Rotor of a rotating electrical machine

Abstract

When the rotor core body (121) is viewed in the axial direction, the rotor core body (121) has a bridge (150) arranged in a manner connecting the first inner surface (S1) and the second inner surface (S2) of the innermost magnetic flux barrier (124), and the innermost magnetic flux barrier (124) is formed with an outer diameter side closed space (124a) as a space divided between the bridge (150) and the outer edge of the rotor core body (121), and a reinforcement portion (160) made of a non-magnetic body is embedded in the outer diameter side closed space (124a) in the axial direction of the rotor core body (121).

Description

Technical Field

[0001] The present invention relates to a rotor for a rotating electrical machine. Background Art

[0002] Conventionally, a rotor of a permanent magnet embedded rotating electrical machine described in Patent Document 1 is known.

[0003] The above-mentioned rotor has a cylindrical rotor core formed by stacking electromagnetic steel sheets on the inner circumference side of the stator on which the coil is wound. The rotor core is configured so that the outer circumference of the rotor core faces the inner circumference of the stator. In the rotor core, permanent magnet insertion holes are formed in multiple layers in the radial direction and permanent magnets are inserted. The rotor core has multiple magnetic pole regions in the circumferential direction and has a flux barrier adjacent to the permanent magnet insertion hole. The flux barrier extends along the q-axis magnetic circuit. Among the flux barriers, the flux barrier located on the innermost diameter side of the rotor core extends to near the outer circumference of the rotor core.

[0004] Patent Document 2 discloses a rotor for a permanent magnet rotating electrical machine comprising wedge-shaped slots or holes, permanent magnets mounted in the slots or holes, and a filler material. The wedge-shaped slots or holes have tapered surfaces that gradually decrease in width as they move radially outward and are formed across the entire axial direction of the rotor core. The filler material is then applied to other slots or holes adjacent to the slots or holes for mounting the permanent magnets, thereby compacting the permanent magnets by die-casting. The filler material then presses the circumferential ends of the permanent magnets into the space between the permanent magnets and the rotor core.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6020629

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 7-312837 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, in the rotor of the rotating electric machine disclosed in Patent Document 1, as the magnetic flux barriers located on the innermost diameter side of the rotor core are extended closer to the outer circumference of the rotor core, the rotor core wall thickness at the extended tip of the innermost diameter side magnetic flux barriers decreases. Consequently, the rotor core strength decreases. Therefore, when attempting to maintain rotor core strength by increasing the wall thickness, leakage flux may increase in this thick wall portion.

[0011] In addition, in the rotor of the rotating electrical machine of Patent Document 1, a shaft is inserted through the center of a rotor core formed by stacking electromagnetic steel sheets, and the shaft and the rotor core are fastened by shrink fitting, for example. When the rotation speed increases, the electromagnetic steel sheets forming the rotor core may warp.

[0012] The rotor of the rotating electric machine disclosed in Patent Document 2 also has a shaft inserted through the center of a rotor core constructed of stacked electromagnetic steel sheets. For example, when the shaft and rotor core are shrink-fitted, the resulting stress can cause the electromagnetic steel sheets to bend and warp. This warping reduces the fastening force between the shaft and the rotor core. Furthermore, at high speeds, rotor deformation increases, sometimes leading to a deterioration in rotational balance. Since the rotor of a rotating electric machine rotates at high speeds, it is desirable to easily maintain rotational balance.

[0013] The present invention has been made in view of the problems existing in the conventional technology, and an object of the present invention is to provide a rotor for a rotating electric machine that can easily suppress leakage magnetic flux and maintain strength.

[0014] Another object of the present invention is to provide a rotor for a rotating electrical machine that can suppress warping of electromagnetic steel sheets constituting a rotor core, firmly fix the sheets, and easily achieve rotational balance.

[0015] Solutions for solving problems

[0016] The rotor of a rotating electric machine according to a first embodiment of the present invention for solving the above-mentioned problems has a cylindrical rotor core, the rotor core including a rotor core body, the rotor core body having a plurality of permanent magnet insertion holes formed in the radial direction for inserting permanent magnets, in the rotor of the rotating electric machine, the rotor core has a plurality of magnetic pole regions in the circumferential direction, and has a flux barrier adjacent to the permanent magnet insertion holes and extending along the q-axis magnetic path, the flux barrier extending in the axial direction of the rotor core, when the flux barrier located on the innermost diameter side of the rotor core is set as the innermost flux barrier. When forming a magnetic barrier, the innermost magnetic flux barrier has a first inner surface located radially inward of the innermost magnetic flux barrier and a second inner surface located radially outward of the innermost magnetic flux barrier. When the rotor core body is viewed in the axial direction, the rotor core body has a bridge arranged in a manner connecting the first inner surface and the second inner surface. The innermost magnetic flux barrier forms an outer diameter side closed space which is a space divided between the bridge and the outer edge of the rotor core body. In the outer diameter side closed space, a reinforcement portion composed of a non-magnetic body is embedded in the axial direction of the rotor core body.

[0017] Thus, the rotor core's strength is maintained by the reinforcement inserted into the enclosed space on the outer diameter side of the rotor core. Furthermore, since the rotor core's strength is maintained by the bridge and reinforcement, the rotor core's wall thickness at the extended tip of the innermost magnetic flux barrier can be reduced, making it easier to suppress magnetic flux leakage. This makes it easier to suppress magnetic flux leakage and maintain the rotor core's strength.

[0018] In the rotor of the rotating electrical machine described above, the innermost magnetic flux barrier may include a radially inner closed space defined between the permanent magnet and the bridge.

[0019] Sometimes, the reinforcement is formed by pouring molten non-magnetic material into the enclosed space on the outer diameter side of the rotor core. In this case, when the bridge is arranged to sandwich the permanent magnets, the heat of the molten non-magnetic material poured into the enclosed space on the outer diameter side is transferred to the permanent magnets, potentially degrading their performance.

[0020] In this regard, the enclosed space on the inner diameter side of the rotor core functions as a heat insulating layer, thereby suppressing the influence of heat on the permanent magnets inserted into the permanent magnet insertion holes of the rotor core.

[0021] In the rotor of the above-mentioned rotating electrical machine, the above-mentioned rotor core may have a cover member stacked on both ends of the above-mentioned rotor core body in the axial direction, and the above-mentioned cover member has: a cover hole, which is connected to the above-mentioned outer diameter side closed space; and a cover portion, which covers the above-mentioned permanent magnets from the above-mentioned permanent magnet insertion hole located on the radially innermost diameter side to the above-mentioned bridge, and covers the above-mentioned permanent magnet insertion hole located radially outward compared to the above-mentioned permanent magnet insertion hole located on the innermost diameter side, and the above-mentioned reinforcement portion is embedded in the above-mentioned cover hole.

[0022] With this arrangement, when molten non-magnetic material is poured into the enclosed outer diameter space of the rotor core, the cover member prevents the molten metal from adhering to the permanent magnets and instead pours only into the cover holes and the enclosed outer diameter space. This effectively reduces the effects of heat on the permanent magnets inserted into the permanent magnet insertion holes of the rotor core.

[0023] In the rotor of the above-mentioned rotating electrical machine, the above-mentioned first inner surface may have a protruding portion, and the above-mentioned protruding portion protrudes toward the adjacent magnetic pole region compared to an imaginary inner surface formed by extending the inner surface located on the radial inner side with which the above-mentioned permanent magnet abuts in the above-mentioned permanent magnet insertion hole in the direction along the q-axis magnetic circuit.

[0024] This increases the width of the innermost magnetic flux barrier in the d-axis magnetic path, thereby increasing the reluctance torque.

[0025] In the above-mentioned rotor of the rotating electrical machine, the rotor core body may be formed by stacking a plurality of electromagnetic steel sheets in the axial direction, the rotor core may include a clamping portion that clamps the rotor core body in the axial direction, and the clamping portion may be integrally provided with the reinforcement portion.

[0026] Thus, the clamping portion provided integrally with the reinforcement portion can fix the plurality of electromagnetic steel sheets so as not to separate in the axial direction. Therefore, the plurality of electromagnetic steel sheets can be appropriately fixed without preparing fixing members such as screws for fixing the plurality of electromagnetic steel sheets.

[0027] A second aspect of the present invention for solving the above-mentioned problems is directed to a rotor for a rotating electric machine, wherein the outer circumferential surface of a cylindrical rotor core faces the inner circumferential side of a stator around which a coil is wound. In the rotor for the rotating electric machine, the rotor core is constructed by laminating electromagnetic steel sheets, with a shaft inserted through the center. A permanent magnet insertion hole extending in the axial direction is formed in the rotor core for each magnetic pole, and permanent magnets are inserted into the permanent magnet insertion holes. Filling holes extending in the axial direction are formed between adjacent magnetic poles or within adjacent magnetic poles in the rotor core, and the electromagnetic steel sheets are secured by filling the filling holes with non-magnetic metal or resin.

[0028] In addition, in the rotor of the above-mentioned rotating electrical machine, the above-mentioned permanent magnet insertion hole includes an outer diameter side permanent magnet insertion hole arranged on the radially outer side of the above-mentioned rotor core and an inner diameter side permanent magnet insertion hole arranged on the inner diameter side compared to the above-mentioned outer diameter side permanent magnet insertion hole, the above-mentioned permanent magnet includes an outer diameter side permanent magnet inserted into the above-mentioned outer diameter side permanent magnet insertion hole and an inner diameter side permanent magnet inserted into the above-mentioned inner diameter side permanent magnet insertion hole, a magnetic flux barrier is continuously formed on the circumferential outer side of the above-mentioned inner diameter side permanent magnet insertion hole of the above-mentioned rotor core, and the above-mentioned filling hole is formed in an area sandwiched by the above-mentioned magnetic flux barrier between adjacent above-mentioned magnetic poles.

[0029] Accordingly, in the rotor core, the filling holes extend in the axial direction in the area sandwiched by the flux barriers between adjacent magnetic poles, and the electromagnetic steel sheets are fixed by the non-magnetic metal or resin filled in the filling holes, thereby making it possible to firmly fix the electromagnetic steel sheets constituting the rotor core and suppress warping of the electromagnetic steel sheets constituting the rotor core.

[0030] Furthermore, in the rotor of the rotating electrical machine described above, the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole of each of the magnetic poles may be arc-shaped.

[0031] This is particularly useful when the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole are arc-shaped.

[0032] In addition, in the rotor of the rotating electrical machine, a filling hole extending in the axial direction may be further formed at a distance outside the circumferential direction of the flux barrier of the rotor core, and the electromagnetic steel sheet may be fixed by filling the filling hole with non-magnetic metal or resin.

[0033] In this case, the electromagnetic steel sheets constituting the rotor core can be fixed more firmly, and warping of the electromagnetic steel sheets constituting the rotor core can be further suppressed.

[0034] In addition, in the rotor of the rotating electrical machine of the second embodiment of the present invention, it may be that a clamping portion made of the above-mentioned non-magnetic metal or resin is integrally formed on both end surfaces in the axial direction of the above-mentioned rotor core, and the above-mentioned clamping portion has: a thick-walled portion, which is connected to the rod-shaped portion made of the non-magnetic metal or resin filled in the above-mentioned filling hole; and a thin-walled portion, which is formed at multiple locations in the circumferential direction, and a pin for achieving rotational balance is integrally formed in the above-mentioned thin-walled portion in a manner protruding axially outward.

[0035] In this manner, the electromagnetic steel sheets are secured by nonmagnetic metal or resin filling holes extending axially between or within adjacent magnetic poles in the rotor core. Since the thick-walled portion of the clamping section, made of nonmagnetic metal or resin, is connected to the rod-shaped portion of the nonmagnetic metal or resin filling the holes, the connection strength of the rod-shaped portion of the nonmagnetic metal or resin is enhanced, thereby securely securing the electromagnetic steel sheets that constitute the rotor core. Furthermore, pins for achieving rotational balance are integrally formed in the thin-walled portions formed in multiple locations of the clamping section, projecting axially outward. This facilitates achieving rotational balance using these pins.

[0036] Furthermore, in the rotor of the rotating electrical machine described above, a cover member having only the filling hole formed therein may be arranged between the electromagnetic steel sheet having the permanent magnet insertion hole and the filling hole formed therein and the clamping portion of the rotor core.

[0037] In this case, the non-magnetic metal or resin filled in the filling hole can be prevented from flowing into the permanent magnet insertion hole.

[0038] In addition, in the rotor of the above-mentioned rotating electrical machine, the above-mentioned permanent magnet insertion hole may include: an outer diameter side permanent magnet insertion hole, which extends in the above-mentioned axial direction and is arranged on the radially outer side; and an inner diameter side permanent magnet insertion hole, which extends in the above-mentioned axial direction and is arranged on the inner diameter side compared to the above-mentioned outer diameter side permanent magnet insertion hole, the outer diameter side permanent magnet is inserted into the above-mentioned outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet is inserted into the above-mentioned inner diameter side permanent magnet insertion hole, a magnetic flux barrier is continuously formed on the circumferential outer side of the above-mentioned inner diameter side permanent magnet insertion hole of the above-mentioned rotor core, and the above-mentioned filling hole is formed in a manner extending in the axial direction in an area sandwiched by the above-mentioned magnetic flux barrier between adjacent magnetic poles in the above-mentioned rotor core.

[0039] Furthermore, in the rotor of the rotating electrical machine described above, the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole of each of the magnetic poles may be arc-shaped.

[0040] This is particularly useful when the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole are arc-shaped.

[0041] In addition, in the rotor of the rotating electrical machine, a filling hole extending in the axial direction may be further formed at a distance outside the circumferential direction of the flux barrier of the rotor core, and the electromagnetic steel sheet may be fixed by filling the filling hole with non-magnetic metal or resin.

[0042] In this case, the electromagnetic steel sheets constituting the rotor core can be fixed more firmly.

[0043] Effects of the Invention

[0044] According to this invention, it is possible to easily suppress leakage magnetic flux and maintain strength. In addition, it is possible to suppress warping of the electromagnetic steel sheets constituting the rotor core, firmly fix them, and easily achieve rotational balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the rotating electrical machine according to the first embodiment.

[0046] Figure 2 It is a schematic diagram of the rotor of the rotating electrical machine according to the first embodiment.

[0047] Figure 3 It is a plan view of the electromagnetic steel sheets of the rotor core according to the first embodiment.

[0048] Figure 4 It is a plan view of the rotor core cover member according to the first embodiment.

[0049] Figure 5 This is a partial plan view of the electromagnetic steel sheets of the rotor core according to the first embodiment.

[0050] Figure 6 It is a partial plan view of electromagnetic steel sheets of a rotor core according to a modification of the first embodiment.

[0051] Figure 7 It is a partial plan view of electromagnetic steel sheets of a rotor core according to a modification of the first embodiment.

[0052] Figure 8 It is a schematic diagram of a rotating electrical machine according to a second embodiment.

[0053] Figure 9 It is a perspective view of a rotor and a shaft of a rotating electrical machine according to a second embodiment.

[0054] Figure 10 It is an exploded perspective view of the rotor and the shaft according to the second embodiment.

[0055] Figure 11 This is a front view of the rotor and shaft according to the second embodiment.

[0056] Figure 12 yes Figure 11 Cross-sectional view at line AA.

[0057] Figure 13 It is a perspective view of a longitudinal section of a rotor and a shaft according to a second embodiment.

[0058] Figure 14 This is a perspective view of the rotor core and the shaft without the clamping portion and the cover member according to the second embodiment.

[0059] Figure 15 It is a perspective view of a longitudinal section of the rotor core and the shaft in a state without the clamping portion and the cover member according to the second embodiment.

[0060] Figure 16 This is a perspective view of a part of the rotor and shaft of the second embodiment in a cutaway state ( Figure 9 partial cutaway view).

[0061] Figure 17 This is a side view of the rotor and shaft of the second embodiment ( Figure 11 B-direction view).

[0062] Figure 18 It shows Figure 9 A three-dimensional view of an aluminum die-cast molded product.

[0063] Figure 19 This is a cross-sectional view of a rotor according to another example of the second embodiment. DETAILED DESCRIPTION

[0064] First embodiment

[0065] Below, refer to Figures 1 to 5 A first embodiment that embodies the rotor core will be described. In describing the rotor core of this embodiment, the configuration of a rotating electrical machine that employs the rotor core of this embodiment will be described first.

[0066] like Figure 1 As shown, the rotating electrical machine 10 is a permanent magnet embedded synchronous motor. The rotating electrical machine 10 includes a rotor 20 and a stator 100. The stator 100 is arranged so as to surround the outer circumference of the rotor 20. The inner circumferential surface of the stator 100 faces the outer circumferential surface of the rotor 20 with a gap therebetween. The figures are schematic diagrams, with shapes emphasized. The rotating electrical machine 10 has four poles, and the permanent magnets are arranged at 90° intervals in the circumferential direction.

[0067] The stator 100 has a stator core 101. The stator core 101 is cylindrical. A plurality of slots 102 are formed in the circumferential direction on the inner circumferential side of the stator core 101. Each slot 102 is open on the inner circumferential surface of the stator core 101. Teeth 103 are formed between the slots 102. Coils (windings) 104 are wound around the teeth 103. In this way, the stator 100 is configured such that the teeth 103 with the coils 104 wound around the inner circumferential side are arranged side by side in the circumferential direction and are wound with the coils 104. The rotor 20 is provided so as to form a gap between the rotor 20 and the inner circumferential surface of the stator core 101. The rotor 20 is configured so that the outer circumferential surface of the rotor core 21 is opposite to the inner circumferential side of the stator 100 with a gap therebetween.

[0068] like Figure 1 and Figure 2 As shown, the rotor 20 includes a cylindrical rotor core 21 and a shaft 50. The rotor 20 is rotatably supported by a bearing of a housing (not shown) via the shaft 50, with the outer circumferential surface of the rotor core 21 spaced a predetermined distance from the teeth 103. The shaft 50 is inserted through a through hole 21a extending through the center of the rotor core 21 and is shrink-fitted to the rotor core 21.

[0069] like Figure 2 As shown, the rotor core 21 includes a rotor core body 121. The rotor core body 121 is composed of a plurality (e.g., dozens) of substantially disk-shaped electromagnetic steel sheets 22 stacked in the axial direction extending along the axis m of the rotor core 21. Figure 2 The rotor core body 121 described is shown with a state where a plurality of electromagnetic steel sheets 22 are stacked.

[0070] Reference Figure 3 The structure of the rotor core body 121 will be described in detail. Figure 3 The structure of the electromagnetic steel sheet 22 is shown, but all of the plurality of electromagnetic steel sheets 22 have the same structure. Therefore, the structure of the electromagnetic steel sheet 22 can be regarded as the same as the structure of the rotor core body 121, so refer to Figure 3 The structure of the rotor core body 121 will be described.

[0071] like Figure 3 As shown, when the rotor core body 121 is viewed in the axial direction, it has four magnetic pole regions R in the circumferential direction, matching the number of poles of the rotating electrical machine 10. Each of the four magnetic pole regions R has a central angle of 90° about the axis m of the rotor core 21. In the rotor core body 121, a plurality of permanent magnet insertion holes 122 are formed in the radial direction about the axis m of the rotor core 21 in each of the four magnetic pole regions R. In the first embodiment, the rotor core body 121 has two layers of permanent magnet insertion holes 122 formed radially on the inner and outer diameter sides of each of the four magnetic pole regions R. The permanent magnet insertion holes 122 extend axially through the rotor core body 121. In other words, the permanent magnet insertion holes 122 are formed by axially connecting the permanent magnet insertion holes 122 formed in all of the plurality of electromagnetic steel sheets 22. The permanent magnet insertion hole 122 has an arc shape that extends toward the adjacent magnetic pole region R while moving away from the axis m of the rotor core 21. The permanent magnet insertion hole 122 has an arc shape that is convex toward the center of the rotor core 21 (centered on the outer diameter of the rotor core 21). Permanent magnets 90 are inserted into the permanent magnet insertion hole 122 of the rotor core body 121. The permanent magnets 90 have an arc shape that matches the shape of the permanent magnet insertion hole 122. The permanent magnets 90 are inserted into the permanent magnet insertion hole 122 so that the magnetic poles located radially outward of the rotor core 21 in adjacent magnetic pole regions R are different. For example, if the permanent magnet 90 in one of the four magnetic pole regions R is inserted into the permanent magnet insertion hole 122 with the south pole radially outward of the rotor core 21, the permanent magnet 90 in the adjacent magnetic pole region R is inserted into the permanent magnet insertion hole 122 with the north pole radially outward of the rotor core 21. Therefore, among the four magnetic pole regions R of the rotor core body 121 , adjacent magnetic pole regions R have different magnetic poles.

[0072] like Figure 5 As shown in FIG. 1 , a flux barrier 123 is formed at both ends of the permanent magnet insertion hole 122 of the rotor core body 121. The flux barrier 123 is adjacent to the permanent magnet insertion hole 122 and extends along the q-axis magnetic path. The q-axis magnetic flux of the permanent magnet 90 is as shown in FIG. Figure 6 The diagram extends along the direction in which the permanent magnet 90 is bent.

[0073] The magnetic flux barrier 123 extends in the axial direction. The magnetic flux barrier 123 axially penetrates the rotor core body 121. The magnetic flux barrier 123 located on the innermost radial side of the rotor core 21 is referred to as the innermost magnetic flux barrier 124. When the rotor core body 121 is viewed in the axial direction, the innermost magnetic flux barrier 124 has an arc shape that extends away from the axis m of the rotor core 21. Furthermore, the innermost magnetic flux barrier 124 extends to near the outer periphery of the rotor core 21.

[0074] The innermost flux barrier 124 has a first inner surface S1 located radially inward of the innermost flux barrier 124 and a second inner surface S2 located radially outward of the innermost flux barrier 124. The first inner surface S1 is the inner surface of the innermost flux barrier 124 that is closer to the axis m of the rotor core 21. Furthermore, the second inner surface S2 is the inner surface of the innermost flux barrier 124 that is farther from the axis m of the rotor core 21. The rotor core body 121 has a bridge 150 that connects the first inner surface S1 and the second inner surface S2. The bridge 150 is provided axially along the entire length of the rotor core body 121. In other words, the bridge 150 is formed by axially overlapping the bridges 150 formed on all of the plurality of electromagnetic steel sheets 22. The bridge 150 is made of the same material as the electromagnetic steel sheets 22. Therefore, if the bridge 150 is positioned too close to the permanent magnets 90, or if the bridge 150 is too wide, the magnetic flux of the permanent magnets 90 may leak from the bridge 150, potentially reducing the magnetic flux effective for torque when the rotor core 21 is used in the rotating electric machine 10. Therefore, when designing the rotor core 21, the bridge 150 is provided after confirming in advance the position and width at which the magnetic flux effective for torque of the permanent magnets 90 will not be reduced.

[0075] The innermost magnetic flux barrier 124 includes a radially outer closed space 124a, which defines the space between the bridge 150 and the outer edge of the rotor core body 121. Like the magnetic flux barrier 123, the radially outer closed space 124a axially penetrates the rotor core body 121. Furthermore, the innermost magnetic flux barrier 124 includes a radially inner closed space 124b, which defines the space between the permanent magnets 90 and the bridge 150. Like the magnetic flux barrier 123, the radially inner closed space 124b axially penetrates the rotor core body 121.

[0076] The outer diameter side closed space 124a is filled with a reinforcement portion 160 made of a non-magnetic metal. The reinforcement portion 160 is filled over the entire length of the rotor core body 121 in the axial direction. The reinforcement portion 160 is made of aluminum.

[0077] like Figure 2As shown, the rotor core 21 includes a cover member 70 stacked axially on the rotor core body 121. The cover member 70 is stacked axially on both ends of the rotor core body 121. The cover member 70 is arranged at both axial ends of the stacked electromagnetic steel sheets 22. The cover member 70 is made of electromagnetic steel sheets.

[0078] like Figure 4 As shown, the outer shape of the cover member 70 is the same as that of the electromagnetic steel sheet 22. The cover member 70 includes a cover hole 71 and a cover portion 72. The cover hole 71 has the same shape as the outer diameter-side enclosed space 124a. The cover hole 71 is axially located at the same position as the outer diameter-side enclosed space 124a of the rotor core body 121 and extends through the thickness of the cover member 70. That is, when the cover member 70 is stacked on the rotor core body 121, the cover hole 71 communicates with the outer diameter-side enclosed space 124a. A reinforcement portion 160 is inserted into the cover hole 71 to fill the outer diameter-side enclosed space 124a. When the cover member 70 is stacked on the rotor core body 121, the cover portion 72 covers the permanent magnets 90 to the bridges 150 in the permanent magnet insertion holes 122 located on the radially innermost side of the rotor core 21. Furthermore, the cover portion 72 covers the permanent magnet insertion holes 122 located radially outward of the innermost permanent magnet insertion holes 122. The cover portion 72 refers to the entire plate-like portion of the cover member 70 excluding the cover hole 71 and the hole for inserting the shaft 50. Specifically, the cover member 70 is a member in which the cover hole 71 is formed only at the position corresponding to the outermost diameter closed space 124a, the portion of the innermost diameter closed space 124b and the permanent magnet 90, and the portion corresponding to the inner diameter closed space 124a.

[0079] like Figure 2 As shown, the rotor core 21 has a clamping portion 80 that clamps the rotor core body 121 from both sides in the axial direction. The clamping portion 80 clamps the rotor core body 121 and the cover member 70 in the axial direction. The clamping portion 80 and the reinforcement portion 160 (by Figure 2 That is, clamping portion 80 is made of aluminum and is provided integrally with reinforcing portion 160, thereby having the function of preventing the plurality of electromagnetic steel sheets constituting rotor core body 121 and cover member 70 from being separated in the axial direction.

[0080] Here, the rotor core 21 of the first embodiment is formed by aluminum die casting. A method for forming the rotor core 21 will be described below.

[0081] With permanent magnets 90 inserted into the permanent magnet insertion holes 122 of the rotor core body 121, the cover members 70 are axially stacked on both ends of the rotor core body 121 to form an assembly. This assembly is housed in a mold, and molten aluminum is poured into the mold. The aluminum poured into the mold fills the cover holes 71 of the cover member 70 and the outer diameter side closed space 124a of the rotor core body 121. The mold is provided with an internal space for forming the clamping portion 80 for forming the rotor core 21. Therefore, when the aluminum poured into the mold is sufficiently cooled and the mold is removed, the reinforcement portion 160 is formed in the cover holes 71 of the cover member 70 of the assembly and the outer diameter side closed space 124a of the rotor core body 121, and the clamping portion 80 provided integrally with the reinforcement portion 160 is formed. Thus, the rotor core 21 is formed.

[0082] The operation of the first embodiment will be described.

[0083] Strictly speaking, the electromagnetic steel sheets 22 that comprise the rotor core 21 exhibit slight undulations. This is true, as the rotor core 21 and shaft 50 are press-fitted together, and the electromagnetic steel sheets 22 are susceptible to outward bending deformation. When the rotor core 21 is installed in the rotating electrical machine 10 and rotated in this state, centrifugal force is generated within the rotor core 21. This generates bending stress in the thin-walled portion of the rotor core 21 formed between the extended tip of the innermost magnetic flux barrier 124 and the outer edge of the rotor core 21, generating forces that cause the electromagnetic steel sheets 22 of the rotor core 21 to curl. However, in the aforementioned rotor core 21, the bending stress generated in the thin-walled portion of the rotor core 21 is mitigated by the reinforcement 160 and bridge 150 embedded in the outer diameter-side enclosed space 124a and the cover hole 71 of the cover member 70. Furthermore, the multiple electromagnetic steel sheets 22 and the cover member 70 are axially clamped by a clamping portion 80 formed by aluminum die casting, further preventing curling. Thus, the rotor core 21 maintains strength through the bridge 150 and the reinforcement portion 160 , and the strength of the rotor core 21 is further improved by forming the clamping portion 80 integrally provided with the reinforcement portion 160 .

[0084] The effects of the first embodiment will be described.

[0085] (1) In the first embodiment, the strength of the rotor core 21 is maintained by the reinforcement portion 160 embedded in the outer diameter side closed space 124a of the rotor core 21. Furthermore, since the strength of the rotor core 21 is maintained by the bridge 150 and the reinforcement portion 160, the wall thickness of the rotor core 21 at the extended tip of the innermost magnetic flux barrier 124 can be reduced, making it easier to suppress leakage magnetic flux. Therefore, it is possible to easily suppress leakage magnetic flux and maintain the strength of the rotor core 21.

[0086] (2) In the first embodiment, the inner diameter side enclosed space 124b of the rotor core 21 functions as a heat insulating layer. Therefore, even when molten aluminum is poured into the outer diameter side enclosed space 124a of the rotor core body 121, the influence of heat on the permanent magnets 90 inserted into the permanent magnet insertion holes 122 of the rotor core 21 can be suppressed.

[0087] (3) In the first embodiment, when molten aluminum is poured into the outer diameter-side enclosed space 124a of the rotor core 21, the molten aluminum does not adhere to the permanent magnets 90 due to the cover portion 72 of the cover member 70, but is poured only into the cover hole 71 and the outer diameter-side enclosed space 124a. Therefore, the influence of heat on the permanent magnets 90 inserted into the permanent magnet insertion holes 122 of the rotor core 21 can be suppressed.

[0088] (4) In the first embodiment, the plurality of electromagnetic steel sheets 22 can be fixed so as not to separate in the axial direction by the clamping portion 80 provided integrally with the reinforcing portion 160. Therefore, the plurality of electromagnetic steel sheets 22 can be appropriately fixed without preparing fixing members such as screws for fixing the plurality of electromagnetic steel sheets 22.

[0089] (5) In the first embodiment, the reinforcement portion 160 is made of aluminum. Aluminum is lightweight, and thus can suppress the centrifugal force generated in the reinforcement portion 160 by the rotation of the rotor core 21. Therefore, the strength of the rotor core 21 can be more easily maintained.

[0090] (6) The shaft 50 is shrink-fitted into the through-hole 21a of the rotor core 21. When the shaft 50 is shrink-fitted into the rotor core 21, a fitting force is generated between the electromagnetic steel sheet 22 and the cover member 70, and the electromagnetic steel sheet 22 and the cover member 70 may be twisted in the axial direction by being compressed and curled.

[0091] In this regard, in the first embodiment, the torsional force generated in all of the electromagnetic steel sheets 22 and the cover member 70 is mitigated by the reinforcement 160. Therefore, the torsional force of the electromagnetic steel sheets 22 and the cover member 70 can be suppressed.

[0092] (7) Providing the bridge 150 on the rotor core body 121 improves the strength balance of the rotor core 21 when cut along a plane perpendicular to the axis m of the rotor core 21. In other words, the strength of the rotor core 21 against external forces in the radial direction of the rotor core 21 can be improved.

[0093] (8) Even when the sizes of the permanent magnets 90 inserted into the permanent magnet insertion holes 122 located on the outermost diameter side and the permanent magnet insertion holes 122 located on the innermost diameter side of the rotor core 21 are different, the bridge 150 can improve the balance of the strength of the rotor core 21.

[0094] (9) In the first embodiment, the cover member 70 is formed of electromagnetic steel sheets. Therefore, the cover member 70 can be manufactured by partially changing the processing steps of the electromagnetic steel sheets 22 constituting the rotor core body 121. This reduces the manufacturing cost of the rotor core 21.

[0095] (10) In the first embodiment, the reinforcing portion 160 and the clamping portion 80 are formed by aluminum die casting. Therefore, the plurality of electromagnetic steel sheets 22 can be appropriately fixed without preparing fixing members such as screws, and the manufacturing cost of the rotor core 21 can be reduced.

[0096] Furthermore, the first embodiment can be implemented with the following modifications: The first embodiment and the following modifications can be implemented in combination with each other within a range that does not technically conflict.

[0097] The innermost flux barrier 124 of the first embodiment may be modified as follows.

[0098] like Figure 6 and Figure 7 As shown, the first inner surface S1 may also have a protruding portion 110, and the protruding portion 110 is formed by extending the inner surface located on the radial inner side in the permanent magnet insertion hole 122, which is in contact with the permanent magnet 90, in the direction along the q-axis magnetic circuit (the imaginary inner surface C). Figure 6 In other words, the first inner surface S1 may extend further toward the adjacent magnetic pole region R than the position along the q-axis magnetic path. Figure 6 More specifically, the first inner surface S1 of the outer diameter side closed space 124a extends further toward the adjacent magnetic pole region R than the position along the q-axis magnetic path. Specifically, the protruding portion 110 is provided on the inner surface of the outer diameter side closed space 124a of the innermost magnetic flux barrier 124, which is located radially inward. Figure 7 In more detail, the extension portion 110 is provided on the inner surface of the inner diameter side closed space 124b of the innermost magnetic flux barrier 124, which is located radially inward. Figure 6 and Figure 7 In the illustrated modifications, the protruding portion 110 protrudes to a degree sufficient to ensure a width of the magnetic path passing between adjacent magnetic pole regions R.

[0099] By making such a change, the width of the innermost flux barrier 124 in the d-axis magnetic circuit becomes wider, which can hinder the d-axis magnetic flux. As a result, the d-axis inductance is reduced, which can increase the magnetic resistance torque. In addition, the self-short-circuiting magnetic flux of the permanent magnet 90 can be reduced. Therefore, the magnetic flux effective for the torque of the permanent magnet 90 can be more appropriately transmitted to the stator 100 located on the outer peripheral side of the rotor core 21. Furthermore, the performance of the rotating electrical machine 10 can be improved. In addition, the extension portion 110 of this modified example can also be provided on the inner surface of the radially inner side of the outer diameter side closed space 124a of the innermost flux barrier 124.

[0100] The magnetic flux barrier 123 does not necessarily need to penetrate the rotor core body 121 in the axial direction.

[0101] The reinforcement portion 160 is provided over the entire axial length of the rotor core body 121 , but is not limited thereto and may be provided in a portion of the axial length inside the outer diameter side closed space 124 a of the rotor core body 121 .

[0102] The reinforcement portion 160 is made of aluminum, but is not limited thereto. For example, it may be made of brass. In other words, the reinforcement portion 160 is preferably made of a non-magnetic metal. Alternatively, it may be made of resin.

[0103] In the first embodiment, the clamping portion 80 may be omitted. Even with such a change, the aluminum constituting the reinforcing portion 160 enters between the electromagnetic steel sheets 22 and the cover member 70 , thereby suppressing separation of the electromagnetic steel sheets 22 and the cover member 70 in the axial direction.

[0104] In the first embodiment, the rotor core body 121 is composed of a plurality of electromagnetic steel sheets 22, but this is not limiting. For example, the rotor core body 121 may be composed of a single cylindrical member. Alternatively, the rotor core body 121 may be composed of a single electromagnetic steel sheet 22. However, in such a case, the thickness of the electromagnetic steel sheet 22 is preferably increased to a level sufficient to accommodate the insertion of the permanent magnets 90.

[0105] In the first embodiment and the above-described modified examples, the reinforcement 160 is made of non-magnetic metal. However, the reinforcement 160 only needs to be made of a non-magnetic material, and the material of the non-magnetic material may be appropriately changed if the strength of the rotor core 21 can be increased.

[0106] The cover hole 71 does not need to have the same shape as the outer diameter side closed space 124a.

[0107] The rotor core 21 may be composed of the rotor core body 121 and the reinforcement portion 160 , and the cover member 70 may be omitted.

[0108] The innermost magnetic flux barrier 124 may be formed only of the outer diameter side closed space 124a and the inner diameter side closed space 124b may be omitted. In such a case, the permanent magnet 90 inserted into the permanent magnet insertion hole 122 may be formed of a material having high thermal resistance.

[0109] - In the radial direction of the rotor core 21, the permanent magnet insertion holes 122 are provided in two layers, but the present invention is not limited thereto. For example, the permanent magnet insertion holes 122 may be provided in three or more layers.

[0110] The number of poles of the rotating electrical machine 10 is "4", but is not limited to this. The number of poles may be changed as appropriate. When such a change is made, it is preferable that the magnetic pole region R of the rotor core 21 is also changed as appropriate according to the number of poles.

[0111] Second embodiment

[0112] Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

[0113] like Figure 8 As shown, the rotating electrical machine 10 is a permanent magnet embedded synchronous motor comprising a rotor 20 and a stator 100. Stator 100 is arranged on the outer circumference of the cylindrical rotor 20. The inner circumference of stator 100 faces the outer circumference of rotor 20 with a gap therebetween. The figures are schematic diagrams, emphasizing the shapes. The rotating electrical machine 10 has four poles, and the permanent magnets are arranged at 90° intervals in the circumferential direction.

[0114] like Figure 8 As shown, in stator 100, stator core 101 is cylindrical, with multiple slots 102 formed circumferentially on the inner circumference of stator core 101. Each slot 102 opens on the inner circumference of stator core 101. Teeth 103 are formed between slots 102. Coils (windings) 104 are wound around teeth 103. Thus, stator 100 has a configuration in which teeth 103, with coils 104 wound around the inner circumference, are arranged side by side in the circumferential direction and are wound with coils 104.

[0115] The rotor 20 is arranged inside the stator 100. The rotor 20 includes a cylindrical rotor core 21 formed by laminating a plurality (e.g., several dozen) of substantially disk-shaped electromagnetic steel sheets 22. All of the electromagnetic steel sheets 22 have the same structure. Figure 14 In the rotor 20 described, a state where a plurality of electromagnetic steel sheets 22 are stacked is omitted. In the rotor core 21, the stacked electromagnetic steel sheets 22 are connected by pin rivets. Figure 9 As shown, the rotor 20 has: cover members 23a, 23b, which are arranged at both axial ends of the stacked electromagnetic steel sheets 22; and clamping parts 24a, 24b formed by aluminum die casting, which are arranged on the axial outside of the cover members 23a, 23b in a manner of sandwiching the stacked electromagnetic steel sheets 22.

[0116] like Figure 8 As shown, the rotor 20 is rotatably supported by bearings of a housing (not shown) via a shaft 50, with the outer circumferential surface of the rotor core 21 spaced a predetermined distance from the teeth 103. Thus, the rotor 20 is arranged such that the outer circumferential surface of the rotor core 21 faces the inner circumferential side of the stator 100 with a gap therebetween.

[0117] like Figure 9 、 Figure 11 、 Figure 14 As shown in FIG. 1 , a shaft 50 is inserted through the center of a rotor core 21 formed by stacking electromagnetic steel sheets 22. The rotor core 21 is fitted and fastened to the shaft 50 by shrink fitting (or press fitting, etc.). Figure 12 As shown, the rotor core 21 has an outer diameter side permanent magnet insertion hole 25 , an inner diameter side permanent magnet insertion hole 26 , flux barriers 29 , 30 , 37 , 38 , and die-cast holes 31 , 33 , 35 .

[0118] like Figure 12 、 Figure 14 、 Figure 15 As shown, the rotor core 21 is formed with: an outer diameter side permanent magnet insertion hole 25 extending in the axial direction and arranged radially outward; and an inner diameter side permanent magnet insertion hole 26 extending in the axial direction and arranged radially inward relative to the outer diameter side permanent magnet insertion hole 25 for each magnetic pole. The outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 of each magnetic pole are arc-shaped. In detail, as shown in FIG. Figure 12 As shown, the outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 are arc-shaped with the center side of the rotor core 21 being convex (centered on the outer diameter side of the rotor core 21 ).

[0119] like Figure 13 As shown, outer diameter side permanent magnet 27 is inserted into outer diameter side permanent magnet insertion hole 25, and inner diameter side permanent magnet 28 is inserted into inner diameter side permanent magnet insertion hole 26. Outer diameter side permanent magnet 27 is bonded and fixed to outer diameter side permanent magnet insertion hole 25. Inner diameter side permanent magnet 28 is bonded and fixed to inner diameter side permanent magnet insertion hole 26.

[0120] like Figure 13 As shown, the outer diameter side permanent magnet 27 is arranged in a state of being divided in the axial direction. The inner diameter side permanent magnet 28 is arranged in a state of being divided in the axial direction. By using the permanent magnets divided in the axial direction, it is possible to reduce losses and improve economic efficiency.

[0121] like Figure 12 As shown, the inserted permanent magnets 27 and 28 are arc-shaped. In each magnetic pole, the outer diameter side permanent magnet 27 is located on the d-axis and is magnetized in the thickness direction. In each magnetic pole, the inner diameter side permanent magnet 28 is located on the d-axis and is magnetized in the thickness direction. The outer diameter side permanent magnets 27 and the inner diameter side permanent magnets 28 arranged in adjacent magnetic pole areas (one pole) are arranged so that the outer circumferential side of the rotor 20 has different poles. For example, when a certain outer diameter side permanent magnet 27 is arranged so that the tooth 103 side is the south pole, the outer diameter side permanent magnet 27 arranged in the adjacent magnetic pole area (one pole) is arranged so that the tooth 103 side is the north pole.

[0122] like Figure 12 、 Figure 14 As shown, a flux barrier 29 is formed continuously on one circumferential outer side of the inner diameter side permanent magnet insertion hole 26 of the rotor core 21. Furthermore, a flux barrier 30 is formed continuously on the other circumferential outer side of the inner diameter side permanent magnet insertion hole 26 of the rotor core 21. Magnetic flux barriers 29 and 30 are arc-shaped. A flux barrier 37 is formed continuously on one circumferential outer side of the outer diameter side permanent magnet insertion hole 25 of the rotor core 21. Furthermore, a flux barrier 38 is formed continuously on the other circumferential outer side of the outer diameter side permanent magnet insertion hole 25 of the rotor core 21. Magnetic flux barriers 37 and 38 are arc-shaped.

[0123] In the rotor core 21, a die-cast hole 31 is formed as a filling hole extending in the axial direction in the area between adjacent magnetic poles and sandwiched between the flux barriers 29 and 30. The die-cast hole 31 is filled with pure aluminum 32 as a non-magnetic metal. The electromagnetic steel sheet 22 is fixed by the pure aluminum 32 filled in the die-cast hole 31. The pure aluminum 32 filled in the die-cast hole 31 is fixed from the Figure 14 、 Figure 15 The status shown is Figure 11 、 Figure 12 、 Figure 13 As shown, it is formed by aluminum die casting. Figure 16 、 Figure 17 、 Figure 18 As shown, the rod-shaped portion 39 is formed of pure aluminum 32 filled in the die-cast hole 31 .

[0124] In each magnetic pole of the rotor core 21, a die-cast hole 33 is formed as a filling hole extending in the axial direction at a distance from the circumferential outside of the flux barrier 29. In addition, in each magnetic pole of the rotor core 21, a die-cast hole 35 is formed as a filling hole extending in the axial direction at a distance from the circumferential outside of the flux barrier 30. The die-cast hole 33 is filled with pure aluminum 34 as a non-magnetic metal. The die-cast hole 35 is filled with pure aluminum 36 as a non-magnetic metal. The electromagnetic steel sheet 22 is fixed by the pure aluminum 34, 36 filled in the die-cast holes 33, 35. The pure aluminum 34, 36 filled in the die-cast holes 33, 35 is fixed from Figure 14 、 Figure 15 The status shown is Figure 11 、 Figure 12 、 Figure 13 As shown, it is formed by aluminum die casting. Figure 16 、 Figure 17 、 Figure 18 As shown, the rod-shaped portion 40 is formed of pure aluminum 34 filled into the die-casting hole 33 , and the rod-shaped portion 41 is formed of pure aluminum 36 filled into the die-casting hole 35 .

[0125] like Figure 11 、 Figure 13As shown, the rotor core 21 has clamping parts 24a and 24b on both sides of the rotor core 21 in the axial direction. The clamping parts 24a and 24b are made of pure aluminum. Figure 14 、 Figure 15 The status shown is Figure 11 、 Figure 13 As shown, it is formed by aluminum die casting. Figure 16 、 Figure 17 、 Figure 18 As shown, the rotor core 21 has two axial end surfaces integrally formed with clamping portions 24a and 24b made of pure aluminum. Figure 14 、 Figure 15 The status shown is Figure 11 、 Figure 13 As shown, it is formed by aluminum die casting.

[0126] like Figure 16 、 Figure 17 、 Figure 18 As shown, the clamping parts 24a and 24b have a thick wall part 42 connected to the rod-shaped part 39 made of pure aluminum 32 filled in the die-cast hole 31, and a thin wall part 43 formed at multiple locations in the circumferential direction. Figure 17 In the embodiment, thin-walled portions 43 are formed at a total of eight locations at intervals of 45° in the circumferential direction. Each thin-walled portion 43 is formed by the bottom surface of a semicircular notch opened on the outer circumference of the clamping portions 24a, 24b. A pin 44 for achieving rotational balance is integrally formed in the central portion of the thin-walled portion 43 in a manner protruding axially outward. The pin 44 is cylindrical. By inserting an annular washer Wa (see FIG. 1 ) of a desired thickness as a balancing weight into the pin 44, the rotational balance is achieved. Figure 9 ), and the portion of the pin 44 that protrudes outward from the washer Wa is pressed and deformed to fix the washer Wa.

[0127] In addition, regarding the relationship between the number of poles and the number of pins 44 (the number of thin-walled portions 43 ), 4 poles and 8 pins are used, but 4 poles and 12 pins may be used, for example.

[0128] like Figure 9 、 Figure 10 、 Figure 11 、 Figure 13 As shown, between the electromagnetic steel sheet 22 formed with the permanent magnet insertion holes 25, 26 and the die-cast holes 31, 33, 35 and the clamping parts 24a, 24b of the rotor core 21, cover members 23a, 23b are arranged. They do not have the outer diameter side permanent magnet insertion holes 25 and the inner diameter side permanent magnet insertion holes 26, but only have the die-cast holes 31, 33, 35. The cover members 23a, 23b have the same outer diameter as the electromagnetic steel sheet 22. Figure 14 、 Figure 15 The status shown is Figure 11 、 Figure 12 、 Figure 13As shown, aluminum is injected into the die casting holes 31 , 33 , 35 by aluminum die casting.

[0129] Next, the operation of the rotating electrical machine 10 according to the second embodiment configured as described above will be described.

[0130] When the rotating electrical machine is driven, current is supplied to coils 104 of stator 100, generating a rotating magnetic field in stator 100. The rotating magnetic field acts on rotor 20. Due to the magnetic attraction and repulsion between the rotating magnetic field and permanent magnets 27 and 28, rotor 20 rotates synchronously with the rotating magnetic field.

[0131] In the rotor core 21, die-cast holes 31 extend axially within the region sandwiched between adjacent magnetic poles by flux barriers 29 and 30. The electromagnetic steel sheets 22 are secured by pure aluminum 32 filling these die-cast holes 31. This securely secures the electromagnetic steel sheets 22 that comprise the rotor core 21, suppressing warping of the electromagnetic steel sheets 22. Specifically, within the generally inverted arc-shaped cross-section of the double-layered magnet rotor, by arranging die-cast holes between the magnetic poles, sandwiched by flux barriers and without the influence of shrink-fit tightening forces, a rotor structure that achieves both performance and strength is achieved.

[0132] The clamping parts 24a and 24b are reinforced at the connection between the thick-walled portion 42 and the rod-shaped portion 39 made of pure aluminum 32 filling the die-cast holes 31, thereby firmly securing the electromagnetic steel sheet 22. Pins 44 for achieving rotational balance are provided axially outwardly in the thin-walled portions 43 formed at multiple locations in the clamping parts 24a and 24b, facilitating rotational balance. This connection between the thick-walled portion 42 of the clamping parts 24a and 24b and the rod-shaped portion 39 made of pure aluminum 32 filling the die-cast holes 31 improves the connection strength of the rod-shaped portion 39. Furthermore, the pins 44 for achieving rotational balance protruding axially outwardly in the thin-walled portion 43 of the clamping parts 24a and 24b ensure rotational balance of the rotor.

[0133] The following describes this in detail.

[0134] The length of the permanent magnet insertion hole on the inner diameter side tends to increase, and the balance between performance and strength is not sufficient. Specifically, the electromagnetic steel sheet tends to warp due to centrifugal force, and when bending stress is applied to the thin-walled bridge portion, the strength is greatly reduced. In this case, if a non-magnetic end plate with thickness is added to the rotor end to take measures to improve the strength of the rotor core, it will lead to increased costs. In other words, when two layers of permanent magnets are arranged on the outer diameter side and the inner diameter side, the internal stress caused by the shrinkage of the shaft will cause warping in the right-angle direction of the cross section, resulting in a reduction in the fitting and fastening force between the rotor core and the shaft. In the case of arranging a rigid end plate fixed to the rotor end face to suppress this warping, the manufacturing cost will increase due to the increased cost caused by the rigid end plate and its fixing device (screws, rivets, etc.).

[0135] In the second embodiment, die-casting technology and equipment are used, provided that induction motor manufacturing equipment is available. If induction motor manufacturing equipment is already available, the aluminum die-cast fixture minimizes new equipment investment, resulting in a cost-effective structure. Furthermore, die-cast fixtures eliminate the need for rigid end plates and end plate fixtures, reducing component costs.

[0136] Generally, aluminum die casting uses a high-strength material such as ADC12, but in order to be inexpensive without requiring additional equipment investment, it is made of pure aluminum, which is the same material used in the manufacture of induction motors.

[0137] Here, when using pure aluminum to improve the rigidity of the rotor structure, the arrangement of the die-cast holes connecting the cross section of the rotor core is important. Although it is a synchronous motor, due to the alternating magnetic field from the stator, if the die-cast holes are arranged in an inappropriate position, the output may be reduced due to the generation of induced current, which may have an adverse effect on performance. Therefore, the impact of arranging the die-cast holes closer to the outer periphery of the rotor core cross section needs to be carefully studied. In addition, in order to reduce costs, the rotor core and the shaft are fixed by heat-fitting. When the die-cast holes are arranged on the inner circumference, there may be an adverse effect on strength such as a reduction in the heat-fitting fastening force. That is, in the rotor of an electric motor with permanent magnets inserted in the rotor core, the vicinity of the permanent magnets becomes a magnetic path, so die-cast holes cannot be formed. In addition, the inner diameter side of the rotor core is the area used for heat-fitting, so die-cast holes cannot be formed.

[0138] In the second embodiment, die-cast holes 31 are formed in the area between adjacent magnetic poles, sandwiched between flux barriers 29 and 30, which are located closer to the inner diameter between the magnetic poles. This prevents interference with the q-axis magnetic flux that constitutes the rotor core's magnetic circuit and prevents the shrink-fit fastening strength of the inner diameter shaft. The die-cast holes are preferably formed in a location that does not interfere with the q-axis magnetic circuit between the magnetic poles, that is, a location where the magnetic flux density on the rotor core is not high. The die-cast holes are preferably formed in a location between the left and right branches of the q-axis magnetic flux traveling from the outer diameter to the inner diameter. This ensures that the q-axis magnetic flux of the rotor core is not obstructed, and that the shrink-fitting strength of the inner diameter shaft is not hindered.

[0139] This ensures sufficient strength in the fastening between the rotor and the shaft, even when shrink-fitting the shaft to the rotor core. When manufacturing rotor 20, electromagnetic steel sheets 22 are stacked and one cover member 23a is laminated onto one end face of the stack. Permanent magnets 27 and 28 are then inserted, and the other cover member 23b is positioned. This is then secured by caulking, using pure aluminum 32, 34, and 36 within die-cast holes 31, 33, and 35 for die-casting.

[0140] Therefore, the electromagnetic steel sheet is likely to warp due to shrinkage during manufacturing and is also likely to warp due to centrifugal force when the rotation speed is increased during normal operation. However, the second embodiment can suppress the warping of the electromagnetic steel sheet.

[0141] Furthermore, the pin 44 is formed by thickening the areas where strength is required in the clamping parts 24a and 24b and thinning the areas where strength is not required as much. The clamping parts 24a and 24b and the pin 44 are formed by die-casting of pure aluminum equivalent to that used in induction motors. In this case, the thinned areas of the clamping parts 24a and 24b form the thin-walled portion 43, but the pin 44 is positioned in the thin-walled portion 43 to avoid the rod-shaped portion 39 made of aluminum die-cast and penetrating in the axial direction. In this case, the manufacturing equipment of the induction motor can be used, and the rotor structure can be made inexpensive while achieving a thinner axial length ( Figure 11 ΔL) of this degree of miniaturization.

[0142] Regarding the positional relationship between the rod-shaped portion 39 and the thin-walled portion 43 formed by aluminum die-casting, the configuration of the die-casting hole needs to be optimized from the perspective of strength and performance. Therefore, the rod-shaped portion 39 arranged in the die-casting hole 31 is connected to the thick-walled portion 42 of the clamping portions 24a and 24b arranged on both sides of the axial direction to firmly fix the rotor core 21.

[0143] Moreover, the clamping portions 24a and 24b have both the function of serving as strength portions for suppressing warping of the rotor core and the function of achieving rotational balance of the rotor. The die-cast structure is made of pure aluminum so that the existing manufacturing line of the induction motor can be used. Therefore, by riveting the washer Wa to the pin 44 formed in the clamping portions 24a and 24b, the rotational balance of the rotor can be achieved inexpensively.

[0144] However, during high-speed rotation of the rotor, hoop stress is distributed in the clamping portions 24a, 24b, concentrating stress at the connection between the clamping portions 24a, 24b and the rod-shaped portion 39, particularly at the inner corners. Therefore, to mitigate this stress, the wall thickness of the connection must ensure a certain degree of strength. Although the cover members 23a, 23b are positioned at the connection between the clamping portions 24a, 24b and the rod-shaped portion 39, they lack permanent magnet insertion holes, resulting in a superior strength compared to electromagnetic steel sheets with permanent magnet insertion holes. Furthermore, the cover members 23a, 23b constructed from electromagnetic steel sheets can be manufactured simultaneously and inexpensively by switching the blades of the electromagnetic steel sheet stamping die. Therefore, the placement of the cover members 23a, 23b at the connection between the clamping portions 24a, 24b and the rod-shaped portion 39 strengthens the connection. Furthermore, the cover members 23a and 23b also function to prevent pure aluminum from flowing into the permanent magnet insertion holes. Furthermore, the portions of the clamping portions 24a and 24b where the connecting portion of the rod-shaped portion 39 is not located can be made thinner. By making this thinner portion into which the pin 44 is located, it is possible to achieve both strength and miniaturization.

[0145] In addition, if Figure 17 As shown, a portion of the connection between the clamping portions 24a, 24b and the rod-shaped portions 40, 41 is located in the thin-walled portion 43, but this is because the rod-shaped portions 40, 41 are located on the outer peripheral side compared to the rod-shaped portion 39, and the circumferential stress is correspondingly reduced, and there is no problem with the strength of the portion where the thin-walled portion coincides with the connecting portion.

[0146] Thus, the rotor core 21 is provided with cover members 23a and 23b at both axial ends to enhance die-cast strength and protect the permanent magnets from the effects of the die-cast molten metal. Regarding the axial wall thickness of the clamping portions 24a and 24b, the portion where the die-cast holes 31 are located is thick, while the remaining portion is thin. Furthermore, a pin 44 for achieving rotational balance is located in the thin-walled portion 43. This method, by inserting a pure aluminum pin 44 into a washer and then compressing the pin protrusion (washer weighting method), provides a low-cost rotational balance correction method compared to the method of achieving rotational balance by drilling holes in a flat surface (weight reduction method). Furthermore, the arrangement of pins and thin-walled portions results in a compact and robust rotor with die-cast clamping portions 24a and 24b. Furthermore, by using high-strength cover members 23a and 23b (which lack permanent magnet insertion holes), the strength of the connection between the clamping portions 24a and 24b and the rod-shaped portion 39, where stress concentration occurs, is enhanced.

[0147] According to the second embodiment, the following effects can be obtained.

[0148] (1) The rotor 20 of the rotating electrical machine 10 is configured such that the outer circumferential surface of the cylindrical rotor core 21 faces the inner circumferential side of the stator 100 around which the coil 104 is wound. The rotor core 21 is formed by stacking electromagnetic steel sheets 22, with a shaft 50 inserted through the center. The rotor core 21 is provided with an outer diameter-side permanent magnet insertion hole 25 extending in the axial direction and located radially outward, and an inner diameter-side permanent magnet insertion hole 26 extending in the axial direction and located radially inward relative to the outer diameter-side permanent magnet insertion hole 25, for each magnetic pole. An outer diameter-side permanent magnet 27 is inserted into the outer diameter-side permanent magnet insertion hole 25, and an inner diameter-side permanent magnet 28 is inserted into the inner diameter-side permanent magnet insertion hole 26. Magnetic flux barriers 29 and 30 are formed continuously on the circumferential outside of the inner diameter-side permanent magnet insertion hole 26 of the rotor core 21. In the rotor core 21 , die-cast holes 31 are formed as filling holes extending in the axial direction in regions sandwiched between adjacent magnetic poles by the flux barriers 29 and 30 . The electromagnetic steel sheets 22 are fixed by pure aluminum 32 , which is a non-magnetic metal, filling the die-cast holes 31 .

[0149] Therefore, in the rotor core 21, the die-cast hole 31 extends axially in the area sandwiched by the flux barriers 29 and 30 between adjacent magnetic poles, and the electromagnetic steel sheet 22 is fixed by the pure aluminum 32 filled in the die-cast hole 31, so that the electromagnetic steel sheet 22 constituting the rotor core 21 can be firmly fixed and the warping of the electromagnetic steel sheet 22 constituting the rotor core 21 can be suppressed.

[0150] (2) Clamping portions 24a and 24b made of pure aluminum, a non-magnetic metal, are integrally formed on both axial end surfaces of the rotor core 21. Clamping portions 24a and 24b have thick-walled portions 42 connected to the pure aluminum rod-shaped portion 39 that fills the die-cast hole 31, and thin-walled portions 43 formed at multiple locations in the circumferential direction. Pins 44 for achieving rotational balance are integrally formed in the thin-walled portions 43 so as to protrude axially outward.

[0151] Therefore, the electromagnetic steel sheet 22 is fixed by the pure aluminum 32 filled in the die-cast holes 31 extending in the axial direction between adjacent magnetic poles in the rotor core 21. Since the thick-walled portion 42 of the clamping portion 24a, 24b made of pure aluminum is connected to the rod-shaped portion 39 made of pure aluminum filled in the die-cast hole 31, the connection strength of the rod-shaped portion 39 made of pure aluminum can be improved, so that the electromagnetic steel sheet 22 constituting the rotor core 21 can be firmly fixed. In addition, the pin 44 for achieving rotational balance is integrally formed in a manner protruding outward in the axial direction in the thin-walled portion 43 formed in multiple locations in the clamping portion 24a, 24b, so that the rotational balance can be easily achieved using the pin 44. In addition, the thin-walled portion 43 having the pin 44 extending in the axial direction can be miniaturized in the axial direction by an amount thinner than the thick-walled portion 42 ( Figure 11 of ΔL).

[0152] (3) Cover members 23a and 23b having only die-cast holes are arranged between the electromagnetic steel sheet 22 of the rotor core 21, which is formed with the permanent magnet insertion holes 25 and 26 and the die-cast holes 31 serving as filling holes, and the clamping portions 24a and 24b. This prevents pure aluminum filled in the die-cast holes from flowing into the permanent magnet insertion holes.

[0153] (4) The permanent magnet insertion holes include: an outer diameter side permanent magnet insertion hole 25 extending in the axial direction and arranged radially outward; and an inner diameter side permanent magnet insertion hole 26 extending in the axial direction and arranged radially inward relative to the outer diameter side permanent magnet insertion hole 25. An outer diameter side permanent magnet 27 is inserted into the outer diameter side permanent magnet insertion hole 25, and an inner diameter side permanent magnet 28 is inserted into the inner diameter side permanent magnet insertion hole 26. Magnetic flux barriers 29 and 30 are continuously formed circumferentially outward of the inner diameter side permanent magnet insertion hole 26 of the rotor core 21. The die-cast hole 31 is formed in the rotor core 21 so as to extend in the axial direction in a region sandwiched between adjacent magnetic poles between the magnetic flux barriers 29 and 30. This is preferable.

[0154] (5) The outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 of each magnetic pole are arc-shaped. This is particularly useful when the outer diameter side permanent magnet insertion hole 25 and the inner diameter side permanent magnet insertion hole 26 are arc-shaped.

[0155] (6) Die-cast holes 33 and 35, which serve as filling holes extending in the axial direction, are further formed within each magnetic pole of the rotor core 21 at a distance from the circumferential outside of the flux barriers 29 and 30. The electromagnetic steel sheets 22 are secured by pure aluminum 34 and 36, which serve as a non-magnetic metal, filled into the die-cast holes 33 and 35. In this case, the electromagnetic steel sheets 22 constituting the rotor core 21 can be more firmly secured, thereby further suppressing warping of the electromagnetic steel sheets 22 constituting the rotor core 21.

[0156] The second embodiment is not limited to the above-mentioned embodiment, and can be implemented with the following modifications: The second embodiment and the following modifications can be implemented in combination with each other within a range that does not technically conflict.

[0157] The non-magnetic metal is pure aluminum, but is not limited to this. Other non-magnetic metals include aluminum alloys such as ADC12 and copper. In addition to non-magnetic metals, resins can also be used, and resin molding can be used to form the structure.

[0158] Specifically, by configuring the die-cast holes 31 as resin mold holes and the pure aluminum 32 as resin, an axially extending filling hole is formed in the region of the rotor core 21 between adjacent magnetic poles, sandwiched between the flux barriers 29 and 30. The electromagnetic steel sheet 22 is secured by the resin filled in this filling hole. Furthermore, by configuring the die-cast holes 33 and 35 as resin mold holes and configuring the pure aluminum 34 and 36 as resin, an axially extending filling hole is further formed within each magnetic pole of the rotor core 21, spaced circumferentially outside the flux barriers 29 and 30. The electromagnetic steel sheet 22 is secured by the resin filled in this filling hole.

[0159] - It is also possible to have no die-cast holes 33, 35, for example, they can be replaced by flux barriers. Specifically, if Figure 12 of Figure 19 As shown, if there is no influence on the strength, by eliminating the die-cast holes 33 and 35, a flux barrier 60 and 61 extending continuously from the permanent magnet insertion hole 26 is formed, so that a bridge-less structure can be achieved. Since the design is carried out in the direction of improving performance, there are no rod-shaped parts 40 and 41, so that the thin-walled parts of the clamping parts 24a and 24b can be further expanded and the amount of aluminum can also be reduced.

[0160] - The number of poles is not limited to 4. It can be more or less than 4.

[0161] - The permanent magnet can also be V-shaped instead of arc-shaped.

[0162] In the rotor core 21, radially outer permanent magnet insertion holes 25 and radially inner permanent magnet insertion holes 26 are formed in two radially arranged layers. Outer permanent magnets 27 are inserted into the radially outer permanent magnet insertion holes 25, and inner permanent magnets 28 are inserted into the radially inner permanent magnet insertion holes 26. However, this configuration is not limiting. Instead of having the permanent magnet insertion holes and permanent magnets arranged in two radially arranged layers, a configuration in which the permanent magnet insertion holes and permanent magnets are arranged in a single radially arranged layer is also acceptable. In short, as long as the rotor core 21 has axially extending permanent magnet insertion holes formed for each magnetic pole and permanent magnets inserted into the permanent magnet insertion holes, it is sufficient.

[0163] - Die-cast holes 31, serving as filling holes extending in the axial direction, are formed between adjacent magnetic poles in the rotor core 21. However, alternatively, die-cast holes or resin-molded holes serving as filling holes extending in the axial direction may be formed within the magnetic poles in the rotor core 21. For example, in a configuration where the permanent magnet insertion holes and the permanent magnets are arranged in a single layer in the radial direction, the die-cast holes or resin-molded holes serving as filling holes may be formed in the space radially inner of the permanent magnet insertion holes and the permanent magnets.

[0164] - The electric motor does not need to be a synchronous motor, but it can be any electric motor with embedded permanent magnets.

[0165] Description of Reference Numerals

[0166] 10…Rotary motor

[0167] 20…Rotor

[0168] 21…Rotor core

[0169] 121…Rotor core body

[0170] 22…Electromagnetic steel plate

[0171] 72…Cover

[0172] 70, 23a, 23b ... cover member

[0173] 80, 24a, 24b…clamping portion

[0174] 122…Permanent magnet insertion hole

[0175] 90...Permanent magnet

[0176] 25…Outer diameter side permanent magnet insertion hole

[0177] 26…Inner diameter side permanent magnet insertion hole

[0178] 27…Permanent magnet on outer diameter side

[0179] 28…Inner diameter side permanent magnet

[0180] 123, 29, 30, 37, 38… flux barrier

[0181] 124…Innermost flux barrier

[0182] 71…cover hole

[0183] 31, 33, 35…die-cast holes

[0184] 32, 34, 36…pure aluminum

[0185] 39, 40, 41…Rod-shaped part

[0186] 42…Thick wall part

[0187] 43…Thin-walled part

[0188] 44…pin

[0189] 50…Axis

[0190] 100…stator

[0191] 104…Coil

[0192] 124a…Outer diameter side closed space

[0193] 124b…Inner diameter side closed space

[0194] 150…bridge

[0195] 160…Reinforcement Department

[0196] 110…Extension

[0197] m…axis

[0198] C…Imaginary inner surface

[0199] R…Magnetic pole region

[0200] S1…1st inner surface

[0201] S2...the second inner surface.

Claims

1. A rotor for a rotating electric machine, comprising a cylindrical rotor core, the rotor core including a rotor core body, the rotor core body having a plurality of permanent magnet insertion holes formed in a radial direction for inserting permanent magnets, wherein the rotor of the rotating electric machine is characterized in that: The rotor core has a plurality of magnetic pole regions in the circumferential direction and a flux barrier adjacent to the permanent magnet insertion hole and extending along the q-axis magnetic path. The flux barrier extends in the axial direction of the rotor core. When the magnetic flux barrier located on the innermost radial side of the rotor core among the magnetic flux barriers is defined as the innermost magnetic flux barrier, the innermost magnetic flux barrier has a first inner surface located radially inward of the innermost magnetic flux barrier and a second inner surface located radially outward of the innermost magnetic flux barrier. When the rotor core body is viewed in the axial direction, the rotor core body has a bridge provided so as to connect the first inner surface and the second inner surface. The innermost magnetic flux barrier is formed with an outer diameter side closed space as a space divided between the bridge and the outer edge of the rotor core body. In the outer diameter side closed space, a reinforcement portion made of a non-magnetic material is embedded in the axial direction of the rotor core body. The first inner surface has a protruding portion that protrudes toward an adjacent magnetic pole region relative to a virtual inner surface formed by extending the inner surface located on the radially inner side, with which the permanent magnet abuts in the permanent magnet insertion hole, in a direction along the q-axis magnetic path. The bridge is provided so as to approach the d-axis as it moves from the first inner surface to the second inner surface. The rotor core body is composed of a plurality of electromagnetic steel sheets stacked in the axial direction. The rotor core has: a cover member stacked on both ends of the rotor core body in the axial direction; and a clamping portion that clamps the rotor core body and the cover member in the axial direction, The clamping portion and the reinforcing portion are integrally provided.

2. The rotor of the rotating electrical machine according to claim 1, wherein The innermost magnetic flux barrier forms a radially inner closed space that is a space partitioned between the permanent magnet and the bridge.

3. The rotor of a rotating electrical machine according to claim 1 or claim 2, characterized in that: The cover member has: a cover hole communicating with the outer diameter side closed space; and a cover portion that covers the permanent magnets of the permanent magnet insertion holes located on the innermost radial side to the bridge, and covers the permanent magnet insertion holes located radially outward of the permanent magnet insertion holes located on the innermost radial side, The reinforcement portion is embedded in the cover hole.

4. A rotor for a rotating electrical machine, wherein the outer peripheral surface of a cylindrical rotor core is arranged opposite to the inner peripheral side of a stator on which a coil is wound, characterized in that: The rotor core is made of stacked electromagnetic steel sheets, with a shaft inserted through the center. The rotor core is provided with a permanent magnet insertion hole extending in the axial direction for each magnetic pole. Insert the permanent magnet into the permanent magnet insertion hole. In the rotor core, filling holes extending in the axial direction are formed between adjacent magnetic poles or within the magnetic poles, and the electromagnetic steel sheets are fixed by non-magnetic metal or resin filled in the filling holes. The rotor core includes a rotor core body. The rotor core body is composed of a plurality of electromagnetic steel sheets stacked in the axial direction. The rotor core has: a cover member stacked on both ends of the rotor core body in the axial direction; and a clamping portion that clamps the rotor core body and the cover member in the axial direction, The clamping portion and the reinforcing portion are integrally provided.

5. The rotor of the rotating electrical machine according to claim 4, wherein: The permanent magnet insertion holes include an outer diameter side permanent magnet insertion hole arranged radially outward of the rotor core and an inner diameter side permanent magnet insertion hole arranged radially inward of the outer diameter side permanent magnet insertion hole. The permanent magnets include an outer diameter side permanent magnet inserted into the outer diameter side permanent magnet insertion hole and an inner diameter side permanent magnet inserted into the inner diameter side permanent magnet insertion hole. A magnetic flux barrier is continuously formed on the circumferential outer side of the inner diameter side permanent magnet insertion hole of the rotor core. The filling hole is formed in a region between adjacent magnetic poles and sandwiched by the magnetic flux barriers.

6. The rotor of the rotating electrical machine according to claim 5, wherein: The outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole of each of the magnetic poles are arc-shaped.

7. The rotor of the rotating electrical machine according to claim 6, wherein: A filling hole extending in the axial direction is further formed at a distance outside the magnetic flux barrier of the rotor core in the circumferential direction, and the electromagnetic steel sheet is fixed by a non-magnetic metal or resin filled in the filling hole.

8. The rotor of the rotating electrical machine according to claim 4, wherein The clamping parts made of the non-magnetic metal or resin are integrally formed on both axial end surfaces of the rotor core. The clamping portion includes: a thick-walled portion connected to a rod-shaped portion made of a non-magnetic metal or resin filled in the filling hole; and a thin-walled portion formed at a plurality of locations in the circumferential direction. A pin for achieving rotational balance is integrally formed in the thin-walled portion so as to protrude axially outward.

9. The rotor of the rotating electrical machine according to claim 8, wherein The cover member having only the filling hole formed therein is arranged between the electromagnetic steel sheet having the permanent magnet insertion hole and the filling hole formed therein of the rotor core and the clamping portion.

10. The rotor of a rotating electrical machine according to claim 8 or 9, characterized in that: The permanent magnet insertion hole includes: an outer diameter side permanent magnet insertion hole extending in the axial direction and arranged radially outward; and an inner diameter side permanent magnet insertion hole extending in the axial direction and arranged radially inward of the outer diameter side permanent magnet insertion hole. The outer diameter side permanent magnet is inserted into the outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet is inserted into the inner diameter side permanent magnet insertion hole. A magnetic flux barrier is continuously formed on the circumferential outer side of the inner diameter side permanent magnet insertion hole of the rotor core. The filling hole is formed in the rotor core in a region between adjacent magnetic poles and sandwiched by the magnetic flux barriers so as to extend in the axial direction.

11. The rotor of a rotating electrical machine according to claim 10, wherein: The outer diameter side permanent magnet insertion hole and the inner diameter side permanent magnet insertion hole of each of the magnetic poles are arc-shaped.

12. The rotor of the rotating electrical machine according to claim 11, wherein A filling hole extending in the axial direction is further formed at a distance outside the magnetic flux barrier of the rotor core in the circumferential direction, and the electromagnetic steel sheet is fixed by a non-magnetic metal or resin filled in the filling hole.

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