JP6100538B2 - motor - Google Patents

Description

  The present invention relates to a motor.

  Conventionally, for the purpose of suppressing the cogging torque in order to reduce the vibration, there has been known one in which a groove is formed in the stator (for example, see Patent Document 1).

JP 2005-94901 A

  By the way, in the motor as described above, a groove is formed to suppress the cogging torque. However, when the rotor position is held using the cogging torque, it is counterproductive to suppress the cogging torque as described above.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a motor capable of improving the holding force of the rotor by cogging torque.

Motor to achieve the above SL problem, there teeth extending radially circumferential direction on the stator core having a plurality, and a stator having a winding which is wound around the teeth, the motor comprising a rotor having a plurality of magnetic poles The number of poles of the rotor is 2n (where n is a natural number), the number of slots of the stator is 3n, and the ratio of the number of poles to the number of slots is 2: 3. A groove portion extending in the axial direction is formed at substantially the center in the circumferential direction, and each of the rotors has a plurality of claw-shaped magnetic poles on the outer peripheral portion of the substantially disk-shaped core base at equal intervals on the outer side in the radial direction. Between the first and second rotor cores that are projected and extended in the axial direction, and in which the claw-shaped magnetic poles are alternately arranged in the circumferential direction with the core bases facing each other, and the axial direction between the core bases Arranged, By being magnetized in the axial direction, the claw-shaped magnetic pole of the first rotor core functions as a first magnetic pole, and the field magnet that functions the claw-shaped magnetic pole of the second rotor core as a second magnetic pole is adjacent to An interpole magnet disposed between the claw-shaped magnetic poles of the matching first rotor core and the claw-shaped magnetic poles of the second rotor core, wherein the rotor is adjacent to the first rotor core. The circumferential direction width of the claw-shaped magnetic pole of the second rotor core and the claw-shaped magnetic pole of the second rotor core, and the circumferential width of the interpolar magnet sandwiches the groove portion at the tip of the teeth. It is smaller than the circumferential width of one of the portions on both sides.
According to this configuration, in the motor configured so that the ratio of the number of poles to the number of slots is 2: 3, the groove is formed at the substantially center in the circumferential direction on the surface of the tip of the tooth, thereby obtaining the configuration shown in FIGS. As shown, the cogging torque can be improved. Thereby, the retention strength of the rotor can be increased. Further, in a so-called Landel-type rotor in which a field magnet is sandwiched between first and second rotor cores having claw-shaped magnetic poles, the cogging torque can be increased to improve the holding power of the rotor.

  In the motor, when the angle formed by the groove center line passing through the circumferential center of the groove and the tooth center line passing through the circumferential center of the teeth is a, the groove is −24 / n ≦ a ≦. It is preferably formed so as to be in the range of 24 / n.

  According to this configuration, the cogging torque can be improved as shown in FIG. 3A by setting the range of approximately −24 / n ≦ a ≦ 24 / n as the range of the substantially center in the circumferential direction described above. The holding power of the rotor can be increased.

In the motor, it is preferable that the groove part has an angle a of 0 degrees formed by the groove center line and the teeth center line.
According to this configuration, the groove portion is formed at the angle a = 0, that is, at the center in the circumferential direction of the teeth, so that the cogging torque can be further improved as shown in FIG. It can be further increased.

  In the motor, when the circumferential width of the groove is b and the opening width of the slot is W, the groove may be formed in a range of 0.25 ≦ b / W ≦ 2.0. preferable.

  According to this configuration, by forming the groove so as to be in the range of 0.25 ≦ b / W ≦ 2.0, the cogging torque can be improved as shown in FIG. Can be increased.

In the motor, it is preferable that the groove is formed so as to satisfy a range of 1.5 ≦ b / W ≦ 2.0.
According to this configuration, by forming the groove so as to be in the range of 1.5 ≦ b / W ≦ 2.0, the contribution of cogging torque improvement is high as shown in FIG. More preferably, the cogging torque can be improved to increase the holding force of the rotor.

  In the motor, when the radial length of the groove is c and the radial length of the tooth tip is H, the groove is in a range of 0.0 <c / H ≦ 2.0. Preferably it is formed.

  According to this configuration, by forming the groove so as to be in the range of 0.0 <c / H ≦ 2.0, the cogging torque can be improved as shown in FIG. Can be increased.

  According to the motor of the present invention, the holding force of the rotor by the cogging torque can be improved.

It is a top view of the motor in one embodiment. It is the schematic for demonstrating teeth. (A) is explanatory drawing for demonstrating the change of the cogging torque by the difference in the groove part formation position with respect to teeth, (b) is a figure for demonstrating the change of the torque ratio by the difference in the groove part formation position with respect to teeth. . (A) is explanatory drawing for demonstrating the change of cogging torque by the difference in the circumferential direction width | variety of a groove part, (b) is for demonstrating the change of the torque ratio by the difference in the circumferential direction length (width) of a groove part. It is explanatory drawing of. (A) is explanatory drawing for demonstrating the change of the cogging torque by the difference in radial direction length (depth) of a groove part, (b) is the torque ratio by the difference in radial direction length (depth) of a groove part. It is explanatory drawing for demonstrating the change of this. It is a top view of the motor in another example. It is a perspective view of the rotor in another example. It is a top view of the motor provided with the rotor in the same as the above. It is sectional drawing of the rotor in the same as the above.

Hereinafter, an embodiment of the motor will be described.
As shown in FIG. 1, the motor 10 of the present embodiment is configured by arranging a rotor 12 on the radially inner side of a substantially annular stator 11.

  As shown in FIG. 1, the rotor 12 has a substantially annular rotor core 22 made of a magnetic metal material fixed to an outer peripheral surface of a rotating shaft 21 rotatably supported by a bearing (not shown), for example. On the outer periphery of the rotor core 22, magnets 23 a having a radially outer magnetization of N poles and magnets 23 b having a radially outer magnetization of S poles are alternately arranged in the circumferential direction. Each of the magnets 23a and 23b has a circumferential width that is substantially constant, and is disposed on the outer peripheral portion of the rotor core 22 with a constant gap in the circumferential direction. Four magnets 23a and 23b are provided. For this reason, the rotor 12 of this embodiment has a total of eight magnetic poles (the number of poles).

  As shown in FIG. 1, the stator core 31 of the stator 11 has a total of twelve teeth 33 extending in a radial direction from the annular portion 32. Therefore, the number of slots 34 formed between the teeth 33 is also twelve. That is, the number of poles of the rotor 12 is 2n (where n is a natural number, 4 in this embodiment), the number of slots 34 (slot number) is 3n, and the ratio of the number of poles to the number of slots is 2: 3. It is configured as follows.

  As shown in FIG. 1, the teeth 33 are formed at equal intervals in the circumferential direction, and U-phase, V-phase, and W-phase coils 35 are wound around each tooth 33 in a concentrated manner. Protrusions 33 a projecting on both sides in the radial direction are formed on the tip side of each tooth 33, and a tip surface 33 b (radial inner side surface) of each tooth 33 is a circle centering on the axis L of the motor 10. It has an arc shape. In addition, the front end surface 33b of the teeth 33 is formed from one projecting portion 33a to the other projecting portion 33a.

  As shown in FIG. 1, a tooth side groove portion 40 is formed on the tip end surface 33 b of each tooth 33. Teeth-side groove portion 40 is formed such that a groove having a concave shape in the radial direction is continuously formed along one axial direction (the direction in which axis L1 extends). Each tooth side groove 40 is formed in substantially the same shape at the same position in the circumferential direction of each tooth 33.

  As shown in FIG. 2, the teeth side groove portion 40 has −24 / n ≦ a ≦, where a (°) is an angle formed by the circumferential center line L1 of the teeth 33 and the circumferential center line L2 of the teeth side groove portion 40. It is set to be in the range of 24 / n. Here, since n is 4 (n = the number of poles / 2 or n = the number of slots / 3), the teeth side groove portion 40 is in a range of −6 ≦ a ≦ 6. More preferably, the teeth side groove portion 40 is formed so that a circumferential center line L2 which is a circumferential center thereof coincides with the circumferential center line L1 of the teeth, that is, at the circumferential center of the teeth. By setting it as such a structure, the teeth 33 of this embodiment are comprised so that it may become line symmetrical with respect to the circumferential direction centerline L1.

  Moreover, the teeth side groove part 40 has a pair of side surface parts 41 and 42 which oppose the circumferential direction. When the length (the circumferential width of the teeth side groove portion 40) between one side surface portion 41 and the other side surface portion 42 of the teeth side groove portion 40 is b and the opening width of the slot 34 is W, the teeth The side groove part 40 is set to be in a range of 1.5 ≦ b / W ≦ 2.0. Incidentally, the opening width W of the slot 34 is the length in the circumferential direction of the protrusions 33a adjacent in the circumferential direction among the teeth 33 adjacent in the circumferential direction.

  Further, the tooth side groove portion 40 has a radial length (depth of the tooth side groove portion 40) as c, and a radial length (thickness) of the protruding portion 33a as the tip portion of the tooth 33 as H. The teeth side groove 40 is set to be in the range of 0.0 <c / H ≦ 0.25.

Next, the operation of the motor 10 will be described.
Here, a change in cogging torque due to a difference in groove forming position with respect to the teeth is shown in FIG. 3 (a), and a change in the torque ratio due to a difference in groove forming position with respect to the teeth is shown in FIG. 3 (b). In FIGS. 3A and 3B, the thick line indicates the case of “with groove” in which the teeth side groove portion 40 is formed, and the broken line indicates the case of “without groove” in which the teeth side groove portion 40 is not formed. In addition, the teeth side groove part 40 in the case of “with groove” is set so that b / W = 0.75 and c / H = 0.5.

  As shown in FIG. 3A, the cogging torque is improved by forming the tooth side groove portion 40 in a range of −6 ≦ a ≦ 6 as compared with the case where the tooth side groove portion 40 is not formed. . In particular, when a = 0, the cogging torque is increased most.

  Further, as shown in FIG. 3B, when the torque ratio when the teeth side groove portion 40 is not formed is 100%, the teeth side groove portion is in a range of −6 ≦ a ≦ 6 as described above. When 40 is formed, although the torque ratio slightly decreases, approximately 95% or more can be secured.

  Here, the change in cogging torque due to the difference in the circumferential width of the groove is shown in FIG. 4A, and the change in torque ratio due to the difference in the circumferential width of the groove is shown in FIG. 4B. 4 (a) and 4 (b), the thick line indicates the case of “with groove” in which the teeth side groove portion 40 is formed, and the broken line indicates the case of “without groove” in which the teeth side groove portion 40 is not formed. In addition, the teeth side groove part 40 in the case of “with groove” is set so that a = 0 and c / H = 0.5.

  As shown in FIG. 4A, by forming the tooth side groove portion 40 in a range of 0 <b / W ≦ 2.0, the cogging torque is reduced as compared with the case where the teeth side groove portion 40 is not formed. improves. Moreover, a higher cogging torque can be obtained by forming the teeth side groove 40 so as to be in the range of 0.25 ≦ b / W ≦ 2.0. In particular, in the range of 1.5 ≦ b / W ≦ 2.0, the amount of increase in the cogging torque with respect to the change amount of b / W is significant, and the range of 1.5 ≦ b / W ≦ 2.0 is satisfied. By forming the teeth side groove 40, the contribution of the cogging torque increase is high.

  Further, as shown in FIG. 4B, when the torque ratio when the teeth side groove portion 40 is not formed is 100%, as described above, the range is 0 <b / W ≦ 2.0. When the teeth side groove portion 40 is formed, although the torque ratio slightly decreases, it is possible to ensure approximately 90% or more. Further, in the range of 1.5 ≦ b / W ≦ 2.0, the reduction ratio of the torque ratio with respect to the b / W variation is small.

  Here, the change in cogging torque due to the difference in the radial length (depth) of the groove is shown in FIG. 5A, and the change in torque ratio due to the difference in the radial length (depth) of the groove is shown in FIG. Shown in b). 5 (a) and 5 (b), the thick line indicates the case of “with groove” in which the teeth side groove portion 40 is formed, and the broken line indicates the case of “without groove” in which the teeth side groove portion 40 is not formed. In addition, the teeth side groove part 40 in the case of “with groove” is set so that a = 0 and b / W = 1.0.

  As shown in FIG. 5 (a), cogging is achieved by forming the tooth side groove portion 40 in a range of 0.0 <c / H ≦ 2.5, as compared with the case where the tooth side groove portion 40 is not formed. Torque is improved. In particular, in the range of 0.0 <c / H ≦ 2.0, the amount of increase in the cogging torque with respect to the change amount of c / H is remarkable, and in the range of 2.0 <c / H ≦ 2.5, c / H The amount of increase in cogging torque with respect to the amount of change is suppressed. For this reason, the contribution of cogging torque increase is high by forming the teeth side groove part 40 so that it may become the range of 0.0 <c / H <= 2.0. Incidentally, as shown in FIG. 5 (b), when the torque ratio when the teeth side groove 40 is not formed is 100%, the teeth side groove is set to be in the range of 0.0 <c / H ≦ 1.0. When 40 is formed, although the torque ratio slightly decreases, approximately 90% or more can be secured. Further, in the range of 0.0 <c / H ≦ 0.25, the reduction ratio of the torque ratio with respect to the change amount of c / H is small.

Next, the effect of this embodiment will be described.
(1) In the motor 10 configured such that the ratio of the number of poles to the number of slots is 2: 3, the teeth side groove portion 40 is provided at the substantially center in the circumferential direction of the distal end portion of the teeth 33 and the distal end surface 33b as the distal end portion surface. By forming, the cogging torque can be improved as shown in FIGS. Thereby, the retention strength of the rotor 12 can be increased.

  (2) As a range of the above-described substantially center in the circumferential direction, a range of −24 / n ≦ a ≦ 24 / n (a range of −24 / 6 ≦ a ≦ 24/6) is obtained. As shown, the cogging torque can be improved, and the holding force of the rotor 12 can be increased. By forming the teeth side groove 40 at the angle a = 0, that is, at the center in the circumferential direction of the teeth 33, the cogging torque can be further improved, as shown in FIG. Can be increased.

  (3) By forming the teeth side groove 40 so as to be in the range of 0.25 ≦ b / W ≦ 2.0, the cogging torque can be improved as shown in FIG. You can increase your power.

  (4) By forming the teeth side groove 40 so as to be in the range of 1.5 ≦ b / W ≦ 2.0, the contribution of cogging torque improvement is high as shown in FIG. More preferably, the cogging torque can be improved to increase the holding force of the rotor.

  (5) By forming the teeth side groove 40 so as to be in the range of 0.0 <c / H ≦ 2.0, the cogging torque can be improved as shown in FIG. You can increase your power.

In addition, you may change the said embodiment as follows.
In the above embodiment, the number of poles of the rotor 12 is 8 and the number of slots of the stator 11 is 12. However, the present invention is not limited to this. If the ratio between the number of poles and the number of slots is 2: 3, the number of poles of the rotor 12 and the number of slots of the stator 11 may be changed as appropriate.

  In the above embodiment, the tooth side groove portion 40 formed in the stator 11 is configured such that the angle a formed by the circumferential center line L2 of the groove portion 40 and the circumferential center line L1 of the teeth 33 is 0 degree. However, you may change suitably in the range of -24 / n <= a <= 24 / n.

  In the above embodiment, the teeth side groove portion 40 formed in the stator 11 has a range of 1.5 ≦ b / W ≦ 2.0, where b is the circumferential width of the groove portion and W is the opening width of the slot. However, it may be appropriately changed within the range of 0.25 ≦ b / W ≦ 2.0 or 0 <b / W ≦ 2.0.

  In the above embodiment, a motor having a so-called full magnet type rotor is employed in which N-pole magnets 23a and S-pole magnets 23b are alternately arranged in the circumferential direction. However, the present invention is not limited to this. .

  For example, as shown in FIG. 6, a so-called continuous pole type (half magnet type) rotor in which salient poles of a rotor core arranged with a gap (gap) between magnets is used as a substitute for a magnet is provided. Also good. As shown in FIG. 6, in the rotor 50 of this configuration, four N-pole magnets 23 a are arranged at equal intervals in the circumferential direction of the outer peripheral portion of the rotor core 51, and the protrusion formed integrally with the outer peripheral portion of the rotor core 51. The pole 52 is disposed with a gap K between the magnets 23a. That is, the magnets 23a and the salient poles 52 are alternately arranged at equal angular intervals, and the rotor 50 is an 8-pole so-called continuous pole type that causes the salient poles 52 to function as S poles with respect to the N pole magnets 23a. It is configured. The gap K has a circumferential width W2 of either one of the protrusions 33a of the teeth 33 and one of the side surfaces 41 and 42 of the teeth side groove 40 that is close to the protrusion 33a in the circumferential direction. It is formed to be equal to or less than the distance W1 in the circumferential direction. Further, when any one of the gaps K is arranged to wrap when the distance W1 is viewed in the radial direction, the other gaps K are also wrapped with the distance W1 in the radial direction.

  For example, a so-called permanent magnet is provided that includes a rotor core that is combined with a plurality of claw-shaped magnetic poles in the circumferential direction, and an annular magnet as a field magnet is disposed between them to alternately function the claw-shaped magnetic poles as different magnetic poles. A magnet field Randell type rotor may be adopted.

  As shown in FIGS. 7 to 9, the rotor 60 of this configuration includes first and second rotor cores 61 and 62, an annular magnet 63 as a field magnet, back auxiliary magnets 64 and 65, an interpole magnet 66, 67.

  The first rotor core 61 includes a plurality of (five in the present embodiment) first claw-shaped magnetic poles 61b that protrude radially outwardly at equal intervals on the outer peripheral portion of a substantially disc-shaped first core base 61a. It is formed extending in the direction.

  The second rotor core 62 has the same shape as the first rotor core 61, and a plurality of second claw-shaped magnetic poles 62b are projected radially outwardly at equal intervals on the outer periphery of a substantially disk-shaped second core base 62a. And extending in the axial direction. The second rotor core 62 is axially disposed between the first core base 61a and the second core base 62a such that the second claw-shaped magnetic poles 62b are disposed between the corresponding first claw-shaped magnetic poles 61b. The annular magnet 63 (see FIG. 4) is disposed (sandwiched) between the first rotor core 61 and the annular magnet 63 (see FIG. 4).

  As shown in FIG. 9, the outer diameter of the annular magnet 63 is set to be the same as the outer diameter of the first and second core bases 61a and 62a, and the first claw-shaped magnetic pole 61b is used as the first magnetic pole (this embodiment). Is magnetized in the axial direction so that the second claw-shaped magnetic pole 62b functions as a second magnetic pole (S pole in this embodiment). Therefore, the rotor 60 of this configuration is a so-called Landell type rotor using the annular magnet 63 as a field magnet. In the rotor 60, first claw-shaped magnetic poles 61b that are N poles and second claw-shaped magnetic poles 62b that are S poles are alternately arranged in the circumferential direction, and the number of magnetic poles is eight (as in the above embodiment). The number of pole pairs is 4).

  As shown in FIG. 9, a back auxiliary magnet 64 is disposed between the back surface 61c (the radially inner surface) of each first claw-shaped magnetic pole 61b and the outer peripheral surface 62d of the second core base 62a. The back auxiliary magnet 64 has a substantially fan-shaped cross section in the direction perpendicular to the axis, and the second core base 62a has a side that abuts on the back surface 61c of the first claw-shaped magnetic pole 61b as the N pole having the same polarity as the first claw-shaped magnetic pole 61b. Is magnetized so that the side in contact with the outer peripheral surface 62d becomes the S pole having the same polarity as the second core base 62a.

  Further, similarly to the first claw-shaped magnetic pole 61b, a back auxiliary magnet 65 is arranged between the back surface 62c of each second claw-shaped magnetic pole 62b and the outer peripheral surface 61d of the first core base 61a. The back auxiliary magnet 65 has a fan-shaped cross section in the direction perpendicular to the axis, and is magnetized so that the side in contact with the back surface 62c is an S pole and the side in contact with the outer peripheral surface 61d of the first core base 61a is an N pole. . As the back auxiliary magnets 64 and 65, for example, ferrite magnets can be used.

As shown in FIG. 7, interpolar magnets 66 and 67 are disposed between the circumferential directions of the first claw-shaped magnetic pole 61b and the second claw-shaped magnetic pole 62b.
Further, the interpolar magnets 66 and 67 have a circumferential width W3 of any one of the protruding portions 33a of the teeth 33 and the side surface portions 41 and 42 of the tooth side groove portions 40 that are close to the protruding portions 33a in the circumferential direction. On the other hand, it is formed to be equal to or less than the distance W1 in the circumferential direction.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 11 ... Stator, 12, 50, 60 ... Rotor, 22, 51 ... Rotor core, 23a, 23b ... Magnet, 31 ... Stator core, 33 ... Teeth, 33b ... Tip part and tip surface as tip part surface, 34 DESCRIPTION OF SYMBOLS ... Slot, 35 ... Coil as winding, 40 ... Teeth side groove part, 52 ... Salient pole, 61 ... 1st rotor core, 62 ... 2nd rotor core, a ... Angle, W ... Opening width.

Claims (6)

A stator core having a plurality of teeth extending in the circumferential direction in the circumferential direction, a stator having a winding wound around the teeth, and a rotor having a plurality of magnetic poles,
The number of poles of the rotor is 2n (where n is a natural number), the number of slots of the stator is 3n, and the ratio of the number of poles to the number of slots is 2: 3.
One groove portion along the axial direction is formed at the approximate center in the circumferential direction on the tip portion surface of each tooth,
The rotor is
A plurality of claw-shaped magnetic poles project radially outward and extend in the axial direction on the outer periphery of each substantially disk-shaped core base, and the claw-shaped magnetic poles are formed with the core bases facing each other. First and second rotor cores arranged alternately in the circumferential direction;
The claw-shaped magnetic poles of the first rotor core function as the first magnetic poles by being arranged between the axial directions of the core bases and magnetized in the axial direction, and the claw-shaped magnetic poles of the second rotor core are made to function as the first magnetic poles. A field magnet that functions as a second magnetic pole;
An interpole magnet disposed between the claw-shaped magnetic poles of the adjacent first rotor core and the claw-shaped magnetic pole of the second rotor core; and
With
The rotor has a circumferential width between the claw-shaped magnetic poles of the adjacent first rotor core and the claw-shaped magnetic pole of the second rotor core, and a circumferential width of the interpole magnet is equal to that of the teeth. A motor characterized by being smaller than one circumferential width of portions on both sides in the circumferential direction across the groove at the tip. The motor according to claim 1 ,
When the angle formed by the groove center line passing through the circumferential center of the groove and the tooth center line passing through the circumferential center of the teeth is a,
The motor is characterized in that the groove is formed to be in a range of −24 / n ≦ a ≦ 24 / n. The motor according to claim 2 ,
The motor according to claim 1, wherein the groove part has an angle a of 0 degrees formed by the groove center line and the tooth center line. In the motor according to any one of claims 1 to 3 ,
When the circumferential width of the groove is b and the opening width of the slot is W,
The said groove part is formed so that it may become the range of 0.25 <= b / W <= 2.0, The motor characterized by the above-mentioned. The motor according to claim 4 ,
The said groove part is formed so that it may become the range of 1.5 <= b / W <= 2.0, The motor characterized by the above-mentioned. In the motor according to any one of claims 1 to 5 ,
When the radial length of the groove is c and the radial length of the tip of the tooth is H,
The said groove part is formed so that it may become the range of 0.0 <c / H <= 2.0. The motor characterized by the above-mentioned.