JP6801396B2 - Double rotor structure motor - Google Patents

Description

The present invention relates to a motor having a double rotor structure in which an inner rotor and an outer rotor are provided on the inner peripheral side and the outer peripheral side of the stator.

Conventionally, Patent Document 1 discloses a dual rotor motor including a stator in which a winding is wound around a stator core including a yoke and a plurality of teeth, and an inner rotor and an outer rotor. In this motor, the stator core includes an annular yoke member for forming the yoke and a plurality of tooth members for forming the teeth. The stator core is formed by fitting each tooth member into the annular yoke member so that one end of the tooth member projects from the annular yoke member to the inner peripheral side and the other end protrudes from the annular yoke member to the outer peripheral side.

International release WO2010 / 047098

In the dual rotor motor of Patent Document 1, since the tooth members adjacent to each other in the circumferential direction are connected by the annular yoke member, the leakage flux from the tooth member to the annular yoke member increases, and iron loss (hysteresis loss and eddy current) occurs. There is a problem that the loss) becomes large.

An object of the present invention is to provide a motor having a double rotor structure capable of suppressing iron loss in a stator and increasing motor efficiency.

In the motor having a double rotor structure according to the present invention, a plurality of teeth members are arranged in an annular shape around a rotation axis, and a stator in which a coil is wound around the teeth member and a stator on the inner peripheral side with the stator in between. A motor having a double rotor structure, which is provided on the outer peripheral side and includes an inner rotor and an outer rotor that can rotate with respect to the stator. The teeth member is a main body to which the coil is assembled and the main body. It has a fastening portion that is formed so as to project in the circumferential direction and has a bolt through hole, and the bolt penetrates through the bolt through hole to fasten the fastening portion and the motor case in the axial direction of the motor. it is fixed in a state where the end face of the contact with the motor case, a yoke of magnetic material for coupling the tooth members together in the circumferential direction is not present.

According to the stator of the motor having a double rotor structure according to the present invention, each tooth member is fixed in a state where the end face in the axial direction is in contact with the motor case, and a magnetic yoke that connects the tooth members in the circumferential direction is formed. not exist. Therefore, since the leakage flux from the tooth member to the yoke is not generated, iron loss in the stator can be suppressed and the motor efficiency can be increased.

It is an end view of the motor of the double rotor structure which is 1st Embodiment of this invention as seen from the axial direction. (A) is a perspective view showing one of a large number of magnetic steel plates constituting the teeth member, and (b) is a perspective view showing a teeth member formed by laminating magnetic steel plates. It is a perspective view which shows the state which the inner coil and the outer coil are assembled to the tooth member of FIG. 2B. It is a perspective view which shows the fixing part provided in the motor case to which a tooth member is fixed. It is a perspective view which shows the state which the tooth member with a coil shown in FIG. 3 is assembled to the motor case of FIG. (A) is a top view showing a state in which two bolts are inserted into the fastening portion of the tooth member shown in FIG. 5, and (b) is a cross-sectional view taken along the line AA in (a). FIG. 6 is a cross-sectional view taken along the line AA showing a tooth member when a bolt is tightened from the state shown in FIG. 6B. (A) is a conceptual diagram showing a rotational operation in the motor of this embodiment, and (b) is a diagram showing a flow of magnetic flux in a tooth member. It is a perspective view which shows the modification which fixes the tooth member to a motor case using a ring member. It is a cross-sectional view similar to FIG. 6B, showing a state when a bolt is inserted into the insertion hole of the ring member shown in FIG. 9 and the tooth member is fastened to the motor case. (A) is a perspective view showing one of a large number of magnetic steel plates constituting a tooth member in the motor having a double rotor structure according to the second embodiment, and (b) is configured by laminating magnetic steel plates. It is a perspective view which shows the tooth member. It is a perspective view which shows the state which the inner coil and the outer coil are assembled to the tooth member of FIG. 11B. It is a partial plan view which shows the motor case in 2nd Embodiment. It is a perspective view which shows the ring member in 2nd Embodiment. FIG. 5 is a perspective view showing a state when the coiled tooth member of FIG. 12 is fastened to the motor case of FIG. 13 with the ring member of FIG. FIG. 15 is a cross-sectional view taken along the line BB in FIG.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, etc. are examples for facilitating the understanding of the present invention, and can be appropriately changed according to applications, purposes, specifications, and the like. In addition, when a plurality of embodiments and modifications are included in the following, it is assumed from the beginning that these configurations are used in appropriate combinations.

<First Embodiment>
FIG. 1 is an end view of the motor 10 having a double rotor structure according to the first embodiment of the present invention as viewed from the axial direction. In FIG. 1, the axial direction is indicated by an arrow X, the radial direction is indicated by an arrow R, and the circumferential direction is indicated by an arrow C.

The motor 10 includes a stator 16 including a plurality of (18 in this embodiment) tooth members 14 arranged in an annular shape around the rotating shaft 12. An inner coil 18 is wound around the inner end in the radial direction, and an outer coil 20 is wound around the outer end of each tooth member 14. In the present embodiment, the inner coil 18 and the outer coil 20 are wound around the tooth member 14 in a concentrated winding manner. Further, in the present embodiment, the stator 16 is composed of the tooth member 14, the inner coil 18, and the outer coil 20. The fixing of each tooth member 14 to the motor case will be described later with reference to FIGS. 2 and 2.

The motor 10 includes an inner rotor 22 and an outer rotor 24 provided on the inner peripheral side and the outer peripheral side with the stator 16 interposed therebetween. The inner rotor 22 has a cylindrical shape and is fixed to the outer peripheral surface of the rotating shaft 12 by, for example, tightening. The outer peripheral surface of the inner rotor 22 faces the inner end of each tooth member 14 of the stator 16 with a gap. Further, the inner rotor 22 is provided with a plurality of (12 in this embodiment) permanent magnets 26 at equal pitches in the circumferential direction.

The outer rotor 24 has a cylindrical shape and is arranged on the outer peripheral side of the stator 16. The inner peripheral surface of the outer rotor 24 faces the outer end of each tooth member 14 of the stator 16 with a gap. The outer rotor 24 is provided with a plurality of (12 in this embodiment) permanent magnets 28 at equal pitches in the circumferential direction. Further, the outer rotor 24 is connected to at least one of the rotating shaft 12 and the inner rotor 22 via a connecting member (not shown). As a result, the outer rotor 24 can rotate integrally with the rotating shaft 12 and the inner rotor 22.

The permanent magnets 26 of the inner rotor 22 and the permanent magnets 28 of the outer rotor 24 are arranged in the same phase around the rotation shaft 12. In the present embodiment, the permanent magnets 26 and 28 arranged in the same phase have surfaces facing each other magnetized to different polarities. Further, each permanent magnet 26 of the inner rotor 22 is arranged so that the outer surface in the radial direction is alternately N pole and S pole in the circumferential direction, and each permanent magnet 28 of the outer rotor 24 has a circumferential inner surface in the radial direction. They are arranged so as to have S poles and N poles alternately in the direction.

FIG. 2A is a perspective view showing one of a large number of magnetic steel plates constituting the teeth member 14, and FIG. 2B is a perspective view showing a teeth member formed by laminating magnetic steel plates. As shown in FIG. 2A, the magnetic steel plate 15 has, for example, a rectangular main body portion 15a and a pair of projecting pieces 15b protruding from both side edge portions at the central portion in the longitudinal direction of the main body portion 15a. The pair of projecting pieces 15b are bent in the same direction with respect to the main body portion 15a so as to be inclined at a predetermined angle with respect to the main body portion 15a. Further, through holes 15c are formed in each of the pair of projecting pieces 15b. As shown in FIG. 2B, the teeth member 14 is configured by laminating a large number of such magnetic steel plates 15 and integrating them by caulking or the like. The main body portion 15a of the magnetic steel plate 15 may be formed in a trapezoidal shape in which one end has a short side and the other end has a long side.

As shown in FIG. 2B, the tooth member 14 is formed by stacking a main body portion 15a of a magnetic steel plate 15 to form a tooth main body 14a and a pair of projecting pieces 15b laminated to form a pair of fastening portions. It has 14b and. Each fastening portion 14b has a bolt insertion hole 14c formed by connecting the through holes 15c in the stacking direction S. Here, when the teeth member 14 is assembled as the stator 16, the longitudinal direction of the teeth body 14a coincides with the radial direction R of the motor 10, the lateral direction thereof coincides with the circumferential direction C of the motor 10, and the stacking direction S. Corresponds to the axial direction X of the motor 10.

The tip of the fastening portion 14b of the tooth member 14 has a substantially triangular shape when viewed from above. Further, since the fastening portion 14b is formed by laminating the projecting pieces 15b of the magnetic steel plate 15, the axial direction X thereof is formed.
Is formed so as to be inclined by a predetermined angle with respect to the end face of the tooth body 14a.

FIG. 3 is a perspective view showing a state in which the inner coil 18 and the outer coil 20 are assembled to the tooth member 14 of FIG. 2 (b). As shown in FIG. 3, in the teeth body 14a of the teeth member 14, the inner coil 18 is assembled to one end 14d in the longitudinal direction, and the outer coil 20 is attached to the other end 14e in the longitudinal direction (see FIG. 2B). Is assembled. As a result, the coils 18 and 20 are wound around the tooth member 14. In the present embodiment, the circumferential width of the outer coil 20 is formed larger than the circumferential width of the inner coil 18. By making the sizes different in this way, the inner coils 18 arranged on the inner peripheral side of the stator 16 do not interfere with each other adjacent to each other in the circumferential direction, and the outer coils 18 arranged on the outer peripheral side of the stator 16 do not interfere with each other. The coil 20 can increase the amount of magnetic flux generated by increasing the number of turns.

FIG. 4 is a perspective view showing a fixing portion 32 provided in the motor case 30 to which the tooth member 14 is fixed. The motor case 30 is made of a non-magnetic material such as an aluminum alloy. A fixing portion 32 for fixing the tooth member 14 in a positioned state is provided on the surface of the motor case 30. The fixing portion 32 is formed so as to project in the axial direction X from the surface of the motor case 30.

The fixed portion 32 includes an annular portion 34 that protrudes in the axial direction X and extends in the circumferential direction C, and a protruding portion 36 that further protrudes in the axial direction X from the annular portion 34 and protrudes outward in the radial direction R. .. The end portion of the protruding portion 36 is formed in a shape that narrows in a taper shape toward the outside in the radial direction and then widens in a triangular shape in the axial direction. Further, the protruding portions 36 are formed at equal pitches in the circumferential direction by the same number as the teeth members 14 fixed to the motor case 30. As a result, the two protrusions 36 adjacent to the circumferential direction C are formed with circumferential recesses 38 having a V-shape or a wedge shape in the axial direction on the side surfaces facing each other. Further, in the motor case 30, two female screw holes 40 (see FIG. 6B) are formed between two protrusions 36 adjacent to each other in the circumferential direction C along the axial direction X.

FIG. 5 is a perspective view showing a state in which the coiled tooth member 14 shown in FIG. 3 is assembled to the motor case 30. 6 (a) is a top view showing a state in which two bolts are inserted into the fastening portion of the tooth member shown in FIG. 5, and FIG. 6 (b) is a top view showing a state in which two bolts are inserted, and FIG. 6 (b) is A- in FIG. 6 (a). A cross-sectional view.

As shown in FIG. 5, the tooth member 14 to which the inner coil 18 and the outer coil 20 are attached is assembled so as to be inserted into the fixed portion 32 of the motor case 30 from the axial direction X. Specifically, as shown in FIG. 6A, the tooth member 14 is fitted so that the pair of fastening portions 14b of the tooth member 14 are fitted between the two projecting portions 36 adjacent to each other in the circumferential direction in the fixing portion 32. Assemble to the motor case 30. At this time, since the fastening portion 14b of the teeth member 14 is formed so as to be inclined upward with respect to the teeth main body 14a, a gap is formed between the fastening portion 14b and the side surface of the circumferential recess 38. Therefore, the tooth member 14 can be easily assembled to the fixed portion 32 of the motor case 30.

In this state, as shown in FIGS. 6A and 6B, when the bolt 42 is inserted into the bolt insertion hole 14c of the fastening portion 14b, the tip of the screw portion of the bolt 42 faces the female screw hole 40 of the motor case 30. Is located. Then, when the bolt 42 is tightened, the tip of the screw portion is screwed into the female screw hole 40.

FIG. 7 is a cross-sectional view taken along the line AA showing the tooth member 14 when the bolt 42 is tightened from the state shown in FIG. 6 (b). As the bolt 42 is tightened, as shown in FIG. 7, the fastening portion 14b of the tooth member 14 is bent by being pressed by the head of the bolt 42. When the tightening of the bolt 42 is completed, the axial end surface of the fastening portion 14b is fastened and fixed in close contact with the surface of the motor case 30 together with the axial end surface of the tooth body 14a. At this time, the fastening portion 14b is bent to increase the overhanging dimension in the circumferential direction. As a result, there is no gap between the protrusion 36 and the side surface of the circumferential recess 38, and the protrusion 36 is in close contact with the side surface. As a result, the tooth member 14 is accurately positioned in the circumferential direction and is fastened and fixed to the motor case 30 in a stable state without rattling.

FIG. 8A is a conceptual diagram showing a rotational operation of the motor 10 of the present embodiment, and FIG. 8B is a diagram showing a flow of magnetic flux in the tooth member 14. In FIG. 8A, the inner coil 18 and the outer coil 20 are shown as one coil. Further, in FIGS. 8A and 8B, the flow of magnetic flux is indicated by an arrow F.

By passing a current through the coil 21 in the opposite direction to the two tooth members 14 adjacent to each other in the circumferential direction, one tooth member 14 and the other tooth member 14 are magnetized to opposite polarities. Specifically, in one tooth member 14, the inner peripheral side end portion facing the inner rotor 22 is magnetized to the S pole, and the outer peripheral side end portion facing the outer rotor 24 is magnetized to the N pole. On the contrary, in the other tooth member 14, the inner peripheral side end portion is magnetized to the N pole, and the outer peripheral side end portion facing the outer rotor 24 is magnetized to the S pole. By magnetizing each tooth member 14 in this way, the inner rotor 22 has an attractive force and a repulsive force with the permanent magnet 26 of the inner rotor 22 and an attractive force and a repulsive force with the permanent magnet 28 of the outer rotor 24. And the outer rotor 24 rotates in the direction of the arrow together with the rotation shaft 12.

In the motor 10 of the present embodiment, the teeth member 14 is magnetically connected to each other between both end faces in the axial direction only when one end surface in the axial direction is in contact with and fixed to the motor case 30. There is no magnetic yoke. Therefore, as shown in FIG. 8B, the magnetic flux F flows through the teeth body 14a of the teeth member 14 along the longitudinal direction (that is, the radial direction R). Therefore, the generation of leakage flux can be suppressed. Further, since the bolt 42 penetrates the fastening portion 14b protruding from the tooth body 14a, it is out of the path (magnetic path) through which the magnetic flux F passes. Therefore, it is possible to suppress the occurrence of eddy current loss in the bolt 42. From these facts, according to the motor 10 of this embodiment, the efficiency of the motor 10 can be improved by reducing the iron loss.

FIG. 9 is a perspective view showing a modified example in which the tooth member 14 is fixed to the motor case 30 by using the ring member 50. Further, FIG. 10 is a cross-sectional view similar to FIG. 6B, showing a state in which the bolt 42 is inserted into the insertion hole of the ring member 50 shown in FIG. 9 and the tooth member 14 is fastened to the motor case 30. Is.

As shown in FIGS. 9 and 10, each tooth member 14 may be fixed to the motor case 30 by a bolt 42 via a ring member 50. The ring member 50 is preferably formed of a non-magnetic metal material such as an aluminum alloy or stainless steel. The ring member 50 is formed with one through hole 52 corresponding to each tooth member 14. Then, one bolt 42 is inserted into the through hole 52 and tightened into the female screw hole 40 of the motor case 30. At this time, the ring member 50 is fitted between the inner coil 18 and the outer coil 20 and bends by pressing the inclined fastening portion 14b. As a result, as described with reference to FIG. 7, the tooth member 14 can be securely fastened and fixed in a state of being accurately positioned and without rattling. Further, in this case, since each tooth member 14 is fixed by one bolt 42, the assemblability of the stator 16 is improved.

<Second Embodiment>
FIG. 11A is a perspective view showing one of a large number of magnetic steel plates constituting the teeth member 19 in the motor 10A having a double rotor structure according to the second embodiment, and FIG. 11B is a magnetic steel plate. It is a perspective view which shows the tooth member 19 which is formed by laminating.

As shown in FIG. 11A, the magnetic steel plate 17 constituting the teeth member 19 in the present embodiment has, for example, a main body portion 17a having a storage method shape and projecting to both side edges at the central portion in the longitudinal direction of the main body portion 17a. It has a pair of projecting pieces 17b. In the present embodiment, the pair of projecting pieces 17b are flush with the main body portion 17a without being bent. Further, through holes 17c are formed in each of the pair of projecting pieces 17b. The through hole 17c is for making the projecting piece 17b easy to bend. As shown in FIG. 11B, the teeth member 19 is configured by laminating a large number of such magnetic steel plates 17 and integrating them by caulking or the like.

As shown in FIG. 11B, the teeth member 19 is formed by stacking a main body 17a of a magnetic steel plate 17 to form a tooth main body 19a and a pair of projecting pieces 17b laminated to form a pair of fittings. It has a part 19b. Each fitting portion 19b has a deflection absorbing hole 19c formed by connecting the through holes 17c in the stacking direction S. Further, the tip of the fitting portion 19b has a substantially triangular shape when viewed from the side when viewed from the stacking direction S. Here, when the teeth member 19 is assembled as the stator 16, the longitudinal direction of the teeth body 19a coincides with the radial direction R of the motor 10, the lateral direction thereof coincides with the axial direction X of the motor 10, and the stacking direction S. Corresponds to the circumferential direction C of the motor 10.

FIG. 12 is a perspective view showing a state in which the inner coil 18 and the outer coil 20 are assembled to the tooth member 19 of FIG. 11B. As shown in FIG. 12, in the teeth body 19a of the teeth member 19, the inner coil 18 is assembled to one end 19d in the longitudinal direction, and the outer coil 20 is attached to the other end 19e in the longitudinal direction (see FIG. 11B). Is assembled. As a result, the coils 18 and 20 are wound around the tooth member 19. The point that the circumferential width of the outer coil 20 is formed larger than the circumferential width of the inner coil 18 is the same as in the case of the first embodiment.

FIG. 13 is a partial plan view showing the motor case 30A in the second embodiment. A plurality of fitting recesses 31 are formed on the surface of the motor case 30A at equal pitches in the circumferential direction. The fitting recess 31 has a shape corresponding to the tip of the fitting portion 19b of the tooth member 19 being fitted, specifically, a bottom surface recessed in a substantially V shape. Further, a female screw hole 40 is formed on the surface of the motor case 30A. A plurality of female screw holes 40 are formed at intervals in the circumferential direction.

FIG. 14 is a perspective view showing the ring member 50A in the second embodiment. In the motor 10A of the present embodiment, the tooth member 19 is fastened and fixed to the motor case 30A by using the ring member 50A, as in the modification of the first embodiment described with reference to FIG. As shown in FIG. 14, a plurality of fitting recesses 51 are formed at equal pitches in the circumferential direction on one surface of the ring member 50A forming an annular shape. The fitting recess 51 has a shape corresponding to the tip of the fitting portion 19b of the tooth member 19 being fitted, specifically, a bottom surface recessed in a substantially V shape. Further, the ring member 50A is formed with a plurality of through holes 52 at intervals in the circumferential direction.

FIG. 15 is a perspective view showing a state when the tooth member 19 to which the coils 18 and 20 of FIG. 12 are assembled is fastened to the motor case 30A by the ring member 50A. Further, FIG. 16 is a cross-sectional view taken along the line BB in FIG. As shown in FIGS. 15 and 16, the tooth member 19 to which the inner coil 18 and the outer coil 20 are assembled is placed on the motor case 30A. At this time, the fitting portion 19b on one side (lower side) of the tooth member 19 is fitted into the fitting recess 31 of the motor case 30A. In this way, all the tooth members 19 constituting the stator 16A are arranged in an annular shape.

Then, the ring member 50A is assembled. The ring member 50A is arranged in a state in which the fitting portion 19b on the other side (upper side) of the tooth member 19 is fitted in the fitting recess 51. Then, the bolt 42 is inserted into the through hole 52 of the ring member 50A, and the tip of the screw portion is tightened into the female screw hole 40 of the motor case 30A. As a result, the tooth member 19 is pressed by the ring member 50A and fastened and fixed to the motor case 30A. In the present embodiment, the end face of the fitting portion 19b fitted in the fitting recess 31 of the motor case 30A in the teeth member 19 corresponds to one end face in the axial direction of the teeth member in the present invention.

According to the motor 10A of the present embodiment, the tooth member 19 is fastened and fixed only by abutting and fixing the end face of one fitting portion 19b, which is the end face in the axial direction, to the motor case 30A. There is no magnetic yoke that magnetically connects the tooth members 19 to each other. Therefore, when operating as the motor 10, it is possible to suppress the generation of leakage flux from the tooth member 19. Further, since the bolt 42 is located away from the tooth body 19a, it is possible to effectively suppress the occurrence of eddy current loss in the bolt 42. From these facts, according to the motor 10A of this embodiment, the motor efficiency can be improved by reducing the iron loss.

Further, the pair of fitting portions 19b are fitted and fixed to the fitting recess 31 of the motor case 30A and the fitting recess 51 of the ring member 50A, so that the tooth member 19 is accurately positioned in the circumferential direction. Further, the ring member 50A presses the fitting portion 19b of the tooth member 19, so that the fitting portion 19b is bent. By acting the elastic rebound force due to this bending, the tooth member 19 can be fastened and fixed to the motor case 30A in a stable state without rattling.

The present invention is not limited to the above-described embodiments and modifications thereof, and various changes and improvements can be made within the matters described in the claims of the present application and the equivalent scope thereof. Needless to say.

10,10A double rotor structure motor, 12 rotating shafts, 14,19 tooth members, 14a, 19a teeth body, 14b fastening part, 14c bolt insertion hole, 14d, 19d one end, 14e, 19e other end, 15 , 17 Magnetic steel plate, 15a, 17a main body, 15b, 17b projecting piece, 15c, 17c through hole, 16, 16A stator, 18 inner coil, 19b fitting part, 19c deflection absorption hole, 20 outer coil, 21 coil, 22 Inner rotor, 24 outer rotor, 26,28 permanent magnet, 30,30A motor case, 31,51 fitting recess, 32 fixing part, 34 annular part, 36 protrusion, 38 circumferential recess, 40 female screw hole, 42 bolts, 50, 50A ring member, 52 through hole, C circumferential direction, F magnetic flux, R radial direction, S stacking direction, X-axis direction.

Claims (1)

A stator in which a plurality of tooth members are arranged in an annular shape around a rotation axis and a coil is wound around the tooth member,
A motor having a double rotor structure, which is provided on the inner peripheral side and the outer peripheral side of the stator and includes an inner rotor and an outer rotor that can rotate with respect to the stator.
The teeth member has a main body to which the coil is assembled and a fastening portion formed so as to project in the circumferential direction from the main body and having a bolt through hole, and the bolt penetrates through the bolt through hole to fasten the teeth member. an end face in the axial direction of the motor by the parts and the motor casing is fastened is fixed in contact with the said motor case, a yoke of magnetic material for coupling the tooth members together in the circumferential direction does not exist, the two A motor with a heavy rotor structure.

Images