JP2013198240A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine that provides efficient cooling for a stator core, and the like, thereof.SOLUTION: A rotary electric machine includes: a stator core 31 that surrounds a rotor; a stator frame 40 which is arranged so as to surround the stator core 31 from a radially outer side and onto which the stator core 31 is fitted; and a plurality of plate-like radiating fins 45 that project radially outward from an outer circumferential surface of the stator frame 40 and extend axially and that are formed at predetermined circumferential intervals on the outer circumferential surface of the stator frame 40. The stator core 31 has a plurality of axial holes 34 that are formed, at predetermined circumferential intervals, nearer the radially outer side. Outer circumferential grooves 36 are formed, on a radially outer side of the axial holes 34, at circumferential positions that correspond to those of the axial holes 34 and that are located between adjacent pairs of the radiating fins 45.

Description

  The present invention relates to a rotating electrical machine having a stator core.

  The rotating electrical machine includes a rotor, a stator core that surrounds the rotor from the outside in the radial direction, and a stator frame that accommodates the stator core.

  A cooling fan is provided in the stator frame to cool the inside of the stator frame. Further, fins for heat dissipation are formed on the outside of the stator frame. In a fan-cooled rotating electrical machine, the contact surface pressure between the stator frame and the stator core is usually maintained by fitting such as shrink fitting.

  Heat generated from the stator windings or the like during operation of the rotating electrical machine is transmitted from the stator core to the stator frame and is radiated from the radiation fins.

  As a rotating electrical machine configured such that a stator frame is in contact with a stator core and heat is transmitted from the stator core to the stator frame, for example, the one disclosed in Patent Document 1 is known. Further, as disclosed in Patent Document 2, there is known a device that transfers heat by providing a heat transfer element or the like from a stator winding to a stator frame.

JP-A-6-141509 JP-A-63-144733

  Some stator iron cores are formed with through holes penetrating in the axial direction. This through hole includes one into which a bolt is inserted, one formed for weight reduction, and one serving as a cooling air flow path.

  The through hole is often formed in a portion close to the outer peripheral surface of the stator core. When the stator core is fixed to the stator frame by shrink fitting, the through hole is deformed to extend in the radial direction. In this case, the radially outer portion of the through hole in the outer peripheral surface of the stator core presses the inner surface of the stator frame more strongly than the outer peripheral surface of the other portion. As a result, the contact surface pressure acting between the outer peripheral surface of the stator core and the inner surface of the stator frame is reduced except for the portion having the through hole.

  The heat of the stator core is transmitted to the stator frame from the part where the contact surface pressure is large, but when the through hole is close to the outer peripheral surface of the stator core, the space between the through hole and the outer peripheral surface is thin. Therefore, there is a possibility that the heat cannot be circulated efficiently.

  As a result, heat transfer from the stator core to the stator frame may become inefficient. If the heat transfer efficiency is low, there arises a problem that a cooling device or the like for cooling the stator core or the like has to have a higher performance, and as a result, the manufacturing cost may increase.

  The present invention has been made to solve the above-described problems, and an object thereof is to efficiently transfer the heat of the stator core to the stator frame.

  In order to achieve the above object, a rotating electrical machine according to the present invention has a rotor that is rotatable around a predetermined axis, and a cylindrical shape that is disposed so as to surround the rotor from the outside in the radial direction, and has an opening on an inner peripheral surface. A stator core formed with an inner circumferential groove extending in the axial direction, a stator winding disposed so as to be partially inside the inner circumferential groove, and surrounding the stator core from the outside in the radial direction. A stator frame arranged to fit the stator core, and a plate-like shape projecting radially outward from the outer peripheral surface of the stator frame and extending in the axial direction. In the rotating electrical machine having a plurality of heat dissipating fins formed on the outer peripheral surface of the stator frame at intervals in the direction, the stator core has an axial hole on a radially outer side than the inner peripheral groove. A plurality of these are formed at intervals in the circumferential direction. An outer circumferential groove extending in the axial direction is formed outside the directional hole in the radial direction so that the circumferential position is aligned with each of the axial holes, and the circumferential position of each of the outer circumferential grooves is between the adjacent heat transfer fins. It is formed so that it may become.

  According to the present invention, it is possible to efficiently transfer the heat of the stator core to the stator frame.

1 is a schematic front sectional view of a rotating electrical machine according to an embodiment of the present invention. It is a partial side view which shows a part of II-II arrow view of FIG. FIG. 3 is an enlarged side view in which a periphery of an outer through hole in FIG. 2 is enlarged. It is a schematic side view which shows typically a deformation | transformation of the outer side through-hole of FIG. It is a comparative example of embodiment of FIG. 2, and is a schematic side view of a stator core etc. when there is no outer periphery groove | channel. FIG. 6 is a schematic front sectional view in which a spacing plate is added to the steel plate group in the modification of FIG. 1.

  Hereinafter, an embodiment of a rotating electrical machine according to the present invention will be described with reference to the drawings (FIGS. 1 to 5).

  FIG. 1 is a schematic front sectional view of a rotating electrical machine according to the present embodiment. FIG. 1 is a cross-sectional view of a portion of the stator frame 40 that houses the stator 30 and the like.

  FIG. 2 is a partial side view showing a part of the view taken along arrows II-II in FIG. In FIG. 2, illustration of the rotor 20 is omitted. FIG. 3 is an enlarged side view in which the periphery of the outer through hole 34 of FIG. 2 is enlarged. FIG. 4 is a schematic side view schematically showing deformation of the outer through hole 34 of FIG.

  FIG. 5 is a comparative side view of the embodiment of FIG. 2, and is a schematic side view of the stator core 31 and the like when there is no outer peripheral groove 36.

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

  As shown in FIG. 1, the rotating electrical machine includes a rotating shaft 10, a rotor 20, a stator 30, a stator frame 40, heat radiation fins 45, and a fan 48.

  The rotating shaft 10 rotates around a horizontally extending shaft and is rotatably supported by a bearing (not shown). The bearing is attached to the stator frame 40. The rotor 20 is fixed to the rotating shaft 10 and rotates coaxially with the rotating shaft 10.

  The stator 30 is configured to surround the rotor 20 from the outside in the radial direction, and includes a stator core 31 and a stator winding 38.

  The stator core 31 is a cylindrical member, and includes a plurality of steel plate groups 32 and presser plates 37 disposed on both sides in the axial direction. The holding plate 37 is formed with a ventilation path (not shown) extending in the radial direction. Cooling air for cooling the stator core 31 etc. flows through this ventilation path.

  The steel plate group 32 is formed by laminating a plurality of steel plates.

  Each steel plate has a perforated disk shape in which one central through hole 33, a plurality of outer through holes 34, a plurality of inner peripheral grooves 39, and a plurality of notches 35 are formed. The central through hole 33 and the outer through hole 34 will be described below with respect to those formed in the steel plate, and the central through hole 33 and the outer through hole 34 formed in the holding plate 37 are the same as those of each steel plate. Therefore, the description is omitted.

  When the steel plate group 32 in which the steel plates are laminated constitutes the stator core 31 together with the presser plate 37, the central through hole 33 of each steel plate communicates in the axial direction. The rotor 20 is inserted inside. The rotor 20 is disposed so as to maintain a predetermined gap 49 between the inner peripheral surface of the central through hole 33 communicating in the axial direction and the outer peripheral surface of the rotor 20.

  The inner circumferential groove 39 is a groove extending radially outward from the inner circumference (edge) of the central through hole 33. When the stator core 31 is configured, the inner circumferential grooves 39 of the respective steel plates communicate in the axial direction, and the stator windings 38 are inserted into the communicated inner circumferential grooves 39.

  A plurality of outer through holes 34 are formed at equal intervals in the circumferential direction on the outer side in the radial direction from the inner circumferential groove 39 of the steel plate. The cross-sectional shape in the axial direction of each outer peripheral through hole 34 is a circle. In this example, since the outer through holes 34 are arranged at equal intervals in the circumferential direction with the same dimensions, the outer through holes 34 arranged in the circumferential direction communicate with each other in the axial direction when the steel plates are stacked.

  Since the outer through-hole 34 is formed in the holding plate 37 as well as each steel plate, when the stator core 31 is formed, the outer through-hole 34 penetrates in the communication axial direction. The center through hole 33 of the press plate 37 is formed to have a larger hole diameter than the center through hole 33 formed in each steel plate so as not to interfere with the stator winding 38.

  The notch 35 is formed on the outer side in the radial direction of the outer peripheral through hole 34. Each notch 35 has a substantially semicircular cross-sectional shape in the axial direction. The circumferential position of the center of the semicircle is formed so as to be aligned with the circumferential position of the center (circular center) of the axial cross section of the outer through hole 34. When the steel plates are stacked, the notch 35 of each steel plate communicates in the axial direction and becomes the outer peripheral groove 36. In this example, the outer circumferential groove 36 extends from one axial end of the steel plate group 32 to the other axial end.

  Bolts (not shown) are inserted into some of these communicating outer through holes 34. Although illustration is omitted, the bolt heads and nuts are arranged so that they are on the axially outer side of the presser plates 37 on both sides in the axial direction, and the steel plate group 32 sandwiched between the presser plates 37 is tightened and fixed inward in the axial direction. .

  The fan 48 is attached to the rotary shaft 10 on the outer side in the axial direction of the rotor 20, rotates with the rotation of the rotary shaft 10, and causes cooling air to flow into the stator frame 40. At this time, the cooling air flows through the outer through hole 34 in which no bolt is inserted.

  The stator frame 40 is disposed so as to surround the stator 30 from the outside in the radial direction, and is configured to fit the stator core 31. The stator core 31 is fixed to the stator frame 40 by shrink fitting. That is, the stator core 31 is inserted in a state where the stator frame 40 is heated to expand the inner diameter of the portion where the stator core 31 is inserted, and then cooled to fix the stator core 31. The contact surface pressure between the outer periphery of the stator core 31 and the inner periphery of the stator frame 40 is maintained by fixing with shrink fitting.

  The presser plate 37 is formed so that the outer diameter is smaller than that of the steel plate group 32. That is, the presser plate 37 is not in contact with the inner surface of the stator frame 40. Further, in this example, the notch 35 is not formed in the presser plate 37.

  In addition, a bearing housing (not shown) for fixing the above-described bearing is attached to the axial end portion of the stator frame 40.

  A plurality of radiating fins 45 are formed on the outer periphery (radially outward) of the stator frame 40. Each of the heat dissipating fins 45 has a plate shape extending outward in the radial direction and extending in the axial direction, and is arranged in parallel at a predetermined circumferential interval.

  The direction in which the radiating fin 45 extends and the direction in which the outer through hole 34 communicates are the same and axial. In the present embodiment, as shown in FIG. 2, the outer peripheral groove 36 is formed at a position corresponding to the central circumferential position of the radiating fins 45 adjacent to each other in the circumferential direction.

  Next, the operation when the heat of the stator core 31 of the rotating electrical machine of the present embodiment is transmitted to the radiation fins 45 of the stator frame 40 will be described.

  When the rotating electrical machine is in an operating state, that is, when a current flows through the stator winding 38 and the rotary shaft 10 or the like is rotating, heat is generated from the stator winding 38, and this heat is generated in the stator core 31. It is transmitted. The heat transmitted to the stator core 31 is transmitted from the inner surface of the stator frame 40 to the heat radiation fins 45 and is radiated to the outside air.

  As described above, the stator core 31 is fitted to the stator frame 40 by shrink fitting. At this time, the outer peripheral hole receives a force (arrow B1 in FIG. 4) compressed in the circumferential direction as shown in FIG. By this force, it is deformed into a long ellipse (for example, an ellipse) in the radial direction (the direction of arrow B2 in FIG. 4). Due to the deformation, the steel plate group 32 on the outer side in the radial direction of the outer through hole 34 tends to be deformed toward the outer side in the radial direction.

  As shown in FIG. 5, when there is no outer circumferential groove 36, the contact surface pressure with the inner surface of the stator frame 40 applied to the portion where the radiation fins 45 are present on the outer circumferential surface of the steel plate group 32 is not present. It becomes larger than the contact surface pressure with the inner surface of the stator frame 40 relating to the portion. As a result, the contact surface pressure varies in the circumferential direction with a distribution as shown in C1 portion of FIG. 5, and the contact surface pressure of the relatively thin portion shown in C2 portion of FIG. 5 increases.

  The C1 portion shows a part of the distribution of contact surface pressure between the outer peripheral surface of the steel plate group 32 and the inner surface of the stator frame 40 when the outer peripheral groove 36 is not present, and when the contour of the C1 portion is above, the contact surface The pressure is high.

  On the other hand, in this embodiment, even when the outer through hole 34 is deformed as shown in FIG. 4, the outer peripheral groove 36 is formed, so that the steel plate corresponding to the circumferential position where the outer through hole 34 is located. The outer peripheral surface of the group 32 does not contact the inner surface of the stator frame 40. That is, the contact surface pressure does not act on the inner periphery of the stator frame 40 on the outer peripheral surface of the steel plate group 32 corresponding to the circumferential position where the outer through hole 34 is located.

  For this reason, the contact surface pressure is distributed as shown in part A of FIG. The part A shows a part of the distribution of contact surface pressure between the outer peripheral surface of the steel plate group 32 and the inner surface of the stator frame 40 when the outer peripheral groove 36 is present, and when the contour of the A part is above, the contact surface The pressure is high.

  As shown in part A, the formation of the outer circumferential groove 36 prevents the contact surface pressure acting on the inner surface of the stator frame 40 by the outer circumferential surface of the steel sheet group 32 from being extremely increased. As a result, the contact surface pressure approaches a state where the contact surface pressure acts more uniformly, and variations in heat transfer from the stator core 31 to the stator frame 40 can be suppressed.

  The radiating fin 45 is located at a position different from the circumferential position of the outer through hole 34 and the outer circumferential groove 36. That is, the radiation fin 45 is formed at a circumferential position corresponding to a portion where the contact surface pressure is more uniformly maintained. For this reason, the heat transmitted to the stator frame 40 is efficiently transmitted to the radiation fins 45.

  As can be seen from the above description, according to this embodiment, the heat of the stator core 31 can be efficiently transmitted to the stator frame. Further, since the cooling structure can be further simplified, the rotating electrical machine can be further reduced in size.

  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 the said embodiment, A various deformation | transformation is possible within the technical scope as described in a claim.

  Moreover, in the said embodiment, although the radiation fin 45 and the stator frame 40 are formed integrally, it is not restricted to this, A separate member may be sufficient.

  Moreover, although the outer through-hole 34 in the axial direction has been described with respect to one in which a bolt is inserted and one in which cooling air flows, the present invention is not limited thereto. It may be formed for weight reduction. In this case, it is not necessary to penetrate through a partially blocked state.

  In addition, although the stator core 31 is described as an example having the plurality of steel plate groups 32 and the pressing plates 37 disposed on both sides in the axial direction, the present invention is not limited to this. FIG. 6 is a schematic front sectional view in which a spacing plate 50 is added to the steel plate group 32 in the modification of FIG. As shown in FIG. 6, in the case of a large rotating electrical machine, the steel plate group 32 of FIG. 1 may be divided into two, and a spacing plate 50 may be disposed between them. In this case, the steel plate groups 32 and the spacing plates 50 may be arranged alternately in the axial direction and fixed in a state of being pressed against each other in the axial direction by the pressing plates 37 on both sides in the axial direction. Similar to the presser plate 37, a ventilation passage (not shown) extending in the radial direction is formed in the spacing plate 50. This ventilation path is configured such that the cooling air described above flows. A plurality of spacing plates 50 may be arranged, and the number thereof is determined by the axial dimension of the stator core 31.

  Further, the stator frame 40 may be sealed or opened.

  In this example, the circumferential position of the center of the semicircle of the outer circumferential groove 36 is formed so as to be aligned with the circumferential position of the center (circular center) of the axial cross section of the outer through hole 34. However, the circumferential position of each center may be slightly shifted. In this case, the semicircle and the circle may be formed so as to partially overlap in the radial direction.

  Moreover, although the outer peripheral groove | channel 36 is formed in the center of the radiation fin 45 adjacent to the circumferential direction mutually, it is not restricted to this. What is necessary is just between the radiation fins 45 adjacent to each other in the circumferential direction.

DESCRIPTION OF SYMBOLS 10 ... Rotating shaft 20 ... Rotor 30 ... Stator 31 ... Stator iron core 32 ... Steel plate group 33 ... Central through hole 34 ... Outer through hole 35 ... Notch 36 ... Outer peripheral groove 37 ... Presser plate 38 ... Stator winding 39 ... inner circumferential groove 40 ... stator frame 45 ... radiating fin 48 ... fan 49 ... gap 50 ... interval plate

Claims (8)

A rotor that can rotate around a predetermined axis;
A stator core that is arranged in a cylindrical shape so as to surround the rotor from the outside in the radial direction, and has an inner circumferential groove that opens in the inner circumferential surface and extends in the axial direction;
A stator winding arranged such that a portion is in the inner circumferential groove;
A stator frame arranged so as to surround the stator core from the outside in the radial direction and configured to fit the stator core;
A plurality of heat dissipating fins formed on the outer peripheral surface of the stator frame, each having a plate shape extending in the radial direction from the outer peripheral surface of the stator frame and extending in the axial direction; ,
In a rotating electrical machine having
In the stator core, a plurality of axial holes are formed on the outer side in the radial direction of the inner circumferential groove and spaced apart from each other in the circumferential direction. An outer circumferential groove extending in the axial direction is formed so that the circumferential position is aligned,
The circumferential position of each of the outer peripheral grooves is formed so as to be between the adjacent heat transfer fins,
Rotating electric machine.   The rotating electrical machine according to claim 1, wherein the axial hole penetrates in the axial direction.   3. The rotating electrical machine according to claim 2, wherein a bolt is inserted into a part of the axial holes, and the bolts together with the nuts fix the stator core so as to be compressed from the outside in the axial direction.   The rotating electrical machine according to claim 2, wherein the axial hole is configured to allow air to flow in an axial direction.   The stator iron core is configured by shrink fitting so that the stator frame is cooled and fixed in the stator frame after being inserted into the heated stator frame. The rotating electrical machine according to any one of claims 1 to 4. The cross-sectional shape perpendicular to the axial direction of the outer circumferential groove is a substantially semicircle,
The circumferential position of the center of the semicircle and the circumferential position of the center of the cross section perpendicular to the axial direction of the axial hole are aligned,
The rotating electrical machine according to any one of claims 1 to 5, wherein:   The rotation according to any one of claims 1 to 6, wherein the outer circumferential groove extends from one axial end of the stator core to the other axial end. Electric.   The rotating electrical machine according to any one of claims 1 to 7, wherein a circumferential position of each of the outer circumferential grooves is formed to be a center of the adjacent heat transfer fins.

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