JP6503329B2 - Electric rotating machine and stator cooling structure - Google Patents

Description

  The present invention relates to a rotating electrical machine and a stator cooling structure.

  The rotary electric machine includes a rotor and a stator, and the fully closed rotary electric machine generally further includes a cooler. In the fully closed type rotary electric machine, a closed space is formed by the frame and the cooler cover. The cooling pipe passes through the inside of the closed space, and the outside of the cooling pipe is an atmosphere of the closed space. Normally, a cooling gas such as air circulates in the closed space.

  The cooling gas cools the rotor core, the stator core, the stator windings and the like. The cooling gas is cooled in the cooler.

  The cooler may be, for example, a system in which cooling water flows in a cooling pipe. Alternatively, in the case of a totally closed fan-shaped electric rotating machine, an outer fan is provided at one end (anti-coupling side) of the rotor shaft of the rotor, and the outside air driven by the outer fan extends in the axial direction of the cooler The cooling fluid flows into the cooling pipe from one opening of each and flows out from the other opening.

JP, 2013-66341, A

  As described above, the cooling gas cools the rotor core, the stator core, the stator winding and the like, and is cooled in the cooler. In particular, in the case of a stator having a large amount of heat generation, a plurality of ducts are usually provided at intervals in the axial direction of the stator core, and cooling efficiency is raised by flowing cooling gas radially outward in the ducts.

  That is, since the stator core usually has, for example, a laminated structure in which electromagnetic steel sheets such as silicon steel sheets having relatively high permeability and low cost are laminated in the axial direction, positions mutually spaced in the axial direction A spacer is provided to form a duct by providing a gap between the laminated structures adjacent to each other, thereby securing a flow path from the radially inner side to the radially outer side of the stator core.

  Inside the stator core, the stator winding generates heat due to copper loss, that is, Joule heat, and inside the laminated structure, iron loss, that is, heat due to eddy current loss or magnetic hysteresis loss. For this reason, a heat flux to the outer surface is generated inside the stator by heat conduction. Therefore, in terms of cooling efficiency, it is preferable to increase the surface area for heat dissipation by providing a large number of ducts.

  On the other hand, in the duct where the electromagnetic steel sheet which is a ferromagnetic material does not exist, since the magnetic resistance is large, it is preferable that the ratio occupied by the duct in the stator core is low in terms of electromagnetic performance such as securing torque.

  As a method for solving such a problem, a bolt for fastening the stator core in the axial direction of the stator core is used as a bolt for fastening the stator core, and a hole passing in the axial direction is used as a flow path for the cooling gas. There is known a method of improving the cooling capacity by the In the case of a perforated bolt, it is necessary to increase the diameter to some extent, but it is not preferable from the viewpoint of the efficiency of the rotating electrical machine that a large diameter magnetic resistance is present in the magnetic flux path.

  Then, an object of this invention is to ensure cooling efficiency, without exerting big influence on efficiency ensuring of a rotary electric machine.

In order to achieve the above object, the present invention provides a rotor having an axially extending and rotatably supported rotor shaft, and a rotor core provided radially outward of the rotor shaft; A cylinder provided with a stator cooling structure, a plurality of laminated structures each having a plurality of electromagnetic steel plates, and a plurality of fastening bolts axially binding the plurality of laminated structures, provided on the radially outer side of the iron core A stator having a stator core in the form of a stator, and a stator winding axially penetrating the inside of the stator core, the rotor core and the stator being disposed radially outward of the stator A frame for housing, a coupled bearing and an uncoupled bearing for supporting the rotor shaft on both sides of the rotor shaft in an axial direction sandwiching the rotor core, the coupled bearing and the uncoupled bearing, A rotary electric machine comprising: a coupling-side bearing bracket and an anti-coupling-side bearing bracket which are fixedly supported and connected to the end of the frame in the axial direction; and an internal fan attached to the rotor shaft to drive a cooling gas. The stator cooling structure includes a spacer which is interposed between the stacked structures axially adjacent to each other to form a plurality of ducts in which the cooling gas flows radially inward from radially inward, and the plurality of ducts. And a plurality of cooling bolts each made of a material having a thermal conductivity higher than that of the material of the tightening bolt and a plurality of screwing bolts respectively for the plurality of cooling bolts. It has a nut, the arranged plurality of at least one duct, and a heat dissipating spacer having a high thermal conductivity the cooling bolt penetrates the material And wherein the door.

The present invention also includes a rotor having a rotor shaft and a rotor core, a plurality of laminated structures provided on the radially outer side of the rotor core and each having a plurality of electromagnetic steel sheets, and the plurality of laminated structures. A stator having a cylindrical stator core comprising a plurality of clamping bolts axially bound and a stator winding axially passing through the stator core; the rotor core and the stator A coupling-side bearing and an anti-coupling-side bearing for supporting the rotor shaft on both sides of the rotor shaft in an axial direction sandwiching the rotor core, the coupling-side bearing and the anti-coupling side bearing; A coupling bearing bracket and an anticoupling bearing bracket which are respectively fixedly supported and connected to the end of the frame in the axial direction, and are attached to the rotor shaft to drive a cooling gas. A stator cooling structure for cooling the stator core of a rotating electrical machine including an internal fan, the cooling gas being radially interposed from the inside in the radial direction between the stacked structures axially adjacent to each other A plurality of ducts formed to flow outward, and a plurality of ducts circumferentially spaced from each other, axially penetrating to contact each of the laminated structure, and a material having a thermal conductivity higher than that of the material of the tightening bolt A plurality of cooling bolts using the plurality of nuts and a plurality of nuts engaged with the plurality of cooling bolts, and at least one of the plurality of ducts, the thermal conductivity through which the cooling bolts pass And a heat dissipation spacer using a high material .

  According to the present invention, it is possible to secure the cooling efficiency without significantly affecting the efficiency of the rotating electrical machine.

FIG. 2 is an elevation sectional view cut along a rotation axis showing a configuration of a rotary electric machine according to a first embodiment. It is a half longitudinal cross-sectional view of the stator core of the rotary electric machine which concerns on 1st Embodiment which shows the structure of the II-II arrow of FIG. It is a half front view in the III-III arrow line of Drawing 2 seen from the direction of an axis of the stator core of the rotation electrical machinery concerning the 1st embodiment to the direction outside. FIG. 4 is a cross-sectional view taken along a line IV-IV in FIG. 2, showing a stator cooling structure of the rotary electric machine according to the first embodiment. FIG. 6 is a partial cross-sectional view of the stator cooling structure cut along the rotation axis for explaining the operation of the stator cooling structure of the rotating electrical machine according to the first embodiment; It is a half longitudinal cross-sectional view of the VI-VI arrow of FIG. 7 which shows the structure of the stator core of the rotary electric machine which concerns on 2nd Embodiment. FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6, viewed from the axial direction outer side of the stator core, showing the stator cooling structure of the rotary electric machine according to the second embodiment; It is a fragmentary sectional view showing a modification of stator cooling structure of rotation electrical machinery concerning a 2nd embodiment.

  Hereinafter, with reference to the drawings, a rotating electrical machine according to an embodiment of the present invention will be described. Here, parts that are the same as or similar to each other are given the same reference numerals, and duplicate explanations are omitted.

First Embodiment
FIG. 1 is an elevation sectional view cut along a rotation axis showing a configuration of a rotary electric machine according to a first embodiment. The rotary electric machine 200 has a rotor 10, a stator 20, a frame 40, and a stator cooling structure 100 (see FIG. 2).

  The rotor 10 has a rotor shaft 11 extending horizontally in the rotation axis direction, and a rotor core 12 provided radially outward of the rotor shaft 11. In the rotor shaft 11, inner fans 51a and 51b are attached to both sides in the axial direction of the rotor core 12, respectively.

  The stator 20 has a cylindrical stator core 21 provided radially outward of the rotor core 12, and a stator winding 22 penetrating in the vicinity of the radially inner surface of the stator core 21 in the rotational axis direction. .

  The frame 40 surrounds the radially outer sides of the stator 20 and the rotor core 12 so as to accommodate them. Anti-coupling side bearing brackets 45a and coupling side bearing brackets 45b are provided on both sides in the rotational axis direction of the frame 40, and fixedly support the non-coupling side bearings 30a and the coupling side bearings 30b, respectively. At the top of the frame 40, a cooler 60 is provided. Hereinafter, of the two directions parallel to the rotation axis, the direction (right direction in FIG. 1) from the rotor core 12 toward the non-coupling bearing 30a is the non-coupling direction, and from the rotor core 12 to the coupling bearing 30b The direction toward the direction (left direction in FIG. 1) is referred to as the coupling side direction.

  An outer fan 55 is provided on one side (anti-coupling side direction) of the rotor shaft 11 in order to cool the rotary electric machine 200 by itself. Further, on the other side (coupling side direction) of the rotor shaft 11, there is provided a coupling portion 11a for coupling with a driving object in the case of an electric motor or a motor in the case of a generator. An outer fan cover 56 is attached to the frame 40 and the end plate 62 a so as to cover the outer fan 55. The outer fan cover 56 is formed with an inflow port 56a which is an intake port of the outside air.

  The cooler 60 has a plurality of cooling pipes 61, a cooler cover 63 for housing the cooling pipes 61, end plates 62a and 62b, and guide plates 66a and 66b. The end plates 62 a and 62 b are provided on both sides in the rotational axis direction of the cooler cover 63.

  The plurality of cooling pipes 61 are arranged in parallel to one another and extend in the rotational axis direction. Each of the cooling pipes 61 passes through the end plates 62a and 62b at both ends, and is fixed and supported by the end plates 62a and 62b. Both ends of each cooling pipe 61 are open.

  The frame 40, the non-coupling bearing bracket 45a, the coupling bearing bracket 45b, the cooler cover 63, and the end plates 62a and 62b together form a closed space 40a. Further, in the cooler 60, the cooling pipe 61 is also an element forming the sealed space 40a, and the outside of the cooling pipe 61 is a part of the sealed space 40a. The space in the frame 40 constituting the enclosed space 40a and the space in the cooler cover 63 communicate with each other at the cooler inlet opening 64 and the cooler outlet openings 65a and 65b.

  The inside of the enclosed space 40a is filled with a cooling gas such as air, for example. The cooling gas is driven by the inner fans 51a and 51b to circulate in the closed space 40a. The cooling gas driven by the inner fans 51a and 51b flows into the rotor core 12 and the stator 20 from both sides in the axial direction.

  The cooling gas passing through and cooling the rotor core 12 and the stator 20 flows out to the stator core radial outer space 41 and flows into the cooler 60 via the cooler inlet opening 64. The cooling gas that has flowed into the cooler 60 passes between the guide plate 66 a and the end plate 62 a while passing through the outside of the cooling pipe 61 while being cooled by the outer surfaces of the plurality of cooling pipes 61. Thereafter, the direction is changed in the upper communication space 67 to separate into two directions.

  The cooling gas, which has been turned in the anti-coupling side direction, is turned downward further and passes through the outside of the cooling pipe 61 while being cooled by the outer surfaces of the plurality of cooling pipes 61 between the guide plate 66a and the end plate 62a. And then exit the cooler 60 via the cooler outlet opening 65a. The cooling gas that has flowed out of the cooler 60 flows into the frame 40 and flows into the internal fan 51a.

  The cooling gas, which has been turned in the coupling side direction, is turned downward further and passes through the outside of the cooling pipe 61 while being cooled by the outer surfaces of the plurality of cooling pipes 61 between the guide plate 66b and the end plate 62b. , And then flow out of the cooler 60 via the cooler outlet opening 65b. The cooling gas flowing out of the cooler 60 flows into the frame 40 and flows into the internal fan 51b.

  FIG. 2 is a longitudinal sectional view taken along line II-II in FIG. 3 showing the configuration of the stator core of the rotary electric machine according to the first embodiment. Moreover, FIG. 3 is a half front view of III-III arrow of FIG. 2 seen from the axial direction outer side of a stator core.

  The stator core 21 has a plurality of laminated structures 23 in which a plurality of ferromagnetic members, for example, electromagnetic steel plates such as silicon steel plates, are laminated in the axial direction to form one group, and a plurality of laminated structures laminated in the axial direction It has two end clamping plates 25 clamping the body 23 from both sides in the axial direction, a plurality of clamping bolts 27 and nuts 27 a clamping the end clamping plates 25, and a stator cooling structure 100.

  The stator cooling structure 100 has a plurality of cooling bolts 28 and nuts 28 a, and a plurality of spacers 24 (FIG. 4) that form a plurality of ducts 24 a between the laminated structures 23. The material of the cooling bolt 28 is, for example, a thermally good conductor such as aluminum or copper, that is, a material having a high thermal conductivity.

  The electromagnetic steel plate constituting the laminated structure 23 is a perforated disc in which a circular opening through which the rotor penetrates is formed at the center. The stacked structure 23 adjacent to each other forms a duct 24 a which is a space having a gap in the axial direction. Each duct 24a is maintained in gap size by the spacer 24 (FIG. 4). The ducts 24 a are formed to be spaced apart from each other in the axial direction of the stator core 21. The duct 24a is a flow path in which the cooling gas flowing into the gap 18 (see FIG. 1) or the cooling gas flowing radially out of the rotor core 12 flows radially inward from the radially inner side.

  The two end clamping plates 25 are perforated discs having a circular opening at the center. Clamping bolts 27 and cooling bolts 28 alternately pass through the end clamping plates 25 circumferentially spaced from one another. Since the plurality of tightening bolts 27 and the corresponding nuts 27 a fasten the stator core 21 from both sides in the axial direction via the end tightening plates 25, the number is the strength of each tightening bolt 27 and the stator It is determined in consideration of the reaction force from the iron core 21.

  As shown in FIG. 3, the clamping bolts 27 and the cooling bolts 28 are alternately arranged. However, it is not limited to this. If the strength of the end clamping plate 25 is satisfactory and dimensionally satisfied, two or more cooling bolts may be disposed between the clamping bolts 27 adjacent to each other.

  As shown in FIG. 3, the central positions of the penetration positions of the tightening bolt 27 and the cooling bolt 28 are substantially the same as the radial outer peripheral surface of the laminated structure 23. This is to minimize the presence of the clamping bolts 27 and the cooling bolts 28 as magnetic resistance in the stator core 21 in the region through which the magnetic lines of force pass. However, if there is no problem in the magnetic performance, it is preferable in terms of cooling performance that the cooling bolts 28 be disposed radially inside the stator core 21 which is a higher temperature region.

  A plurality of axially extending slots 21 b are formed on the inner side in the radial direction of the laminated structure 23 at intervals in the circumferential direction. Further, as a result, a plurality of teeth 21a are formed. The conductor of the stator winding 22 is disposed in each of the slots 21b.

  Between the outermost one in the axial direction in the laminated structure 23 and the end clamping plate 25, a perforated disk-shaped end retainer 26 is disposed. The end presser 26 has a plurality of radially inward projections, each pressing the end of the tooth 21 a in the axial direction.

  FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2 and showing a stator cooling structure. The cross section perpendicular | vertical to an axial direction shows the cross section cut | disconnected in the position of the duct 24a. A plurality of spacers 24 extending in the radial direction and arranged radially are attached to the electromagnetic steel plates constituting the laminated structure 23. The angular position in the circumferential direction of each spacer is the angular position at which the clamping bolt 27 is provided, and the cooling gas flows from the radially inner side to the outer side in the respective angular regions sandwiched therebetween.

  FIG. 5 is a partial cross-sectional view of the stator cooling structure taken along the rotation axis for explaining the operation of the stator cooling structure. A duct 24 a is formed between the laminated structures 23 adjacent to each other. Illustration of a spacer for securing the axial width of the duct 24a is omitted. The solid line shows the flow of the cooling gas.

  The broken arrows in FIG. 5 indicate the transfer of heat generated in the stator core 21. In the laminated structure 23, a plurality of electromagnetic steel plates are axially stacked, for example, through an insulating film, and the flow of heat is basically as shown by H1 in FIG. Heat transfer is the main factor. Further, since the conductor for the stator winding 22 generating Joule heat is disposed radially inward, the temperature distribution in the stator core 21 basically becomes lower toward the radially outer side, so the diameter The heat transfer from the inside to the outside is the main direction.

  The radially outer cooling bolts 28 alternately have high temperature areas in contact with the laminated structure 23 and low temperature areas open in the duct 24 a in the axial direction. When the heat transferred in the laminated structure 23 reaches the cooling bolt 28, it moves in the cooling bolt 28 to the low temperature side opened in the duct 24a as indicated by the broken arrows H2 and H3.

  The heat transferred to the low temperature side in the cooling bolt 28 as indicated by the broken arrows H2 and H3 is respectively cooled by the cooling gas flowing in the duct 24a, and as indicated by the broken arrows H4 and H5, the stator core radially outward It is dissipated into the space 41.

  As described above, the stator cooling structure 100 in the present embodiment can enhance the removal of heat generated in the stator 20. As a result, the cooling efficiency can be ensured without significantly affecting the efficiency of the rotary electric machine.

Second Embodiment
FIG. 6 is a longitudinal cross-sectional view of the stator core of the rotary electric machine according to the second embodiment taken along the line VI-VI in FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6, viewed from the axial direction outer side of the stator core, showing the stator cooling structure.

  The second embodiment is a modification of the first embodiment. The stator cooling structure 100 in the present embodiment further includes a plurality of heat dissipation spacers 29. The heat dissipating spacer 29 also has a role of a spacer for forming the duct 24 a. As the spacer, a spacer may be provided in addition to the heat dissipating spacer 29, or the heat dissipating spacer 29 alone may be provided.

  Each of the heat radiation spacers 29 radially extends in the mounted state, and a cooling bolt 28 passes through the central portion thereof. The radially inner portion of the heat dissipating spacer 29 is narrowed toward the radially inner side, and the radially outer portion protrudes radially outward of the laminated structure. The heat dissipating spacer 29 is preferably made of a thermally good conductor such as aluminum or copper, that is, a material having a high thermal conductivity.

  The heat dissipating spacer 29 has an example in which the tip is pointed in FIG. 7, but the heat dissipating spacer 29 may be rounded as long as the flow resistance in the radial direction of the cooling gas can be reduced. Alternatively, the angle of the tip may be large. In order to prevent the heat dissipating spacer 29 from rotating about the cooling bolt 28, a protrusion or the like (not shown) for preventing rotation is provided on one of the heat dissipating spacer 29 or the cooling bolt 28 to form a fitting structure (not shown). .

  Although FIG. 6 shows the case where the heat dissipating spacer 29 is provided in all the ducts 24a, the heat dissipating spacer 29 may not necessarily be provided in all the ducts 24a. For example, the heat dissipating spacer 29 may be partially provided in the duct 24 a on the axial flow rate distribution of the cooling gas in the gap 18.

  Although FIG. 7 shows the case where the heat dissipating spacers 29 are provided for all the cooling bolts 28, the heat dissipating spacers 29 may be provided for only a part of the cooling bolts 28.

  When the heat dissipating spacer 29 is not provided, the area of the cooling bolt 28 that can dissipate heat by the duct 24 a is only the surface area of a length corresponding to the axial gap of the duct 24 a. On the other hand, by providing the heat dissipating spacer 29, the heat dissipating area in the duct 24a is increased, and the cooling performance is improved.

  FIG. 8 is a partial cross-sectional view showing a modification of the stator cooling structure of the rotary electric machine according to the second embodiment. In this modification, the cross section of the cooling bolt 28 is a square, and the heat dissipating spacer 29 through which the cooling bolt 28 passes is prevented from rotating about the cooling bolt 28. By setting it as such a shape, processing burdens, such as a fitting structure for rotation prevention, can be reduced.

Other Embodiments
While the embodiments of the present invention have been described above, the embodiments are presented as examples and are not intended to limit the scope of the invention. For example, in the embodiment, the case where the rotating electrical machine is a horizontal type is shown, but the present invention is not limited thereto, and may be a vertical case. Further, in the embodiment, the case where the rotating electrical machine is the totally closed outer fan type is shown, but the invention is not limited thereto, and may be an open type.

  Furthermore, the embodiment can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. The embodiments and the modifications thereof are included in the invention described in the claims and the equivalents thereof as well as included in the scope and the gist of the invention.

  DESCRIPTION OF SYMBOLS 10 ... Rotor 11, 11 ... Rotor shaft, 11a ... Coupling part, 12 ... Rotor core, 18 ... Gap, 20 ... Stator, 21 ... Stator core, 21a ... Tees, 21b ... Slot, 22 ... Stator winding Wire, 23: laminated structure, 24: spacer, 24a: duct, 25: end clamping plate, 26: end pressing, 27: clamping bolt, 27a: nut, 28: cooling bolt, 28a: nut, 29 ... Heat dissipation spacer, 30a: anti-coupling side bearing, 30b: coupling side bearing, 40: frame, 40a: sealed space, 41: stator core radial direction outer space, 45a: anticoupling side bearing bracket, 45b: coupling side bearing bracket, 51a, 51b ... inner fan, 55 ... outer fan, 56 ... outer fan cover, 56a ... inlet, 60 ... cooler, 61 ... cooling pipe, 62a, 62b ... end plate, 62c ... cooling pipe Through hole, 63: cooler cover, 64: cooler inlet opening, 65a, 65b: cooler outlet opening, 66a, 66b: guide plate, 67: upper communication space, 100: stator cooling structure, 200: totally closed outer sector Electric rotating machine

Claims (5)

A rotor having an axially extending and rotatably supported rotor shaft, and a rotor core provided radially outward of the rotor shaft;
The stator core comprises a stator cooling structure, a plurality of laminated structures each having a plurality of electromagnetic steel plates, and a plurality of fastening bolts axially binding the plurality of laminated structures, provided on the radially outer side of the rotor core. A stator having a cylindrical stator core and a stator winding axially passing through the stator core;
A frame disposed radially outward of the stator and housing the rotor core and the stator;
A coupling side bearing and an anticoupling side bearing for supporting the rotor shaft on both sides of the rotor shaft in the axial direction sandwiching the rotor core;
A coupled bearing bracket and a non-coupled bearing bracket for fixedly supporting the coupled bearing and the non-coupled bearing respectively and connecting them to the end of the frame in the axial direction;
An internal fan attached to the rotor shaft to drive a cooling gas;
A rotating electric machine equipped with
The stator cooling structure is
A spacer which is interposed between the laminated structures axially adjacent to each other to form each of a plurality of ducts in which the cooling gas flows radially inward from radially inward;
A plurality of cooling bolts and a plurality of cooling bolts each made of a material having a thermal conductivity higher than that of the material of the fastening bolt are axially penetrated so as to contact with each of the plurality of laminated structures. With multiple nuts to
A heat dissipating spacer using a material having high thermal conductivity, which is disposed in at least one of the plurality of ducts and through which the cooling bolt passes;
A rotary electric machine characterized by having: The heat dissipating spacer extends in the radial direction, and the radially inner portion is narrowed toward the inner side in the radial direction, and the radially outer portion protrudes radially outward more than the laminated structure. The rotating electrical machine according to claim 1, wherein The rotating electrical machine according to claim 1 , wherein the cooling bolt is disposed in a circumferential direction at a distance from the tightening bolt . The rotary electric machine according to any one of claims 1 to 3, further comprising a cooler that cools the cooling gas .   A plurality of rotors having a rotor shaft and a rotor core, and a plurality of lamination structures provided on the radially outer side of the rotor cores and having a plurality of electromagnetic steel plates and a plurality of lamination structures in the axial direction A stator having a cylindrical stator core provided with the following tightening bolts, and a stator winding axially passing through the stator core, a frame for housing the rotor core and the stator, A coupling side bearing and an anticoupling side bearing for supporting the rotor shaft on both sides of the rotor shaft in an axial direction sandwiching the rotor core, and a coupling side bearing and an anticoupling side bearing are respectively fixed and supported in the axial direction And an anti-coupling bearing bracket connected to the end of the frame, and an inner fan attached to the rotor shaft and driving a cooling gas. The stator core of a rotating electric machine a stator cooling structure for cooling that,
  A plurality of ducts which are formed so as to flow the cooling gas radially outward from the radially inner side by being sandwiched between the laminated structures axially adjacent to each other;
  A plurality of cooling bolts and a plurality of coolings, which are circumferentially spaced from each other and axially penetrated so as to contact each of the laminated structures, and using a material having a thermal conductivity higher than that of the material of the tightening bolt A plurality of nuts screwed to each of the bolt
  A heat dissipating spacer using a material having high thermal conductivity, which is disposed in at least one of the plurality of ducts and through which the cooling bolt passes;
  Stator cooling structure characterized by having.

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