Rotating Electric Machine

Abstract

To provide a rotary electric machine capable of efficiently cooling a stator winding by increasing the amount of cooling air flowing to an air duct, and improving strength against twisting vibration by increasing the second moment of area of an interval piece and the stator winding.SOLUTION: An air duct 10 is provided with stator windings 101b housed in slots 109, and interval pieces 108 arranged between the stator windings 101b for maintaining an axial gap as the air duct 10. The stator winding 101b and the interval piece 108 are provided so as to be inclined in a rotational direction of a rotator 2 with respect to a radial direction of a stator iron core 1a.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine such as a generator, and more particularly to a rotating electric machine having a ventilation duct provided in a stator core. [Background technology]

[0002] Rotating electric machines, such as DC machines, synchronous machines, and induction machines, are composed of a stator and a rotor, and functionally convert between electrical energy and mechanical energy (rotational energy) using the principle of electromagnetic induction. These rotating electric machines generate heat in the stator and rotor due to copper loss and iron loss, so they require cooling for normal operation. For this reason, rotating electric machines are cooled by installing a centrifugal fan on the rotating shaft, for example, and using the wind generated by the centrifugal fan as the rotor rotates.

[0003] On the other hand, in an engine-driven rotating electric machine, torsional vibration acts on the stator and rotor, and it is known that the stator and rotor must have the strength to withstand the torsional vibration.

[0004] Here, an example of the configuration of a conventional rotating electric machine will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a cross-sectional view showing the configuration of a conventional rotating electric machine, and Fig. 6 is a cross-sectional view of the periphery of a ventilation duct provided in a stator core of the conventional rotating electric machine. The rotating electric machine is mainly composed of a stator 1, a rotor 2, and a bearing 5 that supports the rotor 2.

[0005] As shown in Fig. 5, the stator 1 is composed of a stator core 1a in which doughnut-shaped (annular) electromagnetic steel sheets are stacked in the axial direction (left-right direction in Fig. 5), and a stator winding 1b housed in slots 9 (Fig. 6) provided on the inner diameter side of the stator core 1a. The stator core 1a is also provided with a plurality of ventilation ducts 10, which are axial gaps, spaced apart in the axial direction. The portion of the stator winding 1b located within the ventilation ducts 10 is exposed from the slots 9, and is cooled by the cooling air passing through the ventilation ducts 10.

[0006] The rotor 2 is disposed with a gap in the radial direction from the inner diameter surface of the stator 1, and is rotatable relative to the stator 1. The rotor 2 is composed of a rotating shaft 3, magnetic poles 4, and a centrifugal fan 7 provided on the coupling 6 side, and is rotatably supported by bearings 5. The magnetic poles 4 are configured by winding rotor windings 4b around a rotor core 4a made of electromagnetic steel sheets laminated in the axial direction.

[0007] As shown in Fig. 6, in the ventilation duct 10, the stator windings 1b housed in the slots 9 and the spacers 8 are alternately arranged at intervals in the circumferential direction of the stator core 1a. In other words, in the ventilation duct 10, the stator windings 1b and the spacers 8 are radially arranged from the axial center of the stator core 1a (i.e., the center of rotation of the rotor 2). The spacers 8 are members for maintaining the axial gap of the ventilation duct 10, and extend from the inner diameter side to the outer diameter side of the stator core 1a. The spacers 8 are arranged in the center between the stator windings 1b (i.e., between the slots 9).

[0008] An example of an invention relating to a ventilation duct for a stator core is Patent Document 1 listed below. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 10-174320 Summary of the Invention [Problem to be solved by the invention]

[0010] 4 in addition to Fig. 6, the direction of the cooling air flowing into the inlet of ventilation duct 10 is the direction of a resultant vector 14 of a rotational component 12 caused by the rotation of rotor 2 and a radial component 13 flowing by centrifugal fan 7 (Fig. 5). Therefore, the direction of the cooling air flowing into the inlet of ventilation duct 10 located on the inner diameter side of stator core 1a is inclined toward the rotational direction of rotor 2 with respect to the radial direction of stator core 1a.

[0011] In conventional rotating electric machines, the slots 9 and spacers 8 are arranged radially from the axis of the stator core 1a, so that the cooling air that flows into the inlet of the ventilation duct 10 and is tilted in the rotational direction relative to the radial direction is forced to bend in the radial direction by the stator windings 1b and spacers 8 housed in the slots 9, as shown by arrow 11 in Fig. 6. For this reason, in conventional rotating electric machines, there is a problem in that the pressure loss at the inlet of the ventilation duct 10 becomes large, preventing the cooling air from flowing into the ventilation duct 10.

[0012] As shown in Fig. 7, which is an enlarged view of one of the spacers 8 shown in Fig. 6, torsional vibration 15 acts alternately on spacer 8 in the rotational direction 17 and reverse rotational direction 18 of the rotating electric machine. The following equation (1) shows a calculation formula for the second moment of area I about the central axis 16 of spacer 8. In addition, in equation (1), b is the longitudinal length of spacer 8 having a rectangular cross section as viewed from the axial direction, and a is the lateral length of spacer 8 having a rectangular cross section as viewed from the axial direction.

[0013]

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[0014] The spacer 8 is attached so that the central axis 16 passing through the center of the short-side length a is perpendicular to the direction of the torsional vibration 15 (rotation direction 17 and reverse rotation direction 18), and therefore the second moment of area about the central axis 16 is minimized. Therefore, in conventional rotating electric machines, there was a risk that the spacer 8 would be damaged by the torsional vibration 15. Furthermore, like the spacer 8, the stator winding 1b housed in the slot 9 also had a risk of being damaged by the torsional vibration.

[0015] The present invention has been made to solve the above-mentioned problems, and has an object to increase the amount of cooling air flowing into a ventilation duct in a rotating electric machine to efficiently cool the stator winding, and to increase the second moment of area of ​​the spacer and the stator winding to improve strength against torsional vibration. [Means for solving the problem]

[0016] In order to achieve the above object, a rotating electric machine according to the present invention provides a rotating electric machine that includes a stator including an annular stator core and stator windings housed in slots provided at intervals in the circumferential direction of the stator core on the inner diameter side of the stator core, a rotor including a rotor core fixed to a rotating shaft and a rotor winding provided on the rotor core, magnetic poles provided inside the stator core, and a centrifugal fan fixed to the rotating shaft, and an air duct is formed in the stator core as an axial gap, and torsional vibration acts on the stator and the rotor. The air duct is provided with the stator windings housed in the slots and spacers arranged between the stator windings to maintain the axial gap as the air duct, and the stator windings and the spacers are inclined in the rotational direction of the rotor with respect to the radial direction of the stator core so as to increase the moment of inertia of the stator windings and the spacers to improve strength against the torsional vibration. The stator winding has a rectangular outer shape when viewed in the axial direction of the rotor, and is inclined in the rotational direction of the rotor with respect to the radial direction of the stator core so as to be approximately perpendicular to the spacer pieces.

[0017] In this way, by arranging the stator windings and spacers in the ventilation duct so as to be inclined in the direction of rotation of the rotor with respect to the radial direction of the stator core, it is possible to increase the amount of cooling air flowing into the ventilation duct and to increase the second moment of area of ​​the stator windings and spacers. Effect of the Invention

[0018] According to the present invention, in a rotating electric machine, the amount of cooling air flowing into the ventilation duct can be increased to efficiently cool the stator winding, and the second moment of area of ​​the spacer and the stator winding can be increased to improve strength against torsional vibration. [Brief description of the drawings]

[0019] [Figure 1] 2 is a cross-sectional view of a periphery of a ventilation duct provided in the rotating electric machine according to the first embodiment. FIG. [Diagram 2] 11 is a cross-sectional view of a periphery of a ventilation duct provided in a rotating electric machine according to a second embodiment. FIG. [Diagram 3] 2 is an enlarged view of a spacer provided in the rotating electric machine according to the first embodiment. FIG. [Figure 4] 4 is a cross-sectional view showing the direction of cooling air flowing into an inlet portion of a ventilation duct. FIG. [Diagram 5] FIG. 11 is a cross-sectional view showing the configuration of a conventional rotating electric machine. [Figure 6] 11 is a cross-sectional view of a periphery of a ventilation duct provided in a conventional rotating electric machine. [Figure 7] FIG. 13 is an enlarged view of a spacer provided in a conventional rotating electric machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0021] 1. First embodiment First, a first embodiment of the present invention will be described. Fig. 1 is a cross-sectional view of a periphery of a ventilation duct 10 provided in a stator core 1a of a rotating electric machine 100 according to the first embodiment. Note that the configuration other than that shown in Fig. 1 (i.e., the stator 1, the rotor 2, and the bearings 5) is the same as that of the conventional rotating electric machine shown in Fig. 5, so the drawings and explanations are omitted.

[0022] 1, in an air duct 10 provided in a stator core 1a of a rotating electric machine 100 according to the first embodiment, stator windings 101b housed in slots 109 are arranged at intervals in the circumferential direction of the stator core 1a. Furthermore, in the air duct 10, a spacer 108, which is a member for maintaining a gap in the axial direction of the air duct 10, is arranged in the center between the stator windings 101b (i.e., between the slots 109).

[0023] The slots 109 are provided on the inner diameter side of the stator core 1a and have a rectangular cross section extending in a direction from the inner diameter side to the outer diameter side of the stator core 1a. The stator windings 101b are housed in the slots 109 in accordance with the shape of the slots 109.

[0024] On the other hand, the spacer pieces 108 extend from the inner diameter side to the outer diameter side of the stator core 1a, and have a rectangular cross section that is thinner and longer than the slots 109.

[0025] In conventional rotating electric machines, the spacers 8 and slots 9 are arranged along the radial direction of the stator core 1a as shown in FIG. 6, whereas in the rotating electric machine 100 of the first embodiment, the spacers 108 and slots 101 are arranged inclined in the rotation direction of the rotor 2 with respect to the radial direction of the stator core 1a as shown in FIG. 1.

[0026] More specifically, the spacers 108 and slots 109 are inclined in the rotation direction of the rotor 2 with respect to the radial direction of the stator core 1a so as to follow the direction of resultant vector 14, which is the direction of the cooling air flowing into the inlet of the ventilation duct 10. In other words, the spacers 108 and slots 109 are inclined in the rotation direction of the rotor 2 with respect to the radial direction of the stator core 1a by the angle formed by the radial component 13 of the cooling air and resultant vector 14.

[0027] Furthermore, by tilting the slots 109 in this manner, the stator windings 101b housed in the slots 109 are also tilted toward the rotational direction of the rotor 2 with respect to the radial direction of the stator core 1a by an angle between the radial component 13 of the cooling air and the resultant vector 14. The rotating electric machine 100 according to the first embodiment is configured as described above.

[0028] As described above, in the first embodiment, a rotating electric machine 100 is provided that includes a stator 1 including an annular stator core 1a and stator windings 101b housed in slots 109 provided at intervals in the circumferential direction of the stator core 1a on the inner diameter side of the stator core 1a, a rotor 2 including a rotor core 4a fixed to a rotating shaft 3 and rotor windings 4b provided on the rotor core 4a, magnetic poles 4 provided on the inside of the stator core 1a, and a centrifugal fan 7 fixed to the rotating shaft 3, and in which a ventilation duct 10 is formed in the stator core 1a as an axial gap. In the ventilation duct 10, a stator winding 101b is housed in the slot 109, and a spacer 108 is arranged between the stator windings 101b (i.e., between the slots 109) to maintain an axial gap as the ventilation duct 10, and the stator winding 101b and the spacer 108 extend from the inner diameter side to the outer diameter side of the stator core 1a and are inclined in the rotational direction of the rotor 2 with respect to the radial direction of the stator core 1a so as to follow the direction of the cooling air flowing into the inlet portion of the ventilation duct 10 (i.e., the direction of the resultant vector 14).

[0029] In this way, in the rotating electric machine 100 according to the first embodiment, the stator winding 101b and the spacer 108 are inclined in the rotation direction of the rotor 2 with respect to the radial direction of the stator core 1a so as to follow the direction of the cooling air flowing into the inlet portion of the ventilation duct 10, so that the cooling air that has flowed into the inlet portion of the ventilation duct 10 can be made to flow in the same direction as shown by arrow 201 in Fig. 1, thereby reducing pressure loss at the inlet portion of the ventilation duct 10. Thus, according to the rotating electric machine 100 according to the first embodiment, the amount of cooling air flowing into the ventilation duct 10 can be increased, and the stator winding 101b can be efficiently cooled.

[0030] Furthermore, as shown in FIG. 3, which is an enlarged view of one of the spacers 108 shown in FIG. 1, torsional vibration 15 acts on the spacer 108 alternately in the rotational direction 17 and reverse rotation direction 18 of the rotating electric machine 100. In the rotating electric machine 100 according to the first embodiment, the spacer 108 is inclined toward the rotational direction of the rotor 2 with respect to the radial direction of the stator core 1a, so that the second moment of area about the central axis 16 of the spacer 108 can be increased compared to the conventional case.

[0031] As a specific example, the calculation formula for the second moment of area I about the central axis 16 of the spacer 108 is shown in the following equation (2). Note that in equation (2), b is the longitudinal length of the spacer 108 whose cross section is rectangular when viewed from the axial direction, and a is the lateral length of the spacer 108 whose cross section is rectangular when viewed from the axial direction. Also, θ is the inclination angle of the spacer 108.

[0032]

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[0033] As an example, when a=1 mm, b=200 mm, and θ=1° in the formula (2), the second moment of area I of the spacer 108 of the rotating electric machine 100 according to the first embodiment is calculated as I=1.87 mm. 4 It becomes.

[0034] In contrast, when a = 1 mm and b = 200 mm in formula (1), the second moment of area I of the spacer 8 of the conventional rotating electrical machine is calculated as I = 1.67 mm 4 It becomes.

[0035] In this way, in the rotating electric machine 100 according to the first embodiment, the geometric moment of inertia of the spacer 108 about the central axis 16 can be increased as compared to the conventional case. Thus, according to the rotating electric machine 100 according to the present embodiment, the geometric moment of inertia of the spacer 108 can be increased, thereby improving the strength against the torsional vibration 15.

[0036] Furthermore, in the rotating electric machine 100 according to the first embodiment, similarly to the spacer pieces 108, the slots 109 are inclined and the stator windings 101b housed in the slots 109 are also inclined, thereby increasing the second moment of area of ​​the stator windings 101b and improving their strength against torsional vibration 15.

[0037] 2. Second embodiment Next, a second embodiment of the present invention will be described. Fig. 2 is a cross-sectional view of a periphery of a ventilation duct 10 provided in a stator core 1a of a rotating electric machine 200 according to the second embodiment. Note that the configuration other than that shown in Fig. 2 (i.e., the stator 1, the rotor 2, and the bearing 5) is the same as that of the conventional rotating electric machine shown in Fig. 5, so the drawings and explanations are omitted.

[0038] 2, in the rotating electric machine 200 according to the second embodiment, like the rotating electric machine 100 according to the first embodiment, the stator winding 101b and the spacer 108 are inclined in the rotation direction of the rotor 2 with respect to the radial direction of the stator core 1a. On the other hand, the rotating electric machine 200 according to the second embodiment differs from the rotating electric machine 100 according to the first embodiment in that the spacer 108 is provided adjacent to the stator winding 101b inside the ventilation duct 10.

[0039] Specifically, the spacer piece 108 is arranged adjacent to the stator winding 101b on the downstream side in the rotation direction of the rotor 2 (on the right side in FIG. 2).

[0040] As a result, in the rotating electric machine 200 of the second embodiment, branching loss of the cooling air flowing into the inlet portion of the ventilation duct 10 is eliminated, and the pressure loss at the inlet portion of the ventilation duct 10 can be further reduced compared to the rotating electric machine 100 of the first embodiment.

[0041] 3. Other embodiments Next, another embodiment (modification) of the present invention will be described. In the above-mentioned first embodiment, the inclination angle of the spacer 108 and the slot 109 is the angle between the radial component 13 of the cooling air and the resultant vector 14. However, the inclination angle of the spacer 108 and the slot 109 may be shifted from the angle between the radial component 13 of the cooling air and the resultant vector 14 within a range in which the pressure loss at the inlet portion of the ventilation duct 10 can be reduced and the moment of inertia about the central axis 16 of the spacer 108 can be increased, as compared with the conventional case (i.e., when the inclination angle of the spacer 108 and the slot 109 is 0°). The same applies to the second embodiment.

[0042] In the second embodiment described above, the spacer 108 is arranged adjacent to the stator winding 101b on the downstream side (right side in FIG. 2) in the rotation direction of the rotor 2. However, the present invention is not limited to this, and the spacer 108 may be arranged adjacent to the stator winding 101b on the upstream side (left side in FIG. 2) in the rotation direction of the rotor 2.

[0043] Furthermore, in the first and second embodiments described above, the present invention is applied to a rotating electric machine having a synchronous generator configuration. However, the present invention is not limited to this, and may be applied to a rotating electric machine having a configuration partially different from the configurations of the first and second embodiments described above, so long as the rotating electric machine has a configuration including a ventilation duct in a stator core.

[0044] Furthermore, the present invention is not limited to the above-described embodiments, and the scope of application of the present invention extends to embodiments in which the first and second embodiments are combined with part or all of the other embodiments, or embodiments in which parts are extracted. [Industrial Applicability]

[0045] The present invention can be widely used in rotating electric machines such as synchronous machine generators. [Explanation of symbols]

[0046] 1...stator, 1a...stator core, 1b, 101b...stator winding, 2...rotor, 3...rotating shaft, 4...magnetic pole, 4a...rotor core, 4b...rotor winding, 5...bearing, 6...coupling, 7...centrifugal fan, 8, 108...spacer, 9, 109...slot, 10...ventilation duct, 12...rotational component, 13...radial component, 14...resultant vector, 15...torsional vibration, 16...central shaft, 100, 200...rotating electric motor.

Claims

1. a stator including an annular stator core and a stator winding housed in slots provided at intervals in a circumferential direction of the stator core on an inner diameter side of the stator core; a rotor including a rotor core fixed to a rotating shaft and a rotor winding provided on the rotor core, the rotor having magnetic poles provided inside the stator core, and a centrifugal fan fixed to the rotating shaft; In an engine-driven rotating electric machine, a ventilation duct is formed as an axial gap in the stator core, and torsional vibration acts on the stator and the rotor, the ventilation duct is provided with the stator winding housed in the slot and a spacer arranged between the stator windings for maintaining an axial gap as the ventilation duct; the stator winding and the spacers are inclined in a rotational direction of the rotor with respect to a radial direction of the stator core so as to increase a moment of inertia of the stator winding and the spacers and thereby improve strength against the torsional vibration; The stator winding has a rectangular outer shape when viewed from the axial direction of the rotor, and is inclined in the rotation direction of the rotor with respect to the radial direction of the stator core so as to be approximately perpendicular to the spacer. A rotating electric machine characterized by:

2. The spacer is provided adjacent to the stator winding.

2. The rotating electric machine according to claim 1 .

3. The spacer is provided adjacent to the stator winding on the upstream side in the direction of rotation of the rotor.

3. The rotating electric machine according to claim 2.

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