JP2008295288A - Magnet embedded motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnet embedded motor for reducing the number of components and a leakage magnetic flux even if many magnets are used for increasing a torque. <P>SOLUTION: Accommodation holes in a rotor core having P magnetic poles are formed by P/2 radial accommodation holes 8a radially and linearly extended, and P/2 V-shaped accommodation holes 8b (a pair of magnet accommodation sections 8e) radially and outwardly protruded. They are circumferentially and alternately formed. The magnet 9 within the radial accommodation hole 8a and the magnet 10 within the magnet accommodation section 8e circumferentially adjacent to one side of the magnet 9 compose one magnetic pole. The magnet 9 within the radial accommodation hole 8a and the magnet 10 within the magnet accommodation section 8e circumferentially adjacent to the other side of the magnet 9 compose the other magnetic pole. A circumferential width angle θa in a radial air gap 8c at a radial outer end of the radial accommodation hole 8a is configured so as to be the same as a circumferential width angle θb in a V-shaped air gap 8f at a radial outer end of the V-shaped accommodation hole 8b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an interior magnet type motor.

2. Description of the Related Art Conventionally, an embedded magnet type motor includes a rotor in which a plurality of housing holes penetrating in the axial direction are formed in the rotor core in the circumferential direction, and a magnet is disposed in each housing hole.
As such an embedded magnet type motor, there is one in which one magnetic pole is constituted by a pair of magnets arranged in a substantially V-shape projecting radially inward (for example, Patent Documents). 1). In such an embedded magnet type motor, more magnets can be used and higher torque can be achieved as compared with a case where the magnet is simply a curved or linear magnet disposed along the circumferential direction.
Japanese Patent Laid-Open No. 2005-51982

  However, in the embedded magnet type motor as described above, two magnets having a rectangular parallelepiped shape are required for one magnetic pole, and when the number of magnetic poles is P, the number of magnets is 2P as a whole. There is a problem that the number of parts is increased as compared with a case where the magnets are curved or linear (one per magnetic pole) disposed along. This causes an increase in parts management cost and assembly cost.

  Further, in the embedded magnet type motor as described above, two outer bridge portions formed between the outer peripheral surfaces of the rotor cores on the outer sides in the radial direction of the respective housing holes for housing the magnets are formed for each magnetic pole. Therefore, there is a problem that there is much leakage magnetic flux that passes through the outer bridge portion. This causes the effective magnetic flux in the embedded magnet type motor to be reduced and hinders the increase in torque. Further, regardless of the number of outer bridge portions, a magnetic path (including the outer bridge portion) having a low magnetic resistance is formed at each end portion (around the end portion) in the radial direction of the accommodation hole, thereby further reducing leakage magnetic flux. Is desired.

  The present invention has been made to solve the above-described problems, and its purpose is to reduce the number of parts and reduce the magnetic flux leakage while increasing the torque by using many magnets. An object of the present invention is to provide an embedded magnet type motor that can be used.

  According to the first aspect of the present invention, the rotor includes a rotor core in which a plurality of housing holes penetrating in the axial direction are formed in the circumferential direction, and a magnet is disposed in the housing hole so that the number of magnetic poles is P. The housing hole includes a radial housing hole extending in a substantially radial direction and a substantially V-shaped housing hole protruding outward in the radial direction. The two magnets are alternately formed in the circumferential direction, and the magnet is disposed in the radial accommodation hole and is formed on each straight line forming the V-shape of the V-shaped accommodation hole. One magnet is disposed in each corresponding magnet housing portion and disposed in the radial housing hole, and one magnet is disposed in the magnet housing portion adjacent to one of the circumferential directions. A magnetic pole, and the magnet disposed in the radial accommodation hole; A different magnetic pole is formed by the magnet disposed in the magnet housing portion adjacent to the other in the circumferential direction, and the radial direction in which the magnet is not disposed at the radially outer end of the radial housing hole A side gap is formed, and a V-shaped side gap in which the magnet is not disposed is formed at a radially outer end of the V-shaped receiving hole. A circumferential width angle θa of the radial side gap and the V-shaped side gap are formed. Was set to satisfy 0.60 <θa / θb <1.60.

  According to this configuration, the magnet disposed in the radial accommodation hole constitutes a part of the magnetic pole formed on one side in the circumferential direction and also has a part of the magnetic pole formed on the other side in the circumferential direction. Constitute. That is, the magnet disposed in the radial accommodation hole is shared by the two magnetic poles. Therefore, when the number of magnetic poles is P, the number of magnets is (3/2) P as a whole, and therefore the number of magnets can be reduced as compared with the conventional case (2P as a whole). Further, according to the same configuration, since the radial accommodation hole is shared by the two magnetic poles, in the outer bridge portion formed between the radial outer side of the radial accommodation hole and the outer peripheral surface of the rotor core. Are also common to the two magnetic poles. Therefore, the number of outer bridge portions in the rotor core is reduced, and the leakage magnetic flux that passes through the outer bridge portion can be reduced. Moreover, the circumferential width angle θa of the radial side gap at the radial outer end of the radial accommodation hole and the circumferential width angle θb of the V-shaped gap at the radial outer end of the V-shaped accommodation hole are 0 Since .60 <θa / θb <1.60 is satisfied, the cogging torque does not reach the rated torque (see FIG. 6), and the startability of the motor can be ensured. In other words, when 0.60 <θa / θb <1.60 is not satisfied, the cogging torque reaches the rated torque and the motor may not start, but this can be avoided.

  According to a second aspect of the present invention, in the interior magnet type motor of the first aspect, a circumferential width angle θa of the radial side gap and a circumferential width angle θb of the V-shaped gap are: It was set to satisfy 70 ≦ θa / θb ≦ 1.35.

  According to this configuration, since the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap satisfy 0.70 ≦ θa / θb ≦ 1.35, the cogging torque is the rated torque. (See FIG. 6), high startability and responsiveness of the motor can be ensured.

  According to a third aspect of the present invention, in the interior magnet type motor according to the first aspect, the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are: It was set to satisfy 92 ≦ θa / θb ≦ 1.10.

  According to this configuration, since the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap satisfy 0.92 ≦ θa / θb ≦ 1.10. 10% or less (see FIG. 6), and extremely high startability and responsiveness of the motor can be secured.

  According to a fourth aspect of the present invention, in the interior magnet type motor of the first aspect, the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are: 94 ≦ θa / θb ≦ 1.09 was set.

  According to this configuration, since the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap satisfy 0.94 ≦ θa / θb ≦ 1.09, the cogging torque is the lowest limit. It becomes a small value within the range including the value (see FIGS. 3 to 5).

  According to a fifth aspect of the present invention, in the interior magnet type motor according to the first aspect, the circumferential width angle θa of the radial-side gap and the circumferential width angle θb of the V-shaped gap are: It was set to satisfy 98 ≦ θa / θb ≦ 1.03.

  According to this configuration, since the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap satisfy 0.98 ≦ θa / θb ≦ 1.03, the cogging torque is the lowest limit. It becomes a smaller value within the range including the value (see FIGS. 3 to 5).

  According to a sixth aspect of the present invention, in the interior magnet type motor according to the first aspect, the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are: It was set to satisfy 99 ≦ θa / θb ≦ 1.02.

  According to this configuration, since the circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap satisfy 0.99 ≦ θa / θb ≦ 1.02, the cogging torque is the lowest limit. It becomes a substantially lower limit within a range including the value (see FIGS. 3 to 5).

  ADVANTAGE OF THE INVENTION According to this invention, while using many magnets and achieving high torque, the number of components can be reduced and the embedded magnet type motor which can reduce a leakage magnetic flux can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the embedded magnet type motor includes a stator 1 and a rotor 2.
The stator 1 is formed in a substantially cylindrical shape as a whole, and is formed so as to extend from the inner peripheral surface of the cylindrical portion 3 forming the outer shape toward the axial center (inward in the radial direction) at equal circumferential intervals. The stator core 5 having the teeth 4 and the windings 6 wound around the teeth 4 by concentrated winding via insulators (not shown) (partially shown by a two-dot chain line in FIG. 1). . In the present embodiment, twelve teeth 4 are formed. And every four windings 6 of each tooth 4 are classified into three phases (U phase, V phase, W phase) and connected in series as shown in FIG. In addition, one end thereof is connected to a common neutral point Z, and an alternating current having a phase difference of 120 degrees is supplied to the other end of each phase.

  The rotor 2 includes a rotating shaft 7, a rotor core 8 fixed to the rotating shaft 7, and magnets disposed in accommodation holes (radial accommodation holes 8 a and V-shaped accommodation holes 8 b) formed in the rotor core 8. 9 and 10. Note that the number of magnetic poles in the rotor 2 is P poles and is set to 8 poles in the present embodiment.

  The rotor core 8 is formed in a substantially cylindrical shape by stacking core sheets in the axial direction, and the rotation shaft 7 is fitted in the center hole thereof, and is supported rotatably inside the stator 1. In addition, the housing hole that penetrates in the axial direction to accommodate the magnets 9 and 10 in the rotor core 8 includes a radial housing hole 8a that extends in the radial direction and a substantially V-shaped V-shaped housing that protrudes radially outward. The number of the holes 8b is P / 2, and in the present embodiment, four (8/2 =) are formed, and they are alternately formed in the circumferential direction at equal angular intervals.

  A radial-side gap 8c in which the magnet 9 is not disposed is formed at the radially outer end of the radial accommodation hole 8a. Specifically, the radial-side gap 8c of the present embodiment is formed to have a width (in the direction orthogonal to the radial direction) that is larger than the other portions when viewed from the axial direction. In addition, the radial side gap 8c of the present embodiment is formed in a substantially fan shape, and the radial outer end thereof maintains a constant distance in the circumferential direction from the outer peripheral surface of the rotor core 8, in other words, the rotor core 8 It is formed in an arc shape centered on the axis center. Further, on the radially outer side of the radial accommodation hole 8a, the radially inner side of the radial space 8c is viewed from the axial direction (in the direction orthogonal to the radial direction) so as to restrict the movement of the magnet 9 to the radially outer side. A protruding portion 8d that protrudes in a direction perpendicular to the radial direction is formed so that the width is smaller than other portions. The protruding portions 8d are formed to protrude from the both sides in the circumferential direction by the same amount.

  The V-shaped accommodation hole 8b includes a pair of magnet housing portions 8e corresponding to two straight lines forming the V-shape. The pair of magnet housing portions 8e of the present embodiment are formed as independent holes (through in the axial direction) so that the distance in the circumferential direction is closer toward the outer side in the radial direction but the outer end portions in the radial direction are not communicated with each other. ing. A V-shaped air gap 8f in which the magnet 10 is not disposed is formed at the radially outer end of the V-shaped receiving hole 8b, that is, at the radially outer end of each magnet receiving portion 8e. The V-shaped side gap 8f of the present embodiment is formed so that the width viewed from the axial direction is substantially the same as other portions (portions that accommodate the magnet 10). In addition, the V-shaped side gap 8f of the present embodiment is a circle centered on the axial center of the rotor core 8 so that the radially outer end thereof maintains a constant distance from the outer peripheral surface of the rotor core 8 in the circumferential direction. It is formed in an arc shape. Further, on the radially inner side of the V-shaped gap 8f on the radially outer side of the magnet housing portion 8e, the width seen from the axial direction is smaller than other portions so as to restrict the movement of the magnet 10 to the radially outer side. A protruding portion 8g that protrudes in the shape is formed. The protruding portions 8g are formed so as to protrude by the same amount from the opposing sides of the pair of magnet housing portions 8e to the separated sides.

  Here, the circumferential width angle θa of the radial side gap 8c in the radial accommodation hole 8a of the present embodiment and the circumferential width of the (a pair of) V-shaped gap 8f in the V-shaped accommodation hole 8b. The angle θb (see FIG. 1) is set within a range satisfying 0.99 ≦ θa / θb ≦ 1.02, and θa / θb is set to be 1.00 (that is, the same). This value (θa / θb) is set based on data obtained from experimental results described later (see the angle ratio-cogging torque characteristic diagrams shown in FIGS. 3 to 5).

  Further, the circumferential width angle θ1 between the radial space 8c of the radial accommodation hole 8a and the V-shaped space 8f of the V-shaped accommodation hole 8b, which are adjacent to each other in the circumferential direction, is the radially inner end of the tooth 4. Is set to be larger than the circumferential width angle θ2. Further, the circumferential width angle θa of the radial side gap 8c of the radial direction receiving hole 8a and the circumferential width angle θb of the V-shaped side gap 8f of the V-shaped receiving hole 8b are the circumference of the radially inner end portion of the tooth 4. It is set smaller than the direction width angle θ2. Further, the circumferential width angle θ2 of the radially inner end of the tooth 4 in the present embodiment is set to 27.4 °. Further, the angle θ3 formed by the radial accommodation hole 8a and the magnet accommodation portion 8e adjacent in the circumferential direction in the present embodiment is set to 62.5 °.

  In addition, the radially inner end of the magnet housing portion 8e in the present embodiment is orthogonal to the radial direction on the side portion of the radial housing hole 8a, more specifically on the radially inner side of the radial housing hole 8a, as viewed from the axial direction. It is formed to face the side (inner wall surface) that faces the direction. And the width | variety seen from the axial direction of the inner side bridge | bridging part 8h formed between the radial direction inner side of the magnet accommodating part 8e and the radial direction accommodating hole 8a is formed so that it may become constant along a radial direction. In addition, this is implement | achieved by extending substantially triangular-shaped extension part 8i (the magnet 10 is not arrange | positioned) seeing from an axial direction at the radial direction inner side edge part of the magnet accommodating part 8e. The rotor core 8 having the above-described shape has an outer bridge portion 8j formed between the radial side gap 8c of the radial accommodation hole 8a and the outer peripheral surface of the rotor core 8, and the V-shaped side gap 8f of the magnet accommodation portion 8e. The outer bridge portion 8k is formed between the outer peripheral surface of the rotor core 8. The radial thicknesses of the outer bridge portions 8j and 8k are set to be constant (in the circumferential direction) and set to be the same. Here, the circumferential width angle θa of the radial side gap 8c in the radial accommodation hole 8a is different when the radial thickness of the outer bridge portion 8j is constant as in the present embodiment. This is an angle that coincides with the circumferential width angle from the start end to the end of the outer bridge portion 8j extending so as to connect (S pole and N pole). In the case where the radial side gap 8c is formed in a substantially fan shape as in the present embodiment, the circumferential width angle is constant regardless of the radial position of the radial side gap 8c. The circumferential width angle θa of the direction side gap 8c is an angle that coincides with the circumferential width angle at each radial position of the radial side gap 8c. Further, the circumferential width angle θb (see FIG. 1) of the (a pair of) V-side gaps 8f in the V-shaped receiving hole 8b is constant in the radial thickness of the outer bridge portion 8k as in the present embodiment. In this case, the angle coincides with the circumferential width angle from the start end to the end of the outer bridge portion 8k extending so as to connect different magnetic poles (S pole and N pole). Further, as in the present embodiment, in the case where (a pair of) the V-shaped side gaps 8f are formed so that the circumferential width angle thereof becomes larger toward the inside in the radial direction, the circumference of the (a pair of) V-shaped side gaps 8f. The direction width angle θb is an angle that coincides with the circumferential width angle at the outermost radial direction of the V-shaped gap 8f. In this embodiment, the pair of magnet housing portions 8e are formed as independent holes so as not to communicate with each other, and the V-shaped side gap 8f and the outer bridge portion 8k are separately disposed, The circumferential width angle θb is determined by treating them as being connected. Magnets 9 and 10 are disposed in the radial accommodation hole 8a and the magnet accommodation portion 8e, respectively.

  The magnets 9 and 10 are formed in a substantially rectangular parallelepiped shape magnetized in the short direction when viewed from the axial direction. And the magnet 9 arrange | positioned in the radial direction accommodation hole 8a and the magnet 10 arrange | positioned in the magnet accommodating part 8e adjacent to the one of the circumferential direction comprise one magnetic pole (for example, S pole). In addition, a different magnetic pole (for example, N pole) is configured by the magnet 9 disposed in the radial accommodation hole 8a and the magnet 10 disposed in the magnet accommodation portion 8e adjacent to the other in the circumferential direction. is doing. In addition, the residual magnetic flux density of each magnet 9 and 10 of this Embodiment is set to 1.26 [T]. Further, the length of the magnet 9 disposed in the radial accommodation hole 8a of the present embodiment as viewed from the axial direction is set to 6.7 [mm], and the length in the short direction is set to 2. It is set to 4 [mm]. Further, the length of the magnet 10 disposed in the magnet housing portion 8e of the present embodiment as viewed from the axial direction is set to 7.3 [mm], and the length in the short direction is 1.8. [Mm] is set. The length (7.3 [mm]) in the longitudinal direction of the magnet 10 disposed in the magnet housing portion 8e is the length in the longitudinal direction of the magnet 9 disposed in the radial housing hole 8a. Is set to be about 1.5 times the axial length obtained by subtracting the length (6.7 [mm]) from which the magnet accommodating portion 8e (the extending portion 8i) is opposed. Yes. The axial lengths of the magnets 9 and 10 are set to be the same as the axial length of the rotor core 8.

  Here, the angle ratio-cogging torque characteristic diagrams shown in FIGS. 3 to 5 are data obtained from experimental results. Specifically, in the characteristic X1 indicated by the solid line in FIGS. 3 to 5, the circumferential width angle θ2 of the radially inner end of the tooth 4 is set to 27.4 °, and the number of magnetic poles is ( P =) 8 poles, and the residual magnetic flux density of each of the magnets 9 and 10 is set to 1.26 [T]. The other characteristics X2 to X6 shown in FIGS. 3 to 5 are obtained by changing the values from those of the characteristic X1. That is, the characteristic X2 indicated by a broken line in FIG. 3 is obtained when the circumferential width angle θ2 of the radially inner end of the tooth 4 is set to 26 °. A characteristic X3 indicated by a broken line in FIG. 4 is obtained when the number of magnetic poles is set to (P =) 6 poles. A characteristic X4 indicated by a two-dot chain line in FIG. 4 is obtained when the number of magnetic poles is set to (P =) 10 poles. Further, a characteristic X5 indicated by a broken line in FIG. 5 indicates that when the residual magnetic flux density of the magnet 9 disposed in the radial accommodation hole 8a is set to 1.42 [T] (the magnet 10 is 1.26 [T ])belongs to. Further, the characteristic X6 indicated by a two-dot chain line in FIG. 5 indicates that the residual magnetic flux density of the magnet 10 disposed in the V-shaped accommodation hole 8b (magnet accommodation portion 8e) is set to 1.42 [T] ( The magnet 9 is of 1.26 [T]).

  In the above characteristics X1 to X6 (FIGS. 3 to 5), even if each value is changed, the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped gap 8f are different. When 0.94 ≦ θa / θb ≦ 1.09 is satisfied, the cogging torque is a small value within the range including the lowest limit value (0.027 [Nm] or less within the experimental range). Further, when the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped side gap 8f satisfy 0.98 ≦ θa / θb ≦ 1.03, the cogging torque reaches the lowest limit value. It can be seen that the value is even smaller within the range of inclusion (0.016 [Nm] or less within the experimental range). Further, when the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped side gap 8f satisfy 0.99 ≦ θa / θb ≦ 1.02, the cogging torque reaches the lowest limit value. It can be seen that the lower limit value is approximately the lower limit within the range (0.015 [Nm] or less within the experimental range). Based on this, in the present embodiment, θa / θb is set to 1.00.

  Furthermore, the angle ratio-cogging torque characteristic diagram shown in FIG. 6 is data obtained from experimental results. Specifically, the data shown in FIG. 6 indicates that the characteristic X2 in which the cogging torque increases most rapidly when θa / θb is smaller than 1.00 and θa / θb is larger than 1.00. In this case, θa / θb is changed in a wide range of 0.60 to 1.60 with respect to the characteristic X4 in which the cogging torque rises most rapidly.

  In the above characteristics X2 and X4 (see FIG. 6), the circumferential width angle θa of the radial-side gap 8c and the circumferential width angle θb of the V-shaped gap 8f are 0.60 <θa / θb <1. When .60 is satisfied, the cogging torque does not reach the rated torque (0.3 [Nm] in this example), and it can be seen that the startability of the motor can be ensured. When the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped gap 8f satisfy 0.70 ≦ θa / θb ≦ 1.35, the cogging torque is half of the rated torque. (0.15 [Nm] in this example) or less, it can be seen that high startability and responsiveness of the motor can be secured. Further, when the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped side gap 8f satisfy 0.92 ≦ θa / θb ≦ 1.10, the cogging torque is 1 of the rated torque. It can be seen that the motor can be secured with extremely high startability and responsiveness (less than 0.03 [Nm] in this example).

Next, characteristic effects of the above embodiment will be described below.
(1) The magnet 9 disposed in the radial accommodation hole 8a constitutes a part of a magnetic pole (one magnetic pole in the rotor 2, for example, the S pole) formed on one side in the circumferential direction. It also constitutes a part of a magnetic pole (the other magnetic pole in the rotor 2, for example, N pole) formed on the other side in the direction. That is, the magnet 9 disposed in the radial accommodation hole 8a is shared by the two magnetic poles. Therefore, when the number of magnetic poles is P, the number of the magnets 9 and 10 is (3/2) P as a whole, so that the number of magnets can be reduced compared to the conventional (2P as a whole). In this embodiment, there are 12 magnets 9 and 10 with 8 poles. As a result, the number of parts can be reduced, and as a result, parts management costs and assembly costs can be reduced.

  Further, according to the same configuration, since the radial accommodation hole 8a is shared by the two magnetic poles, the radial outside (radial side gap 8c) of the radial accommodation hole 8a and the outer peripheral surface of the rotor core 8 are provided. The outer bridge portion 8j formed between the two magnetic poles is shared by the two magnetic poles. Therefore, the number of outer bridge portions in the rotor core 8 is reduced, and the leakage magnetic flux that passes through the outer bridge portion can be reduced.

  Moreover, the circumferential width angle θa of the radial side gap 8c at the radial outer end of the radial accommodation hole 8a and the circumferential width angle θb of the V-shaped gap 8f at the radial outer end of the V-shaped accommodation hole 8b. Means satisfying 0.99 ≦ θa / θb ≦ 1.02, and therefore the cogging torque is substantially the lower limit (see FIGS. 3 to 5). Note that the cogging torque value of the present embodiment is a value when the angle ratio (θa / θb) of the characteristic X1 shown by the solid line in FIGS. 3 to 5 is 1.0, and is about 0.010 [Nm ].

  Of course, the circumferential width angle θa of the radial-side gap 8c and the circumferential width angle θb of the V-shaped gap 8f satisfy 0.92 ≦ θa / θb ≦ 1.10. Therefore, it is possible to ensure extremely high startability and responsiveness of the motor.

  (2) The circumferential width angle θ1 between the radial-side gap 8c and the V-shaped gap 8f adjacent in the circumferential direction and the substantial magnetic pole of the rotor 2 facing the stator 1 is the radial direction of the teeth 4. Since it is set larger than the circumferential width angle θ2 of the inner end portion, the width angle of the magnetic flux received by the teeth 4 from the rotor 2 becomes wider than that set smaller, so that the efficiency can be improved.

  (3) Since the circumferential width angles θa and θb of the radial side gap 8c and the V-shaped side gap 8f are set smaller than the circumferential width angle θ2 of the radially inner end of the tooth 4, the radial direction of the tooth 4 Since the inner end portion can always be opposed to the substantial magnetic pole of the rotor 2 (between the radial direction gap 8c and the V-shaped gap 8f), high efficiency can be achieved.

The above embodiment may be modified as follows.
In the above embodiment, the circumferential width angle θa of the radial-side gap 8c of the radial receiving hole 8a and the circumferential width angle θb of the V-shaped gap 8f of the V-shaped receiving hole 8b are 0.99 ≦ θa /Θb≦1.02 is set (to 1.00), but is not limited to this, and within a range satisfying 0.94 ≦ θa / θb ≦ 1.09 (radial side gap) 8c and the shape of the V-shaped side gap 8f) may be changed. Thus, if 0.94 ≦ θa / θb ≦ 1.09 is satisfied, the cogging torque becomes a small value within the range including the lowest limit value (0.027 [Nm] or less within the experimental range) (FIG. 3). To FIG. 5). Further, it may be changed within a range satisfying 0.98 ≦ θa / θb ≦ 1.03 (the shape of the radial side gap 8c or the V-shaped side gap 8f). When 0.98 ≦ θa / θb ≦ 1.03 is satisfied, the cogging torque becomes a smaller value within the range including the lowest limit (0.016 [Nm] or less within the experimental range) (FIGS. 3 to 3). 5).

  Further, the circumferential width angle θa of the radial side gap 8c and the circumferential width angle θb of the V-shaped gap 8f do not satisfy 0.94 ≦ θa / θb ≦ 1.09, but 0.60 <θa You may change within the range which satisfy | fills /(theta)b<1.60 (The shape of the radial direction space | gap 8c and the V-shaped space | gap 8f). As described above, when 0.60 <θa / θb <1.60 is satisfied, the cogging torque does not reach the rated torque (see FIG. 6), and the startability of the motor can be ensured. In other words, when 0.60 <θa / θb <1.60 is not satisfied, there is a possibility that the cogging torque reaches the rated torque and the motor does not start (the rotor 2 does not rotate), but this can be avoided. it can. Further, it may be changed within a range satisfying 0.70 ≦ θa / θb ≦ 1.35 (the shape of the radial side gap 8c and the V-shaped side gap 8f). If 0.70 ≦ θa / θb ≦ 1.35 is satisfied, the cogging torque becomes half or less than the rated torque (see FIG. 6), and high startability and responsiveness of the motor can be ensured.

  In the above embodiment, the radial side gap 8c is a circle centered on the axial center of the rotor core 8 so that the radially outer end thereof maintains a constant distance from the outer peripheral surface of the rotor core 8 in the circumferential direction. It is formed in an arc shape, and the radial thickness of the outer bridge portion 8j is constant in the circumferential direction, but is not limited to this, and may be changed to another shape.

  For example, you may change as shown to Fig.7 (a). In this example (FIG. 7A), the radial gap 8l is inclined obliquely inward in the radial direction at both ends in the radial direction at the outer end in the radial direction. A linear inclined portion 8m that is gradually separated as it goes is formed. Accordingly, the radial thickness of the outer bridge portion 8n is formed so as to change at both ends in the circumferential direction (increase gradually toward the end portion). Further, in this example (FIG. 7 (a)), the radial gap 8l has a circumferential central portion that is spaced apart from the inclined portion 8m at the radially outer end thereof and the outer circumferential surface of the rotor core 8. A small diameter portion 8o having a large distance is formed. In such a change, the circumferential width angle θa of the radial-side gap 8l is defined and determined as follows from experimental results and the like so as to have substantially the same characteristics as the shape of the above-described embodiment. . That is, a straight line connecting the point P1 that is radially outermost on the outermost circumferential side of the radial gap 8l and the point P2 that is outermost circumferentially on the outermost radial side of the radial gap 8l (ie, the inclined portion 8m). And an area S1 surrounded by a virtual arc having a constant distance from the point P2 to the outer peripheral surface of the rotor core 8 and a virtual radial straight line extending radially outward from the point P1 (in FIG. 7A, schematically In particular, the angle of the line L1 that bisects the area of the hatched portion in the circumferential direction is defined as the circumferential width angle θa of the radial-side gap 8l. If determined in this manner, the same characteristics as the experimental results described in the above embodiment (see FIGS. 3 to 6) can be obtained, so that the same effects as in the above embodiment can be obtained.

  Further, for example, it may be changed as shown in FIG. In this example (FIG. 7B), the radial gap 8 p is curved radially inward at both ends in the radial direction at the radially outer end, and goes toward the outer peripheral surface of the rotor core 8 and both ends in the circumferential direction. A curved curved portion 8q that is gradually separated is formed. Thus, the radial thickness of the outer bridge portion 8r is formed so as to change at both ends in the circumferential direction (increase gradually toward the end portion). In such a change, the circumferential width angle θa of the radial side gap 8p is defined and determined as follows from experimental results and the like so as to have substantially the same characteristics as the shape of the above embodiment. . That is, a curve connecting the point P1 that is radially outermost on the outermost side in the radial direction of the radial gap 8p and the point P2 that is outermost in the radial direction of the radial side gap 8p (that is, the curved portion 8q). And an area S2 surrounded by a virtual arc having a constant distance from the point P2 to the outer peripheral surface of the rotor core 8 and a virtual radial straight line extending radially outward from the point P1 (in FIG. 7B, schematically In particular, the angle of the line L2 that bisects the area of the portion illustrated by hatching in the circumferential direction is defined as the circumferential width angle θa of the radial side gap 8p. If determined in this manner, the same characteristics as the experimental results described in the above embodiment (see FIGS. 3 to 6) can be obtained, so that the same effects as in the above embodiment can be obtained.

  In the above embodiment, the V-shaped air gap 8f is a circle centered on the axial center of the rotor core 8 so that the radially outer end thereof maintains a constant distance from the outer peripheral surface of the rotor core 8 in the circumferential direction. It is formed in an arc shape, and the radial thickness of the outer bridge portion 8k is assumed to be constant in the circumferential direction. However, the thickness is not limited to this and may be changed to another shape.

  For example, you may change as shown in FIG.7 (c). In this example (FIG. 7C), the V-shaped side gap 8s is inclined obliquely inward in the radial direction at both ends in the radial direction at the outer end in the radial direction, and on the outer peripheral surface of the rotor core 8 and both ends in the circumferential direction. A linear inclined portion 8t that is gradually separated as it goes is formed. Thereby, the radial thickness of the outer bridge portion 8u is formed so as to change at both circumferential end portions (increase gradually toward the end portion). When changed in this way, the circumferential width angle θb of the V-shaped gap 8s is defined and determined as follows based on experimental results and the like so as to have substantially the same characteristics as the shape of the above embodiment. . That is, a straight line connecting the point P3 that is radially outermost on the outermost side in the circumferential direction of the V-shaped gap 8s and the point P4 that is outermost in the radial direction on the outermost side in the radial direction of the V-shaped gap 8s (that is, the inclined portion 8t). And an area S3 surrounded by a virtual arc having a constant distance from the point P4 to the outer peripheral surface of the rotor core 8 and a virtual radial straight line extending radially outward from the point P3 (in FIG. 7C, schematically In particular, the angle of the line L3 that bisects the area of the hatched portion in the circumferential direction is defined as the circumferential width angle θb of the V-shaped gap 8s. If determined in this manner, the same characteristics as the experimental results described in the above embodiment (see FIGS. 3 to 6) can be obtained, so that the same effects as in the above embodiment can be obtained.

  Further, as shown in FIG. 7 (d), the V-shaped side gap 8f is maintained at a constant distance from the outer circumferential surface of the rotor core 8 in the circumferential direction (from the V-shaped side gap 8f). It is good also as the V-shaped side space | gap 8w provided with the circumferential direction extension part 8v protruded to the circumferential direction outer side. In this case, the outermost circumferential direction outer side of the V-shaped side gap 8w may be simply set as the circumferential width angle θb of the V-shaped side gap 8f.

  In the above embodiment, the circumferential width angle θ2 of the radially inner end of the tooth 4 is set to 27.4 °, but is not limited thereto, and other circumferential width angles θ2 (for example, 26 °).

  In the above embodiment, the number of magnetic poles is (P =) 8 poles, but is not limited to this, and may be changed to another number of magnetic poles (for example, 6 poles or 10 poles). Of course, the number of teeth 4 may be changed including this case.

  In the above embodiment, the residual magnetic flux density of each of the magnets 9 and 10 is set to 1.26 [T]. However, the present invention is not limited to this, and other residual magnetic flux densities (for example, either one is set to 1). .42 [T]) may be changed to a magnet.

  In the above embodiment, the radial gap 8c is formed to have a larger width (in the direction perpendicular to the radial direction) than the other part (the part where the magnet 9 is disposed) as viewed from the axial direction. If at least the above 0.60 <θa / θb <1.60 can be satisfied, it may be changed. For example, while changing the length in the short direction viewed from the axial direction of the magnet 9, the radial gap 8 c and the other portion (portion where the magnet 9 is disposed) viewed from the axial direction (the radial direction The width (in the orthogonal direction) may be the same.

  In the above embodiment, the pair of magnet accommodating portions 8e in the V-shaped accommodating hole 8b is formed as independent holes so as not to communicate with each other, but is not limited thereto, and the radially outer end portion, That is, the pair of V-shaped gaps 8f in the V-shaped receiving hole 8b may be communicated with each other.

  In the above embodiment, when the width of the inner bridge portion 8h formed between the radially inner side of the magnet housing portion 8e and the radial housing hole 8a as viewed from the axial direction is constant along the radial direction. However, it is not limited to this, You may change so that the width | variety seen from the axial direction of the inner side bridge part 8h may change along a radial direction. For example, the extending portion 8i of the above embodiment may not be formed.

  In the above embodiment, the rotor core 8 is formed by laminating the core sheets in the axial direction, but is not limited to this, and is formed by other methods (for example, sintered by sintering magnetic powder) Core).

The technical idea that can be grasped from the above embodiments will be described below together with the effects thereof.
(A) In the embedded magnet type motor according to any one of claims 1 to 6, the stator is provided with windings around a plurality of teeth provided radially outward of the rotor and extending radially inward. The circumferential width angle between the radial side gap and the V-shaped side gap adjacent in the circumferential direction is set larger than the circumferential width angle of the radially inner end of the teeth. An embedded magnet type motor.

  According to this configuration, the circumferential width angle between the radial side gap and the V-shaped side gap adjacent in the circumferential direction and the substantial magnetic pole of the rotor facing the stator is radially inward of the teeth. Since the width is set larger than the circumferential width angle of the end portion, the width angle of the magnetic flux received from the rotor by the teeth is wider than that set smaller, and the efficiency can be improved.

  (B) In the interior magnet type motor according to any one of claims 1 to 6 and (A), windings are provided on a plurality of teeth provided on the radially outer side of the rotor and extending radially inward. A buried stator having a wound stator, wherein the circumferential width angle of the radial side gap and the V-shaped side gap is set smaller than the circumferential width angle of the radially inner end portion of the teeth. Magnet type motor.

  According to this configuration, the radially inner end of the teeth can always be opposed to the substantial rotor magnetic pole (between the radial gap and the V-shaped gap), so that high efficiency can be achieved. Can do.

The top view of the stator and rotor of an embedded magnet type motor in this Embodiment. The connection diagram of the coil | winding in this Embodiment. Angle ratio-cogging torque characteristic diagram. Angle ratio-cogging torque characteristic diagram. Angle ratio-cogging torque characteristic diagram. Angle ratio-cogging torque characteristic diagram. (A)-(d) The partial enlarged plan view of the rotor in another example.

Explanation of symbols

  2 ... rotor, 8 ... rotor core, 8a ... radial accommodation hole, 8b ... V-shaped accommodation hole, 8c, 8l, 8p ... radial direction gap, 8e ... magnet accommodation part, 8f, 8s, 8w ... V-shaped gap, 9, 10: Magnet, θa: Circumferential width angle of the radial side gap, θb: Circumferential width angle of the V-shaped gap.

Claims (6)

An embedded magnet type motor having a rotor core in which a plurality of housing holes penetrating in the axial direction are formed in the circumferential direction and having a rotor in which magnets are disposed in the housing holes so that the number of magnetic poles is P. There,
The housing hole is formed by forming P / 2 radial housing holes extending in a substantially radial direction and substantially V-shaped housing holes protruding outward in the radial direction. Formed alternately,
The magnets are disposed in the radial accommodating holes and are disposed in the respective magnet accommodating portions corresponding to the respective straight lines forming the V shape of the V-shaped accommodating holes,
The magnet arranged in the radial accommodation hole and the magnet arranged in the magnet accommodation part adjacent to one of the circumferential directions constitute one magnetic pole, and the radial accommodation hole A different magnetic pole is constituted by the magnet disposed in the magnet and the magnet disposed in the magnet housing portion adjacent to the other in the circumferential direction,
A radial side gap in which the magnet is not disposed is formed at a radially outer end of the radial accommodation hole, and a V-shaped gap in which the magnet is not disposed at a radial outer end of the V-shaped accommodation hole. The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.60 <θa / θb <1.60
An embedded magnet type motor characterized by being set to satisfy The interior magnet type motor according to claim 1,
The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.70 ≦ θa / θb ≦ 1.35
An embedded magnet type motor characterized by being set to satisfy The interior magnet type motor according to claim 1,
The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.92 ≦ θa / θb ≦ 1.10.
An embedded magnet type motor characterized by being set to satisfy The interior magnet type motor according to claim 1,
The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.94 ≦ θa / θb ≦ 1.09
An embedded magnet type motor characterized by being set to satisfy The interior magnet type motor according to claim 1,
The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.98 ≦ θa / θb ≦ 1.03
An embedded magnet type motor characterized by being set to satisfy The interior magnet type motor according to claim 1,
The circumferential width angle θa of the radial side gap and the circumferential width angle θb of the V-shaped gap are:
0.99 ≦ θa / θb ≦ 1.02
An embedded magnet type motor characterized by being set to satisfy

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