JP2009296841A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine for preventing the generation of an in-plane eddy current loss of a rotor when stage skew of the rotor is carried out. <P>SOLUTION: The rotary electric machine 10 has a rotor 3, in which two or more rotor units 20a, 20b, 20c with permanent magnets 8 arranged in a circumferential direction at intervals are laminated and each rotor unit 20a, 20b, 20c is dislocated in the circumferential direction so that the locations of the permanent magnets 8 of each rotor unit 20a, 20b, 20c may be dislocated in the circumferential direction. The rotary electric machine includes hollow spaces 30a, 30b arranged in places corresponding to the locations of the permanent magnets 8 at the jointing portion of the rotor units 20a, 20b, 20c laminated adjacently, and having their cross section, which is perpendicular to the axial direction of the rotating shaft of the rotor 3 and is larger than that of the permanent magnet 8. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine, and more particularly, to a rotating electrical machine having a rotor in which a plurality of rotor portions are stacked while being shifted in the circumferential direction.

  2. Description of the Related Art A permanent magnet rotating electric machine using a permanent magnet as a field magnet is known as a rotating electric machine used for a hybrid vehicle, an electric vehicle, and the like. As a typical permanent magnet rotating electrical machine, a surface magnet type permanent magnet rotating electrical machine in which a permanent magnet is attached to the outer periphery of a rotor core and an embedded permanent magnet rotating electrical machine in which a permanent magnet is embedded in the rotor core are known. As a rotating electrical machine suitable for variable characteristics, a permanent magnet type reluctance rotating electrical machine that uses both reluctance torque and magnet torque is known. In particular, the permanent magnet type reluctance type rotating electrical machine uses a reluctance torque that can obtain a torque equal to or higher than the magnet torque, together with the magnet torque. And magnet torque, and mainly driven by reluctance torque during high-speed rotation.

  However, in a motor using such a permanent magnet, an induced voltage is generated in the rotating electrical machine when the rotor is rotated. Further, the concentrated winding method has a problem that the induced voltage generated by the permanent magnet magnetic flux is greatly distorted and the torque ripple is larger than that of the normally used distributed winding method. Therefore, in Patent Document 1, a stator having an armature winding, a rotor that is rotatably provided inside the stator, and having a rotor core, and a magnetic pole of an iron core adjacent to the rotor are provided. A permanent magnet reluctance type rotating electrical machine having a permanent magnet disposed in the rotor core so as to cancel the magnetic flux from the armature winding that passes through the rotor, the rotor being divided into two in the direction of the rotation axis, The divided rotors are arranged shifted in the circumferential direction, and the skew angle θ is an angle formed by the magnetic pole center of one of the divided rotor cores and the magnetic pole center of the other divided rotor core with respect to the rotation axis. , The skew angle θ is disclosed as 13 degrees <θ <31 degrees.

JP 2006-304546 A

  According to the configuration of Patent Document 1, it is possible to reduce the maximum value of the generated induced voltage waveform and the torque ripple. However, in the configuration of Patent Document 1, when a plurality of rotor portions are stacked while being shifted in the circumferential direction as shown in FIG. Leakage magnetic flux (arrow A) is generated along the axial direction of the rotating shaft. Then, as shown in FIG. 10B, an eddy current (arrow B) is generated in the adjacent rotor portion, and this causes a problem that in-plane eddy current loss occurs.

  An object of the present invention is to provide a rotating electrical machine that suppresses occurrence of in-plane eddy current loss of a rotor when the rotor is skewed.

  The rotating electrical machine according to the present invention includes a plurality of rotor portions each having permanent magnets arranged at predetermined intervals in the circumferential direction, and each rotor portion is rotated so that the positions of the permanent magnets in the circumferential direction are shifted. A rotating electrical machine having a rotor that is shifted in a direction, provided at a position corresponding to the position of a permanent magnet at a joint portion of adjacently stacked rotor portions, and perpendicular to the axial direction of the rotor rotation shaft. A hollow portion having a size larger in area than the permanent magnet is provided.

  In the rotating electrical machine according to the present invention, it is preferable that the cavity is filled with a nonmagnetic material.

  Further, in the rotating electrical machine according to the present invention, the axial flow path is connected to one end and the other end in the axial direction of the rotating shaft of the rotor, and the axial flow for flowing the refrigerant in the axial direction at the axial center of the rotor It is preferable to include a channel, an inflow channel for allowing the refrigerant to flow into each cavity from the axial channel, and an outflow channel for returning the refrigerant from each cavity to the axial channel.

  According to the rotating electrical machine configured as described above, the hollow portion having a cross-sectional area perpendicular to the axial direction of the rotating shaft of the rotor is larger than that of the permanent magnet at a position corresponding to the position of the permanent magnet in the joint portion. The magnetic permeability of the hollow portion is lower than the magnetic permeability of a rotor formed by stacking steel plates, for example, and the magnetic flux hardly leaks. Thereby, generation | occurrence | production of the in-plane eddy current loss of a rotor can be suppressed.

  According to the rotating electrical machine in which the hollow portion having the above configuration is filled with a nonmagnetic material, leakage of magnetic flux can be suppressed. Thereby, generation | occurrence | production of the in-plane eddy current loss of a rotor can be suppressed. Further, since the non-magnetic material restricts the movement of the permanent magnet in the axial direction, it is possible to prevent the axial displacement of the permanent magnet.

  According to the rotating electric machine having the refrigerant inflow channel and the outflow channel having the above-described configuration, the refrigerant can flow from the shaft channel provided in the shaft core of the rotor to the cavity. Thereby, the cooling effect of a rotor can be improved.

  Embodiments according to the present invention will be described below in detail with reference to the accompanying drawings. Further, in this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating understanding of the present invention, and can be appropriately changed according to the use, purpose, specification, and the like.

  FIG. 1 is a diagram illustrating a rotor 3 of a rotating electrical machine 10 according to a first embodiment of the present invention. FIG. 2 is a view of the region 4 in FIG. The rotating electrical machine 10 includes the rotor 3 and a stator (not shown).

  The rotor 3 includes rotor portions 20a, 20b, 20c and joint portions 40a, 40b. The rotor 3 functions as a rotor that rotates in the circumferential direction around the rotation shaft 9. The stator has a winding connected to the inverter circuit, and a magnetic flux is generated by a current flowing through the winding.

  Each rotor portion 20a, 20b, 20c has a cylindrical shape formed by laminating electromagnetic steel plates, and a skew arrangement is provided in which the rotor shafts 20 are laminated while being shifted by a predetermined angle θ in the circumferential direction about the rotating shaft 9. ing.

  Each rotor part 20a, 20b, 20c is provided with a hole 7 for embedding the permanent magnet 8 respectively. In the hole 7, a set of two permanent magnets 8 having a substantially V shape when viewed from the arrow D side is arranged side by side in the circumferential direction at a predetermined interval. The hole 7 is a substantially quadrangular prism-shaped through-hole penetrating each rotor part 20a, 20b, 20c in the axial direction.

  The permanent magnet 8 is a quadrangular prism-shaped magnet that is press-fitted into each hole 7. Then, the positions of the corresponding permanent magnets 8 before skewing the rotor portions 20a, 20b, and 20c are shifted by an angle θ in the circumferential direction with respect to the rotor portion 20a, and the rotor portion 20c is rotated. The angle θ is further shifted in the direction.

The axial thickness of the rotating shaft 9 of the rotor portions 20a, 20b, and 20c is d ₁ as shown in FIG. The axial length of the rotary shaft 9 of the rotor portion 20a, 20,20c permanent magnet 8 is also d _1.

The joint portions 40a and 40b are disk-shaped members configured by laminating electromagnetic steel plates. Joint 40a is arranged between the rotor portion 20a and the rotor part 20b, the axial thickness of the rotary shaft 9 is d _2. Cavities 30a are provided in the joint 40a at predetermined intervals in the circumferential direction. The joining portion 40b is disposed between the rotor portion 20b and the rotor section 20c, the axial thickness of the rotary shaft 9 is d _2. Cavities 30b are provided in the joint 40b at a predetermined interval in the circumferential direction.

The hollow portions 30a and 30b have a sum (S ₁ + S ₁₎ of the area S ₁ of the permanent magnet 8 that forms an approximately V-shaped area S ₂ on a plane perpendicular to the axial direction of the rotary shaft 9 as shown in FIG. ) Is a substantially triangular through-hole having a larger area (S ₂ > 2S ₁ ). Moreover, since the insides of the hollow portions 30a and 30b are filled with air, the magnetic permeability is lower than that of the rotor portions 20a, 20b, and 20c made of electromagnetic steel plates.

  The relationship between the set of permanent magnets 8 having a substantially V shape and the cavity 30a will be described. In FIG. 2, the set of permanent magnets 8 having a substantially V shape is formed inside the outer shape of the cavity 30a. The positional relationship is such that it is located. Although not shown, the relationship between the hollow portion 30b and the set of permanent magnets 8 corresponding to the hollow portion 30b is such that the set of permanent magnets 8 is positioned inside the outer shape constituting the hollow portion 30b. Yes.

  Next, the operation of the rotating electrical machine 10 having the above configuration will be described with reference to FIGS. In the rotating electrical machine 10, the magnetic flux generated by the current flowing through the stator winding is canceled by the magnetic flux generated by the permanent magnet 8 of the rotor 3 that rotates in the circumferential direction. At this time, for example, in the rotor portion 20a, the magnetic flux from the stator or the magnetic flux generated by the permanent magnet 8 travels inside the rotor portion 20a toward the adjacent rotor portion 20b along the axial direction of the rotary shaft 9. However, since there is a joint 40a having a cavity 30a having a low magnetic permeability between the rotor portion 20a and the rotor portion 20b, leakage magnetic flux can be suppressed. Similarly, in the rotor portion 20b, the magnetic flux from the stator and the permanent magnet 8 are directed toward the adjacent rotor portion 20c along the axial direction of the rotary shaft 9 inside the rotor portion 20b. However, since there is a joint 40b having a cavity 30b with a low permeability in the path of the magnetic flux, the leakage magnetic flux can be suppressed.

  As described above, since there are the joint portions 40a and 40b at the joint portions of the rotor portions 20a, 20b, and 20c, the leakage magnetic flux can be suppressed. Thereby, the in-plane eddy current loss by the eddy current generation of the rotor 3 can be suppressed.

  FIG. 3 shows a modification of the rotating electrical machine 10. FIG. 3 is a diagram corresponding to FIG. 2 in a modified example. The difference from the first embodiment is that it has a filling portion 50 that fills the cavities 30a and 30b. The filling portion 50 is made of a non-magnetic material, has the same shape as the hollow portions 30a and 30b, and can fill the hollow portions 30a and 30b. Thereby, the leakage of magnetic flux can be suppressed similarly to the above. Further, the presence of the filling portion 50 in the space portions of the hollow portions 30a and 30b can restrict the movement of the permanent magnet 8 in the axial direction. Thereby, the possibility that the permanent magnet 8 is displaced in the axial direction can be eliminated.

FIG. 4 shows another modification of the rotating electrical machine 10. FIG. 4 is a diagram corresponding to FIG. 2 in another modified example. The difference between the first embodiment, the cavity 30a, as compared with 30b, a point having a cavity 31a having a larger area S _3. Thereby, the leakage of magnetic flux can be further suppressed.

FIG. 5 shows still another modification of the rotating electrical machine 10. FIG. 5 is a diagram corresponding to FIG. 2 in still another modification. The difference from the first embodiment, the cavity 32a of a substantially V-shape which is larger area S ₄ slightly than the sum of the areas of the permanent magnets 8 (S ₁ + S ₁₎ to form a substantially V-shaped, 32a It is. This can also suppress magnetic flux leakage.

  Next, the rotary electric machine 11 which is 2nd Embodiment of this invention is demonstrated with reference to FIG. FIG. 6 is a diagram illustrating the rotor 3 of the rotating electrical machine 11 according to the second embodiment of the present invention. In FIG. 6, the description of the permanent magnet 8 and some of the hollow portions 30a and 30b is omitted and simplified. 7 is a cross-sectional view taken along line EE in FIG. FIG. 8 is a view of the joint 40a as viewed from above. FIG. 9 is a view of the joint 40b as seen from above. Here, since the rotating electrical machine 11 has substantially the same configuration as that of the rotating electrical machine 10 of the first embodiment, the same constituent elements are denoted by the same reference numerals, and redundant descriptions are omitted with the aid of the same. A structure and its effect | action are demonstrated.

  The rotating electrical machine 11 further includes an axial channel 60, an inflow channel 70, a relay channel 80, an outflow channel 90, and central circles 6a and 6b. The center circular portions 6a and 6b are circular through holes provided at the centers of the joint portions 40a and 40b, respectively.

The inflow channel 70 is provided in the joint portion 40a, and is provided radially from the central circle portion 6a toward each cavity portion 30a as shown in FIG. The inflow channel 70 is a channel for allowing the coolant to flow from the central circle portion 6a located at the axial center to each of the hollow portions 30a. Inlet channel 70 also axial thickness is d _2.

  The relay flow path 80 is provided in the rotor portion 20b so as to communicate with each of the hollow portions 30a corresponding to each of the hollow portions 30a that are shifted in the circumferential direction by an angle θ. The relay flow path 80 is a flow path for sending out the refrigerant that has flowed into each cavity 30a to each cavity 30b.

The outflow channel 90 is provided in the joint 40b, and is provided radially from each cavity 30b toward the center circle 6b as shown in FIG. The outflow channel 90 is a channel for allowing the coolant to flow from the hollow portions 30b to the central circle portion 6b that is an axial center. Outlet channel 90 is also in the axial direction thickness is d _2.

  The axial flow channel 60 includes an axial flow channel portion 60a and an axial flow channel portion 60c. The axial flow path 60 is a flow path for allowing a coolant for cooling the rotor 3 to flow from the axial center side that is the central axis of the rotor 3. The axial flow path portion 60 a is a cylindrical flow path that allows a coolant to flow into the central circle portion 6 a of the joint portion 40 a from above the end surface 100 on one side of the rotor 3 along the axial center of the rotor 3. The axial flow path portion 60c is a cylindrical flow path that protrudes from the end face 101 on the other side of the rotor 3 along the axial center of the rotor 3 from the central circle portion 6b of the joint portion 40b and discharges the refrigerant downward. is there. A refrigerant pump and a heat exchanging unit are connected between one end 600a of the axial flow passage 60a and one end 600c of the axial flow passage 60c, and the refrigerant circulates inside the rotating electrical machine 11. It is configured as follows.

  Next, the operation of the rotating electrical machine 11 having the above configuration will be described with reference to FIGS. Since the rotating electrical machine 11 has the hollow portions 30a and 30b like the rotating electrical machine 10, leakage of magnetic flux can be suppressed. Further, in the configuration of the rotating electrical machine 11, since the refrigerant can flow from the axial flow path 60 to the hollow portion 30 a and the hollow portion 30 b, not only the central portion of the rotor 3 but also the outer peripheral portion can be cooled. Thereby, the cooling effect of the whole rotor 3 can also be improved.

It is a figure which shows the rotor of the rotary electric machine which is 1st Embodiment of this invention. FIG. 2 is a view of a region in FIG. It is a figure equivalent to FIG. 2 in the modification of 1st Embodiment of this invention. It is a figure equivalent to FIG. 2 in another modification of 1st Embodiment of this invention. It is a figure equivalent to Drawing 2 in another modification of a 1st embodiment of the present invention. It is a figure which shows the rotor of the rotary electric machine which is 2nd Embodiment of this invention. It is the EE sectional view taken on the line in FIG. 6 of the rotary electric machine which is 2nd Embodiment of this invention. It is the figure which looked at the junction part of the rotary electric machine which is 2nd Embodiment of this invention from the upper surface. It is the figure which looked at the junction part of the rotary electric machine which is 2nd Embodiment of this invention from the upper surface. It is an enlarged view of the periphery of the permanent magnet provided in the rotor of the rotary electric machine of a prior art.

Explanation of symbols

  3 rotor, 4 region, 6a, 6b central circular part, 7 holes, 8 permanent magnet, 9 rotating shaft, 10, 11 rotating electrical machine, 20a, 20b, 20c rotor part, 30a, 30b, 31a, 31b hollow part, 40a, 40b Joint part, 50 filling part, 60 axial flow path, 60a, 60c axial flow path part, 70 inflow flow path, 80 relay flow path, 90 outflow flow path, 100, 101 end face, 600a, 600c one end.

Claims (3)

A rotor that is provided by laminating a plurality of rotor portions each having permanent magnets arranged at predetermined intervals in the circumferential direction and shifting each rotor portion in the circumferential direction so that the circumferential position of the permanent magnet of each rotor portion is shifted. A rotating electrical machine comprising:
A cavity portion is provided at a position corresponding to the position of the permanent magnet at a joint portion of the rotor portions stacked adjacent to each other, and has a cavity portion whose cross-sectional area perpendicular to the axial direction of the rotating shaft of the rotor is larger than that of the permanent magnet. Rotating electric machine characterized by that. In the rotating electrical machine according to claim 1,
A rotating electrical machine, wherein a hollow portion is filled with a nonmagnetic material. In the rotating electrical machine according to claim 1,
An axial flow path connected to one end and the other end in the axial direction of the rotating shaft of the rotor, the axial flow path for flowing the refrigerant in the axial direction at the axial center of the rotor;
An inflow channel for allowing the coolant to flow into each cavity from the axial channel;
An outflow channel for returning the refrigerant from each cavity to the axial channel;
A rotating electric machine comprising:

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