JP2019068655A - Rotor of rotary electric machine - Google Patents

Abstract

To provide a rotor of a rotary electric machine that reduces an area in which a magnet contacts an inner wall surface of a magnet insertion hole as compared to a case where the magnet is simply inserted by tilting the magnet into the magnet insertion hole.SOLUTION: A rotor core is formed by laminating electromagnetic steel sheets. In a magnet insertion hole 16a in the rotor core, a first protrusion 26 made of a magnetic steel sheet is provided in the vicinity of a lower end of one of an inner wall surface. In the vicinity of an upper end of a facing inner wall surface, a second projection 28 made of a magnetic steel sheet is provided. A permanent magnet 30 is formed thinner than the magnet insertion hole 16a and is fixed in the magnet insertion hole 16a in an attitude of contacting an upper side of the protrusion 26, and a front-end side of the protrusion 28.SELECTED DRAWING: Figure 4

Description

  The present invention relates to the structure of a rotating electrical machine, and more particularly to the structure of a rotor.

  As a rotor of a rotating electrical machine, there is a type called an IPM (Interior Permanent Magnet) type rotor in which a magnet is inserted into a magnet insertion hole provided in a rotor core.

  The following Patent Document 1 discloses a technique of fixing the magnet in an inclined posture when fixing a magnet inserted into a magnet insertion hole with an insulating filler in an IPM type rotor. Further, the contact portion between the magnet and the rotor core can be made smaller, which makes it possible to limit the formation of a large eddy current loop path flowing to the rotor core through the magnet even when the insulating film is not formed on the magnet surface. Have been described.

International Publication No. 2012/169043

  In the IPM type rotor, even when the magnet is simply inclined and inserted into the magnet insertion hole, the corners of the magnet contact the inner wall surface (rotor core) of the magnet insertion hole to some extent. Moreover, it is imagined that the process of installing a magnet in a desired position takes time.

  An object of the present invention is to reduce the area in which the magnet contacts the inner wall surface of the magnet insertion hole, as compared to the case where the magnet is simply inserted in an inclined manner into the magnet insertion hole.

  Another object of the present invention is to facilitate the positioning of the magnet as compared to the case where the magnet is simply inserted into the magnet insertion hole at an angle.

  In the rotor of the rotating electrical machine according to the present embodiment, the elongated holes are overlapped with a rotor core formed by laminating a plurality of electromagnetic steel plates provided with elongated holes having a pair of opposing long sides in the rotation axis direction. A magnet insertion hole formed in the rotor core, a permanent magnet inserted in the magnet insertion hole, and an insulating filler filled in the magnet insertion hole to fix the permanent magnet in the magnet insertion hole; A first protrusion of an electromagnetic steel plate is provided in the vicinity of one end in the rotation axis direction on the surface of one long side of the magnet insertion hole, and the surface of the other long side of the magnet insertion hole is A second protrusion of an electromagnetic steel plate is provided near the other end in the rotation axis direction, and the permanent magnet is formed thinner than the distance between the long sides, and the other end side of the first protrusion in the rotation axis direction And in contact with the tip of the second protrusion Serial and is fixed to the magnet insertion hole, characterized in that.

  According to the rotor of the rotating electrical machine according to the present embodiment, the area in which the magnet contacts the inner wall surface of the magnet insertion hole is smaller than in the case where the magnet is simply inclined and inserted into the magnet insertion hole. It is possible to limit the eddy current loop path flowing to the rotor core and to reduce the eddy current loss.

  From another point of view, it can be expected that the process of inserting the magnet into a desired position can be simplified when manufacturing the rotor of this rotating electrical machine.

It is a schematic end elevation of a rotor concerning an embodiment. It is an end elevation of two magnet insertion holes. It is a perpendicular sectional view of a magnet insertion hole. It is a time series figure showing the process of inserting a permanent magnet in a magnet insertion hole.

  An example of the present embodiment will be described below. Here, in order to facilitate understanding, although the description is made including a specific example, the present embodiment is not limited to the contents described here, and can be appropriately modified. is there.

  FIG. 1 is a schematic end view of a rotor 10 of a rotating electrical machine. The rotor 10 includes a shaft 12 which is a rotating shaft, and a rotor core 14 provided around the shaft 12. Near the outer periphery of the rotor core 14, a plurality of magnet insertion holes 16a, 16b, 16c, 16d,... ) Is provided. Then, permanent magnets (not shown) are inserted into the magnet insertion holes 16.

  The shaft 12 is made, for example, by processing a round bar steel material. The rotor core 14 is configured, for example, by axially laminating a large number of electromagnetic steel plates formed by punching a silicon steel plate having a thickness of 0.3 mm or the like in a concentric annular shape. Further, the magnet insertion holes 16 are formed by laminating the holes of the respective electromagnetic steel plates made by punching and having a depth in the axial direction. In the magnet insertion holes 16, two adjacent magnet insertion holes (for example, a set of 16a and 16b, a set of 16c and 16d) form a pair to form one magnetic pole. The magnet insertion holes 16 are arranged at equal intervals such that the magnetic poles are equally spaced in the circumferential direction of the rotor core 14. The formed magnetic poles receive an electromagnetic force from a stator disposed around the rotor 10 (not shown), and rotate around the rotation axis (in the circumferential direction).

  FIG. 2 is an enlarged view of the vicinity of the pair of magnet insertion holes 16a and 16b in the rotor core 14 of FIG. The magnet insertion hole 16 a has an elongated rectangular end face (cross section) formed by the long sides 18, 22 and the short sides 20, 24. The magnet insertion holes 16a are formed through all the electromagnetic steel plates, and are formed in a rectangular parallelepiped shape as a whole. Among these, a protrusion 26 is provided on the inner wall surface including the long side 18 on the inner side in the radial direction, near the center of the long side 18 and near the lower end in the rotation axis direction. The projections 26 are formed leaving a part of a certain electromagnetic steel sheet when it is punched. Further, projections 28 are also provided on the inner wall surface (inner wall surface including the long side 22 on the radially outer side) facing this surface, in the vicinity of the center of the long side 22 and near the upper end in the rotational axis direction. The projections 28 are also formed when punching out a single electromagnetic steel sheet similar to the projections 26. The protrusions 26, 28 are provided in all the magnet insertion holes 16 including the adjacent magnet insertion holes 16b.

  FIG. 3 is a cross-sectional view of the magnet insertion hole 16a taken along the plane AA of FIG. The magnet insertion holes 16a are sandwiched on both sides by the rotor core 14 made of laminated electromagnetic steel sheets. Then, on the inner wall surface of the long side 18, a protrusion 26 is provided in a layer slightly above the lowermost layer. Further, on the inner wall surface of the long side 22 opposed to this, a protrusion 28 is provided in a layer slightly lower than the uppermost layer.

  FIG. 4 is a diagram showing the process of inserting the permanent magnet 30 into the magnet insertion hole 16a in time series in the same cross section as that shown in FIG. As shown to Fig.4 (a), the permanent magnet 30 is inserted from the opening part of the upper side of a paper surface with respect to the magnet insertion hole 16a. In this process, the rotor core 14 is maintained in a posture in which the magnetic steel plates are substantially horizontal, and the permanent magnet 30 is inserted vertically downward. At the time of insertion, the permanent magnet 30 is inserted into the magnet insertion hole 16 a so as to be in contact with the inner wall surface of the long side 18 or along the inner wall surface of the long side 18 without contacting. Thereby, the lower end of the permanent magnet 30 contacts the upper surface of the protrusion 26. When the worker or the robot holding the permanent magnet stops holding the permanent magnet at this stage, the permanent magnet 30 is inclined toward the long side 22 by its own weight.

  FIG. 4 (b) is a diagram showing this stage. The permanent magnet 30 rests on the projection 26 such that a part of the lower surface 32 contacts the projection 26. That is, in the permanent magnet 30, the contact portion 34 at a part of the lower surface 32 is in contact with the protrusion 26. The contact point 34 contacts near the tip of the upper surface of the projection 26 (the surface on the side where the permanent magnet 30 has been inserted). The corner 36 on the long side 18 side of the lower surface 32 of the permanent magnet 30 may or may not be in contact with the inner wall surface of the long side 18. This is determined by the distance between the permanent magnet 30 and the inner wall surface of the long side 18 as described later. The upper surface or corner 40 of the surface 38 on the long side 22 side of the permanent magnet 30 is in contact with the tip of the projection 28.

  FIG. 4C shows that the magnet insertion hole 16a is thereafter filled with an insulating filler (for example, resin). By solidifying the filler, the permanent magnet 30 is fixed in the magnet insertion hole 16a. In FIG. 4C, it is assumed that the filler is filled in the entire gap of the magnet insertion hole 16a. However, the filler may only be filled in a part of the space, as long as the permanent magnet 30 is fixed at such a strength as to withstand high speed rotation. End plates are then installed at both ends of the rotor core 14 as necessary.

  For example, a permanent magnet 30 in which the long side 22 side is an N pole and the long side 18 side is an S pole is inserted into the magnet insertion hole 16 a. Similarly, a permanent magnet having an N pole on the outer long side and an S pole on the inner long side is inserted into the adjacent magnet insertion hole 16b. As a result, in the magnet insertion holes 16a and 16b, magnetic poles whose radially outer side becomes N pole as a whole are configured. Further, on both sides of this magnetic pole, a magnetic pole whose outer side in the radial direction as a whole is an S pole is formed. Thus, the rotor cores 14 have magnetic poles alternately arranged at equal intervals in the circumferential direction. Then, by performing control to temporally change the magnetic poles of the stator placed around the rotor core 14, the rotor rotates in the circumferential direction. In this process, an eddy current is generated in the permanent magnet 30 or the magnetic steel sheet. However, as described above, since the permanent magnet 30 is fixed so that the contact area with the magnet insertion hole 16a is small, the loop of the eddy current is limited, and the energy loss accompanying the eddy current can be suppressed. It becomes possible. As a result, it is also possible to limit the temperature rise in the permanent magnet 30 or the rotor core 14.

  As apparent from the above description, the projections 26, 28 control the position and attitude of the permanent magnet 30 to be inserted. Therefore, the positions of the protrusions 26 and 28 are determined in consideration of the size of the magnet insertion hole 16a, the size of the permanent magnet 30, the posture of the permanent magnet 30, and the like. When the permanent magnet is to be disposed near the axial center of the magnet insertion hole 16a, the protrusions 26, 28 are disposed at substantially symmetrical positions. For example, when the axial height of the rotor core 14 is 30 mm and the height of the permanent magnet is 26 mm, the lower protrusion 26 is provided 3 mm above the lower end surface of the rotor core 14 and the upper protrusion 28 is the rotor core 14. It is conceivable to provide it 3 mm below the upper end face of In consideration of asymmetry in which the permanent magnet 30 contacts the upper surface of the lower protrusion 26 and contacts the tip side of the upper protrusion 28, for example, the distance between the lower protrusion 26 and the lower end face of the rotor core 14 is The distance between the upper projection 28 and the upper end surface of the rotor core 14 may be shorter. In addition, when end plates are installed on the upper and lower end surfaces of the rotor core 14 and the magnet insertion holes 16a are covered, it is necessary to install the permanent magnets 30 at a position that does not cause interference with the end plates. is there.

  The shape and size of the projections 26 and 28 also affect the position and attitude of the permanent magnet 30. As illustrated in FIG. 4B, when the permanent magnet 30 falls down to the inner wall surface side of the long side 22 by its own weight, the installation process of the magnet is simplified. For this purpose, it is desirable that the length of the lower protrusion 26 (the length of the protrusion from the inner wall surface of the long side 18 to the tip) be equal to or less than half the thickness of the permanent magnet 30. As a result, the center of gravity of the permanent magnet 30 is positioned closer to the tip end than the protrusion 26, and the permanent magnet 30 falls to the inner wall surface side of the long side 22. Moreover, it is preferable to set the protrusion 28 on the upper side as short as possible to allow the fall-in. If the protrusion length of the protrusion 28 is too long, the work efficiency for inserting the permanent magnet 30 is degraded. In addition, when the inclination of the permanent magnet 30 is small, the permanent magnet 30 tends to move when the filler is filled.

  The width (the length in the side direction of the long sides 18 and 22) of the protrusions 26 and 28 can also be set variously. If the width is narrow, the contact area with the magnetic steel sheet is reduced, but the stability when installing the permanent magnet 30 is reduced. Conversely, when the width is increased, the contact area with the magnetic steel sheet is increased, but the stability when installing the permanent magnet 30 is increased. Also, only one protrusion 26 or protrusion 28 may be provided on the inner wall surface, but two or three or more may be provided. Moreover, although the protrusion 26 or the protrusion 28 may be made only of one electromagnetic steel plate, it may be made of a plurality of electromagnetic steel plates. In this case, it is also possible to control a three-dimensional contact state of the projection 26 or the projection 28 and the permanent magnet 30.

  Further, the inner wall surface on which the projections 26 and 28 are provided can be freely selected. In the above description, in the magnet insertion hole 16a, the projection 26 provided on the surface of the long side 18 inside in the radial direction is to await the permanent magnet 30 to be inserted at the back side. By changing this, the protrusion 26 provided on the surface of the long side 18 inside in the radial direction may be provided on the insertion end side (upper end side) of the permanent magnet 30. The other magnet insertion holes 16b that form a pair of magnetic poles may have the same positional relationship as the magnet insertion holes 16a, or may have a different positional relationship. Similarly, the projection position in the magnet insertion hole 16 other than this can be freely selected.

  In the above description, at the timing shown in FIG. 4B, it has not been sufficiently paid attention to whether the corner 36 of the lower surface 32 of the permanent magnet 30 contacts the inner wall surface of the long side 18. When the corner portion 36 contacts the inner wall surface of the long side 18, the stability of the permanent magnet 30 is enhanced, but the contact area between the permanent magnet 30 and the magnetic steel sheet is increased. Taking this into consideration, the permanent magnet 30 may be installed slightly apart from the inner wall surface so that the corner portion 36 does not contact the inner wall surface of the long side 18. The permanent magnet 30 may be placed close to the inner wall so as to contact the inner wall. Further, when the corner portion 36 of the permanent magnet 30 is brought into contact with the inner wall surface of the long side 18, the shape of the electromagnetic steel sheet of the portion where the corner portion 36 contacts may be changed so as to reduce the contact area. For example, when a portion of the inner wall surface of the magnetic steel plate within 3 mm above the protrusion 26 is recessed from the periphery, the corner portion contacts only the non-recessed portion and the recessed portion Since there is no contact, the contact area can be reduced.

  In the above description, the magnet insertion hole 16 has been described as having a rectangular shape in each electromagnetic steel sheet and having a rectangular shape as a whole. However, the shape of the magnet insertion hole 16 is not limited to this. For example, in addition to the rectangle corresponding to a magnet, the said patent document 1 has further described the magnet insertion hole which made the swelling space which a little circular near the outside of both short sides gave. The present embodiment is also applicable to a magnet insertion hole having such a deformed shape. Moreover, although the shape of the permanent magnet 30 to insert is also assumed to be a rectangular parallelepiped shape thinner than the magnet insertion hole 16, it is not limited to this. For example, in the case where the corner portion does not protrude from the upper end surface or the lower end surface of the rotor core 14 when inserted obliquely into the magnet insertion hole 16, the upper end surface or the lower end surface is the upper end surface or the lower end surface of the rotor core 14 There is an example of parallelograms parallel to.

Reference Signs List 10 rotor, 12 shaft, 14 rotor core, 16, 16a, 16b, 16c, 16d magnet insertion hole, 18, 22 long side, 20, 24 short side, 26, 28 protrusion, 30 permanent magnet, 32 lower surface, 34 contact point, 36, 40 corners, 38 faces.

Claims (1)

A rotor core formed by laminating a plurality of electromagnetic steel plates provided with elongated holes having a pair of opposed long sides in the rotation axis direction;
A magnet insertion hole formed in the rotor core by overlapping the elongated holes;
A permanent magnet inserted into the magnet insertion hole;
An insulating filler filled in the magnet insertion hole to fix the permanent magnet in the magnet insertion hole;
Equipped with
A first protrusion of an electromagnetic steel plate is provided in the vicinity of one end in the rotation axis direction on the surface of one long side of the magnet insertion hole,
On the other long side of the magnet insertion hole, a second protrusion of an electromagnetic steel plate is provided in the vicinity of the other end in the rotation axis direction,
The permanent magnet is formed thinner than the distance between the long sides, and is in contact with the other end side of the first protrusion in the direction of the rotation axis and the tip of the second protrusion in the magnet insertion hole The rotor of a rotating electrical machine, characterized in that it is fixed to.

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