An air turbine starter based on magnetic deceleration

Abstract

The present invention relates to an air turbine starter based on magnetic deceleration, belonging to the technical field of aviation air turbine starters, and solves the problems of complex structure, large weight, large volume and poor reliability of the existing air turbine starters. The present invention uses a coaxial magnetic gear as the deceleration transmission mechanism of the air turbine starter, realizes a large speed ratio non-contact variable speed transmission, and has the characteristics of low vibration noise, high power-to-weight ratio, no friction and no need for lubrication. For the air turbine starter of the present invention, an analysis method for the loss characteristics of the magnetic gear, an analysis method for the deformation amount of the stator core, a starting response characteristic analysis method, an impact vibration analysis method based on transient dynamics, a temperature distribution analysis method based on fluid mechanics and heat transfer, a stator core shape parameter optimization method based on the response surface method and genetic algorithm, and a permanent magnet arrangement optimization method based on the Halbach array are also proposed, and finally a comprehensive optimization design method for the coaxial magnetic gear structure is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of aviation air turbine starters, and particularly relates to an air turbine starter based on magnetic deceleration, and more particularly to an air turbine starter based on magnetic gear transmission. Background Art

[0002] Limited by the structure and cycle process, an aeroengine cannot start by itself and needs a starter to drive the aeroengine to operate and start. Therefore, a starter must be installed on the aeroengine to meet the working requirements of the aeroengine.

[0003] At present, the air turbine starter has become a starting auxiliary device for almost all high bypass ratio aeroengines. During the starting process of the aeroengine, the Auxiliary Power Unit generates compressed air and supplies it to the air turbine starter. Driven by the high-pressure gas, the air turbine starter drives the aeroengine to rotate. When the starting speed is reached, the engine injects fuel and ignites and disengages from the starter to complete the starting process.

[0004] The air turbine starter based on magnetic gear transmission is very different from the conventional air turbine starter based on planetary gear transmission. The conventional air turbine starter based on planetary gear transmission has the following problems:

[0005] 1. The planetary gear transmission system has a complex structure and numerous components, resulting in a large volume and weight of the air turbine starter based on planetary gear transmission.

[0006] 2. When the planetary gear transmission system works, the noise and vibration are obvious.

[0007] 3. The lubrication method of the planetary gear transmission system is complex and the later maintenance is difficult.

[0008] In order to solve or improve the above problems, an air turbine starter based on magnetic deceleration is invented. Summary of the Invention

[0009] In view of the above problems, the present invention provides an air turbine starter based on magnetic deceleration, which solves the problems of complex structure, large weight, large volume and poor reliability of the existing air turbine starter.

[0010] On the one hand, the present invention provides an air turbine starter based on magnetic deceleration, including a housing, a guide vane assembly structure and a magnetic gear;

[0011] The magnetic gear includes a rotor, a magnetic gear stator assembly structure and a magnetic gear rotor support structure;

[0012] The rotor includes an output rotor assembly structure and an input rotor assembly structure separately arranged within the housing and the guide assembly structure. The output rotor assembly structure is axially provided with a hollow portion for sleeving the input rotor assembly structure.

[0013] The output rotor assembly structure, the magnetic gear stator assembly structure, and the input rotor assembly structure are sleeved with each other and are all installed within the housing and the guide assembly structure.

[0014] A first annular cavity is formed between the input rotor assembly structure and the output rotor assembly structure.

[0015] The output rotor assembly structure is axially protruded from one end of the input rotor assembly structure, and a connecting portion is circumferentially arranged thereon. An output shaft coaxial with the input rotor assembly structure penetrates through the connecting portion.

[0016] A second annular cavity is formed between the output shaft and the input rotor assembly structure. The magnetic gear rotor support structure is axially arranged within the housing and the guide assembly structure in the second annular cavity. The magnetic gear rotor support structure is respectively connected to the input rotor assembly structure and the output shaft to support the output rotor assembly structure and the input rotor assembly structure.

[0017] The magnetic gear stator assembly structure includes a stator support frame, a stator core assembly, a stator injection molding filler, and a stator end plate. The stator core assembly includes a plurality of stator cores arranged at intervals.

[0018] The input rotor assembly structure includes a rotor shaft, a guide rotation assembly, and a magnetic portion. The magnetic portion includes an input rotor permanent magnet assembly.

[0019] Inner air gaps and outer air gaps are respectively formed between the input rotor assembly structure, the output rotor assembly structure, and the magnetic gear stator assembly structure.

[0020] Optionally, one end of the first annular cavity is communicated with the hollow portion, and the other end is communicated with the interior of the housing and the guide assembly structure. The magnetic gear stator assembly structure is arranged within the housing and the guide assembly structure in the first annular cavity. The connection portion between the magnetic gear stator assembly structure and the housing and the guide assembly structure is located within the communication portion between the first annular cavity and the interior of the housing and the guide assembly structure.

[0021] Optionally, the housing and the guide assembly structure includes a clamping portion. The clamping portion is circumferentially assembled on the output shaft, and the clamping portion is located on the side of the connecting portion away from the output rotor assembly structure. Among them, two groups of first support components are arranged at the assembly portion of the clamping portion and the output shaft.

[0022] On the other hand, the present invention also discloses an analysis method for the loss characteristics of a magnetic gear, which is used to analyze the loss characteristics of the magnetic gear of the aforementioned air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0023] S1. Obtain the distribution of the magnetic field of the magnetic gear, perform Fourier series decomposition on the waveform of the magnetic flux density amplitude varying with time, and obtain the alternating frequency and magnetic flux density amplitude of each magnetic field harmonic;

[0024] S2. Obtain the total energy loss of the magnetic gear based on the eddy current loss model and the iron loss separation model.

[0025] 5. A method for analyzing the deformation amount of the stator core of a magnetic gear, which is used to analyze the deformation amount of the stator core of the air turbine starter based on magnetic deceleration described in any one of claims 1-3. The specific steps are as follows:

[0026] S1: Analyze the distribution of the magnetic field of the magnetic gear to obtain the electromagnetic force distribution of the stator core assembly in the stator assembly structure of the magnetic gear;

[0027] S2: Model the stator core assembly as a cantilever beam model; take the electromagnetic force distribution of the stator core assembly as an external load, and analyze the structural deformation of the stator core assembly based on the cantilever beam model.

[0028] On the other hand, the present invention also discloses a method for analyzing the starting response characteristics of a magnetic gear, which is used to analyze the starting response characteristics of the magnetic gear of the air turbine starter based on magnetic deceleration described above. The specific steps are as follows:

[0029] S1: Set the stable speed, test duration and step value of the rotor shaft of the input rotor assembly structure; obtain the speed-time curve of the rotor shaft based on the stable speed, test duration and step value of the rotor shaft; take the speed-time curve of the rotor shaft as the driving condition of the magnetic gear;

[0030] S2: Obtain the critical value of the input angular acceleration of the magnetic gear The expression is:

[0031]

[0032] where J is the rotor inertia, t is the time, f is the damping coefficient, ω is the angular velocity, T is the input torque, and T' is the load torque;

[0033] S3: The rotor shaft is loaded from the initial speed to the stable speed set in step S1 at the critical value of the input angular acceleration of the magnetic gear obtained in step S2 to obtain the starting response characteristics of the no-load starting and load starting of the input rotor assembly structure and the output rotor assembly structure of the magnetic gear.

[0034] On the other hand, the present invention also discloses a method for analyzing the impact vibration of an air turbine starter after being impacted by high-pressure gas based on transient dynamics, which is used to analyze the impact vibration of the aforementioned air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0035] S1: Take the pressure difference on both sides of the turbine blade of the air turbine starter as the excitation source of the impact vibration of the air turbine starter and apply it to the pressure surface of the turbine for a preset continuous excitation time;

[0036] S2: Use the transient dynamics calculation formula to analyze the impact vibration characteristics of the air turbine starter after being impacted by high-pressure gas.

[0037] On the other hand, the present invention also discloses a method for analyzing the temperature distribution of an air turbine starter based on fluid mechanics and heat transfer, which is used to analyze the temperature distribution of the aforementioned air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0038] S1: Take the iron loss generated during the magnetic gear transmission process as the heat source, and use the volume heat source calculation formula to analyze the unit volume heat generation rate of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure during the magnetic gear transmission process; use the equivalent thermal conductivity calculation formula to analyze the heat dissipation performance of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure of the air turbine starter;

[0039] S2: Use computational fluid dynamics and heat transfer to analyze the temperature distribution of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure of the magnetic gear when the air turbine starter performs axial ventilation.

[0040] On the other hand, the present invention also discloses a method for optimizing the shape parameters of the stator core based on the response surface method and genetic algorithm, which is used to optimize the shape parameters of the stator core of the aforementioned air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0041] S1: Determine the shape parameters to be optimized and their numbers of the stator core of the coaxial magnetic gear;

[0042] S2: Obtain multiple stator core samples located in the surface area of the optimization design variable space; obtain the values of the shape parameters to be optimized for each stator core sample;

[0043] S3: Perform magnetic field and structural field simulations on all the obtained stator core samples to obtain the maximum simulated structural deformation of each stator core sample;

[0044] S4: Construct the objective function of the maximum structural deformation of the stator core;

[0045] S5: Construct constraint conditions;

[0046] S6: Based on the values of the shape parameters to be optimized and the maximum structural deformation amounts obtained from Steps S2 and S3 for multiple stator core samples, use a second-order multivariate function to fit the relationship function between the reciprocal of the maximum structural deformation amount of the stator core and the shape parameters to be optimized of the stator core;

[0047] S7: Based on the relationship function between the reciprocal of the maximum structural deformation amount of the stator core and the shape parameters to be optimized of the stator core and the constraint conditions, construct an optimal shape optimization problem for minimizing the maximum structural deformation amount of the stator core;

[0048] S8: Use a genetic algorithm to solve the optimal shape optimization problem of the maximum structural deformation amount of the stator core; obtain the optimal values of the shape parameters to be optimized of the stator core corresponding to the minimum value of the maximum structural deformation amount of the stator core.

[0049] On the other hand, the present invention also discloses a method for optimizing the arrangement of permanent magnets based on a Halbach array, which is used to optimize the arrangement of the permanent magnet assembly of the magnetic gear input rotor of the air turbine starter based on magnetic deceleration described above. The specific steps are as follows: evenly divide the input rotor permanent magnet assembly into N groups along the circumferential direction of the input rotor magnetic conduction ring assembly to obtain N groups of single permanent magnet components; each group of single permanent magnet components includes M single permanent magnets arranged axially along the input rotor magnetic conduction ring assembly; each group of single permanent magnet components includes M single permanent magnets that form a complete magnetic pole pair with radially magnetized N poles and S poles.

[0050] Compared with the prior art, the present invention has at least the following beneficial effects:

[0051] (1) The air turbine starter of the present invention uses a magnetic gear for transmission, which not only meets the starting power requirements of an aeroengine, but also reduces the volume and weight of the air turbine starter, and has the characteristics of a compact structure, high reliability, and convenient maintenance, realizing the high power density, miniaturization, and lightweight of the air turbine starter.

[0052] (2) The nested coaxial independent dual-rotor inner support setting method of the air turbine starter of the present invention makes the input and output rotors of the air turbine starter independent of each other except for the magnetic field coupling effect, reducing the friction and loss of the system, and is beneficial to accurately obtaining the dynamic characteristics of the rotor system.

[0053] (3) The magnetic gear stator assembly of the air turbine starter of the present invention is provided with a stator support structure, which improves the magnetic field modulation performance of the stator core assembly on the basis of ensuring the mechanical strength of the stator assembly.

[0054] (4) The housing and guide assembly of the air turbine starter of the present invention is provided with an output rotor positioning sleeve, which can effectively limit the radial displacement of the output rotor and improve the working stability of the system.

[0055] (5) The housing and guide of the air turbine starter of the present invention are provided with air outlets, which can effectively control the temperature rise of the permanent magnet during operation.

[0056] (6) In the output rotor assembly of the air turbine starter of the present invention, a dovetail structure is provided on the inner surface of the output rotor magnetic conductive ring, which can effectively fix the output rotor permanent magnet.

[0057] (7) In the output rotor assembly of the air turbine starter of the present invention, the power transmission between the output main shaft and the output end driven shaft welded part is carried out through an overrunning clutch, which can prevent the air turbine starter from being reversely driven and simplify the structure at the same time.

[0058] (8) The input rotor assembly of the air turbine starter of the present invention is provided with a carbon fiber protective sleeve, which can fix the input rotor permanent magnet assembly and effectively prevent it from falling off during high-speed rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The drawings are only for the purpose of showing specific embodiments and are not considered to be a limitation of the present invention.

[0060] Figure 1 is a sectional view of the overall structure of the air turbine starter of the present invention;

[0061] Figure 2 is a sectional view of the structure of the housing and guide assembly of the present invention;

[0062] Figure 3 is a schematic view of the input rotor assembly of the air turbine starter of the present invention;

[0063] Figure 4 is a sectional view of the structure of the input rotor assembly of the air turbine starter of the present invention;

[0064] Figure 5 is a schematic view of the structure of the output rotor assembly of the present invention;

[0065] Figure 6 is a sectional view of the output rotor assembly of the present invention;

[0066] Figure 7 is a schematic view of the structure of the stator assembly of the air turbine starter of the present invention;

[0067] Figure 8 is a sectional view of the stator assembly of the air turbine starter of the present invention;

[0068] Figure 9 Schematic diagram of air flow in the air turbine starter cavity of the present invention;

[0069] Figure 10 Schematic diagram of one - side structure of the magnetic gear rotor support structure of the present invention;

[0070] Figure 11 Schematic diagram of the structure of the air turbine starter of the present invention;

[0071] Figure 12 Schematic diagram showing the circumferential angles of the magnetic - conducting material and non - magnetic - conducting material in the stator assembly structure of the magnetic gear stator assembly of the present invention respectively;

[0072] Figure 13 Schematic diagram of the dovetail structure of the magnetic - conducting ring of the present invention;

[0073] Figure 14 Schematic diagram of the circumferential segmentation of the permanent magnet of the present invention.

[0074] Reference numerals:

[0075] 1 Housing and guide vane assembly structure, 101 Turbine guide vane, 102 Flow - guiding cone, 103 Bearing stator, 104 First stator outer cover, 105 Second stator outer cover, 106 Rear end cover, 107 Shaft - end sealing ring, 108 Output rotor positioning sleeve, 2 Input rotor assembly structure, 201 Air turbine, 202 Input rotor magnetic - conducting ring, 203 Input rotor permanent magnet assembly, 204 Input rotor sheath, 205 Input rotor baffle, 206 High - speed angular contact ball bearing, 207 Bearing retaining ring, 208 Locking ring, 209 Input rotor damper, 210 Double - layer spiral circlip, 3 Output rotor assembly structure, 301 Output rotor permanent magnet assembly, 302 Output rotor magnetic - conducting ring, 303 Output main shaft, 304 Over - running clutch, 305 Output shaft of the output rotor assembly structure, 306 Output - end driven shaft, 307 Bearing spacer, 308 Angular contact ball bearing A, 309 Angular contact ball bearing B, 310 Double - layer spiral circlip for shaft, 311 Needle bearing A, 312 Needle bearing B, 4 Magnetic gear stator assembly structure, 401 Stator core, 402 Stator support frame, 403 Stator injection molding filler, 404 Stator end plate, 5 Support stator. Detailed implementation manners

[0076] In order to more clearly understand the above - mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific implementation manners. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. In addition, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

[0077] A specific embodiment of the present invention, such as Figure 1-14 , discloses an air turbine starter based on magnetic deceleration, including a housing, a guide vane assembly structure 1, and a magnetic gear;

[0078] The magnetic gear includes a rotor, a magnetic gear stator assembly structure 4, and a magnetic gear rotor support structure;

[0079] The rotor includes an output rotor assembly structure 3 and an input rotor assembly structure 2 that are separately arranged in the housing and the guide vane assembly structure 1. The output rotor assembly structure 3 is axially provided with a hollow part for sleeving the input rotor assembly structure 2;

[0080] The output rotor assembly structure 3, the magnetic gear stator assembly structure 4, and the input rotor assembly structure 2 are sleeved with each other and are all installed in the housing and the guide vane assembly structure 1;

[0081] Wherein, there are intervals between the inner wall of the housing and the guide vane assembly structure 1 and the outer wall of the output rotor assembly structure 3, between the output rotor assembly structure 3 and the magnetic gear stator assembly structure 4, and between the magnetic gear stator assembly structure 4 and the input rotor assembly structure 2, forming an inner air gap and an outer air gap to allow gas to flow through;

[0082] The magnetic gear rotor support structure includes a support stator 5 with a ring-shaped fixed structure in the middle, and a three-point support and positioning structure arranged at both the inner and outer ends of the support stator 5; the three-point support and positioning structure includes two second support components and a third support component, and they are not on the same straight line, so that the first support component and the second support component form a triangular stable support structure at the same end, ensuring the stable guiding and supporting of the output shaft 305 of the output rotor assembly structure and the input rotor assembly structure during rotation.

[0083] The magnetic gear rotor support structure provided by the present invention minimizes the total length of the rotor and the radial size of the rotor, reduces the total weight of the starter. Compared with the traditional planetary gear starter, the magnetic gear of the present invention reduces complex support mechanisms and components, and uses the coaxial nesting method of the input and output rotors as the support scheme, reducing the complexity of the entire system; the stator core assembly in the magnetic gear stator assembly is fixed by a stator support frame, canceling the connection bridge structure, and further reducing the total weight of the starter.

[0084] Further, a first annular cavity is formed between the outer side of the input rotor assembly structure 2 and the inner side of the output rotor assembly structure 3, and the radial width of the first annular cavity is equal in the circumferential direction of the input rotor assembly structure 2; a connecting portion is circumferentially provided at one end of the output rotor assembly structure 3 protruding axially from the input rotor assembly structure 2, and an output shaft 305 coaxial with the input rotor assembly structure 2 is penetrated through the connecting portion; a second annular cavity is formed between the outer side of the output shaft 305 and the inner side of the input rotor assembly structure 2, and a support mechanism is axially arranged in the second annular cavity between the housing and the guide vane assembly structure 1, and the support mechanism is respectively connected to the input rotor assembly structure 2 and the output shaft 305 to support the output rotor assembly structure 3 and the input rotor assembly structure 2.

[0085] Further, by forming a first annular cavity for placing the stator assembly structure 4 between the input rotor assembly structure 2 and the output rotor assembly structure 3, on the one hand, a gap can be formed between the stator assembly structure 4 and the input rotor and the output rotor, and on the other hand, they can be independent of each other except for the magnetic field coupling effect with the output rotor, reducing the complexity of the entire rotor structure.

[0086] Furthermore, by forming a first annular cavity with a circumferentially equal radial width along the input rotor assembly structure 2, during the high-speed rotation of the input rotor and the output rotor, there is no direct contact between the inner and output rotors, resulting in relatively small vibration and noise. At the same time, it also has an overload protection function. That is, in the case of overload, the magnetic gear can protect the structure from physical damage through out-of-step operation. When overload occurs, the resultant torque on the low-speed rotor suddenly increases, causing its rotational speed to rapidly decrease, and the angular displacement difference between the two rotors to quickly increase. When the maximum value of the transmitted torque is less than the load torque, the low-speed rotor continues to decelerate, and the angular displacement difference between the rotors continues to expand. After that, regardless of how the angular displacement difference changes, the transmitted torque is less than the load torque, and the load torque will reduce the speed of the low-speed rotor to 0. During this process, the transmitted torque on the high-speed rotor gradually increases and alternates between the positive and negative maximum values. From the above analysis, it can be seen that when overload occurs, the speed of the low-speed rotor gradually decreases to 0, the speed of the high-speed rotor changes and begins to oscillate, and the angular displacement difference between the high-speed rotor and the low-speed rotor continuously expands. It can still work normally after removing the load, demonstrating the advantage of automatic overload protection; it solves the instability during rotation caused by the large magnetism between the stator assembly structure 4, the input rotor assembly structure 2, and the output rotor assembly structure 3. For the air turbine starter based on magnetic gear transmission, an output stator positioning sleeve is installed in its housing and the guide vane assembly. There are 8 rollers evenly distributed circumferentially on the inner cylindrical surface of the output rotor positioning sleeve. The output rotor positioning sleeve is sleeved on the outer cylindrical surface of the output rotor magnetic conduction ring, which can effectively limit the radial displacement of the output rotor and improve the stability during rotation. At the same time, a dovetail structure is designed on the inner surface of the output rotor magnetic conduction ring in the output rotor assembly, and this structure is used to fix the output rotor permanent magnet. In the output rotor assembly, the output main shaft and the output end driven shaft weldment transmit power through an overrunning clutch, which can prevent the reverse drive of the air turbine starter and further improve the stability.

[0087] Optionally, one end of the first annular cavity is connected to the hollow part, and the other end is connected to the inside of the shell and the guide assembly structure 1; the shell and the guide assembly structure 1 is provided with a stator assembly structure 4 in the first annular cavity, and the connection between the stator assembly structure 4 and the shell and the guide assembly structure 1 is located in the connection between the first annular cavity and the inside of the shell and the guide assembly structure 1. Thus, the first annular cavity can not only be used for the installation of the stator assembly structure 4, but also guide the internal flowing air through the gap between the stator assembly structure 4 and the input rotor and the output rotor, and by fixing the stator assembly structure 4 at the connection between the shell and the guide assembly structure 1 and arranging it in the connection between the first annular cavity and the inside of the shell and the guide assembly structure 1, the connection that affects the uniformity of the first annular cavity can be arranged at the end of the air guiding flow, so as to ensure the uniformity of the gap between the stator assembly structure 4 and the input rotor and the output rotor, further reduce the interference with the air flow inside the device, make the rotation of the input rotor and the output rotor more stable, and reduce energy loss and body wear.

[0088] Optionally, the housing and guide assembly structure 1 includes a clamping portion, which is circumferentially assembled on the output shaft 305, and the clamping portion is located on the side of the connecting portion away from the output rotor assembly structure 3; wherein two groups of first support components are arranged at the assembly point between the clamping portion and the output shaft 305.

[0089] Optionally, with the connecting part as the boundary, the input rotor and the output rotor are both located on one side of the connecting part, and a clamping part for guiding and clamping the output shaft 305 is circumferentially arranged on the other side of the connecting part. The overall connection structure between the output rotor and the output shaft 305 can have guiding rotating parts at both ends, further improving the stability of the high-speed working parts inside the device, reducing vibration or eccentric movement during high-speed rotation, improving transmission stability, and reducing losses.

[0090] Optionally, the support stator 5 has one end away from the connection portion connected to the shell and the guide assembly structure 1, and the other end is arranged in the connection portion between the first annular cavity and the hollow portion; at least two second support components are provided, for connecting the support stator 5 and the input rotor assembly structure 2; the third support component is used to connect the support stator 5 and the output shaft 305, and is located between adjacent second support components along the axial direction of the output shaft 305.

[0091] Optionally, each set of the first support assembly and the second support assembly includes at least one angular contact bearing 206 , and the third support assembly includes a needle bearing 312 .

[0092] Optionally, the input rotor and the bearing stator are supported by angular contact bearings to achieve stability at higher speeds while allowing it to withstand larger loads; a needle bearing 312 is used between the output rotor and the stator to make the radial structure of the entire coaxial structure more compact and reduce the overall mass.

[0093] Optionally, a power part is circumferentially arranged at one end of the input rotor assembly structure 2 axially protruding from the output rotor assembly structure 3 , and the power part is located on a side of the connection away from the output rotor assembly structure 3 .

[0094] Optionally, along the axial direction, the power unit is arranged at one end of the input rotor assembly structure 2 protruding from the output rotor assembly structure 3, and the power unit is further located on the side of the connection away from the output rotor assembly structure 3, which can reduce the impact of external airflow on the rotation of the final output rotor assembly structure 3 when driving the power unit, and further reduce the interference of the flowing air on the internal rotating structure.

[0095] Optionally, radial distances between the centers of rolling elements of the needle roller bearing 312 and the angular contact bearings 206 of the first support assembly and the second support assembly and the axis of the output shaft 305 are not equal.

[0096] Optionally, by setting the rolling centers of the bearings at different positions in the radial direction relative to the axis position after the output, damage to the bearing structure due to excessive axial force can be avoided. At the same time, by setting the bearings at multiple different radial positions, the stable rotation of the input rotor assembly structure, the output rotor assembly structure and the output shaft 305 during rotation is guaranteed.

[0097] Optionally, the projections of the clamping portion, the input rotor assembly structure 2, the output rotor assembly structure 3, and the stator assembly structure 4 along the axis of the output shaft 305 of the second support assembly are all located on the connecting portion; and the projections of the third support assembly and the support stator 5 along the axis of the output shaft 305 are all located on the output shaft 305.

[0098] Optionally, when arranging the positions of the structures, the annular area of ​​the connecting portion is considered in advance, and the projections of the clamping portion, the input rotor assembly structure 2, the output rotor assembly structure 3, and the stator assembly structure 4 along the axis of the output shaft 305 of the second support component are all located on the connecting portion in the axial direction, and the annular area of ​​the connecting portion is limited and reduced according to the size of each structure when it is used specifically, so that the overall structure is more compact and can effectively reduce the radial length, and the input rotor, stator assembly structure 4, output rotor, support structure, and the output shaft 305 corresponding to the support structure adopt a layered structure, which can effectively reduce the axial multi-section layout defects and can reduce the overall axial size of the device.

[0099] Optionally, a magnetic gear stator assembly structure is arranged between the input rotor assembly structure and the output rotor assembly structure, and the magnetic gear stator assembly structure comprises:

[0100] Stator support frame 402, the stator support frame 402 includes a plurality of support plates circumferentially arranged at equal intervals and a plurality of mounting parts, and the mounting parts are arranged between two adjacent support plates;

[0101] Stator core assembly 401, the stator core assembly 401 includes a plurality of stator cores axially arranged at equal intervals; the stator cores are inserted into the mounting parts and are in interference fit with two adjacent support plates forming the mounting parts;

[0102] The axis of the support plate is horizontal with the axis of the stator core; a groove is formed between two adjacent stator cores and the support plate;

[0103] Stator injection molding filler 403, filled in the groove;

[0104] Stator end plate 404, used to cooperate with the stator support frame 402 to fix the stator core assembly 401 between two adjacent support plates.

[0105] The magnetic gear stator assembly structure provided by the present invention cancels the connection bridge structure of the stator core 401 and uses a stator support frame 402 for fixation. It has better torque performance and can transmit a larger torque compared with the structure with a connection bridge, improving the torque performance by 5%-50%. At the same time, in terms of transmission efficiency, it can improve the efficiency by 3% compared with the existing double connection bridge, inner connection bridge and outer connection bridge. And there is less end leakage magnetic flux. Specifically, the stator is composed of a stator support frame 402, an iron core and a stator injection molding material. Permanent magnets are attached to the surfaces of the inner and output rotors, and magnetic conductive and non-magnetic conductive material blocks are arranged at intervals to form a magnetic modulation ring. Considering that the alternating magnetic field frequency of the stator core is relatively high, the iron core is stacked with amorphous materials and has relatively low losses in the high-frequency state. At the same time, the support frame is made of 7075 aluminum alloy with a relatively low density and non-magnetic conductivity, which not only reduces the mass of the reducer, but also does not affect the magnetic field formed by the common action of the inner rotating rotor and the magnetic modulation stator. The interval arrangement is realized through the support frame structure, and a thermosetting material is used for filling to achieve the purpose of improving the structural strength and reducing the weight. There is a uniform annular gap filled with air between the inner and output rotors and the stator. Due to the low requirement for torque performance and being trapped in the misunderstanding that a connection bridge is needed to increase the structural strength due to inertial thinking, in fact, without a connection bridge, it can not only be superior to other structures in torque performance, but even by changing the structure and using a support frame and a thermosetting material to fill the support frame structure interval, the purpose of improving the structural strength and having a lighter mass can be achieved. On the premise of greatly improving the performance, the structural strength and cost can still meet the requirements of the structure with a connection bridge. For the magnetic gear stator assembly 4 in the air turbine starter of the present invention, a stator support frame 402 is provided, which can reduce the blockage of the stator core along the radial direction of the stator support frame on the basis of ensuring the mechanical strength of the stator assembly 4 and improve the magnetic field modulation performance of the stator core 401. And such a structure of a gear stator without a connection bridge can bring a more obvious torque transmission effect. At the same time, torque performance is also one of the important performance parameters of a magnetic reducer, which can intuitively reflect the working characteristics, maximum working torque and bearing capacity and other indicators of the magnetic reducer.

[0106] Optionally, a plurality of bolts are assembled on the stator end plate 404, the support plate is axially provided with holes matching the bolts along the stator assembly 4, and fixing holes are provided on the side wall of the end of the stator support frame 402 away from the support plate; and / or

[0107] A positioning groove is provided on the end face of the stator end plate 404 close to the stator support frame 402, and a positioning block inserted into the positioning groove is provided on the stator core 401.

[0108] Optionally, the stator support frame 402 is connected to the outside by means of opening fixing holes, and the stator end plate 404 is assembled and fixed to the support plate by bolts. Specifically, the axes of the holes and the fixing holes are perpendicular to each other;

[0109] For the stator end plate 404 having positioning grooves, after clamping the stator core 401, positioning is achieved through the insertion of the positioning grooves and positioning blocks, realizing the radial positioning of the stator core 401.

[0110] Optionally, the stator support frame 402 is a circumferential ring structure and has an axis; a plurality of support plates are arranged circumferentially along the axis; the installation part is connected and communicated inside the stator support frame 402, and the installation part is arranged through the stator support frame 402 in the radial direction.

[0111] Optionally, in order to interact with the output rotor and the input rotor, the stator support frame 402 is set as a circumferential ring structure so that it has an axis; the installation part is arranged through the stator support frame 402 in the radial direction, so that the stator core 401 can be exposed before and after in the radial direction of the stator support frame 402 after being clamped and fixed, further improving the utilization efficiency of the iron core.

[0112] Optionally, the wall thickness of the support plate gradually increases from the inside to the outside along the radial direction of the stator support frame 402, so that the support plate forms two inclined side walls; the axis is located in the plane where all the inclined side walls of the support plates are located at the same time; the side wall of the stator core 401 cooperating with the support plate is parallel to the inclined side wall, and / or the side wall of the stator core 401 cooperating with the support plate is provided with an installation groove for accommodating the end of the support plate.

[0113] Optionally, the groove includes a first groove and a second groove arranged radially along the stator support frame 402; an outer air gap communicating with the first groove is formed between the stator assembly 4 and the output rotor; an inner air gap communicating with the second groove is formed between the stator assembly 4 and the input rotor.

[0114] Optionally, by dividing the groove into a first groove and a second groove along the radial direction of the stator support frame 402 and respectively filling the stator injection molding filler 403, the smoothness of the inner and outer walls of the stator support frame 402 can be optimized after installing the stator core assembly.

[0115] Optionally, the outer air gap and the inner air gap are coaxially arranged with the axis; the thicknesses of the outer air gap and the inner air gap along the radial direction of the stator support frame 402 are equal, and the thickness of the inner air gap is calculated by the following formula:

[0116] h in =k*maxU total +Z;

[0117] Wherein, h in is the thickness of the inner air gap, k is the safety margin coefficient, maxU total is the change amount of the thickness of the inner air gap of the input rotor during operation, and Z is the thermal expansion amount of the input rotor;

[0118] For the thickness of the inner air gap of the stator assembly 4, maxUtotal <0.22 mm, Z = 0.15 mm, k = 1.5, and the following formula needs to be satisfied:

[0119] h in >0.22 * 1.5 + 0.15. Considering the manufacturing cost, for h in = 0.5 mm.

[0120] Optionally, first in the structural design, since core loss is inevitable in the initial design of the magnetic modulation stator, in order to reduce its loss coefficient during design, thereby reducing its core loss, the loss coefficient is reduced in material selection and dimension design; second, the size of the internal and external air gap thicknesses of the magnetic gear reducer affects the magnetic field distribution of the system, and the change of the air gap will directly affect the performance of the entire magnetic reducer. Therefore, by analyzing the following three situations: (1) the loss change under only changing the internal air gap; (2) the loss change under only changing the external air gap; (3) the loss change under changing both the internal and external air gaps together, the relationship between the magnetic loss and the air gap thickness is determined, and then variables such as load and vibration are added in the Abaqus software to calculate that the optimal air gap thickness is 0.5 mm; in addition, when considering the influence of end leakage magnetic flux on the torque performance, a three-dimensional finite element analysis model of 4 different structural magnetic reducers is established, and the static torque change diagram of the output rotor of different structural magnetic reducers considering the end leakage magnetic flux effect is obtained. It is found that the structure without a connection bridge will reduce the magnetic resistance between the internal output rotors, and more magnetic force lines will reach the output rotor permanent magnets, thus reducing the magnetic force lines in the air domain and alleviating the end leakage magnetic flux effect.

[0121] Furthermore, for U total which is the change amount of the internal air gap thickness during the operation of the input rotor, it is calculated using the following formula:

[0122] maxU total = u1 + u2 + u3;

[0123] where u1 is the displacement change amount caused by centrifugal load and torque load, u2 is the displacement change amount caused by vibration, and u3 is the process tolerance of the reducer;

[0124] Specifically, based on the finite element platform, after applying the maximum load of 45000 rpm, the maximum displacement caused by centrifugal force was observed to be 0.0803 mm for u1. For u2, based on the finite element platform, a harmonic response analysis was performed on the input rotor. Since the rotational speed of the input rotor of the reducer does not exceed 45000 rpm and the highest frequency is less than 750 Hz, there will be no resonance phenomenon in the input rotor during actual operation. And the maximum value of the vibration displacement of the input rotor at a frequency of 750 Hz is less than 0.0005 mm. The tolerance of the magnetic modulation ring stator is set to 0.046 mm, and the tolerance of the permanent magnet sheath of the input rotor is set to 0.074 mm. Therefore, the total tolerance u3 of the two will not exceed 0.12 mm.

[0125] Optionally, on the same stator assembly structure, the circumferential angle occupied by the magnetic conductive material in the stator assembly structure is θ sp , and the circumferential angle occupied by the non-magnetic conductive material in the stator assembly structure is τ sp， The slotting rate of this stator assembly structure is α, and the following formula is satisfied:

[0126]

[0127] Among them, the value of α is [0, 1], and the slotting rate α is the opening rate of the installation part along the circumference of the stator assembly structure;

[0128] It can be understood that the stator core is made of magnetic conductive material, and the support plate and filling material are made of non-magnetic conductive material;

[0129] Under the magnetic field intensity of the same stator core group, calculate the output torque of the stator assembly structure on the input rotor and output rotor at different slotting rates, and obtain the slotting rate corresponding to the maximum output torque, which is α = 0.45.

[0130] Optionally, through a certain optimization of the gear stator structure, its working state can be better. Study the output torque at different slotting rates of the magnetic modulation ring, and thus select the optimal slotting rate of the magnetic modulation ring of 0.45, which increases the output torque by 4 Nm. Optimize the structural parameters of the magnetic modulation stator through the surface response method and genetic algorithm. On the basis of not reducing the peak torque of the coaxial magnetic gear, the optimal parameter combination is found, effectively improving the stability of the magnetic modulation stator structure.

[0131] Optionally, the stator support frame 402 is made of 7075 aluminum alloy, the magnetic conductive part of the stator core 401 is composed of amorphous laminations stacked on top of each other, and the stator injection molding filler 403 is a thermosetting plastic.

[0132] Optionally, the magnetic gear stator assembly 4 includes a stator core 4011, a stator support frame 402, a stator injection molding filler 403, and a stator end plate 404. Among them, the material of the stator core 401 is amorphous soft magnetic, the material of the stator support frame 402 is 7075 aluminum alloy, and the stator core 401 is installed in the partition of the stator support frame 402 through interference connection to achieve uniform circumferential distribution. The stator injection molding filler 403 uses thermosetting plastic and is filled in the inner and outer gaps of the stator support frame 402 to make the stator assembly 4 into a cylinder. The stator end plate 404 is connected to the stator support frame 402 by bolts.

[0133] Optionally, the structure of the magnetic gear output rotor assembly includes:

[0134] A first shaft body for connecting to an external driven end and outputting the power generated by the output rotor assembly structure;

[0135] A second shaft body, a middle through hole for sleeving the second shaft body is axially penetrated in the first shaft body, and a one-way transmission is arranged between the first shaft body and the second shaft body;

[0136] A magnetic part for connecting to the second shaft body and transmitting torsional force, the magnetic part includes a plurality of output rotor permanent magnet assemblies 301 and an output rotor magnetic conductive ring 302 for connecting the output rotor permanent magnet assemblies 301 to the second shaft body;

[0137] A plurality of grooves for installing the rotor permanent magnet assemblies are circumferentially arranged on the inner wall of the output rotor magnetic conductive ring 302, and the groove width of the grooves gradually decreases along the direction from the bottom to the opening;

[0138] A plurality of output rotor permanent magnet assemblies 301 are axially inserted in each groove along the second shaft body, and the output rotor permanent magnet assemblies 301 are composed of at least two permanent magnets spliced along the circumference of the second shaft body.

[0139] In the structure of the magnetic gear output rotor assembly provided by the present invention, a plurality of grooves with dovetail structures are designed on the inner wall of the output rotor magnetic conductive ring 302, and the output rotor permanent magnet assemblies 301 are fixedly attached by using epoxy resin, so that the output rotor permanent magnet assemblies 301 can be effectively fixed;

[0140] The power is transmitted to the first shaft body and the second shaft body through the one-way transmission setting, which can simplify the structure while preventing the second shaft body from being driven by the first shaft body in the reverse rotation direction;

[0141] Further, each single magnetic pole of the radially magnetized permanent magnet is evenly divided into multiple pieces and installed and fixed. That is, on the basis of the above permanent magnet assembly, each single permanent magnet is evenly divided into multiple pieces, and it is still installed and fixed at its installation position. After being divided into pieces, the permanent magnets form an integral magnetic pole for installation; thereby reducing the eddy current loss of the permanent magnet. The permanent magnet assembly of the output rotor assembly in the improved air turbine starter magnetic gear reducer is circumferentially divided into pieces, which can effectively reduce the iron loss of the permanent magnet.

[0142] In some embodiments, an extension edge is formed outward along the circumference on the outer wall of the second shaft body, and an annular groove communicating with the edge of the extension edge is provided on the inner wall of the output rotor magnetic conduction ring 302, and the annular groove communicates with the groove;

[0143] Wherein, a positioning plate is formed along the circumference on the side wall edge of the extension edge, and a rib plate abutted against the positioning plate is formed between adjacent grooves.

[0144] In this embodiment, when the second shaft body and the output rotor magnetic conduction ring 302 are installed, an extension edge is formed by extending and stretching the outer wall of the second shaft body outward, which can increase the circumferential installation dimension of the second shaft body, facilitating the installation and connection of a larger diameter output rotor magnetic conduction ring 302. The surface of the output rotor magnetic conduction ring 302 for installing the output rotor permanent magnet assembly 301 is larger, so that more output rotor permanent magnet assemblies 301 can be installed, and it is easy to cooperate with the external stator; by forming a positioning plate circumferentially on the extension edge, the annular groove can be abutted to position the output rotor magnetic conduction ring 302, and after the positioning plate abuts against the rib plate, the output rotor permanent magnet assembly 301 placed in the groove can be limited unilaterally, which helps the stable installation of the output rotor permanent magnet assembly 301.

[0145] Specifically, a notch communicating with the annular groove is provided on the end face of the output rotor magnetic conduction ring 302, and a plug block capable of being inserted into the notch is provided on the edge of the extension edge, so that the output rotor magnetic conduction ring 302 and the second shaft body with the extension edge are bite-fixed, and the plug block and the notch are fixed by screwing bolts through drilling in the axial direction of the output rotor magnetic conduction ring 302 to form a fixed assembly in the axial and radial directions.

[0146] In some embodiments, the second shaft body and the first shaft body are connected by a transmission mechanism, and the transmission mechanism is used to make the first shaft body rotate following the second shaft body rotating in a preset direction or the second shaft body does not follow the first shaft body rotating in the opposite direction.

[0147] In this embodiment, the second shaft body and the first shaft body are connected by a transmission mechanism to achieve one-way transmission, so as to achieve that the transmission mechanism is used to make the first shaft body rotate following the second shaft body rotating in a preset direction or the second shaft body does not follow the first shaft body rotating in the opposite direction, avoiding the second shaft body being driven to rotate by an external reverse torsional force.

[0148] Specifically, the transmission mechanism is an output end clutch.

[0149] Specifically, the first shaft body is the output end driven shaft 306, the second shaft body is the output main shaft 303, and the output shaft assembly includes the output main shaft 303, the output end driven shaft 306, the output shaft 305, and the output end clutch; the output end driven shaft 306 and the output shaft 305 are welded to form a driven shaft welded assembly; the driven shaft welded assembly is connected to the output main shaft 303 through the output end clutch; the output end clutch is an overrunning clutch 304, and the overrunning clutch 304 is a one-way clutch, so as to prevent the air turbine starter from being reversely driven.

[0150] In some embodiments, the end of the first shaft body near the magnetic part extends radially outward to form a first extended edge communicating with the middle through hole, and the edge of the extended edge near the second shaft body extends toward the magnetic part along the axial direction of the second shaft body to form a second extended edge;

[0151] The first extended edge, the second extended edge and the outer wall of the second shaft body jointly enclose an annular accommodating cavity with an opening;

[0152] Wherein, the transmission mechanism is installed at one end of the annular accommodating cavity near the second shaft body.

[0153] In this embodiment, the end of the first shaft body near the magnetic part is extended outward to form an L-shaped first extended edge, so as to form a circumferential annular inner table body of the first shaft body in the middle through hole. By extending the edge of the extended edge near the second shaft body toward the magnetic part, the extended edge has a Z-shaped structure on one side after being axially cut along the first shaft body, and an annular concave table body is formed on the edge near the second shaft body, and the concave table body and the annular inner table body are arranged opposite to each other, so as to cooperate with the outer wall of the second shaft body to form an annular accommodating cavity with an opening;

[0154] Setting the transmission mechanism at one end of the annular accommodating cavity near the second shaft body can directly arrange the transmission mechanism in the radial direction between the second shaft body and the first shaft body.

[0155] In some embodiments, an angular contact ball bearing B309 for connecting the second shaft body and the external housing is arranged in the annular accommodating cavity, and the outer wall of the first shaft body is connected to the external housing through an angular contact ball bearing A308, and the end face of the angular contact ball bearing A308 is connected to the first extended edge; and / or

[0156] One end of the outer wall of the second shaft body is connected to the middle through hole through a needle roller bearing A311, the other end of the second shaft body is connected to the external housing through a needle roller bearing B312, and the transmission mechanism is located between the needle roller bearing A311 and the needle roller bearing B312.

[0157] Further, bearing spacer rings 307 are respectively arranged between the two angular contact ball bearings A308 and the two angular contact ball bearings B309 to maintain the axial distance between the two bearings;

[0158] Further, a double - layer spiral snap ring for shaft 310 is arranged at one end of the angular contact ball bearing A308 close to the output shaft for axial positioning of the angular contact ball bearing A308;

[0159] Further, a double - layer spiral snap ring for hole 313 is arranged on the needle roller bearing A311 located between the first shaft body and the second shaft body for axial positioning of the needle roller bearing A311.

[0160] In some embodiments, the height and length of the permanent magnet are the same as those of the output rotor permanent magnet assembly 301 formed by it, and the width of the permanent magnet is smaller than the width of the output rotor permanent magnet assembly 301 formed by it.

[0161] In this embodiment, when multiple permanent magnets are assembled into the output rotor permanent magnet assembly 301, through lateral circumferential butt - joint arrangement and combination, the width of the rotor permanent magnet assembly increases, while the size in the length and height directions remains unchanged, so as to be installed in the groove and for continuous butt - joint installation of multiple output rotor permanent magnet assemblies 301 in the same groove.

[0162] In this embodiment, the number of pole pairs on the inner rotor is 4, the number of pole pairs on the outer rotor is 29, and the number of magnetic modulation stator blocks is 33. When parameters such as the iron core size and permanent magnet size are fixed, the specific data is shown in Table 1.

[0163] Table 1 Variation of iron loss of outer rotor permanent magnets, considering circumferential segmentation of permanent magnets

[0164]

[0165] Table 1 shows that when other conditions remain unchanged, circumferential segmentation of the output rotor permanent magnet can effectively reduce the iron loss of the permanent magnet in different working environments.

[0166] In some embodiments, the inner diameter of the output rotor magnetic conductive ring 302 is greater than the radial distance between the connection of the second shaft body sleeved on the first shaft body and the axis of the second shaft body.

[0167] In this embodiment, by making the inner diameter of the output rotor magnetic conductive ring 302 greater than the radial distance between the connection of the second shaft body sleeved on the first shaft body and the axis of the second shaft body, the rotation of the first shaft body and the second shaft body in the middle is more stable, and at the same time, increasing the force arm is beneficial to driving the first shaft body and the second shaft body.

[0168] Optionally, the structure of the magnetic gear input rotor assembly includes:

[0169] The rotor shaft is axially penetrated with a hollow part for an external shaft body to pass through; a guiding and rotating assembly is arranged on the inner wall of the hollow part and is used for restricting the axial movement between the external shaft body and the rotor shaft when there is a circumferential relative rotation between the external shaft body and the rotor shaft; a magnetic part is circumferentially arranged on the outer side wall of the rotor shaft and is used for generating magnetic force with an external stator to drive the rotor shaft to rotate circumferentially; an input rotor sheath 204 covers the outside of the magnetic part, and the distance from any point on the outer wall of the input rotor sheath 204 to the axis of the rotor shaft along the radial direction of the rotor shaft is a fixed value; wherein, the distance between each pair of corresponding points on the opposite surfaces of the external stator and the input rotor sheath 204 along the radial direction of the rotor shaft is equal.

[0170] In the structure of the magnetic gear input rotor assembly provided by the present invention, by providing the input rotor sheath 204, the magnetic part can be fixed, effectively preventing it from falling off during high-speed rotation.

[0171] When setting the distances between various surfaces, the distance from any point on the outer wall of the input rotor sheath 204 to the axis of the rotor shaft along the radial direction of the rotor shaft is a fixed value, and the distance between each pair of corresponding points on the opposite surfaces of the external stator and the input rotor sheath 204 along the radial direction of the rotor shaft is equal, so that the input rotor sheath 204 can ensure that the air gap between the input rotor and the external magnetic modulation stator has better uniformity, and further enables the aeroengine air turbine 201 starter to have better reliability, stability and working performance.

[0172] Specifically, the air turbine 201 is integrally formed on the rotor shaft.

[0173] In some embodiments, an annular groove is coaxially formed on the outer wall of the rotor shaft, and at least one is axially formed along the rotor shaft. Annular rib plates protruding from the bottom of the annular groove are formed at both ends of the annular groove along the axial direction of the rotor shaft, and the magnetic part includes an input rotor magnetic conduction ring 202 abutted against the annular rib plates; wherein, a strain cavity is formed between the input rotor magnetic conduction ring 202, the annular rib plates and the annular groove.

[0174] In this embodiment, by radially forming annular rib plates on the annular groove and abutting against the input rotor magnetic conduction ring 202, the overall support of the magnetic part is realized. By forming a strain cavity, when the rotor shaft receives a force during high-speed rotation and generates radial deformation or radial thermal expansion, the volume can be accommodated to avoid directly acting on the input rotor magnetic conduction ring 202, and further acting on the input rotor sheath 204 through the input rotor permanent magnet assembly, resulting in uneven surfaces during work.

[0175] In some embodiments, the guide assembly includes a plurality of high-speed angular contact ball bearings 206 arranged at the end of the hollow portion, and the inner end faces of adjacent high-speed angular contact ball bearings 206 are connected by a bearing retaining ring 207 to form a cover for the middle portion of the inner wall of the hollow portion; wherein the plurality of high-speed angular contact ball bearings 206 respectively correspond to the input rotor sleeve 204 and the air turbine 201 on the rotor shaft along the radial direction of the rotor shaft.

[0176] In this embodiment, the rotor shaft and the shaft body of the external output rotor can be assembled by setting up a plurality of high-speed angular contact ball bearings 206, and the two can be connected under relative rotation. The plurality of high-speed angular contact ball bearings 206 correspond to the input rotor sleeve 204 and the air turbine 201 on the rotor shaft, respectively, so that the air turbine 201 and the corresponding position of the rotor shaft corresponding to the magnetic part generating the torsional force corresponding to the input rotor sleeve 204 can be guided and supported, thereby ensuring the stability of the rotor shaft during rotation and further enhancing the uniformity of the gap between the input rotor sleeve 204 and the external stator during relative rotation.

[0177] Furthermore, the inner wall of the hollow part and the outer end surface of the high-speed angular contact ball bearing 206 are jointly installed with an input rotor damper 209 to suppress the vibration of the high-speed angular contact ball bearing 206 and reduce its collision and wear; the inner wall of the rotor shaft is equipped with a locking ring 208 for limiting the high-speed angular contact ball bearing 206.

[0178] In some embodiments, the magnetic part also includes an input rotor permanent magnet assembly 203, which is arranged between the input rotor sleeve 204 and the input rotor magnetic ring 202; the input rotor permanent magnet assembly 203 includes multiple pairs of permanent magnets arranged along the circumference of the input rotor magnetic ring 202 assembly; wherein, along the circumferential and axial directions of the input rotor magnetic ring 202, the magnetic poles of adjacent permanent magnets are different.

[0179] In this embodiment, the input rotor permanent magnet is disposed between the input rotor sleeve 204 and the input rotor magnetic ring 202, and the permanent magnet is clamped and limited by the complete inner walls of the input rotor sleeve 204 and the input rotor magnetic ring 202, thereby further ensuring the stability of the rotor permanent magnet during rotation, so that the structure is stable during long-term use.

[0180] In some embodiments, when the high-speed angular contact ball bearing 206 corresponds to the input rotor sleeve 204 along the radial direction of the rotor shaft, the high-speed angular contact ball bearing 206 corresponds to the strain cavity; and / or the docking gap between the same pair of permanent magnets and the annular ribs are staggered along the axial direction of the rotor shaft; and / or a receiving portion connected to the end face of the input rotor magnetic conductive ring 202 is provided on the rotor shaft.

[0181] In this embodiment, for the high-speed angular contact ball bearing 206 installed radially opposite to the input rotor sheath 204 along the rotor axis, by further aligning the high-speed angular contact ball bearing 206 radially with the strain cavity along the rotor axis, after the rotor axis is subjected to the eccentric force of the high-speed angular contact ball bearing 206, vibration and outward protrusion can be absorbed through the strain cavity, and by keeping away from deformation through the annular rib plate, the gap uniformity during high-speed operation is ensured, further suppressing the problem that the peak torque of the coaxial magnetic gear will decrease significantly, while the pulsating torque amplitude, starting response time, and iron loss will increase to a certain extent;

[0182] When two or more annular grooves are provided, by staggering the butt joint gap of the two butt-jointed permanent magnets axially along the rotor axis with the annular rib plate, the butt joint gaps of the annular rib plates on adjacent annular grooves are staggered from the butt joint gaps of the permanent magnets, ensuring that when the rotor axis is impacted, the gap between the stator and the input rotor sheath 204 remains stable and unchanged;

[0183] By providing a receiving portion, the input rotor magnetic conduction ring 202 can be limited and fixed, avoiding the influence of vibration generated during high-speed rotation on the position of the input rotor magnetic conduction ring 202, and making the radial relative position between the permanent magnet and the stator stable.

[0184] Specifically, the strain cavity is a ring body and gradually narrows radially outward along the ring body, such that the opposite surface of the strain cavity to the input rotor magnetic conduction ring 202 is smaller than the end surface of the strain cavity away from the input rotor magnetic conduction ring 202, so as to reduce the force applied to the input rotor magnetic conduction ring 202.

[0185] In some embodiments, an input rotor baffle 205 is assembled at one end of the outer wall of the input rotor magnetic conduction ring 202, and the input rotor baffle 205 is used to axially support the permanent magnet along the input rotor magnetic conduction ring 202; wherein, the permanent magnet is arranged in the accommodation cavity formed by the input rotor magnetic conduction ring 202, the input rotor baffle 205, and the input rotor sheath 204.

[0186] In this embodiment, by providing the input rotor baffle 205, axial support can be provided for one end of the permanent magnet, so that the position of the permanent magnet is limited in the axial direction to avoid movement caused by vibration during operation, and further, the accommodation cavity formed by the input rotor magnetic conduction ring 202, the input rotor baffle 205, and the input rotor sheath 204 is used to install and fix the permanent magnet. When there are multiple pairs of permanent magnets, it is convenient to ensure that the distances between them are equal.

[0187] In some embodiments, the permanent magnet and the input rotor magnetic conduction ring are fixed by bonding with epoxy resin glue; and / or the input rotor sheath is fixed by gap fillers and covers the outside of the permanent magnet.

[0188] In this embodiment, the strength of the structure during high-speed rotation is ensured; the carbon fiber material does not affect the distribution of the air-gap magnetic field; the uniformity of the air gap is ensured, and the negative impact of the uneven air gap on the working performance of the coaxial magnetic gear is reduced, specifically, the peak torque decreases, and the pulsating torque amplitude, starting response time, and iron loss increase.

[0189] In this embodiment, the carbon fiber sleeve is light in weight and high in tensile strength, and does not generate eddy current loss during operation. It has good temperature resistance, fast heat conduction, and is non-magnetic. It has strong dynamic balance during high-speed rotation; the permanent magnet material has a relatively large compressive strength and a very small tensile strength, specifically ≤80 MPa. In the case where the centrifugal force of the high-speed rotor becomes the main load, considering that the permanent magnet is difficult to withstand the huge centrifugal force, protection measures must be taken for the permanent magnet, and the material has certain machinability, and the smooth surface quality ensures the uniformity of the air gap.

[0190] In some embodiments, the number of pairs of permanent magnets satisfies the following relational expression: p in +p out =n s ; where n s is the number of magnetic core blocks of the magnetic tuning ring of the input rotor permanent magnet assembly, that is, the number of permanent magnets, P in is the number of pairs of permanent magnets, P out is the number of pairs of permanent magnets of the output rotor where the external shaft body is located.

[0191] In this embodiment, the speed ratio of the input and output rotors can be changed by changing the number of pole pairs to meet the required technical indicators.

[0192] In some embodiments, the magnetization angle of circumferentially adjacent permanent magnets is set to a preset angle; where the preset angle is 60°, and the single permanent magnet is magnetized by adopting the Halbach array arrangement.

[0193] In this embodiment, the air-gap magnetic field of the magnetic gear is effectively improved, and the pulsating torque is reduced; the permanent magnet Halbach array can weaken the negative effect of the non-uniform air gap while improving the basic torque performance and reducing the initial starting response time.

[0194] Optionally, the housing and the guide assembly structure include:

[0195] A housing, which is provided with an air inlet and a plurality of air outlets, and the inner wall of one end of the housing far from the air inlet is rotationally connected with the outer rotor structure;

[0196] An output rotor positioning sleeve 108, which is installed inside the housing, and the output rotor positioning sleeve 108 is sleeved on the outer wall of the outer rotor structure;

[0197] The bearing stator 103 is coaxially arranged inside the housing. The air inlet of the housing is connected to the bearing stator 103 through the turbine guide 101, and the turbine guide 101 is used for rotatably connecting the turbine;

[0198] Wherein, support parts for connecting the outer rotor structure are respectively arranged at one end of the housing far from the air inlet and the inner wall of the bearing stator 103. An annular cavity for gas flow is formed between the housing and the bearing stator 103, and the annular cavity is divided into multiple flow guide cavities by the inner rotor structure, stator structure and outer rotor structure sleeved from the inside to the outside.

[0199] The air turbine starter housing and guide assembly structure provided by the present invention has an air turbine starter housing and guide assembly that can limit the radial displacement of the rotor and improve the working performance of the starter, and can operate safely and stably under working conditions such as high speed, high temperature and high pressure. The achievable gain effect: Due to the existence of the air outlet, during the pneumatic and energy exchange process, the temperature of the expanded gas can be effectively reduced, thereby improving the working conditions and increasing the working life and reliability of the impeller. Due to the existence of the output rotor positioning sleeve 108, the radial displacement of the output rotor is restricted, so the occurrence of rubbing and resonance phenomena is avoided. The housing also plays a role in protecting the internal parts from being damaged by foreign objects, and at the same time can construct an air flow channel to improve the transmission performance.

[0200] An air outlet is provided, which can effectively control the temperature rise of the permanent magnet during the working process. In the air turbine starter, compressed air is used as the energy source to drive the turbine working blades to output power and torque, and at the same time, after expansion and cooling, it can be used as a cooling medium to cool the components in the starter cavity, ensuring that each component works under suitable temperature conditions; during the air flow process, the compressed air enters from the inlet and passes through the turbine stator vane row and rotor vane row in sequence, driving the turbine working blades to rotate. At this time, the compressed air expands and cools down, and a part of the air flows into the outside from the front end outlet of the stator outer cover, and the remaining part of the air cools the magnetic reducer part through the inner and outer air gaps and the outer flow channel on the outside of the outer rotor, and flows out through the air outlet at the rear end of the air turbine starter.

[0201] Specifically, a flow guide cone 102 is inserted at one end of the bearing stator 103 close to the air inlet;

[0202] Specifically, the outer rotor structure penetrates through one end of the housing far from the air inlet and is connected to the housing by setting a shaft end seal ring 107;

[0203] In some embodiments, 8 rollers evenly distributed in the circumferential direction are arranged on the inner cylindrical surface of the output rotor positioning sleeve. The output rotor positioning sleeve is sleeved on the outer cylindrical surface of the output rotor magnetic conductive ring, which can effectively restrict the radial displacement of the output rotor.

[0204] In this embodiment, when the starter is working, the rotational speed of the rotor will continuously increase to the critical speed, specifically 45000 rpm. When the rotor speed crosses the critical speed stage, the vibration is the most intense, and at this time, the radial displacement of the rotor is the largest. When the rotor has a large radial displacement, the positioning sleeve can effectively limit the radial displacement by sleeving on the cylindrical surface outside the output rotor magnetic conductive ring, preventing the rotor from rubbing or avoiding harmful rubbing. In an aeroengine, rubbing is generally divided into harmless rubbing and harmful rubbing. Harmless rubbing mainly has the following two characteristics: the blade vibration caused by rubbing is not large; the blade vibration caused by rubbing can gradually disappear over time. And some rubbing that causes continuous and intense blade vibration may induce more serious problems such as blade fracture and scrapping, shaft bending, and severe vibration of the whole machine. Therefore, the positioning sleeve can effectively control rubbing, and even convert harmful rubbing into harmless rubbing by controlling its intense vibration.

[0205] The positioning sleeve can also avoid resonance to a certain extent. Judging the structural design comprehensively from the critical speed and modal identification, modal calculation models are established for the inner and outer rotors respectively. The surface units of the parts where each bearing contacts the rotor are set as rigid bodies, and the calculated bearing stiffness is added to the corresponding reference points in the form of springs. The modal calculation results are interpreted. The characteristics of the first eight-order vibration modes of the inner and outer rotors are similar: the natural frequencies of the third-order and higher-order modes are much greater than the frequencies corresponding to the working speed of the rotor, so the possibility of resonance is very small.

[0206] In some embodiments, the housing includes an end cover, a first stator outer cover 104, and a second stator outer cover 105;

[0207] The diversion cavity is located inside the first stator outer cover 104 and the second stator outer cover 105, and the air outlets are circumferentially arranged on the first stator outer cover 104 and the second stator outer cover 105 respectively, and the air outlets are all located at the ends of the diversion cavity;

[0208] Among them, the end cover includes a front end cover and a rear end cover 106 provided with an exhaust gas port.

[0209] Furthermore, the connection and fixation method between the first stator outer cover and the guide is thread fixation plus riveting.

[0210] In this embodiment, adopting a segmented assembly structure for the housing can facilitate installation and design. The multi-layer divided diversion cavity is even located inside the first stator outer cover and the second stator outer cover, and then the air outlets are respectively arranged on the first stator outer cover and the second stator outer cover and correspond to the ends of the diversion cavity, so that when the gas flows inside the multi-layer diversion cavity, it can be more stable, avoiding the gas flow outside causing air flow disorder in the diversion cavity, and further ensuring the radial stability of the stator, inner rotor, and outer rotor of the divided diversion cavity.

[0211] In some embodiments, the flow guiding cavity includes: an inner air gap cavity located between the stator structure and the inner rotor structure;

[0212] an outer air gap cavity located between the stator structure and the outer rotor structure and having the same thickness as the inner air gap cavity;

[0213] an outer flow channel cavity located between the outer rotor structure and the housing, the thickness of the outer flow channel cavity being greater than that of the inner air gap cavity, and two end portions of the outer flow channel cavity being circumferentially corresponding and communicating with the air outlet respectively.

[0214] In this embodiment, the multi-layer flow guiding cavity is specifically divided into an inner air gap cavity, an outer air gap cavity and an outer flow channel cavity. Since they respectively face the inner rotor and the outer rotor on the premise of facing the same stator, and both are in a rotating state during operation, it is necessary to keep the thickness of the outer air gap cavity and the inner air gap cavity the same along the radial direction of the stator. When facing the same internal air flow condition, the simultaneous rotation of the inner rotor and the outer rotor can be kept stable;

[0215] By setting the thickness of the outer flow channel cavity to be greater than that of the inner air gap cavity and the outer air gap cavity, more space of the annular cavities in the first stator outer cover and the second stator outer cover can be borne, so as to discharge some of the flowing air from the air outlet holes on the first stator outer cover and the second stator outer cover.

[0216] In some embodiments, one end of the stator structure close to the air inlet protrudes axially beyond the inner rotor structure and the outer rotor structure; and / or

[0217] An air inlet cavity communicating with the air inlet is formed between the front end cover and the turbine, and the air inlet cavity axially corresponds to the air inlet cavity and the outer rotor structure along the bearing stator 103.

[0218] In this embodiment, by setting one end of the stator structure close to the air inlet to protrude beyond the inner rotor structure and the outer rotor structure, the air flowing into the inner air gap cavity and the outer air gap cavity can be pre-guided, and the turbulent flow at the ends of the inner air gap cavity and the outer air gap cavity close to the air inlet can be reduced, further ensuring the stability of the air flowing inside the inner air gap cavity and the outer air gap cavity;

[0219] The air inlet cavity formed by the front end cover and the turbine and communicating with the air inlet is the initial inlet flow channel for the air flowing into the housing. And the air will be pressurized in this flow channel so as to form a thrust to finally drive the turbine to rotate. Therefore, by setting the air inlet cavity to axially correspond to the air inlet cavity and the outer rotor structure along the annular cavity, the high-pressure flowing air can be prevented from directly contacting the inner rotor for internal power transmission, ensuring the stability of the subsequent force transmission.

[0220] In some embodiments, a end cover axially covering the outer rotor structure, the stator structure, the inner rotor structure and the bearing stator 103 is provided at one end of the outer rotor structure close to the exhaust port;

[0221] A current collecting cavity is provided inside the end cap and is respectively communicated with the outer air gap cavity and the outer flow channel cavity.

[0222] In this embodiment, since the outer rotor needs to finally transmit power to the coaxial output shaft, an end cap is provided to penetrate and connect the output shaft to ensure the output of power. On the other hand, when the air inside the inner air gap cavity and the outer air gap cavity gathers towards the exhaust port, it is collected first to avoid the concentrated gathering of the flowing air inside multiple cavities, which may cause internal turbulence and affect the rotating components of the device.

[0223] In some embodiments, a communication hole for communicating the current collecting and the exhaust port is axially provided on the end cap, and the communication hole is axially located between the exhaust port and the outer flow channel cavity along the annular cavity.

[0224] In this embodiment, the communication hole is provided to conduct the flowing air collected from the inner air gap cavity and the outer air gap cavity. Since the outer rotor is in a rotating state during operation, the end cap provided with the communication hole is also in a rotating state. Further, a plurality of communication holes are equally spaced along the circumferential direction of the end cap. Under the rotation of the plurality of communication holes, an intermittent conduction phenomenon will occur at the same circumferential position, avoiding the complete airflow presented by the airflow led out by the end cap, which helps the gathering between the exhaust ports to be more stable, avoids the non-corresponding conduction between multiple cavities and holes, resulting in gas disorder, and ensures the stable rotation of the high-speed rotating inner rotor and outer rotor.

[0225] In some embodiments, the output rotor positioning sleeve 108 corresponds to the air outlet on the first stator outer cover 104 along the radial direction of the bearing stator 103.

[0226] In this embodiment, since the high-pressure air introduced into the housing from the intake cavity will be shunted in multiple directions, and is respectively shunted by the air outlet on the first stator outer cover, the inner air gap cavity, the outer air gap cavity and the outer flow channel cavity, and the intake cavity corresponds to the outer rotor, which easily leads to unstable rotation of the outer rotor. Therefore, the output rotor positioning sleeve is correspondingly arranged with the air outlet. On the one hand, it can ensure the stable rotation of the outer rotor when the high-pressure air is shunted, and on the other hand, it can suppress the eccentric force generated by the outer rotor when the air is guided out from the air outlet, ensuring the stable rotation of the outer rotor.

[0227] On the other hand, the present invention also provides an analysis method for the loss characteristics of a magnetic gear, which is used to analyze the loss characteristics of the magnetic gear of the air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0228] S1. Obtain the distribution of the magnetic field of the magnetic gear, perform Fourier series decomposition on the waveform of the magnetic density amplitude (i.e., magnetic induction intensity) changing with time, and obtain the alternating frequency and magnetic density amplitude of each magnetic field harmonic;

[0229] S2. Obtain the total energy loss of the magnetic gear based on the eddy current loss model and the iron loss separation model;

[0230] Optionally, analyze the eddy current loss distribution of the inner rotor permanent magnet (i.e., the output rotor permanent magnet 301) and the outer rotor permanent magnet (i.e., the input rotor permanent magnet 203) using the eddy current loss model; analyze the core loss distribution of the inner rotor magnetic conduction ring, the outer rotor magnetic conduction ring, and the magnetic modulation ring stator using the iron loss separation model; obtain the total energy loss of the magnetic gear from the sum of the eddy current losses and core losses of the inner rotor magnetic conduction ring, the outer rotor magnetic conduction ring, the inner rotor permanent magnet, the outer rotor permanent magnet, and the magnetic modulation ring stator.

[0231] Among them, the expression of the iron loss separation model is:

[0232]

[0233] In the formula, p Fe is the core loss, p h is the hysteresis loss, p e is the eddy current loss, K e and K h are the core loss coefficients respectively, n is the magnetic field harmonic order, f is the alternating frequency of the magnetic field, ρ is the core density, V is the core volume, B nr and B nt are the radial and tangential components of the nth magnetic field harmonic respectively.

[0234] The inner rotor permanent magnet and the outer rotor permanent magnet have extremely high electrical conductivity, and the magnetic gear will generate many alternating magnetic field harmonics. When the reducer works, these harmonics cut the permanent magnet to generate strong induced eddy currents, thus forming eddy current losses. The expression of the eddy current loss model is:

[0235]

[0236] In the formula, p v is the eddy current loss, b is the width of the permanent magnet, h is the height of the permanent magnet, ρ R is the resistivity of the permanent magnet, V PM is the volume of the permanent magnet, f n is the alternating frequency of the nth magnetic field harmonic, B n is the magnetic induction intensity of the alternating magnetic field of the nth magnetic field harmonic.

[0237] The expression of the total energy loss of the magnetic gear is:

[0238] P loss = p Fe + p v .

[0239] On the other hand, the present invention also provides a method for analyzing the deformation amount of the stator core of a magnetic gear, which is used to analyze the deformation amount of the stator core of the magnetic gear of the air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0240] S1: Analyze the distribution of the magnetic field of the magnetic gear. Through electromagnetic force analysis, obtain the electromagnetic force distribution of the stator core assembly in the stator assembly structure of the magnetic gear;

[0241] It can be understood that the stator core assembly includes a plurality of stator cores, and the electromagnetic force distribution of each stator core is obtained.

[0242] S2: Model the stator core assembly in the stator assembly structure of the magnetic gear as a cantilever beam model, take its electromagnetic force distribution as an external load, and analyze the structural deformation of the stator core assembly with the help of the cantilever beam model;

[0243] The expression of the electromagnetic force of the stator core is:

[0244]

[0245] Among them, F r and F t are the radial and tangential electromagnetic forces received by the stator core respectively, L is the axial length of the coaxial magnetic gear, B r and B t are the radial and tangential magnetic flux densities of the stator core, μ0 is the air permeability, and R is the radius of the stator core.

[0246] On the other hand, the present invention also provides a method for analyzing the starting response characteristics of a magnetic gear, which is used to analyze the starting response characteristics of the magnetic gear of the air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0247] S1: Set the stable speed, test duration and step value of the driving rotor (i.e., the input rotor) of the input rotor assembly structure; obtain the speed-time curve of the driving rotor based on the stable speed, test duration and step value of the driving rotor; take the speed-time curve of the driving rotor as the driving condition of the magnetic gear;

[0248] Exemplarily, the angular acceleration of the input rotor assembly structure is 640 rpm / s;

[0249] S2: Obtain the critical value of the input angular acceleration of the magnetic gear The expression is:

[0250]

[0251] Among them, J is the moment of inertia of the rotor, t is the time, f is the damping coefficient, ω is the angular velocity, T is the input torque, and T’ is the load torque.

[0252] S3: The driving rotor uses the critical value of the input angular acceleration of the magnetic gear obtained in step 2 Load from the initial speed to the stable rotational speed set in step 1, and obtain the starting response characteristics of the magnetic gear input rotor assembly structure and the magnetic gear output rotor assembly structure under no-load and loaded conditions.

[0253] On the other hand, the present invention also provides an impact vibration analysis method for an air turbine starter based on transient dynamics after being impacted by high-pressure gas, which is used to analyze the impact vibration of the air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0254] S1: Take the pressure difference on both sides of the moving blades of the air turbine of the air turbine starter as the excitation source of the impact vibration of the air turbine starter, apply it to the pressure surface of the turbine moving blades, and continuously excite for a preset time;

[0255] S2: Use the transient dynamics calculation formula to analyze the impact vibration characteristics of the air turbine starter after being impacted by high-pressure gas.

[0256] The expression of transient dynamics in step S2 is:

[0257]

[0258] Among them, F(t) is the external load mechanism; u is the nodal displacement vector; is the nodal velocity vector; is the nodal acceleration vector; [C] is the damping matrix, [M] is the mass matrix; [K] is the stiffness matrix.

[0259] On the other hand, the present invention also provides a temperature distribution analysis method for an air turbine starter based on fluid mechanics and heat transfer, which is used to analyze the temperature distribution of the air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0260] S1: Take the iron loss generated during the magnetic gear transmission process as the heat source, use the volume heat source calculation formula to analyze the unit volume heat generation rate of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure during the magnetic gear transmission process; use the equivalent thermal conductivity calculation formula to analyze the heat dissipation performance of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure of the air turbine starter;

[0261] The expression of the volume heat source is:

[0262]

[0263] Among them, q vis a volumetric heat source, P loss is the iron loss of each component during the magnetic gear drive, V loss is the volume of the magnetic gear component that generates iron loss.

[0264] The expression for the equivalent thermal conductivity is:

[0265]

[0266] where, λ eff is the equivalent thermal conductivity, R r is the radius of the rotor surface in contact with the air gap, R s is the radius of the stator surface in contact with the air gap, R e is the air gap Reynolds number.

[0267] S2: When using computational fluid dynamics and heat transfer to analyze the axial ventilation of an air turbine starter, determine the temperature distribution of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure, and the magnetic gear stator assembly structure of the magnetic gear.

[0268] On the other hand, the present invention also provides an optimization method for the stator core shape parameters based on the response surface method and the genetic algorithm, which is used to optimize the stator core shape parameters of an air turbine starter based on magnetic deceleration. The specific steps are as follows:

[0269] S1: Determine the shape parameters to be optimized and their number K of the stator core of the coaxial magnetic gear;

[0270] Optionally, the parameters to be optimized are the outer circumferential angle, the inner circumferential angle, and the radial height of the stator core; K = 3.

[0271] S2: Obtain N sample stator core samples located in the surface area of the optimization design variable space; obtain the values of the shape parameters to be optimized for each stator core sample;

[0272] S3: Perform magnetic field and structural field simulations on all the obtained stator core samples, and obtain the maximum structural deformation amount of each stator core sample;

[0273] S4: Construct an objective function for the maximum structural deformation amount of the stator core;

[0274] The expression for the objective function of the maximum structural deformation amount D of the stator core is:

[0275] Y(D) = f(X1, X2,..., X k ); (1)

[0276] where, X k is the k-th shape parameter to be optimized of the stator core sample, k = 1, 2,..., K;

[0277] Take the reciprocal L of the maximum structural deformation as the objective function of the maximum structural deformation D of the stator core, and the expression is:

[0278] Y(L) = f(X1, X2,..., X k ); (2)

[0279] S5: Construct the constraint conditions;

[0280] S6: Based on the values of the shape parameters to be optimized and the simulated maximum structural deformation of the N sample stator core samples obtained in steps S2 and S3, use a second-order multivariate function to fit the relationship function between the reciprocal of the maximum structural deformation of the stator core and the shape parameters to be optimized of the stator core;

[0281] Use a second-order function to fit the objective function of the reciprocal L of the maximum structural deformation. The expression of the second-order function is:

[0282]

[0283] Among them, β0 is the intercept of the second-order multivariate function; β i is the coefficient of the i-th shape parameter to be optimized of the stator core; β ij is the coefficient of the product of the i-th and j-th shape parameters to be optimized of the stator core; x i is the i-th shape parameter to be optimized of the stator core, x j is the j-th shape parameter to be optimized of the stator core, i, j = 1, 2,..., K; ε is the random error;

[0284] Estimate the regression coefficient matrix β by the least squares method. The expression is:

[0285]

[0286] Among them, β is composed of the intercept β0 of the second-order multivariate function, the coefficient β i of the i-th shape parameter to be optimized of the stator core and the coefficient β ij of the product of the i-th and j-th shape parameters to be optimized of the stator core to form the regression coefficient matrix; is the regression coefficient matrix β calculated by the least squares method; X is the vector of shape parameters to be optimized; obtain the fitting relationship between the reciprocal vector of the maximum structural deformation and the vector X of shape parameters to be optimized. The expression is:

[0287]

[0288] Substitute the values of the shape parameters to be optimized and the maximum simulated structural deformation of each stator core sample into Equations (3) to (5), and obtain the relationship function Y(L)=f(X) between the reciprocal of the maximum structural deformation of the stator core and the shape parameters to be optimized of the stator core by fitting;

[0289] S7: Based on the relationship function between the reciprocal of the maximum structural deformation of the stator core and the shape parameters to be optimized of the stator core and the constraint conditions, construct an optimal shape optimization problem for minimizing the maximum structural deformation of the stator core;

[0290] S8: Use the genetic algorithm to solve the optimal shape optimization problem of the maximum structural deformation of the stator core; obtain the optimal values of the shape parameters to be optimized of the stator core corresponding to the minimum value of the maximum structural deformation of the stator core.

[0291] On the other hand, the present invention also provides a method for optimizing the arrangement of permanent magnets based on the Halbach array, which is used to optimize the arrangement of individual permanent magnets in the permanent magnet assembly of the input rotor of the magnetic gear of an air turbine starter based on magnetic deceleration, so as to improve the peak torque and transmission efficiency of the magnetic gear. The specific steps are as follows: Divide the permanent magnet assembly of the input rotor into N groups evenly along the circumferential direction of the magnetic conductive ring 202 assembly of the input rotor to obtain N groups of individual permanent magnet assemblies; each group of individual permanent magnet assemblies includes M individual permanent magnets arranged axially along the magnetic conductive ring 202 assembly of the input rotor; each group of individual permanent magnet assemblies includes M individual permanent magnets to form a complete magnetic pole with a pair of radially magnetized N poles and S poles.

[0292] Preferably, N = 4 and M = 6; at this time, the magnetization angles of the 6 individual permanent magnets of each group of individual permanent magnet assemblies of the complete magnetic pole are 0°, 300°, 240°, 180°, 120°, and 60° in the counterclockwise direction respectively.

[0293] As described above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. An air turbine starter based on magnetic deceleration, characterized in that, It includes a housing, a guide assembly structure and a magnetic gear; The magnetic gear includes a rotor, a magnetic gear stator assembly structure and a magnetic gear rotor support structure; The rotor includes an output rotor assembly structure and an input rotor assembly structure which are separately arranged in the housing and the guide assembly structure. The output rotor assembly structure is axially provided with a hollow portion for sleeve-mounting the input rotor assembly structure. The output rotor assembly structure, the magnetic gear stator assembly structure and the input rotor assembly structure are sleeved with each other and are all installed in the housing and guide assembly structure; A first annular cavity is formed between the input rotor assembly structure and the output rotor assembly structure; The output rotor assembly structure is provided with a connection portion in the circumferential direction at one end thereof which protrudes axially from the input rotor assembly structure, and an output shaft coaxial with the input rotor assembly structure is provided through the connection portion; A second annular cavity is formed between the output shaft and the input rotor assembly structure; the magnetic gear rotor support structure is arranged along the axial direction of the housing and the guide assembly structure in the second annular cavity; the magnetic gear rotor support structure is connected to the input rotor assembly structure and the output shaft respectively to support the output rotor assembly structure and the input rotor assembly structure; The magnetic gear stator assembly structure includes a stator support frame, a stator core assembly, a stator injection molded filler and a stator end plate; the stator core assembly includes a plurality of stator cores arranged at intervals; The input rotor assembly structure includes a rotor shaft, a guide assembly and a magnetic part; the magnetic part includes an input rotor permanent magnet assembly; An inner air gap and an outer air gap are respectively formed between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure.

2. The air turbine starter according to claim 1, characterized in that, One end of the first annular cavity is connected to the hollow portion, and the other end is connected to the interior of the shell and guide assembly structure; the shell and guide assembly structure is provided with a magnetic gear stator assembly structure in the first annular cavity; the connection between the magnetic gear stator assembly structure and the shell and guide assembly structure is located in the connection between the first annular cavity and the interior of the shell and guide assembly structure.

3. The air turbine starter according to claim 1, characterized in that, The housing and guide assembly structure includes a clamping portion, which is circumferentially assembled on the output shaft and located on the side of the connecting portion away from the output rotor assembly structure; wherein two sets of first support components are arranged at the assembly point of the clamping portion and the output shaft.

4. A method for analyzing the loss characteristics of magnetic gears, for analyzing the loss characteristics of magnetic gears of an air turbine starter based on magnetic deceleration as claimed in any one of claims 1 to 3, the specific steps being as follows: S1. Obtain the distribution of the magnetic field of the magnetic gear, perform Fourier series decomposition on the waveform of the magnetic flux density amplitude changing with time, and obtain the alternating frequency and magnetic flux density amplitude of each magnetic field harmonic; S2. The overall energy loss of the magnetic gear is obtained based on the eddy current loss model and the iron loss separation model.

5. A method for analyzing the deformation of the stator core of a magnetic gear, used for analyzing the deformation of the stator core of an air turbine starter based on magnetic deceleration according to any one of claims 1 to 3, the specific steps being: S1: Analyze the distribution of the magnetic field of the magnetic gear and obtain the electromagnetic tension distribution of the stator core component in the magnetic gear stator assembly structure; S2: Model the stator core assembly as a cantilever beam model; take the electromagnetic force distribution of the stator core assembly as the external load, and analyze the structural deformation of the stator core assembly based on the cantilever beam model.

6. A starting response characteristic analysis method for a magnetic gear, which is used to analyze the starting response characteristics of the magnetic gear of the air turbine starter based on magnetic deceleration according to any one of claims 1-3. The specific steps are as follows: S1: Set the stable speed, test duration and step value of the rotor shaft of the input rotor assembly structure; obtain the speed-time curve of the rotor shaft based on the stable speed, test duration and step value of the rotor shaft; take the speed-time curve of the rotor shaft as the driving condition of the magnetic gear. S2: Obtain the critical value of the input angular acceleration of the magnetic gear The expression is: Among them, J is the rotor inertia, t is the time, f is the damping coefficient, ω is the angular velocity, T is the input torque, and T' is the load torque. S3: The input angular acceleration critical value of the magnetic gear obtained by the rotor shaft in step S2 From the initial speed to the stable speed set in step S1, the starting response characteristics of the magnetic gear input rotor assembly structure and the magnetic gear output rotor assembly structure under no-load starting and load starting are obtained.

7. An impact vibration analysis method for an air turbine starter after being impacted by high-pressure gas based on transient dynamics, which is used to analyze the impact vibration of the air turbine starter based on magnetic deceleration according to any one of claims 1-3 after being impacted by high-pressure gas. The specific steps are as follows: S1: Take the pressure difference on both sides of the turbine blade of the air turbine starter as the excitation source of the impact vibration of the air turbine starter and apply it to the pressure surface of the turbine for a preset time of continuous excitation. S2: Use the transient dynamics calculation formula to analyze the impact vibration characteristics of the air turbine starter after being impacted by high-pressure gas.

8. A temperature distribution analysis method for an air turbine starter based on fluid mechanics and heat transfer, which is used to analyze the temperature distribution of the air turbine starter based on magnetic deceleration according to any one of claims 1-3. The specific steps are as follows: S1: Take the iron loss generated during the magnetic gear transmission process as the heat source, and use the volume heat source calculation formula to analyze the unit volume heat generation rate of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure during the magnetic gear transmission process; use the equivalent thermal conductivity calculation formula to analyze the heat dissipation performance of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure of the air turbine starter. S2: Use computational fluid mechanics and heat transfer to analyze the temperature distribution of the inner air gap and the outer air gap between the input rotor assembly structure, the output rotor assembly structure and the magnetic gear stator assembly structure of the magnetic gear when the air turbine starter conducts axial ventilation.

9. A stator core shape parameter optimization method based on the response surface method and genetic algorithm, which is used to optimize the stator core shape parameters of the air turbine starter based on magnetic deceleration according to any one of claims 1-3. The specific steps are as follows: S1: Determine the shape parameters to be optimized and their numbers of the stator core of the coaxial magnetic gear. S2: Obtain multiple stator core samples located in the surface area of the optimization design variable space; obtain the values of the shape parameters to be optimized for each stator core sample. S3: Conduct magnetic field and structural field simulations on all the obtained stator core samples, and obtain the maximum simulated structural deformation amount of each stator core sample. S4: Construct the objective function of the maximum structural deformation amount of the stator core. S5: Construct the constraint conditions. S6: Based on the values of the shape parameters to be optimized and the maximum structural deformation amounts obtained by simulation of multiple stator core samples in steps S2 and S3, use a second-order multivariate function to fit the relationship function between the reciprocal of the maximum structural deformation amount of the stator core and the shape parameters to be optimized of the stator core; S7: Based on the relationship function between the reciprocal of the maximum structural deformation amount of the stator core and the shape parameters to be optimized of the stator core and the constraint conditions, construct an optimal shape optimization problem for minimizing the maximum structural deformation amount of the stator core; S8: Use a genetic algorithm to solve the optimal shape optimization problem of the maximum structural deformation amount of the stator core; obtain the optimal values of the shape parameters to be optimized of the stator core corresponding to the minimum value of the maximum structural deformation amount of the stator core.

10. A method for optimizing the arrangement of permanent magnets based on Halbach arrays, which is used to optimize the arrangement of the permanent magnet assembly of the magnetic gear input rotor of the air turbine starter based on magnetic deceleration described in any one of claims 1-3, characterized in that, The specific steps are as follows: Divide the input rotor permanent magnet assembly evenly into N groups along the circumferential direction of the input rotor magnetic conductive ring assembly to obtain N groups of single permanent magnet assemblies; each group of single permanent magnet assemblies includes M single permanent magnets arranged axially along the input rotor magnetic conductive ring assembly; each group of single permanent magnet assemblies includes M single permanent magnets to form a complete magnetic pole with N poles and S poles magnetized radially in pairs.

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