JP5394890B2 - motor - Google Patents

Description

  The present invention relates to a motor having a rotor adopting a continuous pole type structure.

  Conventionally, in a motor, for example, as shown in Patent Document 1, a plurality of magnets of one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the core are arranged between the magnets, One having a so-called consequent pole type rotor in which the salient pole functions as the other magnetic pole is known.

JP 9-327139 A

  By the way, a rotor having a consequent pole type structure as in Patent Document 1 is composed of a magnetic pole in which a magnet having a magnetic flux forcing force (induction) and a salient pole without a magnetic flux forcing force are mixed. Magnetic imbalance is likely to occur, which leads to deterioration in rotational performance such as increased vibration due to the generation of cogging torque.

  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 reducing vibration and improving rotational performance.

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that a plurality of magnets of one magnetic pole are arranged in the circumferential direction of the rotor core, and the salient poles integrally formed with the rotor core have gaps between the magnets. A rotor arranged to function as the other magnetic pole, and a stator having a plurality of teeth provided at equal intervals in the circumferential direction and facing the magnet and the salient pole in the radial direction. A first auxiliary groove having a pair of side surfaces facing each other in the circumferential direction is recessed in a surface of the salient pole facing the teeth portion, and the circumferential center line of the salient pole The angle C1 centered on the motor axis to the side surface portion on the circumferential centerline side in the first auxiliary groove is the opening angle between the circumferential ends of the teeth portion tip centered on the axis. The opening angle between the circumferential ends of the salient poles around the axis as B, and characterized in that it is configured to satisfy C1 = A-B / 2.

  In the present invention, since the first auxiliary groove is formed so as to satisfy C1 = A−B / 2, the tooth portion and the salient pole face each other in the radial direction when the rotor rotates, and the periphery of the tip of the tooth portion is When one end in the direction overlaps with one end in the circumferential direction of the salient pole in the radial direction, the other end in the circumferential direction of the tooth portion overlaps in a radial direction with the side surface portion on the circumferential center line side of the salient pole in the first auxiliary groove. At this time, the cogging torque generated at the other circumferential end of the tooth portion is a canceling component that suppresses the cogging torque (main component) generated at one circumferential end of the tooth portion overlapping the circumferential end of the salient pole. The cogging torque generated as a whole can be reduced, and the rotational performance of the rotor can be improved.

  According to a second aspect of the present invention, in the motor according to the first aspect, a pair of the first auxiliary grooves are arranged in parallel in the circumferential direction so as to be symmetrical with respect to the circumferential center line of the salient pole. It is characterized by that.

In the present invention, since the first auxiliary grooves are provided in pairs corresponding to both ends in the circumferential direction of the salient poles, the cogging torque can be further reduced.
According to a third aspect of the present invention, in the motor according to the first or second aspect, a ratio W1 / T between a circumferential width W1 of the first auxiliary groove and a spacing T between teeth portions adjacent in the circumferential direction is , 0 <W1 / T <3.5.

  In the present invention, the ratio W1 / T between the circumferential width W1 of the first auxiliary groove and the interval T between the teeth adjacent in the circumferential direction is set within the range of 0 <W1 / T <3.5. . As a result, the cogging torque can be reduced (see FIG. 4), which can contribute to improvement of the rotational performance of the rotor.

  According to a fourth aspect of the present invention, a plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles are arranged on the other side. A motor comprising a rotor configured to function as a magnetic pole and a stator having a plurality of teeth provided at equal intervals in the circumferential direction and having a plurality of teeth portions radially opposed to the salient poles. A second auxiliary groove having a pair of side surfaces facing in the circumferential direction is recessed in a surface of the pole facing the teeth portion, and the second auxiliary groove in the second auxiliary groove from the circumferential center line of the salient pole. The angle C2 centered on the axis of the motor up to the side surface opposite to the circumferential center line is A, and the opening angle between the circumferential ends of the teeth section centered on the axis is A, and the axis is centered. The opening angle between the circumferential ends of the salient pole is B, and the opening angle between the magnet and the salient pole with the axis as the center is D, so that C2 = A−B / 2−D is satisfied. It is characterized by that.

  In the present invention, since the second auxiliary groove is formed so as to satisfy C2 = A−B / 2−D, one end in the circumferential direction of the tip of the teeth portion is one end in the circumferential direction of the magnet adjacent to the opposing salient pole. When overlapping in the radial direction, the other circumferential end of the teeth portion overlaps in the radial direction with the side surface portion opposite to the circumferential center line of the salient pole in the second auxiliary groove. At this time, the cogging torque generated at the other circumferential end of the teeth portion is a canceling component that suppresses the cogging torque (main component) generated at one circumferential end of the teeth portion that overlaps one circumferential end of the magnet. The cogging torque generated in the above can be reduced, and the rotational performance of the rotor can be improved.

  According to a fifth aspect of the present invention, in the motor according to the fourth aspect, a pair of the second auxiliary grooves are arranged in parallel in the circumferential direction so as to be symmetrical with respect to the circumferential center line of the salient pole. It is characterized by that.

  In the present invention, a pair of the second auxiliary grooves are arranged in parallel in the circumferential direction so as to be axisymmetric with respect to the circumferential center line of the salient pole. That is, since the second auxiliary grooves formed on the salient poles are provided in pairs corresponding to the circumferential ends of the magnets adjacent to the salient poles, the cogging torque can be further reduced.

  According to a sixth aspect of the present invention, in the motor according to the fourth or fifth aspect, a ratio W2 / T between a circumferential width W2 of the second auxiliary groove and a spacing T between teeth portions adjacent in the circumferential direction is , 0 <W2 / T <1.2.

  In the present invention, the ratio W2 / T between the circumferential width W2 of the second auxiliary groove and the interval T between the teeth adjacent in the circumferential direction is set within the range of 0 <W2 / T <1.2. . As a result, the cogging torque can be reduced (see FIG. 4), which can contribute to improvement of the rotational performance of the rotor.

  According to the seventh aspect of the present invention, a plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles are arranged on the other side. A motor comprising: a rotor configured to function as a magnetic pole; and a stator having a plurality of teeth provided at equal intervals in the circumferential direction and facing the magnet and the salient poles in a radial direction. The first auxiliary groove according to any one of claims 1 to 3 and the second auxiliary groove according to any one of claims 4 to 6 are provided.

In the present invention, since both the first auxiliary groove and the second auxiliary groove are provided on the salient pole of the rotor, the cogging torque can be further reduced.
According to the eighth aspect of the present invention, a plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles are arranged on the other side. A motor configured to function as a magnetic pole, and a stator having a plurality of teeth provided at equal intervals in the circumferential direction and having a plurality of teeth portions radially opposed to the magnet and the salient poles, A tooth side auxiliary groove having a pair of side surfaces facing in the circumferential direction is recessed in a tip surface facing the magnet and the salient pole in the teeth portion, and the teeth side auxiliary from the circumferential center line of the teeth portion. An angle C3 centered on the axis of the motor to the side surface opposite to the circumferential center line in the groove is a circumferential direction of the tip of the teeth portion centered on the axis. The opening angle between the end portions is A, the opening angle between the circumferential ends of the salient pole around the axis is B, and the angle between the circumferential center lines of the teeth portions adjacent in the circumferential direction is E, It is configured to satisfy C3 = A / 2 + E−B.

  In the present invention, since the tooth side auxiliary groove is formed so as to satisfy C3 = A / 2 + E−B, when the rotor rotates, one end in the circumferential direction of the tip of the teeth portion opposed to one end in the circumferential direction of the salient pole and the radial direction The other end in the circumferential direction of the salient pole is the radial direction of the side surface portion opposite to the circumferential center line of the teeth portion in the teeth side auxiliary groove of the teeth portion adjacent to the teeth portion opposed to one end in the circumferential direction. Overlapping. At this time, the cogging torque generated by the teeth side auxiliary groove serves as a canceling component that suppresses the cogging torque (main component) generated at one end in the circumferential direction of the tooth portion overlapping the one end in the circumferential direction of the salient pole. Torque can be reduced, and the rotational performance of the rotor can be improved.

  According to a ninth aspect of the present invention, in the motor according to the eighth aspect, a pair of the teeth side auxiliary grooves are arranged in parallel in the circumferential direction so as to be axisymmetric with respect to a circumferential center line of the teeth portion. It is characterized by that.

In the present invention, since the pair of teeth side auxiliary grooves are arranged in parallel in the circumferential direction so as to be symmetrical with respect to the center line in the circumferential direction of the tooth portion, the cogging torque can be further reduced.
According to a tenth aspect of the present invention, in the motor according to the eighth or ninth aspect, a ratio W3 / T between a circumferential width W3 of the teeth side auxiliary groove and a spacing T between adjacent teeth portions in the circumferential direction is: It is set within the range of 0 <W3 / T <1.125.

  In the present invention, the ratio W3 / T between the circumferential width W3 of the tooth side auxiliary groove and the interval T between the teeth portions adjacent in the circumferential direction is set within the range of 0 <W3 / T <1.125. As a result, the cogging torque can be reduced (see FIG. 11), which can contribute to improvement of the rotational performance of the rotor.

  Therefore, according to the above-described invention, the vibration can be reduced and the rotational performance of the motor can be improved.

(A) is a top view of the motor in 1st Embodiment, (b) is a partial top view which shows a part of the same figure (a). (A) is the partial top view of the motor which shows the state in which the rotor in the embodiment is located in rotation angle R1, (b) is the partial top view of the motor which shows the state in which a rotor is located in rotation angle R2. is there. It is a characteristic view which shows the relationship between the rotation angle of the rotor in the same embodiment, and cogging torque. It is a characteristic view which shows the relationship between W1 / T and W2 / T, and a cogging torque ratio. (A) is a top view of the motor in 2nd Embodiment, (b) is a partial top view which shows a part of the same figure (a). (A) is the partial top view of the motor which shows the state in which the rotor in the embodiment is located in rotation angle R3, (b) is the partial top view of the motor in which the rotor is located in rotation angle R1 (C) is a partial plan view of the motor showing a state where the rotor is located at the rotation angle R2, and (d) is a partial plan view of the motor showing a state where the rotor is located at the rotation angle R4. It is a characteristic view which shows the relationship between the rotation angle of the rotor in the same embodiment, and cogging torque. It is a top view of the motor in 3rd Embodiment, (b) is a partial top view which shows a part of the same figure (a). (A) is the partial top view of the motor which shows the state in which the rotor in the embodiment is located in rotation angle R5, (b) is the partial top view of the motor in which the rotor is located in rotation angle R6 is there. It is a characteristic view which shows the relationship between the rotation angle of the rotor in the same embodiment, and cogging torque. It is a characteristic view which shows the relationship between W3 / T and a cogging torque ratio.

(First embodiment)
A first embodiment of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1A and 1B, the inner rotor type motor 1 of the present embodiment is configured by a rotor 3 being disposed inside a substantially annular stator 2.

  The stator core 11 of the stator 2 has twelve teeth portions 13 that extend radially inward from the annular portion 12. Teeth portions 13 are formed at equal intervals in the circumferential direction, and U-phase, V-phase, and W-phase coils 14 are sequentially wound around each tooth portion 13 by concentrated winding. Protrusions 13 a projecting on both sides in the radial direction are formed at the tips of the teeth 13, and the tips 13 b (diameter inner surfaces) of the teeth 13 are centered on the axis L of the motor 1. It has an arc shape. In addition, the front end surface 13b of the teeth part 13 is formed from one protrusion part 13a to the other protrusion part 13a. Moreover, the teeth part 13 is comprised so that it may become line symmetrical with respect to the circumferential direction centerline.

  In the rotor 3, a substantially annular rotor core 22 made of a magnetic metal material is fixed to the outer peripheral surface of the rotating shaft 21, and four N-pole magnets 23 are arranged at equal circumferential intervals on the outer peripheral portion of the rotor core 22. In addition, salient poles 24 integrally formed on the outer periphery of the rotor core 22 are disposed between the magnets 23. That is, the magnets 23 and the salient poles 24 are alternately arranged at equal angular intervals, and the rotor 3 is an 8-pole so-called continuous pole type that causes the salient pole 24 to function as the S pole with respect to the N pole magnet 23. It is configured. The number of magnetic poles (eight magnetic poles) of the rotor 3 is 2/3 times the number of the tooth portions 13 (12), and the ratio of the magnetic poles of the rotor 3 to the number of the tooth portions 13 is 2: 3. It has become.

  The magnet 23 of the rotor 3 has an outer surface 23 a radially opposed to the tip surface 13 b of the tooth portion 13, and the outer surface 23 a has an arc shape centered on the axis L. Further, the magnet 23 is formed to have a larger circumferential length than the salient pole 24. The inner surface of the magnet 23 is fixed to a fixing surface 25 provided between adjacent salient poles 24 of the rotor core 22, and a circumferential gap is provided between the magnets 23. The magnets 23 are configured such that their outer side surfaces 23a are positioned on the same circumference.

  Each salient pole 24 has a shape that protrudes radially outward in a substantially fan shape, and its outer side surface 24 a (radially outer side surface) that forms a curved shape is in relation to the circumferential center line S of the salient pole 24. A pair of auxiliary grooves 31 and 32 (both are first auxiliary grooves) provided at positions that are line-symmetric are formed. Each auxiliary groove 31, 32 has the same shape as each other and has a pair of side surface portions 31a, 31b, 32a, 32b facing each other in the circumferential direction. Of the side surfaces of the auxiliary grooves 31 and 32, those on the inner side (circumferential centerline S side) are the side surfaces 31a and 32a, respectively, and those on the outer side (circumferential end portion side of the salient pole 24) are side surfaces. The parts 31b and 32b are used.

  The auxiliary grooves 31 and 32 extend linearly in the axial direction. The depth (diameter dimension) of the auxiliary grooves 31 and 32 is set to about ３ of the radial dimension of the salient pole 24. Further, as described above, the auxiliary grooves 31 and 32 are formed so as to be line-symmetric with respect to the circumferential center line S of the salient poles 24, so that the inner side of the auxiliary groove 31 from the circumferential center line S. The angle centered on the axis L to the side surface portion 31a and the angle centered on the axis L from the circumferential center line S to the side surface portion 32a inside the auxiliary groove 32 are equal to each other. The angle is defined as a position angle C1 of the auxiliary grooves 31 and 32 (see FIG. 1B).

  Here, in the present embodiment, the opening angle A between the circumferential ends 13c and 13d of the tip surface 13b of the tooth portion 13 centered on the axis L is the circumferential ends 24b of the salient pole 24 centered on the axis L. The opening angle B between 24c is larger. The position angle C1 of the auxiliary grooves 31 and 32 is set to satisfy C1 = A−B / 2. That is, as a result, as shown in FIG. 2A, the circumferential end 13 c of the tip surface 13 b of the tooth portion 13 is in the circumferential direction of the salient pole 24 with the teeth portion 13 facing the salient pole 24 in the radial direction. When overlapping one end 24b (specifically, the apex angle portion formed by the circumferential side surface of the salient pole 24 and the radially outer surface 24a) in the radial direction, the other circumferential end 13d of the distal end surface 13b of the tooth portion 13 is The auxiliary groove 31 overlaps the side surface portion 31a (specifically, the apex angle portion formed by the side surface portion 31a and the outer surface 24a of the salient pole 24) in the radial direction. Similarly, as shown in FIG. 2B, when the other circumferential end 13 d of the tip end surface 13 b of the tooth portion 13 overlaps with the other circumferential end 24 c of the salient pole 24 in the radial direction, the tip end of the tooth portion 13. One end 13c in the circumferential direction of the surface 13b overlaps the side surface portion 32a of the auxiliary groove 32 in the radial direction. Note that “overlapping in the radial direction” described above indicates that each of them is located on a straight line in the radial direction.

  Here, FIG. 3 shows a cogging torque waveform when the rotor 3 rotates. The waveform of the two-dot chain line in FIG. 3 is the waveform of the main component of the cogging torque (the cogging torque waveform in the configuration in which the auxiliary grooves 31 and 32 are not formed on each salient pole 24), and the waveform of the one-dot chain line is This is a cogging torque waveform generated by the auxiliary grooves 31 and 32. The solid line waveform is the waveform of the cogging torque generated in the motor 1 of the present embodiment. The waveform of the main component of the cogging torque (the waveform of the two-dot chain line) and the cogging torque waveform generated by the auxiliary grooves 31 and 32 (1 The waveform of the dotted line).

  In FIG. 3, the rotation angle R1 of the rotor 3 shown in FIG. 2A, that is, the rotation angle R1 when the circumferential one end 24b of the salient pole 24 overlaps the circumferential one end 13c of the opposing tooth portion 13 in the radial direction. Is shown in FIG. At this rotation angle R1, the circumferential end 24b of the salient pole 24 and the circumferential end 13c of the tooth portion 13 overlap in the radial direction, so that the magnetic flux tends to concentrate on the circumferential end 13c side of the tooth portion 13. The main component of cogging torque is increased, and the main component of cogging torque (the waveform of the two-dot chain line) has a negative peak.

  Here, in the motor 1 of the present embodiment, since the position angle C1 of the auxiliary grooves 31 and 32 is set as C1 = A−B / 2 as described above, the circumferential direction of the teeth portion 13 and the like at the rotation angle R1. The end 13d overlaps the side surface portion 31a of the auxiliary groove 31 in the radial direction. Thereby, the magnetic flux at this time is easily dispersed to the other circumferential end 13d side of the tooth portion 13, and the magnetic flux is less likely to concentrate on the circumferential one end 13c side of the tooth portion 13. As shown in FIG. 3, the cogging torque generated by the auxiliary grooves 31 and 32 has a peak opposite to the main component of the cogging torque at the rotation angle R1, that is, a cancel component for the main component of the cogging torque. This peak is caused by the auxiliary groove 31. Therefore, the cogging torque (solid line waveform) of the entire motor 1 which is a combination of the main component of the cogging torque and the cogging torque generated by the auxiliary grooves 31 and 32 has a peak of the main component of the cogging torque at the rotation angle R1. The waveform is suppressed. As described above, the cogging torque can be reduced by the auxiliary groove 31 and the rotational performance of the rotor 3 can be improved. Note that the absolute value of the peak of the cogging torque generated by the auxiliary grooves 31 and 32 is smaller than the absolute value of the peak of the main component of the cogging torque.

  Further, the same effect as that of the auxiliary groove 31 is produced in the other auxiliary groove 32. Specifically, as shown in FIG. 2 (b), in the state where the salient pole 24 and the tooth portion 13 face each other, the other circumferential end 24 c of the salient pole 24 is in the radial direction with the other circumferential end 13 d of the tooth portion 13. When overlapped (rotation angle R2 in FIG. 3), one end 13c in the circumferential direction of the tooth portion 13 overlaps the side surface portion 32a of the auxiliary groove 32 in the radial direction. Thus, as in the case of the auxiliary groove 31 described above, the cogging torque generated by the auxiliary grooves 31 and 32 has a peak opposite to the main component of the cogging torque at the rotation angle R2, as shown in FIG. It becomes a canceling component for the main component of torque. Thereby, the cogging torque can be further reduced, and the rotational performance of the rotor 3 can be improved.

  The solid line graph in FIG. 4 shows the circumferential width W1 of the auxiliary grooves 31, 32 with reference to the side surfaces 31a, 32a on the inner side (circumferential centerline S side) of the auxiliary grooves 31, 32 (FIG. 2B). The cogging torque ratio when the ratio W1 / T between the circumferential interval T (see FIG. 1B) between the tip portions of the adjacent tooth portions 13 (between the protruding portions 13a) (see FIG. 1B) is changed. Yes. In FIG. 4, when W1 / T = 0, that is, when the cogging torque in the configuration in which the auxiliary grooves 31 and 32 are not formed is “1”, the cogging is performed from W1 / T = 0 to W1 / T = 2.5. The torque decreases, and the cogging torque becomes the minimum value of about “0.5” at W1 / T = 2.5. Then, from W1 / T = 2.5 to W1 / T = 3.5, the cogging torque increases from the minimum value, but is smaller than “1”. That is, since the cogging torque is smaller than “1” in the range of 0 <W1 / T <3.5, the auxiliary grooves 31 and 32 are not formed if W1 / T is set within this range. The cogging torque can be reduced more than the configuration, and when W1 / T = 2.5, the cogging torque is about half, and the cogging torque reduction effect is greatest.

Next, characteristic effects of the present embodiment will be described.
(1) In the present embodiment, auxiliary grooves 31 and 32 are formed on the outer surface 24a of the salient pole 24 of the rotor 3, and the position angle C1 is configured to satisfy C1 = A−B / 2. Therefore, when the rotor 3 rotates, the tooth portion 13 and the salient pole 24 face each other in the radial direction, and the circumferential end (one end 13 c or the other end 13 d) of the tip end surface 13 b of the tooth portion 13 is the salient pole 24. When overlapping with the circumferential end (one end 24b or the other end 24c) in the radial direction, the other circumferential end (the other end 13d or one end 13c) of the tooth portion 13 is the side surface portion 31a or the auxiliary groove of the auxiliary groove 31. It overlaps with the side part 32a of 32 in radial direction. At this time, cogging torque (cogging torque generated by the auxiliary grooves 31, 32 d) generated at the circumferential end portions 13 c, 13 d of the tooth portion 13 overlapping the side surfaces 31 a, 32 a of the auxiliary grooves 31, 32 is the circumference of the salient pole 24. Since the cogging torque (principal component) generated on the circumferential end portions 13c and 13d of the teeth portion 13 that overlaps the radial end portions 24b and 24c in the radial direction becomes a canceling component, the cogging torque generated in the entire motor 1 is reduced. Thus, the rotation performance of the rotor 3 can be improved.

  (2) In the present embodiment, a pair of auxiliary grooves 31 and 32 are arranged in parallel in the circumferential direction so as to be line-symmetric with respect to the circumferential center line S of the salient pole 24. That is, since the auxiliary grooves 31 and 32 are provided in pairs corresponding to the circumferential ends 24b and 24c of the salient pole 24, respectively, the cogging torque can be further reduced.

  (3) In this embodiment, the ratio W1 / T between the circumferential width W1 of the auxiliary grooves 31 and 32 and the interval T between the teeth 13 adjacent in the circumferential direction is in the range of 0 <W1 / T <3.5. Set in. As a result, the cogging torque can be reduced (see FIG. 4), which can contribute to the improvement of the rotation performance of the rotor 3.

(Second Embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
As shown in FIGS. 5A and 5B, in addition to the configuration of the first embodiment, the motor 40 of this embodiment includes an inner auxiliary groove 41 as a second auxiliary groove on the outer surface 24a of the salient pole 24. , 42 are formed. In the following, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The inner auxiliary grooves 41 and 42 are formed on the inner side in the circumferential direction with respect to the auxiliary grooves 31 and 32 (first auxiliary grooves), and are formed so as to be symmetrical with respect to the circumferential center line S of the salient pole 24. Has been. Each inner auxiliary groove 41, 42 has the same shape as each other and has a pair of side surface portions 41a, 41b, 42a, 42b facing each other in the circumferential direction. Of the side surface portions of the inner auxiliary grooves 41 and 42, the inner side (circumferential centerline S side) is the side surface portion 41a and 42a, and the outer side (circumferential end portion side) of the salient pole 24 is respectively. The side portions 41b and 42b are used.

  The inner auxiliary grooves 41, 42 extend linearly in the axial direction like the outer auxiliary grooves 31, 32, and the inner auxiliary grooves 41, 42 have a depth (dimension in the radial direction). It is substantially equal to the depth of and is set to about 1/3 of the radial dimension of the salient pole 24. Further, as described above, the inner auxiliary grooves 41 and 42 are formed so as to be line-symmetric with respect to the circumferential center line S of the salient poles 24, so that the inner auxiliary grooves 41 are formed from the circumferential center line S. The angle centered on the axis L to the outer side surface 41b and the angle centered on the axis L from the circumferential center line S to the outer side surface 42b of the inner auxiliary groove 42 are equal to each other. Hereinafter, the angle is defined as a position angle C2 of the inner auxiliary grooves 41 and 42 (see FIG. 5B).

  Here, the position angle C2 of the inner auxiliary grooves 41 and 42 is set so that C2 = A−B / 2−D, where D is the open angle between the magnet 23 and the salient pole 24 with the axis L as the center. ing. In addition, A and B are the open angle A of the front end surface 13b of the teeth part 13 and the open angle B of the salient pole 24 similarly to the said 1st Embodiment (refer Fig.2 (a)). As a result, as shown in FIG. 6A, one end 13c in the circumferential direction of the tip surface 13b of the tooth portion 13 is one end 23b in the circumferential direction of the magnet 23 adjacent to the opposing salient pole 24 (specifically, the circumference of the magnet 23). The circumferential other end 13d of the teeth portion 13 is the outer side surface portion 41b (specifically, the side surface portion) of the inner auxiliary groove 41 when overlapping in the radial direction with the apex angle portion comprising the directional side surface and the radial outer surface 23a. 41b and the apex angle portion formed by the outer surface 24a of the salient pole 24) and overlaps in the radial direction. Similarly, as shown in FIG. 6D, the magnet 23 adjacent to the salient pole 24 opposite to the other circumferential end 13d of the teeth portion 13 (the magnet 23 adjacent on the opposite side to FIG. 6A). The circumferential end 13c of the tip end surface 13b of the tooth portion 13 is overlapped with the outer side surface portion 42b of the inner auxiliary groove 42 in the radial direction.

  Here, the cogging torque waveform at the time of rotation of the rotor 3 in this embodiment is shown in FIG. The waveform of the two-dot chain line in FIG. 7 is a waveform of the main component of cogging torque (cogging torque waveform in a configuration in which the auxiliary grooves 31 and 32 and the inner auxiliary grooves 41 and 42 are not formed on each salient pole 24). The waveform of the one-dot chain line is a cogging torque waveform generated by the auxiliary grooves 31 and 32 and the inner auxiliary grooves 41 and 42. The solid line waveform is the waveform of the cogging torque generated in the motor 40 of the present embodiment. The waveform of the main component of the cogging torque (the waveform of the two-dot chain line), the auxiliary grooves 31, 32, and the inner auxiliary grooves 41, 42. And a cogging torque waveform (a waveform of a one-dot chain line) generated by the above.

  The rotation angle of the rotor 3 shown in FIG. 6A, that is, the rotation angle when the circumferential end 13c of the teeth portion 13 overlaps the circumferential end 23b of the magnet 23 adjacent to the opposing salient pole 24 is R3. At this time, since at least a part of the tooth portion 13 shifts from the state facing the magnet 23 in the radial direction to the non-opposing state, the magnetic flux is easily concentrated on the circumferential end 13c side of the tooth portion 13, and as a result. The main component of cogging torque is increased.

  Here, in the motor 40 of the present embodiment, since the position angle C2 of the inner auxiliary grooves 41 and 42 is set as C1 = AB / 2 as described above, the circumferential direction of the teeth portion 13 at the rotation angle R3. The other end 13d overlaps the outer side surface portion 41b of the inner auxiliary groove 41 in the radial direction. Thereby, the magnetic flux at this time is easily dispersed to the other circumferential end 13d of the tooth portion 13, and the magnetic flux is less likely to concentrate on the circumferential one end 13c side of the tooth portion 13. As shown in FIG. 7, the cogging torque generated by the auxiliary grooves 31 and 32 and the inner auxiliary grooves 41 and 42 is a component having a phase opposite to that of the main component of the cogging torque at the rotation angle R3, that is, the main component of the cogging torque. The canceling component is generated by the inner auxiliary groove 41. Therefore, the cogging torque (solid line waveform) in the entire motor 40 is a waveform in which the peak portion of the main component of the cogging torque at the rotation angle R3 is suppressed. In this way, the cogging torque can be reduced by the inner auxiliary groove 41, and the rotational performance of the rotor 3 can be improved.

  Also, the other inner auxiliary groove 42 has the same effect as the inner auxiliary groove 41. Specifically, as shown in FIG. 6D, when the other circumferential end 13d of the tooth portion 13 overlaps the circumferential end 23c of the magnet 23 adjacent to the opposing salient pole 24 in the radial direction (in FIG. 7, At the rotation angle R4), one end 13c in the circumferential direction of the tooth portion 13 overlaps the side surface portion 42b on the outer side of the inner auxiliary groove 42 in the radial direction. Thus, as in the case of the inner auxiliary groove 41 described above, the cogging torque generated by the auxiliary grooves 31 and 32 and the inner auxiliary grooves 41 and 42 becomes the main component of the cogging torque at the rotation angle R4 as shown in FIG. Is a cancel component for the anti-phase component, that is, the main component of the cogging torque. Thereby, the cogging torque can be further reduced, and the rotational performance of the rotor 3 can be improved.

  Further, in this embodiment, since the auxiliary grooves 31 and 32 are provided together with the inner auxiliary grooves 41 and 42, as described in the first embodiment, the cogging torque is also reduced at the rotation angles R1 and R2. (Refer to FIG. 6B, FIG. 6C and FIG. 7).

  The graph of the alternate long and short dash line in FIG. 4 shows the circumferential width W2 of the inner auxiliary grooves 41 and 42 with reference to the outer side surface portions 41b and 42b of the inner auxiliary grooves 41 and 42 (see FIG. 5B). The cogging torque ratio is shown when the ratio W2 / T to the circumferential interval T (see FIG. 5B) between the tips of adjacent teeth 13 (between the protrusions 13a) is changed. In FIG. 4, W2 / T = 0, that is, the cogging torque in the configuration in which the inner auxiliary grooves 41 and 42 are not formed is “1”. As shown in the figure, the cogging torque decreases from W2 / T = 0 to W2 / T = 0.6, and the cogging torque becomes a minimum value of about “0.7” at W2 / T = 0.6. . Then, from W2 / T = 0.6 to W2 / T = 1.2, the cogging torque increases from the minimum value, but is smaller than “1”. That is, in the range of 0 <W2 / T <1.2, the cogging torque becomes smaller than “1”. Therefore, if W2 / T is set within this range, the inner auxiliary grooves 41 and 42 are not formed. The cogging torque can be further reduced, and when W2 / T = 0.6, the cogging torque is about 70%, and the cogging torque reduction effect is greatest.

Next, characteristic effects of the present embodiment will be described.
(4) In this embodiment, the inner auxiliary grooves 41 and 42 are formed on the outer surface 24a of the salient pole 24 of the rotor 3, and the position angle C2 is configured to satisfy C2 = A−B / 2−D. The For this reason, when the rotor 3 rotates, the circumferential end (one end 13c or the other end 13d) of the tip surface 13b of the tooth portion 13 is connected to the circumferential ends 23b and 23c of the magnet 23 adjacent to the opposing salient pole 24. When overlapping in the radial direction, the other circumferential end (the other end 13d or one end 13c) of the tooth portion 13 overlaps the side surface portion 41b of the inner auxiliary groove 41 or the side surface portion 42b of the inner auxiliary groove 42 in the radial direction. At this time, the cogging torque (cogging torque generated by the inner auxiliary grooves 41, 42) generated on the circumferential end portions 13 c, 13 d of the teeth portion 13 that overlaps the side surfaces 41 b, 42 b of the inner auxiliary grooves 41, 42 is Since the cogging torque (principal component) generated on the circumferential end portions 13c and 13d side of the teeth portion 13 that overlaps the circumferential ends 23b and 23c in the radial direction is a canceling component, the cogging torque generated in the entire motor 40 is reduced. Thus, the rotation performance of the rotor 3 can be improved.

  (5) In the present embodiment, a pair of inner auxiliary grooves 41, 42 are arranged in parallel in the circumferential direction so as to be line symmetric with respect to the circumferential center line S of the salient poles 24. That is, since the inner auxiliary grooves 41 and 42 are provided in pairs corresponding to the circumferential ends 23b and 23c of the magnets 23 adjacent to the salient pole 24, the cogging torque can be further reduced.

  (6) In the present embodiment, the ratio W2 / T between the circumferential width W2 of the inner auxiliary grooves 41 and 42 and the circumferential interval T between the teeth 13 adjacent in the circumferential direction is 0 <W2 / T <1. 2 is set. As a result, the cogging torque can be reduced (see FIG. 4), which can contribute to the improvement of the rotation performance of the rotor 3.

  (7) In the present embodiment, the salient pole 24 is provided with both the auxiliary grooves 31 and 32 as the first auxiliary grooves and the inner auxiliary grooves 41 and 42 as the second auxiliary grooves, so that the cogging torque is further increased. Can be reduced.

(Third embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
The motor 50 of the present embodiment is different from the first embodiment in that an auxiliary groove (tooth side auxiliary grooves 51 and 52) is provided not on the salient pole 24 side but on the teeth portion 13 side. Therefore, in the following, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIGS. 8 (a) and 8 (b), a pair of teeth side auxiliary grooves 51 and 52 are formed on the tip surface 13 b of the tooth portion 13. Each of the teeth side auxiliary grooves 51, 52 has a pair of side surface portions 51a, 51b, 52a, 52b facing each other in the circumferential direction, and has a shape extending in the axial direction. The teeth side auxiliary grooves 51 and 52 have the same shape as each other, and are formed so as to be line symmetric with respect to the circumferential center line H of the tooth portion 13. Of the side surfaces of the teeth side auxiliary grooves 51 and 52, those on the inner side (circumferential center line H side) are the side surfaces 51a and 52a, respectively, and those on the outer side (the circumferential end portion side of the teeth portion 13). The side portions 51b and 52b are used.

  Since the teeth side auxiliary grooves 51 and 52 are formed so as to be line-symmetric with respect to the circumferential center line H of the teeth portion 13, the side surface portions 51 b outside the teeth side auxiliary grooves 51 from the circumferential center line H. The angle centered on the axis L and the angle centered on the axis L from the circumferential center line H to the outer side surface portion 52b of the teeth side auxiliary groove 52 are equal to each other. Is a position angle C3 of the teeth side auxiliary grooves 51 and 52 (see FIG. 8B).

  Here, the position angle C3 of the teeth side auxiliary grooves 51, 52 is set to be C3 = A / 2 + EB, where E is the angle between the circumferential centerlines H of the teeth 13 adjacent in the circumferential direction. ing. In addition, A and B are the open angle A of the front end surface 13b of the teeth part 13 and the open angle B of the salient pole 24 similarly to the said 1st Embodiment (refer Fig.2 (a)). As a result, as shown in FIG. 9A, when the circumferential end 24b of the salient pole 24 overlaps the circumferential end 13c of the distal end surface 13b of the tooth portion 13 facing the radial direction, The other end 24c in the direction is a side surface portion 51b on the outer side of the tooth side auxiliary groove 51 in the tooth portion adjacent to the tooth portion 13 (the tooth portion 13e in FIG. 9A) that overlaps the one end 24b in the circumferential direction (specifically, The apex angle part which consists of the side part 51b and the front end surface 13b of the teeth part 13) overlaps with the radial direction. Similarly, as shown in FIG. 9B, when the other circumferential end 24 c of the salient pole 24 overlaps the circumferential other end 13 d of the opposing tooth portion 13 in the radial direction, the circumferential direction of the salient pole 24. The one end 24b overlaps with the side surface portion 52b on the outer side of the tooth side auxiliary groove 52 in the tooth portion adjacent to the tooth portion 13 overlapping with the other end 24c in the circumferential direction (the tooth portion 13f in FIG. 9B) in the radial direction. It is like that.

  Here, the cogging torque waveform at the time of rotation of the rotor 3 in this embodiment is shown in FIG. The waveform of the two-dot chain line in FIG. 10 is a waveform of the main component of cogging torque (the cogging torque waveform in a configuration in which the teeth side auxiliary grooves 51 and 52 are not formed in each tooth portion 13). Is a cogging torque waveform generated by the teeth side auxiliary groove 52. The waveform of the solid line is the waveform of the cogging torque generated in the motor 50 of the present embodiment. The waveform of the main component of the cogging torque (the waveform of the two-dot chain line) and the cogging torque waveform generated by the teeth side auxiliary grooves 51 and 52. (One-dot chain line waveform).

  The rotation angle of the rotor 3 shown in FIG. 9A, that is, the rotation angle when the circumferential end 24b of the salient pole 24 overlaps with the circumferential end 13c of the teeth portion 13 facing each other is R5. At this time, the magnetic flux tends to concentrate on the side of the circumferential end 24b of the salient pole 24. As a result, the main component of the cogging torque increases, and the waveform of the main component of the cogging torque has a negative peak (FIG. 10). reference).

  Here, in the motor 50 of the present embodiment, since the position angle C3 of the teeth side auxiliary grooves 51 and 52 is set as C3 = A / 2 + E−B as described above, the salient pole 24 is rotated at the rotation angle R5. The other circumferential end 24c overlaps the side surface portion 51b outside the teeth side auxiliary groove 51 of the tooth portion 13e in the radial direction. As a result, the magnetic flux at this time is easily distributed to the other end 24c in the circumferential direction of the salient pole 24, and the magnetic flux is less likely to concentrate on the one end 24b in the circumferential direction of the salient pole 24. As shown in FIG. 10, the cogging torque generated by the teeth side auxiliary grooves 51 and 52 is a peak in the opposite phase (plus) to the main component of the cogging torque at the rotation angle R5, that is, a cancel component for the main component of the cogging torque. This canceling component is generated by the teeth side auxiliary groove 51. Therefore, the cogging torque (solid waveform) in the entire motor 50 is a waveform in which the peak of the main component of the cogging torque at the rotation angle R5 is suppressed. Thus, the cogging torque can be reduced by the teeth side auxiliary groove 51, and the rotational performance of the rotor 3 can be improved.

  In addition, the same operation as that of the teeth side auxiliary groove 51 occurs in the other teeth side auxiliary groove 52. Specifically, as shown in FIG. 9 (b), when the other circumferential end 24c of the salient pole 24 overlaps the other circumferential end 13d of the tooth portion 13 facing (rotation angle R6 in FIG. 10). Moreover, the circumferential direction one end 13c of the teeth portion 13 overlaps the side surface portion 52b outside the teeth side auxiliary groove 52 of the teeth portion 13f in the radial direction. As a result, as in the case of the teeth side auxiliary groove 51 described above, the cogging torque generated by the teeth side auxiliary grooves 51 and 52 has a phase opposite to the main component of the cogging torque at the rotation angle R6 as shown in FIG. It becomes a cancellation component for the peak, that is, the main component of the cogging torque, and the cogging torque (solid waveform) in the entire motor 50 at the rotation angle R6 is suppressed to a small value. Thereby, the cogging torque can be further reduced, and the rotational performance of the rotor 3 can be improved.

  FIG. 11 shows the circumferential width W3 (see FIG. 9B) of the teeth side auxiliary grooves 51, 52 with reference to the outer side surface parts 51b, 52b of the teeth side auxiliary grooves 51, 52, and the adjacent tooth parts 13. The cogging torque ratio when the ratio W3 / T to the circumferential interval T (see FIG. 9B) between the tip portions (between the protruding portions 13a) is changed is shown. In FIG. 11, the cogging torque in the configuration in which W3 / T = 0, that is, the teeth side auxiliary grooves 51 and 52 are not formed is “1”. As shown in the figure, the cogging torque decreases as W3 / T increases from 0, and the cogging torque reaches a minimum value (about 50%) in the vicinity of W3 / T = 0.7. As W3 / T further increases, the cogging torque starts to increase from the minimum value, but in the range of W3 / T <1.125, the cogging torque is smaller than “1”. That is, since the cogging torque is smaller than “1” in the range of 0 <W3 / T <1.125, if the W3 / T is set within this range, the teeth side auxiliary grooves 51 and 52 are not formed. The cogging torque can be reduced more than the configuration. When W3 / T = about 0.7, the cogging torque is about 50%, and the cogging torque reduction effect is the greatest.

Next, characteristic effects of the present embodiment will be described.
(8) In the present embodiment, the tooth side auxiliary grooves 51 and 52 are formed in the distal end surface 13b of the tooth portion 13, and the position angle C3 is configured to satisfy C3 = A / 2 + EB. For this reason, when the rotor 3 rotates, when the circumferential end (one end 24b or the other end 24c) of the salient pole 24 overlaps with the circumferential end 13c, 13d of the tooth portion 13 facing the salient pole 24, The other circumferential end portion 24 (the other end 24c or the one end 24b) of the side surface portion 51b of the tooth side auxiliary groove 51 in the tooth portion 13e (or the tooth portion 13f) adjacent to the tooth portion 13 where the circumferential end portion overlaps. (Or the side surface portion 52b of the teeth side auxiliary groove 52) overlaps in the radial direction. At this time, the cogging torque generated by the teeth side auxiliary grooves 51 and 52 serves as a canceling component that keeps the main component of the cogging torque small, so that the cogging torque generated in the entire motor 50 can be reduced and the rotational performance of the rotor 3 is improved. Can be made.

  (9) In the present embodiment, the teeth side auxiliary grooves 51 and 52 are arranged in parallel in the circumferential direction so as to be line-symmetric with respect to the circumferential center line H of the teeth portion 13, so that the cogging torque is further increased. Can be reduced.

  (10) In the present embodiment, the ratio W3 / T between the circumferential width W3 of the teeth side auxiliary grooves 51 and 52 and the circumferential interval T between the teeth portions 13 adjacent in the circumferential direction is 0 <W3 / T <1. .125 is set within the range. As a result, the cogging torque can be reduced (see FIG. 11), which can contribute to the improvement of the rotation performance of the rotor 3.

Each embodiment of the present invention may be modified as follows.
In the second embodiment, both the auxiliary grooves 31 and 32 as the first auxiliary grooves and the inner auxiliary grooves 41 and 42 as the second auxiliary grooves are provided, but only the inner auxiliary grooves 41 and 42 are provided. It is good also as a structure.

In the third embodiment, the auxiliary grooves 51 and 52 provided in the first embodiment and the inner auxiliary grooves 41 and 42 provided in the second embodiment may be added.
In each of the above embodiments, the auxiliary grooves 31 and 32, the inner auxiliary grooves 41 and 42, or the teeth side auxiliary grooves 51 and 52 are provided as a pair.

-You may change suitably the numerical range about the said embodiment according to a condition.
In the above embodiments, the shape of the magnet 23 and the shape of the rotor core 22 including the salient poles 24 may be changed as appropriate.

  In each of the above embodiments, the magnet 23 is configured as the N pole and the salient pole 24 is configured to function as the S pole. Conversely, the magnet 23 is configured as the S pole and the salient pole 24 is configured to function as the N pole. May be.

  In each of the above embodiments, the present invention is applied to the 8-pole rotor 3 constituted by the four salient poles 24 and the four magnets 23, but the number of magnetic poles may be changed as appropriate. Along with this, the number of magnetic poles on the stator 2 side is appropriately changed.

  In each of the above embodiments, the present invention is applied to the inner rotor type motors 1, 40, 50, but may be applied to an outer rotor type motor.

  DESCRIPTION OF SYMBOLS 1,40,50 ... Motor, 2 ... Stator, 3 ... Rotor, 13, 13e, 13f ... Teeth part, 13b ... Tip surface, 22 ... Rotor core, 23 ... Magnet, 24 ... Salient pole, 31, 32 ... Auxiliary groove ( 1st auxiliary groove), 31a, 31b, 32a, 32b ... side surface portion of auxiliary groove, 41, 42 ... inner auxiliary groove as second auxiliary groove, 41a, 41b, 42a, 42b ... side surface portion of inner auxiliary groove , 51, 52 ... teeth side auxiliary groove, 51a, 51b, 52a, 52b ... side surface portion of teeth side auxiliary groove, A ... opening angle of tip of tooth portion, B ... opening angle of salient pole, C1 ... first auxiliary groove C2: Position angle of the inner auxiliary groove, C3: Position angle of the teeth side auxiliary groove, D: Open angle between the magnet and salient pole, E: Angle between the circumferential center lines of the teeth part, H: Teeth Center line in the circumferential direction, L ... of the motor S, the circumferential center line of the salient poles, T, the circumferential interval between the teeth, W1, the circumferential width of the first auxiliary groove, W2, the circumferential width of the inner auxiliary groove, W3, the teeth side auxiliary groove. Circumferential width.

Claims (10)

A plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles function as the other magnetic poles. Rotor and
A motor provided with a stator having a plurality of teeth portions provided at equal intervals in the circumferential direction and facing the salient poles in a radial direction,
A first auxiliary groove having a pair of side portions facing in the circumferential direction is recessed in a surface of the salient pole that faces the teeth portion,
An angle C1 about the axis of the motor from the circumferential center line of the salient pole to the side surface portion on the circumferential center line side in the first auxiliary groove is
The opening angle between the circumferential ends of the teeth portion centered on the axis is A, and the opening angle between the circumferential ends of the salient poles centered on the axis is B,
C1 = A−B / 2
A motor characterized by being configured to satisfy. The motor according to claim 1,
A pair of the first auxiliary grooves are arranged in the circumferential direction so as to be axisymmetric with respect to the circumferential center line of the salient pole. The motor according to claim 1 or 2,
The ratio W1 / T between the circumferential width W1 of the first auxiliary groove and the interval T between the teeth portions adjacent in the circumferential direction is set within a range of 0 <W1 / T <3.5. Characteristic motor. A plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles function as the other magnetic poles. Rotor and
A motor provided with a stator having a plurality of teeth portions provided at equal intervals in the circumferential direction and facing the salient poles in a radial direction,
A second auxiliary groove having a pair of side portions facing in the circumferential direction is recessed in the surface of the salient pole facing the teeth portion,
An angle C2 about the axis of the motor from the circumferential center line of the salient pole to the side surface of the second auxiliary groove opposite to the circumferential center line is
The opening angle between the circumferential ends of the teeth portion centered on the axis is A, the opening angle between the circumferential ends of the salient poles centered on the axis is B, and the axis is centered on the axis. Let D be the open angle between the magnet and the salient pole.
C2 = A−B / 2−D
A motor characterized by being configured to satisfy. The motor according to claim 4,
A pair of the second auxiliary grooves are arranged in parallel in the circumferential direction so as to be line-symmetric with respect to the circumferential center line of the salient pole. The motor according to claim 4 or 5,
The ratio W2 / T between the circumferential width W2 of the second auxiliary groove and the interval T between the teeth portions adjacent in the circumferential direction is set within a range of 0 <W2 / T <1.2. Characteristic motor. A plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles function as the other magnetic poles. Rotor and
A motor provided with a stator having a plurality of teeth portions provided at equal intervals in the circumferential direction and facing the salient poles in a radial direction,
A motor comprising both the first auxiliary groove according to any one of claims 1 to 3 and the second auxiliary groove according to any one of claims 4 to 6. A plurality of magnets having one magnetic pole are arranged in the circumferential direction of the rotor core, and salient poles integrally formed with the rotor core are arranged with gaps between the magnets, and the salient poles function as the other magnetic poles. Rotor and
A motor provided with a stator having a plurality of teeth portions provided at equal intervals in the circumferential direction and facing the salient poles in a radial direction,
A tooth side auxiliary groove having a pair of side surfaces facing each other in the circumferential direction is recessed in the tip surface facing the magnet and the salient pole in each tooth portion,
An angle C3 centered on the axis of the motor from the circumferential center line of the teeth portion to the side surface portion on the opposite side of the circumferential center line in the teeth side auxiliary groove,
An opening angle between the circumferential ends of the teeth section with the axis as the center is A, an opening angle between the circumferential ends of the salient poles with the axis as the center, B, and the teeth adjacent in the circumferential direction. The angle between the circumferential centerlines of the part is E,
C3 = A / 2 + EB
A motor characterized by being configured to satisfy. The motor according to claim 8, wherein
A pair of teeth-side auxiliary grooves are arranged in the circumferential direction so as to be axisymmetric with respect to the circumferential center line of the teeth portion. The motor according to claim 8 or 9,
A ratio W3 / T between the circumferential width W3 of the tooth side auxiliary groove and the interval T between the teeth portions adjacent in the circumferential direction is set within a range of 0 <W3 / T <1.125. Motor.

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