A trans-medium electric propulsion radial-axial composite excitation fault-tolerant motor

Abstract

The present invention provides a trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor, comprising: a stator assembly, comprising a stator support, a stator core arranged on the stator support, and a winding arranged on the stator core; a rotor assembly, rotating around the central axis of the stator assembly, comprising a rotor core and a rotor permanent magnet arranged in the rotor core, and the rotor core is also connected to the rotor support; a fault-tolerant assembly, comprising a magnetic end plate arranged on the stator support, an electric excitation winding arranged in the magnetic end plate, a positioning groove is provided in the stator core, and a positioning pull rod is provided in the yoke of the stator core and connected to the magnetic end plate; a high magnetic load design of the motor is realized, and the goal of high power density of the motor is achieved; the position of the magnetic end plate is controlled by the electric excitation winding, the armature impedance during a fault is changed, and the short-circuit current is suppressed. At the same time, the fault-tolerant assembly is simple and easy to process, and can improve the strong fault tolerance capability of the motor under high magnetic load conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of trans-medium motors, and in particular to a trans-medium electric propulsion radial-axial composite excitation fault-tolerant motor. Background Art

[0002] As a key technology for trans-medium aircraft, trans-medium propulsion systems must be able to operate continuously and stably in both water and air, meeting the power requirements of high speed and high power in air and low speed and high torque underwater. Permanent magnet motors, with their high power density and high efficiency, meet the technical requirements of trans-medium propulsion systems and constitute a highly promising trans-medium propulsion motor.

[0003] When an aircraft propulsion system operates in the same medium, the required torque is proportional to the square of the rotational speed, eliminating the need to consider the motor's ability to operate with field-weakening and extended speed. Furthermore, given the design requirements for permanent magnet propulsion motors, which require high magnetic loads to ensure high power density, surface-mount rotor structures are often used for both inner and outer rotors, as well as for axial magnetic field structures. To achieve good airgap flux density, reduce harmonic content, and reduce rotor weight, medium- and high-power permanent magnet motor rotors employ a Halbach array magnetization scheme. To achieve high motor power density, composite excitation structures formed by the superposition of radial and axial magnetic fluxes have been mentioned in multiple patents. Patent CN110120716A discloses a combined array outer rotor axial-radial hybrid flux permanent magnet motor. The stator teeth include axial and radial teeth, with axial and radial coils wound on the teeth, respectively. Patent CN105790470A discloses a dual-stator composite rotor radial-axial hybrid magnetic circuit permanent magnet synchronous motor and method. The motor contains a radial-axial stator with two sets of stator slots and windings. Although the above two structural schemes have a certain improvement in power density and magnetic concentration effect, the motor structure is complex, the risk of motor failure is increased, and the short-circuit current cannot be suppressed under fault conditions, which reduces the reliability of the system.

[0004] Permanent magnet motors must possess strong fault tolerance to ensure reliability and safety. To achieve high motor reliability, fault tolerance methods for the motor itself have been mentioned in multiple patents. Patent CN113255281A discloses a fault-tolerant, low-short-circuit current dual-three-phase permanent magnet motor winding design method. This method can reduce the mutual inductance of the motor while increasing the self-inductance amplitude of the motor, effectively suppressing short-circuit current. However, considering the operating characteristics of the trans-dielectric propulsion motor, this design method cannot meet the high power density requirements under normal motor operation. Summary of the Invention

[0005] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0006] Therefore, the technical problem to be solved by the present invention is: while ensuring the high power density requirements of the motor, avoid the failure risk of the motor under high magnetic load conditions, thereby providing a cross-medium electric propulsion radial-axial composite excitation fault-tolerant motor.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions: a trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor, comprising: a stator assembly, including a stator bracket, a stator core arranged on the stator bracket, and a winding arranged on the stator core; a rotor assembly, which rotates around the central axis of the stator assembly, including a rotor core and a rotor arranged in the rotor core, and the rotor core is also connected to a rotor bracket; and a fault-tolerant assembly, including a magnetic end plate arranged on the stator bracket, an electric excitation winding is arranged in the magnetic end plate, a positioning groove is opened in the stator core, and a positioning pull rod is arranged in the yoke of the stator core and connected to the magnetic end plate.

[0008] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the rotor permanent magnets include radial rotor permanent magnets and axial rotor permanent magnets, the radial rotor permanent magnets include radial inner rotor permanent magnets and radial outer rotor permanent magnets, which are radially inserted into the rotor core, the radial inner rotor permanent magnets and the radial outer rotor permanent magnets are circular rings formed by several pairs of arc-shaped magnetic steels, and are arranged in contact with the inner wall of the rotor core, and air gaps are left between the radial inner rotor permanent magnets and the radial outer rotor permanent magnets and the stator core.

[0009] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the axial rotor permanent magnet is mounted in the rotor core, and the axial rotor permanent magnet includes a circular ring surrounded by several fan-shaped magnetic steels, which is arranged in contact with the inner wall of the rotor core, and the inner and outer diameters of the axial rotor permanent magnet are connected to the common ends of the radial inner rotor permanent magnet and the radial outer rotor permanent magnet.

[0010] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the rotor assembly is connected to a rotating shaft, and the rotating shaft is coaxially arranged with the central axis of the rotor assembly.

[0011] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the radial inner rotor permanent magnet and the radial outer rotor permanent magnet respectively include two magnetic steels of different sizes arranged alternately.

[0012] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, a sealing shield is provided between the stator core and the radial rotor and the axial rotor.

[0013] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, a bearing is provided on the outside of the rotating shaft, the bearing is fixed in the stator bracket, and a gap is provided in the axial direction between the stator bracket and the stator core.

[0014] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the inner and outer diameters of the magnetic end plate are consistent with the inner and outer diameters of the stator core.

[0015] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, an electric excitation winding is provided radially on the magnetic end plate.

[0016] As a preferred solution of the trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor described in the present invention, the positioning rod is arranged along the axial direction, the number of the positioning rods is consistent with the number of the positioning slots, one end of the positioning rod penetrates the magnetic end plate and is inserted into the interior of the stator bracket, and the other end is inserted into the yoke of the stator core, and is flush with an end face of the stator core close to the axial rotor permanent magnet.

[0017] The beneficial effects of the present invention include: by integrating and reconstructing traditional motor topologies, a motor with a three-dimensional magnetic circuit structure containing radial and axial rotors is provided, enabling a high magnetic load design for the motor and achieving the goal of high power density. The electric excitation winding is used to control the position of the magnetic end plate, changing the instantaneous value of the armature impedance to suppress short-circuit current. Simultaneously, the fault-tolerant components are simple and easy to process, enhancing the motor's fault tolerance under high magnetic load conditions. Stator sealing achieves sealed isolation of the stator assembly, meeting the dual-medium operation requirements of a trans-medium electric propulsion system, both in water and air, and overcoming the motor's inability to continuously and stably output power in both water and air. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0019] Figure 1 A schematic diagram of the overall structure of the motor provided by the present invention;

[0020] Figure 2 An exploded schematic diagram of the motor provided by the present invention;

[0021] Figure 3 It is a side view of the motor in normal operation and fault status;

[0022] Figure 4 This is a structural diagram of the motor in normal operation and fault conditions; DETAILED DESCRIPTION

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0024] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0025] Example 1

[0026] This embodiment provides a cross-medium electric propulsion radial-axial composite excitation fault-tolerant motor, such as Figure 1-4 As shown,

[0027] It includes a stator assembly 100, a rotor assembly 200 and a fault-tolerant assembly 300. The rotor assembly 200 is used to rotate around the stator assembly 100 to generate power. The fault-tolerant assembly 300 can timely increase the armature impedance when a fault occurs, thereby achieving short-circuit current suppression and preventing damage to the motor.

[0028] Specifically, the stator assembly 100 includes a stator bracket 101, a stator core 102 arranged on the stator bracket 101, and a winding is arranged on the stator core 102. The stator bracket 101 is used to fix the stator core 102 and is a base for installing other components. Its shape is not specified, but it is generally preferably a circular plate with a circular hole in the center for passing the rotating shaft. The stator core 102 is a circular ring structure, and the inner and outer sides of the stator core 102 are both provided with a slotted structure. The winding is a plurality of turns of coil wound on the stator teeth.

[0029] The rotor assembly 200 rotates around the central axis of the stator assembly 100, and includes a rotor core 201 and a rotor permanent magnet 210 arranged in the rotor core 201. The rotor core 201 is also connected to a rotor bracket 204, wherein the rotor core is a circular shell, and the rotor permanent magnet 210 is attached to the inner wall of the rotor core 201. The rotor bracket 204 is used to connect the two into a whole. Rotating the rotor bracket 204 can simultaneously rotate the rotor core 201 and the internal rotor permanent magnet 210. The rotor bracket 204 and the stator core 102 are coaxially arranged so that the radial rotor permanent magnet rotates around the stator core 102.

[0030] The fault-tolerant component 300 includes a magnetic end plate 301 arranged on the stator bracket 101, an electric excitation winding 302 is arranged in the magnetic end plate 301, a positioning groove is opened in the stator core 102, and a positioning rod 304 is arranged in the yoke of the stator core 102 to be connected to the magnetic end plate 301. The magnetic end plate 301 can slide along the positioning rod 304. Under normal operating conditions, the magnetic end plate 301 and the positioning rod 304 are fixed to the side of the stator bracket 101 by interference fit, and a certain distance is maintained between them and the stator core 102 to avoid magnetic leakage. When a fault occurs, the electric excitation winding 302 applies pulse excitation, and the electromagnetic force causes the magnetic end plate 301 to slide along the positioning rod 304, so that it contacts the stator core 102 and a magnetic short circuit occurs. At the same time, a closed slot is formed on one side of the stator axial direction, the armature impedance is increased, the short-circuit current is suppressed, and the motor is prevented from being damaged.

[0031] Example 2

[0032] This embodiment is based on the previous embodiment, but is different from the previous embodiment in that Figure 1-4 As shown,

[0033] The rotor assembly 200 includes radial rotor permanent magnets 202, axial rotor permanent magnets 203 and a rotor core 201. The radial rotor permanent magnets 202 include radial inner rotor permanent magnets 202a and radial outer rotor permanent magnets 202b. Through this radial-axial composite excitation structure, a high magnetic load design of the motor is realized, achieving the goal of high power density of the motor.

[0034] Specifically, the radially inner rotor permanent magnet 202a and the radially outer rotor permanent magnet 202b are radially inserted into the rotor core 201. The radially inner rotor permanent magnet 202a and the radially outer rotor permanent magnet 202b are circular rings formed by several pairs of arc-shaped magnetic steels and are arranged in contact with the radial inner wall of the rotor core 201. An air gap is left between the radially inner rotor permanent magnet 202a and the radially outer rotor permanent magnet 202b and the stator core 102.

[0035] The axial rotor permanent magnet 203 is mounted inside the rotor core 201. The axial rotor permanent magnet 203 includes a circular ring formed by several sector-shaped magnetic steels and is arranged in contact with the axial inner wall of the rotor core 201. The inner and outer diameters of the axial rotor permanent magnet 203 are connected to the common ends of the radial inner rotor permanent magnet 202a and the radial outer rotor permanent magnet 202b. A sealing shield 206 is provided between the stator core 102 and the radial rotor permanent magnet 202 and the axial rotor permanent magnet 203.

[0036] The radially inner rotor permanent magnet 202a and the radially outer rotor permanent magnet 202b are respectively formed by alternating arrangement of two magnets of different sizes. The magnets are bonded in blocks and then magnetized as a whole using a Halbach array. The outer side of the radially inner rotor permanent magnet 202a is wrapped with carbon fiber to form a high-strength sheath for protection.

[0037] Furthermore, a rotating shaft 205 is connected to the rotor assembly 200 , and the rotating shaft 205 is coaxially arranged with the central axis of the rotor assembly 200 . A bearing is arranged on the outside of the rotating shaft 205 , and the bearing is fixed in the stator bracket 101 . A gap is arranged axially between the stator bracket 101 and the stator core 102 .

[0038] The inner and outer diameters of the magnetic end plate 301 are consistent with the inner and outer diameters of the stator core 102. An electric excitation winding 302 is provided radially on the magnetic end plate 301, and the positioning rod 304 is arranged axially. The number of the positioning rods 304 is consistent with the number of the positioning slots. One end of the positioning rod 304 penetrates the magnetic end plate 301 and is inserted into the interior of the stator bracket 101, and the other end is inserted into the yoke of the stator core 102, and is flush with one end face of the stator core 102 close to the axial rotor permanent magnet 203.

[0039] In this embodiment, the traditional inner rotor, outer rotor, and axial permanent magnet motor topologies are integrated and reconstructed, and a radial-axial composite excitation structure is proposed. By integrating and reconstructing the traditional motor topologies, a radial-axial composite excitation motor topology is provided, which realizes the high magnetic load design of the motor and achieves the goal of high power density of the motor; the fault-tolerant component composed of the electric excitation winding, the positioning rod, and the magnetic end plate, under normal operating conditions, the magnetic end plate and the positioning rod are fixed to the side of the stator bracket by interference fit, and a certain distance is maintained between the end plate and the stator core to avoid magnetic leakage. When a fault occurs, the electric excitation winding applies pulse excitation, and the electromagnetic force causes the magnetic end plate to be displaced, causing it to contact the stator core and cause a magnetic short circuit. At the same time, a closed slot is formed on the axial side of the stator, and the armature impedance is increased to achieve short-circuit current suppression. At the same time, the fault-tolerant device is simple and easy to process, which can enhance the strong fault tolerance of the motor under high magnetic load conditions.

[0040] It is important to note that the construction and arrangement of the present application shown in a number of different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without departing substantially from the novel teachings and advantages of the subject matter described in this application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete elements may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means plus function" clause is intended to cover the structure described herein that performs the function, and is not only structurally equivalent but also equivalent structures. Other replacements, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments without departing from the scope of the present invention. Therefore, the invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0041] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0042] It will be appreciated that in the development of any actual embodiment, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will, for those of ordinary skill having the benefit of this disclosure, be a routine undertaking of design, fabrication, and production without undue experimentation.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A trans-medium electric propulsion radial-axial composite excitation fault-tolerant motor, characterized by: include, A stator assembly (100) comprises a stator bracket (101), a stator core (102) arranged on the stator bracket (101), and a winding arranged on the stator core (102); A rotor assembly (200) rotates around the central axis of the stator assembly (100), comprising a rotor core (201) and a rotor permanent magnet (210) disposed within the rotor core (201); a rotor support (204) is further connected to the rotor core (201); and A fault-tolerant component (300) comprises a magnetic end plate (301) arranged on a stator bracket (101), an electric excitation winding (302) being arranged in the magnetic end plate (301), a positioning groove being provided in the stator core (102), and a positioning rod (304) being provided in a yoke of the stator core (102) and connected to the magnetic end plate (301); The rotor permanent magnet (210) includes a radial rotor permanent magnet (202) and an axial rotor permanent magnet (203); the radial rotor permanent magnet (202) includes a radial inner rotor permanent magnet (202a) and a radial outer rotor permanent magnet (202b), and is radially sleeved into the rotor core (201); the radial inner rotor permanent magnet (202a) and the radial outer rotor permanent magnet (202b) are circular rings formed by a plurality of pairs of arc-shaped magnetic steels, and are arranged in contact with the radial inner wall of the rotor core (201); and air gaps are left between the radial inner rotor permanent magnet (202a) and the radial outer rotor permanent magnet (202b) and the stator core (102); The axial rotor permanent magnet (203) is sleeved in the rotor core (201), and the axial rotor permanent magnet (203) comprises a ring formed by a plurality of fan-shaped magnetic steels, and is arranged to fit the axial inner wall of the rotor core (201). The inner and outer diameters of the axial rotor permanent magnet (203) are connected to the common ends of the radial inner rotor permanent magnet (202a) and the radial outer rotor permanent magnet (202b).

2. The trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 1, characterized in that: A rotating shaft (205) is connected to the rotor assembly (200), and the rotating shaft (205) is coaxially arranged with the central axis of the rotor assembly (200).

3. The trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 1, characterized in that: The radially inner rotor permanent magnet (202a) and the radially outer rotor permanent magnet (202b) respectively comprise two types of magnetic steel of different sizes, which are alternately arranged.

4. The trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 1, characterized in that: A sealing shield (206) is provided between the stator core (102) and the rotor assembly (200).

5. The trans-medium electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 2, characterized in that: A bearing is provided on the outside of the rotating shaft (205), and the bearing is fixed in the stator bracket (101). A gap is provided in the axial direction between the stator bracket (101) and the stator core (102).

6. The trans-dielectric electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 1, characterized in that: The inner and outer diameters of the magnetic end plate (301) are consistent with the inner and outer diameters of the stator core (102); the positioning rods (304) are arranged along the axial direction; the number of the positioning rods (304) is consistent with the number of the positioning slots; one end of the positioning rod (304) is interference-fitted to penetrate the magnetic end plate (301) and inserted into the interior of the stator bracket (101); the other end is inserted into the yoke of the stator core (102) and is flush with an end face of the stator core (102) close to the axial rotor permanent magnet (203).

7. The trans-medium electric propulsion radial-axial composite excitation fault-tolerant motor according to claim 6, characterized in that: The electric excitation winding (302) is arranged radially along the magnetic end plate (301). In a healthy state, the magnetic end plate (301) is positioned on the side of the stator bracket (101) by interference pressure. In a fault state, a pulse current is passed through the electric excitation winding (302), and the magnetic end plate (301) and the stator core (102) generate electromagnetic force, so that the magnetic end plate (301) is displaced to fit the stator core (102), the main magnetic flux is reduced and the inductance is increased, so that the open circuit back electromotive force and the short circuit current are effectively suppressed.

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