Rotary transformer, stator and motor system
By using a rotary transformer with an arc-shaped stator and rotor design, the installation problem of traditional rotary transformers in space-constrained scenarios has been solved, achieving compact structure, low cost and high precision signal detection.
Patent Information
- Application Number
- CN202520501810.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2026-05-15
- Estimated Expiration
- 2035-03-21
AI Technical Summary
Traditional rotary transformers are difficult to install and apply in space-constrained or highly integrated scenarios, and they are also large in size and weight, resulting in high costs.
The stator design features an arc-shaped structure, covering only a portion of the circumference. The rotor has alternating convex and concave sections, combined with a well-designed central angle, ensuring the stability and accuracy of signal detection.
It significantly reduces the structural size and weight of the rotary transformer, lowers production costs, while maintaining the accuracy and stability of signal detection, making it suitable for space-constrained applications.
Smart Images
Figure CN224247051U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of motor technology. More specifically, this utility model relates to a rotary transformer. Background Technology
[0002] A resolver is an electromagnetic induction sensor used to measure rotation angles and positions. It converts mechanical angles into electrical signals to achieve high-precision position feedback and angle measurement, and is widely used in industrial automation, precision instruments, and electric vehicles.
[0003] In traditional rotary transformer designs, a complete annular stator and rotor structure is typically used for signal detection and transmission. The rotor is rotatably mounted radially inside the stator, and its outer circumferential surface has a special concave-convex shape design. The stator structure includes excitation windings and detection windings. During operation, by applying an AC excitation signal to the excitation winding, the detection winding will induce sine and cosine signals related to the rotor position. By calculating the ratio of these two signals, the angular position information of the rotor can be accurately obtained.
[0004] However, in certain specific application scenarios, especially those with space constraints or requiring high integration, rotary transformers with complete toroidal stators and rotors are often difficult to install and apply effectively.
[0005] Therefore, a rotary transformer that can reduce the structural volume is needed. Utility Model Content
[0006] One object of this invention is to provide a rotary transformer with reduced structural volume. Another object of this invention is to provide a rotary transformer that can save costs. Yet another object of this invention is to provide a rotary transformer that can reduce weight.
[0007] One aspect of this utility model provides a rotary transformer, comprising: a stator having an arcuate structure extending in a circumferential direction; and a rotor disposed radially inside the stator and configured to be rotatable relative to the stator, wherein the rotor includes N protrusions and N recesses, the protrusions (21) and recesses being alternately arranged in a circumferential direction, N being an integer and greater than or equal to 2, wherein the central angle θ of the stator (10) satisfies: 360 degrees / N≤θ<360 degrees.
[0008] According to an embodiment of this utility model, the central angle θ of the stator satisfies: k 360 degrees / N ≤ θ < 360 degrees, where 1.5 ≤ k < N.
[0009] According to an embodiment of this utility model, the central angle θ of the stator is less than or equal to 180 degrees.
[0010] According to an embodiment of the present invention, the stator includes an excitation winding, a first detection winding for generating a sine signal, and a second detection winding for generating a cosine signal.
[0011] According to an embodiment of the present invention, the stator further includes a stator core, which includes a plurality of teeth extending radially inward, and an excitation winding, a first detection winding, and a second detection winding are configured to be wound on the teeth.
[0012] According to an embodiment of the present invention, the convex and concave portions of the rotor are configured to be smoothly connected to each other to form a wavy outer peripheral surface.
[0013] Another aspect of this utility model provides a stator for a rotary transformer, including an excitation winding, a first detection winding for generating a sine signal and a second detection winding for generating a cosine signal, and the stator has an arc-shaped structure extending along the circumferential direction, and the central angle θ of the stator satisfies: 360 degrees / M≤θ<360 degrees, where M is the number of poles of the stator.
[0014] According to an embodiment of this utility model, the central angle θ of the stator is less than or equal to 180 degrees.
[0015] According to an embodiment of the present invention, the stator further includes a stator core, which includes a plurality of teeth extending radially inward, and an excitation winding, a first detection winding, and a second detection winding are configured to be wound on the teeth.
[0016] Another aspect of the present invention provides an electric motor system comprising: an electric motor; and a rotary transformer according to an embodiment of the present invention, which is coaxially mounted with the electric motor.
[0017] Therefore, this invention provides an innovative rotary transformer design. By employing an arc-shaped stator structure, with the stator covering only a portion of the circumference (central angle less than 360 degrees), the overall structural size of the rotary transformer is significantly reduced. The non-completely ring-shaped stator design allows the rotary transformer to maintain its basic functions while achieving structural simplification and compactness. The rational design of the stator's central angle ensures sufficient signal detection capability. This design significantly reduces production costs by reducing material usage, while simplifying the manufacturing process and thus improving production efficiency. Furthermore, the rotary transformer of this invention significantly reduces weight. This rotary transformer is not only suitable for space-constrained environments but also reduces manufacturing costs and weight without compromising performance. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of a rotary transformer.
[0019] Figure 2 yes Figure 1The diagram shows the waveforms generated by the rotary transformer during operation.
[0020] Figure 3 This is a schematic diagram of a rotary transformer according to an embodiment of the present invention.
[0021] Figure 4 yes Figure 3 The diagram shows the waveforms generated by the rotary transformer during operation. Detailed Implementation
[0022] Hereinafter, embodiments of the present invention are described with reference to the accompanying drawings. The following detailed description and drawings are provided to exemplarily illustrate the principles of the present invention. The present invention is not limited to the described preferred embodiments, and the scope of the present invention is defined by the claims. The present invention will now be described in detail with reference to exemplary embodiments, some of which are illustrated in the accompanying drawings. The following description is made with reference to the accompanying drawings, and unless otherwise indicated, the same reference numerals in different drawings represent the same or similar elements. The solutions described in the following exemplary embodiments do not represent all solutions of the present invention. Rather, these solutions are merely examples of systems and methods of various aspects of the present invention covered by the appended claims.
[0023] Figure 1 This is a schematic diagram of a rotary transformer. (For example...) Figure 1 As shown, in existing rotary transformer designs, a complete annular stator 1 and rotor 2 are typically required for signal detection and transmission. The rotor 2 is rotatably mounted radially inside the stator 1. The outer periphery of the rotor 2 has an uneven shape. For example... Figure 1 As shown, stator 1 includes an excitation winding, a sine detection winding, and a cosine detection winding. Figure 2 yes Figure 1 The diagram shows the waveforms generated by the rotary transformer during operation. This is achieved by applying an AC excitation signal (such as...) to the excitation winding. Figure 2 As shown in Figure A), sine and cosine signals related to the position of rotor 2 will be induced in the sine detection winding and cosine detection winding, respectively (e.g., ...). Figure 2 (As shown in B and C). By calculating the ratio of the sine signal to the cosine signal, the precise angular position of rotor 2 can be obtained.
[0024] However, in certain specific applications, especially those with space constraints or requiring high integration, rotary transformers with complete toroidal stators and rotors often face challenges in installation and application. For example, limited internal layout space, compatibility between mechanical components, and mutual interference between components can all lead to inconvenience or even make installation impossible. Therefore, it is desirable to explore new structural design schemes to adapt to more stringent space requirements while maintaining the functionality of the rotary transformer.
[0025] To address the aforementioned problems, this invention proposes an innovative rotary transformer design. This design aims to reduce size and weight through optimized structural design, while maintaining or improving the performance and functionality of the rotary transformer. In an exemplary embodiment, the rotary transformer of this invention is applied to an electric motor system, wherein the electric motor system includes an electric motor and a rotary transformer mounted coaxially with the electric motor.
[0026] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Figure 3 This is a schematic diagram of a rotary transformer according to an embodiment of the present invention. Figure 4 yes Figure 3 The diagram shows a waveform generated during the operation of the rotary transformer.
[0027] According to embodiments of the present invention, such as Figure 3 As shown, the rotary transformer includes a stator 10 and a rotor 20.
[0028] According to an embodiment of this utility model, the stator 10 adopts a non-complete annular design. Specifically, the stator 10 has an arc-shaped structure extending along the circumference, with a central angle θ less than 360 degrees. This non-complete annular structural design allows the stator 10 to cover only a portion of the circumference of the rotor 20, thereby significantly reducing the overall size of the rotary transformer while ensuring functionality.
[0029] The stator 10 includes a stator core 11 and a winding 12. According to an embodiment of the present invention, the stator core 11 has a plurality of teeth 111 extending radially inward. The winding 12 is wound around the teeth 111. In an exemplary embodiment, the plurality of teeth 111 are evenly distributed circumferentially along the stator core 11, and winding slots are formed between adjacent teeth 111 for accommodating the winding.
[0030] According to an embodiment of the present invention, the winding 12 includes an excitation winding, a first detection winding, and a second detection winding. The excitation winding is used to generate an alternating magnetic field when alternating current is applied. The first detection winding is used to induce a sinusoidal signal related to the angle of the rotor 20. The second detection winding is used to induce a cosine signal related to the angle of the rotor 20.
[0031] According to an embodiment of the present invention, the stator 10 has a pole number M. M is a positive integer and is greater than or equal to 2.
[0032] During the operation of the rotary transformer, when alternating current is applied to the excitation winding, magnetic flux passes through the air gap between the stator 10 teeth 111 and the rotor 20 under the action of the alternating magnetic field generated by the excitation winding. As the rotor 20 rotates, the magnetic circuit undergoes periodic changes. The first and second detection windings respectively sense this change in the magnetic circuit and output sine and cosine signals related to the position of the rotor 20.
[0033] According to an embodiment of this utility model, the rotor 20 is disposed radially inside the stator 10 and is rotatable relative to the stator 10. The rotor 20 includes N protrusions 21 and N recesses 22, wherein the protrusions 21 and recesses 22 are arranged alternately along the circumferential direction. N represents the number of poles of the rotor 20. N is a positive integer and greater than or equal to 2. The specific value of N can be selected according to the requirements of the application scenario. Figure 3 In the illustrated embodiment, N equals 6, meaning the rotor 20 has 6 protrusions 21 and 6 recesses 22. The alternating design of the protrusions and recesses ensures a varying magnetic field during each rotation cycle, thus improving signal accuracy and stability. In the exemplary embodiment, as... Figure 3 As shown, the protrusions 21 and concave portions 22 of the rotor 20 are configured to be smoothly connected to each other, thereby forming a wavy outer peripheral surface. In an exemplary embodiment, in order to ensure the dynamic balance performance of the rotor 20, all protrusions 21 are of the same shape and size, all concave portions 22 are of the same shape and size, and are uniformly distributed in the circumferential direction.
[0034] According to an embodiment of the present invention, the number of poles M of the stator 10 of the rotary transformer is equal to the number of poles N of the rotor 20, that is, M=N.
[0035] When the stator 10 adopts a non-complete ring design, the central angle of the stator needs to be reasonably selected in order to ensure the detection stability and sensitivity of the rotary transformer.
[0036] According to an embodiment of this invention, the central angle θ of the stator 10 satisfies: 360 degrees / N ≤ θ < 360 degrees. As mentioned above, N is the number of protrusions 21 (or concave portions 22) of the rotor 20, and also represents the number of poles of the rotor 20. This design ensures that the stator 10 can be electromagnetically coupled with at least one complete protrusion-concave combination, thereby guaranteeing the continuity and stability of the signal.
[0037] In some embodiments, the central angle θ of the stator 10 can be set as: k 360 degrees / N ≤ θ < 360 degrees, where 1.5 ≤ k < N. Therefore, the central angle θ of stator 10 can be adjusted using parameter k. This ensures that the rotor generates a stronger signal output during rotation, thereby improving the sensitivity and accuracy of detection. Furthermore, this design provides sufficient margin for stator 10 while ensuring signal detection accuracy.
[0038] According to an embodiment of this utility model, as mentioned above, M=N, therefore the central angle θ of the stator 10 can also be designed to satisfy: 360 degrees / M≤θ<360 degrees. In some embodiments, the central angle θ of the stator 10 can be set to: k 360 degrees / M ≤ θ < 360 degrees, where 1.5 ≤ k < M.
[0039] A larger central angle θ can provide stronger signal strength, but it also increases the size and cost of the resolver. A smaller central angle θ can save space and materials, but may affect signal stability. Therefore, in practical applications, a suitable central angle θ value can be flexibly selected based on specific needs, while meeting the above-mentioned range requirements. By reasonably selecting the central angle θ of the stator 10, a good balance can be achieved among the above factors. In an exemplary embodiment, the central angle θ of the stator 10 can be set to no more than 180 degrees, a configuration particularly suitable for space-constrained applications.
[0040] Figure 4 yes Figure 3 The diagram shows the waveforms generated by the rotary transformer during operation. This is achieved by applying an AC excitation signal (such as...) to the excitation windings in stator 10. Figure 4 As shown in Figure A), sine and cosine signals related to the position of rotor 20 will be induced in the first and second detection windings of stator 10, respectively (e.g., ...). Figure 4 (As shown in B and C). By calculating the ratio of the sine and cosine signals, the precise angular position of rotor 20 can be obtained. Compared to Figure 2 The waveform exhibited by a rotary transformer using a complete toroidal stator, such as... Figure 4 As shown, the rotary transformer according to an embodiment of the present invention adopts a non-complete ring structure. Although this may cause a reduction in the amplitude of the detected sine and cosine signals, the ratio of the sine and cosine signals remains unchanged, ensuring that the accuracy and stability of rotor position detection are not affected.
[0041] According to embodiments of this invention, by employing a non-complete annular stator design, the stator only covers a portion of the rotor's circumference, significantly reducing the overall size, volume, and weight of the rotary transformer. This makes it particularly suitable for applications with limited space or requiring high integration. By rationally designing the stator's central angle, electromagnetic coupling between the stator and at least one complete convex-concave combination is ensured, guaranteeing signal continuity and stability.
[0042] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the construction and methods of the above embodiments. Rather, the present invention is intended to cover various modifications and equivalent configurations. Furthermore, although various elements and method steps of the disclosed invention have been shown in various exemplary combinations and constructions, other combinations including more or fewer elements or methods also fall within the scope of the present invention.
[0043] List of reference numerals
[0044] 1. Stator;
[0045] 2 rotors;
[0046] 10 stators;
[0047] 11. Stator core;
[0048] 12 windings;
[0049] 111 teeth;
[0050] 20 rotors;
[0051] 21 convex part;
[0052] 22 recess.
Claims
1. A rotary transformer, characterized in that, The rotary transformer includes: Stator (10), which has an arc-shaped structure extending along the circumferential direction; and A rotor (20) is disposed radially inside the stator (10) and configured to be rotatable relative to the stator (10). The rotor (20) includes N protrusions (21) and N recesses (22), which are arranged alternately along the circumferential direction. N is an integer greater than or equal to 2. The central angle θ of the stator (10) satisfies: 360 degrees / N≤θ<360 degrees.
2. The rotary transformer according to claim 1, characterized in that, The central angle θ of the stator (10) satisfies: k*360 degrees / N≤θ<360 degrees, where 1.5≤k<N.
3. The rotary transformer according to claim 2, characterized in that, The central angle θ of the stator (10) is less than or equal to 180 degrees.
4. The rotary transformer according to any one of claims 1 to 3, characterized in that, The stator (10) includes an excitation winding, a first detection winding for generating a sine signal, and a second detection winding for generating a cosine signal.
5. The rotary transformer according to claim 4, characterized in that, The stator (10) further includes a stator core (11) having a plurality of teeth (111) extending radially inward, the excitation winding, the first detection winding and the second detection winding being configured to be wound around the teeth (111).
6. The rotary transformer according to any one of claims 1 to 3, characterized in that, The protrusion (21) and the recess (22) of the rotor (20) are configured to be smoothly connected to each other to form a wavy outer peripheral surface.
7. A stator (10) for a rotary transformer, characterized in that, The stator (10) includes an excitation winding, a first detection winding for generating a sine signal and a second detection winding for generating a cosine signal, and the stator (10) has an arc-shaped structure extending along the circumferential direction. The central angle θ of the stator (10) satisfies: 360 degrees / M≤θ<360 degrees, where M is the number of poles of the stator (10).
8. The stator according to claim 7, characterized in that, The central angle θ of the stator (10) is less than or equal to 180 degrees.
9. The stator according to claim 7 or 8, characterized in that, The stator (10) further includes a stator core (11) having a plurality of teeth (111) extending radially inward, the excitation winding, the first detection winding and the second detection winding being configured to be wound around the teeth (111).
10. A motor system, characterized in that, The motor system includes: Electric motor; and The rotary transformer according to any one of claims 1 to 6 is mounted coaxially with the motor.