Rotation detector

Abstract

To provide a rotation detector that enhances the continuity of its function of outputting a signal corresponding to the rotation angle. [Solution] The rotation detector comprises a rotor, a stator facing the rotor, a plurality of output coils provided on the rotor, and a plurality of detection coils provided on the stator and facing each of the plurality of output coils. The rotor has a plate-shaped portion having a first surface and a second surface, and the plate-shaped portion is rotatable about a rotation axis intersecting the plate-shaped portion. The plurality of output coils include a first output coil provided on the first surface of the rotor and a second output coil provided on the second surface. The plurality of detection coils include a first detection coil facing the first output coil and a second detection coil facing the second output coil.

Description

Technical Field

[0001] The present disclosure relates to a rotation detector.

Background Art

[0002] A rotation detector for detecting the rotation angle of a detection object such as a motor is known (see, for example, Patent Document 1). The rotation detector of Patent Document 1 is a resolver. Specifically, the rotation detector (resolver) includes a rotor and a stator, one output coil is provided on the rotor, and one detection coil is provided on the stator. Thus, the rotation detector (resolver) of Patent Document 1 is of a one-channel type.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the rotation detector of Patent Document 1, for example, when at least one of the output coil and the detection coil is damaged, the rotation detector may not output a signal corresponding to the rotation angle.

[0005] The present disclosure has been made in view of the above, and an object thereof is to provide a rotation detector with enhanced continuity of the function of outputting a signal corresponding to the rotation angle.

Means for Solving the Problems

[0006] To achieve the above object, a rotation detector according to one aspect of the present disclosure includes a rotor, a stator facing the rotor, a plurality of output coils provided on the rotor, and a plurality of detection coils provided on the stator and facing each of the plurality of output coils.

[0007] As mentioned above, in the rotation detector of Patent Document 1, the rotor and stator are each provided with one output coil and one detection coil. Therefore, if, for example, damage occurs to at least one of the output coil and the detection coil, the rotation detector may malfunction. In contrast, the rotation detector of this disclosure is a multi-channel type having multiple output coils and multiple detection coils facing each of the multiple output coils. Therefore, for example, even if some of the multiple output coils and detection coils are damaged, the signal corresponding to the rotation angle will continue to be output, resulting in higher redundancy.

[0008] In another embodiment of the rotation detector described above, the rotor has a plate-like portion having a first surface and a second surface opposite to the first surface, the plate-like portion being rotatable about a rotation axis intersecting the plate-like portion, the plurality of output coils having a first output coil provided on the first surface of the rotor and a second output coil provided on the second surface, and the plurality of detection coils having a first detection coil facing the first output coil in the axial direction and a second detection coil facing the second output coil in the axial direction.

[0009] In this disclosure, since the first and second output coils are provided on a single rotor, the rotation angle output from the first output coil and the rotation angle output from the second output coil can be detected by a single external device. Thus, according to this disclosure, redundancy can be implemented with a simpler structure.

[0010] Furthermore, according to this disclosure, since the first and second output coils are provided on both sides of the plate-shaped portion of the rotor, the axial length of the rotation detector can be shortened, and the rotation detector can be made more compact.

[0011] In another embodiment of the rotation detector described above, the rotor has a plate-like portion having a first surface facing one side in the axial direction and a second surface opposite to the first surface, and the plate-like portion is rotatable about a rotation axis intersecting the plate-like portion, and the plurality of output coils have a first output coil provided on the first or second surface of the rotor and a third output coil provided on the outer circumferential surface of the rotor, and the plurality of detection coils have a first detection coil facing the first output coil in the axial direction and a third detection coil facing the third output coil in the radial direction. In this embodiment, even when the third output coil is provided on the outer circumferential surface of the rotor and the third output coil is provided on the inner circumferential surface of the stator, it is possible to detect the rotation angle of the object to be detected.

[0012] In another embodiment of the rotation detector described above, the rotor has a shaft portion fixed to the plate-shaped portion and extending in the axial direction of the rotation axis, and a bearing is provided between the stator and the shaft portion to rotatably support the shaft portion.

[0013] Thus, in this disclosure, a bearing is provided to rotatably support the shaft portion of the rotor relative to the stator. Therefore, the relative positional accuracy (i.e., air gap accuracy and coaxiality) between the output coil provided on the rotor and the detection coil provided on the stator is less likely to change, resulting in higher detection accuracy for the rotation angle of the object to be detected.

[0014] In another embodiment of the rotation detector described above, the bearing comprises a first bearing located on one side in the axial direction relative to the plate-shaped portion, and a second bearing located on the other side in the axial direction relative to the plate-shaped portion.

[0015] In this configuration, the first and second bearings are positioned on both sides of the plate-shaped portion in the axial direction. Therefore, the rotor shaft is supported more stably than when both the first and second bearings are positioned on only one side of the plate-shaped portion in the axial direction. Consequently, the detection accuracy of the rotation angle of the object being detected is improved.

[0016] As another aspect of the above rotation detector, the stator has an insertion portion into which the output shaft of the detected object can be inserted, and a bearing for rotatably supporting the output shaft is provided in the insertion portion.

[0017] For example, when the detected object is a motor, the output shaft of the motor can be inserted into the insertion portion and supported by the bearing. Thus, according to the rotation detector of the present disclosure, it is possible to detect a detected object such as a motor having an output shaft.

[0018] As another aspect of the above rotation detector, the bearing has a third bearing located on one side in the axial direction with respect to the plate-like portion and a fourth bearing located on the other side in the axial direction with respect to the plate-like portion.

[0019] In this way, the third bearing and the fourth bearing are arranged on both sides in the axial direction sandwiching the plate-like portion. Therefore, the output shaft of the detected object is more stably supported than when both the third bearing and the fourth bearing are arranged on one side in the axial direction of the plate-like portion. Thus, the detection accuracy of the rotation angle of the detected object becomes higher.

Advantages of the Invention

[0020] According to the rotation detector according to the present disclosure, it is possible to provide a rotation detector with enhanced continuity of the function of outputting a signal corresponding to the rotation angle.

Brief Description of the Drawings

[0021] [Figure 1] FIG. 1 is a perspective view of the rotation detector of the first embodiment. [Figure 2] FIG. 2 is a cross-sectional view of FIG. 1. [Figure 3] FIG. 3 is an exploded perspective view of the rotation detector of FIG. 1. [Figure 4] FIG. 4 is an exploded perspective view of the rotation detector of FIG. 1. [Figure 5] FIG. 5 is a perspective view of the rotation detector of the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view of FIG. 5. [Figure 7] FIG. 7 is a perspective view of the rotation detector according to the third embodiment. [Figure 8] FIG. 8 is a cross-sectional view of FIG. 7. [Figure 9] FIG. 9 is an exploded perspective view of the rotation detector of FIG. 7. [Figure 10] FIG. 10 is an exploded perspective view of the rotation detector of FIG. 7. [Figure 11] FIG. 11 is a perspective view of the rotation detector according to the fourth embodiment. [Figure 12] FIG. 12 is a cross-sectional view of FIG. 11. [Figure 13] FIG. 13 is a perspective view of the rotation detector according to the fifth embodiment. [Figure 14] FIG. 14 is a cross-sectional view of FIG. 13.

MODE FOR CARRYING OUT THE INVENTION

[0022] The mode (embodiment) for carrying out the invention will be described in detail with reference to the drawings. The present invention is not limited by the content described in the following embodiments. Further, the constituent elements described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the constituent elements described below can be combined as appropriate. In the drawings, the X direction is orthogonal (crosses) to the Y direction and the Z direction, the Y direction is orthogonal (crosses) to the X direction and the Z direction, and the Z direction is orthogonal (crosses) to the X direction and the Y direction. The X1 side is the opposite side of the X2 side, the Y1 side is the opposite side of the Y2 side, and the Z1 side is the opposite side of the Z2 side.

[0023] [First Embodiment] First, the first embodiment will be described. FIG. 1 is a perspective view of the rotation detector according to the first embodiment. FIG. 2 is a cross-sectional view of FIG. 1. FIG. 3 is an exploded perspective view of the rotation detector of FIG. 1. FIG. 4 is an exploded perspective view of the rotation detector of FIG. 1. As shown in FIGS. 1 to 4, the rotation detector 100 according to the first embodiment includes a rotor 2, a case (stator) 110, a plurality (two in this embodiment) of resolver units 4, a plurality (two in this embodiment) of detection coils, and a bearing. Each will be described in detail below.

[0024] As shown in Figures 1 to 4, the rotor 2 is rotatable in the direction of the axis of rotation AX. The rotor 2 has a plate-shaped portion 20 and a shaft portion 120.

[0025] The plate-like portion 20 has a disc shape. The plate-like portion 20 has a first surface 21, a second surface 22 opposite to the first surface 21, and an outer circumferential surface. For example, the first surface 21 is the surface on the X1 side, and the second surface 22 is the surface on the X2 side. The outer circumferential surface is a cylindrical surface extending in the circumferential direction about the axis of rotation AX. The shaft portion 120 is integral with the plate-like portion 20. The shaft portion 120 extends in the X direction. More specifically, the shaft portion 120 extends in the axial direction of the rotation axis AX intersecting the plate-like portion 20. That is, the X direction coincides with the axial direction of the rotation axis AX.

[0026] Case 110 is also called the stator. Case 110 has a first case 111, a second case 112, and a cover 113. The rotor 2, the first bearing 31, and the second bearing 32 are housed between the first case 111 and the second case 112. The first case 111 and the second case 112 face the plate-shaped portion 20 of the rotor 2 in the X direction. The cover 113 is attached to the X2 side of the second case 112.

[0027] Here, a first bearing 31 is provided on the X1 side (one side in the axial direction) of the plate-shaped portion 20. The first bearing 31 is fitted to the inner circumferential surface of the through hole 111a (see Figures 3 and 4) of the first case 111. In detail, the first bearing 31 has an inner ring, an outer ring, and rolling elements, with the outer circumferential surface of the outer ring fitted to the inner circumferential surface of the through hole 111a, and the inner circumferential surface of the inner ring fitted to the outer circumferential surface of the portion 120a of the shaft portion 120 on the X1 side of the plate-shaped portion 20.

[0028] Furthermore, a second bearing 32 is provided on the X2 side (the other side in the axial direction) of the plate-shaped portion 20. The second bearing 32 is fitted to the inner circumferential surface of the through hole 112a (see Figures 3 and 4) of the second case 112. In detail, the second bearing 32 has an inner ring, an outer ring, and rolling elements, with the outer circumferential surface of the outer ring fitted to the inner circumferential surface of the through hole 112a, and the inner circumferential surface of the inner ring fitted to the outer circumferential surface of the portion 120b of the shaft portion 120 on the X2 side of the plate-shaped portion 20.

[0029] The two resolver sections 4 are provided on the plate-shaped section 20 of the rotor 2. The two resolver sections 4 are a first resolver section 41 and a second resolver section 42. The first resolver section 41 includes a first output coil 411 and a first detection coil 412. The second resolver section 42 includes a second output coil 421 and a second detection coil 422.

[0030] The first output coil 411 is formed on the first surface 21 of the plate-shaped portion 20, and the second output coil 421 is formed on the second surface 22 of the plate-shaped portion 20.

[0031] The first detection coil 412 is formed on the X2-side surface of the first case 111. The first detection coil 412 faces the first output coil 411 in the axial direction. The second detection coil 422 is formed on the X1-side surface of the second case 112. The second detection coil 422 faces the second output coil 421 in the axial direction. The first detection coil 412 and the second detection coil 422 are arranged at equal intervals in the circumferential direction around the axis of the rotation axis AX. However, the present invention is not limited to this, and the first detection coil 412 and the second detection coil 422 may be arranged at unequal intervals in the circumferential direction around the axis of the rotation axis AX.

[0032] Furthermore, in the plate-shaped portion 20 of the rotor 2, a first receiving transformer 52 and a second receiving transformer 54 are formed in an annular shape on the inner circumference sides of the first output coil 411 and the second output coil 421. Specifically, the first receiving transformer 52 is formed on the inner circumference side of the first output coil 411, and the second receiving transformer 54 is formed on the inner circumference side of the second output coil 421.

[0033] Furthermore, a ring-shaped first transmitting transformer 51 is formed on the inner circumference side of the first detection coil 412, and a ring-shaped second transmitting transformer 53 is formed on the inner circumference side of the second detection coil 422. The first transmitting transformer 51 faces the first receiving transformer 52 in the axial direction, and the second transmitting transformer 53 faces the second receiving transformer 54 in the axial direction.

[0034] Let's briefly explain the operation of this configuration. First, as shown in Figure 2, when an AC voltage is applied to the first transmitting transformer 51, the AC voltage is excited to the first receiving transformer 52, and then when the AC voltage is excited to the first output coil 411, a signal corresponding to the rotation angle of the first detection coil 412 is output from the first detection coil 412.

[0035] As described above, the rotation detector 100 according to the first embodiment comprises a rotor 2, a case (stator) 110, a plurality of output coils provided on the rotor 2, and a plurality of detection coils provided on the case 110.

[0036] As mentioned above, in the rotation detector of Patent Document 1, the rotor and stator are each provided with one output coil and one detection coil. Therefore, if, for example, damage occurs to at least one of the output coil and the detection coil, the rotation detector may malfunction. In contrast, the rotation detector 100 of this embodiment has multiple output coils and multiple detection coils facing each of the multiple output coils. Therefore, even if, for example, some of the multiple output coils and detection coils are damaged, the signal corresponding to the rotation angle will continue to be output, resulting in higher redundancy.

[0037] The multiple output coils include a first output coil 411 provided on the first surface 21 of the rotor 2 and a second output coil 421 provided on the second surface 22. The multiple detection coils include a first detection coil 412 and a second detection coil 422.

[0038] In this embodiment, since the first output coil 411 and the second output coil 421 are provided on a single rotor 2, the rotation angle output from the first output coil 411 and the rotation angle output from the second output coil 421 can be detected by a single external device. However, the present invention is not limited to this, and the rotation angle output from the first output coil 411 and the rotation angle output from the second output coil 421 can be detected by multiple external devices. Thus, according to this embodiment, reliable detection is possible through redundancy.

[0039] In this embodiment, the first output coil 411 and the second output coil 421 are provided on both sides of the plate-shaped portion 20 of the rotor 2. Therefore, the axial thickness of the rotor 2 can be made thinner, and thus the rotation detector 100 can be made smaller.

[0040] The rotor 2 has a shaft portion 120, and a bearing 3 is provided between the case 110 and the shaft portion 120 to rotatably support the shaft portion 120.

[0041] As described above, in this embodiment, a bearing 3 is provided to rotatably support the shaft portion 120 of the rotor 2 with respect to the case 110. Therefore, the relative positional accuracy (i.e., air gap accuracy and coaxiality) between the output coil provided on the rotor 2 and the detection coil provided on the case 110 is less likely to change, thus improving the detection accuracy of the rotation angle of the object to be detected.

[0042] The bearing 3 includes a first bearing 31 located on the X1 side of the plate-shaped portion 20, and a second bearing 32 located on the X2 side of the plate-shaped portion 20.

[0043] In this configuration, the first bearing 31 and the second bearing 32 are positioned on both sides of the plate-shaped portion 20 in the axial direction. Therefore, the shaft portion 120 of the rotor 2 is supported to rotate more stably than when both the first bearing 31 and the second bearing 32 are positioned on the X1 side of the plate-shaped portion 20. Consequently, the detection accuracy of the rotation angle of the object to be detected is improved.

[0044] [Second Embodiment] Next, a second embodiment will be described. Figure 5 is a perspective view of the rotation detector of the second embodiment. Figure 6 is a cross-sectional view of Figure 5. As shown in Figures 5 and 6, the rotation detector 100A according to the second embodiment differs from the rotation detector 100 according to the first embodiment in the configuration of the rotor 2A. The following description will focus on the differences from the first embodiment.

[0045] The rotor 2 according to the first embodiment has a plate-shaped portion 20 and a shaft portion 120. In contrast, the rotor 2A according to the second embodiment has only a plate-shaped portion 20A and no shaft portion 120. That is, the case (stator) 110 according to the second embodiment is provided with an insertion portion 130 into which the output shaft 200 of the motor (detected object) can be inserted. The insertion portion 130 extends in the X direction (axial direction). The cover 113 is also provided with a shaft fixing screw 121. The inner circumference of the plate-shaped portion 20A is provided with a fitting portion 20A1. A third bearing 31A is provided on the X1 side (one side in the axial direction) of the plate-shaped portion 20A, and a fourth bearing 32A is provided on the X2 side (the other side in the axial direction) of the plate-shaped portion 20A.

[0046] Here, the output shaft 200 of the motor (detected object) is a so-called stepped shaft. More specifically, as shown in Figure 6, the output shaft 200 has a first portion 210, a second portion 220, a third portion 230, a fourth portion 240, and a fifth portion 250 along the X direction. The second portion 220, the third portion 230, and the fourth portion 240 have the same outer diameter. The outer diameters of the second portion 220, the third portion 230, and the fourth portion 240 are larger than those of the first portion 210 and smaller than those of the fifth portion 250.

[0047] The first section 210 is also referred to as the small diameter section, the second section 220, the third section 230, and the fourth section 240 as the medium diameter section, and the fifth section 250 as the large diameter section. Accordingly, the first stepped section 260 is formed between the first section 210 and the second section 220, and the second stepped section 270 is formed between the fourth section 240 and the fifth section 250. The first section 210 is located at the X2 side end of the output shaft 200, and a male thread is formed on the outer circumference of the first section 210. A female thread is formed on the inner circumference of the shaft fixing screw 121. The male thread of the first section 210 engages with the female thread of the shaft fixing screw 121. The second section 220 fits into the inner ring of the fourth bearing 32A. The third section 230 fits into the fitting section 20A1. The fourth section 240 fits into the inner ring of the third bearing 31A.

[0048] Furthermore, when the male thread of the first part 210 is engaged with the female thread of the shaft fixing screw 121, the X1-side end of the shaft fixing screw 121 abuts against the inner ring of the fourth bearing 32A, pressing the inner ring toward the X1 side. Note that the X1-side end of the shaft fixing screw 121 does not abut against the first stepped portion 260. The second stepped portion 270 abuts against the inner ring of the third bearing 31A, pressing the inner ring toward the X2 side. In this way, by sandwiching the inner ring of the third bearing 31A, the inner ring of the fourth bearing 32A, and the rotor 2A between the shaft fixing screw 121 and the first stepped portion 260, the rotor 2A and the output shaft 200 become able to rotate as a single unit.

[0049] As described above, the case 110 has an insertion portion 130 into which the output shaft of the object to be detected can be inserted, and the insertion portion 130 is provided with a bearing 3A that rotatably supports the output shaft of the object to be detected.

[0050] For example, if the object to be detected is a motor, the output shaft of the motor can be inserted into the insertion section 130, and the output shaft can be supported by the bearing 3A. In this way, the rotation detector 100A according to this embodiment makes it possible to detect the rotation angle even for objects to be detected, such as motors that have an output shaft.

[0051] The bearing 3A includes a third bearing 31A located on the X1 side of the plate-shaped portion 20A, and a fourth bearing 32A located on the X2 side of the plate-shaped portion 20A.

[0052] In this configuration, the third bearing 31A and the fourth bearing 32A are positioned on both sides of the plate-shaped portion 20A in the axial direction. Therefore, the output shaft of the object to be detected is supported more stably than when both the third bearing 31A and the fourth bearing 32A are positioned on one side of the plate-shaped portion 20A in the axial direction. Consequently, the detection accuracy of the rotation angle of the object to be detected is improved.

[0053] [Third Embodiment] Next, a third embodiment will be described. Figure 7 is a perspective view of the rotation detector of the third embodiment. Figure 8 is a cross-sectional view of Figure 7. Figure 9 is an exploded perspective view of the rotation detector of Figure 7. Figure 10 is an exploded perspective view of the rotation detector of Figure 7. As shown in Figures 7 to 10, the rotation detector 100B according to the third embodiment differs from the rotation detector 100 according to the first embodiment in the position of the second output coil, second receiving transformer, second detection coil, and second transmitting transformer. The following description will focus on the differences from the first embodiment.

[0054] As shown in Figures 7 to 10, the rotor 2B has a plate-shaped portion 20. The first output coil 411 is formed on the first surface 21 of the plate-shaped portion 20, and the third output coil 421B is formed on the outer circumferential surface of the plate-shaped portion 20. The third receiving transformer 54B is also formed on the outer circumferential surface of the plate-shaped portion 20.

[0055] The first detection coil 412 is formed on the X2-side surface of the first case 111. The third detection coil 422B is formed on the inner circumferential surface of the cylindrical portion 112b of the second case 112. The third transmitting transformer 53B is also formed on the inner circumferential surface of the cylindrical portion 112b. The third output coil 421B and the third detection coil 422B face each other in the radial direction. The third transmitting transformer 53B faces the third receiving transformer 54B in the radial direction. Note that the first output coil 411 shown in Figure 8 may be formed on the second surface 22 on the X2 side of the plate-shaped portion 20. In this case, the first detection coil 412 facing the first output coil 411 is provided, for example, in the second case 112.

[0056] As described above, the third output coil 421B is formed on the outer circumferential surface 23 of the plate-shaped portion 20, and the third detection coil 422B is formed on the inner circumferential surface of the cylindrical portion 112b in the second case 112. The third output coil 421B and the third detection coil 422B face each other in the radial direction.

[0057] Thus, even in a configuration where the third output coil 421B is provided on the outer peripheral surface 23 of the plate-shaped portion 20 and the third output coil 421B is provided on the inner peripheral surface of the cylindrical portion 112b in the second case 112, it is possible to detect the rotation angle of the object to be detected.

[0058] [Fourth Embodiment] Next, a fourth embodiment will be described. Figure 11 is a perspective view of the rotation detector of the fourth embodiment. Figure 12 is a cross-sectional view of Figure 11. As shown in Figures 11 and 12, the rotation detector 100C according to the fourth embodiment differs from the rotation detector 100B according to the third embodiment in the configuration of the rotor 2C. The following description will focus on the differences from the third embodiment.

[0059] The rotor 2B according to the third embodiment has a plate-shaped portion 20 and a shaft portion 120. In contrast, the rotor 2C according to the fourth embodiment has only a plate-shaped portion 20A and no shaft portion 120. That is, the case (stator) 110 according to the fourth embodiment is provided with an insertion portion 130 into which the output shaft 200 of the motor can be inserted. The insertion portion 130 extends in the X direction (axial direction). The configuration in the fourth embodiment is the same as that of Figure 6 described above, so it will be briefly explained below. When the male thread of the first portion 210 of the output shaft 200 is engaged with the female thread of the shaft fixing screw 121, the X1 side end of the shaft fixing screw 121 abuts against the inner ring of the fourth bearing 32A and presses the inner ring toward the X1 side. Note that the X1 side end of the shaft fixing screw 121 does not abut against the first stepped portion 260. The second stepped portion 270 then contacts the inner ring of the third bearing 31A and presses the inner ring toward X2. In this way, the inner ring of the third bearing 31A, the inner ring of the fourth bearing 32A, and the rotor 2C are clamped between the shaft fixing screw 121 and the first stepped portion 260, allowing the rotor 2C and the output shaft 200 to rotate as a single unit.

[0060] The first output coil 411 shown in Figure 12 may be formed on the second surface 22 on the X2 side of the plate-shaped portion 20A. In this case, the first detection coil 412 facing the first output coil 411 is provided, for example, in the second case 112.

[0061] As described above, the third output coil 421B is formed on the outer circumferential surface 23 of the plate-shaped portion 20, and the third detection coil 422B is formed on the inner circumferential surface of the cylindrical portion 112b in the second case 112. The third output coil 421B and the third detection coil 422B face each other in the radial direction.

[0062] Thus, even in a configuration where the third output coil 421B is provided on the outer peripheral surface 23 of the plate-shaped portion 20 and the third detection coil 422B is provided on the inner peripheral surface of the cylindrical portion 112b in the second case 112, it is possible to detect the rotation angle of the object to be detected.

[0063] [Fifth Embodiment] Next, a fifth embodiment will be described. Figure 13 is a perspective view of the rotation detector of the fifth embodiment. Figure 14 is a cross-sectional view of Figure 13. As shown in Figures 13 and 14, the rotation detector 100D according to the fifth embodiment differs from the rotation detector 100 according to the first embodiment in the position of the bearing. The following description will focus on the differences from the first embodiment.

[0064] In the first embodiment, a first bearing 31 is provided on the X1 side (one side in the axial direction) of the plate-shaped portion 20. A second bearing 32 is provided on the X2 side (the other side in the axial direction) of the plate-shaped portion 20.

[0065] In contrast, in the fifth embodiment, both the first bearing 31 and the second bearing 32 are adjacent to each other and are located on the X1 side (one side in the axial direction) of the plate-shaped portion 20. The first bearing 31 is located on the X1 side of the second bearing 32. That is, the portion of the shaft portion 120 of the rotor 2D that is on the X1 side of the plate-shaped portion 20 is rotatably supported by both the axially adjacent first bearing 31 and the second bearing 32.

[0066] Although not shown in the illustrations, a modified version of the embodiment may be constructed by removing the shaft portion 120 from Figures 13 and 14. Furthermore, in the embodiments described above, the output coil was provided on the plate-shaped portion of the rotor, but in the case of a rotor with a shaft portion, the output coil may be provided on the side surface or axial end face of the shaft portion. In that case, two or more output coils may be provided on the shaft portion.

[0067] As described above, the portion of the shaft portion 120 of the rotor 2D that is closer to X1 than the plate-shaped portion 20A is rotatably supported by both the axially adjacent first bearing 31 and second bearing 32.

[0068] Thus, even in an configuration where both the first bearing 31 and the second bearing 32 are positioned on the X1 side of the plate-shaped portion 20A, the shaft portion 120 is supported to rotate more stably, and the accuracy of detecting the rotation angle of the object to be detected is further improved.

[0069] The rotation detector relating to this disclosure may also be a combination of the following configurations. (1) Rotor and, A stator facing the rotor, Multiple output coils provided on the rotor, A rotation detector comprising a plurality of detection coils provided on the stator and facing each of the plurality of output coils. (2) The rotor is It has a plate-like portion having a first surface facing one side in the axial direction and a second surface opposite to the first surface, and the plate-like portion is rotatable about a rotation axis that intersects the plate-like portion. The plurality of output coils include a first output coil provided on the first surface of the rotor and a second output coil provided on the second surface. The rotation detector according to (1), wherein the plurality of detection coils include a first detection coil facing the first output coil in the axial direction and a second detection coil facing the second output coil in the axial direction. (3) The rotor is It has a plate-like portion having a first surface facing one side in the axial direction and a second surface opposite to the first surface, and the plate-like portion is rotatable about a rotation axis that intersects the plate-like portion. The plurality of output coils include a first output coil provided on the first surface of the rotor and a third output coil provided on the outer circumferential surface of the rotor. The plurality of detection coils include a first detection coil facing the first output coil in the axial direction and a third detection coil facing the third output coil in the radial direction. (1) The rotation detector described above. (4) The rotor has a shaft portion that is fixed to the plate-shaped portion and extends in the axial direction of the rotation axis, A bearing is provided between the stator and the shaft portion to rotatably support the shaft portion. A rotation detector as described in any one of (1) to (3). (5) The aforementioned bearing is A first bearing located on one side in the axial direction from the plate-shaped portion, A second bearing is located on the other side in the axial direction from the plate-shaped portion, (4) The rotation detector described above. (6) The stator has an insertion portion into which the output shaft of the object to be detected can be inserted. A bearing is provided in the insertion portion to rotatably support the output shaft. A rotation detector as described in any one of (1) to (5). (7) The aforementioned bearing is A third bearing located on one side in the axial direction from the plate-shaped portion, The rotation detector according to (6), further comprising a fourth bearing located on the other side in the axial direction from the plate-shaped portion. [Explanation of symbols]

[0070] 2, 2A, 2B, 2C, 2D rotors 20, 20A Plate-shaped part 20A1 Mating part 21 Page 1 22 Side 2 23 Outer surface 3 Bearings 31 First bearing 32 Second bearing 31A Third bearing 32A Fourth bearing 4. Resolver section 41. First resolver section 411 First Output Coil 412 First detection coil 42 Second Resolver Section 421 Second Output Coil 422 Second detection coil 421B Third Output Coil 422B Third detection coil 51 First Transmitting Transformer 52 First Receiving Transformer 53, 53B Second Transmitting Transformer 54. Second receiving transformer 100, 100A, 100B, 100C, 100D Rotation Detector 110 Case (Stator) 111 Case 1 111a Through hole 112 Case 2 112a Through hole 112b Cylindrical part 113 Cover 120 Shaft section 121 Shaft fixing screw 130 Insertion part AX rotation axis

Claims

1. Rotor and, A stator facing the rotor, Multiple output coils provided on the rotor, The stator is provided with a plurality of detection coils, each of which is facing the plurality of output coils, Rotation detector.

2. The rotor is It has a plate-like portion having a first surface facing one side in the axial direction and a second surface opposite to the first surface, and the plate-like portion is rotatable about a rotation axis that intersects the plate-like portion. The plurality of output coils include a first output coil provided on the first surface of the rotor and a second output coil provided on the second surface. The plurality of detection coils include a first detection coil facing the first output coil in the axial direction and a second detection coil facing the second output coil in the axial direction. The rotation detector according to claim 1.

3. The rotor has a plate-like portion having a first surface facing one side in the axial direction and a second surface opposite to the first surface, and the plate-like portion is rotatable about a rotation axis that intersects the plate-like portion. The plurality of output coils include a first output coil provided on the first or second surface of the rotor, and a third output coil provided on the outer circumferential surface of the rotor. The plurality of detection coils include a first detection coil facing the first output coil in the axial direction and a third detection coil facing the third output coil in the radial direction. The rotation detector according to claim 1.

4. The rotor has a shaft portion that is fixed to the plate-shaped portion and extends in the axial direction of the rotation axis, A bearing is provided between the stator and the shaft portion to rotatably support the shaft portion. The rotation detector according to claim 2 or 3.

5. The aforementioned bearing is A first bearing located on one side in the axial direction from the plate-shaped portion, A second bearing is located on the other side in the axial direction from the plate-shaped portion, The rotation detector according to claim 4.

6. The stator has an insertion portion into which the output shaft of the object to be detected can be inserted. A bearing is provided in the insertion portion to rotatably support the output shaft. The rotation detector according to claim 2 or 3.

7. The aforementioned bearing is A third bearing located on one side in the axial direction from the plate-shaped portion, A fourth bearing is located on the other side in the axial direction from the plate-shaped portion, The rotation detector according to claim 6.

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