Multi-layer coaxial direct drive motor assembly pretightening force optimization method and motor

Abstract

The invention relates to a multi-layer coaxial direct drive motor assembly pre-tightening force optimization method and a motor, and the method comprises the steps: S10, building a spring mass system of a multi-layer motor structure, the spring mass system of the multi-layer motor structure comprises a plurality of springs and bolt pre-tightening mechanisms which connect an upper gland and a stator together, the axial movement of the multi-layer rotor is restrained; s20, calculating a peak acceleration under the most stringent working condition according to aviation airborne vibration and impact standards; and S30, based on the vibration displacement response function and the impact response function of the spring mass system, the number and the elastic coefficient of the parallel springs are adjusted, so that the tail end displacement response displacement obtained when the external load and the peak acceleration are applied to the spring mass system is not larger than a preset numerical value. The invention provides a pre-tightening force theoretical method to guide mechanical design and assembly.

Description

Technical Field

[0001] This disclosure relates to the field of multi-layer coaxial direct drive motor technology, and in particular to a method for optimizing the assembly preload of a multi-layer coaxial direct drive motor and the motor itself. Background Technology

[0002] Traditional VICTS (Video Communications on the Move) satellite antennas employ a multi-layer coaxial large-diameter drive system using a conventional servo motor to drive a large disk (ring) via mechanical transmission methods such as synchronous belts or gears. This system suffers from problems such as a long transmission chain, low efficiency, and mechanical backlash affecting accuracy. Several improvement solutions have been proposed in existing technologies to address these issues:

[0003] For example, independent movement is achieved through multi-layer rotary supports, and permanent magnets are designed on the outside of the rotary supports to form a rotor structure, eliminating the intermediate links of traditional mechanical transmission; or, high-precision ceramic balls are used to isolate the movement between layers, so that adjacent layers form a transmission form similar to angular contact ball bearings, which improves the resistance to vibration and impact.

[0004] Although the above technologies have solved the problems of direct drive transmission and dynamic performance, the overall assembly performance of multi-layer motors still has the following shortcomings: 1) The preload distribution has not been quantitatively modeled under vibration environment. Uneven preload distribution will lead to inter-layer motion interference. In servo mode, one layer may rotate and drive another layer. 2) The quantity, location and torque of the preload directly affect the inter-layer coupling stability under vibration and shock environment. The lack of synchronous control of multiple preload mechanisms leads to assembly stress concentration. Improper assembly will lead to functional layer separation. 3) There is no theoretical calculation framework for the spring-bolt preload mechanism. There is no mathematical model for preload and vibration tolerance. There is no aviation-grade preload standard, which does not meet the quality assurance requirements of airborne products. 4) For multi-layer transmission mechanisms, there is a lack of theoretical analysis methods to guide the selection and design of assembly preload mechanisms to meet the needs of different application environments. 5) The coaxial multi-layer direct drive motor also does not consider the influence of buffer filters on vibration and shock response. Summary of the Invention

[0005] To address the aforementioned technical problems mentioned in the background section, this disclosure proposes a method for optimizing the preload of multi-layer coaxial direct-drive motor assembly to solve at least one of the above technical problems.

[0006] According to one aspect of this disclosure, a method for optimizing the assembly preload of a multi-layer coaxial direct drive motor is provided, comprising the following steps:

[0007] S10. Establish a spring mass system for a multi-layer motor structure, wherein the spring mass system for the multi-layer motor structure includes multiple springs and bolt preload mechanisms that connect the upper cover and the stator together to constrain the axial movement of the multi-layer rotor.

[0008] S20. Calculate the peak acceleration under the most stringent operating conditions based on airborne vibration and shock standards.

[0009] S30. Based on the vibration displacement response function and impact response function of the spring-mass system, adjust the number of parallel springs and the elastic coefficient so that the end displacement response displacement obtained when the external load and the peak acceleration are applied to the spring-mass system is not greater than a preset value.

[0010] Optionally, the method further includes installing a damping filter at the bottom of the multi-layer coaxial direct drive motor, the transfer function of which is:

[0011]

[0012] The values ​​of T1 and T2 are 2.0 ± 9.798i.

[0013] Optionally, the vibration displacement response function of the spring-mass system is expressed as follows:

[0014]

[0015] Where X2(s) is the end displacement response displacement, X1(s) is the amplitude of the displacement vibration spectrum, and m i Let be the mass of the motor structure at each level, c be the damping coefficient of the mass spring system, K be the elastic coefficient, and s be the Laplace operator.

[0016] Optionally, the impact response function is expressed as:

[0017]

[0018] Where X3(s) is the impact acceleration, m i The mass of each layer in a multi-layer motor structure.

[0019] Optionally, the preset value is 0.2 mm.

[0020] According to another aspect of this disclosure, a multi-layer coaxial direct drive motor implementing the method described above is also provided, comprising:

[0021] Multilayer rotor and stator;

[0022] Top cap;

[0023] A spring bolt preload mechanism is used to connect the upper cover and the stator;

[0024] A damping filter is installed at the bottom of the multi-layer coaxial direct drive motor.

[0025] Optionally, the spring bolt preload mechanism includes multiple springs and bolt preload mechanisms, wherein the multiple bolt preload mechanisms apply to multiple springs to ensure uniform assembly preload force.

[0026] Optionally, the number of springs is determined based on the hollow dimensions of the motor.

[0027] Optionally, each of the spring bolt preload mechanisms includes a spring with which a bolt engages, and the number of bolts and springs is optimized by vibration displacement response and impact response analysis.

[0028] Optionally, the multi-layer motor structure includes an upper cover, a polarization layer, a radiation layer, and a power supply layer stacked sequentially.

[0029] Compared to the prior art, the beneficial effects of this disclosure are as follows:

[0030] 1) This disclosure provides a theoretical method for the quantification of preload force, which can guide mechanical design and assembly.

[0031] 2) This disclosure ensures that the product meets the requirements of airborne vibration / shock environment (e.g., 20g peak acceleration).

[0032] 3) This disclosure reduces the risk of interlayer separation through standardized calculation and synchronous tightening process, improves the stability of the antenna under extreme conditions, and ensures production consistency and reliability.

[0033] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure.

[0034] Other features and aspects of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0035] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the specification, serve to illustrate the technical solutions of this disclosure.

[0036] Figure 1 A flowchart of the multi-layer coaxial direct drive motor assembly preload optimization method in this embodiment is shown;

[0037] Figure 2 A structural diagram of the spring-mass system of the multi-layer motor structure in this embodiment is shown;

[0038] Figure 3 A structural diagram of the spring and bolt preload mechanism in this embodiment is shown;

[0039] Figure 4 The impact test curve is shown;

[0040] Figure 5 The vibration test curve is shown;

[0041] Figure 6 The buffer filter below the antenna mounting base in this embodiment is shown;

[0042] Figure 7 A schematic diagram of the preload force effect of the antenna multilayer mechanism in this embodiment is shown;

[0043] Figure 8 A structural diagram of the synchronous multi-axis tightening mechanism in this embodiment is shown. Detailed Implementation

[0044] Various exemplary embodiments, features, and aspects of this disclosure will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0045] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0046] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0047] Furthermore, to better illustrate this disclosure, numerous specific details are set forth in the following detailed description. Those skilled in the art will understand that this disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art have not been described in detail in order to highlight the main points of this disclosure.

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0049] This disclosure proposes a method for optimizing the preload force during assembly of a multi-layer coaxial direct-drive motor. Figure 1 A flowchart is shown for a method to optimize the preload force in the assembly of a multi-layer coaxial direct drive motor. The method includes:

[0050] S10. Establish a spring-mass system for a multi-layer motor structure, such as... Figure 2 As shown, the spring-mass system of the multi-layer motor structure includes multiple springs and bolt preload mechanisms 3 that connect the upper cover 1 and the stator 2 together to constrain the axial movement of the multi-layer rotor; as Figure 3 As shown, the spring and bolt preload mechanism 3 consists of a bolt 31 and a spring 32.

[0051] S20. Calculate the peak acceleration under the most stringent operating conditions based on airborne vibration and shock standards.

[0052] Figure 4 The impact test curves for relevant equipment are specified in "RTCA / DO160-G" regarding environmental conditions and experimental procedures for airborne equipment. Here, D represents the nominal pulse duration; A represents the nominal peak pulse acceleration; T1 is the shortest time for which the pulse should be monitored when generated by a standard pulse testing machine; and T2 is the shortest time for which the pulse should be monitored when generated by a vibration table. The test process is divided into standard operating impact, low-frequency operating impact, crash safety impact, and low-frequency crash safety impact. The peak acceleration of the standard operating impact is 6g, and the nominal pulse duration is 11ms; the peak acceleration of the crash safety impact is 20g, and the nominal pulse duration is 11ms. The antenna spring preload system is designed considering the most stringent operating conditions, i.e., a peak acceleration of 20g and a nominal pulse duration of 11ms.

[0053] Figure 5 The vibration test curves for relevant equipment specified in the "RTCA / DO160-G" environmental conditions and experimental procedures for airborne equipment are divided into standard random vibration curves and reinforced random vibration curves. Both vibration tests must be met for direct-drive VICTS antennas.

[0054] S30. Based on the vibration displacement response function and impact response function of the spring-mass system, adjust the number of parallel springs and the elastic coefficient so that the end displacement response displacement obtained when the external load and the peak acceleration are applied to the spring-mass system is not greater than a preset value.

[0055] As an optional implementation, a damping filter is also included at the bottom of the multi-layer coaxial direct drive motor, such as... Figure 6 As shown, a buffer filter 5 is installed below the direct-drive VICTS antenna mounting base 4 to reduce the vibration and impact of moving vehicles such as aircraft on the antenna. The transfer function of the damping filter is:

[0056]

[0057] Based on engineering experience, the center frequency of the shock absorber should not exceed 10Hz, the damping ratio should be 0.2 (polyurethane or modified nitrile rubber), and the values ​​of T1 and T2 should be 2.0±9.798i.

[0058] As an optional implementation, the vibration displacement response function of the spring-mass system is expressed as follows:

[0059]

[0060] Where X2(s) is the end displacement response displacement, X1(s) is the amplitude of the displacement vibration spectrum, and m i Let be the mass of the motor structure at each level, c be the damping coefficient of the mass spring system, K be the elastic coefficient, and s be the Laplace operator.

[0061] Figure 7 This is a schematic diagram of the preload force in the multi-layer antenna structure. The multi-layer antenna structure is connected by planar rotational supports, forming a relative motion mechanism. There are no rigid connections. Figure 7 In the case of M1 and M2, under external vibration loads, if the vibration acceleration exceeds the acceleration of M1 or M2 under preload (combined with gravity in a vertical state), interlayer separation will occur, causing antenna malfunction or even damage. In the dynamic response, the bandwidth of the oscillation system formed by M1+M2 and the spring is smaller than that of the system formed by M1 and the spring. Therefore, above the lower system bandwidth, the mass block will detach, resulting in relative displacement.

[0062] 1. With the assistance of a damping filter, Figure 5 The enhanced random vibration curve is used as the input to the synthetic system composed of transfer functions, when m i When choosing different combinations, with the goal of the maximum relative displacement response not exceeding 0.2mm, select an appropriate number of parallel springs and spring constant K.

[0063] for Figure 4 The impact test curves shown focus on the most severe scenario, i.e., impact in the vertical direction. Clearly, in static analysis, the inertial force generated by the impact acceleration on each layer of the antenna should be less than the spring preload, i.e., the inertial force is less than the number of springs * elastic coefficient * spring compression. The spring compression is then obtained and converted into bolt preload or preload displacement. The impact response function is expressed as:

[0064]

[0065] Where X3(s) is the impact acceleration, m i The mass of each layer in a multi-layer motor structure.

[0066] Will Figure 4 The impact signal shown is expressed as follows during a crash safety impact:

[0067]

[0068] The maximum amplitude of the system's impact dynamic response under the action of the damping filter can be obtained, thus confirming that the spring preload or preload displacement also meets the impact dynamic response requirements. Therefore, we have selected a suitable number of parallel preload springs and obtained a suitable preload value, and then adopted... Figure 8 The synchronous multi-axis tightening mechanism shown completes the spring preload.

[0069] According to another aspect of this disclosure, such as Figure 2-3 As shown in Figures 6 and 7, a multi-layer coaxial direct drive motor implementing the method described in the above embodiments is also provided, comprising:

[0070] Multilayer rotor and stator 2;

[0071] Upper pressure cap 1;

[0072] Spring bolt preload mechanism 3 is used to connect the upper cover 1 and the stator 2;

[0073] Damping filter 5 is installed at the bottom of the multi-layer coaxial direct drive motor.

[0074] The spring bolt preload mechanism includes multiple springs and bolt preload mechanisms 3, wherein the multiple bolt preload mechanisms 3 apply to multiple springs 32 to ensure uniform assembly preload force.

[0075] The number of springs 32 is determined based on the hollow dimensions of the motor.

[0076] Each of the spring bolt preload mechanisms includes a bolt 31 and a spring 32 that engages with it. The number of bolts 31 and springs 32 is obtained by optimization analysis of vibration displacement response and impact response.

[0077] The multi-layer motor structure includes an upper cover, a polarization layer, a radiation layer, and a power feeding layer stacked sequentially.

[0078] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than those shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0079] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for optimizing the preload force in the assembly of a multi-layer coaxial direct-drive motor, characterized in that, Includes the following steps: S10. Establish a spring mass system for a multi-layer motor structure, wherein the spring mass system for the multi-layer motor structure includes multiple springs and bolt preload mechanisms that connect the upper cover and the stator together to constrain the axial movement of the multi-layer rotor. S20. Calculate the peak acceleration under the most stringent operating conditions based on airborne vibration and shock standards. S30. Based on the vibration displacement response function and impact response function of the spring-mass system, adjust the number of parallel springs and the elastic coefficient so that the end displacement response displacement obtained when the external load and the peak acceleration are applied to the spring-mass system is not greater than a preset value.

2. The method according to claim 1, characterized in that, It also includes installing a damping filter at the bottom of the multi-layer coaxial direct drive motor, the transfer function of which is: The values ​​of T1 and T2 are 2.0 ± 9.798i.

3. The method according to claim 2, characterized in that, The vibration displacement response function of the spring-mass system is expressed as follows: Where X2(s) is the end displacement response displacement, X1(s) is the amplitude of the displacement vibration spectrum, and m i Let be the mass of the motor structure at each level, c be the damping coefficient of the mass spring system, K be the elastic coefficient, and s be the Laplace operator.

4. The method according to claim 3, characterized in that, The impact response function is expressed as: Where X3(s) is the impact acceleration, m i The mass of each layer in a multi-layer motor structure.

5. The method according to claim 4, characterized in that, The preset value is 0.2mm.

6. A multi-layer coaxial direct-drive motor implementing the method as described in any one of claims 1-5, characterized in that, include: Multilayer rotor and stator; Top cap; A spring bolt preload mechanism is used to connect the upper cover and the stator; A damping filter is installed at the bottom of the multi-layer coaxial direct drive motor.

7. The multi-layer coaxial direct drive motor according to claim 6, characterized in that, The spring bolt preload mechanism includes multiple springs and bolt preload mechanisms, wherein the multiple bolt preload mechanisms apply to multiple springs to ensure uniform assembly preload force.

8. The multi-layer coaxial direct drive motor according to claim 7, characterized in that, The number of springs is determined based on the hollow dimensions of the motor.

9. The multi-layer coaxial direct drive motor according to claim 7, characterized in that, Each of the spring bolt preload mechanisms includes a spring with which a bolt engages, and the number of bolts and springs is optimized by vibration displacement response and impact response analysis.

10. The multi-layer coaxial direct drive motor according to claim 7, characterized in that, The multi-layer motor structure includes an upper cover, a polarization layer, a radiation layer, and a power supply layer stacked sequentially.

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