Resolver

Abstract

This resolver comprises an excitation coil to which an excitation signal is input and a detection coil for outputting a detection signal, and detects the movement amount of a moving body provided with one among an excitation coil and a detection coil on the basis of the detection signal. In the excitation coil and the detection coil, a coil pattern is formed in a planar shape, and at least one among the excitation coil and the detection coil is formed in a coil pattern including a sinusoidal pattern.

Description

Resolver

[0001] The present technology relates to the technical field of resolver structures.

[0002] There is known a resolver that includes two-phase excitation coils outputting excitation signals having a phase difference of 90°, and a detection coil provided on a rotating part and outputting a detection signal, wherein the resolver detects the rotation angle of the rotating part based on the phase difference between the excitation signal and the detection signal.

[0003] In such resolvers, there has been proposed a resolver in which coil parts each having rectangular wave-shaped coil patterns respectively formed on the front surface and the back surface of a sheet coil are arranged with a phase difference of 180° (for example, Patent Document 1).

[0004] In this resolver, for at least one sheet coil among the two-phase excitation coils and the detection coil, the phases of the coil parts formed on the front surface and the back surface are differ by a predetermined electrical angle to cancel the harmonic components of the magnetic flux distribution.

[0005] Japanese Unexamined Patent Publication No. 2021-32718

[0006] In the resolver as disclosed in Patent Document 1, in order to cancel the harmonic components of the magnetic flux distribution, even the magnetic flux necessary for angle detection is mutually canceled, which may rather reduce the angle detection accuracy.

[0007] The present proposal has been made based on such background, and aims to reduce harmonic components of magnetic flux distribution on the detection coil and improve the detection accuracy of the movement amount of a moving body.

[0008] The resolver according to the present technology includes an excitation coil to which an excitation signal is input and a detection coil that outputs a detection signal, and detects the movement amount of a moving body provided with one of the excitation coil and the detection coil based on the detection signal. In the resolver, the excitation coil and the detection coil each have a coil pattern formed in a planar shape, and at least one of the excitation coil and the detection coil is formed into a coil pattern including a sinusoidal pattern. This enables the resolver to reduce harmonic components of the magnetic flux distribution generated on the detection coil.

[0009] This technology reduces the harmonic components of the magnetic flux distribution on the detection coil, thereby improving the accuracy of detecting the amount of movement of a moving object.

[0010] This is a block diagram showing the configuration of the resolver. This is a side cross-sectional view showing the internal structure of the main body. This is a schematic side cross-sectional view showing the positional relationship between the detection side sheet coil and the excitation side sheet coil. This is a diagram showing the schematic structure of the detection side sheet coil and the excitation side sheet coil. This is a diagram showing a normal coil pattern. This is a diagram showing Example 1 of a sinusoidal reduction coil pattern. This is a diagram showing Example 2 of a sinusoidal reduction coil pattern. This is a diagram showing Example 3 of a sinusoidal reduction coil pattern. This is a diagram showing Example 4 of a sinusoidal reduction coil pattern. This is a diagram showing an example of a combined reduction coil pattern. This is a diagram showing the relationship between the ratio p and the output voltage index a(p). This is a diagram showing the relationship between the ratio p and the index of low harmonic components b(p). This is a diagram showing the relationship between the ratio p and the harmonic mean M(p).

[0011] <1. Resolver Configuration> Figure 1 is a block diagram showing the configuration of resolver 1. Figure 2 is a side cross-sectional view showing the internal structure of the main body 2. As shown in Figure 1, resolver 1 comprises a main body 2 and a signal processing unit 3.

[0012] As shown in Figure 2, the main body 2 comprises a casing 20, a rotating part 21 which is an example of a movable body and is rotatably supported at the center of the casing 20, and a fixed part 22 which is fixed to the casing 20.

[0013] The rotating section 21 is composed of a rotating shaft 31, a rotating plate 32, an iron core 33, a primary coil 34, an iron core 35, and a detection-side sheet coil section 36.

[0014] A rotating plate 32 is fixed to the rotating shaft 31 and rotates integrally with the rotating plate 32. An iron core 33 is also fixed to the rotating shaft 31. A primary coil 34 is attached to the iron core 33. The primary coil 34 is positioned opposite the secondary coil 43, which will be described later, and together with the secondary coil 43, constitutes the output transformer 15 (see Figure 1).

[0015] A ring-shaped iron core 35 is fixed to the rotating plate 32 on the side facing the fixed part 22. A detection-side sheet coil portion 36, formed from a flexible printed circuit board or the like, is attached to the side of the iron core 35 opposite to the rotating plate 32 (the side facing the fixed part 22).

[0016] Figure 3 is a schematic side cross-sectional view showing the positional relationship between the detection-side sheet coil section 36 and the excitation-side sheet coil sections 45 and 46. As shown in Figure 3, the detection-side sheet coil section 36 comprises an insulating layer 51 and detection coils 52 (52a, 52b). The insulating layer 51 is formed in a ring shape, and the detection coils 52a and 52b are formed in a planar (sheet) shape on the surface 51a and back surface 51b of the insulating layer 51, respectively.

[0017] Returning to Figure 2, the fixed portion 22 has a base portion 41, an iron core 42, a secondary coil 43, an iron core 44, and excitation side sheet coil portions 45 and 46.

[0018] The base portion 41 is formed in a ring shape and fixed to the casing 20. A secondary coil 43 is provided near the center of the base portion 41, opposite the primary coil 34, via an iron core 42. The secondary coil 43, together with the primary coil 34, constitutes the output transformer 15.

[0019] Furthermore, a ring-shaped iron core 44 is fixed to the surface of the base portion 41 that is closer to the outer circumference and on the side facing the rotating portion 21.

[0020] On the side of the iron core 44 opposite to the base portion 41 (the side facing the rotating portion 21), excitation-side sheet coil portions 45 and 46, formed from a flexible printed circuit board or the like, are mounted so as to face the detection-side sheet coil portion 36.

[0021] As shown in Figure 3, the excitation-side sheet coil section 45 comprises an insulating layer 53 and excitation coils 54 (54a, 54b). The insulating layer 53 is formed in a ring shape, and the excitation coils 54a and 54b are formed in a planar manner on the surface 53a and back surface 53b of the insulating layer 53, respectively.

[0022] The excitation-side sheet coil section 46 comprises an insulating layer 55 and excitation coils 56 (56a, 56b). The insulating layer 55 is formed in a ring shape, and the excitation coils 56a and 56b are formed in a planar manner on the surface 55a and back surface 55b of the insulating layer 55, respectively. An insulating layer (not shown) is interposed between excitation coil 54a and excitation coil 56b.

[0023] The excitation-side sheet coil sections 45 and 46 are arranged such that the excitation coils 54 and 56 are superimposed with a 90° phase difference in electrical angle. As a result, excitation coil 54 functions as the sine-phase excitation coil, and excitation coil 56 functions as the cosine-phase excitation coil.

[0024] Returning to Figure 1, the signal processing unit 3 includes a signal generation unit 11, a first signal output unit 12, a second signal output unit 13, and an angle detection unit 14.

[0025] The signal generation unit 11 generates counter pulses based on a clock signal generated using a crystal oscillator (not shown), and generates a high-frequency signal Sh with a frequency of approximately 1 MHz based on the generated counter pulses. The signal generation unit 11 also generates excitation signals Sx and Sy with a frequency of approximately 1 kHz based on the generated high-frequency signal Sh.

[0026] The first signal output unit 12 receives a high-frequency signal Sh and an excitation signal Sx from the signal generation unit 11. The first signal output unit 12 reverses the polarity of the high-frequency signal Sh at the polarity reversal position of the excitation signal Sx, and modulates the reversed high-frequency signal Sh with the excitation signal Sx to generate a modulated signal Smx. The first signal output unit 12 supplies the generated modulated signal Smx to the excitation coil 54.

[0027] The second signal output unit 13 receives the high-frequency signal Sh and the excitation signal Sy from the signal generation unit 11. The second signal output unit 13 reverses the polarity of the high-frequency signal Sh at the polarity reversal position of the excitation signal Sy, and modulates the reversed high-frequency signal Sh with the excitation signal Sy to generate a modulated signal Smy. The second signal output unit 13 supplies the generated modulated signal Smy to the excitation coil 56.

[0028] In this way, by supplying the modulation signal Smx to the excitation coil 54 and the modulation signal Smy to the excitation coil 56, two-phase magnetic flux exhibiting a periodic change with a 90° phase difference is simultaneously generated in the excitation coils 54 and 56, and this two-phase magnetic flux is detected as a modulation signal Smo by the detection coil 52 of the detection-side sheet coil section 36. The modulation signal Smo detected by the detection coil 52 is supplied to the angle detection section 14 via the output transformer 15.

[0029] The angle detection unit 14 demodulates the modulated signal Smo output from the secondary coil 43 of the output transformer 15 and obtains a detection signal So by performing various correction processes as necessary. The angle detection unit 14 also obtains signals necessary for angle detection, such as counter pulses obtained from the signal generation unit 11.

[0030] The phase of the detection signal So changes according to the rotation of the rotating part 21. The angle detection unit 14 detects the phase difference of the detection signal So based on the signal acquired from the signal generation unit 11, and calculates the rotation angle (amount of movement) of the rotating part 21 based on the detected phase difference. The angle detection unit 14 outputs the calculated rotation angle information to an external device or the like.

[0031] Thus, in the resolver 1 of this embodiment, the modulated signals Smx, Smy, and Smo, modulated by the high-frequency signal Sh, flow through the excitation coils 54 and 56 and the detection coil 52, respectively. Therefore, even if each coil is formed in the form of a sheet coil with fewer windings, a sufficient voltage can be induced in the detection coil 52.

[0032] <2. Structure of the detection-side sheet coil section and the excitation-side sheet coil section> Figure 4 shows the schematic structure of the detection-side sheet coil section 36 and the excitation-side sheet coil sections 45 and 46. In Figure 4, the detection coil 52a formed on the surface 51a of the insulating layer 51 is shown with a solid line, and the detection coil 52b formed on the back surface 51b of the insulating layer 51 is shown with a dashed line. Also in Figure 4, the coil pattern of the detection coils 52a and 52b is shown as a normal coil pattern 71 (see Figure 5). The same applies to the excitation-side sheet coil sections 45 and 46.

[0033] Here, the detection-side sheet coil section 36 and the excitation-side sheet coil sections 45 and 46 are identical in other configurations, although the coil patterns of the detection coil 52 and the excitation coils 54 and 56 may differ. Therefore, for the sake of explanation, the structure of the detection-side sheet coil section 36 will be described here, and the structure of the excitation-side sheet coil sections 45 and 46 will be omitted. However, the combinations of coil patterns used in the detection coil 52 and the excitation coils 54 and 56 will be explained separately.

[0034] As shown in Figures 3 and 4, in the detection-side sheet coil section 36, a detection coil 52a is formed on the surface 51a of the insulating layer 51, and a detection coil 52b is formed on the back surface 51b of the insulating layer 51.

[0035] The detection coils 52a and 52b are each formed in an annular (ring-shaped) manner using the same coil pattern configured in a multi-pole format. In the example in Figure 4, the number of pole pairs is 16, but the number of pole pairs is not limited to this and can be any number from 2 to 512, for example.

[0036] Furthermore, detection coils 52a and 52b are positioned such that detection coil 52b is 180° out of phase with respect to detection coil 52a in terms of electrical angle. Therefore, although detection coils 52a and 52b are shown slightly offset in Figure 4 for illustrative purposes, the conductors extending in the radial direction RD are actually positioned to overlap in the front-back direction.

[0037] A connection terminal 63 is provided at one end of the detection coil 52a. The connection terminal 63 is connected to one end of the primary coil 34 that constitutes the output transformer 15 (see Figure 1). The other end of the detection coil 52a is connected to a through-hole 64 formed in the insulating layer 51. One end of the detection coil 52b is connected to a connection terminal 65. The through-hole 64 and the connection terminal 65 are connected by a conductor 66. Therefore, the other end of the detection coil 52a and one end of the detection coil 52b are connected via the through-hole 64, the connection terminal 65, and the conductor 66. A connection terminal 67 is provided at the other end of the detection coil 52b. The connection terminal 67 is connected to the other end of the primary coil 34 that constitutes the output transformer 15 (see Figure 1). The modulated signal Smo generated in the detection coil 52 in accordance with the rotation of the rotating part 21 is supplied to the angle detection unit 14 via the output transformer 15 (see Figure 1).

[0038] Thus, in the detection-side sheet coil section 36, the detection coil 52a and the detection coil 52b are connected in series. Therefore, current flows in the same direction through the conductors that overlap radially RD in the detection coil 52a and the detection coil 52b, and an effective magnetic flux is generated by adding the magnetic flux generated by both conductors.

[0039] In addition, the excitation-side sheet coil section 45 is configured in the same way as the detection-side sheet coil section 36, so that one end of the excitation coil 54a is connected to one end of the first signal output section 12, and the other end of the excitation coil 54b is connected to the other end of the first signal output section 12.

[0040] Furthermore, the excitation-side sheet coil section 46 is configured in the same way as the detection-side sheet coil section 36, so that one end of the excitation coil 56a is connected to one end of the second signal output section 13, and the other end of the excitation coil 56b is connected to the other end of the second signal output section 13.

[0041] <3. Coil Patterns> The coil patterns of the detection coil 52 and the excitation coils 54 and 56 will be described below.

[0042] Coil patterns are broadly classified into normal coil patterns formed only by rectangular patterns, and reduction coil patterns that include sinusoidal patterns and reduce harmonic components of the magnetic flux distribution (mutual inductance) on the detection coil 52. Hereinafter, a rectangular pattern is referred to as a rectangular-wave pattern, and a sinusoidal pattern is referred to as a sinusoidal pattern.

[0043] Further, reduction coil patterns are broadly classified into sinusoidal reduction coil patterns formed by a combination of two sinusoidal patterns, and combined reduction coil patterns formed by a combination of a sinusoidal pattern and a rectangular-wave pattern.

[0044] [3.1 Normal coil pattern] Figure 5 is a diagram showing a normal coil pattern. In the following figures (Figures 5 to 10), the coil pattern on the front surface side is shown by a solid line, and the coil pattern on the back surface side is shown by a broken line. Further, in the following figures, among coil patterns configured in a multipolar format, only one cycle of the coil pattern is illustrated, and the circumferential direction CD is illustrated as a straight line. Furthermore, in the following figures, the coil pattern on the back surface side may be illustrated slightly shifted relative to the coil pattern on the front surface side, but in reality, the radial conductive wires respectively formed on the front surface and the back surface overlap each other in the front-back direction.

[0045] As shown in Figures 4 and 5, the normal coil pattern 71 is formed into a rectangular-wave pattern by alternately connecting radial conductive wires 61 substantially along the radial direction RD and circumferential conductive wires 62 along the circumferential direction CD at substantially right angles.

[0046] When the excitation coils 54 and 56 are formed by the normal coil pattern 71, the magnetic flux distribution on the detection coil 52 generated by the excitation coils 54 and 56 contains many harmonic components, and these harmonic components affect angle detection error. The harmonic components contained herein are n-th order harmonic components (where n is an odd number of 3 or more), such as 3rd-order, 5th-order, and 7th-order.

[0047] Therefore, by using a reduction coil pattern for at least one of the detection coil 52 and the excitation coils 54, 56, harmonic components contained in the modulated signal Smo detected by the detection coil 52 are reduced.

[0048] [3.2 Example 1 of sinusoidal reduction coil pattern] Fig. 6 is a diagram showing Example 1 of a sinusoidal reduction coil pattern. As shown in Fig. 6, the sinusoidal reduction coil pattern 72 of Example 1 is formed by combining a first sinusoidal pattern 81 that changes sinusoidally along the circumferential direction CD, and a second sinusoidal pattern 82 that changes sinusoidally along the circumferential direction CD and has a phase difference of 1 / 2 period from the first sinusoidal pattern 81. Note that the first sinusoidal pattern 81 and the second sinusoidal pattern 82 each have a length corresponding to 1 / 2 period.

[0049] The first sinusoidal pattern 81 is disposed on the outer side in the radial direction RD, and the second sinusoidal pattern 82 is disposed on the inner side in the radial direction RD.

[0050] Let h1 be the ratio of the first sinusoidal pattern 81 in the radial direction RD, and h2 be the ratio of the second sinusoidal pattern 82 in the radial direction RD.

[0051] In the sinusoidal reduction coil pattern 72 of Example 1, the ratio h1 and the ratio h2 are arbitrarily set.

[0052] Furthermore, in a sinusoidal pattern, harmonic components are not included in the magnetic flux distribution, or harmonic components can be reduced. Therefore, even when, for example, the excitation coils 54 and 56 are formed as a normal coil pattern 71 and the detection coil 52 is formed as the sinusoidal reduction coil pattern 72, the harmonic components of the magnetic flux distribution on the detection coil 52 can be reduced.

[0053] Furthermore, in the sinusoidal reduction coil pattern 72, the ratio between the first sinusoidal pattern 81 and the second sinusoidal pattern 82 can be arbitrarily set. Therefore, even in a case where the magnetic flux distribution is biased in the radial direction RD by the first sinusoidal pattern 81 and the second sinusoidal pattern 82 in the sinusoidal reduction coil pattern 72, the bias of the magnetic flux distribution in the radial direction RD can be reduced by adjusting the ratio of these patterns.

[0054] [3.3 Example 2 of the sinusoidal reduction coil pattern] Figure 7 shows Example 2 of the sinusoidal reduction coil pattern. As shown in Figure 7, the sinusoidal reduction coil pattern 73 of Example 2 is formed by combining a first sinusoidal pattern 81 and a second sinusoidal pattern 82, similar to the sinusoidal reduction coil pattern 72 of Example 1.

[0055] In the sinusoidal wave reduction coil pattern 73, the ratio h1 of the radial RD of the first sinusoidal wave pattern 81 and the ratio h2 of the radial RD of the second sinusoidal wave pattern 82 are set to 1:1. Therefore, in the sinusoidal wave reduction coil pattern 73, one sinusoidal wave pattern is formed by the first sinusoidal wave pattern 81 and the second sinusoidal wave pattern 82.

[0056] Thus, even when the ratio h1 and the ratio h2 are 1:1, the sinusoidal reduction coil pattern 73, like the sinusoidal reduction coil pattern 72, can prevent harmonic components from being included in the magnetic flux distribution on the detection coil 52, or reduce harmonic components.

[0057] [3.4 Example 3 of the sinusoidal reduction coil pattern] Figure 8 shows Example 3 of the sinusoidal reduction coil pattern. As shown in Figure 8, the sinusoidal reduction coil pattern 74 of Example 3 is formed by combining a first sinusoidal pattern 81 and a second sinusoidal pattern 82, similar to the sinusoidal reduction coil pattern 72 of Example 1.

[0058] In the sinusoidal wave reduction coil pattern 74, the ratio h1 of the radial RD of the first sinusoidal wave pattern 81 and the ratio h2 of the radial RD of the second sinusoidal wave pattern 82 are set to 1:0. Therefore, in the sinusoidal wave reduction coil pattern 73, the portion of the second sinusoidal wave pattern 82 is formed to extend in a straight line along the circumferential direction CD.

[0059] Thus, even when the ratio h1 and the ratio h2 are 1:0, the sinusoidal reduction coil pattern 74, like the sinusoidal reduction coil pattern 72, can prevent harmonic components from being included in the magnetic flux distribution on the detection coil 52, or reduce harmonic components.

[0060] [3.5 Example 4 of the sinusoidal reduction coil pattern] Figure 9 shows Example 4 of the sinusoidal reduction coil pattern. As shown in Figure 9, the sinusoidal reduction coil pattern 75 of Example 4 has the sinusoidal reduction coil pattern 74 of Example 3 and the sinusoidal reduction coil pattern 76 which is obtained by shifting the phase of the sinusoidal reduction coil pattern 74 of Example 3 by 1 / 2 period and inverting it in the radial direction RD formed on the same plane. However, the sinusoidal reduction coil pattern 74 and the sinusoidal reduction coil pattern 76 are offset in the radial direction RD so that they do not come into contact with each other. The sinusoidal reduction coil pattern 74 and the sinusoidal reduction coil pattern 76 are connected at their ends in the circumferential direction CD.

[0061] The sinusoidal wave reduction coil pattern 74 has a ratio h2 of the radial RD to the second sinusoidal wave pattern 82 of 0 and is formed in a straight line along the circumferential direction CD, so the outer side in the radial direction RD is empty. Therefore, the first sinusoidal wave pattern 81 of the sinusoidal wave reduction coil pattern 76 is placed in that empty space.

[0062] As a result, the sinusoidal reduction coil pattern 75 can increase the magnetic flux generated by the sinusoidal reduction coil patterns 74 and 76, thereby increasing the output voltage.

[0063] [3.6 Example of a Combined Reduction Coil Pattern] Figure 10 shows an example of a combined reduction coil pattern. As shown in Figure 10, the combined reduction coil pattern 77 of the example is formed by combining a sinusoidal wave pattern 83 that changes sinusoidally along the circumferential direction CD and a rectangular wave pattern 84 that changes rectangularly along the circumferential direction CD. The sinusoidal wave pattern 83 and the rectangular wave pattern 84 each have a length of 1 / 2 period.

[0064] The sinusoidal wave pattern 83 is positioned on the outside in the radial direction RD, and the rectangular wave pattern 84 is positioned on the inside in the radial direction RD.

[0065] The rectangular wave pattern 84 includes radial conductors 84a, one end of which is connected to each end of the sinusoidal wave pattern 83, and an inner circumferential conductor 84b, which connects the other end of the radial conductor 84a adjacent to the circumferential direction CD. The radial conductor 84a and the inner circumferential conductor 84b are connected at approximately a right angle.

[0066] If the ratio of the radial RD of the sinusoidal wave pattern 83 is p, and the ratio of the radial RD of the rectangular wave pattern 84 is 1-p, then the range in which the ratio p can take is 0 ≤ p ≤ 1. In the combined reduction coil pattern 77, the ratio p and the ratio 1-p are set arbitrarily.

[0067] Here, if the coil pattern is sinusoidal, the magnetic flux distribution on the detection coil 52 will not contain harmonic components, or the harmonic components can be reduced. On the other hand, if the coil pattern is sinusoidal, the amount of magnetic flux generated will decrease, and the output voltage of the resolver 1 will decrease.

[0068] Furthermore, if the coil pattern is a rectangular wave pattern, the magnetic flux distribution on the detection coil 52 will include harmonic components. On the other hand, if the coil pattern is a rectangular wave pattern, the amount of magnetic flux generated will increase, and the output voltage of the resolver 1 can be improved.

[0069] Therefore, by combining the sinusoidal wave pattern 83 and the rectangular wave pattern 84, the combined reduction coil pattern 77 can suppress the decrease in output voltage while reducing harmonic components.

[0070] Figure 11 shows the relationship between the ratio p and the output voltage index a(p). Figure 12 shows the relationship between the ratio p and the harmonic component low index b(p). Figure 13 shows the relationship between the ratio p and the harmonic mean M(p).

[0071] As described above, in the combined reduction coil pattern 77, the ratio of the sinusoidal wave pattern 83 and the rectangular wave pattern 84 can be arbitrarily set. However, increasing the ratio p of the sinusoidal wave pattern 83 reduces harmonic components but lowers the output voltage, and decreasing the ratio p of the sinusoidal wave pattern 83 suppresses the decrease in output voltage but increases harmonic components.

[0072] Therefore, we will investigate the optimal ratio p to suppress the decrease in output voltage while reducing harmonic components. Here, we assume that a normal coil pattern 71 is used as the excitation coils 54 and 56, and a combined reduction coil pattern 77 is used as the detection coil 52. Furthermore, we assume that the magnetic flux density within the coil of the combined reduction coil pattern 77 is uniform in both the in-plane and axial directions.

[0073] Therefore, since the output voltage is proportional to the amount of flux linkage of the detection coil 52, under a uniform magnetic field, it can be considered to be proportional to the area A(p) enclosed by the combined reduction coil pattern 77. Thus, A(p) is used to calculate the indicator of the output voltage. Note that area A(p) is the area of ​​the region shown by hatching in Figure 10.

[0074] Furthermore, the harmonic components are calculated by convolution of the normal coil pattern 71 and the combined reduction coil pattern 77.

[0075] Furthermore, the output voltage index a(p) and the harmonic component low index b(p) are defined as shown in equations (1) and (2) below. These indices take values ​​in the range of 0 to 1, with values ​​closer to 1 indicating better performance. Also, H ３ (p) represents the ratio of the third harmonic component to the fundamental component (first harmonic component).

[0076] As shown in Figure 11, the output voltage index a(p) decreases as p increases. In other words, in the combined reduction coil pattern 77, the output voltage decreases as the ratio of the sinusoidal wave pattern 83 increases.

[0077] Furthermore, as shown in Figure 12, the index b(p) of the low harmonic component increases as p increases. In other words, in the combined reduction coil pattern 77, the higher the ratio of the sinusoidal pattern 83, the lower the harmonic component.

[0078] Then, the harmonic mean M(p) is calculated using equation (3) below.

[0079] As shown in Figure 13, the harmonic mean M(p) reaches its maximum value when p = 0.53, and decreases as p moves away from 0.53. In other words, in the combined reduction coil pattern 77, the best balance is achieved in reducing harmonic components and suppressing the decrease in output voltage when the ratio of the sinusoidal pattern 83 is 0.53.

[0080] However, even when p is not 0.53, it is possible to achieve a good balance between reducing harmonic components and suppressing the decrease in output voltage. For example, when 0.25 ≤ p ≤ 0.75, the harmonic mean M(p) can be made approximately 0.35 or higher, which can be said to achieve a good balance between reducing harmonic components and suppressing the decrease in output voltage.

[0081] Therefore, in the combined reduction coil pattern 77, it is preferable that the ratio p of the sinusoidal wave pattern 83 is 0.25 or more and 0.75 or less.

[0082] Furthermore, in a rotary axial gap type resolver like resolver 1, the magnetic flux distribution contains more harmonic components at positions further from the center in the radial direction RD. Therefore, the combined reduction coil pattern 77 can further reduce harmonic components by arranging the sinusoidal pattern 83 on the outside in the radial direction RD.

[0083] <4. Coil Pattern Combinations> Next, we will explain the combinations of coil patterns for the detection coil 52 and the excitation coils 54 and 56.

[0084] When using any of the sinusoidal reduction coil patterns 72, 73, 74, 75 and the combined reduction coil pattern 77 for the detection coil 52, the excitation coils 54 and 56 may use the normal coil pattern 71.

[0085] Furthermore, when using any of the sinusoidal reduction coil patterns 72, 73, 74, 75 and the combined reduction coil pattern 77 for the detection coil 52, the excitation coils 54 and 56 may also use any of the sinusoidal reduction coil patterns 72, 73, 74, 75 and the combined reduction coil pattern 77.

[0086] Furthermore, when the standard coil pattern 71 is used for the detection coil 52, the excitation coils 54 and 56 may be one of the sinusoidal reduction coil patterns 72, 73, 74, 75, or the combined reduction coil pattern 77.

[0087] However, for the excitation coils 54 and 56, it is desirable to use the standard coil pattern 71 to make the magnetic flux density in the radial direction RD uniform, and to use one of the sinusoidal reduction coil patterns 72, 73, 74, 75 or the combined reduction coil pattern 77 for the detection coil 52, and the standard coil pattern 71 for the excitation coils 54 and 56.

[0088] <5. Modifications> It should be noted that the embodiments are not limited to the specific examples described above, and various other configurations as modifications are possible.

[0089] For example, in the embodiment described above, the case where resolver 1 is of the axial gap type was explained. However, resolver 1 may also be of the linear or radial gap type.

[0090] Furthermore, in the above-described embodiment, the excitation-side sheet coil section 45 and the excitation-side sheet coil section 46 are provided. However, it is also possible to provide only one of the excitation-side sheet coil section 45 and the excitation-side sheet coil section 46. In this case, for example, the excitation coil 54a on the front side of the excitation-side sheet coil section 45 may function as the excitation coil on the sin phase side, and the excitation coil 54b on the back side may function as the excitation coil on the cos phase side.

[0091] Furthermore, in the above-described embodiment, the detection coil 52 and the excitation coils 54 and 56 are configured as multi-pole units. However, the detection coil 52 and the excitation coils 54 and 56 may also be configured as single-pole units.

[0092] Furthermore, in the above-described embodiment, the sinusoidal wave pattern 83 is arranged on the outside in the radial direction RD in the combined reduction coil pattern 77, and the rectangular wave pattern 84 is arranged on the inside in the radial direction RD. However, in the combined reduction coil pattern, the sinusoidal wave pattern 83 may be arranged on the inside in the radial direction RD, and the rectangular wave pattern 84 may be arranged on the outside in the radial direction RD.

[0093] <6. Summary> As described above, resolver 1 includes excitation coils 54 and 56 to which an excitation signal is input, and a detection coil 52 to which a detection signal is output. Based on the detection signal, resolver 1 detects the amount of movement (angle) of a moving body (rotating part 21) to which one of the excitation coils 54 and 56 or the detection coil 52 is provided. The excitation coils 54 and 56 and the detection coil 52 have coil patterns formed in a planar shape, and at least one of the excitation coils 54 and 56 and the detection coil 52 is formed in a coil pattern (sine wave reduction coil patterns 72, 73, 74, 75 and combined reduction coil pattern 77) that includes sinusoidal patterns (81, 82, 83). As a result, resolver 1 can reduce the harmonic components of the magnetic flux distribution by the sinusoidal patterns. Thus, resolver 1 improves the detection accuracy of the amount of movement of the moving body (rotating part 21).

[0094] The coil pattern including a sinusoidal wave pattern (combination reduction coil pattern 77) is formed by a combination of a sinusoidal wave pattern 83 and a rectangular wave pattern 84. As a result, the resolver 1 can reduce the harmonic components of the magnetic flux distribution while suppressing the decrease in the output voltage of the resolver 1.

[0095] The coil pattern including the sinusoidal wave pattern (combination reduction coil pattern 77) is formed in an annular shape, with the sinusoidal wave pattern 83 formed outside the radial RD and the rectangular wave pattern 84 formed inside the radial RD. As a result, the resolver 1 can further reduce the harmonic components of the magnetic flux distribution.

[0096] When the ratio of sinusoidal wave patterns 83 in the orthogonal direction (radial direction RD) perpendicular to the direction of movement of the moving body is p, and the ratio of rectangular wave patterns 84 is 1-p, the condition 0 ≤ p ≤ 1 is satisfied. This allows the resolver 1 to arbitrarily set a balance between reducing the harmonic components of the magnetic flux distribution and suppressing the decrease in output voltage.

[0097] The ratio p of the sinusoidal wave pattern 83 satisfies 0.25 ≤ p ≤ 0.75. This allows the resolver 1 to balance the reduction of harmonic components in the magnetic flux distribution with the suppression of the decrease in output voltage.

[0098] The ratio p of the sinusoidal wave pattern 83 is 0.53. This allows the resolver 1 to achieve the best balance between reducing the harmonic components of the magnetic flux distribution and suppressing the decrease in output voltage.

[0099] Coil patterns including sinusoidal patterns (sinusoidal reduction coil patterns 72, 73, 74, 75) are formed by a combination of a first sinusoidal pattern 81 and a second sinusoidal pattern 82. As a result, even if the magnetic flux distribution is biased in the radial direction RD, the resolver 1 can adjust the ratio of these patterns to reduce the bias in the magnetic flux distribution in the radial direction RD, and can also reduce the harmonic components of the magnetic flux distribution.

[0100] When the ratio of the first sinusoidal wave pattern 81 in the orthogonal direction perpendicular to the direction of movement of the moving object is h1 and the ratio of the second sinusoidal wave pattern 82 is h2, then h1 = h2. As a result, the resolver 1 can reduce the harmonic components of the magnetic flux distribution.

[0101] When the ratio of the first sinusoidal wave pattern 81 in a direction perpendicular to the direction of movement of the moving object is h1 and the ratio of the second sinusoidal wave pattern 82 is h2, the ratio of h1:h2 = 1:0 is satisfied. As a result, the resolver 1 can reduce the harmonic components of the magnetic flux distribution.

[0102] The coil pattern, which includes a sinusoidal wave pattern, has a first coil pattern (sinusoidal wave reduction coil pattern 74) in which the ratio h1 of the first sinusoidal wave pattern 81 in the orthogonal direction perpendicular to the direction of movement of the moving body is 1 and the ratio h2 of the second sinusoidal wave pattern 82 is 0, and a second coil pattern (sinusoidal wave reduction coil pattern 76) is formed on the same plane, with the phase of the first coil pattern shifted by 1 / 2 period and inverted in the orthogonal direction. As a result, the resolver 1 can reduce the harmonic components of the magnetic flux distribution and increase the output voltage.

[0103] The excitation coils 54 and 56 are formed in a coil pattern consisting of a rectangular wave pattern (a conventional coil pattern 71), while the detection coil 52 is formed in a coil pattern that includes a sinusoidal wave pattern. As a result, by using the conventional coil pattern 71 for the excitation coils 54 and 56, the magnetic flux density in the radial direction RD can be made uniform.

[0104] 1 resolver 21 rotating part 52 detection coil 54 excitation coil 56 excitation coil

Claims

1. A resolver comprising an excitation coil to which an excitation signal is input and a detection coil to which a detection signal is output, wherein the amount of movement of a moving body to which one of the excitation coil and the detection coil is provided is detected based on the detection signal, wherein the excitation coil and the detection coil have coil patterns formed in a planar shape, and at least one of the excitation coil and the detection coil is formed in a coil pattern including a sinusoidal pattern.

2. The resolver according to claim 1, wherein the coil pattern including the sinusoidal wave pattern is formed by a combination of the sinusoidal wave pattern and the rectangular wave pattern.

3. The resolver according to claim 2, wherein the coil pattern including the sinusoidal wave pattern is formed in an annular shape, the sinusoidal wave pattern is formed on the radially outer side, and the rectangular wave pattern is formed on the radially inner side.

4. The resolver according to claim 2, wherein when the ratio of the sinusoidal wave pattern in the orthogonal direction perpendicular to the direction of movement of the moving body is p, and the ratio of the rectangular wave pattern in the orthogonal direction is 1-p, the resolver satisfies 0 ≤ p ≤ 1.

5. The resolver according to claim 4, wherein the ratio p of the sinusoidal wave pattern satisfies 0.25 ≤ p ≤ 0.

75.

6. The resolver according to claim 4, wherein the ratio p of the sinusoidal wave pattern is 0.

53.

7. The resolver according to claim 1, wherein the coil pattern including the sinusoidal wave pattern is formed by a combination of a first sinusoidal wave pattern and a second sinusoidal wave pattern.

8. The resolver according to claim 7, wherein when the ratio of the first sinusoidal wave pattern in a direction perpendicular to the direction of movement of the moving body is h1 and the ratio of the second sinusoidal wave pattern is h2, h1 = h2.

9. The resolver according to claim 7, wherein when the ratio of the first sinusoidal wave pattern in a direction perpendicular to the direction of movement of the moving body is h1 and the ratio of the second sinusoidal wave pattern is h2, the ratio of h1:h2 = 1:

0.

10. The resolver according to claim 7, wherein the coil pattern including the sinusoidal wave pattern is formed on the same plane as a first coil pattern in which the ratio h1 of the first sinusoidal wave pattern in a direction perpendicular to the direction of movement of the moving body is 1 and the ratio h2 of the second sinusoidal wave pattern is 0, and a second coil pattern in which the phase of the first coil pattern is shifted by 1 / 2 period and inverted in the direction perpendicular to the direction perpendicular.

11. The resolver according to any one of claims 1 to 10, wherein the excitation coil is formed in a coil pattern consisting of a rectangular wave pattern, and the detection coil is formed in a coil pattern including the sinusoidal wave pattern.

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