JP5992898B2 - Rotating electrical machine rotor - Google Patents

Description

  In the embodiment of the present invention, a plurality of grooves along the axial direction for accommodating the conductor are formed near the outer peripheral surface of the main body portion that is formed in a columnar shape, and whose axial center is concentric with the rotational center of the rotating shaft. The present invention relates to a rotor of a rotating electrical machine provided at equal intervals in the circumferential direction.

  As a rotor of a rotating electrical machine, a body portion formed in a columnar shape is integrally configured so that its axial center is concentric with the rotational center of the rotating shaft, and for accommodating a conductor near its outer peripheral surface There is one in which a plurality of grooves along the axial direction are provided at equal intervals in the circumferential direction (see, for example, Patent Document 1).

  In such a rotor, during the operation of the rotating electrical machine, stress is generated in a portion called a tooth that forms a magnetic path between a plurality of grooves provided near the outer periphery of the main body as the motor rotates. This stress is a hoop stress caused by centrifugal force due to the rotation of the rotor, and increases as the rotation speed increases.

  For this reason, in order to increase the speed of a rotating electrical machine such as an electric motor, it has been necessary to change the design significantly or to make the punching plate constituting the main body of the rotor high in strength.

  However, it is almost the limit in terms of design, and increasing the punched plate strength raises the problem of availability, such as a rise in material costs.

JP 2009-254011 A

  Thus, the speeding up of the rotating electrical machine is limited by the hoop stress generated in the teeth, and the relaxation of this stress has been desired.

  The problem to be solved by the present invention is to provide a rotor for a rotating electrical machine that is resistant to stress and that can reduce the hoop stress generated in the tooth portion, which is the magnetic path of the rotor body, and enables high-speed rotation. .

  The rotor of the rotating electrical machine according to the embodiment of the present invention has a main body portion that is formed in a columnar shape, the center of which is concentric with the center of rotation of the rotating shaft, and is close to the outer peripheral surface of the main body. A rotor of a rotating electrical machine provided with a plurality of grooves along the axial direction for accommodating conductors at equal intervals in the circumferential direction, and adjacent to the plurality of grooves provided in the main body portion In the teeth between the matching grooves, the stress relaxation hole along the axial direction is located in the intermediate part between the adjacent grooves in the circumferential direction of the main body part, and in the radial direction of the main body part, When the radius of the hole is a, the distance from the center of rotation to the center of the hole is r, and the distance from the center of rotation to the bottom of the groove is R, positioning is performed so that R−a <r <R + a is satisfied. It is characterized by that.

  According to the said structure, the stress by centrifugal force can be relieve | moderated and the maximum speed can be raised. In addition, since it is only necessary to change the punching die, no significant design change is required.

It is a principal part enlarged view of the rotor of the rotary electric machine which concerns on one embodiment of this invention. It is a cross-sectional view which shows the whole structure of the rotor of the rotary electric machine shown in FIG. It is a figure which shows the direction of the force which acts on a teeth part with rotation. It is a figure explaining a stress concentration state. It is a figure explaining a stress relaxation state. It is a figure which shows the stress concentration state when not providing a stress relaxation hole in the teeth part. It is a figure which shows the stress relaxation state at the time of providing a stress relaxation hole in the teeth part. It is a figure which shows the modification of the cross-sectional shape of a groove | channel and the conductor accommodated. It is a figure which shows the other modification of the cross-sectional shape of a groove | channel and the conductor accommodated. It is a principal part enlarged view of the rotor of the rotary electric machine which concerns on other embodiment of this invention. It is a principal part enlarged view of the rotor of the rotary electric machine which concerns on other embodiment of this invention. It is a figure which shows the other example of a shape of the stress relaxation hole used for embodiment of this invention. It is a figure which shows the further another example of shape of the stress relaxation hole used for embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  First, the entire structure of the rotor according to this embodiment will be described with reference to FIG. FIG. 2 shows a cross section of the rotor 10 and has a main body 11 formed in a cylindrical shape. The main body 11 is formed by laminating steel plates in the axial direction, and is configured integrally with the rotation shaft 12 so that the center of the shaft is concentric with the rotation center of the rotation shaft 12. Further, near the outer peripheral surface of the main body 11, a plurality of grooves (slots) 13 along the axial direction (direction orthogonal to the paper surface) are provided at equal intervals in the circumferential direction. A conductor 14 is accommodated in the groove 13. The conductor 14 becomes a rotor bar when the rotating electrical machine to which the rotor 10 is applied is an induction machine, and becomes a field coil or a damper bar when the rotor is a synchronous machine.

  Next, the structure of the groove 13 provided in the main body 11 of the rotor 10 will be described with reference to FIG. A portion 21 between adjacent grooves 13 of the plurality of grooves 13 provided in the main body portion 11 is a portion that becomes a magnetic path and is called a tooth. In this embodiment, the teeth 21 are provided with stress relaxation holes 22 along the axial direction.

  With respect to the position where the stress relaxation hole 22 is provided, the center of the hole 22 is an intermediate portion between adjacent grooves 13 in the circumferential direction of the main body 11. As for the radial direction of the main body 12, the radius of the hole 22 is a, the distance from the rotation center of the main body 11 to the center of the hole 22 is r, and the distance from the rotation center of the main body 11 to the bottom of the groove 13 is also the same. Is set so that the center of the hole 22 is located in a range satisfying R−a <r <R + a.

  Normally, when the main body portion 11 of the rotor 10 provided with the groove 13 near the outer periphery rotates, a portion of the teeth 21 between the grooves 13 has a force F1 and an outward force to expand laterally as shown in FIG. A force F2 that tries to extend is applied. As shown in FIG. 6, the stress indicated by the line S <b> 1 is concentrated on the teeth 21 by these forces F <b> 1 and F <b> 2. That is, since stress concentrates on the lower portion of the tooth 21 shown in the figure, when the rotational speed of the rotor 10 is increased, stress concentrates on the bottom corner portion 13a in the structurally weak groove 13, and this portion may be damaged. is there. Therefore, there is a limit to speeding up the rotating electrical machine. In other words, this means that if the stress concentration in the lower portion of the tooth 21 in the figure is alleviated, even the main body 11 made of the same material can be made faster.

  Therefore, in this embodiment, as shown in FIG. 1, a stress relaxation hole (hereinafter referred to as a stress relaxation hole) 22 is provided in the lower portion of the tooth 21 in the figure in the positional relationship described above.

  In general, as shown in FIG. 4, when a round hole 32 is formed in the plate material 31 and the plate material 31 is pulled left and right as shown by an arrow F <b> 11, the stress shown by the line S <b> 11 is generated in the plate material 31. Concentrate on the top and bottom of the figure. On the other hand, as shown in FIG. 5, when two relatively small-diameter round holes 33 are opened in the same plate material 31 and this plate material 31 is pulled to the left and right as shown by arrow F11, the stress generated in the plate material 31 is It is known to those skilled in the art that it is dispersed and relaxed along the two round holes 33 as shown by line S21.

  In this embodiment, the stress relaxation action described above is used, and the stress relaxation hole 22 is provided in the lower portion of the tooth 21 in the illustrated manner in a positional relationship that satisfies the above-described R−a <r <R + a. As shown by line S2 in FIG. 7, the stress is dispersed and relaxed. As a result, even with the main body 11 made of the same material, the rotational speed can be increased more than ever.

  In addition, if the axial direction both ends of the stress relaxation hole 22 are opened, air is ventilated in the axial direction of the rotor body 11 through the hole 22 during operation as a rotating electric machine, so that the function of increasing the cooling effect is achieved. Also occurs. However, in terms of the stress relaxation function, which is the original purpose, it is not always necessary to open both ends, and they may be closed. In the case of an induction machine, a rotor bar is provided as the conductor 14 in the groove 13, but this rotor bar is manufactured by die casting. In this case, it is better to close the rotor bar.

  Moreover, the cross-sectional shape of the conductor 14 and the groove | channel 13 which accommodates it is not restricted to a rectangle. For example, the cross section shown in FIG. 8 may be trapezoidal, or the cross section shown in FIG. 9 may be inverted trapezoidal. 8 and 9, the position of the hole 22 is set to a positional relationship that satisfies the above-described Ra-r <r <R + a. However, the size of the hole 22 is appropriately adjusted as illustrated in accordance with the illustrated lateral width of the tooth 21 in which the hole 22 is provided.

  Furthermore, as an example of the groove shape. The groove 13 may have a shape as shown in FIGS. That is, the plurality of grooves 13 are shaped from a portion having parallel groove width intervals and a portion in which the groove width intervals decrease toward the groove bottom. The shape in which the groove width is reduced is a linear taper shape shown in FIG. 10 or an arc shape shown in FIG. The stress relaxation holes 22 along the axial direction are provided in the teeth 21 between the adjacent grooves of the plurality of grooves 13, and the positional relationship is determined as follows. That is, the stress relaxation hole 22 is positioned at the intermediate portion between the adjacent grooves 13 in the circumferential direction of the main body portion 11. Further, in the radial direction of the main body 11, when the radius of the stress relaxation hole 22 is a and the distance from the center of rotation of the main body 11 to the center of the stress relaxation hole 22 is r, as in FIG. Positioning is performed so that R1-a <r <R2 + a is satisfied, where R1 is the distance from the rotation center of 11 to the bottom of the groove 13 and R2 is the radius from the rotation center to the reduction start point of the groove width reduction portion of the groove 13. .

  Thus, even if the shape of the groove 13 is formed from a portion having a parallel groove width interval and a portion in which the groove width interval is reduced toward the groove bottom portion, the positional relationship satisfying R1−a <r <R2 + a described above. If the stress relaxation hole 22 is provided in the lower part of the tooth 21 in the figure, the stress is dispersed and relaxed. As a result, even with the main body 11 made of the same material, the rotational speed can be increased more than ever.

  Furthermore, the cross-sectional shape of the stress relaxation hole 22 is not limited to a circle, and may be a long round shape shown in FIG. 12, a rice ball shape shown in FIG. Even if such stress relaxation holes 22 having a cross-sectional shape are provided in the teeth 21 between the grooves 13 having the shapes shown in FIGS. 8 to 11, the same effects can be obtained.

  Here, even in the prior art, in the case of an electrically permanent magnet motor, there is a structure in which a hole is formed around the magnet in order to reduce iron loss. However, as in this embodiment, the center of the tooth that is a magnetic path is used. There is no configuration that relieves stress by providing a hole. In terms of stress, a cutout, a dent, or the like may be provided in the outer diameter portion, but no work is performed on the inner diameter side as in this embodiment. Further, although cooling holes may be provided around the heating element for cooling, no holes are formed in the center of the magnetic path.

  Thus, providing the stress relaxation holes 22 in this embodiment in the positional relationship described above is different from any of the conventional techniques.

  According to this embodiment, since the stress relaxation hole 22 is provided in the lower center portion of the teeth of the rotor of the rotating electrical machine, stress due to centrifugal force can be relaxed, and the maximum speed as the rotating electrical machine is increased. be able to. Further, since the hole 22 is formed only by changing the punching die, no significant design change is required.

  Although several embodiments of the present invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 ... Rotor 11 ... Main-body part 12 ... Rotating shaft 13 ... Groove 14 ... Conductor 21 ... Teeth 22 ... Hole for stress relaxation

Claims (5)

It has a main body part that is formed in a columnar shape, the axis center of which is concentric with the rotation center of the rotating shaft, and there are a plurality of grooves along the axial direction for accommodating the conductors near the outer peripheral surface of the main body part. A rotor of a rotating electrical machine provided at equal intervals in the circumferential direction,
In the teeth between adjacent grooves of the plurality of grooves provided in the main body portion, stress relaxation holes along the axial direction are provided, and in the circumferential direction of the main body portion, between the adjacent grooves. In the radial direction of the main body located at the middle part, the radius of the hole is a, the distance from the rotation center to the center of the hole is r, and the distance from the rotation center to the groove bottom is R. When positioned so as to satisfy R−a <r <R + a,
A rotor of a rotating electrical machine characterized by that. It has a main body part that is formed in a columnar shape, the axis center of which is concentric with the rotation center of the rotating shaft, and there are a plurality of grooves along the axial direction for accommodating the conductors near the outer peripheral surface of the main body part. A rotor of a rotating electrical machine provided at equal intervals in the circumferential direction,
The plurality of grooves provided in the main body portion are composed of a portion having a parallel groove width interval and a portion in which the groove width interval is reduced toward the groove bottom portion, and between the adjacent grooves of the plurality of grooves. In the teeth, a stress relaxation hole along the axial direction is located in the middle portion between the adjacent grooves in the circumferential direction of the main body portion, and the radius of the hole in the radial direction of the main body portion. A, a distance from the rotation center to the center of the hole, r, a distance from the rotation center to the groove bottom, R1, and a radius from the rotation center to the reduction start point of the groove width reduction portion of the groove R2. When positioned, it was positioned so as to satisfy R1-a <r <R2 + a.
A rotor of a rotating electrical machine characterized by that.   The rotor of a rotating electrical machine according to claim 1, wherein the main body is formed by stacking steel plates in the axial direction.   The rotor of a rotating electrical machine according to any one of claims 1 to 3, wherein the conductor is a rotor bar manufactured by die casting.   The rotor of a rotating electrical machine according to any one of claims 1 to 4, wherein both ends of the stress relaxation hole are closed.

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