motor stator

Abstract

To provide a stator of a motor that can increase a space factor of a coil with easy winding work without causing deterioration of roundness of the inner peripheral surface of the stator.SOLUTION: A stator 10 of a motor comprises: a stator core 20 including an annular yoke 21 and multiple teeth 22 protruding in an inner radial direction from the yoke 21; and coils 35. The coil 35 is part of a coil assembly 30 that is accommodated in a concave part 29 arranged in the stator core 20 so as to penetrate through in the axis direction. The coil assembly 30 is made of a core laminate 31 wound with the coil 35.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a stator of a motor, and particularly to a technique that enables easy winding work and increases the occupation ratio of coils without causing a decrease in the roundness of the inner peripheral surface of the stator.

Background Art

[0002] An inner rotor type motor has a configuration in which a rotor that rotates with respect to a stator is disposed inside the stator. Generally, the stator includes a stator core having an annular yoke and a plurality of teeth protruding radially inward from an inner peripheral edge of the annular yoke, and a coil is wound around each tooth.

[0003] For example, Patent Document 1 discloses a stator in which a stator core is divided into a plurality of core pieces, and the divided plurality of core pieces are connected and assembled. In such a stator, since the winding work can be performed at the stage of the core pieces, the winding work of feeding the winding from a nozzle is facilitated, and at the same time, the occupation ratio of the winding can be increased.

[0004] More specifically, the stator of the motor disclosed in Patent Document 1 includes a stator core 5 composed of teeth 3 and a coil winding portion 4, and a coil is wound around the coil winding portion 4 to form a divided core 7. The tip of the coil winding portion 4 is formed in a hook shape, and the hook-shaped portion is press-fitted into a recess formed at the base of the tooth 3, and the divided cores 7 are continuously connected in this way to form an annular stator 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the stator of Patent Document 1, considering the variations in dimensional accuracy of each part of each segmented core 7, the roundness of the inner surface of the teeth 3 decreases after the segmented cores 7 are connected and assembled into a ring.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a motor stator that allows for easy winding work without causing a decrease in the roundness of the inner circumferential surface of the stator, and also allows for a high coil space factor. [Means for solving the problem]

[0008] The present invention relates to a motor stator comprising a stator core having an annular yoke and a plurality of teeth projecting radially inward from the yoke, and a coil, wherein the coil is a coil assembly housed in an axially penetrating recess provided in the stator core, and the coil assembly is a motor stator in which a coil is wound around a core laminate. [Effects of the Invention]

[0009] According to the present invention, a motor stator is provided that allows for easy winding work without reducing the roundness of the inner circumferential surface of the stator, and also allows for a high winding space factor. [Brief explanation of the drawing]

[0010] [Figure 1] This is an exploded perspective view showing a stator according to an embodiment of the present invention. [Figure 2] (A) is a plan view showing the cores constituting the stator core in an embodiment of the present invention, and (B) is a plan view showing a modified example of (A). [Figure 3] This is a perspective view showing the state of the coil before it is wound to form a coil assembly in an embodiment of the present invention. [Figure 4] This is an exploded perspective view showing the state of the coil before it is wound to form a coil assembly in an embodiment of the present invention. [Modes for carrying out the invention]

[0011] 1. Stator configuration An embodiment of the present invention will be described with reference to Figures 1 to 4. Figure 1 is an exploded perspective view showing the stator 10 of the embodiment. In the following description, the vertical direction in Figure 1 will be referred to as the axial direction, the direction perpendicular to the axial direction will be referred to as the radial direction, and the rotational direction with the axial direction as the central axis will be referred to as the circumferential direction. In Figure 1, reference numeral 20 denotes the stator core. The stator core 20 is constructed by stacking a plurality of cores made of magnetic material (for example, electromagnetic steel sheets) rotated 120° in the axial direction.

[0012] The stator core 20 includes an annular yoke 21. Multiple teeth 22 (six in this example) are formed at equal intervals in the circumferential direction on the inner periphery of the yoke 21, projecting radially inward. The stator core 20 is applied as a stator for an inner rotor type motor, in which a rotor (not shown) is positioned inside the teeth 22.

[0013] Each tooth 22 is composed of a base 23 that narrows radially inward and arms 24 that extend circumferentially from the tip of the base 23, forming a T-shape in plan view. Slots 25 are formed between the arms 24 of adjacent teeth 22.

[0014] Multiple cavities 26 (four in this example) are formed in the base 23 of the teeth 22. These cavities 26 function as flux barriers that obstruct the passage of magnetic flux. The cavities 26 penetrate axially, and bridges 27 are formed between each cavity 26, maintaining the strength of the stator core 20.

[0015] The number and arrangement of the multiple cavities 26 are not limited to the configuration described above, and are arbitrary as long as they maintain the strength of the stator core 20 and the cavities 26 act as appropriate flux barriers. The number of cavities 26 can be two or one, and their shape and arrangement are not particularly limited.

[0016] On the outer peripheral surface of the stator core 20, a plurality of notch portions 28 (three locations at intervals of 120° in the circumferential direction) are formed. The notch portions 28 are used to position the stator core 20 by engaging with pins provided on, for example, the casing of the motor.

[0017] Between the bases 23 of the teeth 22 adjacent to each other, a recess 29 is formed. The recess 29 has a substantially rectangular shape and penetrates in the axial direction. The recess 29 is composed of a body portion 29a having a substantially spindle shape and an end portion 29b having a rectangular shape narrower than the body portion 29a. And a coil assembly 30 is disposed in the recess 29.

[0018] Figs. 3 and 4 show the state before winding the coil to form the coil assembly 30. In Fig. 4, reference numeral 31 is a core laminate. The core laminate 31 has an I shape in plan view and is formed by laminating a plurality of cores made of a magnetic material (for example, an electromagnetic steel sheet).

[0019] The core laminate 31 is composed of a body portion 31a having a rectangular shape and flange portions 31b formed at both ends of the body portion 31a. An insulator 32 composed of a first insulator 32a and a second insulator 32b is attached to such a core laminate 31.

[0020] The first insulator 32a includes a U-shaped cross-section base portion 33 that fits into the body portion 31a of the core laminate 31. Flange portions 34 are formed at both ends of the base portion 33. The flange portion 34 is composed of a head portion 34a that protrudes in the axial direction, circumferential direction, and radial direction from the base portion 33, and a plate portion 34b that extends from the head portion 34a toward the other insulator 32b side. By winding the coil in the space sandwiched by such flange portions 34, the coil is prevented from being deformed.

[0021] The head 34a is formed with a notch 34c that is recessed in the axial direction. The notch 34c is used to draw out the end wire of the coil. One side of the notch 34c is formed deeper than the other side. This is for inserting the coil from the deeper notch 34c and starting winding, and then drawing out the end wire of the coil from the shallower notch 34c after winding is finished.

[0022] The above is the configuration of the first insulator 32a. The second insulator 32b is configured in the same manner as the first insulator 32a except that the notch 34c is not formed, so the same reference numerals are used and the description thereof is omitted.

[0023] The first and second insulators 32a and 32b are mounted so as to sandwich the core laminate 31 from both axial sides. In that state, the flange portions 34 of the first and second insulators 32a and 32b are made to closely contact the axial-side surface of the head 34a and the circumferential-side surface of the plate portion 34b with the flange portion 31b of the core laminate 31. And in that state, by winding the coil 35 around the insulator 32, the coil assembly 30 is formed (see FIG. 1).

[0024] 2. Connection of the Coil Assembly to the Stator Core The coil assembly 30 is press-fitted into the recess 29 formed in the stator core 20. As a result, the circumferential end face of the core laminate 31 of the coil assembly 30 and the end portion 29b of the recess 29 of the stator core 20 are in close contact. That is, a state where there is no air gap between the stator core 20 and the coil assembly 30 is achieved. Also, the coil 35 of the coil assembly 30 is housed in the body portion 29a of the recess 29. Note that a conductive adhesive can also be used in combination when making the circumferential end face of the core laminate 31 and the end portion 29b of the recess 29 of the stator core 20 in close contact.

[0025] The end wires of the coil 35, which are drawn out from a notch 34c formed on one side of the flange 34 of the first insulator 32a, are electrically connected by predetermined means. These predetermined means may include directly soldering the end wires of the coils 35 of the coil assembly 30 together, or connecting them to pads of a wiring pattern formed on a circuit board (not shown). Furthermore, a busbar (not shown) may be provided on a motor (not shown), and the coils may be connected to the busbar.

[0026] 3. Action and Effects Magnetic flux emanating from the permanent magnets of a rotor (not shown) positioned inside the stator core 20 enters the teeth 22 of the stator core 20. The magnetic flux that enters the tip of the teeth 22 flows through the teeth 22 and into the core stack 31 which is in close contact with the stator core 20, and returns to the rotor from the adjacent tooth 22 on the other side. This magnetic flux flowing through the core stack 31 becomes a magnetic flux that links with the coil 35, generating a magnetomotive force in the coil 35.

[0027] In the stator 10 with the above configuration, a recess 29 is provided in the stator core 20, which has an annular yoke 21 and a plurality of teeth 22 projecting radially inward from the yoke 21, and a coil assembly 30 is housed in the recess 29. Since the stator core 20 is formed integrally with the yoke 21 and teeth 22, the position of the teeth 22 is fixed by the yoke 21, and the roundness of the inner circumferential surface of the teeth 22 can be maintained. Furthermore, since the coil assembly 30 is manufactured as a separate component, the movement of the nozzle that unwinds the coil is not restricted compared to conventional stators in which the coil is wound around the teeth 22, and the space factor of the coil 35 wound around the coil assembly 30 can be increased.

[0028] In particular, in the above embodiment, since the recess 29 is located between adjacent teeth 22, the yoke 21 is positioned radially outward of the recess 29. As a result, the width dimension of the yoke 21 is limited, and the cross-sectional area of ​​the yoke 21 forms a low-permeability section. On the other hand, the cross-sectional area of ​​the core laminate 31 of the coil assembly 30 adjacent to the radially inward side of the yoke 21 has significantly lower magnetic resistance compared to the cross-sectional area of ​​the yoke 21, thus forming a high-permeability section. Therefore, the magnetic flux flowing through the teeth 22 flows efficiently into the core laminate 31.

[0029] In addition, in the above embodiment, a cavity 26 is provided in the base 23 of the teeth 22 that penetrates in the axial direction. As a result, the cavity 26 acts as a flux barrier, and much of the magnetic flux flowing through the teeth 22 avoids the cavity 26 and heads towards the core laminate 31. Therefore, the magnetic flux flowing through the teeth 22 flows more efficiently to the core laminate 31.

[0030] Furthermore, in the above embodiment, since a notch 34c is formed in the flange portion 34 of the first insulator 32a, the end wires of the coil 35 can be easily routed by pulling them out from the notch 34c, and the occurrence of wire breakage can be prevented by passing the end wires from one notch 34c to the other.

[0031] Furthermore, since the notch 34c on one side is deeper than the notch 34c on the other side, the workability when winding the coil around the insulator 32 can be improved.

[0032] 4. Example of changes The present invention is not limited to the embodiments described above, and various modifications can be made as follows. i) When joining the end face of the core laminate 31 of the coil assembly 30 to the stator core 20, a key may be formed on one side of either the coil laminate 31 or the stator core 20, and a keyway on the other side, and the key may be engaged with the keyway to join them.

[0033] ii) Although the insulator 32 is composed of first and second insulators 32a and 32b, the insulator 32 and the core laminate 31 can be integrally molded by using the core laminate 31 as an insert material.

[0034] iii) As shown in Figure 2(B), three rows of cavities 26 can be provided in the radial direction. In this case, the rows of cavities 26 facing the recesses 29 can be arranged in an arc shape that is concave toward the recesses 29. With this configuration, the magnetic flux flowing through the teeth 22 is guided toward the core laminate 31, so that the magnetic flux flowing through the teeth 22 flows more efficiently toward the core laminate 31. [Industrial applicability]

[0035] This invention can be used as a stator for motors used in air supply, ventilation, cooling, etc., in home appliances, office automation equipment, and industrial and vehicle air conditioning systems. [Explanation of symbols]

[0036] 10... Stator, 20... Stator core, 21... Yoke, 22... Teeth, 23... Base, 24... Arms, 25... Slot, 26... Cavity, 27... Bridge, 28... Notch, 29... Recess, 29a... Body, 29b... End, 30... Coil assembly, 31... Core stack, 31a... Body, 31b... Flange, 32... Insulator, 32a... First insulator, 32b... Second insulator, 33... Base, 34... Flange, 34a... Head, 34b... Plate, 34c... Notch, 35... Coil.

Claims

1. A stator core having an annular yoke and a plurality of teeth projecting radially inward from the yoke and formed continuously with the yoke, coil and A motor stator equipped with, The coil is a coil assembly housed in an axially penetrating recess provided in the stator core, and the coil assembly is formed by winding a coil around a core laminate. A cavity is provided at the base of the tooth on the radially outer side, which penetrates in the axial direction. Motor stator.

2. The stator of the motor according to claim 1, wherein the recess is located between adjacent teeth.

3. The stator of the motor according to claim 2, wherein the aforementioned cavities are arranged in multiple rows in the radial direction, and the rows of cavities facing the recess are arranged in an arc shape that is concave toward the recess.

4. The stator of a motor according to any one of claims 1 to 3, wherein the coil assembly is a core stack in which substantially rectangular cores are stacked, an insulator is provided on the core stack, and a coil is wound around the insulator.

5. The stator of a motor according to any one of claims 1 to 4, wherein the core laminate is in close contact with the stator core in the circumferential direction or bonded to the stator core with a conductive adhesive.

6. The stator of the motor according to claim 4, wherein the insulator is provided with flange portions that protrude in the axial direction at both ends, and the flange portions are provided with notches that are recessed in the axial direction.

7. The stator of the motor according to claim 6, wherein the notch in one flange portion is deeper than the notch in the other flange portion.

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