WO2021215076A1 - Rotation detector - Google Patents

Abstract

This rotation detector comprises a first magnet and second magnet that rotate together with a rotating shaft and are disposed with a first phase difference in the rotation direction of the rotating shaft, one or more power generation elements that generate power as a result of the magnetic field fluctuation produced by the rotation of the first magnet and second magnet together with the rotating shaft, and first to fourth magnetic sensors that operate on the basis of the power generated by the one or more power generation elements and detect the magnetic field generated by the first magnet and the magnetic field generated by the second magnet. The first magnet has a north pole and a south pole disposed further inward in the radial direction of the rotating shaft than the north pole. The second magnet has a south pole and a north pole disposed further inward in the radial direction of the rotating shaft than the south pole.

Description

Rotation detector

This disclosure relates to a rotation detector. The present disclosure particularly relates to a rotation detector that detects the rotation of a rotating shaft.

Conventionally, a rotation detector that detects the rotation of the rotation shaft of a motor is known. For example, Patent Document 1 includes a disk-shaped magnet provided on a shaft and three power generation units composed of a magnetic wire and a pickup coil, and the three power generation units are configured on the end face side of the magnet. A rotation detector is disclosed, which is arranged on each of a plurality of sides of a virtual triangle.

However, the rotation detector of Patent Document 1 requires three or more power generation units, and it is difficult to reduce the size.

Japanese Patent No. 6336232

Therefore, an object of the present disclosure is to provide a rotation detector that can be easily miniaturized.

The rotation detector according to one aspect of the present disclosure includes a first magnet and a second magnet that rotate together with a rotation shaft and are arranged with a first phase difference from each other in the rotation direction of the rotation shaft, and the first magnet and the first magnet. One or more power generation elements that generate power by changing the magnetic field due to the rotation of the second magnet with the rotation axis, and the magnetic field generated by the first magnet that operates based on the power generated by the one or more power generation elements. And a plurality of magnetic sensors for detecting the magnetic field generated by the second magnet, the first magnet has a first north pole and a radial inner side of the rotation axis from the first north pole. The second magnet has a first S pole arranged in, and the second magnet is arranged inward of the second S pole and the second S pole in the radial direction of the rotation axis. It has the north pole of.

According to the rotation detector according to one aspect of the present disclosure, the size can be easily reduced.

FIG. 1 is a diagram showing a motor including a rotation detector according to the first embodiment. It is a figure which shows the substrate and the rotating plate of the rotation detector of FIG. FIG. 3 is a block diagram showing a functional configuration of the rotation detector of FIG. FIG. 4 is a diagram for explaining a determination operation of the rotation detector of FIG. 1 when the rotation axis is rotated counterclockwise. FIG. 5 is a diagram for explaining a determination operation of the rotation detector of FIG. 1 when the rotation axis is rotated clockwise. FIG. 6 is a diagram showing a table showing the states of one or more power generation elements and the first to fourth magnetic sensors at each rotation position. FIG. 7 is a diagram showing a table showing a predetermined displacement of a predetermined rotation position of the rotation shaft. FIG. 8 is a diagram showing a rotation detector according to the second embodiment. FIG. 9 is a diagram showing a modified example of the rotation detector according to the second embodiment. FIG. 10 is a diagram showing a rotation detector according to the third embodiment. FIG. 11 is a diagram showing a modified example of the rotation detector according to the third embodiment. FIG. 12 is a diagram showing a rotating plate of the rotation detector according to the fourth embodiment. FIG. 13 is a diagram showing a rotating plate of the rotation detector according to the fifth embodiment. FIG. 14 is a diagram showing another example of the arrangement of the first magnet and the second magnet. FIG. 15 is a diagram showing another example of arrangement of one or more power generation elements. FIG. 16 is a diagram showing another example of the arrangement of the plurality of magnetic sensors. FIG. 17 is a diagram showing a rotation detector according to another embodiment. FIG. 18 is a diagram showing a rotation detector according to another embodiment.

Hereinafter, embodiments of the present disclosure will be described. It should be noted that all of the embodiments described below show a specific example of the present disclosure. Therefore, the numerical values, the components, the arrangement positions and connection forms of the components, the steps, the order of the steps, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims indicating the highest level concept of the present disclosure will be described as arbitrary components.

Also, each figure is a schematic view and is not necessarily exactly illustrated. In each figure, substantially the same configuration is designated by the same reference numerals, and duplicate description will be omitted or simplified.

[Embodiment 1]
(Configuration of rotation detector)
Hereinafter, the rotation detector 14 according to the first embodiment will be described with reference to the drawings.

FIG. 1 is a diagram showing a motor 1 including a rotation detector 14 according to the first embodiment. FIG. 2 is a diagram showing a substrate 18 and a rotating plate 16 of the rotation detector 14 of FIG. In FIG. 2, (a) shows the substrate 18 of the rotation detector 14 of FIG. 1, and (b) shows the rotating plate 16 of the rotation detector 14 of FIG. In FIG. 1, the case 12 is shown in cross section. The configuration of the rotation detector 14 according to the first embodiment and the motor 1 including the rotation detector 14 will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the motor 1 includes a main body 4, a rotor 6, a stator 8, a rotating shaft 10, a case 12, and a rotation detector 14. The axial direction of the rotating shaft 10 is the direction indicated by the arrow X in FIG. The radial direction of the rotating shaft 10 is the direction indicated by the arrow Y in FIG. The circumferential direction of the rotating shaft 10 is the direction indicated by the arrow Z in FIG. The radial and circumferential directions of the rotating shaft 10 are orthogonal to the axial direction.

The rotor 6 and the stator 8 are housed in the main body 4. The rotor 6 rotates with respect to the stator 8.

The rotating shaft 10 has a rod shape such as a columnar shape. The rotating shaft 10 is fixed to the rotor 6. The rotating shaft 10 rotates around the axis A of the rotating shaft 10. For example, when electric power is supplied to the motor 1, the rotating shaft 10 rotates with the rotor 6 about the axis A as the center of rotation based on the electric power. The rotation direction of the rotation shaft 10 coincides with the circumferential direction of the rotation shaft 10 (see arrow Z in FIG. 2). A rotation detector 14 is provided at one end of the rotation shaft 10 in the axial direction. A load (not shown) or the like that is rotationally driven by the rotation of the rotating shaft 10 is attached to the other end of the rotating shaft 10 in the axial direction. For example, the rotating shaft 10 is made of a magnetic metal such as iron.

The case 12 is attached to the main body 4 so as to cover one end of the rotating shaft 10 in the axial direction and the rotation detector 14. For example, the case 12 is made of a magnetic metal such as iron.

The rotation detector 14 detects the rotation of the rotation shaft 10. Specifically, the rotation detector 14 detects the rotation position of the rotation shaft 10, the rotation direction of the rotation shaft 10, the rotation speed of the rotation shaft 10, and the like. For example, the rotation detector 14 is an absolute encoder. As described above, the rotation detector 14 is provided at one end of the rotation shaft 10 in the axial direction. As shown in FIGS. 1 and 2, the rotation detector 14 includes a rotating plate 16, a substrate 18, a first magnet 20, a second magnet 22, and one or more power generation elements (24, 26) described later. , A plurality of magnetic sensors (46, 48, 50, 52) described later, and a control circuit 36.

The rotating plate 16 extends in a direction orthogonal to the axial direction of the rotating shaft 10. Specifically, the rotating plate 16 has a disk shape having a main surface extending in a direction orthogonal to the axial direction of the rotating shaft 10. The rotating plate 16 is circular when viewed from the axial direction of the rotating shaft 10. The rotary plate 16 is attached to one end of the rotary shaft 10 in the axial direction. The axis of the rotating plate 16 and the axis A of the rotating shaft 10 coincide with each other. The rotating plate 16 rotates together with the rotating shaft 10.

The substrate 18 extends in a direction orthogonal to the axial direction of the rotating shaft 10. Specifically, the substrate 18 has a disk shape having a main surface extending in a direction orthogonal to the axial direction of the rotating shaft 10. The substrate 18 is circular when viewed from the axial direction of the rotating shaft 10. The substrate 18 is arranged at a distance from one end of the rotating shaft 10 and the rotating plate 16 in the axial direction of the rotating shaft 10, and faces the rotating plate 16. The axis of the substrate 18 and the axis A of the rotating shaft 10 coincide with each other. The substrate 18 is fixed to the inner surface of the case 12 and does not rotate together with the rotating shaft 10.

The first magnet 20 and the second magnet 22 are arranged with a first phase difference from each other in the rotation direction of the rotation shaft 10. The first phase difference is 90 °. The first magnet 20 and the second magnet 22 are arranged at positions shifted by 90 ° in the rotation direction of the rotation shaft 10. Here, the first phase difference extends in the radial direction of the rotating shaft 10 and passes through the center in the width direction of the first magnet 20 and the center line B extends in the radial direction of the rotating shaft 10 and extends in the width direction of the second magnet 22. It is an angle formed by the center line C passing through the center of. In other words, here, the first phase difference passes through the center of the first magnet 20 in the direction orthogonal to the direction in which the magnetic poles of the first magnet 20 are lined up (the radial direction of the rotating shaft 10), and is in the radial direction of the rotating shaft 10. A center line C extending in the radial direction of the rotating shaft 10 and passing through the center of the second magnet 22 in a direction orthogonal to the direction in which the magnetic poles of the second magnet 22 are lined up (the radial direction of the rotating shaft 10). It is the angle that makes a difference.

The first magnet 20 is a rod-shaped magnet that extends in the radial direction of the rotating shaft 10. The first magnet 20 is arranged on the main surface of the rotating plate 16 on the substrate 18 side. The first magnet 20 has an N pole and an S pole arranged inward in the radial direction of the rotation shaft 10 with respect to the N pole. In this way, the first magnet 20 is arranged so that the north pole and the south pole are aligned in the radial direction of the rotating shaft 10. When the rotating shaft 10 rotates, the first magnet 20 rotates together with the rotating plate 16, the second magnet 22, and the rotating shaft 10.

The second magnet 22 is a rod-shaped magnet that extends in the radial direction of the rotating shaft 10. The second magnet 22 is arranged on the main surface of the rotating plate 16 on the substrate 18 side. The second magnet 22 is arranged with a first phase difference from the first magnet 20 as described above. The second magnet 22 is arranged at a distance from the first magnet 20 in the rotation direction of the rotation shaft 10. The second magnet 22 is arranged side by side with the first magnet 20 in the direction of the rotation axis 10. The second magnet 22 has an S pole and an N pole arranged inward in the radial direction of the rotation shaft 10 with respect to the S pole. In this way, the second magnet 22 is arranged so that the north pole and the south pole are aligned in the radial direction of the rotating shaft 10. When the rotating shaft 10 rotates, the second magnet 22 rotates together with the rotating plate 16, the first magnet 20, and the rotating shaft 10.

One or more power generation elements include a first power generation element 24 and a second power generation element 26. The first power generation element 24 and the second power generation element 26 generate power by changing the magnetic field due to the rotation of the first magnet 20 and the second magnet 22 together with the rotation shaft 10. The first power generation element 24 and the second power generation element 26 are arranged with a second phase difference from each other in the rotation direction of the rotation shaft 10. The second phase difference is 180 °, and the first power generation element 24 and the second power generation element 26 are arranged at positions shifted by 180 ° in the rotation direction of the rotation shaft 10. Here, the second phase difference extends in the radial direction of the rotating shaft 10 and extends in the radial direction of the rotating shaft 10 with the center line D passing through the center (axis center) of the first magnetic sensing portion 38 (described later). 2 This is the angle formed by the center line E passing through the center (axis center) of the magnetically sensitive portion 42 (described later). The second phase difference and the first phase difference are different.

The first power generation element 24 extends in the radial direction of the rotating shaft 10 and is arranged on the main surface of the substrate 18 on the opposite side of the rotating shaft 10 (opposite to the rotating plate 16). The first power generation element 24 has a first magnetic sensitive portion 38 and a first coil 40 wound around the first magnetic sensitive portion 38. The first magnetic sensing portion 38 is a magnetic material extending in the radial direction of the rotating shaft 10. The first magnetic sensing portion 38 is located on the side opposite to the rotating plate 16 of the substrate 18. For example, the first magnetic sensing portion 38 is a magnetic material that exhibits a large Barkhausen effect, and is a Wiegand wire extending in the radial direction of the rotating shaft 10. The Wiegand wire is a magnetic material whose magnetization direction is aligned so as to be one of the longitudinal directions when a magnetic field of a predetermined value or more is applied along the longitudinal direction of the Wiegand wire. When the direction of the magnetic flux flowing along the longitudinal direction of the Wiegand wire changes, the magnetization direction of the Wiegand wire is dramatically reversed, and voltage pulses are induced at both ends of the coil wound around the Wiegand wire. In this way, the first power generation element 24 generates power.

The second power generation element 26 extends in the radial direction of the rotating shaft 10 and is arranged on the main surface of the substrate 18 on the opposite side of the rotating shaft 10 (opposite to the rotating plate 16). The second power generation element 26 has a second magnetic sensitive portion 42 and a second coil 44 wound around the second magnetic sensitive portion 42. The second magnetic sensitive portion 42 is a magnetic material extending in the radial direction of the rotating shaft 10. The second magnetic sensitive portion 42 is located on the side opposite to the rotating plate 16 of the substrate 18. For example, the second magnetic sensitive portion 42 is a magnetic material that exhibits a large Barkhausen effect, and is a Wiegand wire that extends in the radial direction of the rotation axis 10. The second power generation element 26 generates power in the same manner as the first power generation element 24.

The plurality of magnetic sensors include a first magnetic sensor 46, a second magnetic sensor 48, a third magnetic sensor 50, and a fourth magnetic sensor 52. Each of the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 operates based on the power from the first power generation element 24 when the first power generation element 24 generates power. Then, the magnetic field generated by the first magnet 20 and the magnetic field generated by the second magnet 22 are detected. Each of the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 operates based on the power from the second power generation element 26 when the second power generation element 26 generates power. Then, the magnetic field generated by the first magnet 20 and the magnetic field generated by the second magnet 22 are detected.

The first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 are arranged on the main surface of the substrate 18 on the rotating shaft 10 side (rotating plate 16 side). The first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 are arranged with a phase difference in the rotation direction of the rotation shaft 10. The first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 are arranged side by side in the rotation direction of the rotation shaft 10. The first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52 overlap with the first power generation element 24 and the second power generation element 26 when viewed from the axial direction of the rotating shaft 10. It doesn't become. Specifically, the first magnetic sensor 46 is arranged with a phase difference of 120 ° from the first magnetic sensing portion 38, and is arranged with a phase difference of 60 ° from the second magnetic sensing portion 42. There is. The second magnetic sensor 48 is arranged with a phase difference of 60 ° from the first magnetic sensing portion 38, and is arranged with a phase difference of 120 ° from the second magnetic sensing portion 42, and is arranged with a phase difference of 120 °. It is arranged with a phase difference of 60 ° from the sensor 46. The third magnetic sensor 50 is arranged with a phase difference of 60 ° from the first magnetic sensing portion 38, and is arranged with a phase difference of 120 ° from the second magnetic sensing portion 42, and is arranged with a phase difference of 120 °. It is arranged with a phase difference of 180 ° from the sensor 46. The fourth magnetic sensor 52 is arranged with a phase difference of 120 ° from the first magnetic sensing portion 38, and is arranged with a phase difference of 60 ° from the second magnetic sensing portion 42, and is arranged with a phase difference of 60 °. It is arranged with a phase difference of 120 ° from the sensor 46.

The control circuit 36 is arranged at the center of the main surface of the substrate 18 on the rotating shaft 10 side (rotating plate 16 side). The control circuit 36 is electrically connected to the first power generation element 24 and the like. Details of the control circuit 36 will be described later.

FIG. 3 is a block diagram showing a functional configuration of the rotation detector 14 of FIG. The functional configuration of the rotation detector 14 will be described with reference to FIG.

The control circuit 36 includes a full-wave rectifier unit 54, a voltage regulator 56, a disconnection diagnosis unit 58, and a backflow prevention switch 60.

The full-wave rectifying unit 54 is connected to the first power generation element 24 and rectifies the voltage pulse generated by the first power generation element 24.

The voltage regulator 56 outputs a constant voltage with the ground potential as the reference potential and the voltage between the terminals of the capacitor charged by the output voltage of the full-wave rectifying unit 54 as the input voltage. The output voltage of the voltage regulator 56 is supplied to the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, the fourth magnetic sensor 52, the information processing unit 82 (described later), and the like (black in FIG. 3). See diamond). The voltage is output from the voltage regulator 56 during the period when the first power generation element 24 generates power and generates a voltage pulse. That is, during the period in which the first power generation element 24 generates power and generates a voltage pulse, the voltage from the voltage regulator 56 is the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor. It is supplied to 52, the information processing unit 82, and the like, and these operate. For example, the voltage regulator 56 is an LDO (Low Drop Out) regulator.

The disconnection diagnosis unit 58 is connected to the input terminal of the full-wave rectifier unit 54 to diagnose the presence or absence of disconnection.

The backflow prevention switch 60 is connected in series between the full-wave rectifying unit 54 and the voltage regulator 56 to prevent current from flowing from the voltage regulator 56 to the full-wave rectifying unit 54.

The control circuit 36 further includes a full-wave rectifier unit 62, a voltage regulator 64, a disconnection diagnosis unit 66, and a backflow prevention switch 68.

The full-wave rectifying unit 62 is connected to the second power generation element 26 and rectifies the voltage pulse generated by the second power generation element 26.

The voltage regulator 64 outputs a constant voltage with the ground potential as the reference potential and the voltage between the terminals of the capacitor charged by the output voltage of the full-wave rectifying unit 62 as the input voltage. The output voltage of the voltage regulator 64 is supplied to the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, the fourth magnetic sensor 52, the information processing unit 82 (described later), and the like (black in FIG. 3). See diamond). The voltage is output from the voltage regulator 64 during the period when the second power generation element 26 generates power and generates a voltage pulse. That is, during the period in which the second power generation element 26 generates power and generates a voltage pulse, the voltage from the voltage regulator 64 is the first magnetic sensor 46, the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor. It is supplied to 52, the information processing unit 82, and the like, and these operate. For example, the voltage regulator 64 is an LDO (Low Drop Out) regulator.

The disconnection diagnosis unit 66 is connected to the input terminal of the full-wave rectifier unit 62 to diagnose the presence or absence of disconnection.

The backflow prevention switch 68 is connected in series between the full-wave rectifying unit 62 and the voltage regulator 64 to prevent current from flowing from the voltage regulator 64 to the full-wave rectifying unit 62.

The control circuit 36 further includes a comparator 70, 72, 74, 76, 78, 80, an information processing unit 82, a storage unit 84, and a communication unit 86.

The comparator 70 receives the detection signal of the first magnetic sensor 46, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82. The comparator 72 receives the detection signal of the second magnetic sensor 48, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82. The comparator 74 receives the detection signal of the third magnetic sensor 50, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82. The comparator 76 receives the detection signal of the fourth magnetic sensor 52, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82.

The comparator 78 receives the output voltage of the voltage regulator 56, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82. The comparator 80 receives the output voltage of the voltage regulator 64, compares it with a predetermined voltage value, and outputs the output voltage, which is the comparison result, to the information processing unit 82.

The information processing unit 82 uses the power generation information indicating which of the one or more power generation elements has generated power and the detection information including the detection results of the first to fourth magnetic sensors 46, 48, 50, 52 to rotate the axis of rotation. At least one of the rotation position and the rotation direction of 10 may be determined, and the determination result may be stored in the storage unit 84. Preferably, the information processing unit 82 determines both the rotation position and the rotation direction of the rotation shaft 10, and stores the determination result in the storage unit 84. The information processing unit 82 determines which of the one or more power generation elements generated power, that is, which of the first power generation element 24 and the second power generation element 26 generated power, based on the output voltages from the comparators 78 and 80. do. The information processing unit 82 determines the detection results of the first to fourth magnetic sensors 46, 48, 50, and 52 based on the output voltages from the comparators 70, 72, 74, and 76.

The information processing unit 82 determines the rotation position of the rotation shaft 10 using the detection information each time one or more power generation elements generate power. The information processing unit 82 stores the determined rotation position of the rotation shaft 10 in the storage unit 84. The information processing unit 82 counts used to calculate the rotation speed of the rotation shaft 10 based on the rotation position of the rotation shaft 10 determined this time and the rotation position of the rotation shaft 10 previously determined stored in the storage unit 84. The value is updated and the count value is stored in the storage unit 84. Although the details will be described later, the information processing unit 82 increments the count value each time the rotation shaft 10 makes one rotation counterclockwise. On the other hand, the information processing unit 82 decrements the count value each time the rotation shaft 10 makes one rotation clockwise. In this way, the information processing unit 82 calculates the rotation speed of the rotation shaft 10 by updating the count value. Note that clockwise means clockwise when viewed from the side opposite to the rotating plate 16 of the substrate 18 in the axial direction of the rotating shaft 10. The counterclockwise direction means a counterclockwise direction when viewed from the side opposite to the rotating plate 16 of the substrate 18 in the axial direction of the rotating shaft 10. The same applies to the following description.

Further, the information processing unit 82 associates the rotation position of the rotation shaft 10 with the power generation information and stores it in the storage unit 84. As a result, the rotational position of the rotating shaft 10 when the first power generation element 24 and the second power generation element 26 generate power can be known.

The storage unit 84 stores the rotation position, rotation direction, and the like of the rotation shaft 10. For example, the storage unit 84 is composed of a non-volatile memory such as FRAM (Ferroelectric Random Access Memory, registered trademark).

The communication unit 86 is connected to an ASIC (Application Specific Integrated Circuit, an integrated circuit for a specific purpose) so as to be able to communicate by wire or wirelessly.

The configuration of the rotation detector 14 according to the first embodiment and the motor 1 including the rotation detector 14 has been described above.

(Judgment operation of rotation detector)
Next, an example of the determination operation of the rotation detector 14 according to the first embodiment will be described.

FIG. 4 is a diagram for explaining the determination operation of the rotation detector 14 of FIG. 1 when the rotation shaft 10 is rotated counterclockwise, and FIG. 4A is a diagram in which the arrow F is located at the position I. (B) is the state where the arrow F is located at the position II, (c) is the state where the arrow F is located at the position III, and (d) is the state where the arrow F is located at the position IV. Indicates the state of being. 5A and 5B are views for explaining the determination operation of the rotation detector 14 of FIG. 1 when the rotation shaft 10 is rotated clockwise, and FIG. 5A is a diagram in which the arrow F is located at the position V. (B) is the state where the arrow F is located at the position VI, (c) is the state where the arrow F is located at the position VII, and (d) is the state where the arrow F is located at the position VIII. Indicates the state of FIG. 6 is a diagram showing a table showing the states of one or more power generation elements and the first to fourth magnetic sensors 46, 48, 50, 52 at each rotation position. In FIG. 6, CCW (Counter ClockWise) indicates a counterclockwise direction, and CW (ClockWise) indicates a clockwise direction. FIG. 7 is a diagram showing a table showing a predetermined displacement of a predetermined rotation position of the rotation shaft 10.

In the following description, as shown in FIGS. 4 and 5, a position between the first magnet 20 and the second magnet 22 in the rotation direction of the rotation shaft 10 is indicated by a virtual arrow F. .. Specifically, the arrow F is at a position having a phase difference of 45 ° from the first magnet 20 and a position having a phase difference of 45 ° from the second magnet 22 in the rotation direction of the rotation shaft 10. ..

The direction in which the first power generation element 24 is arranged (see D in FIG. 2) when viewed from the axial center (center in the radial direction) of the substrate 18 is 0 ° (360 °) in the rotation direction of the rotation shaft 10. , The position of 330 ° is referred to as position I, the position of 240 ° is referred to as position II, the position of 150 ° is referred to as position III, and the position of 60 ° is referred to as position IV. The position of 30 ° will be referred to as position V, the position of 120 ° will be referred to as position VI, the position of 210 ° will be referred to as position VII, and the position of 300 ° will be referred to as position VIII.

The first power generation element 24 is magnetized by the first magnet 20 whose north pole is located outside the south pole, and the second power generation element 26 has the north pole located outside the south pole. The state of being magnetized by the first magnet 20 is described as a HIGH state. The first power generation element 24 is magnetized by the second magnet 22 whose S pole is located outside the N pole, and the second power generation element 26 has the S pole located outside the N pole. The state of being magnetized by the second magnet 22 is described as a LOW state. The first power generation element 24 and the second power generation element 26 generate power when the state changes from the HIGH state to the LOW state and when the state changes from the LOW state to the HIGH state. In FIG. 6, the case of transitioning from the HIGH state to the LOW state to generate electricity is indicated by ●, and the case of transitioning from the LOW state to the HIGH state to generate electricity is indicated by ◯.

When the first magnet 20 or the second magnet 22 is located near the first magnetic sensor 46, the first magnetic sensor 46 outputs a high level signal, and the first magnet 20 and the second magnet 22 Is not located in the vicinity of the first magnetic sensor 46, the first magnetic sensor 46 will be described as outputting a low level signal. Similarly, when the first magnet 20 or the second magnet 22 is located in the vicinity of the second magnetic sensor 48, the second magnetic sensor 48 outputs a high level signal, and the first magnet 20 and the second magnet When 22 is not located in the vicinity of the second magnetic sensor 48, the second magnetic sensor 48 will be described as outputting a low level signal. When the first magnet 20 or the second magnet 22 is located in the vicinity of the third magnetic sensor 50, the third magnetic sensor 50 outputs a high level signal, and the first magnet 20 and the second magnet 22 are second. 3 When not located in the vicinity of the magnetic sensor 50, the third magnetic sensor 50 will be described as outputting a low level signal. When the first magnet 20 or the second magnet 22 is located in the vicinity of the fourth magnetic sensor 52, the fourth magnetic sensor 52 outputs a high level signal, and the first magnet 20 and the second magnet 22 are second. 4 When not located in the vicinity of the magnetic sensor 52, the fourth magnetic sensor 52 will be described as outputting a low level signal. In FIG. 6, the HIGH state, the LOW state, the high level and the low level are displayed as H, L, h, and l, respectively.

First, a case where the rotation shaft 10 rotates counterclockwise will be described with reference to FIG. In this case, when the arrow F is located at the position I, the position II, the position III, and the position IV, one of the first power generation element 24 and the second power generation element 26 generates power.

For example, when the arrow F is located at the position of 0 °, the first power generation element 24 is in the HIGH state, and the second power generation element 26 is in the LOW state, the rotation shaft 10 rotates counterclockwise. Will be described.

As shown in FIG. 4A, when the arrow F is located at the position I, the second magnet 22 is located near the first power generation element 24, and the first power generation element 24 is magnetized by the second magnet 22. .. As a result, the first power generation element 24 transitions from the HIGH state to the LOW state and generates power. On the other hand, the second power generation element 26 remains in the LOW state and does not generate power. Here, when viewed from the axial direction of the rotating shaft 10, at least a part of the first magnet 20 is within a range of 30 ° centered on the first magnetic sensitive portion 38 in the rotating direction of the rotating shaft 10. Is located, the first magnet 20 will be described as being located in the vicinity of the first power generation element 24. When at least a part of the second magnet 22 is located within a range of 30 ° centered on the first magnetic sensing portion 38, it is assumed that the second magnet 22 is located in the vicinity of the first power generation element 24. explain. The same applies to the second power generation element 26.

When the first power generation element 24 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the first power generation element 24. When the arrow F is located at the position I, the first magnet 20 is located near the third magnetic sensor 50. Therefore, the third magnetic sensor 50 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the second magnetic sensor 48, and the fourth magnetic sensor 52, and the first magnetic sensor 46 and the second magnetic sensor The 48 and the fourth magnetic sensor 52 output a low level signal. Here, when viewed from the axial direction of the rotating shaft 10, at least a part of the first magnet 20 is within a range of 30 ° centered on the third magnetic sensor 50 in the rotating direction of the rotating shaft 10. If it is located, the first magnet 20 will be described as being located in the vicinity of the third magnetic sensor 50. When at least a part of the second magnet 22 is located within a range of 30 ° centered on the third magnetic sensor 50, it is assumed that the second magnet 22 is located in the vicinity of the third magnetic sensor 50. do. The same applies to the first magnetic sensor 46, the second magnetic sensor 48, and the fourth magnetic sensor 52.

As shown in FIG. 6, when the arrow F is located at the position I, the first power generation element 24 generates power, the second power generation element 26 does not generate power, the third magnetic sensor 50 outputs a high level signal, and the third magnetic sensor 50 outputs a high level signal. The 1 magnetic sensor 46, the 2nd magnetic sensor 48, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the first power generation element 24 is generating power, the second power generation element 26 is not generating power, the third magnetic sensor 50 outputs a high level signal, and the first magnetic sensor 46 , The second magnetic sensor 48, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located near the position I.

When the rotating shaft 10 further rotates counterclockwise and the arrow F is located at position II as shown in FIG. 4B, the first magnet 20 is located near the second power generation element 26, and the second magnet 20 is located. The power generation element 26 is magnetized by the first magnet 20. As a result, the second power generation element 26 transitions from the LOW state to the HIGH state and generates power. On the other hand, the first power generation element 24 remains in the LOW state and does not generate power.

When the second power generation element 26 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the second power generation element 26. When the arrow F is located at position II, the second magnet 22 is located near the third magnetic sensor 50. Therefore, the third magnetic sensor 50 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the second magnetic sensor 48, and the fourth magnetic sensor 52, and the first magnetic sensor 46 and the second magnetic sensor The 48 and the fourth magnetic sensor 52 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position II, the second power generation element 26 generates power, the first power generation element 24 does not generate power, the third magnetic sensor 50 outputs a high level signal, and the third magnetic sensor 50 outputs a high level signal. The 1 magnetic sensor 46, the 2nd magnetic sensor 48, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the second power generation element 26 is generating power, the first power generation element 24 is not generating power, the third magnetic sensor 50 outputs a high level signal, and the first magnetic sensor 46 , The second magnetic sensor 48, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located in the vicinity of the position II.

When the rotating shaft 10 further rotates counterclockwise and the arrow F is located at position III as shown in FIG. 4 (c), the second magnet 22 is located near the second power generation element 26, and the second magnet 22 is located. The power generation element 26 is magnetized by the second magnet 22. As a result, the second power generation element 26 transitions from the HIGH state to the LOW state and generates power. On the other hand, the first power generation element 24 remains in the LOW state and does not generate power.

When the second power generation element 26 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the second power generation element 26. When the arrow F is located at position III, the first magnet 20 is located near the first magnetic sensor 46. Therefore, the first magnetic sensor 46 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52, and the second magnetic sensor 48 and the third magnetic sensor The 50 and the fourth magnetic sensor 52 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position III, the second power generation element 26 generates power, the first power generation element 24 does not generate power, the first magnetic sensor 46 outputs a high level signal, and the first The 2 magnetic sensor 48, the 3rd magnetic sensor 50, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the second power generation element 26 is generating power, the first power generation element 24 is not generating power, the first magnetic sensor 46 outputs a high level signal, and the second magnetic sensor 48 , The third magnetic sensor 50, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located in the vicinity of the position III.

When the rotating shaft 10 further rotates counterclockwise and the arrow F is located at the position IV as shown in FIG. 4D, the first magnet 20 is located near the first power generation element 24, and the first magnet 20 is located. The power generation element 24 is magnetized by the first magnet 20. As a result, the first power generation element 24 transitions from the LOW state to the HIGH state and generates power. On the other hand, the second power generation element 26 remains in the LOW state and does not generate power.

When the first power generation element 24 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the first power generation element 24. When the arrow F is located at position IV, the second magnet 22 is located near the first magnetic sensor 46. Therefore, the first magnetic sensor 46 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the second magnetic sensor 48, the third magnetic sensor 50, and the fourth magnetic sensor 52, and the second magnetic sensor 48 and the third magnetic sensor The 50 and the fourth magnetic sensor 52 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position IV, the first power generation element 24 generates power, the second power generation element 26 does not generate power, the first magnetic sensor 46 outputs a high level signal, and the second The 2 magnetic sensor 48, the 3rd magnetic sensor 50, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the first power generation element 24 is generating power, the second power generation element 26 is not generating power, the first magnetic sensor 46 outputs a high level signal, and the second magnetic sensor 48 , The third magnetic sensor 50, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located in the vicinity of the position IV.

When the rotating shaft 10 further rotates counterclockwise and the arrow F is repositioned at the position I as shown in FIG. 4A, the first power generation element 24 generates power and the second power generation as described above. The element 26 does not generate electricity, the third magnetic sensor 50 outputs a high level signal, and the first magnetic sensor 46, the second magnetic sensor 48, and the fourth magnetic sensor 52 output a low level signal.

When the arrow F is displaced from the position IV to the position I, the information processing unit 82 increments the count value of the rotation speed. Specifically, the information processing unit 82 adds 1 to the count value of the current rotation speed. As a result, when the initial value of the count value is 0, the count value becomes 1, and it can be seen that the rotation axis 10 has rotated once counterclockwise. When the rotation shaft 10 further rotates once counterclockwise, the information processing unit 82 further adds 1 and the count value becomes 2. As a result, it can be seen that the rotation shaft 10 has rotated twice counterclockwise.

A case where the rotating shaft 10 rotates clockwise will be described with reference to FIG. In this case, when the arrow F is located at the position V, the position VI, the position VII, and the position VIII, one of the first power generation element 24 and the second power generation element 26 generates power.

For example, from the case where the arrow F is located at the position of 0 °, the first power generation element 24 is in the LOW state, and the second power generation element 26 is in the HIGH state, the rotation shaft 10 rotates clockwise. explain.

As shown in FIG. 5A, when the arrow F is located at the position V, the first magnet 20 is located near the first power generation element 24, and the first power generation element 24 is magnetized by the first magnet 20. .. As a result, the first power generation element 24 transitions from the LOW state to the HIGH state and generates power. On the other hand, the second power generation element 26 remains in the HIGH state and does not generate power.

When the first power generation element 24 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the first power generation element 24. When the arrow F is located at the position V, the second magnet 22 is located in the vicinity of the second magnetic sensor 48. Therefore, the second magnetic sensor 48 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the third magnetic sensor 50, and the fourth magnetic sensor 52, and the first magnetic sensor 46 and the third magnetic sensor 22 are not located. The 50 and the fourth magnetic sensor 52 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position V, the first power generation element 24 generates power, the second power generation element 26 does not generate power, the second magnetic sensor 48 outputs a high level signal, and the second The 1 magnetic sensor 46, the 3rd magnetic sensor 50, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the first power generation element 24 is generating power, the second power generation element 26 is not generating power, the second magnetic sensor 48 outputs a high level signal, and the first magnetic sensor 46 , The third magnetic sensor 50, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located in the vicinity of the position V.

When the rotating shaft 10 further rotates clockwise and the arrow F is located at the position VI as shown in FIG. 5 (b), the second magnet 22 is located near the second power generation element 26, and the second power generation is performed. The element 26 is magnetized by the second magnet 22. As a result, the second power generation element 26 transitions from the HIGH state to the LOW state and generates power. On the other hand, the first power generation element 24 remains in the HIGH state and does not generate power.

When the second power generation element 26 generates electric power, the first to fourth magnetic sensors 46 to 52 operate based on the electric power from the second power generation element 26. When the arrow F is located at the position VI, the first magnet 20 is located in the vicinity of the second magnetic sensor 48. Therefore, the second magnetic sensor 48 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the third magnetic sensor 50, and the fourth magnetic sensor 52, and the first magnetic sensor 46 and the third magnetic sensor 22 are not located. The 50 and the fourth magnetic sensor 52 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position VI, the second power generation element 26 generates power, the first power generation element 24 does not generate power, the second magnetic sensor 48 outputs a high level signal, and the second The 1 magnetic sensor 46, the 3rd magnetic sensor 50, and the 4th magnetic sensor 52 output a low level signal. Therefore, in the information processing unit 82, the second power generation element 26 is generating power, the first power generation element 24 is not generating power, the second magnetic sensor 48 outputs a high level signal, and the first magnetic sensor 46 , The third magnetic sensor 50, and the fourth magnetic sensor 52 output a low level signal, it is determined that the arrow F is located in the vicinity of the position VI.

When the rotating shaft 10 further rotates clockwise and the arrow F is located at the position VII as shown in FIG. 5 (c), the first magnet 20 is located near the second power generation element 26 and the second power generation is performed. The element 26 is magnetized by the first magnet 20. As a result, the second power generation element 26 transitions from the LOW state to the HIGH state and generates power. On the other hand, the first power generation element 24 remains in the HIGH state and does not generate power.

When the second power generation element 26 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the second power generation element 26. When the arrow F is located at position VII, the second magnet 22 is located near the fourth magnetic sensor 52. Therefore, the fourth magnetic sensor 52 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the second magnetic sensor 48, and the third magnetic sensor 50, and the first magnetic sensor 46 and the second magnetic sensor are not located. The 48 and the third magnetic sensor 50 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position VII, the second power generation element 26 generates power, the first power generation element 24 does not generate power, the fourth magnetic sensor 52 outputs a high level signal, and the second The 1 magnetic sensor 46, the 2nd magnetic sensor 48, and the 3rd magnetic sensor 50 output a low level signal. Therefore, in the information processing unit 82, the second power generation element 26 is generating power, the first power generation element 24 is not generating power, the fourth magnetic sensor 52 outputs a high level signal, and the first magnetic sensor 46 , The second magnetic sensor 48, and the third magnetic sensor 50 output a low level signal, it is determined that the arrow F is located in the vicinity of the position VII.

When the rotating shaft 10 further rotates clockwise and the arrow F is located at the position VIII as shown in FIG. 5D, the second magnet 22 is located near the first power generation element 24 and the first power generation is performed. The element 24 is magnetized by the second magnet 22. As a result, the first power generation element 24 transitions from the HIGH state to the LOW state and generates power. On the other hand, the second power generation element 26 remains in the HIGH state and does not generate power.

When the first power generation element 24 generates electric power, the first to fourth magnetic sensors 46, 48, 50, 52 operate based on the electric power from the first power generation element 24. When the arrow F is located at position VIII, the first magnet 20 is located near the fourth magnetic sensor 52. Therefore, the fourth magnetic sensor 52 outputs a high level signal. On the other hand, the first magnet 20 and the second magnet 22 are not located in the vicinity of the first magnetic sensor 46, the second magnetic sensor 48, and the third magnetic sensor 50, and the first magnetic sensor 46 and the second magnetic sensor are not located. The 48 and the third magnetic sensor 50 output a low level signal.

As shown in FIG. 6, when the arrow F is located at the position VIII, the first power generation element 24 generates power, the second power generation element 26 does not generate power, the fourth magnetic sensor 52 outputs a high level signal, and the second The 1 magnetic sensor 46, the 2nd magnetic sensor 48, and the 3rd magnetic sensor 50 output a low level signal. Therefore, in the information processing unit 82, the first power generation element 24 is generating power, the second power generation element 26 is not generating power, the fourth magnetic sensor 52 outputs a high level signal, and the first magnetic sensor 46 , The second magnetic sensor 48, and the third magnetic sensor 50 output a low level signal, it is determined that the arrow F is located near the position VIII.

When the rotating shaft 10 further rotates clockwise and the arrow F is repositioned at the position V as shown in FIG. 5A, the first power generation element 24 generates power and the second power generation element generates power as described above. 26 does not generate electricity, the second magnetic sensor 48 outputs a high level signal, and the first magnetic sensor 46, the third magnetic sensor 50, and the fourth magnetic sensor 52 output a low level signal.

When the arrow F is displaced from the position VIII to the position V, the information processing unit 82 decrements the count value of the rotation speed. Specifically, the information processing unit 82 subtracts 1 from the current count value. As a result, when the initial value of the count value is 0, the count value becomes -1, and it can be seen that the rotation axis 10 has rotated once clockwise. When the rotation shaft 10 further rotates once clockwise, the information processing unit 82 further subtracts 1 and the count value becomes -2. As a result, it can be seen that the rotating shaft 10 has rotated twice clockwise.

As described above, the information processing unit 82 determines which of the first power generation element 24 and the second power generation element 26 is generating power, and the first magnetic sensor 46, the second magnetic sensor 48, and the third. Based on the detection results of the magnetic sensor 50 and the fourth magnetic sensor 52, the position of the arrow F, that is, the rotation position of the rotation shaft 10 and the rotation direction are determined.

Next, a determination operation for determining an error when the displacement of the rotation position of the rotation shaft 10 is a displacement other than a predetermined displacement will be described.

FIG. 7 is a diagram showing a table showing a predetermined displacement of a predetermined rotation position of the rotation shaft 10. In other words, in FIG. 7, the displacement that the rotating shaft 10 can take is predetermined. In the table shown in FIG. 7, the rotation position this time indicates the rotation position of the rotation shaft 10 determined this time, and indicates the rotation position after displacement. The previous rotation position is a rotation position stored in the storage unit 84 that was determined last time, and indicates a rotation position before displacement. The previous first power generation indicates the rotation position when the first power generation element 24 last generated power before being located at the rotation position after the displacement. The previous second power generation indicates the rotation position when the second power generation element 26 last generated power before being located at the rotation position after the displacement.

As shown in FIG. 7, the displacement where the rotation position of the previous time is the position V, the rotation position of the previous time is the position VIII, the rotation position of the first power generation of the previous time is the position VIII, and the rotation position of the second power generation of the previous time is the position VII is determined. Has been done. In this case, since the position of the arrow F is displaced from the position VIII to the position V, the count is decremented. When the position of the arrow F is displaced in this way, it can be seen that the arrow F has passed in the order of the position VII, the position VIII, and the position V, and it can be seen that the rotation axis 10 has rotated counterclockwise.

In addition, the displacement is defined such that the rotation position is position I this time, the rotation position last time is position IV, the rotation position of the first power generation last time is position IV, and the rotation position of the second power generation last time is position III. In this case, since the position of the arrow F is displaced from the position IV to the position I, the count is incremented. When the position of the arrow F is displaced in this way, it can be seen that the arrow F has passed in the order of the position III, the position IV, and the position I, and it can be seen that the rotation axis 10 has rotated clockwise.

Further, the displacement is defined in which the rotation position this time is the position I, the rotation position last time is the position V, the rotation position of the first power generation last time is the position V, and the rotation position of the second power generation last time is the position VII. In this case, since the arrow F is located at the position I, the count is incremented. When the position of the arrow F is displaced in this way, it is found that the arrow F has passed in the order of position VII, position VIII, position V, and position I, and the rotation axis 10 is rotated clockwise and then inverted. It can be seen that it was rotating counterclockwise.

Further, the displacement is defined such that the rotation position this time is the position I, the rotation position last time is the position V, the rotation position of the first power generation last time is the position V, and the rotation position of the second power generation last time is the position III. In this case, since the arrow F is located at the position I, the count is incremented. When the position of the arrow F is displaced in this way, it is found that the arrow F has passed in the order of position III, position IV, position I, position V, and position I, and after the rotation axis 10 has rotated counterclockwise. It can be seen that it was inverted and rotated clockwise, and then inverted and rotated counterclockwise.

Further, the displacement is defined in which the rotation position this time is the position V, the previous rotation position is the position VII, the rotation of the first power generation last time is the position I, and the rotation position of the second power generation last time is the position VII. In this case, since the arrow F is located at the position V, the count is decremented. When the position of the arrow F is displaced in this way, it is found that the arrow F has passed in the order of position I, position II, position III, position VII, position VIII, and position V, and the rotation axis 10 is counterclockwise. It can be seen that after rotating, it was reversed and rotated clockwise.

Further, the displacement is defined in which the rotation position this time is the position V, the previous rotation position is the position VII, the rotation position of the first power generation last time is the position IV, and the rotation position of the second power generation last time is the position VII. In this case, since the arrow F is located at the position V, the count is decremented. When the arrow F is displaced in this way, it can be seen that the arrow F has passed in the order of position IV, position VI, position VII, position VIII, and position V. Originally, when the arrow F is displaced in this way, the first power generation element 24 should generate power when the arrow F is located at the position VIII, but the rotation position of the first power generation last time is the position IV. From this, it can be seen that the first power generation element 24 did not generate power when the arrow F was located at the position VIII, that is, RUNT was generated.

As described above, in the table shown in FIG. 7, a predetermined displacement of the rotation position of the rotation shaft 10 is defined. For example, when the information processing unit 82 determines that the rotation position is the position I this time and the rotation position is the position VIII last time, the displacement from the position VIII to the position I is not in the chart shown in FIG. Therefore, in the information processing unit 82, the displacement from the previously determined rotation position of the rotation shaft 10 stored in the storage unit 84 to the rotation position of the rotation shaft 10 determined this time is other than a predetermined displacement determined in advance. It is a displacement and is judged as an error. The information processing unit 82 stores error information related to the error in the storage unit 84.

The rotation detector 14 according to the first embodiment has been described above.

As described above, the rotation detector 14 in the present embodiment has the first magnet 20 and the second magnet 22 which rotate together with the rotation shaft 10 and are arranged with a first phase difference in the rotation direction of the rotation shaft 10, and the first magnet. It operates based on one or more power generation elements generated by the change in the magnetic field caused by the rotation of the magnet 20 and the second magnet 22 together with the rotating shaft 10, and the power generated by one or more power generation elements, and is generated by the first magnet 20. The first to fourth magnetic sensors 46, 48, 50, 52 for detecting the magnetic field generated by the second magnet 22 and the magnetic field generated by the second magnet 22 are provided, and the first magnet 20 has an N pole and a rotation axis 10 more than the N pole. The second magnet 22 has an S pole arranged inward in the radial direction of the magnet 22 and an N pole arranged inward in the radial direction of the rotation shaft 10 with respect to the S pole. ..

According to this, the first magnet 20 and the second magnet 22 are arranged with a first phase difference from each other in the rotation direction of the rotation shaft 10, and the first magnet 20 has an N pole and a rotation axis rather than the N pole. The second magnet 22 has an S pole arranged inward in the radial direction of 10 and an N pole arranged inward in the radial direction of the rotation shaft 10 with respect to the S pole. .. Further, one or more power generation elements generate power by changing the magnetic field due to the rotation of the first magnet 20 and the second magnet 22 together with the rotating shaft 10, and the first to fourth magnetic sensors 46, 48, 50, 52 generate electricity. It operates based on the power generated by one or more power generation elements, and detects a magnetic field generated by the first magnet 20 and a magnetic field generated by the second magnet 22. In this way, the first to fourth magnetic sensors 46, 48, 50, 52 can be operated by at least one power generation element to detect the rotation position of the rotation shaft 10, so that the rotation detector 14 can be easily miniaturized. Can be transformed into.

Further, in the rotation detector 14 of the present embodiment, one or more power generation elements include a first power generation element 24 and a second power generation element 26 that are arranged with a second phase difference from each other in the rotation direction of the rotation shaft 10. Have.

According to this, the number of times of power generation can be increased by rotating the first magnet 20 and the second magnet 22 together with the rotating shaft 10. Therefore, the number of times that the first to fourth magnetic sensors 46, 48, 50, 52 operate can be increased. As a result, it is possible to prevent the accuracy of detecting the rotation of the rotation shaft 10 from being lowered.

Further, in the rotation detector 14 of the present embodiment, the first phase difference and the second phase difference are different.

According to this, the number of times of power generation due to the rotation of the first magnet 20 and the second magnet 22 together with the rotating shaft 10 can be further increased. Therefore, the number of times that the first to fourth magnetic sensors 46, 48, 50, 52 operate can be further increased. As a result, it is possible to further suppress a decrease in the accuracy of detecting the rotation of the rotation shaft 10.

Further, in the rotation detector 14 of the present embodiment, the first to fourth magnetic sensors 46, 48, 50, 52 are arranged with a phase difference in the rotation direction of the rotation shaft 10, and the axial direction of the rotation shaft 10 When viewed from, it does not overlap with one or more power generation elements.

According to this, it is possible to further suppress a decrease in the accuracy of detecting the rotation of the rotating shaft 10.

Further, the rotation detector 14 in the present embodiment detects the power generation information indicating which of the one or more power generation elements generated power and the detection results of the first to fourth magnetic sensors 46, 48, 50, 52. An information processing unit 82 that determines the rotation position and rotation direction of the rotation shaft 10 by using information, and a storage unit 84 that stores the rotation position and rotation direction of the rotation shaft 10 are further provided.

According to this, the rotation position (segment within one rotation such as positions I to VIII) and the rotation direction of the rotation shaft 10 can be uniquely determined, and the detected rotation position and rotation direction can be stored.

Further, in the rotation detector 14 of the present embodiment, the information processing unit 82 determines and determines the rotation position of the rotation shaft 10 by using the detection information each time one or more power generation elements generate power. The rotation position of the rotation shaft 10 is stored in the storage unit 84, and the rotation shaft 10 is stored based on the rotation position of the rotation shaft 10 determined this time and the rotation position of the rotation shaft 10 previously determined stored in the storage unit 84. The count value used to calculate the number of revolutions of is updated.

According to this, the rotation shaft is updated by updating the count value used for calculating the rotation speed of the rotation shaft 10 based on the rotation position of the rotation shaft 10 determined this time and the rotation position of the rotation shaft 10 determined last time. The number of rotations of 10 can be calculated.

Further, in the rotation detector 14 of the present embodiment, the information processing unit 82 displaces the rotation shaft 10 determined this time from the rotation position of the rotation shaft 10 previously determined stored in the storage unit 84 to the rotation position. However, if the displacement is other than the predetermined displacement, it is determined that the displacement is an error, and the error information related to the error is stored in the storage unit 84.

According to this, if the displacement of the rotating shaft 10 determined this time from the previously determined rotational position of the rotating shaft 10 to the rotational position of the rotating shaft 10 determined this time is a displacement other than a predetermined predetermined displacement, it is determined as an error. Therefore, it is possible to detect an abnormality such as that one or more power generation elements do not generate power normally and the rotation position is determined.

Further, in the rotation detector 14 of the present embodiment, the information processing unit 82 determines the rotation position of the rotation shaft 10 using the detection information, and associates the rotation position of the rotation shaft 10 with the power generation information to store the storage unit 84. To memorize.

According to this, it is possible to store the rotation position of the rotation shaft 10 when one or more power generation elements generate power.

Further, the rotation detector 14 according to the present embodiment further includes a substrate 18 extending in a direction orthogonal to the axial direction of the rotating shaft 10 and arranged at an interval from one end in the axial direction of the rotating shaft 10. The first to fourth magnetic sensors 46, 48, 50, 52 are arranged on the main surface of the substrate 18 on the rotating shaft 10 side, and one or more power generating elements are on the main surface of the substrate 18 opposite to the rotating shaft 10. Is placed in.

According to this, the first to fourth magnetic sensors 46, 48, 50, 52 can be easily arranged near the first magnet 20 and the second magnet 22 that rotate together with the rotation shaft 10. Therefore, the first to fourth magnetic sensors 46, 48, 50, and 52 make it easier to detect the magnetic fields generated by the first magnet 20 and the second magnet 22.

[Embodiment 2]
Next, the second embodiment will be described.

FIG. 8 is a diagram showing a rotation detector 14a according to the second embodiment. In FIG. 8, the control circuit 36 and the like are not shown, and the reflection pattern 92 is shown in cross section. The rotation detector 14a is mainly different from the rotation detector 14 in that it further includes a reflective optical sensor 88. In the following description, the differences from the rotation detector 14 will be mainly described.

As shown in FIG. 8, the rotation detector 14a further includes a reflection type optical sensor 88. The optical sensor 88 is an optical encoder having a light receiving / receiving element 90 and a reflection pattern 92 and detecting the rotational position of the rotating shaft 10.

The light emitting / receiving element 90 is arranged on the main surface of the substrate 18 on the rotating plate 16 side, and operates based on the electric power from an external power source (not shown). The light emitting / receiving element 90 is arranged outside the first to fourth magnetic sensors 46, 48, 50, 52 in the radial direction of the rotating shaft 10. The light receiving / receiving element 90 faces the reflection pattern 92 in the axial direction of the rotating shaft 10 and emits light toward the reflection pattern 92. The light receiving / receiving element 90 receives the light reflected by the reflection pattern 92. The light reflected by the reflection pattern 92 changes according to the rotation position of the rotation shaft 10. The optical sensor 88 detects the rotational position of the rotating shaft 10 based on the light reflected by the reflection pattern 92. In this embodiment, the light emitting / receiving element 90 corresponds to the light emitting element and the light receiving element.

The reflection pattern 92 is arranged on the main surface of the rotating plate 16 on the substrate 18 side. The reflection pattern 92 is arranged along the rotation direction of the rotation shaft 10 and is annular. For example, the reflection pattern 92 has a reflection region that easily reflects light and a non-reflection region that hardly reflects light. For example, the reflective regions and the non-reflective regions are alternately arranged in the rotation direction of the rotation shaft 10.

The first magnet 20 and the second magnet 22 are arranged on the main surface of the rotating plate 16 opposite to the substrate 18. The first magnet 20 and the second magnet 22 are arranged so as to overlap the reflection pattern 92 when viewed from the axial direction of the rotating shaft 10.

The information processing unit 82 is stored in the storage unit 84 when the optical sensor 88 changes from a non-power supply state in which power is not supplied from an external power source to a power supply state in which power is supplied from an external power source. The rotation position of the rotation shaft 10 is determined based on the latest rotation position of the rotation shaft 10 and the rotation position of the rotation shaft 10 detected by the optical sensor 88.

For example, after the first power generation element 24 or the second power generation element 26 generates power in a non-powered state, the rotation position of the rotation shaft 10 is determined, and the determined rotation position of the rotation shaft 10 is stored in the storage unit 84. Consider a case where the rotating shaft 10 rotates within a range in which the first power generation element 24 and the second power generation element 26 do not generate power, and the power is supplied. In this case, the latest rotation position stored in the storage unit 84 is the position before the rotation shaft 10 rotates within the range in which the first power generation element 24 and the second power generation element 26 do not generate power. Therefore, there is a difference between the rotation position detected by the optical sensor 88 and the latest rotation position stored in the storage unit 84. Therefore, the information processing unit 82 updates the latest rotation position stored in the storage unit 84 based on the rotation position detected by the optical sensor 88, and the latest rotation position stored in the storage unit 84. And the rotation position detected by the optical sensor 88 are matched. As described above, the information processing unit 82 has the rotation shaft 10 based on the latest rotation position of the rotation shaft 10 stored in the storage unit 84 and the rotation position of the rotation shaft 10 detected by the optical sensor 88. The rotation position of is determined, and the latest rotation position stored in the storage unit 84 is updated according to the determination result.

In the power supply state, the rotation position of the rotation shaft 10 determined by the information processing unit 82 based on the detection information should substantially match the rotation position detected by the optical sensor 88. When the difference between the rotation position of the rotation shaft 10 determined based on the detection information and the rotation position detected by the optical sensor 88 in the power supply state is larger than a predetermined value, the information processing unit 82 determines. Judge as an error.

FIG. 9 is a diagram showing a modified example of the rotation detector 14a according to the second embodiment. As shown in FIG. 9, the first magnet 20 and the second magnet 22 may be arranged on the main surface of the rotating plate 16 on the substrate 18 side. In this case, for example, the first magnet 20 and the second magnet 22 are arranged inward of the reflection pattern 92 in the radial direction of the rotating shaft 10. The first magnet 20 and the second magnet 22 may be arranged outside the reflection pattern 92 in the radial direction of the rotating shaft 10.

The rotation detector 14a according to the second embodiment has been described above.

As described above, the rotation detector 14a in the present embodiment includes a light receiving / receiving element 90 that is driven based on the electric power from the power source, and further includes an optical sensor 88 that detects the rotational position of the rotating shaft 10. An optical sensor. When the 88 is in the power supply state in which the power is supplied from the power supply from the non-power supply state in which the power supply is not received from the power supply, the information processing unit 82 changes the latest rotating shaft 10 stored in the storage unit 84. The rotation position of the rotation shaft 10 is determined based on the rotation position of the rotation shaft 10 and the rotation position of the rotation shaft 10 detected by the optical sensor 88.

According to this, the information processing unit 82 has a rotation shaft based on the latest rotation position of the rotation shaft 10 stored in the storage unit 84 and the rotation position of the rotation shaft 10 detected by the optical sensor 88. The rotation position of 10 is determined. Therefore, the rotation position of the rotation shaft 10 can be detected more accurately.

Further, in the rotation detector 14a of the present embodiment, the information processing unit 82 determines the rotation position of the rotation shaft 10 using the detection information and the rotation position of the rotation shaft 10 detected by the optical sensor 88. If the difference is larger than the predetermined value, it is determined as an error.

According to this, if the difference between the rotation position of the rotation shaft 10 determined by the information processing unit 82 and the rotation position of the rotation shaft 10 detected by the optical sensor 88 is larger than a predetermined value, it is determined as an error. NS. Therefore, when it is determined that an error occurs, it can be estimated that either the determination by the information processing unit 82 or the detection by the optical sensor 88 is incorrect.

[Embodiment 3]
Next, the third embodiment will be described.

FIG. 10 is a diagram showing a rotation detector 14b according to the third embodiment. In FIG. 10, the control circuit 36 and the like are not shown, and the transmission pattern 102 is shown in cross section. The rotation detector 14b is mainly different from the rotation detector 14 in that it further includes a transmissive optical sensor 94. In the following description, the differences from the rotation detector 14 will be mainly described.

As shown in FIG. 10, the rotation detector 14b further includes a transmission type optical sensor 94. The optical sensor 94 is an optical encoder having a substrate 96, a light emitting element 98, a light receiving element 100, and a transmission pattern 102, and detecting the rotational position of the rotating shaft 10.

The substrate 96 is arranged on the side of the rotating plate 16 opposite to the substrate 18 in the axial direction of the rotating shaft 10, and faces the rotating plate 16 at intervals. The substrate 96 is electrically connected to the substrate 18 via the connector 104.

The light emitting element 98 is arranged on the main surface of the substrate 96 on the rotating plate 16 side. The light emitting element 98 faces the transmission pattern 102 in the axial direction of the rotation shaft 10 and emits light toward the transmission pattern 102. The rotating plate 16 transmits light from the light emitting element 98.

The light receiving element 100 is arranged on the main surface of the substrate 18 on the rotating plate 16 side. The light receiving element 100 is arranged outside the first to fourth magnetic sensors 46, 48, 50, 52 in the radial direction of the rotating shaft 10. The light receiving element 100 faces the transmission pattern 102 in the axial direction of the rotating shaft 10. The light receiving element 100 receives the light emitted from the light emitting element 98 and transmitted by the transmission pattern 102. The light transmitted by the transmission pattern 102 changes according to the rotation position of the rotation shaft 10. The optical sensor 94 detects the rotational position of the rotating shaft 10 based on the light transmitted by the transmission pattern 102.

The transmission pattern 102 is arranged on the main surface of the rotating plate 16 on the substrate 18 side. The transmission pattern 102 is arranged along the rotation direction of the rotation shaft 10 and is annular. For example, the transmission pattern 102 has a plurality of slits (not shown) that allow light to pass through. For example, the plurality of slits are arranged side by side in the rotation direction of the rotation shaft 10.

The first magnet 20 and the second magnet 22 are arranged on the main surface of the rotating plate 16 opposite to the substrate 18.

Similar to the case of the rotation detector 14a, the information processing unit 82 changes from a non-power supply state in which the optical sensor 94 does not receive power from an external power source to a power supply state in which power is supplied from an external power source. In that case, the rotation position of the rotation shaft 10 is determined based on the latest rotation position of the rotation shaft 10 stored in the storage unit 84 and the rotation position of the rotation shaft 10 detected by the optical sensor 94. ..

Further, as in the case of the rotation detector 14a, the information processing unit 82 differs between the rotation position of the rotation shaft 10 determined based on the detection information and the rotation position detected by the optical sensor 94 in the power supply state. However, if it is larger than a predetermined value, it is determined as an error.

FIG. 11 is a diagram showing a modified example of the rotation detector 14b according to the third embodiment. As shown in FIG. 11, the first magnet 20 and the second magnet 22 may be arranged on the main surface of the rotating plate 16 on the substrate 18 side. In this case, for example, the first magnet 20 and the second magnet 22 are arranged inward of the transmission pattern 102 in the radial direction of the rotating shaft 10. The first magnet 20 and the second magnet 22 may be arranged outside the transmission pattern 102 in the radial direction of the rotating shaft 10.

The rotation detector 14b according to the third embodiment has been described above.

According to the rotation detector 14b, it has the same action and effect as the rotation detector 14a.

[Embodiment 4]
Next, the fourth embodiment will be described.

FIG. 12 is a diagram showing a rotating plate 16 of the rotation detector 14c according to the fourth embodiment. The rotation detector 14c is mainly different from the rotation detector 14 in that it further has a first counterweight 106 and a second counterweight 108. In the following description, the differences from the rotation detector 14 will be mainly described.

As shown in FIG. 12, the rotation detector 14c further has a first counterweight 106 and a second counterweight 108. The first counterweight 106, the second counterweight 108, the first magnet 20, and the second magnet 22 have the same weight as each other. In the first counterweight 106 and the second counterweight 108, the position of the center of gravity of the first counterweight 106, the second counterweight 108, the first magnet 20 and the second magnet 22 is located on the axis A of the rotation axis 10. Arranged to be located. Specifically, the first counterweight 106 has a phase difference of 180 ° from the first magnet 20 and a phase difference of 90 ° from the second magnet 22, and has a main surface of the rotating plate 16 on the substrate 18 side. It is located in. The second counterweight 108 has a phase difference of 90 ° from the first magnet 20 and has a phase difference of 180 ° from the second magnet 22 and is arranged on the main surface of the rotating plate 16 on the substrate 18 side.

The rotation detector 14c according to the fourth embodiment has been described above.

As described above, the rotation detector 14c in the present embodiment further includes a first counterweight 106 and a second counterweight 108. In the first counterweight 106 and the second counterweight 108, the position of the center of gravity of the first magnet 20, the second magnet 22, the first counterweight 106, and the second counterweight 108 is located on the axis A of the rotation axis 10. Arranged to be located.

According to this, since the position of the center of gravity of the first magnet 20, the second magnet 22, the first counterweight 106, and the second counterweight 108 is located on the axis A of the rotation axis 10, the rotation axis 10 It is possible to prevent the rotation from becoming unbalanced.

[Embodiment 5]
Next, the fifth embodiment will be described.

FIG. 13 is a diagram showing a rotating plate 16 of the rotation detector 14d according to the fifth embodiment. The rotation detector 14d is mainly the rotation detector 14c in that it has a first counterweight 110 instead of the first counterweight 106 and a second counterweight 112 instead of the second counterweight 108. Different to. In the following description, the differences from the rotation detector 14c will be mainly described.

As shown in FIG. 13, the rotation detector 14d has a first counterweight 110 instead of the first counterweight 106 and a second counterweight 112 instead of the second counterweight 108. The first counterweight 110 and the second counterweight 112 are members containing a magnetic material as a main component and containing 50% or more of the magnetic material. Here, the first counterweight 110 is a magnet having an N pole and an S pole located inward in the radial direction of the rotation shaft 10 with respect to the N pole. Further, here, the second counterweight 112 is a magnet having an S pole and an N pole located inward in the radial direction of the rotation shaft 10 with respect to the S pole.

The rotation detector 14d according to the fifth embodiment has been described above.

As described above, in the rotation detector 14d according to the present embodiment, the first counterweight 110 and the second counterweight 112 are members containing 50% or more of magnetic material.

According to this, the angle interval is adjusted by equalizing the angle interval in which the voltage pulse induced at both ends of the first coil 40 wound around the first magnetic sensitive portion 38 (Wiegand wire) is generated. Can be done. Similarly, the angle interval can be adjusted by equalizing the angle interval in which the voltage pulse induced at both ends of the second coil 44 wound around the second magnetic sensitive portion 42 (Wiegand wire) is generated. ..

In the rotation detector 14d according to the present embodiment, the first counterweight 110 and the second counterweight 112 do not have to be magnets, and may be members whose main component is a magnetic material.

According to this, it is possible to suppress the imbalance of rotation of the rotating shaft 10 and increase the number of times of power generation of one or more power generation elements. As a result, it is possible to prevent the accuracy of detecting the rotation of the rotation shaft 10 from being lowered.

[Other embodiments, etc.]
As described above, the first to fifth embodiments have been described as examples of the techniques disclosed in the present application. However, the technique according to the present disclosure is not limited to these, and can be applied to embodiments or modifications in which modifications, replacements, additions, omissions, etc. are appropriately made as long as the gist of the present disclosure is not deviated.

In the above-described embodiment, the case where the first phase difference between the first magnet 20 and the second magnet 22 is 90 ° has been described, but the present invention is not limited to this. 14A and 14B are views showing another example of the arrangement of the first magnet and the second magnet, in which FIG. 14A is an arrangement in which the first phase difference is 45 °, and FIG. 14B is an arrangement in which the first phase difference is 130. The arrangement in which ° is, (c) shows the arrangement in which the first phase difference is 180 °. For example, as shown in FIG. 14 (a), the first phase difference may be smaller than 90 ° or 45 °. The first phase difference may be larger than 90 °, may be 130 ° as shown in FIG. 14 (b), or may be 180 ° as shown in FIG. 14 (c). ..

In the above-described embodiment, the rotation detectors 14 to 14d have the first power generation element 24 and the second power generation element 26, and the second phase difference between the first power generation element 24 and the second power generation element 26 is 180. The case of ° has been described, but the present invention is not limited to this. 15A and 15B are views showing another example of the arrangement of one or more power generation elements, in which FIG. 15A is an arrangement in which the second phase difference is 90 °, and FIG. 15B is an arrangement in which the second phase difference is 120 °. (C) is an arrangement in which the second phase difference is 150 °, (d) is an arrangement in which the second phase difference is 60 °, and (e) is an arrangement in which the second power generation element 26 is not provided. Is shown. For example, the second phase difference may be 90 ° as shown in FIG. 15 (a) or 120 ° as shown in FIG. 15 (b). The second phase difference may be 150 ° as shown in FIG. 15 (c) or 60 ° as shown in FIG. 15 (d). As shown in FIG. 15 (e), the rotation detector does not have to have the second power generation element 26. When there is one power generation element, the information processing unit may determine the rotation position and rotation direction of the rotation axis based on the detection results of a plurality of magnetic sensors without using the power generation information.

In the above-described embodiment, the case where the rotation detectors 14, 14a, to 14d have the first power generation element 24, the second power generation element 26, and the first to fourth magnetic sensors 46, 48, 50, 52 will be described. However, it is not limited to this. 16A and 16B are views showing another example of arrangement of a plurality of magnetic sensors, in which FIG. 16A is an arrangement in which the rotation detector does not have the fourth magnetic sensor 52, and FIG. 16B is an arrangement in which the rotation detector is arranged. , The arrangement without the first magnetic sensor 46 and the fourth magnetic sensor 52, (c) shows the arrangement in which the rotation detector further has the third power generation element 116. For example, as shown in FIG. 16A, the rotation detector does not have to have the fourth magnetic sensor 52. As shown in FIG. 16B, the rotation detector may not have the first magnetic sensor 46 and the fourth magnetic sensor 52. As shown in FIG. 16 (c), the rotation detector is arranged at a position having a phase difference of 135 ° from the first power generation element 24 and a phase difference of 45 ° from the second power generation element 26. 3 The power generation element 116 may be further provided.

FIG. 17 is a diagram showing a rotation detector according to another embodiment. As shown in FIG. 17, the rotation detector does not have the second power generation element 26, the second magnetic sensor 48, and the third magnetic sensor 50, and the first magnet 20 and the second magnet 22 are the first. The phase difference may be 130 °.

In the above-described embodiment, the first power generation element 24 and the second power generation element 26 are arranged on the main surface of the substrate 18 opposite to the rotating plate 16, and the first to fourth magnetic sensors 46, 48, 50, The case where the 52 and the control circuit 36 are arranged on the main surface of the substrate 18 on the rotating plate 16 side has been described, but the present invention is not limited thereto. FIG. 18 is a diagram showing a rotation detector according to another embodiment, and in FIG. 18A, the first to fourth magnetic sensors 46, 48, 50, 52 are opposite to the rotating plate 16 of the substrate 18. The configuration (b) arranged on the main surface on the side shows the configuration in which the first power generation element 24 and the second power generation element 26 are arranged on the main surface of the substrate 18 on the rotating plate 16 side. For example, as shown in FIG. 18A, the first to fourth magnetic sensors 46, 48, 50, 52 may be arranged on the main surface of the substrate 18 opposite to the rotating plate 16. As shown in FIG. 18B, the first power generation element 24 and the second power generation element 26 are arranged on the main surface of the substrate 18 on the rotating plate 16 side, and the control circuit 36 is connected to the rotating plate 16 of the substrate 18. May be placed on the opposite main surface.

The rotation detector according to the present disclosure can be used for detecting the rotation of the rotating shaft of a motor that rotationally drives a load.

1 Motor 4 Main body 6 Rotator 8 Fixture 10 Rotating shaft 12 Case 14, 14a, 14b, 14c, 14d Rotation detector 16 Rotating plate 18 Substrate 20 1st magnet 22 2nd magnet 24 1st power generation element 26 2nd power generation element 36 Control circuit 38 1st magnetic sensor 40 1st coil 42 2nd magnetic sensor 44 2nd coil 46 1st magnetic sensor 48 2nd magnetic sensor 50 3rd magnetic sensor 52 4th magnetic sensor 54 Full-wave rectifier 56 Voltage Regulator 58 Disconnection diagnosis unit 60 Backflow prevention switch 62 Full-wave rectifier 64 Voltage regulator 66 Disconnection diagnosis unit 68 Backflow prevention switch 70, 72, 74, 76, 78, 80 Comparator 82 Information processing unit 84 Storage unit 86 Communication unit 88, 94 Optical sensor 90 Light receiving element 92 Reflection pattern 96 Substrate 98 Light emitting element 100 Light receiving element 102 Transmission pattern 104 Connector 106,110 1st counter weight 108, 112 2nd counter weight

Claims (13)

1. By rotating with the rotation axis and arranging the first magnet and the second magnet with a first phase difference in the rotation direction of the rotation axis, and the first magnet and the second magnet rotating with the rotation axis. One or more power generation elements that generate power by changing the magnetic field, and a plurality of that operate based on the power generated by the one or more power generation elements and detect a magnetic field generated by the first magnet and a magnetic field generated by the second magnet. The first magnet has a first north pole and a first south pole arranged inward of the first north pole in the radial direction of the rotation axis. The second magnet is a rotation detector having a second south pole and a second north pole arranged inward of the second south pole in the radial direction of the rotation axis.
2. The rotation detector according to claim 1, wherein the one or more power generation elements have a first power generation element and a second power generation element arranged with a second phase difference from each other in the rotation direction of the rotation shaft.
3. The rotation detector according to claim 2, wherein the first phase difference and the second phase difference are different.
4. Any of claims 1 to 3, wherein the plurality of magnetic sensors are arranged with a phase difference in the rotation direction of the rotation axis and do not overlap with the one or more power generation elements when viewed from the axis direction of the rotation axis. The rotation detector according to item 1.
5. Information for determining at least one of the rotation position and the rotation direction of the rotation axis by using the detection information including the power generation information indicating which of the one or more power generation elements generated power and the detection results of the plurality of magnetic sensors. The rotation detector according to any one of claims 1 to 4, further comprising a processing unit and a storage unit that stores at least one of the rotation position and the rotation direction of the rotation axis.
6. Each time any of the one or more power generation elements generates power, the information processing unit determines the rotation position of the rotation shaft by using the detection information, and stores the determined rotation position of the rotation shaft in the storage unit. The count value used for calculating the rotation number of the rotation axis is updated based on the rotation position of the rotation axis determined this time and the rotation position of the rotation axis determined last time stored in the storage unit. The rotation detector according to claim 5.
7. In the information processing unit, the displacement from the previously determined rotation position of the rotation shaft stored in the storage unit to the rotation position of the rotation shaft determined this time is a displacement other than a predetermined predetermined displacement. The rotation detector according to claim 6, wherein if there is, an error is determined and error information related to the error is stored in the storage unit.
8. It has a light emitting element and a light receiving element that operate based on the power from the power source, further includes an optical sensor that detects the rotational position of the rotating shaft, and the optical sensor is not supplied with power from the power source. When the power supply state is changed from the power supply state to the power supply state in which power is supplied from the power supply, the information processing unit detects the latest rotation position of the rotation shaft stored in the storage unit and the optical sensor. The rotation detector according to claim 6 or 7, wherein the rotation position of the rotation shaft is determined based on the rotation position of the rotation shaft.
9. When the difference between the rotation position of the rotation shaft determined by using the detection information and the rotation position of the rotation shaft detected by the optical sensor is larger than a predetermined value, the information processing unit causes an error. The rotation detector according to claim 8, wherein the rotation detector is determined.
10. Any of claims 5 to 9, wherein the information processing unit determines the rotation position of the rotation shaft using the detection information, and stores the rotation position of the rotation shaft and the power generation information in the storage unit in association with each other. The rotation detector according to item 1.
11. A counter weight is further provided, and the counter weight is arranged so that the position of the center of gravity of the first magnet, the second magnet, and the counter weight is located on the axis of the rotation axis. 10. The rotation detector according to any one of 10.
12. The rotation detector according to claim 11, wherein the counterweight is a member containing 50% or more of a magnetic material.
13. Further comprising a substrate extending in a direction orthogonal to the axial direction of the rotating shaft and arranged at a distance from one end in the axial direction of the rotating shaft, the plurality of magnetic sensors are provided on the rotating shaft side of the substrate. The rotation detector according to any one of claims 1 to 12, wherein the one or more power generation elements are arranged on the main surface of the substrate, which is arranged on the main surface of the substrate opposite to the rotation axis.

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