JP2017099045A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in iron loss in a stator core and a rotor core.SOLUTION: In a motor 20 formed such that widths in a circumferential direction of end portions 34a and 34b of teeth 34 of a stator core 32 in an axial direction are made smaller than those of a central part 34c in the axial direction, the end portions 34a and 34b are formed such that lengths Lt in a radial direction thereof are smaller than those of the central part 34c. By this configuration, gaps between a rotor core 42 and the stator core 32 at the end portions 34a and 34b are greater than those at the central part 34c, a permeance coefficient is made small, and magnetic flux density at a working point determined by an intersection point between a straight line with the permeance coefficient as a slope and a B-H demagnetization curve is made small. Consequently, since magnetic flux across from the end portions 34a and 34b to the rotor core 42 or from the rotor core 42 to the end portions 34a and 34b is made small, an increase in iron loss in the end portions 34a and 34b, i.e., in the stator core 32 and the rotor core 42 can be suppressed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotating electrical machine.

  Conventionally, as this kind of rotary electric machine, what is provided with a stator and a rotor is proposed (for example, refer to patent documents 1). The stator includes a stator core having a plurality of teeth and a stator coil wound around each tooth. The rotor is configured as a squirrel-cage rotor and includes a rotor core and a conductor bar embedded in the rotor core and extending in the axial direction. In this rotating electrical machine, the width in the circumferential direction of the teeth is formed to be narrower than the central portion in the axial direction at the end in the axial direction of the teeth of the stator core. Thereby, the width of the end portion in the axial direction of the slot formed between the teeth is widened, and the contact between the stator core and the stator coil in the vicinity of the end portion is suppressed.

JP 2010-124637 A

  By the way, in a rotating electric machine of the type having a permanent magnet in the rotor, in order to suppress the contact between the stator core and the stator coil near the end, if the width in the circumferential direction of the end of the tooth is reduced, the teeth As a result, the magnetic flux density at the end of the iron increases and the iron loss increases. It is desirable to suppress such an increase in iron loss.

  The main purpose of the rotating electrical machine of the present invention is to suppress an increase in iron loss of the stator core and the rotor core.

  The rotating electrical machine of the present invention employs the following means in order to achieve the main object described above.

The rotating electrical machine of the present invention is
A stator formed by winding a coil around a plurality of teeth formed on the stator core;
A rotor having a rotor core and a magnet extending in the axial direction, and disposed on the inner peripheral side of the stator and attached to a rotating shaft;
With
A rotating electrical machine in which an end portion in the axial direction of the teeth is formed so that a width in a circumferential direction is narrower than a central portion in the axial direction,
The end portion of the teeth is formed so that the length in the radial direction is shorter than the central portion.
This is the gist.

  In this rotating electrical machine of the present invention, the rotor has a rotor core and a magnet extending in the axial direction, and the axial end of the stator teeth is smaller in the circumferential direction than the axial central portion. It is formed to become. The ends of the teeth are formed so that the length in the radial direction is shorter than the center. Therefore, the gap between the rotor core and the stator core is larger at the end portion of the tooth than at the center portion of the tooth, the permeance coefficient is decreased, and the intersection of the straight line having the permeance coefficient as an inclination and the BH demagnetization curve. The magnetic flux density at the determined operating point is reduced. Therefore, since the magnetic flux from the rotor core to the stator core is less at the end portion of the teeth than at the center portion, it is possible to suppress an increase in iron loss at the end portions of the teeth, that is, the stator core and the rotor core.

It is a block diagram which shows the outline of a structure of the motor 20 as one Example of this invention. It is an enlarged view which expands and shows the part enclosed with the broken line of FIG. It is an external view which shows the external appearance which looked at the motor 20 from the axial direction outer side of FIG. It is an enlarged view which shows the periphery of the teeth 34 in an enlarged manner. It is the schematic which shows the outline of the cross section in the AA line of FIG.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a motor 20 as an embodiment of the present invention. FIG. 2 is an enlarged view showing a portion surrounded by a broken line in FIG. 3 is an external view showing the external appearance of the motor 20 as viewed from the outside in the axial direction of FIG. In FIG. 3, the coil end 36a of the coil 36 is not shown.

  The motor 20 of the embodiment is configured as a three-phase AC motor, for example, and includes a stator 30 and a rotor 40 as shown in FIG.

  As shown in FIGS. 1 to 3, the stator 30 is configured by laminating a plurality of stator members formed by punching a non-oriented electrical steel sheet. The stator 30 includes a stator core 32 having a plurality of teeth 34 protruding radially inward (inner peripheral side), and a coil 36 having a coil end 36a wound around the teeth 34 and protruding outward in the axial direction. Prepare. FIG. 4 is an enlarged view showing the periphery of the tooth 34 in an enlarged manner. FIG. 5 is a schematic view showing an outline of a cross section taken along line AA of FIG. As shown in FIGS. 4 and 5, the end portions 34 a and 34 b of the teeth 34 are formed so that the circumferential width Wt is narrower and the radial length Lt is shorter than the central portion 34 c. Yes.

  As shown in FIGS. 1 to 3, the rotor 40 includes a rotor core 42 formed by stacking a plurality of rotor members formed by punching a non-oriented electrical steel sheet into a ring shape, and embedded in the rotor core 42 and extending in the axial direction. A plurality of permanent magnets 44 having an existing shape are attached to the rotary shaft 22 by shrink fitting or spline fitting. The permanent magnet 44 is formed so as to extend from one end face in the axial direction of the rotor core 42 to the other end face.

  In the motor 20 according to the embodiment thus configured, the end portions 34a and 34b in the axial direction of the teeth 34 are formed so that the circumferential width Wt is narrower than the central portion 34c. Contact with the portions 34a and 34b can be suppressed. Furthermore, since the end portions 34a and 34b are formed so that the radial length Lt is shorter than the central portion 34c, the gap between the end portions 34a and 34b and the stator core 32 is larger than that of the central portion 34c. Thus, the permeance coefficient becomes small, and the magnetic flux density at the operating point determined by the intersection of the straight line having the permeance coefficient as an inclination and the BH demagnetization curve becomes small. Accordingly, since the magnetic flux from the end portions 34a and 34b to the rotor core 42 or from the rotor core 42 to the end portions 34a and 34b is reduced, it is possible to suppress an increase in iron loss of the end portions 34a and 34b, that is, the stator core 32 and the rotor core 42. it can.

  According to the motor 20 of the embodiment described above, the end portions 34a, 34b of the teeth 34a, 34b of the stator core 32 in which the axial width ends 34a, 34b are smaller than the central portion 34c. Is formed such that the length Lt in the radial direction is smaller than the central portion 34c, whereby an increase in iron loss of the stator core 32 and the rotor core 42 can be suppressed.

  In the embodiment, the present invention is applied to an embedded magnet type motor in which the permanent magnet 44 is embedded in the rotor core 42. However, the present invention is applied to a surface magnet type motor in which a permanent magnet is incorporated on the surface of the rotor core. You may apply.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the teeth 34 correspond to “teeth”, the stator 30 corresponds to “stator”, the rotor core 42 corresponds to “rotor core”, the permanent magnet 44 corresponds to “permanent magnet”, and the rotor 40 corresponds to “ Corresponds to “rotor”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of rotating electrical machines.

 20 motor, 22 rotating shaft, 30 stator, 32 stator core, 34 teeth, 34a, 34b end, 34c center, 36 coil, 36a coil end, 40 rotor, 42 rotor core, 44 permanent magnet.

Claims (1)

A stator formed by winding a coil around a plurality of teeth formed on the stator core;
A rotor having a rotor core and a magnet extending in the axial direction, and disposed on the inner peripheral side of the stator and attached to a rotating shaft;
With
A rotating electrical machine in which an end portion in the axial direction of the teeth is formed so that a width in a circumferential direction is narrower than a central portion in the axial direction,
The end portion of the teeth is formed so that the length in the radial direction is shorter than the central portion.
Rotating electric machine.

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