Rotor of motor

Abstract

To provide a rotor of a motor capable of reducing the axial length, weight, and moment of inertia of the rotor.SOLUTION: A rotor 10 comprises: a rotor core 30 which is supported by a rotary shaft 20 and is composed of a plurality of electromagnetic steel sheets 35 laminated in a vertical direction Z; a magnet insertion hole 40 which is formed in the rotor core 30 and extends in the vertical direction Z; a magnet 50 which is inserted into the magnet insertion hole 40; a first end face plate 60 which is provided on the upper side of the rotor core 30, prevents the magnet 50 from falling from the upper side, and is formed of a non-magnetic body; and a second end face plate 70 which is provided on the lower side of the rotor core 30, prevents the magnet 50 from falling from the lower side, and is formed of the non-magnetic body. A thickness TB of the second end face plate 70 in the vertical direction Z is thinner than a thickness TA of the first end face plate 60 in the vertical direction Z.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotor for a motor. [Background technology]

[0002] Conventionally, a rotor of a motor includes a rotor core made of multiple electromagnetic steel plates, magnets inserted into magnet insertion holes formed in the rotor core, and end plates provided on both axial ends of the rotor core to prevent the inserted magnets from falling off from the rotor core. For example, Patent Document 1 discloses a motor rotor that includes non-magnetic end plates (i.e., end plates) provided on both ends of the rotor core to prevent the permanent magnets from falling off. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-181254 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, it is necessary to provide end plates at both ends of the rotor core to prevent the permanent magnets from falling out, which increases the axial length of the motor's rotor, and there is a risk of the motor becoming larger. There is also a problem that the weight of the rotor increases due to the end plates. Furthermore, there is a possibility that the increased weight due to the end plates will increase the moment of inertia of the rotor.

[0005] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a motor rotor capable of reducing the axial length, weight, and moment of inertia of the rotor. [Means for solving the problem]

[0006] The rotor of the motor of the present invention comprises a rotating shaft extending in a first direction, a rotor core supported by the rotating shaft and made of a plurality of electromagnetic steel plates stacked in the first direction, magnet insertion holes formed in the rotor core and extending in the first direction, magnets inserted into the magnet insertion holes, a first end plate provided on one side of the rotor core in the first direction and configured to prevent the magnets inserted into the magnet insertion holes from falling out from the one side in the first direction and configured to be made of a non-magnetic material, and a second end plate provided on the other side of the rotor core in the first direction and configured to prevent the magnets inserted into the magnet insertion holes from falling out from the other side in the first direction and configured to be made of the non-magnetic material, wherein the thickness of the second end plate in the first direction is thinner than the thickness of the first end plate in the first direction.

[0007] In the rotor of the motor according to the present invention, the thickness of the second end plate in the first direction is thinner than the thickness of the first end plate in the first direction. Therefore, the axial length of the rotor can be reduced (shortened) compared to a case in which the thickness of the first end plate in the first direction and the thickness of the second end plate in the first direction are the same. In addition, because the thickness of the second end plate in the first direction is relatively thin, the weight of the rotor can be reduced and the moment of inertia of the rotor can be reduced.

[0008] A rotor of another motor according to the present invention comprises a rotating shaft extending in a first direction, a rotor core supported by the rotating shaft and composed of a plurality of electromagnetic steel sheets stacked in the first direction, magnet insertion holes formed in the rotor core and extending in the first direction, magnets inserted into the magnet insertion holes, and an end plate made of a non-magnetic material and provided on one side of the rotor core in the first direction and suppressing the magnets inserted into the magnet insertion holes from falling out from the one side in the first direction, wherein the electromagnetic steel sheets include a plurality of first electromagnetic steel sheets stacked in the first direction and a second electromagnetic steel sheet provided on the other side in the first direction of the first electromagnetic steel sheet that is located on the other side in the first direction of the first electromagnetic steel sheet among the plurality of first electromagnetic steel sheets and suppressing the magnets inserted into the magnet insertion holes from falling out from the other side in the first direction.

[0009] In the rotor of the other motor according to the present invention, the magnets inserted into the magnet insertion holes are prevented from falling out of the magnet insertion holes by the end plates and the second electromagnetic steel plate. In this way, in the rotor of the other motor, since no end plates are provided on the other side of the rotor core in the first direction, the axial length of the rotor can be reduced (shortened). Also, since it is not necessary to provide an end plate on the other side of the rotor core in the first direction, the weight of the rotor is reduced by the amount of the end plate, and the moment of inertia of the rotor can be reduced. Effect of the Invention

[0010] According to the present invention, it is possible to provide a rotor for a motor that can reduce the axial length, weight, and moment of inertia of the rotor. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of a rotor of a motor according to one embodiment. [Diagram 2] FIG. 2 is a plan view of an electrical steel sheet according to one embodiment. [Diagram 3] FIG. 3 is a plan view of a first end plate according to one embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a rotor of a motor according to another embodiment. [Diagram 5] FIG. 5 is a plan view of a second electromagnetic steel sheet according to another embodiment. [Figure 6] FIG. 6 is a plan view of a second electromagnetic steel sheet according to a modified example. [Figure 7] FIG. 7 is a plan view of a second electromagnetic steel sheet according to another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a rotor for a motor according to the present invention will be described with reference to the drawings. Note that the embodiment described here is, of course, not intended to limit the present invention in particular. Also, the same reference numerals are used for members and parts that perform the same function, and duplicated descriptions are omitted or simplified as appropriate.

[0013] First Embodiment Fig. 1 is a cross-sectional view of a rotor 10 of a motor according to a first embodiment. A motor (not shown) includes a rotor 10 and a stator (not shown) that houses the rotor. As shown in Fig. 1, the rotor 10 includes a rotating shaft 20, a rotor core 30, a magnet insertion hole 40, a magnet 50, a first end plate 60, a second end plate 70, a first bearing 80, and a second bearing 90.

[0014] As shown in FIG. 1, the rotating shaft 20 extends in the vertical direction Z. The vertical direction Z is an example of a first direction. The direction in which the rotating shaft 20 extends is not limited to the vertical direction Z. A part of the rotating shaft 20 protrudes upward from a stator (not shown). Other members are attached to an upper end portion 20A of the rotating shaft 20.

[0015] As shown in FIG. 1, the rotor core 30 is an annular member centered on the axis 20C of the rotating shaft 20. The rotor core 30 is supported by the rotating shaft 20. The rotor core 30 is composed of a plurality of electromagnetic steel plates 35 stacked in the vertical direction Z. The rotor core 30 is formed with a rotating shaft insertion hole 38 and a magnet insertion hole 40. The rotating shaft insertion hole 38 is a hole into which the rotating shaft 20 is inserted. The magnet insertion hole 40 is a hole into which the magnet 50 is inserted. The rotating shaft insertion hole 38 and the magnet insertion hole 40 extend in the vertical direction Z.

[0016] As shown in FIG. 1, the thickness T1 of one electromagnetic steel sheet 35 in the vertical direction Z is, for example, 0.15 mm to 0.5 mm. The electromagnetic steel sheet 35 is processed into a predetermined shape by punching using a press die. As shown in FIG. 2, the electromagnetic steel sheet 35 is formed in an annular shape. The electromagnetic steel sheet 35 has a rotating shaft insertion hole 38 and a plurality of magnet insertion holes 40. The magnet insertion hole 40 is located radially outside the rotating shaft insertion hole 38. The rotating shaft insertion hole 38 is formed in a substantially circular shape. The magnet insertion hole 40 is formed in a substantially L-shape. Two magnets 50 are inserted into one magnet insertion hole 40. The magnet insertion hole 40 has a first portion 40A into which one magnet 50 is inserted and a second portion 40B into which another magnet 50 is inserted. The first portion 40A and the second portion 40B are continuous. The shape of the magnet insertion hole 40 and the number of magnets 50 inserted into the magnet insertion hole 40 are not limited to those described above. The electromagnetic steel sheet 35 has a plurality of circular first through holes 44 and a plurality of substantially trapezoidal second through holes 45. The stacked electromagnetic steel sheets 35 are fixed to each other, for example, by crimping, bonding, welding, etc. The multiple electromagnetic steel sheets 35 are fixed to each other, for example, by crimping. Note that FIG. 2 shows a state in which two magnets 50 are inserted into only one magnet insertion hole 40.

[0017] As shown in FIG. 1, the magnet 50 is inserted into the magnet insertion hole 40. The magnet 50 extends in the upward direction Z. The magnet 50 is formed in a flat plate shape. The magnet 50 is, for example, a permanent magnet. The magnet 50 is, for example, a rare earth magnet. The magnet 50 is, for example, a neodymium magnet containing neodymium (Nd), iron (Fe) and boron (B).

[0018] As shown in FIG. 1, the first end plate 60 is provided above the rotor core 30. The first end plate 60 is provided on the uppermost electromagnetic steel plate 35A among the multiple electromagnetic steel plates 35 of the rotor core 30. The first end plate 60 is fixed to the rotating shaft 20 by, for example, press-fitting. The first end plate 60 may be fixed to the rotating shaft 20 by press-fitting the rotor core 30 into the rotating shaft 20. At this time, the first end plate 60 is not press-fitted into the rotating shaft 20. The first end plate 60 prevents the magnet 50 inserted into the magnet insertion hole 40 from falling out from above the magnet insertion hole 40. The first end plate 60 overlaps the entire magnet insertion hole 40 in a plan view. As shown in Figs. 1 and 3, the first end plate 60 has a first through hole 62 formed penetrating in the up-down direction Z, and an opening 65 opening in the up-down direction Z (here, opening only upward). The rotating shaft 20 is inserted into the first through hole 62. The opening 65 is formed in a circular shape in a plan view. The opening 65 is located above the magnet insertion hole 40. A portion of the opening 65 overlaps with the magnet insertion hole 40 in a plan view. The shape and number of the openings 65 are not particularly limited. The diameter of the opening 65 is smaller than the diameter of the first through hole 62.

[0019] As shown in FIG. 1, the second end plate 70 is provided below the rotor core 30. The second end plate 70 is provided below the electromagnetic steel plate 35B located at the lowest position among the multiple electromagnetic steel plates 35 of the rotor core 30. The second end plate 70 is fixed to the rotating shaft 20 by, for example, press fitting. The second end plate 70 prevents the magnet 50 inserted into the magnet insertion hole 40 from falling out from below the magnet insertion hole 40. The second end plate 70 overlaps the entire magnet insertion hole 40 in a plan view. The second end plate 70 has a second through hole 72 formed to penetrate in the vertical direction Z. Note that the second end plate 70 does not have an opening that opens in the vertical direction Z (for example, opening only downward), but may have such an opening. When the second end plate 70 has an opening, the opening 65 of the first end plate 60 is defined as the first opening, and the opening of the second end plate 70 is defined as the second opening, and the volume of the first opening is larger than the volume of the second opening. When a plurality of first openings and a plurality of second openings are provided, the total volume of the plurality of first openings is larger than the total volume of the plurality of second openings. The first opening is open only upward, but may be open only downward. The second opening is open only downward, but may be open only upward. The first opening and the second opening may be through holes formed penetrating in the vertical direction Z.

[0020] The first end plate 60 and the second end plate 70 are made of a non-magnetic material (for example, stainless steel (for example, SUS303)). The first end plate 60 and the second end plate 70 are made of the same material. The first end plate 60 and the second end plate 70 are formed in a disk shape. The first end plate 60 and the second end plate 70 have, for example, the same shape in a plan view. The diameters of the first end plate 60 and the second end plate 70 are smaller than the diameter of the electromagnetic steel plate 35. The thickness TB of the second end plate 70 in the vertical direction Z is smaller than the thickness TA of the first end plate 60 in the vertical direction Z. The thickness TB of the second end plate 70 in the vertical direction Z is, for example, 0.5 mm to 1.5 mm. The thickness TA of the first end plate 60 in the vertical direction Z is, for example, 3 mm to 5 mm. The thickness TB of the second end plate 70 in the vertical direction Z is, for example, less than or equal to the thickness T5 of the five stacked electromagnetic steel sheets 35 in the vertical direction Z. The thickness TB of the second end plate 70 in the vertical direction Z is, for example, thinner than the thickness T2 of the two stacked electromagnetic steel sheets 35 in the vertical direction Z. The thickness TB of the second end plate 70 in the vertical direction Z is, for example, the same as the thickness T1 of one electromagnetic steel sheet 35 in the vertical direction Z. The thickness TB of the second end plate 70 in the vertical direction Z may be, for example, thicker than the thickness T1 of one electromagnetic steel sheet 35 in the vertical direction Z. The thickness TB of the second end plate 70 in the vertical direction Z may be, for example, the same as the thickness T2 of the two stacked electromagnetic steel sheets 35 in the vertical direction Z.

[0021] The first bearing 80 and the second bearing 90 are rolling bearings. The first bearing 80 and the second bearing 90 are, for example, ball bearings. The first bearing 80 is a load side bearing. The first bearing 80 rotatably supports the rotating shaft 20. The second bearing 90 is a non-load side bearing. The second bearing 90 rotatably supports the lower end 20B of the rotating shaft 20. The first bearing 80 and the second bearing 90 are fixed to a stator (not shown) of the motor.

[0022] As described above, in the rotor 10 of the motor of this embodiment, the thickness TB of the second end plate 70 in the vertical direction Z is thinner than the thickness TA of the first end plate 60 in the vertical direction Z. Therefore, the length of the rotor 10 in the axial direction (here, the vertical direction Z) can be reduced (shortened) compared to a case in which the thickness TA of the first end plate 60 in the vertical direction Z and the thickness TB of the second end plate 70 in the vertical direction Z are the same. In addition, because the thickness TB of the second end plate 70 in the vertical direction Z is relatively thin, the weight of the rotor 10 can be reduced and the moment of inertia of the rotor 10 can be reduced.

[0023] In the rotor 10 of the motor of this embodiment, the thickness TB of the second end plate 70 in the vertical direction Z is thinner than the thickness T2 in the vertical direction Z of the two laminated electromagnetic steel plates 35. According to the above aspect, the length of the rotor 10 in the axial direction (here, the vertical direction Z) can be further reduced (shortened). In addition, because the thickness TB of the second end plate 70 in the vertical direction Z is very thin, the weight of the rotor 10 can be further reduced, and the moment of inertia of the rotor 10 can be further reduced.

[0024] In the rotor 10 of the motor of this embodiment, the thickness TB of the second end plate 70 in the vertical direction Z is the same as or thicker than the thickness T1 in the vertical direction Z of one electromagnetic steel sheet 35. According to the above aspect, the length of the rotor 10 in the axial direction (here, the vertical direction Z) can be further reduced (shortened).

[0025] In the rotor 10 of the motor of this embodiment, the thickness TB of the second end plate 70 in the vertical direction Z is the same as the thickness T1 in the vertical direction Z of one electromagnetic steel sheet 35. According to the above aspect, the length of the rotor 10 in the axial direction (here, the vertical direction Z) can be further reduced (shortened). Also, because the thickness TB of the second end plate 70 in the vertical direction Z is very thin, the weight of the rotor 10 can be further reduced and the moment of inertia of the rotor 10 can be further reduced.

[0026] In the rotor 10 of the motor of this embodiment, the thickness TB of the second end plate 70 in the vertical direction Z is equal to or less than the thickness T5 in the vertical direction Z of the five laminated electromagnetic steel plates 35. According to the above aspect, the length of the rotor 10 in the axial direction (here, the vertical direction Z) can be reduced (shortened).

[0027] In the rotor 10 of the motor of this embodiment, the first end plate 60 has a first through hole 62 into which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, and an opening 65 which opens in the vertical direction Z, while the second end plate 70 has a second through hole 72 into which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, but has no opening which opens in the vertical direction Z. According to the above aspect, the weight of the rotor 10 can be further reduced, and the moment of inertia of the rotor 10 can be further reduced. In addition, the weight balance of the entire rotor 10 can be adjusted by the shape of the opening 65 of the first end plate 60.

[0028] In the rotor 10 of the motor of this embodiment, the openings 65 of the first end plate 60 are open only upward. The openings 65 are usually formed using a drill or the like after the first end plate 60, the rotor core 30, the magnets 50, and the second end plate 70 are assembled to the rotating shaft 20. Therefore, by forming the openings 65 of the first end plate 60 so as to be open only upward, damage to the rotor core 30 and the magnets 50 by a drill or the like is suppressed.

[0029] In the rotor 10 of the motor of this embodiment, the first end plate 60 may have a first through hole 62 into which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, and a first opening portion which is formed penetrating in the vertical direction Z. According to the above aspect, the weight of the rotor 10 can be further reduced, and the moment of inertia of the rotor 10 can be further reduced. In addition, the weight balance of the entire rotor 10 can be adjusted by the shape of the first opening portion of the first end plate 60.

[0030] In the rotor 10 of the motor of this embodiment, the second end plate 70 may have a second through hole 72 into which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, and a second opening portion which is formed penetrating in the vertical direction Z. According to the above aspect, the weight of the rotor 10 can be further reduced, and the moment of inertia of the rotor 10 can be further reduced. In addition, the weight balance of the entire rotor 10 can be adjusted by the shape of the second opening portion of the second end plate 70.

[0031] In the rotor 10 of the motor of this embodiment, the first end plate 60 has a first through hole 62 through which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, and a first opening (e.g., an opening 65) which opens in the vertical direction Z, and the second end plate 70 has a second through hole 72 through which the rotating shaft 20 is inserted and which is formed penetrating in the vertical direction Z, and a second opening which opens in the vertical direction Z, and the volume of the first opening may be larger than the volume of the second opening. According to the above aspect, the weight of the rotor 10 is further reduced, and the moment of inertia of the rotor 10 can be further reduced. In addition, the weight balance of the entire rotor 10 can be adjusted by the shape of the opening 65 of the first end plate 60.

[0032] In the rotor 10 of the motor of this embodiment, the first opening (e.g., opening 65) may be open only upward, and the second opening may be open only downward. The first opening and the second opening are usually formed using a drill or the like after the first end plate 60, the rotor core 30, the magnets 50, and the second end plate 70 are assembled to the rotating shaft 20. Therefore, by forming the first opening of the first end plate 60 to open only upward and the second opening of the second end plate 70 to open only downward, damage to the rotor core 30 and the magnets 50 by a drill or the like is suppressed.

[0033] <Second embodiment> Fig. 4 is a cross-sectional view of a rotor 110 of a motor according to the second embodiment. The motor (not shown) includes the rotor 110 and a stator (not shown) that houses the rotor 110. As shown in Fig. 4, the rotor 110 includes a rotating shaft 20, a rotor core 130, a magnet insertion hole 40, a magnet 50, a first end plate 60, a first bearing 80, and a second bearing 90. The rotor 110 does not include a second end plate 70 (see Fig. 1).

[0034] As shown in FIG. 4, the rotor core 130 is an annular member centered on the axis 20C of the rotating shaft 20. The rotor core 130 is supported by the rotating shaft 20. The rotor core 130 is composed of a plurality of electromagnetic steel sheets 135 stacked in the vertical direction Z. A rotating shaft insertion hole 38 and a magnet insertion hole 40 are formed in the rotor core 130. The electromagnetic steel sheets 135 include a plurality of first electromagnetic steel sheets 135A and second electromagnetic steel sheets 135B stacked in the vertical direction Z. The first electromagnetic steel sheets 135A have the same configuration as the electromagnetic steel sheets 35 according to the first embodiment.

[0035] As shown in FIG. 4, the second electromagnetic steel sheet 135B is provided below the first electromagnetic steel sheet 135AB, which is located at the lowest position among the plurality of stacked first electromagnetic steel sheets 135A. The second electromagnetic steel sheet 135B is fixed to the first electromagnetic steel sheet 135AB by, for example, crimping, bonding, welding, or the like. The second electromagnetic steel sheet 135B and the first electromagnetic steel sheet 135AB are fixed to each other by, for example, crimping. The thickness T3 of the second electromagnetic steel sheet 135B in the vertical direction Z is, for example, 0.15 mm to 0.5 mm. The thickness T3 of the second electromagnetic steel sheet 135B is the same as the thickness T1 of the first electromagnetic steel sheet 135A. The second electromagnetic steel sheet 135B is processed into a predetermined shape by punching using a press die. As shown in FIG. 5, the second electromagnetic steel sheet 135B is formed into an annular shape. The second electromagnetic steel sheet 135B has a rotation shaft insertion hole 38. The second electromagnetic steel sheet 135B has a plurality of circular first through holes 44 and a plurality of substantially trapezoidal second through holes 45. The second electromagnetic steel sheet 135B does not have a magnet insertion hole 40 (see FIG. 2). The second electromagnetic steel sheet 135B prevents the magnet 50 inserted into the magnet insertion hole 40 from falling out from below the magnet insertion hole 40. The second electromagnetic steel sheet 135B has a fall-out prevention portion 140. The fall-out prevention portion 140 overlaps with the magnet insertion hole 40 when viewed from the up-down direction Z (i.e., in a plan view). The fall-out prevention portion 140 overlaps with the entire magnet insertion hole 40 in a plan view. The second electromagnetic steel sheet 135B has substantially the same configuration as the first electromagnetic steel sheet 135A, except that the second electromagnetic steel sheet 135B has the fall-out prevention portion 140.

[0036] As described above, according to the motor rotor 110 of this embodiment, the magnet 50 inserted into the magnet insertion hole 40 is prevented from falling out of the magnet insertion hole 40 by the first end plate 60 and the second electromagnetic steel plate 135B. In this manner, in the motor rotor 110, since no end plate is provided below the rotor core 130, the length in the axial direction (here, the vertical direction Z) of the rotor 110 can be reduced (shortened). Also, since it is not necessary to provide an end plate below the rotor core 130, the weight of the rotor 110 is reduced by the amount of the end plate, and the moment of inertia of the rotor 110 can be reduced.

[0037] In the rotor 110 of the motor of this embodiment, the second electromagnetic steel sheet 135B has a fall-out suppression portion 140 that overlaps with the magnet insertion hole 40 when viewed from the up-down direction Z. According to the above aspect, the fall-out suppression portion 140 can reliably suppress the magnet 50 inserted into the magnet insertion hole 40 from falling out from below.

[0038] In the motor rotor 110 of this embodiment, the fall-out prevention portion 140 overlaps with the entire magnet insertion hole 40 when viewed from the up-down direction Z. According to the above aspect, the fall-out prevention portion 140 can more reliably prevent the magnet 50 inserted into the magnet insertion hole 40 from falling out from below.

[0039] As shown in FIG. 6, the electromagnetic steel sheet 135 may include a second electromagnetic steel sheet 135C instead of the second electromagnetic steel sheet 135B (see FIG. 5). The second electromagnetic steel sheet 135C has a plurality of through holes 255. The through holes 255 and the magnet insertion holes 40 are in a substantially similar relationship. The through holes 255 are smaller than the magnet insertion holes 40. The second electromagnetic steel sheet 135C includes a fall-off prevention portion 240. The fall-off prevention portion 240 overlaps with a portion of the magnet insertion hole 40 when viewed from the up-down direction Z (i.e., in a plan view). The fall-off prevention portion 240 is a portion that defines the through hole 255. The fall-off prevention portion 240 prevents the magnet 50 inserted into the magnet insertion hole 40 from passing through the through hole 255.

[0040] As shown in FIG. 7, the electromagnetic steel sheet 135 may include a second electromagnetic steel sheet 135D instead of the second electromagnetic steel sheet 135B (see FIG. 5). The second electromagnetic steel sheet 135D has a plurality of through holes 355. The second electromagnetic steel sheet 135D includes a falling-off prevention portion 340. When viewed from the up-down direction Z (i.e., in a plan view), the falling-off prevention portion 340 overlaps with a part of the magnet insertion hole 40. The falling-off prevention portion 340 is a protrusion that protrudes toward the through hole 355. The falling-off prevention portion 340 prevents the magnet 50 inserted into the magnet insertion hole 40 from passing through the through hole 355. In this modified example, when the falling-off prevention portion 340 is not provided, the magnet 50 is formed to a size that allows it to pass through the through hole 355.

[0041] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0042] In the first embodiment described above, the thickness TB of the second end plate 70 in the vertical direction Z is smaller than the thickness TA of the first end plate 60 in the vertical direction Z, but is not limited to this. For example, the thickness TA of the first end plate 60 in the vertical direction Z may be smaller than the thickness TB of the second end plate 70 in the vertical direction Z.

[0043] In the second embodiment described above, the rotor 110 includes the first end plate 60, but may include a second end plate 70 instead of the first end plate 60. In this case, the second electromagnetic steel sheet 135B is provided above the first electromagnetic steel sheet 135A that is located at the uppermost position among the multiple stacked first electromagnetic steel sheets 135A.

[0044] In each of the above-described embodiments, the first end plate 60 has the opening 65 formed therein, but the first end plate 60 does not have to have the opening 65. Furthermore, when the first end plate 60 does not have the opening 65 formed therein, the second end plate 70 may have an opening formed therein. [Explanation of symbols]

[0045] 10 Rotor 20 Rotational Axis 30 Rotor core 35 Electrical steel sheet 38 Rotating shaft insertion hole 40 Magnet insertion hole 50 Magnet 60 1st end plate 65 Opening 70 Second end plate 110 Rotor 130 Rotor core 135 Electrical steel sheet 135A No. 1 electromagnetic steel plate 135B 2nd electromagnetic steel plate 140 Falling prevention part

Claims

1. A rotation axis extending in a first direction; a rotor core supported by the rotating shaft and made of a plurality of electromagnetic steel plates laminated in the first direction; a magnet insertion hole formed in the rotor core and extending in the first direction; A magnet inserted into the magnet insertion hole; a first end plate that is provided on one side of the rotor core in the first direction, that prevents the magnets inserted into the magnet insertion holes from falling out of the one side in the first direction, and that is made of a non-magnetic material; a second end plate that is provided on the other side of the rotor core in the first direction, that prevents the magnets inserted into the magnet insertion holes from falling out of the other side in the first direction, and that is made of the non-magnetic material; A rotor for a motor, wherein the thickness of the second end plate in the first direction is thinner than the thickness of the first end plate in the first direction.

2. 2 . The motor rotor according to claim 1 , wherein the thickness of the second end plate in the first direction is smaller than the thickness of each of the two laminated electromagnetic steel plates in the first direction.

3. 2. The motor rotor according to claim 1, wherein the thickness of the second end plate in the first direction is the same as or greater than the thickness of one of the electromagnetic steel plates in the first direction.

4. 4. The motor rotor according to claim 3, wherein a thickness of the second end plate in the first direction is the same as a thickness of one of the electromagnetic steel plates in the first direction.

5. 4. The motor rotor according to claim 3, wherein the thickness of the second end plate in the first direction is equal to or smaller than the thicknesses of the five laminated electromagnetic steel plates in the first direction.

6. the first end plate has a first through hole into which the rotation shaft is inserted and which is formed penetrating in the first direction, and an opening which opens in the first direction, 3. A rotor of a motor as described in claim 1 or 2, wherein the second end plate has a second through hole through which the rotating shaft is inserted and which is formed penetrating in the first direction, and has no opening which opens in the first direction.

7. The rotor of a motor according to claim 6 , wherein the opening of the first end plate is open only towards one side in the first direction.

8. 3. The rotor of a motor as described in claim 1 or 2, wherein the first end plate has a first through hole into which the rotating shaft is inserted and which is formed penetrating in the first direction, and a first opening which is formed penetrating in the first direction.

9. 9. The motor rotor according to claim 8, wherein the second end plate has a second through hole through which the rotating shaft is inserted and which is formed penetrating in the first direction, and a second opening portion which is formed penetrating in the first direction.

10. the first end plate has a first through hole into which the rotation shaft is inserted and which is formed penetrating in the first direction, and a first opening which opens in the first direction, the second end plate has a second through hole into which the rotation shaft is inserted and which is formed penetrating in the first direction, and a second opening which opens in the first direction, The rotor of a motor according to claim 1 or 2, wherein a volume of the first opening is larger than a volume of the second opening.

11. The first opening is open only toward one side in the first direction, The rotor of the motor according to claim 10 , wherein the second opening is open only toward the other side in the first direction.

12. A rotation axis extending in a first direction; a rotor core supported by the rotating shaft and made of a plurality of electromagnetic steel plates laminated in the first direction; a magnet insertion hole formed in the rotor core and extending in the first direction; A magnet inserted into the magnet insertion hole; an end plate that is provided on one side of the rotor core in the first direction, that prevents the magnets inserted into the magnet insertion holes from falling out of the one side in the first direction, and that is made of a non-magnetic material; The electromagnetic steel sheet is A plurality of first electromagnetic steel sheets stacked in the first direction; a second electromagnetic steel sheet provided on the other side in the first direction of the first electromagnetic steel sheet located furthest on the other side in the first direction among the plurality of first electromagnetic steel sheets, and suppressing the magnet inserted in the magnet insertion hole from falling off from the other side in the first direction, Motor rotor.

13. The rotor of the motor according to claim 12 , wherein the second electromagnetic steel sheet has a fall-out prevention portion that overlaps with the magnet insertion hole when viewed from the first direction.

14. The rotor of the motor according to claim 13 , wherein the fall-off prevention portion overlaps with the entire magnet insertion hole when viewed from the first direction.

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