (1 .3) according to Claim 2, characterized by each of them comprise at least two blades or a single helical blade, and the propeller blades having a fixed pitch or variable pitch design. The software according to Claim 1 , characterized by comprising driver algorithms that are programmed separately or together for each of the electric motors (1) and enable them to operate in different rotational modulations, thus enabling them to rotate at the most ideal rotational speed by comparing the instant torque value of the motors and the pitch angles (attack angles) of the propeller blades simultaneously.

10. The stator (1.1) according to Claim 2, characterized by comprises a lamination prepared by cutting iron-silicium alloy sheets, and contains coils of copper wire, and is covered with waterproof materials that insulate these windings.

11. The stator (1.1) according to Claim 2, characterized by being "ironless" without iron lamination, and comprising coils of copper wire, and being covered with waterproof materials that insulate these windings.

12. The hydrodynamic bearing (1.5) according to Claim 5, characterized by comprising water channels on it.

13. The in-line coaxial motor propulsion system for electric marine vessels according to Claim 6, characterized by comprising a joint on the axial shaft (1 .4) between each motor.