Rotor of rotary electric machine, and rotary electric machine

Abstract

To provide a rotor of a rotary electric machine capable of increasing magnet torque, securing necessary allowable centrifugal stress, and easily forming a skew, and to provide the rotary electric machine.SOLUTION: The rotor 5 according to the embodiment includes the inner iron core 13 provided with the recesses 15, and the outer iron core 14 disposed in each of the recesses 15, wherein each of the recesses 15 has the pair of inclined surfaces 17 increasing in width toward the radially outer side, and the outer iron core 14 is provided with the through hole through which the coupling member 11 passes in the axial direction, and has the inner peripheral side formed in a shape corresponding to the inclined surfaces 17 of the recesses 15. Housing parts 24 for housing the permanent magnets 19 are respectively formed by being arranged via a predetermined interval between the recessed parts 15, and the respective housing parts 24 are opened (BO, SO) at end parts on the outer peripheral side, and the sizes of the respective openings (BO, SO) are different to form a skew.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a rotor for a rotating electric machine and a rotating electric machine. [Background technology]

[0002] Conventionally, in rotating electric machines such as IPM motors in which permanent magnets are embedded inside the stator, a bridge section connected to the rotor core is formed on the outer edge of the housing section that houses the permanent magnets. Because leakage magnetic flux occurs at this bridge section, as described in Patent Document 1, for example, it is sometimes possible to generate greater magnetic torque even with the same amount of magnet by narrowing or eliminating the bridge section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-104962 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a trade-off between the bridge section and the characteristics of the rotating electric machine: narrowing or eliminating the bridge section reduces the allowable centrifugal stress, thereby reducing the maximum applicable rotation speed. Also, although forming a skew is required to improve the characteristics of a rotating electric machine, it is undesirable for the manufacturing process to become complicated in order to form the skew.

[0005] Therefore, the present invention provides a rotor for a rotating electric machine and a rotating electric machine that can increase the magnet torque, ensure the required allowable centrifugal stress, and further, easily form a skew. [Means for solving the problem]

[0006] A rotor for a rotating electric machine according to an embodiment includes an inner core having a plurality of recesses formed on an outer peripheral surface thereof, a plurality of outer cores disposed in the recesses, and end plates disposed on both axial ends of the inner core and the outer core, respectively, to support the inner core and the outer core from the axial direction. and a connecting member that penetrates the outer core and connects each end plate, the recess has a pair of inclined surfaces that become wider radially outward, the outer core has a through hole through which the connecting member penetrates in the axial direction, and the inner side is formed in a shape that corresponds to the inclined surfaces of the recess, and is arranged with a predetermined gap between it and the recess, thereby forming a storage section that stores a permanent magnet between the pair of inclined surfaces, and each storage section has an open end on the outer peripheral side, and the sizes of the openings are different to form a skew.

[0007] Moreover, the rotating electric machine of the embodiment includes the rotor having the above-described configuration. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of a rotating electric machine according to an embodiment; [Figure 2] A diagram showing a schematic example of the inner core configuration [Figure 3] A diagram showing a schematic example of the configuration of the outer core [Figure 4] 1 is a diagram schematically illustrating an example of the configuration of an end plate and a connecting member; [Figure 5] A diagram showing an example of the rotor assembly procedure [Figure 6] Diagram 1 showing a schematic example of another rotor configuration [Figure 7] Diagram 2 showing a schematic example of another rotor configuration DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment will be described with reference to the drawings. As shown in Fig. 1(a), the internal structure of a rotating electric machine 1 according to this embodiment is schematically shown. The rotating electric machine 1 includes a stator 4 fixed to the inner surface of a hollow frame 2 and having a coil 3 attached thereto, a rotor 5 disposed on the inner periphery of the stator 4, and a shaft member 6 fixed to the center of the rotor 5 by press-fitting or shrink-fitting. The shaft member 6 is rotatably supported by a bearing 8a provided on a flange 7a that closes the opening on the right end side of the frame 2 in the illustration, and a bearing 8b provided on a flange 7b that closes the opening on the left end side in the illustration. In the following description, the left-right direction in the illustration along the rotation axis (J) of the shaft member 6 will be referred to as the axial direction.

[0010] The rotor 5 has a rotor core 9, end plates 10 arranged at both axial ends of the rotor core 9 to support the rotor core 9 from the axial direction, and connecting members 11 that pass through the rotor core 9 and connect the end plates 10 together.

[0011] In this embodiment, the rotor core 9 is formed by stacking four core blocks 12 in the axial direction. As shown in FIGS. 1(b) and 1(c), which schematically show cross sections of the bb and cc wires, each core block 12 has an inner core 13 and multiple outer cores 14 arranged on the outer periphery of the inner core 13. As will be described in detail later, adjacent core blocks 12 in the axial direction are stacked in an inverted manner, and have different cross-sectional shapes. Note that hatching of the cores is omitted in FIGS. 1(b) and 1(c) to make the drawings easier to understand. Furthermore, the number of layers of the core blocks 12 is an example and is not limited to this.

[0012] 2 which shows a portion of inner core 13 viewed from the axial direction, has an overall outer shape in which a plurality of recesses 15 are formed on the outer peripheral surface of a virtual cylinder (X), and has an insertion hole 16 and key groove 16a formed in the center for inserting shaft member 6. Inner core 13 is formed in such a way that the required layer thickness is ensured by stacking a predetermined number of core materials punched into the same shape by a press, for example, and these are then further stacked in the axial direction while being inverted in units of core block 12.

[0013] Each recess 15 has a pair of inclined surfaces 17a and 17b that widen radially outward, and an inner end 18a located counterclockwise from an imaginary line (CL) passing through the center of the recess 15 and the key groove 16a has a different shape from an inner end 18b located clockwise from the imaginary line (CL). Specifically, the radially outer shape of the inner end 18a is inclined counterclockwise from an extension of the inclined surface 17, while the inner end 18b is formed flat as an extension of the inclined surface 17. Note that the number, arrangement, shape, etc. of the recesses 15 are not limited to this.

[0014] That is, inner core 13 is formed in a shape that is asymmetrical between the left and right sides of imaginary line (CL) in the drawing. However, insertion hole 16 and inclined surface 17 are symmetrical, and are in the same position even when inverted. In this embodiment, restricting portions 20 are provided on the inner circumferential side of each inclined surface 17 and on inclined surface 17b to restrict movement of permanent magnet 19 (see FIG. 1). Note that the shape of each inner end 18 and the arrangement and shape of restricting portions 20 are merely examples and are not limited to these.

[0015] Outer core 14 is disposed at a predetermined distance from recess 15, and as shown in Fig. 3 which shows a portion thereof viewed from the axial direction, has an inner circumferential side with flat portions 21a and 21b corresponding to recess 15, and an outer circumferential side corresponding to the outer periphery of the cylinder (X), i.e., the outer edge of inner core 13, forming a generally fan-shaped overall shape. Each outer core 14 is formed with outer through-hole 22 for passing connecting member 11 (see Fig. 5), which will be described later. Outer core 14 is formed, for example, in such a way that the required layer thickness is ensured by stacking a predetermined number of core materials punched into the same shape by a press, and these are then further stacked in the axial direction while being inverted in units of core block 12.

[0016] Furthermore, taking the upper end of outer core 14 as an example, outer end 23a, which is located counterclockwise from imaginary line (CL), has a different shape from outer end 23b, which is located clockwise from imaginary line (CL). Specifically, outer end 23a is formed such that the distance (L1) from the imaginary line is longer than the distance (L2) from outer end 23b, and accordingly, the inner circumferential side is also inclined counterclockwise from the extension of flat portion 21a. On the other hand, outer end 23b has a flat shape that is an extension of flat portion 21b. In this embodiment, each outer core 14 is formed to have the same shape.

[0017] In other words, outer core 14 is formed in a shape that is asymmetrical on the left and right sides of imaginary line (CL) in the drawing. However, flat portion 21 and outer through-hole 22 are symmetrical and are in the same position even when inverted. The shape of each outer end 23 is an example. Then, outer core 14 is arranged in each recess 15 of inner core 13 at a predetermined interval, thereby forming housing portion 24 that houses permanent magnet 19 between outer core 14 and recess 15. Then, permanent magnet 19 is housed in housing portion 24 while being bonded to inclined surface 17 and flat portion 21.

[0018] Each accommodation section 24 is formed such that the front side of recess 15 is closed by outer core 14 and both radially outer ends are open. The openings of each accommodation section 24 are different in size, with large and small openings alternately arranged in the circumferential direction. Hereinafter, the relatively large openings will be referred to as large openings (BO), and the relatively small openings will be referred to as small openings (SO).

[0019] As shown in Fig. 1(a), inner core 13 and outer core 14 are supported on both axial sides by end plates 10 arranged at both axial ends and connecting members 11 that penetrate outer core 14 and connect end plates 10. As shown in Fig. 4(a), end plate 10 is a disk having roughly the same outer shape as rotor core 9, with plate-side insertion hole 25 formed in its center, into which shaft member 6 is inserted, and a step formed on the outer periphery, forming contact surface 26 that comes into contact with the end faces of inner core 13 and outer core 14. Plate-side through hole 27, through which connecting member 11 passes, is formed in contact surface 26.

[0020] As shown in FIG. 4( b ), connecting member 11 is a so-called half-screw having a thread formed on the end on the left side in the figure and a screw head on the end on the right side in the figure, and is fastened by nut 28 or the like while passing through outer core 14 and end plate 10. This allows inner core 13 and outer core 14, which are separated from each other, to rotate together. Furthermore, even when centrifugal force is applied, outer core 14 is supported by connecting member 11, and therefore is prevented from coming off or from changing its positional relationship with inner core 13. In other words, the provision of end plate 10 and connecting member 11 ensures the required allowable centrifugal stress.

[0021] The configuration of the end plates 10 and connecting member 11 is merely an example and is not limited to this. For example, the plate-side through-hole 27 of one of the end plates 10 can be made into a female screw to fasten the connecting member 11 to the end plate 10, or a protrusion can be provided on the end plate 10 at a position corresponding to the gap between the permanent magnets 19 to determine the position of the inner iron core 13 to make assembly easier, or a configuration without a step can be used.

[0022] Rotor core 9 is formed by assembling inner core 13, outer core 14, end plates 10, and connecting members 11. Specifically, as shown in Fig. 5(a), a predetermined number of core pieces for inner core 13 are first stacked to form inner blocks 13A to 13D of the same shape, and these are then stacked by alternately flipping them in the axial direction. This forms inner core 13 having multiple recesses 15 on the outer periphery, with inner ends 18a and 18b of each recess 15 arranged alternately in the circumferential direction.

[0023] Next, as shown in Fig. 5(b), permanent magnets 19 are adhered to each inclined surface 17 of inner core 13, and as shown in Fig. 5(c), blocks of the same shape, formed by stacking core pieces for outer core 14, are stacked inverted in recess 15 of inner core 13. At this time, the blocks of outer core 14 are stacked inverted for each core block 12. In this way, rotor core 9 is formed in which large openings (BO) and small openings (SO) are alternately arranged in the circumferential direction and also in the axial direction, and permanent magnets 19 are accommodated in each accommodation portion 24 formed between inner core 13 and outer core 14.

[0024] Then, as shown in Fig. 5(d), end plates 10 are placed on both axial ends of rotor core 9 and fastened together with connecting members 11, and shaft member 6 is inserted as shown in Fig. 5(e), thereby forming rotor 5. Note that the assembly procedure shown in Fig. 5 is an example and is not limited to this. For example, other procedures are also possible, such as placing inner core 13 with permanent magnets 19 attached on one end plate 10, and then placing outer block 10 with connecting members 11 passing through end plate 10, or forming multiple core blocks 12 in advance and then stacking them while flipping them axially.

[0025] According to the embodiment described above, the following effects can be obtained. The rotor 5 according to the embodiment comprises an inner core 13 having a plurality of recesses 15 formed on its outer peripheral surface, a plurality of outer cores 14 each arranged in the recesses 15, end plates 10 arranged at both axial ends of the inner core 13 and the outer core 14 and supporting the inner core 13 and the outer core 14 from the axial direction, and a connecting member 11 passing through the outer core 14 to connect the end plates 10 together.

[0026] The recess 15 has a pair of inclined surfaces 17 that become wider radially outward, and the outer core 14 has a through hole provided in the axial direction through which the connecting member 11 passes, and its inner side is formed in a shape that corresponds to the inclined surfaces 17 of the recess 15.By being arranged with a predetermined gap between it and the recess 15, each of the inclined surfaces 17 forms a storage section 24 that stores a permanent magnet 19, and each of the storage sections 24 has an open end on the outer circumferential side, and the sizes of the openings adjacent to each other in the circumferential direction are different, forming a skew.

[0027] With this configuration, rotor 5 without bridge portions can be formed by the simple procedure of stacking the blocks, and connecting member 11 can support the centrifugal force acting on outer core 14. Furthermore, the simple assembly procedure of reversing the blocks in the axial direction makes it possible to make the sizes of adjacent openings in the axial direction different, thereby forming a skew. Therefore, the absence of bridge portions allows for increased magnetic torque and ensures the necessary allowable centrifugal stress, and further allows for easy formation of a skew without complicating the manufacturing process.

[0028] Furthermore, outer core 14 is formed by stacking blocks made of core materials with different shapes at both circumferential ends, with the ends of adjacent blocks in the axial direction being positioned on opposite sides, and housing section 24 has an opening of a different size in the axial direction for each block. This makes it possible to vary the opening size by stacking the blocks of outer core 14 inverted, making it easy to form a skew, and since blocks of outer core 14 with the same shape can be used, reductions in manufacturing costs and parts management costs can be expected.

[0029] Furthermore, inner core 13 is formed by stacking blocks of core materials with different shapes for the ends of inclined surfaces 17 of recesses 15, such that the ends of adjacent blocks in the axial direction are positioned on opposite sides, and accommodating section 24 has an opening of a different size in the axial direction for each block. This makes it possible to vary the opening size by stacking the blocks of inner core 13 inverted, making it easy to form a skew, and since blocks of outer core 14 with the same shape can be used, reductions in manufacturing costs and parts management costs can be expected.

[0030] Rotor 5 also includes restricting portion 20 that is provided in at least one of recess 15 and outer core 14 and restricts movement of the permanent core. This prevents permanent magnet 19 from shifting position even when it is placed between inner core 13 and outer core 14, that is, in housing portion 24 that is separated from each other and has no bridge portion on the outer periphery.

[0031] Furthermore, even with a rotating electric machine 1 equipped with a rotor 5 having such a configuration, the absence of a bridge portion allows for increased magnet torque, ensures the necessary allowable centrifugal stress, and makes it easy to form skew, thereby achieving the various effects described above.

[0032] While the examples shown so far have illustrated configurations in which the shapes of the ends of both inner core 13 and outer core 14 are different, it is also possible to configure recess 15 such that inner end 18a and inner end 18b have the same shape and outer end 23a and outer end 23b of outer core 14 have different shapes, as shown in Fig. 6(a) . Even with such a configuration, it is possible to obtain the same effects as those of rotor 5 and rotating electric machine 1 described above.

[0033] 6(b), recess 15 may have two ends with different shapes, and outer core 14 may have two ends with different shapes. Even with such a configuration, the same effects as those of rotor 5 and rotating electric machine 1 described above can be obtained. Although not shown in the drawings, recess 15 may have different shapes, or outer core 14 with different shapes may be arranged.

[0034] Furthermore, outer through hole 22 may be formed in a shape other than a circle, such as a rectangle, a square, or a polygon, or in an ellipse (not shown), as shown in Fig. 7(a), or a plurality of outer through holes 22 may be provided as shown in Fig. 7(b), thereby making it possible to prevent outer core 14 from rotating relative to connecting member 11. Even with such a configuration, it is possible to obtain the same effects as those of rotor 5 and rotating electric machine 1 described above.

[0035] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0036] In the drawings, 1 denotes a rotating electric machine, 5 denotes a rotor, 10 denotes an end plate, 11 denotes a connecting member, 12 denotes a core block, 13 denotes an inner core, 14 denotes an outer core, 15 denotes a recess, and 20 denotes a restricting portion.

Claims

1. an inner core having a plurality of recesses on its outer circumferential surface; a plurality of outer cores respectively disposed in the recesses; end plates arranged at both axial ends of the inner core and the outer core, respectively, to support the inner core and the outer core in the axial direction; a connecting member that penetrates the outer core and connects the end plates together, The recess has a pair of inclined surfaces that become wider radially outward, the outer core is provided with a through hole through which the connecting member passes in the axial direction, and the inner circumferential side is formed into a shape corresponding to the inclined surfaces of the recesses, and is disposed with a predetermined gap between itself and the recesses, thereby forming accommodation portions for accommodating the permanent magnets between itself and the pair of inclined surfaces, The rotor for a rotating electric machine, wherein each of the housing portions has an opening at an end on the outer circumferential side, and the openings have different sizes, forming a skew.

2. the outer core is formed by stacking blocks of core materials having different shapes at both ends in the circumferential direction, such that the ends of adjacent blocks in the axial direction are positioned on opposite sides, 2. The rotor for a rotating electric machine according to claim 1, wherein the accommodating portion has openings of different sizes in the axial direction for each block.

3. the inner core is formed by stacking blocks of core materials having different shapes of end portions of the inclined surfaces of the recesses, such that end positions of adjacent blocks in the axial direction are opposite to each other, 2. The rotor for a rotating electric machine according to claim 1, wherein the accommodating portion has openings of different sizes in the axial direction for each block.

4. 2. The rotor of claim 1, further comprising a restricting portion provided in at least one of the recess and the outer core for restricting movement of the permanent core.

5. A rotating electric machine comprising the rotor according to any one of claims 1 to 4.

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