Rotation sensor device, rotation sensor unit, and method for attaching rotation sensor device

Abstract

To provide a magnetic rotation sensor device allowing the center of a functional film to be positioned on a rotation axis.SOLUTION: A rotation sensor device 3 detects rotational state of a magnetic field generation part 2 rotating around a rotation axis O, such as rotation angle θ. The magnetic field generation part 2 generates magnetic field H symmetrical to the rotation axis O, and includes all or at least part of cylindrical surfaces 22 located a first distance R1 away from the rotation axis O. The rotation sensor device 3 comprises: a functional film 42 including a magnetic detection element 42E detecting the magnetic field H generated by the magnetic field generation part 2; and a guide member 52 provided with a second distance R2 from a normal line N passing through the center of the functional film 42. The second distance R2 is same as or slightly greater than the first distance R1, and the guide member 52 is disposed facing the cylindrical surface 22.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present disclosure relates to a rotation sensor device, a rotation sensor unit, and a method for installing a rotation sensor device. [Background technology]

[0002] Known rotation sensor devices for measuring rotational conditions such as rotation angle, rotation speed, and rotation count at the end of a rotating body include magnetic, optical, and electromagnetic induction types. Optical rotation sensor devices measure the rotation angle using a slit protruding radially from the output shaft (see, for example, Patent Document 1). Similarly, electromagnetic induction rotation sensor devices measure the rotation angle using a coil protruding radially from the output shaft. In these devices, the slit and coil become larger as the measurement resolution and measurement accuracy increase, making it difficult to miniaturize the device. In contrast, magnetic rotation sensor devices measure the rotation angle using a magnet attached to the axial extension of the output shaft. Therefore, magnetic rotation sensor devices can be made more compact and less expensive to manufacture than rotation sensor devices based on other principles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 6,563,108 Summary of the Invention [Problem to be solved by the invention]

[0004] However, magnetic rotation sensor devices suffer from measurement errors when the detection point of the magnetic sensor deviates from the center of rotation of the output shaft. While it is possible to align the rotation sensor device with the housing of an electric motor or the like by marking the housing, there is a misalignment between the housing and the rotating body within the range of assembly accuracy. It is preferable to directly align the rotating body with the rotation sensor device. It is also possible to adjust the position by installing the rotation sensor device and checking the electronic signal, but this requires a complicated assembly procedure and places a heavy burden on the worker.

[0005] The present disclosure has been made in view of the above circumstances, and aims to provide a technique that can align the center of a functional film on a rotation axis in a magnetic rotation sensor device. [Means for solving the problem]

[0006] A rotation sensor device according to one aspect of the present disclosure is a rotation sensor device that detects the rotation state of a magnetic field generating unit that rotates around a rotation axis. The magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a portion of a cylindrical surface that is all or a part of a cylindrical surface that is a first distance from the rotation axis. The rotation sensor device includes a functional film including a magnetic detection element that detects the magnetic field generated by the magnetic field generating unit, and a guide unit that is provided at a second distance from a normal line passing through the center of the functional film. The second distance is the same as or slightly greater than the first distance, and each of the multiple guide units is arranged to face at least a portion of the cylindrical surface.

[0007] A rotation sensor unit according to one embodiment of the present disclosure includes a magnetic field generating unit that rotates about a rotation axis, and a rotation sensor device that detects the rotation state of the magnetic field generating unit. The magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a portion of a cylindrical surface that is all or part of a cylindrical surface located a first distance from the rotation axis. The rotation sensor device includes a functional film including a plurality of magnetic detection elements that detect the magnetic field generated by the magnetic field generating unit, and a guide unit disposed a second distance from a normal line passing through the center of the functional film. The second distance is the same as or slightly greater than the first distance, and the guide unit is disposed to face the cylindrical surface.

[0008] A method for mounting a rotation sensor device according to one embodiment of the present disclosure is a method for mounting a rotation sensor device that detects the rotational state of a magnetic field generating unit that rotates around a rotation axis. The magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a portion of a cylindrical surface that is a first distance from the rotation axis. The rotation sensor device includes a functional film including a magnetic detection element that detects the magnetic field generated by the magnetic field generating unit, and a guide unit disposed a second distance from a normal line passing through the center of the functional film. The second distance is the same as or slightly greater than the first distance. The method includes fixing the magnetic field generating unit to the tip of a rotating body, placing the rotation sensor device over the magnetic field generating unit so that the guide unit faces at least a portion of the cylindrical surface, and fixing the rotation sensor device, whose movement is restricted by the positional relationship between at least a portion of the cylindrical surface and the guide unit, to a housing that rotatably supports the rotating body.

[0009] According to these aspects, the center of the functional film can be aligned on the rotation axis by the cylindrical surface of the magnetic field generating portion and the guide portion of the rotation sensor device.

[0010] In the above aspect, at least a portion of the guide portion may be in contact with at least a portion of the cylindrical surface.

[0011] According to this aspect, the rotation sensor device can be aligned with the magnetic field generating unit with high precision.

[0012] In the above aspect, the gap between the guide portion and at least a portion of the cylindrical surface may be 0.2 mm or less.

[0013] According to this aspect, since a gap may exist between the magnetic field generating unit and the rotation sensor device, power loss due to frictional resistance can be suppressed.

[0014] In the above aspect, a plurality of guide portions may be provided. In other words, the at least one guide portion may include a plurality of guide portions.

[0015] According to this aspect, the contact area can be made smaller than in an aspect in which one guide portion is formed in a ring shape and faces the cylindrical surface from all directions, so that loss of power due to frictional resistance can be suppressed.

[0016] In the above aspect, the plurality of guide portions may be formed of a polyacetal resin, a polyamide resin, or a polybutylene terephthalate resin.

[0017] According to this embodiment, a guide portion having excellent properties such as mechanical strength, wear resistance, and self-lubricating properties can be obtained.

[0018] In the above aspect, a cavity may be formed to house the magnetic field generating unit, and each of the plurality of guide portions may be formed in a hemispherical shape that protrudes from the inner wall of the cavity toward the normal line.

[0019] In the above aspect, a cavity is formed to accommodate the magnetic field generating unit, and each of the multiple guide parts is flush with the inner wall of the cavity on the side closer to the functional film than a plane perpendicular to the normal, and protrudes from the inner wall of the cavity on the side farther from the functional film than the plane, and may be inclined so that the amount of protrusion decreases as it goes away from the functional film.

[0020] According to these aspects, the contact area between the cylindrical surface and the tip of the guide portion is small, thereby suppressing power loss due to frictional resistance. The guide portion is inclined so that the amount of protrusion decreases as it moves away from the functional film in the plane perpendicular to the normal, which is parallel to the normal, making it easy to attach a rotation sensor device to the magnetic field generating unit. If the inner wall of the cavity is flush on the side closer to the functional film than the plane perpendicular to the normal, the plane serves as the mold parting plane, making it less likely to get caught when removing a molded product including the guide portion from the mold.

[0021] In the above aspect, a cavity is formed to accommodate the magnetic field generating unit, and when viewed along the normal, at least a portion of the contour of the cavity is a tangent to a circle which is the contour of at least a portion of the cylindrical surface, and the multiple guide portions may be points of contact between the tangent and the circle.

[0022] According to this aspect, it is possible to select a guide portion that is not a protruding portion.

[0023] In the above aspect, each of the plurality of guide portions may be provided on a guide member that is an integral structure.

[0024] When a separable structure is provided with multiple guide parts, the positional relationship between the multiple guide parts is likely to be displaced depending on the assembly accuracy and cumulative dimensional tolerances of the multiple parts that make up the structure. According to this aspect, the multiple guide parts are each provided on a guide member that is an integral structure, so the positional relationship between the multiple guide parts is less likely to be displaced.

[0025] In the above aspect, the magnetic field generating unit may include a magnet that is magnetized in a direction perpendicular to the rotation axis and is arranged on the rotation axis.

[0026] In the above aspect, the magnetic field generating unit may include a pair of magnets that are magnetized parallel to the rotation axis and in opposite directions to each other, and are arranged symmetrically with respect to the rotation axis.

[0027] According to these aspects, it is possible to obtain a magnetic field generating section that generates a magnetic field symmetrical with respect to the rotation axis.

[0028] In the above aspect, the rotation state may be a rotation angle of the magnetic field generating unit.

[0029] According to this aspect, the rotation sensor device can be used as an angle sensor that detects the rotation angle of the magnetic field generating unit.

[0030] An electric motor according to one embodiment of the present disclosure may include the rotation sensor unit of the above aspect, and may further include a housing to which the rotation sensor device is attached, and an output shaft to which a magnetic field generating unit is attached.

[0031] A rotation mechanism according to an embodiment of the present disclosure may include the electric motor of the above aspect. The rotation mechanism may be an autonomous mobile robot, a battery electric vehicle, a hybrid electric vehicle, an elevator, or an actuator.

[0032] These aspects allow the rotation sensor device to be applied for various purposes. [Effects of the Invention]

[0033] According to the present disclosure, it is possible to provide a technique that can align the center of a functional film on the rotation axis in a magnetic rotation sensor device. [Brief explanation of the drawings]

[0034] [Figure 1] FIG. 1 is an exploded perspective view of a rotation sensor unit according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a perspective view showing a rotation sensor device attached to a housing of an electric motor. [Figure 3] FIG. 3 is a perspective view showing a magnetic field generating unit attached to the output shaft of the electric motor. [Figure 4] FIG. 4 is a block diagram showing an example of a rotation mechanism including the electric motor shown in FIG. [Figures 5A-5C] 5A to 5C are diagrams schematically illustrating an example of the magnetic field generating unit shown in FIG. [Figure 6] FIG. 6 is a bottom view showing the rotation sensor unit shown in FIG. [Figure 7] FIG. 7 is a bottom view showing the rotation sensor device shown in FIG. [Figure 8] FIG. 8 is a cross-sectional view of the rotation sensor unit shown in FIG. [Figure 9] FIG. 9 is a bottom view schematically showing the functional film shown in FIG. [Figure 10]FIG. 10 is a flow chart illustrating a method for installing the rotation sensor device. [Figure 11] FIG. 11 is a perspective view showing a guide portion according to the first embodiment. [Figure 12] FIG. 12 is a perspective view showing a guide portion according to the second embodiment. [Figure 13] FIG. 13 is a bottom view schematically showing a guide portion according to the third embodiment. [Figure 14] FIG. 14 is a bottom view schematically showing the magnetic field generating unit according to the fourth embodiment. [Figure 15] FIG. 15 is a bottom view showing a guide portion according to the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0035] A preferred embodiment will be described with reference to the accompanying drawings. In each drawing, components with the same reference numerals have the same or similar configurations. Each configuration will be described in detail below with reference to Figures 1 to 15.

[0036] FIG. 1 is an exploded perspective view of a rotation sensor unit 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the rotation sensor unit 1 includes a magnetic field generating unit 2, a rotation sensor device 3, and the like. The magnetic field generating unit 2 has at least a portion of a cylindrical surface 22 and an end surface 23. As will be described later, the cylindrical surface 22 may be the entire 360-degree circumference, or a portion of the entire 360-degree circumference. In the following description, "at least a portion of the cylindrical surface 22" may be simply referred to as "cylindrical surface 22." The rotation sensor device 3 detects the rotation state, such as the rotation angle θ, of the magnetic field generating unit 2 rotating about a rotation axis O. A flange 32 having an elongated hole for mounting is provided on a housing 31 of the rotation sensor device 3.

[0037] Fig. 2 is a perspective view showing the rotation sensor device 3 attached to a housing (motor housing) 110 of an electric motor 100. As shown in Fig. 2, the rotation sensor device 3 is fixed to the housing 110 by a fastening screw 33 inserted into an elongated hole in a flange 32. Fig. 3 is a perspective view showing the magnetic field generating unit 2 attached to an output shaft (motor shaft) 120 of the electric motor 100. The output shaft 120 of the electric motor 100 is an example of a rotating body. The above-mentioned housing 110 is an example of a housing that rotatably supports a rotating body such as the output shaft 120.

[0038] In the illustrated example, the magnetic field generating unit 2 is configured to be separable from a rotating body such as the output shaft 120. The magnetic field generating unit 2 is formed, for example, in a cylindrical shape, and rotates together with the rotating body when fixed to the rotating body by an embedded screw 24 or the like. The configuration of the magnetic field generating unit 2 is not limited to the illustrated example, and the magnetic field generating unit 2 may be embedded in the rotating body to form an integrated structure.

[0039] Fig. 4 is a block diagram showing an example of a rotation mechanism 200 including the electric motor 100 shown in Fig. 2. The rotation mechanism 200 includes a load 230 that is rotationally driven by the electric motor 100 that includes the rotation sensor unit 1. In the example shown, the rotation mechanism 200 is configured as an autonomous mobile robot that travels and transports luggage while automatically avoiding workers and obstacles.

[0040] The rotation mechanism 200 is not limited to an autonomous traveling transport robot, but may also be a battery electric vehicle, a hybrid electric vehicle, an elevator, or an actuator.

[0041] The autonomous traveling transport robot includes a load 230 that is rotationally driven by the electric motor 100, such as wheels 232 for traveling, and a transmission mechanism 231 that connects the output shaft 120 of the electric motor 100 and the wheels 232. The autonomous traveling transport robot may further include a power supply unit 220 such as a battery that supplies power to the electric motor 100, and a control unit 210 that controls the power supply unit 220. The control unit 210 sends a motor drive signal to the power supply unit 220 based on a feedback signal received from the rotation sensor unit 1, and controls the rotation of the electric motor 100.

[0042] 5A to 5C are diagrams showing an example of the magnetic field generating unit 2 shown in FIG. 1. The magnetic field generating unit 2 generates a magnetic field H that is symmetrical with respect to the rotation axis O. In the example shown in FIG. 5A, the magnetic field generating unit 2 includes a magnet 21 that is magnetized in a direction perpendicular to the rotation axis O and is arranged on the rotation axis O. In the example shown in FIG. 5A, the north and south poles of the magnet 21 are positioned symmetrically with respect to the rotation axis O. The magnet 21 may not be disk-shaped, but may be a bar magnet with both ends magnetized to the north and south poles, respectively.

[0043] In the examples shown in FIGS. 5B and 5C, the magnetic field generating unit 2 includes a pair of magnets 21 that are magnetized parallel to the rotation axis O and have opposite magnetization directions. The pair of magnets 21 are arranged symmetrically around the rotation axis O. More specifically, in the example shown in FIG. 5A, the pair of magnets 21 are arranged close to each other. In the example shown in FIG. 5C, the pair of magnets 21 are arranged spaced apart from each other. In the examples shown in FIGS. 5B and 5C, the north pole of one magnet 21 is symmetrically positioned with respect to the south pole of the other magnet 21 with respect to the rotation axis O. Similarly, the south pole of one magnet 21 is symmetrically positioned with respect to the north pole of the other magnet 21 with respect to the rotation axis O. It is also known that the presence of a yoke on the bottom side strengthens the magnetic field H.

[0044] When using a magnetic field generated from multiple poles, it is difficult to obtain high accuracy compared to when using a magnetic field generated from two poles, an N pole and an S pole, due to the influence of magnetization accuracy. In all of the examples shown in Figures 5A to 5C, the magnetic field H can be generated from two poles, an N pole and an S pole.

[0045] Fig. 6 is a bottom view showing the rotation sensor unit 1 shown in Fig. 1. As shown in Fig. 6, the rotation sensor device 3 includes a substrate 4 and a guide member 5 housed in a housing 31. A cavity 51 for housing the magnetic field generating unit 2 is formed in the guide member 5.

[0046] The guide member 5 has at least one guide portion 52. The number of guide portions 52 is preferably three or more. In the illustrated example, four guide portions 52 are formed. The number of guide portions 52 may also be one. In that case, the shape of the guide portion 52 may be a cylinder that follows the cylindrical surface 22 of the entire 360-degree circumference, or may be a concave cylindrical surface that follows a partial cylindrical surface 22.

[0047] The material of the guide member 5 including the plurality of guide portions 52 is preferably an engineering plastic such as polyacetal resin, polyamide resin, or polybutylene terephthalate resin, which has excellent properties such as mechanical strength, abrasion resistance, and self-lubrication. Each of the plurality of guide portions 52 is disposed so as to face the cylindrical surface 22 of the magnetic field generating unit 2. In the illustrated example, at least a portion of the plurality of guide portions 52 is in contact with the cylindrical surface 22. While the rotation sensor unit 1 is being used, the guide member 52 may wear out and the guide portion 52 may no longer contact the cylindrical surface 22.

[0048] Fig. 7 is a bottom view showing the rotation sensor device 3 shown in Fig. 6. As shown in Fig. 7, a magnetic sensor 41 that detects the rotation state, such as the rotation angle θ, of the magnetic field generating unit 2, a connector 44 that is connected to a power source or external devices, and the like are mounted on the substrate 4. The substrate 4 may be a rigid substrate or a flexible substrate.

[0049] 8 is a cross-sectional view of the rotation sensor unit 1 shown in FIG. 6. As shown in FIG. 8, the magnetic sensor 41 faces the end face 23 and includes a functional film 42. The end face 23 is parallel to the XY plane described below. Each of the multiple guide portions 52 is provided at a second distance R2 from a normal line N passing through the center of the functional film 42. In the example shown, the distance from the tip (vertex) of the guide portion 52 to the normal line N is the second distance R2. Furthermore, in the example shown, a circle can be drawn that passes through the tips of all of the guide portions 52 and has a radius of the second distance R2.

[0050] The magnetic field generating unit 2 has at least a partial cylindrical surface 22 that is all or a part of a cylindrical surface that is located at a first distance R1 from the rotation axis O. In other words, the magnetic field generating unit 2 has a cylindrical surface 22 that is at least a part of a cylindrical surface that is formed by rotation of a generatrix L that is located at the first distance R1 from the rotation axis O. The second distance R2 is the same as or slightly greater than the first distance R1.

[0051] Fig. 9 is a bottom view schematically showing the functional film 42 shown in Fig. 8. As shown in Fig. 9, the functional film 42 includes at least one magnetic detection element 42E that detects the magnetic field H generated by the magnetic field generating unit 2 and generates a detection signal. In the example shown, the functional film 42 includes at least one magnetic detection element array 42A, an inorganic film surrounding the magnetic detection element array 42A, and the like. Each magnetic detection element array 42A is made up of a plurality of magnetic detection elements 42E connected in a daisy chain and arranged in a matrix.

[0052] The inorganic film may be an inorganic film whose main component is silica (silicon dioxide SiO2), or may be a laminated film of an inorganic film whose main component is silica and an inorganic film whose main component is alumina (aluminum oxide Al2O3). In the illustrated example, the functional film 42 includes four magnetic detection arrays 42A, and the four magnetic detection arrays 42A are connected to each other by a wiring layer 42W.

[0053] The detection point of the magnetic sensor 41 is the center of the functional film 42. When there are two or more magnetic detection element arrays 42A, the magnetic detection element arrays 42A are arranged point-symmetrically about the center of the functional film 42. In other words, the center of symmetry of the multiple magnetic detection element arrays 42A is the center of the functional film 42. When there is one magnetic detection element array 42A, the center of the magnetic detection element array 42A is the center of the functional film 42. When there is one magnetic detection element 42E, the center of the magnetic detection element 42E is the center of the functional film 42.

[0054] When each magnetic detection element array 42A is composed of a plurality of magnetic detection elements 42E connected in a daisy chain and arranged in a matrix, the plurality of magnetic detection elements 42E are arranged along the XY plane. A normal N of the functional film 42 is perpendicular to the XY plane and parallel to the direction perpendicular to the surface Z.

[0055] An example of the magnetic detection element 42E is a TMR (tunneling magnetoresistance effect) element. The magnetic detection element 42E is not limited to a TMR element, but may be a GMR (giant magnetoresistance effect) element, an AMR (anisotropic magnetoresistance effect) element, a Hall element, or another type of magnetic detection element. A TMR element is particularly suitable for the magnetic detection element 42E because, compared to other types of MR elements, it has a smaller junction area, allowing the magnetic sensor 41 to be miniaturized, and has a larger MR ratio, allowing the output of the magnetic sensor 41 to be increased.

[0056] The rotation sensor device 3 detects a first component of the magnetic field H generated by the magnet 21, which is a magnetic field component applied to the rotation sensor device 3, in a direction parallel to the X direction, and generates a first detection signal representing the intensity of the first component, and detects a second component of the magnetic field H generated by the magnet 21 in a direction parallel to the Y direction, and generates a second detection signal representing the intensity of the second component. The processor calculates the arc tangent of the ratio between the first detection signal and the second detection signal to calculate the rotation angle θ that the magnetic field H generated by the magnet 21 makes with respect to a reference direction. The magnetic sensor 41 may include an ASIC (Application Specific Integrated Circuit) 43 including a processor, etc.

[0057] Fig. 10 is a flow chart illustrating a method for installing a rotation sensor device. As shown in Fig. 10, the method for installing rotation sensor device 3 involves, in step S1, fixing magnetic field generating unit 2 to the tip of a rotating body such as output shaft 120. In step S2, placing rotation sensor device 3 over magnetic field generating unit 2 so that guide unit 52 faces at least a portion of cylindrical surface 22. In step S3, fixing rotation sensor device 3 to housing 110, which rotatably supports a rotating body such as output shaft 120, in a state where movement is restricted by the positional relationship between at least a portion of cylindrical surface 22 and guide unit 52.

[0058] Fig. 11 is a perspective view showing a guide portion 52 according to the first embodiment. As shown in Fig. 11, each of the guide portions 52 may be formed in a hemispherical shape protruding from the inner wall of the cavity 51 toward the normal line N.

[0059] 12 is a perspective view showing a guide portion 52 according to the second embodiment. As shown in Fig. 12, each of the multiple guide portions 52 is flush with the inner wall of the cavity 51 on a side closer to the functional film 42 than an imaginary plane P perpendicular to the normal N, and may protrude from the inner wall of the cavity 51 on a side farther from the functional film 42 than the plane P, and may be inclined so that the amount of protrusion from the cavity 51 decreases with increasing distance from the functional film 42. In the example shown, each of the multiple guide portions 52 is formed into a spherical shape divided into approximately four equal parts.

[0060] 13 is a bottom view schematically illustrating a guide portion 52 according to the third embodiment. As shown in FIG. 13, when viewed along the normal line N, at least a part of the contour of the cavity 51 is a tangent to a circle that is the contour of the cylindrical surface 22, and the plurality of guide portions 52 may be points of contact between such a tangent and the circle.

[0061] In the illustrated example, the cavity 51 is configured as a polygonal hole that penetrates the guide member 5 in the plane-perpendicular direction Z that is parallel to the normal line N. Instead of a through hole, an L-shaped notch may be formed in the guide member 5, and the space between the notch and the housing 31 may be configured as the cavity.

[0062] FIG. 14 is a bottom view schematically illustrating a magnetic field generating unit according to a fourth embodiment. In the illustrated example, the magnetic field generating unit 2 has a cylindrical surface 22 that does not extend 360 degrees. To more clearly indicate that the cylindrical surface 22 is a portion of the 360-degree cylindrical surface, the term "cylindrical surface 22" may be rephrased as "partial cylindrical surface 22." In the circumferential direction of the cylindrical surface 22, one end and the other end of the cylindrical surface 22 are connected by a connecting surface 25. The connecting surface 25 may be a flat surface, a convex surface with a different curvature from the cylindrical surface 22, or a concave surface.

[0063] For example, in a construction machine such as a shovel, the rotation angle of the bucket or arm is less than 360 degrees. The rotation sensor unit 1 of the present disclosure may be attached to detect the rotation angle of the bucket or arm. In this case, the rotation sensor unit 1 may be equipped with the magnetic field generating unit 2 of the fourth embodiment.

[0064] In the illustrated example, two guide portions 52 are provided as the multiple guide portions 52. If there are two or more guide portions 52, the distance from each of the two guide portions 52 to the normal N is known as the second distance R2, and the spacing between the two guide portions 52 is also known, so the position of the normal N can be calculated from the two guide portions 52. If the guide portions 52 are arranged to face the cylindrical surface 22, the normal N can be aligned with the rotation axis O.

[0065] Fig. 15 is a bottom view showing a guide portion 52 according to the fifth embodiment. As shown in Fig. 15, there may be a gap G between each of the plurality of guide portions 52 and the cylindrical surface 22. In the example shown, the gap G between each of the plurality of guide portions 52 and the cylindrical surface 22 is in the range of 0.1 mm or more and 0.2 mm or less, and the position of the rotation sensor device 3 is adjusted so that all of the gaps G are visually equal to one another.

[0066] According to the rotation sensor device 3 and related technology of the present disclosure configured as described above, the center of the functional film 42 can be aligned on the rotation axis O by the cylindrical surface 22 of the magnetic field generating unit 2 and the multiple guide parts 52 of the rotation sensor device 3. Errors caused by misalignment between the magnetic field generating unit 2 and the magnetic sensor 41 can be reduced.

[0067] 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. The elements of the embodiments, as well as their arrangement, materials, conditions, shape, and size, are not limited to those illustrated and can be modified as appropriate. Furthermore, the configurations shown in different embodiments can be partially substituted or combined. For example, a guide portion may be provided on the cylindrical surface 22 of the magnetic field generating unit 2, rather than on the guide member 5. [Explanation of symbols]

[0068] 1...Rotation sensor unit, 2...Magnetic field generating section, 21...Magnet, 22...Cylindrical surface, 23...End face, 24...Embedded screw, 25...Connection surface, 3...Rotation sensor device, 31...Housing, 32...Flange, 33...Tightening screw, 4...Substrate, 41...Magnetic sensor, 42...Functional film, 42A...Magnetic detection element array, 42E...Magnetic detection element, 42W...Wiring layer, 43...ASIC, 44...Connector, 5...Guide 1. A rotor member, 51...cavity, 52...guide portion, 100...electric motor, 110...housing, 120...output shaft, 200...rotation mechanism, 210...control portion, 220...power supply portion, 230...load, 231...transmission mechanism, 232...wheel, G...gap, H...magnetic field, L...generator, N...normal, O...rotation axis, P...plane, R1...first distance, R2...second distance, X, Y...in-plane direction, Z...direction perpendicular to the plane, θ...rotation angle.

Claims

1. A rotation sensor device for detecting a rotation state of a magnetic field generating unit that rotates around a rotation axis, the magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a part of a cylindrical surface that is all or a part of a cylindrical surface that is at a first distance from the rotation axis, The rotation sensor device a functional film including a magnetic detection element that detects the magnetic field generated by the magnetic field generating unit; a guide portion provided at a second distance from a normal line passing through the center of the functional film, the second distance is the same as or slightly greater than the first distance; The guide portion is arranged to face at least a portion of the cylindrical surface. Rotation sensor device.

2. At least a portion of the guide portion is in contact with the cylindrical surface. The rotation sensor device according to claim 1 .

3. The gap between the guide portion and the cylindrical surface is 0.2 mm or less. The rotation sensor device according to claim 1 .

4. The guide portion is provided in plurality. The rotation sensor device according to claim 1 .

5. The guide portion is formed of polyacetal resin, polyamide resin, or polybutylene terephthalate resin. The rotation sensor device according to claim 1 .

6. a cavity for accommodating the magnetic field generating unit is formed; Each of the plurality of guide portions is formed in a hemispherical shape protruding from the inner wall of the cavity toward the normal line. The rotation sensor device according to claim 4.

7. a cavity for accommodating the magnetic field generating unit is formed; the guide portion is flush with the inner wall of the cavity on a side closer to the functional film than a plane perpendicular to the normal line, and protrudes from the inner wall of the cavity on a side farther from the functional film than the plane, and is inclined so that the amount of protrusion decreases as the distance from the functional film increases. The rotation sensor device according to claim 1 .

8. a cavity for accommodating the magnetic field generating unit is formed; When viewed along the normal line, at least a portion of the contour of the cavity is a tangent to a circle that is the contour of the cylindrical surface; The plurality of guide portions are points of contact between the tangent line and the circle. The rotation sensor device according to claim 4.

9. Each of the plurality of guide portions is provided on the guide member which is an integral structure. The rotation sensor device according to claim 4.

10. the magnetic field generating unit includes a magnet that is magnetized in a direction perpendicular to the rotation axis and is disposed on the rotation axis. The rotation sensor device according to claim 1 .

11. The magnetic field generating unit includes a pair of magnets that are magnetized parallel to the rotation axis and in opposite directions to each other and are arranged symmetrically with respect to the rotation axis. The rotation sensor device according to claim 1 .

12. The rotation state is a rotation angle of the magnetic field generating unit. The rotation sensor device according to claim 1 .

13. a magnetic field generating unit that rotates around a rotation axis; a rotation sensor device for detecting a rotation state of the magnetic field generating unit, the magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a part of a cylindrical surface that is all or a part of a cylindrical surface that is at a first distance from the rotation axis, The rotation sensor device a functional film including a magnetic detection element that detects the magnetic field generated by the magnetic field generating unit; a plurality of guide portions provided at a second distance from a normal line passing through the center of the functional film; the second distance is the same as or slightly greater than the first distance; The guide portion is disposed so as to face the cylindrical surface. Rotation sensor unit.

14. A rotation sensor unit according to claim 13, a housing in which the rotation sensor device is mounted; An output shaft to which the magnetic field generating unit is attached, Electric motor.

15. A motor comprising the electric motor according to claim 14. Rotation mechanism.

16. A method for mounting a rotation sensor device that detects the rotation state of a magnetic field generating unit that rotates around a rotation axis, comprising: the magnetic field generating unit generates a magnetic field symmetrical with respect to the rotation axis and has at least a part of a cylindrical surface at a first distance from the rotation axis, The rotation sensor device a functional film including a plurality of magnetic detection elements that detect the magnetic field generated by the magnetic field generating unit; a plurality of guide portions provided at a second distance from a normal line passing through the center of the functional film; the second distance is the same as or slightly greater than the first distance; The method comprises: fixing the magnetic field generating unit to a tip of a rotating body; The rotation sensor device is placed over the magnetic field generating unit so that the guide portion faces at least the part of the cylindrical surface; and and fixing the rotation sensor device, the movement of which is restricted by a positional relationship between the cylindrical surface and the guide portion, to a housing that rotatably supports the rotating body. How to install an angle sensor.

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