(19)
(11)EP 3 687 040 A1

(12)EUROPEAN PATENT APPLICATION
published in accordance with Art. 153(4) EPC

(43)Date of publication:
29.07.2020 Bulletin 2020/31

(21)Application number: 17926094.8

(22)Date of filing:  21.09.2017
(51)International Patent Classification (IPC): 
H02K 3/34(2006.01)
H02K 3/46(2006.01)
H02K 1/18(2006.01)
(86)International application number:
PCT/JP2017/034130
(87)International publication number:
WO 2019/058486 (28.03.2019 Gazette  2019/13)
(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated Extension States:
BA ME
Designated Validation States:
MA MD

(71)Applicant: Mitsubishi Electric Corporation
Chiyoda-ku Tokyo 100-8310 (JP)

(72)Inventors:
  • KATO, Masahiro
    Tokyo 100-8310 (JP)
  • OZAKI, Junichi
    Tokyo 100-8310 (JP)
  • YAJIMA, Katsutoshi
    Tokyo 100-8310 (JP)
  • TOKUMARU, Hiroyuki
    Tokyo 100-8310 (JP)

(74)Representative: Witte, Weller & Partner Patentanwälte mbB 
Postfach 10 54 62
70047 Stuttgart
70047 Stuttgart (DE)

  


(54)STATOR, ELECTRIC MOTOR, AND VENT FAN


(57) A stator (1) includes a stator core (5), a winding frame (11) wound with a winding (12), and an insulator (33). The stator core (5) includes a yoke (21), which is an outer core, and a plurality of tooth portions (22), which are inner cores surrounded by the outer core. The winding frame (11) covers the inner core. The insulator (33) is disposed between the winding (12) and the outer core. The winding frame (11) is provided with a guide portion (31) that guides the insertion of the insulator (33) between the winding (12) and the outer core. The stator (1) can reduce the displacement of the position of the insulator (33) and ensure stable insulation between the stator core (5) and the winding (12).




Description

Field



[0001] The present invention relates to a stator, an electric motor, and a ventilation fan that include a winding frame that covers an inner core.

Background



[0002] A so-called concentrated winding motor including a stator core including an outer core and a plurality of tooth portions, which are inner cores, surrounded by the outer core is known, in which windings are concentratedly wound around the tooth portions. The concentrated winding motor is provided with a winding frame for insulation between the stator core and the winding in some cases. In the case of a concentrated winding motor including the winding frame, the winding is wound around the winding frame that covers the tooth portions. Patent Literature 1 discloses a technology of a single-phase alternating current concentrated winding motor provided with a winding frame.

Citation List


Patent Literature



[0003] Patent Literature 1: Japanese Patent No. 5627819

Summary


Technical Problem



[0004] A clearance for insulation is ensured between the winding, which is a charging part, and the stator core, which is a non-charging part, in the electric motor. The winding frame is used for insulation between the inner core and the winding, while a wedge, which is an insulator, is sometimes used for insulation between the outer core and the winding.

[0005] If a displacement occurs in the position of the wedge between the winding wound around the winding frame and the outer core, insulation failure may occur between the winding and the stator core. When the wedge is inserted between the winding and the outer core while the wedge is kept in contact with the outer core to reduce the displacement of the position of the wedge, there is a case where the insertion of the wedge is disturbed by the frictional force between the wedge and the outer core. Since it is difficult to insert the wedge, the position of the wedge is likely to be displaced. Furthermore, when the clearance between the outer core and the winding is expanded to facilitate the insertion of the wedge, it becomes difficult to ensure stable insulation between the winding and the stator core.

[0006] The present invention has been made in view of the above circumstances, and it is an object of the present invention to obtain a stator that can reduce the displacement of the position of the insulator and ensure stable insulation between the stator core and the winding.

Solution to Problem



[0007] In order to solve the above-described problems and achieve the object, a stator according to the present invention includes: a stator core including an outer core and an inner core surrounded by the outer core; a winding frame that covers the inner core and is wound with a winding; and an insulator disposed between the winding and the outer core. The winding frame is provided with a guide portion that guides the insertion of the insulator between the winding and the outer core.

Advantageous Effects of Invention



[0008] The stator according to the present invention has an effect of being able to reduce the displacement of the position of the insulator, and ensure stable insulation between the stator core and the winding.

Brief Description of Drawings



[0009] 

FIG. 1 is a schematic longitudinal sectional view of an electric motor including a stator according to a first embodiment of the present invention.

FIG. 2 is a plan view of a stator core illustrated in FIG. 1.

FIG. 3 is a perspective view of the stator illustrated in FIG. 1.

FIG. 4 is a side view of a tooth portion and a winding frame illustrated in FIG. 1.

FIG. 5 is a view for explaining the insertion of a wedge in the winding frame illustrated in FIG. 1.

FIG. 6 is a view illustrating: the tooth portions before the wedges illustrated in FIG. 5 are inserted; and the winding frames attached to the tooth portions.

FIG. 7 is a view illustrating a state after the wedges are inserted into the winding frames illustrated in FIG. 6.

FIG. 8 is a sectional view of a ventilation fan according to a second embodiment of the present invention.


Description of Embodiments



[0010] Hereinafter, a stator, an electric motor, and a ventilation fan according to embodiments of the present invention will be described in detail with reference to the drawings. Note that this invention is not limited by these embodiments.

First Embodiment.



[0011] FIG. 1 is a schematic longitudinal sectional view of an electric motor 100 including a stator 1 according to a first embodiment of the present invention. In the first embodiment, the electric motor 100 is a three-phase alternating current concentrated winding motor. In FIG. 1, the cross sections of a part of components of the electric motor 100 are hatched, and hatching on the cross sections of the other components are omitted.

[0012] The electric motor 100 includes a stator 1, a rotor 2 surrounded by the stator 1, and a rotating shaft 3 coupled to the rotor 2. The stator 1 generates a force for rotating the rotor 2. The rotor 2 rotates inside the stator 1. The rotor 2 is formed by laminating electromagnetic steel plates. The rotating shaft 3 is disposed on a central axis 4, which is the rotation center of the rotor 2. Note that FIG. 1 illustrates a portion of the electric motor 100 on one side in a radial direction from the central axis 4, and the other portions are omitted.

[0013] The stator 1 includes a stator core 5 and a winding frame 11 around which a winding 12 is wound. The stator core 5 is formed by laminating electromagnetic steel plates. The winding frame 11 is formed of an insulating material. The winding 12 wound around the winding frame 11 constitutes a coil.

[0014] A frame 7 and a bracket 8 constitute an outer shell of the electric motor 100. The stator 1 is press-fitted into the frame 7. The rotating shaft 3 extends through the frame 7 from the inside to the outside of the electric motor 100, and transmits a rotational force of the rotor 2 to the outside of the electric motor 100.

[0015] The electric motor 100 includes two bearings 10 that rotatably support the rotating shaft 3. One bearing 10 is disposed inside a bearing housing 9 formed in the frame 7. The other bearing 10 is disposed inside a bearing housing 9 formed in the bracket 8.

[0016] A secondary conductor 6 is inserted into a slot provided in the rotor 2. The secondary conductor 6 is formed by die casting of an aluminum material. Note that, in FIG. 1, the illustration of the slot of the rotor 2 is omitted.

[0017] A terminal block 13 is fixed to the winding frame 11. The terminal block 13 is formed of a resin that is an insulating material. The terminal block 13 houses mounted components such as a terminal plate or a thermal fuse. The terminal plate is used for wire connection of each phase. The thermal fuse disconnects a line when detecting an excessive temperature rise in the coil. The terminal block 13 may house a mounted component other than the terminal plate and the thermal fuse. Note that, in FIG. 1, the illustration of the mounted components is omitted.

[0018] A conductive pin 14 is attached to the winding frame 11, and an end portion of the coil of the winding 12 is wound around the conductive pin 14. The conductive pin 14 is inserted into the inside of the terminal block 13. The winding 12 is connected to the mounted components in the terminal block 13 via the conductive pin 14. A lead wire 16 connects an external power supply that supplies power to the electric motor 100, and the conductive pin 14.

[0019] FIG. 2 is a plan view of the stator core 5 illustrated in FIG. 1. FIG. 3 is a perspective view of the stator 1 illustrated in FIG. 1. FIG. 3 illustrates the stator 1 in a state in which the winding 12 is not wound.

[0020] The stator core 5 includes: an annular yoke 21, which is an outer core; and a plurality of tooth portions 22, which are inner cores surrounded by the outer core. A slot 23 of the stator core 5 is constituted by adjacent tooth portions 22 and the yoke 21. In the first embodiment, the stator core 5 includes twelve tooth portions 22 and twelve slots 23.

[0021] The winding frame 11 illustrated in FIG. 1 is provided in each tooth portion 22. The winding frame 11 covers the tooth portion 22. The stator 1 includes twelve winding frames 11. The winding 12 is concentratedly wound around every one or plurality of tooth portions 22. Since the electric motor 100 includes a concentrated winding coil, the size of the coil in the direction of the central axis 4 can be decreased as compared with the case of distributed winding in which the winding 12 is distributedly wound around the plurality of tooth portions 22. The electric motor 100, which is a concentrated winding motor, can decrease the size of the outer shape.

[0022] The stator core 5 can be divided into the yoke 21, which is an outer core, and the plurality of tooth portions 22, which are inner cores. Each tooth portion 22 is joined to an inner side surface of the yoke 21. Since the winding 12 can be wound around the tooth portion 22 which is removed from the yoke 21, thus the winding 12 can be wound around the tooth portion 22 with high density. Accordingly, a coil in which the winding 12 is wound with high density can be mounted on the electric motor 100.

[0023] A clearance for insulation is ensured between the winding 12, which is a charging part, and the stator core 5, which is a non-charging part, in the electric motor 100. The winding frame 11 is used for insulation between the tooth portion 22 and the winding 12. A wedge to be subsequently described is used for insulation between the yoke 21 and the winding 12.

[0024] FIG. 4 is a side view of the tooth portion 22 and the winding frame 11 illustrated in FIG. 1. FIG. 5 is a view for explaining the insertion of a wedge 33 in the winding frame 11 illustrated in FIG. 1. FIGS. 4 and 5 illustrate a side surface of the tooth portion 22 joined to the yoke 21. The stator 1 illustrated in FIG. 1 includes the wedge 33, which is an insulator, inserted between the winding 12 and the yoke 21. The wedge 33 is a plate member formed of an insulating material. Bending may be added to the wedge 33.

[0025] The winding frame 11 is provided with a guide portion 31 that guides the insertion of the wedge 33 between the winding 12 and the yoke 21, and an abutment portion 32 that abuts on the inserted wedge 33. The guide portion 31 and the abutment portion 32 each are a projecting portion that protrudes from a surface of the winding frame 11, and are a rectangular parallelepiped or a polyhedron. The guide portion 31 and the abutment portion 32 are provided on the winding frame 11 protruding toward the yoke 21. The height of the guide portion 31 and the height of the abutment portion 32 from the surface of the winding frame 11 are set higher than the thickness of the wedge 33. The height of the guide portion 31 and the height of the abutment portion 32 from the surface of the winding frame 11 may be set lower than the thickness of the wedge 33.

[0026] As illustrated in FIG. 5, the wedge 33 is inserted by being slid between a pair of the guide portions 31. The pair of guide portions 31 are disposed at intervals corresponding to the width of the wedge 33. Facing surfaces of the two guide portions 31 are parallel to each other. By placing the wedge 33 along the guide portions 31, the wedge 33 can be easily inserted between the winding 12 and the yoke 21. Since a situation in which the insertion of the wedge 33 is disturbed by the frictional force with the yoke 21 can be avoided, the wedge 33 can be inserted smoothly. Furthermore, since the wedge 33 is disposed between a pair of the guide portions 31, lateral displacement of the wedge 33 can be reduced.

[0027] A tip of the inserted wedge 33 abuts the abutment portion 32. Since the wedge 33 is held against the abutment portions 32, lateral displacement of the wedge 33 can be reduced. Since the displacement of the position of the wedge 33 can be reduced, insulation failure between the winding 12 and the yoke 21 can be reduced. In addition, since positional displacement of the wedge 33 can be reduced, the width of the wedge 33 can be narrowed. Since the wedge 33 can be downsized, the material cost of the wedge 33 can be reduced.

[0028] FIG. 6 is a view illustrating the tooth portions 22 before the wedges 33 illustrated in FIG. 5 are inserted and the winding frames 11 attached to the tooth portions 22. FIG. 7 is a view illustrating a state after the wedges 33 are inserted into the winding frames 11 illustrated in FIG. 6. FIGS. 6 and 7 illustrate a state in which the winding 12 is not wound. The wedge 33 is inserted between the tooth portions 22. The wedge 33 is disposed between the yoke 21 and the winding 12 in the slot 23 illustrated in FIG. 2.

[0029] According to the first embodiment, in the stator 1, since the wedge 33 can be inserted along the guide portions 31, the wedge 33 can be easily inserted. In the stator 1, the wedge 33 can be easily inserted and thus the displacement of the position of the wedge 33 can be reduced. Consequently, the stator 1 has an effect of being able to reduce the displacement of the position of the wedge 33, and ensure stable insulation between the stator core 5 and the winding 12. The electric motor 100 can reduce defects due to insulation failure in the stator 1.

Second Embodiment.



[0030] FIG. 8 is a sectional view of a ventilation fan 200 according to a second embodiment of the present invention. The ventilation fan 200 is installed on a ceiling 53 in a room and is connected to a duct laid out to communicate the ceiling cavity with the outside of the room. The ventilation fan 200 causes the air sucked from the room to flow into the duct. In FIG. 8, the illustration of the duct is omitted. Hatching is omitted in a part of the cross section illustrated in FIG. 8.

[0031] The ventilation fan 200 includes the electric motor 100 of the first embodiment, and a fan 52 that rotates in conjunction with the rotation of the rotor 2 illustrated in FIG. 1 and generates an air flow. The ventilation fan 200 also includes a fan casing 51 in which the fan 52 is housed, and a design grill 54 that covers a suction port on the indoor side. The fan 52 is attached to the rotating shaft 3 of the electric motor 100. The ventilation fan 200 causes the electric motor 100 to rotate the fan 52, thereby generating an air flow moving as indicated by an arrow A.

[0032] According to the second embodiment, the ventilation fan 200 includes the electric motor 100 of the first embodiment, such that stable insulation between the stator core 5 and the winding 12 can be ensured, and defects due to insulation failure can be reduced in the stator 1.

[0033] The configuration illustrated in the above embodiments indicates examples of the content of the present invention and can be combined with another known technology. A part of the configuration can also be omitted and modified without departing from the gist of the present invention.

Reference Signs List



[0034] 1 stator; 2 rotor; 3 rotating shaft; 4 central axis; 5 stator core; 6 secondary conductor; 7 frame; 8 bracket; 9 bearing housing; 10 bearing; 11 winding frame; 12 winding; 13 terminal block; 14 conductive pin; 16 lead wire; 21 yoke; 22 tooth portion; 23 slot; 31 guide portion; 32 abutment portion; 33 wedge; 51 fan casing; 52 fan; 53 ceiling; 54 design grill; 100 electric motor; 200 ventilation fan.


Claims

1. A stator comprising:

a stator core including an outer core and an inner core surrounded by the outer core;

a winding frame to cover the inner core and be wound with a winding; and

an insulator disposed between the winding and the outer core, wherein

the winding frame is provided with a guide portion to guide insertion of the insulator between the winding and the outer core.


 
2. The stator according to claim 1, wherein the insulator is inserted between a pair of the guide portions located at an interval corresponding to a width of the insulator.
 
3. The stator according to claim 1 or 2, wherein the winding frame is provided with an abutment portion to abut the inserted insulator.
 
4. An electric motor comprising:

a stator; and

a rotor surrounded by the stator, wherein

the stator includes:

a stator core including an outer core and an inner core surrounded by the outer core;

a winding frame to cover the inner core and be wound with a winding; and

an insulator disposed between the winding and the outer core, and

the winding frame is provided with a guide portion to guide insertion of the insulator between the winding and the outer core.


 
5. A ventilation fan comprising:

an electric motor including a stator, and a rotor surrounded by the stator; and

a fan to rotate in conjunction with rotation of the rotor and generates an air flow, wherein

the stator includes:

a stator core including an outer core and an inner core surrounded by the outer core;

a winding frame to cover the inner core and be wound with a winding; and

an insulator disposed between the winding and the outer core, and

the winding frame is provided with a guide portion to guide insertion of the insulator between the winding and the outer core.


 




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Cited references

REFERENCES CITED IN THE DESCRIPTION



This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description