Rotary electric machine

Abstract

To provide a rotary electric machine capable of reducing assembly man-hours and efficiently cooling.SOLUTION: A motor 1 includes a rotor core 10 having a magnet 3 that is a permanent magnet disposed therein, and end plates 17 and 18 configured to cover both axial end portions of the rotor core 10. The motor 1 further includes a support member 30 that is an elastic member supported by the end plate 17 and supports an upper end surface of the magnet 3, a support member 31 that is an elastic member supported by the end plate 18 and supports a lower end surface of the magnet 3, and a coolant passage 28 provided in the rotor core 10 to allow a coolant to pass along a side surface of the magnet 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a magnet fixing structure in a rotor of a rotating electric machine. [Background technology]

[0002] Many rotating electrical machines such as motors and alternators have a permanent magnet on one of the rotor and the stator, and an electromagnet on the other. For example, Patent Document 1 discloses a rotating electric machine in which magnets are provided in holes formed in a rotor core, and the magnets are fixed to the rotor core by applying adhesive or resin. Furthermore, Patent Document 2 discloses a rotating electric machine having magnets in a rotor core, and the rotor core is provided with refrigerant passages that allow a refrigerant (such as cooling oil) to pass along the magnets, thereby cooling the magnets. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-002144 [Patent Document 2] Japanese Patent Application Publication No. 2021-191034 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 has a problem in that the assembly cost increases due to the man-hours required for applying adhesive or the like. Furthermore, when a refrigerant passage for cooling the magnets is provided in the rotor as in Patent Document 2, if an adhesive or the like is used to fix the magnets, there is a problem in that the adhesive or the like adheres to the surface of the magnets, reducing the heat exchange rate.

[0005] The present invention has been made in consideration of these problems, and its purpose is to provide a rotating electric machine that has magnets fixed to a rotor and is equipped with a refrigerant passage, which reduces the assembly labor and can be efficiently cooled by a refrigerant. [Means for solving the problem]

[0006] In order to achieve the above object, the rotating electric machine of the present invention is a rotating electric machine having a magnet inside a rotor core and a support member that supports the magnet on the rotor core, wherein the rotor core is provided with a refrigerant passage that extends in the axial direction of the rotor core and faces the side of the magnet to allow a refrigerant to pass through, and the support member is formed of an elastic member and is not positioned in the refrigerant passage but is positioned at at least one of both axial ends of the rotor core to support the axial end of the magnet. [Effects of the Invention]

[0007] According to the rotating electric machine of the present invention, the ends of the magnets are supported by the support members, which are elastic members, so that the magnets can be easily fixed and the number of steps required to assemble the rotor can be reduced. Furthermore, by providing a refrigerant passage along the side of the magnet, the refrigerant can pass through the refrigerant passage without being obstructed by the magnet support member, and the magnet can be cooled efficiently by heat exchange between the refrigerant passing through the refrigerant passage and the magnet. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a vertical cross-sectional view of a motor according to a first embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of an axial end portion of a rotor in the motor of the first embodiment. FIG. [Figure 3] FIG. 3 is a full view showing the shape of a refrigerant introduction member. [Figure 4] FIG. 6 is a longitudinal sectional view of a rotor in a motor according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a longitudinal sectional view of a rotor in a motor according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a longitudinal sectional view of a rotor in a motor according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a longitudinal sectional view of a rotor in a motor according to a fifth embodiment of the present invention. [Figure 8] 10A and 10B are explanatory diagrams showing other examples of the arrangement of magnets and refrigerant passages in the motor according to the embodiment of the present invention. [Figure 9] 10A and 10B are explanatory diagrams showing other examples of the arrangement of magnets and refrigerant passages in the motor according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of a motor 1 (rotating electric machine) according to a first embodiment of the present invention, taken along a plane passing through the axis of the motor 1. FIG. 2 is a transverse cross-sectional view of the motor 1, taken along the line AA in FIG. 1. FIG. 3 is an outline drawing showing the shape of a support member 30 used in the rotor 2 of the motor 1. In the following description, the axial and radial directions refer to the axial and radial directions of the rotor 2 and shaft 5.

[0010] An electric motor (hereinafter referred to as motor 1), which is a rotating electric machine according to a first embodiment of the present invention, is a driving motor that is mounted on a vehicle such as a plug-in hybrid vehicle (PHEV), a hybrid vehicle (HEV), or an electric vehicle (EV) that is equipped with an engine and capable of external charging and external power supply, and drives the running wheels. A rotor 2, which is the rotor of the motor 1, is provided with a permanent magnet (hereinafter referred to as a magnet 3), and a stator, which is the fixed part (not shown), is provided with an electromagnet.

[0011] The rotor 2 includes a cylindrical rotor core 10 provided coaxially with the shaft 5, and a magnet 3 inside the rotor core 10. A plurality of magnets 3 are arranged in the axial direction in rectangular holes (magnet storage holes 11) that penetrate the rotor core 10 in the axial direction at positions close to the outer peripheral surface of the rotor core 10. The magnet storage holes 11 are arranged in pairs, spaced apart in a generally V-shape, and there are, for example, ten pairs of magnet storage holes 11 arranged at equal intervals in the circumferential direction of the rotor core 10. The two rows of magnets 3 inserted into one set of magnet storage holes 11 are arranged so that the outer peripheries have either an S pole or an N pole, and the magnets 3 of adjacent sets have opposite poles.

[0012] One axial end face (upper end face 15 in FIG. 1 ) of rotor core 10 is provided with an annular end plate 17 that covers upper end face 15. The other axial end face (lower end face 16 in FIG. 1 ) of rotor core 10 is provided with an annular end plate 18 that covers lower end face 16. Note that, to define the circumferential positions of end plate 17 and end plate 18 relative to rotor core 10, it is preferable to provide projections and holes on their mating surfaces or to provide alignment lines on the outer circumferential surfaces.

[0013] The cylindrical shaft 5 is inserted into the center of the end plate 17, and its inner peripheral end is in close contact with the outer peripheral surface of the shaft 5 all around. The outer peripheral end has a flange 19 that extends vertically all around toward the upper end face 15 of the rotor core 10, and a space separated from the outside is formed between the end plate 17 and the upper end face 15 of the rotor core 10. The space between the upper end face 15 of the rotor core 10 and the end plate 17 becomes a refrigerant introduction space 20 that introduces refrigerant into the rotor core 10.

[0014] The end plates 18 have the shaft 5 inserted into their centers, and have flanges 21 at their inner peripheral ends that are in close contact with the outer peripheral surface of the shaft 5 and extend perpendicularly toward the lower end face 16 of the rotor core 10 around their entire circumference, and flanges 22 at their outer peripheral ends that extend perpendicularly toward the lower end face 16 of the rotor core 10 around their entire circumference, forming a space separated from the outside between the end plates 18 and the lower end face 16 of the rotor core 10. The space between the lower end face 16 of the rotor core 10 and the end plates 18 becomes a refrigerant discharge space 23 that receives the refrigerant discharged from the rotor core 10.

[0015] A refrigerant passage 25 through which a refrigerant such as an automatic transmission fluid (ATF) of a vehicle passes is provided at the axial center of a cylindrical shaft 5 of the motor 1. The shaft 5 is provided with a communication passage 26 extending in the radial direction and connecting the refrigerant introduction space 20 and the refrigerant passage 25 . Five communication passages 26 are arranged at equal intervals around the circumference of the shaft 5. The communication passages 26 are each arranged at a circumferential position between one set of magnet storage holes 11 arranged in a V shape and an adjacent set of magnet storage holes 11 arranged in a V shape.

[0016] Further, the end plate 18 facing the refrigerant discharge space 23 is provided with a refrigerant discharge path 27 for discharging the refrigerant from the refrigerant discharge space 23. The refrigerant discharged from the refrigerant discharge path 27 is collected in, for example, an ATF storage section. The magnet storage holes 11 of the rotor core 10 are formed to be larger radially inward than the shape of the magnets 3. That is, when a magnet 3 is inserted into each magnet storage hole 11 in the rotor core 10, a space (refrigerant passage 28) extending axially is formed radially inward of the magnet 3. The refrigerant passage 28 passes through the rotor core 10 in the axial direction and faces the radially inner side surface of the magnet 3.

[0017] As a result, a portion of the refrigerant passing through the refrigerant passage 25 of the shaft 5 passes through the communication passage 26, the refrigerant introduction space 20, the refrigerant passage 28, and the refrigerant discharge space 23 in that order, and is discharged from the refrigerant discharge passage 27 to the outside of the motor 1. One axial end of each row of magnets 3 inserted into magnet storage holes 11 is supported by end plate 17 via support member 30, and the other axial end of magnet 3 is supported by end plate 18 via support member 31. Support members 30 and 31 are made of an elastic material such as rubber.

[0018] Five support members 30 are arranged in the refrigerant introduction space 20 and are lined up in the circumferential direction of the refrigerant introduction space 20. Each support member 30 supports two sets (four rows) of magnets 3. The support member 30 has partition sections 32 that divide the refrigerant introduction space 20 into two sets (four rows) of magnets, and is also equipped with four pressing sections 33, for example, of a substantially cylindrical shape, that press the magnets 3 of each row against the inside of the rotor core 10. The partition sections 32 and the four pressing sections 33 are integrally formed from an elastic member.

[0019] The partitioning portion 32 is a generally sector-shaped plate-like member that covers the upper portions of the two sets (four rows) of magnets 3 along the inner wall surface of the end plate 17. When the partitioning portion 32 is installed in the refrigerant introduction space 20, its radially inner end is in close contact with the outer peripheral surface of the shaft 5, and its radially outer end is formed with a flange 34 so as to be in close contact with the inner wall surface of the flange 19 of the end plate 17 and the upper end surface 15 of the rotor core 10. The flange 34 provided at the end of the support member 30 is provided not only at the radially outer end but also around the entire circumference except for a portion of the portion that is in close contact with the shaft 5. The circumferential center of the partitioning portion 32 of the support member 30 is provided with a central partition 35 that extends radially inward from the flange 34 at the radially outer end toward the shaft 5. The central partition 35 is in close contact with the upper end surface 15 of the rotor core 10, and its radially inner end extends to a position several centimeters radially outward from the outer peripheral surface of the shaft 5. The radially inner end of the partition portion 32 is disposed so as to straddle one of the communication passages 26 provided in the shaft 5 in the circumferential direction.

[0020] The partitioning section 32 of the support member 30 partitions the refrigerant introduction space 20 into two sets (four rows) of magnets 3, and the refrigerant is introduced into these compartments through the communication passages 26 provided in the shaft 5. The refrigerant introduced from the communication passages 26 of the shaft 5 is divided into two by the central partitioning section 35, and the refrigerant is introduced into the spaces for each set (two rows) of magnets 3. The pressing portion 33 of the support member 30 is, for example, about as thick as the width of the magnet 3, and extends from the inner wall surface of the partition portion 32 in the same direction as the flange portion 34, i.e., toward the upper end surface 15 of the rotor core 10, and is positioned so as to press against the center of the axial end surface of the magnet 3.

[0021] In the support member 30, the pressing portion 33 extends slightly from the outer wall surface of the partition portion 32 in the direction opposite to the flange portion 34, forming a cylindrical outer protrusion 36. The end plate 17 is formed with a positioning hole 37 into which the outer protrusion 36 is inserted to position the support member 30. The positioning hole 37 may be several millimeters deep on the inner surface so as not to penetrate the end plate 17, but it is preferable that the diameter of the positioning hole 37 is slightly smaller than the outer diameter of the outer protrusion 36 of the support member 30 so that the outer protrusion 36 of the support member 30 does not come off or move when inserted.

[0022] Support members 31 installed in refrigerant discharge space 23 include pressing portions 42 that support the end faces of magnets 3 inserted into magnet storage holes 11 of rotor core 10 (the lower faces of magnets 3 in FIG. 1), and outward protrusions 43. Support members 31 are provided for each row of magnets 3 as shown in FIG. 2, but may also be formed into a single sheet, for example, by a single annular plate member that closely contacts the inner wall surfaces of end plates 18. Furthermore, the outer peripheral end of the single support member 31 may be provided with a flange that closely contacts the inner wall surfaces of flanges 22 of end plates 18 and the lower end surface 16 of rotor core 10.

[0023] Like the end plate 17, the end plate 18 is provided with a positioning hole 44 into which the outer protrusion 43 of the support member 31 is inserted for positioning. The shaft 5 is provided with a stepped portion 47 that protrudes radially outward from the outer circumferential surface in order to support the end plate 18. In addition, a threaded portion 49 for fastening a thin plate-shaped nut 48 is formed on the outer circumferential surface of the shaft 5 near the axial position where the end plate 17 is disposed.

[0024] An example of the procedure for assembling the rotor 2 will be described below. First, the five support members 30 are fixed to the end plate 17, and each support member 31 is fixed to the end plate 18. Furthermore, the magnets 3 are inserted into the magnet housing holes 11 of the rotor core 10, respectively. Next, the tip end of the shaft 5 (the axial end opposite the stepped portion 47) is passed through the end plate 18, the rotor core 10, and the end plate 17, in that order. At this time, the end plate 17 and the end plate 18 are positioned relative to the rotor core 10 in the rotational direction.

[0025] Then, by tightening the nuts 48 onto the threaded portions 49, the end plates 17 and 18 are fixed to the rotor core 10, and the assembly of the rotor 2 is completed. As described above, in the motor 1 of the first embodiment, the magnets 3 provided inside the rotor core 10 are fixed to the end plates 17, 18 provided at the axial ends of the rotor core 10 by the support members 30, 31 which are elastic members.

[0026] Therefore, it is possible to fix the magnet 3 more easily than fixing the magnet 3 to the rotor core 10 with adhesive, resin, or the like, and the number of steps required to assemble the motor 1 can be reduced. Since the support members 30 and 31 are made of elastic materials such as rubber, the magnet 3 can be firmly supported without rattle, and noise when the motor 1 is operating can be reduced. Additionally, the side of magnet 3 is provided with refrigerant passage 28 for passing a refrigerant, and as the refrigerant passes through refrigerant passage 28 while in contact with magnet 3, heat exchange occurs between the refrigerant and magnet 3, thereby cooling the magnet. As described above, support members 30, 31 support only the axial end of magnet 3, and no support members are provided on the side of magnet 3, so the refrigerant can pass smoothly through refrigerant passage 28 without being obstructed by support members 30, 31, improving the efficiency with which the refrigerant cools magnet 3.

[0027] Support member 30 supports a portion of the upper end face of magnet 3 by pressing portion 33, with the remainder of the upper end face exposed to refrigerant introduction space 20. Support member 31 supports a portion of the lower end face of magnet 3 by pressing portion 42, with the remainder of the lower end face exposed to refrigerant discharge space 23. This allows heat exchange with the refrigerant not only on the radially inner side of the magnet 3, but also on parts of the upper and lower end faces of the magnet 3, further improving the cooling performance of the magnet 3.

[0028] Furthermore, the flange portion 34 of the support member 30 is in close contact with the inner wall surface of the flange portion 19 of the end plate 17 and the upper end surface 15 of the rotor core 10, and is arranged to cover the abutment portion between the end plate 17 and the rotor core 10 from the inner wall surface side, thereby preventing refrigerant from leaking from the refrigerant introduction space 20 through the abutment portion between the end plate 17 and the rotor core 10. FIG. 4 is a vertical cross-sectional view showing the internal structure of the rotor 2 in the motor 51 of the second embodiment.

[0029] In the motor 51 of the second embodiment, the shapes of the pressing portions 33 and 42 of the support members 30 and 31 are different from those of the motor 1 of the first embodiment. In this embodiment, the pressing portion 33 of the support member 30 has a trapezoidal vertical cross section (axial cross section) with a larger diameter on the end plate 17 side than on the magnet 3 side. In addition, the pressing portion 42 of the support member 31 has a trapezoidal vertical cross section (axial cross section) with a larger diameter on the end plate 18 side than on the magnet 3 side.

[0030] This reduces the contact area of ​​the pressing portions 33, 42 on the magnet 3 side, ensuring the exposed area of ​​the end face of the magnet 3, while ensuring a large contact area of ​​the pressing portions 33, 42 on the end plates 17, 18 side, thereby enabling stable support of the magnet 3. FIG. 5 is a cross-sectional view showing the internal structure of the rotor 2 in the motor 61 of the third embodiment. The motor 61 of the second embodiment differs from the motor 1 of the first embodiment in that it has a positioning portion 62 that positions the magnet 3.

[0031] The positioning portion 62 is composed of a hole 63 several millimeters deep formed in the axial outer end face (upper end face and lower end face) of the magnet, and pressing portions 33, 42 of the support members 30, 31 protruding toward the magnet 3 so as to be inserted into the hole 63 with almost no gap. This restricts movement of the magnet 3 in a direction perpendicular to the axial direction relative to the rotor core 10. Therefore, the magnet 3 can be accurately supported relative to the rotor core 10, improving the weight balance of the rotor 2 and reducing noise and increasing output when the rotor is rotating.

[0032] FIG. 6 is a cross-sectional view showing the internal structure of the rotor 2 in the motor 71 of the fourth embodiment. In a motor 71 of the fourth embodiment, the shapes of the pressing portions 33 and 42 of the support members 30 and 31 are different from those of the motor 1 of the first embodiment. For example, as shown in FIG. 6, the contact surfaces of the pressing portions 33, 42 that come into contact with the magnet 3 are inclined radially inward toward the magnet 3 side.

[0033] Therefore, when the magnet 3 is supported by being sandwiched between the pressing portions 33 and 42 in the axial direction, the magnet 3 is biased radially outward. As a result, the magnets 3 are pressed against the radially outer wall surfaces of the magnet storage holes 11 of the rotor core 10, thereby determining the radial position of the magnets 3. Furthermore, the radially inner portion of the magnet storage holes 11 becomes the refrigerant passages 28, making it possible to maximize the flow area of ​​the refrigerant passages 28. Therefore, the refrigerant can pass through the refrigerant passages 28 efficiently, improving the cooling of the magnets 3 by the refrigerant.

[0034] Furthermore, since the pressing portions 33, 42 are arranged to urge the magnet 3 radially outward, the force is urged in the same direction as the centrifugal force acting on the magnet 3 when the rotor rotates, and the magnet 3 can be strongly pressed against the rotor core 10 and supported when the rotor rotates. The pressing portions 33 and 42 in this embodiment correspond to the pressing portion of the present invention. FIG. 7 is a cross-sectional view showing the internal structure of the rotor 2 in the motor 81 of the fifth embodiment.

[0035] In the motor 81 of the fifth embodiment, compared to the motor 51 of the second embodiment, the support member 30 arranged in the refrigerant introduction space 20 does not have a partition portion 32 and a flange portion 34, like the support member 31 arranged in the refrigerant discharge space 23, and is composed of a pressing portion 33 and an outward protruding portion 36. In this embodiment, the function of suppressing refrigerant leakage from the refrigerant introduction space 20 is reduced compared to the motor 51 of the second embodiment, but the magnet 3 can be easily fixed with a simple configuration, and component costs and assembly costs can be reduced.

[0036] Although the description of the embodiment has been completed, the aspects of the present invention are not limited to this embodiment, and the details of the control in this embodiment may be changed as appropriate. For example, in the above embodiment, the refrigerant passage 28 is formed in the rotor core 10 only on one radially inner side of the rectangular box-shaped magnet 3, but the refrigerant passage 28 may also be provided on the radially outer side of the magnet 3, as in the rotor core 10 of the motor 91 shown in Figure 8, or the refrigerant passage 92 may be provided facing the other two side faces of the magnet 3, which has a rectangular cross section.

[0037] The cooling performance of the magnet 3 can be further improved by further providing refrigerant passage 28 and refrigerant passage 92. In this embodiment as well, support members 30, 31 restrict axial movement of the magnet 3, and the elastic force of support members 30, 31 can also suppress movement of the magnet 3 in a direction perpendicular to the axial direction. Note that, in order to further ensure the flow path area of ​​refrigerant passages 28, 92, it is advisable to set the shape inside magnet storage hole 11 so that the magnet 3 is less likely to move in a direction perpendicular to the radial direction inside magnet storage hole 11.

[0038] 9, the present invention can also be applied to a motor 101 in which the longitudinal direction of the rectangular end face of magnet 3 extends in the tangential direction of rotor core 10. Refrigerant passages 28, 92 may be provided facing the four side faces of magnet 3, as in the case of FIG. 8, for example. Even in this configuration, by supporting the axial end faces of magnet 3 with support members 30, 31 and providing refrigerant passages 28, 92 on the side faces of magnet 3, it is possible to improve the cooling performance of magnet 3 by the refrigerant while properly fixing magnet 3.

[0039] Furthermore, as in the above-described embodiment, the present invention can be applied to electric motors other than motors used to drive plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and electric vehicles (EVs), and can also be widely applied to rotating electric machines other than electric motors, such as alternators, which have magnets in their rotors. [Explanation of symbols]

[0040] 1, 51, 61, 71, 81, 91, 101 Motor (rotating electric machine) 3. Magnets 10 rotor core 17, 18 End plates 28 Refrigerant passage 30, 31 Support members 36, 43 Outer protrusion (positioning part) 20 Refrigerant introduction space (space) 33, 42 Pressing section

Claims

1. A rotating electric machine including a magnet inside a rotor core and a support member that supports the magnet on the rotor core, The rotor core is provided with a refrigerant passage that extends in the axial direction of the rotor core and faces a side surface of the magnet, and through which a refrigerant passes, The support member is made of an elastic member, is not disposed in the refrigerant passage, and is disposed at least at one of both axial ends of the rotor core to support the axial ends of the magnets. A rotating electric machine characterized by:

2. The support member supports a portion of the axial end face of the magnet, and the remainder of the end face is exposed to a space through which a refrigerant passes.

2. The rotating electrical machine according to claim 1.

3. The support member is provided with a positioning portion that positions the magnet relative to the rotor core in a direction perpendicular to the axial direction.

2. The rotating electrical machine according to claim 1.

4. The support member has a pressing portion that presses the magnet in a direction perpendicular to the axial direction, and the refrigerant passage is disposed on a side surface opposite to the pressing direction.

2. The rotating electrical machine according to claim 1.

5. The pressing portion presses the magnet radially outward of the rotor core.

5. The rotating electrical machine according to claim 4.

6. end plates covering axial end faces of the rotor core; a refrigerant introduction space for introducing a refrigerant into the refrigerant passage is provided between the end plate and the rotor core; The support member is disposed in the refrigerant introduction space and has a portion that covers the contact portion between the end plate and the rotor core from the inner wall surface side of the end plate.

2. The rotating electrical machine according to claim 1.

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