Interaction force control device, electromagnetic brake equipped with the same, and rotating electric machine equipped with 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 including the same, and a rotating electric machine including the same. [Background technology]

[0002] Patent Document 1 discloses a technique for generating a braking torque that maintains the rotating state of a rotor by energizing it. [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 technology only generates a braking torque by energizing, and therefore has low versatility.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention 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 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. [Effects of the Invention]

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

[0008] [Figure 1] FIG. 1 is a conceptual diagram of an interaction force control device. [Figure 2] FIG. 1 is an external view of a rotating electric machine. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. 2 is a view of the rotor viewed from the direction of the axis. [Figure 6] FIG. 3 is a partially enlarged view of FIG. 2. [Figure 7] FIG. 10 is an explanatory diagram of positions where permanent magnets can be installed. [Figure 8] FIG. 10 is a diagram showing a first modified example of the position of the permanent magnet. [Figure 9] FIG. 10 is a diagram showing a second modified example of the position of the permanent magnet. [Figure 10] FIG. 10 is an external view of a first modified example of the rotating electric machine. [Figure 11] FIG. 11 is a partially enlarged view of FIG. [Figure 12] FIG. 10 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. 10 is an external view of a third modified example of the rotating electric machine. DETAILED DESCRIPTION OF THE INVENTION

[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. Element 10 includes a permanent magnet m. Element 30 includes a coil C and a permanent magnet M. Element 10 is an example of a first element. Element 30 is an example of a second element. Permanent magnet m is an example of a first permanent magnet. 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 elements 10 and 30 is fixed, and the other is supported by a guide rail or the like so that it can move freely toward or away from the other. The permanent magnets m and M are arranged so that their opposite polarities face each other. Specifically, the south pole of permanent magnet m faces the north pole of permanent magnet M. The coil C is wound around a central axis that corresponds to the direction in which the south pole and north pole of permanent magnet M are aligned. When the coil C is in a non-energized state with no current flowing, 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 coil C and placing it in an excited state, the magnetic force generated by coil C can weaken the magnetic force of permanent magnet M. This reduces the attractive force, which is an interaction force. Furthermore, by increasing the excitation current to coil C, the magnetic force generated by coil C can be canceled out by the magnetic force of permanent magnet M. This eliminates the interaction force. Furthermore, by increasing the excitation current to coil C, the magnetic force generated by coil C can generate a repulsive force as an interaction force. Furthermore, by switching the direction of the excitation current to coil C and placing coil C in a reverse excitation state, the attractive force, which is an interaction force, can be increased by the magnetic force generated by coil C. In this way, by controlling the direction and magnitude of the excitation current to coil C to change the magnetic force generated by 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 electromagnetic brakes and rotating electrical machines. Note that FIG. 1 is intended to explain the concept of the interaction force control device 1 and does not take into account practical design limitations such as magnetic short-circuiting of permanent magnets M and m.

[0011] The element 10 may not be provided with a 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 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, which 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 circular plate-shaped. 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 a south pole, and the iron core 12b is magnetized to a north 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 iron core 12a. A plurality of pole teeth 13b are formed at a predetermined pitch on the outer peripheral surface of iron core 12b. Here, the pitch of pole teeth 13a is the same as the pitch of pole teeth 13b. Iron core 12a and iron core 12b are fixed to shaft 11 with a shift of half this pitch. Therefore, as shown in FIG. 5, when viewed from the direction of axis A, pole teeth 13b are located between adjacent pole teeth 13a. Similarly, pole teeth 13a are located between 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 to 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 to 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. Therefore, the tips of the teeth 33a to 33h face the outer peripheral surface of the rotor 10a. The teeth 33a to 33h are arranged at equal angular intervals in the circumferential direction. FIG. 2 illustrates the center lines La to Lh of the teeth 33a to 33h, respectively. 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, respectively. The coils Ca to Ch are wound around the teeth 33a to 33h via insulators (not shown). When current is applied to the coils Ca to Ch, 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 on the yoke portion 31 near the base of each 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 of 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. The permanent magnets Ma to Mh are all the same size and shape. For each of the permanent magnets Ma to Mh, one of the south and north poles faces radially inward, and the other of the south and north poles faces radially outward. Specifically, for each of the permanent magnets Ma, Mb, Me, and Mf, the north pole faces radially inward, and the south pole faces radially outward. Each of the permanent magnets Mc, Md, Mg, and Mh has its south pole facing radially inward and its north pole facing radially outward. In other words, the polarity of the radially inner sides of two permanent magnets facing each other across the axis A is 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 has eight second elements.

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

[0019] FIG. 6 is a partial enlarged view of FIG. 2. The description will be given taking the tooth portion 33a as an example. The tooth portion 33a includes a rod portion 331 and a flange portion 333. The rod portion 331 extends radially inward from the inner circumferential surface 312 of the yoke portion 31, and has a substantially constant width in a direction perpendicular to the center line La. The flange portion 333 continues radially inward from the rod portion 331 and is wider in the circumferential direction than the rod portion 331. A plurality of pole teeth 334 are formed in the circumferential direction on the surface of the flange portion 333 facing the rotor 10a. Specifically, six pole teeth 334 are formed on each of the tooth portions 33a to 33h. The pitch of the pole teeth 334 is narrower than the pitch 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] The case where coils Ca to Ch are in a non-excited state will be described. As shown in FIG. 6, pole tooth 13a faces pole tooth 334 of tooth portion 33a in the radial direction, with a slight clockwise offset. Here, tooth portion 33a is magnetized to the north pole, and pole tooth 13a is magnetized to the south 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 rotor 10a by tooth portion 33a. Similarly, pole tooth 13a faces pole tooth 334 of tooth portion 33b in the radial direction, with a slight counterclockwise offset. Therefore, a clockwise force and a radially outward force act on rotor 10a by tooth portion 33b. Here, the counterclockwise force and the clockwise force cancel each other out.

[0021] Similarly, the counterclockwise force acting on rotor 10a from tooth 33c and the clockwise force acting on rotor 10a from tooth 33d cancel each other out. The same applies to teeth 33e to 33h. As a result, a radially outward force acts on rotor 10a, causing rotor 10a to remain stationary. As described above, when coils Ca to 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 shown in 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, with a slight clockwise shift. 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, with a slight counterclockwise shift. Therefore, the tooth portion 33b applies a counterclockwise force and a radially outward force to the rotor 10a. The clockwise force and counterclockwise force cancel each other out. 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 shown in 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, the rotation of the rotor 10a can be stopped and maintained when the coils Ca to Ch are in a non-excited state. Therefore, when the rotating electric machine 1a is used in applications where the rotor 10a is stopped for long standby times, power consumption can be reduced. Furthermore, since the rotor 10a can be stopped even in the event of a power loss, for example, safety is excellent. Furthermore, by forming multiple holes in the stator core 30a and inserting permanent magnets Ma to Mh into the multiple holes, the stator core 30a can be given the function of stopping the rotation of the rotor 10a without energizing it. This suppresses increases in manufacturing costs for the rotating electric machine 1a. Furthermore, compared to, for example, a friction brake mechanism used to stop the rotation of the rotor 10a, the rotating electric machine 1a does not require moving or wearing parts and is therefore superior in durability. Furthermore, the rotor 10a can be stopped every half the pitch of each of the pole teeth 13a and 13b, improving the resolution of the stopping position.

[0024] In addition, by energizing all coils Ca through Ch to cancel the magnetic flux of the permanent magnets Ma through Mh, the attractive force between the rotor 10a and the stator core 30a is released. This allows the rotor 10a to enter a free rotation state where it can rotate freely. Furthermore, by individually setting the excitation of the coils Ca through Ch between an excited state and a de-excited state, it is possible to apply a brake that is weaker than the brake that is applied when the coils Ca through Ch are de-excited. For example, only four of the coils Ca through Ch, namely, coils Ca, Cc, Ce, and Cg, may be excited. Alternatively, the currents of the coils Ca through Ch may be individually set to intermediate values ​​between the excited and de-excited states. For example, the currents of four of the coils Ca through Ch, namely, coils Cb, Cd, Cf, and Ch, may be set to 50% of the current in the excited state where they do not act as brakes, and the currents of the other four coils may be set to 100%. In this way, the braking effect can be adjusted by individually changing the excitation of the coils Ca through Ch.

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

[0026] When the rotor 10a is shifted from the state shown in FIG. 2 by half the pitch 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 to cancel the magnetic flux of the permanent magnets Mb, Md, Mf, and Mh, respectively. This releases the attraction between the rotor 10a and the teeth 33b, 33d, 33f, and 33h, respectively, and causes the rotor 10a to rotate clockwise. By switching between the de-energized and energized states at predetermined timings, the rotor 10a can continue to rotate.

[0027] Furthermore, 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 allows the rotor 10a and the stator core 30a to be more tightly constrained.

[0028] The teeth 33a are formed symmetrically with respect to the center line La. As described above, the permanent magnet Ma is disposed at a position overlapping the center line La. FIG. 6 also 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. Because the permanent magnet Ma is disposed at a position overlapping the center line La and the width W is longer than the thickness T, magnetic short-circuiting with respect to the rod portion 331, which forms the magnetic path of the magnetic flux of the permanent magnet Ma, can be reduced, thereby allowing the magnetic force of the permanent magnet Ma to be efficiently applied to the rotor 10a. This allows the rotation of the rotor 10a to be stopped and maintained. 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 permanent magnet Ma, permanent magnets Mb-Mh are positioned so as to overlap center lines Lb-Lh, and each of permanent magnets Mb-Mh is wider than it is thick. As a result, the magnetic forces of permanent magnets Ma-Mh can be efficiently applied to rotor 10a, stopping 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 have been 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 possible installation positions of the permanent magnet Ma. FIG. 7 illustrates the thickness T of the permanent magnet Ma from the tip surface of the flange portion 333, the thickness T of the permanent magnet Ma from the outer peripheral surface 311 of the yoke portion 31, and the installable range R. The installable range R is the length from the tip surface of the flange portion 333 to the outer peripheral surface 311 in the direction of the center line La, excluding the thickness T from the tip surface of the flange portion 333 and the thickness T from the outer peripheral surface 311. The permanent magnet Ma is installed within the installable range R. In other words, the permanent magnet Ma is spaced radially outward from the tip surface of the flange portion 333 by a distance equal to or greater than the thickness T of the permanent magnet Ma, and is spaced radially inward from the outer peripheral surface 311 by a distance equal to or greater 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 using the stator core 30a, while ensuring the strength of the stator core 30a.

[0032] The above-mentioned conditions also apply to the permanent magnets Mb-Mh. That is, each of the permanent magnets Mb-Mh is spaced radially outward from the tip surfaces of the teeth 33b-33h by a distance equal to or greater than the thickness T, and is spaced radially inward from the outer circumferential surface 311 by a distance equal to or greater than the thickness T. This allows the magnetic forces of the permanent magnets Mb-Mh to act efficiently on the rotor 10a using 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. Unlike the above-described rotating electric machine 1a, the rotating electric machine 1b has a stator core 30b 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 lower than that of the above-described 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] The 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 tooth 33a in the radial direction. Here, the tooth 33a is magnetized to the north pole, and the pole tooth 13a is magnetized to the south pole. Therefore, a magnetic circuit is formed between them, generating an attractive force. The same applies to the tooth 33e. Also, in this state, the pole tooth 13b faces the pole tooth 334 of the tooth 33c and 33g in the radial direction. Here, the tooth 33c and 33g are magnetized to the south pole, and the pole tooth 13b is magnetized to the north pole. Therefore, a magnetic circuit is formed between them, generating an attractive force. This acts as a brake on the rotor 10a. Furthermore, the coils Ca, Cc, Ce, and Cg may be in a reverse excited state to strengthen the magnetic flux of the permanent magnets Ma, Mc, Me, and Mg, respectively.

[0037] Stator core 30a is provided with permanent magnets Ma to Mh, and stator core 30b is provided with four permanent magnets Ma, Mc, Me, and Mg, but this is not limited to this. For example, only one of permanent magnets Ma to Mh may be provided. Also, only two of permanent magnets Ma to Mh may be provided, facing each other across axis A. For example, only 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. Unlike the rotating electric machine 1a described above, the rotating electric machine 1c has four permanent magnets Mha, Mbc, Mde, and Mfg provided in the yoke portion 31 of the stator core 30c. The permanent magnet Mha is provided in the yoke portion 31 between the teeth portions 33h and 33a in the circumferential direction. The permanent magnet Mbc is provided in the yoke portion 31 between the teeth portions 33b and 33c in the circumferential direction. The permanent magnet Mde is provided in the yoke portion 31 between the teeth portions 33d and 33e in the circumferential direction. The permanent magnet Mfg is provided in the yoke portion 31 between the teeth portions 33f and 33g in the circumferential direction.

[0039] FIG. 12 illustrates section 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 positioned so as to overlap with the section lines Lha, Lbc, Lde, and Lfg, respectively. The section line Lha passes midway between adjacent center lines Lh and La. The section line Lbc passes midway between adjacent center lines Lb and Lc. The section line Lde passes midway between adjacent center lines Ld and Le. The section line Lfg passes midway between adjacent center lines Lf and Lg. The section lines Lha and Lbc are the same as the section 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] In each of the permanent magnets Mha, Mbc, Mde, and Mfg, one of the S and N poles faces one side in the circumferential direction, and the other of the S and N poles faces the other side in the circumferential direction. Specifically, in each of the permanent magnets Mha and Mde, the N pole faces clockwise and the S pole faces counterclockwise. In each of the permanent magnets Mbc and Mfg, the N pole faces counterclockwise and the S pole faces clockwise.

[0041] When coils Ca to Ch are in a non-energized state with no current flowing through them, teeth 33h and 33a are magnetized to south and north poles by permanent magnet Mha. Similarly, teeth 33b and 33c are magnetized to north and south poles by permanent magnet Mbc, teeth 33d and 33e are magnetized to south and north poles by permanent magnet Mde, and teeth 33f and 33g are magnetized to north and south poles by permanent magnet Mfg. In this way, one permanent magnet magnetizes two teeth. Therefore, the manufacturing costs of stator core 30c of rotating electric machine 1c are lower than those of stator core 30a described above, which is provided with eight permanent magnets Ma to Mh.

[0042] FIG. 13 is a partially enlarged view of FIG. 12. An example will be described using permanent magnet Mha. Thickness T is the thickness of permanent magnet Mha in a direction perpendicular to section line Lha. Width W is the width of permanent magnet Mha in a direction parallel to section line Lha. Permanent magnet Mha is positioned so that the boundary between the south and north poles of permanent magnet Mha overlaps with section line Lha. This allows permanent magnet Mha to efficiently magnetize teeth 33h and 33a to different polarities. The same applies to 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 to this. 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 rotor type.

[0045] The permanent magnets ma to md are provided on the outer peripheral surface of the iron core 12. The permanent magnets ma to md are formed in an arc shape. The permanent magnets ma to md are all the same size and shape. For each of the permanent magnets ma to md, one of the south and north poles faces radially inward, and the other of the south and north poles faces radially outward. Specifically, for each of the permanent magnets ma and mc, the north pole faces radially inward and the south pole faces radially outward. For each of the permanent magnets mb and md, the south pole faces radially inward and the north pole faces radially outward. FIG. 14 shows only the outer polarities of the permanent magnets ma to md. In this way, the outer peripheral surface of the rotor 10b is magnetized with four polarities equally spaced 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 has 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 south, north, south, and north poles, respectively. This causes a brake to act on the rotor 10b. Note that, unlike the teeth portions 33a to 33h described above, the teeth portions 34a to 34f do not have pole teeth at their tips.

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

[0048] Although the rotor 10b described above has four different polarities in the circumferential direction, this is not limited thereto 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, each with a coil wound around it.

[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. Also, 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] While a rotating electric machine equipped with an electromagnetic brake has been described using Figures 2 to 14, the present invention is not limited to this. The electromagnetic brake may not have the function of a rotating electric machine. In other words, the electromagnetic brake may not have the purpose of rotating the rotor.

[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 as defined 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 axes 12, 12a, 12b iron core 13a, 13b Jimo (return to Guanzi Jimo) 30a, 30b, 30c fixed sub-iron core 33a~33h, 34a~34f Tiss Club 334 Polarimeter (Fixed Subpolarimeter) C、Ca~Ch コイル Ma~Mh permanent magnet (second permanent magnet) mA, ma~md permanent magnets (first permanent magnet) A axis La~Lh center line W width T thick

Claims

1. 1. An electromagnetic brake with an interaction force control device, comprising: the interaction force control device comprises a first element including a first permanent magnet, and 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, The interaction force is controlled by changing the magnetic force generated by the coil; 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, 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 remains unchanged; 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.

2. 2. The electromagnetic brake according to claim 1, wherein when the coil is in a reversely excited state, the interaction force increases and the rotor and stator are more strongly constrained than when the coil is in a non-excited state.

3. 3. The electromagnetic brake according to claim 2, wherein the rotor is rotatable by controlling the direction and magnitude of the excitation current of the coil.

4. 4. The electromagnetic brake according to claim 1, wherein the rotor includes a plurality of the first elements.

5. 4. The electromagnetic brake according to claim 1, wherein the stator includes a plurality of the second elements.

6. 4. The electromagnetic brake according to claim 1, 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.

7. The electromagnetic brake of claim 3 is provided, 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 circumferentially shifted from each other 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 tooth and one of the first and second rotor pole teeth facing the stator pole tooth when the coil is energized;

8. The electromagnetic brake of claim 3 is provided, the rotor is an internal rotor type, and includes a rotor core provided with at least one first permanent magnet, and having an outer circumferential surface with magnetic poles whose number is an integral multiple of two and spaced equally 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 tooth and a magnetic pole of the rotor core facing the stator pole tooth, The rotor is rotatable by a magnetic force generated between the stator pole teeth and the magnetic poles of the rotor core that face the stator pole teeth when the coils are energized.

9. the stator core includes a substantially annular yoke portion surrounding the rotor, and first and second teeth portions projecting radially inward from an inner peripheral 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; 9. A rotating electric machine according to claim 7 or 8, wherein the second permanent magnet is provided on the first tooth portion, and is spaced radially outward from the tip end surface of the first tooth 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.

10. The rotating electric machine according to claim 9 , wherein the second permanent magnet is spaced radially outward from the first coil.

11. The rotating electric machine according to claim 9 , wherein at least a portion of the second permanent magnet overlaps with the first coil.

12. The rotating electric machine according to claim 9 , wherein the second permanent magnet is spaced radially inward from the first coil.

13. 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, a thickness of the second permanent magnet in a direction parallel to the center line is greater than a 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, The rotating electric machine according to claim 10 , wherein the other magnetic pole of the second permanent magnet faces radially outward.

14. 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, a thickness of the second permanent magnet in a direction parallel to the center line is greater than a 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, The rotating electric machine according to claim 11 , wherein the other magnetic pole of the second permanent magnet faces radially outward.

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, a thickness of the second permanent magnet in a direction parallel to the center line is greater than a 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, 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 inward from an inner peripheral 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 on the yoke portion between the first and second teeth portions in the circumferential direction, one magnetic pole of the second permanent magnet faces one side in the circumferential direction, 9. The rotating electric machine according to claim 7, wherein the other magnetic pole of the second permanent magnet faces the other side in the circumferential direction.

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