Rotary device

Abstract

[Problem] To provide a rotary device capable of suppressing the effect of movement of a rotary shaft in the axial direction on the detected rotation angle. [Solution] A rotary device 1 comprises an angle sensor 2, a rotary shaft 3, a motor 4, and a conductor 5. The angle sensor 2 is provided with a rotor 6 having a plurality of metal bodies 10 and a stator 7 having a plurality of coils 20. The rotary shaft 3 is fixed to the rotor 6 of the angle sensor 2. The motor 4 has a frame 30 and a cover 40 that covers an opening 31 in the frame 30. The angle sensor 2 is fixed to the cover 40.

Description

Rotating Equipment

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

[0002] Conventionally, rotating devices having a motor or the like are equipped with a sensor for detecting the rotation angle of the device. There are various types of sensors for detecting the rotation angle. Among such angle sensors for detecting the rotation angle is an inductive sensor (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2019-200106

[0004] Conventional inductive sensors are formed on a plane perpendicular to the axis of the rotating shaft. Therefore, conventional inductive sensors are easily affected by axial movement of the rotating shaft. Thus, in rotating equipment equipped with conventional inductive sensors, the detected rotation angle is easily affected by axial movement.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotating device that can suppress the influence of axial movement of a rotating shaft on a detected rotation angle.

[0006] A rotating device according to one aspect of the present invention comprises an angle sensor having a rotor with multiple metal bodies and a stator with multiple coils, a motor having a rotating shaft fixed to the rotor of the angle sensor, a frame, and a cover covering an opening of the frame, and a conductor, wherein the angle sensor is fixed to the cover.

[0007] 11 is a diagram schematically illustrating the configuration of a rotating device according to an embodiment of the present invention. FIG. 12 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 by transmitting through some members of the angle sensor. FIG. 13 is a perspective view schematically illustrating the configuration of the angle sensor. FIG. 14 is a front view schematically illustrating the configuration of the angle sensor. FIG. 15 is a side view schematically illustrating the configuration of the angle sensor. FIG. 16 is a transparent perspective view schematically illustrating a specific example of a rotor. FIG. 17 is a perspective view schematically illustrating a specific example of a stator. FIG. 18 is a cross-sectional view showing the A-A cross section of FIG. 7. FIG. 19 is a side view schematically illustrating a specific example of a stator. FIG. 19 is a perspective view showing a specific example of a coil structure formed by a plurality of coils. FIG. 19 is a diagram showing a cover to which a stator is attached, as seen from the front. FIG. 11 is a partially enlarged view of FIG. 11, showing an enlarged view of the vicinity of the stator mounting portion and the cover mounting portion. FIG. 19 is a diagram showing the cover to which a stator is attached, and is a side view of the vicinity of the stator mounting portion and the cover mounting portion. FIG. 19 is a diagram showing the cover to which a stator is attached, and is a transparent perspective view of the vicinity of the stator mounting portion and the cover mounting portion. FIG. 19 is an exploded perspective view of a rotating device provided with a cover according to a modified example. 10 is a diagram illustrating a schematic configuration of a rotating device according to another embodiment of the present invention;FIG. 11 is a perspective view illustrating a modified example of a stator;FIG.

[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 some of the reference numerals of the components may be omitted. FIG. 1 is a diagram schematically illustrating the configuration of a rotating device 1 according to an embodiment of the present invention. FIG. 2 is a diagram schematically illustrating the configuration of an angle sensor 2 according to an embodiment of the present invention, and is a transparent perspective view showing the internal configuration through some of the components of the angle sensor 2. FIG. 3 is a perspective view schematically illustrating the configuration of the angle sensor 2, FIG. 4 is a front view schematically illustrating the configuration of the angle sensor 2, and FIG. 5 is a side view schematically illustrating the configuration of the angle sensor 2. As shown in FIGS. 1 to 5 , the rotating device 1 includes an angle sensor 2, a rotating shaft 3, a motor 4, and a conductor 5. The angle sensor 2 includes a rotor 6 having a plurality of metal bodies 10 and a stator 7 having a plurality of coils 20. The rotating shaft 3 is fixed to the rotor 6 of the angle sensor 2. The motor 4 includes a frame 30 and a cover 40 that covers an opening 31 of the frame 30. The angle sensor 2 is fixed to the cover 40. The configuration of the rotating device 1 will be described in detail below. Note that the rotor 6 and the stator 7 are shown in a predetermined positional relationship in Figures 3 to 5. This predetermined positional relationship is an example of the positional relationship between the rotor 6 and the stator 7 when the angle sensor 2 is attached to the rotating device 1 and in use. In the angle sensor 2, the rotor 6 is disposed inside the stator 7.

[0009] As shown in Figures 2 to 5, the rotor 6 has a cylinder 11, and multiple metal bodies 10 serving as conductors are provided on the cylinder 11. The conductor may be a metal body or a member having a conductive material (a member capable of generating so-called eddy currents or induced currents (electric currents) within one surface), and the following description will use a metal body as an example. The metal body 10 is made of a conductive metal material. The multiple metal bodies 10 are, for example, arranged in a circumferential direction around an axis x, which is the rotation axis of the rotating device 1. As shown schematically in Figure 2, the multiple metal bodies 10 form a cylindrical shape (hereinafter referred to as a metal body structure 12) extending annularly around the axis x. The metal body structure 12 may be embedded inside the cylinder 11 or provided on the surface of the cylinder 11. The metal body 10 has a portion extending along the axis x. Furthermore, the multiple metal bodies 10 may be connected to each other. The multiple metal bodies 10 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 10 may be electrically connected.

[0010] As shown in FIGS. 2 to 5 , the cylinder 11 of the rotor 6 is a cylindrical member extending along the axis x. For example, as shown in FIGS. 3 to 5 , the cylinder 11 of the rotor 6 has an inner circumferential surface 13, which is a cylindrical surface extending along a cylindrical surface with the axis x as its center axis, and an outer circumferential surface 14, which is a cylindrical surface facing away from the inner circumferential surface 13 on the radially outer side (hereinafter also referred to as the "outer circumferential side"). The radial direction is a direction perpendicular to the axis x. The cylinder 11 also has end faces 15 and 16, which are surfaces facing in the respective directions along which the axis x extends. The inner circumferential surface 13 and the outer circumferential surface 14 extend between the end face 15 (at one end) and the end face 16 (at the other end). The cylinder 11 of the rotor 6 is made of, for example, a resin material, a non-magnetic material, a non-conductive material, or the like. The resin material of the cylinder 11 is, for example, an epoxy-based resin (thermosetting resin). The material of the tube 11 may be other resins. For example, a recyclable resin may be used for the material of the tube 11. The non-magnetic material may be non-conductive.

[0011] FIG. 6 is a see-through perspective view schematically illustrating a specific example of the rotor 6. In FIG. 6, the interior of the cylinder 11 is shown in a see-through manner. As shown in FIG. 6, multiple metal bodies 10 are arranged in an annular shape, forming a cylindrical shape (hereinafter referred to as a metal body structure) 12 (see FIG. 2). Each metal body 10 extends along the axis x of the cylinder 11 and also extends circumferentially along the cylinder 11, forming a plate-like shape facing radially and forming a surface facing the outer periphery. Also, as shown in FIG. 6, the multiple metal bodies 10 are arranged at a predetermined distance apart in the circumferential direction of the cylinder 11. In other words, two adjacent metal bodies 10 are spaced a predetermined distance apart around the axis x. The multiple metal bodies 10 are arranged, for example, at equal or approximately equal angular intervals in the circumferential direction along a cylindrical surface whose central axis is the axis x. The shape of the metal bodies 10 is not limited to the above-described shape. For example, the multiple metal bodies 10 have a curved shape. The metal bodies 10 each have, in the circumferential direction, two end portions and a portion (middle portion) between the two end portions. In the radial direction, the distance between the end portion of the metal body 10 and the outer peripheral surface 14 of the cylinder 11 of the rotor 6 (described later) is greater than the distance between the middle portion of the metal body 10 and the outer peripheral surface 14 of the cylinder 11 of the rotor 6, and the end portion of the metal body 10 is farther from the outer peripheral surface 16 of the cylinder 11 of the rotor 6 than the middle portion.

[0012] As shown in FIGS. 2 to 5 , the stator 7 has a cylindrical portion 21 that corresponds to the cylinder 10 of the rotor 6. The cylindrical portion 21 defines a space capable of accommodating the rotor 6 and has an inner circumferential surface 22 that defines this space. The inner circumferential surface 22 is a cylindrical surface extending along the axis x and faces the outer circumferential surface 14 of the cylinder 11 of the rotor 6 across an annular gap. The inner circumferential surface 22 is, for example, a cylindrical surface extending along a cylindrical surface with the axis x as its central axis. The multiple coils 20 are supported within the cylindrical portion 21, for example. The multiple coils 20 may be provided on the surface of the cylindrical portion 21. Alternatively, the multiple coils 20 may be embedded in the cylindrical portion 21 and disposed inside the cylindrical portion 40. The coils 20 are formed of a conductive material, for example, a magnet wire.

[0013] As shown in FIGS. 2 to 5 , the stator 7 has a mounting portion 24 that is attached to a cover 40 of an external device (e.g., the rotating device 1) to which the stator 7 is applied. As shown in FIGS. 2 to 5 , the mounting portion 24 is provided, for example, on the outer peripheral surface 23 of the tube 11 and protrudes outward from the tube portion 21. The outer peripheral surface 23 of the tube portion 21 is a cylindrical surface facing away from the inner peripheral surface 22. The mounting portion 24 also has a through hole 24a through which a fixing member such as a bolt is passed, allowing the mounting portion 24 to be attached to the cover 40 by the fixing member. The stator 7 has, for example, three mounting portions 24. Note that the number of mounting portions 24 included in the stator 7 is not limited to this. As shown in FIGS. 2 to 4 , the mounting portion 24 has an opening 24b formed therein. The opening 24b is a through hole that forms a space that penetrates the mounting portion 24 in the direction of the axis x. 2 to 4, the opening 24b is formed on the inner peripheral side of the through-hole 24a. Note that the mounting portion 24 does not necessarily have to have the opening 24b.

[0014] 2 to 5, the stator 7 has a holding portion 25 that is a portion that houses a substrate 8, which is an electric circuit device having a circuit portion such as an IC and a calculation portion. As shown in FIGS. 2 to 5, the holding portion 25 extends from the outer peripheral surface 23 of the cylindrical portion 21 in one direction along the axis x. Note that, as shown in FIGS. 2 and 3, in the angle sensor 2, the substrate 8 is attached to the holding portion 25 of the stator 7. The substrate 8 is provided with, for example, one or more electronic components and one or more wirings.

[0015] Although the above description shows a configuration in which one or more wirings are provided on the substrate 8, the configuration of the substrate 8 is not limited to this. For example, a configuration without wiring for communication may be possible in which power supply and wireless communication are performed using electricity generated by the angle sensor 2 or another power generation device. In this case, the substrate 8 may be provided with wiring for supplying power for excitation.

[0016] The stator 7 has an insulator 7a. The insulator 7a is made of an insulating material, for example, a resin material, and is integrally formed therewith. The stator is made of, for example, a resin material, a non-magnetic material, or a non-conductive material. Note that the non-magnetic material may be non-conductive. The resin material forming the insulator 7a is, for example, an epoxy-based resin (thermosetting resin). Note that the material forming the insulator 7a may also be another resin.

[0017] As described above, multiple coils 20 are wound around the insulator 7a. The multiple coils 20 are, for example, arranged in the circumferential direction around the axis x. As shown schematically in FIG. 2 , the multiple coils 20 are connected together to form a cylindrical shape (hereinafter referred to as a coil structure) 26 extending in an annular shape around the axis x. The coil structure 26 is a shape formed by the arrangement of the multiple coils 20. In the coil structure 26, the multiple coils 20 are, for example, arranged in an annular shape so as to be aligned along an annular surface around the axis x. The multiple coils 20 are, for example, arranged in an annular shape so as to be aligned along a cylindrical surface with the axis x as the central axis. Furthermore, each coil 20 has, for example, a shape that surrounds a space. Furthermore, each coil 20 has, for example, a shape such that the space surrounded by each coil 20 follows an annular surface around the axis x.

[0018] The conductor 5 is made of a conductive material and is, for example, annular around the axis x as shown in Fig. 2. The conductor 5 is attached to, for example, the cylindrical portion 21 of the stator 7. Specifically, the conductor 5 is attached to the outer periphery, which is the outer peripheral portion of the cylindrical portion 21 of the stator 7. The conductor 5 may be exposed on the surface of the cylindrical portion 21 of the stator 7, or may be buried inside the cylindrical portion 21.

[0019] FIG. 7 is a perspective view schematically illustrating a specific example of the stator 7, FIG. 8 is a cross-sectional view showing the A-A cross section of FIG. 7, and FIG. 9 is a side view schematically illustrating a specific example of the stator 7. As shown in FIG. 7, the insulator 7a of the stator 7 has multiple protrusions 27 protruding toward the inner periphery. The multiple protrusions 27 are portions that protrude from the inner periphery surface 22 of the cylindrical portion 21 toward the inner periphery (inward in the radial direction r). The multiple protrusions 27 are provided on the inner periphery surface 22, for example, at predetermined angles or predetermined intervals (e.g., equiangular or approximately equiangular intervals in the illustrated example) around the axis x. The protrusions 27 protrude from the inner periphery surface 22 in the radial direction r. Each protrusion 27 has a surface 27a facing the inner periphery, and the surface 27a faces the outer periphery surface 14 of the cylindrical portion 11 of the rotor 6 with an annular gap therebetween. The surfaces 27a of the plurality of protrusions 27 are arranged, for example, along a cylindrical surface whose central axis is the axis x. As shown in Fig. 8 , the protrusions 27 each include a connecting portion 27b that connects to the inner circumferential surface 22 and an end portion 27c on the rotor 2 side. The end portion 27c on the rotor 2 side includes a surface 27a that extends in the circumferential direction and in the direction of the axis x. The surface 27a of the end portion 27c has an area (a predetermined surface area) larger than the cross section of the connecting portion 27b and faces the side surface of the rotor 3.

[0020] The coil 20 is formed by, for example, winding a magnet wire as a conductive member. As shown in Fig. 7 , the coil 20 is formed by winding the magnet wire around a plurality of protrusions 27. The coil 20 has an annular shape wound around the radial direction r of the cylindrical portion 21, and surrounds a planar space facing the radial direction. A plurality of coils 20 are formed in the cylindrical portion 21 of the stator 7, lined up around the axis x, to form a coil structure 26.

[0021] FIG. 10 is a perspective view showing a specific example of a coil structure 26 formed by multiple coils 20. As shown in FIG. 10 , the coil structure 26 has two pieces (hereinafter referred to as coil structure pieces) 26a and 26b. The coil structure piece 26a is formed by multiple coils 20a, which are the coil 20 described above, connected in series in an annular shape. Similarly, the coil structure piece 26b is formed by multiple coils 20b, which are the coil 20 described above, connected in series in an annular shape. That is, multiple annular coils 20a or 20b are arranged in the circumferential direction. The coil structure pieces 26a and 26b are formed of conductive materials. The coil structure pieces 26a and 26b are coated with, for example, an insulating material (an insulating film or coating) and are electrically insulated from each other. As shown in FIG. 10 , the coil structure pieces 26a and 26b overlap radially to form the coil structure 26. In the coil structure pieces 26a and 26b, a portion of the space surrounded by the coil 20a is offset from a portion of the space surrounded by the coil 20b in the circumferential direction, and another portion of the space surrounded by the coil 20a is overlapped in the circumferential direction with another portion of the space surrounded by the coil 20b. Specifically, the space surrounded by the stator coil 20a is offset from the space surrounded by the coil 20b in the circumferential direction by half the width of the space surrounded by the coil 20a. The number of coils 20a and 20b in each of the coil structure pieces 26a and 26b corresponds to the axial multiplier angle set for the angle sensor 2. The number of coil structure pieces 26a and 26b also corresponds to the number of detection signals output by the coil structure 26.

[0022] A plurality of coils are wound around the plurality of protrusions 27. As shown in FIG. 7 , a magnet wire serving as a conductive member is wound around each of the protrusions 27 in the radial direction r, and a plurality of annular coils 20 are formed around the plurality of protrusions 27 in the radial direction r, thereby forming a coil structure 26 in the stator 7. For example, the coil structure pieces 26a, 26b are each formed by winding one magnet wire around the plurality of protrusions 27 of the cylindrical portion 21. Specifically, for example, for each of two adjacent protrusions 27 toward one side in the circumferential direction, the magnet wire is wound around the protrusions 27 alternately from one side in the axial x direction and the other side in the axial x direction, and after going around the cylindrical portion 21 once, the magnet wire is turned back and wound around the protrusions 27 once again toward the other side in the circumferential direction, thereby forming the coil structure pieces 26a, 26b. In this case, each of the coils 20a, 20b is formed around two protrusions 27. Furthermore, the coil structure pieces 26a and 26b are offset from each other in the circumferential direction by one protrusion 27. Note that each of the coils 20a, 20b is not limited to being formed around two protrusions 27, but may be formed around other numbers of protrusions 27. While the magnet wire has been described as being wound around one circumference, the winding pattern of the magnet wire is not limited to this, and the magnet wire may be wound around two or more circumferences. In other words, the coil formed by winding the magnet wire may have multiple layers, such as two, three, four, or five layers, in addition to one layer in the radial or axial direction. In this case, the output signal or the detected signal (e.g., the amplitude of the signal waveform) can be amplified compared to the case of one circumference or one layer.

[0023] As shown in FIG. 9 , an annular step 28 is provided around the axis x on the outer circumferential portion 21b of the cylindrical portion 21 of the insulator 7a. The step 28 is formed on the side surface 21a of the cylindrical portion 21, as shown in FIG. 8 , for example. The side surface 21a of the cylindrical portion 21 is an annular surface facing one side in the direction of the axis x. The step 28 is an annular portion protruding from the side surface 21a in the direction of the axis x, forming a step surface 28a, which is an annular surface facing the outer circumferential side. The outer size (diameter) of the step surface 28a is smaller than the outer size (diameter) of the outer circumferential surface 23 of the cylindrical portion 21. The step surface 28a is, for example, a cylindrical surface extending along a cylindrical surface with the axis x as its central axis. The step surface 28a is formed with an annular recess 28b recessed toward the inner circumferential side. The conductive wire 5 is accommodated in the recess 28b. Hereinafter, the outer size will be described as a diameter as an example.

[0024] As described above, FIGS. 3 to 5 show the angle sensor 2 in use. The multiple metal bodies 10 and the multiple coils 20 face each other in the radial direction with an annular gap between them. As shown in FIGS. 2 and 5, the width W1 of the metal body 10 is, for example, wider than the width W2 of the coil 20. Note that the width W1 is the distance of the metal body 10 in the axial x direction, and the width W2 is the distance of the coil 20 in the axial x direction. This allows the entire width of the coil 20 in the axial x direction to face the metal body 10 in the radial direction (see FIG. 5). The metal body 10 also protrudes beyond the coil 20 in both directions along the axial x direction (see FIG. 5).

[0025] The rotor 6 and the stator 7 form an inductive angle sensor, and the multiple coils 20 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 2, a radially directed magnetic flux whose magnitude periodically changes acts on the multiple coils 20. Specifically, the conductor 5 provided on the stator 7 forms a magnetic circuit that generates a periodically changing magnetic flux acting on each of the multiple coils 20. In other words, the conductor 5 forms an excitation circuit. Meanwhile, as described above, the multiple metal bodies 10 are arranged in the circumferential direction around the axis x, and cross the magnetic flux generated by the conductor 5 (excitation circuit) as the rotor 6 rotates. Furthermore, the projection of the metal body 10, which has a portion extending along the axis x, onto the coils 20 in the radial direction moves as the rotor 6 rotates. For this reason, the magnetic fluxes from the conductors (excitation circuits) acting on each of the multiple coils 20 are affected by eddy currents generated in the metal body 10 and cancel each other out, causing the magnetic fluxes to change periodically with the rotation of the rotor 6. As a result, electromotive forces that change with the rotation of the rotor 6 are generated in the multiple coils 20 due to electromagnetic induction, and signals that change with the rotation of the rotor 6 are detected from the multiple coils 20. Based on the detection signals from the multiple coils 20, the rotation angle of the rotor 6 is detected in a device having an electric circuit.

[0026] As described above, in the rotating device 1, the angle sensor 2 is fixed to the cover 40. Note that Fig. 1 shows the angle sensor 2 having one specific example of the stator 6 shown in Figs. 7 and 9. As shown in Fig. 1, the motor 4 of the rotating device 1 includes a rotor 4a and a stator 4b, and the rotating shaft 3 is fixed to the rotor 4a. As described above, the motor 4 has a frame 30 and a cover 40, and the frame 30 houses the rotor 4a and the stator 4b. Furthermore, the cover 40 covers the opening 31 of the frame 30.

[0027] An opening 31 in the frame 30 opens the interior space of the frame 30 to the outside of the frame 30. The rotor 4a and the stator 4b are housed in the interior space of the frame 30. As shown in Fig. 1, the frame 30 is, for example, a cylindrical member. The frame 30 has an annular end portion 30a that surrounds the opening 31, and the end portion 30a faces in the direction of the axis x.

[0028] The rotor 6 of the angle sensor 2 is fixed to the rotating shaft 3, and one end 3a of the rotating shaft 3 (hereinafter referred to as the tip) passes through the rotor 6 and is rotatably supported by a bearing 9 fixed to the cover 40. The stator 7 of the angle sensor 2 is fixed to the cover 40. In the rotating device 1, the rotor 6 is located at a predetermined position relative to the stator 7 as described above, and the outer circumferential surface 14 of the rotor 6 faces the protruding portion 27 and the coil structure 26 of the cylindrical portion 21 of the stator 7 with an annular gap therebetween (see FIGS. 5 and 7 ).

[0029] As shown in FIG. 1 , the cover 40 is a plate-shaped member having a pair of opposing surfaces 41 and 42. The cover 40 is made of, for example, metal, specifically, aluminum. In the rotating device 1, one of the pair of opposing surfaces 41 and 42 of the cover 40, for example, the surface 41, covers the opening 31 of the frame 30. That is, the cover 40 is fixed to the frame 30 with the surface 41 in contact with the end 30 a of the frame 30. For example, the surface 41 of the cover 40 is adhered to the end 30 a of the frame 30, thereby fixing the cover 40 to the frame 30. The cover 40 may be fixed to the frame 30 by a method other than adhesion. For example, the cover 40 may be fixed to the frame 30 by a fixing means such as a bolt or a locking means such as a claw.

[0030] The angle sensor 2 is attached to a surface 41, which is one of a pair of surfaces of the cover 40. For example, the surface 41 of the cover 40 is provided with a plurality of connecting portions 43 corresponding to the plurality of mounting portions 24 of the stator 7. The connecting portions 43 are portions to which the mounting portions 24 of the stator 7 of the angle sensor 2 are attached, and connect the angle sensor 2 to the cover 40. The connecting portions 43 are arranged, for example, at predetermined intervals or predetermined angular intervals around the axis x (for example, at equal angular intervals or approximately equal angular intervals in the illustrated example) at radial positions corresponding to the respective mounting portions 24 of the stator 7. As shown in FIG. 1 , the connecting portions 43 are portions that protrude from the surface 41 and have threaded holes formed therein. Bolts 45 are threaded into the threaded holes of the connecting portions 43 via the mounting portions 24 of the stator 7, and each mounting portion 24 is fixed to the corresponding connecting portion 43 by the bolts 45, thereby fixing the stator 7 to the cover 40. In this way, the stator 7 is fixed to the surface 41 of the cover 40, and the angle sensor 2 is provided on the surface 41 of the cover 40. Therefore, in the rotating device 1, the angle sensor 2 is housed in the space inside the frame 30.

[0031] 1 , a surface 41 of the cover 40 is formed with, for example, an annular protrusion 44 that supports a bearing 9. The protrusion 44 is an annular tube that protrudes from the surface 41 of the cover 40 and has a recess formed therein. The protrusion 44 is also a flange that extends a predetermined distance in the radial direction. The protrusion 44 houses the bearing 9, and the bearing 9 is fitted and fixed in place. For example, the bearing 9 is press-fitted into the recess formed by the protrusion 44, and the bearing 9 is fixed to the protrusion 44. In this way, the bearing 9 that rotatably supports the tip end 3 a of the rotary shaft 3 attached to the motor 4 is supported by the cover 40.

[0032] 11 to 14 are diagrams showing the cover 40 to which the stator 7 is attached, with Fig. 11 being a diagram of the cover 40 as seen from the front, and Fig. 12 being a partially enlarged view of Fig. 11, showing an enlarged view of the vicinity of the mounting portion 24 of the stator 7 and the connecting portion 43 of the cover 40. Fig. 13 is a side view of the vicinity of the mounting portion 24 of the stator 7 and the connecting portion 43 of the cover 40, and Fig. 14 is a see-through perspective view of the vicinity of the mounting portion 24 of the stator 7 and the connecting portion 43 of the cover 40. In Fig. 14, the connecting portion 43 of the cover 40 is shown through the mounting portion 24 of the stator 27.

[0033] As shown in FIGS. 11 to 14 , the mounting portion 24 of the stator 7 of the angle sensor 1 is fixed to a connecting portion 43 provided on the cover 40 by a bolt 45 serving as a fixing member. The connecting portion 43 serves as a mounting receiving portion for the mounting portion 24. As shown in FIGS. 13 and 14 , for example, the connecting portion 43 of the cover 40 has a boss portion 43 a and a protruding portion 43 b. The boss portion 43 a supports the mounting portion 24 of the stator 7 in the direction of the axis x and has a through hole 45 a formed therein for inserting the bolt 45. For example, when inserting the bolt 45, the through hole 45 a is a threaded hole, but is not limited thereto. The mounting portion 24 and the connecting portion 43 may be fixed by inserting a resin boss into the through hole 45 a and thermally caulking the boss. The protruding portion 43 b faces the mounting portion 24 of the stator 7 from the outer periphery in the radial direction. The protrusion 43b is adjacent to the boss 43a on the outer periphery side and protrudes further in the direction of the axis x than the boss 43a. As shown in FIGS. 11, 12, and 14, the protrusion 43b contacts the mounting portion 24 of the stator 7 from the outer periphery side. This contact allows the angle sensor 2 to be positioned. The contact surface has a curved shape that follows the outer periphery of the mounting portion 24. Note that the protrusion 43b does not contact the mounting portion 24 of the stator 7 from the outer periphery side, and a predetermined gap may be formed between the protrusion 43b and the mounting portion 24 in the radial direction.

[0034] Furthermore, a through-hole (not shown) may be provided in the mounting portion 24 in the direction of the axis x, and a knock pin may be inserted into this through-hole as a member (stopper). In this case, the through-hole is connected to the boss portion 43a, and the knock pin is inserted until it reaches the boss portion 43a. Furthermore, the connecting portion 43 may have a protrusion (not shown) extending in the radial direction. This protrusion extends to a position where it partially overlaps with the mounting portion 24 in the circumferential direction. This prevents the angle sensor 1 from rotating.

[0035] 11, 12, and 114, the opening 24b formed in the mounting portion 24 of the stator 7 is positioned more inward than the connecting portion 43 of the cover 40. Also, as shown in FIG. 13, the radial distance (distance r) between the boss portion 43a and the recess 28b formed in the step portion 28 of the cylindrical portion 21 of the stator 7 is a predetermined distance. Since the conductor 5, which is an excitation circuit, is wound around the recess 28b, the proximity of a metal member may affect the magnetic field generated by the conductor 5. Therefore, the distance r between the recess 28b and the metal boss portion 43a is a predetermined distance so that the boss portion 43a does not affect the magnetic field generated by the conductor 5.

[0036] The rotating device 1 has the above-described configuration, and when the motor 4 is driven and the rotating shaft 3 rotates, the rotor 6 of the angle sensor 2 fixed to the rotating shaft 3 rotates around the axis x together with the rotating shaft 3. As a result, the metal body 10 of the rotor 6 rotates facing the coils 20 formed by the coil structure 26 of the stator 7 of the angle sensor 2, and the magnetic flux from the conductor 5 (excitation circuit) acting on each of the multiple coils 20 changes periodically. As a result, signals that change as the rotor 6 rotates are detected from the multiple coils 20. Based on the detection signals from the multiple coils 20, an electric circuit device, which is an external device connected to the angle sensor 2, detects the rotation angle of the rotor 6.

[0037] Next, a modified example of the cover 40 included in the rotating device 1 described above will be described. Fig. 15 is an exploded perspective view of the rotating device 1 including a cover 46 according to the modified example. The cover 46 differs from the above-described cover 40 in that the angle sensor 2 is provided at a different position. Hereinafter, regarding the configuration of the cover 46, components that are the same as or have similar functions to the above-described cover 40 will be denoted by the same reference numerals and will not be described again, and components that differ from the cover 40 will be described.

[0038] As shown in FIG. 15 , the angle sensor 2 is provided on the surface 42 of the cover 46, which is the other of the pair of surfaces of the cover 46. A plurality of connecting portions 43 corresponding to the plurality of mounting portions 24 of the stator 7 are provided on the surface 42 of the cover 46. Furthermore, instead of the protruding portions 44 of the cover 40, the cover 46 has holes (hereinafter referred to as through holes) 47 that penetrate between the surfaces 41 and 42, and the bearings 9 are supported in the through holes 47. For example, the bearings 9 are housed and press-fitted into the through holes 47, and the bearings 9 are fixed in the through holes 47. In this way, the bearings 9 that rotatably support the rotating shaft 3 attached to the motor 4 are supported by the cover 46.

[0039] The stator 7 is fixed to the cover 46 in the same manner as the fixation to the cover 40 described above. The rotor 6 of the angle sensor 2 is fixed to the tip 3 a of the rotating shaft 3 protruding from the surface 42 of the cover 46 through a bearing 9 fixed in a through-hole 47 of the cover 46. As described above, the rotor 6 is located at a predetermined position relative to the stator 7, and the outer circumferential surface 14 of the rotor 6 faces the protruding portion 27 of the cylindrical portion 21 of the stator 7 and the coil structure 26 with an annular gap therebetween (see FIGS. 5 and 7 ). In this manner, the stator 7 is fixed to the surface 42 of the cover 46, and the angle sensor 2 is provided on the surface 42 of the cover 46. Therefore, in the rotating device 1 including the cover 46, the angle sensor 2 is not housed in the internal space of the frame 30 but is located outside the frame 30 and exposed to the outside of the rotating device 1, or the angle sensor 2 is covered by a cup-shaped protective cover (protective member). Covering the angle sensor 2 with a protective cover can provide waterproof and dustproof performance.

[0040] In the above structure, the angle sensor 2 is located outside the frame 30, so the diameter of the rotating shaft 3 can be reduced without being affected by the structure of the motor 4, and therefore the diameter of the rotor 6 of the angle sensor 2 can be reduced. As a result, the size of the angle sensor 2 itself can be reduced.

[0041] The rotating device 1 has the above-described configuration, and each metal body 10 of the angle sensor 2 faces in the radial direction. Therefore, the metal bodies 10 can suppress the influence of movement of the rotor 6 in the axial x direction. For example, the rigidity of the metal bodies 10 against vibration of the rotor 6 in the axial x direction is increased, which increases the accuracy of the angle sensor 2 and also increases the strength of the metal bodies 10 against vibration of the rotor 6 in the axial x direction. Furthermore, the metal bodies 10 are fixed to the cylinder 11 of the rotor 6, which also increases the strength of the metal bodies 10 against vibration of the rotor 6 in the axial x direction.

[0042] Furthermore, the cylinder 11 of the rotor 6 is cylindrical and extends along the axis x, and even if the thickness in the radial direction is reduced, the strength of the cylinder 11 against vibration in the direction of the axis x of the rotor 6 can be maintained at a high level. Therefore, the thickness in the radial direction of the cylinder 11 can be reduced, making the rotor 6 lighter and reducing the installation space for the rotor 6.

[0043] As described above, the coil structure 26 has a cylindrical shape extending along the axis x, and each coil 20 is aligned along the axis x and faces in the radial direction. This allows the coils 20 to suppress the effects of movement of the stator 7 in the direction of the axis x. For example, the stiffness of the coils 20 against vibration of the stator 7 in the direction of the axis x is increased, which improves the accuracy of the angle sensor 2 and also increases the strength of the coils 20 against vibration of the stator 7 in the direction of the axis x.

[0044] Furthermore, by making the width W1 of the metal body 10 in the axial x direction larger than the width W2 of the coil 20 in the axial x direction, the metal body 10 can be extended beyond the coil 20 in both directions along the axial x. As a result, even if relative movement occurs between the rotor 6 and the stator 7 in the axial x direction and the positional relationship between the rotor 6 and the stator 7 in the axial x direction deviates from the desired positional relationship, the entire width W2 of the coil 20 can face the metal body 10. Therefore, even if the positional relationship between the rotor 6 and the stator 7 in the axial x direction deviates from the desired positional relationship, the accuracy of the detected angle is not affected or the effect on the accuracy of the detected angle can be reduced. Furthermore, even if eccentricity occurs between the rotor 6 and the stator 7, the portions where the radial spacing between the multiple metal bodies 10 and the coil structure 26 widens and the portions where it narrows are balanced, so in this case too, the accuracy of the detected angle is not affected or the effect on the accuracy of the detected angle can be reduced.

[0045] In this way, the rotating device 1 according to the embodiment of the present invention can suppress the influence of movement of the rotating shaft 3 in the direction of the axis x on the detected rotation angle. Therefore, the rotating device 1 can increase the accuracy of the detected rotation angle.

[0046] As described above, the radial distance r between the recess 28b formed in the cylindrical portion 21 of the stator 7, in which the conductor 5 is housed, and the boss portion 43a is set to a predetermined distance so that the metallic boss portion 43a does not affect the magnetic field generated by the conductor 5. In this respect as well, the rotating device 1 can improve the accuracy of the rotation angle that is detected.

[0047] 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.

[0048] 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.

[0049] For example, the metal body 10 and metal body structure 12 included in the angle sensor 2 are not limited to the form shown in Fig. 6, but may have other forms. Similarly, the stator 7, coil 20, and coil structure 26 included in the angle sensor 2 are not limited to the forms shown in Figs. 7 to 9, but may have other forms.

[0050] For example, in the above-described embodiment, the stator 7 includes the cylindrical portion 21, which is a cylindrical portion, and has a circumferentially continuous annular shape. However, the shape of the stator 7 is not limited to this. FIG. 17 is a perspective view showing a modified example of the stator 7. For example, as shown in FIG. 17, the stator 7 may be arc-shaped, or may extend only along a partial circumferential section of the entire circumference of the stator 7 described above. The stator 7 according to the modified example is formed from the same material as the stator 7 described above. The stator 7 according to the modified example is formed, for example, from an insulating resin member. The stator 7 according to the modified example will be specifically described below. Note that, with regard to the configuration of the stator 7 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 7 described above, and their description will be omitted.

[0051] As shown in FIG. 17 , the stator 7 according to the modified example has, for example, instead of the cylindrical tubular portion 21, a portion 21A extending in an arc-like or substantially arc-like shape (hereinafter referred to as the arc portion) corresponding to a circumferential section of the tubular portion 21. As shown in FIG. 17 , a plurality of protrusions 27 are formed in a row on the inner circumferential surface 22 of the arc portion 21A, similar to the stator 7 described above. The arc portion 21A has a plurality of protrusions 27 formed in a portion of the tubular portion 21 corresponding to the arc portion 21A. The stator 7 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 20, similar to the detection coil (coil structure 26) provided in the stator 7 described above. Specifically, the plurality of coils 20 are arranged so as to form coil structure pieces 26a and 26b located in the portion of the tubular portion 21 corresponding to the arc portion 21A. In the stator 7 according to the modified example, similar to the plurality of coils 20 in the above-described stator 7, the plurality of coils 20 are formed by winding a conductive member such as a magnet wire around the protruding portion 27. Similar to the above-described excitation circuit, the excitation circuit is a magnetic circuit that generates a periodically changing magnetic flux that acts on each of the plurality of coils 20 formed in the arc portion 21A.

[0052] Similarly to the stator 7 described above, the stator 7 according to the modified example also has mounting portions 24, which are portions that are attached to an external device as an application target. In the stator 7 according to the modified example, the mounting portions 24 are provided, for example, at two circumferential ends of the arc portion 21A. Furthermore, the stator 7 according to the modified example has an electric circuit device mounted or fixed to the substrate 8 described above, which includes a circuit unit (not shown), such as an IC, and a computing unit. Specifically, for example, the stator 7 according to the modified example has a holding portion 25 that accommodates the electric circuit device, similar to the stator 7 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 24 in the circumferential direction. In this case, the limited space in the stator 7 can be effectively utilized, contributing to the miniaturization of the angle sensor 2.

[0053] In addition, in the above-described stator 7 and the stator 7 according to the modified example, the stator 7 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 7 and the electric circuit device from foreign matter and the like.

[0054] Furthermore, the stator 7 described above and the stator 7 according to the modified example may 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 2.

[0055] Furthermore, the rotating device according to the present invention includes not only rotating devices such as motors, but also rotating devices other than motors. For example, as shown in Fig. 16, the rotating device 1A includes a rotating shaft 3A such as a power steering, an accelerator pedal, a brake pedal, a seat reclining mechanism, and an electric parking system for an automobile.

[0056] REFERENCE SIGNS LIST 1, 1A Rotating device, 2 Angle sensor, 3, 3A Rotating shaft, 3a Tip portion, 4 Motor, 4a Rotor, 4b Stator, 5 Conductor, 6 Rotor, 7 Stator, 7a Insulator, 8 Substrate, 9 Bearing, 10 Metal body, 11 Cylinder, 12 Metal body structure, 13 Inner peripheral surface, 14 Outer peripheral surface, 15, 16 End surface, 20, 20a, 20b Coil, 21 Cylinder portion, 21A Arc portion, 21a Side surface, 21b Outer peripheral portion, 22 Inner peripheral surface, 23 Outer peripheral surface, 24 Mounting portion, 24a Through hole, 24b Opening, 25 Holding portion, 26 Coil structure, 26a, 26b Coil structure piece, 27 Protrusion, 27a Surface, 28 Step portion, 28a Step surface, 28b Recess, 29 Excitation circuit, 30 Frame, 30a End face, 31 Opening, 40, 46 Cover, 41, 42 Surface, 43 Connecting portion, 43a Boss portion, 43b Protrusion, 44 Protrusion, 45 Bolt, 45a Through hole, 47 Through hole, r Distance, x Axis, W1, W2 Width

Claims

1. A rotating device comprising: an angle sensor having a rotor with multiple metal bodies and a stator having multiple coils; a rotating shaft fixed to the rotor of the angle sensor; a motor having a frame and a cover that covers an opening of the frame; and a conductor, wherein the angle sensor is fixed to the cover.

2. The rotating device according to claim 1, wherein the angle sensor is provided on its outer periphery with a mounting portion that is attached to the cover.

3. The rotating device according to claim 2, wherein a connecting portion for attaching the mounting portion of the angle sensor is provided on an outer periphery of the cover.

4. The rotating device according to claim 3, wherein the mounting portion of the angle sensor has an opening on the inside in the radial direction relative to the connecting portion of the cover.

5. A rotating device according to any one of claims 1 to 4, wherein the conductor is disposed in a recess formed in the outer periphery of the stator.

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