Interaction force control device, electromagnetic brake having the same, and rotary electric machine having the same

Abstract

To provide an interaction force control device having excellent versatility, an electromagnetic brake having the same, and a rotary electric machine having the same.SOLUTION: An interaction force control device includes: a first element including a first permanent magnet and a second element including a second permanent magnet and a coil, in which the relative positional relationship between the first and second elements is variable, an interaction force is generated between the first and second elements due to the mutual magnetic force of the first and second permanent magnets, the magnetic force of the second permanent magnet can be increased or decreased according to the magnetic force generated by the coil, and the interaction force is controlled by the variation of the magnetic force generated by the coil.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an interaction force control device, an electromagnetic brake equipped with the same, and a rotating electric machine equipped with the same. [Background technology]

[0002] Patent Document 1 discloses a technique for generating a brake torque that maintains the rotating state of a rotor by energizing the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-341590 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned technology only generates a braking torque by energizing, and therefore has low versatility.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an interaction force control device with excellent versatility, an electromagnetic brake equipped with the same, and a rotating electric machine equipped with the same. [Means for solving the problem]

[0006] The above-mentioned object can be achieved by an interaction force control device comprising a first element including a first permanent magnet and a second element including a second permanent magnet and a coil, wherein the relative positional relationship between the first and second elements is variable, an interaction force is generated between the first and second elements due to the mutual magnetic force of the first and second permanent magnets, the magnetic force of the second permanent magnet can be increased or decreased depending on the magnetic force generated by the coil, and the interaction force is controlled by changing the magnetic force generated by the coil. Effect of the Invention

[0007] It is possible to provide an interaction force control device with excellent versatility, an electromagnetic brake equipped with the same, and a rotating electric machine equipped with the same. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a conceptual diagram of an interaction force control device. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 2 is a view of the rotor viewed from the axial direction. [Figure 6] FIG. 3 is a partially enlarged view of FIG. [Figure 7] FIG. 4 is an explanatory diagram of possible positions for installing permanent magnets. [Figure 8] FIG. 13 is a diagram showing a first modified example of the position of the permanent magnet. [Figure 9] FIG. 13 is a diagram showing a second modified example of the position of the permanent magnet. [Figure 10] FIG. 11 is an external view of a first modified example of a rotating electric machine. [Figure 11] FIG. 11 is a partially enlarged view of FIG. [Figure 12] FIG. 11 is an external view of a second modified example of the rotating electric machine. [Figure 13] FIG. 13 is a partially enlarged view of FIG. [Figure 14] FIG. 11 is an external view of a third modified example of the rotating electric machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Configuration of interaction force control device] FIG. 1 is a conceptual diagram of an interaction force control device 1. The interaction force control device 1 includes elements 10 and 30. The element 10 includes a permanent magnet m. The element 30 includes a coil C and a permanent magnet M. The element 10 is an example of a first element. The element 30 is an example of a second element. The permanent magnet m is an example of a first permanent magnet. The permanent magnet M is an example of a second permanent magnet. The elements 10 and 30 are provided so that their relative positional relationship can be changed. For example, one of the elements 10 and 30 is fixed, and the other is supported by a guide rail or the like so as to be able to move forward and backward toward the other. The permanent magnets m and M are arranged so that their different polarities face each other. Specifically, the S pole of the permanent magnet m faces the N pole of the permanent magnet M. The coil C is wound around a central axis that is aligned in the direction in which the S pole and N pole of the permanent magnet M are aligned. When the coil C is in a non-energized state with no current passing therethrough, an interaction force is generated between the elements 10 and 30 due to the mutual magnetic force of the permanent magnets m and M. In the example of Fig. 1, the interaction force is an attractive force.

[0010] By energizing the coil C to an excited state, the magnetic force of the permanent magnet M can be weakened by the magnetic force generated by the coil C. This can reduce the attractive force, which is an interaction force. Furthermore, by increasing the excitation current to the coil C, the magnetic force generated by the coil C and the magnetic force of the permanent magnet M can be offset. This can eliminate the interaction force. Furthermore, by increasing the excitation current to the coil C, a repulsive force can be generated as an interaction force by the magnetic force generated by the coil C. Furthermore, by switching the direction of the excitation current to the coil C to put the coil C in a reverse excitation state, the attractive force, which is an interaction force, can be increased by the magnetic force generated by the coil C. In this way, by controlling the direction and magnitude of the excitation current to the coil C to change the magnetic force generated by the coil C, the interaction force can be controlled in a variety of ways. Therefore, the mechanism of the interaction force control device 1 can be used in a variety of devices, and the interaction force control device 1 is highly versatile. For example, the mechanism of the interaction force control device 1 can be used in an electromagnetic brake or a rotating electric machine. Note that FIG. 1 is intended to explain the concept of the interaction force control device 1, and does not take into consideration practical design limitations such as magnetic short-circuiting of the permanent magnets M and m.

[0011] The element 10 may not be provided with the permanent magnet m, and may be a member made of a magnetic material such as an iron core. In this case, a magnetic attraction force acts between the element 10 and the permanent magnet M. This attraction force can be reduced or eliminated by the magnetic force generated by the coil C.

[0012] [Configuration of rotating electric machine] FIG. 2 is an external view of the rotating electric machine 1a. The rotating electric machine 1a is a hybrid type stepping motor. The rotating electric machine 1a has an electromagnetic brake function that utilizes an interaction force control device. The rotating electric machine 1a includes a rotor 10a, a stator core 30a, coils Ca to Ch, and permanent magnets Ma to Mh. FIG. 2 illustrates an axis A that is the central axis of rotation of the rotor 10a. Therefore, FIG. 2 is a view of the rotating electric machine 1a viewed from the direction of the axis A. The rotor 10a is an internal rotation type.

[0013] FIG. 3 is a side view of the rotor 10a. FIG. 4 is a perspective view of the rotor 10a. FIG. 5 is a view of the rotor 10a viewed from the direction of the axis A. The rotor 10a includes a shaft 11, iron cores 12a and 12b, and a permanent magnet mA. The permanent magnet mA is disposed between the iron cores 12a and 12b and is in contact with the iron cores 12a and 12b. The iron cores 12a and 12b and the permanent magnet mA are each in the shape of a circular plate. The permanent magnet mA is magnetized with different polarities in the direction of the axis A. As a result, the polarity of the iron core 12a and the polarity of the iron core 12b are different from each other. For example, the iron core 12a is magnetized to the S pole, and the iron core 12b is magnetized to the N pole. The permanent magnet mA is an example of a first permanent magnet.

[0014] A plurality of pole teeth 13a are formed at a predetermined pitch on the outer peripheral surface of the iron core 12a. A plurality of pole teeth 13b are formed at a predetermined pitch on the outer peripheral surface of the iron core 12b. Here, the pitch of the pole teeth 13a is the same as the pitch of the pole teeth 13b. The iron cores 12a and 12b are fixed to the shaft 11 with a shift of half this pitch. Therefore, as shown in FIG. 5, when viewed from the direction of the axis A, the pole teeth 13b are located between the adjacent pole teeth 13a. Similarly, the pole teeth 13a are located between the adjacent pole teeth 13b.

[0015] The stator core 30a shown in Fig. 2 is formed by stacking a plurality of thin plates made of electromagnetic steel in the thickness direction. The stator core 30a includes a yoke portion 31 and teeth portions 33a-33h. The yoke portion 31 is substantially annular and surrounds the rotor 10a. The yoke portion 31 includes an outer peripheral surface 311 and an inner peripheral surface 312. When viewed from the direction of the axis A, the outer peripheral surface 311 is substantially rectangular. If the teeth portions 33a-33h were not present in the yoke portion 31, the inner peripheral surface 312 would be substantially circular when viewed from the direction of the axis A.

[0016] The teeth 33a to 33h protrude radially inward from the inner peripheral surface 312 of the yoke portion 31. Thus, the tips of the teeth 33a to 33h face the outer peripheral surface of the rotor 10a. The teeth 33a to 33h are provided at equal angular intervals in the circumferential direction. FIG. 2 illustrates center lines La to Lh of the teeth 33a to 33h. The center lines La to Lh pass through the axis A and are parallel to the radial direction. The center lines La to Ld are the same as the center lines Le to Lh. The coils Ca to Ch are wound around the teeth 33a to 33h via insulators (not shown). When the coils Ca to Ch are energized, magnetic flux is generated in the yoke portion 31 and the teeth 33a to 33h, which are the main magnetic paths.

[0017] The permanent magnets Ma to Mh are provided in the yoke portion 31 near the base side of the teeth portions 33a to 33h. The permanent magnets Ma to Mh are provided at positions overlapping the center lines La to Lh, respectively. The permanent magnets Ma to Mh are located radially outward from the coils Ca to Ch, respectively. The permanent magnets Ma to Mh are inserted into a plurality of holes pre-formed in the stator core 30a, respectively. The permanent magnets Ma to Mh have the same size and shape. In each of the permanent magnets Ma to Mh, one of the S pole and the N pole faces inward in the radial direction, and the other of the S pole and the N pole faces outward in the radial direction. Specifically, in each of the permanent magnets Ma, Mb, Me, and Mf, the N pole faces inward in the radial direction, and the S pole faces outward in the radial direction. Each of the permanent magnets Mc, Md, Mg, and Mh has its S pole facing radially inward and its N pole facing radially outward. In other words, the polarities of the radially inner sides of two permanent magnets facing each other across the axis A are the same. Each of the permanent magnets Ma to Mh is an example of a second permanent magnet. Each of the permanent magnets Ma to Mh and the yoke portion 31 corresponds to a second element. Therefore, the stator core 30a includes eight second elements.

[0018] When the coils Ca to Ch are in a non-energized state with no current flowing therethrough, the teeth 33a, 33b, 33e, and 33f are magnetized to N poles by the permanent magnets Ma, Mb, Me, and Mf. Similarly, the teeth 33c, 33d, 33g, and 33h are magnetized to S poles by the permanent magnets Mc, Md, Mg, and Mh.

[0019] FIG. 6 is a partial enlarged view of FIG. 2. The teeth 33a will be described as an example. The teeth 33a includes a rod 331 and a flange 333. The rod 331 extends radially inward from the inner circumferential surface 312 of the yoke 31, and has a substantially constant width in a direction perpendicular to the center line La. The flange 333 continues radially inward from the rod 331, and is wider in the circumferential direction than the rod 331. A plurality of pole teeth 334 are formed in the circumferential direction on the surface of the flange 333 facing the rotor 10a. Specifically, six pole teeth 334 are formed on each of the teeth 33a to 33h. The pitch of the pole teeth 334 is narrower than the pitch of each of the pole teeth 13a and 13b. The pole teeth 334 are an example of a stator pole tooth. The coil Ca is wound around the rod portion 331 .

[0020] A case where the coils Ca to Ch are in a non-excited state will be described. As shown in FIG. 6, the pole tooth 13a faces the pole tooth 334 of the teeth 33a in the radial direction, with a slight deviation in the clockwise direction. Here, the teeth 33a is magnetized to the N pole, and the pole tooth 13a is magnetized to the S pole. Therefore, a magnetic circuit is formed between them, and an attractive force is generated between them. That is, a counterclockwise force and a radially outward force act on the rotor 10a by the teeth 33a. Similarly, the pole tooth 13a faces the pole tooth 334 of the teeth 33b in the radial direction, with a slight deviation in the counterclockwise direction. Therefore, a clockwise force and a radially outward force act on the rotor 10a by the teeth 33b. Here, the counterclockwise force and the clockwise force are offset.

[0021] Similarly, the counterclockwise force acting on rotor 10a by teeth 33c and the clockwise force acting on rotor 10a by teeth 33d cancel each other out. The same applies to teeth 33e-33h. As a result, a radially outward force acts on rotor 10a, and rotor 10a remains stopped. As described above, when coils Ca-Ch are in a non-excited state, rotor 10a and stator core 30a are constrained so that their relative positional relationship remains unchanged. In other words, a brake is applied to rotor 10a.

[0022] Similarly, assume that the rotor 10a is shifted from the state of FIG. 2 by half the pitch of each of the pole teeth 13a and 13b. In this case, the pole tooth 13b faces the pole tooth 334 of the tooth portion 33a in the radial direction while being slightly shifted in the clockwise direction. Therefore, the tooth portion 33a applies a clockwise force and a radially outward force to the rotor 10a. Similarly, the pole tooth 13b faces the pole tooth 334 of the tooth portion 33b in the radial direction while being slightly shifted in the counterclockwise direction. Therefore, the tooth portion 33b applies a counterclockwise force and a radially outward force to the rotor 10a. The above clockwise force and counterclockwise force are offset. The same applies to the teeth portions 33c to 33h. Therefore, even if the rotor 10a is shifted by half a pitch from the state of FIG. 2, a brake is applied to the rotor 10a in the non-excited state. As described above, the rotor 10a can be stopped at a position shifted from the position shown in FIG. 2 by half the pitch of each of the pole teeth 13a and 13b.

[0023] In this way, when the coils Ca to Ch are in a non-excited state, the rotation of the rotor 10a can be stopped and maintained. Therefore, when the rotating electric machine 1a is used for an application in which the rotor 10a is stopped for a long standby time, the amount of power consumption can be suppressed. In addition, the rotor 10a can be stopped even when, for example, a power source is lost, so that the safety is excellent. Furthermore, by forming a plurality of holes in the stator core 30a and inserting the permanent magnets Ma to Mh into the plurality of holes, the stator core 30a can be provided with a function of stopping the rotation of the rotor 10a without energizing it. Therefore, an increase in the manufacturing cost of the rotating electric machine 1a is suppressed. Furthermore, compared to a case in which the rotation of the rotor 10a is stopped using, for example, a friction brake mechanism, the rotating electric machine 1a does not require any moving parts or wearing parts and is therefore excellent in durability. In addition, the rotor 10a can be stopped every half of the pitch of each of the pole teeth 13a and 13b, so that the resolution of the stopping position is improved.

[0024] In addition, when all the coils Ca to Ch are excited to cancel the magnetic flux of the permanent magnets Ma to Mh, the attraction force between the rotor 10a and the stator core 30a is released. This allows the rotor 10a to be in a free rotation state in which it can rotate freely. Furthermore, by individually setting the excitation of the coils Ca to Ch to an excited state and a non-excited state, it is possible to apply a brake weaker than the brake that acts when the coils Ca to Ch are non-excited. For example, only four of the coils Ca to Ch, namely, coils Ca, Cc, Ce, and Cg, are excited. Also, the current of the coils Ca to Ch may be individually set to an intermediate amount between the excited state and the non-excited state. For example, the current of the four coils Cb, Cd, Cf, and Ch of the coils Ca to Ch is set to 50% of the current in the excited state that does not act as a brake, and the current of the other four coils is set to 100%. In this way, the excitation of the coils Ca to Ch can be individually changed to adjust the brake action.

[0025] By controlling the excitation of the coils Ca to Ch, the brake action can be adjusted and the rotor 10a can be rotated. For example, in the state shown in Fig. 2, the coils Cb, Cd, Cf, and Ch are in a non-excited state, and the coils Ca, Cc, Ce, and Cg are in an excited state so as to cancel the magnetic fluxes of the permanent magnets Ma, Mc, Me, and Mg, respectively. This releases the attraction forces between the teeth portions 33a, 33c, 33e, and 33g and the rotor 10a, causing the rotor 10a to rotate clockwise.

[0026] When the rotor 10a is shifted from the state shown in FIG. 2 by half the pitch of each of the pole teeth 13a and 13b, the coils Ca, Cc, Ce, and Cg are de-energized, and the coils Cb, Cd, Cf, and Ch are energized so as to cancel the magnetic fluxes of the permanent magnets Mb, Md, Mf, and Mh. This releases the attraction forces between the teeth 33b, 33d, 33f, and 33h and the rotor 10a, causing the rotor 10a to rotate clockwise. In this way, the rotor 10a can continue to rotate by switching between the de-energized state and the energized state at a predetermined timing.

[0027] Also, the coils Ca to Ch may be in a reverse excitation state to strengthen the magnetic flux of each of the permanent magnets Ma to Mh. This may further increase the interaction force, which is the attractive force between the rotor 10a and the stator core 30a, compared to the non-excitation state. This makes it possible to more strongly bind the rotor 10a and the stator core 30a.

[0028] The teeth portion 33a is formed symmetrically with respect to the center line La. As described above, the permanent magnet Ma is provided at a position overlapping the center line La. FIG. 6 illustrates the thickness T and width W of the permanent magnet Ma. The thickness T is the thickness of the permanent magnet Ma in a direction parallel to the center line La. The width W is the width of the permanent magnet Ma in a direction perpendicular to the center line La. As illustrated in FIG. 6, the width W is longer than the thickness T. In this way, the permanent magnet Ma is provided at a position overlapping the center line La, and the width W is longer than the thickness T, so that the magnetic short circuit with respect to the rod portion 331, which is the magnetic path of the magnetic flux of the permanent magnet Ma, can be reduced, and the magnetic force of the permanent magnet Ma can be efficiently applied to the rotor 10a. This makes it possible to stop and hold the rotation of the rotor 10a. The length of each of the permanent magnets Ma to Mh in a direction parallel to the axis A is approximately the same as the thickness of the stator core 30a in a direction parallel to the axis A.

[0029] Like the permanent magnet Ma, the permanent magnets Mb-Mh are provided at positions overlapping with the center lines Lb-Lh, and the width of each of the permanent magnets Mb-Mh is greater than the thickness. As a result, the magnetic forces of the permanent magnets Ma-Mh can be efficiently applied to the rotor 10a to stop the rotor 10a.

[0030] The permanent magnets Ma to Mh are spaced radially outward from the coils Ca to Ch, respectively. Therefore, even after the coils Ca to Ch are wound around the stator core 30a, the permanent magnets Ma to Mh can be inserted into their respective holes in the stator core 30a. This improves the ease of assembly of the rotating electric machine 1a.

[0031] FIG. 7 is an explanatory diagram of a position where the permanent magnet Ma can be installed. FIG. 7 illustrates the thickness T of the permanent magnet Ma from the tip surface of the flange 333, the thickness T of the permanent magnet Ma from the outer circumferential surface 311 of the yoke part 31, and the installable range R. The installable range R illustrates the length from the tip surface of the flange 333 to the outer circumferential surface 311 in the direction of the center line La, excluding the thickness T from the tip surface of the flange 333 and the thickness T from the outer circumferential surface 311. The permanent magnet Ma is provided within the installable range R. In other words, the permanent magnet Ma is spaced radially outward from the tip surface of the flange 333 by more than the thickness T of the permanent magnet Ma, and is spaced radially inward from the outer circumferential surface 311 by more than the thickness T of the permanent magnet Ma. This allows the magnetic force of the permanent magnet Ma to be efficiently applied to the rotor 10a by using the stator core 30a, and the strength of the stator core 30a is also ensured.

[0032] The above-mentioned conditions also hold for the permanent magnets Mb-Mh. That is, each of the permanent magnets Mb-Mh is spaced radially outward from the tip faces of the teeth portions 33b-33h by a distance equal to or greater than thickness T, and is spaced radially inward from the outer circumferential surface 311 by a distance equal to or greater than thickness T. This allows the magnetic forces of the permanent magnets Mb-Mh to act efficiently on the rotor 10a by utilizing the stator core 30a, and also ensures the strength of the stator core 30a.

[0033] Fig. 8 is a diagram showing a first modified example of the position of the permanent magnets. Fig. 8 corresponds to Fig. 6. The width W1 of the permanent magnet Ma1 shown in Fig. 8 is narrower than the width W of the permanent magnet Ma described above, but the thickness T is the same. The permanent magnet Ma1 is provided in a position overlapping the coil Ca. The permanent magnets Mb to Mh may also be provided in the same positions as the permanent magnet Ma1 in Fig. 8.

[0034] Fig. 9 is a diagram showing a second modified example of the position of the permanent magnets. Fig. 9 corresponds to Fig. 6. The width W2 of the permanent magnet Ma2 shown in Fig. 9 is narrower than the width W of the permanent magnet Ma, but the thickness T is the same. The permanent magnet Ma2 is provided radially inward of the coil Ca. The permanent magnets Mb to Mh may also be provided in the same position as the permanent magnet Ma2 in Fig. 9.

[0035] [Configuration of the first modified example of the rotating electric machine] Fig. 10 is an external view of a first modified example of a rotating electric machine. Fig. 10 corresponds to Fig. 2. The rotating electric machine 1b differs from the above-mentioned rotating electric machine 1a in that the stator core 30b is provided with four permanent magnets Ma, Mc, Me, and Mg. Therefore, the manufacturing cost of the stator core 30b of the rotating electric machine 1b is reduced compared to the above-mentioned stator core 30a provided with eight permanent magnets Ma to Mh. Fig. 11 is a partially enlarged view of Fig. 10. Fig. 11 corresponds to Fig. 6.

[0036] A case where the coils Ca to Ch are in a non-excited state will be described. As shown in FIG. 11, the pole tooth 13a faces the pole tooth 334 of the teeth 33a in the radial direction. Here, the teeth 33a is magnetized to the N pole, and the pole tooth 13a is magnetized to the S pole. Therefore, a magnetic circuit is formed between them, and an attractive force is generated. The same is true for the teeth 33e. In addition, in this state, the pole tooth 13b faces the pole tooth 334 of the teeth 33c and 33g in the radial direction. Here, the teeth 33c and 33g are magnetized to the S pole, and the pole tooth 13b is magnetized to the N pole. Therefore, a magnetic circuit is formed between them, and an attractive force is generated. This acts as a brake on the rotor 10a. Also, the coils Ca, Cc, Ce, and Cg may be in a reverse excited state so as to strengthen the magnetic flux of each of the permanent magnets Ma, Mc, Me, and Mg.

[0037] The stator core 30a is provided with permanent magnets Ma to Mh, and the stator core 30b is provided with four permanent magnets Ma, Mc, Me, and Mg, but is not limited to this. For example, only one of the permanent magnets Ma to Mh may be provided. Also, only two of the permanent magnets Ma to Mh may be provided, facing each other across the axis A. For example, only the permanent magnets Ma and Me may be provided.

[0038] [Configuration of the second modified example of the rotating electric machine] Fig. 12 is an external view of a second modified example of a rotating electric machine. Fig. 12 corresponds to Fig. 2. The rotating electric machine 1c is different from the rotating electric machine 1a described above, and four permanent magnets Mha, Mbc, Mde, and Mfg are provided on the yoke portion 31 of the stator core 30c. The permanent magnet Mha is provided on the yoke portion 31 between the teeth portions 33h and 33a in the circumferential direction. The permanent magnet Mbc is provided on the yoke portion 31 between the teeth portions 33b and 33c in the circumferential direction. The permanent magnet Mde is provided on the yoke portion 31 between the teeth portions 33d and 33e in the circumferential direction. The permanent magnet Mfg is provided on the yoke portion 31 between the teeth portions 33f and 33g in the circumferential direction.

[0039] FIG. 12 illustrates sectional lines Lha, Lbc, Lde, and Lfg that pass through the axis A and are parallel to the radial direction. Permanent magnets Mha, Mbc, Mde, and Mfg are provided at positions that overlap with the sectional lines Lha, Lbc, Lde, and Lfg, respectively. The sectional line Lha passes between adjacent center lines Lh and La. The sectional line Lbc passes between adjacent center lines Lb and Lc. The sectional line Lde passes between adjacent center lines Ld and Le. The sectional line Lfg passes between adjacent center lines Lf and Lg. The sectional lines Lha and Lbc are the same as the sectional lines Lde and Lfg, respectively. Therefore, the angle between the dividing line Lha and the center line Lh, the angle between the dividing line Lha and the center line La, the angle between the dividing line Lbc and the center line Lb, the angle between the dividing line Lbc and the center line Lc, the angle between the dividing line Lde and the center line Ld, the angle between the dividing line Lde and the center line Le, the angle between the dividing line Lfg and the center line Lf, and the angle between the dividing line Lfg and the center line Lg are the same.

[0040] Each of the permanent magnets Mha, Mbc, Mde, and Mfg has one of its S and N poles facing one side in the circumferential direction, and the other of its S and N poles facing the other side in the circumferential direction. Specifically, each of the permanent magnets Mha and Mde has its N pole facing clockwise and its S pole facing counterclockwise. Each of the permanent magnets Mbc and Mfg has its N pole facing counterclockwise and its S pole facing clockwise.

[0041] In the non-excited state where the coils Ca to Ch are not energized, the teeth 33h and 33a are magnetized to the S and N poles by the permanent magnet Mha. Similarly, the teeth 33b and 33c are magnetized to the N and S poles by the permanent magnet Mbc, the teeth 33d and 33e are magnetized to the S and N poles by the permanent magnet Mde, and the teeth 33f and 33g are magnetized to the N and S poles by the permanent magnet Mfg. In this manner, one permanent magnet magnetizes two teeth. For this reason, the manufacturing cost of the stator core 30c of the rotating electric machine 1c is reduced compared to the above-mentioned stator core 30a provided with eight permanent magnets Ma to Mh.

[0042] Fig. 13 is a partially enlarged view of Fig. 12. An explanation will be given taking the permanent magnet Mha as an example. The thickness T is the thickness of the permanent magnet Mha in a direction perpendicular to the section line Lha. The width W is the width of the permanent magnet Mha in a direction parallel to the section line Lha. The permanent magnet Mha is provided so that the boundary between the south pole and north pole of the permanent magnet Mha overlaps with the section line Lha. This allows the permanent magnet Mha to efficiently magnetize the teeth portions 33h and 33a to different polarities. The same applies to the permanent magnets Mbc, Mde, and Mfg.

[0043] The stator core 30c is provided with permanent magnets Mha, Mbc, Mde, and Mfg, but is not limited thereto. For example, only one of the permanent magnets Mha, Mbc, Mde, and Mfg may be provided. Also, only two of the permanent magnets Mha, Mbc, Mde, and Mfg may be provided, facing each other across the axis A. For example, only the permanent magnets Mha and Mde may be provided.

[0044] [Configuration of the third modified example of the rotating electric machine] Fig. 14 is an external view of a third modified example of a rotating electric machine. Fig. 14 corresponds to Fig. 2. The rotating electric machine 1e is a synchronous motor. The rotor 10b includes a shaft 11, an iron core 12, and permanent magnets ma to md. The iron core 12 is cylindrical. The shaft 11 is inserted into a central hole of the iron core 12, and the iron core 12 is fixed to the shaft 11. The rotor 10b is rotatably supported by the shaft 11. The rotor 10b is an internal rotation type.

[0045] The permanent magnets ma to md are provided on the outer circumferential surface of the iron core 12. The permanent magnets ma to md are formed in an arc shape. The permanent magnets ma to md have the same size and shape. In each of the permanent magnets ma to md, one of the S pole and the N pole faces inward in the radial direction, and the other of the S pole and the N pole faces outward in the radial direction. Specifically, in each of the permanent magnets ma and mc, the N pole faces inward in the radial direction, and the S pole faces outward in the radial direction. In each of the permanent magnets mb and md, the S pole faces inward in the radial direction, and the N pole faces outward in the radial direction. In FIG. 14, only the outer polarities of the permanent magnets ma to md are shown. In this way, the outer circumferential surface of the rotor 10b is magnetized with four polarities at equal intervals in the circumferential direction. Each of the permanent magnets ma to md is an example of a first permanent magnet. Each of the permanent magnets ma to md and the iron core 12 corresponds to a first element. Therefore, the rotor 10b includes four first elements.

[0046] The stator core 30d includes a yoke portion 31d and teeth portions 34a to 34f. Permanent magnets Mb, Mc, Me, and Mf are provided on the yoke portion 31d of the stator core 30d. The permanent magnets Mb, Mc, Me, and Mf are provided at positions corresponding to the teeth portions 34b, 34c, 34e, and 34f, respectively. When the coils Ca to Cf are in a non-excited state, the teeth portions 34b, 34c, 34e, and 34f are magnetized to the S pole, N pole, S pole, and N pole, respectively. This causes the rotor 10b to apply a brake. Note that unlike the above-mentioned teeth portions 33a to 33h, the teeth portions 34a to 34f do not have pole teeth at their tips.

[0047] In addition, by controlling the current supply to coils Cb, Cc, Ce, and Cf, the magnetic flux of permanent magnets Mb, Mc, Me, and Mf can be canceled or increased at predetermined timing, respectively, thereby generating a rotational force in rotor 10b.

[0048] The rotor 10b described above has four different polarities in the circumferential direction, but is not limited to this and may have magnetic poles that are an integer multiple of 2. For example, the outer circumferential surface of the rotor 10b may be magnetized with eight polarities at equal intervals in the circumferential direction. In this case, for example, the stator core 30d may have 12 teeth and a coil wound around each tooth.

[0049] Each of the stator cores 30a, 30b, and 30c has eight teeth 33a to 33h, and the stator core 30d has six teeth 34a to 34f, but the number of teeth is not limited to this. In addition, in the case of the synchronous motor of Fig. 14, the brake position accuracy of the rotor can be improved by increasing the number of poles of the rotor 10b and the number of slots of the stator core 30a.

[0050] Although a rotating electric machine equipped with an electromagnetic brake has been described with reference to Fig. 2 to Fig. 14, the present invention is not limited to this. An electromagnetic brake that does not have the function of a rotating electric machine may be used. In other words, an electromagnetic brake that does not have the purpose of rotating a rotor may be used.

[0051] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and variations are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0052] 1. Interaction force control device 1a Rotating Electric Machine 10 First Element 30 Second Element 10a, 10b Rotor 11 Axis 12, 12a, 12b Iron core 13a and 13b pole teeth (rotor pole teeth) 30a, 30b, and 30c stator cores 33a to 33h, 34a to 34f tooth portions 334 pole teeth (stator pole teeth) C, Ca to Ch coils Ma to Mh permanent magnets (second permanent magnets) mA, ma to md permanent magnets (first permanent magnets) Axis A La to Lh center lines Width W Thickness T

Claims

1. a first element including a first permanent magnet; a second element including a second permanent magnet and a coil; The relative positional relationship between the first and second elements is variable; an interaction force is generated between the first and second elements due to the mutual magnetic force of the first and second permanent magnets; The magnetic force of the second permanent magnet can be increased or decreased according to the magnetic force generated by the coil, An interaction force control device, in which the interaction force is controlled by changing the magnetic force generated by the coil.

2. the first element is a part of a rotor of a rotating electric machine, the second element is a part of a stator of the rotating electric machine, the coil is a stator winding of the rotating electric machine, The relative positional relationship changes in a circumferential direction around the axis of the rotor. The interaction force control device of claim 1 .

3. An interaction force control device according to claim 2, When the coil is in a non-excited state, the rotor and the stator are constrained by the interaction force so that the relative positional relationship is unchanged; An electromagnetic brake in which, when the coil is in an excited state, the magnetic force generated by the coil and the magnetic force of the second permanent magnet cancel each other out, thereby releasing the constraint of the rotor and stator by the interaction force.

4. 4. The electromagnetic brake according to claim 3, wherein when the coil is in a reverse excited state, the interaction force is increased and the rotor and the stator are more strongly constrained compared to when the coil is in a non-excited state.

5. 5. The electromagnetic brake according to claim 4, wherein the rotor is rotatable by controlling the direction and magnitude of an exciting current in the coil.

6. 6. The electromagnetic brake according to claim 3, wherein the rotor includes a plurality of the first elements.

7. 6. The electromagnetic brake according to claim 3, wherein the stator includes a plurality of the second elements.

8. 6. The electromagnetic brake of claim 3, wherein the second element includes a stator core usable as part of the rotating electric machine, and the second permanent magnet embedded in a hole formed by processing the stator core.

9. The electromagnetic brake according to claim 5, the rotor is an internal rotor type and includes a shaft, first and second rotor cores fixed to the shaft, and the first permanent magnet disposed between the first and second rotor cores in the axial direction and magnetized in the axial direction; First rotor pole teeth are formed at a predetermined pitch on the outer circumferential surface of the first rotor core, Second rotor pole teeth are formed at the predetermined pitch on the outer circumferential surface of the second rotor core, the first and second rotor pole teeth are shifted from each other in the circumferential direction by half the predetermined pitch, the stator includes a stator core around which the coil is wound, The stator core has stator pole teeth, a magnetic circuit can be formed between the stator pole tooth and one of the first and second rotor pole teeth that faces the stator pole tooth, a rotating electric machine in which the rotor can be rotated by a magnetic force generated between the stator pole teeth and either one of the first and second rotor pole teeth facing the stator pole teeth when the coil is energized.

10. The electromagnetic brake according to claim 5, the rotor is an internal rotor type, and includes a rotor core having at least one of the first permanent magnets and an outer circumferential surface having magnetic poles, the number of which is an integer multiple of two, equally spaced in the circumferential direction; the stator includes a stator core around which the coil is wound, The stator core has stator pole teeth, A magnetic circuit can be formed between the stator pole teeth and the magnetic poles of the rotor core that face the stator pole teeth, a rotating electric machine in which the rotor can be rotated by a magnetic force generated between the stator pole teeth and the magnetic poles of the rotor core facing the stator pole teeth when the coil is energized.

11. the stator core includes a substantially annular yoke portion surrounding the rotor, and first and second teeth portions projecting radially inwardly from an inner circumferential surface of the yoke portion and spaced apart from each other in the circumferential direction, the coil includes first and second coils wound around the first and second teeth portions, respectively; A rotating electric machine according to claim 9 or 10, wherein the second permanent magnet is provided on the first teeth portion, and is spaced radially outward from the tip surface of the first teeth portion by a distance greater than the thickness of the second permanent magnet, and is spaced radially inward from the outer peripheral end surface of the yoke portion by a distance greater than the thickness of the second permanent magnet.

12. The rotating electric machine according to claim 11 , wherein the second permanent magnet is spaced radially outward from the first coil.

13. The rotating electric machine according to claim 11 , wherein at least a portion of the second permanent magnet overlaps with the first coil.

14. The rotating electric machine according to claim 11 , wherein the second permanent magnet is spaced radially inward from the first coil.

15. the second permanent magnet is disposed at a position overlapping a center line that passes through the first teeth and is parallel to a radial direction when viewed from the axial direction, The thickness of the second permanent magnet in a direction parallel to the center line is greater than the width of the second permanent magnet in a direction perpendicular to the center line, One magnetic pole of the second permanent magnet faces inward in the radial direction, 15. The rotating electric machine according to claim 12, wherein the other magnetic pole of the second permanent magnet faces radially outward.

16. the stator core includes a substantially annular yoke portion surrounding the rotor, and first and second teeth portions projecting radially inwardly from an inner circumferential surface of the yoke portion and spaced apart from each other in the circumferential direction, the coil includes first and second coils wound around the first and second teeth portions, respectively; the second permanent magnet is provided in the yoke portion between the first and second teeth portions in a circumferential direction, One magnetic pole of the second permanent magnet faces one side in the circumferential direction, 11. The rotating electric machine according to claim 9, wherein the other magnetic pole of the second permanent magnet faces the other side in the circumferential direction.

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