Hollow outer rotor single-channel winding type rotary transformer and system
By designing a hollow external rotor single-channel wound rotary transformer, with the rotor located outside the stator and a special layout of the excitation winding and signal winding, the transformer volume is reduced and the measurement accuracy is improved. This solves the problems of large size and large error of traditional wound rotary transformers, making it suitable for high-precision measurement in harsh environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-23
- Publication Date
- 2026-03-13
AI Technical Summary
Traditional wound rotary transformers suffer from problems such as large size, large measurement error, and difficulty in achieving high-precision measurement. Especially when used in harsh environments such as high temperature, extreme cold, humidity, high speed, and high vibration, the rotor structure of traditional wound rotary transformers is complex and it is difficult to realize a multi-pole structure.
A hollow external rotor single-channel wound rotary transformer was designed. The rotor is set outside the stator, the excitation winding is set on the rotor, and the sine signal winding and cosine signal winding are set on the stator. A gap is set in the middle of the rotor, and the two ends of the gap are sinusoidal corrugated structures. The sinusoidal corrugated structure is used to reduce the size of the transformer and improve the measurement accuracy.
It achieves small transformer size and high measurement accuracy, enables multi-pole structure design, solves the integer turn error problem of traditional wound rotary transformers, and is suitable for harsh environments such as high temperature, extreme cold, humidity, high speed, and high vibration.
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Figure CN121662580A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of transformer technology, and in particular to a hollow external rotor single-channel wound rotary transformer and system. Background Technology
[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.
[0003] A wound-rotor rotary transformer is a position sensor, typically with a brushed structure or used in conjunction with a coupling transformer. It is widely used in applications where rotary encoders cannot function properly, such as high-temperature, low-temperature, humid, high-speed, and high-vibration environments. These applications include robotics systems, machine tools, automobiles, power generation, metallurgy, textiles, and printing. Traditional wound-rotor rotary transformers usually have a single-pole rotor structure with sinusoidal winding, making rotor winding setup difficult. Furthermore, the size of internal rotor wound-rotor rotary transformers increases significantly with the number of pole pairs, resulting in a large size. In addition, while traditional wound-rotor rotary transformers allow for coupled magnetic circuit setup, significant errors can occur, hindering high-precision measurements. Summary of the Invention
[0004] To address the aforementioned problems, this invention proposes a hollow external rotor single-channel wound rotary transformer and system, which features high measurement accuracy and small size.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: In the first aspect, a hollow external rotor single-channel wound rotary transformer is proposed, including: stator, rotor, excitation winding, sine signal winding and cosine signal winding; The rotor is fitted onto the outside of the stator; The rotor includes magnetic materials located at both ends of the rotor, with a gap between the two magnetic materials. Sine wave structures are provided on the surfaces of the two magnetic materials in contact with the gap; the peaks and troughs of the two sinusoidal wave structures are arranged opposite each other. The excitation winding is located on the rotor; the sine signal winding and the cosine signal winding are located on the stator.
[0006] Furthermore, the sinusoidal function expression for the sinusoidal corrugation structure at the upper end of the rotor is: ; The sinusoidal function expression for the sinusoidal corrugation structure at the lower end of the rotor is: ; In the formula, ω is the angular frequency of the sine function; V 1 is the angular frequency The corresponding amplitude of the sine function; Angular frequency The initial phase of the corresponding sine function.
[0007] Furthermore, both the stator and rotor are made of multiple stacked silicon steel sheets.
[0008] Furthermore, multiple stator teeth are arranged along the circumferential direction on the outer surface of the stator, and the sine signal winding and cosine signal winding are wound on the stator teeth at intervals.
[0009] Furthermore, the total number of turns in the sinusoidal signal winding is equal to the total number of turns in the cosine signal winding.
[0010] Furthermore, the cosine signal winding is wound in the same way as the sine signal winding, but with a phase difference of 90° electrical degrees.
[0011] Furthermore, multiple sets of rotor slots are arranged on the rotor, and each set of rotor slots is equipped with an excitation winding; the multiple sets of rotor slots are arranged in parallel, and the winding directions of the excitation windings in adjacent rotor slots are opposite.
[0012] Furthermore, each set of rotor slots includes two symmetrically arranged rotor slots, through which the excitation winding passes.
[0013] Furthermore, the number of turns of the excitation winding in the rotor slots is equal.
[0014] Secondly, a hollow external rotor single-channel wound rotary transformer system is proposed, including the hollow external rotor single-channel wound rotary transformer proposed in the first aspect.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a hollow external rotor single-channel wound rotary transformer and system. The transformer reduces the transformer size and improves measurement accuracy by placing the rotor outside the stator, the excitation winding on the rotor, and the sine and cosine signal windings on the stator. A gap is set in the middle of the rotor, and the two ends of the gap are two sine wave structures with opposite peaks and troughs. This also enables a multi-pole structure design and solves the integer turn error problem of traditional wound rotary transformers.
[0016] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.
[0018] Figure 1 This is a schematic diagram of a hollow external rotor single-channel wound rotary transformer structure proposed in an embodiment of the present invention; Figure 2 This is a schematic diagram of the axial section of a hollow external rotor single-channel wound rotary transformer according to an embodiment of the present invention; Figure 3 This is a diagram showing the turn distribution of the sine and cosine signal windings of a hollow external rotor single-channel wound rotary transformer according to an embodiment of the present invention. Figure 4 This is a three-dimensional schematic diagram of the rotor structure proposed in an embodiment of the present invention; Figure 5 This is a schematic front view of the rotor structure proposed in an embodiment of the present invention; Figure 6 This is a top view schematic diagram of the rotor structure proposed in an embodiment of the present invention; Figure 7 This is a planar unfolded schematic diagram of the rotor proposed in an embodiment of the present invention; Figure 8 This is a schematic diagram of the rotor and excitation winding as presented in an embodiment of the present invention.
[0019] Among them: 1. Rotor, 2. Stator, 3. Air gap, 4. Excitation winding, 5. Sine signal winding, 6. Cosine signal winding, 7. Stator axis, 8. Stator axis, 9. Rotor axis, 1-1. Upper magnetic material, 1-2. Gap, 1-3. Lower magnetic material. Detailed Implementation
[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0021] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.
[0022] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.
[0023] In this invention, terms such as "fixed connection," "connected," and "linked" should be interpreted broadly, indicating a fixed connection, an integral connection, or a detachable connection; a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can determine the specific meaning of these terms in this invention based on the specific circumstances, and they should not be construed as limitations on the invention.
[0024] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.
[0025] Traditional wound-rotor rotary transformers require a sinusoidal distribution of turns in the rotor windings to achieve a sinusoidal change in the air gap flux between the stator and rotor. This makes it difficult to implement a dual-channel magnetic circuit structure. The challenge lies in the fact that a dual-channel magnetic circuit requires the synthesis of sinusoidal functions of different frequencies, resulting in an asymmetrical distribution of the windings across the entire circumference. The winding process is extremely cumbersome. Furthermore, with traditional sinusoidal winding methods, the number of turns distributed in each rotor slot is an integer. Even if the winding is achieved through this cumbersome process, the integer turn distribution can lead to significant signal output errors. Therefore, traditional wound-rotor rotary transformers are not suitable for dual-channel structures, and even single-channel designs are limited by integer turn errors.
[0026] To improve the measurement accuracy and reduce the size of wound-rotor rotary transformers, this invention proposes a hollow external rotor single-channel wound-rotor rotary transformer, such as... Figures 1-8 As shown, it includes: stator 2, rotor 1, excitation winding 4, sine signal winding 5 and cosine signal winding 6; The rotor 1 is fitted onto the outside of the stator 2; The rotor 1 includes magnetic conductive materials located at both ends of the rotor, with a gap between the two magnetic conductive materials, and a sinusoidal corrugated structure on the surface of the two magnetic conductive materials in contact with the gap; the crests and troughs of the two sinusoidal corrugated structures are arranged opposite to each other; The excitation winding 4 is mounted on the rotor 1; the sine signal winding 5 and the cosine signal winding 6 are mounted on the stator 2.
[0027] This invention proposes a hollow external rotor single-channel wound rotary transformer. By placing the rotor outside the stator, the excitation winding on the rotor, and the sine and cosine signal windings on the stator, and by setting a gap in the middle of the rotor with two sinusoidal corrugated structures at both ends of the gap having opposite peaks and troughs, the transformer volume is reduced, the measurement accuracy is improved, and a multi-pole structure design can be realized, thus solving the integer turn error problem of traditional wound rotary transformers.
[0028] like Figure 1 As shown, rotor 1 is fitted outside stator 2, and air gap 3 is provided between rotor 1 and stator 2.
[0029] like Figures 4-7 As shown, rotor 1 is located outside stator 2 and has a cylindrical structure. The middle part of rotor 1 is a sinusoidal wave-shaped hollow structure, and the two sides of rotor are made of magnetic material.
[0030] The magnetic material at the upper end of rotor 1 is called upper magnetic material 1-1, and the magnetic material at the lower end of rotor 1 is called lower magnetic material 1-2. There is a gap between upper magnetic material 1-1 and lower magnetic material 1-2. The end face of upper magnetic material 1-1 facing lower magnetic material 1-2 has a sinusoidal wave structure, which is defined as the upper end sinusoidal wave structure of rotor. The end face of lower magnetic material 1-2 facing upper magnetic material 1-1 also has a sinusoidal wave structure, which is defined as the lower end sinusoidal wave structure of rotor.
[0031] Sine function expression of the sinusoidal corrugated structure at the upper end of the rotor Y 1 is: ; Sine function expression of the sinusoidal corrugation structure at the lower end of the rotor Y 2 is: ; In the formula, ω is the angular frequency of the sine function; V 1 is the angular frequency The corresponding amplitude of the sine function; Angular frequency The initial phase of the corresponding sine function.
[0032] like Figure 4 As shown, multiple sets of rotor slots are arranged on rotor 1, and each set of rotor slots contains an excitation winding 4. The multiple sets of rotor slots are arranged in parallel, and the winding directions of the excitation windings in adjacent rotor slots are opposite. Each set of rotor slots includes two symmetrically arranged rotor slots, and the excitation winding is wound around the rotor by passing through the two rotor slots; the number of turns of the excitation winding in each rotor slot is equal. Specifically: The excitation winding 4 is mounted on rotor 1, and the number of turns distributed in each rotor slot is equal. For example... Figure 8 As shown, with rotor axis 9 as the reference, the 360° mechanical angle is divided into 2P parts in a counterclockwise direction, each part having a mechanical angle of 180° / P. The excitation winding is wound in the forward direction within the first 180° / P mechanical angle, and wound in the reverse direction within the second 180° / P mechanical angle. The winding method for the other 2P-2 excitation winding parts is similar.
[0033] It should be noted that: rotor shaft 9 is taken The location.
[0034] The number of rotor slots provided on rotor 1 is an even number of not less than 4P.
[0035] The stator 2 is located inside the rotor 1. Both the stator 2 and the rotor 1 are made of multiple silicon steel sheets stacked together. The stator 2 is an iron core made of stacked annular silicon steel sheets.
[0036] Multiple stator teeth are arranged circumferentially on the outer surface of stator 2, and the sine signal winding 5 and the cosine signal winding 6 are wound alternately on the stator teeth. Specifically: The outer surface of stator 2 has 4NP toothed slots along the axial direction, and stator teeth are provided between adjacent toothed slots, so the outer surface of the stator has 4NP stator teeth.
[0037] The sine signal winding 5 and the cosine signal winding 6 are arranged in a single layer on 4NP stator teeth. Both the sine signal winding 5 and the cosine signal winding 6 are concentrated windings, and they change according to a sine law. The total number of turns of the sine signal winding 5 is equal to the total number of turns of the cosine signal winding 6.
[0038] Arbitrarily select a plane passing through the stator axis 8 that does not intersect with the stator teeth. Divide the 4NP stator teeth into two sets of 2NP stator teeth, alternating between sine and cosine phases, in a clockwise direction. Then, according to the winding method, divide the 2NP stator teeth of each phase signal winding into P parts. For the sine signal winding 5, starting from the stator axis 8, divide the first part in a clockwise direction... The stator teeth are divided into two groups. In the first group The stator teeth are wound counterclockwise, in the second group The stator teeth are wound clockwise; the cosine signal winding is wound in the same way as the sine signal winding, but with a 90° electrical phase difference. The other P-1 section stator teeth are wound in the same way as the first and second groups of stator teeth.
[0039] The air gap magnetic permeability of each stator tooth It is a periodic function of the rotor's electrical angle. Expressed as a Fourier series:
[0040] In the formula For mechanical rotation angle; Average permeability; The amplitude of the μ-th harmonic permeability; P is the number of rotor pole pairs; This refers to the number of stator teeth.
[0041] The excitation flux under each stator tooth is:
[0042] In the formula, It is a constant component of the magnetic flux; It represents the amplitude of the μth harmonic magnetic flux.
[0043] Based on the connection method of the sine and cosine windings, the flux linkage between the sine and cosine windings can be expressed as:
[0044] Simplified, we can obtain
[0045] Therefore, the output potential of the sine winding and the cosine winding can be expressed as:
[0046] In the formula The amplitude of the induced electromotive force. N 2 represents the number of turns of the sine signal winding and the cosine signal winding on a single stator tooth.
[0047] Amplitude of sine signal winding and cosine signal winding E s and E c It can be represented as:
[0048] As can be seen from the above formula, the rotor shape has sinusoidal properties, so that the amplitude of the induced electromotive force output by the sinusoidal winding and the cosine winding is a sine or cosine function of the rotor angle.
[0049] The hollow external rotor single-channel wound rotary transformer proposed in this invention reduces the transformer volume, improves measurement accuracy, and enables a multi-pole structure design, thus solving the integer turn error problem of traditional wound rotary transformers. This is achieved by setting the rotor outside the stator, the excitation winding on the rotor, and the sine and cosine signal windings on the stator. A gap is set in the middle of the rotor, and the two ends of the gap are two sinusoidal corrugated structures with opposite peaks and troughs.
[0050] This invention also proposes a hollow external rotor single-channel wound rotary transformer system, including a hollow external rotor single-channel wound rotary transformer proposed in this invention.
[0051] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.
Claims
1. A hollow external rotor single-channel wound rotary transformer, characterized in that, include: Stator, rotor, excitation winding, sine signal winding, and cosine signal winding; The rotor is fitted onto the outside of the stator; The rotor includes magnetic materials located at both ends of the rotor, with a gap between the two magnetic materials. Sine wave structures are provided on the surfaces of the two magnetic materials in contact with the gap; the peaks and troughs of the two sinusoidal wave structures are arranged opposite each other. The excitation winding is located on the rotor; the sine signal winding and the cosine signal winding are located on the stator.
2. The hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The sinusoidal function expression for the sinusoidal corrugated structure at the upper end of the rotor is: ； The sinusoidal function expression for the sinusoidal corrugation structure at the lower end of the rotor is: ； In the formula, ω is the angular frequency of the sine function; V 1 is the angular frequency The corresponding sine function amplitude; Angular frequency The initial phase of the corresponding sine function.
3. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Both the stator and rotor are made of multiple silicon steel sheets stacked together.
4. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Multiple stator teeth are arranged along the circumferential direction on the outer surface of the stator, and the sine signal winding and cosine signal winding are wound on the stator teeth at intervals.
5. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The total number of turns in the sine signal winding is equal to the total number of turns in the cosine signal winding.
6. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The winding method of the cosine signal winding is the same as that of the sine signal winding, but the phase difference is 90° electrical degrees.
7. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Multiple sets of rotor slots are set on the rotor, and each set of rotor slots is equipped with an excitation winding; the multiple sets of rotor slots are arranged in parallel, and the winding directions of the excitation windings in adjacent rotor slots are opposite.
8. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, Each rotor slot group includes two symmetrically arranged rotor slots, and the excitation winding passes through the two rotor slots.
9. A hollow external rotor single-channel wound rotary transformer as described in claim 1, characterized in that, The number of turns of the excitation winding in the rotor slots is equal.
10. A hollow external rotor single-channel wound rotary transformer system, characterized in that, Including the hollow external rotor single-channel wound rotary transformer as described in any one of claims 1-9.