JP2010004609A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor capable of improving the efficiency of cooling without degrading the efficiency of motor operation. <P>SOLUTION: The motor includes: a plurality of first thinning holes 70 formed along an axial direction from an end surface 61a of a rotor yoke 61; a housing hole 62 disposed on the outside of a diameter direction from the first thinning holes 70 and opened on the end surface 61a to house a permanent magnet 63; an end surface plate 80 disposed on the end of the rotor yoke 61 in an axial direction and closing the opening of the housing hole 62; and a plurality of second thinning holes 90 formed on the end surface plate 80. At least part of all the first thinning holes 70 are exposed through the second thinning holes 90 when viewed from the axial direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor.

  A motor is used as a power source for automobiles such as hybrid vehicles and fuel cell vehicles. The motor includes a cylindrical stator portion, a columnar rotor portion disposed inside the stator portion, and a shaft that is coaxially press-fitted and rotatably supported at the center of the rotor portion. The rotor portion includes a rotor yoke in which a plurality of magnetic plate materials are stacked. The rotor yoke is provided with a first through hole penetrating in the axial direction in order to reduce the weight of the motor and improve the operation efficiency. An accommodation hole is formed along the axial direction from the end face of the rotor yoke, and a permanent magnet is accommodated in the accommodation hole. In order to prevent the permanent magnet from jumping out of the accommodation hole, end face plates are provided at both axial ends of the rotor yoke. Similarly to the rotor yoke, the end face plate is also provided with a second cutout hole.

In Patent Document 1, a plurality of cavities are provided in the axial direction, and a rotor core in which permanent magnets for preventing magnetic flux leakage into the cavities are provided in the axial direction, and both side surfaces of the rotor core are provided. In a rotor of a rotating electrical machine having a pressing plate for pressing, an opening corresponding to the cavity of the rotor core is provided in the pressing plate, and a partition plate is provided in a cavity formed by the cavity and the opening. There is described a rotor of a rotating electrical machine which is provided and has an end protruding from a side surface of the rotor. By providing the holding plate with an opening corresponding to the cavity of the rotor core, when the rotating electrical machine is driven and the rotor rotates, air flows into the cavity through the opening. It can be cooled. In addition, since the partition plate is provided in the cavity formed by the cavity and the opening so as to protrude from the side surface of the rotor, the air flow to the cavity is improved, so that the rotor can be further cooled. Therefore, it is said that the cooling performance of the rotating electrical machine can be improved.
Japanese Patent No. 3749098

However, the technique described in Patent Document 1 has a problem that the cost and weight increase because the partition plate is used. Further, since the partition plate is used, the motor operation efficiency is significantly reduced due to air resistance in the high rotation region. In particular, in the case of a motor used in cooling oil, there is a problem that operation efficiency is further reduced.
Therefore, an object of the present invention is to provide a motor capable of improving the cooling performance without reducing the operation efficiency.

  In order to solve the above-mentioned problem, the invention according to claim 1 includes a shaft that is rotatably supported (for example, the shaft 24 in the embodiment) and a cylindrical rotor yoke that is press-fitted and fixed coaxially with the shaft. (For example, the rotor yoke 61 in the embodiment) and a plurality of first lightening holes (for example, the first lightening in the embodiment) formed along the axial direction from the end surface of the rotor yoke (for example, the end surface 61a in the embodiment). Hole 70) and a housing hole (for example, a housing hole in the embodiment) that is disposed on the outer side in the radial direction from the first cutout hole and opens to the end face to house a permanent magnet (for example, the permanent magnet 63 in the embodiment). 62) and an end face plate (for example, an end face plate in the embodiment) that is disposed at the end portion of the rotor yoke in the axial direction and closes the opening portion of the accommodation hole 0) and a plurality of second lightening holes (for example, second lightening holes 90 in the embodiment) formed in the end face plate, and all the first lightening holes as viewed from the axial direction. At least a part of the above is exposed through the second hollow hole.

  In the invention according to claim 2, the diameter of the circumference (for example, the diameter φb in the embodiment) passing through the outermost portion (for example, the outermost portion 91 in the embodiment) in the radial direction is the diameter. It is characterized by being larger than the diameter of the circumference (for example, the diameter φa in the embodiment) passing through the outermost portion (for example, the outermost portion 71 in the embodiment) of the first cutout hole in the direction.

  In the invention according to claim 3, the distance (for example, the distance Rb in the embodiment) from the central axis of the shaft to the innermost portion (for example, the innermost 92 in the embodiment) of the second hollow hole in the radial direction is The distance from the central axis to the innermost portion (for example, the innermost portion 72 in the embodiment) of the first cutout hole in the radial direction is smaller than the distance (for example, the distance Ra in the embodiment). .

  In the invention according to claim 4, the first lightening hole is formed in a polygonal shape, and when viewed from the axial direction, all the corners of the first lightening hole (for example, the corners 73, 73 in the embodiment). 74, 75) are exposed through the second cutout hole.

  In the invention according to claim 5, a convex portion (for example, the annular plate 82 in the embodiment) that closes the opening portion of the accommodation hole is formed on the peripheral portion of the end surface on the rotor yoke side of the end surface plate, and the diameter The diameter of the circumference (for example, the diameter φc in the embodiment) passing through the innermost portion of the convex portion in the direction (for example, the bottom surface 96 in the embodiment) is the outermost portion of the first cutout hole in the radial direction (for example, It is characterized by being larger than the diameter of the circumference passing through the outermost part 71 in the embodiment (for example, the diameter φa in the embodiment).

  The invention according to claim 6 is characterized in that the end face plate sandwiches the annular plate between the annular plate (for example, the annular plate 82 in the embodiment) that closes the opening of the accommodation hole and the rotor yoke. A support plate (for example, the support plate 84 in the embodiment) that is press-fitted and fixed to the shaft, the annular plate is made of a nonmagnetic material, and the support plate is made of a material having a linear expansion coefficient equivalent to that of the shaft. The convex portion is constituted by the annular plate.

  The invention according to claim 7 is characterized in that the support plate is press-fitted and fixed to the shaft in a state where the central portion is bent and deformed toward the rotor yoke.

  According to the first aspect of the present invention, even if the cooling oil flows into the first lightening hole, the cooling oil can flow out through the second lightening hole. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. In that case, since a partition plate like patent document 1 is not used, motor operation efficiency is not reduced.

  According to the second aspect of the present invention, the cooling oil that has flowed into the first cutout hole below the shaft flows out through the second cutout hole without being blocked by the end face plate. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved.

  According to the invention of claim 3, the cooling oil that has flowed into the first cutout hole above the shaft flows out through the second cutout hole without being blocked by the end face plate. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved.

In the rotating state of the rotor yoke, the cooling oil that has flowed into the first cutout hole receives centrifugal force and concentrates at any corner of the first cutout hole formed in a polygonal shape.
According to the fourth aspect of the present invention, the cooling oil concentrated on any one corner of the first cutout hole flows out through the second cutout hole without being blocked by the end face plate. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved.

  According to the invention which concerns on Claim 5, a groove part is formed between a rotor yoke and an end surface board. Therefore, the cooling oil that has flowed into the first cutout hole flows out into the groove without being blocked by the end face plate. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, it is not necessary to position the rotor yoke and the end face plate in the circumferential direction, and the manufacturing process can be simplified.

  According to the invention which concerns on Claim 6, since the cyclic | annular board is comprised with the nonmagnetic material, the short circuit of the magnetic flux through an end surface board can be suppressed. Further, since the support plate is made of a material having a linear expansion coefficient equivalent to that of the shaft, the end face plate can be fixed to the shaft even if the motor generates heat during operation. And the groove part which makes the inner peripheral surface of a cyclic | annular board the bottom face is formed between a rotor yoke and a support plate, and the cooling oil which flowed into the 1st cut-out hole flows out into this groove part. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved.

  According to the seventh aspect of the invention, since the annular plate is pressed toward the rotor yoke by the restoring force of the support plate that has been bent and deformed, it is possible to reliably prevent the permanent magnet from jumping out of the accommodation hole. Even in this case, a groove portion whose bottom surface is the inner peripheral surface of the annular plate is formed between the rotor yoke and the support plate, so that the cooling efficiency of the motor can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Vehicle drive motor unit)
FIG. 1 is a schematic sectional view of a vehicle drive motor unit.
As shown in FIG. 1, a vehicle drive motor unit (hereinafter referred to as a motor unit) 10 includes a motor housing 11 that houses a motor 23 having a stator portion 21 and a rotor portion 60, and one axial direction of the motor housing 11. A transmission housing 12 that houses a power transmission portion (not shown) that transmits power from a shaft (shaft) 24 of the motor 23, and is fastened to the other axial side of the motor housing 11 to rotate the motor 23. A sensor housing 13 that houses the sensor 25. The mission housing 12 includes a common housing 12A fastened to the motor housing 11 and a gear housing 12B fastened to the common housing 12A. A motor chamber 36 is formed in the motor housing 11, a mission chamber 37 is formed in the mission housing 12, and a sensor chamber 38 is formed in the sensor housing 13.

  The motor housing 11 is formed in a substantially cylindrical shape so as to cover the entire motor 23. A water jacket 55 for cooling the motor 23 is provided inside the motor housing 11 so as to cover the entire circumference of the stator portion 21. The stator portion 21 is shrink-fitted into the motor housing 11 and is disposed so as to be in close contact with the inner peripheral surface of the motor housing 11.

A bearing 27 that rotatably supports one end side of the shaft 24 is fixed to a partition wall between the motor chamber 36 and the sensor chamber 38. On the other hand, a bearing 26 that rotatably supports the other end of the shaft 24 is fixed to a partition wall between the motor chamber 36 and the mission chamber 37.
Inside the motor unit 10, cooling oil 40 for cooling the bearings 26, 27, the motor 23, and the like is introduced. The motor 23 described above is arranged in a state where the lower portion of the stator portion 21 is immersed in the cooling oil 40. The mission chamber 37 is provided with an oil pump 41 so that the cooling oil 40 pumped up by the oil pump 41 circulates in the motor unit 10 through the oil passage 42. The cooling oil 40 circulating in the motor unit 10 is supplied to the bearings 26, 27, etc., so that the bearings 26, 27, etc. are cooled.

(motor)
The motor 23 of this embodiment is an inner rotor type motor, and is coaxial with the cylindrical stator portion 21, the columnar rotor portion 60 disposed inside the stator portion 21, and the center of the rotor portion 60. And a shaft 24 that is press-fitted and supported rotatably.
The stator portion 21 is formed by laminating magnetic plate materials in the axial direction, and includes a tooth 21a that extends radially inward. A coil 21b is wound around the tooth 21a via an insulator (not shown).

  2 and 3 are explanatory views of the rotor portion of the motor according to the first embodiment, FIG. 2 is a cross-sectional view taken along the line PP in FIG. 3, and FIG. 3 is a side view. As shown in FIG. 2, the rotor unit 60 includes a rotor yoke 61 on which magnetic plate materials are laminated. The shaft 24 is fixed to the central portion of the rotor yoke 61 in the radial direction. Around the shaft 24, a plurality of (for example, eight) first through holes 70 penetrating the rotor yoke 61 in the axial direction are provided. Specifically, as shown in FIG. 3, a plurality of ribs 78 are stretched between the central portion and the peripheral portion of the rotor yoke 61, and a first cutout hole 70 is formed between the adjacent ribs 78. Yes. The ribs 78 extend to one side in the tangential direction with respect to the outer periphery of the shaft 24, and are arranged uniformly along the circumferential direction of the rotor yoke 61. Thereby, the 1st thinning hole 70 is formed in the substantially triangular shape.

  Returning to FIG. 2, a plurality of receiving holes 62 penetrating the rotor yoke 61 in the axial direction are formed on the radially outer side of the first cutout hole 70. A permanent magnet 63 made of a rare earth such as neodymium is inserted into each housing hole 62. The permanent magnet 63 is magnetized in the radial direction of the rotor yoke 61. As shown in FIG. 3, the permanent magnets 63 are arranged at substantially equal intervals along the circumferential direction of the rotor yoke 61, and the permanent magnets 63 adjacent in the circumferential direction are alternately magnetized in the opposite direction. As shown in FIG. 2, the permanent magnet 63 is divided into a plurality along the axial direction of the rotor yoke 61. Thus, by dividing the permanent magnet 63 into a plurality of parts, eddy current loss generated in the permanent magnet 63 can be reduced.

As shown in FIG. 2, the permanent magnets 63 divided into a plurality along the axial direction of the rotor yoke 61 repel each other and may jump out of the accommodation hole 62. Therefore, end face plates 80 and 80 are arranged at both axial ends of the rotor yoke 61. The end face plate 80 is press-fitted and fixed to the shaft 24 and closes the opening portion of the accommodation hole 62 at the peripheral edge portion thereof. This prevents the permanent magnet from jumping out of the accommodation hole 62.
As shown in FIG. 3, around the shaft 24, a plurality of (for example, eight) second hollow holes 90 that penetrate the end face plate 80 in the axial direction are formed. The second lightening holes 90 have, for example, a circular shape, and are arranged uniformly in the circumferential direction of the end face plate 80.

(First and second cutout holes)
The first cutout hole 70 of the rotor yoke 61 and the second cutout hole 90 of the end face plate 80 are formed so as to satisfy the following relative relationship.
As shown in FIG. 3, on a certain circumference, the distance between the adjacent second lightening holes 90 is longer than the opening width of the first lightening holes 70. For example, on a circumference C <b> 1 passing through the center 90 c of the second lightening hole 90, the distance B <b> 1 between the adjacent second lightening holes 90 is longer than the opening width A <b> 1 of the first lightening hole 70. As a result, when viewed from the axial direction of the rotor yoke 61, at least a part of all the first lightening holes 70 are exposed through the second lightening holes 90. Thereby, even if the cooling oil flows into the first lightening hole 70, the cooling oil can flow out through the second lightening hole 90. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, since the cooling oil does not stay in the first cutout hole 70, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

  The outermost portion 91 of the second lightening hole 90 in the radial direction of the rotor yoke 61 is disposed outside the outermost surface 71 of the first lightening hole 70. That is, the diameter φb of the circumference passing through the outermost portion 91 is larger than the diameter φa of the circumference passing through the outermost portion 71. Thereby, the cooling oil that has flowed into the first lightening hole 70 below the shaft 24 flows out through the second lightening hole 90 without being blocked by the end face plate 80.

  Further, the innermost portion 92 of the second lightening hole 90 in the radial direction of the rotor yoke 61 is disposed on the inner side of the innermost portion 72 of the first lightening hole 70. That is, the distance Rb from the central axis of the shaft 24 to the innermost part 92 is smaller than the distance Ra from the central axis to the innermost part 72. Thereby, the cooling oil that has flowed into the first lightening hole 70 above the shaft 24 flows out through the second lightening hole 90 without being blocked by the end face plate 80.

  By the way, in the rotation state of the rotor yoke 61, the cooling oil that has flowed into the first cutout hole 70 receives centrifugal force and concentrates on any corner of the first cutout hole 70 formed in a substantially triangular shape. become. Therefore, in this embodiment, when viewed from the axial direction of the rotor yoke 61, all the corners 73, 74, 75 in the substantially triangular first hollow hole 70 are exposed through the second hollow hole 90. As a result, the cooling oil concentrated on any corner of the first lightening hole 70 flows out through the second lightening hole 90 without being blocked by the end face plate 80. Therefore, it is possible to reduce mechanical loss and to improve motor efficiency. Further, since the cooling oil does not stay in the first cutout hole 70, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

  As described above in detail, in the motor according to this embodiment, at least a part of all the first lightening holes 70 is exposed through the second lightening holes 90 when viewed from the axial direction of the rotor yoke 61. The configuration. As a result, the cooling oil that has flowed into the first lightening hole 70 flows out through the second lightening hole 90 without being blocked by the end face plate 80. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, since the cooling oil does not stay in the first cutout hole 70, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

(Second Embodiment)
4 and 5 are explanatory views of the rotor portion of the motor according to the second embodiment, FIG. 4 is a sectional view taken along the line Q-Q in FIG. 5, and FIG. 5 is a side view. The second embodiment shown in FIG. 4 is different from the first embodiment in that a gap 87 is formed between the rotor yoke 61 and the end face plate 180. Note that detailed description of portions having the same configuration as in the first embodiment is omitted.

  In the first embodiment shown in FIG. 2, when the end face plate 80 is formed of a magnetic material (for example, iron), the magnetic flux generated by the permanent magnet 63 is short-circuited via the end face plate 80. Therefore, it can be considered that the end face plate 80 is formed of a nonmagnetic material (for example, stainless steel). However, if the linear expansion coefficients of the end face plate 80 and the shaft 24 (for example, iron) are different, the end face plate 80 is loosely fixed to the shaft 24 due to heat generated by the operation of the motor. Accordingly, when the end face plate 80 moves in the axial direction, the permanent magnet 63 may jump out of the accommodation hole 62. Further, when the end face plate 80 rotates in the circumferential direction, the rotational balance of the motor may be lost.

  On the other hand, in the second embodiment shown in FIG. 4, the end plate 180 is constituted by the annular plate 82 and the support plate 84. The annular plate 82 is formed so as to close the opening of the accommodation hole 62 of the permanent magnet 63. Since the annular plate 82 is formed of a nonmagnetic material (for example, stainless steel), a short circuit of magnetic flux through the end face plate 180 can be suppressed. A disc-shaped support plate 84 is provided so as to sandwich the annular plate 82 with the rotor yoke 61. This support plate 84 (for example, made of iron) has the same linear expansion coefficient as that of the shaft 24. Therefore, even if the motor generates heat during operation, the end face plate 180 is not loosely fixed to the shaft 24.

  A circular protrusion 86 that protrudes toward the rotor yoke 61 is formed at the center of the support plate 84. The outer periphery of the protrusion 86 is fitted to the inner periphery of the annular plate 82, and the annular plate 82 is supported in the radial direction. The height of the protrusion 86 is smaller than the thickness of the annular plate 82. Thereby, a gap 87 is formed between the rotor yoke 61 and the support plate 84. The support plate 84 is press-fitted and fixed to the shaft 24 in a state where the center portion of the support plate 84 is bent and deformed toward the rotor yoke 61 so as to crush the gap 87. Since the annular plate 82 is pressed toward the rotor yoke 61 by the restoring force of the support plate 84 that has been bent and deformed, the permanent magnet 63 can be reliably prevented from jumping out of the accommodation hole 62.

  The central portion of the support plate 84 is close to the rotor yoke 61, but the peripheral portion of the support plate 84 is spaced from the rotor yoke 61 with the annular plate 82 interposed therebetween. Therefore, a groove portion 95 whose bottom surface is the inner peripheral surface of the annular plate 82 is formed at the peripheral portion between the rotor yoke 61 and the support plate 84. The groove 95 opens toward the central axis of the rotor yoke 61 and is formed over the entire circumference of the rotor yoke 61.

  As shown in FIG. 5, the bottom surface of the groove portion 95 (that is, the inner peripheral surface of the annular plate 82) 96 is disposed outside the outermost portion 71 of the first lightening hole 70 in the radial direction of the rotor yoke 61. That is, the diameter φc of the bottom surface 96 of the groove 95 is larger than the diameter φa of the circumference passing through the outermost part 71. As a result, the cooling oil that has flowed into the first cutout hole 70 flows out into the groove portion 95 due to the centrifugal force when the rotor yoke rotates. Similarly to the first embodiment, the outermost portion 91 of the second lightening hole 90 in the radial direction of the rotor yoke 61 is disposed outside the outermost surface 71 of the first lightening hole 70. Therefore, the cooling oil overflowing from the groove portion 95 flows out through the second lightening hole 90.

  Thereafter, when the rotation of the rotor yoke 61 stops, the cooling oil remaining on the entire circumference of the groove portion 95 falls through the gap 87 shown in FIG. The cooling oil flows out through the second lightening hole 90 below the shaft 24. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, since the cooling oil does not stay in the first cutout hole 70 and the groove portion 95, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

  By the way, in the first embodiment shown in FIG. 3, the rotor yoke 61 and the end face plate 80 are arranged in the circumferential direction in order to expose all the corners 73, 74, 75 in the first cutout hole 70 through the second cutout hole 90. It was necessary to position and press-fit into the shaft 24 so as to be a predetermined relative position (phase). On the other hand, in the second embodiment shown in FIG. 5, since the groove portion 95 through which the cooling oil flows is formed on the entire circumference, it is not necessary to position the rotor yoke 61 and the end face plate 80 in the circumferential direction. Therefore, the manufacturing process of the motor can be simplified.

(Third embodiment)
FIG. 6 is a side view of the rotor portion of the motor according to the third embodiment. In the third embodiment, the first lightening hole 170 having a larger opening area than the above embodiment is formed. For example, among a plurality of (for example, eight) first lightening holes in the second embodiment, a plurality of (for example, four) first lightening holes 170 are connected by connecting a pair of adjacent first lightening holes. Is formed.
Thereby, the circumferential distance B2 between the outermost portions 91 of the adjacent second lightening holes 90 is shorter than the circumferential length A2 of the outermost portion 171 of the first lightening holes 170. In this case, as viewed from the axial direction of the rotor yoke 61, at least a part of the circumferential length of the outermost portion 171 of the first cutout hole 170 is always exposed through the second cutout hole 90. As a result, the cooling oil that has flowed into the first cutout hole 170 flows out through the second cutout hole 90 even if it concentrates on the outermost part 171 due to centrifugal force in the rotational state of the rotor yoke 61. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, since the cooling oil does not stay in the first cutout hole 170, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

(Fourth embodiment)
FIG. 7 is a side view of the rotor portion of the motor according to the fourth embodiment. In the fourth embodiment, a second lightening hole 190 having an opening area larger than that of the above embodiment is formed. For example, among a plurality of (for example, eight) second lightening holes in the first embodiment, a plurality of (for example, four) second lightening holes 190 are connected by connecting a pair of adjacent second lightening holes. Is formed.
Thereby, on a certain circumference C3, the opening width B3 of the second lightening hole 190 is larger than the total width (A3 + 2 × D) of the width A3 of the first lightening hole 70 and the width D of the ribs 78 on both sides thereof. It is desirable that In this case, the plurality of first lightening holes 70 are exposed through the second lightening holes 190. Accordingly, the cooling oil that has flowed into the first lightening hole 70 is likely to flow out through the second lightening hole 190. Therefore, it becomes possible to circulate the cooling oil, and the cooling efficiency of the motor can be improved. Further, since the cooling oil does not stay in the first cutout hole 70, the deterioration of the rotor yoke 61 due to the cooling oil can be prevented.

The technical scope of the present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention. That is, the specific structure and shape described in the embodiment are merely examples, and can be changed as appropriate.
For example, in the embodiment, the first cutout hole has a substantially triangular shape and the second cutout hole has a circular shape, but the first cutout hole and the second cutout hole may have other shapes. .

It is a schematic structure sectional view of a drive motor unit for vehicles. It is explanatory drawing of the rotor part of the motor which concerns on 1st Embodiment, and is sectional drawing in the PP line of FIG. It is a side view of the rotor part of the motor which concerns on 1st Embodiment. It is explanatory drawing of the rotor part of the motor which concerns on 2nd Embodiment, and is sectional drawing in the QQ line of FIG. It is a side view of the rotor part of the motor which concerns on 2nd Embodiment. It is a side view of the rotor part of the motor which concerns on 3rd Embodiment. It is a side view of the rotor part of the motor which concerns on 4th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 23 ... Motor 24 ... Shaft 60 ... Rotor part 61 ... Rotor yoke 61a ... End surface 62 ... Accommodating hole 63 ... Permanent magnet 70 ... 1st cutout hole 71 ... Outermost 72 ... Innermost 73, 74, 75 ... Corner | angular part 80 ... End Face plate 82 ... annular plate (convex part) 84 ... support plate 87 ... gap 90 ... second cutout hole 91 ... outermost part 92 ... innermost part 95 ... groove part 180 ... end face plate

Claims (7)

A shaft that is rotatably supported, a cylindrical rotor yoke that is press-fitted and fixed coaxially with the shaft, a plurality of first cutout holes that are formed along an axial direction from an end surface of the rotor yoke, and An accommodation hole that is arranged on the outer side in the radial direction from the first cutout hole and that opens to the end face to accommodate the permanent magnet, and an end that is arranged at the end of the rotor yoke in the axial direction and closes the opening of the accommodation hole A face plate, and a plurality of second hollow holes formed in the end face plate,
The motor according to claim 1, wherein at least a part of all the first lightening holes are exposed through the second lightening holes when viewed from the axial direction.   The diameter of the circumference passing through the outermost part of the second lightening hole in the radial direction is larger than the diameter of the circumference passing through the outermost part of the first lightening hole in the radial direction. The motor according to claim 1.   The distance from the central axis of the shaft to the innermost portion of the second cutout hole in the radial direction is smaller than the distance from the central axis to the innermost portion of the first cutout hole in the radial direction. The motor according to claim 1 or 2, characterized by the above-mentioned. The first cutout hole is formed in a polygonal shape,
4. The device according to claim 1, wherein when viewed from the axial direction, all corner portions of the first lightening hole are exposed through the second lightening hole. 5. Motor. On the peripheral edge of the end face on the rotor yoke side of the end face plate, a convex part that closes the opening of the accommodation hole is formed,
The diameter of the circumference passing through the innermost part of the convex part in the radial direction is larger than the diameter of the circumference passing through the outermost part of the first cutout hole in the radial direction. The motor according to any one of claims 4 to 4. The end face plate includes an annular plate that closes the opening of the accommodation hole, and a support plate that is sandwiched between the rotor yoke and the press fitting to the shaft.
The annular plate is made of a nonmagnetic material, and the support plate is made of a material having a linear expansion coefficient equivalent to that of the shaft,
The motor according to claim 5, wherein the convex portion is constituted by the annular plate.   The motor according to claim 6, wherein the support plate is press-fitted and fixed to the shaft in a state in which a central portion is bent and deformed toward the rotor yoke.

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