Encoder coil assembly and encoder

Abstract

The utility model relates to encoder technical field, specifically disclose a kind of encoder coil assembly and encoder, by first rotor coil and second rotor coil are spaced apart along the direction of encoder axis, can greatly reduce the radial dimension of rotor coil group, to facilitate the realization of compact and light weight of encoder in turn;Meanwhile, along the direction of encoder axis, the overlapping area of the projection of first rotor coil and the projection of second rotor coil is smaller, to avoid first rotor coil and second rotor coil mutual occlusion, reduce the mutual interference between main code path and vice code path, it is favorable to improve the measurement accuracy of encoder, and simplify the control logic of encoder.

Description

Technical Field

[0001] This utility model relates to the field of encoder technology, and in particular to encoder coil assemblies and encoders. Background Technology

[0002] Inductive encoders, as a non-contact position measurement element, do not rely on optical or magnetic elements in their working principle. This gives them excellent tolerance to harsh working environments such as oil, dust, vibration, and strong magnetic fields, making them widely used in fields with high reliability requirements, such as robot joints and CNC machine tools.

[0003] In related technologies, inductive encoders often adopt a single-layer flat, nested structure, in which the rotor coil and stator coil are arranged side by side on a plane. Their measurement accuracy largely depends on the encoder having a sufficiently large radial dimension to ensure that the rotor coil and stator coil can obtain sufficient physical space, thereby forming a stable and distinguishable electromagnetic induction signal.

[0004] However, with increasingly stringent requirements for compact and lightweight structures in applications such as robotics, the reliance of traditional inductive encoders on radial dimensions presents a fundamental challenge to their miniaturization applications. When attempting to directly scale down the planar structure proportionally, the geometric dimensions of the rotor and stator coils are forced to shrink, resulting in a sharp reduction in the effective magnetic flux linkage area, a significant attenuation of the induced signal strength, and a deterioration in the signal-to-noise ratio. This causes measurement accuracy to decrease rapidly as the radial dimension shrinks, creating an irreconcilable constraint between the two core performance indicators of miniaturization and high precision. Utility Model Content

[0005] The purpose of this invention is to provide an encoder coil assembly and an encoder that can reduce the radial dimension of the encoder while ensuring measurement accuracy.

[0006] On the one hand, the present invention provides an encoder coil assembly for an encoder, including an encoder coil unit, the encoder coil unit including a rotor coil group, the rotor coil group including a first rotor coil and a second rotor coil spaced apart along the encoder axis;

[0007] The first rotor coil includes at least one first coil branch arranged along the circumferential direction of the encoder and connected end to end. The first coil branch includes a first arc segment and a second arc segment extending along the circumferential direction of the encoder, and a first straight segment and a second straight segment extending radially along the encoder. The radius of the first arc segment is not equal to the radius of the second arc segment. The center of the first arc segment and the center of the second arc segment coincide with the axis of the encoder. The first arc segment and the second arc segment are staggered along the circumferential direction of the encoder. The two ends of the first straight segment are connected to the first arc segment and the second arc segment respectively. The second straight segment is connected to the end of the second arc segment away from the first straight segment.

[0008] The second rotor coil includes at least two second coil branches arranged along the circumference of the encoder and connected end to end. Each second coil branch includes an arc segment 1 and an arc segment 2 extending along the circumference of the encoder, and a straight segment 1 and a straight segment 2 extending radially along the encoder. The radius of the arc segment 1 is not equal to the radius of the arc segment 2. The center of the arc segment 1 and the center of the arc segment 2 coincide with the axis of the encoder. The arc segment 1 and the arc segment 2 are offset along the circumference of the encoder. The two ends of the straight segment 1 are connected to the arc segment 1 and the arc segment 2, respectively. The straight segment 2 is connected to the end of the arc segment 2 that is away from the straight segment 1.

[0009] As an alternative to the encoder coil assembly, the encoder coil unit further includes a shield and an induction coil group, with the shield and the induction coil group located on opposite sides of the rotor coil group along the encoder axis.

[0010] As an optional embodiment of the encoder coil assembly, the encoder coil unit further includes an induction coil group, which includes a first induction coil corresponding to the first rotor coil and a second induction coil corresponding to the second rotor coil. The first induction coil and the second induction coil are spaced apart along the encoder axis.

[0011] As an optional solution for the encoder coil assembly, the encoder coil unit is provided in two parts, referred to as the first encoder coil unit and the second encoder coil unit respectively.

[0012] The rotor coil group of the first encoder coil unit is sleeved on the outside of the rotor coil group of the second encoder coil unit;

[0013] The induction coil group of the first encoder coil unit is sleeved on the outside of the induction coil group of the second encoder coil unit.

[0014] As an alternative to the encoder coil assembly, the encoder coil assembly further includes an excitation coil group, which includes at least one excitation coil for transmitting excitation signals to the first rotor coil and the second rotor coil.

[0015] As an alternative to the encoder coil assembly, the excitation coil is located on one side of the first induction coil along the encoder axis; or,

[0016] The excitation coil is located on one side of the first induction coil along the radial direction of the encoder; or,

[0017] The excitation coil is located on one side of the second induction coil along the encoder axis; or,

[0018] The excitation coil is located on one side of the second induction coil along the radial direction of the encoder.

[0019] As an alternative to the encoder coil assembly, the excitation coil is provided in multiple ways, with at least two of the excitation coils connected in series, and / or at least two of the excitation coils connected in parallel, and / or at least two of the excitation coils being set independently of each other.

[0020] As an alternative to the encoder coil assembly, when the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are coprime.

[0021] When the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are coprime.

[0022] When the first rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the first rotor coil of the first encoder coil unit and the number of pole pairs of the second rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the first rotor coil of the first encoder coil unit and the number of pole pairs of the second rotor coil of the second encoder coil unit are coprime.

[0023] When the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are coprime.

[0024] As an alternative to the encoder coil assembly, the number of pole pairs of the first rotor coil and the number of pole pairs of the second rotor coil are coprime.

[0025] As an alternative to the encoder coil assembly, the number of pole pairs of the first rotor coil is not equal to the number of pole pairs of the second rotor coil.

[0026] As an alternative to the encoder coil assembly, the difference between the number of pole pairs of the first rotor coil and the number of pole pairs of the second rotor coil is 1.

[0027] On the other hand, the present invention provides an encoder, including an encoder coil assembly as described in any of the preceding claims.

[0028] As an alternative to the encoder, the encoder also includes a rotor circuit board, on which both the first rotor coil and the second rotor coil are disposed.

[0029] As an optional encoder solution, the encoder coil unit further includes an induction coil group and an excitation coil group, and the encoder further includes a stator circuit board;

[0030] Both the induction coil group and the excitation coil group are located on the stator circuit board; or, the encoder further includes a first circuit board, both the induction coil group and the excitation coil group are located on the first circuit board, and the first circuit board is electrically connected to the stator circuit board.

[0031] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0032] The encoder coil assembly and encoder of this utility model, by arranging the first rotor coil and the second rotor coil at intervals along the encoder axis, can significantly reduce the radial dimension of the rotor coil assembly, thereby facilitating the compactness and weight reduction of the encoder; at the same time, the first rotor coil includes at least one first coil branch arranged along the circumference of the encoder and connected end to end. The first coil branch includes a first arc segment and a second arc segment extending along the circumference of the encoder, and a first straight segment and a second straight segment extending radially along the encoder. The radius of the first arc segment is not equal to the radius of the second arc segment. The center of the first arc segment and the center of the second arc segment coincide with the axis of the encoder. The first arc segment and the second arc segment are staggered along the circumference of the encoder. The two ends of the first straight segment are connected to the first arc segment and the second arc segment respectively. The second straight segment is connected to the end of the second arc segment away from the first straight segment. The second rotor coil includes at least two second coil branches arranged end-to-end along the circumference of the encoder. Each second coil branch includes an arc segment 1 and an arc segment 2 extending along the circumference of the encoder, and a straight segment 1 and a straight segment 2 extending radially along the encoder. The radii of arc segment 1 and arc segment 2 are not equal. The centers of arc segment 1 and arc segment 2 coincide with the encoder axis. Arc segment 1 and arc segment 2 are staggered along the circumference of the encoder. The two ends of straight segment 1 are connected to arc segment 1 and arc segment 2 respectively. Straight segment 2 is connected to the end of arc segment 2 away from straight segment 1. This reduces the overlap area of ​​the projections of the first rotor coil and the second rotor coil along the encoder axis, thereby avoiding mutual obstruction between the first and second rotor coils, reducing mutual interference between the main code track and the auxiliary code track, improving the measurement accuracy of the encoder, and simplifying the encoder control logic. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the first structure of the encoder in an embodiment of the present utility model;

[0034] Figure 2 This is a schematic diagram of the rotor coil assembly in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of the first rotor coil with a pole pair number of one in an embodiment of this utility model;

[0036] Figure 4 This is a schematic diagram of the structure of the first rotor coil or the second rotor coil with a pole pair number of two in an embodiment of this utility model;

[0037] Figure 5 This is a schematic diagram of the structure of the first rotor coil or the second rotor coil with three pole pairs in an embodiment of this utility model;

[0038] Figure 6This is a schematic diagram of the structure of the first rotor coil or the second rotor coil with a pole pair number of four in an embodiment of this utility model;

[0039] Figure 7 This is a schematic diagram of the structure of the first rotor coil or the second rotor coil with a pole pair number of sixteen in an embodiment of this utility model;

[0040] Figure 8 This is a first structural schematic diagram of the induction coil group and the excitation coil group in an embodiment of the present utility model;

[0041] Figure 9 This is a schematic diagram of the second structure of the induction coil group and the excitation coil group in an embodiment of this utility model;

[0042] Figure 10 This is a schematic diagram of the second structure of the encoder in an embodiment of the present utility model;

[0043] Figure 11 This is a third structural schematic diagram of the induction coil group and excitation coil group in an embodiment of this utility model;

[0044] Figure 12 This is a schematic diagram of the first working state of the rotor coil group and the excitation coil group in an embodiment of this utility model;

[0045] Figure 13 This is a schematic diagram of the second working state of the rotor coil group and the excitation coil group in an embodiment of this utility model;

[0046] Figure 14 This is a third structural schematic diagram of the induction coil group and excitation coil group in an embodiment of this utility model;

[0047] Figure 15 This is a schematic diagram of the third working state of the rotor coil group and the excitation coil group in an embodiment of this utility model.

[0048] In the picture:

[0049] 10. Encoder coil unit; 10a. First encoder coil unit; 10b. Second encoder coil unit; 1. Rotor coil group; 11. First rotor coil; 111. First coil branch; 1111. First arc segment; 1112. Second arc segment; 1113. First straight segment; 1114. Second straight segment; 12. Second rotor coil; 121. Second coil branch; 1211. Arc segment one; 1212. Arc segment two; 1213. Straight segment one; 1214. Straight segment two; 2. Induction coil group; 21. First induction coil; 22. Second induction coil; 3. Excitation coil group; 31. Excitation coil; 31a. First excitation coil; 31b. Second excitation coil; 31c. Excitation coil one; 31d. Excitation coil two; 4. Shielding component. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0052] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0053] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0054] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0056] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0057] like Figures 1 to 15 As shown, this embodiment provides an encoder coil assembly and an encoder. The encoder includes an encoder coil assembly, which includes an encoder coil unit 10. The encoder coil unit 10 includes a rotor coil group 1. The rotor coil group 1 includes a first rotor coil 11 and a second rotor coil 12 spaced apart along the encoder axis, which can significantly reduce the radial dimension of the rotor coil group 1, thereby facilitating the compactness and weight reduction of the encoder. One of the first rotor coil 11 and the second rotor coil 12 is a main code track rotor coil, and the other is a secondary code track rotor coil.

[0058] The first rotor coil 11 includes at least one first coil branch 111 arranged along the circumference of the encoder and connected end to end. The first coil branch 111 includes a first arc segment 1111 and a second arc segment 1112 both extending along the circumference of the encoder, and a first straight segment 1113 and a second straight segment 1114 both extending radially along the encoder. The radius of the first arc segment 1111 is not equal to the radius of the second arc segment 1112. The center of the first arc segment 1111 and the center of the second arc segment 1112 are both coincident with the axis of the encoder. The first arc segment 1111 and the second arc segment 1112 are staggered along the circumference of the encoder. The two ends of the first straight segment 1113 are connected to the first arc segment 1111 and the second arc segment 1112 respectively. The second straight segment 1114 is connected to the end of the second arc segment 1112 that is away from the first straight segment 1113. It is understandable that one end of the second straight segment 1114 is connected to one end of the second arc segment 1112 away from the first straight segment 1113, and the other end of the second straight segment 1114 is connected to the first rotor coil 11 adjacent to the second straight segment 1114. In other words, the other end of the second straight segment 1114 is connected to the next first rotor coil 11.

[0059] The second rotor coil 12 includes at least two second coil branches 121 arranged along the circumference of the encoder and connected end to end. Each second coil branch 121 includes an arc segment 1211 and an arc segment 1212 extending along the circumference of the encoder, and a straight segment 1213 and a straight segment 1214 extending radially along the encoder. The radius of the arc segment 1211 is not equal to the radius of the arc segment 1212. The center of the arc segment 1211 and the center of the arc segment 1212 are both coincident with the axis of the encoder. The arc segment 1211 and the arc segment 1212 are offset along the circumference of the encoder. The two ends of the straight segment 1213 are connected to the arc segment 1211 and the arc segment 1212 respectively. The straight segment 1214 is connected to the end of the arc segment 1212 that is away from the straight segment 1213. It is understandable that one end of the straight segment 2 1214 is connected to the end of the arc segment 2 1212 that is away from the straight segment 1 1213, and the other end of the straight segment 2 1214 is connected to the second rotor coil 12 adjacent to the straight segment 2 1214. In other words, the other end of the straight segment 2 1214 is connected to the next second rotor coil 12.

[0060] By adopting the above-described arrangement, the first rotor coil 11 and the second rotor coil 12 can reduce the overlapping area of ​​the projections of the first rotor coil 11 and the second rotor coil 12 along the encoder axis, thereby avoiding mutual obstruction between the first rotor coil 11 and the second rotor coil 12, reducing mutual interference between the main code track and the sub-code track, which is beneficial to improving the measurement accuracy of the encoder and simplifying the control logic of the encoder.

[0061] It should be noted that the first arc segment 1111 and the second arc segment 1112 are located on the circumferences of two concentric circles with different radii. Arc segment one 1211 and arc segment two 1212 are located on the circumferences of two concentric circles with different radii.

[0062] It should be further explained that the first arc segment 1111 and the second arc segment 1112 are offset along the circumference of the encoder. That is, along the radial direction of the encoder, the projections of the first arc segment 1111 and the second arc segment 1112 do not overlap. In other words, the first arc segment 1111 and the second arc segment 1112 are located on opposite sides of the first straight segment 1113 along the circumference of the encoder. Similarly, the first arc segment 1211 and the second arc segment 1212 are offset along the circumference of the encoder. That is, along the radial direction of the encoder, the projections of the first arc segment 1211 and the second arc segment 1212 do not overlap. In other words, the first arc segment 1211 and the second arc segment 1212 are located on opposite sides of the first straight segment 1213 along the circumference of the encoder.

[0063] In some embodiments, the number of pole pairs of the first rotor coil 11 is not equal to the number of pole pairs of the second rotor coil 12, which can further reduce the mutual interference between the main code track and the sub-code track, thereby improving the measurement accuracy of the encoder.

[0064] In some embodiments, the difference between the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 is 1. That is, the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 are adjacent positive integers. This further reduces the mutual interference between the main code track and the sub-code track, thereby improving the measurement accuracy of the encoder.

[0065] In some embodiments, the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 are coprime, which can further reduce the mutual interference between the main code track and the sub-code track, thereby improving the measurement accuracy of the encoder.

[0066] For example, the correspondence between the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 is shown in the table below:

[0067]

[0068] For ease of understanding, please refer to the following: Figures 3 to 7 The structure of the first rotor coil 11 or the second rotor coil 12 with different numbers of pole pairs is introduced. Figure 3 This is a schematic diagram of the structure of the first rotor coil 11 with a pole pair number of one. Figure 4 This is a schematic diagram of the structure of the first rotor coil 11 or the second rotor coil 12, which has two pole pairs. Figure 5This is a schematic diagram of the structure of the first rotor coil 11 or the second rotor coil 12, which has three pole pairs. Figure 6 This is a schematic diagram of the structure of the first rotor coil 11 or the second rotor coil 12, which has four pole pairs. Figure 7 This is a schematic diagram of the structure of the first rotor coil 11 or the second rotor coil 12, which has a pole pair number of sixteen.

[0069] In some embodiments, such as Figure 1 and Figure 8 As shown, the encoder coil unit 10 also includes an induction coil group 2. The induction coil group 2 includes a first induction coil 21 corresponding to the first rotor coil 11 and a second induction coil 22 corresponding to the second rotor coil 12. The first induction coil 21 and the second induction coil 22 are spaced apart along the encoder axis, which can significantly reduce the radial dimension of the induction coil group 2, thereby facilitating the compactness and weight reduction of the encoder. One of the first induction coil 21 and the second induction coil 22 is the main code track induction coil, and the other is the auxiliary code track induction coil.

[0070] It should be noted that the number of pole pairs of the first induction coil 21 is equal to the number of pole pairs of the first rotor coil 11. The number of pole pairs of the second induction coil 22 is equal to the number of pole pairs of the second induction coil 22.

[0071] In some embodiments, the secondary code track rotor coil, the main code track rotor coil, the main code track induction coil, and the secondary code track induction coil are arranged sequentially along the encoder axis, thereby minimizing the spacing between the main code track rotor coil and the main code track induction coil and maximizing the encoder's signal-to-noise ratio, thus resulting in higher measurement accuracy of the encoder.

[0072] In other embodiments, the main code track rotor coil, the secondary code track rotor coil, the main code track induction coil, and the secondary code track induction coil can be arranged sequentially along the encoder axis, thereby making the spacing between the main code track rotor coil and the main code track induction coil equal to the spacing between the secondary code track rotor coil and the secondary code track induction coil, thus achieving a larger working air gap (i.e., the gap between the rotor and the stator). Alternatively, the secondary code track rotor coil, the main code track rotor coil, the secondary code track induction coil, and the main code track induction coil can be arranged sequentially along the encoder axis.

[0073] Of course, in other embodiments, the main code track rotor coil, the secondary code track rotor coil, the secondary code track induction coil, and the main code track induction coil can be arranged sequentially along the encoder axis.

[0074] In some embodiments, such as Figure 8As shown, the wires of the first induction coil 21 extend in a sinusoidal periodic pattern. The wires of the second induction coil 22 also extend in a sinusoidal periodic pattern. This allows for more accurate monitoring of parameters such as the number of rotations of the rotor coil group 1, which is beneficial for improving the measurement accuracy of the encoder. As an alternative, such as Figure 9 As shown, the wires of the first induction coil 21 can also extend periodically in a zigzag pattern. The wires of the second induction coil 22 can also extend periodically in a zigzag pattern. Of course, the first induction coil 21 and the second induction coil 22 can also adopt other forms of induction coils in the prior art, which are not limited here.

[0075] It should be noted that the encoder coil unit 10 also includes an excitation coil group 3, which includes at least one excitation coil 31 for transmitting excitation signals to the first rotor coil 11 and the second rotor coil 12.

[0076] In some embodiments, the induction coil group 2 is provided with an excitation coil 31 on at least one of the two sides along the encoder axis and the two sides along the encoder radial direction.

[0077] In this embodiment, there are two excitation coils 31, referred to as the first excitation coil 31a and the second excitation coil 31b respectively. The first excitation coil 31a is sleeved on the outside of the induction coil group 2, and the induction coil group 2 is sleeved on the outside of the second excitation coil 31b. This allows the magnetic field strength and induced voltage generated by the excitation coil group 3 to be greater, which is beneficial to improving the measurement accuracy of the encoder.

[0078] In other embodiments, an excitation coil 31 can be provided, sleeved outside the induction coil group 2. This results in a longer excitation coil 31, generating a stronger magnetic field and a larger induced voltage, which improves the encoder's measurement accuracy. It is understood that providing only one excitation coil 31 also simplifies the encoder's structure, improves space utilization, and reduces costs. Of course, when other structures exist outside the induction coil group 2, to avoid interference, the induction coil group 2 can also be sleeved outside the excitation coil 31. This increases the complexity of encoder design and manufacturing, meeting various design and usage requirements.

[0079] In other embodiments, three excitation coils 31 may be provided, for example, excitation coils 31 may be provided on both sides of the induction coil group 2 along the radial direction of the encoder and on one side of the induction coil group 2 along the axial direction of the encoder. Four excitation coils 31 may also be provided, for example, excitation coils 31 may be provided on both sides of the induction coil group 2 along the radial direction of the encoder and on both sides of the induction coil group 2 along the axial direction of the encoder.

[0080] In other words, the excitation coil 31 can be located on one side of the first induction coil 21 along the encoder axis; or, the excitation coil 31 can be located on one side of the first induction coil 21 along the encoder radial direction; or, the excitation coil 31 can be located on one side of the second induction coil 22 along the encoder axis; or, the excitation coil 31 can be located on one side of the second induction coil 22 along the encoder radial direction. This embodiment does not limit the location or number of the excitation coil 31.

[0081] In some embodiments, the excitation coil 31 and the first induction coil 21 are disposed on the same layer, which simplifies the stator layout and improves the ease of stator fabrication. Alternatively, the excitation coil 31 and the second induction coil 22 can also be disposed on the same layer. The excitation coil 31 can also be located on one side of the first induction coil 21 or the second induction coil 22 along the encoder axis.

[0082] In some embodiments, when at least two excitation coils 31 are provided, each excitation coil 31 is set independently, which facilitates time-division control of each coil and can reduce magnetic field interference.

[0083] In other embodiments, when multiple excitation coils 31 are provided, at least two of the multiple excitation coils 31 can be connected in series, and / or at least two of the multiple excitation coils 31 can be connected in parallel, and / or at least two of the multiple excitation coils 31 can be arranged independently. This satisfies various design and usage requirements. It should be noted that when at least two excitation coils 31 are connected in series, the current on the series-connected excitation coils 31 is equal everywhere, resulting in better uniformity of the generated magnetic field strength.

[0084] It should be noted that in this embodiment, the first rotor coil 11, the second rotor coil 12, the first induction coil 21, the second induction coil 22 and the excitation coil 31 are all ring structures, and the axes of the first rotor coil 11, the second rotor coil 12, the first induction coil 21, the second induction coil 22 and the excitation coil 31 are all coincident with the axis of the encoder.

[0085] In some embodiments, the encoder further includes a rotor circuit board, on which the first rotor coil 11 and the second rotor coil 12 are both disposed, thereby simplifying the rotor layout and improving the convenience of rotor manufacturing.

[0086] In some embodiments, the encoder further includes a stator circuit board; both the induction coil group 2 and the excitation coil group 3 are disposed on the stator circuit board, that is, both the first induction coil 21 and the second induction coil 22 are disposed on the stator circuit board. This arrangement simplifies the stator layout and improves the convenience of stator manufacturing.

[0087] In other embodiments, the encoder may also include a stator circuit board and a first circuit board, with the induction coil group 2 and the excitation coil group 3 both located on the first circuit board. The first circuit board is electrically connected to the stator circuit board, thus allowing the stator circuit board and the first circuit board to be manufactured separately and then assembled, enabling different production methods and improving the versatility of the encoder.

[0088] It should be noted that when the encoder is working, the stator circuit board is fixed, and the rotor circuit board can rotate relative to the stator circuit board around the encoder axis. In other words, the rotor coil group 1 can rotate relative to the induction coil group 2 and the excitation coil group 3 around the encoder axis.

[0089] It should be noted that the stator circuit board and the first circuit board are usually provided with screw holes for fasteners such as screws. These screw holes are usually located on the outer ring of the stator circuit board and the first circuit board, so that the excitation coil 31 is sleeved on the outside of the induction coil group 2. The screw holes can also be used as through holes for the excitation coil 31, thereby improving the utilization rate of the stator circuit board and the first circuit board.

[0090] In some embodiments, such as Figure 1 As shown, the encoder coil unit also includes a shield 4. Along the encoder axis, the shield 4 and the induction coil group 2 are located on opposite sides of the rotor coil group 1. It should be noted that the encoder also includes a metal mounting base or metal housing. The rotor circuit board is mounted on the metal mounting base or metal housing. By placing the shield 4 on the side of the rotor coil group 1 away from the induction coil group 2 along the encoder axis, the interference of the metal mounting base or metal housing on the rotor coil group 1 can be reduced, which is beneficial to improving the measurement accuracy of the encoder.

[0091] For example, the shielding element 4 is a circular copper foil.

[0092] In some embodiments, such as Figures 10 to 15 As shown, there are two encoder coil units 10, referred to as the first encoder coil unit 10a and the second encoder coil unit 10b, respectively. That is, the encoder is a dual encoder. Dual encoders not only improve measurement accuracy but also enable redundancy and backup functions. Specifically, the rotor coil group 1 of the first encoder coil unit 10a is sleeved outside the rotor coil group 1 of the second encoder coil unit 10b. Further, the induction coil group 2 of the first encoder coil unit 10a is sleeved outside the induction coil group 2 of the second encoder coil unit 10b. This arrangement reduces the size of the dual encoder, thus facilitating a compact and lightweight design.

[0093] The following section introduces dual encoders.

[0094] Specifically, there are two rotor circuit boards, referred to as the first rotor circuit board and the second rotor circuit board. The rotor coil group 1 of the first encoder coil unit 10a is located on the first rotor circuit board, and the rotor coil group 1 of the second encoder coil unit 10b is located on the second rotor circuit board. The first rotor circuit board is driven to rotate by a first rotating mechanism, and the second rotor circuit board is driven to rotate by a second rotating mechanism. That is to say, the first rotor circuit board and the second rotor circuit board rotate independently of each other.

[0095] Furthermore, the induction coil group 2 and excitation coil group 3 of the first encoder coil unit 10a, and the induction coil group 2 and excitation coil group 3 of the second encoder coil unit 10b are all located on the stator circuit board.

[0096] In some embodiments, if the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are located on the same layer, then one of the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b has an odd number of pole pairs, and the other has an even number of pole pairs. This reduces mutual interference between the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0097] In some embodiments, when the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are located on the same layer, the pole pairs of the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are coprime. This reduces the mutual interference between the first rotor coil 11 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0098] In some embodiments, if the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b are located on the same layer, then one of the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b has an odd number of pole pairs, and the other has an even number of pole pairs. This reduces mutual interference between the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0099] In some embodiments, the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b are located on the same layer, and the pole pairs of the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b are coprime. This reduces mutual interference between the second rotor coil 12 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0100] In other embodiments, the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b can be located on the same layer. In this case, the number of pole pairs of one of the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b is odd, and the number of pole pairs of the other is even. This can reduce the mutual interference between the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0101] In other embodiments, when the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b are located on the same layer, the pole pairs of the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b are coprime. This reduces mutual interference between the first rotor coil 11 of the first encoder coil unit 10a and the second rotor coil 12 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0102] In other embodiments, the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are located on the same layer. In this case, one of the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b has an odd number of pole pairs, and the other has an even number of pole pairs. This reduces mutual interference between the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder.

[0103] In other embodiments, when the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are located on the same layer, the pole pairs of the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b are coprime. This reduces mutual interference between the second rotor coil 12 of the first encoder coil unit 10a and the first rotor coil 11 of the second encoder coil unit 10b, thereby improving the measurement accuracy of the encoder. In this embodiment, in either the first encoder coil unit 10a or the second encoder coil unit 10b, along the encoder axis, the first rotor coil 11 is farther away from the induction coil group 2 than the second rotor coil 12. Of course, in other embodiments, in either the first encoder coil unit 10a or the second encoder coil unit 10b, along the encoder axis, the second rotor coil 12 may be farther away from the induction coil group 2 than the first rotor coil 11.

[0104] For example, the correspondence between the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 of the first encoder coil unit 10a, and the number of pole pairs of the first rotor coil 11 and the number of pole pairs of the second rotor coil 12 of the second encoder coil unit 10b, is shown in the table below:

[0105]

[0106] It should be noted that in this embodiment, since there are two encoder coil units 10, that is, each of the two encoder coil units 10 has its own excitation coil group 3. Further, as... Figure 11 As shown, in the first encoder coil unit 10a, the excitation coil group 3 includes an excitation coil 31, denoted as excitation coil one 31c, and the excitation coil 31 is sleeved outside the induction coil group 2. Further, in the second encoder coil unit 10b, the excitation coil group 3 includes an excitation coil 31, denoted as excitation coil two 31d, and the induction coil group 2 is sleeved outside the excitation coil two 31d. By performing time-division control on excitation coil one 31c and excitation coil two 31d, for example... Figure 12 As shown, when excitation coil 31c is energized, excitation coil 31d is not energized. At this time, current is generated in both the first rotor coil 11 and the second rotor coil 12 of the first encoder coil unit 10a, while no current is generated in either the first rotor coil 11 or the second rotor coil 12 of the second encoder coil unit 10b. Figure 13As shown, when the second excitation coil 31d is energized, the first excitation coil 31c is not energized. At this time, no current is generated in the first rotor coil 11 and the second rotor coil 12 of the first encoder coil unit 10a, while current is generated in the first rotor coil 11 and the second rotor coil 12 of the second encoder coil unit 10b. This can reduce magnetic field interference and improve the measurement accuracy of the encoder.

[0107] In other embodiments, such as Figure 14 As shown, the encoder coil assembly can also include an excitation coil group 3. That is, the first encoder coil unit 10a and the second encoder coil unit 10b share an excitation coil group 3. The excitation coil group 3 includes an excitation coil 31. The induction coil group 2 of the first encoder coil unit 10a is sleeved outside the excitation coil 31, and the excitation coil 31 is sleeved outside the induction coil group 2 of the second encoder coil unit 10b. With this configuration, the first rotor coil 11 and the second rotor coil 12 of the first encoder coil unit 10a, as well as the first rotor coil 11 and the second rotor coil 12 of the second encoder coil unit 10b, can be driven simultaneously by the excitation coil 31. In other words, as shown... Figure 15 As shown, when the excitation coil 3 is energized, current is generated in the first rotor coil 11 and the second rotor coil 12 of the first encoder coil unit 10a, and in the first rotor coil 11 and the second rotor coil 12 of the second encoder coil unit 10b. This helps to reduce the space occupied by the encoder coil assembly, simplify the structure of the dual encoder, improve the convenience of manufacturing the dual encoder, and reduce the cost.

[0108] Furthermore, the excitation coil 31 is disposed on the same layer as the first induction coil 21 of the first encoder coil unit 10a or the second encoder coil unit 10b, thereby simplifying the stator layout and improving the convenience of stator manufacturing. Alternatively, the excitation coil 31 can also be disposed on the same layer as the second induction coil 22 of the first encoder coil unit 10a or the second encoder coil unit 10b. The excitation coil 31 can also be located on one side of the first induction coil 21 of the first encoder coil unit 10a or the second encoder coil unit 10b along the encoder axis; or the excitation coil 31 can be located on one side of the second induction coil 22 of the first encoder coil unit 10a or the second encoder coil unit 10b along the encoder axis.

[0109] It should be noted that this embodiment does not limit the number of excitation coils 31 or the arrangement of the excitation coils 31 (including at least two excitation coils 31 connected in series, in parallel, or independently).

[0110] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. An encoder coil assembly for an encoder, characterized in that, The encoder coil unit includes an encoder coil unit, which includes a rotor coil group, which includes a first rotor coil and a second rotor coil spaced apart along the encoder axis. The first rotor coil includes at least one first coil branch arranged along the circumferential direction of the encoder and connected end to end. The first coil branch includes a first arc segment and a second arc segment extending along the circumferential direction of the encoder, and a first straight segment and a second straight segment extending radially along the encoder. The radius of the first arc segment is not equal to the radius of the second arc segment. The center of the first arc segment and the center of the second arc segment coincide with the axis of the encoder. The first arc segment and the second arc segment are staggered along the circumferential direction of the encoder. The two ends of the first straight segment are connected to the first arc segment and the second arc segment respectively. The second straight segment is connected to the end of the second arc segment away from the first straight segment. The second rotor coil includes at least two second coil branches arranged along the circumference of the encoder and connected end to end. Each second coil branch includes an arc segment 1 and an arc segment 2 extending along the circumference of the encoder, and a straight segment 1 and a straight segment 2 extending radially along the encoder. The radius of the arc segment 1 is not equal to the radius of the arc segment 2. The center of the arc segment 1 and the center of the arc segment 2 coincide with the axis of the encoder. The arc segment 1 and the arc segment 2 are offset along the circumference of the encoder. The two ends of the straight segment 1 are connected to the arc segment 1 and the arc segment 2, respectively. The straight segment 2 is connected to the end of the arc segment 2 that is away from the straight segment 1.

2. The encoder coil assembly according to claim 1, characterized in that, The encoder coil unit also includes a shield and an induction coil group, with the shield and the induction coil group located on opposite sides of the rotor coil group along the encoder axis.

3. The encoder coil assembly according to claim 1, characterized in that, The encoder coil unit further includes an induction coil group, which includes a first induction coil corresponding to the first rotor coil and a second induction coil corresponding to the second rotor coil. The first induction coil and the second induction coil are spaced apart along the encoder axis.

4. The encoder coil assembly according to claim 3, characterized in that, The encoder coil unit is provided in two parts, which are referred to as the first encoder coil unit and the second encoder coil unit respectively. The rotor coil group of the first encoder coil unit is sleeved on the outside of the rotor coil group of the second encoder coil unit; The induction coil group of the first encoder coil unit is sleeved on the outside of the induction coil group of the second encoder coil unit.

5. The encoder coil assembly according to claim 4, characterized in that, The encoder coil assembly further includes an excitation coil group, which includes at least one excitation coil for transmitting excitation signals to the first rotor coil and the second rotor coil.

6. The encoder coil assembly according to claim 5, characterized in that, The excitation coil is located on one side of the first induction coil along the encoder axis; or, The excitation coil is located on one side of the first induction coil along the radial direction of the encoder; or, The excitation coil is located on one side of the second induction coil along the encoder axis; or, The excitation coil is located on one side of the second induction coil along the radial direction of the encoder.

7. The encoder coil assembly according to claim 5, characterized in that, The excitation coil is provided in multiple ways, with at least two of the excitation coils connected in series, and / or at least two of the excitation coils connected in parallel, and / or at least two of the excitation coils being set up independently of each other.

8. The encoder coil assembly according to claim 4, characterized in that, When the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the first rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are coprime. When the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the second rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are coprime. When the first rotor coil of the first encoder coil unit and the second rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the first rotor coil of the first encoder coil unit and the number of pole pairs of the second rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the first rotor coil of the first encoder coil unit and the number of pole pairs of the second rotor coil of the second encoder coil unit are coprime. When the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are located on the same layer, the number of pole pairs of one of the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit is odd and the number of pole pairs of the other is even, and / or the number of pole pairs of the second rotor coil of the first encoder coil unit and the first rotor coil of the second encoder coil unit are coprime.

9. The encoder coil assembly according to any one of claims 1-8, characterized in that, The number of pole pairs of the first rotor coil and the number of pole pairs of the second rotor coil are coprime.

10. The encoder coil assembly according to any one of claims 1-8, characterized in that, The number of pole pairs of the first rotor coil is not equal to the number of pole pairs of the second rotor coil.

11. The encoder coil assembly according to any one of claims 1-8, characterized in that, The difference between the number of pole pairs of the first rotor coil and the number of pole pairs of the second rotor coil is 1.

12. An encoder, characterized in that, Includes the encoder coil assembly as described in any one of claims 1-11.

13. The encoder according to claim 12, characterized in that, The encoder also includes a rotor circuit board, on which both the first rotor coil and the second rotor coil are disposed.

14. The encoder according to claim 12, characterized in that, The encoder coil unit further includes an induction coil group and an excitation coil group, and the encoder further includes a stator circuit board; Both the induction coil group and the excitation coil group are located on the stator circuit board; or, the encoder further includes a first circuit board, both the induction coil group and the excitation coil group are located on the first circuit board, and the first circuit board is electrically connected to the stator circuit board.

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