Lightweight motor rotor and tail rotor direct-drive motor

Abstract

The application discloses a lightweight motor rotor and tail rotor direct-drive motor, which comprises a rotating shaft, a rotor hub, a permanent magnet assembly, wherein the rotor hub is sleeved on the periphery of the rotating shaft and connected with the rotating shaft; the permanent magnet assembly comprises a plurality of permanent magnets arranged on the rotor hub in a Halbach array structure. The single-side magnetic gathering characteristic of the Halbach array can guarantee the required magnetic field intensity and electromagnetic output performance of the motor without an iron core, the iron core components such as silicon steel sheets in the conventional motor are directly saved, the number of parts is reduced, the weight of the motor rotor is greatly reduced, and the design requirements of high power density, high torque density and light weight of the helicopter tail rotor direct-drive motor are met.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a lightweight motor rotor and tail rotor direct drive motor. Background Technology

[0002] The motor rotor is a crucial component of the tail rotor direct drive motor, playing a key role in the helicopter tail rotor electric drive system. The helicopter tail rotor requires stable counter-torque and control force, thus placing stringent demands on the tail rotor direct drive motor for high power density and high torque density to ensure efficient power output within limited space and weight constraints.

[0003] Conventional motor rotors are generally composed of components such as rotor steel sheets, permanent magnets, and motor shafts. While these materials provide the necessary structural strength and magnetic properties, the large amount of steel sheets and numerous parts in the motor rotor result in a heavy motor rotor, which is not conducive to the overall weight reduction design of the motor and makes it difficult to achieve the design goals of high power density and high torque density. This limits the performance optimization of tail rotor direct drive motors in aviation applications. Summary of the Invention

[0004] In view of this, the present invention provides a lightweight motor rotor and tail rotor direct drive motor to solve the problem that conventional motor rotors are too heavy and it is difficult to achieve the design goals of high power density and high torque density.

[0005] In a first aspect, the present invention provides a lightweight electric motor rotor, comprising: Shaft; A rotor hub, which is sleeved around the shaft and connected to the shaft; A permanent magnet assembly, comprising a plurality of permanent magnets arranged in a Halbach array structure on the rotor hub.

[0006] The beneficial effects of the aforementioned lightweight motor rotor are as follows: through the unilateral magnetic focusing characteristics of the Halbach array, the required magnetic field strength and electromagnetic output performance of the motor can still be guaranteed even without an iron core, realizing the design of an iron coreless rotor. This directly eliminates the iron core components such as silicon steel sheets in conventional motors, reduces the number of parts, and significantly reduces the weight of the motor rotor. At the same time, it meets the design requirements of helicopter tail rotor direct drive motors for high power density, high torque density, and lightweight design.

[0007] In one alternative embodiment, the permanent magnet is divided into multiple blocks radially along the rotor hub and into multiple segments axially along the rotor hub.

[0008] In one alternative embodiment, a positioning structure is provided between the permanent magnet and the rotor hub.

[0009] The beneficial effects of the above technical solution are as follows: it ensures that the permanent magnet is installed in the rotor hub with accurate positioning, effectively preventing it from shifting, loosening or falling off under high-speed rotation or complex vibration conditions of the motor, thereby maintaining the unilateral magnetic focusing characteristics of the Halbach array, ensuring the uniformity of the motor's magnetic field strength and distribution, and stabilizing electromagnetic output performance; at the same time, it simplifies the assembly process of the permanent magnet and the rotor hub, improves production efficiency, enhances the reliability and durability of the overall rotor structure, and better adapts to the stringent requirements of helicopter tail rotor direct drive motors for operational stability and long-term service capability.

[0010] In one optional embodiment, the positioning structure includes a matching limiting groove and a limiting boss. The limiting groove is provided on the side of the permanent magnet near the rotor hub, and the limiting boss is provided on the outer side of the rotor hub. The permanent magnet is positioned and installed on the rotor hub by the cooperation of the limiting groove and the limiting boss, and is fixed by adhesive.

[0011] The beneficial effects of the above technical solution are as follows: the mechanical cooperation between the limiting groove and the limiting boss can quickly achieve precise pre-positioning of the permanent magnet, avoid positional deviations during manual assembly, and significantly improve assembly efficiency; combined with the chemical fixing effect of the adhesive, a double fixing structure is formed, which can effectively suppress the risk of permanent magnet displacement, loosening or falling off under high-speed motor rotation, frequent start-stop and complex vibration conditions, ensure that the unilateral magnetic focusing characteristics of the Halbach array are not damaged, maintain the uniformity of the motor's magnetic field strength and distribution, and stabilize electromagnetic output performance.

[0012] In one alternative embodiment, the inner side of the rotor hub has a hollow structure and is provided with multiple reinforcing structures.

[0013] The beneficial effects of the above technical solution are as follows: the hollow structure, with its perforated holes, effectively reduces the overall weight of the rotor hub, aligning with the design concept of lightweight motor rotors. The reinforcing structure can be reinforced with ribs; multiple reinforcing structures can enhance the structural rigidity and deformation resistance of the rotor hub while reducing weight, resisting centrifugal force and complex vibration loads during high-speed rotation, preventing permanent magnet positioning deviation or magnetic field imbalance due to structural deformation, and further ensuring long-term stable operation of the motor.

[0014] In one alternative embodiment, a plurality of heat dissipation structures are provided on the circumference of the inner wall of the rotor hub.

[0015] The beneficial effects of the above technical solution are: effectively increasing the heat dissipation area inside the rotor hub, accelerating the exchange and dissipation of heat generated during motor operation with the outside air, timely removing the heat accumulated inside the rotor when the motor rotor is working, avoiding overheating of the motor rotor which would lead to a decrease in the working performance of the permanent magnet, avoiding aging and failure of the adhesive or thermal deformation of structural components due to excessive temperature, and extending the service life of the motor.

[0016] In one alternative embodiment, the rotor hub is made of a lightweight, high-strength material; and / or, the motor shaft is made of a lightweight, high-strength material.

[0017] In one optional embodiment, a first bearing and a second bearing are respectively provided at both ends of the rotating shaft.

[0018] In a second aspect, the present invention provides a tail rotor direct drive motor, comprising: Tail rotor direct drive motor stator; The lightweight motor rotor is installed inside the stator of the tail rotor direct drive motor.

[0019] In one alternative implementation, the tail rotor direct drive motor is mounted on the helicopter platform via a mounting bracket to drive the helicopter tail rotor.

[0020] In summary, the technical solution of the present invention has the following advantages: The present invention provides a lightweight motor rotor that does not contain silicon steel sheets, has fewer parts, meets the dimensional constraints of limited installation space in helicopters, has good heat dissipation performance, and significantly reduces weight. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 A first-view structural schematic diagram of a lightweight motor rotor provided by the present invention; Figure 2 This is a second-view structural schematic diagram of a lightweight motor rotor provided by the present invention; Figure 3 A schematic diagram of the structure of a permanent magnet for a lightweight motor rotor provided by the present invention; Figure 4 A schematic diagram of the rotor hub of a lightweight motor rotor provided by the present invention; Figure 5 This is a schematic diagram of a conventional motor rotor structure.

[0023] Explanation of reference numerals in the attached figures: 1. Permanent magnet, 2. Rotor hub, 3. Shaft, 4. Screw, 5. First bearing, 6. Second bearing, 7. Limiting groove, 8. Limiting boss, 9. Reinforcing structure, 10. Heat dissipation structure, 11. Rotor steel sheet. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] The motor rotor is a crucial component of the tail rotor direct drive motor, playing a key role in the helicopter tail rotor electric drive system. The helicopter tail rotor requires stable counter-torque and control force, thus placing stringent demands on the tail rotor direct drive motor for high power density and high torque density to ensure efficient power output within limited space and weight constraints.

[0026] Combination Figure 5 As shown, a conventional motor rotor is generally composed of components such as rotor steel sheets 11, permanent magnets 1, and rotating shaft 3. Although these materials provide the necessary structural strength and magnetic properties, the large amount of steel sheets and the large number of parts in the motor rotor result in a heavy motor rotor, which is not conducive to the overall weight reduction design of the motor and makes it difficult to achieve the design goals of high power density and high torque density, thus limiting the performance optimization of tail rotor direct drive motors in aviation applications.

[0027] Based on this, the present invention provides a lightweight coreless motor rotor that can meet the requirements of helicopter tail rotor direct drive motors under various operating conditions, ensuring strength and lifespan while satisfying the electromagnetic output performance of the motor.

[0028] The specific embodiments of the present invention will now be described in detail with reference to the lightweight motor rotor of the first aspect of the present invention and the tail rotor direct drive motor of the second aspect of the present invention.

[0029] According to an embodiment of the present invention, in a first aspect, a lightweight motor rotor is provided, combined with... Figures 1 to 4 As shown, the device includes a rotating shaft 3, a rotor hub 2, and a permanent magnet assembly. The rotor hub 2 is fitted around and connected to the rotating shaft 3. The permanent magnet assembly includes multiple permanent magnets 1, which are arranged in a Halbach array structure on the rotor hub 2.

[0030] The Halbach array is a special structure that arranges permanent magnets in a rotating pattern at a specific angle. Its core principle is to utilize the alternating magnetization directions of adjacent permanent magnets according to a specific rule (such as 90°, 45°, etc.) to make the magnetic field highly concentrated on one side (the working side), while the magnetic fields on the other side (the non-working side) cancel each other out. This unilateral magnetic concentration characteristic can form a strong and uniform magnetic field on the working side, eliminating the need for an iron core to enhance the magnetic circuit, thus realizing a coreless rotor.

[0031] In traditional motors, the main function of the iron core is to conduct magnetism and enhance the magnetic field, but this significantly increases the rotor weight. This embodiment, however, utilizes the unilateral magnetic focusing characteristics of the Halbach array to ensure the required magnetic field strength and electromagnetic output performance of the motor even without an iron core. This achieves a coreless rotor design, directly eliminating the need for iron core components such as silicon steel sheets found in conventional motors, reducing the number of parts, significantly reducing the rotor weight, and simultaneously meeting the design requirements of helicopter tail rotor direct-drive motors for high power density, high torque density, and lightweight construction.

[0032] Specifically, the Halbach array structure is a ring-shaped Halbach array structure, with the magnetic field concentrated outside the ring.

[0033] In some embodiments, the rotor hub 2 is connected and fixed to the rotating shaft 3 by screws 4, and the number of screws 4 can be multiple.

[0034] In some embodiments, the permanent magnet 1 is divided into multiple blocks radially along the rotor hub 2 and into multiple segments axially along the rotor hub 2, which can flexibly adapt to the design requirements of motors with different power levels, facilitate precise adjustment of magnetic field strength and distribution uniformity according to actual working conditions, and further optimize electromagnetic output performance. The specific number of blocks is determined according to design needs and considering motor manufacturing process.

[0035] In some embodiments, a positioning structure is provided between the permanent magnet 1 and the rotor hub 2 to ensure that the permanent magnet 1 is installed accurately on the rotor hub 2, effectively preventing it from shifting, loosening or falling off under high-speed rotation or complex vibration conditions of the motor, thereby maintaining the unilateral magnetic focusing characteristics of the Halbach array without damage, ensuring the uniformity of the magnetic field strength and distribution of the motor, and stabilizing the electromagnetic output performance; at the same time, it simplifies the assembly process of the permanent magnet and the rotor hub, improves production efficiency, enhances the reliability and durability of the overall rotor structure, and better adapts to the stringent requirements of helicopter tail rotor direct drive motors for operational stability and long-term service capability.

[0036] Specifically, the positioning structure includes mutually matching limiting grooves 7 and limiting bosses 8. A limiting groove 7 is provided on the side of the permanent magnet 1 closest to the rotor hub 2, facilitating the positioning and installation of the permanent magnet 1 on the rotor hub 2; a limiting boss 8 is provided on the outer side of the rotor hub 2. The permanent magnet 1 is positioned and installed on the rotor hub 2 through the cooperation of the limiting groove 7 and the limiting boss 8, and is fixed with adhesive. The adhesive used is a high-strength adhesive.

[0037] In this embodiment, the mechanical cooperation between the limiting groove 7 and the limiting boss 8 can quickly achieve precise pre-positioning of the permanent magnet 1, avoiding positional deviations during manual assembly and significantly improving assembly efficiency. Combined with the chemical fixing effect of the adhesive, a double fixing structure is formed, which can effectively suppress the risk of permanent magnet displacement, loosening or falling off under high-speed motor rotation, frequent start-stop and complex vibration conditions, ensuring that the unilateral magnetic focusing characteristics of the Halbach array are not damaged, maintaining the uniformity of the motor's magnetic field strength and distribution, and stabilizing electromagnetic output performance.

[0038] Furthermore, the number of limiting slots 7 and limiting bosses 8 can be set to multiple, and the number can be flexibly adjusted according to the size, weight, and installation stability requirements of the permanent magnet 1. For example, each permanent magnet can correspond to one or two sets of matching structures of limiting slots and limiting bosses. The arrangement of limiting slots 7 and limiting bosses 8 can be set in various ways. For example, the arrangement can be arranged in a one-to-one circumferential array, or it can be arranged in an interlaced manner to adapt to the installation of irregularly shaped permanent magnets and to adapt to the design requirements of tail rotor direct drive motor rotors of different specifications.

[0039] In some embodiments, the inner side of the rotor hub 2 adopts a hollow structure, and multiple reinforcing structures 9 are provided on the inner side of the rotor hub 2 to ensure structural strength while reducing weight. The hollow structure is a hollow hole, which effectively reduces the overall weight of the rotor hub 2, in line with the design concept of lightweight motor rotors. The reinforcing structures 9 can be reinforcing ribs. Multiple reinforcing structures 9 can enhance the structural rigidity and deformation resistance of the rotor hub while reducing weight, resist centrifugal force and complex vibration loads during high-speed rotation, avoid permanent magnet positioning deviation or magnetic field distribution imbalance caused by structural deformation, and further ensure the long-term stable operation of the motor.

[0040] In some embodiments, a plurality of heat dissipation structures 10 are provided on the inner circumference of the rotor hub 2, which effectively increases the heat dissipation area inside the rotor hub 2, accelerates the exchange and dissipation of heat generated during motor operation with the outside air, and promptly removes the heat accumulated on the inner side of the rotor when the motor rotor is working, thereby preventing the motor rotor from overheating and causing a decrease in the working performance of the permanent magnet 1, and preventing the adhesive from aging and failing or the structural components from thermally deforming due to excessive temperature, thus extending the service life of the motor.

[0041] The heat dissipation structure 10 is finned, ribbed, or other structural forms with heat dissipation function.

[0042] In some embodiments, the rotor hub 2 is made of a lightweight and high-strength material, specifically a lightweight and high-strength aluminum alloy or magnesium alloy, which has the characteristics of sufficient strength and light weight.

[0043] In some embodiments, the motor shaft 3 is made of lightweight and high-strength material, specifically lightweight and high-strength titanium alloy. High-strength aluminum alloy can also be selected if the structural strength requirements are met, which has the characteristics of sufficient strength and light weight.

[0044] In some embodiments, a first bearing 5 and a second bearing 6 are respectively provided at both ends of the rotating shaft 3. The first bearing 5 is a deep groove ball bearing, used for auxiliary support of the motor. The second bearing 6 is a double-row angular contact ball bearing, which is the main load bearing and used to bear the tail rotor load.

[0045] According to an embodiment of the present invention, in a second aspect, a tail rotor direct drive motor is provided, comprising a tail rotor direct drive motor stator and a lightweight motor rotor. The lightweight motor rotor is mounted inside the tail rotor direct drive motor stator. The tail rotor direct drive motor is mounted on a helicopter platform via a mounting bracket and is used to drive the helicopter tail rotor.

[0046] After the stator of the tail rotor direct drive motor is energized, the lightweight motor rotor interacts with the alternating magnetic field generated by the tail rotor direct drive motor stator, causing the lightweight motor rotor to rotate and output the power, torque and speed required by the design, driving the helicopter tail rotor to work.

[0047] This invention uses finite element analysis to evaluate and assess whether it meets the requirements for motor output power, torque, and speed; and the results have been verified by experiments to be good.

[0048] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A lightweight motor rotor, characterized in that, include: Rotating shaft (3); Rotor hub (2), which is sleeved around the rotating shaft (3) and connected to the rotating shaft (3); The permanent magnet assembly includes a plurality of permanent magnets (1), which are arranged on the rotor hub (2) in a Halbach array structure.

2. The lightweight motor rotor according to claim 1, characterized in that, The permanent magnet (1) is divided into multiple blocks radially along the rotor hub (2) and into multiple segments axially along the rotor hub (2).

3. The lightweight motor rotor according to claim 1, characterized in that, A positioning structure is provided between the permanent magnet (1) and the rotor hub (2).

4. The lightweight motor rotor according to claim 3, characterized in that, The positioning structure includes a matching limiting groove (7) and a limiting boss (8). The permanent magnet (1) is provided with the limiting groove (7) on the side near the rotor hub (2). The limiting boss (8) is provided on the outer side of the rotor hub (2). The permanent magnet (1) is positioned and installed on the rotor hub (2) by the cooperation of the limiting groove (7) and the limiting boss (8), and is fixed by adhesive.

5. The lightweight motor rotor according to claim 1, characterized in that, The inner side of the rotor hub (2) adopts a hollow structure and is provided with multiple reinforcing structures (9).

6. The lightweight motor rotor according to claim 1, characterized in that, The rotor hub (2) has multiple heat dissipation structures (10) on its inner circumference.

7. The lightweight motor rotor according to claim 1, characterized in that, The rotor hub (2) is made of lightweight and high-strength material; and / or the motor shaft (3) is made of lightweight and high-strength material.

8. The lightweight motor rotor according to any one of claims 1-7, characterized in that, The two ends of the rotating shaft (3) are respectively provided with a first bearing (5) and a second bearing (6).

9. A tail rotor direct drive motor, characterized in that, include: Tail rotor direct drive motor stator; The lightweight motor rotor according to any one of claims 1-8, wherein the lightweight motor rotor is mounted inside the stator of the tail rotor direct drive motor.

10. The tail rotor direct drive motor according to claim 9, characterized in that, The tail rotor direct drive motor is mounted on the helicopter platform via a mounting bracket and is used to drive the helicopter tail rotor.

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