Structure of bearing integrated axial rotary transformer

Abstract

The application provides a novel structure of bearing integrated axial rotating transformer, aiming at solving the problems of low precision, poor stability, difficult heat dissipation and complex manufacturing of traditional rotating transformer, and belongs to the field of motor structure. The structure comprises upper and lower stator discs and a double-sided magnetic resistance bearing rotor arranged between the two stator discs. The stator discs are multilayer PCB windings manufactured by using photoetching process, ensuring high precision and mass production. The rotor integrates the rotor part of silicon steel sheet and the high-strength alloy steel bearing part, forms fine and coarse double channels, and can be directly sleeved on the motor shaft, realizing zero-error coaxial rotation and high rigidity. An axial through hole is formed on the rotor, combined with the flow guide port of the stator disc and the drainage groove on the surface of the rotor, forming a high-efficiency cooling airflow channel. The temperature sensor integrated on the PCB can realize real-time thermal compensation and overheat protection. The application is suitable for the application of rotating transformer.

Description

Technical Field

[0001] This invention belongs to the field of motor structure technology, specifically relating to the structure of a bearing-integrated axial rotary transformer. Background Technology

[0002] Rotary transformers, as high-precision angle measurement sensors, exhibit significant technological advantages in the field of position detection due to their unique electromagnetic induction principle and mechanical structure. Improving accuracy and extending their service life are key issues in rotary transformer research.

[0003] However, traditional rotary transformers have a series of inherent defects in structure, performance, and manufacturing processes, limiting their application in scenarios requiring higher precision, harsher environments, and more compact designs. Specifically, traditional structures typically treat the rotary transformer as a separate unit, connecting and fixing it to the motor shaft via mechanical components such as couplings and mounting flanges. This split-type installation method inevitably introduces additional mechanical transmission links between the motor shaft and the rotary transformer rotor. The accumulated assembly errors, connection gaps, and wear after long-term operation of these links can lead to a deviation between the actual rotation center of the rotor and the motor shaft, i.e., coaxiality error, which directly affects the absolute accuracy and long-term stability of angle measurements.

[0004] In terms of mechanical stability, traditional split bearing support structures are prone to rotor shaft misalignment when subjected to axial or radial forces transmitted from the motor end, leading to uneven or even dynamic changes in the air gap between the stator and rotor. Changes in the air gap directly alter the electromagnetic coupling coefficient, causing fluctuations in the output signal amplitude, introducing measurement errors, and easily inducing rotor eccentric vibration during high-speed rotation. Furthermore, the complex multi-component assembly structure not only results in a large overall size and high material and processing costs, but also makes the air gap uniformity dependent on the superposition accuracy of multiple components, making control difficult. This structure typically has a low natural frequency, making it prone to resonance or relative fretting between components under external vibration or impact conditions. This reduces reliability and couples mechanical vibration noise into the electrical signal, affecting the signal-to-noise ratio.

[0005] In terms of thermal management, traditional rotary transformers, especially stators using precision wire winding technology, suffer from poor heat dissipation paths, resulting in significant temperature rise in the windings. High temperatures can alter the resistance and insulation properties of the windings, and even cause thermal deformation, leading to drift in electrical parameters and decreased accuracy, thus limiting their continuous operating power density.

[0006] In terms of manufacturing and functional expansion, the production of traditional wound stators relies on manual or semi-automatic winding and embedding processes, making it difficult to guarantee consistency, resulting in low production efficiency, and the pole ratio design is limited by the process. The discretely mounted two-phase windings cannot guarantee absolute mechanical concentricity and electrical orthogonality, becoming one of the bottlenecks in accuracy. Furthermore, traditional structures cannot integrate real-time, direct temperature monitoring functions, making it impossible to effectively compensate for thermally induced errors.

[0007] In summary, traditional rotary transformers face numerous challenges in terms of structure, thermal management, manufacturing processes, and functional integration in order to meet the demands of modern industrial applications for higher precision, longer lifespan, stronger environmental adaptability, and better economic efficiency. Therefore, an innovative design solution is urgently needed to address these issues from the fundamental levels of structural integration, manufacturing process innovation, and functional intelligence. Summary of the Invention

[0008] This invention aims to provide a structure for an axial rotary transformer with an integrated bearing. By integrating the bearing with the rotor and directly and rigidly connecting it to the motor shaft, and combining it with the photolithography process of the PCB stator disk and integrated design, it achieves collaborative innovation from three levels: structure, manufacturing and function, fundamentally solving the shortcomings of traditional rotary transformers in terms of accuracy, stability, heat dissipation and manufacturability.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] In a first aspect, the present invention provides a structure for an axial rotary transformer with an integrated bearing, the structure comprising an upper stator disk, a lower stator disk, and a double-sided reluctance bearing rotor disposed between the two.

[0011] Both the upper stator disk and the lower stator disk are PCB stator disks, employing a multi-layer PCB winding structure;

[0012] The double-sided reluctance bearing rotor is a structure that integrates the bearing and the rotor into one unit. It integrates a rotor part and a bearing part. The rotor part, together with the upper stator disk and the lower stator disk, respectively constitutes a fine channel rotary transformer and a coarse channel rotary transformer. The bearing part is used to be directly mounted on the motor shaft to eliminate intermediate mechanical transmission links.

[0013] The double-sided reluctance bearing rotor has a rotor axial through hole, and the upper stator disk and the lower stator disk have stator axial through holes at the positions corresponding to the rotor axial through holes. The stator axial through holes of the upper stator disk and the lower stator disk are respectively formed with upper and lower guide ports. The upper and lower guide ports are connected with the rotor axial through holes to form a cooling airflow channel, forming a cooling cycle of air inlet at the lower stator disk guide port - air outlet at the rotor axial through hole - air outlet at the upper stator disk guide port.

[0014] The rotor disk of the double-sided reluctance bearing rotor has a surface drainage groove near the center hole to break the plane, allowing the airflow to diffuse more easily and flow to the rotor axial through hole and the stator axial through hole, preventing local hot air stagnation.

[0015] Furthermore, the rotor portion of the aforementioned double-sided reluctance bearing rotor is made of stacked silicon steel sheets, with fine channel rotor slots and coarse channel rotor slots on its front and back sides respectively. The fine channel rotor slots correspond to the upper stator disk to form a fine channel rotary transformer, and the coarse channel rotor slots correspond to the lower stator disk to form a coarse channel rotary transformer.

[0016] Furthermore, the aforementioned fine-channel rotary transformer and coarse-channel rotary transformer can achieve single-channel operation by inputting different signals.

[0017] Furthermore, the aforementioned fine channel rotor has a 64-tooth slot structure, and the aforementioned coarse channel rotor has a 16-tooth slot structure, and the slot structure satisfies a sinusoidal reluctance pattern.

[0018] Furthermore, the bearing portion of the aforementioned double-sided reluctance bearing rotor includes: an inner side of a non-magnetic high-strength alloy steel bearing disposed on the outer side of the rotor body, wherein the inner side of the bearing is machined with an inner ring raceway of an angular contact bearing; an independent outer ring; and bearing steel balls installed between the inner ring raceway and the outer ring.

[0019] Furthermore, the upper stator plate and the lower stator plate are fixed to the sensor housing by screws or clips, and the two are arranged parallel to each other.

[0020] Furthermore, the multi-layer PCB winding of the aforementioned PCB stator disk includes: a first layer of excitation winding, a second layer of sine winding, a third layer of cosine winding, and a fourth layer of excitation winding.

[0021] Furthermore, a temperature sensor is provided in the winding area of ​​the upper or lower stator disk. The temperature sensor is used to detect the temperature in real time and provide data for angle compensation, and also serves as a monitoring point for the operating temperature of the motor winding.

[0022] Furthermore, the opening direction of the above-mentioned rotor axial through holes is parallel to the direction of the motor shaft center axis, and the rotor axial through holes are evenly arranged around the center of the rotor disk to achieve rotor balance under high-speed operation.

[0023] The stator axial through-hole is opened in the non-effective working area of ​​the PCB winding to avoid affecting the signal integrity of the PCB winding.

[0024] The specific flow rate of the cooling cycle is dynamically adjusted based on data obtained from the temperature sensor.

[0025] Secondly, the present invention also provides an angle measurement and compensation method based on the structure of the bearing-integrated axial rotary transformer described above, wherein the method is as follows:

[0026] High-frequency sinusoidal signals are input to the excitation windings of the upper and lower stator disks to establish a stable alternating magnetic field in the air gap between the stator and the rotor with double-sided reluctance bearings.

[0027] When the rotor of the double-sided reluctance bearing, which is directly connected to the motor shaft, rotates with the motor, the sinusoidal reluctance pattern on its two sides spatially modulates the alternating magnetic field.

[0028] Two high-frequency induced signals, which follow the sine and cosine function relationship of the rotor instantaneous angle, are generated through the sine and cosine windings on the upper and lower stator disks.

[0029] The absolute angle of the double-sided reluctance bearing rotor is calculated in real time based on the amplitude ratio of the two high-frequency induction signals.

[0030] The temperature data of the PCB winding is acquired in real time by a temperature sensor, and the calculated absolute angle is compensated for in real time based on the temperature data.

[0031] The beneficial effects of this invention are as follows:

[0032] 1. This invention addresses the shortcomings of traditional rotary transformers by providing a bearing-integrated axial rotary transformer structure. Compared to traditional rotary transformer structures, the rotor is directly mounted on the motor shaft via an integrated bearing, eliminating all intermediate mechanical transmission links. This allows for ideal coaxial rotation with zero error to the motor shaft. Furthermore, the pre-tightened integrated bearing provides excellent bidirectional axial and radial stiffness. This results in minimal air gap change when the rotor is subjected to axial or radial forces from the motor end, ensuring signal amplitude stability and preventing eccentricity during high-speed rotation. The reduced number of parts leads to a more compact structure, saving materials and reducing processing time. With the integrated design, air gap uniformity is primarily ensured by the rotational accuracy of the motor shaft and the machining accuracy of the stator disk mounting surface, both of which are easier to control, significantly improving the accuracy of the rotary transformer. The rigid connection and compact structure give the entire assembly a higher natural frequency, making it less susceptible to resonance from external vibrations. In impact environments, the relative movement between components is smaller, resulting in higher reliability. A more stable air gap leads to a more stable electrical signal amplitude, reducing electrical noise caused by mechanical vibration. Traditional rotary transformers suffer from heat dissipation difficulties, and high temperatures can cause a decline in PCB winding performance. Forced cooling can be achieved by introducing gas through the inlet, allowing the rotary transformer to operate at higher current densities. Simultaneously, protective gas can be introduced through the inlet, enabling the rotary transformer to operate in harsh environments. Since the rotary transformer directly reflects the condition of the bearing, changes in its output signal can predict bearing wear, providing data support for condition monitoring and predictive protection.

[0033] 2. Compared with traditional rotary transformers, this invention utilizes photolithography to mass-produce the PCB stator disk, greatly simplifying the production process. The PCB stator disk allows for precise control of signal orthogonality, improving the accuracy of the rotary transformer from the source. In terms of control, different input signals can enable single-channel operation of a dual-channel rotary transformer (fine-channel and coarse-channel). PCB technology can easily achieve higher, more complex, and non-integer pole ratios while maintaining consistent accuracy. The PCB stator disk ensures absolute concentricity of the mechanical axes of the two windings, eliminating concentricity errors caused by separate installations. In addition to the signal windings, temperature sensor traces can be etched onto the PCB for real-time, direct measurement of stator disk hotspot temperatures. The controller can compensate for angle errors caused by thermal deformation based on this temperature in real time, or actively reduce the excitation voltage or frequency to suppress temperature rise under high loads. The smooth and flat surface of the PCB stator disk, along with the airflow channels, allows cooling air to flow evenly and efficiently across the entire heating surface and rotor air gap. This enables the system to withstand higher continuous power densities. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of an axial rotary transformer with an integrated bearing as described in this invention;

[0036] Figure 2 This is a schematic diagram of the rotor part structure described in this invention;

[0037] Figure 3 This is a schematic diagram of the bearing structure described in this invention;

[0038] Figure 4 This is a schematic diagram of the rotor structure of the double-sided reluctance bearing described in this invention.

[0039] Among them, 1-upper stator disk, 2-double-sided reluctance bearing rotor, 3-lower stator disk, 4-temperature sensor, 5-bearing part, 6-rotor axial through hole, 7-surface drainage groove, 8-stator axial through hole. Detailed Implementation

[0040] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. The following examples will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

[0041] Implementation Method 1: Combination Figures 1 to 4 This embodiment aims to provide a structure for an axial rotary transformer with an integrated bearing. By integrating the bearing with the rotor and directly and rigidly connecting it to the motor shaft, and combining it with the photolithography process and integrated design of the PCB stator disk, this embodiment achieves collaborative innovation from three levels: structure, manufacturing, and function. This fundamentally solves the shortcomings of traditional rotary transformers in terms of accuracy, stability, heat dissipation, and manufacturability.

[0042] like Figure 1 As shown, the structure of a bearing-integrated axial rotary transformer includes an upper stator disk 1, a lower stator disk 3, and a double-sided reluctance bearing rotor 2 disposed between the two.

[0043] Both the upper stator disk 1 and the lower stator disk 3 are PCB stator disks, and adopt a multi-layer PCB winding structure;

[0044] The double-sided reluctance bearing rotor 2 is a structure that integrates the bearing and the rotor. It integrates a rotor part and a bearing part 5. The rotor part, the upper stator disk 1, and the lower stator disk 3 respectively constitute a fine channel rotary transformer and a coarse channel rotary transformer. The bearing part 5 is used to be directly mounted on the motor shaft to eliminate intermediate mechanical transmission links.

[0045] The double-sided reluctance bearing rotor 2 is provided with a rotor axial through hole 6. The upper stator disk 1 and the lower stator disk 3 are provided with stator axial through holes 8 at the positions corresponding to the rotor axial through hole 6. Upper and lower guide ports are formed at the stator axial through holes 8 of the upper stator disk 1 and the lower stator disk 3, respectively. The upper and lower guide ports are connected with the rotor axial through hole 6 to form a cooling airflow channel, forming a cooling cycle of air inlet at the lower stator disk guide port - air outlet at the rotor axial through hole 6 - air outlet at the upper stator disk guide port.

[0046] The rotor disk of the double-sided reluctance bearing rotor 2 has a surface drainage groove 7 near the center hole. This groove breaks the plane and allows the airflow to diffuse more easily, flowing towards the rotor axial through hole 6 and the stator axial through hole 8, thus preventing local hot air from stagnating.

[0047] Furthermore, the double-sided reluctance bearing rotor 2 proposed in this invention will be described;

[0048] Figure 4 The diagram shown is a structural diagram of a double-sided reluctance bearing rotor 2. It can be seen that the double-sided reluctance bearing rotor 2 is divided into a rotor section and a bearing section 5, and the two are integrated into a single design; wherein, as... Figure 2 As shown, the rotor material in the rotor section is made of laminated silicon steel sheets, and its front and back sides are precision machined. The front rotor surface is a fine-channel rotor with 64 slots, and the back rotor surface is a coarse-channel rotor with 16 slots. The slot structure of both conforms to the sinusoidal reluctance pattern, and they correspond to the upper stator disk 1 and the lower stator disk 3 to form a fine-channel rotary transformer and a coarse-channel rotary transformer, respectively; as shown... Figure 3 As shown, in bearing section 5, a non-magnetic high-strength alloy steel bearing is installed on the outside of the rotor body. The inner raceway of the angular contact bearing is machined through precision machining. An independent outer ring of the bearing is a separate part, and the bearing steel balls are installed between the inner raceway of the rotor and the outer ring of the bearing.

[0049] Through the above design, the rotor of the rotary transformer described in this invention is directly mounted on the motor shaft via an integrated bearing, eliminating all intermediate mechanical transmission links. This allows for ideal coaxial rotation with zero error to the motor shaft. Furthermore, the pre-tightened integrated bearing provides excellent bidirectional axial and radial stiffness. This results in minimal air gap change when the rotor is subjected to axial or radial forces from the motor end, ensuring signal amplitude stability and preventing eccentricity during high-speed rotation. The reduced number of parts and more compact structure saves materials and reduces processing time. With the integrated design, air gap uniformity is primarily ensured by the rotational accuracy of the motor shaft and the machining accuracy of the stator disk's mounting surface, both of which are easier to control, significantly improving the accuracy of the rotary transformer. The rigid connection and compact structure give the entire assembly a higher natural frequency, making it less susceptible to resonance from external vibrations. In impact environments, the relative movement between components is smaller, resulting in higher reliability. A more stable air gap leads to a more stable electrical signal amplitude, reducing electrical noise caused by mechanical vibration.

[0050] Furthermore, the upper stator plate 1 and the lower stator plate 3 are directly fixed to the sensor housing by screws or clips. The two stator plates need to be precision machined to ensure that they are parallel to each other. Both the upper and lower stator plates use multi-layer PCB windings. The first layer is the excitation winding, the second layer is the sine winding, the third layer is the cosine winding, and the fourth layer is the excitation winding. By giving different signals to the PCB windings on the upper and lower stator plates, the dual-channel rotary transformer (fine channel rotary transformer and coarse channel rotary transformer) can achieve single-channel operation under special working conditions. At the same time, a temperature sensor 4 is installed near the winding.

[0051] The PCB stator disk proposed in this invention can be mass-produced using photolithography technology, greatly simplifying the production process. The PCB stator disk can precisely control the orthogonality of signals, improving the accuracy of the rotary transformer from the source. In terms of control, by inputting different signals, a dual-channel rotary transformer can achieve single-channel operation. PCB technology can easily achieve higher, more complex, and non-integer pole ratios while maintaining consistent accuracy. The PCB stator disk ensures the absolute concentricity of the mechanical axes of the two windings, eliminating concentricity errors caused by separate installations. In addition to the signal windings, temperature sensor traces can be etched onto the PCB for real-time, direct measurement of stator disk hotspot temperatures. The controller can compensate for angle errors caused by thermal deformation in real time based on this temperature, or actively reduce the excitation voltage or frequency to suppress temperature rise under high loads. The smooth and flat surface of the PCB stator disk, along with the airflow guides, allows cooling airflow to uniformly and efficiently pass over the entire heating surface and rotor air gap. This enables the system to withstand higher continuous power densities.

[0052] Furthermore, temperature sensor 4 uses a PTM117 digital temperature sensor, installed near the sine and cosine windings of the excitation winding. Real-time temperature data is used to control the calculated angle compensation, improving accuracy across the entire temperature range. Simultaneously, the rotary transformer is coaxially connected to the motor, ensuring a tight fit. This temperature point can also serve as a monitoring point for the motor winding's operating temperature, providing overheat warning and protection. Through temperature sensor 4, when the temperature is too high and damages the rotary transformer's PCB windings, the signal to one of the upper or lower stator disks can be cut off, allowing the rotary transformer to switch to single-channel operation. After cooling, the signal is re-inputted, enabling the rotary transformer to return to dual-channel operation.

[0053] Furthermore, such as Figure 1 As shown, the opening direction of the rotor axial through hole 6 is parallel to the direction of the motor shaft center axis. The double-sided reluctance bearing rotor 2 is directly mounted on the motor shaft through the bearing part 5. Therefore, by making the opening direction of the rotor axial through hole 6 parallel to the direction of the motor shaft center axis, and cooperating with the design of the rotor axial through holes 6 being evenly distributed around the center of the rotor disk, the dynamic balance of the double-sided reluctance bearing rotor 2 under high-speed operation can be guaranteed. The stator axial through hole 8 is opened in the non-effective working area of ​​the PCB winding to avoid affecting the signal integrity of the PCB winding. The stator axial through holes 8 of the upper stator disk 1 and the lower stator disk 3 respectively form upper and lower guide ports. The upper and lower guide ports are connected with the rotor axial through hole 6 to form a cooling airflow channel, forming a cooling cycle of air inlet at the lower stator guide port - air inlet at the rotor axial through hole 6 - upper air gap - air outlet at the upper stator guide port. The upper air gap is the axial gap between the front side of the double-sided reluctance bearing rotor 2 and the upper stator disk 1. The specific flow rate is adjusted according to the data obtained from the temperature sensor 4.

[0054] Furthermore, such as Figure 1 As shown, the rotor disk of the double-sided magnetic reluctance bearing rotor 2 has a surface drainage groove 7 near the center hole. Its main function is to break the plane and allow the airflow to diffuse more easily and flow to the rotor axial through hole 6 and the stator axial through hole 8 to prevent local hot air from stagnating.

[0055] Traditional rotary transformers suffer from heat dissipation difficulties, and high temperatures can lead to a decline in the performance of PCB windings. This invention introduces gas through a flow channel for forced cooling, allowing the rotary transformer to operate at higher current densities. At the same time, protective gas can be introduced through the flow channel, enabling the rotary transformer to operate in harsh environments. Since the rotary transformer directly reflects the condition of the bearing, changes in its output signal can predict bearing wear, providing data support for condition detection and predictive protection.

[0056] In summary, the bearing-integrated axial rotary transformer proposed in this invention integrates the rotor of the rotary transformer with the bearing, making the rotor itself a bushing that can be directly fitted onto the motor bearing. This eliminates all intermediate mechanical transmission links in traditional rotary transformers, significantly improving absolute positioning accuracy and providing the system with extremely high torsional rigidity. Structurally, this highly integrated design greatly reduces axial installation space and lowers the overall system mass, making it better suited for working environments with stringent space and weight requirements. Furthermore, this invention eliminates a series of standard components such as couplings and independent bearing housings, simplifying the assembly process and enabling… By reducing potential failure points and improving signal purity and reliability under vibration through a more stable mechanical structure, the system achieves greater reliability. The airflow channels on the PCB stator allow the cooling medium to flow directly through the air gap and PCB surface, resulting in more uniform temperature distribution in the magnetic circuit and windings, and reducing errors caused by thermal deformation. The rotor disc features surface drainage grooves, primarily designed to break up the plane and allow airflow to diffuse more easily, flowing towards the axial through-holes and preventing localized heat stagnation. Temperature sensors mounted on the PCB stator simultaneously monitor the temperature data of both the PCB windings and the motor windings in real time, compensating for the accuracy of the rotary transformer, making the cooling system more efficient, predicting faults, and ultimately enhancing system reliability.

[0057] Implementation Method 2: This implementation method provides a detailed explanation of the working principle and application of the bearing-integrated axial rotary transformer described in this invention.

[0058] The structure of the bearing-integrated axial rotary transformer described in this invention enables angle measurement and compensation, as detailed below:

[0059] A high-frequency sinusoidal signal is input into the excitation windings of the upper and lower stator disks. This signal establishes a stable alternating magnetic field in the air gap between the stator and rotor. Since the double-sided reluctance bearing rotor of the rotary transformer of this invention is directly connected to the motor shaft, when the motor rotates, it drives the double-sided reluctance bearing rotor to rotate synchronously. The sinusoidal reluctance pattern on its surface continuously modulates the air gap magnetic field. At this time, the sine and cosine windings on the upper and lower stator disks cut the magnetic field, inducing two high-frequency signals. These signals strictly follow the sine and cosine function relationship of the rotor's instantaneous angle, thus encoding the mechanical position information into the electrical signal. The subsequent decoding circuit can extract and compare the amplitude ratio of these two signals to calculate the absolute angle of the rotor in real time.

[0060] When the rotary transformer is working, the PCB windings generate heat, which is accurately captured by the temperature sensor. Through calculation, the temperature of the windings on the PCB stator disk can be read instantly. The flow rate of the cooling medium can be artificially increased to compensate for the accuracy of the rotary transformer in real time.

[0061] The above description of the technical solution provided by the present invention through several specific embodiments is intended to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above-described specific embodiments are not intended to limit the present invention. Any reasonable modifications and improvements to the present invention, reasonable combinations of implementation methods and equivalent substitutions based on the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A structure of an axial rotary transformer with integrated bearing, characterized in that, It includes an upper stator disk (1), a lower stator disk (3), and a double-sided reluctance bearing rotor (2) disposed between the two. The upper stator disk (1) and the lower stator disk (3) are both PCB stator disks, and adopt a multi-layer PCB winding structure; The double-sided reluctance bearing rotor (2) is a structure in which the bearing part and the rotor part are integrated. It integrates the rotor part and the bearing part (5) disposed on the outside of the rotor part. The bearing part (5) includes an inner bearing ring machined on the outside of the rotor part, the inner bearing ring being machined with an inner ring raceway of an angular contact bearing; an independent outer bearing ring; and bearing steel balls installed between the inner ring raceway and the outer bearing ring. The rotor section, together with the upper stator disk (1) and the lower stator disk (3), respectively constitutes a fine channel rotary transformer and a coarse channel rotary transformer. The inner ring of the bearing section (5) is directly mounted on the motor shaft through the rotor section to eliminate intermediate mechanical transmission links. The double-sided reluctance bearing rotor (2) is provided with a rotor axial through hole (6), and the upper stator disk (1) and the lower stator disk (3) are provided with stator axial through holes (8) at the positions corresponding to the rotor axial through hole (6). The stator axial through holes (8) of the upper stator disk (1) and the lower stator disk (3) are respectively formed with upper and lower guide ports. The upper and lower guide ports are connected with the rotor axial through hole (6) to form a cooling airflow channel, forming a cooling cycle of air inlet of the lower stator disk guide port - air outlet of the rotor axial through hole (6) - air outlet of the upper stator disk guide port. The rotor portion of the double-sided reluctance bearing rotor (2) has a surface drainage groove (7) near the center hole to break the plane, allowing the airflow to diffuse more easily and flow to the rotor axial through hole (6) and the stator axial through hole (8) to prevent local hot air from stagnating.

2. The structure of the bearing-integrated axial rotary transformer according to claim 1, characterized in that, The rotor portion of the double-sided reluctance bearing rotor (2) is provided with fine channel rotor tooth grooves and coarse channel rotor tooth grooves on its front and back sides respectively. The fine channel rotor tooth grooves correspond to the upper stator disk (1) to form a fine channel rotary transformer, and the coarse channel rotor tooth grooves correspond to the lower stator disk (3) to form a coarse channel rotary transformer.

3. The structure of the bearing-integrated axial rotary transformer according to claim 2, characterized in that, Fine-channel rotary transformers and coarse-channel rotary transformers can achieve single-channel operation by inputting different signals.

4. The structure of a bearing-integrated axial rotary transformer according to claim 2, characterized in that, The fine channel rotor has a 64-tooth slot structure, and the coarse channel rotor has a 16-tooth slot structure. The slot structure satisfies a sinusoidal reluctance pattern.

5. The structure of a bearing-integrated axial rotary transformer according to claim 1, characterized in that, The rotor section is made of stacked silicon steel sheets; the inner ring of the bearing on the outer side of the rotor section is made of non-magnetic high-strength alloy steel.

6. The structure of a bearing-integrated axial rotary transformer according to claim 1, characterized in that, The upper stator plate (1) and the lower stator plate (3) are fixed to the sensor housing by screws or clips, and the two are arranged parallel to each other.

7. The structure of a bearing-integrated axial rotary transformer according to claim 1, characterized in that, The multi-layer PCB winding of the PCB stator disk includes: the first layer is the excitation winding, the second layer is the sine winding, the third layer is the cosine winding, and the fourth layer is the excitation winding.

8. The structure of a bearing-integrated axial rotary transformer according to claim 7, characterized in that, Temperature sensors (4) are provided in the winding area of ​​the upper stator disk (1) or the lower stator disk (3). The temperature sensors (4) are used to detect the temperature in real time and provide data for angle compensation, and at the same time serve as monitoring points for the working temperature of the motor windings.

9. The structure of a bearing-integrated axial rotary transformer according to claim 8, characterized in that, The opening direction of the rotor axial through hole (6) is parallel to the direction of the motor shaft center axis, and the rotor axial through hole (6) is evenly arranged around the center of the rotor disk to achieve rotor balance under high speed operation. The stator axial through hole (8) is opened in the non-effective working area of ​​the PCB winding to avoid affecting the signal integrity of the PCB winding; The specific flow rate of the cooling cycle is dynamically adjusted based on the data obtained from the temperature sensor (4).

10. A method for angle measurement and compensation based on the structure of a bearing-integrated axial rotary transformer as described in claim 9, characterized in that, The method is as follows: High-frequency sinusoidal signals are input to the excitation windings of the upper and lower stator disks to establish a stable alternating magnetic field in the air gap between the stator and the rotor with double-sided reluctance bearings. When the rotor of the double-sided reluctance bearing, which is directly connected to the motor shaft, rotates with the motor, the sinusoidal reluctance pattern on its two sides spatially modulates the alternating magnetic field. Two high-frequency induced signals, which follow the sine and cosine function relationship of the rotor instantaneous angle, are generated through the sine and cosine windings on the upper and lower stator disks. The absolute angle of the double-sided reluctance bearing rotor is calculated in real time based on the amplitude ratio of the two high-frequency induction signals. The temperature data of the PCB winding is acquired in real time by a temperature sensor, and the calculated absolute angle is compensated for in real time based on the temperature data.

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