Rotor

Abstract

The present invention addresses the problem of suppressing the occurrence of uneven supply of a cooling medium in each magnetic flux barrier. A rotor is used in a motor, the rotor comprises a rotor core fixed on a rotating shaft and a plurality of permanent magnets embedded in corresponding embedding holes to form magnetic flux barriers at two ends of the embedding holes formed in the rotor core so as to form a plurality of magnetic poles, and the rotor comprises a first flow path, a second flow path, a third flow path and a fourth flow path, a cooling medium supply unit for supplying a cooling medium from a position closer to one end side than the axial center part of the rotor to the outer diameter side of the magnetic flux barriers at the two ends; and a second flow path that supplies a cooling medium from a position closer to the other end side than the central portion in the axial direction of the rotor to the inner diameter side of the flux barriers at both ends, and that is provided so as not to merge with the first flow path.

Description

Technical Field

[0001] This invention relates to a rotor. Background Technology

[0002] Conventionally, a rotor has been proposed that includes a rotor core fixed to a rotating shaft, multiple permanent magnets embedded in corresponding holes to form multiple magnetic poles such that magnetic flux barriers are formed at both ends of multiple embedded holes formed on the rotor core, and end plates mounted on both axial end faces of the rotor core (for example, see Patent Document 1). In this rotor, a flow path is provided for supplying cooling medium to the magnetic flux barriers from one axial end of the rotor towards the inner diameter side. Thus, the cooling medium supplied to the magnetic flux barriers on the inner diameter side cools the permanent magnets as it flows towards the magnetic flux barriers on the outer diameter side.

[0003] Patent Document 1: Japanese Patent No. 7430129 Summary of the Invention

[0004] However, in the aforementioned rotor, during rotation, the cooling medium supplied to the inner diameter side is subjected to centrifugal force, causing it to flow towards the magnetic flux barrier on the outer diameter side. Therefore, the cooling medium cannot be adequately supplied to the magnetic flux barrier on the inner diameter side, and the permanent magnet as a whole cannot be sufficiently cooled.

[0005] The main purpose of the rotor of the present invention is to suppress uneven supply of cooling medium in each magnetic flux barrier.

[0006] The rotor of the present invention employs the following scheme to achieve the aforementioned main objectives.

[0007] The main point of the rotor of the present invention is that it is used in a motor, said rotor comprising:

[0008] A rotor core fixed to a rotating shaft and multiple permanent magnets embedded in corresponding holes formed in the rotor core to form multiple magnetic poles, thereby creating magnetic flux barriers at both ends.

[0009] The rotor includes:

[0010] The first flow path supplies cooling medium from a position closer to one end than the axial center of the rotor to the outer diameter side of the magnetic flux barrier at both ends; and

[0011] The second flow path supplies the cooling medium from a position further to the other end than the central portion of the rotor's axial direction to the inner diameter side of the magnetic flux barrier at both ends, and is configured not to merge with the first flow path.

[0012] The rotor of the present invention includes: a first flow path that supplies cooling medium from a position further to one end of the rotor's axial center to the outer diameter side of the magnetic flux barrier at both ends; and a second flow path that supplies cooling medium from a position further to the other end of the rotor's axial center to the inner diameter side of the magnetic flux barrier at both ends, and is configured not to merge with the first flow path. Thus, cooling medium can be supplied from the first and second flow paths to the outer diameter side and the inner diameter side of the magnetic flux barrier, respectively. As a result, uneven cooling medium supply in each magnetic flux barrier can be suppressed.

[0013] In such a rotor of the present invention, the rotor may include: a first supply hole formed on the rotating shaft in a radially opening manner for supplying the cooling medium; and a second supply hole formed on the rotating shaft in a radially opening manner but at a different position than the first supply hole, for supplying the cooling medium; the first flow path communicates with the first supply hole and extends at least a portion therein; the second flow path communicates with the second supply hole and extends at least a portion therein. In this way, in the radially extending portions of the first and second flow paths, due to the centrifugal force accompanying the rotation of the rotor, the cooling medium thickens on the outer diameter side, supplying magnetic flux barriers on the outer and inner diameter sides. This suppresses uneven cooling medium supply within each magnetic flux barrier.

[0014] In the rotor of the present invention having at least a portion of radially extending first and second flow paths, it can be as follows: the first and second supply holes are formed at the central portion of the axial direction of the rotating shaft; the first flow path extends from the first supply hole along the axial direction and bends radially to communicate with the magnetic flux barrier on the outer diameter side; the second flow path extends from the second supply hole along the axial direction and bends radially to communicate with the magnetic flux barrier on the inner diameter side. Alternatively, it can be as follows: the first supply hole is formed at a position closer to one end than the central portion of the axial direction of the rotating shaft; the second supply hole is formed at a position closer to the other end than the central portion of the axial direction of the rotating shaft; the first flow path extends from the first supply hole radially to communicate with the magnetic flux barrier on the outer diameter side; the second flow path extends from the second supply hole radially to communicate with the magnetic flux barrier on the inner diameter side. In this way, in the radially extending portions of the first and second flow paths, due to the centrifugal force accompanying the rotor's rotation, the cooling medium thickens on the outer diameter side, supplying the magnetic flux barriers on both the outer and inner diameter sides. This suppresses uneven cooling medium supply within each magnetic flux barrier.

[0015] Furthermore, in the rotor of the present invention, the rotor may include: a first end plate disposed on one end side of the rotor core along the axial direction; a second end plate disposed on the other end side of the rotor core along the axial direction and mating with the first end plate to clamp the rotor core from both sides; a first supply hole formed on the first end plate, opening along the axial direction and communicating with the first flow path; and a first receiving member mounted on the first end plate on the side of the first end plate further outward than the first supply hole. The first and second end plates are positioned such that the cooling medium sprayed onto the first end plate is erected axially outward and directed to the first supply hole; a second supply hole is formed on the second end plate, opening axially and communicating with the second flow path; and a second receiving member is mounted on the second end plate at a position further outward than the second supply hole, erected axially outward and directed to the second supply hole. In this way, due to the centrifugal force accompanying the rotor's rotation, the cooling medium supplied to the first and second end plates is received by the first and second receiving members and supplied to the first and second supply holes with a certain thickness. This suppresses uneven cooling medium supply within each flux barrier. Attached Figure Description

[0016] Figure 1 This is a schematic structural diagram showing the structure of the rotor 20 according to an embodiment of the present invention.

[0017] Figure 2 This indicates rotor 20. Figure 1 Simplified schematic diagrams of cross sections (a) on line AA, (b) on line BB, and (c) on line CC.

[0018] Figure 3 This is a schematic structural diagram showing the structure of rotor 120 in another embodiment.

[0019] Figure 4 This indicates rotor 120. Figure 3 Simplified schematic diagrams of cross sections on the EE line ((a)), the FF line ((b)), and the GG line ((c)).

[0020] Figure 5 This is a schematic structural diagram showing the structure of rotor 220 in another embodiment. Detailed Implementation

[0021] Embodiments of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a schematic structural diagram showing the structure of the rotor 20 according to an embodiment of the present invention. Figure 2 This indicates rotor 20. Figure 1 Simplified schematic diagrams of cross sections (a) on line AA, (b) on line BB, and (c) on line CC. Figure 1 yes Figure 2 A schematic diagram of the cross section on line AA ((a)) and a schematic diagram of the cross section on line DD. Rotor 20 is used, for example, as a motor rotor for use in electric vehicles or hybrid vehicles as a driving source or as a generator.

[0022] The rotor 20 is rotatably disposed within a stator (not shown) via an air gap, as... Figure 1 , Figure 2 As shown, the rotor 20 includes a rotating shaft 22, a rotor core 24, a plurality of (in embodiments, for example, 16) permanent magnets 28, and first and second end plates 30 and 32.

[0023] The rotating shaft 22 is hollow, and a cooling medium is introduced inside it. The cooling medium is stored below the motor having the rotor 20 and is supplied to the interior of the rotating shaft 22 by a pump (not shown). At the axial center of the rotating shaft 22, a plurality of (in this embodiment, for example, four) first supply holes 22h and a plurality of (in this embodiment, for example, four) second supply holes 23h are formed in a radially opening manner along the rotor 20. Each of the first supply holes 22h and the second supply holes 23h is formed at a different position.

[0024] The rotor core 24 is fixed to the rotating shaft 22 and is formed by stacking multiple core plates made of electromagnetic steel plates or the like in a ring shape. Figure 1 , Figure 2 As shown, the rotor core 24 has a plurality of (e.g., 8) magnet embedding holes 29. Further to the inner diameter side than the magnetic flux barrier (magnetic flux barrier on the inner diameter side) FB2 of the rotor core 24, a plurality of (e.g., 4) inflow grooves 24a are formed extending radially from each of the first supply holes 22h and bending axially toward the first end plate 30, and a plurality of (e.g., 4) inflow grooves 24b are formed extending radially from each of the second supply holes 23h and bending axially toward the second end plate 32, and are formed in a manner that does not merge with each of the inflow grooves 24a.

[0025] The permanent magnet 28 is, for example, a rare-earth sintered magnet such as a neodymium magnet, and is formed in a generally rectangular parallelepiped shape. Two pairs of permanent magnets 28 are inserted into and fixed in corresponding magnet embedding holes 29 with their poles identical on the outer periphery of the rotor 20. Multiple magnet embedding holes 29 are arranged in pairs on the rotor core 24, passing through it axially, and at predetermined intervals (90° intervals in this embodiment). The pairs of magnet embedding holes 29 are formed to be separated from each other (generally V-shaped) from the axial side of the rotor 20 toward the outer periphery. Each magnet embedding hole 29 has a width longer than the width of the permanent magnet 28. Therefore, when a permanent magnet 28 is placed in a magnet embedding hole 29, a magnetic flux barrier (magnetic flux barrier on the outer diameter side) FB1 and a magnetic flux barrier (magnetic flux barrier on the inner diameter side) FB2 are formed at both ends of the magnet embedding hole 29 as gaps to suppress short circuits of magnetic flux from the permanent magnet 28.

[0026] The first end plate 30 is fixed to the rotating shaft 22 at one axial end of the rotor core 24. The second end plate 32 is fixed to the rotating shaft 22 at the other axial end of the rotor core 24. The first and second end plates 30 and 32 clamp and press the rotor core 24 from both sides in pairs. On the rotor core 24 side of the first end plate 30, there are radial grooves 30g that communicate with each inflow groove 24a and extend radially, circumferential grooves 30gr that are continuous with the radial grooves 30g and are circumferentially shaped and overlap with the end of the first end plate 30 side of each flux barrier FB1 and communicate with them, and a plurality of (in this embodiment, for example, four) discharge holes 30h that communicate with the flux barrier FB2. On the rotor core 24 side of the second end plate 32, radial grooves 32g are formed that communicate with each inflow groove 24b and extend radially; circumferential grooves 32gr are formed that are continuous with the radial grooves 32g and are circular in shape, overlapping and communicating with the ends of each flux barrier FB2 on the second end plate 32 side; and a plurality of (e.g., 8 in this embodiment) discharge holes 32h are formed that communicate with the flux barrier FB1. Each inflow groove 24a, each radial groove 30g, and each circumferential groove 30gr, each inflow groove 24b, and each radial groove 32g and circumferential groove 32gr are formed to be non-merging.

[0027] Next, the flow of the cooling medium in the rotor 20 thus configured will be explained. In the rotor 20, the cooling medium within the rotating shaft 22 is supplied to the first and second supply holes 22h and 23h. The cooling medium supplied to the first supply hole 22h is as follows... Figure 1 , Figure 2As indicated by the thick solid arrows, the centrifugal force accompanying the rotation of the rotor 20 supplies the cooling medium to each flux barrier FB1 through each inflow groove 24a, each radial groove 30g, and each circumferential groove 30gr. That is, each inflow groove 24a, each radial groove 30g, and each circumferential groove 30gr constitutes a first flow path FP1, which is a flow path for the cooling medium extending radially outward from the first supply hole 22h, bending towards the first end plate 30, extending axially, and further bending radially outward on the first end plate 30, and communicating with each flux barrier FB1. The cooling medium supplied to each flux barrier FB1 is discharged from each discharge hole 32h of the second end plate 32 to the outside of the rotor 20 (motor) and stored below the motor. The cooling medium supplied to the second supply hole 23h is as follows... Figure 1 , Figure 2 As indicated by the thick dashed arrows, the centrifugal force generated by the rotation of the rotor 20 supplies the cooling medium to each flux barrier FB2 through each inflow groove 24b, each radial groove 32g, and each circumferential groove 32gr. That is, each inflow groove 24b, each radial groove 32g, and each circumferential groove 32gr forms a second flow path FP2, which is the flow path for the cooling medium extending radially outward from the second supply hole 23h, bending towards the second end plate 32, extending axially, and further bending radially outward on the second end plate 32, and communicating with each flux barrier FB2. The cooling medium supplied to each flux barrier FB2 is discharged from each discharge hole 30h of the first end plate 30 to the outside of the rotor 20 (motor) and stored below the motor. The first and second flow paths FP1 and FP2, thus configured, are formed so that they do not merge with each other.

[0028] A portion of the first and second flow paths FP1 and FP2 (radial grooves 30g and 32g) is formed radially. Therefore, due to the centrifugal force accompanying the rotation of the rotor 20, the cooling medium of the first and second flow paths FP1 and FP2 contacts the ends of the magnetic flux barriers FB1 and FB2 with sufficient thickness at the circumferential grooves 30gr and 32gr. This suppresses uneven cooling medium supply in each magnetic flux barrier FB1 and FB2. Furthermore, cooling medium is supplied to the first and second flow paths FP1 and FP2 respectively from the first and second supply holes 22h and 23h, and cooling medium is supplied to the magnetic flux barrier FB1 from the first flow path FP1 and to the magnetic flux barrier FB2 from the second flow path FP2. Therefore, the temperature difference between each permanent magnet 28 and the cooling medium increases, promoting heat dissipation of each permanent magnet 28. This allows for appropriate cooling of the permanent magnets 28.

[0029] The rotor 20 of this embodiment described above includes: a first flow path FP1, which supplies cooling medium to the magnetic flux barrier FB1 from one end further away from the center of the rotor 20 in the axial direction; and a second flow path FP2, which supplies cooling medium to the magnetic flux barrier FB2 from the other end further away from the center of the rotor 20 in the axial direction, and is arranged in a manner that does not merge with the first flow path FP1, thereby suppressing the occurrence of uneven cooling medium supply in each magnetic flux barrier FB1, FB2.

[0030] Furthermore, it includes: a first supply hole 22h, which is formed on the rotating shaft 22 in a radially open manner along the rotor 20 for supplying cooling medium; and a second supply hole 23h, which is formed on the rotating shaft 22 in a radially open manner and at a different position than the first supply hole 22h for supplying cooling medium. The first flow path FP1 is connected to the first supply hole 22h and at least a portion of it extends radially, and the second flow path FP2 is connected to the second supply hole 23h and at least a portion of it extends radially. This enables the suppression of uneven cooling medium supply in each flux barrier FB1, FB2.

[0031] Furthermore, the first and second supply holes 22h and 23h are formed at the central part of the axial direction of the rotating shaft 22. The first flow path FP1 extends axially from the first supply hole 22h and extends radially and bends to communicate with the magnetic flux barrier FB1. The second flow path FP2 extends axially from the second supply hole 23h and extends radially and bends to communicate with the magnetic flux barrier FB2. This can suppress the uneven supply of cooling medium in each magnetic flux barrier FB1 and FB2.

[0032] In the above embodiment, a plurality of first and second supply holes 22h and 23h are formed at the central portion of the axial direction of the rotating shaft 22. However, it is also possible to form a plurality of first supply holes 22h at one end (the side of the first end plate 30) further than the central portion of the axial direction of the rotating shaft 22, and to form a plurality of second supply holes 23h at one end (the side of the second end plate 32) further than the central portion of the axial direction of the rotating shaft 22. Figure 3 This is a schematic structural diagram showing the structure of rotor 120 in another embodiment. Figure 4 This indicates rotor 120. Figure 3The cross-sections on the EE line ((a)), FF line ((b)), and GG line ((c)) are schematic diagrams. In this case, multiple radial grooves 130g and 132g are formed on the rotor core 24 side of the first and second end plates 30 and 32, communicating with the first and second supply holes 22h and 23h and extending radially, so that each radial groove 130g and 132g communicates with the circumferential grooves 30gr and 32gr. In this way, the cooling medium is supplied to each magnetic flux barrier FB1 and FB2 through each radial groove 130g and 132 and the circumferential grooves 30gr and 32gr by the centrifugal force accompanying the rotation of the rotor 20. That is, each radial groove 130g and circumferential groove 30gr constitutes the first flow path FP1 as the flow path of the cooling medium extending radially outward from each first supply hole 22h and communicating with each magnetic flux barrier FB1. Each radial groove 132g and circumferential groove 32gr constitutes a second flow path FP2, which is a flow path for the cooling medium extending radially outward from each second supply hole 23h and communicating with each magnetic flux barrier FB2. In the rotor 120, the cooling medium of each radial groove 130g and 132g is supplied to the circumferential grooves 30gr and 32gr by the centrifugal force accompanying the rotation of the rotor 120. Since the centrifugal force acts radially, the cooling medium of each radial groove 130g and 132g contacts the circumferential grooves 30gr and 32gr side with sufficient thickness. As a result, uneven supply of cooling medium in each magnetic flux barrier FB1 and FB2 can be suppressed. Furthermore, cooling media are supplied from the first and second supply holes 22h and 23h to the first and second flow paths FP1 and FP2 respectively, cooling media are supplied from the first flow path FP1 to the magnetic flux barrier FB1, and cooling media are supplied from the second flow path FP2 to the magnetic flux barrier FB2. Therefore, the temperature difference between each permanent magnet 28 and the cooling media increases, which can promote heat dissipation of each permanent magnet 28. Thus, the permanent magnets 28 can be cooled appropriately.

[0033] In the above embodiment, a plurality of first and second supply holes 22h and 23h are formed on the rotating shaft 22. However, a plurality of first supply holes 22h may also be formed on the first and second end plates 30 and 32. Figure 5This is a schematic structural diagram showing the structure of rotor 220 according to another embodiment. In rotor 220, a plurality of first supply holes 22h are formed to open axially along rotor 20 on first end plate 30 and communicate with circumferential groove 30gr (first flow path FP1), and a plurality of second supply holes 23h are formed to open axially along rotor 20 on second end plate 32 and communicate with circumferential groove 32gr (second flow path FP2). Furthermore, a first receiving member 30R is installed on first end plate 30 at a position further outward from the first end plate 30 than the first supply holes 22h. A second receiving member 32R is installed on second end plate 32 at a position further outward from the second end plate 32 than the second supply holes 23h. Furthermore, in the rotor 220, the cooling medium is sprayed from the axial outer side towards the radial inner side of the first and second receiving members 30R and 32R of the first and second end plates 30 and 32. As a result, the cooling medium is received by the first and second receiving members 30R and 32R by the centrifugal force accompanying the rotation of the rotor 220 and supplied to the first and second supply holes 22h and 23h with sufficient thickness. This suppresses uneven cooling medium supply in each flux barrier FB1 and FB2. Moreover, since cooling medium is supplied from the first and second supply holes 22h and 23h to the first and second flow paths FP1 and FP2 respectively, and cooling medium is supplied from the first flow path FP1 to the flux barrier FB1 and from the second flow path FP2 to the flux barrier FB2, the temperature difference between each permanent magnet 28 and the cooling medium increases, promoting heat dissipation of each permanent magnet 28. This allows for appropriate cooling of the permanent magnets 28.

[0034] In the above embodiment, the circumferential grooves 30gr and 32gr overlap and communicate with the magnetic flux barriers FB1 and FB2. The circumferential grooves 30gr and 32gr may not completely overlap with the magnetic flux barriers FB1 and FB2, or they may overlap and communicate with a portion of the ends of the magnetic flux barriers FB1 and FB2.

[0035] The correspondence between the main elements of the implementation method and the main elements of the invention described in the solution to the problem section will be explained. In the implementation method, the rotor core 24 is equivalent to "rotor core", the permanent magnet 28 is equivalent to "permanent magnet", the first flow path FP1 is equivalent to "first flow path", and the second flow path FP2 is equivalent to "second flow path".

[0036] Furthermore, the correspondence between the principal elements of the implementation method and the principal elements of the invention described in the "Means for Solving the Problem" column is merely an example of how the implementation method is used to carry out the invention described in the "Means for Solving the Problem" column, and therefore does not limit the elements of the invention described in the "Means for Solving the Problem" column. That is, the interpretation of the invention described in the "Means for Solving the Problem" column should be based on the description in that column, and the implementation method is simply a specific example of the invention described in the "Means for Solving the Problem" column.

[0037] The present invention has been described above using embodiments, but the present invention is not limited to such embodiments and can of course be implemented in various ways without departing from the spirit of the present invention.

[0038] This invention can be used in industries such as rotor manufacturing.

[0039] Symbol Explanation

[0040] 20-Rotor, 22-Rotating shaft, 22h-First supply hole, 23h-Second supply hole, 24-Rotor core, 24a-Inflow groove, 24b-Inflow groove, 28-Permanent magnet, 29-Magnet embedding hole, 30-First end plate, 30R-First receiving component, 30g-Radial groove, 30gr-Circumferential groove, 30h-Discharge hole, 32-Second end plate, 32R-Second receiving component, 32g-Radial groove, 32gr-Circumferential groove, 32h-Discharge hole, 120-Rotor, 130g-Radial groove, 132g-Radial groove, 220-Rotor, FB1-Magnetic flux barrier, FB2-Magnetic flux barrier, FP1-First flow path, FP2-Second flow path.

Claims

1. A rotor for use in a motor, the rotor comprising a rotor core fixed to a rotating shaft and a plurality of permanent magnets embedded in corresponding embedded holes formed in the rotor core to form a plurality of magnetic poles such that magnetic flux barriers are formed at both ends of the embedded holes. The rotor is characterized by having: The first flow path supplies cooling medium from a position closer to one end than the axial center of the rotor to the outer diameter side of the magnetic flux barrier at both ends; and The second flow path supplies the cooling medium from a position further to the other end than the central portion of the rotor's axial direction to the inner diameter side of the magnetic flux barrier at both ends, and is configured not to merge with the first flow path.

2. The rotor according to claim 1, characterized in that, have: A first supply hole, which is formed on the rotating shaft in a radially opening manner along the rotor, is used to supply the cooling medium; and A second supply hole, which is formed on the rotating shaft in a radially open manner and at a different position than the first supply hole, is used to supply the cooling medium. The first flow path communicates with the first supply hole and extends at least a portion along the radial direction. The second flow path is in communication with the second supply hole and extends at least a portion of it along the radial direction.

3. The rotor according to claim 2, characterized in that, The first and second supply holes are formed at the central portion of the axial direction of the rotating shaft. The first flow path extends from the first supply hole along the axial direction and bends along the radial direction, communicating with the magnetic flux barrier on the outer diameter side. The second flow path extends from the second supply hole along the axial direction and bends along the radial direction, communicating with the magnetic flux barrier on the inner diameter side.

4. The rotor according to claim 2, characterized in that, The first supply hole is formed at a position closer to one end than the central portion of the axial direction of the rotating shaft. The second supply hole is formed at a position closer to the other end than the central portion of the axial direction of the rotating shaft. The first flow path extends radially from the first supply hole and communicates with the magnetic flux barrier on the outer diameter side. The second flow path extends radially from the second supply hole and communicates with the magnetic flux barrier on the inner diameter side.

5. The rotor according to claim 1, characterized in that, have: The first end plate is disposed on one end side of the rotor core in the axial direction; The second end plate is disposed on the other end side of the rotor core in the axial direction and is paired with the first end plate to clamp the rotor core from both sides. A first supply hole is formed on the first end plate, and opens along the axial direction and communicates with the first flow path; The first receiving component is mounted on the first end plate at a position further outward than the first supply hole, and stands upright from the first end plate toward the axially outward side, guiding the cooling medium sprayed onto the first end plate to the first supply hole; A second supply hole is formed on the second end plate, opens along the axial direction, and communicates with the second flow path; and The second receiving component is mounted on the second end plate at a position further outward than the second supply hole, and stands upright from the second end plate toward the axially outward side, guiding the cooling medium sprayed onto the second end plate to the second supply hole.

Images