Rotator of motor, and motor equipped with rotator of motor

Abstract

To provide a rotator of a motor which can reduce the axial length, the weight, and the moment of inertia of the rotator while suppressing magnetic flux leakage of a magnet.SOLUTION: A rotator 10 of a motor 100 comprises: a rotating shaft 15 which extends in a vertical direction Z; a rotator core 20, made of a plurality of rotator-side electromagnetic steel plates 25 laminated in the vertical direction Z, which has a magnet insertion hole 30 extending in the vertical direction Z, and which is fixed to the rotating shaft 15; and a magnet 40 which extends in the vertical direction Z and is inserted into the magnet insertion hole 30. The length Z1 in the vertical direction Z of the rotator core 20 is longer than the length Z2 in the vertical direction Z of the magnet 40. The first distance in the vertical direction Z between the lower end 40D of the magnet 40 and the lower end 20D of the rotator core 20 is shorter than the second distance in the vertical direction Z between the upper end 40U of the magnet 40 and the upper end 20U of the rotator core 20.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a rotor of a motor and a motor including the rotor of the motor.

Background Art

[0002] Conventionally, a rotor of a motor includes a rotating shaft, a rotor core composed of a plurality of electromagnetic steel sheets, magnets inserted into magnet insertion holes formed in the rotor core, and end plates provided at both axial ends of the rotor core and inserted to suppress the protrusion of the inserted magnets. For example, Patent Document 1 discloses a rotor of a motor including end plates with holes provided at both ends of a rotor core to suppress the protrusion of magnets and to suppress magnetic flux leakage, which is a phenomenon in which magnetic flux emitted from the magnets leaks to the end plate side instead of heading toward the stator.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in Patent Document 1, since it is necessary to provide two types of end plates at both ends of the rotor core to suppress the protrusion of the magnets and the magnetic flux leakage of the magnets, the assembly work is complicated, and the axial length of the rotor of the motor increases, which may lead to an increase in the size of the motor. In addition, there is also a problem that the weight of the rotor increases due to the end plates. Furthermore, an increase in the weight due to the end plates may also cause a problem that the moment of inertia of the rotor increases.

[0005] The present invention has been made in view of such a point, and an object thereof is to provide a rotor of a motor and a motor including the rotor of the motor that can avoid the complexity during assembly, suppress magnetic flux leakage of a magnet, and reduce the axial length, weight, and moment of inertia of the rotor.

Means for Solving the Problems

[0006] The rotor of the motor according to the present invention includes a rotating shaft extending in a first direction, a rotor core having a magnet insertion hole extending in the first direction, fixed to the rotating shaft, and composed of a plurality of electromagnetic steel sheets laminated in the first direction, and a magnet extending in the first direction and inserted into the magnet insertion hole. The length of the rotor core in the first direction is longer than the length of the magnet in the first direction, and a first distance in the first direction between one end of the magnet in the first direction and one end of the rotor core in the first direction is shorter than a second distance in the first direction between the other end of the magnet in the first direction and the other end of the rotor core in the first direction.

[0007] According to the rotor of the motor according to the present invention, the first distance in the first direction between one end of the magnet in the first direction and one end of the rotor core in the first direction is shorter than the second distance in the first direction between the other end of the magnet in the first direction and the other end of the rotor core in the first direction. According to the above aspect, it is possible to suppress at least magnetic flux leakage of the magnet from the other end of the magnet in the first direction. That is, even if a steel plate made of the same material as the electromagnetic steel sheet constituting the rotor core is used on the other side of the rotor core in the first direction, magnetic flux leakage of the magnet can be suppressed, and it is not necessary to provide a non-magnetic end face plate. Therefore, the axial length of the rotor can be reduced (shortened), the weight of the rotor can be reduced, and the moment of inertia of the rotor can be reduced.

Effects of the Invention

[0008] According to the present invention, it is possible to provide a rotor of a motor and a motor including the rotor of the motor that can avoid the complexity during assembly, suppress magnetic flux leakage of a magnet, and reduce the axial length, weight, and moment of inertia of the rotor.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0010] Hereinafter, embodiments of the motor according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are not intended to limit the present invention in particular. Also, members and parts having the same function are denoted by the same reference numerals, and redundant descriptions are omitted or simplified as appropriate.

[0011] FIG. 1 is a side view of the motor 100. As shown in FIG. 1, the motor 100 includes a rotor 10 and a stator 60 disposed outside the rotor 10 in the radial direction.

[0012] As shown in FIG. 3, the rotor 10 includes a rotating shaft 15, a rotor core 20, magnet insertion holes 30, magnets 40, end plates 50, a first bearing 58, and a second bearing 59.

[0013] As shown in FIG. 3, the rotating shaft 15 extends in the vertical direction Z. The vertical direction Z is an example of a first direction. Here, the downward direction D is an example of one side of the first direction, and the upward direction U is an example of the other side of the first direction. Note that the direction in which the rotating shaft 15 extends is not limited to the vertical direction Z. The protruding length L1 of the rotating shaft 15 downward D from the rotor core 20 is longer than the protruding length L2 of the rotating shaft 15 upward U from the rotor core 20. As shown in FIG. 1, a part (here, the lower end portion 15B) of the rotating shaft 15 protrudes downward D from the stator 60. An output member is attached to the lower end portion 15B of the rotating shaft 15. That is, the lower end portion 15B of the rotating shaft 15 is configured to be able to attach the output member.

[0014] As shown in FIG. 3, the rotor core 20 is an annular member centered on the axis 15C of the rotating shaft 15. The rotor core 20 is fixed to the rotating shaft 15. The rotor core 20 is composed of a plurality of rotor-side electromagnetic steel sheets 25 laminated in the vertical direction Z. The plurality of laminated rotor-side electromagnetic steel sheets 25 are fixed to each other by, for example, caulking, adhesion, welding, or the like. The plurality of rotor-side electromagnetic steel sheets 25 are fixed to each other by, for example, caulking. The rotor core 20 has a press-fitting hole 28, magnet insertion holes 30, a first hole 31 (see FIG. 4), a second hole 32 (see FIG. 4), and a through hole 33 (see FIG. 4). The press-fitting hole 28, magnet insertion holes 30, first hole 31, second hole 32, and through hole 33 extend in the vertical direction Z.

[0015] As shown in Fig. 3, the thickness T of a single rotor-side electromagnetic steel sheet 25 in the vertical direction Z is, for example, 0.15 mm to 0.5 mm. The rotor-side electromagnetic steel sheet 25 is processed into a predetermined shape by punching using a press die. The rotor-side electromagnetic steel sheet 25 includes a plurality of first rotor-side electromagnetic steel sheets 25A laminated in the vertical direction Z and a second rotor-side electromagnetic steel sheet 25B. As will be described later, the second rotor-side electromagnetic steel sheet 25B has the same configuration as the first rotor-side electromagnetic steel sheet 25A except that it does not have a magnet insertion hole 30 and instead has a dropout prevention portion 38 (see Fig. 5). Therefore, for the common part between the first rotor-side electromagnetic steel sheet 25A and the second rotor-side electromagnetic steel sheet 25B, the first rotor-side electromagnetic steel sheet 25A will be described as an example.

[0016] As shown in Fig. 4, the first rotor-side electromagnetic steel sheet 25A is formed in an annular shape. The first rotor-side electromagnetic steel sheet 25A has a press-fitting hole 28, a plurality of magnet insertion holes 30, a plurality of first holes 31, a plurality of second holes 32, and a plurality of through holes 33.

[0017] As shown in Fig. 3, the press-fitting hole 28 is a hole into which the rotating shaft 15 is press-fitted. As shown in Fig. 4, the press-fitting hole 28 is substantially circular in plan view (i.e., when viewed from the vertical direction Z). A plurality of recesses 28A that are recessed outward in the radial direction are formed in the press-fitting hole 28. The recesses 28A are arranged at equal intervals in the circumferential direction S. The recesses 28A are semi-circular in plan view. Note that the shape of the recesses 28A is not limited to semi-circular.

[0018] As shown in FIG. 3, the magnet insertion hole 30 is a hole into which the magnet 40 is inserted. As shown in FIG. 4, the magnet insertion hole 30 is located radially outside the press-fitting hole 28. The magnet insertion hole 30 includes a first magnet hole 30A and a second magnet hole 30B. The first magnet hole 30A is formed in a V shape in a plan view so as to widen toward the outside in the radial direction. The first magnet hole 30A has a first portion 30AA into which one magnet 40 is inserted and a second portion 30AB into which another magnet 40 is inserted. The first portion 30AA, the second portion 30AB, and the second magnet hole 30B are continuous. The second magnet hole 30B extends radially inward from the radially inner end of the first magnet hole 30A. The second magnet hole 30B is located on a straight line LN2 passing through the center 28C of the press-fitting hole 28 and the second hole 32. The straight line LN2 is an example of another straight line. The plurality of magnet insertion holes 30 are arranged at equal intervals in the circumferential direction S. Note that the shape of the magnet insertion hole 30 and the number of magnets 40 inserted into the magnet insertion hole 30 are not limited to those described above. Also, FIG. 4 shows a state in which two magnets 40 are inserted only into the first magnet hole 30A of one magnet insertion hole 30.

[0019] As shown in FIG. 4, the first hole 31 is located radially outside the press-fitting hole 28. The first hole 31 is located radially inside the magnet insertion hole 30. The first hole 31 is located on a straight line LN1 passing through the center 28C of the press-fitting hole 28 and the circumferential center 28AC of the concave portion 28A. The first hole 31 is substantially trapezoidal in a plan view. The circumferential length SA1 of the radially inner portion of the first hole 31 in the circumferential direction S is longer than the circumferential length SA2 of the radially outer portion of the first hole 31 in the circumferential direction S. The plurality of first holes 31 are arranged at equal intervals in the circumferential direction S.

[0020] As shown in FIG. 4, the second hole 32 is located radially outside the press-fitting hole 28. The second hole 32 is located radially inside the magnet insertion hole 30. The second hole 32 is located between the press-fitting hole 28 and the magnet insertion hole 30 in the radial direction. The second hole 32 is substantially trapezoidal in a plan view. The circumferential length SB1 of the radially inner portion of the second hole 32 in the circumferential direction S is shorter than the circumferential length SB2 of the radially outer portion of the second hole 32 in the circumferential direction S. The plurality of second holes 32 are arranged at equal intervals in the circumferential direction S.

[0021] As shown in FIG. 4, in the circumferential direction S, the first holes 31 and the second holes 32 are alternately arranged. In the circumferential direction S, a part of the first holes 31 and a part of the second holes 32 overlap. The radially inner end portion 31H of the first hole 31 is located radially inward of the radially inner end portion 32H of the second hole 32. The radially outer end portion 31J of the first hole 31 is located radially inward of the radially outer end portion 32J of the second hole 32. The circumferential length SA1 in the circumferential direction S of the radially inner portion of the first hole 31 is longer than the circumferential length SB1 in the circumferential direction S of the radially inner portion of the second hole 32. The circumferential length SA2 in the circumferential direction S of the radially outer portion of the first hole 31 is shorter than the circumferential length SB2 in the circumferential direction S of the radially outer portion of the second hole 32.

[0022] As shown in FIG. 4, the through hole 33 is located radially outside the press-fitting hole 28. The through hole 33 is located on the straight line LN1. The through hole 33 is circular in plan view. The through hole 33 overlaps the first hole 31 in the radial direction. The through hole 33 overlaps the second magnet hole 30B of the magnet insertion hole 30 in the circumferential direction S. The through hole 33 includes a first through hole 33A and a second through hole 33B that are arranged point-symmetrically with respect to the center 28C of the press-fitting hole 28. The plurality of through holes 33 are arranged at equal intervals in the circumferential direction S. In the circumferential direction S, the through holes 33 and the magnet insertion holes 30 are alternately arranged.

[0023] As shown in FIG. 4, the rotor core 20 includes an outer peripheral edge 20A having a plurality of arc portions 20H arranged in the circumferential direction S and a plurality of protruding portions 20B respectively located between adjacent arc portions 20H. The plurality of protruding portions 20B are arranged at equal intervals in the circumferential direction S. The protruding portion 20B is located on the straight line LN1. The protruding portion 20B is located between adjacent magnet insertion holes 30 with respect to the circumferential direction S. The plurality of arc portions 20H are arranged at equal intervals in the circumferential direction S. The arc portion 20H is located on the straight line LN2. The outermost diameter portion 20HM having the largest radius with the center 28C of the press-fitting hole 28 as the center point among the arc portions 20H is located on the straight line LN2. In this embodiment, the radius of the outermost diameter portion 20HM and the radius of the protruding portion 20B are the same, but they may be different.

[0024] As shown in Fig. 3, the second rotor-side electromagnetic steel plate 25B is provided above U of the uppermost first rotor-side electromagnetic steel plate 25U among the plurality of laminated first rotor-side electromagnetic steel plates 25A. The end face plate 50 is not provided above U of the second rotor-side electromagnetic steel plate 25B. That is, the second rotor-side electromagnetic steel plate 25B is exposed to the outside. As shown in Fig. 5, the second rotor-side electromagnetic steel plate 25B has a press-fitting hole 28, a plurality of first holes 31, a plurality of second holes 32, and a plurality of through holes 33. The second rotor-side electromagnetic steel plate 25B does not include a magnet insertion hole 30 (see Fig. 4). The second rotor-side electromagnetic steel plate 25B includes a dropout prevention portion 38 that suppresses the magnet 40 inserted into the magnet insertion hole 30 from dropping out (popping out) of the magnet insertion hole 30. The dropout prevention portion 38 overlaps the magnet insertion hole 30 in a plan view. The dropout prevention portion 38 overlaps the entire magnet insertion hole 30 in a plan view.

[0025] As shown in Fig. 3, the magnet 40 is inserted into the magnet insertion hole 30. The magnet 40 extends in the upward direction Z. The magnet 40 is formed in a flat plate shape. The magnet 40 is, for example, a permanent magnet. The magnet 40 is, for example, a rare earth magnet. The magnet 40 is, for example, a neodymium magnet containing neodymium (Nd), iron (Fe), and boron (B).

[0026] As shown in FIG. 3, the length Z1 in the vertical direction Z of the rotor core 20 is longer than the length Z2 in the vertical direction Z of the magnet 40. The first distance in the vertical direction Z between the lower end 40D of the magnet 40 and the lower end 20D of the rotor core 20 is shorter than the second distance in the vertical direction Z between the upper end 40U of the magnet 40 and the upper end 20U of the rotor core 20. The lower end 40D is an example of one end on one side in the first direction of the magnet 40, and the upper end 40U is an example of one end on the other side in the first direction of the magnet 40. The lower end 20D is an example of one end on one side in the first direction of the rotor core 20, and the upper end 20U is an example of one end on the other side in the first direction of the rotor core 20. The first distance is, for example, 2T or less (i.e., the thickness in the vertical direction Z of two laminated rotor-side electromagnetic steel sheets 25). The second distance is, for example, 3T to 6T. In the present embodiment, the first distance is 0 and the second distance is 5T (i.e., the thickness in the vertical direction Z of five laminated rotor-side electromagnetic steel sheets 25), but the first distance and the second distance are not limited to this.

[0027] As shown in Fig. 3, the end face plate 50 is provided below D of the rotor core 20. The end face plate 50 is provided under the lowermost first rotor-side electromagnetic steel plate 25D among the plurality of first rotor-side electromagnetic steel plates 25A of the rotor core 20. The end face plate 50 is fixed to the rotary shaft 15 by press-fitting, for example. Note that the end face plate 50 may be fixed to the rotary shaft 15 when the rotor core 20 is press-fitted into the rotary shaft 15. At this time, the end face plate 50 is not press-fitted into the rotary shaft 15. As shown in Fig. 7, the end face plate 50 is formed in a disk shape. The diameter of the end face plate 50 is smaller than the diameter of the rotor-side electromagnetic steel plate 25. The end face plate 50 overlaps the entire magnet insertion hole 30 in plan view. The end face plate 50 suppresses the magnet 40 inserted into the magnet insertion hole 30 from dropping off (popping out) from below D of the magnet insertion hole 30. The end face plate 50 is made of a non-magnetic material (for example, stainless steel (for example, SUS303)). The thickness H in the vertical direction of the end face plate 50 (see Fig. 3) is thicker than the thickness T of one rotor-side electromagnetic steel plate 25. As shown in Fig. 6, a press-fitting hole 52 and a plate hole 54 are formed in the end face plate 50. The press-fitting hole 52 is a hole into which the rotary shaft 15 is press-fitted. The plate hole 54 is a hole into which a mounting jig (not shown) is inserted. The plate hole 54 includes a first plate hole 54A and a second plate hole 54B that are arranged point-symmetrically with respect to the center 52C of the press-fitting hole 52. As shown in Fig. 7, the plate hole 54 overlaps the through hole 33 in plan view. The plate hole 54 does not overlap the magnet insertion hole 30. The first plate hole 54A overlaps the first through hole 33A in plan view, and the second plate hole 54B overlaps the second through hole 33B in plan view. The diameter of the press-fitting hole 52 is larger than the diameter of the plate hole 54.

[0028] As shown in FIG. 1, the stator 60 houses the rotor 10. The stator 60 rotatably supports the rotor 10. As shown in FIG. 2, the stator 60 includes a stator core 70 and a plurality of windings 75 wound around the stator core 70. The stator core 70 is an annular member centered on the axis 15C (see FIG. 3) of the rotating shaft 15. The stator core 70 is fixed to a cover (not shown) of the motor 100. The stator core 70 is composed of a plurality of stator-side electromagnetic steel sheets 80 laminated in the vertical direction Z. The stator-side electromagnetic steel sheets 80 are processed into a predetermined shape by punching using a press die. As shown in FIG. 1, the connection portions 75A between the plurality of windings 75 are located above the rotating shaft 15 (the other side in the vertical direction Z). Note that the plurality of windings 75 may be star-connected or delta-connected. As shown in FIG. 2, the difference between the length Z1 of the rotor core 20 in the vertical direction Z and the length Z3 of the stator core 70 in the vertical direction Z is equal to or less than the thickness 2T of the two laminated rotor-side electromagnetic steel sheets 25 in the vertical direction Z. In the present embodiment, the length Z1 of the rotor core 20 in the vertical direction Z is equal to the length Z3 of the stator core 70 in the vertical direction Z.

[0029] As shown in FIG. 1, the motor 100 includes a rotation sensor 90 that detects the rotation angle of the rotating shaft 15. The rotation sensor 90 is provided on the side of the upper end portion 15A of the rotating shaft 15. The rotation sensor 90 is fixed to the stator 60. Examples of the rotation sensor 90 include a resolver, an encoder, and an MR sensor.

[0030] As shown in FIG. 3, the first bearing 58 and the second bearing 59 are rolling bearings. The first bearing 58 and the second bearing 59 are, for example, ball bearings. The first bearing 58 is a bearing on the load side. The first bearing 58 rotatably supports the rotating shaft 15. The second bearing 59 is a bearing on the non-load side. The second bearing 59 rotatably supports the upper end portion 15A of the rotating shaft 15. The first bearing 58 and the second bearing 59 are fixed to the stator 60 (see FIG. 1).

[0031] As described above, according to the rotor 10 of the motor 100 of the present embodiment, the first distance in the vertical direction Z between the lower end 40D of the magnet 40 and the lower end 20D of the rotor core 20 is shorter than the second distance in the vertical direction Z between the upper end 40U of the magnet 40 and the upper end 20U of the rotor core 20. According to the above aspect, it is possible to suppress at least the magnetic flux leakage of the magnet 40 from the upper end 40U of the magnet 40. That is, even if a steel plate (for example, the second rotor-side electromagnetic steel plate 25B) made of the same material as the first rotor-side electromagnetic steel plate 25A constituting the rotor core 20 is used for the upper end 20U of the rotor core 20, the magnetic flux leakage of the magnet 40 can be suppressed, and since there is no need to provide the non-magnetic end face plate 50, the axial length (i.e., the length in the vertical direction Z) of the rotor 10 can be reduced (shortened), the weight of the rotor 10 can be reduced, and the moment of inertia of the rotor 10 can be reduced.

[0032] The rotor 10 of the motor 100 of the present embodiment is provided below the rotor core 20, and includes a magnet 40 inserted into the magnet insertion hole 30 and suppresses the magnet 40 from falling off from below, and includes an end face plate 50 made of a non-magnetic material. According to the above aspect, since the non-magnetic end face plate 50 is provided below the rotor core 20, it is possible to suppress the magnetic flux leakage of the magnet 40 while suppressing the protrusion of the magnet 40 in the axial direction (here, the vertical direction Z).

[0033] In the rotor 10 of the motor 100 of the present embodiment, the first distance is equal to or less than the thickness 2T in the vertical direction Z of the two laminated rotor-side electromagnetic steel plates 25. According to the above aspect, it is possible to concentrate the arrangement of heavy objects in the vertical direction Z downward.

[0034] In the rotor 10 of the motor 100 of the present embodiment, the lower end portion 15B of the rotating shaft 15 is configured to be attachable to an output member. According to the above aspect, it is possible to concentrate the arrangement of heavy objects in the vertical direction Z downward.

[0035] In the rotor 10 of the motor 100 of the present embodiment, the protruding length L1 of the rotary shaft 15 downward from the rotor core 20 is longer than the protruding length L2 of the rotary shaft 15 upward from the rotor core 20. According to the above aspect, the arrangement of heavy objects in the vertical direction Z can be concentrated downward.

[0036] The motor 100 of the present embodiment is provided at the upper end portion 15A of the rotary shaft 15 and includes a rotation sensor 90 that detects the rotation angle of the rotary shaft 15. According to the above aspect, since the magnetic flux leakage of the magnet 40 from the upper end 40U of the magnet 40 is suppressed, malfunction of the rotation sensor 90 can be suppressed.

[0037] In the motor 100 of the present embodiment, the connection portions 75A between the plurality of windings 75 of the stator 60 are located above the rotary shaft 15. According to the above aspect, since the magnetic flux leakage of the magnet 40 from the upper end 40U of the magnet 40 is suppressed, the overcurrent loss of the strands of the winding 75 can be reduced (the overcurrent in the strands due to the magnetic flux of the magnet 40 can be reduced).

[0038] In the motor 100 of the present embodiment, the difference between the length Z1 of the rotor core 20 in the vertical direction Z and the length Z3 of the stator core 70 in the vertical direction Z is equal to or less than the thickness 2T of the two laminated rotor-side electromagnetic steel sheets 25 in the vertical direction Z. According to the above aspect, leakage of the magnet magnetic flux of the magnet 40 and the cross-magnetizing magnetic flux of the winding 75 in the vertical direction Z can be suppressed.

[0039] In the motor 100 of the present embodiment, the length Z1 of the rotor core 20 in the vertical direction Z is equal to the length Z3 of the stator core 70 in the vertical direction Z. According to the above aspect, leakage of the magnet magnetic flux of the magnet 40 and the cross-magnetizing magnetic flux of the winding 75 in the vertical direction Z can be more reliably suppressed.

[0040] The preferred embodiments of the present invention have been described above. However, the above-described embodiments are merely examples, and the present invention can be implemented in various other forms. In the above-described embodiment, the rotor 10 includes the end face plate 50 provided below the rotor core 20. However, the rotor 10 may include another end face plate having the same configuration as the end face plate 50 above the rotor core 20.

[0041] In the above-described embodiment, the inner end portion 31H in the radial direction of the first hole 31 is located radially inward of the inner end portion 32H in the radial direction of the second hole 32, and the outer end portion 31J in the radial direction of the first hole 31 is located radially inward of the outer end portion 32J in the radial direction of the second hole 32. However, the present invention is not limited to this. For example, the inner end portion 31H in the radial direction of the first hole 31 may be located radially outward of the inner end portion 32H in the radial direction of the second hole 32, and the outer end portion 31J in the radial direction of the first hole 31 may be located radially outward of the outer end portion 32J in the radial direction of the second hole 32.

[0042] In the above-described embodiment, the length SA1 in the circumferential direction S of the inner portion in the radial direction of the first hole 31 is longer than the length SB1 in the circumferential direction S of the inner portion in the radial direction of the second hole 32, and the length SA2 in the circumferential direction S of the outer portion in the radial direction of the first hole 31 is shorter than the length SB2 in the circumferential direction S of the outer portion in the radial direction of the second hole 32. However, the present invention is not limited to this. For example, the length SA1 in the circumferential direction S of the inner portion in the radial direction of the first hole 31 may be shorter than the length SB1 in the circumferential direction S of the inner portion in the radial direction of the second hole 32, and the length SA2 in the circumferential direction S of the outer portion in the radial direction of the first hole 31 may be longer than the length SB2 in the circumferential direction S of the outer portion in the radial direction of the second hole 32.

Explanation of Reference Numerals

[0043] 10 Rotor 15 Rotation shaft 20 Rotor core 25 Rotor-side electromagnetic steel sheet 28 Press-fitting hole 28C Center 28A Recess 28AC Center 30 Magnet insertion hole 30A First magnet hole 30B Second magnet hole 31 First hole 32 Second Hole 33 Through-Hole 33A First Through-Hole 33B Second Through-Hole 40 Magnet 50 End Panel 52 Press-Fit Hole 54 Plate Hole 54A First Plate Hole 54B Second Plate Hole 60 Stator 70 Stator Core 75 Coil 75A Connection Part 90 Rotation Sensor 100 Motor

Claims

1. a rotating shaft extending in a first direction, a rotor core having a magnet insertion hole extending in the first direction, fixed to the rotating shaft, and composed of a plurality of electromagnetic steel sheets laminated in the first direction, a magnet extending in the first direction and inserted into the magnet insertion hole, wherein the length of the rotor core in the first direction is longer than the length of the magnet in the first direction, a rotor of a motor, wherein a first distance in the first direction between one end of the magnet in the first direction and one end of the rotor core in the first direction is shorter than a second distance in the first direction between the other end of the magnet in the first direction and the other end of the rotor core in the first direction.

2. An end face plate provided on one side of the rotor core in the first direction, inserted into the magnet insertion hole, configured to prevent the magnet from falling off from one side in the first direction, and composed of a non-magnetic material, the rotor of the motor according to claim 1.

3. The rotor of the motor according to claim 1, wherein the first distance is equal to or less than the thickness in the first direction of two laminated electromagnetic steel sheets.

4. The rotor of the motor according to claim 1, wherein an output member can be attached to one end of the rotating shaft in the first direction.

5. The rotor of the motor according to claim 1, wherein a protruding length of the rotating shaft from the rotor core to one side in the first direction is longer than a protruding length of the rotating shaft from the rotor core to the other side in the first direction.

6. A rotor of a motor according to any one of claims 1 to 5, a rotation sensor provided on a side of the other end of the rotating shaft in the first direction, configured to detect a rotation angle of the rotating shaft, a motor.

7. A rotor of a motor according to any one of claims 1 to 5, a stator configured to rotatably support the rotor, wherein the stator includes a stator core and a plurality of windings wound around the stator core, a motor, wherein connection portions between the plurality of windings are located on the other side of the rotating shaft in the first direction.

8. A rotor of a motor according to any one of claims 1 to 5, a stator configured to rotatably support the rotor, wherein the stator includes a stator core and a plurality of windings wound around the stator core, A motor in which the difference between the length of the rotor core in the first direction and the length of the stator core in the first direction is equal to or less than the thickness of two laminated electromagnetic steel sheets in the first direction.

9. The motor according to claim 8, wherein the length of the rotor core in the first direction is equal to the length of the stator core in the first direction.

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