Angle sensor and rotary device

Abstract

An angle sensor (1) is provided with a rotor (2) and a stator (3). The rotor (2) includes: an inner member (10) that is an inner tubular member; an outer member (20) that is an outer tubular member; and a plurality of metal bodies (30). The stator (3) includes a plurality of coils (40) facing the rotor (2). In the radial direction, the plurality of metal bodies (30) are sandwiched by the inner member (10) and the outer member (20).

Description

Angle sensors and rotating devices

[0001] The present invention relates to an angle sensor and a rotating device, and more particularly to an inductive angle sensor and a rotating device equipped with an inductive angle sensor.

[0002] Conventionally, various sensors have been used to detect the rotation angle of a motor, etc. An inductive sensor is one of such angle sensors for detecting the rotation angle (see, for example, Patent Document 1).

[0003] JP 2017-67600 A

[0004] Conventional inductive sensors have room for improvement in terms of detection accuracy.

[0005] Therefore, an object of the present invention is to provide an angle sensor and a rotating device that can improve detection accuracy.

[0006] An angle sensor according to one aspect of the present invention comprises a rotor having an inner cylindrical member, an outer cylindrical member, and a plurality of metal bodies, and a stator having a plurality of coils facing the rotor, wherein the plurality of metal bodies are sandwiched between the inner cylindrical member and the outer cylindrical member in the radial direction.

[0007] 18 is a diagram schematically illustrating the configuration of an angle sensor according to an embodiment of the present invention, and is a transparent perspective view schematically illustrating the internal configuration through some members of the angle sensor. FIG. 19 is a perspective view schematically illustrating the configuration of the angle sensor. FIG. 19 is a front view schematically illustrating the configuration of the angle sensor. FIG. 20 is a side view schematically illustrating the configuration of the angle sensor. FIG. 21 is an exploded perspective view of a rotor provided in the angle sensor. FIG. 22 is an exploded perspective view of the rotor provided in the angle sensor. FIG. 23 is a side view of a metal body provided in the rotor. FIG. 24 is a perspective view of an inner member of the rotor. FIG. 25 is a perspective view of the inner member of the rotor. FIG. 26 is a rear view of the inner member. FIG. 27 is a perspective view of the outer member of the rotor. FIG. 28 is a rear view of the outer member. FIG. 29 is a perspective view of the outer member of the rotor. FIG. 29 is a perspective view of the outer member of the rotor. FIG. 29 is a perspective view of the outer member of the rotor. FIG. 20 is a perspective view of the outer member of the rotor.

[0008] An embodiment of the present invention will be described below with reference to the accompanying drawings. Note that in the drawings, not all of the components are designated by reference numerals, and the reference numerals of some of the components may be omitted. FIG. 1 is a diagram schematically illustrating the configuration of an angle sensor 1 according to an embodiment of the present invention, and is a transparent perspective view schematically illustrating the internal configuration by seeing through some of the components of the angle sensor 1. FIG. 2 is a perspective view schematically illustrating the configuration of the angle sensor 1, FIG. 3 is a front view schematically illustrating the configuration of the angle sensor 1, and FIG. 4 is a side view schematically illustrating the configuration of the angle sensor 1. Also, FIGS. 5 and 6 are exploded perspective views of a rotor 2 included in the angle sensor 1. Note that FIGS. 5 and 6 show the exploded rotor 2 as viewed from different directions. As shown in FIGS. 1 to 5 , the angle sensor 1 includes a rotor 2 and a stator 3. The rotor 2 includes an inner member 10, which is an inner cylindrical member, an outer member 20, which is an outer cylindrical member, and multiple metal bodies 30. The stator 3 includes multiple coils 40 facing the rotor 2. The multiple metal bodies 30 are sandwiched between the inner member 10 and the outer member 20 in the radial direction. The configuration of the angle sensor 1 will be described in detail below. Note that in Figures 2 to 4, the rotor 2 and the stator 3 are shown in a predetermined positional relationship. This predetermined positional relationship is an example of the positional relationship between the rotor 2 and the stator 3 when the angle sensor 1 is attached to an application object and in use. In the angle sensor 1, the rotor 2 is disposed inside the stator 3.

[0009] 1, 5, and 6, the rotor 2 is formed by assembling an inner member 10, an outer member 20, and a plurality of metal bodies 30. In the assembled state of the rotor 2 shown in FIG. 1, in which the inner member 10, the outer member 20, and the plurality of metal bodies 30 are assembled, the plurality of metal bodies 30 are sandwiched between the inner member 10 and the outer member 20 and are positioned inside the rotor 2.

[0010] The rotor 2 has multiple conductors, and the multiple metal bodies 30 are an example of these multiple conductors. As shown in FIGS. 1, 5, and 6, the multiple metal bodies 30 are arranged in a circumferential direction around the axis x. The axis x is the rotation axis of the angle sensor 1. The conductors may be metal bodies or components having conductive materials (components capable of generating so-called eddy currents or induced currents (currents) within one surface). The multiple metal bodies 30 are arranged at predetermined distances in the circumferential direction of the rotor 2. In other words, two adjacent metal bodies 30 are separated by a predetermined distance around the axis x. The multiple metal bodies 30 are arranged at equal or approximately equal angular intervals in the circumferential direction, for example, along a cylindrical surface whose central axis is the axis x. Each of the multiple metal bodies 30 has, for example, a curved shape. The multiple metal bodies 30 may be connected to each other. The multiple metal bodies 30 are connected by one or more connecting parts, and the one or more connecting parts may be formed from a non-conductive material (e.g., resin) or a conductive material (e.g., metal), and the multiple metal bodies 30 may be electrically connected.

[0011] 7 is a side view of the metal body 30. As shown in FIGS. 1 and 5 to 7, the metal body 30 is a plate-like member and has a curved shape as described above. The metal body 30 is curved with respect to, for example, an inner circumferential surface 61 a or an outer circumferential surface 61 b ​​of a cylindrical portion 61 of the stator 3, which will be described later.

[0012] Specifically, for example, as shown in FIGS. 1 and 5 to 7 , the metal body 30 has an outer surface 31 and an inner surface 32, which are a pair of opposing surfaces, and end surfaces 33 to 36, which are surfaces extending between the edge of the outer surface 31 and the edge of the inner surface 32. Thus, the metal body 30 is plate-shaped. Furthermore, the metal body 30 has a rectangular or approximately rectangular shape when viewed from the radial direction. As shown in FIGS. 1 and 5 to 7 , the end surfaces 33 and 34 are opposite to each other, and the end surfaces 35 and 36 are opposite to each other in the direction in which the metal body 30 extends. The metal body 30 is curved along the end surfaces 33 and 34. That is, the outer surface 31 is curved along the end surfaces 33 and 34, and the inner surface 32 is curved along the end surfaces 33 and 34. The outer surface 31 is curved so as to protrude in the direction in which the outer surface 31 faces. For example, the outer surface 31 is curved in an arc shape with a constant or approximately constant radius of curvature R1. The inner surface 32 extends parallel or approximately parallel to the outer surface 31, and the thickness of the metal body 30 is uniform or approximately uniform.

[0013] 8 and 9 are perspective views of the inner member 10 of the rotor 2, and FIG. 10 is a rear view of the inner member 10. In FIG. 8, the inner member 10 is viewed from the front side, and in FIG. 9, the inner member 10 is viewed from the rear side. As shown in FIGS. 8 to 10, the inner member 10 is a cylindrical member extending along the axis x. The inner member 10 has an outer peripheral surface 11, which is an outer surface that is a cylindrical surface extending along the axis x, and an inner peripheral surface 12, which is a cylindrical surface extending along the axis x. The outer peripheral surface 11 and the inner peripheral surface 12 are opposite to each other in the radial direction, with the outer peripheral surface 11 facing the outside in the radial direction (hereinafter also referred to as the "outer peripheral side") and the inner peripheral surface 12 facing the inside in the radial direction (hereinafter also referred to as the "inner peripheral side"). The radial direction is a direction perpendicular to the axis x. The inner circumferential surface 12 is, for example, a cylindrical surface or a substantially cylindrical surface with the axis x as its central axis. The angle sensor 1 is applied to, for example, a motor, and the shape of the inner circumferential surface 12 is such that the rotating shaft of the motor passes through the inner circumferential surface 12 and the inner member 10 is fixed to the shaft.

[0014] 8 to 10 , the outer peripheral surface 11 has mounting surfaces 13 that are multiple curved portions. The mounting surfaces 13 are portions that correspond to the inner surface 32 of the metal body 30, and the outer peripheral surface 11 is formed with the same number of mounting surfaces 13 as the number of metal bodies 30. The multiple mounting surfaces 13 are provided at predetermined positions, for example, at the same or approximately the same positions in the radial direction, and at equal or approximately equal angular intervals. The mounting surfaces 13 have a shape that corresponds to the inner surface 32 of the metal body 30, for example, they have the same or approximately the same shape as the inner surface 32 of the metal body 30, and the entire or approximately the entire mounting surface 13 is shaped so that it can come into contact with the inner surface 32 of the metal body 30.

[0015] 8 to 10, between two adjacent mounting surfaces 13, protruding surfaces 14 are formed on the outer peripheral surface 11, which protrude outward from the mounting surfaces 13. The protruding surfaces 14 are, for example, curved surfaces, and specifically, for example, the plurality of protruding surfaces 14 are curved so as to extend on a cylindrical surface or a substantially cylindrical surface with the axis x as the central axis.

[0016] The outer peripheral surface 11 also has a plurality of walls 15 extending radially. As shown in FIGS. 8 to 10 , the walls 15 extend between the end of each mounting surface 13 and the end of the protruding surface 14 adjacent to that mounting surface 13, forming a step between the adjacent mounting surfaces 13 and the protruding surfaces 14. The walls 15 have a shape corresponding to the end faces 35, 36 of the metal bodies 30, and are shaped so as to be able to contact the end faces 35, 36 of the metal bodies 30 over their entirety. Furthermore, the metal bodies 30 can be arranged between two walls 15 that face each other across each mounting surface 13, and each of the multiple metal bodies 30 is arranged between a pair of walls 15 that face each other across the mounting surface 13. The end faces 35, 36 of each metal body 30 are each configured to contact the pair of walls 15 that face each other across the corresponding mounting surface 13.

[0017] As shown in Figures 8 to 10, the inner member 10 has annular end faces 16, 17 at both ends in the axial x direction. The end face 16 is a surface extending between one end of the outer peripheral surface 11 in the axial x direction and one end of the inner peripheral surface 12 in the axial x direction, and the end face 17 is a surface extending between the other end of the outer peripheral surface 11 in the axial x direction and the other end of the inner peripheral surface 12 in the axial x direction. The inner peripheral side portion of the end face 16 is recessed, for example, toward the other side in the axial x direction, and an annular recess 16a forming an annular step is formed in the end face 16. Furthermore, the inner member 10 has a flange portion 18, which is a portion protruding outward from the outer peripheral surface 11, at, for example, the other end in the axial x direction. The flange 18 has, for example, a disk-like or approximately disk-like shape centered on the axis x.

[0018] 11 and 12 are perspective views of the outer member 20 of the rotor 2, and FIG. 13 is a rear view of the outer member 20. In FIG. 11, the outer member 20 is viewed from the front side, and in FIG. 12, the outer member 20 is viewed from the rear side. As shown in FIGS. 11 to 13, the outer member 20 is a cylindrical member extending along the axis x. The outer member 20 has an outer peripheral surface 21, which is a cylindrical surface extending along the axis x, and an inner peripheral surface 22, which is a cylindrical surface extending along the axis x. The outer peripheral surface 21 and the inner peripheral surface 22 are radially opposed to each other, with the outer peripheral surface 21 facing the outer peripheral side and the inner peripheral surface 22 facing the inner peripheral side. The outer peripheral surface 21 is, for example, a cylindrical surface or a substantially cylindrical surface with the axis x as its central axis. The outer peripheral surface 21 is formed so as to be flush or approximately flush with the outer peripheral surface of the flange portion 18 of the inner member 10 in the assembled rotor 2, for example.

[0019] As shown in FIGS. 11 to 13 , the inner circumferential surface 22 has a shape corresponding to the outer circumferential surface 11 of the inner member 10, and is shaped so that the outer circumferential surface 11 of the inner member 10 can be accommodated inside the inner circumferential surface 22. The inner circumferential surface 22 has mounting surfaces 23 as an inner surface that is a plurality of curved portions. The mounting surfaces 23 are portions that correspond to the outer surfaces 31 of the metal bodies 30, and the same number of mounting surfaces 23 are formed on the inner circumferential surface 22 as the number of metal bodies 30. Furthermore, each of the multiple mounting surfaces 23 is provided at the same angular position around the axis x as the multiple mounting surfaces 13 on the outer circumferential surface 11 of the inner member 10, and in the assembled rotor 2, the multiple mounting surfaces 23 face the multiple outer circumferential surfaces 11 of the inner member 10 at intervals. The multiple mounting surfaces 23 are provided, for example, at the same or approximately the same position in the radial direction, at equal or approximately equal angular intervals. The mounting surface 23 has a shape that corresponds to the outer surface 31 of the metal body 30, and for example, has the same or approximately the same shape as the outer surface 31 of the metal body 30, and is shaped so that the entire or approximately the entire mounting surface 23 can come into contact with the outer surface 31 of the metal body 30. In other words, in the assembled rotor 2, the distance between the multiple mounting surfaces 23 on the inner circumferential surface 22 of the outer member 20 and the multiple mounting surfaces 13 on the outer circumferential surface 11 of the inner member 10 is the same or approximately the same as the thickness of the metal body 30. Note that, in the assembled rotor 2, the distance between the multiple mounting surfaces 23 on the inner circumferential surface 22 of the outer member 20 and the multiple mounting surfaces 13 on the outer circumferential surface 11 of the inner member 10 may be greater than the thickness of the metal body 30.

[0020] 11 to 13 , between two adjacent mounting surfaces 23, a concave surface 24 is formed on the inner circumferential surface 22. The concave surfaces 24 are recessed radially outward from the mounting surfaces 23. Each of the concave surfaces 24 is located at the same angular position around the axis x as the corresponding one of the protruding surfaces 14 on the outer circumferential surface 11 of the inner member 10. In the assembled rotor 2, the concave surfaces 24 face the corresponding one of the protruding surfaces 14 on the outer circumferential surface 11 of the inner member 10. The concave surfaces 24 are located at the same or substantially the same radial positions, at equal or substantially equal angular intervals. The concave surfaces 24 are, for example, curved surfaces. Specifically, the concave surfaces 24 are curved so as to extend along a cylindrical or substantially cylindrical surface with the axis x as the central axis. In the assembled rotor 2, the concave surfaces 24 are in contact with the corresponding one of the protruding surfaces 14 on the outer circumferential surface 11 of the inner member 20. In this case, the concave surfaces 24 have, for example, the same or substantially the same shape as the protruding surfaces 14 on the outer peripheral surface 11 of the inner member 20. Note that the multiple concave surfaces 24 may be spaced apart and not in contact with each other, in the assembled rotor 2. The shape of the concave surfaces 24 may also be different from the shape of the protruding surfaces 14 on the outer peripheral surface 11 of the inner member 20.

[0021] The inner circumferential surface 22 also has a plurality of walls 25 extending in the radial direction. As shown in Figures 11 to 13, the walls 25 extend between the end of each mounting surface 23 and the end of the recessed surface 24 adjacent to that mounting surface 23, forming a step between adjacent mounting surfaces 23 and recessed surfaces 24. The walls 25 each face the walls 15 on the outer circumferential surface 11 of the inner member 10 in the assembled rotor 2. In other words, the two walls 25 extending at both ends of each of the mounting surfaces 23 on the inner circumferential surface 22 of the outer member 20 face the two walls 15 extending at both ends of the mounting surface 13 on the outer circumferential surface 11 of the inner member 10 that faces that mounting surface 23 in the assembled rotor 2. For example, the two walls 25 extending at both ends of each of the multiple mounting surfaces 23 on the inner circumferential surface 22 of the outer member 20 are configured to contact the two walls 15 extending at both ends of the mounting surface 13 on the outer circumferential surface 11 of the inner member 10 that faces the mounting surface 23 in the assembled rotor 2. Note that the multiple walls 25 may not be configured to contact the multiple walls 15 of the inner member 10 that face them.

[0022] As shown in FIGS. 11 to 13 , the outer member 20 has a flange portion 26, which is an annular portion extending inward from the outer peripheral surface 21, at one end in the axial x direction. The flange portion 26 extends inward beyond the inner peripheral surface 22. The flange portion 26 has an inner peripheral end surface 26a, which is an annular surface, at its inner end. The inner peripheral end surface 26a is formed so as to be flush or approximately flush with the inner peripheral surface 12 of the inner member 10, for example, in the assembled rotor 2. The inner peripheral end surface 26 has, for example, a shape extending on a cylindrical surface or approximately cylindrical surface with the axis x as its central axis. The flange portion 26 has an end surface 26b on one side in the axial x direction, i.e., the surface facing outward from the outer member 20, and an end surface 26c on the other side in the axial x direction, i.e., the surface facing inward from the outer member 20. The end surface 26c has a shape that allows contact with the end surface 16 of the inner member 10, for example, and has an annular protrusion 26d that can be accommodated in the recess 16a of the end surface 16 of the inner member 10. The protrusion 26d is a portion that protrudes from the end surface 26c to the other side in the axial x direction. The outer member 20 also has an annular end surface 27 at its end on the other side in the axial x direction. The end surface 27 is a surface that extends between the other end of the outer peripheral surface 21 in the axial x direction and the other end of the inner peripheral surface 22 in the axial x direction.

[0023] The outer member 20 also has a protrusion 28 that is accommodated in a recess (see FIG. 19) of the rotating shaft to which the angle sensor 1 is fixed. For example, as shown in FIGS. 11 to 13, the protrusion 28 is provided on the inner peripheral end surface 26a of the flange portion 26. The protrusion 28 protrudes inward from the inner peripheral end surface 26a. The protrusion 28 may also be provided on the inner member 10. In this case, for example, the protrusion 28 that protrudes inward from the inner peripheral surface 12 is formed on the inner peripheral surface 12 of the inner member 10.

[0024] The inner member 10 is made of, for example, a resin material, a non-magnetic material, a non-conductive material, etc. The non-magnetic material may be non-conductive. Similarly, the outer member 20 is made of, for example, a resin material, a non-magnetic material, a non-conductive material, etc. The non-magnetic material may be non-conductive.

[0025] As described above, the rotor 2 is formed by assembling the inner member 10, the outer member 20, and the plurality of metal bodies 30 having the above-described configurations. Specifically, the plurality of metal bodies 30 are attached to the inner member 10 so as to face the plurality of mounting surfaces 13 of the inner member 10, respectively. At this time, the metal bodies 30 are held by two walls 15 extending from both ends of the opposing mounting surfaces 13. In other words, the ends 35, 36 of the metal body 30 contact the two walls 15 extending from both ends of the mounting surface 13 that the metal body 30 faces, and the metal body 30 is fixed between these two walls 15. Note that the two walls 15 may face each other with a small gap between them, without contacting the ends 35, 36 of the metal body 30, respectively. As a result, the metal body 30 is fixed in the circumferential direction around the axis x. For example, the metal body 30 is fixed to the inner member 10 by being inserted between two walls 15 extending from both ends of the mounting surface 13 that the metal body 30 faces. At this time, the two walls 15 and the ends 35, 36 of the metal body 30 are in contact with each other in the circumferential direction, or face each other with a small gap between them. This prevents deformation of the metal body 30 when the metal body 30 is inserted between the two walls 15 extending from both ends of the mounting surface 13 that the metal body 30 faces. Furthermore, when the metal body 30 is fixed to the inner member 10, the inner surface 32 of the metal body 30 is in contact with the mounting surface 13 that the metal body 30 faces. Note that the inner surface 32 of the metal body 30 may be bonded to the mounting surface 13 that the metal body 30 faces with an adhesive or the like.

[0026] The rotor 2 is assembled by attaching the outer member 20 to the inner member 10, to which the multiple metal bodies 30 are attached. The outer peripheral surface 11 of the inner member 10, to which the multiple metal bodies 30 are attached, is housed inside the inner peripheral surface 21 of the outer member 20, and the outer member 20 is attached to the inner member 10. When the outer member 20 is attached to the inner member 10, the multiple mounting surfaces 23 of the outer member 20 come into contact with the outer surfaces 31 of the multiple metal bodies 30 fixed to the inner member 10, and the multiple metal bodies 30 are sandwiched between the multiple mounting surfaces 13 of the inner member 10 and the multiple mounting surfaces 23 of the outer member 20, and fixed in the radial direction. When the distance between the multiple mounting surfaces 23 on the inner circumferential surface 22 of the outer member 20 and the multiple mounting surfaces 13 on the outer circumferential surface 11 of the inner member 10 is greater than the thickness of the metal bodies 30, the multiple metal bodies 30 are sandwiched with gaps between the multiple mounting surfaces 13 of the inner member 10 and the multiple mounting surfaces 23 of the outer member 20. In this case, the multiple metal bodies 30 may be fixed in the radial direction by being adhered to the multiple mounting surfaces 13 of the inner member 10 with an adhesive or the like. Also, the multiple metal bodies 30 may be fixed in the radial direction by being adhered to the multiple mounting surfaces 23 of the outer member 20 with an adhesive or the like.

[0027] When the outer member 20 is attached to the inner member 10, the multiple protruding surfaces 14 of the inner member 10 each face and contact the multiple concave surfaces 24 of the outer member 20. Furthermore, the two walls 15 extending from both ends of each of the multiple protruding surfaces 14 of the inner member 10 each face and contact the two walls 25 extending from both ends of the concave surface 24 of the outer member 20 that the protruding surface 14 faces. This fixes the inner member 10 and the outer member 20 to each other in the radial and circumferential directions. For example, the multiple protruding portions defined by the multiple protruding surfaces 14 and multiple walls 15 of the inner member 10 are press-fitted into the multiple recessed portions defined by the multiple concave surfaces 24 and multiple walls 25 of the outer member 20, thereby fixing the inner member 10 and the outer member 20 to each other. The two walls 15 extending from both ends of each of the multiple protruding surfaces 14 of the inner member 10 may face, via a small gap, two walls 25 extending from both ends of the concave surface 24 of the outer member 20 that faces the protruding surface 14. Furthermore, the two walls 15 extending from both ends of each of some of the multiple protruding surfaces 14 of the inner member 10 may be in contact with or face, via a small gap, two walls 25 extending from both ends of the concave surface 24 of the outer member 20 that faces the protruding surface 14.

[0028] The inner member 10 and the outer member 20 may be fixed to each other by bonding with an adhesive or the like. In this case, for example, each of the multiple protruding surfaces 14 of the inner member 10 does not have to be in contact with each of the multiple concave surfaces 24 of the outer member 20. Also, in this case, each of the two walls 15 extending from both ends of each of the multiple protruding surfaces 14 of the inner member 10 does not have to be in contact with each of the two walls 25 extending from both ends of the concave surface 24 of the outer member 20 that faces the protruding surface 14.

[0029] Furthermore, when the outer member 20 is attached to the inner member 10, the recess 16a on the end face 16 of the inner member 10 contacts the protrusion 26d of the flange portion 26 of the outer member 20. This determines the assembly position of the outer member 20 and the inner member 10, thereby preventing deformation of the metal body 5. Furthermore, when the outer member 20 is attached to the inner member 10, the end face 27 of the outer member 20 faces the flange portion 18 of the inner member 10 with a small gap between them. Note that when the outer member 20 is attached to the inner member 10, the recess 16a on the end face 16 of the inner member 10 does not have to contact the end face 26c of the flange portion 26 of the outer member 20. Furthermore, when the outer member 20 is attached to the inner member 10, the end face 27 of the outer member 20 may contact the flange portion 18 of the inner member 10.

[0030] Furthermore, when the outer member 20 is attached to the inner member 10, the inner peripheral end surface 26a of the flange portion 26 of the outer member 20 is flush or approximately flush with the inner peripheral surface 12 of the inner member 10. Note that when the outer member 20 is attached to the inner member 10, the inner peripheral end surface 26a of the flange portion 26 of the outer member 20 does not have to be flush with the inner peripheral surface 12 of the inner member 10. In this case, the inner peripheral end surface 26a of the flange portion 26 of the outer member 20 is located outer than the inner peripheral surface 12 of the inner member 10. Furthermore, the protrusion 28 of the flange portion 26 of the outer member 20 protrudes inner than the inner peripheral surface 12 of the inner member 10.

[0031] As described above, the rotor 2 is formed by attaching the outer member 20 to the inner member 10 to which the plurality of metal bodies 30 are attached. In the rotor 2, the plurality of metal bodies 30 are arranged at equal or approximately equal angular intervals in the circumferential direction along a cylindrical surface whose central axis is the axis x. The rotor 2 is attached to a rotating member of an external device to which the angle sensor 1 is applied, so that the axis x coincides or approximately coincides with the rotation axis of the rotating member of the external device.

[0032] Although the multiple metal bodies 30 are attached to the inner member 10 before the outer member 20 is attached to the inner member 10, the multiple metal bodies 30 may also be attached to the outer member 20 before the outer member 20 is attached to the inner member 10. In this case, the multiple metal bodies 30 are attached to the outer member 20 so as to face the multiple mounting surfaces 23 of the outer member 20, respectively, and at this time, the metal bodies 30 are held by two walls 25 extending from both ends of the opposing mounting surfaces 23. If the metal bodies 30 are not held by two walls 25 extending from both ends of the opposing mounting surfaces 23, the multiple metal bodies 30 may each be adhered to the multiple mounting surfaces 23 of the outer member 20 with an adhesive or the like.

[0033] FIG. 14 is a perspective view schematically illustrating the configuration of the stator 3, and FIG. 15 is a perspective view of a coil structure 4 formed by a plurality of coils 40. FIG. 16 is a diagram schematically illustrating the configuration of the coil structure 4. As shown in FIGS. 1 to 4 and 14 , the stator 3 has a cylindrical portion 61 that is a cylindrical part corresponding to the rotor 2. The cylindrical portion 61 forms a space capable of accommodating the rotor 2 therein and has an inner circumferential surface 61 a that defines this space. The inner circumferential surface 61 a is a cylindrical surface extending along the axis x and is configured to face the outer circumferential surface 21 of the outer member 20, which is the outer circumferential surface of the rotor 2, with an annular gap therebetween. The inner circumferential surface 61 a is, for example, a cylindrical surface extending along a cylindrical surface with the axis x as its central axis.

[0034] As shown in FIGS. 2 to 4 and 14 , the stator 3 has an attachment portion 62 that is attached to an external device as an application target. As shown in FIGS. 3 and 14 , the attachment portion 62 is provided, for example, on the outer peripheral surface 61b of the cylindrical portion 61 and protrudes outward from the cylindrical portion 61. The outer peripheral surface 61b of the cylindrical portion 61 is a cylindrical surface facing away from the inner peripheral surface 61a. The attachment portion 62 also has a through hole 62a through which a fixing member such as a bolt is passed, allowing the attachment portion 62 to be attached to an external device via the fixing member. The stator 3 has, for example, three attachment portions 62. However, the number of attachment portions 62 included in the stator 3 is not limited thereto. As shown in FIG. 14 , the stator 3 also has a holding portion 63 that houses, for example, an electric circuit device having a circuit unit and a computing unit (not shown). 3 and 14, the holding portion 63 extends from the outer peripheral surface 61b of the cylindrical portion 61 along the axis x in the other direction of the axis x. The holding portion 63 is also provided between the multiple mounting portions 62 in the circumferential direction.

[0035] As shown in FIGS. 1 to 4 and 14 , the stator 3 has multiple protrusions 60 protruding toward the rotor 2. The multiple protrusions 60 are portions that protrude inward from the inner circumferential surface 61 a of the cylindrical portion 61, as shown in FIG. 14 , for example. The protrusions 60 are provided on the inner circumferential surface 61 a, for example, at equal or approximately equal angular intervals around the axis x. The protrusions 60 protrude radially from the inner circumferential surface 61 a, and for example, a cross section perpendicular to the radial direction is rectangular or approximately rectangular. Note that the cross-sectional shape of the protrusions 60 is not limited to a rectangle and may be other shapes. Each protrusion 60 has a surface 60 a facing the inner circumferential side, and the surface 60 a faces the outer circumferential surface 21 of the rotor 2 with an annular gap therebetween. The surfaces 60 a of the multiple protrusions 60 are arranged, for example, along a cylindrical surface whose central axis is the axis x. The protruding portion 60 has, for example, a connecting portion 60b that connects to the cylindrical portion 61 and an end portion 60c on the rotor 2 side. A surface 60a is formed on the end portion 60c. The end portion 60c protrudes further in the circumferential direction and the direction of the axis x than the connecting portion 60b, and an annular groove is formed between the connecting portion 60b and the cylindrical portion 61.

[0036] The coil 40 is made of a conductive material. The multiple coils 40 are, for example, lined up and connected in a circumferential direction around the axis x. As schematically shown in FIG. 15 , the multiple coils 40 form a cylindrical shape (hereinafter referred to as a "coil structure") 4 extending annularly around the axis x. The coil structure 4 is a shape formed by arranging the multiple coils 40. In the coil structure 4, the multiple coils 40 are, for example, lined up annularly so as to be aligned along an annular surface around the axis x. The multiple coils 40 are, for example, lined up annularly so as to be aligned along a cylindrical surface with the axis x as the central axis. Furthermore, each coil 40 has, for example, a shape that surrounds a space. Furthermore, each coil 40 has, for example, a shape such that the space surrounded by each coil 40 follows the annular surface around the axis x. The multiple coils 40 radially face the multiple metal bodies 30.

[0037] The coil 40 is formed by, for example, winding a magnet wire 41, which is an example of a conductive member. The coil 40 is formed by winding the magnet wire 41 around a plurality of protrusions 60, as shown in Figures 13 and 14, for example. The coil 40 has an annular shape wound around the radial direction r of the rotor 2, and surrounds a planar space facing the radial direction r. A plurality of coils 40 are formed in a cylindrical portion 61 of the stator 3, lined up around the axis x, to form the coil structure 4.

[0038] As shown in FIGS. 15 and 16 , the coil structure 4 has two pieces (hereinafter referred to as “coil structure pieces”) 4a and 4b. The coil structure piece 4a is formed by a plurality of annular coils 40a, which are the coil 40 described above, connected in series. Similarly, the coil structure piece 4b is formed by a plurality of annular coils 40b, which are the coil 40 described above, connected in series. That is, in each of the coil structure pieces 4a and 4b, a plurality of annular coils 40a and 40b are arranged in the circumferential direction. Note that the coil structure piece 4a and the coil structure piece 4b are coated with, for example, an insulating material (an insulating film or coating) and are electrically insulated from each other. As shown in FIGS. 15 and 16 , the coil structure piece 4a and the coil structure piece 4b overlap in the radial direction to form the coil structure 4. In the coil structure pieces 4a and 4b, a portion of the space surrounded by the coil 40a is offset in the circumferential direction from a portion of the space surrounded by the coil 40b, and another portion of the space surrounded by the coil 40a is overlapped in the circumferential direction. Specifically, the space surrounded by the coil 40a is offset in the circumferential direction from the space surrounded by the coil 40b by half the width of the space surrounded by the coil 40a. The number of coils 40a and 40b in each of the coil structure pieces 4a and 4b corresponds to the axial multiplier angle set for the angle sensor 1. The number of coil structure pieces 4a and 4b also corresponds to the number of detection signals output by the coil structure 4.

[0039] 14 and 16 , a magnet wire 41 as a conductive member is wound around each of the protruding portions 60 of the stator 3 in the radial direction, and a plurality of annular coils 40 are formed around the plurality of protruding portions 60 in the radial direction, thereby forming a coil structure 4 in the stator 3. Specifically, the magnet wire 41 is wound around the connecting portion 60b of the protruding portions 60. The coil structure pieces 4a, 4b are each formed by, for example, winding one magnet wire 41a, 41b around the plurality of protruding portions 60 of the cylindrical portion 61. Specifically, for example, the magnet wire 41a, 41b is wound around the protrusions 60 alternately from one side in the axial x direction and the other side in the axial x direction for every two adjacent protrusions 60 toward one side in the circumferential direction, and then turned back after making one full turn around the cylindrical portion 61, and the magnet wire 41a, 41b is wound around the protrusions 60 again toward the other side in the circumferential direction to form the coil structure pieces 4a, 4b. In this case, each of the coils 40a, 40b is formed around two of the protrusions 60. Furthermore, the coil structure pieces 4a and 4b are offset from each other by one of the protrusions 60 in the circumferential direction. Note that the coils 40a, 40b are not limited to being formed around two of the protrusions 60, and may be formed around other numbers of protrusions 60. Furthermore, although the magnet wire 41 (41a, 41b) is described as being wound around one turn, the winding pattern of the magnet wire 41 is not limited to this, and the magnet wire 41 may be wound around two or more turns. In other words, the coil formed by winding the magnet wire 41 may have, for example, one layer or multiple layers such as two, three, four, or five layers in the radial or axial direction. If the number of turns or layers is large, the output signal or the signal to be detected (for example, the amplitude of the signal waveform) can be amplified.

[0040] As shown in Figures 14 to 16, each coil 40 (40a, 40b) formed by being wound around the multiple protrusions 60 of the tubular portion 61 extends linearly. That is, the portions of each coil 40 extending along each protrusion 60 on one side in the axial x direction and the other side in the axial x direction extend linearly. Furthermore, between two adjacent protrusions 10, the portions of the coil structure pieces 4a, 4b (magnet wires 41a, 41b) extending between one side in the axial x direction and the other side in the axial x direction intersect. Specifically, between two adjacent protrusions 60, the magnet wires 41a, 41b intersect. The intersection of the portions of the coil structure pieces 4a, 4b (magnet wires 41a, 41b) connects the two adjacent coils 40 (40a, 40b).

[0041] Both ends of the magnet wire 41 wound around the protruding portions 60 to form the multiple coils 40 are drawn out from the cylindrical portion 61. For example, as shown in Fig. 16 , both ends 41a1 and 41a2 of the magnet wire 41a and both ends 41b1 and 41b2 of the magnet wire 41b are drawn out from between two adjacent protruding portions 60. As shown in Fig. 16 , as an example, the ends 41a1 and 41a2 of the magnet wire 41a and the ends 41b1 and 41b2 of the magnet wire 41b are drawn out through the gap between the first protruding portion 60 and the second protruding portion 60.

[0042] The stator 3 is, for example, integrally molded from the same material, and each component of the stator 3 is connected together. The stator 3 is an insulating member, for example, a resin member. The stator 3 is made of, for example, a resin material, a non-magnetic material, or a non-conductive material. The non-magnetic material may be non-conductive. Any or all of the components of the stator 3 may be formed as separate bodies. In this case, the stator 3 is formed by assembling the components formed as separate bodies by adhesive or the like.

[0043] The rotor 2 and the stator 3 form an inductive angle sensor, and the multiple coils 40 form detection coils. A magnetic space or magnetic gap is formed between the rotor 2 and the stator 3. For example, in the angle sensor 1, a radially directed magnetic flux whose magnitude periodically changes acts on the multiple coils 40. Specifically, the stator 3 is provided with an excitation circuit 5 (see FIG. 4 ), which is a magnetic circuit that generates a periodically changing magnetic flux acting on each of the multiple coils 40. Meanwhile, the multiple metal bodies 30 are arranged in the circumferential direction around the axis x as described above, and cross the magnetic flux generated by the excitation circuit 5 as the rotor 2 rotates. Furthermore, the radial projection of the metal body 30, which has a portion extending along the axis x, onto the coils 40 moves as the rotor 2 rotates. For this reason, the magnetic fluxes from the excitation circuit 5 acting on each of the plurality of coils 40 are affected by eddy currents generated in the metal body 30 and cancel each other out, thereby changing periodically with the rotation of the rotor 2. As a result, electromotive forces that change with the rotation of the rotor 2 are generated in the plurality of coils 40 due to electromagnetic induction, and signals that change with the rotation of the rotor 2 are detected from the plurality of coils 40. Based on the detection signals from the plurality of coils 40, the rotation angle of the rotor 2 is detected in the electric circuit device.

[0044] The angle sensor 1 has the above-described configuration, in which the metal body 30 is curved, and the radial distance between the outer surface 31 of the metal body 30 and the coil 40 or the space surrounded by the coil 40 is smallest at the center of the outer surface 31 of the metal body 30 and increases toward both edges of the outer surface 31. As a result, the influence of eddy currents generated in the metal body 30 rotating with the rotation of the rotor 2 on the magnetic flux from the excitation circuit 5 acting on each coil 40 varies in the circumferential direction of the metal body 30. Therefore, the output waveform obtained from the detection signal detected by the coil structure 4 can be made closer to a sine wave, and the output waveform can be prevented from becoming a waveform close to a triangular wave. This improves the detection accuracy of the angle sensor 1.

[0045] Furthermore, in the rotor 2, the multiple metal bodies 30 are each sandwiched between the multiple mounting surfaces 13 on the outer peripheral surface 11 of the inner member 10 and the multiple mounting surfaces 23 on the inner peripheral surface 22 of the outer member 20. This allows each of the multiple metal bodies 30 to be held in a shape that conforms to the multiple mounting surfaces 13 on the inner member 10 and the multiple mounting surfaces 23 on the outer member 20, and the multiple metal bodies 30 can be curved into a desired curved shape. When the multiple metal bodies 30 are in contact with the multiple mounting surfaces 13 on the inner member 10 or the multiple mounting surfaces 23 on the outer member 20, the curved shape of the multiple metal bodies 30 can be more accurately formed into a desired curved shape. When the multiple metal bodies 30 are in contact with the multiple mounting surfaces 13 on the inner member 10 and the multiple mounting surfaces 23 on the outer member 20, the curved shape of the multiple metal bodies 30 can be more accurately formed into a desired curved shape.

[0046] In this way, in the rotor 2, the curved shapes of the multiple metal bodies 30 can be made into a desired curved shape, which also improves the detection accuracy of the angle sensor 1. Furthermore, by sandwiching each of the multiple metal bodies 30 between the multiple mounting surfaces 13 of the inner member 10 and the multiple mounting surfaces 23 of the outer member 20, the curved shapes of the multiple metal bodies 30 can be easily made into a desired curved shape. This allows for improved productivity of the rotor 2.

[0047] In this way, the angle sensor 1 according to the embodiment of the present invention can improve detection accuracy.

[0048] Next, an application of the angle sensor 1 will be described. Fig. 17 is an exploded perspective view of a specific example of a rotating device as an application of the angle sensor 1. Fig. 17 shows a rotating device 70 as a specific example of a rotating device in an exploded state. In Fig. 17, a portion of the configuration of a rotating device 60 is shown in a see-through manner.

[0049] As shown in FIG. 17 , the rotating device 70 includes an angle sensor 1, a rotating shaft 71, and a motor 72. In the rotating device 70, the axes of the rotating shaft 71 and the motor 72 coincide or substantially coincide with the axis x of the angle sensor 1. For this reason, in the following description, the axis of the rotating device 70 will be referred to as the axis x, and the axes of the angle sensor 1, the rotating shaft 71, and the motor 72 will be referred to as the axis x. The motor 72 includes a rotor 73 and a stator 74, and the rotating shaft 71 is fixed to the rotor 73. The motor 72 also includes a frame 75 and a cover 80. The frame 75 houses the rotor 73 and the stator 74. The frame 75 also has an opening 75 a. The cover 80 covers the opening 75 a of the frame 75.

[0050] An opening 75a of the frame 75 opens the internal space of the frame 75 to the outside of the frame 75. The internal space of the frame 75 houses the rotor 73 and the stator 74. As shown in Fig. 17, the frame 75 is, for example, a cylindrical member. The frame 75 has an annular end portion 75b that surrounds the opening 75a, and the end portion 75b faces in the direction of the axis x.

[0051] The rotor 2 of the angle sensor 1 is fixed to a rotating shaft 71, and one end 71a of the rotating shaft 71 (hereinafter referred to as the "tip") passes through the rotor 2 and is rotatably supported by a bearing 76 fixed to a cover 80. The stator 3 of the angle sensor 1 is fixed to the cover 80. In the rotating device 70, the rotor 2 is located at a predetermined position relative to the stator 3 as described above, and the outer circumferential surface 21 of the rotor 2 faces the protruding portion 60 of the stator 3 and the plurality of coils 40 that form the coil structure 4, with an annular gap between them (see FIGS. 2 and 3).

[0052] The cover 80 is a plate-shaped member having a pair of opposing surfaces 81 and 82, as shown in FIG. 17 . In the rotating device 70, one of the pair of opposing surfaces 81 and 82 of the cover 80, for example, the surface 81, covers the opening 75a of the frame 75. That is, the cover 80 is fixed to the frame 75 with the surface 81 in contact with the end 75b of the frame 75. For example, the surface 81 of the cover 80 is adhered to the end 75b of the frame 75, thereby fixing the cover 80 to the frame 75. The cover 80 may be fixed to the frame 75 by a method other than adhesion. For example, the cover 80 may be fixed to the frame 75 by a fixing means such as a bolt or a locking means such as a claw.

[0053] The angle sensor 1 is attached to a surface 81, which is one of a pair of surfaces of the cover 80. For example, the surface 81 of the cover 80 is provided with a plurality of mounting portions (hereinafter referred to as "boss portions") 83 corresponding to the plurality of mounting portions 62 of the stator 3. As shown in FIG. 17 , the boss portions 83 are portions that protrude from the surface 81 and have threaded holes formed therein. Bolts 85 are threaded into the threaded holes of the bosses 83 via the mounting portions 62 of the stator 3, and the mounting portions 62 are fixed to the corresponding boss portions 83 by the bolts 85, thereby fixing the stator 3 to the cover 80. In this way, the stator 3 is fixed to the surface 81 of the cover 80, and the angle sensor 1 is provided on the surface 81 of the cover 80. Therefore, in the rotating device 70, the angle sensor 1 is housed in the space inside the frame 75.

[0054] 17 , for example, an annular protrusion 84 that supports the bearing 76 is formed on the surface 81 of the cover 80. The protrusion 84 is an annular tube that protrudes from the surface 81 of the cover 80 and has a recess formed therein. The protrusion 84 is a flange that extends a predetermined distance in the radial direction. The protrusion 84 houses the bearing 76, and the bearing 76 is fitted and fixed in place. For example, the bearing 76 is press-fitted into the recess formed by the protrusion 84, and the bearing 76 is fixed to the protrusion 84. In this way, the bearing 76, which rotatably supports the tip end 71 a of the rotary shaft 71 attached to the motor 72, is supported by the cover 80.

[0055] The rotating device 70 has the above-described configuration, and when the motor 72 is driven and the rotating shaft 71 rotates, the rotor 2 of the angle sensor 1 fixed to the rotating shaft 71 rotates together with the rotating shaft 71 around the axis x. As a result, the metal body 30 of the rotor 2 rotates facing the coils 40 (40a, 40b) formed by the coil structure 4 of the stator 3 of the angle sensor 1, and the magnetic flux from the excitation circuit 5 acting on each of the multiple coils 40 changes periodically. As a result, signals that change as the rotor 2 rotates are detected from the multiple coils 40. Based on the detection signals from the multiple coils 40, an electric circuit device, which is an external device connected to the angle sensor 1, detects the rotation angle of the rotor 2.

[0056] Next, a modified example of the cover 80 provided in the rotating device 70 described above will be described. Fig. 18 is an exploded perspective view of the rotating device 70 provided with a cover 86 according to the modified example. The cover 86 differs from the cover 80 described above in that the position at which the angle sensor 1 is provided is different. Hereinafter, regarding the configuration of the cover 86, the same configurations as those of the cover 80 described above or configurations having similar functions will be assigned the same reference numerals and description thereof will be omitted, and configurations different from the cover 80 will be described.

[0057] As shown in FIG. 18 , the angle sensor 1 is provided on a surface 82, which is the other of the pair of surfaces of the cover 86. Bosses 83 serving as a plurality of mounting targets corresponding to the plurality of mounting portions 62 of the stator 3 are provided on the surface 82 of the cover 86. Furthermore, instead of the protrusions 84 of the cover 80, holes (hereinafter referred to as "through holes") 87 are formed in the cover 86 that penetrate between the surfaces 81 and 82, and the bearings 76 are supported in the through holes 87. For example, the bearings 76 are housed and press-fitted into the through holes 87, and the bearings 76 are fixed in the through holes 87. In this way, the bearings 76 that rotatably support the rotating shaft 71 attached to the motor 72 are supported by the cover 86.

[0058] The stator 3 is fixed to the cover 86 in the same manner as the fixation to the cover 80 described above. The rotor 2 of the angle sensor 1 is fixed to the tip 71a of the rotating shaft 71 protruding from the surface 82 of the cover 86 through a bearing 76 fixed in a through-hole 87 of the cover 86. As described above, the rotor 2 is located at a predetermined position relative to the stator 3, and the outer circumferential surface 21 of the rotor 2 faces the protruding portion 60 of the stator 3 and the plurality of coils 40 forming the coil structure 4, with an annular gap therebetween (see FIGS. 2 and 3 ). In this manner, the stator 3 is fixed to the surface 82 of the cover 86, and the angle sensor 1 is provided on the surface 82 of the cover 86. Therefore, in the rotating device 70 including the cover 86, the angle sensor 1 is not housed in the internal space of the frame 75 but is located outside the frame 75 and exposed to the outside of the rotating device 70, or the angle sensor 1 is covered by a cup-shaped protective cover. Covering the angle sensor 1 with a protective cover can provide waterproof and dustproof performance.

[0059] In the above structure, the angle sensor 1 is located outside the frame 75, so the diameter of the rotating shaft 71 can be made small without being affected by the structure of the motor 72, and therefore the diameter of the rotor 2 of the angle sensor 1 can be made small. This allows the size of the angle sensor 1 itself to be made small.

[0060] Next, a description will be given of the fixing configuration between the rotating shaft 71 and the rotor 2 of the angle sensor 1 in the rotating device 70. Fig. 19 is a perspective view showing the tip 71a of the rotating shaft 71 and its vicinity. As shown in Fig. 19, a recess 71b is formed on the outer circumferential surface of the tip 71a of the rotating shaft 71. Furthermore, as shown in Figs. 5 and 6, the rotor 2 is formed with a protrusion 28 that is received in the recess 71b of the rotating shaft 71.

[0061] 19 , a step is formed on the tip end 71a of the rotating shaft 71, and the rotating shaft 71 has a first outer peripheral surface 71c, a second outer peripheral surface 71d, and a third outer peripheral surface 71e. The first outer peripheral surface 71c is the main outer peripheral surface of the rotating shaft 71 and is a cylindrical surface extending along the axis x from the tip end 71a to the other end of the rotating shaft 71. The second outer peripheral surface 71d and the third outer peripheral surface 71e are formed on the tip end 71a. The second outer peripheral surface 71d is a cylindrical surface extending along the axis x and is adjacent to the first outer peripheral surface 71c. The third outer peripheral surface 71e is a cylindrical surface extending along the axis x and is adjacent to the second outer peripheral surface 71d on the side opposite to the first outer peripheral surface 71c.

[0062] 19 , the second outer peripheral surface 71d has a radial width smaller than that of the first outer peripheral surface 71c, and a stepped surface 71f, which is an annular surface, is formed between the first outer peripheral surface 71c and the second outer peripheral surface 71d. The third outer peripheral surface 71e has a radial width smaller than that of the second outer peripheral surface 71d, and a stepped surface 71g, which is an annular surface, is formed between the second outer peripheral surface 71d and the third outer peripheral surface 71e. The stepped surfaces 71f and 71g face in the direction of the axis x.

[0063] As shown in FIG. 19 , the recess 71b is formed in the second outer peripheral surface 71d, forming a groove recessed toward the interior of the rotating shaft 71. The recess 71b extends along the axis x. The recess 71b extends to the step surface 71g and opens at the step surface 71g. The recess 71b does not extend to the step surface 71f. The inner peripheral surface 12 of the inner member 10, which is the inner peripheral surface of the rotor 2, is fixed to the second outer peripheral surface 71d. For example, a portion of the second outer peripheral surface 71d of the rotating shaft 71 is press-fitted into a space surrounded by the inner peripheral surface 12 of the rotor 2, thereby fixing the inner peripheral surface 12 of the rotor 2 to the second outer peripheral surface 71d. The configuration for fixing the rotor 2 to the outer peripheral surface 71d of the rotating shaft 71 is not limited to the configuration in which the rotor 2 is fixed by press-fitting. For example, the second outer peripheral surface 71d of the rotating shaft 71 may be inserted into the space surrounded by the inner peripheral surface 12 of the rotor 2, and the inner peripheral surface 12 of the rotor 2 and the second outer peripheral surface 71 may be bonded together with an adhesive or the like to fix the inner peripheral surface 12 of the rotor 2 to the second outer peripheral surface 71d. Alternatively, a separate member such as a metallic ring 77 may be press-fitted to sandwich and fix the rotor 2 between the stepped surface 71f of the rotating shaft 71 and the ring 77 (see FIG. 17 ). If the ring 77 is metallic, it may be made of the same material as the rotating shaft 71. In this case, the linear expansion coefficient of the ring 77 is the same as that of the rotating shaft 71, thereby preventing the ring 77 from coming loose due to thermal deformation. Furthermore, the ring 77 may be made of a different material from that of the rotating shaft 71.

[0064] As described above, the recess 71b does not extend to the step surface 71f, which shortens the cutting time. In addition, the cutting area can be reduced, which prevents a decrease in the strength of the rotating shaft 71.

[0065] 19, the first outer peripheral surface 71c and the third outer peripheral surface 71e at the position of the recess 71b in the circumferential direction are curved surfaces. The second outer peripheral surface 71d is, for example, a cylindrical or approximately cylindrical surface extending along the axis x, and the third outer peripheral surface 71e is, for example, a cylindrical or approximately cylindrical surface extending along the axis x.

[0066] 5 and 6, the protrusion 28 is formed on the inner peripheral end surface 26a of the flange portion 26 of the outer member 20, which is part of the inner peripheral surface of the rotor 2. The protrusion 28 is a portion that protrudes inward from the inner peripheral surface 12, and extends in the direction of the axis x, for example, as shown in Figures 5 and 6. Note that the protrusion 28 may also be formed on the inner peripheral surface 12 of the inner member 10 of the rotor 2.

[0067] When the rotor 2 is molded from a resin material, it is easy to mold the protrusions 28 small in the direction of the axis x, which allows the length of the recesses 71b that accommodate the protrusions 28 in the direction of the axis x to be reduced.

[0068] By inserting the tip end 71a of the rotating shaft 71 into the rotor 2 so that the protrusion 28 of the rotor 2 fits into the recess 71b of the rotating shaft 71, the circumferential position of the rotor 2 relative to the rotating shaft 71 is set to a predetermined position. In this way, in this specific example, the circumferential positioning of the rotor 2 relative to the rotating shaft 71 is facilitated when fixing the rotor 2 to the rotating shaft 71. When the rotor 2 is fixed to the rotating shaft 71, the end face 17 of the inner member 10, which is the end face of the rotor 2, is in contact with the stepped surface 71f of the rotating shaft 71. When the rotor 2 is fixed to the rotating shaft 71, the end face 17 of the rotor 2 does not have to be in contact with the stepped surface 71f of the rotating shaft 71.

[0069] The rotating device 70 according to the embodiment of the present invention has the above-described configuration and includes the angle sensor 1. Therefore, the rotating device 70 can also achieve the functions and effects of the angle sensor 1 described above, and can improve the detection accuracy of the rotation angle of the rotor 2.

[0070] In the above-described embodiment, the stator 3 includes the cylindrical portion 61, which is a cylindrical portion, and has a circumferentially continuous annular shape. However, the shape of the stator 3 is not limited to this. FIG. 20 is a perspective view showing a modified example of the stator 3. For example, as shown in FIG. 20 , the stator 3 may be arc-shaped, or may extend only along a partial circumferential section of the entire circumference of the stator 3 described above. The stator 3 according to the modified example is formed from the same material as the stator 3 described above. The stator 3 according to the modified example is formed, for example, from an insulating resin member. The stator 3 according to the modified example will be specifically described below. Note that, with regard to the configuration of the stator 3 according to the modified example, the same reference numerals will be used to designate components that have the same configuration or similar functions as the stator 3 described above, and their description will be omitted.

[0071] As shown in FIG. 20 , the stator 3 according to the modified example specifically has, for example, an arc-shaped or substantially arc-shaped portion (hereinafter referred to as the arc portion) 61A corresponding to a circumferential section of the cylindrical portion 61, instead of the cylindrical portion 61. As shown in FIG. 20 , a plurality of protrusions 60 are formed in a row on the inner circumferential surface 61a of the arc portion 61A, similar to the stator 3 described above. The arc portion 61A has a plurality of protrusions 60 formed in a portion of the cylindrical portion 61 corresponding to the arc portion 61A. The stator 3 according to the modified example is provided with a detection coil and an excitation circuit. The detection coil is formed by a plurality of coils 40, similar to the detection coil (coil structure 4) provided in the stator 3 described above. Specifically, the plurality of coils 40 are arranged so as to form the portions of the coil structures 4a and 4b located in the portion of the cylindrical portion 61 corresponding to the arc portion 61A. In the stator 3 according to the modified example, like the plurality of coils 40 in the above-described stator 3, the plurality of coils 40 are formed by winding a conductive member such as a magnet wire around the protruding portion 60. Like the above-described excitation circuit 5, the excitation circuit is a magnetic circuit that generates a periodically changing magnetic flux that acts on each of the plurality of coils 40 formed in the arc portion 61A.

[0072] Similarly to the stator 3 described above, the stator 3 according to the modified example also has mounting portions 62, which are portions that are attached to an external device as an application target. In the stator 3 according to the modified example, the mounting portions 62 are provided, for example, at two circumferential ends of the arc portion 61A. Furthermore, the stator 3 according to the modified example has an electric circuit device mounted or fixed thereto, including a circuit unit (not shown), such as an IC, and a calculation unit. Specifically, for example, the stator 3 according to the modified example has a holding portion 63 that accommodates the electric circuit device, similar to the stator 3 described above. The electric circuit device may be provided on one of the circumferential ends of the stator. In this case, a large area can be secured for the excitation circuit and the detection coil, contributing to improved detection accuracy. Furthermore, the electric circuit device and the excitation circuit or the detection coil may be adjacent to each other in the circumferential direction. In other words, the electric circuit device is sandwiched between the detection coil or excitation circuit and the mounting portion 62 in the circumferential direction. In this case, the limited space in the stator 3 can be effectively utilized, contributing to the miniaturization of the angle sensor 1.

[0073] In addition, in the above-described stator 3 and the stator 3 according to the modified example, the stator 3 and the electric circuit device may be sealed with an insulating resin member or the like. In this case, the resin can protect the stator 3 and the electric circuit device from foreign matter and the like.

[0074] Furthermore, the stator 3 described above and the stator 3 according to the modified example may also include a connector that can be electrically connected to an external device. The connector may be provided adjacent to the electric circuit device. In this case, the electric circuit device and the connector can be connected via the shortest path, which contributes to miniaturization of the angle sensor 1.

[0075] Although the present invention has been described above through the above embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0076] The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the present invention. Furthermore, the above-described embodiments do not limit the scope of the present invention, and the present invention may include any and all applications. The components of the above-described embodiments, as well as their arrangement, materials, conditions, shape, size, etc., are not limited to those illustrated and may be modified as appropriate. For example, the present invention includes differences that arise during implementation due to manufacturing tolerances, etc. Furthermore, components illustrated in different embodiments may be partially substituted or combined within the scope of technical inconsistency. Furthermore, the various configurations may be selectively combined as appropriate to achieve at least some of the above-described problems and effects.

[0077] REFERENCE SIGNS LIST 1 Angle sensor, 2 Rotor, 3 Stator, 4 Coil structure, 4a, 4b Coil structure piece, 5 Excitation circuit, 10 Inner member, 11 Outer peripheral surface, 12 Inner peripheral surface, 13 Mounting surface, 14 Protruding surface, 15 Wall, 16, 17 End surface, 16a Recessed portion, 18 Flange portion, 20 Outer member, 21 Outer peripheral surface, 22 Inner peripheral surface, 23 Mounting surface, 24 Concave surface, 25 Wall, 26 Flange portion, 26a Inner peripheral end surface, 26b, 26c End surface, 26d Protruding portion, 27 End surface, 28 Convex portion, 30 Metal body, 31 Outer surface, 32 Inner surface, 33, 34, 35, 36 End surface, 40, 40a, 40b Coil, 41, 41a, 41b Magnet wire, 41a1, 41a2, 41b1, 41b2, end, 50, protrusion, 50a, surface, 50b, connecting portion, 50c, end, 51, cylindrical portion, 51a, inner peripheral surface, 51b, outer peripheral surface, 52, mounting portion, 52a, through hole, 53, holding portion, x-axis, 60, protrusion, 60a, surface, 60b, connecting portion, 60c, end, 61, cylindrical portion, 61A, arc portion, 61a, inner peripheral surface, 61b, outer peripheral surface, 62, mounting portion, 62a, through hole, 63, holding portion, 70, rotating device, 71, rotating shaft, 71a, tip, 71b, recess, 71c, first outer peripheral surface, 71d, second outer peripheral surface, 71e, third outer peripheral surface, 71f, 71g, stepped surface, 72, motor, 73, rotor, 74 Stator, 75 Frame, 75a Opening, 75b End, 76 Bearing, 77 Press-fit ring, 80, 86 Cover, 81, 82 Surface, 83 Boss, 84 Protrusion, 85 Bolt, 87 Through hole, R1 Radius of curvature, r Radial direction, x Axis

Claims

1. An angle sensor comprising: a rotor having an inner cylindrical member, an outer cylindrical member, and a plurality of metal bodies; and a stator having a plurality of coils facing the rotor, wherein in the radial direction, the plurality of metal bodies are sandwiched between the inner cylindrical member and the outer cylindrical member.

2. The angle sensor according to claim 1, wherein each of the plurality of metal bodies has a curved shape.

3. The angle sensor according to claim 1 or 2, wherein the outer surface of the inner cylindrical member includes a plurality of curved portions.

4. The angle sensor according to any one of claims 1 to 3, wherein the outer cylindrical member includes a plurality of curved inner surfaces.

5. The angle sensor according to any one of claims 1 to 4, wherein the outer surface of the inner cylindrical member includes a plurality of walls extending in the radial direction, and the plurality of metal bodies are disposed between the plurality of walls.

6. The angle sensor according to any one of claims 1 to 5, wherein the inner cylindrical member or the outer cylindrical member includes a convex portion that is received in a recess of a rotation axis to which the angle sensor is fixed.

7. A rotating device comprising: the angle sensor according to any one of claims 1 to 6; a rotation axis fixed to the rotor of the angle sensor; and a motor including a rotor fixed to the rotation axis and a stator.

8. The rotating device according to claim 7, wherein the motor includes a frame that houses the rotor and the stator, and a cover that covers an opening of the frame, and the angle sensor is fixed to the cover.

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