JP6532574B1 - Rotation angle detection device - Google Patents

Abstract

A conventional rotation angle detection device has a problem that deterioration in detection accuracy can not be suppressed with respect to a change in eccentricity. A rotation angle detection device according to the present invention, as a rotation angle detection unit, faces a rotor (1) having an uneven portion (12) formed of a magnetic material on an outer peripheral surface, and the uneven portion (12) And a stator (2) having a magnetic field generator (22), a magnetic body (24) and a magnetic detector (23), the stator (2) and the rotor (1) The concavo-convex portion (12) is a concavo-convex portion for N cycles (N is an integer of 1 or more) with respect to a mechanical angle of 360 degrees in the circumferential direction of the rotation of the rotor The angular errors at the time of maximum eccentricity at the time of maximum eccentricity at the time of maximum eccentricity at the time of maximum eccentricity of the above and the above-mentioned direction are equal. [Selected figure] Figure 2

Description

  The present application relates to a rotation angle detection device using a change in magnetic intensity.

  The rotation angle detection device is attached to a rotation shaft of a motor or the like and is used to detect the rotation angle of the rotation shaft. The rotation angle detection device includes a rotor having a magnetic body on its outer peripheral surface, The stator is provided opposite to the rotor, the rotor is eccentric with respect to the center of the rotation axis, and the gap between the rotor and the stator is changed by rotation of the rotation axis. The plurality of detection coils are configured to detect the amount of movement of the rotor as a change in reluctance between the rotor and the stator.

  In this rotation angle detection device, the output waveform from the detection coil is a waveform that includes harmonic distortion (permeance error) in an ideal waveform (sine wave or cosine wave). The outer peripheral shape is detected by the action of the shape of the uneven portion provided on the rotor as a structure having a plurality of uneven portions smaller than a predetermined eccentricity with respect to the perfect circle so as to cancel out the permeance error of the detected waveform. The output waveform of the coil is designed to increase the amplitude of the fundamental wave component and to be closer to a sine wave so as to reduce the permeance error.

JP-A-8-163847

In the prior art, there is a problem that deterioration in detection accuracy can not be suppressed with respect to an increase in the amount of eccentricity. When eccentricity occurs due to a mounting error other than a predetermined amount of eccentricity and vibration or the like, there is a problem that the worst value of the angular error at the time of maximum eccentricity of either positive or negative is increased, and the detection accuracy is deteriorated.
The present application discloses a technique for solving the problems as described above, and an object thereof is to provide a rotation angle detection device in which the deterioration of detection accuracy is suppressed.

  The rotation angle detection device according to the present application includes a rotor having a concavo-convex portion formed of a magnetic material on an outer peripheral surface, and a stator provided opposite to the concavo-convex portion and having a magnetic field generating portion, a magnetic body and a magnetic detection portion. The stator and the rotor are eccentric, and the concavo-convex portion corresponds to N cycles (N is an integer of 1 or more) with respect to a mechanical angle of 360 degrees in the circumferential direction of the rotation of the rotor It is characterized in that it comprises a rotation angle detection unit which is an outer peripheral shape which is uneven and whose angular errors at the maximum eccentricity in a predetermined direction and at the maximum eccentricity in the opposite direction to the predetermined direction are equal.

  By equalizing the angular error at the time of maximum eccentricity in one direction and the opposite at the maximum eccentricity, it is possible to reduce the worst value of the angular error in the case of maximum eccentricity in either one, and suppress the deterioration of detection accuracy It is possible to

FIG. 1 is a configuration diagram showing a configuration of a rotation angle detection device of a first embodiment. FIG. 2 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection unit according to Embodiment 1. FIG. 1 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection device according to Embodiment 1. FIG. 1 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection device according to Embodiment 1. It is a schematic diagram which shows the relationship between the amount of eccentricity of FIG. 1, and an angle error. FIG. 7 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection device according to Embodiment 2. It is a schematic diagram which shows cancellation of the harmonic component accompanying one rotation of the rotor of FIG. It is a block diagram which shows an example of calculation of the magnetic flux density of the magnetic detection part of FIG. It is a block diagram which shows an example of calculation of the magnetic flux density of the magnetic detection part of FIG. FIG. 7 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection device according to Embodiment 2. FIG. 13 is a cross-sectional view showing a configuration of a stator and a rotor of a rotation angle detection device according to Embodiment 3. FIG. 16 is an enlarged view of a part A of the rotation angle detection device according to the third embodiment. FIG. 16 is a schematic view showing a gap length at circumferential positions in the third embodiment.

Embodiment 1
FIG. 1 shows the configuration of the main part of the first embodiment of the rotation angle detection device. The rotation angle detection device includes a rotation angle detection unit 100, a processor 200, a storage device 300, a controller 400, and a data bus 500. The rotation angle detection unit 100 is connected to the processor 200, and the processor 200 is connected to the controller 400 through the data bus 500, and performs various controls based on the values detected by the rotation angle detection unit 100.

  Although details of the storage device 300 are not illustrated, the storage device 300 includes volatile storage devices such as random access memory and non-volatile auxiliary storage devices such as flash memory. Also, instead of the flash memory, an auxiliary storage device of a hard disk may be provided. The processor 200 executes a program input from the storage device 300. In this case, the program is input from the auxiliary storage device to the processor 200 via the volatile storage device. Further, the processor 200 may output data such as an operation result to the volatile storage device of the storage device 300, or may store data in the auxiliary storage device via the volatile storage device. Also, the processor 200 operates the controller 400 based on the result obtained by executing the program.

  FIG. 2 is a cross-sectional view showing the configuration of the rotor 1 and the stator 2 of the rotation angle detection unit 100 according to the first embodiment of the present invention, and the rotor 1 in a state of being cut in a direction perpendicular to the rotation axis. And the relationship of the stator 2 are shown. The rotation angle detection unit 100 according to the first embodiment includes the rotor 1 and the stator 2, and the stator 2 has a gap in the radial direction of the outer periphery of the rotor 1 (direction of arrow A in the figure). It extends in the outer circumferential direction (the direction of arrow B in the figure) in an opposite manner.

  The rotor 1 includes a central axis 11 of rotation, and a concavo-convex portion 12 of a magnetic body provided on the outer side in the radial direction of the central axis 11 of rotation. The uneven portion 12 is formed to change by N cycles with respect to a mechanical angle of 360 degrees in the circumferential direction when N is an integer of 1 or more. That is, as the shape of the outer periphery, the uneven shape with N cycles is used. In the rotation angle detection unit 100 shown in FIG. 1, the uneven portion in the case of N = 12 is shown.

  The stator 2 is provided opposite to the uneven portion 12 of the rotor 1 with a gap. The stator 2 includes a magnetic field generation unit 22, one or more magnetic detection units 23 provided on the inner side in the radial direction of the magnetic field generation unit 22, and a magnetic body 24 extending in the circumferential direction. . The magnetic field generation unit 22 is a coil or a magnet and generates a magnetic field to be a bias. The magnetic detection unit 23 is a coil, a Hall element or a magnetoresistive element (MR element). The magnetic field generation unit 22 extends in the circumferential direction so as to cover the outside of the magnetic detection unit 23. The magnetic detection unit 23 is provided to face the uneven portion 12 of the rotor 1.

  The magnetic body 24 has a magnetic body radial direction outer side portion 241 provided on the radial outer side of the magnetic field generating portion 22 and a pair of magnetic body circumferential outer side portions 242 sandwiching the magnetic field generating portion 22. The magnetic material radial direction outer side portion 241 extends in the circumferential direction so as to overlap the magnetic field generating portion 22. The magnetic body circumferential direction outer side portion 242 protrudes inward in the radial direction from the magnetic field generating portion 22 and is connected to the magnetic body radial direction outer side portion 241 in the circumferential direction.

  The central axis 21 of the inner circumferential surface 243 of the magnetic material circumferential direction outer portion 242 facing the uneven portion 12 of the rotor 1 of the stator 2 is different from the central axis 11 of the rotor 1. In FIG. 2, the central axis 21 of the stator 2 is located in the direction of the arrow C1 on a plane with respect to the central axis 11 of the rotor 1 (that is, the lower direction in the drawing). Since the central axis 21 of the stator 2 is located on the lower side on a plane with respect to the central axis 11 of the rotor 1, the surface of the stator 2 facing the uneven portion 12 of the rotor 1 and the uneven portion 12 The gap length is shorter than the gap length when the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 are the same. The uneven portion 12 of the rotor 1 has a shape in which the gap permeance of the surface of the stator 2 facing the uneven portion 12 and the uneven portion 12 changes sinusoidally according to the rotation angle of the rotor 1.

  FIG. 3 shows the case where the central axis 21 of the stator 2 is located on the upper side in the plane (the direction of the arrow C3 in the figure) with respect to the central axis 11 of the rotor 1. As shown in FIG. 2, since the central axis 21 of the stator 2 is located on the upper side on a plane with respect to the central axis 11 of the rotor, the surface of the stator 2 facing the uneven portion 12 of the rotor 1 The gap length of the uneven portion 12 is longer than the gap length when the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 are the same. The uneven portion 12 of the rotor 1 has a shape in which the gap permeance of the uneven portion 12 of the surface of the stator 2 facing the uneven portion 12 and the uneven portion 12 of the rotor 1 changes sinusoidally according to the rotation angle of the rotor 1 doing.

FIG. 4 shows the case where the central axis 21 of the stator 2 is eccentrically located in the lateral direction (the direction of the arrow C3) on the plane with respect to the central axis 11 of the rotor 1. In FIG. 4, the gap lengths of the inner circumferential surface 243 of the magnetic material circumferential direction outer side portion 242 and the uneven portion 12 of the rotor 1 are different on the left and right. The uneven portion 12 of the rotor 1 has a shape in which the gap permeance of the surface of the stator 2 facing the uneven portion 12 and the uneven portion 12 changes sinusoidally according to the rotation angle of the rotor 1.
That is, as shown in FIG. 2, FIG. 3 and FIG. 4, when the stator 2 is a partial arc, the position of the central axis 21 of the stator 2 and the position of the central axis 11 of the rotor 1 approach and move away There are 3 patterns in the horizontal direction.

  In order to improve the detection accuracy of the rotation angle, it is necessary to reduce the harmonic component of the magnetic flux density detected by the magnetic detection unit 23 according to the rotation angle of the rotor 1. The magnetic flux density is determined by the product of the gap permeance of the magnetomotive force of the magnetic field generator 22 and the surface of the stator 2 facing the uneven portion 12 of the rotor 1 and the uneven portion 12 of the rotor 1. Since the magnetomotive force of the magnetic field generator 22 is constant, the amount of change in magnetic flux density is defined by the amount of change in gap permeance. The reduction of the harmonic component of the magnetic flux density is equivalent to the reduction of the harmonic component of the gap permeance. In the conventional rotation angle detection unit 100, since the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 coincide with each other, there arises a problem that an angular error increases when eccentricity occurs.

  In the rotation angle detection unit 100 according to the first embodiment, the central axis 21 of the inner peripheral surface of the stator 2 in the circumferential direction of the magnetic body facing the uneven portion 12 of the rotor 1 is different from the central axis 11 of the rotor 1 . At this time, the uneven portion 12 of the rotor 1 has a shape in which the gap permeance between the surface of the stator 2 opposed to the uneven portion 12 and the uneven portion 12 of the rotor 1 is sinusoidal. The concavo-convex portion 12 of the rotor 1 is formed in advance so that the gap permeance of the stator 2 and the rotor 1 becomes a sine wave at a position where the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 are eccentrically different. By doing this, the detection accuracy of the rotation angle detection unit 100 at the time of eccentricity can be improved.

  In FIG. 2, the central axis 21 of the stator is located below the central axis 11 of the rotor. FIG. 5 shows the relationship between the amount of eccentricity and the angular error. In FIG. 5, a broken line (1) indicates the present invention, and a solid line (2) indicates the case of the prior art. As shown in this figure, assuming that the stator 2 and the rotor 1 move away (when the gap length becomes large) and when the stator 2 approaches (when the gap length becomes short), compared to the case where the gap length becomes far. Thus, in the case where the gap lengths of the stator 2 and the rotor 1 approach, the sensitivity of the gap permeance to the amount of eccentricity is higher.

  Therefore, in the case where the gap lengths of the stator 2 and the rotor 1 approach each other, the rate at which the harmonic component is included with respect to the amount of eccentricity becomes higher, and the angular error with respect to the amount of eccentricity becomes larger. In the conventional rotation angle detection device, the concavo-convex portion of the rotor 1 is made so that the gap permeance of the stator 2 and the rotor 1 becomes a sine wave at the same position of the central axis 21 of the stator and the central axis 11 of the rotor 1 Although it has formed 12, it has shown that the subject that the angle error becomes large in the position of the maximum eccentricity amount when the stator 2 and the rotor 1 eccentrically move in the direction which approaches is present.

  In the rotation angle detection unit 100 of FIG. 2, the concavo-convex portion 12 of the rotor 1 is formed so that the gap permeance of the stator 2 and the rotor 1 becomes a sine wave at a position where the gap length between the stator 2 and the rotor 1 approaches. It is formed. The shape of the concavo-convex portion 12 of the rotor 1 has a shape which changes so that an angular error at the time of maximum eccentricity in a certain direction and at the time of maximum eccentricity on the opposite side becomes equal. As a result, as shown in FIG. 5, it is possible to suppress an angular error at the position of the maximum eccentricity when the stator 2 and the rotor 1 are decentered in the approaching direction. As a result, deterioration in detection accuracy at the position of the maximum eccentricity can be suppressed.

  In the rotation angle detection unit 100 according to the first embodiment, the stator 2 is opposed to the rotor 1 at a portion of an angle within a predetermined range of 360 degrees. That is, the stator 2 faces only a part of the circumferential direction of the rotor 1. Further, although the outer end portion 244 and the outer end portion 245 of the magnetic material circumferential direction outer side portion sandwiching the magnetic field generating portion 22 configured as a part of the circumferential direction of the stator 2 are provided to a predetermined range, It did not go around the whole of child 1. Therefore, the weight of the magnetic material circumferential direction outer side portion 242 can be minimized.

Second Embodiment
FIG. 6 is a cross-sectional view showing a rotation angle detection unit 100 according to the second embodiment. In rotation angle detection unit 100 according to the second embodiment, the same stator 2 as in the first embodiment is disposed, and second stator 3 is disposed on the opposing surface located at the mechanical angle of 180 degrees in the circumferential direction. ing. The inner circumferential surface 243 of the magnetic body circumferential direction outer portion 242 of the stator 2 and the inner circumferential surface 343 of the second magnetic body circumferential outer portion of the second stator 3 are located on the same circumference.

  In FIG. 6, the central axis 21 of the stator 2 is located on the upper side in the plane with respect to the central axis 11 of the rotor 1 (in the direction of the arrow C4). The case in which the central axis 21 of the stator 2 is deviated upward and the case in which it is displaced downward with respect to the central axis 11 of the rotor 1 have the same meaning. The shape of the uneven portion 12 of the rotor 1 is such that the gap permeance of the surface of the stator 2 facing the uneven portion 12 and the uneven portion 12 changes sinusoidally according to the rotation angle of the rotor 1 There is.

  The other configuration is the same as that of the first embodiment. As in the first embodiment, when the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 are eccentric in advance, the gap permeance of the stator 2 and the rotor 1 becomes a sine wave in advance. By forming the uneven portion 12 of 1, it is possible to obtain the effect of improving the detection accuracy of the rotation angle detection unit 100 at the time of eccentricity.

  By forming one more stator 2 on the opposing surface located at a mechanical angle of 180 degrees, it is possible to cancel out the harmonic components involved when the rotor 1 makes one rotation. Among the magnetic flux density waveforms of the magnetic detection unit 23 and the second magnetic detection unit 33 of the stator 2 in FIG. 7, harmonic components accompanying rotation in the rotor 1 are shown. In the rotation angle detection unit 100, a sine wave of a fundamental wave of N cycles is obtained as the rotor 1 makes one rotation. As a component that degrades detection accuracy, as shown in FIG. 7, a sine wave of one cycle appears with one rotation of the rotor 1, but the magnetic flux density waveform A of the magnetic detection unit 23 and the second magnetic detection unit 33 Since the magnetic flux density waveform B has an opposite phase, it is possible to cancel out by adding the magnetic flux density waveform A of the magnetic detection unit 23 and the magnetic flux density waveform B of the second magnetic detection unit 33. As a result, detection accuracy can be improved.

  FIG. 8 is a block diagram showing the calculation of the magnetic flux density of the magnetic detection unit 23 of the stator 2 and the magnetic flux density of the second magnetic detection unit 33. A calculation is performed to add the plurality of magnetic flux densities of the magnetic detection unit 23 and the second magnetic detection unit 33. FIG. 8 illustrates an operation of adding detection values of the magnetic detection units at corresponding positions. By adding the detection values as shown in FIG. 8, as described in FIG. 7, it is possible to cancel the harmonic components involved when the rotor 1 makes one rotation. In addition, although it is a block diagram of three magnetic flux densities in each, two or three or more magnetic flux densities are the same. Moreover, after carrying out arithmetic processing of a plurality of magnetic flux densities, they may be added together. For example, as shown in FIG. 9, the plurality of magnetic flux densities of the first and second magnetic detection units may be converted into the magnetic flux densities of SIN and COS, respectively, and may be added together with SIN and with each other.

  This arithmetic processing is performed in the processor 200 shown in FIG. For example, the processor 200 executes arithmetic processing on the output data of the magnetic detection unit 23 and the second magnetic detection unit 33 in the rotation angle detection unit 100 based on the program stored in the storage device 300.

  FIG. 10 shows the case where the central axis 21 of the stator 2 is located in the lateral direction (the direction of the arrow C3) on a plane with respect to the central axis 11 of the rotor 1. The uneven portion 12 of the rotor 1 has a shape in which the gap permeance changes sinusoidally in accordance with the rotation angle of the rotor 1 between the uneven portion 12 and the surface of the stator 2 facing the uneven portion 12. Also in the shape of FIG. 10, the same effect as the shape of FIG. 6 can be obtained.

Third Embodiment
FIG. 11 is a cross-sectional view showing a rotation angle detection unit 100 according to the third embodiment. FIG. 12 is an enlarged view showing a portion A of the rotation angle detection unit 100 of FIG. In FIG. 11, the central axis 21 of the stator 2 is eccentric to the central axis 11 of the rotor 1 in the direction of the arrow C4, as in the first embodiment.

  12, the gap length between the stator 2 and the uneven portion 12 of the rotor 1 is Lg, the maximum value of the gap length between the stator 2 and the uneven portion 12 is Lgmax, and the minimum value is Lgmin. The thickness in the radial direction is Lm, the relative permeability of the magnetic field generating unit 22 is μr, the amplitude of the zeroth-order component of the magnetic flux density linked to the magnetic detection unit 23 is Bo, and the amplitude of the first-order component is B1. The difference between the inner diameters of the stator 2 and the magnetic field generator 22 is L1, and the constant is A. When the central axis 21 of the stator 2 and the central axis 11 of the rotor 1 are different, the gap length between the stator 2 and the rotor 1 in the concavo-convex portion 12 of the rotor 1 becomes the following equation (1).

  In the equation (1), the gap length Lg between the stator 2 facing the concavo-convex portion 12 of the rotor 1 and the concavo-convex portion 12 of the rotor 1 when the term Asin2Nθ is removed is the center axis 21 of the stator 2 and rotation. The shape of the uneven portion 12 in the case where the central axis 11 of the child 1 is the same is shown. Therefore, the term Asin2Nθ is a correction term when the position of the central axis 21 of the stator 2 and the position of the central axis 11 of the rotor 1 are different. When the position of the central axis 21 of the stator 2 and the position of the central axis 11 of the rotor 1 are different, in addition to the fundamental wave component of gap permeance, the 2Nth component of gap permeance with respect to one mechanical angle cycle occurs. Therefore, by adding the correction term Asin2Nθ to the gap length Lg of the stator 2 and the concavo-convex part 12 facing the concavo-convex part 12 of the rotor 1, it is possible to make the gap permeance sinusoidal.

式（４）において、定数をＣ、ｉ、ｊは、次の式（５）、（６）、（７）としている。 Expressions (2) and (3) represent mathematical expressions for calculating the amplitude B0 of the zero-order component and the amplitude B1 of the first-order component of the magnetic flux density linked to the magnetic detection unit 23 in the expression (1).
In equation (1), assuming that the constants are C, i, j, the gap length between the rotor 1 and the stator 2 in the concavo-convex portion 12 can be converted to the following equation (4).

In the equation (4), C, i, j are constants of the following equations (5), (6), (7).

  In the case where the central axis 21 of the stator and the central axis 11 of the rotor are different, the shape of the uneven portion 12 of the rotor 1 is expressed by equation (4), that is, the shape of the uneven portion 12 is that of the stator and the rotor Since the gap length has a dimension given by equation (4), it is possible to provide the rotation angle detection unit 100 that improves the detection accuracy even at the time of eccentricity.

  The first and third terms in Equation (4) are components where the gap permeance is a sine wave. The second term Asin2Nθ is a harmonic component. By superimposing harmonic components in a state before the occurrence of eccentricity, it is possible to equalize the positive and negative angular errors at the time of maximum eccentricity and reduce the worst value of the angular error at the time of maximum eccentricity. .

  FIG. 13 is a schematic view showing how the gap length of the inner surface of the stator 2 facing the concavo-convex part 12 of the rotor 1 and the concavo-convex part 12 form a point sequence with respect to the circumferential position. In fabrication, sampling of the gap length is performed at circumferential intervals of constant intervals. In FIG. 13, linear interpolation is performed between point sequences. Linear interpolation between point sequences can be simply performed, and deterioration in detection accuracy can also be suppressed. In addition, point sequence interpolation of gap length is also possible by spline interpolation or Lagrange interpolation.

While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and features described in one or more embodiments are of particular embodiments. The invention is not limited to the application, and can be applied to the embodiment alone or in various combinations.
Accordingly, numerous modifications not illustrated are contemplated within the scope of the technology disclosed herein. For example, when deforming at least one component, adding or omitting it, it is further included that at least one component is extracted and combined with a component of another embodiment.

1 rotor, 2 stators, 3 second stator, 11 rotor central axis,
12 uneven portion, 21 central axis of stator, 22 magnetic field generating portion, 23 magnetic detection portion, 24 magnetic body, 241 magnetic body radially outer side portion, 242 magnetic body circumferential outer side portion,
243 inner circumferential surface, 244, 245 outer end, 33 second magnetic detection unit,
343 inner circumferential surface of second magnetic body circumferential direction outer portion, 100 rotation angle detection unit,
200 processor, 300 storage devices, 400 controller, 500 data bus

Claims (6)

  The rotor includes: a rotor having an uneven portion formed of a magnetic body on an outer peripheral surface; and a stator provided opposite to the uneven portion and having a magnetic field generating portion, a magnetic body, and a magnetic detecting portion; The concavo-convex portion is a concavo-convex portion for N cycles (N is an integer of 1 or more) with respect to a mechanical angle of 360 degrees in the circumferential direction of rotation of the rotor, and the maximum is a maximum in a predetermined direction. A rotation angle detection device comprising: a rotation angle detection unit having an outer peripheral shape having equal angular errors at the time of eccentricity and at the time of maximum eccentricity in the opposite direction to the predetermined direction.   The rotation angle detection device according to claim 1, wherein the stator faces a part of the rotor in the circumferential direction.   When the stator and the rotor are decentered in the direction in which the gap length between the stator and the concavo-convex portion is shortened, the outer peripheral shape of the concavo-convex portion is the gap permeance of the stator and the rotor. The rotation angle detection device according to claim 2, wherein the rotation angle detection device has a shape that changes sinusoidally according to the rotation angle.   The gap length between the stator and the concavo-convex portion is 2N in addition to the component in which the gap permeance between the concavo-convex portion of the rotor and the stator becomes a sine wave before the occurrence of eccentricity. The rotation angle detection device according to claim 1, wherein the rotation angle detection device has a component that becomes a next sine wave. Assuming that the gap length between the uneven portion of the rotor and the stator is Lg and the constants are A, C, i, j, the uneven portion has a gap length between the stator and the rotor of the following formula The rotation angle detection device according to claim 1 having the following dimensions.

  A second stator having a second magnetic detection unit is provided at a mechanical angle of 180 degrees in the circumferential direction of the rotor with respect to the position where the stator is provided, and detection of the magnetic detection unit 2. The rotation angle detection device according to claim 1, wherein a calculation process is performed to add the value and the detection value of the second magnetic detection unit.

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