JP2007195391A - Embedded magnet type motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an embedded magnet type motor in which the number of components can be decreased and leakage flux can be reduced while attaining high torque by using many magnets, and cogging torque and torque ripple can also be reduced. <P>SOLUTION: Containing hole of a rotor core having the number of poles P consists of P/2 of radial containing holes 8a extending in the substantially radial direction, and P/2 of substantially V-shaped containing holes 8b (a pair of magnet containing sections 8f) which becomes convex on the radially outside. One magnetic pole is constituted of a magnet 9 in the radial containing hole and a magnet 10 in the magnet containing section contiguous in one circumferential direction, and one different magnetic pole is constituted of a magnet 9 in the radial containing hole and a magnet 10 in the magnet containing section contiguous in the other circumferential direction. At the radial outside ends of the radial containing hole and the V-shaped containing hole, unequal portions 8c and 8h where the distance from each circumferential center in their other portions is set to differ in one and the other circumferential direction are formed partially in the axial direction. <P>COPYRIGHT: (C)2007,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. In addition, in the embedded magnet type motor as described above, a sudden flow (change) of magnetic flux occurs between the stator and the rotor as the torque is increased. Reduction is also 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. Another object of the present invention is to provide an embedded magnet type motor that can reduce cogging torque and torque ripple.

  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; One magnetic pole different from the magnet disposed in the magnet housing portion adjacent to the other in the circumferential direction is configured, and the radially outer end portion of the radial housing hole and the V-shaped housing hole has the The non-uniform part set so that the distance from the center in the circumferential direction in the radial accommodation hole and the other part of the V-shaped accommodation hole is different between one and the other in the circumferential direction is different from the other part in the axial direction. It was formed to have a shape.

  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. In addition, at the radially outer ends of the radial accommodation holes and the V-shaped accommodation holes, the distances from the respective circumferential centers in the other portions of the radial accommodation holes and the V-shaped accommodation holes are different between one and the other in the circumferential direction. The non-uniform portion set differently is formed to have a different shape from other portions in the axial direction. Therefore, for example, compared with a case where the radially outer end portions of the radial accommodation hole and the V-shaped accommodation hole have the same shape in the axial direction, a rapid flow (change) of magnetic flux with the stator is suppressed, and the cogging torque is reduced. And torque ripple can be reduced. In addition, according to the same structure, as a matter of course, more magnets can be used and higher torque can be achieved as compared with a case where the magnets are simply curved or linear arranged along the circumferential direction.

  According to a second aspect of the present invention, in the interior magnet type motor according to the first aspect, at least a part of the radially outer end portion including the non-uniform portion in the radial accommodation hole is viewed from the axial direction. The circumferential width was set larger than the width of the magnet disposed in the radial accommodation hole.

  According to this configuration, at least a part of the radially outer end portion including the unequal portion in the radial accommodation hole has a width in the circumferential direction viewed from the axial direction in the radial accommodation hole. Since the magnetic resistance is set larger, the magnetic resistance in that portion increases (the magnetic path becomes far), and the leakage magnetic flux can be further reduced.

  According to a third aspect of the present invention, in the interior magnet type motor according to the first or second aspect, a radially inner end portion of the magnet housing portion of the magnet disposed in the radial housing hole. While facing the magnetic flux outflow surface or the magnetic flux inflow surface, the width viewed from the axial direction of the inner bridge portion formed between the radial inner side of the magnet housing portion and the radial housing hole is constant along the radial direction. An embedded magnet type motor characterized by being formed as follows.

  According to this configuration, the magnetic flux outflow surface or magnetic flux inflow surface of the magnet disposed in the radial accommodation hole, and the magnetic flux inflow surface or magnetic flux outflow surface facing the radially inner side of the magnet disposed in the magnet housing portion, , The magnetic flux is directed to the different magnets, the leakage magnetic flux from the N-pole of the magnet to the S-pole of the magnet is reduced, and the effective magnetic flux is increased. And since the width | variety seen from the axial direction of the inner side bridge part formed between the radial direction inner side and radial direction accommodation hole of a magnet accommodating part is constant along a radial direction, it is from the axial direction of an inner bridge part. The seen width can be made evenly narrow, and the leakage magnetic flux from the N pole of the magnet to the S pole of the magnet can be further reduced in the portion.

  According to a fourth aspect of the present invention, in the interior magnet type motor according to any one of the first to third aspects, the pair of magnet housings corresponding to each straight line forming the V-shape of the V-shaped housing hole. By forming the portions independently of each other, an inter-accommodating portion bridge portion extending in the radial direction is formed radially outward between the pair of magnet accommodating portions.

  According to this configuration, since the outer bridge portion formed between the magnet housing portion and the outer peripheral surface of the rotor core is connected to the inter-housing portion bridge portion (as compared with the one having a top portion that allows the magnet housing portions to communicate with each other). The strength of the rotor core is increased and its deformation is prevented.

  According to a fifth aspect of the present invention, in the interior magnet type motor according to any one of the first to fourth aspects, the rotor core is formed by stacking core sheets in the axial direction, and the core At a position corresponding to the radially outer end of each of the radial accommodation holes in the sheet, the distance from the circumferential center in the portion corresponding to the other part of the radial accommodation hole is between one and the other in the circumferential direction. Pre-lamination non-uniform portions set differently are partially formed in the circumferential direction, and the rotor core is formed by laminating the core sheets so that the pre-lamination non-uniform portions are evenly arranged in the circumferential direction. Become.

  According to this configuration, the rotor core in the interior magnet type motor according to any one of claims 1 to 4 can be easily formed in a balanced manner in the circumferential direction with one type of core sheet.

  According to the present invention, it is possible to reduce the number of parts, reduce the magnetic flux leakage, and reduce the cogging torque and torque ripple while increasing the torque by using many magnets. An embedded magnet type motor can be provided.

Hereinafter, an embodiment of the present invention will be described with reference to FIG. 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 has a plurality of teeth 4 formed so as to extend from the inner peripheral surface of the cylindrical portion 3 forming the outer shape toward the axial center at equal circumferential intervals. The stator core 5 is provided with a winding 6 (only part of which is shown by a two-dot chain line in FIG. 1) wound around each tooth 4 by concentrated winding via an insulator (not shown). In the present embodiment, twelve teeth 4 are formed.

  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.

  As shown in FIGS. 2 and 3, the rotor core 8 is formed in a substantially cylindrical shape by stacking the core sheets 11 in the axial direction, and the rotating shaft 7 is fitted in the center hole thereof, and the rotor core 8 is formed inside the stator 1. It is rotatably supported. 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.

  At the radially outer end of the radial accommodation hole 8a, the unequal part 8c is set such that the distance from the circumferential center in the other part of the radial accommodation hole 8a is different between one and the other in the circumferential direction. However, it is formed so as to have a shape different from that of other portions in the axial direction.

  Specifically, all the portions of the radially outer end portion (including the non-uniform portion 8c) in the radial accommodation hole 8a have a circumferential width as viewed in the axial direction disposed in the radial accommodation hole 8a. The width is set to be larger than 9. In addition, the width seen from the axial direction is smaller than the other portion in the radial direction outside the radial accommodation hole 8a and inside the non-uniform portion 8c in the radial direction so as to restrict the movement of the magnet 9 outward in the radial direction. A protruding portion 8d protruding so as to be formed is formed. Further, the width of the portion excluding the radially outer end portion (including the non-uniform portion 8c and the protruding portion 8d in the present embodiment) of the radial accommodation hole 8a is constant in the radial direction when viewed from the axial direction. . And the radial direction outer end part of the radial direction accommodation hole 8a is a non-uniform part set so that the distance from the circumferential direction center in the other part of the radial direction accommodation hole 8a is different between one and the other in the circumferential direction. 8c and equal portions 8e set so that the distance from the circumferential center in the other part of the radial accommodation hole 8a is the same in one and the other in the circumferential direction are alternately formed in the axial direction. Yes. Further, in the present embodiment, four radial accommodation holes 8a are formed in the circumferential direction, but at the same position in the axial direction (that is, for each core sheet 11), two radial accommodation holes that are continuous in the circumferential direction. An uneven portion 8c is formed in 8a, and an equal portion 8e is formed in the other two radial accommodation holes 8a that are continuous in the circumferential direction. In the present embodiment, the two non-uniform portions 8c that continue in the circumferential direction at the same position in the axial direction (that is, for each core sheet 11) are set so that the sides that extend greatly in the circumferential direction face each other.

  The V-shaped accommodation hole 8b includes a pair of magnet accommodation portions 8f corresponding to two straight lines forming the V-shape, and a top portion 8g that communicates the radially outer sides of the magnet accommodation portions 8f. At the radially outer end (top 8g) of the V-shaped receiving hole 8b, the distance from the circumferential center in the other part of the V-shaped receiving hole 8b is set to be different between one side and the other in the circumferential direction. The non-uniform portion 8h is formed to have a different shape from other portions in the axial direction.

  Specifically, the V-shaped accommodation hole 8b (magnet accommodation portion 8f) protrudes radially outward so that the width seen from the axial direction is smaller than the other part so as to restrict the movement of the magnet 10 outward in the radial direction. The protruding portion 8i is formed. The magnet housing portion 8f is linear when viewed from the axial direction, and its width is constant in the radial direction. In addition, the angle which a pair of magnet accommodating part 8f (V shape) of the V-shaped accommodation hole 8b of this Embodiment makes is set to about 50 degrees. And the radial direction outer side edge part (top part 8g) of the V-shaped accommodation hole 8b is set so that the distance from the circumferential direction center in the other part of this V-shaped accommodation hole 8b may differ in one and the other of the circumferential direction. The uneven portions 8h and the uniform portions 8j set so that the distance from the circumferential center in the other part of the V-shaped receiving hole 8b is the same in one and the other in the circumferential direction are alternately arranged in the axial direction. Is formed. In the present embodiment, four V-shaped receiving holes 8b are formed in the circumferential direction. However, at the same position in the axial direction (that is, for each core sheet 11), two V-shaped receiving holes that are continuous in the circumferential direction. The non-uniform part 8h is formed in 8b, and the uniform part 8j is formed in the other two V-shaped accommodation holes 8b continuous in the circumferential direction. In the present embodiment, the two non-uniform portions 8h that are continuous in the circumferential direction at the same position in the axial direction (that is, for each core sheet 11) are set such that the sides that greatly extend in the circumferential direction face each other. Yes.

  Further, the radially inner end of the magnet housing portion 8f in the present embodiment is perpendicular 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 so as to face the side (inner wall surface) facing the direction (see a partially enlarged view in FIG. 1). And the width | variety seen from the axial direction of the inner side bridge | bridging part 8k formed between the radial direction inner side of the magnet accommodating part 8f and the radial direction accommodation hole 8a is formed so that it may become constant along a radial direction. In addition, this is implement | achieved by extending the extending part 8l of substantially triangular shape seeing from an axial direction at the radial direction inner side edge part of the magnet accommodating part 8f. In the present embodiment, the longitudinal direction of the magnet housing portion 8f is inclined at about 70 degrees with respect to the longitudinal direction of the radial housing hole 8a. In addition, the rotor core 8 having the above-described shape is formed with an outer bridge portion 8m between the radially outer side (the non-uniform portion 8c and the equal portion 8e) of the radial accommodation hole 8a and the outer peripheral surface of the rotor core 8, and the magnet housing portion. An outer bridge portion 8 n is formed between the radially outer side of 8 f (specifically, the top portion 8 g) and the outer peripheral surface of the rotor core 8.

  Here, as shown in FIG. 2, at the position corresponding to the radially outer end of each radial accommodation hole 8a (see FIG. 1) in the core sheet 11, it corresponds to the other part of the radial accommodation hole 8a. The pre-stacking unequal portion 11a in which the distance from the circumferential center in the portion is different between one and the other in the circumferential direction is partially formed in the circumferential direction (in this example, two continuous in the circumferential direction). ing. Further, in the portion corresponding to the radially outer end portion of each of the radial accommodation holes 8a (see FIG. 1) in the core sheet 11, a portion where the pre-lamination non-uniform portion 11a is not formed is a radial accommodation hole. A pre-stacking uniform portion 11b is formed in which the distance from the circumferential center in the portion corresponding to the other portion of 8a is set to be the same in one and the other in the circumferential direction.

  Further, as shown in FIG. 2, at the position corresponding to the radially outer end of each V-shaped receiving hole 8b (see FIG. 1) in the core sheet 11, a portion corresponding to the other part of the V-shaped receiving hole 8b. The pre-stacking unequal portion 11c set so that the distance from the center in the circumferential direction is different between one and the other in the circumferential direction is partially formed in the circumferential direction (in this example, two continuous in the circumferential direction). Yes. Further, at the position corresponding to the radially outer end of each V-shaped receiving hole 8b (see FIG. 1) in the core sheet 11, the V-shaped receiving hole 8b is not formed in the portion where the pre-stacking uneven portion 11c is not formed. A pre-stacking uniform portion 11d is formed such that the distance from the circumferential center in the portion corresponding to the other portion is the same in one and the other in the circumferential direction.

  In the rotor core 8, the pre-stacking non-uniform portions 11a and 11c (and the pre-stacking uniform portions 11b and 11d) that become non-uniform portions 8c and 8h (and uniform portions 8e and 8j) are evenly arranged in the circumferential direction. Thus, the core sheet 11 is laminated. In the present embodiment, the rotor core 8 is laminated while the core sheets 11 are rotated one by one (180 °) about the axis (see FIG. 3).

Magnets 9 and 10 are disposed in the radial accommodating hole 8a and the magnet accommodating portion 8f, 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 8f 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 formed by the magnet 9 disposed in the radial accommodation hole 8a and the magnet 10 disposed in the magnet accommodation portion 8f adjacent to the other in the circumferential direction. is doing.

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.

  In addition, according to the same configuration, the radial accommodation hole 8 a is shared by the two magnetic poles, and therefore, the outer side formed between the radial outer side of the radial accommodation hole 8 a and the outer peripheral surface of the rotor core 8. The bridge portion 8m is also shared for 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.

  In addition, at the radially outer ends of the radial accommodation hole 8a and the V-shaped accommodation hole 8b, the distances from the respective circumferential centers in other portions of the radial accommodation hole 8a and the V-shaped accommodation hole 8b are in the circumferential direction. The non-uniform portions 8c and 8h set differently on the other side are formed so as to have a different shape from other portions in the axial direction. Therefore, for example, compared with a case where the radially outer end portions of the radial accommodation hole and the V-shaped accommodation hole have the same shape in the axial direction, a rapid flow (change) of magnetic flux with the stator 1 is suppressed, and cogging is performed. Torque and torque ripple can be reduced. FIG. 4 is an angle-cogging torque characteristic diagram obtained from an experiment, in which the unequal portions 8c and 8h are not formed, and the radially outer ends of the radial accommodation holes and the V-shaped accommodation holes are the same in the axial direction. A characteristic X1 in the case of the shape and a characteristic X2 in the present embodiment are shown. In addition, according to the same configuration, of course, more magnets can be used and higher torque can be achieved compared to a case where the magnets are simply curved or linear arranged along the circumferential direction.

  (2) All the portions of the radially outer end portions (the non-uniform portion 8c and the uniform portion 8e) in the radial accommodation hole 8a have a circumferential width as viewed in the axial direction disposed in the radial accommodation hole 8a. Therefore, the magnetic resistance at that portion increases (the magnetic path becomes far), and the leakage magnetic flux can be further reduced.

  (3) The radially inner end of the magnet housing portion 8f faces the short-side surface of the magnet 9 disposed in the radial housing hole 8a, that is, the magnetic flux outflow surface or the magnetic flux inflow surface ( In FIG. 1, refer to a partially enlarged view). Therefore, the magnetic flux outflow surface or magnetic flux inflow surface of the magnet 9 disposed in the radial accommodation hole 8a and the magnetic flux inflow surface or magnetic flux outflow surface facing the radially inner side of the magnet 10 disposed in the magnet accommodation portion 8f. And the magnetic flux (refer to the arrow A indicated by the two-dot chain line in the partially enlarged view in FIG. 1) is directed to the different magnets 9 and 10. As a result, the leakage magnetic flux (refer to the arrow B indicated by the broken line in the partial enlarged view in FIG. 1) from the N pole of the magnet 9 to the S pole of itself is reduced and the effective magnetic flux increases. Moreover, since the width of the inner bridge portion 8k formed between the radially inner side of the magnet housing portion 8f and the radial housing hole 8a as viewed from the axial direction is constant along the radial direction, the inner bridge portion 8k. The width viewed from the axial direction of the magnet 9 can be made evenly narrow, and the leakage magnetic flux from the N pole of the magnet 9 to the S pole of the magnet 9 at that portion is further reduced.

(4) By configuring and laminating the core sheet 11 as described above, the rotor core 8 can be easily formed with a single core sheet 11 in a balanced manner in the circumferential direction.
(5) Since the rotor core 8 is laminated while the core sheets 11 are rotated one by one around the axial center, a large number of pre-lamination non-uniform portions 11a and 11c (non-uniform portions 8c and 8h) are arranged in the axial direction. As a result, the deformation of the rotor core 8 is prevented. In other words, if a large number of circumferentially extending portions in the pre-lamination non-uniform portions 11a and 11c (non-uniform portions 8c and 8h) are arranged in the axial direction, a long gap is formed in the axial direction, and the rotor core 8 is partially bent easily. However, this is prevented.

  (6) The width of the portion excluding the radially outer end (including the non-uniform portion 8c and the protruding portion 8d in the present embodiment) of the radial accommodation hole 8a is constant in the radial direction when viewed from the axial direction. The magnet 9 disposed in the radial accommodation hole 8a has a substantially rectangular parallelepiped shape. Therefore, for example, the magnet 9 has a simpler shape as compared with a trapezoidal magnet when viewed from the axial direction.

  (7) The magnet housing portion 8f is linear when viewed from the axial direction and the width thereof is constant in the radial direction, and the magnet 10 disposed in the magnet housing portion 8f has a substantially rectangular parallelepiped shape. Therefore, for example, the magnet 10 has a simpler shape than a magnet having a curved shape when viewed from the axial direction.

  (8) In the V-shaped accommodation hole 8b, the radially outer sides of the pair of magnet accommodation portions 8f communicate with each other at the top portion 8g. Therefore, in this portion, N of the magnets 10 disposed in each magnet accommodation portion 8f. Leakage magnetic flux from the pole to its own S pole is prevented.

The above embodiment may be modified as follows.
In the above embodiment, the V-shaped accommodation hole 8b has the top portion 8g that communicates the radially outer sides of the magnet housing portion 8f. However, the present invention is not limited to this. The pair of magnet housing portions 8f may be formed independently without communicating. For example, as shown in FIG. 5, the top portion 8g (see FIG. 1) of the above embodiment has a shape that is divided so as not to communicate with the magnet housing portions 8f, and the pair of magnet housing portions 8f are independent of each other. Thus, the inter-accommodating portion bridge portion 21 extending in the radial direction may be formed radially outward between the pair of magnet accommodating portions 8f. If it does in this way, since the said outside bridge part 8n formed between the magnet accommodating part 8f and the outer peripheral surface of the rotor core 8 will connect with the bridge part 21 between accommodating parts, (the top part 8g which connects the magnet accommodating parts 8f mutually) The strength of the rotor core 8 is increased and its deformation is prevented.

  In the above embodiment, all of the radially outer end portions (the non-uniform portion 8c and the uniform portion 8e) in the radial accommodation hole 8a have a circumferential width in the radial accommodation hole 8a as viewed from the axial direction. Is set to be larger than the width of the magnet 9 disposed in the at least one portion, but at least a part of the radially outer end (the non-uniform portion 8c and the uniform portion 8e) is set to be larger than the width of the magnet 9. May be. For example, only the non-uniform portion 8 c may be set larger than the width of the magnet 9. Moreover, you may set so that all the parts of a radial direction outer side edge part (unequal part 8c and uniform part 8e) may become below the width | variety of the said magnet 9. FIG.

  In the above embodiment, when the width of the inner bridge portion 8k formed between the radially inner side of the magnet housing portion 8f and the radial housing hole 8a 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 8k may change along a radial direction. For example, it is not necessary to form the extending portion 8l of the above embodiment.

  In the above embodiment, the radially inner end of the magnet housing portion 8f is opposed to the magnetic flux outflow surface or the magnetic flux inflow surface of the magnet 9 disposed in the radial housing hole 8a. Without being limited, the radially inner end portion of the magnet housing portion 8f may not be opposed to the magnetic flux outflow surface and the magnetic flux inflow surface of the magnet 9 disposed in the radial housing hole 8a.

  In the above embodiment, the rotor core 8 is laminated while the core sheets 11 are rotated one by one around the axis center. However, the present invention is not limited to this, and a substantially similar rotor core is configured by another method (structure). May be. For example, the core sheets 11 may be stacked while being rotated every plural sheets. If it does in this way, since the frequency | count of rotating the core sheet 11 reduces, the manufacture becomes easy. In addition, if the pre-lamination non-uniform portion (non-uniform portion) can be evenly arranged in the circumferential direction, the rotor core may be configured by laminating the core sheet while reversing the front and back. In this case as well, the core sheets may be reversed and stacked one by one on the front and back, or the core sheets may be reversed and stacked on the front and back for each plurality. Moreover, in such a case, it is not necessary to invert the front and back during the process of laminating, and the core sheet (1) is formed from the core sheet group that has been turned face up and the core sheet group that has been turned face down. Alternatively, the sheets may be stacked alternately (every sheet or every plural sheets). If it does in this way, since it is not necessary to rotate a core sheet | seat centering on an axis | shaft (control of a fine rotation angle is unnecessary), the manufacture becomes easy. Of course, the number of core sheets 11 (four in FIG. 3) may be changed.

  In the above embodiment, the rotor core 8 is configured with one type of core sheet 11, but the present invention is not limited to this, and the rotor core may be configured with a plurality of types of core sheets. For example, a core sheet in which only the pre-stacking non-uniform portions 11a and 11c are formed (the pre-stacking uniform portions 11b and 11d are not formed) and only the pre-stacking uniform portions 11b and 11d are formed. Alternatively, the rotor core may be configured by stacking these two types (one not formed with the pre-stacking non-uniform portions 11a and 11c). Also, for example, as shown in FIG. 6, in the case where the inter-accommodating portion bridge portion 21 (see FIG. 5) is formed, only the pre-lamination non-uniform portions 11a and 11c are formed on the core sheet (see above). A core sheet 31 in which the pre-lamination uniform portions 11b and 11d are not formed) and a core sheet 32 in which only the pre-lamination uniform portions 11b and 11d are formed (the pre-lamination non-uniform portions 11a and 11c are not formed). And the rotor core may be configured by stacking them. In this example (FIG. 6), the ratio of the number of core sheets 31 and 32 is 3 to 1 (in FIG. 6, it is 3 to 1 but, for example, 6 to 2 is the same). This ratio may be changed to other ratios (for example, 1 to 1, 3 to 2, 9 to 1, etc.). If it does in this way, the ratio (cross-sectional area) in the axial direction of the said unequal part 8c, 8h (equal part 8e, 8j) can be selected easily (freely) by changing the said ratio. Since the torque-torque ripple characteristic varies depending on the ratio, for example, increasing the ratio of the non-uniform portions 8c and 8h in the axial direction, that is, the ratio of the core sheet 31, greatly increases the torque ripple at low torque. Can be reduced.

  In the above embodiment, the width of the portion excluding the radially outer end (including the non-uniform portion 8c and the protruding portion 8d) of the radial accommodation hole 8a is constant in the radial direction when viewed from the axial direction. The magnet 9 disposed in the direction accommodation hole 8a is assumed to have a substantially rectangular parallelepiped shape. However, the shape is not limited to this, and the shape and width of the radial accommodation hole and the magnet viewed from the axial direction are changed. Also good.

  For example, the portion excluding the radially outer end of the radial accommodation hole has a trapezoidal shape that becomes narrower as the width increases in the radial direction when viewed from the axial direction, and the magnet disposed in the radial accommodation hole is The width of the outer end portion in the radial direction may be narrower as viewed from the direction toward the outer side in the radial direction, and the trapezoidal shape may be larger than the width of the radial outer end portion of the trapezoidal shape of the radial accommodation hole. If it does in this way, the magnet arrange | positioned in a radial direction accommodation hole will receive the force which is a force which goes to a radial direction outer side by the centrifugal force at the time of rotation of a rotor, and is pressed on the inner wall face of a radial direction accommodation hole. Therefore, the gap between the magnet and the rotor core can be stably reduced, and as a result, the torque can be increased stably.

  In addition, for example, the portion of the radial accommodation hole except for the radially outer end is formed in a trapezoidal shape so that the width thereof increases in the radial direction when viewed from the axial direction, and a magnet disposed in the radial accommodation hole is provided. The trapezoidal shape may be larger as the width of the inner end portion in the radial direction is wider toward the outer side in the axial direction, and the width of the inner end portion in the radial direction is larger than the width of the inner end portion in the radial direction. In this way, the magnetic path from the N-pole of the magnet to the S-pole immediately can be increased regardless of the shape of the non-uniform portion at the radially outer end, so that leakage magnetic flux can be reduced. Moreover, you may arrange | position the nonmagnetic component for urging | biasing a magnet to the direction where the width | variety seen from the axial direction is narrow in the radial direction accommodation hole of these examples.

  In the above embodiment, the magnet housing portion 8f is linear when viewed from the axial direction, the width thereof is constant in the radial direction, and the magnet 10 disposed in the magnet housing portion 8f has a substantially rectangular parallelepiped shape. However, the present invention is not limited to this, and the shape and width of the magnet housing portion and the magnet viewed from the axial direction may be changed. That is, the substantially V-shape of the V-shaped accommodation hole is a shape including those in which each straight line (a pair of straight lines) forming the V-shape is curved, or the width of the straight line is not constant. The magnet housing portions corresponding to the straight lines forming the V-shape of the V-shaped housing holes include those that are curved with respect to the straight lines and those that are not constant in width.

  For example, as shown in FIG. 7, the pair of magnet accommodating portions 41a in the V-shaped accommodating hole 41 are curved in a direction in which their centers approach each other when viewed from the axial direction, and are disposed in the magnet accommodating portion 41a. The magnet 42 may be similarly curved (so as to be accommodated in the magnet accommodating portion 41a). If it does in this way, many magnets can be used compared with the magnet of a substantially rectangular parallelepiped shape, and also higher torque can be attained. In this example (FIG. 7), only the non-uniform portion 44 a at the radially outer end of the radial accommodation hole 44 that extends in the radial direction and accommodates the magnet 43 is the width in the circumferential direction (short direction) of the magnet 43. It is set larger. Of course, for example, the pair of magnet housing portions in the V-shaped housing hole and the pair of magnets disposed in the magnet housing portion may have a shape curved in a direction in which their centers are separated from each other when viewed from the axial direction.

  In the above embodiment, the radially outer ends of the radial accommodation holes 8a and the V-shaped accommodation holes 8b are formed with non-uniform portions 8c and 8h and uniform portions 8e and 8j alternately formed in the axial direction. However, as long as at least one type of non-uniform portion is formed to have a shape different from that of other portions in the axial direction, the configuration may be changed to another configuration. For example, the radially outer ends of the radial accommodation holes and the V-shaped accommodation holes may be formed of two types of non-uniform parts and different parts (different in circumferential width). Further, for example, the radially outer ends of the radial accommodation holes and the V-shaped accommodation holes may be formed from two types of non-uniform portions (different in circumferential width).

  The magnets 9 and 10 and the rotor core 8 according to the above embodiment may be divided in the axial direction and arranged so as to be shifted in the circumferential direction. In this way, the rapid magnetic flux flow (change) between the stator 1 and the rotor 2 can be further reduced, and the cogging torque and torque ripple can be further reduced.

  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 number of teeth 4 and the number of magnetic poles (magnets 9 and 10) in the above embodiment may be changed to other numbers.
The technical idea that can be grasped from the above embodiments will be described below together with the effects thereof.

  (A) The embedded magnet type motor according to claim 5, wherein the rotor core is laminated while the core sheets are rotated one by one around the axis.

  According to this configuration, it is possible to prevent the rotor core from being deformed by preventing a large number of uneven portions before lamination from being arranged in the axial direction. That is, if a large number of portions extending in the circumferential direction in the uneven portion before lamination are arranged in the axial direction, there is a possibility that a long gap is formed in the axial direction and the rotor core is partially bent easily, but this is prevented.

  (B) The interior magnet type motor according to claim 5, wherein the rotor core is laminated while the core sheet is rotated about a plurality of sheets about the axis.

According to this configuration, since the number of times of rotating the core sheet is reduced, its manufacture becomes easy.
(C) The embedded magnet type motor according to claim 5, wherein the core sheet is laminated while being reversed on the front and back sides.

According to this configuration, since it is not necessary to rotate the core sheet about the axis, the manufacture becomes easy.
(D) In the embedded magnet type motor according to any one of claims 1 to 4, the rotor core is formed by stacking core sheets in an axial direction, and the core sheet is formed in the radial direction. Before stacking, the distance from the center in the circumferential direction in the part corresponding to the other part of the radial accommodation hole is set to be different between the one in the circumferential direction and the other in the position corresponding to the uneven part of the accommodation hole The distance from the center in the circumferential direction in the portion corresponding to the other portion of the radial receiving hole at the position corresponding to the non-uniform portion of the radial receiving hole and the position where the uneven portion is formed is the circumferential direction. An embedded magnet type motor characterized by having at least two types, one having a pre-stacking uniform portion set so as to be the same in one and the other.

  According to this configuration, the rotor core in the interior magnet type motor according to any one of claims 1 to 3 can be easily obtained with a plurality of types of core sheets. Moreover, according to the same structure, the ratio (cross-sectional area) in the axial direction of a non-uniform | heterogenous part (equal part) can be selected easily (freely) by changing the ratio of the number of different core sheets.

  (E) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (d) above, a portion excluding the radially outer end of the radial accommodation hole is a shaft. An embedded magnet type motor characterized in that the width thereof is constant in the radial direction when viewed from the direction, and the magnet disposed in the radial accommodation hole has a substantially rectangular parallelepiped shape.

According to this configuration, since the magnet has a substantially rectangular parallelepiped shape, for example, the magnet has a simple shape as compared to a trapezoidal magnet when viewed from the axial direction.
(F) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (d) above, a portion excluding the radially outer end portion of the radially accommodating hole is a shaft. The trapezoidal shape becomes narrower as the width goes outward in the radial direction when viewed from the direction, and the magnet disposed in the radial accommodation hole is narrower as the width goes outward in the radial direction when viewed from the axial direction. An embedded magnet type motor having a trapezoidal shape in which a width of a radially outer end is larger than a width of a trapezoidal radially outer end of the radial accommodation hole.

  According to this configuration, the magnet disposed in the radial accommodation hole receives a force that is directed outward in the radial direction by a centrifugal force when the rotor rotates and is pressed against the inner wall surface of the radial accommodation hole. Therefore, the gap between the magnet and the rotor core can be stably reduced, and as a result, the torque can be increased stably.

  (G) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (d) above, a portion excluding the radially outer end of the radial accommodation hole is a shaft. The trapezoidal shape becomes wider as it goes radially outward when viewed from the direction, and the magnet disposed in the radial accommodation hole is wider as it goes radially outward when viewed from the axial direction. An embedded magnet type motor having a trapezoidal shape in which a width of a radially inner end portion is larger than a width of a radially inner end portion of the trapezoidal shape of the radial accommodation hole.

According to this configuration, regardless of the shape of the non-uniform portion in the radial accommodation hole, the magnetic path from the N-pole of the magnet to the S-pole of the magnet can be made far away, so that leakage flux can be reduced.
(H) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (g), the magnet housing portion is linear when viewed in the axial direction and has a width thereof. The interior magnet motor is characterized in that the magnet is fixed in the radial direction, and the magnet disposed in the magnet housing portion has a substantially rectangular parallelepiped shape.

According to this configuration, the magnet has a substantially rectangular parallelepiped shape, and thus has a simpler shape than, for example, a curved magnet as viewed from the axial direction.
(I) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (g), the magnet housing portion has a curved shape when viewed in the axial direction, The embedded magnet type motor, wherein the magnet disposed in the magnet housing portion has a curved shape along the magnet housing portion.

According to this configuration, since the magnet has a curved shape, more magnets can be used than a substantially rectangular parallelepiped magnet, and a higher torque can be achieved.
(Nu) Claim 1 thru | or 3, 5 and the interior magnet type motor as described in any one of said (i)-(ri) WHEREIN: The said V-shaped accommodation hole is radial direction outer sides of the said magnet accommodation part. An embedded magnet type motor having a top portion for communicating with each other.

  According to this configuration, since the outer sides in the radial direction of the magnet housing portions communicate with each other at the top, the leakage magnetic flux that immediately goes from the N pole of the magnet disposed in each magnet housing portion toward its own S pole. Is prevented.

  (L) In the interior magnet type motor according to any one of claims 1 to 5 and (a) to (n) above, the radial outer end portion including the non-uniform portion in the radial accommodation hole. All the parts are embedded magnet type motors characterized in that the width in the circumferential direction as viewed from the axial direction is set larger than the width of the magnet disposed in the radial accommodation hole.

  According to the same configuration, all the portions of the radially outer end including the unequal portion in the radial accommodation hole have a width in the circumferential direction viewed from the axial direction of the magnet disposed in the radial accommodation hole. Since the magnetic resistance is set larger, the magnetic resistance in that portion increases (the magnetic path becomes far), and the leakage magnetic flux can be further reduced.

The top view of the stator and rotor of an embedded magnet type motor in this Embodiment. The top view of the core sheet in this Embodiment. The exploded perspective view of the rotor core in this Embodiment. Angle-cogging torque characteristic diagram. The top view of the rotor in another example. The disassembled perspective view of the rotor core in another example. The top view of the rotor in another example.

Explanation of symbols

  2 ... rotor, 8 ... rotor core, 8a, 44 ... radial accommodation hole, 8b, 41 ... V-shaped accommodation hole, 8c, 8h, 44a ... non-uniform part, 8f, 41a ... magnet accommodation part, 8k ... inner bridge part, 9, 10, 42, 43... Magnet, 11... Core sheet, 11a, 11c.

Claims (5)

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,
At the radially outer ends of the radial accommodation holes and the V-shaped accommodation holes, distances from the respective circumferential centers in the other portions of the radial accommodation holes and the V-shaped accommodation holes are one and the other in the circumferential direction. And a non-uniform portion set differently for each of the other portions in a different shape from the other portions in the axial direction. The interior magnet type motor according to claim 1,
At least a part of the radially outer end including the non-uniform portion in the radial accommodation hole has a circumferential width as viewed from the axial direction larger than the width of the magnet disposed in the radial accommodation hole. An embedded magnet type motor characterized by being set. The interior magnet type motor according to claim 1 or 2,
A radially inner end portion of the magnet housing portion opposes a magnetic flux outflow surface or a magnetic flux inflow surface of the magnet disposed in the radial housing hole, and the radially inner side and the radial direction of the magnet housing portion. An embedded magnet type motor characterized in that the inner bridge portion formed between the housing holes is formed so that the width viewed from the axial direction is constant along the radial direction. The interior magnet type motor according to any one of claims 1 to 3,
A pair of magnet housing portions corresponding to each straight line forming the V-shape of the V-shaped housing hole are independently formed, so that the housing extends radially outwardly between the pair of magnet housing portions. An embedded magnet type motor characterized in that an inter-unit bridge is formed. The interior magnet type motor according to any one of claims 1 to 4,
The rotor core is formed by laminating core sheets in the axial direction,
At the position corresponding to the radially outer end of each of the radial accommodation holes in the core sheet, the distance from the circumferential center in the part corresponding to the other part of the radial accommodation hole is one and the other in the circumferential direction. And the pre-lamination non-uniform portion set to be different in and partially formed in the circumferential direction,
The rotor core is an embedded magnet type motor in which the core sheets are laminated so that the pre-lamination non-uniform portions are evenly arranged in the circumferential direction.

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