Variable reluctance type angle detector

Abstract

[Technical Problem] In a variable reluctance angle detector, a cancellation effect is produced when the rotor is eccentric, and the decrease in the synthesized voltage is suppressed when it is not eccentric. [Solution] A variable reluctance angle detector comprises: a rotor with a shaft angle of 1X; a stator having 12 teeth arranged circumferentially from the first to the twelfth teeth; an excitation coil; a first output coil; and a second output coil, wherein the excitation coil is wound with the first and seventh teeth in the forward direction with a winding number N1, and wound with the fourth and tenth teeth in the reverse direction with a winding number N1; the first output coil is wound with the first, second, and twelfth teeth in the forward direction, and wound with the sixth, seventh, and eighth teeth in the reverse direction; and the second output coil is wound with the third, fourth, and fifth teeth in the reverse direction, and wound with the ninth, tenth, and eleventh teeth in the forward direction.

Description

Technical Field

[0001] This disclosure relates to a variable reluctance angle detector, which is configured such that a rotor with a shape in which the gap permeability varies sinusoidally with respect to the angle θ is configured to rotate freely relative to a stator in which excitation windings and output windings are wound in the teeth. Background Technology

[0002] In a variable reluctance angle detector (hereinafter referred to as a "rotary transformer") with shaft angles of 2X, 4X, etc., the in-phase voltage coils are positioned 180 degrees symmetrically about the center of the stator, and the rotor shape is also 180 degrees symmetrical about the rotation center. Therefore, when the rotor's rotation center is eccentrically removed from the center of the stator, on one side of the eccentricity, the gap between the coil and the rotor narrows, increasing the output voltage; on the other side, the gap widens, decreasing the output voltage. When this canceling effect occurs, the combined voltage does not increase or decrease significantly even with rotor eccentricity.

[0003] However, in a rotary transformer with a shaft angle of 1X, the rotor shape is not 180 degrees symmetrical about the center of rotation, thus failing to produce a canceling effect. Therefore, when the rotor is eccentric, the output voltage changes drastically, and the detection accuracy of the rotation angle decreases.

[0004] In Patent Document 1, in a rotary transformer with a shaft angle of 1X and 12 slots, by means of... Figure 3 As shown, the excitation winding 7, the SIN output winding 8, and the COS output winding 9 are selectively wound on teeth 1 to teeth 12. The SIN output winding 8 and the COS output winding 9 are also necessarily wound on teeth that are 180° apart, thus producing a canceling effect.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 4790478.

[0008] The technical problem that the invention aims to solve

[0009] In the structure of Patent Document 1, the secondary coil used to generate the cancellation effect always outputs a reverse voltage to the main coil regardless of whether the rotor is eccentric. This results in a decrease in the combined voltage of the output coil. Conversely, if the number of turns in the main coil is increased to increase the output voltage, the fluctuation range of the output voltage when the rotor is eccentric becomes larger, thus impairing the cancellation effect. Summary of the Invention

[0010] The purpose of this disclosure is to produce a cancellation effect when the rotor is eccentric in a variable reluctance angle detector, and to suppress the decrease of the synthesized voltage when it is not eccentric.

[0011] Methods for solving problems

[0012] (1) The variable reluctance angle detector disclosed herein comprises: a rotor having an axial multiple angle of 1X; a stator having 12 teeth arranged circumferentially from the first to the twelfth teeth; an excitation coil; a first output coil; and a second output coil, wherein the excitation coil is wound in the forward direction with a winding number N1 on the first and seventh teeth and wound in the reverse direction with a winding number N1 on the fourth and tenth teeth, the first output coil is wound in the forward direction on the first, second, and twelfth teeth and wound in the reverse direction on the sixth, seventh, and eighth teeth, and the second output coil is wound in the reverse direction on the third, fourth, and fifth teeth and wound in the forward direction on the ninth, tenth, and eleventh teeth.

[0013] If the above structure is present, it can counteract rotor eccentricity and ensure the combined voltage when the rotor is not eccentric.

[0014] (2) Alternatively, the excitation coil may be wound with a number of turns N2 in at least one of the second tooth section, the third tooth section, the fifth tooth section, the sixth tooth section, the eighth tooth section, the ninth tooth section, the eleventh tooth section and the twelfth tooth section, wherein the number of turns N2 is less than half of the number of turns N1.

[0015] (3) Alternatively, the number of turns of the first output coil in each tooth section is equal to the number of turns of the second output coil in each tooth section.

[0016] (4) Alternatively, in a top view along the axial direction of the rotor, with the Y-axis as the axis from the convex part to the concave part of the rotor and the X-axis as the axis passing through the rotation center of the rotor and orthogonal to the Y-axis, the rotor has a cavity that is linearly symmetrical about the Y-axis on the side closer to the convex part than the X-axis.

[0017] (5) Alternatively, in the first tooth section, the fourth tooth section, the seventh tooth section, and the tenth tooth section, the excitation coil is located on the radial inner side of each tooth section, and the first output coil or the second output coil is located on the radial outer side of each tooth section, and the excitation coil is separated from the first output coil or the second output coil.

[0018] With the above structure, the output voltage can be ensured with fewer winding turns, thus enabling the miniaturization and lightweighting of variable magnetoresistive angle detectors.

[0019] (6) The variable reluctance angle detector disclosed herein comprises: a rotor having an axial multiple angle of 1X; a stator having 16 teeth arranged circumferentially from the first to the sixteenth teeth; an excitation coil; a first output coil; and a second output coil, wherein the excitation coil is wound in the forward direction with a winding number N1 on the first and ninth teeth and wound in the reverse direction with a winding number N1 on the fifth and thirteenth teeth, the first output coil is wound in the forward direction on the first, second, and sixteenth teeth and wound in the reverse direction on the eighth, ninth, and tenth teeth, and the second output coil is wound in the reverse direction on the fourth, fifth, and sixth teeth and wound in the forward direction on the twelfth, thirteenth, and fourteenth teeth.

[0020] (7) Alternatively, the excitation coil, the first output coil and the second output coil may not be wound around the third tooth, the seventh tooth, the eleventh tooth and the fifteenth tooth.

[0021] The effects of the invention

[0022] According to this disclosure, in a variable reluctance angle detector, a cancellation effect can be generated when the rotor is eccentric, and the reduction of the synthesized voltage can be suppressed when it is not eccentric. Attached Figure Description

[0023] Figure 1 The main structure of the variable magnetoresistive angle detector 1 according to the first embodiment is shown.

[0024] Figure 2 The structure of stator 4 is shown.

[0025] Figure 3 The teeth of the wound excitation coil, the first output coil, and the second output coil are schematically shown.

[0026] Figure 4 The winding method of the excitation coil, the first output coil and the second output coil is illustrated schematically.

[0027] Figure 5 Explain the rotor convex angle θ.

[0028] Figure 6 The graph shows the relationship between the measured and simulated values ​​of the rotor convex angle θ and the induced voltage of the first output coil S101.

[0029] Figure 7 The graph shows the relationship between the measured and simulated values ​​of the rotor convex angle θ and the induced voltage of the first output coil S102.

[0030] Figure 8 The graph shows the relationship between the measured and simulated values ​​of the rotor convex angle θ and the combined voltage of the first output main coil.

[0031] Figure 9 The graph shows the relationship between the measured and simulated values ​​of the rotor convex angle θ and the combined voltage of the first output sub-coil.

[0032] Figure 10 Example of eccentric rotors 5.

[0033] Figure 11 (A) is a table illustrating the measured and analog values ​​of the induced voltages of the first output coils S101 and S102 with and without rotor 5 eccentricity, and (B) is a table illustrating the measured and analog values ​​of the combined voltages of the first output main coil and the first output secondary coil with and without rotor 5 eccentricity.

[0034] Figure 12 The stator 4 according to the second embodiment is shown.

[0035] Figure 13 The coil structure of the variable magnetoresistive angle detector according to the second embodiment is shown.

[0036] Figure 14 Rotor 5 is shown in the modified example.

[0037] Figure 15 (A) is a top view along the rotor axis of the modified example involving the winding structure. Figure 15 (B) is a diagram illustrating the double-layer winding structure involved in the prior art.

[0038] Figure 16 This is a table comparing the combined voltage of the output coil under the winding structure involved in the comparative example with that under the double-layer winding structure involved in the prior art.

[0039] Figure 17 The main structure of the external rotor type variable reluctance rotary transformer involved in the modified example is shown. Detailed Implementation

[0040] Hereinafter, preferred embodiments of the variable magnetoresistive angle detector according to this disclosure will be described with reference to the accompanying drawings. Furthermore, the following embodiments are merely examples of this disclosure, and this disclosure is not intended to be limited thereto; it is self-evident that the embodiments can be suitably modified without altering the spirit of this disclosure.

[0041] [First Implementation Method]

[0042] like Figures 1 to 4 As shown, the variable reluctance angle detector (hereinafter referred to as "1X rotary transformer") 1 according to the first embodiment of this disclosure includes a stator 4 and a rotor 5.

[0043] [Stator 4]

[0044] like Figure 1 and Figure 2 As shown, when viewed from the axial direction of the rotor 5, the stator 4 has a stator core 6 in a generally annular shape. The stator core 6 is formed, for example, by stamping a steel plate of a specified thickness into this annular shape, stacking multiple sheets of the steel plate, and fixing them integrally by riveting or the like. The stator 4 has 12 teeth 2 on its inner circumferential side, arranged at equal intervals along the circumferential direction, from the first to the twelfth teeth. Each of the 12 teeth 2 protrudes from the stator core 6 toward the center of the annular shape. A coil 3 is wound around the teeth 2. The specific composition of the coil 3 varies depending on the teeth 2, and includes one or more of an excitation coil, a first output coil, and a second output coil. The stator 4 has a flange portion 10 formed on its outer circumferential side. A screw hole 10a is provided in the flange portion 10 for fixing the stator 4 in a desired position. Furthermore, the shape of the flange portion 10 is arbitrary, and other methods can also be used to fix the stator 4.

[0045] [Rotor 5]

[0046] The rotor 5 is generally circular in shape. The outer periphery of the rotor 5 has a shape that varies sinusoidally (hereinafter referred to as a "SIN wave") with respect to the angle θ of the gap permeability of the stator 4 relative to the rotation direction of the rotor 5. Like the stator core 6, the rotor 5 is formed, for example, by stamping a steel plate of a specified thickness into this circular shape, stacking multiple sheets of the steel plate, and fixing them integrally by riveting or the like. Furthermore, a through hole is provided at the center of the rotor 5, and a rotor shaft 5a is embedded therein. In this embodiment, the rotor 5 is a component with an outer periphery shape having a SIN wave shape where the angle θ of the gap permeability of the stator 4 varies only one cycle with respect to the rotation direction of the rotor 5, a so-called shaft double angle 1X component. Therefore, a protrusion and a recess are formed on each of the outer peripheries. In this embodiment, the angle by which the rotor 5 rotates clockwise is called the rotor convex angle θ. Figure 5 In this design, the axis passing through the center of the first and seventh teeth of stator 4 is taken as the Y-axis, and the axis passing through the center of the fourth and tenth teeth is taken as the X-axis. The rotor convex angle θ when the convex part of rotor 5 faces the positive direction of the Y-axis is set to 0 degrees.

[0047] [Teeth 2]

[0048] As described above, the teeth 2 are 12 protrusions located on the inner circumference of the stator core 6. Figure 2 As shown, the 12 teeth 2 are numbered sequentially from the first to the twelfth. Figure 2In the above, the numbers are labeled in a clockwise direction, but they can also be labeled in a counterclockwise direction. Furthermore, any of the 12 teeth 2 can be the first. The method of labeling the teeth 2 is not limited as long as the numbers are labeled in the order of arrangement without skipping any teeth 2. In addition, in the following, when distinguishing each tooth 2 in conjunction with the above-described numbering, the symbols and letters for the first tooth 2a to the twelfth tooth 2l are used. The same applies to the second embodiment.

[0049] The coil 3, wound around the 12 teeth 2, includes excitation coils E01, E04, E07, and E10; first output coils S101, S102, S106, S107, S108, and S112; and second output coils S203, S204, S205, S209, S210, and S211. All coils are wound together. The winding direction of one side of the coil wound around the teeth 2 is called "forward winding," and the opposite direction is called "reverse winding." Forward and reverse winding only require opposite winding directions. Therefore, forward winding itself can be either of the two winding directions.

[0050] Therefore, as Figure 3 As shown, in the first tooth section 2a, the excitation coil E01 and the first output coil S101 are wound in the forward direction. In the second tooth section 2b, the first output coil S102 is wound in the forward direction. In the third tooth section 2c, the second output coil S203 is wound in the reverse direction. In the fourth tooth section 2d, the excitation coil E04 and the second output coil S204 are wound in the reverse direction. In the fifth tooth section 2e, the second output coil S205 is wound in the reverse direction. In the sixth tooth section 2f, the first output coil S206 is wound in the reverse direction. In the seventh tooth section 2g, the excitation coil E07 is wound in the forward direction, and the first output coil S107 is wound in the reverse direction. In the eighth tooth section 2h, the first output coil S108 is wound in the reverse direction. In the ninth tooth section 2i, the second output coil S209 is wound in the forward direction. In the tenth tooth section 2j, the excitation coil E10 is wound in the reverse direction, and the second output coil S210 is wound in the forward direction. In the eleventh tooth section 2k, the second output coil S211 is wound in the forward direction. In the twelfth tooth section 2l, the first output coil S112 is wound in the forward direction.

[0051] [Excitation coil]

[0052] Excitation coils E01, E04, E07, and E10 are wound with a predetermined number of turns N1 on the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j, respectively. The winding directions of excitation coils E01 and E07 are opposite to those of excitation coils E04 and E10. In this embodiment, excitation coils E01 and E07 are wound in the forward direction, while excitation coils E04 and E10 are wound in the reverse direction. Excitation coils E01 and E07 have the same polarity, and excitation coils E04 and E10 also have the same polarity. On the other hand, excitation coils E01 and E07 have opposite polarities to excitation coils E04 and E10. Excitation coils E01, E04, E07, and E10 are wound in series with respect to the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j. Furthermore, the winding method for excitation coils E01, E04, E07, and E10 is not particularly limited. However, if a fork-type or nozzle-type winding machine is used to continuously wind a copper wire around each tooth section 2, and the transition wire between each tooth section 2 is wound around the hanging part formed in the stator core 6, then excitation coils E01, E04, E07, and E10 can be effectively concentrated and wound in the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j. Furthermore, in this embodiment, the excitation coil is not wound around the second tooth 2b, the third tooth 2c, the fifth tooth 2e, the sixth tooth 2f, the eighth tooth 2h, the ninth tooth 2i, the eleventh tooth 2k, and the twelfth tooth 2l.

[0053] [First output coil and second output coil]

[0054] The first output coils S101, S102, S106, S107, S108, and S112 are wound together with a predetermined number of turns on the first tooth section 2a, the second tooth section 2b, the sixth tooth section 2f, the seventh tooth section 2g, the eighth tooth section 2h, and the twelfth tooth section 2l. The winding direction of the first output coils S101, S102, and S112 is forward winding, while the winding direction of the first output coils S106, S107, and S108 is reverse winding. Therefore, the first output coils S101, S102, and S112 have the same polarity. The first output coils S106, S107, and S108 are of the same polarity, but opposite polarity to the first output coils S101, S102, and S112. The first output coils S101, S102, S106, S107, S108, and S112 are wound in series with respect to the first tooth 2a, the second tooth 2b, the sixth tooth 2f, the seventh tooth 2g, the eighth tooth 2h, and the twelfth tooth 2l.

[0055] The second output coils S203, S204, S205, S209, S210, and S211 are wound together with a predetermined number of turns on the third tooth section 2c, the fourth tooth section 2d, the fifth tooth section 2e, the ninth tooth section 2i, the tenth tooth section 2j, and the eleventh tooth section 2k. The winding direction of the second output coils S203, S204, and S205 is reverse winding, while the winding direction of the second output coils S209, S210, and S211 is forward winding. Therefore, the second output coils S203, S204, and S205 have the same polarity. The second output coils S209, S210, and S211 are of the same polarity, but opposite polarity to the second output coils S203, S204, and S205. The second output coils S203, S204, S205, S209, S210, and S211 are wound in series with respect to the third tooth 2c, fourth tooth 2d, fifth tooth 2e, ninth tooth 2i, tenth tooth 2j, and eleventh tooth 2k.

[0056] The first output coils S101, S102, S106, S107, S108, and S112, and the second output coils S203, S204, S205, S209, S210, and S211, are positioned at a position rotated 90 degrees around the rotor shaft 5a. Therefore, the first output voltages of the first output coils S101, S102, S106, S107, S108, and S112, and the second output voltages of the second output coils S203, S204, S205, S209, S210, and S211, are SIN wave signals with a 90-degree phase shift. The SIN wave, with its phase advanced by 90 degrees, coincides with the cosine wave (hereinafter referred to as the "COS wave"). In this embodiment, the first output voltage becomes the COS wave signal.

[0057] The winding method of the first output coils S101, S102, S106, S107, S108, and S112, and the second output coils S203, S204, S205, S209, S210, and S211, is the same as the winding method of the excitation coils E01, E04, E07, and E10. While not specifically limited, if a fork or nozzle is used... The winding machine continuously winds a copper wire around each tooth 2 and winds the transition wire between each tooth 2 around the hanging part formed in the stator core 6. This effectively concentrates the first output coil S101, first output coil S102, first output coil S106, first output coil S107, first output coil S108 and first output coil S112 with the second output coil S203, second output coil S204, second output coil S205, second output coil S209, second output coil S210 and second output coil S211 on each tooth 2.

[0058] The first output coils S101, S102, S106, S107, S108, and S112 are wound with the second output coils S203, S204, S205, S209, S210, and S211 on different tooth sections 2. No tooth section 2 will have more than two output coils wound on it. In addition, the excitation coils E01, E04, E07, and E10 are wound on the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j, and are not wound on other tooth sections 2. Therefore, apart from the excitation coil and output coil wound in the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j, the second tooth section 2b, the third tooth section 2c, the fifth tooth section 2e, the sixth tooth section 2f, the eighth tooth section 2h, the ninth tooth section 2i, the eleventh tooth section 2k, and the twelfth tooth section 2l each have only one output coil wound in them. Therefore, only the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j require insulation between the coils; the other tooth sections 2 do not require insulation. Furthermore, for the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j, it is sufficient to insulate only the excitation coil from the output coil; therefore, there is only one insulation point. In this way, due to the fewer insulation points, the reliability of the insulation is improved. In addition, because the total number of coils is small, the winding operation time for forming the coils can be reduced, and the component cost of the 1X rotary transformer 1 can also be reduced.

[0059] [Individual induced voltage of the output coil]

[0060] Regarding the individual induced voltage of the first output coil, with the rotor 5 uneccentric, the rotor convex angle θ was measured and simulated at 45-degree intervals from 0 degrees to 315 degrees. In addition, the excitation current of the excitation coil was set to 58mA (RMS: Root Mean Square), 10KHz, and the impedance was 120Ω. Figure 6 The induced voltage of the first output coil S101 is shown. Figure 7 The induced voltage of the first output coil S102 is shown. Figure 6 , Figure 7 In the diagram, the solid line represents the curve of the measured value, and the dashed line represents the curve of the simulated value.

[0061] like Figure 6As shown, the induced voltage of the first output coil S101, in both the measured value curve V101a and the simulated value curve V101b, approximately exhibits a COS wave shape. When the rotor convex angle θ is 0 degrees, the convex portion of rotor 5 is opposite to the first tooth 2a, thus minimizing the distance from rotor 5 to the excitation coil E01 and the first output coil S101. Consequently, the induced voltage is at its highest, with a measured value of approximately 3,400 mV. As rotor 5 rotates and moves away from the excitation coil E01 and the first output coil S101, the induced voltage of the first output coil S101 decreases.

[0062] When the rotor convex angle θ reaches 180 degrees, the concave portion of rotor 5 is aligned with the first tooth 2a, thus maximizing the distance from rotor 5 to the excitation coil E01 and the first output coil S101. Consequently, the induced voltage is minimized, with a measured value of approximately 1,900 mV. If rotor 5 rotates further, it moves closer to the excitation coil E01 and the first output coil S101, causing the induced voltage in the first output coil S101 to rise.

[0063] Both the first output coils S101 and S102 are wound in the forward direction. The magnetic flux generated by the excitation coil E01 passes through the first output coil S102 in the opposite direction to the magnetic flux passing through the first output coil S101. Therefore, the induced voltages in the first output coils S101 and S102 have opposite signs.

[0064] The first output coil S101 is wound on a first tooth 2a that is common to the excitation coil E01. The first output coil S102 is wound on a second tooth 2b that is different from the first tooth 2a wound on the excitation coil E01. The excitation coil is not wound on the second tooth 2b wound on the first output coil S102. Compared to the first output coil S101, the excitation coil is not wound on the first output coil S102, therefore the absolute value of the induced voltage of the first output coil S102 is smaller than the absolute value of the induced voltage of the first output coil S101.

[0065] like Figure 7As shown, both the measured value curve V102a and the analog value curve V102b of the induced voltage of the first output coil S102 roughly exhibit a COS wave shape. When the rotor convex angle θ is 0 degrees, the induced voltage of the first output coil S102 reaches its highest value, with a measured value of approximately -250 mV. As the rotor 5 rotates, the induced voltage of the first output coil S102 decreases. When the rotor convex angle θ reaches 180 degrees, the induced voltage of the first output coil S102 reaches its lowest value, with a measured value of approximately -390 mV. If the rotor 5 rotates further, the induced voltage of the first output coil S102 increases. Furthermore, the induced voltage of the first output coil S101 has a negative sign. Therefore, the absolute value is smallest when the induced voltage is highest, and the absolute value is largest when the induced voltage is lowest.

[0066] Hereinafter, the first output coil S101 and the first output coil S107 are referred to as the first main output coils, and the combined voltage of the induced voltages of the first output coils S101 and S107 is referred to as the combined voltage of the first main output coils. The induced voltage of the first output coil S107 has the opposite sign to the induced voltage of the first output coil S101, and their phases are offset by 180 degrees with respect to the rotor convex angle θ. Figure 8 As shown, both the measured curve Vma and the simulated curve Vmb of the combined voltage of the first output main coil change in a COS wave pattern with the rotation of rotor 5, and the amplitude is approximately 3,000 mV.

[0067] The first output coils S102, S106, S108, and S112 are referred to as the first output secondary coils. The combined voltage of the induced voltages of the first output coils S102, S106, S108, and S112 is called the combined voltage of the first output secondary coils. The induced voltages of the first output coils S102 and S112 vary approximately in the same way with respect to the rotor convex angle θ. The induced voltages of the first output coils S106 and S108 have opposite signs to those of the first output coils S102 and S112, and are 180 degrees out of phase with respect to the rotor convex angle θ. Figure 9 As shown, both the measured curve Vsa and the simulated curve Vsb of the combined voltage of the first output sub-coil exhibit a COS wave-like variation, with an amplitude of approximately 560 mV.

[0068] The first output voltage is formed by combining the combined voltage of the first output main coil and the combined voltage of the first output secondary coil. Because the combined voltages of the first output main coil and the first output secondary coil have the same polarity, even when combined, the absolute value of the first output voltage will not be less than the absolute value of the combined voltage of the first output main coil. This ensures the magnitude of the absolute value of the first output voltage.

[0069] [The effect of bias]

[0070] For the induced voltages of the first output coils S101 and S102, the combined voltage of the first main output coil, and the combined voltage of the first secondary output coil, calculate the measured and simulated values ​​for both the case where rotor 5 is not eccentric and the case where rotor 5 is eccentric. As an example of rotor 5 being eccentric, such as... Figure 10 As shown, the rotor 5 is offset by 50 micrometers from the center of the stator 4 toward the first tooth 2a side (positive direction of the Y-axis). Furthermore, the measured and simulated values ​​are those when the rotor convex angle θ is 0 degrees.

[0071] Due to the eccentricity of rotor 5, when the rotor convexity angle θ is 0 degrees, if the distance from rotor 5 to excitation coil E01 and first output coil S101 decreases, the absolute value of the induced voltage in the first output coil S101 increases. Figure 11 In (A), the absolute value of the measured induced voltage of the first output coil S101 increases from 3383.8 [mV] to 3467.1 [mV]. The absolute value of the analog value also increases from 3018.2 [mV] to 3175.9 [mV].

[0072] Due to the eccentricity of rotor 5, when the rotor convexity angle θ is 0 degrees, if the distance from rotor 5 to excitation coil E01 and first output coil S101 decreases, then similarly to the induced voltage of first output coil S101, the absolute value of the induced voltage of first output coil S102 also increases. Figure 11 In (A), the measured value of the induced voltage of the first output coil S102 decreased from -249.8 [mV] to -264.8 [mV], and the analog value also decreased from -209.6 [mV] to -233.9 [mV]. The absolute value of both increased.

[0073] like Figure 11As shown in (B), if rotor 5 is eccentricated, the measured value of the combined voltage of the first output main coil increases from 1520.5 [mV] to 1579.2 [mV], and the analog value increases from 1704.3 [mV] to 1866.8 [mV]. In contrast, regarding the combined voltage of the first output secondary coil, if the rotor is eccentricated, the measured value decreases from 134.3 [mV] to 118.8 [mV], and the analog value also decreases from 311.6 [mV] to 155.1 [mV].

[0074] As described above, if rotor 5 is eccentric, a cancellation effect occurs in the first output voltage, where the increase in the combined voltage of the first output main coil is offset by the decrease in the combined voltage of the first output secondary coil. Therefore, the fluctuation in the first output voltage caused by the eccentricity of rotor 5 is suppressed.

[0075] Furthermore, the induced voltage characteristics of the first output coil and the second output coil are the same, therefore the above description regarding the first output coil also applies to the second output coil. Thus, the magnitude of the second output voltage can be ensured. Additionally, the second output voltage also produces a canceling effect, thereby suppressing fluctuations caused by the eccentricity of the rotor 5.

[0076] [Second Implementation]

[0077] The second embodiment of the 1X rotary transformer has a structure that is substantially the same as that of the 1X rotary transformer 1 described in the first embodiment, but as... Figure 12 As shown, the stator differs in that it has 16 teeth 302. Hereinafter, components common to the 1X rotary transformer 1 according to the first embodiment will be described using common symbols.

[0078] In this embodiment, a total of 12 coils are wound around the 16 teeth 302. Specifically, as... Figure 13As shown, the first tooth 302a, second tooth 302b, fourth tooth 302d to sixth tooth 302f, eighth tooth 302h to tenth tooth 302j, twelfth tooth 302l to fourteenth tooth 302n, and sixteenth tooth 302p involved in this embodiment correspond to the first tooth 2a to twelfth tooth 2l of the first embodiment described above. A coil common to the first tooth 2a to twelfth tooth 2l of the first embodiment is wound around the first tooth 302a, second tooth 302b, fourth tooth 302d to sixth tooth 302f, eighth tooth 302h to tenth tooth 302j, twelfth tooth 302l to fourteenth tooth 302n, and sixteenth tooth 302p. For example, similar to the excitation coil E01 and the first output coil S101 wound around the first tooth portion 2a in the first embodiment described above, the first tooth portion 302a in this embodiment is wound with an excitation coil E401 and a first output coil S401. The other teeth 302 are also as described above. Figure 13 As shown, the coil is not wound around the third tooth 302c, the seventh tooth 302g, the eleventh tooth 302k, and the fifteenth tooth 302o. Even so, it can ensure the magnitude of the first output voltage and the second output voltage in the same way as the 1X rotary transformer 1 of the first embodiment described above, and produce a canceling effect when the rotor 5 is eccentric.

[0079] [Effects of the Implementation Method]

[0080] (1) According to the 1X rotary transformer of the above embodiment, the decrease in output voltage can be suppressed when the rotor is not eccentric, and a cancellation effect can be generated when the rotor is eccentric. Therefore, the rotor convexity angle θ can be detected with high precision regardless of whether the rotor is eccentric or not.

[0081] In the structure of Patent Document 1, even if the rotor 5 is not eccentric, the secondary coil always outputs a reverse voltage relative to the primary coil. Therefore, a problem arises where the absolute value of the combined voltage, formed by combining the induced voltage of the secondary coil and the induced voltage of the primary coil, becomes smaller. In this embodiment, Figure 8 The combined voltage of the first output main coil shown is... Figure 9 The combined voltage of the first output secondary coil shown always has the same polarity. Therefore, there is no problem that the absolute value of the first output voltage, which is the result of combining the combined voltage of the first output primary coil and the combined voltage of the first output secondary coil, becomes smaller.

[0082] Furthermore, according to the above embodiment, when the rotor 5 is eccentric, the variation in the combined voltage of the first output secondary coil can be offset to counteract the variation in the combined voltage of the first output main coil. Since this offsetting effect is extremely large, even if the rotor 5 is eccentric, the variations in the first and second output voltages are reduced, preventing the deterioration of electrical errors. Therefore, the rotor convexity angle θ can be detected with high precision.

[0083] Unlike brushless angle detectors, variable reluctance angle detectors do not require rotor winding, thus facilitating cost reduction. Furthermore, variable reluctance angle detectors with an shaft angle multiple of 2X or higher require a rotor convexity angle of 2 or more to equalize the output voltage, necessitating origin resetting upon power-on. In contrast, a variable reluctance angle detector with an shaft angle multiple of 1X, where the rotor convexity angle θ corresponds one-to-one with the output voltage, allows for the determination of the rotor convexity angle θ and operation without origin resetting upon power-on. Regarding such a 1X rotary transformer, according to the above embodiment, even with rotor 5 eccentricity, the rotor convexity angle θ can be detected with high accuracy, making it industrially useful.

[0084] (2) It can reduce the number of turns of any one of the excitation coil, the first output coil and the second output coil, and ensure the output voltage, thus enabling the miniaturization and lightweighting of the 1X rotary transformer.

[0085] [Variation Example]

[0086] (1) In the first embodiment described above, the case in which only the first tooth 2a, the fourth tooth 2d, the seventh tooth 2g and the tenth tooth 2j are wound is described as an example. However, it is not necessary to say that this disclosure is not limited to this. The excitation coil may also be wound on the second tooth 2b, the third tooth 2c, the fifth tooth 2e, the sixth tooth 2f, the eighth tooth 2h, the ninth tooth 2i, the eleventh tooth 2k and the twelfth tooth 2l. However, in order to achieve a cancellation effect that is sufficient to maintain the detection accuracy of the rotation angle even when the rotor 5 is eccentric, it is preferable that the number of turns N2 of the excitation coils wound on the second tooth section 2b, the third tooth section 2c, the fifth tooth section 2e, the sixth tooth section 2f, the eighth tooth section 2h, the ninth tooth section 2i, the eleventh tooth section 2k, and the twelfth tooth section 2l is less than half the number of turns N1 of the excitation coils E01, E04, E07, and E10 wound on the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j. This is because if the number of turns N2 exceeds half the number of turns N1, the cancellation effect cannot be obtained.

[0087] In the second embodiment, the case where the excitation coil is not wound in the third tooth section 302c, the seventh tooth section 302g, the eleventh tooth section 302k, and the fifteenth tooth section 302o is described as an example. However, it should be noted that this disclosure is not limited to this. Regarding the excitation coil, as long as the number of winding turns N2 is less than half of the number of winding turns N1 of the excitation coils E401, E404, E407, and E410 wound in the first tooth section 302a, the fifth tooth section 302e, the ninth tooth section 302i, and the thirteenth tooth section 302m, the excitation coil can be wound. Even so, the effects of this disclosure can be obtained. This is because in this case, if the number of winding turns N2 exceeds half of the number of winding turns N1, the cancellation effect cannot be obtained.

[0088] (2) In the above embodiment, the case where the rotor 5 is solid was described as an example, but it should be noted that this disclosure is not limited to this, and a cavity may also be provided in the rotor 5. Figure 14 In the rotor 5, the Y-axis passes through the top of the protrusion and the deepest part of the concave portion. The X-axis is orthogonal to the Y-axis at the rotation center of the rotor 5. A rotor shaft 5a is embedded in the rotor 5. The rotor 5 is continuously connected to the front end of the protrusion along the Y-axis from the outer periphery of the through hole where the rotor shaft 5a is embedded. In addition, in the top view along the direction of the rotor shaft 5a, a pair of hollow portions 5b that are linearly symmetrical about the Y-axis are provided on the protrusion side relative to the X-axis. In this top view, the hollow portions 5b are generally fan-shaped, but needless to say, the top view shape of the hollow portions 5b is not limited to a fan shape and may be other shapes.

[0089] Because the outer periphery of rotor 5 is an unbalanced shape that is not rotationally symmetrical about rotor shaft 5a, it is necessary to prevent vibration during high-speed rotation. Furthermore, since the front end of the convex portion extending from the center of rotor shaft 5a is elongated and has a large mass, it is also necessary to prevent deformation of the convex portion caused by centrifugal force. To address this, providing a cavity 5b can reduce or eliminate the imbalance in mass distribution, thus preventing vibration during high-speed rotation and deformation of the convex portion. Additionally, because a magnetic circuit is formed that does not attenuate the magnetic flux on the Y-axis and X-axis sides, it is possible to prevent a decrease in the first and second output voltages due to the cavity 5b.

[0090] (3) In the above embodiment, excitation coils E01 and E07, and first output coils S101 and S107 are wound in the first tooth portion 2a and the seventh tooth portion 2g, respectively; and excitation coils E04 and E10, and second output coils S204 and S210 are wound in the fourth tooth portion 2d and the tenth tooth portion 2j, respectively. In this modified example, as Figure 15As shown in (A), in the first tooth section 2a, the fourth tooth section 2d, the seventh tooth section 2g, and the tenth tooth section 2j, the excitation coils E01, E04, E07, and E10 are located on the tooth tip side of each tooth section 2, in other words, on the radially inner side. The first output coil S101 and the first output coil S107, and the second output coil S204 and the second output coil S210 are located on the radially outer side of each tooth section 2, and are separate from the excitation coils E01, E04, E07, and E10.

[0091] In the past, for example, Figure 15 As shown in (B), the excitation coil E01 and the first output coil S101 are wound on the peripheral surface of the tooth 2 in a double-layer structure, with the excitation coil E01 as the upper layer and the first output coil S101 as the lower layer. In contrast, if the excitation coil E01 is wound concentrated at the tip of the tooth 2 as in this modified example, the output voltage can be made larger than that of the conventional method. Figure 16 In the example shown, with an output voltage of 1670 mV in the prior art (double-wound), an output voltage of 1802 mV can be obtained according to this variation, even with the same number of winding turns. This is 107.9% larger than the prior art (double-wound). Similarly, if the output voltage is the same, the number of winding turns of the excitation coil E01 can be reduced, thus enabling miniaturization and weight reduction of the 1X rotary transformer.

[0092] (4) In the above embodiments, an inner rotor type 1X rotary transformer 1 was described as an example, but it is not intended to limit this disclosure to this type; the 1X rotary transformer disclosed herein may also be an outer rotor type. In the inner rotor type, the stator 4 surrounds the rotor 5; in contrast, in the outer rotor type, such as Figure 17 As shown, the rotor 605 surrounds the stator 604. Twelve teeth 602 are evenly spaced circumferentially around the outer periphery of the stator 604. The teeth 602 protrude from the outer periphery of the stator 604 toward the inner periphery of the rotor 605. A coil 603 is wound around each tooth 602. The twelve teeth 602 are numbered from first to twelfth. Similar to the 1X rotary transformer 1 of the above embodiment, the numbering of the teeth 602 is arbitrary except for the sequential circumferential markings. The specific composition of the coil 603 wound around the first to twelfth teeth 602 is as follows... Figure 3 same.

[0093] The rotor 605 is supported by a rotor shaft (not shown) and can rotate freely relative to the stator 604. The gap permeability of the inner circumference of the rotor 605 varies sinusoidally with respect to the rotation angle θ. Therefore, when the rotor 605 rotates, the output voltage varies sinusoidally with respect to the rotation angle θ of the rotor 605. The rotation angle θ of the rotor 605 is determined based on this varying output voltage. This external rotor type 1X rotary transformer 601, similar to the internal rotor type 1X rotary transformer 1, can produce a canceling effect when the rotor is eccentric and suppress the decrease in the combined voltage when it is not eccentric.

[0094] Explanation of reference numerals in the attached figures

[0095] 1. 601... Variable magnetoresistive angle detector,

[0096] 2, 302, 602... teeth,

[0097] 3. 603... coil,

[0098] 4. Stator, 304, 604...

[0099] 5, 605... rotor,

[0100] 5a...rotor shaft,

[0101] 6. 306... stator core,

[0102] 10, 310... flange portion,

[0103] 10a, 310a... screw holes

[0104] E01, E04, E07, E10, E401, E404, E407, E410... Excitation coils,

[0105] S101, S102, S106, S107, S108, S112, S401, S402, S406, S407, S408, S412... First output coil,

[0106] S203, S204, S205, S209, S210, S211, S503, S504, S505, S509, S510, S511... Second output coil,

[0107] V101a, V101b, V102a, V102b, Vma, Vmb, Vsa, Vsb... curve graphs.

Claims

1. A variable reluctance type angle detector characterized by, have: The rotor has a shaft angle of 1X; A stator having 12 teeth arranged circumferentially from the first to the twelfth teeth; Excitation coil; First output coil; as well as Second output coil, The excitation coil is wound clockwise on the first and seventh teeth with N1 turns, and wound counterclockwise on the fourth and tenth teeth with N1 turns. The first output coil is wound in the forward direction on the first tooth, the second tooth, and the twelfth tooth, and in the reverse direction on the sixth tooth, the seventh tooth, and the eighth tooth. The second output coil is wound in reverse on the third, fourth and fifth teeth, and wound in the forward direction on the ninth, tenth and eleventh teeth.

2. The variable magnetoresistive angle detector as described in claim 1, characterized in that, The excitation coil is wound with a number of turns N2 in at least one of the second, third, fifth, sixth, eighth, ninth, eleventh, and twelfth tooth sections. The number of winding turns N2 is less than half of the number of winding turns N1.

3. The variable magnetoresistive angle detector as described in claim 1 or 2, characterized in that, The number of turns of the first output coil in each tooth is equal to the number of turns of the second output coil in each tooth.

4. The variable magnetoresistive angle detector as described in claim 1 or 2, characterized in that, In a top view along the axial direction of the rotor, with the Y-axis as the axis from the convex part to the concave part of the rotor, and the X-axis as the axis passing through the rotation center of the rotor and orthogonal to the Y-axis, the rotor has a cavity that is line-symmetrical about the Y-axis on the side closer to the convex part than the X-axis.

5. The variable magnetoresistive angle detector as described in claim 1 or 2, characterized in that, In the first tooth section, the fourth tooth section, the seventh tooth section, and the tenth tooth section, the excitation coil is located on the radial inner side of each tooth section, and the first output coil or the second output coil is located on the radial outer side of each tooth section. The excitation coil is separated from the first output coil or the second output coil.

6. A variable reluctance type angle detector characterized by comprising: have: The rotor has a shaft angle of 1X; A stator having 16 teeth arranged circumferentially from the first to the sixteenth teeth; Excitation coil; First output coil; as well as Second output coil, The excitation coil is wound clockwise on the first and ninth teeth with N1 turns, and wound counterclockwise on the fifth and thirteenth teeth with N1 turns. The first output coil is wound in the first tooth section, the second tooth section, and the sixteenth tooth section, and wound in the reverse direction on the eighth tooth section, the ninth tooth section, and the tenth tooth section. The second output coil is wound in reverse on the fourth, fifth and sixth teeth, and wound in the forward direction on the twelfth, thirteenth and fourteenth teeth.

7. The variable magnetoresistive angle detector as described in claim 6, characterized in that, The excitation coil, the first output coil, and the second output coil are not wound around the third tooth, the seventh tooth, the eleventh tooth, and the fifteenth tooth.

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