Detection device

Abstract

To provide a detection device capable of enhancing accuracy of detecting displacement.SOLUTION: A detection device comprises: a stator base portion 42 fixed to a vehicle body of a vehicle; and a bearing 50. The bearing 50 has an outer ring 51, an inner ring 52, and rolling elements 53 provided between the outer ring 51 and the inner ring 52, and supports a wheel so as to be rotatable relative to the stator base portion 42. The inner ring 52 is fixed to the wheel, and the outer ring 51 is fixed to the stator base portion 42. The detection device comprises: a disk-shaped race portion 80 that is fixed to the inner ring 52 and extends radially outward of the bearing 50; and a detection unit 90. The detection unit 90 is provided at a position, which is away from the bearing 50 in a radial direction and faces the race portion 80 in an axial direction of the bearing 50, on the stator base portion 42. The detection unit 90 outputs a voltage signal corresponding to displacement in the axial direction of the race portion 80 and displacement in a direction orthogonal to the axial direction.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a detection device.

Background Art

[0002] Conventionally, as described in Patent Document 1, a bearing device that rotatably supports a hub fixed to a wheel with respect to a vehicle body is known. The bearing device includes an outer ring fixed to the vehicle body, an inner ring fixed to the hub, and rolling elements between the outer ring and the inner ring. Here, in order to stabilize the running of the vehicle, it is desirable that vehicle running control be performed based on the force acting on the wheel.

[0003] As a configuration for detecting the force acting on the wheel, Patent Document 1 describes an axial strain sensor, a radial strain sensor, and a control unit. The axial strain sensor detects the axial displacement of the outer ring, and the radial strain sensor detects the radial displacement of the outer ring. Since there is a correlation between the displacement and the force acting on the wheel, the displacement can be converted into a force. Therefore, the control unit calculates the axial force of the wheel based on the displacement detected by the axial strain sensor, and calculates the vertical force of the wheel based on the displacement detected by the radial strain sensor.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Each sensor described in Patent Document 1 is provided near the bearing. Therefore, when a force acts on the wheel, the displacement detected by each sensor is small. In this case, there is a concern that the detection accuracy of the displacement deteriorates. Note that the deterioration of the detection accuracy of the displacement is not limited to vehicles.

[0006] The primary objective of this invention is to provide a detection device that can improve the accuracy of displacement detection. [Means for solving the problem]

[0007] The present invention comprises a base portion and The bearing comprises an outer ring member, an inner ring member, and rolling elements provided between the outer ring member and the inner ring member, and rotatably supports a rotating body with respect to the base portion, Of the outer ring member and the inner ring member, the first bearing member is fixed to the rotating body, and the other, the second bearing member, is fixed to the base portion. A disc-shaped detection rotating part is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction.

[0008] In this invention, a detection rotating part is provided so as to rotate integrally with the first bearing member that constitutes the bearing. Therefore, the detection rotating part rotates integrally with a rotating body fixed to the first bearing member.

[0009] Here, when an axial force acts on the rotating body, the axial displacement of the detection rotating part increases as it moves radially outward from the first bearing member. By providing the displacement detection unit at a position where the displacement is large, the accuracy of displacement detection can be improved. Therefore, in the present invention, the displacement detection unit is provided in the base portion at a position radially away from the bearing and axially opposite to the detection rotating part. As a result, compared to a configuration in which the displacement detection unit is provided near the bearing, for example, the change in the voltage signal corresponding to the axial displacement of the displacement detection unit in response to the change in the axial displacement of the detection rotating part can be made larger. This improves the accuracy of axial displacement detection by the displacement detection unit, and for example, it is possible to improve the accuracy of calculating the lateral force based on the detected axial displacement.

[0010] Furthermore, the output voltage signal of the displacement detection unit of the present invention corresponds not only to the axial displacement but also to the displacement of the detection rotating unit in a direction perpendicular to the axial direction. Therefore, based on this signal, for example, the force acting on the rotating body in the perpendicular direction can be calculated. [Brief explanation of the drawing]

[0011] [Figure 1] A longitudinal cross-sectional view of the wheel according to the first embodiment. [Figure 2] Plan view of the racing section. [Figure 3] This diagram shows the state in which the inner wheel is tilted relative to the outer wheel when a lateral force is applied to the tire. [Figure 4] A diagram showing the vertical displacement of the inner wheel when a vertical load is applied to the tire. [Figure 5] A diagram showing the detection unit. [Figure 6] A diagram showing the electrical configuration of the detection unit and processing unit. [Figure 7] Projection view of the excitation coil and the first and second receiving coils in a plan view of a multilayer substrate. [Figure 8] A diagram showing the wiring pattern and vias formed on the first layer of a multilayer substrate. [Figure 9]A diagram showing a wiring pattern and vias formed on the second layer of a multilayer substrate. [Figure 10] A diagram showing a wiring pattern and vias formed on the third layer of a multilayer substrate. [Figure 11] A diagram showing a wiring pattern and vias formed on the fourth layer of a multilayer substrate. [Figure 12] A diagram showing the relative positional relationship of the first and second receiving coils and the shielding part. [Figure 13] A diagram for explaining the detection principle of displacement and rotation angle. [Figure 14] A diagram for explaining the detection principle of displacement and rotation angle. [Figure 15] A simplified plan view of the second receiving coil. [Figure 16] A diagram showing the output voltage signal of the receiving coil and the transition of the envelope of this signal. [Figure 17] A diagram showing the transition of the first and second envelopes. [Figure 18] A characteristic diagram showing the relationship between the displacement signal and the axial displacement. [Figure 19] A diagram showing the change from the reference state of the envelope when a lateral force acts. [Figure 20] A diagram showing the relative positional relationship of the first and second receiving coils and the shielding part when a vertical load acts. [Figure 21] A diagram showing the change from the reference state of the envelope when a vertical load acts. [Figure 22] A characteristic diagram showing the relationship between the displacement signal and the vertical displacement. [Figure 23] A diagram showing the characteristic information in which the first and second displacement signals are associated with the respective displacements ΔY, ΔZ, the lateral force, and the vertical load. [Figure 24] A plan view of a race part according to a modification of the first embodiment. [Figure 25] A perspective view of a race part according to a modification of the first embodiment. [Figure 26] A plan view of a race part according to a modification of the first embodiment. [Figure 27] A plan view of a race part according to a modification of the first embodiment. [Figure 28]A diagram showing the arrangement of the race section and substrate according to a modified example of the first embodiment. [Figure 29] A diagram showing the relative positional relationship between the first and second receiving coils and the shielding portion according to the second embodiment. [Figure 30] A diagram showing a receiving coil according to the third embodiment. [Figure 31] A diagram showing the relative positional relationship between the receiving coil and the shielding section in the reference state, and the transition of the envelope. [Figure 32] A diagram showing the relative positional relationship between the receiving coil and the shielding section, and the change in the envelope, when a lateral force is applied. [Figure 33] A diagram showing the relative positional relationship between the receiving coil and the shielding section, and the transition of the envelope, when a vertical load is applied. [Figure 34] A diagram showing the race section and detection unit according to the fourth embodiment. [Figure 35] A longitudinal cross-sectional view of the wheel according to the fifth embodiment. [Figure 36] A longitudinal cross-sectional view of the wheel according to the sixth embodiment. [Figure 37] A block diagram of the processing unit according to the seventh embodiment. [Figure 38] A diagram showing the relationship between lateral displacement voltage and lateral force. [Figure 39] A flowchart illustrating the procedure for calculating lateral force. [Figure 40] A time chart showing the changes in lateral offset voltage and lateral displacement voltage. [Figure 41] A block diagram of the processing unit according to the eighth embodiment. [Figure 42] A flowchart illustrating the procedure for calculating lateral force. [Figure 43] A time chart showing the changes in lateral offset voltage and lateral displacement voltage. [Figure 44] A block diagram of the processing unit according to the ninth embodiment. [Figure 45] A flowchart illustrating the procedure for calculating lateral force. [Figure 46] A time chart showing the changes in lateral offset voltage and lateral displacement voltage. [Figure 47] A block diagram of the processing unit according to the 10th embodiment. [Figure 48] A flowchart illustrating the procedure for calculating lateral force. [Figure 49] A block diagram of the processing unit according to the 11th embodiment. [Figure 50] A flowchart illustrating the procedure for calculating lateral and vertical loads. [Figure 51] A block diagram of the processing unit according to the 12th embodiment. [Figure 52] A flowchart illustrating the procedure for calculating lateral force and longitudinal load. [Figure 53] A block diagram of the processing unit according to the 13th embodiment. [Figure 54] A diagram showing the characteristics of a low-pass filter. [Figure 55] A diagram showing the relationship between cutoff frequency, vehicle speed, tire pressure, and vehicle weight. [Figure 56] Block diagram of the processing unit according to the 14th embodiment. [Figure 57] A time chart showing the changes in lateral offset voltage and lateral displacement voltage. [Figure 58] Configuration diagram of the in-vehicle system according to the 15th embodiment. [Figure 59] A diagram showing the ECU and circuit section. [Figure 60] A diagram showing the ECU and circuit section. [Figure 61] A diagram showing the ECU and circuit section. [Figure 62] A diagram showing the ECU and circuit section. [Modes for carrying out the invention]

[0012] <First Embodiment> Hereinafter, a first embodiment of the vehicle detection device according to the present invention will be described with reference to the drawings. The detection device of this embodiment is configured to calculate the force acting on a wheel (drive wheel) as a rotating body equipped with an in-wheel motor. The wheel is positioned so that it is horizontal in the normal operating state of the vehicle. The vehicle is, for example, a four-wheeled passenger vehicle having two front wheels and two rear wheels. However, the vehicle is not limited to this, and may be a vehicle other than a four-wheeled vehicle, such as a two-wheeled vehicle. Furthermore, the use of the vehicle is not limited to passenger use.

[0013] As shown in Figure 1, the wheel comprises a wheel 10 and an in-wheel motor 20. The wheel 10 comprises a cylindrical rim portion 11 and a disc portion 12 on a circular surface provided at the outer end of the rim portion 11 in the vehicle width direction. A tire 13 is attached to the outer circumference of the rim portion 11.

[0014] The in-wheel motor 20 is housed in the inner space of the wheel 10, which is surrounded by the rim portion 11 and the disc portion 12, and provides rotational power to the wheel 10. The in-wheel motor 20 is an outer rotor type motor comprising a rotor 30 and a stator 40 arranged radially inward of the rotor 30.

[0015] The rotor 30 comprises a cylindrical magnet holder 31 and a magnet unit 32 provided on the inner circumferential surface of the magnet holder 31. The magnet holder 31 faces the inner circumferential surface of the rim portion 11 from the outer end to the inner end in the axial direction (vehicle width direction) of the in-wheel motor 20. The magnet unit 32 is cylindrical and concentric with the rotational axis of the rotor 30, and has a plurality of magnets fixed to the inner circumferential surface of the magnet holder 31. In other words, the in-wheel motor 20 of this embodiment is a surface magnet type synchronous motor (SPMSM). In the magnet unit 32, the magnets are arranged so that their polarity alternates along the circumferential direction of the rotor 30. As a result, a plurality of magnetic poles are formed in the circumferential direction of the magnet unit 32. The magnets are, for example, sintered neodymium magnets. Incidentally, the in-wheel motor 20 may also be an embedded magnet type synchronous motor (IPMSM).

[0016] The rotor 30 is provided at the outer end in the vehicle width direction of the magnet holding portion 31 and includes a disc-shaped flat plate portion 33 that connects the magnet holding portion 31 and the disc portion 12. The disc portion 12 is fixed to the flat plate portion 33 by bolts. As a result, the rotor 30 and the wheel 10 rotate together.

[0017] The stator 40 comprises a cylindrical stator winding 41 positioned radially opposite to the magnet unit 32, and a cylindrical stator base portion 42 provided radially inside the stator winding 41. The stator winding 41 comprises a coil side portion provided radially opposite to the magnet unit 32, and coil end portions provided at both axial ends of the coil side portion.

[0018] The stator base 42 is fixed to the vehicle body, for example, via a knuckle, and holds the stator windings 41, etc. The stator base 42 includes a cylindrical portion 43 fixed to the vehicle body. The portion of the cylindrical portion 43 adjacent to the stator windings 41 in the radial direction is the stator core 43a.

[0019] The stator base 42 is provided with a fixing portion 44 that extends radially inward from one axial end of the cylindrical portion 43. The rotor 30 is rotatably supported relative to the stator base 42 by the fixing portion 44 and the bearing 50. The radially outer end of the fixing portion 44 is an annular projection 45 that protrudes toward the flat plate portion 33. The portion of the projection 45 facing the flat plate portion 33 is a flat surface.

[0020] The bearing 50 is a rolling bearing (e.g., a radial ball bearing) and comprises an outer ring 51 corresponding to the "first bearing member," an inner ring 52 corresponding to the "second bearing member," and a plurality of rolling elements 53 (e.g., balls) arranged between the outer ring 51 and the inner ring 52. The outer ring 51 is fixed to the fixing part 44 by bolts. The inner ring 52 comprises a cylindrical portion 52a facing the outer ring 51 in the radial direction, and a flange portion 52b extending radially outward from one axial end of the cylindrical portion 52a. The flange portion 52b is fixed to the flat plate portion 33 and the disc portion 12 by bolts. Figure 1 shows the inner ring 52 and the outer ring 51 in a coaxial state.

[0021] The vehicle is equipped with an inverter electrically connected to the stator winding 41 and a power storage unit electrically connected to the inverter. The power storage unit is located in the vehicle body and is, for example, a lithium-ion battery. The switching control of the upper and lower arm switches that make up the inverter is performed by a control device. As a result, the rotor 30 rotates and the wheels rotate. The inverter and control device may be located in the vehicle body or may be built into the in-wheel motor 20.

[0022] The inner space of the wheel 10 is provided with a disc-shaped race section 80 corresponding to a "detection rotation section" and a detection unit 90 corresponding to a "displacement detection section". The race section 80 and the detection unit 90 are used to calculate the rotation angle of the rotor 30 of the in-wheel motor 20 (specifically, the electrical angle or mechanical angle), the rotational speed of the wheel, the lateral force Fy acting between the contact surface (ground) GL and the wheel (tire 13), and the force acting between the contact surface GL and the wheel perpendicular to the contact surface GL (hereinafter referred to as the vertical load Fz). The direction in which the lateral force acts and the direction in which the vertical load acts are orthogonal. For example, the calculated rotation angle (electrical angle) is used in the control device for switching control of the inverter, and the wheel rotational speed, lateral force, and vertical load are used in the control device for vehicle driving control.

[0023] As shown in Figures 1 and 2, the race portion 80 is disc-shaped and made of a metal material (for example, iron or aluminum). A through hole is formed in the center of the race portion 80. The peripheral edge of the through hole in the race portion 80 is a bent portion 80a that bends in the direction of the disc portion 12. The bent portion 80a is fitted into the through hole formed in the center of the flat plate portion 33 of the rotor 30. The race portion 80 is fixed by bolts, spaced apart from the flat plate portion 33 of the rotor 30, and in surface contact with the flange portion 52b of the inner ring 52. As a result, the race portion 80 and the inner ring 52 are coaxial. The race portion 80, rotor 30, and wheel 10 rotate as a single unit.

[0024] The radially outer end of the race portion 80 faces the protruding portion 45 of the stator base portion 42. As shown in Figure 2, the radially outer end of the race portion 80 alternately has a shielding portion 81, which is a metal part, and a notch 82 that penetrates the race portion 80 in the thickness direction, in the circumferential direction. The shielding portion 81 and the notch 82 form an annular "detection target portion". In this embodiment, the circumferential length L1 of the shielding portion 81 is equal to the circumferential length L2 of the notch 82. Also, in the example shown in Figure 2, eight sets of shielding portions 81 and notches 82 are provided. Note that LCi shown in Figure 2 indicates the central axis of the inner ring 52.

[0025] The detection unit 90 is a so-called eddy current type inductive sensor. As shown in Figures 2, 5, and 6, the detection unit 90 comprises a substrate 91, a coil section 92 provided on the substrate 91, and a circuit section 93. Figure 2 is a diagram showing the race section 80 as seen from the wheel 10 side. Figure 5 is a diagram showing the substrate 91 as seen from the wheel 10 side. The substrate 91 is fixed to the flat surface of the protrusion 45. As a result, the substrate 91 extends in a direction perpendicular to the axial direction of the outer ring 51. In this embodiment, the substrate 91 is fixed to the flat surface of the upper end of the annular protrusion 45.

[0026] As shown in Figures 1 and 6, the circuit unit 93 is electrically connected to the processing unit 70. More specifically, a through hole 46 is formed in the protruding portion 45, and the processing unit 70 and the circuit unit 93 are electrically connected via wiring inserted through the through hole 46. The processing unit 70 may be provided on the vehicle body or built into the in-wheel motor 20.

[0027] The coil section 92 comprises an excitation coil 100, a first receiving coil 110, and a second receiving coil 120. Each of the coils 100, 110, and 120 is a planar coil. The circuit section 93 is composed of an integrated circuit. As shown in Figure 6, the circuit section 93 comprises an excitation circuit 94 that supplies a high-frequency excitation voltage to the excitation coil 100, and a receiving circuit 95. When an excitation voltage is supplied to the excitation coil 100, a voltage with the same or equivalent frequency as the excitation voltage is induced in the first receiving coil 110 and the second receiving coil 120. The receiving circuit 95 detects the voltage across each of the receiving coils 110 and 120 as an output voltage signal.

[0028] As shown in Figure 1, when a lateral force Fy acts on the wheel, the inclination θ of the central axis LCo of the inner ring 52 with respect to the central axis LCo of the outer ring 51 increases, as shown in Figure 3. In this case, the axial distance between each receiving coil 110, 120 and the race section 80 changes, and the amplitude of the output voltage signal of each receiving coil 110, 120 changes. Based on this amplitude change, the detection unit 90 calculates the axial displacement ΔY of the race section 80, and calculates the lateral force Fy based on the calculated axial displacement ΔY.

[0029] On the other hand, when a vertical load Fz acts on the wheel, as shown in Figure 4, the central axis LCo of the inner ring 52 is displaced in a direction perpendicular to the central axis LCo of the outer ring 51. As a result, the race portion 80 fixed to the flange portion 52b is also displaced. In this case, the detection unit 90 is configured such that the amplitude of the output voltage signals of each receiving coil 110, 120 changes. This configuration will be described in detail later. Based on this amplitude change, the detection unit 90 calculates the displacement of the race portion 80 in the axial direction and in the direction perpendicular to the vehicle length direction (hereinafter referred to as vertical displacement ΔZ), and calculates the vertical load Fz based on the calculated vertical displacement ΔZ.

[0030] Next, the coil section 92 will be described using Figures 7 to 11. In this embodiment, the substrate 91 is a multilayer substrate (specifically, a four-layer substrate), and the excitation coil 100 and each receiving coil 110, 120 constituting the coil section 92 are formed by wiring patterns on the multilayer substrate. Figures 8 to 11 show the wiring patterns formed on each layer when the substrate 91 is viewed from the lace section 80 side. Figure 7(a) is a diagram showing the wiring patterns of the second to fourth layers projected onto the wiring pattern of the first layer.

[0031] First, the excitation coil 100 will be described. As shown in Figures 8 and 9, the excitation coil 100 is formed in the first and second layers of the substrate 91, which are adjacent in the thickness direction. The wiring patterns of each layer are electrically connected by conductors filled in the excitation-side vias VI. The first layer has a wiring pattern consisting of a first excitation end 101 electrically connected to the excitation circuit 94, and a first excitation pattern 102 formed by making multiple (3) clockwise turns from the first excitation end 101 to the excitation-side via VI. The second layer has a second excitation end 103 electrically connected to the excitation circuit 94, and a second excitation pattern 104 formed by making multiple (3) counterclockwise turns from the second excitation end 103 to the excitation-side via VI. As a result, a 6-turn planar coil excitation coil 100 is formed on the substrate 91. The excitation coil 100 has an arc shape extending in the circumferential direction of the outer ring 51.

[0032] Next, the first receiving coil 110 will be described. The first receiving coil 110 is formed in the 1st to 4th layers, as shown in Figures 8 to 11. As shown in Figure 10, the 3rd layer has a first receiving end 111 which is electrically connected to the receiving circuit 95. The first end of the pattern 112 of the 1st layer is connected to the first receiving end 111 via the first A via VA1. The first end of the pattern 113 of the 2nd layer is connected to the second end of the pattern 112 via the second A via VA2. The first end of the pattern 115 of the 1st layer is connected to the second end of the pattern 115 via the third A via VA3, pattern 114, and the fourth A via VA4. The first end of the pattern 116 of the 2nd layer is connected to the second end of the pattern 115 via the fifth A via VA5. The second receiving end 118 of the 4th layer is connected to the second end of the pattern 116 via the sixth A via VA6, pattern 117, and the seventh A via VA7. The second receiving end 118 is connected to the receiving circuit 95. The receiving circuit 95 detects the potential difference between the first receiving end 111 and the second receiving end 118 as the first output voltage signal v1.

[0033] As shown in Figure 7(a), the first receiving coil 110 is located in the region surrounded by the excitation coil 100 in a plan view of the substrate 91. Furthermore, when an excitation voltage is supplied to the excitation coil 100, the first receiving coil 110 consists of a first part that generates a voltage of first polarity between the first receiving end 111 and the second receiving end 118 of the first receiving coil 110, and a second part that generates a voltage of second polarity which is the opposite polarity to the first polarity. Specifically, as shown in Figure 7(b), in a plan view of the substrate 91, the central part of the circumferential direction of the first receiving coil 110 is a first part 110A with one turn, and both ends of the first part 110A of the first receiving coil 110 are second parts 110B with the same number of turns (1 turn) as the first part 110A. As a result, the pattern shapes of the first and second portions 110A and 110B on one side and the pattern shapes of the first and second portions 110A and 110B on the other side of the first receiving coil 110 are symmetrical with respect to the central axis Lt in the circumferential direction of the first receiving coil 110.

[0034] Next, the second receiving coil 120 will be described. The second receiving coil 120 is formed in the 1st to 4th layers, as shown in Figures 8 to 11. As shown in Figure 10, the 3rd layer has a 3rd receiving end 121 which is electrically connected to the receiving circuit 95. The 3rd receiving end 121 is connected to the 1st end of the pattern 122 of the 2nd layer via the 1st B via VB1. The 2nd end of the pattern 122 is connected to the 1st end of the pattern 123 of the 1st layer via the 2nd B via VB2. The 2nd end of the pattern 123 is connected to the 1st end of the pattern 125 of the 1st layer via the 3rd A via VA3, pattern 124, and 4th B via VB4. The 2nd end of the pattern 125 is connected to the 1st end of the pattern 126 of the 2nd layer via the 5th B via VB5. The 4th receiving end 128 of the 4th layer is connected to the 2nd end of the pattern 126 via the 6th B via VB6, pattern 127, and 7th B via VB7. The fourth receiving end 128 is connected to the receiving circuit 95. The receiving circuit 95 detects the potential difference between the third receiving end 121 and the fourth receiving end 128 as the second output voltage signal v2.

[0035] As shown in Figure 7(a), the second receiving coil 120 is located in the region surrounded by the excitation coil 100 in a plan view of the substrate 91. The circumferential length of the second receiving coil 120 is the same as the circumferential length of the first receiving coil 110. The radial length of the second receiving coil 120 is greater than the radial length of the first receiving coil 110.

[0036] As shown in Figure 7(c), the second receiving coil 120, like the first receiving coil 110, is composed of a first part 120A and a second part 120B. In a plan view of the substrate 91, one side of the second receiving coil 120 with respect to the circumferential central axis Lt is the first part 120A, and the other side is the second part 120B.

[0037] In the first receiving coil 110 and the second receiving coil 120, the circumferential length from the central axis Lt to the circumferential end is the same as the circumferential length L1 of the shielding portion 81 and the notch 82. Also, as shown in Figure 7(a), in a plan view of the substrate 91, the circumferential ends of the second receiving coil 120 are the same as the circumferential ends of the first receiving coil 110.

[0038] In a plan view of the substrate 91, the radially outer end of the second receiving coil 120 lies on the first concentric circle C1 centered on the central axis LCo of the outer ring 51, as shown in Figure 12. The radially outer end of the first receiving coil 110 lies on the second concentric circle C2 centered on the central axis LCo. The radius of the second concentric circle C2 is smaller than the radius of the first concentric circle C1. The radially inner end of the first receiving coil 110 lies on the third concentric circle C3 centered on the central axis LCo. The radius of the third concentric circle C3 is smaller than the radius of the second concentric circle C2. The radially inner end of the second receiving coil 120 lies on the fourth concentric circle C4 centered on the central axis LCo. The radius of the fourth concentric circle C4 is smaller than the radius of the third concentric circle C3.

[0039] The radially outer end of the second receiving coil 120 extends beyond the radially outer end 81a of the shielding portion 81 in the reference state. The reference state can be set arbitrarily. The reference state is, for example, the state in which the vehicle is stationary, specifically, for example, the state in which the vehicle is stationary on a horizontal road surface. The CP shown in Figure 12 is a concentric circle CP centered on the central axis LCo of the outer ring 51 and passing through the radially outer end 81a of the shielding portion 81 in the reference state.

[0040] Next, using Figures 13 to 23, we will explain the principle by which the detection unit 90 can detect displacement and rotation angle.

[0041] First, we will explain the outline of this principle using Figures 13 and 14. As shown in Figure 13, when a high-frequency excitation voltage vr(t) is supplied to the excitation coil, a high-frequency current flows through the excitation coil. This current generates a magnetic flux φ(t), which links with the receiving coil. A voltage ve(t) proportional to the time rate of change of the linked magnetic flux is induced across the ends of the receiving coil.

[0042] Figure 14 shows a state in which a portion of the receiving coil is covered by the shielding portion, which is a metal part. Eddy currents flow in the portion of the shielding portion facing the receiving coil due to the flux linkage caused by the energization of the excitation coil. These eddy currents generate a magnetic flux in a direction that weakens the magnetic flux that generates the induced voltage in the receiving coil, and the amplitude of the induced voltage in the receiving coil becomes smaller. In other words, the amplitude of the potential difference across the ends of the receiving coil is proportional to the area of ​​the receiving coil that is not covered by the shielding portion.

[0043] Based on the explanations in Figures 13 and 14, the detection principle will be explained using Figures 15 and 16, with the second receiving coil 120 as an example. Figures 15 and 16 show the second receiving coil 120 and shielding portion 81 shown in Figure 7, etc., with the circumferential direction being linear. Figure 16 shows the relative positional relationship between the second receiving coil 120 and the shielding portion 81, and the transition of the second output voltage signal v2 of the second receiving coil 120.

[0044] In Figures 15 and 16, the direction in which current flows from the second receiving end 118 to the first receiving end 111 (I+) is referred to as the positive direction, and the direction in which current flows from the first receiving end 111 to the second receiving end 118 (I-) is referred to as the negative direction. Also, in Figures 15 and 16, the magnetic flux from the excitation coil 100 passes from the front of the page to the back of the page.

[0045] At time t1 in Figure 16, the central half of the first part 120A and the central half of the second part 120B are covered by the shielding part 81. A voltage that tends to induce a current in the positive direction is induced in the first part 120A, and a voltage that tends to induce a current in the negative direction is induced in the second part 120B. As a result, the induced voltage generated in the first part 120A and the induced voltage generated in the second part 120B cancel each other out, and the amplitude of the second output voltage signal v2 becomes 0.

[0046] At time t2, the second part 120B of the first part 120A is covered by the shielding part 81. In this case, a voltage that attempts to induce a current in the positive direction is induced in the first part 120A, and the induced voltage in the second part 120B becomes 0. As a result, the amplitude of the second output voltage signal v2 becomes the maximum value on the first polarity (positive polarity) side. This maximum value increases as the race part 80 approaches the second receiving coil 120.

[0047] At time t3, the end half of the first part 120A and the end half of the second part 120B are covered by the shielding part 81. A voltage that tends to induce a current in the positive direction is induced in the first part 120A, and a voltage that tends to induce a current in the negative direction is induced in the second part 120B. As a result, the induced voltage generated in the first part 120A and the induced voltage generated in the second part 120B cancel each other out, and the amplitude of the second output voltage signal v2 becomes 0.

[0048] At time t4, the first part 120A of the second part 120B is covered by the shielding part 81. In this case, a voltage that tends to cause current to flow in the negative direction is induced in the second part 120B, and the induced voltage of the first part 120A becomes 0. As a result, the amplitude of the second output voltage signal v2 becomes the maximum value on the second polarity (negative polarity) side, which is the opposite polarity to the first polarity. This maximum value increases as the race part 80 approaches the second receiving coil 120.

[0049] In this embodiment, shielding portions 81 and notches 82 are alternately formed at the radially outer end of the race portion 80. Therefore, during the rotation of the rotor 30, the amplitude of the second output voltage signal v2 of the second receiving coil 120 changes periodically, and as shown by the dashed lines in Figures 16 and 17, the envelope of the second output voltage signal v2 (hereinafter, second envelope ENV2) becomes sinusoidal. For example, by relating the circumferential spacing of the magnetic pole positions of the magnet unit 32 with the circumferential lengths of the shielding portions 81 and notches 82, the amplitude or envelope can be associated with the electrical angle θe.

[0050] In this embodiment, when an excitation voltage is supplied to the excitation coil 100, the phase difference between the second output voltage signal v2 of the second receiving coil 120 and the first output voltage signal v1 of the first receiving coil 110 is 90 degrees. Therefore, as shown by the dashed line in Figure 17, the phase difference between the envelope of the first output voltage signal v1 (hereinafter referred to as the first envelope ENV1) and the second envelope ENV2 is also 90 degrees.

[0051] As shown in Figure 17, the amplitude of the second envelope ENV2 is smaller than the amplitude of the first envelope ENV1. This is because, as shown in Figure 7(a), in a plan view of the substrate 91, the area surrounded by the second receiving coil 120 is larger than the area surrounded by the first receiving coil 110.

[0052] The receiving circuit 95 outputs to the processing unit 70 as a first displacement signal the amount of deviation of the actual amplitude of the first envelope ENV1 from the amplitude of the first envelope ES1 in the reference state. The receiving circuit 95 also outputs to the processing unit 70 as a second displacement signal the amount of deviation of the actual amplitude of the second envelope ENV2 from the amplitude of the second envelope ES2 in the reference state. In this embodiment, the receiving circuit 95 is configured such that the first and second displacement signals are 0 in the reference state. Each displacement signal is updated each time the maximum amplitude on the positive side and the maximum amplitude on the negative side of the respective output voltage signals v1 and v2 appear.

[0053] This section explains the case where the lateral force acting on the wheel changes.

[0054] When the direction of the lateral force is directed outward in the vehicle width direction, the inner ring 52 tilts relative to the outer ring 51 such that the upper end of the race portion 80 approaches the stator base portion 42 and the lower end approaches the wheel 10. In this case, the axial displacement ΔY and the polarity of each displacement signal are set to positive, as shown in Figure 18. The larger the axial displacement ΔY in the positive direction, the larger each displacement signal becomes in the positive direction. This is because, as shown in Figure 19(a), as the race portion 80 approaches the first and second receiving coils 110 and 120, the actual first and second envelopes ENV1 and ENV2 become larger than the first and second envelopes ES1 and ES2 in the reference state.

[0055] When the direction of the lateral force is directed inward in the vehicle width direction, the inner ring 52 tilts relative to the outer ring 51 such that the lower end of the race portion 80 approaches the stator base portion 42 and the upper end approaches the wheel 10. In this case, the axial displacement ΔY and the polarity of each displacement signal are set to negative, as shown in Figure 18. The larger the axial displacement ΔY becomes in the negative direction, the larger each displacement signal becomes in the negative direction. This is because, as shown in Figure 19(b), the further the race portion 80 moves away from the first and second receiving coils 110 and 120, the smaller the actual first and second envelopes ENV1 and ENV2 become compared to the first and second envelopes ES1 and ES2 in the reference state. On the other hand, the first and second displacement signals in the reference state become 0.

[0056] Next, we will explain the case where the vertical load acting on the wheel changes.

[0057] Figure 20 shows the relative positions of each receiving coil 110, 120 and the shielding portion 81 in the reference state. Figure 20 is a diagram showing the first and second receiving coils 110, 120 and the shielding portion 81 shown in Figure 7, etc., with the circumferential direction being a straight line. In the figure, the hatched parts are the parts of each receiving coil 110, 120 that are covered by the shielding portion 81. Figure 21(a) shows the transition of each envelope in the reference state.

[0058] When the upward vertical load increases, the upper end of the race section 80 is displaced upward. In this case, the vertical displacement ΔZ and the polarity of each displacement signal are set to positive, as shown in Figure 22. The larger the vertical displacement ΔZ is in the positive direction, the larger each displacement signal becomes in the positive direction. This is because, as shown in Figure 20(b), as the race section 80 is displaced upward, the area of ​​the second receiving coil 120 covered by the shielding section 81 increases, and as shown in Figure 21(b), the actual first and second envelopes ENV1 and ENV2 become larger than the first and second envelopes ES1 and ES2 in the reference state.

[0059] On the other hand, when the downward vertical load increases, the upper end of the race portion 80 is displaced downward. In this case, the vertical displacement ΔZ and the polarity of each displacement signal are set to negative, as shown in Figure 22. The larger the vertical displacement ΔZ is in the negative direction, the larger each displacement signal becomes in the negative direction. This is because, as shown in Figure 20(c), as the race portion 80 is displaced downward, the area of ​​the second receiving coil 120 covered by the shielding portion 81 decreases, and as shown in Figure 21(c), the actual first and second envelopes ENV1 and ENV2 become smaller than the first and second envelopes ES1 and ES2 in the reference state.

[0060] As shown in Figure 18, the second lateral force coefficient K2y, which is the change in the second displacement signal per unit change in the axial displacement ΔY, is greater than the first lateral force coefficient K1y, which is the change in the first change signal per unit change in the axial displacement ΔY. This is because, in a plan view of the substrate 91, the area enclosed by the second receiving coil 120 is larger than the area enclosed by the first receiving coil 110.

[0061] As shown in Figure 22, the second vertical load coefficient K2z, which is the change in the second displacement signal per unit change in the vertical displacement ΔZ, is greater than the first vertical load coefficient K1z, which is the change in the first change signal per unit change in the vertical displacement ΔZ. This is because, in a plan view of the substrate 91, the area surrounded by the second receiving coil 120 is larger than the area surrounded by the first receiving coil 110.

[0062] Furthermore, the second vertical load coefficient K2z is smaller than the second lateral force coefficient K2y, and the first vertical load coefficient K1z is smaller than the first lateral force coefficient K1y. This is due, for example, to the fact that the vertical stiffness of the wheel is greater than the stiffness in the vehicle width direction. In this embodiment, the relationship is "K2y>K1y>K2z>K1z".

[0063] From the above, the combination of axial displacement ΔY and vertical displacement ΔZ can be uniquely linked to the combination of the first displacement signal and the second displacement signal. For this reason, the displacement calculation unit 71, which constitutes the processing unit 70, calculates the axial displacement ΔY and vertical displacement ΔZ based on the first and second displacement signals and map information or mathematical formula information relating the first and second displacement signals, the axial displacement ΔY, and the vertical displacement ΔZ.

[0064] The force calculation unit 72, which constitutes the processing unit 70, calculates the lateral force Fy based on the calculated axial displacement ΔY and map information or mathematical formula information relating the axial displacement ΔY and the lateral force Fy. The force calculation unit 72 calculates the vertical load Fz based on the calculated vertical displacement ΔZ and map information or mathematical formula information relating the vertical displacement ΔZ and the vertical load Fz.

[0065] The map information or mathematical formula information mentioned above may be stored in a memory unit (e.g., non-volatile memory) provided by the processing unit 70. The force calculation unit 72 may also calculate the lateral force Fy and the vertical load Fz based on the first and second displacement signals and the map information or mathematical formula information relating the first and second displacement signals, the lateral force Fy, and the vertical load Fz. The calculation of loads based on the first and second displacement signals and the map information or mathematical formula information can be similarly applied to the following embodiments in which the first and second displacement signals appear.

[0066] The angle calculation unit 73, which constitutes the processing unit 70, calculates the rotation angle (e.g., electrical angle θe) of the rotor 30 based on at least one of the first output voltage signal v1 and the second output voltage signal v2.

[0067] Specifically, for example, the angle calculation unit 73 can calculate the electrical angle θe based on the first envelope ENV1 or the second envelope ENV2. This calculation method is based on the fact that the envelope contains information indicating the change in the amplitude of the output voltage signal, and that the amplitude of the output voltage signal depends on the rotation angle.

[0068] Furthermore, for example, the angle calculation unit 73 can calculate the electrical angle θe by taking the first output voltage signal v1, the second output voltage signal v2, and the excitation voltage vr as inputs and using synchronous detection and a low-pass filter. This calculation method is a digital tracking method and is described, for example, in paragraphs 0028 to 0030 of the specification of Japanese Patent Application Publication No. 2015-073407.

[0069] As described in detail above, this embodiment allows for the accurate calculation of axial displacement ΔY and vertical displacement ΔZ, thereby improving the accuracy of the calculation of lateral force Fy and vertical load Fz. Furthermore, this embodiment also provides the following advantages.

[0070] A detection unit 90 is provided in the stator base portion 42 at a position radially away from the bearing 50 and axially opposite to the radial end of the race portion 80. The portion of the race portion 80 that faces the detection unit 90 in the axial direction is the portion radially outward from the bearing 50. Therefore, when a lateral force acts on the wheel, the axial displacement of the portion of the race portion 80 that faces the detection unit 90 in the axial direction can be increased. As a result, the detection accuracy of the axial displacement ΔY can be improved, and consequently, the calculation accuracy of the lateral force Fy of the wheel, which constitutes the unsprung mass of the vehicle, can be improved.

[0071] Because the in-wheel motor 20 is configured as an outer rotor type, the radial end of the race portion 80 can be positioned at a location far enough away radially from the bearing 50. This improves the detection accuracy of the axial displacement ΔY.

[0072] The first receiving coil 110 and the second receiving coil 120 are positioned axially closer to the wheel 10 than the coil end portion that constitutes the stator winding 41. This suppresses the influence of noise and other factors associated with energizing the stator winding 41 on the induced voltage of the first receiving coil 110 and the second receiving coil 120. As a result, the detection accuracy of axial displacement ΔY, vertical displacement ΔZ, and rotation angle can be improved.

[0073] <Modification 1 of the first embodiment> The race section is not limited to the configuration shown in Figure 1, etc., but may also have configurations such as (A) and (B) below.

[0074] (A) As shown in Figure 24, the lace portion 83 is alternately provided with shielding portions 85 and openings 84 that penetrate the lace portion in the circumferential direction. Note that 83a in Figure 24 corresponds to the bent portion 80a shown in Figures 1 and 2. Also, the circumferential length of the opening 84 corresponds to the circumferential length of the notch 82 in Figure 2.

[0075] (B) As shown in Figures 25 and 26, the race portion 83 is alternately provided in the circumferential direction with convex portions 87 that protrude from the flat surface of the race portion 83 in the axial direction of the inner ring 52, and concave portions 88 that protrude from the flat surface of the race portion 83 in the axial direction and are recessed relative to the convex portions 87 in the axial direction of the inner ring 52. The circumferential length of the convex portions 87 corresponds to the circumferential length of the shielding portion 81 in Figure 2, and the circumferential length of the concave portions 88 corresponds to the circumferential length of the notch 82 in Figure 2. Due to the provision of the concave portions 88 and convex portions 87, the axial distance between each receiving coil 110, 120 and the race portion 83 changes during the rotation of the rotor 30. By utilizing this change, the axial displacement ΔY can be detected, similar to the first embodiment.

[0076] <Modification 2 of the first embodiment> The two receiving coils formed on the substrate 91 may be coils of the same shape (for example, the second receiving coil 120). In this case, the phases of the induced voltages of the two receiving coils will be the same.

[0077] <Modification 3 of the First Embodiment> As shown in Figure 27, notches 81b may be formed at both circumferential ends of the radially outer end of the shielding portion 81. In this case, the radially outer end of the shielding portion 81 becomes trapezoidal, and the circumferential length dimension decreases as you move radially outward at the radially outer end of the shielding portion 81. This allows for a larger change in the amplitude of the second envelope ENV2 when the lace portion 80 is displaced vertically, and the lateral force coefficient can be made larger than the vertical load coefficient. As a result, the detection accuracy of the vertical displacement ΔZ can be improved.

[0078] <Modification 4 of the First Embodiment> As shown in Figure 28, the substrate 91 may be tilted in the vertical direction. In the example shown in Figure 28, this tilt increases the axial distance between the substrate 91 and the shielding portion 81 as it goes upwards. This allows the lateral force coefficient and the vertical load coefficient to be changed from the values ​​shown in Figures 18 and 22.

[0079] <Second Embodiment> In this embodiment, as shown in Figure 29, the shapes of the first receiving coil 130 and the second receiving coil 140 have been modified. Figure 29 is a diagram showing the first and second receiving coils 130, 140 and the shielding portion 81 in a linear circumferential direction. The first receiving coil 130 corresponds to the first receiving coil 110 of the first embodiment, and the second receiving coil 140 corresponds to the second receiving coil 120 of the first embodiment. The differences from the first embodiment will be explained below.

[0080] The radial dimensions of the first receiving coil 130 and the second receiving coil 140 are the same. In a plan view of the substrate 91, the radial outer end of the second receiving coil 140 lies on the first concentric circle CA centered on the central axis LCo of the outer ring 51. The radial outer end of the first receiving coil 130 lies on the second concentric circle CB centered on the central axis LCo. The radius of the second concentric circle CB is smaller than the radius of the first concentric circle CA. The radial outer end of the second receiving coil 140 extends beyond the radial outer end 81a of the shielding portion 81 in the reference state.

[0081] In this embodiment as well, the characteristics shown in Figures 18 and 22 are present. Therefore, the displacement calculation unit 71 and the force calculation unit 72 can perform the calculation process in the same manner as in the first embodiment.

[0082] <Third Embodiment> In this embodiment, instead of two receiving coils, the axial displacement ΔY and vertical displacement ΔZ are calculated based on the output voltage signal of a single receiving coil. The differences from the first embodiment will be explained below.

[0083] Figure 30 shows the receiving coil 150 with its circumferential direction linear. The receiving coil 150 corresponds to the second receiving coil 120 of the first embodiment and has a first portion 150A and a second portion 150B. The receiving coil 150 is formed on the substrate 91. The circumferential dimensions of the first portion 150A, the second portion 150B, and the shielding portion 81 are the same.

[0084] In a plan view of the substrate 91, the radially outer end of the first portion 150A lies on a first concentric circle Cα centered on the central axis LCo of the outer ring 51. The radially outer end of the second portion 150B lies on a second concentric circle Cβ centered on the central axis LCo. The radius of the second concentric circle Cβ is smaller than the radius of the first concentric circle Cα. The area enclosed by the first portion 150A is larger than the area enclosed by the second portion 150B. The radially outer end of the first portion 150A extends beyond the radially outer end 81a of the shielding portion 81 in the reference state.

[0085] Next, using Figures 31 to 33, we will explain why the axial displacement ΔY and vertical displacement ΔZ can be calculated based on the output voltage signal of a single receiving coil 150.

[0086] Figure 31 shows the relative positional relationship between the receiving coil 150 and the shielding portion 81 in the reference state, and the transition of the envelope of the output voltage signal (hereinafter referred to as the reference envelope ES) in the reference state. Figure 31(a) shows a plan view of the receiving coil 150 in which a part of the first portion 150A is covered by the shielding portion 81. Figure 31(b) shows the state in which the race portion 80 has rotated and a part of the first portion 150A and the second portion 150B are covered by the shielding portion 81. Figure 31(c) shows the state in which the race portion 80 has rotated further and the entire second portion 150B is covered by the shielding portion 81.

[0087] In the reference envelope ES, relatively small amplitudes and relatively large amplitudes appear alternately. Figure 31 shows the zero-crossing timing of the reference envelope ES as ts0. In Figure 31, when the relative positional relationship between the receiving coil 150 and the shielding part 81 is (a), the reference envelope ES is the value at time tsa (i.e., small amplitude), when it is (b), the reference envelope ES is the value at time tsb, and when it is (c), the reference envelope ES is the value at time tsc (i.e., large amplitude).

[0088] Next, Figure 32 shows the relative positional relationship between the receiving coil 150 and the shielding part 81, and the transition of the envelope ENV of the output voltage signal when a lateral force acts on the wheel in the inward direction in the vehicle width direction. In Figure 32, when the relative positional relationship between the receiving coil 150 and the shielding part 81 is (a), the envelope ENV is the value at time tya (i.e., small amplitude), when it is (b), the envelope ENV is the value at time tyb, and when it is (c), the reference envelope ES is the value at time tyc (i.e., large amplitude).

[0089] When a lateral force acts on the wheel in the direction of the vehicle width, the shielding portion 81 is displaced so as to move away from the receiving coil 150. In this case, the small amplitude of the envelope ENV becomes smaller than the small amplitude of the reference envelope ES, and the large amplitude of the envelope ENV becomes smaller than the large amplitude of the reference envelope ES. Also, the zero-crossing timing ty0 of the envelope ENV lags behind the zero-crossing timing ts0 of the reference envelope ES.

[0090] On the other hand, when a lateral force acts on the wheel from the outside in the vehicle width direction, the shielding portion 81 is displaced so as to move closer to the receiving coil 150. In this case, the small amplitude of the envelope ENV becomes larger than the small amplitude of the reference envelope ES, and the large amplitude of the envelope ENV becomes larger than the large amplitude of the reference envelope ES. Also, the zero-crossing timing ty0 of the envelope ENV becomes earlier than the zero-crossing timing ts0 of the reference envelope ES.

[0091] Therefore, the axial displacement ΔY can be determined based on the large and small amplitudes of the envelope and the difference in the zero-crossing timing of the reference envelope ES and the envelope ENV.

[0092] Next, Figure 33 shows the relative positional relationship between the receiving coil 150 and the shielding part 81, and the change in the envelope ENV of the output voltage signal when the upward vertical load acting on the wheel increases. In Figure 33, when the relative positional relationship between the receiving coil 150 and the shielding part 81 is (a), the envelope ENV is the value at time tza (i.e., small amplitude), when it is (b), the envelope ENV is the value at time tzb, and when it is (c), the reference envelope ES is the value at time tzc (i.e., large amplitude).

[0093] When an upward vertical load increases relative to the reference state, the shielding portion 81 is displaced upward. In this case, the small amplitude of the envelope ENV becomes larger than the small amplitude of the reference envelope ES. This is because the area covered by the shielding portion 81 in the first portion 150A increases, and the induced voltage in the first portion 150A that attempts to cancel out the potential difference generated on the second portion 150B side becomes smaller. Furthermore, the large amplitude of the envelope ENV does not change from the large amplitude of the reference envelope ES. This is because even when the shielding portion 81 is displaced upward, the radial outer end of the second portion 150B does not protrude from the shielding portion 81.

[0094] As the upward vertical load increases relative to the reference state, the zero-crossing timing tz0 of the envelope ENV lags behind the zero-crossing timing ts0 of the reference envelope ES.

[0095] On the other hand, when a downward vertical load increases relative to the reference state, the shielding portion 81 is displaced downward. In this case, the small amplitude of the envelope ENV becomes smaller than the small amplitude of the reference envelope ES, and the large amplitude of the envelope ENV does not change from the large amplitude of the reference envelope ES. Also, the zero-crossing timing tz0 of the envelope ENV becomes earlier than the zero-crossing timing ts0 of the reference envelope ES.

[0096] Therefore, the vertical displacement ΔZ can be determined based on the large and small amplitudes of the envelope and the difference in the zero-crossing timing of the reference envelope ES and the envelope ENV.

[0097] From the above, map information or mathematical information can be created that links the small amplitude and large amplitude of the envelope ENV and the amount of deviation between the zero-crossing timing of the reference envelope ES and the zero-crossing timing of the envelope ENV, with the combination of the axial displacement ΔY and the vertical displacement ΔZ. The displacement calculation unit 71 uses the envelope ENV based on the output voltage signal of the receiving coil 150 to calculate the small amplitude and large amplitude of the envelope ENV and the amount of deviation from the zero-crossing timing of the reference envelope ES. Based on the calculated small amplitude and large amplitude, the above-mentioned deviation amount, and the map information or mathematical information, the displacement calculation unit 71 calculates the axial displacement ΔY and the vertical displacement ΔZ. The force calculation unit 72 calculates the lateral force Fy based on the calculated axial displacement ΔY and the map information or mathematical information relating the axial displacement ΔY and the lateral force Fy. The force calculation unit 72 calculates the vertical load Fz based on the calculated vertical displacement ΔZ and map information or mathematical formula information relating the vertical displacement ΔZ and the vertical load Fz. The displacement calculation unit 71 can, for example, determine the reference timing set in relation to the electrical angle of the rotor 30 as the zero-crossing timing of the reference envelope ES. Alternatively, the storage unit may store map information or mathematical formula information that links the small amplitude, large amplitude of the envelope ENV, the amount of deviation between the zero-crossing timing of the reference envelope ES and the zero-crossing timing of the envelope ENV, and the combination of the lateral force Fy and the vertical load Fz. In this case, the force calculation unit 72 can calculate the lateral force Fy and the vertical load Fz based on this map information or mathematical formula information, the calculated small amplitude and large amplitude, and the calculated amount of deviation.

[0098] <Modified form of the third embodiment> A receiving coil with the shape shown in Figure 7(b) may be used as the receiving coil. In this case, it is sufficient that the radial dimension of one of the first and second parts of the receiving coil is larger than the radial dimension of the other part.

[0099] <Fourth Embodiment> The fourth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the detection unit 90 calculates the force acting between the ground contact surface GL and the wheels in the vehicle's longitudinal direction (hereinafter referred to as the longitudinal load Fx) instead of the vertical load Fz. The direction in which the lateral force Fy acts and the direction in which the longitudinal load Fx acts are orthogonal. The longitudinal load Fx is used in the control device for controlling the vehicle's movement.

[0100] Figure 34 shows the race section 80 and the detection unit 90.

[0101] The first and second receiving coils 110 and 120 formed on the substrate 91 are arranged so as to straddle the horizontal axis HL that passes through the central axis LCi of the inner ring 52 (the rotation center of the race section 80). For example, in a plan view of the flat surface of the race section 80, the substrate 91 is positioned so that the circumferential central axis Lt of the first and second receiving coils 110 and 120 coincides with the horizontal axis HL.

[0102] The first and second receiving coils 110 and 120 are located near the front or rear end of the vehicle, at either end of the race section 80 in the vehicle length direction. The following explanation will use the case where the first and second receiving coils 110 and 120 are located at the front end of the vehicle as an example.

[0103] When the vehicle is accelerating, the longitudinal load Fx is considered positive, and when the vehicle is decelerating, the longitudinal load Fx is considered negative. When the longitudinal load Fx is positive, the shielding portion 81 is displaced toward the direction of vehicle travel. This state corresponds to a state in the first embodiment where the upward vertical load acting on the wheels increases. On the other hand, when the longitudinal load Fx is negative, the shielding portion 81 is displaced toward the opposite direction of vehicle travel. This state corresponds to a state in the first embodiment where the downward vertical load acting on the wheels increases.

[0104] Similar to the first embodiment, the receiving circuit 95 outputs to the processing unit 70 as a first displacement signal the amount of deviation of the actual amplitude of the first envelope ENV1 from the amplitude of the first envelope ES1 in the reference state. The receiving circuit 95 also outputs to the processing unit 70 as a second displacement signal the amount of deviation of the actual amplitude of the second envelope ENV2 from the amplitude of the second envelope ES2 in the reference state.

[0105] The displacement calculation unit 71 calculates the axial displacement ΔY and the vehicle length displacement ΔX based on the first and second displacement signals and map information or mathematical formula information relating the first and second displacement signals, the axial displacement ΔY, and the vehicle length displacement ΔX.

[0106] The force calculation unit 72 calculates the lateral force Fy based on the calculated axial displacement ΔY and map information or mathematical information relating the axial displacement ΔY and the lateral force Fy. The force calculation unit 72 calculates the longitudinal load Fx based on the calculated vehicle length displacement ΔX and map information or mathematical information relating the vehicle length displacement ΔX and the longitudinal load Fx.

[0107] According to the embodiment described above, a single detection unit 90 can detect the axial displacement ΔY and the vehicle length displacement ΔX.

[0108] <Modified form of the fourth embodiment> The first and second receiving coils 130 and 140 shown in Figure 29 may be used as the first and second receiving coils. Furthermore, the receiving coils are not limited to two; one receiving coil, as shown in Figure 30, may also be used.

[0109] <Fifth Embodiment> The fifth embodiment will now be described, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, as shown in Figure 35, a configuration is adopted that allows for a smaller coaxiality between the rotor 30, the race section 80, and the bearing 50. In Figure 35, components that are the same as or corresponding to those shown in Figure 1, etc., are denoted by the same reference numerals for convenience. In addition, the race section 80 of this embodiment does not have a bent portion 80a.

[0110] A through hole 33a is formed in the radial center of the flat plate portion 33 that constitutes the rotor 30. On the inner surface of the flat plate portion 33 in the vehicle width direction, an annular stepped portion 33b is formed, extending radially outward from the radially inner end. The inner surface of the stepped portion 33b in the vehicle width direction is a flat surface. An annular positioning portion 33c is formed at the radially inner end of the stepped portion 33b, projecting inward in the vehicle width direction.

[0111] A through hole 80b is formed in the radial center of the race portion 80. With the flat surface of the race portion 80 in contact with the flat surface of the stepped portion 33b, the positioning portion 33c is fitted into the through hole 80b of the race portion 80. As a result, the rotational axis of the rotor 30 and the rotational axis of the race portion 80 are made coaxial.

[0112] The inner radial end of the flange portion 52b of the inner ring 52 has an annular bearing-side stepped portion 52c that protrudes outward in the vehicle width direction. The portion of the flat plate portion 33 that is radially inward of the positioning portion 33c has an annular recess 33d that is recessed outward in the vehicle width direction. By fitting the bearing-side stepped portion 52c into the recess 33d, the central axis of the inner ring 52, the rotational central axis of the rotor 30, and the rotational central axis of the race portion 80 are made coaxial. In particular, in this embodiment, the flat surface on the outer side in the vehicle width direction of the flange portion 52b is in contact with the flat surfaces of the race portion 80 and the positioning portion 33c. This makes it possible to suitably reduce the coaxiality of the rotational central axis of the rotor 30, the rotational central axis of the race portion 80, and the central axis of the inner ring 52.

[0113] First through-holes are formed in the flat plate portion 33, the race portion 80, and the flange portion 52b, extending axially. Multiple first through-holes are formed in a circumferential direction (for example, at equal intervals in the circumferential direction). A bolt 200 is inserted through each first through-hole. The bolt 200 is inserted into the first through-hole with its head facing outward in the vehicle width direction and its shaft facing inward in the vehicle width direction. In this inserted state, the male thread at the tip of the shaft is screwed into the female thread of the nut 201. As a result, the overlapping flat plate portion 33, the race portion 80, and the flange portion 52b are sandwiched between the head of the bolt 200 and the nut 201. Consequently, the rotor 30, the race portion 80, and the bearing 50 are integrated into a single unit.

[0114] Second through-holes are formed in the flat plate portion 33, the race portion 80, the flange portion 52b, and the disc portion 12, extending axially through them. Multiple second through-holes are formed in a circumferential direction (for example, at equal intervals in the circumferential direction) at positions offset from the formation positions of the first through-holes. A bolt 210 is inserted through each second through-hole. The bolt 210 is inserted into the second through-hole with its head facing inward in the vehicle width direction and its shaft facing outward in the vehicle width direction. In this inserted state, the male thread of the bolt 210 is screwed into the female thread of the nut 211. As a result, the overlapping flat plate portion 33, the flange portion 52b, the race portion 80, and the disc portion 12 are sandwiched between the head of the bolt 210 and the nut 211. Consequently, the rotor 30, bearing 50, race portion 80, and wheel 10 are integrated into a single unit.

[0115] Next, the manufacturing method for the drive wheel will be explained. In this manufacturing method, after assembling the motor assembly equipped with the race section 80, the motor assembly is mounted onto the wheel 10.

[0116] With the flat surface of the race portion 80 in contact with the flat surface of the stepped portion 33b, the positioning portion 33c is fitted into the through hole 80b of the race portion 80. Then, while sandwiching the race portion 80 between the stepped portion 33b and the flange portion 52b, the bearing-side stepped portion 52c is fitted into the recess 33d.

[0117] With the flat plate portion 33, the race portion 80, and the flange portion 52b stacked together, the bolt 200 is inserted through each of the first through holes with its head facing outward from the rotor 30. Then, the female thread of the nut 201 is screwed onto the male thread of the bolt 200. As a result, the stacked flat plate portion 33, the race portion 80, and the flange portion 52b are sandwiched between the head of the bolt 200 and the nut 201. This creates a motor assembly in which the rotor 30, the race portion 80, and the bearing 50 are integrated. Here, since the flat surface of the race portion 80 is in contact with the flat surface of the stepped portion 33b, warping of the race portion 80 when the nut 201 is screwed onto the bolt 200 can be suppressed.

[0118] With the motor assembly and the disc portion 12 stacked together, insert the bolt 210 through each of the second through holes with the head of the bolt 210 facing the stator base portion 42. Then, screw the female thread of the nut 211 onto the male thread of the bolt 210. This integrates the motor assembly and the wheel 10.

[0119] According to the embodiment described above, it is possible to provide a drive wheel in which the coaxiality of the rotor 30, race section 80, and bearing 50 is reduced. This makes it possible to improve the detection accuracy of the detection unit 90.

[0120] <Sixth Embodiment> The sixth embodiment will now be described, focusing on the differences from the fifth embodiment, with reference to the drawings. In this embodiment, as shown in Figure 36, the race portion 80 is fixed to the rotor 30 instead of the inner ring 52. In Figure 36, components that are the same as or corresponding to those shown in Figure 35 and other earlier figures are denoted by the same reference numerals for convenience.

[0121] With the flat surface of the race portion 80 in contact with the flat surface of the stepped portion 33b, the positioning portion 33c is fitted into the through hole 80b of the race portion 80. In this state, the race portion 80 and the stepped portion 33b are fixed together by a bolt 220.

[0122] First through-holes are formed in the flat plate portion 33 and the flange portion 52b, penetrating in the axial direction. Multiple first through-holes are formed in a circumferential direction (for example, at equal intervals in the circumferential direction). A bolt 230 is inserted through each first through-hole. The bolt 230 is inserted into the first through-hole with its head facing inward in the vehicle width direction and its shaft facing outward in the vehicle width direction. In this inserted state, the male thread of the bolt 230 is screwed into the female thread of the nut 231. As a result, the overlapping flat plate portion 33 and flange portion 52b are sandwiched between the head of the bolt 230 and the nut 231. Consequently, the rotor 30, the race portion 80, and the bearing 50 are integrated into one unit.

[0123] Second through-holes are formed in the flat plate portion 33, flange portion 52b, and disc portion 12, extending axially. Multiple second through-holes are formed circumferentially (for example, at equal intervals circumferentially) at positions offset radially from the formation position of the first through-holes. A bolt 240 is inserted through each second through-hole. The bolt 240 is inserted into the second through-hole with its head facing inward in the vehicle width direction and its shaft facing outward in the vehicle width direction. In this inserted state, the male thread of the bolt 240 is screwed into the female thread of the nut 241. As a result, the overlapping flat plate portion 33, flange portion 52b, and disc portion 12 are sandwiched between the head of the bolt 240 and the nut 241. Consequently, the rotor 30 and the wheel 10 are integrated.

[0124] <Seventh Embodiment> The following describes the seventh embodiment, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, the method for calculating the lateral force Fy by the processing unit 70 is changed.

[0125] The processing unit 70 is mainly composed of a microcontroller, which is equipped with a CPU. The functions provided by the microcontroller can be provided by software recorded in a physical memory device and the computer that executes it, by software only, by hardware only, or by a combination thereof. For example, when the microcontroller is provided by electronic circuits which are hardware, it can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcontroller executes a program stored in a non-transitory tangible storage medium which serves as its own storage unit. The program includes, for example, a program for force calculation processing as shown in Figure 39, which will be described later. When the program is executed, the method corresponding to the program is executed. The storage unit is, for example, non-volatile memory. The program stored in the storage unit can be updated via a communication network such as the Internet, for example, OTA (Over The Air).

[0126] Figure 37 shows a block diagram of the processing unit 70 according to this embodiment.

[0127] The displacement calculation unit 71, which constitutes the processing unit 70, includes an offset voltage calculation unit 160 and a displacement voltage calculation unit 161. The electrical angle θe calculated by the angle calculation unit 73 is input to the offset voltage calculation unit 160.

[0128] The offset voltage calculation unit 160 calculates the axial offset voltage vofty based on the electrical angle θe. The axial offset voltage vofty is the first envelope ENV1 in the reference state. In this embodiment, the average value of the axial offset voltage vofty over one period is 0, and the zero-up cross timing and zero-down cross timing are the same signals as the first envelope ENV1 (see Figure 17). The reference state can be set arbitrarily. As described above, the reference state is, for example, the state in which the vehicle is stopped, specifically, for example, the state in which the vehicle is stopped on a horizontal road surface. In this embodiment, one period of the first envelope ENV1 and one electrical angle period of the rotor 30 are set to the same period (see Figure 40). The axial offset voltage vofty may also be, for example, a value adapted during the design of the vehicle detection device, or a value measured during the shipment inspection of the vehicle detection device.

[0129] The displacement voltage calculation unit 161 also functions as a signal acquisition unit that acquires the first envelope ENV1 from the receiving circuit 95. The displacement voltage calculation unit 161 calculates the axial displacement voltage vdy (=ENV1-vofty) by subtracting the axial offset voltage vofty from the first envelope ENV1. Alternatively, the displacement voltage calculation unit 161 may acquire the first output voltage signal v1 from the receiving circuit 95 and calculate the first envelope ENV1 based on the acquired first output voltage signal v1.

[0130] When the current state is the reference state, the first envelope ENV1 and the axial offset voltage vofty are the same signal, and the axial displacement voltage vdy is 0. On the other hand, when the current state deviates from the reference state, the values ​​of the first envelope ENV1 and the axial offset voltage vofty differ during periods other than the zero-crossing timing of the axial offset voltage vofty, and the axial displacement voltage vdy is a value other than 0. The axial displacement voltage vdy is a signal obtained by removing the influence of the fluctuating component associated with the rotation of the rotor 30 from the first envelope ENV1, and is a signal that correlates with the lateral force Fy.

[0131] Of the first and second envelopes ENV1 and ENV2, the first envelope ENV1 is used to calculate the axial displacement voltage vdy because the effect of the vertical load Fz is not present in the first envelope ENV1.

[0132] The force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy. For example, as shown in Figure 38, the force calculation unit 72 calculates the lateral force Fy as the product of the proportionality constant Ky (>0) and the axial displacement voltage vdy. Alternatively, the force calculation unit 72 may calculate the lateral force Fy based on the axial displacement voltage vdy and map information relating the axial displacement voltage vdy and the lateral force Fy.

[0133] Incidentally, in the example shown in Figure 38, the intercept of the linear equation with axial displacement voltage vdy as the independent variable and lateral force Fy as the dependent variable is 0. However, depending on how the reference state is set, the intercept may be a value other than 0.

[0134] Figure 39 shows a flowchart of the calculation process for the lateral force Fy performed by the processing unit 70.

[0135] In step S10, the offset voltage calculation unit 160 calculates the axial offset voltage vofty based on the electrical angle θe.

[0136] In step S11, the displacement voltage calculation unit 161 calculates the axial displacement voltage vdy by subtracting the axial offset voltage vofty from the acquired first envelope ENV1.

[0137] In step S12, the force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy.

[0138] Figure 40 shows the changes in the axial offset voltage vofty and axial displacement voltage vdy when the rotational speed of the rotor 30 is constant. In the example shown in Figure 40, a lateral force Fy acts on the wheel during the period from time t1 to t2. Therefore, during the period from time t1 to t2, the first envelope ENV1 deviates from the axial offset voltage vofty. As a result, during the period from time t1 to t2, except for the zero-crossing timing of the axial offset voltage vofty, the axial displacement voltage vdy becomes a value other than 0, and reflects the lateral force Fy. As a result, the accuracy of calculating the lateral force Fy can be improved.

[0139] <Eighth Embodiment> The eighth embodiment will be described below, focusing on the differences from the seventh embodiment, with reference to the drawings. In this embodiment, the method for calculating the lateral force Fy by the processing unit 70 is changed.

[0140] Figure 41 shows a block diagram of the processing unit 70 according to this embodiment.

[0141] The displacement calculation unit 71 includes an offset voltage calculation unit 162, a displacement voltage calculation unit 163, and a total voltage calculation unit 164. The offset voltage calculation unit 162 receives the electrical angle θe calculated by the angle calculation unit 73 as input.

[0142] The offset voltage calculation unit 162 calculates a first axial offset voltage vofty1 and a second axial offset voltage vofty2 based on the electrical angle θe. The first axial offset voltage vofty1 is the first envelope ENV1 in the reference state, and the second axial offset voltage vofty2 is the second envelope ENV2 in the reference state. In this embodiment, the average value of each axial offset voltage vofty1 and vofty2 over one period is 0. Furthermore, the zero-up cross timing and zero-down cross timing of the first axial offset voltage vofty1 are the same signals as the first envelope ENV1, and the zero-up cross timing and zero-down cross timing of the second axial offset voltage vofty2 are the same signals as the second envelope ENV2. Since the phase difference between the first envelope ENV1 and the second envelope ENV2 is 90° in electrical angle, the phase difference between the first axial offset voltage vofty1 and the second axial offset voltage vofty2 is also 90° in electrical angle (see Figure 43).

[0143] The displacement voltage calculation unit 163 acquires the first envelope ENV1 from the receiving circuit 95. The displacement voltage calculation unit 163 calculates the first axial displacement voltage vdy1 (=ENV1-vofty1) by subtracting the first axial offset voltage vofty1 from the first envelope ENV1. The displacement voltage calculation unit 163 also calculates the second axial displacement voltage vdy2 (=ENV2-vofty2) by subtracting the second axial offset voltage vofty2 from the second envelope ENV2. Alternatively, the displacement voltage calculation unit 161 may acquire the first and second output voltage signals v1 and v2 from the receiving circuit 95 and calculate the first and second envelopes ENV1 and ENV2 based on the acquired first and second output voltage signals v1 and v2.

[0144] If the current state is the reference state, the first envelope ENV1 and the first axial offset voltage vofty1 will have the same signal, and the first axial displacement voltage vdy1 will be 0. On the other hand, if the current state deviates from the reference state, the values ​​of the first envelope ENV1 and the first axial offset voltage vofty1 will differ during periods other than the zero-crossing timing of the first axial offset voltage vofty1, and the first axial displacement voltage vdy1 will be a value other than 0.

[0145] If the current state is the reference state, the second envelope ENV2 and the second axial offset voltage vofty2 will have the same signal, and the second axial displacement voltage vdy2 will be 0. On the other hand, if the current state deviates from the reference state, the values ​​of the second envelope ENV2 and the second axial offset voltage vofty2 will differ during periods other than the zero-crossing timing of the second axial offset voltage vofty2, and the second axial displacement voltage vdy2 will be a value other than 0.

[0146] The total voltage calculation unit 164 calculates the total voltage vdty (=|vdy1|+|vdy2|) by adding the absolute value of the first axial displacement voltage vdy1 and the absolute value of the second axial displacement voltage vdy2.

[0147] The force calculation unit 72 calculates the lateral force Fy based on the total voltage vdty. For example, the force calculation unit 72 calculates the lateral force Fy based on the following equation (eq1). In the following equation (eq1), Ka (>0) is the proportionality constant.

[0148] Fy = Ka × vdty …(eq1) The force calculation unit 72 may also calculate the lateral force Fy based on the total voltage vdty and map information relating the total voltage vdty and the lateral force Fy.

[0149] Figure 42 shows a flowchart of the calculation process for the lateral force Fy performed by the processing unit 70.

[0150] In step S20, the offset voltage calculation unit 162 calculates the first and second axial offset voltages vofty1 and vofty2 based on the electrical angle θe.

[0151] In step S21, the displacement voltage calculation unit 163 calculates the first axial displacement voltage vdy1 by subtracting the first axial offset voltage vofty1 from the acquired first envelope ENV1. Furthermore, the second axial displacement voltage vdy2 is calculated by subtracting the second axial offset voltage vofty2 from the acquired second envelope ENV2.

[0152] In step S22, the total voltage calculation unit 164 calculates the total voltage vdty based on the first and second axial displacement voltages vdy1 and vdy2.

[0153] In step S23, the force calculation unit 72 calculates the lateral force Fy based on the total voltage vdty.

[0154] Figure 43 shows the changes in each axial offset voltage vofty1, vofty2, the first and second axial displacement voltages vdy1, vdy2, and the total voltage vdty when the rotational speed of the rotor 30 is constant. In the example shown in Figure 43, a lateral force Fy acts on the wheel during the period from time t1 to t2. Therefore, during the period from time t1 to t2, the first envelope ENV1 deviates from the first axial offset voltage vofty1, and the second envelope ENV2 deviates from the second axial offset voltage vofty2. As a result, during the period from time t1 to t2, the first axial displacement voltage vdy1 becomes a value other than 0 during the period other than the zero-crossing timing of the first axial offset voltage vofty1, and the second axial displacement voltage vdy2 becomes a value other than 0 during the period other than the zero-crossing timing of the second axial offset voltage vofty2.

[0155] Here, since the phase difference between the first axial offset voltage vofty1 and the second axial offset voltage vofty2 is 90°, in the example shown in Figure 43, the total voltage vdty will be a value other than 0 during the period from time t1 to t2, and the total voltage vdty will not cross zero. Therefore, even if one of the first and second axial offset voltages vofty1 and vofty2 crosses zero, the lateral force Fy can be determined from the other. In other words, the accuracy of calculating the lateral force Fy can be improved by using the total voltage vdty.

[0156] <Ninth Embodiment> The ninth embodiment will be described below, focusing on the differences from the eighth embodiment, with reference to the drawings. In this embodiment, the method for calculating the lateral force Fy by the processing unit 70 is changed.

[0157] Figure 44 shows a block diagram of the processing unit 70 according to this embodiment.

[0158] The displacement calculation unit 71 includes an offset voltage calculation unit 162 and a displacement voltage calculation unit 163.

[0159] The offset voltage calculation unit 162 calculates the first axial offset voltage vofty1 and the second axial offset voltage vofty2 based on the electrical angle θe.

[0160] The displacement voltage calculation unit 163 acquires the first envelope ENV1 from the receiving circuit 95. The displacement voltage calculation unit 163 calculates the first axial displacement voltage vdy1 by subtracting the first axial offset voltage vofty1 from the first envelope ENV1. The displacement voltage calculation unit 163 also calculates the second axial displacement voltage vdy2 by subtracting the second axial offset voltage vofty2 from the second envelope ENV2.

[0161] The force calculation unit 72 includes a candidate lateral force calculation unit 165 and a selection unit 166. The candidate lateral force calculation unit 165 calculates a first lateral force Fy1 (corresponding to the "first axial force") based on a first axial displacement voltage vdy1, and calculates a second lateral force Fy2 (corresponding to the "second axial force") based on a second axial displacement voltage vdy2. For example, the candidate lateral force calculation unit 165 calculates the first lateral force Fy1 as the product of a first proportionality constant Ky1 (>0) and the first axial displacement voltage vdy1, and calculates the second lateral force Fy2 as the product of a second proportionality constant Ky2 (>0) and the second axial displacement voltage vdy2. Note that each lateral force Fy1, Fy2 may be calculated based on map information, similar to the seventh embodiment, etc.

[0162] In this embodiment, a first period L1 in which the absolute value of the first axial offset voltage vofty1 is greater than the absolute value of the second axial offset voltage vofty2, and a second period L2 in which the absolute value of the second axial offset voltage vofty2 is greater than the absolute value of the first axial offset voltage vofty1, are related to the electrical angle θe. Based on the electrical angle θe, the selection unit 166 calculates the first lateral force Fy1 as the lateral force Fy if it determines that the current timing is included in the first period L1, and calculates the second lateral force Fy2 as the lateral force Fy if it determines that the current timing is included in the second period L2. This improves the accuracy of the calculation of the lateral force Fy.

[0163] Figure 45 shows a flowchart of the calculation process for the lateral force Fy performed by the processing unit 70.

[0164] In step S30, the offset voltage calculation unit 162 calculates the first and second axial offset voltages vofty1 and vofty2 based on the electrical angle θe.

[0165] In step S31, the displacement voltage calculation unit 163 calculates the first axial displacement voltage vdy1 by subtracting the first axial offset voltage vofty1 from the acquired first envelope ENV1. Furthermore, the second axial displacement voltage vdy2 is calculated by subtracting the second axial offset voltage vofty2 from the acquired second envelope ENV2.

[0166] In step S32, the candidate lateral force calculation unit 165 calculates the first and second lateral forces Fy1 and Fy2 based on the first and second axial displacement voltages vdy1 and vdy2.

[0167] In step S33, the selection unit 166 calculates the first lateral force Fy1 as the lateral force Fy if it determines that the current timing is included in the first period L1, and calculates the second lateral force Fy2 as the lateral force Fy if it determines that the current timing is included in the second period L2.

[0168] Figure 46 shows the changes in each axial offset voltage vofty1, vofty2 and the first and second axial displacement voltages vdy1, vdy2 when the rotational speed of the rotor 30 is constant. In the example shown in Figure 46, a lateral force Fy acts on the wheel during the period from time t1 to t2. In the selection unit 166, if it is determined that the current timing is included in the first period L1, the first lateral force Fy1 is calculated as the lateral force Fy, and if it is determined that the current timing is included in the second period L2, the second lateral force Fy2 is calculated as the lateral force Fy.

[0169] According to the embodiment described above, the accuracy of calculating the lateral force Fy can be improved.

[0170] <Tenth Embodiment> The following describes the tenth embodiment, focusing on the differences from the ninth embodiment, with reference to the drawings. The method for calculating the lateral force Fy by the processing unit 70 is changed.

[0171] Figure 47 shows a block diagram of the processing unit 70 according to this embodiment.

[0172] The displacement calculation unit 71 includes a selection unit 167. Based on the electrical angle θe, the selection unit 167 determines that the current timing is included in the first period L1, and outputs the first axial displacement voltage vdy1 as the axial displacement voltage vdy to the force calculation unit 72. If it determines that the current timing is included in the second period L2, it outputs the second axial displacement voltage vdy2 as the axial displacement voltage vdy to the force calculation unit 72. The force calculation unit 72 calculates the lateral force Fy based on the input axial displacement voltage vdy. This improves the accuracy of the calculation of the lateral force Fy.

[0173] Figure 48 shows a flowchart of the calculation process for the lateral force Fy performed by the processing unit 70.

[0174] After step S31 is completed, in step S34, if the selection unit 167 determines that the current timing is included in the first period L1, it outputs the first axial displacement voltage vdy1 as the axial displacement voltage vdy to the force calculation unit 72. On the other hand, if it determines that the current timing is included in the second period L2, it outputs the second axial displacement voltage vdy2 as the axial displacement voltage vdy to the force calculation unit 72.

[0175] In step S35, the lateral force Fy is calculated based on the axial displacement voltage vdy.

[0176] According to the embodiment described above, the same effects as those of the ninth embodiment can be achieved.

[0177] <Embodiment 11> The following describes the 11th embodiment, focusing on the differences from the first embodiment, with reference to the drawings. In this embodiment, a method for calculating forces when a lateral force Fy and a vertical load Fz act simultaneously will be described.

[0178] Figure 49 shows a block diagram of the processing unit 70 according to this embodiment.

[0179] The displacement calculation unit 71 includes an offset voltage calculation unit 168 and a displacement voltage calculation unit 169.

[0180] The offset voltage calculation unit 162 calculates the axial offset voltage vofty and the vertical offset voltage voftz based on the electrical angle θe. The vertical offset voltage voftz is the second envelope ENV2 in the reference state. The average value of the vertical offset voltage voftz over one period is 0. Also, the zero-up cross timing and zero-down cross timing of the vertical offset voltage voftz are the same signals as the second envelope ENV1. The phase difference between the axial offset voltage vofty and the vertical offset voltage voftz is 90° in electrical angle.

[0181] The displacement voltage calculation unit 168 acquires the first and second envelopes ENV1 and ENV2 from the receiving circuit 95. The displacement voltage calculation unit 168 calculates the axial displacement voltage vdy by subtracting the axial offset voltage vofty from the first envelope ENV1.

[0182] The displacement voltage calculation unit 168 calculates the vertical correction voltage vcz based on the calculated axial displacement voltage vdy and electrical angle θe. The vertical correction voltage vcz is a signal that quantifies the effect of a lateral force on the second envelope ENV2 when a lateral force acts on the wheel. Specifically, it is a signal that shows the amount of change in the second envelope ENV2 due to the lateral force. The vertical correction voltage vcz fluctuates with the same period as the second envelope ENV2, and the average value of one period is 0. In addition, the zero-up cross timing and zero-down cross timing of the vertical correction voltage vcz are the same signals as those of the second envelope ENV1. That is, the phase difference between the vertical correction voltage vcz and the second envelope ENV2 is 0°. The displacement voltage calculation unit 169 increases the amplitude of the vertical correction voltage vcz as the axial displacement voltage vdy increases, for example.

[0183] The displacement voltage calculation unit 169 calculates the vertical displacement voltage vdz by subtracting the vertical offset voltage voftz and the vertical correction voltage vcz from the second envelope ENV2. By subtracting the vertical correction voltage vcz, the influence of lateral force on the vertical displacement voltage vdz can be eliminated. In other words, the vertical displacement voltage vdz becomes independent of lateral force.

[0184] The force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy and the vertical load Fz based on the vertical displacement voltage vdz. For example, the force calculation unit 72 calculates the vertical load Fz as the product of the proportionality constant Kz (>0) and the vertical displacement voltage vdz. Alternatively, the force calculation unit 72 may calculate the vertical load Fz based on the vertical displacement voltage vdz and map information relating the vertical displacement voltage vdz and the vertical load Fz.

[0185] Figure 50 shows a flowchart of the calculation process for the lateral force Fy and vertical load Fz performed by the processing unit 70.

[0186] In step S40, the offset voltage calculation unit 168 calculates the axial offset voltage vofty and the vertical offset voltage voftz based on the electrical angle θe.

[0187] In step S41, the displacement voltage calculation unit 169 calculates the axial displacement voltage vdy by subtracting the axial offset voltage vofty from the acquired first envelope ENV1.

[0188] In step S42, the displacement voltage calculation unit 169 calculates the vertical correction voltage vcz based on the axial displacement voltage vdy.

[0189] In step S43, the displacement voltage calculation unit 169 calculates the vertical displacement voltage vdz by subtracting the vertical offset voltage voftz and the vertical correction voltage vcz from the second envelope ENV2.

[0190] In step S44, the force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy and the vertical load Fz based on the vertical displacement voltage vdz.

[0191] According to the embodiment described above, the calculation accuracy of the lateral force Fy and the vertical load Fz can be improved.

[0192] <Twelfth Embodiment> The following describes the twelfth embodiment, focusing on the differences from the eleventh embodiment, with reference to the drawings. In this embodiment, the longitudinal load Fx is calculated instead of the vertical load Fz. For this reason, the configuration described in the fourth embodiment (see Figure 34) is used for the race section 80 and the detection unit 90.

[0193] Figure 51 shows a block diagram of the processing unit 70 according to this embodiment.

[0194] The displacement calculation unit 71 includes an offset voltage calculation unit 170 and a displacement voltage calculation unit 171.

[0195] The offset voltage calculation unit 170 calculates the axial offset voltage vofty and the longitudinal offset voltage vofx based on the electrical angle θe. The longitudinal offset voltage vofx is the second envelope ENV2 in the reference state. The average value of the longitudinal offset voltage vofx over one period is 0. In addition, the zero-up cross timing and zero-down cross timing of the longitudinal offset voltage vofx are the same signals as the second envelope ENV1. The phase difference between the axial offset voltage vofty and the longitudinal offset voltage vofx is 90° in electrical angle.

[0196] The displacement voltage calculation unit 171 acquires the first and second envelopes ENV1 and ENV2 from the receiving circuit 95. The displacement voltage calculation unit 171 calculates the axial displacement voltage vdy by subtracting the axial offset voltage vofty from the first envelope ENV1.

[0197] The displacement voltage calculation unit 171 calculates the vehicle length direction correction voltage vcx based on the calculated axial displacement voltage vdy and electrical angle θe. The vehicle length direction correction voltage vcx is a signal that quantifies the effect of lateral force on the second envelope ENV2 when a lateral force acts on the wheel, and specifically indicates the amount of change in the second envelope ENV2 due to the lateral force. The vehicle length direction correction voltage vcx fluctuates with the same period as the second envelope ENV2, and the average value of one period is 0. In addition, the zero-up cross timing and zero-down cross timing of the vehicle length direction correction voltage vcx are the same signals as those of the second envelope ENV1. In other words, the phase difference between the vehicle length direction correction voltage vcx and the second envelope ENV2 is 0°. For example, the displacement voltage calculation unit 171 increases the amplitude of the vehicle length direction correction voltage vcx as the axial displacement voltage vdy increases.

[0198] The displacement voltage calculation unit 171 calculates the longitudinal displacement voltage vdx by subtracting the longitudinal offset voltage voftx and the vehicle length correction voltage vcx from the second envelope ENV2. By subtracting the vehicle length correction voltage vcx, the influence of lateral force on the longitudinal displacement voltage vdx can be eliminated. In other words, the longitudinal displacement voltage vdx becomes independent of lateral force.

[0199] The force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy and the longitudinal load Fx based on the longitudinal displacement voltage vdx. For example, the force calculation unit 72 calculates the longitudinal load Fx as the product of the proportionality constant Kx (>0) and the longitudinal displacement voltage vdx. Alternatively, the force calculation unit 72 may calculate the longitudinal load Fx based on the longitudinal displacement voltage vdx and map information relating the longitudinal displacement voltage vdx and the longitudinal load Fx.

[0200] Figure 52 shows a flowchart of the calculation process for the lateral force Fy and longitudinal load Fx performed by the processing unit 70.

[0201] In step S50, the offset voltage calculation unit 170 calculates the axial offset voltage vofty and the longitudinal offset voltage vofx based on the electrical angle θe.

[0202] In step S51, the displacement voltage calculation unit 171 calculates the axial displacement voltage vdy by subtracting the axial offset voltage vofty from the acquired first envelope ENV1.

[0203] In step S52, the displacement voltage calculation unit 171 calculates the vehicle length correction voltage vcx based on the axial displacement voltage vdy.

[0204] In step S53, the displacement voltage calculation unit 171 calculates the longitudinal displacement voltage vdx by subtracting the longitudinal offset voltage voftx and the vehicle length correction voltage vcx from the second envelope ENV2.

[0205] In step S54, the force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy and the longitudinal load Fx based on the longitudinal displacement voltage vdx.

[0206] According to the embodiment described above, the calculation accuracy of the lateral force Fy and the longitudinal load Fx can be improved.

[0207] <13th Embodiment> The following describes the 13th embodiment, focusing on the differences from the 7th embodiment, with reference to the drawings. In this embodiment, as shown in Figure 53, the first envelope ENV1 used in the displacement voltage calculation unit 161 is subjected to a low-pass filter.

[0208] Figure 53 shows a block diagram of the processing unit 70 according to this embodiment.

[0209] The displacement calculation unit 71 includes a filter unit 172 and a parameter acquisition unit 173. The parameter acquisition unit 173 acquires vehicle speed information, tire pressure information of the wheels 13 that make up the vehicle, and vehicle weight information. The vehicle speed information, tire pressure information, and vehicle weight information are input to the filter unit 172.

[0210] The filter unit 172 acquires the first envelope ENV1 from the receiving circuit 95, applies a low-pass filter to the acquired first envelope ENV1, and outputs it to the displacement voltage calculation unit 161. In the displacement voltage calculation unit 161, the first envelope ENV1, which has been subjected to a low-pass filter to remove high-frequency noise components, is used to calculate the axial displacement voltage vdy. This improves the accuracy of the calculation of the axial displacement voltage vdy.

[0211] As shown in Figure 54, the filter unit 172 has a cutoff frequency fcutoff. In this embodiment, as shown in Figure 55, the filter unit 172 modifies its low-pass filter characteristics so that the cutoff frequency fcutoff becomes lower as the vehicle speed decreases, the air pressure decreases, or the vehicle weight increases.

[0212] The larger the contact area of ​​the tire 13 with the road surface, the lower the frequency of the high-frequency noise components mixed into the first envelope ENV1 tends to be. Therefore, the larger the contact area of ​​the tire 13, the lower the cutoff frequency fcutoff can be, thereby appropriately removing the high-frequency noise components from the first envelope ENV1. Here, the contact area of ​​the tire 13 increases as the vehicle speed decreases, the air pressure decreases, and the vehicle weight increases.

[0213] According to the embodiment described above, the calculation accuracy of the axial displacement voltage vdy can be improved, and consequently, the calculation accuracy of the lateral force Fy can be improved.

[0214] <Modified form of the 13th embodiment> The first and second envelopes ENV1 and ENV2 input to the displacement voltage calculation unit 163 shown in Figures 41, 44, and 47, the first and second envelopes ENV1 and ENV2 input to the displacement voltage calculation unit 169 shown in Figure 49, and the first and second envelopes ENV1 and ENV2 input to the displacement voltage calculation unit 171 shown in Figure 51 may also be subjected to low-pass filtering by the filter unit 172.

[0215] <14th Embodiment> The following describes the 14th embodiment, focusing on the differences from the 7th and 13th embodiments, etc., with reference to the drawings. In this embodiment, the method for calculating the lateral force Fy is changed.

[0216] Figure 56 shows a block diagram of the processing unit 70 according to this embodiment.

[0217] The displacement calculation unit 71 includes a maximum value calculation unit 174 (corresponding to the "amplitude information calculation unit") and a displacement voltage calculation unit 175. The maximum value calculation unit 174 calculates the absolute amplitude value vmaxy (corresponding to the "amplitude information voltage") of the first envelope ENV1 based on the electrical angle θe and the low-pass filtered first envelope ENV1. The maximum value calculation unit 174 calculates the absolute amplitude value vmaxy, for example, every 1 / 2 electrical angle period, every 1 electrical angle period, or every N electrical angle periods (where N is an integer of 2 or more).

[0218] The displacement voltage calculation unit 175 calculates the axial displacement voltage vdy by subtracting the reference amplitude value vmaxofty (corresponding to the "reference voltage") from the calculated absolute amplitude value vmaxy. The reference amplitude value vmaxofty is the absolute amplitude value of the first envelope ENV1 in the reference state.

[0219] If the current state is the reference state, the absolute amplitude value vmaxy and the reference amplitude value vmaxofty will be the same, and the axial displacement voltage vdy will be 0. On the other hand, if the current state deviates from the reference state, the absolute amplitude value vmaxy and the reference amplitude value vmaxofty will be different, and the axial displacement voltage vdy will be a value other than 0. The reference amplitude value vmaxofty may be, for example, a value that was adapted during the design of the vehicle detection device, or a value measured during the shipment inspection of the vehicle detection device. Furthermore, since the absolute amplitude value vmaxy may change depending on the temperature of the detection unit 90, etc., it may be corrected based on the detection value of the temperature sensor that detects that temperature.

[0220] The force calculation unit 72 calculates the lateral force Fy based on the axial displacement voltage vdy.

[0221] Figure 57 shows the changes in the absolute amplitude vmaxy and the reference amplitude vmaxofty when the rotational speed of the rotor 30 is constant. The axial offset voltage vofty is also shown in Figure 57. In the example shown in Figure 57, a lateral force Fy acts on the wheel during the period from time t1 to t2.

[0222] The maximum value calculation unit 174 determines the timing at which the value of the first envelope ENV1 is maximum in each period of the first envelope ENV1 based on the electrical angle θe. The maximum value calculation unit 174 calculates the absolute amplitude value vmaxy based on the electrical angle θe and the first envelope ENV1. In the example shown in Figure 57, the absolute amplitude value vmaxy is updated every electrical angle period. The maximum value calculation unit 174 calculates the axial displacement voltage vdy by subtracting the reference amplitude value vmaxofty from the absolute amplitude value vmaxy. The axial displacement voltage vdy is also updated every electrical angle period.

[0223] The lateral force Fy can also be calculated using the embodiment described above.

[0224] <Modified form of the 14th embodiment> • The filter section 172 does not necessarily have to be provided.

[0225] The maximum value calculation unit 174 may calculate the time integral value of the first envelope ENV1 over a predetermined period (corresponding to the "amplitude information voltage") instead of the absolute amplitude value vmaxy. The predetermined period is, for example, every 1 / 2 electrical angle period, every 1 electrical angle period, or every N electrical angle periods (where N is an integer of 2 or more).

[0226] The maximum value calculation unit 174 calculates the axial displacement voltage vdy by subtracting the reference integral value (corresponding to the "reference voltage") from the calculated time integral value. The reference integral value is the time integral value of the first envelope ENV1 over a predetermined period in the reference state.

[0227] If the current state is the reference state, the time integral value and the reference integral value will be the same, and the axial displacement voltage vdy will be 0. On the other hand, if the current state deviates from the reference state, the time integral value and the reference integral value will be different, and the axial displacement voltage vdy will be a value other than 0.

[0228] <15th Embodiment> The following describes the 15th embodiment, focusing on the differences from the 7th to 14th embodiments, with reference to the drawings. In this embodiment, the mounting positions of the displacement calculation unit 71, the force calculation unit 72, and the angle calculation unit 73 will be described.

[0229] Figure 58 shows an overview of the system installed in vehicle 300.

[0230] Vehicle 300 is equipped with an inverter 310, a battery 320, and a motor ECU 330. The inverter 310 is equipped with a series connection of upper and lower arm switches for the number of phases (for example, three phases). The motor control unit 331 of the motor ECU 330 converts the DC power from the battery 320 into AC power by controlling the switching of the upper and lower arm switches and supplies it to the stator winding 41 of the in-wheel motor 20. As a result, the drive wheels of vehicle 300 rotate and vehicle 300 moves.

[0231] As shown in Figure 59, the circuit unit 93 may be equipped with a displacement calculation unit 71, a force calculation unit 72, and an angle calculation unit 73. More specifically, the common control board of the circuit unit 93 is equipped with the displacement calculation unit 71, the force calculation unit 72, the angle calculation unit 73, the excitation circuit 94, and the receiving circuit 95. The lateral force Fy etc. calculated by the force calculation unit 72 is input to the motor ECU 330.

[0232] The configuration shown in Figure 59 makes it easier to synchronize with the electrical angle θe when calculating the axial offset voltage, etc. This improves the accuracy of the axial displacement voltage calculation, and consequently, the accuracy of the lateral force Fy calculation.

[0233] The axial displacement voltage can be a signal with a very small absolute value. In this case, if the force calculation unit 72 is provided in the motor ECU 330, noise will be introduced into the axial displacement voltage when it is transmitted from the circuit unit 93 to the motor ECU 330, reducing the signal-to-noise ratio of the axial displacement voltage. As a result, the accuracy of the calculation of the lateral force Fy may decrease. In contrast, with the configuration shown in Figure 59, the calculation process of the lateral force Fy is completed in the circuit unit 93, thus improving the accuracy of the calculation of the lateral force Fy.

[0234] Alternatively, the configurations shown in Figures 60 to 62 can be used instead of the configuration shown in Figure 59. The configuration shown in Figure 60 is one in which the force calculation unit 72 is provided in the motor ECU 330. The configuration shown in Figure 61 is one in which the angle calculation unit 73 is provided in the motor ECU 330. The configuration shown in Figure 62 is one in which the displacement calculation unit 71, the force calculation unit 72, and the angle calculation unit 73 are provided in the motor ECU 330.

[0235] By providing at least one of the displacement calculation unit 71, the force calculation unit 72, and the angle calculation unit 73 in the motor ECU 330, the control board of the circuit unit 93 can be miniaturized.

[0236] <Other Embodiments> Furthermore, each of the above embodiments may be implemented with the following modifications.

[0237] In the first to third, fifth, and sixth embodiments, the detection unit 90 may be positioned opposite the lower end of the race portion 80 in the axial direction. Alternatively, the detection unit 90 may be positioned on the disc portion 12 side relative to the race portion 80.

[0238] A non-metallic part, such as synthetic resin, may be provided in the notch 82 in Figure 2 or the opening 84 in Figure 24. In this case, a configuration in which metal and non-metallic parts are alternately provided in the circumferential direction can be realized in the race portion, and the rotation angle can be detected in the same manner as in the first embodiment.

[0239] ·The in-wheel motor 20 shown in FIG. 1 does not have to include the race portion 80. In this case, for example, in the flat plate portion 33 of the in-wheel motor 20, a shielding portion and an opening may be alternately formed in the circumferential direction in a portion facing the coil portion 92 in the axial direction, or a concave portion and a convex portion may be alternately formed in the circumferential direction. In this case, the flat plate portion 33 corresponds to the "rotating portion for detection".

[0240] ·In the first, second, fifth, and sixth embodiments, the receiving coil formed on the substrate 91 may be one.

[0241] ·In the seventh to fourteenth embodiments, instead of the first and second receiving coils 110 and 120 shown in FIG. 7, the first and second receiving coils 130 and 140 shown in FIG. 29 described in the second embodiment may be used.

[0242] ·In the eighth to twelfth embodiments, the position of the radially outer end of the second receiving coil 120 may be on the second concentric circle C2, and the position of the radially inner end of the second receiving coil 120 may be on the third concentric circle C3 (see FIG. 12). In this case, the influence of the vertical load Fz does not affect the second envelope ENV2 based on the second output voltage signal v2 of the second receiving coil 120.

[0243] ·The sensor for detecting displacement is not limited to an eddy current type sensor, and for example, a sensor that detects displacement with laser light may be used.

[0244] ·The bearing is not limited to one in which the outer ring 51 is fixed to the stator base portion 42 and the inner ring 52 is fixed to the wheel 10, and a bearing in which the outer ring is fixed to the wheel 10 and the inner ring is fixed to the stator base portion 42 may be used. In this case, the inner ring corresponds to the "first bearing member", and the outer ring corresponds to the "second bearing member".

[0245] ·The motor is not limited to one housed in the wheel, and for example, an on-vehicle motor provided on the vehicle body may be used. Also, the motor is not limited to an outer rotor type, and an inner rotor type may be used.

[0246] The detection unit 90 may be provided in a state where at least a portion of it is in contact with the race portion 80.

[0247] The detection device is not limited to wheels; it can be applied to any rotating body, such as aircraft propellers, ship propellers, internal combustion engine rotating parts (e.g., crankshafts), or power generation turbines. Furthermore, the rotating body is not limited to those used with its axial direction horizontal; it may also be used with its axial direction in a direction other than horizontal (e.g., vertical).

[0248] The control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. Alternatively, the control unit and its method described herein may be implemented by a dedicated computer provided by configuring a processor by one or more dedicated hardware logic circuits. Alternatively, the control unit and its method described herein may be implemented by one or more dedicated computers configured by a combination of a processor and memory programmed to perform one or more functions and a processor configured by one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by the computer on a computer-readable non-transitional tangible recording medium.

[0249] The following describes the characteristic configurations extracted from each of the embodiments described above. [Configuration 1] Base part (42) and The bearing (50) comprises an outer ring member (51), an inner ring member (52), and rolling elements (53) provided between the outer ring member and the inner ring member, and rotatably supports the rotating body with respect to the base portion. Of the outer ring member and the inner ring member, the first bearing member (52) is fixed to the rotating body, and the other, the second bearing member (51), is fixed to the base portion. A disc-shaped detection rotating part (80, 83, 86) is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit (90) provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction, A detection device equipped with the following features. [Configuration 2] Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, an annular detection target part (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing is formed. The displacement detection unit is Two planar receiving coils (110, 120, 130, 140) are fixed to the base portion and positioned opposite the upper or lower end of the detection target portion in the axial direction, and extending in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, Each of the receiving coils is configured such that a voltage is induced when the excitation voltage is supplied to the excitation coil. In a plan view of each of the receiving coils, the radial outer end of one of the receiving coils (120, 140) protrudes from the radial outer end (81a) of the detection target portion. The radial positions of the outer ends of each of the receiving coils are different in the radial direction. The detection device according to configuration 1, wherein each receiving coil outputs a voltage signal corresponding to the axial displacement and the displacement in a direction perpendicular to the axial direction. [Configuration 3] Each of the aforementioned receiving coils (110, 120) is, A first part (110A, 120A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second part (110B, 120B) which generates a voltage of the second polarity, opposite to the first polarity, across both ends of the receiving coil, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion (120A) is provided on one side of the circumferential center of the receiving coil and the second portion (120B) is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first portion (110A) and the second portion (110B) on one side and the first portion and the second portion on the other side are configured symmetrically with respect to the center of the receiving coil in the circumferential direction. It has become so The circumferential dimensions of each of the receiving coils are the same, The detection device according to configuration 2, wherein the radial dimension of the receiving coil (120) that protrudes from the outer end of each of the receiving coils is larger than the radial dimension of the remaining receiving coils. [Structure 4] Each of the aforementioned receiving coils (130, 140) is, A first part (130A, 140A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second part (130B, 140B) which generates a voltage of the second polarity, opposite to the first polarity, across both ends of the receiving coil, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion (140A) is provided on one side of the circumferential center of the receiving coil and the second portion (140B) is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the reception coil, the first portions (130A) and the second portions (130B) on one side with respect to the center in the circumferential direction of the reception coil and the first portions and the second portions on the other side are symmetrically configured with respect to the center. and the circumferential dimensions of the respective reception coils are the same, and the radial dimensions of the respective reception coils are the same. The detection device according to Configuration 2. [Configuration 5] At a position away from the bearing in the radial direction among the detection rotating portions, annular detection target portions (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing are formed. The displacement detection unit is fixed to the base portion and provided at a position facing the end portion of the detection target portion in the axial direction, and includes a planar reception coil (150) extending in a direction intersecting the axial direction, an excitation coil (100) to which an alternating excitation voltage is supplied, [[ID=1)8]]and has The reception coil has a first portion (150A) that generates a voltage of a first polarity at both ends of the reception coil when the excitation voltage is supplied to the excitation coil, and a second portion (150B) that generates a voltage of a second polarity opposite to the first polarity at both ends of the reception coil when the excitation voltage is supplied to the excitation coil, and has The reception coil In a plan view of the reception coil, the first portion is provided on one side with respect to the center in the circumferential direction of the reception coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the reception coil, the first portions and the second portions on one side with respect to the center in the circumferential direction of the reception coil and the first portions and the second portions on the other side are symmetrically configured with respect to the center. and The circumferential dimensions of the first portion and the circumferential dimensions of the second portion are the same. Of the first and second parts, the radial dimension of one is larger than the radial dimension of the other. In a plan view of the receiving coil, of the first and second portions, the radial outer end of the portion with the larger radial dimension protrudes from the radial outer end (81a) of the portion to be detected. The radial positions of the outer ends of the first and second portions are different, The detection device according to configuration 1, wherein the receiving coil outputs a voltage signal corresponding to the axial displacement and the displacement in a direction perpendicular to the axial direction. [Composition 6] The rotating body is positioned such that its center of rotation is horizontal. A detection device according to any one of configurations 2 to 5, comprising a displacement calculation unit (71) that calculates the axial displacement of the detection rotating unit and the vertical displacement of the detection rotating unit based on the output voltage signal of the receiving coil. [Composition 7] The detection device according to configuration 6, comprising a force calculation unit (72) that calculates the axial force acting on the rotating body based on the calculated axial displacement, and calculates the vertical load acting on the rotating body based on the calculated vertical displacement. [Structure 8] Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, an annular detection target part (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing is formed. The displacement detection unit is A planar receiving coil (110, 120, 130, 140, 150) is fixed to the base portion and positioned opposite the detection target portion in the axial direction, and extends in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, The receiving coil is A first portion (110A, 120A, 130A, 140A, 150A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second portion (110B, 120B, 130B, 140B, 150B) which generates a voltage of the second polarity opposite to the first polarity at both ends, It has, The receiving coil is In a plan view of the receiving coil, the first portion is provided on one side of the circumferential center of the receiving coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first and second portions on one side and the first and second portions on the other side are configured symmetrically with respect to the circumferential center of the receiving coil. It has become so The receiving coil is provided so as to straddle the horizontal axis passing through the rotational axis of the detection rotating part, The detection device according to configuration 1, wherein the receiving coil outputs a voltage signal corresponding to the axial displacement of the detection rotating part and the displacement in a direction perpendicular to the axial direction. [Composition 9] The rotating body is positioned such that its center of rotation is horizontal. The detection device according to configuration 8, further comprising a displacement calculation unit (71) that calculates the axial displacement of the detection rotating part and the front-rear displacement of the detection rotating part, which is perpendicular to the axial and vertical directions, respectively, based on the output voltage signal of the receiving coil. [Configuration 10] The detection device according to configuration 9, comprising a force calculation unit (72) that calculates the axial force acting on the rotating body based on the calculated axial displacement, and calculates the longitudinal force acting on the rotating body based on the calculated longitudinal displacement. [Composition 11] The rotating body is positioned such that its center of rotation is horizontal. Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, an annular detection target part (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing is formed. The displacement detection unit is Two planar receiving coils (110, 120, 130, 140) are fixed to the base portion and positioned opposite the detection target portion in the axial direction, and extending in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, Each of the aforementioned receiving coils is, A first portion (110A, 120A, 130A, 140A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, a second portion (110B, 120B, 130B, 140B) generates a voltage with a second polarity opposite to the first polarity at both ends of the receiving coil, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion is provided on one side of the circumferential center of the receiving coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first and second portions on one side and the first and second portions on the other side are configured symmetrically with respect to the circumferential center of the receiving coil. It has become so Each of the receiving coils is positioned to straddle a horizontal axis passing through the rotational axis of the detection rotating unit. The detection device according to configuration 1, wherein each receiving coil outputs a voltage signal corresponding to the axial displacement of the detection rotating part, and a voltage signal corresponding to the displacement in the front-rear direction, which is perpendicular to the axial and vertical directions of the detection rotating part, respectively. [Composition 12] A signal acquisition unit (161) acquires the envelope (ENV1) of the output voltage signal (v1) of the receiving coil, Based on the rotation angle information of the detection rotating part, an offset voltage calculation unit (160) calculates the axial offset voltage (vofty), which is the envelope in the reference state, A displacement voltage calculation unit (161) calculates the axial displacement voltage (vdy) by subtracting the calculated axial offset voltage from the acquired envelope, A detection device comprising any one of configurations 3, 4, or 11. [Composition 13] The detection device according to configuration 12, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage. [Composition 14] The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A total voltage calculation unit (164) calculates a total voltage (vdty) by adding the absolute value of the calculated first axial displacement voltage and the absolute value of the calculated second axial displacement voltage, A detection device comprising any one of configurations 3, 4, or 11. [Composition 15] The detection device according to configuration 14, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated total voltage. [Composition 16] The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A force calculation unit (72) calculates a first axial force (Fy1), which is the axial force acting on the rotating body, based on the calculated first axial displacement voltage, and calculates a second axial force (Fy2), which is the axial force acting on the rotating body, based on the calculated second axial displacement voltage. Equipped with, The detection device according to any one of configurations 3, 4, and 11, wherein the force calculation unit calculates the first axial force as the axial force acting on the rotating body during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the second axial force as the axial force acting on the rotating body during the period when the second axial offset voltage is greater than the first axial offset voltage. [Composition 17] The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A force calculation unit (72) calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the second axial offset voltage is greater than the first axial offset voltage, A detection device comprising any one of configurations 3, 4, or 11. [Composition 18] The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (169) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. Based on the rotation angle information of the detection rotating unit, an offset voltage calculation unit (168) calculates the axial offset voltage (vofty), which is the first envelope in the reference state, and the vertical offset voltage (voftz), which is the second envelope in the reference state. Displacement voltage calculation unit (169), Equipped with, The displacement voltage calculation unit is, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a vertical correction voltage (vcz) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. The detection device according to configuration 3 or 4, which calculates the vertical displacement voltage (vdz) by subtracting the calculated vertical offset voltage and the calculated vertical correction voltage from the acquired second envelope. [Composition 19] The detection device according to configuration 18, comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage, and calculates the vertical load (Fz) acting on the rotating body based on the calculated vertical displacement voltage. [Configuration 20] The rotating body is positioned such that its center of rotation is horizontal. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (171) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (170) calculates the axial offset voltage (vofty), which is the first envelope in the reference state, and the longitudinal offset voltage (vofx), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, Displacement voltage calculation unit (171), Equipped with, The displacement voltage calculation unit is, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a longitudinal correction voltage (vcx) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. The vehicle detection device according to configuration 11, which calculates the longitudinal displacement voltage (vdx) by subtracting the calculated longitudinal offset voltage and the calculated longitudinal correction voltage from the acquired second envelope. [Composition 21] The detection device according to configuration 20, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage, and calculates the longitudinal force (Fx) acting on the rotating body based on the calculated longitudinal displacement voltage. [Composition 22] The system includes a filter section (172) that applies a low-pass filter to the acquired envelope, The detection device according to any one of configurations 12 to 21, wherein the envelope that has undergone the low-pass filter processing is input to the displacement voltage calculation unit. [Composition 23] A signal acquisition unit (172) acquires the envelope of the output voltage signal (v1) of the receiving coil, An amplitude information calculation unit (174) calculates the amplitude information voltage (vmaxy) of the envelope based on the rotation angle information of the detection rotating unit and the acquired envelope, A displacement voltage calculation unit (175) calculates the axial displacement voltage (vdy) by subtracting the reference voltage (vmaxofty), which is the amplitude information voltage in the reference state, from the calculated amplitude information voltage, A detection device comprising any one of configurations 3, 4, or 11. [Composition 24] The detection device according to configuration 23, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage. [Composition 25] The detection target unit is, A configuration in which metal parts (81) and parts (82) that penetrate in the axial direction are alternately provided in the circumferential direction. A configuration in which recesses (88) that are recessed in the axial direction and protrusions (87) that project in the axial direction relative to the recesses are alternately provided in the circumferential direction, or A configuration in which metal parts and non-metal parts are alternately provided in the circumferential direction. It has become so A detection device according to any one of configurations 2 to 24, comprising an angle calculation unit (73) that calculates the rotation angle of the detection rotating unit based on the output voltage signal of the receiving coil. [Composition 26] In a program applied to the detection device described in any one of configurations 3, 4, or 11, The computer (70) of the aforementioned detection device, A signal acquisition process to acquire the envelope of the output voltage signal (v1) of the receiving coil, Based on the rotation angle information of the detection rotating part, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the envelope in the reference state, A displacement voltage calculation process is performed to calculate the axial displacement voltage (vdy) by subtracting the calculated axial offset voltage from the acquired envelope. A program that executes something. [Composition 27] In a program applied to the detection device described in any one of configurations 3, 4, or 11, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A total voltage calculation process that calculates the total voltage (vdty) by adding the absolute value of the calculated first axial displacement voltage and the absolute value of the calculated second axial displacement voltage, A program that executes something. [Composition 28] In a program applied to the detection device described in any one of configurations 3, 4, or 11, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A force calculation process that calculates a first axial force (Fy1), which is the axial force acting on the rotating body, based on the calculated first axial displacement voltage, and calculates a second axial force (Fy2), which is the axial force acting on the rotating body, based on the calculated second axial displacement voltage, Make it run, A program that, in the force calculation process, calculates the first axial force as the axial force acting on the rotating body during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the second axial force as the axial force acting on the rotating body during the period when the second axial offset voltage is greater than the first axial offset voltage. [Composition 29] In a program applied to the detection device described in any one of configurations 3, 4, or 11, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A force calculation process that calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the second axial offset voltage is greater than the first axial offset voltage, A program that executes something. [Composition 30] In a program applied to the detection device described in configuration 3 or 4, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the first envelope in the reference state, and the vertical offset voltage (voftz), which is the second envelope in the reference state. Displacement voltage calculation process, Make it run, In the displacement voltage calculation process, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a vertical correction voltage (vcz) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. A program that calculates the vertical displacement voltage (vdz) by subtracting the calculated vertical offset voltage and the calculated vertical correction voltage from the acquired second envelope. [Composition 31] In the program applied to the detection device described in configuration 11, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The rotating body is positioned such that its center of rotation is horizontal. The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the first envelope in the reference state, and the longitudinal offset voltage (vofx), which is the second envelope in the reference state. Displacement voltage calculation process, Make it run, In the displacement voltage calculation process, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a longitudinal correction voltage (vcx) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. A program that calculates the longitudinal displacement voltage (vdx) by subtracting the calculated longitudinal offset voltage and the calculated longitudinal correction voltage from the acquired second envelope. [Composition 32] In a program applied to the detection device described in any one of configurations 3, 4, or 11, The computer provided in the aforementioned detection device, A signal acquisition process to acquire the envelope (ENV1) of the output voltage signal (v1) of the receiving coil, An amplitude information calculation process is performed to calculate the amplitude information voltage (vmaxy) of the envelope based on the rotation angle information of the detection rotating part and the acquired envelope. A displacement voltage calculation process calculates the axial displacement voltage (vdy) by subtracting the reference voltage (vmaxofty), which is the amplitude information voltage in the reference state, from the calculated amplitude information voltage. A program that executes something. [Explanation of Symbols]

[0250] 20...In-wheel motor, 30...Rotor, 40...Stator, 50...Bearing, 80...Race section, 90...Detection unit.

Claims

1. Base part (42) and The bearing (50) comprises an outer ring member (51), an inner ring member (52), and rolling elements (53) provided between the outer ring member and the inner ring member, and rotatably supports the rotating body with respect to the base portion. Of the outer ring member and the inner ring member, the first bearing member (52) is fixed to the rotating body, and the other, the second bearing member (51), is fixed to the base portion. A disc-shaped detection rotating part (80, 83, 86) is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit (90) provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction, Equipped with, Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, annular detection target parts (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing are formed. The displacement detection unit is Two planar receiving coils (110, 120, 130, 140) are fixed to the base portion and positioned opposite the upper or lower end of the detection target portion in the axial direction, and extending in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, Each of the receiving coils is configured such that a voltage is induced when the excitation voltage is supplied to the excitation coil. In a plan view of each of the receiving coils, the radial outer end of one of the receiving coils (120, 140) protrudes from the radial outer end (81a) of the detection target portion. The radial positions of the outer ends of each of the receiving coils are different in the radial direction. Each receiving coil is a detection device that outputs a voltage signal corresponding to the axial displacement and the displacement in a direction perpendicular to the axial direction.

2. Each of the aforementioned receiving coils (110, 120) is A first portion (110A, 120A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second portion (110B, 120B) which generates a voltage of a second polarity opposite to the first polarity at both ends, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion (120A) is provided on one side of the circumferential center of the receiving coil and the second portion (120B) is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first portion (110A) and the second portion (110B) on one side and the first portion and the second portion on the other side are configured symmetrically with respect to the center of the receiving coil in the circumferential direction. It has become so The circumferential dimensions of each of the receiving coils are the same, The detection device according to claim 1, wherein the radial dimension of the receiving coil (120) that protrudes from the outer end of each of the receiving coils is larger than the radial dimension of the remaining receiving coils.

3. Each of the aforementioned receiving coils (130, 140) is A first portion (130A, 140A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second portion (130B, 140B) which generates a voltage of a second polarity opposite to the first polarity at both ends, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion (140A) is provided on one side of the circumferential center of the receiving coil and the second portion (140B) is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first portion (130A) and the second portion (130B) on one side and the first portion and the second portion on the other side are configured symmetrically with respect to the center of the receiving coil in the circumferential direction. It has become so The circumferential dimensions of each of the receiving coils are the same, The detection device according to claim 1, wherein the radial dimensions of each of the receiving coils are the same.

4. Base portion (42) and The bearing (50) comprises an outer ring member (51), an inner ring member (52), and rolling elements (53) provided between the outer ring member and the inner ring member, and rotatably supports the rotating body with respect to the base portion. Of the outer ring member and the inner ring member, the first bearing member (52) is fixed to the rotating body, and the other, the second bearing member (51), is fixed to the base portion. A disc-shaped detection rotating part (80, 83, 86) is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit (90) provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction, Equipped with, Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, annular detection target parts (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing are formed. The displacement detection unit is A planar receiving coil (150) is fixed to the base portion and positioned opposite the end of the detection target portion in the axial direction, and extends in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, The receiving coil is A first portion (150A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, A second portion (150B) generates a voltage with a second polarity opposite to the first polarity at both ends of the receiving coil when the excitation voltage is supplied to the excitation coil, It has, The receiving coil is In a plan view of the receiving coil, the first portion is provided on one side of the circumferential center of the receiving coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first and second portions on one side and the first and second portions on the other side are configured symmetrically with respect to the circumferential center of the receiving coil. It has become so The circumferential dimensions of the first portion and the circumferential dimensions of the second portion are the same. Of the first and second parts, the radial dimension of one is larger than the radial dimension of the other. In a plan view of the receiving coil, of the first and second portions, the radial outer end of the portion with the larger radial dimension protrudes from the radial outer end (81a) of the portion to be detected. The radial positions of the outer ends of the first and second portions are different, The receiving coil is a detection device that outputs a voltage signal corresponding to the axial displacement and the displacement in a direction perpendicular to the axial direction.

5. The rotating body is positioned such that its center of rotation is horizontal. The detection device according to any one of claims 1 to 4, further comprising a displacement calculation unit (71) that calculates the axial displacement of the detection rotating unit and the vertical displacement of the detection rotating unit based on the output voltage signal of the receiving coil.

6. The detection device according to claim 5, further comprising a force calculation unit (72) that calculates the axial force acting on the rotating body based on the calculated axial displacement, and calculates the vertical load acting on the rotating body based on the calculated vertical displacement.

7. Base portion (42) and The bearing (50) comprises an outer ring member (51), an inner ring member (52), and rolling elements (53) provided between the outer ring member and the inner ring member, and rotatably supports the rotating body with respect to the base portion. Of the outer ring member and the inner ring member, the first bearing member (52) is fixed to the rotating body, and the other, the second bearing member (51), is fixed to the base portion. A disc-shaped detection rotating part (80, 83, 86) is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit (90) provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction, Equipped with, Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, annular detection target parts (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing are formed. The displacement detection unit is A planar receiving coil (110, 120, 130, 140, 150) is fixed to the base portion and positioned opposite the detection target portion in the axial direction, and extends in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, The receiving coil is A first portion (110A, 120A, 130A, 140A, 150A) that generates a voltage of first polarity across both ends of the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second portion (110B, 120B, 130B, 140B, 150B) which generates a voltage of the second polarity opposite to the first polarity at both ends, It has, The receiving coil is In a plan view of the receiving coil, the first portion is provided on one side of the circumferential center of the receiving coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first and second portions on one side and the first and second portions on the other side are configured symmetrically with respect to the circumferential center of the receiving coil. It has become so The receiving coil is provided so as to straddle the horizontal axis passing through the rotational axis of the detection rotating part, The receiving coil is a detection device that outputs a voltage signal corresponding to the axial displacement of the detection rotating part and the displacement in a direction perpendicular to the axial direction.

8. The rotating body is positioned such that its center of rotation is horizontal. The detection device according to claim 7, further comprising a displacement calculation unit (71) that calculates the axial displacement of the detection rotating part and the front-rear displacement of the detection rotating part, which is perpendicular to the axial and vertical directions, respectively, based on the output voltage signal of the receiving coil.

9. The detection device according to claim 8, further comprising a force calculation unit (72) that calculates the axial force acting on the rotating body based on the calculated axial displacement, and calculates the forward / backward force acting on the rotating body based on the calculated forward / backward displacement.

10. Base portion (42) and The bearing (50) comprises an outer ring member (51), an inner ring member (52), and rolling elements (53) provided between the outer ring member and the inner ring member, and rotatably supports the rotating body with respect to the base portion. Of the outer ring member and the inner ring member, the first bearing member (52) is fixed to the rotating body, and the other, the second bearing member (51), is fixed to the base portion. A disc-shaped detection rotating part (80, 83, 86) is provided to rotate integrally with the first bearing member and extends radially outward from the bearing relative to the first bearing member, The base portion includes a displacement detection unit (90) provided at a position in the radial direction away from the bearing and facing the detection rotating unit in the axial direction of the bearing, which outputs a voltage signal corresponding to the axial displacement of the detection rotating unit and the displacement in a direction perpendicular to the axial direction, Equipped with, The rotating body is positioned such that its center of rotation is horizontal. Of the aforementioned rotating detection part, at a position in the radial direction away from the bearing, annular detection target parts (81, 82, 84, 85, 87, 88) extending in the circumferential direction of the bearing are formed. The displacement detection unit is Two planar receiving coils (110, 120, 130, 140) are fixed to the base portion and positioned opposite the detection target portion in the axial direction, and extending in a direction intersecting the axial direction, An excitation coil (100) to which an AC excitation voltage is supplied, It has, Each of the aforementioned receiving coils is, A first portion (110A, 120A, 130A, 140A) that generates a voltage of first polarity across the receiving coil when the excitation voltage is supplied to the excitation coil, When the excitation voltage is supplied to the excitation coil, the receiving coil has a second portion (110B, 120B, 130B, 140B) which generates a voltage of the second polarity opposite to the first polarity at both ends, It has, Each of the aforementioned receiving coils is, In a plan view of the receiving coil, the first portion is provided on one side of the circumferential center of the receiving coil and the second portion is provided on the other side, and the first portion and the second portion are arranged in the circumferential direction, or In a plan view of the receiving coil, the first and second portions on one side and the first and second portions on the other side are configured symmetrically with respect to the circumferential center of the receiving coil. It has become so Each of the receiving coils is positioned to straddle a horizontal axis passing through the rotational axis of the detection rotating unit. Each receiving coil outputs a voltage signal corresponding to the axial displacement of the detection rotating part, and a voltage signal corresponding to the displacement in the front-rear direction, which is perpendicular to the axial and vertical directions of the detection rotating part, respectively.

11. A signal acquisition unit (161) acquires the envelope (ENV1) of the output voltage signal (v1) of the receiving coil, Based on the rotation angle information of the detection rotating part, an offset voltage calculation unit (160) calculates the axial offset voltage (vofty), which is the envelope in the reference state, A displacement voltage calculation unit (161) calculates the axial displacement voltage (vdy) by subtracting the calculated axial offset voltage from the acquired envelope, A detection device according to any one of claims 2, 3, or 10, comprising:

12. The detection device according to claim 11, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage.

13. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates a first axial offset voltage (vofty1), which is the first envelope in the reference state, and a second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates a first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates a second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A total voltage calculation unit (164) calculates a total voltage (vdty) by adding the absolute value of the calculated first axial displacement voltage and the absolute value of the calculated second axial displacement voltage, A detection device according to any one of claims 2, 3, or 10, comprising:

14. The detection device according to claim 13, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated total voltage.

15. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates a first axial offset voltage (vofty1), which is the first envelope in the reference state, and a second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates a first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates a second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A force calculation unit (72) calculates a first axial force (Fy1), which is the axial force acting on the rotating body, based on the calculated first axial displacement voltage, and calculates a second axial force (Fy2), which is the axial force acting on the rotating body, based on the calculated second axial displacement voltage. Equipped with, The detection device according to any one of claims 2, 3, or 10, wherein the force calculation unit calculates the first axial force as the axial force acting on the rotating body during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the second axial force as the axial force acting on the rotating body during the period when the second axial offset voltage is greater than the first axial offset voltage.

16. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (163) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. An offset voltage calculation unit (162) calculates a first axial offset voltage (vofty1), which is the first envelope in the reference state, and a second axial offset voltage (vofty2), which is the second envelope in the reference state, based on the rotation angle information of the detection rotating unit, A displacement voltage calculation unit (163) calculates a first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates a second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope. A force calculation unit (72) calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the second axial offset voltage is greater than the first axial offset voltage, A detection device according to any one of claims 2, 3, or 10, comprising:

17. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (169) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. Based on the rotation angle information of the detection rotating unit, an offset voltage calculation unit (168) calculates the axial offset voltage (vofty), which is the first envelope in the reference state, and the vertical offset voltage (voftz), which is the second envelope in the reference state. Displacement voltage calculation unit (169), Equipped with, The displacement voltage calculation unit is, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a vertical correction voltage (vcz) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. The detection device according to claim 2 or 3, wherein the vertical displacement voltage (vdz) is calculated by subtracting the calculated vertical offset voltage and the calculated vertical correction voltage from the acquired second envelope.

18. The detection device according to claim 17, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage, and calculates the vertical load (Fz) acting on the rotating body based on the calculated vertical displacement voltage.

19. The rotating body is positioned such that its center of rotation is horizontal. The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). A signal acquisition unit (171) acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil. Based on the rotation angle information of the detection rotating unit, an offset voltage calculation unit (170) calculates the axial offset voltage (vofty), which is the first envelope in the reference state, and the longitudinal offset voltage (voftx), which is the second envelope in the reference state. Displacement voltage calculation unit (171), Equipped with, The displacement voltage calculation unit is, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a longitudinal correction voltage (vcx) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. The detection device according to claim 10, wherein the longitudinal displacement voltage (vdx) is calculated by subtracting the calculated longitudinal offset voltage and the calculated longitudinal correction voltage from the acquired second envelope.

20. The detection device according to claim 19, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage, and calculates the longitudinal force (Fx) acting on the rotating body based on the calculated longitudinal displacement voltage.

21. The system includes a filter section (172) that applies a low-pass filter to the acquired envelope. The detection device according to claim 11, wherein the envelope that has undergone the low-pass filter processing is input to the displacement voltage calculation unit.

22. A signal acquisition unit (172) acquires the envelope (ENV1) of the output voltage signal (v1) of the receiving coil, An amplitude information calculation unit (174) calculates the amplitude information voltage (vmaxy) of the envelope based on the rotation angle information of the detection rotating unit and the acquired envelope, A displacement voltage calculation unit (175) calculates the axial displacement voltage (vdy) by subtracting the reference voltage (vmaxoffty), which is the amplitude information voltage in the reference state, from the calculated amplitude information voltage, A detection device according to any one of claims 2, 3, or 10, comprising:

23. The detection device according to claim 22, further comprising a force calculation unit (72) that calculates the axial force (Fy) acting on the rotating body based on the calculated axial displacement voltage.

24. The detection target unit is, A configuration in which metal parts (81) and parts (82) that penetrate in the axial direction are alternately provided in the circumferential direction. A configuration in which recesses (88) that are recessed in the axial direction and protrusions (87) that project in the axial direction relative to the recesses are alternately provided in the circumferential direction, or A configuration in which metal parts and non-metal parts are alternately provided in the circumferential direction. It has become so The detection device according to any one of claims 1 to 4, 7 to 10, further comprising an angle calculation unit (73) that calculates the rotation angle of the detection rotating unit based on the output voltage signal of the receiving coil.

25. A program applied to the detection device according to any one of claims 2, 3, or 10, The computer (70) provided in the detection device, A signal acquisition process to acquire the envelope of the output voltage signal (v1) of the receiving coil, Based on the rotation angle information of the detection rotating part, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the envelope in the reference state, A displacement voltage calculation process is performed to calculate the axial displacement voltage (vdy) by subtracting the calculated axial offset voltage from the acquired envelope, A program that executes something.

26. A program applied to the detection device according to any one of claims 2, 3, or 10, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A program that performs a total voltage calculation process, which calculates the total voltage (vdty) by adding the absolute value of the first axial displacement voltage calculated and the absolute value of the second axial displacement voltage calculated.

27. A program applied to the detection device according to any one of claims 2, 3, or 10, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A force calculation process that calculates a first axial force (Fy1), which is the axial force acting on the rotating body, based on the calculated first axial displacement voltage, and calculates a second axial force (Fy2), which is the axial force acting on the rotating body, based on the calculated second axial displacement voltage, Make it run, A program that, in the force calculation process, calculates the first axial force as the axial force acting on the rotating body during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the second axial force as the axial force acting on the rotating body during the period when the second axial offset voltage is greater than the first axial offset voltage.

28. A program applied to the detection device according to any one of claims 2, 3, or 10, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the first axial offset voltage (vofty1), which is the first envelope in the reference state, and the second axial offset voltage (vofty2), which is the second envelope in the reference state. A displacement voltage calculation process that calculates the first axial displacement voltage (vdy1) by subtracting the calculated first axial offset voltage from the acquired first envelope, and calculates the second axial displacement voltage (vdy2) by subtracting the calculated second axial offset voltage from the acquired second envelope, A force calculation process that calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the first axial offset voltage is greater than the second axial offset voltage, and calculates the axial force (Fy) acting on the rotating body based on the first axial displacement voltage during the period when the second axial offset voltage is greater than the first axial offset voltage, A program that executes something.

29. In a program applied to the detection device described in claim 2 or 3, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the first envelope in the reference state, and the vertical offset voltage (voftz), which is the second envelope in the reference state. Displacement voltage calculation process, Make it run, In the displacement voltage calculation process, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a vertical correction voltage (vcz) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. A program that calculates the vertical displacement voltage (vdz) by subtracting the calculated vertical offset voltage and the calculated vertical correction voltage from the acquired second envelope.

30. In a program applied to the detection device described in claim 10, The two receiving coils are a first receiving coil (110, 130) and a second receiving coil (120, 140). The rotating body is positioned such that its center of rotation is horizontal. The computer provided in the aforementioned detection device, A signal acquisition process that acquires a first envelope (ENV1), which is the envelope of the first output voltage signal (v1) of the first receiving coil, and a second envelope (ENV2), which is the envelope of the second output voltage signal (v2) of the second receiving coil, Based on the rotation angle information of the detection rotating unit, an offset voltage calculation process is performed to calculate the axial offset voltage (vofty), which is the first envelope in the reference state, and the longitudinal offset voltage (voftx), which is the second envelope in the reference state. Displacement voltage calculation process, Make it run, In the displacement voltage calculation process, The axial displacement voltage (vdy) is calculated by subtracting the calculated axial offset voltage from the acquired first envelope. Based on the calculated axial displacement voltage, a longitudinal correction voltage (vcx) is calculated that quantifies the effect of the axial displacement of the detection rotating part on the second envelope. A program that calculates the longitudinal displacement voltage (vdx) by subtracting the calculated longitudinal offset voltage and the calculated longitudinal correction voltage from the acquired second envelope.

31. A program applied to the detection device according to any one of claims 2, 3, or 10, The computer provided in the aforementioned detection device, A signal acquisition process to acquire the envelope (ENV1) of the output voltage signal (v1) of the receiving coil, An amplitude information calculation process is performed to calculate the amplitude information voltage (vmaxy) of the envelope based on the rotation angle information of the detection rotating part and the acquired envelope. A displacement voltage calculation process calculates the axial displacement voltage (vdy) by subtracting the reference voltage (vmaxoffty), which is the amplitude information voltage in the reference state, from the calculated amplitude information voltage. A program that executes something.

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