Magnetic bearing device

Abstract

This device suppresses the misalignment of the central axis caused by manufacturing tolerances in magnetic bearing devices. [Solution] The magnetic bearing device includes a housing having a first cylindrical member 11 which is a subassembly and a second cylindrical member 12 which is a casing that houses the first cylindrical member 11. The housing has a plurality of protrusions 201 to 204 on the outer circumferential surface of the first cylindrical member 11 as first positioning means that restrict rotation relative to the second cylindrical member 12, and a plurality of recesses 401 to 404 on the inner circumferential surface of the second cylindrical member 12 as second positioning means that restrict rotation of the first cylindrical member 11. By changing the correspondence between the first positioning means and the second positioning means, the circumferential position of the first cylindrical member 11 relative to the second cylindrical member 12 can be changed. Regardless of the position of the first cylindrical member 11 in the circumferential direction, the other end of a wiring connected to one end of the first cylindrical member 11 is connected to a predetermined position on the second cylindrical member 12.

Description

Technical Field

[0001] The present disclosure relates to a magnetic bearing device.

Background Art

[0002] Patent Document 1 describes a centrifugal compressor including a cylindrical casing extending in the axial direction, a motor stator fixed to the inner side in the radial direction of the casing, a shaft portion disposed on the inner side in the radial direction of the motor stator and extending in the axial direction, a motor rotor fixed to the shaft portion and facing the motor stator with a radial gap therebetween, a compression portion fixed to one end of the shaft portion in the axial direction and having at least one impeller, a first thrust magnetic bearing disposed between the motor rotor and the impeller in the axial direction, and a second thrust magnetic bearing disposed on the other side in the axial direction of the motor rotor in the axial direction, wherein the magnetic attractive force of the second thrust magnetic bearing toward the other side in the axial direction is greater than the magnetic attractive force of the first thrust magnetic bearing toward the one side in the axial direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a magnetic bearing compressor, the shaft is levitated at the center of the backup bearing. The gap between the radial magnetic bearing and the shaft formed by the levitation of the shaft is designed on the premise that it is the design nominal value. Therefore, if the actual gap deviates from the design nominal value due to manufacturing errors, the deviation of the central axis occurs, and the control performance of the magnetic bearing compressor deteriorates. In particular, according to Coulomb's law that the force acting between magnetic poles is inversely proportional to the square of the distance (gap) and proportional to the magnetic force of each magnetic pole, the deviation of the central axis in magnetic bearing control has a great influence. This disclosure aims to suppress the misalignment of the central axis caused by manufacturing errors in magnetic bearing devices. [Means for solving the problem]

[0005] A magnetic bearing device of the present disclosure that achieves the above objectives comprises a housing having a first cylindrical member which is a subassembly including at least one of a radial magnetic bearing, a motor, and a gap sensor, and a second cylindrical member which is a casing housing the first cylindrical member, wherein the housing has a plurality of first positioning means on the outer circumferential surface of the first cylindrical member for restricting the rotation of the first cylindrical member relative to the second cylindrical member, and a plurality of second positioning means on the inner circumferential surface of the second cylindrical member for restricting the rotation of the first cylindrical member relative to the second cylindrical member, or a first positioning means on the outer circumferential surface of the first cylindrical member for restricting rotation relative to the second cylindrical member, and the inner circumferential surface of the second cylindrical member The magnetic bearing device has a surface with a plurality of second positioning means for restricting the rotation of the first cylindrical member, or has a plurality of first positioning means for restricting the rotation of the second cylindrical member on the outer circumferential surface of the first cylindrical member, and one second positioning means for restricting the rotation of the first cylindrical member on the inner circumferential surface of the second cylindrical member, and the circumferential position of the first cylindrical member relative to the second cylindrical member can be changed by changing the correspondence between the first positioning means and the second positioning means, and regardless of the position of the first cylindrical member in the circumferential direction, the other end of the wiring, one end of which is connected to the first cylindrical member, is connected to a predetermined position on the second cylindrical member. In this case, the positional relationship of the subassembly with respect to the casing can be made to have less axial misalignment. As a result, manufacturing errors can be suppressed and control performance can be improved. Here, one of the first positioning means and the second positioning means may have a recess, and the other may have a protrusion that fits into the recess. In this case, the portion where the recess and the protrusion fit together restricts the rotation of the first cylindrical member. Furthermore, one or both of the first positioning means and the second positioning means may be flanges having fixing portions that secure the first cylindrical member to the second cylindrical member. In this case, the fixing portions provided on the flange restrict the rotation of the first cylindrical member. Furthermore, the first positioning means may have a first recess, the second positioning means may have a second recess, and an insertion member inserted into the space formed in the portion where the first recess and the second recess face each other may restrict the rotation of the first cylindrical member. In this case, the restricting member inserted into the space formed in the portion where the first recess and the second recess face each other restricts the rotation of the first cylindrical member. Furthermore, the cross-sectional shape of the outer circumference of the first cylindrical member and the cross-sectional shape of the inner circumference of the second cylindrical member may not be circular, and the first positioning means and the second positioning means may restrict the rotation of the first cylindrical member by contact between the outer surface of the first cylindrical member and the inner surface of the second cylindrical member. In this case, since neither the cross-sectional shape of the outer circumference of the first cylindrical member nor the cross-sectional shape of the inner circumference of the second cylindrical member is circular, the rotation of the first cylindrical member can be restricted by a configuration that brings the outer surface of the first cylindrical member and the inner surface of the second cylindrical member into contact. Furthermore, the housing may have the combination of the first positioning means and the second positioning means in a part, multiple parts, or the entirety in the axial direction. In this case, the combination of the first positioning means and the second positioning means can be selected according to the characteristics (shape, position, assembly, etc.) of the first cylindrical member and the second cylindrical member. [Brief explanation of the drawing]

[0006] [Figure 1] This is a cross-sectional view showing an example of the overall configuration of a magnetic bearing device according to the first embodiment. [Figure 2] (A) and (B) are diagrams illustrating the positioning adjustment of a magnetic bearing device according to the first embodiment. [Figure 3] (A) and (B) are diagrams illustrating modified examples of positioning adjustment of a magnetic bearing device according to the first embodiment. [Figure 4](A) is a diagram illustrating the positioning adjustment of a magnetic bearing device according to a second embodiment. (B) is a diagram illustrating a modified example of the positioning adjustment of a magnetic bearing device according to a second embodiment. [Figure 5] (A) is a diagram illustrating the positioning adjustment of a magnetic bearing device according to the third embodiment. (B) is a diagram illustrating a modified example of the positioning adjustment of a magnetic bearing device according to the third embodiment. [Figure 6] Figures (A) through (C) show specific examples of variations when at least one of the first positioning means and the second positioning means is a flange. [Figure 7] (A) is a diagram illustrating the positioning adjustment of the magnetic bearing device according to the fourth embodiment. (B) is a diagram illustrating a modified example of the positioning adjustment of the magnetic bearing device according to the fourth embodiment. (C) is a diagram illustrating another modified example of the positioning adjustment of the magnetic bearing device 4 according to the fourth embodiment. [Figure 8] (A) is a diagram illustrating the positioning adjustment of a magnetic bearing device according to the fifth embodiment. (B) is a diagram illustrating a modified example of the positioning adjustment of a magnetic bearing device according to the fifth embodiment. [Figure 9] This figure shows a specific example of a housing having multiple combinations of a first positioning means and a second positioning means arranged continuously in the axial direction. [Figure 10] Figures (A) through (C) show specific examples of wiring configurations connected to the first cylindrical member and the second cylindrical member. [Modes for carrying out the invention]

[0007] The embodiments will be described in detail below with reference to the attached drawings. <First Embodiment> [Overall configuration of magnetic bearing device 1] Figure 1 is a cross-sectional view showing an example of the overall configuration of a magnetic bearing device 1 according to the first embodiment. The magnetic bearing device 1 is a device used, for example, as a compressor for transporting refrigerant to an air conditioner. One of the features of the magnetic bearing device 1 is that it has a bearing mechanism that levitates the shaft using magnetic force. In other words, the magnetic bearing device 1 creates a space between the bearing and the shaft using magnetic force, and rotates the shaft while it is levitating in that space. This enables oil-free operation. As a result, compared to bearing mechanisms in which the shaft and bearing are in contact, the overall size of the device can be reduced, the rotation speed can be increased, energy saving and maintenance reduction can be achieved.

[0008] As shown in Figure 1, the magnetic bearing device 1 has the following configuration. Specifically, the magnetic bearing device 1 comprises a housing 10 having a first cylindrical member 11 which is a subassembly, and a second cylindrical member 12 which is a casing that houses the first cylindrical member 11 inside. The first cylindrical member 11 includes a motor 111, a radial magnetic bearing 112, and a gap sensor 114.

[0009] The motor 111 is a device composed of a stator, which is a stator that generates torque, a frame that supports the whole, brackets, etc. The radial magnetic bearing 112 is a bearing that supports radial loads applied in a direction perpendicular to the axial direction (radial direction) of the magnetic bearing device 1. The backup bearing 113 is a mechanical bearing provided to limit the range of motion of the rotor of the motor 111 and to prevent contact between the stator and rotor of the radial magnetic bearing 112. The gap sensor is a sensor that detects the amount of physical change of an object using various elements and measures the distance (displacement) to the object by calculating the amount of change as distance.

[0010] The magnetic bearing device 1 is assembled by the following method. First, the first cylindrical member 11 and the second cylindrical member 12, which are components of the magnetic bearing device 1, are manufactured separately. Then, the first cylindrical member 11 is inserted axially into the inside of the second cylindrical member 12 and fixed in place. This completes the assembly of the magnetic bearing device 1.

[0011] Here, in the magnetic bearing device 1, it is desirable that the central axis of the first cylindrical member 11 coincides with the central axis of the second cylindrical member 12. For this reason, when assembling the magnetic bearing device 1 by inserting the first cylindrical member 11 inside the second cylindrical member 12, an adjustment (hereinafter referred to as "positioning adjustment") is performed to reduce the deviation between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12.

[0012] 〔Positioning adjustment〕 FIGS. 2(A) and (B) are diagrams for explaining the positioning adjustment of the magnetic bearing device 1 according to the first embodiment. FIG. 2(A) shows a schematic cross-section of the magnetic bearing device 1 cut in the radial direction before the positioning adjustment. As shown in FIG. 2(A), the magnetic bearing device 1 is formed by disposing the first cylindrical member 11 inside the second cylindrical member 12.

[0013] On the outer peripheral surface of the first cylindrical member 11, a plurality of convex portions 201 to 204 as first positioning means are provided. Also, on the inner peripheral surface of the second cylindrical member 12, a plurality of concave portions 4,01 to 404 as second positioning means are provided.

[0014] In FIG. 2(A), the convex portion 201 and the concave portion 401 are fitted, and the convex portion 202 and the concave portion 402 are fitted. Also, the convex portion 203 and the concave portion 403 are fitted, and the convex portion 204 and the concave portion 404 are fitted. As a result, the convex portions 201 to 204 restrict the rotation of the first cylindrical member 11 with respect to the second cylindrical member 12, and the concave portions 401 to 404 restrict the rotation of the first cylindrical member 11. As a result, the first cylindrical member 11 is positioned with respect to the second cylindrical member 12.

[0015] However, in the state shown in Fig. 2(A), there is a deviation between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12, so positioning adjustment is performed. The positioning adjustment changes the circumferential position of the first cylindrical member 11 with respect to the second cylindrical member 12 by changing the correspondence between the convex portions 201 to 204 and the concave portions 401 to 404. The positioning adjustment work involves temporarily removing the first cylindrical member 11 inserted inside the second cylindrical member 12, rotating the first cylindrical member 11 in the circumferential direction, and then inserting it again inside the second cylindrical member 12. In this work, in the combination of the convex portions 201 to 204 and the concave portions 401 to 404, a correspondence with less axial deviation is selected.

[0016] Fig. 2(B) shows a schematic cross-section of the magnetic bearing device 1 cut in the radial direction after the positioning adjustment. In this positioning adjustment, the first cylindrical member 11 is rotated 180° in the circumferential direction. As a result, the convex portion 201 and the concave portion 403 are fitted, and the convex portion 202 and the concave portion 4 are fitted. Further, the convex portion 203 and the concave portion 401 are fitted, and the convex portion 204 and the concave portion 402 are fitted. As a result, as shown in Fig. 2(B), the deviation between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12 is reduced.

[0017] (Modification example) Figs. 3(A) and (B) are diagrams for explaining a modification example of the positioning adjustment of the magnetic bearing device 1 according to the first embodiment. Fig. 3(A) shows a schematic cross-section of the magnetic bearing device 1 cut in the radial direction before the positioning adjustment. The difference between the example shown in Fig. 2(A) described above and the example shown in Fig. 3(A) is the number of the first positioning means.

[0018] That is, only the convex portion 201 as one first positioning means is provided on the outer peripheral surface of the first cylindrical member 11 shown in Fig. 3(A). On the other hand, on the inner peripheral surface of the second cylindrical member 12, a plurality of concave portions 401 to 404 as the second positioning means are provided as in the example of Fig. 2(A) described above.

[0019] In the example shown in Figure 3(A), the convex portion 201 and the concave portion 401 are fitted together. As a result, the convex portion 201 restricts the rotation of the first cylindrical member 11 relative to the second cylindrical member 12, and the concave portion 401 restricts the rotation of the first cylindrical member 11. Consequently, the first cylindrical member 11 is positioned relative to the second cylindrical member 12. However, in the state shown in Figure 3(A), similar to the example shown in Figure 2(A) above, there is a misalignment between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12. Therefore, positioning adjustment is performed.

[0020] Figure 3(B) shows a schematic cross-section of the magnetic bearing device 1 cut radially after positioning adjustment. In this positioning adjustment, the first cylindrical member 11 is rotated 180° in the circumferential direction, similar to the example shown in Figure 2(A) above. As a result, the convex portion 201 and the concave portion 403 are fitted together. Consequently, as shown in Figure 3(B), the misalignment between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12 is reduced.

[0021] The example shown in Figure 3(B) is easier to manufacture because it has fewer first positioning means compared to the example shown in Figure 2(B) above. However, the example shown in Figure 2(A) has a greater number of first positioning means that engage with the second positioning means, resulting in greater circumferential stability of the first cylindrical member 11.

[0022] <Second Embodiment> Figure 4(A) is a diagram illustrating the positioning adjustment of the magnetic bearing device 2 according to the second embodiment. Figure 4(A) shows a schematic cross-section of the magnetic bearing device 2 when cut radially. As shown in Figure 4(A), the magnetic bearing device 2 is formed by arranging the first cylindrical member 21 inside the second cylindrical member 22. Note that the configuration of the magnetic bearing device 2, other than the first cylindrical member 21 and the second cylindrical member 22, is the same as the configuration of the magnetic bearing device 1 according to the first embodiment described above, so a description is omitted.

[0023] The outer circumferential surface of the first cylindrical member 21 is provided with a plurality of recesses 211 to 214 that serve as first positioning means. The inner circumferential surface of the second cylindrical member 22 is provided with a plurality of protrusions 411 to 414 that serve as second positioning means. In other words, when comparing the first embodiment with the second embodiment, the relationship between the concave and convex shapes of the first positioning means and the second positioning means is reversed.

[0024] In Figure 4(A), the recess 211 and the protrusion 411 are fitted together, and the recess 212 and the protrusion 412 are fitted together. Also, the recess 213 and the protrusion 413 are fitted together, and the recess 214 and the protrusion 414 are fitted together. As a result, the recesses 211 to 214 restrict the rotation of the first cylindrical member 21 relative to the second cylindrical member 22, and the protrusions 411 to 414 restrict the rotation of the first cylindrical member 21. Consequently, the first cylindrical member 21 is positioned relative to the second cylindrical member 22.

[0025] In the state shown in Figure 4(A), there is no misalignment between the central axis of the first cylindrical member 11 and the central axis of the second cylindrical member 12. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 4(A) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 21 relative to the second cylindrical member 22 is changed by changing the correspondence between the recesses 211 to 214 and the protrusions 411 to 414.

[0026] (modified version) Figure 4(B) is a diagram illustrating a modified example of the positioning adjustment of the magnetic bearing device 2 according to the second embodiment. Figure 4(B) shows a schematic cross-section of the magnetic bearing device 2 cut radially. The difference between the example shown in Figure 4(A) and the example shown in Figure 4(B) is the number of second positioning means.

[0027] In other words, the inner circumferential surface of the second cylindrical member 22 shown in Figure 4(B) is provided with only one protrusion 411 as a second positioning means. In contrast, the outer circumferential surface of the first cylindrical member 21 is provided with a plurality of recesses 211 to 214 as first positioning means, similar to the example in Figure 4(A) described above.

[0028] In the example shown in Figure 4(B), the recess 211 and the protrusion 411 are fitted together. As a result, the recess 211 restricts the rotation of the first cylindrical member 21 relative to the second cylindrical member 22, and the protrusion 411 restricts the rotation of the first cylindrical member 21. Consequently, the first cylindrical member 21 is positioned relative to the second cylindrical member 22.

[0029] In the state shown in Figure 4(B), there is no misalignment between the central axis of the first cylindrical member 21 and the central axis of the second cylindrical member 22. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 4(B) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 21 relative to the second cylindrical member 22 is changed by changing the correspondence between the recesses 211 to 214 and the protrusions 411.

[0030] The example shown in Figure 4(B) is easier to manufacture because it has fewer second positioning means compared to the example shown in Figure 4(A) described above. However, the example shown in Figure 4(A) has a greater number of second positioning means that engage with the first positioning means, resulting in greater circumferential stability of the first cylindrical member 21.

[0031] <Third Embodiment> Figure 5(A) is a diagram illustrating the positioning adjustment of the magnetic bearing device 3 according to the third embodiment. Figure 5(A) shows a schematic cross-section of the magnetic bearing device 3 cut radially. As shown in Figure 5(A), the magnetic bearing device 3 is formed by arranging the first cylindrical member 31 inside the second cylindrical member 32. Note that the configuration of the magnetic bearing device 3, other than the first cylindrical member 31 and the second cylindrical member 32, is the same as the configuration of the magnetic bearing device 1 according to the first embodiment described above, so a description is omitted.

[0032] A flange 220, serving as a first positioning means, is provided on the outer circumferential surface of the first cylindrical member 31. The flange 220 is a flange-shaped portion formed to protrude radially outward from the outer circumferential surface of the first cylindrical member 31. The flange 220 has fixing portions 221 to 224. A flange 420, serving as a second positioning means, is provided on the inner circumferential surface of the second cylindrical member 32. The flange 420 is a flange-shaped portion formed to protrude radially inward from the inner circumferential surface of the second cylindrical member 32. The flange 420 has fixing portions 421 to 424. The fixing portions 221 to 224 and the fixing portions 421 to 424 are holes through which an insertion member 90, made of a metal pin or the like, passes.

[0033] In Figure 5(A), fixing part 221 and fixing part 421 are fixed by the insertion member 90, and fixing part 222 and fixing part 422 are fixed by the insertion member 90. Also, fixing part 223 and fixing part 423 are fixed by the insertion member 90, and fixing part 224 and fixing part 424 are fixed by the insertion member 90. As a result, fixing parts 221 to 224 restrict the rotation of the first cylindrical member 31 relative to the second cylindrical member 32, and fixing parts 421 to 424 restrict the rotation of the first cylindrical member 31. As a result, the first cylindrical member 31 is positioned relative to the second cylindrical member 32.

[0034] In the state shown in Figure 5(A), there is no misalignment between the central axis of the first cylindrical member 31 and the central axis of the second cylindrical member 32. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 5(A) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 31 relative to the second cylindrical member 32 is changed by changing the correspondence between the fixing parts 221 to 224 and the fixing parts 421 to 424.

[0035] (modified version) Figure 5(B) is a diagram illustrating a modified example of positioning adjustment of the magnetic bearing device 3 according to the third embodiment. Figure 5(B) shows a schematic cross-section of the magnetic bearing device 3 cut radially. The difference between the example shown in Figure 5(A) and the example shown in Figure 5(B) is the number of holes provided as fixing parts in the flange 220, which serves as the first positioning means.

[0036] In other words, the flange 220 of the first cylindrical member 31 shown in Figure 5(B) is provided only with a fixing portion 221. In contrast, the flange 420 of the second cylindrical member 32 is provided with fixing portions 421 to 424, similar to the example in Figure 5(A) described above.

[0037] In the example shown in Figure 5(B), the fixing part 221 and the fixing part 421 are fixed together by the insertion member 90. As a result, the fixing part 221 restricts the rotation of the first cylindrical member 31 relative to the second cylindrical member 32, and the fixing part 421 restricts the rotation of the first cylindrical member 31. Consequently, the first cylindrical member 31 is positioned relative to the second cylindrical member 32.

[0038] In the state shown in Figure 5(B), there is no misalignment between the central axis of the first cylindrical member 31 and the central axis of the second cylindrical member 32. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 5(B) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 31 relative to the second cylindrical member 32 is changed by changing the correspondence between the fixing part 221 and the fixing parts 421 to 424.

[0039] The example shown in Figure 5(B) is easier to manufacture because it has fewer holes in the flange 220 for fixing purposes compared to the example shown in Figure 5(A) above. However, the example shown in Figure 5(A) has more holes in the flange 220 for fixing purposes, which increases the circumferential stability of the first cylindrical member 31.

[0040] Figures 6(A) to (C) show specific examples of variations when at least one of the first positioning means and the second positioning means is a flange. Figures 6(A) to 6(C) show schematic cross-sections of the magnetic bearing device 3 when cut in the axial direction. Of these, the variation shown in Figure 6(A) corresponds to the example in Figure 5(A) described above, and flanges are provided on both the first cylindrical member 31 and the second cylindrical member 32. Specifically, as shown in Figure 6(A), the first cylindrical member 31 has a flange 220 and the second cylindrical member 32 has a flange 420.

[0041] In the example shown in Figure 6(A), the fixing part 221 and the fixing part 421 are fixed together by the insertion member 90. As a result, the fixing part 221 restricts the rotation of the first cylindrical member 31 relative to the second cylindrical member 32, and the fixing part 421 restricts the rotation of the first cylindrical member 31. Consequently, the first cylindrical member 31 is positioned relative to the second cylindrical member 32.

[0042] In the variation shown in Figure 6(B), the second cylindrical member 32 is provided with a flange 420, but the first cylindrical member 31 is not. In this case, the first cylindrical member 31 and the second cylindrical member 32 are fixed together by passing the insertion member 90 through the hole 311 provided at the axial front end of the first cylindrical member 31 and the fixing portion 421 of the flange 420.

[0043] In the variation shown in Figure 6(C), the first cylindrical member 31 is provided with a flange 220, but the second cylindrical member 32 is not. In this case, the first cylindrical member 31 and the second cylindrical member 32 are fixed together by passing the insertion member 90 through a hole 322 provided at the axial rear end of a step 321 provided on a part of the inner circumferential surface of the second cylindrical member 32, and through the fixing portion 221 of the flange 220.

[0044] <Fourth Embodiment> Figure 7(A) is a diagram illustrating the positioning adjustment of the magnetic bearing device 4 according to the fourth embodiment. Figure 7(A) shows a schematic cross-section of the magnetic bearing device 4 when cut radially. As shown in Figure 7(A), the magnetic bearing device 4 is formed by arranging the first cylindrical member 41 inside the second cylindrical member 42. Note that the configuration of the magnetic bearing device 4, other than the first cylindrical member 41 and the second cylindrical member 42, is the same as the configuration of the magnetic bearing device 1 according to the first embodiment described above, so a description is omitted.

[0045] The outer circumferential surface of the first cylindrical member 41 is provided with first recesses 231 to 234, which serve as first positioning means. The inner circumferential surface of the second cylindrical member 42 is provided with second recesses 431 to 434, which serve as second positioning means. In Figure 7(A), a space 301 is formed where the first recess 231 and the second recess 431 face each other, and a space 302 is formed where the first recess 232 and the second recess 432 face each other. Furthermore, a space 303 is formed where the first recess 233 and the second recess 433 face each other, and a space 304 is formed where the first recess 234 and the second recess 434 face each other.

[0046] Insertion members 91 are inserted into spaces 301 to 304. The insertion members 91 are, for example, metal rods. As a result, the insertion members 91 restrict the rotation of the first cylindrical member 41 relative to the second cylindrical member 42. Consequently, the first cylindrical member 41 is positioned relative to the second cylindrical member 42.

[0047] In the state shown in Figure 7(A), there is no misalignment between the central axis of the first cylindrical member 41 and the central axis of the second cylindrical member 42. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 7(A) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 41 relative to the second cylindrical member 42 is changed by changing the correspondence between the first recesses 231 to 234 and the second recesses 431 to 434.

[0048] (Variation 1) Figure 7(B) is a diagram illustrating a modified example of the positioning adjustment of the magnetic bearing device 4 according to the fourth embodiment. Figure 7(B) shows a schematic cross-section of the magnetic bearing device 4 cut radially. The difference between the example shown in Figure 7(A) and the example shown in Figure 7(B) is the number of insertion members 91.

[0049] In other words, in the example shown in Figure 7(A), the insertion member 91 is inserted into all of the spaces 301 to 304. In contrast, in the example shown in Figure 7(B), the insertion member 91 is inserted only into space 301. As a result, the insertion member 91 inserted into space 301 restricts the rotation of the first cylindrical member 41. Consequently, the first cylindrical member 41 is positioned relative to the second cylindrical member 42.

[0050] In the state shown in Figure 7(B), there is no misalignment between the central axis of the first cylindrical member 41 and the central axis of the second cylindrical member 42. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 7(B) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 41 relative to the second cylindrical member 42 is changed by changing the correspondence between the first recesses 231 to 234 and the second recesses 431 to 434.

[0051] The example shown in Figure 7(B) is easier to work with because it has fewer insertion members 91 compared to the example shown in Figure 7(A) described above. However, the example shown in Figure 7(A) has a larger number of insertion members 91, which increases the circumferential stability of the first cylindrical member 41.

[0052] (Modification 2) Figure 7(C) illustrates another modified example of the positioning adjustment of the magnetic bearing device 4 according to the fourth embodiment. Figure 7(C) shows a schematic cross-section of the magnetic bearing device 4 cut radially. The difference between the example shown in Figure 7(B) and the example shown in Figure 7(C) is the number of first positioning means.

[0053] In other words, the outer circumferential surface of the first cylindrical member 41 shown in Figure 7(B) is provided with a plurality of first recesses 231 to 234 serving as first positioning means. In contrast, in the example shown in Figure 7(C), only one first recess 231 serving as first positioning means is provided.

[0054] In the example shown in Figure 7(C), the insertion member 91 is inserted into the space 301 formed between the first recess 231 and the second recess 431. As a result, the insertion member 91 inserted into the space 301 restricts the rotation of the first cylindrical member 41. Consequently, the first cylindrical member 41 is positioned relative to the second cylindrical member 42.

[0055] In the state shown in Figure 7(C), there is no misalignment between the central axis of the first cylindrical member 41 and the central axis of the second cylindrical member 42. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 7(C) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 41 relative to the second cylindrical member 42 is changed by changing the correspondence between the first recess 231 and the second recesses 431 to 434.

[0056] The example shown in Figure 7(C) is easier to manufacture because it has fewer first positioning means compared to the example shown in Figure 7(B) above.

[0057] <Fifth Embodiment> Figure 8(A) is a diagram illustrating the positioning adjustment of the magnetic bearing device 5 according to the fifth embodiment. Figure 8(A) shows a schematic cross-section of the magnetic bearing device 5 when cut radially. As shown in Figure 8(A), the magnetic bearing device 5 is formed by arranging the first cylindrical member 51 inside the second cylindrical member 52. Note that the configuration of the magnetic bearing device 5, other than the first cylindrical member 51 and the second cylindrical member 52, is the same as the configuration of the magnetic bearing device 1 according to the first embodiment described above, so a description is omitted.

[0058] As shown in Figure 8(A), the cross-sectional shape of the outer circumference of the first cylindrical member 51 and the cross-sectional shape of the inner circumference of the second cylindrical member 52 are not circular but approximately triangular. The outer circumferential surfaces 241 to 243 of the first cylindrical member 51 function as a plurality of first positioning means. The inner circumferential surfaces 441 to 443 of the second cylindrical member 52 function as a plurality of second positioning means.

[0059] In Figure 8(A), the rotation of the first cylindrical member 51 relative to the second cylindrical member 52 is restricted by contact between the outer peripheral surface 241 and the inner peripheral surface 441, contact between the outer peripheral surface 242 and the inner peripheral surface 442, and contact between the outer peripheral surface 243 and the inner peripheral surface 443. As a result, the first cylindrical member 51 is positioned relative to the second cylindrical member 52.

[0060] In the state shown in Figure 8(A), there is no misalignment between the central axis of the first cylindrical member 51 and the central axis of the second cylindrical member 52. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 8(A) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 51 relative to the second cylindrical member 52 is changed by changing the correspondence between the outer circumferential surfaces 241 to 243 of the first cylindrical member 51 and the inner circumferential surfaces 441 to 443 of the second cylindrical member 52.

[0061] (modified version) Figure 8(B) is a diagram illustrating a modified example of the positioning adjustment of the magnetic bearing device 5 according to the fifth embodiment. Figure 8(B) shows a schematic cross-section of the magnetic bearing device 5 cut radially. The difference between the example shown in Figure 8(A) and the example shown in Figure 8(B) is the second positioning means and the cross-sectional shape of the second positioning means.

[0062] In other words, in the example shown in Figure 8(A), the cross-sectional shape of the outer circumference of the first cylindrical member 51 and the cross-sectional shape of the inner circumference of the second cylindrical member 52 are substantially triangular. Specifically, the cross-sectional shape formed by the outer circumferential surfaces 241 to 243, which function as the first positioning means, and the cross-sectional shape formed by the inner circumferential surfaces 441 to 443, which function as the second positioning means, are substantially triangular.

[0063] In contrast, in the example shown in Figure 8(B), the cross-sectional shape of the outer circumference of the first cylindrical member 51 and the cross-sectional shape of the inner circumference of the second cylindrical member 52 are substantially rectangular. Specifically, the cross-sectional shape formed by the outer circumferential surfaces 241 to 244 that function as the first positioning means and the cross-sectional shape formed by the inner circumferential surfaces 441 to 444 that function as the second positioning means are substantially rectangular.

[0064] In Figure 8(B), the rotation of the first cylindrical member 51 relative to the second cylindrical member 52 is restricted by contact between the outer peripheral surface 241 and the inner peripheral surface 441, contact between the outer peripheral surface 242 and the inner peripheral surface 442, contact between the outer peripheral surface 243 and the inner peripheral surface 443, and contact between the outer peripheral surface 244 and the inner peripheral surface 444. As a result, the first cylindrical member 51 is positioned relative to the second cylindrical member 52.

[0065] In the state shown in Figure 8(B), there is no misalignment between the central axis of the first cylindrical member 51 and the central axis of the second cylindrical member 52. However, if there is a misalignment of the central axes, the positioning adjustment described above is performed. The positioning adjustment in the example of Figure 8(B) is basically the same as the positioning adjustment described above. That is, the circumferential position of the first cylindrical member 51 relative to the second cylindrical member 52 is changed by changing the correspondence between the outer circumferential surfaces 241 to 244 of the first cylindrical member 51 and the inner circumferential surfaces 441 to 444 of the second cylindrical member 52.

[0066] <Configuration common to the first to fifth embodiments> [Rotation restriction mechanism] As described above, in the first to fifth embodiments, the first positioning means and the second positioning means constitute a rotation restricting mechanism that restricts the rotation of the first cylindrical member relative to the second cylindrical member. Specifically, as shown in Figure 8(B), when the result of the calculation of the following formula 1, where r is the distance from the central axis of the first cylindrical member to the boundary with the second cylindrical member and θ is the rotation angle in the circumferential direction, is not always 0 (zero), the rotation of the first cylindrical member is restricted to 360° in the circumferential direction.

[0067]

number

[0068] [Number of rotation restricting mechanisms in the axial direction] Figure 9 shows a specific example of a housing 10 having multiple combinations of the first positioning means and the second positioning means arranged continuously in the axial direction. Figure 9 shows a schematic cross-section of the housing 10 of the magnetic bearing device 3, cut in the axial direction. In the example in Figure 9, the housing 10 has second cylindrical members 62 and 72. Region 501 of the housing 10 contains a first cylindrical member 61 and a second cylindrical member 62, each containing a radial magnetic bearing 112 inside. Region 502 of the housing 10 contains a first cylindrical member 71 and a second cylindrical member 72, each containing a motor 111 inside.

[0069] In region 501 of the housing 10, the first cylindrical member 61 has a protrusion 251 as a first positioning means. The second cylindrical member 62 has a recess 451 as a second positioning means. At this time, the protrusion 251 and the recess 451 fit together. Such a combination of the first positioning means and the second positioning means corresponds to, for example, the first embodiment described above.

[0070] In region 502 of the housing 10, the first cylindrical member 71 has a recess 261 as a first positioning means. The second cylindrical member 72 has a protrusion 461 as a second positioning means. At this time, the recess 261 and the protrusion 461 fit together. Such a combination of the first positioning means and the second positioning means corresponds to, for example, the second embodiment described above.

[0071] Here, the housing 10 shown in Figure 9 has two combinations of the first positioning means and the second positioning means arranged continuously in the axial direction, but is not limited to this. The combinations of the first positioning means and the second positioning means may be located in a portion of the housing in the axial direction, or may be arranged discontinuously in multiple portions. Alternatively, they may be located throughout the entire axial direction of the housing.

[0072] [Wiring configuration] Figures 10(A) to (C) show specific examples of the configuration of the wiring 100 connected to the first cylindrical member 81 and the second cylindrical member 82. Regardless of the embodiment, in a magnetic bearing device, the length of the wiring connected to the first cylindrical member and the second cylindrical member is determined according to the axial position of the first cylindrical member. However, regardless of the position of the first cylindrical member in the circumferential direction, the other end of the wiring, one end of which is connected to the first cylindrical member, is connected to a predetermined position on the second cylindrical member.

[0073] Figure 10(A) shows an example where the connection portion 110 of the wiring 100 is located between the first cylindrical member 81 and the second cylindrical member 82. Figure 10(B) shows an example where the connection portion 110 of the wiring 100 is located on the second cylindrical member 82 side. Figure 10(C) shows an example where the connection portion 110 of the wiring 100 is located on the first cylindrical member 81 side.

[0074] In any of the examples in Figures 10(A) to (C), regardless of the position of the first cylindrical member 81 in the circumferential direction, the other end 102 of the wiring 100, one end 101 of which is connected to the first cylindrical member 81, is connected to a predetermined position 821 on the second cylindrical member 82.

[0075] <Other Embodiments> Furthermore, the configurations described above are not limited to the embodiments and their variations, and can be modified without departing from the spirit of the invention. In other words, it is understood that a variety of changes in form and details are possible without departing from the spirit and scope of the claims. The configurations described above are not the only ones you may use; you may also omit some of the components in each configuration described above, or add other functions to each configuration described above. Furthermore, although multiple embodiments have been described above, it is also possible to swap the configurations included in one embodiment with those included in other embodiments, or to add the configurations included in one embodiment to other embodiments.

[0076] For example, the above-described embodiment has a configuration in which the first cylindrical member has one to four first positioning means and the second cylindrical member has one to four second positioning means, but is not limited thereto. The first cylindrical member may have five or more first positioning means and the second cylindrical member may have five or more second positioning means.

[0077] Furthermore, the configuration may span multiple embodiments of the above-described embodiments. For example, the configuration may be a combination of the configuration according to the first embodiment (where the first positioning means is a convex portion and the second positioning means is a concave portion) and the configuration according to the second embodiment (where the first positioning means is a concave portion and the second positioning means is a convex portion). Specifically, the outer circumferential surface of the first cylindrical member may be provided with a convex portion that fits into the concave portion and a concave portion that fits into the convex portion, and the inner circumferential surface of the second cylindrical member may be provided with a concave portion that fits into the convex portion and a convex portion that fits into the concave portion.

[0078] Here, each of the embodiments described above can be understood as follows. In other words, the magnetic bearing device of the present disclosure (for example, the magnetic bearing device 1 of Figure 1) comprises a housing 10 having a first cylindrical member (for example, the first cylindrical member 11 of Figure 1) which is a subassembly including at least one of a radial magnetic bearing 112, a motor 111, and a gap sensor, and a second cylindrical member (for example, the second cylindrical member 12 of Figure 1) which is a casing that houses the first cylindrical member, wherein the housing 10 has a plurality of first positioning means on the outer circumferential surface of the first cylindrical member that restrict the rotation of the first cylindrical member relative to the second cylindrical member (for example, protrusions 201 to 204 of Figure 2(A)), and a plurality of second positioning means on the inner circumferential surface of the second cylindrical member that restrict the rotation of the first cylindrical member relative to the second cylindrical member (for example, recesses 401 to 404 of Figure 2(A)), or the outer circumferential surface of the first cylindrical member that restricts the rotation of the first cylindrical member relative to the second cylindrical member The magnetic bearing device has one first positioning means for restricting rotation and a plurality of second positioning means on the inner circumferential surface of the second cylindrical member for restricting the rotation of the first cylindrical member, or a plurality of first positioning means on the outer circumferential surface of the first cylindrical member for restricting rotation relative to the second cylindrical member and one second positioning means on the inner circumferential surface of the second cylindrical member for restricting the rotation of the first cylindrical member, and the circumferential position of the first cylindrical member relative to the second cylindrical member can be changed by changing the correspondence between the first positioning means and the second positioning means, so that no matter where the first cylindrical member is positioned in the circumferential direction, the other end (for example, the other end 102 in Figure 10(A)) of a wire (for example, the wire 100 in Figure 10(A)) to which one end (for example, one end 101 in Figure 10(A)) is connected to the first cylindrical member is connected to a predetermined position on the second cylindrical member. In this case, the positional relationship of the subassembly with respect to the casing can be made to have less axial misalignment. As a result, manufacturing errors are suppressed, and control performance can be improved.

[0079] Here, one of the first positioning means and the second positioning means may have a recess, and the other may have a protrusion that fits into the recess. In this case, the portion where the recess and the protrusion fit together restricts the rotation of the first cylindrical member.

[0080] Furthermore, one or both of the first positioning means and the second positioning means may be flanges having a fixing portion (for example, the flange 220 in Figure 5(A)) that fixes the first cylindrical member to the second cylindrical member. In this case, the fixing portion provided on the flange restricts the rotation of the first cylindrical member (for example, the first cylindrical member 31 in Figure 5(A)).

[0081] Alternatively, the first positioning means may have a first recess (for example, the first recesses 231 to 234 in Figure 7(A)), and the second positioning means may have a second recess (for example, the second recesses 431 to 434 in Figure 7(A)), and an insertion member (for example, the insertion member 91 in Figure 7(A)) inserted into a space formed in the portion where the first recess and the second recess face each other (for example, space 301 in Figure 7(A)) may restrict the rotation of the first cylindrical member. In this case, the restricting member inserted into the space formed in the portion where the first recess and the second recess face each other restricts the rotation of the first cylindrical member.

[0082] Furthermore, the cross-sectional shape of the outer circumference of the first cylindrical member (for example, the first cylindrical member 51 in Figure 8(A)) and the cross-sectional shape of the inner circumference of the second cylindrical member (for example, the second cylindrical member 52 in Figure 8(A)) may not be circular (for example, approximately triangular in Figure 8(A)), and the rotation of the first cylindrical member may be restricted by the contact between the outer circumference of the first cylindrical member and the inner circumference of the second cylindrical member of the first positioning means (for example, the outer circumference surfaces 241 to 243 in Figure 8(A)) and the second positioning means (for example, the inner circumference surfaces 441 to 443 in Figure 8(A)). In this case, since neither the cross-sectional shape of the outer circumference of the first cylindrical member nor the cross-sectional shape of the inner circumference of the second cylindrical member is circular, the rotation of the first cylindrical member can be restricted by a configuration that brings the outer circumference of the first cylindrical member and the inner circumference of the second cylindrical member into contact.

[0083] Furthermore, the housing 10 may have the combination of the first positioning means and the second positioning means in a part, multiple parts, or the entire axial direction. In this case, the combination of the first positioning means and the second positioning means can be selected according to the characteristics (shape, position, assembly, etc.) of the first cylindrical member (e.g., the first cylindrical member 61 in Figure 9) and the second cylindrical member (e.g., the second cylindrical member 62 in Figure 9). [Explanation of Symbols]

[0084] 1,2,3,4,5…Magnetic bearing device, 11,21,31,41,51,61,71,81…First cylindrical member, 10…Housing, 12,22,32,42,52,62,72,82…Second cylindrical member, 90,91…Insertion member, 100…Wiring, 110…Connection part, 111…Motor, 112…Radial magnetic bearing, 113…Backup bearing, 201,202,203,204,251,411,412,413,414,461…Convex Parts, 211, 212, 213, 214, 261, 401, 402, 403, 404…recesses, 221, 222, 223, 224, 421, 422, 423, 424…fixing parts, 220, 420…flanges, 241, 242, 243, 244…outer surfaces, 231, 232, 233, 234…first recesses, 431, 432, 433, 434…second recesses, 301, 302, 303, 304…spaces, 441, 442, 443, 444…inner surfaces

Claims

1. The housing comprises a first cylindrical member which is a subassembly including at least one of a radial magnetic bearing, a motor, and a gap sensor, and a second cylindrical member which is a casing that houses the first cylindrical member inside. The aforementioned housing, The outer circumferential surface of the first cylindrical member is provided with a plurality of first positioning means for restricting the rotation of the first cylindrical member relative to the second cylindrical member, The inner circumferential surface of the second cylindrical member is provided with a plurality of second positioning means for restricting the rotation of the first cylindrical member relative to the second cylindrical member, It has, or On the outer circumferential surface of the first cylindrical member, there is a first positioning means that restricts rotation relative to the second cylindrical member, On the inner circumferential surface of the second cylindrical member, there are a plurality of second positioning means that restrict the rotation of the first cylindrical member, It has, or The outer circumferential surface of the first cylindrical member is provided with a plurality of first positioning means that restrict rotation relative to the second cylindrical member, On the inner circumferential surface of the second cylindrical member, there is a second positioning means that restricts the rotation of the first cylindrical member, It has, By changing the correspondence between the first positioning means and the second positioning means, the circumferential position of the first cylindrical member relative to the second cylindrical member can be changed. Regardless of the position of the first cylindrical member in the circumferential direction, the other end of the wiring, one end of which is connected to the first cylindrical member, is connected to a predetermined position on the second cylindrical member. Magnetic bearing device.

2. The first positioning means and the second positioning means have a recess, and the other has a protrusion that fits into the recess. The magnetic bearing device according to claim 1.

3. One or both of the first positioning means and the second positioning means are flanges having a fixing portion for fixing the first cylindrical member to the second cylindrical member. The magnetic bearing device according to claim 1.

4. The first positioning means has a first recess, The second positioning means has a second recess, An insertion member inserted into the space formed in the portion where the first recess and the second recess face each other restricts the rotation of the first cylindrical member. The magnetic bearing device according to claim 1.

5. The cross-sectional shape of the outer circumference of the first cylindrical member and the cross-sectional shape of the inner circumference of the second cylindrical member are not circular. The first positioning means and the second positioning means restrict the rotation of the first cylindrical member by contact between the outer circumferential surface of the first cylindrical member and the inner circumferential surface of the second cylindrical member. The magnetic bearing device according to claim 1.

6. The housing has the combination of the first positioning means and the second positioning means in a part, multiple parts, or the whole in the axial direction. The magnetic bearing device according to claim 1.

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