Double-rotor differential propeller-adjusting type shaftless integrated propelling system and control method thereof

Abstract

The invention discloses a double-rotor differential paddle-adjusting type shaftless integrated propelling system and a control method thereof, the system comprises a salient pole motor rotor and a surface-mounted motor rotor, and the two motor rotors are provided with paddles in a shaftless mode to form propelling paddles of a ship. The salient pole motor rotor adopts a salient pole permanent magnet structure design, and the surface-mounted motor rotor adopts a surface-mounted permanent magnet structure. Rotors of the two motors control the blade angles of the blades through the angle difference. The q-axis torque difference of the two rotors is achieved through the change of an Id current command, and when Id is not zero, the torque difference exists between the two rotors, and the angle difference is formed. A high-resolution angle sensor is arranged between the motor rotors and used for monitoring the angle difference between the two rotors in real time and feeding back an angle difference signal to a control system. According to the device, the torque of the two motors is adjusted through a specific double-rotor angle difference control strategy, and therefore the purpose of controlling the angle difference of the rotors is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of shaftless electric propulsion for ships, and in particular to a dual-rotor differential-speed pitch-adjustable shaftless integrated propulsion system and a control method thereof. Background Art

[0002] In recent years, with the development and utilization of marine resources, the number of marine engineering vessels and underwater vehicles has continued to grow, and the operating environments have become increasingly complex and diverse. Traditional mechanical propulsion systems have gradually demonstrated disadvantages in terms of noise, size, and efficiency, making them unable to meet the high-performance demands of modern ships. Electric propulsion systems, with their advantages of low noise, flexible operation, compact size, excellent maneuverability, and high efficiency, have gradually become the mainstream development direction of marine propulsion systems. In particular, shaftless electric propulsion systems, by integrating the motor rotor with the blades, eliminate the traditional propulsion shaft system, significantly improving space utilization and energy transfer efficiency, and have become a key development direction for future marine propulsion technology.

[0003] Existing technologies for controlling the thrust of shaftless propulsion primarily rely on fixed-pitch propellers or external mechanisms to adjust the blade angle. However, these methods suffer from complex structures, slow response speeds, and low control accuracy. In particular, traditional pitch adjustment devices are difficult to directly apply to shaftless propulsion due to its unique geometric and structural characteristics. Therefore, developing a novel blade angle control device and method that can effectively adjust the magnitude and direction of thrust in shaftless propulsion is of great significance.

[0004] Reference 1 [Y.Shen, P.Hu, S.Jin, Y.Wei, R.Lan, and S.Zhuang, “Design of novel shaftless pump-jet propulsor for multi-purpose long-range and high-speed autonomous underwater vehicle,” IEEE Trans.Magn., vol.52, no.7, pp.1–4, July 2016.] proposed a shaftless electric propulsion system consisting of a high-power density slotless permanent magnet brushless motor with two Halbach permanent magnet arrays to meet the miniaturization and low-noise requirements of underwater vehicles. The motor was then analyzed by coupling thermal and computational fluid dynamics (CFD) analysis under actual fluid conditions.

[0005] Reference 2 [M. Cai, C. Yang, S. Wu, Y. Zhu, and Y. Xie, “Hydrodynamic analysis of arim-driven thruster based on RANS method,” OCEANS 2015-MTS / IEEE Washington, Washington, DC, pp. 1-5, 2015.] used commercial software based on the Reynolds-averaged Navier-Stokes equation solver to analyze the effects of the rim on the wake field and friction of shaftless electric thrusters with different rim lengths. The study showed that the rim length has a certain influence on the torque and wake field of the thruster.

[0006] Reference 3 [H. Bai, B. Yu, W. Ouyang, X. Yan and J. Zhu, “HF-based sensorless control of a FTPMM in a ship shaftless rim-driven thruster system,” IEEE Trans. Intell. Transp. Syst., vol. 23, no. 9, pp. 16867–16877, Sept. 2022.] proposes a shaftless rim-driven thruster (RDT) based on a dual-winding fault-tolerant permanent magnet motor (FTPMM). This sensorless control technique, using a high-frequency SOGI (HF-SOGI) algorithm, achieves accurate rotor position estimation under low-speed and fault conditions, improving system reliability and fault tolerance. The proposed control method is validated through simulation and experiments, and is intended for application in unmanned surface vehicles (USVs) to promote the development of intelligent water transportation systems.

[0007] While these studies have made significant progress in shaftless propulsion motor design and control, existing technologies have yet to offer effective solutions for pitch regulation and thrust vectoring. Therefore, developing a dual-rotor differentially controlled propulsion system and its control method based on blade angle control based on the dual-rotor angle difference has important theoretical significance and engineering application value. Summary of the Invention

[0008] Technical Problem: This invention addresses the shortcomings of existing technologies by providing a dual-rotor, differentially controlled, shaftless integrated propulsion system and its control method. This system simplifies the propeller structure, achieves higher efficiency, and reduces maintenance costs. It is suitable for high-precision ship propulsion systems, enabling more precise blade angle control and improving the ship's maneuverability and stability. Furthermore, by integrating the motor rotor with the blades, the system reduces mechanical transmission components, lowering energy loss and noise.

[0009] Technical solution: A dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system of the present invention includes a motor housing, a stator component, a rotor component and a motor control component;

[0010] The motor housing includes a motor outer shell, a motor inner shell, a first air guide cover and a second air guide cover with a streamlined profile, a sealing cover and a cable connector are placed on the upper end of the motor outer shell, a PCB board is embedded between the first air guide cover and the motor outer shell, the first air guide cover and the second air guide cover are respectively located on the left and right sides of the motor outer shell, and the motor inner shell is two symmetrical split structures installed inside the motor outer shell through bearings;

[0011] The rotor component includes two groups of independent rotor units, including a first rotor magnet, a first rotor, a second rotor, and a second rotor magnet. The first rotor is located inside the first rotor magnet to constitute a first rotor component, and the second rotor is located inside the second rotor magnet to constitute a second rotor component. The first rotor magnet and the second rotor magnet are fixed to the outside of the motor inner shell, and the first rotor and the second rotor are fixed to the inside of the motor inner shell. Since the motor inner shell is a two-symmetrical split structure, the two rotor components can move relative to each other, forming a rotor angle difference to control the blade angle;

[0012] The stator assembly includes a stator winding and a stator core. The stator core includes 48 stator slots. The stator winding is mounted on the stator core, which is fixed to the inner wall of the motor housing. The stator winding is connected to an external power supply via a cable and a cable connector and is isolated from the external environment by a sealing cover. An air gap is provided between the stator core and the first rotor magnetic steel and the second rotor magnetic steel.

[0013] The PCB board is located inside the annular groove on the left side of the motor housing. The PCB board includes an annular DC capacitor, a control board, a drive board and a power module. It is connected to an external power supply through cables and cable connectors and is isolated from the external environment by a sealing cover.

[0014] The number of permanent magnets in the first rotor magnetic steel and the second rotor magnetic steel is 44, and they are distributed in an NS logarithmic manner. The torque distribution of the two rotors is different, resulting in an angle difference.

[0015] The first rotor and the second rotor are integrated with the blades, and the rotation of the motor rotor directly drives the blades to do work; the inner surface of the first rotor is etched with multiple horizontal groove guide rails,

[0016] A first horizontal groove guide rail is etched on the inner surface of the first rotor, and a first salient pole fixing terminal is fixed on the rotor side of the first blade salient pole, and the first salient pole fixing terminal can slide in the first horizontal groove guide rail;

[0017] A second horizontal groove guide rail is etched on the inner surface of the first rotor, and a second salient pole fixing terminal is fixed on the rotor side of the second blade salient pole, and the second salient pole fixing terminal can slide in the second horizontal groove guide rail;

[0018] A third horizontal groove guide is etched on the inner surface of the first rotor, and a third salient pole fixing terminal is fixed on the rotor side of the third blade salient pole, and the third salient pole fixing terminal can slide in the third horizontal groove guide;

[0019] A fourth horizontal groove guide is etched on the inner surface of the first rotor, and a fourth salient pole fixing terminal is fixed on the rotor side of the fourth blade salient pole, and the fourth salient pole fixing terminal can slide in the fourth horizontal groove guide;

[0020] A fifth horizontal groove guide rail is etched on the inner surface of the first rotor, and a fifth salient pole fixing terminal is fixed on the rotor side of the fifth blade salient pole, and the fifth salient pole fixing terminal can slide in the fifth horizontal groove guide rail;

[0021] A sixth horizontal groove guide rail is etched on the inner surface of the first rotor, and a sixth salient pole fixing terminal is fixed on the rotor side of the sixth blade salient pole, and the sixth salient pole fixing terminal can slide in the sixth horizontal groove guide rail;

[0022] A seventh horizontal groove guide rail is etched on the inner surface of the first rotor, and a seventh salient pole fixed terminal is fixed to the rotor side of the seventh blade salient pole. The seventh salient pole fixed terminal can slide in the seventh horizontal groove guide rail.

[0023] The second rotor is fixed to the side root of the first blade surface-mounted rotor via a first surface-mounted fixing terminal;

[0024] The second rotor is fixed to the side root of the second blade surface-mounted rotor via a second surface-mounted fixing terminal;

[0025] The second rotor is fixed to the side root of the third blade surface-mounted rotor via a third surface-mounted fixing terminal;

[0026] The second rotor is fixed to the side root of the fourth blade surface-mounted rotor via a fourth surface-mounted fixing terminal;

[0027] The second rotor is fixed to the side root of the fifth blade surface-mounted rotor via a fifth surface-mounted fixing terminal;

[0028] The second rotor is fixed to the side root of the sixth blade surface-mounted rotor via a sixth surface-mounted fixing terminal;

[0029] The second rotor is fixed to the side root of the seventh blade surface-mounted rotor through the seventh surface-mounted fixing terminal.

[0030] The first salient pole fixing terminal, the second salient pole fixing terminal, the third salient pole fixing terminal, the fourth salient pole fixing terminal, the fifth salient pole fixing terminal, the sixth salient pole fixing terminal and the seventh salient pole fixing terminal are dumbbell-shaped fixing terminals, the upper side of the fixing terminal is fixed on the blade, and the lower end is embedded in the horizontal groove guide rail and can slide in the horizontal groove guide rail.

[0031] The first horizontal groove guide rail, the second horizontal groove guide rail, the third horizontal groove guide rail, the fourth horizontal groove guide rail, the fifth horizontal groove guide rail, the sixth horizontal groove guide rail and the seventh horizontal groove guide rail are T-shaped slots, the width of the horizontal groove guide rail is the diameter of the corresponding salient pole fixed terminal, the lower end of the salient pole fixed terminal is stuck in the horizontal groove guide rail, and the middle part extends out of the horizontal groove guide rail and is connected to the upper end of the fixed terminal.

[0032] The first rotor blades, the second rotor blades, the third rotor blades, the fourth rotor blades, the fifth rotor blades, the sixth rotor blades and the seventh rotor blades are evenly distributed, and an angle of 51.4° is formed between every two blades.

[0033] The permanent magnet distribution pattern of the first rotor magnet is embedded, the first rotor magnet and the first rotor constitute a salient pole motor rotor, the permanent magnet distribution pattern of the second rotor magnet is surface mounted, the second rotor magnet and the second rotor constitute a surface mounted motor rotor; when the ship is sailing normally, there is no angle difference between the first rotor and the second rotor. When the blade angle needs to be changed, the Id current command is changed to achieve the q-axis torque difference between the two rotors. When Id is not 0, a small torque difference is generated between the first rotor and the second rotor, thereby generating a rotor angle difference, and the salient pole fixed terminal slides in the horizontal groove guide rail, thereby changing the ship's blade angle.

[0034] The control method of the dual-rotor differential speed adjustable blade type shaftless integrated propulsion system of the present invention adopts a specific dual-motor rotor angle difference to change the blade angle control method, and the expected propulsion force F thrust * and the ship speed V measured by the sensor boat Through the optimal calculation of the tip speed ratio, the expected motor speed w* and blade angle of attack α are obtained. The expected speed w* and the actual speed w are passed through the speed PI to obtain the expected q-axis current. The blade angle of attack α is looked up in the table or calculated to obtain the expected angle difference Δθ* between the two rotors. The expected angle difference Δθ* between the two rotors and the rotor angle difference Δθ measured by the two rotor sensors are passed through the angle PID to obtain the expected q-axis two-rotor torque difference ΔT q *, the expected d-axis current is calculated through the salient pole motor torque formula. The expected d-axis current and the expected q-axis current pass through the salient pole-surface mounted dual-rotor permanent magnet motor current loop, tracking the actual d-axis current and q-axis current to obtain the required d-axis current and q-axis current, and finally the required expected propulsion force.

[0035] Beneficial Effects: By utilizing dual-rotor angle differential to control blade angle, this design achieves more precise blade angle control compared to traditional single-rotor propulsion systems, improving the ship's maneuverability and stability. Furthermore, by integrating the motor rotor with the propeller blades, the design reduces mechanical transmission components, lowering energy loss and noise. Furthermore, this design utilizes both embedded and surface-mounted permanent magnets. During normal ship operation, Id = 0 control is employed, and with the same Iq input, the dual rotors achieve identical torque, eliminating any torque differential and, consequently, angle differential. When the ship requires blade angle adjustment, Id is non-zero, resulting in a slight torque differential between the dual rotors. The salient pole terminals slide within the horizontal grooved guide rails, creating an angle differential between the dual rotors and enabling blade angle control. Furthermore, the integrated PCB design and streamlined fairing design further enhance system stability and reliability. These advantages result in a simple propulsion system with higher efficiency and lower maintenance costs, making it suitable for high-precision ship propulsion systems. This design also offers excellent scalability, adapting to varying sailing conditions and load requirements, providing a new technological direction for the future development of ship propulsion systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more apparent.

[0037] Figure 1 It is a three-dimensional structural schematic diagram of a dual-rotor differential-speed pitch-adjustable shaftless integrated propulsion system and a control method thereof of the present invention.

[0038] Figure 2 yes Figure 1 Exploded diagram.

[0039] Figure 3 yes Figure 1 Schematic diagram of the three-dimensional structure of the rotor.

[0040] Figure 4 yes Figure 1 Schematic diagram of the rotor's horizontal groove guide.

[0041] Figure 5 This is the principle diagram of the rotor angle difference change.

[0042] Figure 5 (a) is a schematic diagram of a dual rotor with no angular difference.

[0043] Figure 5 (b) is a schematic diagram of the angle difference generated by the dual rotors.

[0044] Figure 6 It is a structural diagram of a control method for a specific dual-rotor differential-speed pitch-adjustable shaftless integrated propulsion system.

[0045] Explanation of the numbers in the figure: first air guide cover 1, PCB board 2, motor housing 3, sealing cover 31, cable connector 32, motor inner housing 4, first rotor magnet 5, first rotor 61, second rotor 62, first blade 71, second blade 72, third blade 73, fourth blade 74, fifth blade 75, sixth blade 76, seventh blade 77, first horizontal groove guide rail 81, second horizontal groove guide rail 82, third horizontal groove guide rail 83, fourth horizontal groove guide rail 84, fifth horizontal groove guide rail 85, sixth horizontal groove guide rail 86, seventh horizontal groove guide rail 87, first Salient pole fixing terminal 811, second salient pole fixing terminal 821, third salient pole fixing terminal 831, fourth salient pole fixing terminal 841, fifth salient pole fixing terminal 851, sixth salient pole fixing terminal 861, seventh salient pole fixing terminal 871, first surface mount fixing terminal 812, second surface mount fixing terminal 822, third surface mount fixing terminal 832, fourth surface mount fixing terminal 842, fifth surface mount fixing terminal 852, sixth surface mount fixing terminal 862, seventh surface mount fixing terminal 872, second rotor magnet 9, stator winding 10, stator core 11, second air guide cover 12. DETAILED DESCRIPTION

[0046] The embodiments of the present invention will be described below with reference to the accompanying drawings.

[0047] The embodiment of the present invention discloses a dual-rotor differential-speed pitch-adjustable shaftless integrated propulsion system and a control method thereof, which are suitable for scenarios requiring high efficiency and integration of high-precision ship propulsion systems and high controllability.

[0048] like Figures 1 to 5 As shown, this example provides a dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system and a control method thereof, including a motor housing, a stator component, a rotor component and a motor control component.

[0049] The motor housing includes a motor outer shell 3, a motor inner shell 4, a first air duct 1 and a second air duct 12 with a streamlined profile. A sealing cover 31 and a cable connector 32 are placed on the upper end of the motor outer shell 3. A PCB board 2 is embedded between the first air duct 1 and the motor outer shell 3. The motor inner shell 4 adopts a symmetrical split structure and is installed inside the motor outer shell 3 through bearings.

[0050] The rotor component includes two groups of independent rotor units, including a first rotor magnet 5, a first rotor 61, a second rotor 62, and a second rotor magnet 9. The first rotor 61 is located inside the first rotor magnet 5 to constitute a first rotor component, and the second rotor 62 is located inside the second rotor magnet 9 to constitute a second rotor component. The first rotor magnet 5 and the second rotor magnet 9 are fixed to the outside of the motor inner housing 4, and the first rotor 61 and the second rotor 62 are fixed to the inside of the motor inner housing 4. Since the motor inner housing 4 is divided into two, the two rotor components can move relative to each other, forming a rotor angle difference to control the blade angle;

[0051] The stator assembly includes a stator winding 10 and a stator core 11. The stator winding 10 is wound with copper wire. The stator core 11 includes 48 stator slots. The stator winding 10 is mounted on the stator core 11. The stator core 11 is fixed to the inside and outside of the motor housing 3. The stator winding 10 is connected to an external power supply via a cable and a cable connector 32 and is isolated from the external environment by a sealing cover 31. An air gap is provided between the stator core 11 and the first rotor magnet 5 and the second rotor magnet 9.

[0052] In this embodiment, the PCB board 2 is located inside the annular groove on the left side of the motor housing 3. The PCB board 2 includes an annular DC capacitor, a control board, a driver board, and a power module. The PCB board 2 is connected to an external power supply via a cable and a cable connector 32 and is isolated from the external environment by a sealing cover 31.

[0053] This design ensures a tight connection between the PCB and the motor housing, minimizing environmental impact on the circuitry while facilitating maintenance and replacement. Furthermore, the ring-shaped DC capacitor effectively suppresses power supply noise, improving system stability and reliability. The integrated design of the control board, driver board, and power module further simplifies the circuit structure, reducing system complexity and cost.

[0054] In this embodiment, the number of permanent magnets in the first rotor magnetic steel 5 and the second rotor magnetic steel 9 is 44, and they are distributed in an NS logarithmic manner. The torque distribution of the two rotors is different, resulting in an angle difference.

[0055] In this embodiment, the first rotor 61 and the second rotor 62 integrate the motor rotor and the blades, and use the rotation of the motor rotor to directly drive the blades to do work. The first horizontal groove guide rail 81 is etched on the inner surface of the first rotor 61, and the first salient pole fixed terminal 811 is fixed on the salient pole rotor side of the first blade 71, and the first salient pole fixed terminal 811 can slide in the first horizontal groove guide rail 81; the second horizontal groove guide rail 82 is etched on the inner surface of the first rotor 61, and the second salient pole fixed terminal 821 is fixed on the salient pole rotor side of the second blade 72, and the second salient pole fixed terminal 821 can slide in the second horizontal groove guide rail 82; the third horizontal groove guide rail 83 is etched on the inner surface of the first rotor 61, and the third salient pole fixed terminal 831 is fixed on the salient pole rotor side of the third blade 73, and the third salient pole fixed terminal 831 can slide in the third horizontal groove guide rail 83; the fourth horizontal groove guide rail 83 is etched on the inner surface of the first rotor 61 A horizontal groove guide rail 84 is provided. A fourth salient pole fixing terminal 841 is fixed to the salient pole rotor side of the fourth blade 74, and the fourth salient pole fixing terminal 841 can slide within the fourth horizontal groove guide rail 84. A fifth horizontal groove guide rail 85 is etched on the inner surface of the first rotor 61. A fifth salient pole fixing terminal 851 is fixed to the salient pole rotor side of the fifth blade 75, and the fifth salient pole fixing terminal 851 can slide within the fifth horizontal groove guide rail 85. A sixth horizontal groove guide rail 86 is etched on the inner surface of the first rotor 61. A sixth salient pole fixing terminal 861 is fixed to the salient pole rotor side of the sixth blade 76, and the sixth salient pole fixing terminal 861 can slide within the sixth horizontal groove guide rail 86. A seventh horizontal groove guide rail 87 is etched on the inner surface of the first rotor 61. A seventh salient pole fixing terminal 871 is fixed to the salient pole rotor side of the seventh blade 77, and the seventh salient pole fixing terminal 871 can slide within the seventh horizontal groove guide rail 87.

[0056] The second rotor 62 fixes the first blade 71 to the rotor side root via the first surface-mounted fixed terminal 812; the second rotor 62 fixes the second blade 72 to the rotor side root via the second surface-mounted fixed terminal 822; the second rotor 62 fixes the third blade 73 to the rotor side root via the third surface-mounted fixed terminal 832; the second rotor 62 fixes the fourth blade 74 to the rotor side root via the fourth surface-mounted fixed terminal 842; the second rotor 62 fixes the fifth blade 75 to the rotor side root via the fifth surface-mounted fixed terminal 852; the second rotor 62 fixes the sixth blade 76 to the rotor side root via the sixth surface-mounted fixed terminal 862; and the second rotor 62 fixes the seventh blade 77 to the rotor side root via the seventh surface-mounted fixed terminal 872.

[0057] The first salient pole fixing terminal 811, the second salient pole fixing terminal 821, the third salient pole fixing terminal 831, the fourth salient pole fixing terminal 841, the fifth salient pole fixing terminal 851, the sixth salient pole fixing terminal 861 and the seventh salient pole fixing terminal 871 are dumbbell-shaped fixing terminals, the upper side of the fixing terminal is fixed to the blade, and the lower end is embedded in the horizontal groove guide rail and can slide in the horizontal groove guide rail;

[0058] The first horizontal groove guide rail 81, the second horizontal groove guide rail 82, the third horizontal groove guide rail 83, the fourth horizontal groove guide rail 84, the fifth horizontal groove guide rail 85, the sixth horizontal groove guide rail 86 and the seventh horizontal groove guide rail 87 are T-shaped slots. The width of the horizontal groove guide rail is the diameter of the corresponding salient pole fixed terminal. The lower end of the salient pole fixed terminal is clamped in the horizontal groove guide rail, and the middle part extends out of the horizontal groove guide rail to connect with the upper end of the fixed terminal.

[0059] The first rotor blades 71 , the second rotor blades 72 , the third rotor blades 73 , the fourth rotor blades 74 , the fifth rotor blades 75 , the sixth rotor blades 76 and the seventh rotor blades 77 are evenly distributed, with an angle of 51.4° between every two blades;

[0060] This design allows one end of the propeller blade to slide within a horizontal grooved guide. It also ensures uniform force distribution during rotation, reducing vibration and noise while improving propulsion efficiency. The even distribution and precise angle of the propeller blades optimize hydrodynamics, increasing thrust and efficiency. Furthermore, the integrated design of the propeller blades and rotor reduces the number of mechanical transmission components, reducing energy loss and maintenance costs.

[0061] In this embodiment, the permanent magnet distribution pattern of the first rotor magnet 5 is embedded, the first rotor magnet 5 and the first rotor 61 constitute a salient pole motor rotor, the permanent magnet distribution pattern of the second rotor magnet 9 is surface-mounted, the second rotor magnet 9 and the second rotor 62 constitute a surface-mounted motor rotor, when the ship is sailing normally, there is no angle difference between the first rotor 61 and the second rotor 62, when the blade angle needs to be changed, the torque difference of the two rotors q-axis is achieved by changing the Id current command, when Id is not 0, a small torque difference is generated between the first rotor 61 and the second rotor 62, thereby generating a rotor angle difference, and the salient pole fixed terminal slides in the horizontal groove guide rail, thereby changing the ship's blade angle;

[0062] With this design, when the ship is operating normally, Id = 0 control is used, and the same Iq value is input. The torque generated by the salient pole motor rotor and the surface mount motor rotor is consistent, without a torque difference and thus an angle difference. When the ship needs to change the blade angle, Id is not 0, and the q-axis torque between the salient pole motor rotor and the surface mount motor rotor is inconsistent, resulting in a slight torque difference, and the salient pole fixed terminal slides within the horizontal groove guide rail. This ensures that the blade angle can be precisely adjusted through the slight torque difference during the ship's operation, improving the ship's maneuverability and stability. In addition, the independent control design of the dual rotors makes the blade angle adjustment more flexible, adapting to different navigation conditions and load requirements.

[0063] In this embodiment, the control strategy of the dual-rotor ship electric propulsion system adopts a specific dual-motor rotor angle difference control blade angle control strategy, and the expected propulsion force F thrust * and the ship speed V measured by the sensor boat Through the optimal calculation of the tip speed ratio, the expected motor speed w* and blade angle of attack α are obtained. The expected speed w* and the actual speed w are passed through the speed PI to obtain the expected q-axis current. The blade angle of attack α is looked up in the table or calculated to obtain the expected angle difference Δθ* between the two rotors. The expected angle difference Δθ* between the two rotors and the rotor angle difference Δθ measured by the two rotor sensors are passed through the angle PID to obtain the expected q-axis two-rotor torque difference ΔT q *, the d-axis current expectation is calculated by the salient pole motor torque formula. The d-axis current expectation and the q-axis current expectation pass through the salient pole-surface mounted dual rotor permanent magnet motor current loop, tracking the actual d-axis current and q-axis current, and finally obtaining the required d-axis current and q-axis current, and finally obtaining the required expected propulsion force;

[0064] This design ensures dynamic adjustment of the propeller blade angle during navigation through precise control strategies, improving navigation efficiency and safety. The dual-motor rotor angle difference control strategy monitors and adjusts the torque difference between the two rotors in real time, ensuring precise control of the propeller blade angle. Furthermore, this control strategy optimizes motor energy consumption, improving overall system efficiency.

[0065] In this embodiment, the first air deflector 1 and the second air deflector 13 are located on the left and right sides of the motor housing 3 .

[0066] This design ensures effective heat dissipation within the motor housing while minimizing the impact of external water flow on the motor. The streamlined design of the shroud optimizes hydrodynamics, reducing water resistance and noise. Furthermore, the shroud protects the motor's internal components, extending the life of the equipment.

[0067] The present invention provides a dual-rotor, differentially-controlled pitch-shifting, shaftless integrated propulsion system and its control method. Numerous methods and approaches exist for implementing this technical solution. The foregoing description represents only a preferred embodiment of the present invention. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are considered within the scope of protection of the present invention. Components not specified in this embodiment may be implemented using existing technologies.

Claims

1. A dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system, characterized in that: Including motor housing, stator components, rotor components and motor control components; The motor housing comprises a motor housing (3), a motor inner housing (4), a first air duct (1) and a second air duct (12) with a streamlined profile; a sealing cover (31) and a cable connector (32) are placed on the upper end of the motor housing (3); a PCB board (2) is embedded between the first air duct (1) and the motor housing (3); the first air duct (1) and the second air duct (12) are respectively located on the left and right sides of the motor housing (3); the motor inner housing (4) is a two-symmetrical split structure installed inside the motor housing (3) through a bearing; The rotor component comprises two groups of independent rotor units, including a first rotor magnetic steel (5), a first rotor (61), a second rotor (62) and a second rotor magnetic steel (9); the first rotor (61) is located inside the first rotor magnetic steel (5) to constitute a first rotor component; the second rotor (62) is located inside the second rotor magnetic steel (9) to constitute a second rotor component; the first rotor magnetic steel (5) and the second rotor magnetic steel (9) are fixed outside the motor inner shell (4); the first rotor (61) and the second rotor (62) are fixed inside the motor inner shell (4); since the motor inner shell (4) is a two-part symmetrical structure, the two rotor components can move relative to each other, forming a rotor angle difference to control the blade angle; The stator component comprises a stator winding (10) and a stator core (11), the stator core (11) comprises 48 stator tooth slots, the stator winding (10) is mounted on the stator core (11), the stator core (11) is fixed to the inner wall of the motor housing (3), the stator winding (10) is connected to an external power supply via a cable and a cable connector (32), and is isolated from the external environment via a sealing cover (31), and an air gap is provided between the stator core (11) and the first rotor magnetic steel (5) and the second rotor magnetic steel (9).

2. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The PCB board (2) is located inside the annular groove on the left side of the motor housing (3). The PCB board (2) includes an annular DC capacitor, a control board, a drive board and a power module. The PCB board (2) is connected to an external power supply via a cable and a cable connector (32) and is isolated from the external environment via a sealing cover (31).

3. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The number of permanent magnets in the first rotor magnetic steel (5) and the second rotor magnetic steel (9) is 44, and they are distributed in an NS logarithmic pattern. The torque distribution of the two rotors is different, resulting in an angle difference.

4. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The first rotor (61) and the second rotor (62) are integrated with the blades, and the rotation of the motor rotor is used to directly drive the blades to do work; the inner surface of the first rotor (61) is etched with a plurality of horizontal groove guide rails. A first horizontal groove guide rail (81) is etched on the inner surface of the first rotor (61), a first salient pole fixing terminal (811) is fixed on the salient pole rotor side of the first blade (71), and the first salient pole fixing terminal (811) can slide in the first horizontal groove guide rail (81); A second horizontal groove guide rail (82) is etched on the inner surface of the first rotor (61), a second salient pole fixing terminal (821) is fixed on the salient pole rotor side of the second blade (72), and the second salient pole fixing terminal (821) can slide in the second horizontal groove guide rail (82); A third horizontal groove guide rail (83) is etched on the inner surface of the first rotor (61), a third salient pole fixing terminal (831) is fixed on the salient pole rotor side of the third blade (73), and the third salient pole fixing terminal (831) is capable of sliding in the third horizontal groove guide rail (83); A fourth horizontal groove guide rail (84) is etched on the inner surface of the first rotor (61), a fourth salient pole fixing terminal (841) is fixed to the salient pole rotor side of the fourth blade (74), and the fourth salient pole fixing terminal (841) is capable of sliding in the fourth horizontal groove guide rail (84); A fifth horizontal groove guide rail (85) is etched on the inner surface of the first rotor (61), a fifth salient pole fixed terminal (851) is fixed to the salient pole rotor side of the fifth blade (75), and the fifth salient pole fixed terminal (851) is capable of sliding in the fifth horizontal groove guide rail (85); A sixth horizontal groove guide rail (86) is etched on the inner surface of the first rotor (61), a sixth salient pole fixed terminal (861) is fixed to the salient pole rotor side of the sixth blade (76), and the sixth salient pole fixed terminal (861) is capable of sliding in the sixth horizontal groove guide rail (86); A seventh horizontal groove guide rail (87) is etched on the inner surface of the first rotor (61), and a seventh salient pole fixed terminal (871) is fixed to the salient pole rotor side of the seventh blade (77), and the seventh salient pole fixed terminal (871) can slide in the seventh horizontal groove guide rail (87).

5. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The second rotor (62) fixes the first blade (71) to the rotor side root via a first surface-mounted fixing terminal (812); The second rotor (62) fixes the second blade (72) to the rotor side root via a second surface-mount fixing terminal (822); The second rotor (62) fixes the third blade (73) to the rotor side root via a third surface-mounted fixing terminal (832); The second rotor (62) fixes the fourth blade (74) to the rotor side root via a fourth surface-mounted fixing terminal (842); The second rotor (62) fixes the fifth blade (75) to the rotor side root via a fifth surface-mounted fixing terminal (852); The second rotor (62) fixes the sixth blade (76) to the rotor side root via a sixth surface-mounted fixing terminal (862); The second rotor (62) fixes the seventh blade (77) to the rotor side root via the seventh surface-mounted fixing terminal (872).

6. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 4, characterized in that: The first salient pole fixed terminal (811), the second salient pole fixed terminal (821), the third salient pole fixed terminal (831), the fourth salient pole fixed terminal (841), the fifth salient pole fixed terminal (851), the sixth salient pole fixed terminal (861) and the seventh salient pole fixed terminal (871) are dumbbell-shaped fixed terminals, the upper side of the fixed terminal is fixed on the blade, and the lower end is embedded in the horizontal groove guide rail and can slide in the horizontal groove guide rail.

7. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 4, characterized in that: The first horizontal groove guide rail (81), the second horizontal groove guide rail (82), the third horizontal groove guide rail (83), the fourth horizontal groove guide rail (84), the fifth horizontal groove guide rail (85), the sixth horizontal groove guide rail (86) and the seventh horizontal groove guide rail (87) are T-shaped slots, the width of the horizontal groove guide rail is the diameter of the corresponding salient pole fixed terminal, the lower end of the salient pole fixed terminal is clamped in the horizontal groove guide rail, and the middle part extends out of the horizontal groove guide rail and is connected to the upper end of the fixed terminal.

8. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 4, characterized in that: The first rotor blade (71), the second rotor blade (72), the third rotor blade (73), the fourth rotor blade (74), the fifth rotor blade (75), the sixth rotor blade (76) and the seventh rotor blade (77) are evenly distributed, and an angle of 51.4° is formed between every two blades.

9. The dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The permanent magnet distribution pattern of the first rotor magnet (5) is an embedded type, the first rotor magnet (5) and the first rotor (61) constitute a salient pole motor rotor, the permanent magnet distribution pattern of the second rotor magnet (9) is a surface-mounted type, and the second rotor magnet (9) and the second rotor (62) constitute a surface-mounted motor rotor; when the ship is running normally, there is no angle difference between the first rotor (61) and the second rotor (62); when the blade angle needs to be changed, the torque difference of the two rotors q axes is achieved by changing the Id current command; when Id is not 0, a small torque difference is generated between the first rotor (61) and the second rotor (62), thereby generating a rotor angle difference, and the salient pole fixed terminal slides in the horizontal groove guide rail, thereby changing the ship blade angle.

10. A control method for a dual-rotor differential-speed adjustable-pitch shaftless integrated propulsion system according to claim 1, characterized in that: The control method adopts a specific dual-motor rotor angle difference to change the blade angle control method, and the expected propulsion force F thrust * and the ship speed V measured by the sensor boat Through the optimal calculation of the tip speed ratio, the expected motor speed w* and blade angle of attack α are obtained. The expected speed w* and the actual speed w are passed through the speed PI to obtain the expected q-axis current. The blade angle of attack α is looked up in the table or calculated to obtain the expected angle difference Δθ* between the two rotors. The expected angle difference Δθ* between the two rotors and the rotor angle difference Δθ measured by the two rotor sensors are passed through the angle PID to obtain the expected q-axis two-rotor torque difference ΔT q *, the expected d-axis current is calculated through the salient pole motor torque formula. The expected d-axis current and the expected q-axis current pass through the salient pole-surface mounted dual-rotor permanent magnet motor current loop, tracking the actual d-axis current and q-axis current to obtain the required d-axis current and q-axis current, and finally the required expected propulsion force.

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