JP2007195281A - Stator core for dynamo-electric machine, and stator using that stator core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive stator core for dynamo-electric machine by enabling the fastening force for the split core to be controlled, and preventing the split core consisting of a green compact from breaking by excessive fastening force. <P>SOLUTION: A plurality of split cores 1 consisting of green compacts are arranged annularly, and a thin plate 2 is wound around the split cores 1 so as to tighten each split core 1, and circumferential one end and the other end of the thin plate 2 are connected with each other, thus the stator core for dynamo-electric machine is constituted so as to keep the fastening state of the split core 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stator core for a rotating electric machine (for example, an electric motor) incorporated in a hybrid vehicle, a fuel cell vehicle and the like.

  Hybrid vehicles and fuel cell vehicles use electric motors as drive units and regenerative brakes. This motor is often used in a high frequency region in order to reduce the size and increase the output. However, as the frequency increases, the iron loss generated in the stator core increases and the energy conversion efficiency decreases. Therefore, in order to suppress iron loss at high frequencies, the development of stator cores using metal magnetic powder green compacts that have been treated with an insulating film and stator cores using metal magnetic powder green compacts with resin added has been promoted. It has been. Since this stator core confines eddy currents in the particles of the metal magnetic powder, the iron loss is smaller than that of a conventional stator core made of a laminate of electromagnetic steel sheets.

  As a stator core using such a green compact, as shown in FIG. 6, a plurality of split cores 20 made of a green compact are arranged in an annular shape, and a cylindrical housing 21 is shrink-fitted around the outer periphery of the split core 20. And what fixed each division | segmentation core 20 is known.

  However, the split core 20 of this stator core is easily broken. That is, the size of the housing 21 for fastening the split core 20 is constant, but the split core 20 formed by compacting has a variation in size, so the size of the housing 21 needs to be reduced in order to secure a tightening allowance. There is. For this reason, it is difficult to manage the tightening force of the split core 20, and the split core 20 is easily tightened with a force larger than necessary and easily broken.

  Here, what was described in the following patent document 1 is known as a stator core which fixes a division | segmentation core with a small force. In this stator core, the outer periphery of the annularly arranged split core is narrowed with a ring, the ring and the split core are fixed with a pin, and the pin protrudes radially inward from the inner surface of the cylindrical housing. The split core is fixed by sandwiching between the two.

  However, when using a split core made of green compact, it is cumbersome to form pin holes in the split core. Especially in the case of small split cores, the pin holes are also thin, so forming pin holes by compacting Have difficulty. In addition, since the split cores made of green compacts vary in size, if the pressure is narrowed with a ring having a fixed size, the force for tightening the split cores cannot be managed, and the tightening force of the split cores tends to be excessive. In addition, the number of parts is large and the cost is high.

  By the way, the clamping force required to fix the split core to the housing is smaller than the clamping force generated by shrink fitting. Therefore, if the tightening force can be managed, breakage of the split core can be prevented.

Japanese Patent Laid-Open No. 11-308830

  It is an object of the present invention to provide a stator core for a rotating electrical machine that is capable of managing the clamping force of a split core, prevents the split core made of a green compact from being broken by an excessive clamping force, and is inexpensive. To do.

  In order to solve this problem, the thin plate is provided with a plurality of divided cores made of green compacts arranged in an annular shape, and a thin plate wound around the outer periphery of the plurality of divided cores, and the divided core is tightened. The structure to fix is adopted for the stator core for rotating electrical machines. This stator core for rotating electrical machines manages the tightening force of the split core by connecting one end and the other end of the thin plate in a state where the split core is fastened with a constant force even when the size of the split core varies. be able to.

The stator core for a rotating electrical machine is more preferable when the following configuration is added.
1) The thin plate is fixed by welding one end and the other end in the circumferential direction of the thin plate.
2) A sandwiching piece that sandwiches the split core in the axial direction is formed on the thin plate, and at least one of the sandwiching pieces is fitted into a recess formed on an end surface in the axial direction of the split core. Is positioned in the circumferential direction.
3) The concave portion is formed to open radially inward, and a circumferential projecting portion that engages the radial inner surface of the split core is formed on the sandwiching piece that fits into the concave portion.
4) The thin plate is made of a material that is easier to deform than the split core.

  The present invention also provides a stator for a rotating electrical machine in which a coil is mounted on each divided core of the stator core for a rotating electrical machine.

  Since the stator core for a rotating electrical machine of the present invention is tightened by winding a thin plate around the split core, it is possible to manage the tightening force of the split core even when there are variations in the size of the split core. It can be prevented from being destroyed. Moreover, the number of parts is small and inexpensive.

  Furthermore, what welded the one end and the other end of the said thin plate in the circumferential direction is cheaper since the component for a connection is not required, and a connection part does not loosen.

  Further, when the thin plate is formed with a sandwiching piece that faces the axial direction and sandwiches the split core, and the split core is positioned in the circumferential direction by the sandwiching piece, the split core is more securely fixed. In addition, since the sandwiching pieces face each other in the axial direction, they are not easily deformed even when subjected to a circumferential force, and the split cores are not displaced in the circumferential direction.

  Further, in the case where the sandwiching piece is formed with a circumferential protrusion that engages with the radially inner surface of the split core, the protrusion prevents the split core from moving inward in the radial direction. Is more stable.

  In addition, when the thin plate is made of a material that is easier to deform than the split core, the thin plate deforms and absorbs the dimensional error of the split core when the split core is tightened with the thin plate. Excellent.

  FIG. 1 shows an embodiment of a stator core for a rotating electrical machine according to the present invention. The stator core includes a plurality of split cores 1 arranged in an annular shape and a thin plate 2 wound around the outer periphery of the split core 1.

  The split core 1 is made of a green compact of metal magnetic powder, and is disposed with a teeth portion 1a on which a coil is mounted facing radially inward. A yoke portion 1b protruding in the circumferential direction is formed at the radially outer end of the split core 1, and the circumferential end surfaces of the yoke portions 1b of the adjacent split cores 1 and 1 are in contact with each other.

  The thin plate 2 wound around the outer periphery of the split core 1 has an ear portion 3 formed by bending a circumferential end portion radially outward at one end and the other end in the circumferential direction. Are connected by welding. A plurality of pairs of holding pieces 4, 4 facing in the axial direction are formed at intervals in the circumferential direction.

  As shown in FIG. 2, the sandwiching pieces 4 are formed by bending the tongue pieces formed at both ends in the axial direction of the thin plate 2 inward in the radial direction, and sandwiching the divided core 1. Further, the sandwiching piece 4 is fitted in a recess 5 formed on the end surface in the axial direction of the yoke portion 1b of the split core 1 to position the split core 1 in the circumferential direction.

  As shown in the figure, the recess 5 is formed to open radially inward, and the tip of the clamping piece 4 fitted in the recess 5 protrudes radially inward from the yoke portion 1b. ing. On the other hand, the sandwiching piece 4 is formed with a projecting portion 4 a projecting in the circumferential direction, and this projecting portion 4 a is engaged with the radially inner surface of the yoke portion 1 b of the split core 1.

  This stator core for a rotating electrical machine can be assembled, for example, as follows. First, the split core 1 is arranged in an annular shape. At this time, as shown in FIG. 3, when the split core 1 is disposed so that the cylindrical jig J is centered and the radially inner end of the teeth portion 1 a is in contact with the outer periphery thereof, the size of the split core 1 is reduced. Even when there is a variation, it is preferable because the radially inner ends of the teeth 1a are aligned on the same circumference with high accuracy.

  Next, the thin plate 2 is wound around the outer periphery of the split core 1 in an annular shape and tightened. In this state, the tongue portion of the thin plate 2 is bent radially inward as shown in FIG. The split core 1 is clamped from the axial direction by the clamping piece 4. Furthermore, as shown in FIG. 3, the ear | edge parts 3 and 3 of the thin plate 2 are welded, and the one end and other end of the thin plate 2 are connected mutually. Thereafter, the center jig J is removed.

  The stator core for a rotating electrical machine can manage the tightening force by connecting one end and the other end of the thin plate 2 in a state where the split core 1 is tightened with a constant force. Therefore, even when the dimensions of the split core 1 made of green compacts vary, the tightening force is reduced within a range necessary for fixing the split core 1, and the split core 1 is destroyed by an excessive tightening force. Can be prevented.

  The tightening force can be managed, for example, by tightening the split core 1 while applying tension to the thin plate 2 and connecting one end and the other end of the thin plate 2 while measuring the tension of the thin plate 2. Alternatively, the thin plate 2 wound around the outer periphery of the split core 1 can be tightened with a ring-shaped jig, and one end and the other end of the thin plate 2 can be connected while measuring the tightening force.

  Further, since the stator core for rotating electrical machines is connected to each other by welding one end and the other end of the thin plate 2 in the circumferential direction, it does not require parts for connection and is inexpensive. In addition, no loosening occurs in the connection.

  In addition, since the sandwiching piece 4 of the thin plate 2 is fitted in the concave portion 5 of the split core 1 and the split core 1 is positioned in the circumferential direction, the split core 1 is reliably prevented from being displaced in the circumferential direction. Is more secure. In addition, since the sandwiching pieces 4 face each other in the axial direction, they are not easily deformed when subjected to a circumferential force, and it is more reliable to prevent the split core 1 from being displaced in the circumferential direction.

  Further, since the protrusion 4a of the sandwiching piece 4 is engaged with the radially inner surface of the yoke portion 1b of the split core 1, the protrusion 4a prevents the split core 1 from moving inward in the radial direction. Therefore, the position of the split core 1 is difficult to move even when vibration or impact is applied, and the tightened state of the split core 1 is reliably maintained.

  The thin plate 2 is more preferably formed of a material that is more easily deformed than the split core 1. In this way, even when there are variations in the dimensions of the split core 1, the thin plate 2 is deformed along the outer periphery of the split core 1 that is uneven due to the size variations, and absorbs the dimensional error of the split core 1. . Therefore, the positional accuracy of the inner diameter of the split core 1 arranged in an annular shape is excellent.

  Further, if the thin plate 2 is bent before being assembled into a cylindrical shape having a C-shaped cross section in advance, the assembly of the stator core becomes smoother.

  In the above embodiment, the connection between the one end and the other end in the circumferential direction of the thin plate 2 is performed by welding the ear portions 3 formed at the end portions of the thin plate 2, but the ear portions 3 are not essential. As shown in FIG. 4, both end portions in the circumferential direction may be overlapped and welded. Further, the connection method is not limited to welding, and may be connected by, for example, rivets, screws, pins or the like.

  Moreover, in the said embodiment, although the clamping piece 4 was formed by bending the tongue piece formed in the axial direction both ends of the thin plate 2 to radial inside, for example, as shown in FIG. May be. In short, what is necessary is just to be able to sandwich the split core 1 in the axial direction.

  In the figure, each of the split cores 1 is sandwiched by the sandwiching pieces 4 to secure the split cores 1 more securely. However, it is not always necessary to sandwich all of the split cores 1, for example, every other split core 1. May be held within a range where the fixing of the split core does not become unstable. Further, the recesses 5 of the split core 1 are not necessarily formed at both ends in the axial direction, and may be formed only at one end in the axial direction.

  Further, a stator for a rotating electrical machine can be formed by attaching a coil to the tooth portion 1a of each divided core 1 of the stator core described above. In this stator, the tightening force of the split core 1 by the thin plate 2 can be reduced within a range necessary for fixing the split core 1, so that the tightening force by winding the coil acts on the teeth portion 1 a of the split core 1. However, the split core is difficult to break and the quality is stable.

  The split core 1 can be formed of, for example, a green compact of a metal magnetic powder to which a resin is added, or a green compact of a metal magnetic powder to which an insulating film treatment has been applied. Powder may be sufficient.

The perspective view which shows embodiment of the stator core for rotary electric machines of this invention 1 is a partially enlarged perspective view showing the assembly process of the stator core of FIG. Plan view sectional drawing which shows the assembly process of the stator core of FIG. Plan view sectional drawing which shows the modification of the stator core of FIG. The partially expanded perspective view which shows the other modification of the stator core of FIG. A perspective view showing a conventional stator core

Explanation of symbols

1 Divided core 2 Thin plate 4 Clamping piece 4a Protruding part 5 Recessed part

Claims (6)

  For a rotating electrical machine comprising a plurality of divided cores made of green compacts arranged in an annular shape and a thin plate wound around the outer periphery of the plurality of divided cores, the thin plate being fixed so as to tighten the divided cores Stator core.   The stator core for a rotating electrical machine according to claim 1, wherein the thin plate is fixed by welding one end and the other end of the thin plate in the circumferential direction.   A sandwiching piece that faces the axial direction and sandwiches the split core is formed on the thin plate, and at least one of the sandwiching pieces is fitted into a recess formed on an axial end surface of the split core to surround the split core. The stator core for rotating electrical machines according to claim 1 or 2, which is positioned in a direction.   The rotation according to claim 3, wherein the concave portion is formed to be opened radially inward, and a protruding portion in a circumferential direction that engages with a radially inner surface of the split core is formed on the sandwiching piece that fits into the concave portion. Stator core for electric machine.   The stator core for a rotating electrical machine according to any one of claims 1 to 4, wherein the thin plate is made of a material that is more easily deformed than the divided core.   A stator for a rotating electrical machine, wherein a coil is attached to each divided core of the stator core for a rotating electrical machine according to any one of claims 1 to 5.

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