Rotor and rotating electrical machine

Abstract

A rotor according to an embodiment includes: a rotor core extending in an axial direction; a permanent magnet housing hole formed in the axial direction along the outer peripheral surface of the rotor core in a vertical cross-section of the rotating shaft of the rotor core; a permanent magnet housed in the permanent magnet housing hole; a cooling medium flow path which is formed at a position on the radial inner side of the rotor core of the permanent magnet accommodating hole along the permanent magnet accommodating hole in a vertical cross section, and can seal a cooling medium for cooling the permanent magnet; and a sheet which is disposed between the inner wall surface of the permanent magnet housing hole and the surface of the permanent magnet in the permanent magnet housing hole, and which causes the permanent magnet to be in close contact with the inner wall surface.

Description

Technical Field

[0001] Embodiments of the present invention relate to a rotor and a rotating electric machine. Background Art

[0002] In a rotating electrical machine in which permanent magnets are arranged in a rotor, the magnets in the rotor generate heat during operation, which causes a loss. In other words, it is generally known that the output efficiency is reduced due to the heat generated by the magnets.

[0003] In order to realize a rotating electrical machine with high output efficiency, it is important to efficiently cool the magnets of the rotor.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2021-100353

[0007] Patent document 2: Japanese Patent Application Laid-Open No. 2020-141552

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2018-067978 Summary of the invention

[0009] Problems to be solved by the invention

[0010] Conventional rotors and rotating electrical machines have a problem of reduced output efficiency due to heat generated by magnets provided on the rotor. The embodiments of the present invention are made to solve the above-mentioned problems, and an object thereof is to provide a rotor and rotating electrical machine that can efficiently cool the magnets of the rotor and suppress reduction in output efficiency.

[0011] Means for solving problems

[0012] In order to achieve the above-mentioned purpose, the rotor of an embodiment of the present invention comprises: a rotor core extending in the axial direction; a permanent magnet receiving hole formed in the axial direction along the outer peripheral surface of the rotor core in a vertical cross section of the rotating axis of the rotor core; a permanent magnet received in the permanent magnet receiving hole; a cooling medium flow path formed in the vertical cross section along the permanent magnet receiving hole and connected with the permanent magnet receiving hole at a position radially inside the rotor core of the permanent magnet receiving hole, capable of enclosing a cooling medium for cooling the permanent magnet; and a sheet arranged in the permanent magnet receiving hole between the inner wall surface of the permanent magnet receiving hole and the surface of the permanent magnet, so that the permanent magnet is in close contact with the inner wall surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a cross-sectional view showing the structure of the rotating electrical machine according to the first embodiment.

[0014] Figure 2This is an enlarged view of a part of the cross section of the rotor according to the first embodiment.

[0015] Figure 3 It is a cross-sectional view showing a cross section (AA cross section) of the rotor according to the first embodiment.

[0016] Figure 4 This is an enlarged view of a part of the cross section of the rotor according to the second embodiment.

[0017] Figure 5 It is a cross-sectional view showing a cross section (BB cross section) of the rotor according to the second embodiment.

[0018] Figure 6 It is a cross-sectional view showing a cross section (AA cross section) of a rotor according to a third embodiment.

[0019] Figure 7 It is a cross-sectional view showing a cross section (BB cross section) of a rotor according to a fourth embodiment.

[0020] Figure 8 This is an enlarged view of a part of the cross section of the rotor according to the fifth embodiment. DETAILED DESCRIPTION

[0021] Hereinafter, a rotor and a rotating electrical machine according to an embodiment of the present invention will be described with reference to the drawings. Herein, the same or similar parts are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0022] (First Embodiment)

[0023] Figure 1 It is a cross-sectional view showing the structure of the rotating electrical machine 1 according to the embodiment.

[0024] A rotating electrical machine 1 includes a magnet-embedded rotor 100, a cylindrical stator 10, and two bearings (not shown), wherein the rotor 100 includes a rotor shaft 110 extending in the direction of the rotation axis, a cylindrical rotor core 120 also extending in the direction of the rotation axis and mounted on the radially outer side of the rotor shaft 110, and a plurality of permanent magnets 130 (131), the stator 10 is arranged on the radially outer side of the rotor core 120 in a manner of surrounding the rotor core 120 with a gap space therebetween, and the two bearings (not shown) rotatably support the rotor shaft 110. Figure 1 A cross section perpendicular to the rotation axis of the rotor shaft 110 (hereinafter referred to as a “vertical cross section”) is shown.

[0025] The rotor core 120 is formed by stacking a plurality of electromagnetic steel sheets 120a in the direction of the rotation axis. End plates (not shown) are provided at both ends of the stacked electromagnetic steel sheets 120a in the direction of the rotation axis. The electromagnetic steel sheets 120a are provided with punched holes for the rotor shaft 110 to pass through, punched holes for the permanent magnets 130 (131) to pass through, and the like. These punched holes are formed into through holes by stacking the electromagnetic steel sheets 120a. In addition, Figure 1 In the embodiment, the rotor core 120 is formed by stacking electromagnetic steel sheets 120a, but the present invention is not limited thereto. A block-type rotor in which the rotor shaft and the rotor core are integrated can also be applied.

[0026] The rotor core 120 is provided with a plurality of pairs of permanent magnet receiving holes 122 and 123 extending in the axial direction along the circumferential direction of the rotor core 120. The permanent magnet receiving holes 122 and 123 receive the permanent magnets 130 and 131. The pair of permanent magnet receiving holes 122 and 123 corresponds to the magnetic poles in the rotor 100. The permanent magnet receiving holes 122 and 123 are formed along the rotation axis direction of the rotor core 120. The punched holes formed in the plurality of electromagnetic steel sheets 120a are formed by stacking the plurality of electromagnetic steel sheets 120a to form the permanent magnet receiving holes 122 (123) extending in the rotation axis direction of the rotor core 120.

[0027] The permanent magnets 130 and 131 correspond to the magnetic poles of the rotor 100 and are housed in the permanent magnet housing holes 122 and 123, respectively. A pair of permanent magnets 130 and 131 corresponding to each magnetic pole is arranged so that the circumferential interval increases toward the radially outer side. Figure 1 In the example shown, the permanent magnets 130 and 131 are arranged in a configuration (also referred to as a V-shaped configuration) that protrudes toward the radial inner side of the rotor core 120. However, the permanent magnets 130 and 131 are not limited to this configuration. As long as the circumferential spacing of the permanent magnets 130 and 131 increases toward the radial outer side of the rotor 100, other configurations may be adopted. In addition, the permanent magnets 130 and 131 have a flat plate shape.

[0028] Multiple groups of paired permanent magnets 130, 131 are arranged in the same manner along the circumferential surface of the rotor core 120. Figure 1 In the example shown, a total of eight sets of permanent magnets 130 and 131 are provided.

[0029] A cooling medium flow path 150 is formed near the radially inner end of the rotor core 120 in the permanent magnet receiving hole 122 that receives the permanent magnet 130. Similarly, a cooling medium flow path 151 is formed near the radially inner end of the rotor core 120 in the permanent magnet receiving hole 123 that receives the permanent magnet 131.

[0030] The cooling medium paths 150 and 151 are arranged in parallel with the permanent magnet receiving holes 122 and 123. The cooling medium paths 150 and 151 form a space in which the cooling medium can be sealed. The cooling medium flow paths 150 and 151 are connected to the permanent magnet receiving holes 122 and 123. That is, the cooling medium passing through the cooling medium flow paths 150 and 151 can cool the permanent magnets 130 and 131.

[0031] Figure 2 Zoom in to show Figure 1 As shown, a pair of permanent magnets 130, 131 are arranged so as to protrude radially inwardly of the rotor core 120. Figure 2 As shown, the permanent magnet receiving hole 122 accommodates the sheet 160 and the permanent magnet 130 .

[0032] The sheet 160 is disposed along one long side in a cross section of the permanent magnet 130 formed in a plate shape and perpendicular to the rotation axis of the rotor core 120. That is, the sheet 160 is disposed on one of the main surfaces of the permanent magnet 130 formed in a plate shape. The permanent magnet 130 is formed in a plate shape, such as Figure 2 As shown, in the cross section of the permanent magnet 130 perpendicular to the rotation axis of the rotor core 120, there is a pair of long sides constituting the main surface of the permanent magnet 130. The sheet 160 is arranged along the long side (main surface) further behind with respect to the rotation direction X of the rotor 100 of the two long sides.

[0033] Similarly, the permanent magnet receiving hole 123 accommodates the sheet 161 and the permanent magnet 131. The sheet 161 is arranged along one long side in a cross section of the permanent magnet 131 formed in a plate shape and perpendicular to the rotation axis of the rotor core 120. That is, the sheet 161 is arranged on one of the main surfaces of the permanent magnet 131 formed in a plate shape. The permanent magnet 131 is formed in a plate shape, such as Figure 2 As shown, a pair of long sides exist in the cross section of the permanent magnet 131 perpendicular to the rotation axis of the rotor core 120. The sheet 161 is arranged along the long side (main surface) on the rear side with respect to the rotation direction X of the rotor 100 of the two long sides. The same applies to the other groups of permanent magnets.

[0034] Figure 3 Shows Figure 2 That is, Figure 3 FIG. 2 shows a cross section of a plate-shaped permanent magnet 130 along the rotation axis of the rotor 100. Figure 3 As shown in FIG. 1 , a plurality of electromagnetic steel sheets 120a are stacked to form a cylindrical rotor core 120, and end plates 124 and 126 are provided at both ends thereof. Figure 3 In the example shown, the permanent magnet 130 includes a plurality of permanent magnets 130a and 130b in one permanent magnet receiving hole 122. That is, the permanent magnet 130 is divided into a plurality of magnets and received in the permanent magnet receiving hole 122.

[0035] like Figure 3 As shown in FIG. 1 , a sheet 160 is disposed on one long side (main surface) of a cross section of the permanent magnet 130 (130a, 130b) perpendicular to the rotation axis of the rotor 100. In addition, a sheet 160a is also disposed between the permanent magnets 130a and 130b. That is, the permanent magnets 130 (130a, 130b) are provided with sheets on the gaps therebetween and on the main surfaces of the rear sections in the rotation direction of the rotor 100.

[0036] The sheets 160 and 160a play the role of fixing the permanent magnets 130 (130a and 130b) at predetermined positions in the permanent magnet receiving holes 122 and 123. Therefore, the sheets 160 and 160a preferably have the function of being in close contact with the main surfaces of the permanent magnets 130 and 131 and the inner wall surfaces of the corresponding permanent magnet receiving holes 122 and 123.

[0037] In this embodiment, a cooling medium is sealed in cooling medium flow paths 150 and 151 formed near the radially inner end portions of the permanent magnets 130 and 131. The cooling medium flow paths 150 and 151 are connected to the permanent magnet housing holes 122 and 123, so that the surroundings of the permanent magnets 130 and 131 are filled with the cooling medium. Thus, the permanent magnets 130 can be cooled.

[0038] When the rotor core 120 is composed of a stack of electromagnetic steel sheets 120a, the cooling medium may leak out to the outer peripheral surface of the rotor core 120 through the space between the permanent magnets 130 and 131 and the inner wall surfaces of the permanent magnet receiving holes 122 and 123 due to the centrifugal force generated by the rotation of the rotor 120. The sheets 160 and 160a of this embodiment are arranged between the main surfaces of the permanent magnets 130 and 131 on the rear side of the rotation direction of the rotor 100 and the inner wall surfaces of the corresponding permanent magnet receiving holes 122 and 123, so that the cooling medium sealed in the cooling medium flow paths 150 and 151 can be prevented from leaking out from the outer peripheral surface of the rotor 100 due to the centrifugal force generated by the rotation of the rotor 100.

[0039] According to this embodiment, since sheet 160 is provided around permanent magnets 130 and 131 where the coolant is likely to leak, particularly on the rear side of rotor 100 in the rotation direction, a decrease in output efficiency of rotary electric machine 1 due to leakage of the coolant can be suppressed.

[0040] The sheets 160, 160a may have foaming properties in addition to close contact. If the sheets 160, 160a have foaming properties, when the permanent magnets 130, 131 generate heat due to the operation of the rotating electrical machine 1, the sheets 160, 160a expand to improve the close contact between the permanent magnets 130, 131 and the walls of the permanent magnet storage holes 122, 123, and further suppress the leakage of the cooling medium.

[0041] (Second Embodiment)

[0042] Next, refer to Figure 4 and Figure 5 , a rotating electric machine of a second embodiment is described. In the rotating electric machine of this embodiment, the arrangement of the sheet is different from that of the rotating electric machine of the first embodiment. In the following description, the same elements as those of the first embodiment are indicated by the same reference numerals, and repeated descriptions are omitted.

[0043] Figure 4 The pair of permanent magnets 130 and 131 arranged so as to protrude radially inwardly of the rotor core 120 in the second embodiment is shown in an enlarged manner. Figure 4 As shown, the permanent magnet receiving hole 122 a accommodates the sheet 160 b in addition to the sheet 160 and the permanent magnet 130 .

[0044] The sheets 160 and 160b are arranged along two long sides in the cross section of the permanent magnet 130 formed into a plate shape. The permanent magnet 130 is formed into a plate shape, such as Figure 4 As shown, a pair of long sides (main surfaces) exist in the cross section of the permanent magnet 130 perpendicular to the rotation axis of the rotor core 120. The sheets 160 and 160b are arranged along both of the long sides (main surfaces).

[0045] Similarly, the permanent magnet receiving hole 123a accommodates the sheet 161b in addition to the sheet 161 and the permanent magnet 131. The sheets 161 and 161b are arranged along both long sides (main surfaces) in the cross section of the permanent magnet 131 formed in a plate shape. Figure 4 As shown, there is a pair of long sides (main surfaces) in the cross section of the permanent magnet 131 perpendicular to the rotation axis of the rotor core 120. Sheets 161 and 161b are arranged along both of the long sides (main surfaces). The same is true for other groups of permanent magnets.

[0046] Figure 5 Shows Figure 4 That is, Figure 5 FIG. 2 shows a cross section of a plate-shaped permanent magnet 130 along the rotation axis of the rotor 100. Figure 5As shown in FIG. 1 , a plurality of electromagnetic steel sheets 120a are stacked to form a cylindrical rotor core 120, and end plates 124 and 126 are provided at both ends thereof. Figure 5 In the example shown, the permanent magnet 130 includes a plurality of permanent magnets 130a and 130b in one permanent magnet receiving hole 122. That is, the permanent magnet 130 is divided into a plurality of magnets and received in the permanent magnet receiving hole 122.

[0047] like Figure 5 As shown, sheets 160 and 160b are disposed on both long sides (main surfaces) of the permanent magnets 130 (130a, 130b). In addition, the sheet 160a is also disposed between the permanent magnets 130a and 130b.

[0048] The sheets 160, 160a, 160b play a role in fixing the permanent magnets 130 (130a, 130b) at predetermined positions in the permanent magnet storage holes 122. Therefore, the sheets 160, 160a, 160b preferably have a function of being in close contact with the permanent magnets 130, 131 and the rotor core 120. The sheets 160, 160a, 160b may also have foamability.

[0049] The sheets 160, 160a, 160b of this embodiment are disposed between the permanent magnets 130a, 130b and the front and rear surfaces of the permanent magnets 130, 131 in the rotation direction of the rotor 100, so that the cooling medium sealed in the cooling medium flow path 150 can be prevented from leaking from the outer peripheral surface of the rotor 100 due to the centrifugal force generated by the rotation of the rotor 100. In particular, the sheets 160, 160b are provided on the long sides (main surfaces) of the permanent magnets 130 where the cooling medium is likely to leak, so that the reduction in the output efficiency of the rotating electric machine 1 caused by the leakage of the cooling medium can be suppressed.

[0050] (Third Embodiment)

[0051] Next, refer to Figure 6 A rotating electrical machine according to a third embodiment will be described. In the rotating electrical machine according to this embodiment, the arrangement of the sheets in the rotating electrical machine according to the first embodiment is changed. In the following description, the same elements as those in the first embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0052] Figure 6 Shows Figure 2 That is, Figure 6 FIG. 2 shows a cross section of a plate-shaped permanent magnet 130 along the rotation axis of the rotor 100. Figure 6 As shown in FIG. 1 , a plurality of electromagnetic steel sheets 120a are stacked to form a cylindrical rotor core 120, and end plates 124 and 126 are provided at both ends thereof. Figure 6In the example shown, the permanent magnet 130 includes a plurality of permanent magnets 130 a and 130 b . That is, the permanent magnet 130 is divided into a plurality of magnets and housed in the permanent magnet housing hole 122 .

[0053] like Figure 6 As shown in FIG. 1 , a sheet 160 is disposed on one long side (main surface) of a cross section of the permanent magnet 130 (130a, 130b) perpendicular to the rotation axis of the rotor 100. In addition, a sheet 160a is also disposed between the permanent magnets 130a and 130b. That is, the permanent magnets 130 (130a, 130b) are provided with a sheet in the gap between them and at the rear section in the rotation direction of the rotor 100.

[0054] Furthermore, in this embodiment, the sheets 160 c and 160 d are also disposed between the end of the permanent magnet 130 a and the end plate 126 and between the end of the permanent magnet 130 b and the end plate 124 .

[0055] The sheets 160, 160a, 160c, 160d play the role of fixing the permanent magnets 130 (130a, 130b) at predetermined positions in the permanent magnet receiving holes 122. Therefore, the sheets 160, 160a, 160c, 160d preferably have a function of being in close contact with the permanent magnets 130, 131 and the rotor core 120.

[0056] The sheets 160, 160a, 160c, 160d of this embodiment are arranged between the surfaces of the permanent magnets 130, 131 on the rear side of the rotation direction of the rotor 100 and the permanent magnets 130, 131, and between the permanent magnets 130a, 130b and the end plates 126, 124, so that the cooling medium sealed in the cooling medium flow paths 150, 151 can be prevented from leaking from the outer peripheral surface of the rotor 100 due to the centrifugal force generated by the rotation of the rotor 100.

[0057] In addition, in this embodiment, it is more preferable that the sheets 160c and 160d disposed between the end of the permanent magnet 130a and the end plate 126 and between the end of the permanent magnet 130b and the end plate 124 are foamable sheets. According to this structure, the gap between the end surface of the permanent magnet and the end plate can be effectively filled. The sheets 160, 160a, 160c, and 160d may all be foamable.

[0058] (Fourth Embodiment)

[0059] Next, refer to Figure 7 A rotating electrical machine according to a fourth embodiment will be described. In the rotating electrical machine according to this embodiment, the arrangement of the sheets in the second embodiment is further changed. In the following description, the same elements as those in the second embodiment are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0060] Figure 7 Shows Figure 4 That is, Figure 7 FIG. 2 shows a cross section of a plate-shaped permanent magnet 130 along the rotation axis of the rotor 100. Figure 7 As shown in FIG. 1 , a plurality of electromagnetic steel sheets 120a are stacked to form a cylindrical rotor core 120, and end plates 124 and 126 are provided at both ends thereof. Figure 7 In the example shown, the permanent magnet 130 includes a plurality of permanent magnets 130 a and 130 b . That is, the permanent magnet 130 is divided into a plurality of magnets and housed in the permanent magnet housing hole 122 .

[0061] like Figure 7 As shown, sheets 160 and 160b are disposed on both long sides (main surfaces) of the permanent magnets 130 (130a, 130b). In addition, the sheet 160a is also disposed between the permanent magnets 130a and 130b.

[0062] Furthermore, in this embodiment, the sheets 160 c and 160 d are also disposed between the end of the permanent magnet 130 a and the end plate 126 and between the end of the permanent magnet 130 b and the end plate 124 .

[0063] The sheets 160, 160a, 160b, 160c, 160d play the role of fixing the permanent magnets 130 (130a, 130b) at predetermined positions in the permanent magnet receiving holes 122. Therefore, the sheets 160, 160a, 160b, 160c, 160d preferably have a function of being in close contact with the permanent magnets 130, 131 and the rotor core 120.

[0064] The sheets 160, 160a, 160b, 160c, 160d of this embodiment are arranged between the main surface of the permanent magnet 130 on the rear side of the rotation direction of the rotor 100 and the permanent magnets 130a, 130b, and between the permanent magnets 130a, 130b and the end plates 126, 124, so that the cooling medium sealed in the cooling medium flow path 150 can be prevented from leaking from the outer peripheral surface of the rotor 100 due to the centrifugal force generated by the rotation of the rotor 100.

[0065] In this embodiment, it is more preferable that the sheets 160c and 160d disposed between the end of the permanent magnet 130a and the end plate 126 and between the end of the permanent magnet 130b and the end plate 124 are also foamable sheets. According to this structure, the gap between the end surface of the permanent magnet and the end plate can be effectively filled. The sheets 160, 160a, 160c, and 160d may all be foamable.

[0066] (Fifth Embodiment)

[0067] Next, refer to Figure 8 The rotating electrical machine of the fifth embodiment is described. In this embodiment, sheets 160 to 160f are arranged on all surfaces of the permanent magnets 130a and 130b. In this structure, the cooling medium sealed in the cooling medium flow paths 150 and 151 can also be prevented from leaking from the outer peripheral surface of the rotor 100 due to the centrifugal force generated by the rotation of the rotor 100. In addition, all the sheets 160 to 160f can also have foamability.

[0068] Several embodiments of the present invention have been described above, but the embodiments are presented as examples and are not intended to limit the scope of the invention. In addition, the features of the various embodiments may be combined. Moreover, the embodiments may be implemented in various other ways, and various omissions, substitutions, and changes may be made without departing from the scope of the invention. The embodiments and their variations are included in the scope and spirit of the invention, and are also included in the invention described in the claims and their equivalents.

[0069] Description of Reference Numerals

[0070] 1 ... rotating electrical machine; 10 ... stator; 11 ... stator core; 100 ... rotor; 110 ... rotor shaft; 120 ... rotor core; 122 , 123 ... permanent magnet receiving hole; 130 , 131 ... permanent magnet; 150 , 151 ... cooling medium flow path; 160 , 161 ... sheet material.

Claims

1. A rotor, characterized in that: have: A rotor core extending in the axial direction; a permanent magnet receiving hole formed in the axial direction along the outer peripheral surface of the rotor core in a vertical cross section of the rotating shaft of the rotor core; A permanent magnet is received in the permanent magnet receiving hole; a cooling medium flow path formed along the permanent magnet receiving hole in the vertical cross section and communicating with the permanent magnet receiving hole at a position radially inward of the rotor core, capable of enclosing a cooling medium for cooling the permanent magnet; as well as The sheet is disposed in the permanent magnet receiving hole between the inner wall surface of the permanent magnet receiving hole and the surface of the permanent magnet so as to bring the permanent magnet into close contact with the inner wall surface.

2. The rotor according to claim 1, characterized in that The permanent magnet has a plate-like shape. The sheet is disposed on a main surface of the permanent magnet that is located on the rear side in the rotation direction of the rotor.

3. The rotor according to claim 1, characterized in that The permanent magnet comprises a plurality of permanent magnet parts. The sheet is further disposed between the plurality of permanent magnet portions.

4. The rotor according to claim 1, characterized in that The permanent magnet has a plate-like shape. The sheet is disposed on the main surface of the permanent magnet.

5. The rotor according to claim 1, characterized in that The rotor core includes a plurality of stacked electromagnetic steel plates and end plates disposed on both end surfaces of the plurality of stacked electromagnetic steel plates. The sheet is further disposed between the end surface of the permanent magnet and the end plate.

6. The rotor according to claim 1, characterized in that The sheet is disposed on the entire surface of the permanent magnet.

7. The rotor according to claim 1, characterized in that The sheet has foamability.

8. A rotating electrical machine, characterized in that: have: The rotor according to any one of claims 1 to 7; and The stator is arranged to face the circumferential surface of the rotor.

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