JP6539539B2 - Axial gap type electric rotating machine - Google Patents

Description

  The present invention relates to a rotating electrical machine such as a motor or a generator, and more particularly to an axial gap type rotating electrical machine in which a stator having an exciting coil and a rotor having a permanent magnet are spaced apart in the axial direction. .

  The axial gap type rotating electrical machine has the advantage of being able to be made thinner and obtaining a large torque as compared with a radial gap type in which the stator is provided on the outer peripheral side of the rotor, and hence application to electric vehicles etc. Is expected. The said rotary electric machine has a structure where the stator provided with an excitation coil and the rotor provided with a permanent magnet are spaced apart in the axial direction at minute intervals (axial gap). The rotor includes a disk-shaped base material to be a back yoke, and a plurality of permanent magnets disposed and fixed on the surface of the base material. Usually, each of these permanent magnets has a fan-like shape, and the N pole and the S pole are alternately arranged in a ring having a desired number of poles.

  The permanent magnet is exposed to a time-varying magnetic field during rotation of the rotor. For this reason, Joule heat due to the eddy current is generated in the permanent magnet, and this causes a problem that the permanent magnet is heated and its magnetic force is reduced. In order to reduce Joule heat, for example, as disclosed in Patent Document 1, it is effective to divide the permanent magnet into small pieces to reduce the magnitude of the eddy current.

Unexamined-Japanese-Patent No. 2006-14399 (FIG. 13)

  In the above-mentioned rotor, how to fix a plurality of permanent magnets to a disk-like base material often becomes a problem in axial gap type rotating electrical machines. That is, since the rotor is disposed to face the stator via a minute axial gap, a fixing member which protrudes in the axial direction and interferes with the stator can not be adopted, for example, for fixing the permanent magnet. There are limitations in the means. In particular, when the permanent magnet is divided into small pieces as a countermeasure against eddy currents, it is difficult to reliably fix the small magnetic pieces.

  Patent Document 1 discloses a method of fixing magnet pieces to each other using an adhesive. Fixing with an adhesive is advantageous in that it does not use a mechanical fixing member, and is effective for bonding members having different coefficients of linear expansion, such as a base and a permanent magnet. However, even if it is divided into small pieces, eddy currents are generated in the permanent magnet and heat is generated. The high temperature of the permanent magnet generally causes the adhesive to be weakened and may cause problems such as peeling of the bonded permanent magnet from the substrate.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a structure capable of securely attaching a permanent magnet to a disk-like base of a rotor in an axial gap type rotating electric machine. .

An axial gap type rotating electrical machine according to one aspect of the present invention includes a stator including a magnetic core and an exciting coil, a plurality of permanent magnets circumferentially arrayed around a rotation center axis, and a disk supporting these permanent magnets. And a rotor provided axially spaced from the stator, and a fixing member for fixing the permanent magnet to the base, the permanent magnet comprising: A locking portion including a surface facing the stator and a back surface facing the base, and a locking portion at a peripheral edge portion of the locking member, the fixing member engaging with the locking portion; An axial gap type rotation including: a fixing portion forming a mechanical fixing structure with respect to the base material, the locking portion engaging with the locked portion without protruding from the surface of the permanent magnet in electric, the plurality of permanent magnets, each in the one magnetic pole Permanent magnets, each permanent magnet is further divided into a plurality of magnet pieces, each of the magnet pieces having the engaged portion, and the magnet piece having the permanent magnet as the disk-like base material The fan-shaped permanent magnet is formed by arranging the small pieces adjacent to one another in the circumferential direction of the base material, and the engaged portion is the radial direction of the base material of the small magnetic piece. It is arranged at both ends.

According to this rotating electrical machine, the locking portion of the fixing member restrains the permanent magnet by engaging with the locked portion of the permanent magnet, while the locking portion does not protrude from the surface of the permanent magnet. There is no interference with the stator. Moreover, since the said to-be-locked part is arrange | positioned at the peripheral part of a permanent magnet, it does not affect the magnetic circuit which the said permanent magnet makes. Therefore, even if the axial gap is very small, the permanent magnet can be well fixed to the disk-like substrate without reducing the magnetic ability. In addition, since each permanent magnet is further divided into a plurality of magnet pieces, it is possible to reliably prevent peeling of the magnet pieces from the base while suppressing the eddy current generated in the permanent magnet forming one pole. Can. Furthermore, the magnet pieces divided in the circumferential direction are restrained by the locking portion at the locked portions disposed at both end portions in the radial direction. Therefore, the magnet piece can be reliably fixed to the base without reducing the magnetic force generated by the magnet piece.

  In the above-described rotating electrical machine, the locked portion may be a recess which is sunk from the surface to the back surface of the permanent magnet, and the locking portion may be accommodated in the recess. .

  According to this rotating electrical machine, the engaging portion engages with the permanent magnet in a manner to be accommodated in the recess. Therefore, fixation of the permanent magnet to the base material with a simple structure can be realized.

  In the above rotating electric machine, the locked portion is an inclined surface formed on the periphery of the permanent magnet by making the width on the back surface side of the permanent magnet longer than the width on the surface side, The locking portion may be configured to have a thickness substantially the same as that of the permanent magnet and to have a reverse inclined surface in surface contact with the inclined surface.

  According to this rotating electrical machine, the permanent magnet can be fixed to the base material in a stable manner in which the inclined surface formed on the peripheral edge of the permanent magnet is held down by the reverse inclined surface of the locking portion.

  In the above axial gap type rotating electrical machine, the plurality of permanent magnets are permanent magnets each forming one magnetic pole, each permanent magnet is further divided into a plurality of magnet pieces, and these magnet pieces are respectively engaged with the engaged members. It is desirable to have a stop.

  According to this rotating electrical machine, by applying the locking portion and the locked portion according to the present invention while suppressing the eddy current generated in the permanent magnet forming one pole, the base material of the magnet small piece Peeling can be reliably prevented.

  In the above-mentioned electric rotating machine, the magnet piece is a piece obtained by dividing the permanent magnet in the radial direction of the disk-like base material, and the engaged portion is the circumferential direction of the base material of the magnet piece. It is desirable to be disposed at both ends of the

  According to this rotating electrical machine, the magnet pieces divided in the radial direction are restrained by the locking portion at the locked portions arranged at both ends in the circumferential direction. Therefore, the magnet piece can be reliably fixed to the base without reducing the magnetic force generated by the magnet piece.

  In the above-mentioned electric rotating machine, the magnet piece is a piece obtained by dividing the permanent magnet in the circumferential direction of the disk-like base material, and the engaged portion is the radial direction of the base material of the magnet piece. It is desirable to be disposed at both ends of the

  According to this rotating electrical machine, the magnet pieces divided in the circumferential direction are restrained by the locking portion at the locked portions arranged at both end portions in the radial direction. Therefore, the magnet piece can be reliably fixed to the base without reducing the magnetic force generated by the magnet piece.

  In the above-mentioned rotating electrical machine, one of the adjacent permanent magnets and another permanent magnet, or a locked portion provided with one magnet piece and another magnet piece is engaged with the locking portion of one fixing member. It is desirable that they are combined.

  According to this rotating electrical machine, a plurality of permanent magnets or magnet pieces can be fixed with one fixing member. Therefore, the number of parts can be reduced, and the space for arranging the fixing member can be reduced.

  In the case where a recessed portion is employed as a locked portion and a magnet piece divided in a radial direction is used as a permanent magnet, the locked portion is a semicircular shape formed at each circumferential end of the magnet piece. The fixing member includes a body having a circular cross section as the fixing portion, and a head having a larger diameter than the body and having a circular cross section as the locking portion, and one magnetic pole is provided on one magnetic pole. The two adjacent ones are formed such that one substantially circular recess is formed by the semicircular recess of the magnet segment to which it belongs and the semicircular recess of the magnet segment that belongs to the other pole adjacent thereto. Preferably, the adjacent two magnet pieces are fixed in such a manner that a magnet piece is disposed and the head of the fixing member is accommodated in the substantially circular recess.

  Further, in the case where the inclined surface is adopted as the engaged portion and the magnet pieces divided in the circumferential direction are used as the permanent magnet, the engaged portions are respectively formed at both end portions in the radial direction of the magnet piece. The fixing member includes the fixing jig as the locking portion having the reverse inclined surface, and the fastener as the fixing portion for fixing the fixing jig to the base material. The adjacent two magnet pieces are arranged such that one enlarged inclined face is formed by a series arrangement of the inclined faces each having one magnet piece and another magnet piece adjacent thereto. It is desirable that the adjacent two magnet pieces be fixed in such a manner that the reverse inclined surface of the fixing member presses the one enlarged inclined surface.

  According to the present invention, in the axial gap type rotating electrical machine, the permanent magnet can be securely attached to the disk-shaped base of the rotor. Therefore, it is possible to provide an axial gap type rotating electric machine in which peeling of the permanent magnet from the base does not occur.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows roughly the structure of the axial gap type rotary electric machine which concerns on embodiment of this invention. It is a disassembled perspective view which shows the example of a general structure of the stator of the said rotary electric machine, and a rotor. It is a disassembled perspective view which shows the other structural example of the stator of the said rotary electric machine, and a rotor. It is an exploded perspective view showing a stator and a rotor concerning a 1st embodiment of the present invention. It is a perspective view which shows the magnet small piece of 1st Embodiment. It is a top view which shows the attachment state to the rotor base material of the said magnet piece. It is the VII-VII sectional view taken on the line of FIG. It is a top view which shows the modification of 1st Embodiment. It is an exploded perspective view showing a stator and a rotor concerning a 2nd embodiment of the present invention. It is a disassembled perspective view which shows the attachment state to the rotor base material of the magnet small piece in 2nd Embodiment. It is a partially broken perspective view which shows the attachment state to the rotor base material of the said magnet piece. It is sectional drawing which shows the attachment state to the rotor base material of the said magnet piece. It is a top view which shows the modification of 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a view schematically showing a structure of an axial gap type rotary electric machine 1 according to an embodiment of the present invention. In the present invention, the axial gap type rotating electrical machine 1 may take the form of, for example, a motor or a generator, or a combination of these. In the present embodiment, an axial gap type DC brushless motor is illustrated as a preferable example of the axial gap type rotary electric machine.

[Overall structure of axial gap type rotating electric machine]
The axial gap type rotary electric machine 1 includes a casing 10 and a rotating shaft 11 a part of which protrudes from the casing 10. The rotating shaft 11 is an output rotating shaft that generates torque when the rotating electrical machine 1 is used as a motor, and is an input rotating shaft to which a rotational driving force is input when used as a generator.

  The rotary electric machine 1 includes a disk-shaped stator 2 housed in a casing 10 and two disk-shaped rotors 3. The stator 2 and the rotor 3 are arranged in the axial direction of the rotating shaft 11. In this embodiment, one of the rotors 3 faces one of the disk surfaces of the stator 2 and the other of the rotors 3 faces the other disk surface of the stator 2. The double rotor type rotary electric machine 1 of the form by which the stator 2 is pinched | interposed is illustrated. Of course, the rotary electric machine 1 may be a single rotor type in which one rotor 3 is axially opposed to the one stator 2.

  Each rotor 3 is disposed at an interval G in the axial direction with respect to the stator 2. The gap G is a so-called axial gap, and its length is about 1 mm to several mm. The rotating shaft 11 is fixed to the disk-shaped rotor 3 so as to be centered on the rotation center thereof. The two rotors 3 penetrate the hollow portion of the stator 2 and are connected to each other by a connecting shaft (not shown) disposed on the same axis as the rotating shaft 11.

  Here, a structural example of a general stator 2 and rotor 3 in an axial gap type rotating electric machine will be described. FIG. 2 is an exploded perspective view showing a structural example of a general stator 2 and rotor 3. In FIG. 2, a rotation center axis AX (axial center of the rotation axis 11) of the rotor 3 is shown. The stator 2 includes a plurality of electromagnet units 20 arranged in the circumferential direction (rotational direction of the rotor 3). Each electromagnet unit 20 includes a fan-shaped magnetic core 21 and an excitation coil 22 mounted on the magnetic core 21. The plurality of magnetic cores 21 are supported by a core support member (not shown) and uniformly arranged in an annular shape around the rotation center axis AX.

  The magnetic core 21 is preferably a dust core. The dust core is a core formed by firmly pressing iron powder coated with an electrical insulating film. From the viewpoint of suppressing the eddy current, in addition to the dust core, a laminated core made of a laminated body of a plurality of electromagnetic steel sheets can also be used. A dust core is more preferable as the magnetic core 21 because it has higher air tightness and higher freedom of molding than the above-mentioned laminated core. In the present embodiment, the magnetic core 21 has a bobbin shape in which collar portions 211 are formed on both end surfaces in the axial direction.

  The exciting coil 22 is formed by winding an insulated wire by a required number of turns with a bobbin-shaped magnetic core 21 as a winding core. The energization of the direct current to the exciting coil 22 generates a magnetic flux passing through the magnetic core 21 in the direction parallel to the rotating shaft 11. Further, the direction of the magnetic flux can be reversed by reversing the direction of conduction of the direct current to the exciting coil 22. Switching of the energization and the energization direction to each exciting coil 22 is controlled by a driver circuit (not shown), thereby forming magnetic lines of force for rotating the rotor 3 around the rotating shaft 11.

  The rotors 3 each include a plurality of permanent magnets 40 and a disk-shaped base 31 supporting the permanent magnets 40. Each permanent magnet 40 is a fan-shaped flat magnet in an axial direction. The base 31 has, on the side facing the stator 2, a circular support surface 31S orthogonal to the rotation center axis AX. The plurality of permanent magnets 40 has an outer peripheral edge of the support surface 31S such that the S pole and the N pole are alternately arranged in the circumferential direction around the center point O of the support surface 31S (a point intersecting the rotation center axis AX). In the vicinity, it is arranged in a ring.

  The disk-shaped base material 31 is a member formed of a magnetic material such as a steel material, and has both the support function of the permanent magnet 40 described above and the function as a back yoke of the permanent magnet 40. The back surface of the permanent magnet 40 in which the surface facing the stator 2 is magnetized to the S pole is the N pole. The permanent magnet 40 adjacent to this has an N pole on the surface and an S pole on the back. The base material 31 supports the back surface side of the permanent magnets 40 and serves to form a magnetic path between the back surface side S pole and the N pole. Conventionally, the permanent magnet 40 is generally fixed to the support surface 31S of the base 31 using an adhesive such as an epoxy resin adhesive. This is because an adhesive is suitable for joining two members having different linear expansion coefficients, ie, a permanent magnet 40 made of neodymium and a base material 31 made of steel or the like.

  In the rotary electric machine 1 configured as described above, the problem is the heat generation due to the eddy current of the permanent magnet 40. The permanent magnet 40 is exposed to a time-varying magnetic field when the rotor 3 rotates. As a result, an eddy current is induced in the permanent magnet 40, and the Joule heat causes self-heating. When the permanent magnet 40 is heated to a high temperature, its magnetic force is reduced, and the adhesive bonding the permanent magnet 40 to the base 31 is weakened. Due to this weakening, a problem may occur in which the permanent magnet 40 peels off from the base material 31.

  FIG. 3 is an exploded perspective view showing another structural example of the rotor 3. The rotor 3 shown here is configured of a permanent magnet unit 400 in which permanent magnets forming one pole are formed of a plurality of magnet pieces 401, 402, 403. That is, the permanent magnet 40 shown in FIG. 2 is divided into three magnet pieces 401, 402, 403 in the radial direction of the disk-shaped substrate 31. The magnet pieces 401, 402, 403 are similarly fixed to the substrate 31 by an adhesive.

  By using the divided magnet pieces 401, 402, 403, the amount of generated eddy current can be reduced. However, even if the permanent magnets are divided and reduced in volume, eddy currents are inevitably generated in these magnet pieces 401, 402, 403 and heat is generated. Therefore, the phenomenon of weakening of the adhesive described above occurs, and the permanent magnet unit 400 can not completely wipe off the peeling problem from the substrate 31. Hereinafter, an embodiment capable of solving the problem of the separation of permanent magnets in the rotor 3 will be described.

First Embodiment
FIG. 4 is an exploded perspective view showing the stator 2 and the rotor 3 of the axial gap type rotary electric machine according to the first embodiment of the present invention. The basic structure of the rotating electrical machine exemplified in the first embodiment is a double rotor in which one stator 2 is sandwiched between two rotors 3 as in the cases of FIGS. 2 and 3 shown above. Type of electric rotating machine. The configuration of the stator 2 is the same as that described above, so the description is omitted here.

  The rotor 3 includes a disk-shaped base 31 and a plurality of magnetic pole units P each forming one magnetic pole. The disk-shaped base material 31 is provided with a plurality of screw holes 32 penetrating the base material 31 in the axial direction, in addition to the above-described circular support surface 31S. The base 31 supports the magnetic pole unit P at the support surface 31S, and also functions as a back yoke of a permanent magnet provided in the magnetic pole unit P. The plurality of magnetic pole units P are arranged in the circumferential direction around the rotation center axis of the base 31.

  FIG. 5 is an exploded perspective view showing the configuration of one magnetic pole unit P. As shown in FIG. The magnetic pole unit P includes a permanent magnet 4, a fixing member 5 for fixing the permanent magnet 4 to the base 31, and a fixing piece 6 for holding the outer peripheral side of the permanent magnet 4. The permanent magnet 4 is further divided into a plurality of magnet pieces, that is, a first magnet piece 41, a second magnet piece 42 and a third magnet piece 43. Similar to the magnet pieces shown in FIG. 3, these magnet pieces 41 to 43 are pieces divided in the radial direction of the base material 31, and one sector-shaped permanent magnet 4 is formed by arranging these pieces adjacent to one another. Is formed.

  The first to third magnet pieces 41 to 43 each have a substantially trapezoidal shape in an axial direction view. The first magnet piece 41 is a piece closest to the arc center of the sector-shaped permanent magnet 4 and is the piece having the shortest circumferential width. The third magnet piece 43 is a piece that is the farthest from the center of the circular arc and has the longest circumferential width. The second magnet piece 42 is a piece located in the middle of the front two and has a circumferential width between the two.

  The first magnet piece 41 includes a surface 41S facing the stator 2 and a back surface 41R facing the base 31. The front surface 41S and the back surface 41R are both flat trapezoidal surfaces. The surface 41S is oppositely disposed with a predetermined axial gap in parallel with the surface of the ridge portion 211 of the magnetic core 21 which is also a flat trapezoidal surface. The back surface 41 </ b> R is a surface that is in direct pressure contact with the support surface 31 </ b> S of the base 31 by the tightening force of the fixing member 5 or pressure contact via an adhesive. The second magnet piece 42 and the third magnet piece 43 also have front and back surfaces similar to the above.

  The first magnet piece 41 is provided with four side surfaces at its periphery. The four side surfaces include a pair of circumferential side surfaces 411 that are circumferential side surfaces of the first magnet piece 41, a radially inner side surface 413, and an outer side surface 414 longer in the circumferential direction than the inner side surface 413. The circumferential side surface 411 is a surface connecting the inner side surface 413 and the outer side surface 414 having different circumferential lengths, and the distance between the pair of circumferential side surfaces 411 widens outward in the radial direction. These side surfaces are surfaces substantially perpendicular to the support surface 31S.

  On both circumferential end portions of the first magnet piece 41, that is, on the respective circumferential side surfaces 411, concave portions 412 (engaged portions) having a semi-conical shape (semi-circular in an axial direction view) are formed. The recess 412 is a recess sunk from the surface 41S to the back surface 41R, and the surface 41S has a semicircular opening edge convex toward the circumferential center of the first magnet piece 41, and the circumferential surface 411 has the back surface 41R. Each have a convex semicircular opening edge. The recess 412 is a recess serving as a countersink for accommodating the head of a flat head screw described later.

  The 2nd magnet small piece 42 and the 3rd magnet small piece 43 also have the same shape as the 1st magnet small piece 41, except for the length in the circumferential direction being different. That is, the second magnet piece 42 includes a pair of circumferential side surfaces 421, an inner side surface 423, and an outer side surface 424, and the circumferential end portions of the second magnet piece 42, that is, the respective circumferential side surfaces 421 have semiconical recesses 422 (locked portion) is formed. The third magnet piece 43 has a pair of circumferential side surfaces 431, an inner side surface 433, and an outer side surface 434. The circumferential magnet 43 has a semiconical recess at each circumferential end of the third magnet piece 43, that is, each circumferential side surface 431. 432 (locking portion) is formed.

  As the permanent magnet 4, a neodymium magnet, a samarium cobalt magnet, a ferrite magnet etc. can be illustrated, for example. These permanent magnets are manufactured by molding raw material powder into a final shape and then performing a magnetizing operation such as exposing the molded body in a strong magnetic field. For this reason, since it is possible to process the shape of the magnet before it is magnetized, it is possible to freely and easily perform the production of the divided magnet pieces 41 to 43 and the chamfering process for forming the concave portions 412, 422 and 432. it can.

  The fixed piece 6 is a member that prevents the first to third magnet small pieces 41 to 43 from being pulled outward in the radial direction by centrifugal force when the rotor 3 rotates. The fixed piece 6 faces the outer side surface 434 of the third magnet piece 43, and has a pressing surface 61 having a circumferential length substantially equal to that of the outer side surface 434 and the base 31 for fixing the fixed piece 6 concerned. And a stop hole 62. Only one stop hole 62 is provided at the circumferential center of the fixed piece 6.

  When the first to third magnet pieces 41 to 43 are fixed to the base 31, the outer side surface 414 of the first magnet piece 41 and the inner side surface 423 of the second magnet piece 42 are also of the second magnet piece 42. The outer side surface 424 and the inner side surface 433 of the third magnet piece 43 are in close contact with each other. Further, the outer side surface 434 of the third magnet piece 43 and the pressing surface 61 of the fixed piece 6 are in close contact, and the pressing surface 61 receives the centrifugal force of the permanent magnet 4.

  The fixing member 5 is a plurality of countersunk screws in the present embodiment. In the present embodiment, as the fixing member 5, a pair of first countersunk screws 51 for fixing the first magnet piece 41 to the base 31 and a pair of second countersunk head for fixing the second magnet piece 42 to the base 31 A screw 52, a pair of third countersunk screws 53 for fixing the third magnet piece 43 to the base material 31, and one fourth countersunk screw 54 for fixing the fixing piece 6 to the base material 31 are provided.

  The first flat head screw 51 includes a body portion 511 (fixed portion) provided with a threaded portion of a male screw, and a countersunk head 512 (locking portion) connected to one end of the body portion 511 to expand in a tapered shape. . The body 511 has a circular shape in cross section orthogonal to the screw axis direction, and the cross section of the countersunk head 512 is a circle having a diameter larger than that of the body 511. The body portion 511 is a portion that is screwed into the screw hole 32 of the base material 31 to form a mechanical fixing structure with respect to the base material 31. The countersunk head 512 is a portion engaged with the recess 412, and has a hexagonal hole for receiving a hexagonal wrench for screw fastening. The first magnet piece 41 is fixed to the base material 31 by screwing the body 511 to the screw hole 32 at a predetermined position in a state where a part of the countersunk head 512 presses the recess 412. The countersunk head 512 is accommodated in the recess 412 at the time of screw fastening, and is set so as not to protrude from the surface 41S. That is, the countersunk head 512 is engaged with the recess 412 without projecting from the surface 41S (see FIG. 7).

  The other countersunk screws 52, 53, 54 also have the same structure as the first countersunk screw 51. The pair of second flat head screws 52 are screwed onto the base material 31 so as to engage with the recesses 422 arranged at both ends in the circumferential direction of the second magnet piece 42, and the second magnet piece 42 is used as a base material Fix it to 31. The pair of third countersunk screws 53 are screwed to the base material 31 so as to engage with the recesses 432 arranged at both ends in the circumferential direction of the third magnet piece 43, and the third magnet piece 43 is used as a base material Fix it to 31. The fourth flat head screw 54 is screwed into the screw hole of the base 31 through the fixing hole 62 of the fixing piece 6 to fix the fixing piece 6 to the base 31.

  In the present embodiment, the first to third countersunk screws 51 to 53 each show an example in which not only one magnet piece is fixed but other magnet pieces adjacent thereto are also fixed. ing. This point will be described based on FIGS. 6 and 7. FIG. 6 is a plan view showing how the magnet pieces 41 to 43 are attached to the base material 31, and FIG. 7 is a sectional view taken along the line VII-VII in FIG.

  In FIG. 6, a certain magnetic pole unit P (one magnetic pole), an upstream magnetic pole unit PA (other magnetic pole) adjacent in the counterclockwise direction (treated as upstream) of the magnetic pole unit P, and a clockwise direction (treated as downstream) And the downstream magnetic pole unit PB (another magnetic pole) is extracted and shown. The first, second and third magnet small pieces 41P, 42P and 43P of the magnetic pole unit P are respectively spaced apart from the first, second and third magnet small pieces 41PA, 42PA and 43PA of the upstream magnetic pole unit PA with a gap d. They are aligned in the direction, and are circumferentially spaced apart from the first, second, and third magnet pieces 41PB, 42PB, and 43PB of the downstream magnetic pole unit PB with a gap d. That is, magnet pieces of the same size of each magnetic pole unit are circumferentially disposed at the same position in the radial direction with a gap d.

  Thus, for example, as shown also in FIG. 7, the semicircular recess 412 on the upstream side of the first magnet piece 41P of the magnetic pole unit P and the semicircular recess 412 on the downstream side of the first magnet piece 41PA of the upstream magnetic pole unit PA. And a substantially circular recess is formed across the gap d. The adjacent two first magnet pieces 41P and 41PA are fixed in such a manner that the countersunk head 512 of one first countersunk screw 51A is accommodated in the substantially circular recess. The substantially circular concave portions as described above are the concave portions 422 and 423 on the upstream side of the second and third magnet small pieces 42P and 43P of the magnetic pole unit P, and the second and third magnetic small pieces 42PA and 43PA of the upstream magnetic pole unit PA. It is also formed by the recesses 422 and 423 on the downstream side. Two adjacent magnet pieces are fixed to these substantially circular recesses in such a manner that the second and third countersunk screws 52A and 53A are accommodated one by one.

  Similarly, the substantially circular concave portion described above is a concave portion 412, 422, 423 on the downstream side of the first, second, and third magnet small pieces 41P, 42P, 43P of the magnetic pole unit P, and a first, It is also formed by recesses 412, 422, 423 on the upstream side of the second and third magnet pieces 41PB, 42PB, 43PB. Two adjacent magnet pieces are fixed in such a manner that each of the first, second and third countersunk screws 51B, 52B and 53B is accommodated in the substantially circular recess.

  The fixing structure of the magnet piece in one of the substantially circular recesses will be described in more detail with reference to FIG. The first magnet piece 41P of the magnetic pole unit P and the back surface 41R of the first magnet piece 41PA of the upstream magnetic pole unit PA are bonded to the support surface 31S of the base 31 via the adhesive J. Although this adhesive J can be omitted, it is desirable to interpose the layer of the adhesive J in order to fix the magnet pieces 41P, 41PA to the support surface 31S more stably.

  The upstream circumferential surface 411 of the first magnet piece 41P and the downstream circumferential surface 411 of the first magnet piece 41PA face each other, and the two recesses 412 face each other, thereby forming one substantially conical recess. Is formed. The body 511 of the first flat head screw 51 is fastened to the screw hole 32 of the base 31, and the flat head 512 is accommodated in the substantially conical recess. The concave portion 412 of the first magnet small piece 41PA on the left side in FIG. 7 is pressed by the upstream side portion of the conical tapered surface 513 of the disc head 512, and the concave side 412 of the first magnetic small piece 41P on the right side by the downstream side. Is pressed.

  A portion of the body portion 511 above the screwing portion with the screw hole 32 is accommodated between the facing circumferential side surfaces 411. That is, the diameter of the body 511 is set to be slightly smaller than the above-described gap d (FIG. 6). The countersunk head 512 is completely accommodated in a substantially conical recess formed by a pair of recesses 412, and its top surface 51S is substantially flush with the surface 41S of the first magnet pieces 41P, 41PA. The top surface 51S may be flush with the surface 41S, or the top surface 51S may be recessed from the surface 41S and engaged with the recess 412 without protruding from the surface 41S. It should be noted that even if the top surface 51S protrudes slightly from the surface 41S due to the influence of parts tolerance etc., it is a range that does not affect the axial gap (the interval G in FIG. 1). It is a category of “engage without engaging”.

  According to the rotating electrical machine according to the first embodiment described above, the locking portion of the fixing member 5 (the countersunk head 512 of the countersunk screws 51 to 53) is a recess 412 of the first to third magnet pieces 41 to 43. , 422, 423 while constraining these magnet pieces, while the countersunk head 512 does not protrude from the surface 41S of the magnet pieces 41 to 43, and therefore does not interfere with the stator 2. Therefore, even if the axial gap is minute, the magnet pieces 41 to 43 can be fixed to the disk-shaped base material 31 well. In addition, even if the magnet pieces 41 to 43 are heated by the eddy current, they do not peel off the base material 31.

  Moreover, since the recessed parts 412, 422, 423 as a to-be-locked part are arrange | positioned at the peripheral part of the permanent magnet 4 (magnet small pieces 41-43), they do not affect the magnetic circuit which the said permanent magnet 4 makes. When fixing the permanent magnet 4 to the base material 31 using a screw, a method may be considered in which a screw hole is provided in the vicinity of the circumferential center of the permanent magnet 4 and screwing is performed. However, when a screw hole is bored in the vicinity of the center, the screw hole becomes an obstacle in forming the magnetic path, and the magnetic force of the magnetic pole unit P is reduced. However, in the present embodiment, since the chamfered portion for fixing the magnet is disposed at the peripheral portion of the permanent magnet 4, the formation of the magnetic path in the magnetic pole unit P is not affected.

  Furthermore, in the present embodiment, the plurality of magnet pieces 41 to 43 are fixed by one flat head screw 51 to 53. Although countersunk screws may be applied to both circumferential end portions of the magnet pieces 41 to 43 of each magnetic pole unit P, in this case, the number of countersunk screws is increased and the arrangement space for the countersunk screw is required. Become. According to this embodiment, it is possible to reduce the number of countersunk screws used and to reduce the arrangement space of the countersunk screws.

Modified Example of First Embodiment
FIG. 8 is a plan view showing a state of attachment of permanent magnets to a base 31 according to a modification of the first embodiment. In the said embodiment, the permanent magnet 4 of one magnetic pole unit P was divided | segmented into the some magnet small piece 41-43, and the example which these were each fixed to the base material 31 with the countersunk screw 51-53 was shown. Instead of this, in the modification shown in FIG. 8, an aspect is shown in which the permanent magnet of one magnetic pole unit P is fixed to the base material 31 without being divided.

  In FIG. 8, a certain magnetic pole unit P, an upstream magnetic pole unit PA, and a downstream magnetic pole unit PB are extracted and shown. Each of the magnetic pole units P, PA, PB has a fan-shaped one-piece permanent magnet 40P, 40PA, 40PB, respectively. The permanent magnets 40P, 40PA, and 40PB each have a semiconical recess 404 at each circumferential end as a locked portion. One substantially conical concave portion is formed by the adjacent permanent magnet 40P and the concave portion 404 of the upstream permanent magnet 40PA, and one substantially similar concave portion is formed by the adjacent permanent magnet 40P and the downstream permanent magnet 40PB. A conical recess is formed. The permanent magnets 40P, 40PA, 40PB are fixed to the base material 31 in such a manner that one first flat head screw 55A, 55B is accommodated in each of the concave portions. In the case where the problem of the temperature rise due to the eddy current of the permanent magnets 40P, 40PA, 40PB can be overcome by devising the cooling means, the aspect of this modification is preferable because the number of parts can be further reduced.

  In addition to the above, in the above embodiment, the countersunk screw has been exemplified as the fixing member 5, but the present invention is not limited to this. It is possible to apply various screw members and fixing tools at various places as the fixing member 5, and for example, countersunk screws can be used. When a counterbore screw is applied, the shape of the engaged portions provided at both ends of the permanent magnet is semi-cylindrical. Alternatively, a rivet may be used as the fixing member 5. In this case, the fixing portion forming the mechanical fixing structure with the base 31 is a caulking portion of the rivet. Furthermore, in the above embodiment, the magnet pieces 41 to 43 divided into three in the radial direction of the base material 31 are illustrated, but the number of divisions is arbitrary, for example, divided into four, divided into two You may

Second Embodiment
FIG. 9 is an exploded perspective view showing a stator 2 and a rotor 3A of an axial gap type rotary electric machine according to a second embodiment of the present invention. The basic structure of the rotating electrical machine exemplified in the second embodiment is also a double in which one stator 2 is sandwiched between two rotors 3A, similarly to the ones shown in FIGS. 2 and 3 described above. It is a rotor-type electric rotating machine. The configuration of the stator 2 is the same as that described above, so the description is omitted here. The rotor 3A is different from that of the first embodiment in that a magnet piece obtained by dividing a permanent magnet in the circumferential direction is used, and a structure of a locked portion and a fixing member of the magnet piece is different. is there.

  The rotor 3A includes a disk-shaped base 31A and a plurality of magnetic pole units Pa each forming one magnetic pole. The base 31A is a plurality of screw holes that penetrate the base 31A in the axial direction in addition to the circular support surface 31S, and a plurality of inner threads arranged annularly near the middle in the radial direction of the base 31A. A hole 321 and an outer threaded hole 322 arranged annularly near the periphery are provided. The base 31A supports the magnetic pole unit Pa at the support surface 31S, and also functions as a back yoke of a permanent magnet provided in the magnetic pole unit Pa. The plurality of magnetic pole units Pa are arranged in the circumferential direction around the rotation center axis of the base 31A.

  FIG. 10 is an exploded perspective view of the rotor 3A for explaining the structure of the magnetic pole unit Pa according to the second embodiment. Here, a state in which a part of the magnetic pole unit Pa group is attached to the base 31A and one of the magnetic pole units Pa is disassembled is shown. The magnetic pole unit Pa includes a permanent magnet 4A and a fixing block 7 for fixing the permanent magnet 4A to the base 31A.

  The permanent magnet 4A of one magnetic pole unit Pa is further divided into a plurality of magnet pieces, that is, a first magnet piece 44, a second magnet piece 45, and a third magnet piece 46. Unlike the magnet pieces shown in FIG. 3 and FIG. 4, these magnet pieces 44 to 46 are pieces equally divided in the circumferential direction of the disk-shaped base 31A, and they are arranged adjacent to each other. One fan-shaped permanent magnet 4A is formed. Each of the first to third magnet pieces 44 to 46 has a substantially trapezoidal shape elongated in the radial direction when viewed in the axial direction, and the short side of the trapezoid is oriented inward in the radial direction and the long side is oriented outward in the radial direction Are disposed on the base 31A.

  FIG. 11 is a partially cutaway perspective view showing the attachment of the first magnet piece 44 to the base 31A, and FIG. 12 is a cross-sectional view thereof. The first magnet piece 44 has an inner inclined surface 441 (engaged portion) at the radially inner end and an outer inclined surface 442 (engaged portion) at the radially outer end. The inclined surfaces 441 and 442 are formed on the periphery of the first magnet piece 44 by making the radial width on the back surface 44R side of the first magnet piece 44 longer than the radial width on the surface 44S side. It is a face. That is, the inner inclined surface 441 is an inclined surface that descends from the radial inner edge of the surface 44S toward the center point of the base 31A toward the back surface 44R, and the outer inclined surface 442 is the radial outer end of the surface 44S. It is an inclined surface that descends from the edge toward the outer peripheral direction of the base 31A to the back surface 44R.

  The second magnet pieces 45 and the third magnet pieces 46 also have the same shape as the first magnet pieces 44 described above. The first to third magnet pieces 44 to 46, when fixed to the base 31A, include the inner inclined surface 441 of the first magnet piece 44, and the inner inclined surfaces of the second and third magnet pieces 45 and 46, respectively. Are arranged so that one combined inner inclined surface is formed. Similarly, one combined outer inclined surface is formed by a series arrangement of the outer inclined surface 442 of the first magnet piece 44 and the outer inclined surfaces of the second and third magnet pieces 45 and 46 respectively. The first to third magnet pieces 44 to 46 are disposed.

  The fixing block 7 includes a first fixing block 71 (fixing jig) for locking the inner peripheral edge side of the permanent magnet 4A and a second fixing block 72 (fixing jig) for locking the outer peripheral edge side of the permanent magnet 4A. Become. The first fixing block 71 is fixed to the base 31A by the first fixing screw 56 (fastener) using the inner screw hole 321. The second fixing block 72 is fixed to the base 31A using the outer screw hole 322 by the second fixing screw 57 (fastener). In the present embodiment, the fixing member of the present invention is configured by the first and second fixing blocks 71 and 72 (locking portion) and the first and second fixing screws 56 and 57 (fixing portion).

  The first fixed block 71 and the second fixed block 72 are flat and substantially trapezoidal blocks having substantially the same thickness as the first to third magnet pieces 44 to 46 in the axial direction. The first fixing block 71 has a reverse inclined surface 711, a fixing hole 712, and a pair of grips 713. The reverse inclined surface 711 is disposed on the outer peripheral surface side of the first fixed block 71, and is formed by the dense arrangement of the first to third magnet small pieces 44 to 46 (that is, the gathered inner inclined surface (that is, the permanent magnet 4A). In surface contact with the inner inclined surface), the inner inclined surface is pressed. The circumferential width of the reverse sloped surface 711 is substantially the same as the circumferential width of the gathered inner sloped surfaces.

  The fixing hole 712 is a hole through which the first fixing screw 56 is inserted. The first fixing screw 56 is a flathead screw, and the fixing hole 712 is a screw hole having a shape that engages with the flathead of the flathead screw. The pair of gripping portions 713 are portions projecting radially outward from both ends in the circumferential direction of the reverse inclined surface 711 and, as shown in FIG. 10, around the inner inclined surfaces of the first to third magnet pieces 44 to 46 It restrains in the form which grasps the direction both sides. This restraint prevents the arrangement of the first to third magnet pieces 44 to 46 from being disturbed.

  The second fixed block 72 also has a similar reverse inclined surface 721, a fixed hole 722 and a pair of grips 723. The reverse inclined surface 721 is disposed on the inner peripheral surface side of the second fixed block 72, makes surface contact with the gathered outer inclined surfaces of the first to third magnet pieces 44 to 46, and presses the outer inclined surfaces. . The circumferential width of the reverse inclined surface 721 is substantially the same as the circumferential width of the gathered outer inclined surfaces. The fixing hole 722 is a screw hole having a shape into which the second fixing screw 57 consisting of a countersunk screw is inserted and which engages with the countersunk head. The pair of grips 723 are portions projecting radially inward from both circumferential ends of the reverse inclined surface 721, and restrain the circumferential side surfaces in the vicinity of the outer inclined surfaces of the first to third magnet pieces 44 to 46. ing.

  The first magnet pieces 44 are fixed to the base material 31A by the inner inclined surfaces 441 and the outer inclined surfaces 442 disposed at both ends in the radial direction being pressed (restrained) by the reverse inclined surfaces 712 and 721, respectively. Ru. The same applies to the second and third magnet pieces 45 and 46. Specifically, the fixing holes 712 of the first fixing block 71 and the inner screw holes 321 are aligned, and the reverse inclined surface 711 is the inner inclined surface of the first to third magnet pieces 44 to 46. And the first fixing screw 56 is screwed into the inner screw hole 321. Also, the fixing holes 722 of the second fixing block 72 and the outer screw holes 322 are aligned, and the reverse inclined surface 721 is in contact with the gathered outer inclined surfaces of the first to third magnet pieces 44 to 46. In this state, the second fixing screw 57 is screwed into the outer screw hole 322. In this embodiment, the screwing of the first and second fixing screws 56 and 57 forms a mechanical fixing structure with respect to the base 31A.

  By tightening the first and second fixing screws 56 and 57, the reverse inclined surfaces 711 and 721 respectively press the assembled inner and outer inclined surfaces, so that the first to third magnet pieces 44 to 46 It becomes firmly fixed to the material 31A. As shown in FIG. 12, after fastening the first and second fixing screws 56 and 57, the top surface of the countersunk head is flush with the surface 44 S of the first magnet piece 44. As described above, the first and second fixed blocks 71 and 72 and the first to third magnet pieces 44 to 46 have substantially the same thickness. Therefore, even if the axial gap is minute, the member for fixing the permanent magnet 4A does not interfere with the stator 2.

  Further, since the inner inclined surface 441 and the outer inclined surface 442 as the engaged portions are disposed at both radial end portions of the first magnet piece 44, that is, at the peripheral portions thereof, the magnetic circuit formed by the permanent magnet 4A is Not affect. Furthermore, since the magnet pieces 44 to 46 divided into three are fixed by one first fixed block 71 on the inner diameter side and one second fixed block 72 on the outer diameter side, the number of parts is reduced. There is an advantage that can be done.

Modified Example of Second Embodiment
FIG. 13 is a plan view showing a state of attachment of permanent magnets 4B to a base 31A according to a modification of the second embodiment. In the said embodiment, the example which fixes the magnet small piece divided | segmented into the circumferential direction was shown using the 1st, 2nd fixing screw 56, 57 and the 1st, 2nd fixing block 71, 72 as a fixing member. Even in the case of the magnet pieces divided in the circumferential direction, the fixing member exemplified in the first embodiment can also be adopted.

  FIG. 13A shows an example in which the permanent magnet 4B of one magnetic pole unit is composed of the fourth magnet small piece 47 and the fifth magnet small piece 48 divided into two in the circumferential direction. The fourth magnet piece 47 has an inner recess 473 as a locked portion at the radially inner end 471 and an outer recess 474 as a locked portion at the radially outer end 472. The fifth magnet piece 48 also has an inner recess 483 at the radially inner end 481 and an outer recess 484 at the radially outer end 482.

  The inner concave portions 473 and 483 are arc-shaped concave portions each having a central angle of about 90 degrees, and one inner semicircular concave portion 491 is formed by the two being adjacently arranged. Similarly, the outer recesses 474 and 484 are adjacently formed to form one outer semicircular recess 492. Then, as shown in FIG. 13B, the inner semicircular recess 491 engages with the countersunk screw 58 and the outer semicircular recess 492 engages with the countersunk screw 59, and is fixed to the base material 31A. According to this variant, it is possible to dispense with the use of parts such as fixed blocks.

  Besides, in the above embodiment, the permanent magnet 4A of one magnetic pole unit P is divided into a plurality of magnet pieces 44 to 46 in the circumferential direction. Instead of this, the permanent magnet 4A may be fixed to the base 31A using the first and second fixing screws 56 and 57 and the first and second fixing blocks 71 and 72 without dividing the permanent magnet 4A. . In addition, the inclined surfaces 441 and 442 of the magnet piece and the reverse inclined surfaces 711 and 712 of the fixed block may be in any shape as long as they can be in surface contact with each other.

  According to the axial gap type rotary electric machine 1 according to the present invention described above, the permanent magnet can be securely attached to the disk-shaped base of the rotor. Also, it does not affect the magnetic circuit formed by the permanent magnet. Therefore, it is possible to provide an axial gap type rotating electric machine which is excellent in magnetic ability without causing separation of the permanent magnet from the base material.

DESCRIPTION OF SYMBOLS 1 Axial gap type rotary electric machine 2 Stator 21 Magnetic core 22 Excitation coil 3, 3A Rotor 31, 31A Disc-shaped base material 4, 4A, 4B Permanent magnet 41, 42, 43, 44, 45, 46 Magnet small piece 41R back surface 41S Surface 412, 422, 432 Recess (Locked Part)
441, 442 inclined surface 5 fixing member 51, 52, 53 flat head screw (fixed member)
511 body (fixed part)
512 flat head (locking part)
56, 57 Fixing screws (fasteners)
6 Fixing pieces 71, 72 Fixing blocks (fixing jig)
711, 712 Reverse inclined surface AX Rotation center axis P Magnetic pole unit (one magnetic pole)
PA, PB Magnetic pole unit (other magnetic poles)
G interval (axial gap)

Claims (5)

A stator comprising a magnetic core and an excitation coil;
A rotation comprising a plurality of permanent magnets arranged circumferentially around a rotation center axis, and a disk-like base material for supporting these permanent magnets, and axially spaced from the stator. With the child,
A fixing member for fixing the permanent magnet to the base material;
The permanent magnet includes a surface facing the stator and a back surface facing the substrate, and a locking portion is provided on the periphery thereof.
The fixing member includes a locking portion that engages with the locked portion, and a fixing portion that forms a mechanical fixing structure with respect to the base material, and the locking portion is the surface of the permanent magnet. An axial gap type rotating electric machine which engages with the locked portion without protruding from the
The plurality of permanent magnets are permanent magnets each forming one magnetic pole, each permanent magnet is further divided into a plurality of magnet pieces, and each of the magnet pieces has the engaged portion.
The magnet pieces consist of pieces obtained by dividing the permanent magnet in the circumferential direction of the disk-like base material, and these pieces are arranged adjacent to each other to form one fan-shaped permanent magnet.
The axial gap type rotating electrical machine wherein the engaged portions are disposed at both ends of the magnet piece in the radial direction of the base material. In the axial gap type rotating electric machine according to claim 1,
The locked portion is a recess sunk from the front surface of the permanent magnet to the back surface,
The axial gap type rotating electrical machine wherein the locking portion is accommodated in the recess. In the axial gap type rotating electric machine according to claim 1,
The locked portion is an inclined surface formed on the periphery of the permanent magnet by making the width on the back surface side of the permanent magnet longer than the width on the surface side,
The axial gap type rotating electrical machine, wherein the locking portion has a thickness substantially the same as that of the permanent magnet and has a reverse inclined surface in surface contact with the inclined surface. In the axial gap type rotating electric machine according to any one of claims 1 to 3 ,
An axial gap type rotary electric machine, wherein an engaged portion provided with one adjacent magnet piece and another magnet piece is engaged with the engaging portion of one fixed member. In the axial gap type rotating electric machine according to claim 3 ,
The locked portions respectively provided in the adjacent one magnet piece and the other magnet piece are engaged with the locking portion of the one fixed member,
The locked portions are the inclined surfaces respectively formed at both end portions in the radial direction of the magnet piece,
The fixing member includes a fixing jig as the locking portion having the reverse inclined surface, and a fastener as the fixing portion for fixing the fixing jig to the base material.
The two adjacent magnet pieces are arranged such that a spread inclined surface is formed by a series arrangement of the inclined surfaces each having one magnet piece and another magnet piece adjacent thereto.
An axial gap type rotary electric machine, wherein the two adjacent magnet pieces are fixed in such a manner that the reverse inclined surface of the fixing member presses the one enlarged inclined surface.

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