JP2017038475A - Rotor and motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor which inhibits magnets from contacting with each other without increasing the number of assembly work hours.SOLUTION: A motor includes: a shaft 31; a first rotor core 33A having a first upper surface; a second rotor core 33B having a second lower surface facing the first upper surface in an axial direction; first magnets 34A; and second magnets 34B. The first rotor core and the second rotor core have a plurality of plate members. Each of the plate members has a protruding part protruding to one side in the axial direction and a recessed part overlapping with the protruding part in the axial direction and recessed to the one side. In the adjacent plate members, the protruding part of the plate member disposed at the other side is fitted in the recessed part of the plate member disposed at the one side. The first rotor core has a first protrusion part 37Aa which is the protruding part protruding from the first upper surface toward the second lower surface. The first rotor core faces the second rotor core through a gap in at least a part thereof.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a rotor and a motor.

  Conventionally, a rotor for a motor in which a plurality of rotor cores are fixed to a rotor shaft is known. For example, Patent Document 1 describes a configuration in which magnets arranged on the outer periphery of a rotor core have a three-stage product.

JP 2010-141993 A

  In the rotor as described above, when the rotor cores are fixed to the rotor shaft, the magnets fixed to the rotor cores may come into contact with each other and be damaged.

  On the other hand, for example, a method is considered in which a plate member or the like is sandwiched between the rotor cores in the axial direction so that the rotor cores are fixed to the shaft with an interval in the axial direction and the magnets are prevented from colliding with each other. It is done. However, this method has a problem that the number of rotor assembly steps increases because the number of parts of the rotor increases.

  In one aspect of the present invention, in view of the above problems, a rotor having a plurality of rotor cores and a plurality of magnets and having a structure capable of suppressing contact between the magnets without increasing the number of assembly steps, and such An object of the present invention is to provide a motor having a simple rotor.

  A rotor according to an aspect of the present invention includes a shaft disposed along a central axis extending in the vertical direction, a first rotor core fixed to the shaft and having a first upper surface, fixed to the shaft, and the first A second rotor core having a second lower surface facing the upper surface in the axial direction; a first magnet fixed to the first rotor core; and a second magnet fixed to the second rotor core. And the second rotor core has a plurality of plate members laminated in the axial direction, each of the plate members protruding in one axial direction, and overlapping the convex portion in the axial direction, In the plate member stacked adjacent in the axial direction, the concave portion of the plate member disposed on the one side is disposed on the other side in the axial direction. The plate member The first rotor core further includes a first protrusion that is the protrusion protruding from the first upper surface toward the second lower surface, and the first rotor core is the second rotor core. And at least partly facing in the axial direction through a gap.

  A motor according to one aspect of the present invention includes the above-described rotor and a stator disposed on the radially outer side of the rotor.

  According to the motor of one aspect of the present invention, a plurality of rotor cores and a plurality of magnets are provided, and the magnets can be prevented from contacting each other without increasing the number of assembly steps.

FIG. 1 is a cross-sectional view showing the motor of this embodiment. FIG. 2 is a front view showing the rotor of the present embodiment. FIG. 3 is a plan view showing a part of the rotor of the present embodiment. FIG. 4 is a cross-sectional view showing the rotor of the present embodiment. FIG. 5 is a cross-sectional view showing a manufacturing process of the rotor core of the present embodiment. FIG. 6 is a plan view showing a part of a rotor which is another example of the present embodiment. FIG. 7 is a cross-sectional view showing a part of a rotor which is another example of the present embodiment.

  Hereinafter, a motor according to an embodiment of the present invention will be described with reference to the drawings. In the present specification, the upper side of FIG. 1 in the axial direction of the central axis J extending in the vertical direction is simply referred to as “upper side”, and the lower side is simply referred to as “lower side”. Note that the vertical direction does not indicate the positional relationship or direction when incorporated in an actual device. A direction parallel to the central axis J is referred to as an “axial direction”, a radial direction around the central axis J is simply referred to as a “radial direction”, and a circumferential direction around the central axis J is simply referred to as a “circumferential direction”. Call it.

  In the present specification, the term “extending in the axial direction” includes not only the case of extending in the axial direction but also the case of extending in a direction inclined by less than 45 ° with respect to the axial direction. “Extending in the radial direction” includes not only strictly extending in the radial direction, that is, in a direction perpendicular to the axial direction, but also extending in a direction inclined by less than 45 ° with respect to the radial direction. .

  As shown in FIG. 1, the motor 10 is, for example, an inner rotor type motor. The motor 10 includes a housing 20 that can accommodate various components, a rotor 30, a cylindrical stator 40, a bearing holder 50, a lower bearing 60 that is held by the housing 20, and an upper bearing that is held by the bearing holder 50. 61, a lower bus bar assembly 70, an upper bus bar assembly 80, and terminals 92A and 92B.

  The rotor 30 includes a shaft 31, a first rotor core 33A, a second rotor core 33B, a third rotor core 33C, a first magnet 34A, a second magnet 34B, and a third magnet disposed along the central axis J. 34C. The shaft 31 is rotatably supported around the central axis J by the lower bearing 60 and the upper bearing 61. The rotor 30 is rotatable with respect to the stator 40 inside the stator 40.

  The first rotor core 33A, the second rotor core 33B, and the third rotor core 33C are cylindrical. The first rotor core 33A, the second rotor core 33B, and the third rotor core 33C are arranged in this order from the lower side to the upper side in the axial direction. The inner surface of the first rotor core 33A, the inner surface of the second rotor core 33B, and the inner surface of the third rotor core 33C are, for example, cylindrical with the central axis J as the center. The first rotor core 33A, the second rotor core 33B, and the third rotor core 33C are fitted and fixed to the shaft 31, for example, by press fitting. The first rotor core 33A, the second rotor core 33B, and the third rotor core 33C may be indirectly fixed to the shaft 31 via other members.

  The first magnet 34A, the second magnet 34B, and the third magnet 34C are, for example, plate-shaped extending in the circumferential direction. The first magnet 34A is fixed to the outer surface of the first rotor core 33A. The second magnet 34B is fixed to the outer surface of the second rotor core 33B. The third magnet 34C is fixed to the outer surface of the third rotor core 33C.

  A plurality of first magnets 34A, second magnets 34B, and third magnets 34C are provided along the circumferential direction. The first magnet 34A, the second magnet 34B, and the third magnet 34C may each be a single member. In this case, the first magnet 34A, the second magnet 34B, and the third magnet 34C are, for example, annular.

  The stator 40 is opposed to the rotor 30 in the radial direction through a gap. The stator 40 is arrange | positioned at the radial direction outer side of the rotor 30, for example. The stator 40 includes a stator core 40a, a plurality of coils 43, and a plurality of insulators 44. The stator core 40a is configured by stacking a plurality of electromagnetic steel plates, for example. The stator core 40 a includes an annular core back 41 that extends in the circumferential direction, and a plurality of teeth 42 that extend from the core back 41 in the radial direction. That is, the stator 40 includes a core back 41 and teeth 42.

  The core back 41 has, for example, an annular shape centered on the central axis J. The outer peripheral surface of the core back 41 is fixed to the inner peripheral surface of the housing 20 by, for example, press fitting. In this embodiment, the plurality of teeth 42 extend radially inward from the inner surface of the core back 41. The plurality of teeth 42 are arranged at equal intervals along the circumferential direction.

  The coil 43 includes a conductive wire 43 a wound around the tooth 42 via the insulator 44. The coil 43 is disposed on each tooth 42. The coil 43 has a coil end 43b which is an end of the conductive wire 43a. The coil end 43 b extends upward from a portion of the coil 43 wound around the tooth 42. At least a part of the insulator 44 is disposed between the tooth 42 and the coil 43. The insulator 44 covers at least a part of the tooth 42.

  The lower bus bar assembly 70 is substantially cylindrical. The lower bus bar assembly 70 is disposed on the upper side of the stator 40. The lower bus bar assembly 70 includes a neutral point bus bar 90 and a substantially cylindrical lower bus bar holder 71 that holds the neutral point bus bar 90. That is, the motor 10 includes a neutral point bus bar 90 and a lower bus bar holder 71.

  The lower bus bar holder 71 is made of an insulating resin, for example. The lower bus bar holder 71 is fixed to the insulator 44. The neutral point bus bar 90 is electrically connected to the coil 43. More specifically, the neutral point bus bar 90 is connected to the coil end 43b. Thereby, the neutral point bus bar 90 is electrically connected to the stator 40. The neutral point bus bar 90 connects a plurality of coil ends 43b as neutral points.

  The upper bus bar assembly 80 is substantially cylindrical. The upper bus bar assembly 80 is disposed above the lower bus bar assembly 70. The upper bus bar assembly 80 includes a phase bus bar 91 and an upper bus bar holder 81 that holds the phase bus bar 91. That is, the motor 10 includes a phase bus bar 91 and an upper bus bar holder 81.

  The upper bus bar holder 81 has a substantially cylindrical shape, and is made of, for example, an insulating resin. The upper bus bar holder 81 is fixed to the housing 20. The phase bus bar 91 is electrically connected to the coil 43. More specifically, the phase bus bar 91 is connected to the coil end 43b. The phase bus bar 91 is connected to the terminals 92A and 92B. Thereby, the phase bus bar 91 is electrically connected to the stator 40.

  The terminals 92A and 92B are plate-like members extending upward. The upper ends of the terminals 92 </ b> A and 92 </ b> B are disposed above the upper end of the housing 20. Terminals 92A and 92B are connected to an external power source (not shown).

  The rotor 30 will be described in further detail. In FIG. 4, for the sake of explanation, the circumferential positions of the respective protrusions may be appropriately changed and shown.

  The configuration of each rotor core and the configuration of each magnet are the same except that the arrangement with respect to the shaft 31 is different. Therefore, in the following description, only the first rotor core 33A and the first magnet 34A may be described as a representative.

  As shown in FIG. 2, the first magnet 34 </ b> A includes a first magnet 34 </ b> AN having an N pole on the radially outer side and a first magnet 34 </ b> AS having an S pole on the radially outer side. The second magnet 34B includes a second magnet 34BN having an N pole on the radially outer side, and a second magnet 34BS having an S pole on the radially outer side. The third magnet 34C includes a third magnet 34CN whose radially outer side is an N pole, and a third magnet 34CS whose radially outer side is an S pole.

  The first magnets 34AN and the first magnets 34AS are alternately provided along the circumferential direction. The second magnets 34BN and the second magnets 34BS are alternately provided along the circumferential direction. The third magnets 34CN and the third magnets 34CS are alternately provided along the circumferential direction. That is, the magnetic pole of the first magnet 34A, the magnetic pole of the second magnet 34B, and the magnetic pole of the third magnet 34C each have an N pole and an S pole, and the N pole and the S pole alternate along the circumferential direction. Is provided.

  The first magnets 34AN and 34AS, the second magnets 34BN and 34BS, and the third magnets 34CN and 34CS are provided, for example, three each. That is, in each of the first magnet 34A, the second magnet 34B, and the third magnet 34C, the number of poles arranged in the circumferential direction is, for example, six. The number of poles arranged in the circumferential direction of the magnet is not particularly limited.

  The first magnet 34AN and the second magnet 34BN partially overlap in the axial direction. The second magnet 34BN and the third magnet 34CN partially overlap in the axial direction.

  The second center CB that is the center in the circumferential direction of the second magnet 34BN is shifted to one side in the circumferential direction with respect to the first center CA that is the center in the circumferential direction of the first magnet 34AN. The third center CC that is the center in the circumferential direction of the third magnet 34CN is shifted to one side with respect to the second center CB in the circumferential direction. That is, the center of the N pole of the first magnet 34A and the center of the N pole of the second magnet 34B are at different positions in the circumferential direction. The center of the N pole of the second magnet 34B and the center of the N pole of the third magnet 34C are at different positions in the circumferential direction.

  The first magnet 34A, the second magnet 34B, and the third magnet 34C are disposed so as to be skewed. Thereby, the torque ripple of the motor 10, a cogging torque, etc. can be reduced.

  The second rotor core 33B is disposed on the upper side of the first rotor core 33A. The third rotor core 33C is disposed on the upper side of the second rotor core 33B. The first rotor core 33A is opposed to the second rotor core 33B in the axial direction at least partially via the gap DP1. The third rotor core 33C is opposed to the second rotor core 33B in the axial direction at least partially via the gap DP2.

  As shown in FIG. 3, the planar view outer shape of the first rotor core 33 </ b> A is a substantially regular hexagonal shape. A first magnet 34A is fixed to each side surface orthogonal to the radial direction of the first rotor core 33A. In addition, the planar view outer shape of the first rotor core 33A is not particularly limited to the above shape, and may be, for example, a circular shape.

  As shown in FIG. 4, the first rotor core 33A has a first upper surface 33Aa that is an upper surface of the first rotor core 33A and a first lower surface 33Ab that is a lower surface of the first rotor core 33A. The second rotor core 33B has a second upper surface 33Ba that is the upper surface of the second rotor core 33B, and a second lower surface 33Bb that is the lower surface of the second rotor core 33B. The third rotor core 33C includes a third upper surface 33Ca that is an upper surface of the third rotor core 33C, and a third lower surface 33Cb that is a lower surface of the third rotor core 33C.

  The second lower surface 33Bb faces the first upper surface 33Aa in the axial direction. The second upper surface 33Ba faces the third rotor core 33C in the axial direction. The third lower surface 33Cb faces the second upper surface 33Ba in the axial direction.

  As shown in FIG. 3, the first rotor core 33A has a first hole 38a that does not penetrate in the axial direction in the first upper surface 33Aa. The first hole 38a is recessed downward from the first upper surface 33Aa. Note that the first hole 38a may penetrate the first rotor core 33A in the axial direction. The outer shape in plan view of the first hole 38a is, for example, a circular shape.

  The first rotor core 33A has a plurality of first holes 38a. The plurality of first hole portions 38a are arranged at equal intervals along the circumferential direction. In FIG. 3, the number of first holes 38a is six, for example. For example, when the first rotor core 33A is fixed to the shaft 31, a jig used for positioning the first rotor core 33A in the circumferential direction is attached to the first hole 38a.

  As shown in FIG. 4, the first rotor core 33A, the second rotor core 33B, and the third rotor core 33C have a plurality of plate members 38 stacked in the axial direction. The plate member 38 is an electromagnetic steel plate. As shown in FIG. 3, the planar view outline of the plate member 38 is the same as the planar view outline of the first rotor core 33A. That is, in this embodiment, the planar view outer shape of the plate member 38 is a substantially regular hexagonal shape. The planar view outline of the plate member 38 is changed in accordance with the planar view outline of the first rotor core 33A.

  As shown in FIG. 4, in the first rotor core 33A, the second rotor core 33B, and the third rotor core 33C, each of the plate members 38 includes a convex portion 37 that protrudes to one side in the axial direction, and the convex portion 37 and the axial direction. And a recess 36 that is recessed on one side in the axial direction. More specifically, the plate member 38 that constitutes the first rotor core 33A includes a convex portion 37 that protrudes upward from the upper surface of the plate member 38, and overlaps the convex portion 37 in the axial direction, and extends downward from the upper surface of the plate member 38. And a recessed portion 36 that is recessed. Each plate member 38 has a plurality of convex portions 37 and a plurality of concave portions 36, for example. In the second rotor core 33B and the third rotor core 33C, the plate member 38 constituting each rotor core is disposed, for example, upside down with the plate member 38 constituting the first rotor core 33A.

  In FIG. 3, the planar view outer shape of the convex portion 37 is a rectangular shape that is long in the radial direction. In FIG. 4, the cross-sectional shape of the convex portion 37 is a substantially rectangular shape with chamfered corners on the protruding end (upper side in the first rotor core 33 </ b> A). In addition, the planar view external shape of the convex part 37 is not specifically limited, For example, circular shape, elliptical shape, or polygonal shape may be sufficient. The cross-sectional shape orthogonal to the axial direction of the convex portion 37 is not particularly limited, and may be, for example, a semicircular shape, a semielliptical shape, or a polygonal shape.

  The outer shape in plan view of the recess 36 is preferably the same as the outer shape in plan view of the convex portion 37. The cross-sectional shape orthogonal to the axial direction inside the concave portion 36 is preferably the same as the cross-sectional shape of the convex portion 37. The dimension in the axial direction of the concave portion 36 is preferably the same as the dimension in the axial direction of the convex portion 37.

  In plate members 38 stacked in the axial direction and adjacent to each other, a concave portion 36 of the plate member 38 disposed on one side in the axial direction is fitted with a convex portion 37 of the plate member 38 disposed on the other side in the axial direction. The As a result, the adjacent plate members 38 stacked in the axial direction are fixed to each other. The convex portion 37 and the concave portion 36 are made, for example, by caulking a part of the plate member 38 by pressing or the like.

  33 A of 1st rotor cores have 1st projection part 37Aa which is the convex part 37 which protrudes from 1st upper surface 33Aa toward 2nd lower surface 33Bb. Therefore, when the first rotor core 33A and the second rotor core 33B are sequentially fitted and fixed to the shaft 31, when the first rotor core 33A and the second rotor core 33B are brought closer to each other in the axial direction, the first protrusion 37Aa The gap DP1 is easily provided between the first upper surface 33Aa and the second lower surface 33Bb in contact with the second lower surface 33Bb. Thereby, the first magnet 34A and the second magnet 34B can be arranged with an interval in the axial direction. Therefore, it can suppress that the 1st magnet 34A and the 2nd magnet 34B contact, and the 1st magnet 34A and the 2nd magnet 34B are damaged.

  The first projecting portion 37Aa is made, for example, by caulking work by pressing when the plate members 38 adjacent in the axial direction are fixed to each other. Therefore, it is not necessary to arrange another member for providing a space between the first upper surface 33Aa and the second lower surface 33Bb in the axial direction. Thereby, it can suppress that the number of parts of the rotor 30 increases, and can suppress that the assembly man-hour of the rotor 30 increases. Therefore, it can suppress that the manufacturing cost of the rotor 30 increases.

  It is possible to increase the number of plate members constituting the rotor core so that the axial dimension of the rotor core is larger than that of the magnet, and the magnets facing in the axial direction are prevented from contacting each other. In this case, the number of plate members constituting the rotor core tends to be larger than the number of plate members constituting the stator core.

  The plate member constituting the rotor core and the plate member constituting the stator core are manufactured, for example, by punching a strip-shaped electromagnetic steel plate. At this time, there is a method in which a plate member constituting a rotor core and a plate member constituting a stator core are simultaneously punched from a belt-shaped electromagnetic steel sheet. According to this method, since the plate member constituting the rotor core and the plate member constituting the stator core can be simultaneously produced, the production of each plate member is simple.

  In the case of using this punching method, if a method of suppressing the collision between magnets by increasing the number of plate members constituting the rotor core is adopted, the number of plate members constituting the rotor core is more than the number of plate members constituting the stator core. Is also likely to increase. Therefore, there is a problem that the plate member constituting the stator core is excessive and is wasted.

  On the other hand, according to this embodiment, it is possible to prevent the first magnet 34A and the second magnet 34B from colliding without changing the number of the plate members 38. Therefore, when the method of manufacturing the plate member 38 and the plate member constituting the stator core 40a by simultaneously punching from the strip-shaped electromagnetic steel plate is used, it is possible to prevent the punched plate member of the stator core 40a from being wasted.

  The first protrusion 37Aa is in contact with the second lower surface 33Bb. Therefore, the gap DP1 can be provided between the first upper surface 33Aa and the second lower surface 33Bb in the axial direction of the first protrusion 37Aa. Thereby, the gap DP1 can be provided more reliably, and the first magnet 34A and the second magnet 34B can be prevented from coming into contact with each other and the first magnet 34A and the second magnet 34B can be prevented from being damaged.

  In addition, since the axial dimension of the gap DP1 can be made the same as the axial dimension of the first protrusion 37Aa, the axial dimension of the gap DP1 can be adjusted by adjusting the axial dimension of the first protrusion 37Aa. Can be adjusted. Further, the first projecting portion 37Aa is in contact with the second lower surface 33Bb, whereby the relative position in the axial direction between the first rotor core 33A and the second rotor core 33B is determined.

  In this embodiment, the planar view outer shape of the convex portion 37 is a rectangular shape, and the planar view outer shape of the first protrusion 37Aa is a rectangular shape. In the case where the convex portion 37 is made by crimping by pressing, when the planar outer shape of the convex portion 37 is rectangular, the dimension of the convex portion 37 in the axial direction is larger than that of the circular planar shape of the convex portion 37. Easy to enlarge. Therefore, it is easy to ensure a sufficient dimension in the axial direction of the gap DP1.

  The first projecting portion distal end surface 37Ab, which is the upper end surface of the first projecting portion 37Aa, is parallel to the second lower surface 33Bb. Therefore, the first protrusion 37Aa can be stably brought into contact with the second lower surface 33Bb.

  As shown in FIG. 3, the first rotor core 33A has a plurality of first protrusions 37Aa. The multiple first protrusions 37Aa are arranged at equal intervals along the circumferential direction. Therefore, when 1st protrusion part 37Aa contacts 2nd lower surface 33Bb, 2nd rotor core 33B can be supported stably by 1st protrusion part 37Aa. Moreover, it is easy to make the dimension of the gap DP1 in the axial direction uniform.

  In FIG. 3, the first rotor core 33A has, for example, three first protrusions 37Aa. The number of first protrusions 37Aa may be two or less, or four or more. The first protrusions 37Aa are disposed between the first holes 38a adjacent in the circumferential direction. At least a portion of the first protrusion 37Aa is at the same radial position as the first hole 38a. The first protrusion 37Aa extends in the radial direction. On the first lower surface 33Ab of the first rotor core 33A, a recess 36 that is recessed upward from the first lower surface 33Ab is disposed. Note that at least a part of the first protrusion 37Aa and the first protrusion 37Aa may not be arranged as described above.

  As shown in FIG. 4, the second rotor core 33 </ b> B has a second protrusion 37 </ b> Ba that is a protrusion 37 protruding from the second lower surface 33 </ b> Bb toward the first upper surface 33 </ b> Aa.

  For example, in FIG. 4, when the first protrusion 37Aa protrudes downward, the overall axial dimension of the first rotor core 33A, the second rotor core 33B, and the third rotor core 33C is the same as that of the first protrusion 37Aa. Increased by the axial dimension.

  On the other hand, in the present embodiment, the first protrusion 37Aa and the second protrusion 37Ba protrude in opposite directions. Therefore, the entire shaft combining the first rotor core 33A, the second rotor core 33B, and the third rotor core 33C is arranged by shifting the first protrusion 37Aa and the second protrusion 37Ba in a direction orthogonal to the axial direction. It can suppress that the dimension of a direction becomes large. Moreover, when attaching another member to the lower side of the first rotor core 33A, the first protrusion 37Aa does not get in the way.

  On the second upper surface 33Ba of the second rotor core 33B, a recess 36 that is recessed downward from the second upper surface 33Ba is disposed. Other configurations such as the shape and arrangement of the second protrusion 37Ba are the same as those of the first protrusion 37Aa. Note that the configuration of the second protrusion 37Ba may be different from the configuration of the first protrusion 37Aa.

  The third rotor core 33 </ b> C has a third protrusion 37 </ b> Ca that is a protrusion 37 protruding from the third lower surface 33 </ b> Cb toward the second upper surface 33 </ b> Ba. The third protrusion 37Ca is in contact with the second upper surface 33Ba. A gap DP2 is provided between the third lower surface 33Cb and the second upper surface 33Ba in the axial direction.

  On the third upper surface 33Ca of the third rotor core 33C, a recess 36 that is recessed downward from the third upper surface 33Ca is disposed. Other configurations such as the shape and arrangement of the third projection 37Ca are the same as the configuration of the first projection 37Aa. Note that the configuration of the third projection 37Ca may be different from the configuration of the first projection 37Aa.

  In this embodiment, the relative positions of the convex portion 37 and the concave portion 36 with respect to the first magnet 34A in the first rotor core 33A, and the relative positions of the convex portion 37 and the concave portion 36 with respect to the second magnet 34B in the second rotor core 33B. The relative positions of the convex portion 37 and the concave portion 36 with respect to the third magnet 34C in the third rotor core 33C are the same.

  In this case, for example, if the first magnet 34A, the second magnet 34B, and the third magnet 34C are arranged at the same position in the circumferential direction, there is a possibility that the projections or the projections and the recesses 36 interfere with each other. .

  Specifically, for example, when the first magnet 34A and the second magnet 34B are at the same position in the circumferential direction, the first protrusion 37Aa and the second protrusion 37Ba face each other in the axial direction, and the axis of the gap DP1. The direction dimension increases. Therefore, there is a possibility that the rotor 30 is increased in size in the axial direction more than necessary.

  For example, when the 2nd magnet 34B and the 3rd magnet 34C are in the same position in the peripheral direction, the crevice 36 and the 3rd projection part 37Ca arrange | positioned at 2nd upper surface 33Ba will oppose an axial direction. In this case, there is a possibility that the third protrusion 37Ca is fitted into the recess 36 and the gap DP2 is not provided.

  On the other hand, according to the present embodiment, each magnet is arranged with a skew, so that the circumferential position of the convex portion 37 including the protruding portions and the circumferential position of the concave portion 36 are between the rotor cores. Shift. Thereby, it can suppress that the above interference arises. Specifically, for example, as shown by a two-dot chain line in FIG. 3, the circumferential position of the second protrusion 37Ba is shifted in the circumferential direction by an angle skewed with respect to the first protrusion 37Aa. The first protrusion 37Aa and the second protrusion 37Ba can be prevented from facing each other in the axial direction. Although illustration is omitted, it is possible to suppress the concave portion 36 and the third protrusion 37Ca disposed on the second upper surface 33Ba from facing each other in the axial direction.

  Therefore, by providing a skew between the magnets, the gaps DP1 and DP2 can be provided while maintaining the same structure of the rotor cores. Thereby, since each rotor core can be manufactured using the same manufacturing method, the manufacturing cost of the rotor 30 can be reduced.

  For example, when at least a part of the first protrusion 37Aa is at the same position in the radial direction as the first hole 38a, if a skew is applied between the first magnet 34A and the second magnet 34B, the second The protrusion 37Ba may overlap the first hole 38a in the axial direction. In this case, there is a problem that the gap DP1 is not provided when the entire second protrusion 37Ba is fitted in the first hole 38a.

  On the other hand, when each projection is formed in a shape extending in the radial direction, the radial dimension of each projection can be made larger than the diameter of the first hole 38a. Therefore, even when the second protrusion 37Ba and the first hole 38a overlap in the axial direction, the second protrusion 37Ba can be prevented from fitting into the first hole 38a. Therefore, it is possible to prevent the gap DP1 from being provided.

  In addition, when skew is applied between the magnets, the gaps DP1 and DP2 are provided between the magnets so that the magnetic flux emitted from the magnets can be prevented from flowing between the magnets. Thereby, it can suppress that the magnetic flux discharge | released from each magnet is wasted, and the magnetic flux discharge | released from each magnet tends to flow into the stator core 40a. Therefore, the torque of the motor 10 can be improved. As described above, the effect of providing the gaps DP1 and DP2 between the magnets according to the present embodiment is particularly useful when a skew is provided between the magnets.

  As shown in FIGS. 3 and 5, the first rotor core 33A has a second hole 38b. As shown in FIG. 5, the second hole 38b is disposed on the first lower surface 33Ab. The second hole 38b penetrates the first rotor core 33A in the axial direction. Therefore, as shown in FIG. 3, the second hole 38b opens to the first upper surface 33Aa.

  The radial position of the second hole 38b is the same as the radial position of the recess 36 disposed in the first lower surface 33Ab. The first rotor core 33A has at least the same number of second holes 38b as the number of first protrusions 37Aa. That is, in FIG. 3, the first rotor core 33A has three second holes 38b. The second hole 38b is disposed at the center between the first protrusions 37Aa in the circumferential direction. The plurality of second hole portions 38b are arranged at equal intervals along the circumferential direction.

  As shown in FIG. 5, the size of the second hole 38 b can accommodate the convex portion 37 in a state where a gap is provided at least at a part between the second hole 38 b and the convex portion 37. It is a size.

  As a method for manufacturing each rotor core, as shown in FIG. 5, there is a method in which the plate members 38 are sequentially stacked from the upper side and a plurality of rotor cores are stacked in the axial direction. According to this manufacturing method, for example, a plurality of rotor cores can be manufactured collectively by stacking plate members 38 manufactured by punching with a press or the like at the same location. Therefore, the productivity of the rotor core can be improved.

  In the case of using this manufacturing method, a plurality of rotor cores manufactured by being stacked in the axial direction are separated into one rotor core. And after a magnet is fixed to each rotor core, each rotor core is fitted and fixed to the shaft 31 sequentially.

  In the rotor core manufacturing method, the laminated plate members 38 are laminated with the convex portions 37 facing downward. In one rotor core, the convex portion 37 of the plate member 38 that is overlapped on the upper side fits into the concave portion 36 of another plate member 38 that is already arranged on the lower side. Thereby, the recessed part 36 and the convex part 37 are fitted together, and the plate members 38 stacked adjacent to each other in the axial direction are fixed.

  When the predetermined number of plate members 38 are stacked and fixed as described above, one rotor core is completed. For example, FIG. 5 shows a state where a predetermined number of plate members 38 are stacked to form the first rotor core 33A. Note that the vertical direction of the first rotor core 33A in FIG. 5 is opposite to the vertical direction of the first rotor core 33A in FIG.

  After the first rotor core 33A is formed, the plate member 38 is further laminated from the upper side of the first rotor core 33A, and the next rotor core, that is, the second rotor core 33B in FIG. At this time, when the convex portion 37, which is the second protrusion 37Ba, fits into the concave portion 36 of the first lower surface 33Ab, the first rotor core 33A and the second rotor core 33B are fixed, and after manufacturing the plurality of rotor cores, each rotor core Cannot be separated. For this reason, the plate member 38 constituting the second rotor core 33B needs to be laminated in a state shifted in the circumferential direction with respect to the plate member 38 constituting the first rotor core 33A.

  Here, each rotor core of the present embodiment has a protrusion. Therefore, when the convex portion 37 that is the second protrusion portion 37Ba is displaced in the circumferential direction and contacts the first lower surface 33Ab, a gap is generated between the first rotor core 33A and the second rotor core 33B. In this case, the axial dimension of the first rotor core 33A and the second rotor core 33B when stacked and manufactured is increased. Since the axial gaps between the rotor cores are respectively generated between the rotor cores that are manufactured in the axial direction, the larger the number of rotor cores that are stacked, the more the plurality of rotor cores that are stacked and manufactured. The axial dimension of becomes larger. Therefore, when the above rotor core manufacturing method is used, there is a problem that the number of rotor cores that can be stacked together is reduced and productivity is lowered.

  On the other hand, according to this embodiment, since the second hole 38b is provided, the convex portion 37 of the plate member 38 constituting the second rotor core 33B is aligned with the second hole 38b in the circumferential position. By shifting, the convex part 37 which is the second protrusion part 37Ba is accommodated in the second hole part 38b. Accordingly, the first rotor core 33A and the second rotor core 33B can be laminated and manufactured in a state where the first lower surface 33Ab and the second lower surface 33Bb are in contact with each other. In addition, the size of the second hole portion 38b is such that the convex portion 37 can be accommodated in a state where a gap is provided at least in a part between the second hole portion 38b and the convex portion 37. The first rotor core 33A and the second rotor core 33B are not fixed.

  Therefore, it is possible to suppress an increase in the axial dimension of the entire plurality of rotor cores when the rotor cores stacked adjacent to each other in the axial direction are stacked and manufactured. As a result, it is possible to suppress a reduction in the number of rotor cores that can be stacked together. Thereby, the rotor core of this embodiment can be manufactured without reducing productivity.

  Further, when a plurality of rotor cores are manufactured using the above-described rotor core manufacturing method, when the plate member 38 having the convex portion 37 that is the second protrusion 37Ba is stacked on the first rotor core 33A, the second protrusion 37Ba When contacting the first lower surface 33Ab, the tip surface of the second protrusion 37Ba may be crushed by the weight of the plate member 38 or the like.

  On the other hand, the convex part 37 which is 2nd protrusion part 37Ba is accommodated in the 2nd hole part 38b, and the front end surface of 2nd protrusion part 37Ba does not contact 1st lower surface 33Ab. Therefore, it can suppress that the front end surface of 2nd protrusion part 37Ba is crushed by the weight of the plate member 38, etc.

  For example, in the case where a plurality of second protrusions 37Ba are provided, if the tip surface of the second protrusion 37Ba is crushed, the axial dimensions of the second protrusions 37Ba tend to vary from each other, and the first rotor core 33A and the second rotor core There is a possibility that the gap DP between 33B cannot be provided stably.

  On the other hand, in this embodiment, since it can suppress that the front end surface of 2nd projection part 37Ba is crushed, it can suppress that the dimension of the axial direction of each 2nd projection part 37Ba varies. Therefore, the gap DP between the first rotor core 33A and the second rotor core 33B can be provided more stably.

  In the example of FIG. 3, each second hole 38 b is arranged with a 60 ° shift in the circumferential direction with respect to each first protrusion 37 </ b> Aa. Therefore, the plate member 38 constituting the second rotor core 33B is laminated with a 60 ° shift in the circumferential direction with respect to the plate member 38 constituting the first rotor core 33A.

  As shown in FIG. 3, the plan view outline of the second hole 38 b is preferably the same as the plan view outline of the convex portion 37. That is, the planar view outline of the second hole 38b is a rectangular shape here. The second hole portion 38b may not penetrate the first rotor core 33A in the axial direction. In this case, the second hole 38b opens to the first lower surface 33Ab.

  The present invention is not limited to the above-described embodiment, and other configurations can be employed. In the following description, the same configurations as those described above may be omitted by appropriately attaching the same reference numerals.

  The first protrusion 37Aa does not necessarily need to contact the second lower surface 33Bb. In this case, the first rotor core 33A and the second rotor core 33B are opposed to each other in the axial direction with a gap therebetween.

  The first protrusion 37Aa may be configured as shown in FIG.

  As shown in FIG. 6, the first protrusion 137Aa extends in a direction orthogonal to both the axial direction and the radial direction. The first protrusion 137Aa is located at a position different from the first hole 38a of the first rotor core 133A in the radial direction. Therefore, by making the configuration of the second rotor core (not shown) the same as the configuration of the first rotor core 133A, even if a skew is applied between the first magnet 34A and the second magnet 34B, the second protrusion is the first It does not overlap with the first hole 38a of the rotor core 133A. Therefore, it can prevent that the 2nd projection part fits into the 1st hole 38a, and gap DP1 is not provided.

  No skew may be applied between the first magnet 34A, the second magnet 34B, and the third magnet 34C. In this case, for example, it is preferable that the relative positions of the convex portion 37 and the concave portion 36 with respect to the first magnet 34A and the relative positions of the convex portion 37 and the concave portion 36 with respect to the second magnet 34B are different from each other. Further, it is preferable that the relative positions of the convex portions 37 and the concave portions 36 with respect to the second magnet 34B and the relative positions of the convex portions 37 and the concave portions 36 with respect to the third magnet 34C are different from each other.

  When no skew is applied between the first magnet 34A, the second magnet 34B, and the third magnet 34C, for example, the configuration shown in FIG. 7 may be employed.

  As shown in FIG. 7, in each of the first rotor core 233A and the second rotor core 233B, the plate member 238 includes one first plate member 238a and a plurality of second plate members 238b. The first plate member 238a is the plate member 238 disposed on the uppermost side of the plate members 238 constituting each rotor core in each of the first rotor core 233A and the second rotor core 233B.

  The first plate member 238a includes a first convex portion 237a and a first concave portion 236a. The second plate member 238b has a second convex portion 237b and a second concave portion 236b. The shape of the first convex portion 237 a and the shape of the second convex portion 237 b are the same as the shape of the convex portion 37. The shape of the first recess 236 a and the shape of the second recess 236 b are the same as the shape of the recess 36.

  The dimension in the axial direction of the first convex part 237a is, for example, the same as the dimension in the axial direction of the first concave part 236a. The dimension in the axial direction of the second convex part 237b is, for example, the same as the dimension in the axial direction of the second concave part 236b. The axial dimension of the first convex part 237a and the axial dimension of the first concave part 236a are larger than the axial dimension of the second convex part 237b and the axial dimension of the second concave part 236b.

  In the second plate member 238b stacked in the axial direction and adjacent to each other, the second convex portion 237b disposed on the lower side in the axial direction is fitted into the second concave portion 236b disposed on the upper side.

  In each rotor core, the second convex portion 237b of the second plate member 238b that is disposed below the first plate member 238a and is adjacent to the first plate member 238a in the axial direction is fitted into the first concave portion 236a. Since the axial dimension of the first concave portion 236a is larger than the axial dimension of the second convex portion 237b, there is a gap between the axial direction of the bottom surface of the first concave portion 236a and the upper surface of the second convex portion 237b. DP4 is provided.

  A second recess 236b is disposed on the first lower surface 233Ab, which is the lower surface of the first rotor core 233A, and the second lower surface 233Bb, which is the lower surface of the second rotor core 233B.

  The first protrusion 237a in the first rotor core 233A is a first protrusion 237Aa that protrudes upward from the first upper surface 233Aa that is the upper surface of the first rotor core 233A. The first protrusion 237a in the second rotor core 233B is a second protrusion 237Ba that protrudes upward from the second upper surface 233Ba that is the upper surface of the second rotor core 233B.

  The first protrusion 237Aa overlaps the second recess 236b disposed on the second lower surface 233Bb in the axial direction. The axial dimension L1 of the first protrusion 237Aa is larger than the axial dimension L2 of the second recess 236b. Therefore, when the first protrusion 237Aa is fitted into the second recess 236b disposed on the second lower surface 233Bb, the axial direction between the first rotor core 233A and the second rotor core 233B is equal to the difference between the dimension L1 and the dimension L2. A gap DP3 is provided between the two. Accordingly, the first rotor core 233A and the second rotor core 233B have the same configuration, and the gap DP3 can be provided even when no skew is applied between the magnets.

  Even when there is no skew between the magnets, it is useful to use the first magnet 34A, the second magnet 34B, and the third magnet 34C, which are separate members, as the magnets of the rotor 30, respectively. This is because the eddy current loss of the magnet can be reduced as compared with the case where the first magnet 34A, the second magnet 34B, and the third magnet 34C are a single member connected in the axial direction. Even in this case, since the magnets may be damaged when they come into contact with each other, the effect of providing the gaps DP1 and DP2 between the magnets according to the present embodiment is useful.

  The first protrusion 37Aa, the second protrusion 37Ba, and the third protrusion 37Ca may protrude in the same direction. In this case, since the direction fixed to the shaft 31 in each rotor core can be made the same, the assembly of the rotor 30 is easy.

  The number of rotor cores is not particularly limited as long as it is two or more. The number of rotor cores may be two, for example, or four or more.

  The rotor shown in the above embodiment is a rotor used in an SPM (Surface Permanent Magnet) motor that fixes a magnet to the surface of a rotor core, but is not limited thereto. The rotor to which the present invention is applied may be, for example, a rotor used in an IPM (Interior Permanent Magnet) motor that fixes a magnet inside a rotor core.

  Each structure of the said embodiment can be suitably combined in the range which does not contradict each other.

  DESCRIPTION OF SYMBOLS 10 ... Motor, 30, 230 ... Rotor, 31 ... Shaft, 33 ... Rotor core, 33A, 133A, 233A ... First rotor core, 33B, 233B ... Second rotor core, 33C ... Third rotor core, 34A, 34AN, 34AS ... First Magnet, 34B, 34BN, 34BS ... second magnet, 34C, 34CN, 34CS ... third magnet, 36 ... concave, 37 ... convex, 38,238 ... plate member, 38a ... first hole, 38b ... second hole Part, 40 ... stator, 33Aa, 233Aa ... first upper surface, 33Ba, 233Ba ... second upper surface, 33Bb, 233Bb ... second lower surface, 33Cb ... third lower surface, 37Aa, 137Aa, 237Aa ... first protrusion, 37Ba, 237Ba ... 2nd protrusion, 37Ca ... 3rd protrusion, 236a ... 1st recessed part (recessed part), 236b ... 2nd recessed part Recess), 237a ... first convex portion (convex portion), 237b ... second projection (convex portion), J ... central axis, DP1, DP2, DP3 ... clearance

Claims (11)

A shaft disposed along a central axis extending in the vertical direction;
A first rotor core fixed to the shaft and having a first upper surface;
A second rotor core fixed to the shaft and having a second lower surface facing the first upper surface in the axial direction;
A first magnet fixed to the first rotor core;
A second magnet fixed to the second rotor core;
With
The first rotor core and the second rotor core have a plurality of plate members stacked in an axial direction,
Each of the plate members has a convex portion protruding on one side in the axial direction, and a concave portion overlapping the convex portion in the axial direction and recessed on the one side,
In the adjacent plate members stacked in the axial direction, the concave portion of the plate member disposed on the one side is fitted with the convex portion of the plate member disposed on the other side in the axial direction,
The first rotor core further includes a first protrusion that is the protrusion protruding from the first upper surface toward the second lower surface,
The first rotor core is opposed to the second rotor core in the axial direction at least partially through a gap.   The rotor according to claim 1, wherein the first protrusion is in contact with the second lower surface.   The rotor according to claim 1, wherein an upper end surface of the first protrusion is parallel to the second lower surface. The first rotor core has a plurality of the first protrusions,
The rotor according to any one of claims 1 to 3, wherein the plurality of first protrusions are arranged at equal intervals along a circumferential direction. The magnetic pole of the first magnet and the magnetic pole of the second magnet have an N pole and an S pole, respectively.
The N pole and the S pole are provided alternately along the circumferential direction,
The N pole of the first magnet and the N pole of the second magnet partially overlap in the axial direction,
The rotor according to any one of claims 1 to 4, wherein the center of the N pole of the first magnet and the center of the N pole of the second magnet are at different positions in the circumferential direction. The first rotor core has a first hole on the first upper surface,
The rotor according to any one of claims 1 to 5, wherein the first protrusion is in a radial position different from that of the first hole.   The rotor according to any one of claims 1 to 6, wherein the second rotor core includes a second protrusion that is the protrusion protruding from the second lower surface toward the first upper surface. The first protrusion overlaps the concave portion disposed on the second lower surface in the axial direction,
The rotor according to any one of claims 1 to 7, wherein a dimension in the axial direction of the first protrusion is larger than a dimension in the axial direction of the recess disposed on the second lower surface. A third rotor core disposed on the upper side of the second rotor core and at least partially facing the second rotor core in the axial direction via a gap;
A third magnet fixed to the third rotor core;
With
The second rotor core has a second upper surface facing the third rotor core in the axial direction,
The third rotor core has a plurality of the plate members stacked in the axial direction,
The said 3rd rotor core has the 3rd lower surface facing the said 2nd upper surface, and the 3rd projection part which is the said convex part which protrudes toward the said 2nd upper surface from the said 3rd lower surface. The rotor according to claim 8. The first rotor core has a first lower surface on which the concave portion is disposed, and a second hole portion disposed on the first lower surface,
The radial position of the second hole is the same as the radial position of the recess disposed on the first lower surface,
The size of the second hole portion is a size capable of accommodating the convex portion in a state where a gap is provided in at least a part between the second hole portion and the convex portion. The rotor according to any one of 1 to 9. The rotor according to any one of claims 1 to 10,
A stator disposed radially outside the rotor;
Motor with.

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