JP2012070552A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool rotor bars efficiently.SOLUTION: A rotary electric machine comprises: a first steel plate group having laminated layers of first steel plates which include first steel plate group slots with circumferential intervals; a second steel plate group 20 having laminated multiple layers of second steel plates 21 which include second steel plate group slots 22; and rotor bars 41 which penetrate the first steel plate group slots and the second steel plate group slots 22. The circumferential position of the second steel plate group slots 22 is same as the one of the first steel group slots. Grooves 15 having openings, which are covered by surfaces of the rotor bars 41 when the rotor bars 41 are inside the first steel plate slots, are arranged inside the first slots to form axial flow paths 19. When the rotor bars 41 are inside the second steel plate slots, rotor bar surrounding gaps 25 are formed between the inner surfaces of the second steel plate group slots 22 and the outer surfaces of the rotor bars 41. The rotor bar surrounding gaps 25 form radial flow paths 29. The axial flow paths 19 communicate with the radial flow paths 29 to form gaseous medium flow paths 30.

Description

  The present invention relates to a rotating electrical machine capable of circulating a gas medium in a rotor.

  A rotary electric machine such as an induction motor includes a rotor that rotates around a rotation axis, a stator that surrounds the rotor while maintaining a radial gap in the rotor, and a frame that accommodates the stator and the like. The rotor has a rotor core formed by laminating a plurality of steel plates. Some rotors are attached to the rotor core so that a metal bar (rotor bar) penetrates in the axial direction.

  When electric power is supplied to the stator windings, a rotating magnetic field is generated around the rotor core. At this time, the rotor bar generates heat because an induced current flows. The heat generation promotes deterioration of the insulating member attached to the rotor bar. For this reason, it is necessary to suppress the temperature rise of the rotor bar.

  As a method for suppressing the temperature rise, for example, as disclosed in Patent Document 1, a method is known in which a notch groove extending in the axial direction is formed in the rotor bar, and the notch groove circulates cooling air. .

JP-A-10-178755

  In the cooling method as described above, cooling air flows in the axial direction. Even in the case of a large rotating electrical machine in which the axial dimension of the rotor is large, the cooling gas medium flows into the notch groove at one axial end of the rotor and flows in the axial direction. In this case, the temperature of the gas medium is higher on the downstream side than on the upstream side. In this case, the rotor bar can be cooled on the upstream side, but it may be difficult to cool efficiently on the downstream side.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to enable efficient cooling of the rotor bar.

  In order to achieve the above object, a rotating electrical machine according to the present invention includes a rotating shaft that rotates around a predetermined axis and a surface that extends in a radial direction and a circumferential direction, so that the rotating shaft is surrounded from the outside in the radial direction. A rotor core formed by laminating a plurality of substantially disc-shaped steel plates fixed to the outer periphery of the shaft in the axial direction, the rotor rotating together with the rotating shaft, and passing through the rotor core in the axial direction In the rotating electrical machine having a bar having a conductive property and a stator configured to surround the rotor from the outside in the radial direction, the plurality of steel plates are radially outer ends. A plurality of first slots facing inward from each other are stacked in a circumferential direction so that the circumferential positions of the first slots are equal to each other. A plurality of first steel plate groups and the front A plurality of second steel plates arranged so as to be sandwiched between first steel plate groups and having a plurality of second slots extending inwardly from the radially outer end, and spaced apart from each other in the circumferential direction; and The rods are arranged so as to penetrate the first slots and the second slots in the axial direction, and the first slots can be fitted with the rods, respectively, When a bar is present, a groove whose opening is covered with the surface of the bar is formed, and when the first steel plates are laminated in the axial direction, the grooves having the same circumferential position communicate with each other in the axial direction. An axial flow path through which the gas medium can flow, and each of the second slots has an inner surface and an opening edge of each second slot and an outer peripheral surface of the rod when the rod is inside. A bar peripheral gap is formed between the bar peripheral gap, A radial flow path through which the gas medium can flow in a radial direction, and the axial flow path and the radial flow path are configured to communicate with each other to form a gas medium flow path; Features.

  According to the present invention, the rotor bar can be efficiently cooled.

1 is a schematic front view of a rotating electrical machine according to a first embodiment of the present invention. It is a general | schematic partial cross-sectional view which shows a part of II-II arrow view of FIG. It is a general | schematic fragmentary cross-sectional view which shows a part of III-III arrow view of FIG. FIG. 3 is a schematic partial perspective view schematically showing a part of the second steel plate group and the like in FIG. 1. It is a schematic front view of the rotor etc. of the rotary electric machine of 2nd Embodiment which concerns on this invention.

  Hereinafter, embodiments of a rotating electrical machine according to the present invention will be described with reference to the drawings.

[First Embodiment]
A rotating electrical machine according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic front view of the rotating electrical machine of the present embodiment. FIG. 2 is a schematic partial cross-sectional view showing a part of the view taken along the line II-II in FIG. FIG. 3 is a schematic partial cross-sectional view showing a part of the view taken along arrows III-III in FIG. FIG. 4 is a schematic partial perspective view schematically showing a part of the second steel plate group 20 and the like of FIG.

  First, the configuration of the rotating electrical machine of the present embodiment will be described.

  The rotating electrical machine includes a rotating shaft 1 that rotates around a horizontal axis, a substantially cylindrical rotor 2 that rotates together with the rotating shaft 1, and a plurality of bar members that are disposed so as to penetrate the rotor 2 in the axial direction. (Rotor bar 41), a short-circuit ring 42, a stator 4 configured to surround the rotor 2 from the outside in the radial direction, and a frame (not shown) for housing them.

  Although detailed illustration is omitted, an air suction port and an air exhaust port are formed above the frame (vertically above). The air inlet is formed in the vicinity of the upper part of the end portions on both axial sides of the rotor 2. The air exhaust port is formed at the center in the axial direction of the rotor 2.

  A fan (not shown) for sucking air is provided in the frame. This fan generates an air flow in the frame. The air circulates along a cooling air channel 30 described later.

  A predetermined radial gap 3 is formed between the radially outer side of the rotor 2 and the radially inner side of the stator 4. The radial gap 3 allows air to flow along the axial direction.

  The rotor 2 has a rotor core. This rotor core has a plurality of steel plates, and these are laminated. These steel plates include two types of steel plates, that is, a first steel plate 11 and a second steel plate 21.

  The first steel plate 11 has a surface extending in the radial direction and the circumferential direction, that is, a surface perpendicular to the rotating shaft 1, and a perforated circle fixed to the outer periphery of the rotating shaft 1 so as to surround the rotating shaft 1 from the outside in the radial direction. It is plate-shaped. A plurality of first steel plate group slots 12 are formed on the outer side in the radial direction of the first steel plate 11 so as to go inward from the outer peripheral end. These first steel plate group slots 12 are formed at intervals in the circumferential direction along the circumferential direction (FIG. 2).

  Similar to the first steel plate 11, the second steel plate 21 has a surface extending in the radial direction and the circumferential direction, and is a perforated disc fixed to the outer periphery of the rotary shaft 1 so as to surround the rotary shaft 1 from the outside in the radial direction. Is. A plurality of second steel plate group slots 22 are formed on the outer side in the radial direction of the second steel plate 21 so as to go inward from the outer peripheral end. These 2nd steel plate group slots 22 are formed in the circumferential direction at intervals in the circumferential direction (FIG. 3).

  The rotor core includes a first steel plate group 10 having a plurality of first steel plates 11 and a second steel plate group 20 having a plurality of second steel plates 21.

  The first steel plate group 10 includes a plurality of first steel plates 11 laminated in the axial direction. Four first steel plate groups 10 of the present embodiment are arranged in the axial direction with an axial interval therebetween. The second steel plate group 20 is inserted into each axial interval. The first steel plates 11 are laminated so that the circumferential positions of the first steel plate groups slots 12 of the first steel plates 11 of the first steel plate groups 10 are the same. That is, the first steel plate group slot 12 having the same circumferential position forms a through hole penetrating in the axial direction.

  The second steel plate group 20 includes a plurality of second steel plates 12 laminated in the axial direction. As described above, the second steel plate group 20 of the present embodiment is inserted between the first steel plate groups 10 adjacent in the axial direction. That is, the rotor 2 has three second steel plate groups 20. Each second steel plate group 20 is sandwiched and fixed between first steel plate groups 10 on both axial sides.

  The second steel plates 21 are laminated such that the circumferential positions of the second steel plate groups slots 22 of the second steel plates 21 of the second steel plate group 20 are the same.

  The circumferential position of each second steel plate group slot 22 is arranged to be the same as the circumferential position of the first steel plate group slot 12. That is, the first steel plate group slot 12 and the second steel plate group slot 22 having the same circumferential position form a through hole penetrating in the axial direction. The cross-sectional shape perpendicular to the axial direction of the first and second steel plate group slots 12 and 22 will be described later.

  The rotor bar 41 is made of a conductive material such as a copper alloy, and is disposed so as to be fitted into each of the through holes formed by the first steel plate group slot 12 and the second steel plate group slot 22. An axial end portion of each rotor bar 41 protrudes axially outward from the axial end portion of the rotor 2. That is, each rotor bar 41 is disposed such that the axial end portion is on the axially outer side than the first steel plate 11 at the axial end portion of the first steel plate group 10.

  The short-circuit ring 42 is a ring-shaped member formed of a conductive material, and is disposed on each side of the rotor 2 in the axial direction. Each of the short-circuit rings 42 electrically connects each rotor bar 41 protruding from the axial end (left side in FIG. 1).

  Each first steel plate group slot 12 has a cross-sectional shape perpendicular to the axial direction substantially the same as the cross-section of the rotor bar 41, and the rotor bar 41 can be fitted therein. The outer surface in the radial direction of the rotor bar 41 when fitted in the first steel plate group slot 12 faces the radial gap 3 described above.

  A first steel plate group groove 15 is formed on the radially inner side of each first steel plate group slot 12, that is, on the bottom of the first steel plate group slot 12. The opening of the first steel plate group groove 15 is covered with the surface of the rotor bar 41 when the rotor bar 41 is in the first steel plate group slot 12. When the first steel plates 11 are laminated in the axial direction, the first steel plate group grooves 15 having the same circumferential position are linearly communicated in the axial direction so that a gas medium (air) can flow therethrough. 19 is formed.

  Each of the second steel plate group slots 22 is formed so that the cross-sectional shape perpendicular to the axial direction is larger than the cross-section of the rotor bar 41. Therefore, when the rotor bar 41 is inside the second steel plate group slot 22, the second steel plate group slot 22 includes the inner surface of the second steel plate group slot 22 and the edge of the opening, and the outer peripheral surface of the rotor bar 41. A second steel plate group rotor bar peripheral gap 25 is formed between the two. The second steel plate group rotor bar peripheral gap 25 forms a radial flow path 29 through which air can flow in the radial direction (FIG. 3). Since the second steel plate group 20 is configured by laminating a plurality of second steel plates 21 in the axial direction, the gaps adjacent in the axial direction communicate with each other in the axial direction to form one radial flow path 29. To do.

  The axial flow paths 19 of the first steel plate group 10 on both the left and right sides in FIG. 1 communicate with the radial flow path 29, respectively. One cooling air flow path 30 is formed by the axial flow path 19 on both the left and right sides and the central radial flow path 29. That is, the cooling air flow path 30 is formed by the number of first steel plate group slots 12 formed in one first steel plate 11 and the number of second steel plate group slots 22 formed in one second steel plate 21. Is done.

  The stator 4 is formed with three ducts 4a. These ducts 4 a are formed on the outer sides in the radial direction of the respective second steel plate groups 20. In FIG. 1, the duct 4a is virtually shown by a two-dot chain line. These ducts 4 a are formed so that the air flowing inside is discharged to the outside in the radial direction of the stator 4.

  Then, the flow of the air for cooling the rotor bar 41 of the rotary electric machine of this embodiment is demonstrated.

  The fan is driven when the induction motor operates. Air outside the frame flows in from the air intake by driving the fan. The inflowed air flows into the radial gap 3 in the direction of arrow X1 in FIG. 1 from both axial sides of the rotor 2 toward the radial center. At this time, the air also flows into the axial flow path 19 on both axial sides.

  The air flowing through the radial gap 3 flows while cooling the outer peripheral surface of the first steel plate group 10 and the radially outer surface of the rotor bar 41. After the second steel sheet group 20 has circulated to the center in the axial direction, the air flows upward (in the direction of arrow X2 in FIG. 1) toward the air discharge port, and passes through the duct 4a formed in the stator 4. Then, it is discharged radially outward of the stator 4. The air discharged out of the stator 4 is discharged from the air discharge port.

  The air flowing through the axial flow path 19 flows into the radial flow path 29 of the second steel plate group 20 while cooling the first steel plate group 10 and the rotor bar 41. The air that has flowed into the radial flow path 29 flows outward in the radial direction and flows out into the radial gap 3. The air that has flowed into the radial gap 3 flows through the duct 4 a and is discharged to the outside in the radial direction of the stator 4. Thereafter, the air flows upward in FIG. 1 and is discharged from the air discharge port.

  As can be seen from the above description, according to the present embodiment, cooling air can be introduced from both axial sides of the rotor core and discharged as described above. For this reason, even when the rotating electrical machine becomes larger and the axial dimension of the rotor 2 becomes larger, the vicinity of the axial center of the rotor 2 can be efficiently cooled.

  In addition, according to the present embodiment, by forming the axial flow path 19 and the radial flow path 29, it is possible to cool the portions other than the radially outer surface of the rotor bar 41. For this reason, it becomes possible to cool the rotor bar 41 efficiently.

  Moreover, since the radial direction flow path 29 is formed in the 2nd steel plate group 20, the strength reduction of the periphery of the radial direction flow path 29 can be suppressed.

[Second Embodiment]
A rotating electrical machine according to a second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a schematic front view of the rotor 2 and the like of the rotating electrical machine of the present embodiment, and shows the first and second steel plate groups 10 and 20 and the rotor bar 41 and the like of the rotating electrical machine. In addition, this embodiment is a modification of 1st Embodiment (FIGS. 1-4), Comprising: The same code | symbol is attached | subjected to the same part or similar part as 1st Embodiment, and duplication description is carried out. Omitted.

  The rotor 2 of the rotating electrical machine according to the present embodiment has six first steel plate groups 10 and five second steel plates 21. The six first steel plate groups 10 are arranged at intervals in the axial direction. One second steel plate 21 is inserted into each interval. That is, the rotor 2 of this embodiment is arrange | positioned so that the 1st steel plate group 10 and the 2nd steel plate 21 may become alternate from the left, as shown in FIG. Each second steel plate 21 is sandwiched and fixed between first steel plate groups 10 on both axial sides.

  Since cooling air flows radially outward at a position where the second steel plate 21 is present, the cooling distribution in the axial direction of the rotor bar 41 in the rotor 2 becomes more uniform, and the rotor 2 can be efficiently cooled. It becomes possible.

[Other Embodiments]
The description of the above embodiment is an example for explaining the present invention, and does not limit the invention described in the claims. Moreover, each part structure of this invention is not restricted to this embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

  For example, in the second embodiment, each of the five second steel plates 21 may be changed to five second steel plate groups 20. Further, five or more second steel plate groups 20 may be arranged.

  Moreover, in 1st and 2nd embodiment, although it is comprised so that air may distribute | circulate from the axial direction both sides of the rotor 2, it is not restricted to this. You may comprise so that air may flow from the one side of the axial direction of the rotor 2. FIG.

DESCRIPTION OF SYMBOLS 1 ... Rotary shaft, 2 ... Rotor, 3 ... Radial space | gap, 4 ... Stator, 4a ... Duct, 10 ... 1st steel plate group, 11 ... 1st steel plate group, 12 ... 1st steel plate group slot, 15 ... 1st Steel plate group groove, 19 ... axial flow path, 20 ... second steel plate group, 21 ... second steel plate, 22 ... second steel plate group slot, 25 ... second steel plate group rotor bar peripheral gap, 29 ... radial flow path, 30 ... cooling air flow path, 41 ... rotor bar, 42 ... short-circuit ring

Claims (8)

A rotation axis that rotates around a predetermined axis;
A rotor core formed by laminating a plurality of substantially disc-shaped steel plates that are fixed to the outer periphery of the rotary shaft so as to surround the rotary shaft from the outer side in the radial direction and have surfaces that extend in the radial direction and the circumferential direction. A rotor that rotates together with the rotating shaft;
A rod provided with conductive properties arranged to penetrate the rotor core in the axial direction;
A stator configured to surround the rotor from outside in the radial direction;
In a rotating electrical machine having
The plurality of steel plates are:
A plurality of first steel plates in which a plurality of first slots directed inward from the radially outer end are formed in a circumferential direction with a circumferential interval therebetween are laminated, and the circumferential positions of the first slots are the same as each other. A plurality of first steel plate groups configured to be;
A plurality of second steel plates arranged so as to be sandwiched between the first steel plate groups, and having a plurality of second slots directed inward from the radially outer end portions, and spaced apart from each other in the circumferential direction; Including,
The bar is disposed so as to penetrate each first slot and each second slot in the axial direction,
Each of the first slots is formed with a groove in which the bar can be fitted, and the opening is covered with the bar surface when the bar is inside,
When the first steel plates are laminated in the axial direction, the grooves having the same circumferential position form an axial flow path that communicates in the axial direction and allows a gas medium to flow.
When each of the second slots has the bar inside, a bar peripheral gap is formed between the inner surface and the opening edge of each second slot and the outer peripheral surface of the bar,
The bar peripheral gap forms a radial flow path through which the gas medium can flow in the radial direction,
The axial flow path and the radial flow path are configured to communicate with each other to form a gas medium flow path;
Rotating electric machine.   2. The rotating electrical machine according to claim 1, wherein the second steel plates are arranged with an axial interval therebetween, and the first steel plate group is arranged within the axial interval. Having at least one second steel plate group in which a plurality of the second steel plates are laminated in the axial direction;
The second steel plate group is configured such that the gap around the bar of the second slot of the second steel plate adjacent in the axial direction communicates in the axial direction to form one radial flow path. Being
The rotating electrical machine according to claim 1. A plurality of the second steel sheet groups are arranged with an axial interval therebetween,
Each said 2nd steel plate group being arrange | positioned so that it may be pinched | interposed into the said 1st steel plate group,
The rotating electrical machine according to claim 3. The second steel plate group is disposed in the center in the axial direction,
The first steel plate group is disposed on each of both axial sides of the second steel plate group;
The rotating electrical machine according to claim 3.   In the gas medium flow path, the gas medium flowing through the axial flow paths is discharged from the opening of the second slot to the outside in the radial direction of the second steel plate after flowing through the radial flow path. The rotating electrical machine according to any one of claims 1 to 5, wherein the rotating electrical machine is formed as described above.   The gas medium flow path flows into the radial flow path of each of the second steel plates after the gas medium flows from the axial flow path that opens at at least one axial end of the rotor core. The rotating electrical machine according to claim 6, wherein the rotating electrical machine is formed so as to be discharged from the opening of the second slot.   The said each bar is protruded in the axial direction both sides of the said rotor, The short circuit ring which connects the one axial direction edge part of each said bar is arrange | positioned, The 1 thru | or Claim characterized by the above-mentioned. Item 8. The rotating electrical machine according to any one of Items 7 to 9.

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