Electric motor, core block, and stator core

Abstract

This electric motor comprises a stator core in which a plurality of core blocks are annularly connected to each other. A first core block and a second core block which are connected to each other among the plurality of core blocks each have a yoke portion and a tooth portion. The yoke portion of the first core block is provided with a protruding portion, a first surface, and a second surface. The yoke portion of the second core block is provided with a recessed portion fitting the protruding portion, a third surface, and a fourth surface. The first core block and the second core block are connected by allowing the first surface and the third surface to make surface contact with each other or by allowing the second surface and the fourth surface to make surface contact with each other.

Description

Electric motor, core block and stator core

[0001] The present disclosure relates to an electric motor, a core block used in a stator core of the electric motor, and a stator core having a core block.

[0002] 2. Description of the Related Art Electric motors are used in a variety of electrical appliances, such as household appliances and industrial appliances. Known types of electric motors include commutator motors that use brushes and brushless motors that do not use brushes.

[0003] A brushless motor includes, for example, a rotor having a magnet, a stator having a stator core and a winding wound around the stator core. Conventionally, a technique has been proposed in which the stator core is divided into multiple core blocks (divided cores) (see, for example, Patent Document 1).

[0004] When a stator core is constructed from multiple core blocks, conventionally, the stator core is divided into a number of parts corresponding to the number of slots, and the stator core is constructed by combining the same number of core blocks in a circular ring shape.

[0005] However, with this method, the shape of the core block is uniquely determined by the number of slots in the stator. In other words, the core block is dedicated to the number of slots in the stator. Therefore, if you want to manufacture a stator core with a different number of slots, you must design a new core block separately. In this case, you need a mold to manufacture the new core block, an insulator compatible with the new core block, and a jig change for the winding machine to apply windings compatible with the new core block. This results in higher costs.

[0006] As described above, the conventional core block has a problem in that it can only accommodate stators with one pattern of slot numbers.

[0007] JP 2010-259174 A

[0008] The present disclosure has been made to solve such problems, and aims to provide an electric motor, a core block, and a stator core that can accommodate stators with two different numbers of slots using a single core block.

[0009] In order to achieve the above object, one aspect of an electric motor according to the present disclosure includes a stator having a stator core in which a plurality of core blocks are connected in an annular shape, and a rotor having a rotating shaft and arranged inside the stator, wherein the plurality of core blocks include a first core block and a second core block connected together, each of the first core block and the second core block having a yoke portion extending in a circumferential direction centered on an axis of the rotating shaft and a teeth portion extending from the yoke portion toward the rotating shaft, The connecting portion between the yoke portion of the block has a convex portion, a first surface located on the outer periphery of the convex portion, and a second surface located on the inner periphery of the convex portion, and the connecting portion between the yoke portion of the first core block and the yoke portion of the second core block has a concave portion that fits into the convex portion, a third surface located on the outer periphery of the concave portion, and a fourth surface located on the inner periphery of the concave portion, and the first core block and the second core block are connected by surface contact between the first surface and the third surface, or by surface contact between the second surface and the fourth surface.

[0010] It is preferable that the first core blocks and the second core blocks are alternately connected around the entire circumference of the stator core, and that the number of slots in the stator differs when the first surface and the third surface contact and when the second surface and the fourth surface contact.

[0011] The number of slots may be nine when the first surface and the third surface are in surface contact with each other, and six when the second surface and the fourth surface are in surface contact with each other.

[0012] The number of slots may be 12 when the first surface and the third surface are in surface contact with each other, and the number of slots may be 9 when the second surface and the fourth surface are in surface contact with each other.

[0013] When viewed from above, the outline of the yoke portion of the first core block includes a first arc and a second arc having different radii of curvature, and when viewed from above, the outline of the yoke portion of the second core block includes a third arc and a fourth arc having different radii of curvature.

[0014] In the yoke portion of the first core block, the second arc is located closer to the tip of the yoke portion than the first arc, and in the yoke portion of the second core block, the fourth arc is located closer to the tip of the yoke portion than the third arc, and when the first surface and the third surface are in surface contact, the first arc and the third arc may be arcs of the same circle.

[0015] In the yoke portion of the first core block, the second arc is located closer to the tip of the yoke portion than the first arc, and in the yoke portion of the second core block, the fourth arc is located closer to the tip of the yoke portion than the third arc, and when the second surface and the fourth surface are in surface contact, the second arc and the fourth arc may be arcs of the same circle.

[0016] In the yoke portion of the first core block, the second arc is located closer to the tip of the yoke portion than the first arc, and in the yoke portion of the second core block, the fourth arc is located closer to the tip of the yoke portion than the third arc, and when the first surface and the third surface come into surface contact, the first arc and the third arc may be arcs of the same circle. Alternatively, when the second surface and the fourth surface come into surface contact, the second arc and the fourth arc may be arcs of the same circle.

[0017] The diameter of the circle is preferably 50 mm or less.

[0018] In a top view, it is preferable that an intersection of a first straight line when the first surface is extended and a second straight line when the second surface is extended is located within the convex portion.

[0019] The electric motor may be a brushless motor.

[0020] One aspect of the core block according to the present disclosure is a core block that is connected in a circular ring shape to form a stator core, and has a yoke portion extending circumferentially around the stator core and teeth extending from the yoke portion toward the center of the stator core, and one circumferential end of the yoke portion is provided with a convex portion, a first surface located on the outer periphery of the convex portion, and a second surface located on the inner periphery of the convex portion, and the other circumferential end of the yoke portion is provided with a concave portion that can be fitted into the convex portion, a third surface that is located on the outer periphery of the concave portion and is capable of surface contact with the first surface, and a fourth surface that is located on the inner periphery of the concave portion and is capable of surface contact with the second surface.

[0021] One aspect of the stator core according to the present disclosure includes a plurality of the above-described core blocks, and the plurality of core blocks are connected in an annular shape.

[0022] Another aspect of an electric motor according to the present disclosure includes a stator having the above-described stator core and a winding wound around the stator core, and a rotor positioned opposite the stator.

[0023] According to the present disclosure, a stator with two different patterns of the number of slots can be realized using one core block.

[0024] Fig. 1 is a cross-sectional view of an electric motor according to an embodiment when cut along a plane passing through the rotation axis. Fig. 2 is a cross-sectional view of an electric motor according to an embodiment when cut along a plane perpendicular to the rotation axis. Fig. 3 is an exploded perspective view of an electric motor according to an embodiment when viewed obliquely from above. Fig. 4 is a plan view of a stator core according to an embodiment when multiple core blocks are connected using a first connection pattern. Fig. 5 is a plan view of a core block constituting a stator core according to an embodiment. Fig. 6 is a plan view of a stator core according to an embodiment when multiple core blocks are connected using a second connection pattern.

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, components, the arrangement and connection of the components, steps, and the order of steps shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present disclosure will be described as optional components.

[0026] Each figure is a schematic diagram and is not necessarily a precise illustration. In each figure, the same reference numerals are used for components that are substantially the same as those in other figures, and duplicate explanations are omitted or simplified. In this specification, the terms "up" and "down" do not necessarily refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition.

[0027] (Embodiment) First, the configuration of an electric motor 1 according to an embodiment will be described with reference to Figures 1 to 3. Figure 1 is a cross-sectional view of the electric motor 1 according to an embodiment taken along a plane passing through a rotation shaft 31. Figure 2 is a cross-sectional view of the electric motor 1 according to an embodiment taken along a plane perpendicular to the rotation shaft 31. Figure 2 shows a cross section taken along line II-II in Figure 1. Figure 3 is an exploded perspective view of the electric motor 1 according to the embodiment as viewed obliquely from above.

[0028] 1 to 3, the electric motor 1 includes a stator 10, a circuit board 20, and a rotor 30 having a rotating shaft 31. The stator 10 and the circuit board 20 are combined as a stator assembly 2.

[0029] As shown in FIG. 1 , the electric motor 1 further includes a first bearing 41 , a second bearing 42 , a first bracket 51 , and a second bracket 52 .

[0030] The electric motor 1 is a brushless motor. The electric motor 1 can be used, for example, as a blower motor or a drive motor that requires a small size and high output. The size of the electric motor 1 is, for example, 50 mm or less in diameter. Specifically, the size of the electric motor 1 is, for example, 20 mm or 30 mm in diameter.

[0031] 1 and 2 , the electric motor 1 is an inner rotor type motor in which the rotor 30 is disposed inside the stator 10. In other words, the stator 10 is disposed so as to surround the rotor 30. Therefore, the rotor 30 rotates inside the stator 10 around the axis C of the rotating shaft 31 as the rotation center.

[0032] The stator 10 is disposed opposite the rotor 30 with a small air gap between them. Specifically, the stator 10 is disposed so as to surround a rotor core 32 of the rotor 30.

[0033] The stator 10 generates a magnetic force that acts on the rotor 30. Specifically, the stator 10 is configured such that multiple north and south poles alternate along the direction of rotation so as to generate magnetic flux on the air gap surface between the stator 10 and the rotor core 32 of the rotor 30. The stator 10 and the rotor 30 form a magnetic circuit.

[0034] The stator 10 constitutes an armature and includes a stator core 11 (stator core) and a winding 12 arranged on the stator core 11. The winding 12 is a winding coil wound around the stator core 11.

[0035] As shown in Fig. 2, the stator core 11 has a plurality of teeth 11a that protrude toward the rotor 30. Specifically, the plurality of teeth 11a extend radially in a direction (radial direction) perpendicular to the axis C of the rotating shaft 31. The plurality of teeth 11a are arranged at equal intervals in the circumferential direction, with slots 11b formed between two adjacent teeth 11a. The stator core 11 has nine teeth 11a. In other words, the number of slots in the stator 10 is nine.

[0036] The windings 12 are arranged in the slots 11b of the stator core 11. The windings 12 are stator coils that are armature windings of the stator 10. As an example, the windings 12 are concentrated winding coils wound around each of the teeth 11a.

[0037] The windings 12 are three-phase windings that can rotate the rotor 30 as a three-phase synchronous motor. Specifically, the windings 12 are composed of unit coils for three phases, U-phase, V-phase, and W-phase, which are electrically out of phase with each other by 120 degrees. In other words, the windings 12 wound around each tooth 11 a are energized and driven by three-phase alternating current that is applied to each of the U-phase, V-phase, and W-phase units. This generates a main magnetic flux of the stator 10 in each tooth 11 a. In other words, each tooth 11 a is a magnetic pole tooth. Each tooth 11 a is an electromagnet that generates a magnetic force when a current flows through the windings 12.

[0038] The stator core 11 is divided into a plurality of core blocks 110 (divided cores). That is, the stator core 11 of the stator 10 is made up of a plurality of core blocks 110.

[0039] The multiple core blocks 110 are arranged in an annular shape as a whole. Specifically, nine core blocks 110 are arranged to form an annular shape. Adjacent two core blocks 110 are connected to each other. In other words, the stator core 11 is formed by connecting multiple core blocks in an annular shape. A winding 12 is wound around each of the multiple core blocks 110. Since the stator 10 has nine core blocks 110, nine windings 12 are used.

[0040] As shown in FIG. 2 , an intermediate assembly 100 is formed by one core block 110 and one winding 12. The intermediate assembly 100 is an intermediate part used when manufacturing the stator assembly 2. The stator 10 is formed by combining a plurality of intermediate assemblies 100. Specifically, the stator 10 is formed by arranging a plurality of intermediate assemblies 100 in a cylindrical shape. The plurality of intermediate assemblies 100 are combined by connecting the core blocks 110 to form a circular ring shape. The stator 10 is formed by nine intermediate assemblies 100.

[0041] 2 and 3 , a core block 110 is provided for each intermediate assembly 100. The windings 12 of the stator 10 are also provided for each intermediate assembly 100. A connection terminal 120 and an insulator 130 are also provided for each intermediate assembly 100. Therefore, each of the multiple intermediate assemblies 100 has a core block 110, a winding 12, a connection terminal 120, and an insulator 130. The windings 12 are wound around the core block 110 via the insulator 130. The connection terminal 120 is fixed to the insulator 130. A detailed configuration of the core block 110 will be described later.

[0042] As shown in FIGS. 1 and 3 , the circuit board 20 is a printed circuit board (PCB) on which wiring made of a conductive material such as copper is formed in a predetermined pattern. The base substrate of the circuit board 20 can be a resin substrate such as a glass epoxy substrate or a metal substrate such as an aluminum alloy substrate. The circuit board 20 is mounted with a plurality of electronic components (not shown) for generating current to be supplied to the windings 12 of the stator 10. The plurality of electronic components constitute a circuit that generates three-phase alternating current: U-phase, V-phase, and W-phase.

[0043] The circuit board 20 has through holes 21. As shown in FIG. 1 , connection terminals 120 of the intermediate assembly 100 corresponding to the core block 110 are connected to the through holes 21. The connection terminals 120 are connection terminals to which the windings 12 of the stator 10 are connected. The connection terminals 120 have connection pins, and the connection pins of the connection terminals 120 to which the windings 12 are connected are inserted into the through holes 21. This connects the connection terminals 120 and the circuit board 20. In this way, the circuit board 20 is a connection board to which the windings 12 are connected via the connection terminals 120. The circuit board 20 has a plurality of through holes 21.

[0044] The connection pins of the connection terminals 120 are press-fitted into the through holes 21 of the circuit board 20. This allows the connection terminals 120 to be fixed to the circuit board 20. The inner circumferential surface of each through hole 21 is coated with a conductive film (e.g., copper plating) that is electrically connected to the wiring formed on the main surface of the circuit board 20. Therefore, by press-fitting the connection pins of the connection terminals 120 into the through holes 21, the connection terminals 120 are mechanically connected to the circuit board 20. In addition, they are electrically connected to the wiring of the circuit board 20 via the conductive film coated on the inner circumferential surface of the through holes 21.

[0045] The rotor 30 rotates due to the magnetic force generated by the stator 10. The rotor 30 has a configuration in which multiple north and south poles alternate along the direction of rotation. This allows the rotor 30 to generate a magnetic force that acts on the stator 10. The direction of the magnetic flux generated by the rotor 30 is perpendicular to the direction in which the axis C included in the rotating shaft 31 extends (axial direction). In other words, the direction of the magnetic flux generated by the rotor 30 is the radial direction.

[0046] 1 and 2, the rotor 30 has a rotating shaft 31, a rotor core 32, and permanent magnets 33. The rotor 30 is an interior permanent magnet (IPM) rotor in which the permanent magnets 33 are embedded in the rotor core 32. Therefore, the electric motor 1 is an IPM motor.

[0047] The rotating shaft 31 is a long shaft. The rotating shaft 31 is, for example, a metal rod. The rotating shaft 31 is fixed to the rotor core 32. Specifically, the rotating shaft 31 is inserted into a through hole provided in the center of the rotor core 32 and fixed to the rotor core 32 so as to extend on both sides of the rotor core 32 in the direction in which the axis C extends.

[0048] The rotor core 32 is a laminated body in which a plurality of steel plates are stacked along the direction in which the axis C of the rotating shaft 31 extends (axial direction). Each of the plurality of steel plates is, for example, a punched electromagnetic steel plate formed into a predetermined shape. The plurality of steel plates are fixed to one another by, for example, caulking.

[0049] The permanent magnets 33 are inserted into magnet insertion holes 32a provided in the rotor core 32. Six magnet insertion holes 32a are provided in the rotor core 32 at equal intervals around the circumference. Therefore, the rotor 30 has six permanent magnets 33 arranged at equal intervals around the circumference. In other words, the number of poles of the electric motor 1 is six. The permanent magnets 33 are sintered magnets. However, the permanent magnets 33 may also be bonded magnets.

[0050] The rotating shaft 31 of the rotor 30 is provided with a first bearing 41 and a second bearing 42 that rotatably support the rotating shaft 31. The first bearing 41 and the second bearing 42 are bearings that rotatably support the rotating shaft 31. The first bearing 41 supports a portion of the rotating shaft 31 that protrudes from one side of the rotor core 32. On the other hand, the second bearing 42 supports a portion of the rotating shaft 31 that protrudes from the other side of the rotor core 32. The first bearing 41 and the second bearing 42 are ball bearings, for example. However, the present invention is not limited to this.

[0051] The first bracket 51 holds the first bearing 41. Specifically, the first bearing 41 is fixed in a recess provided in the first bracket 51. The second bracket 52 holds the second bearing 42. Specifically, the second bearing 42 is fixed in a recess provided in the second bracket 52. The first bracket 51 and the second bracket 52 are made of a metal material or a resin material.

[0052] The first bracket 51 and the second bracket 52 form the outer shell of the electric motor 1. Specifically, the first bracket 51 is a cylindrical frame (housing) with an opening and a bottom. The second bracket 52 is a bottom plate that closes the opening of the first bracket 51. The first bracket 51 is a metal frame made of metal. The second bracket 52 is a resin plate made of resin.

[0053] The rotating shaft 31 of the rotor 30 passes through the first bracket 51. A portion of the rotating shaft 31 protrudes to the outside from the first bracket 51. Although not shown, a load such as a rotary fan is attached to the portion of the rotating shaft 31 that protrudes to the outside from the first bracket 51. In other words, the portion of the rotating shaft 31 that protrudes to the outside from the first bracket 51 is an output shaft.

[0054] In the electric motor 1 configured as described above, when current is applied to the windings 12 of the stator 10, a field current flows through the windings 12, generating magnetic flux in the stator 10 (stator core 11). This generates magnetic flux that flows from the stator 10 toward the rotor 30. Specifically, magnetic flux is generated from each of the teeth 11a of the stator core 11 of the stator 10 toward the rotor core 32 of the rotor 30. Meanwhile, in the rotor 30, magnetic flux that passes through the stator 10 is generated by the permanent magnets 33 embedded in the rotor core 32. A magnetic force generated by the interaction between the magnetic flux generated by the stator 10 and the magnetic flux generated by the permanent magnets 33 of the rotor 30 becomes torque that rotates the rotor 30. This causes the rotor 30 to rotate.

[0055] Next, the detailed shape of the core blocks 110 constituting the stator core 11 and the connection pattern of the core blocks 110 will be described using Figures 4 and 5 while referring to Figures 1 to 3. Figure 4 is a plan view of the stator core 11 according to the embodiment when a plurality of core blocks 110 are connected in a first connection pattern. Figure 5 is a plan view of the core blocks 110 constituting the stator core 11 according to the embodiment.

[0056] Each of the multiple core blocks 110 is formed by stacking multiple steel plates. Specifically, each core block 110 is a laminate in which multiple punched electromagnetic steel plates are stacked along the direction in which the axis C of the rotating shaft 31 extends. The electromagnetic steel plates that make up the core block 110 have the same shape. The multiple electromagnetic steel plates are fixed to each other by, for example, crimping.

[0057] 2 and 4, each core block 110 has teeth portions 111 and a yoke portion 112. The teeth portions 111 correspond to the teeth 11a of the stator core 11 shown in FIG.

[0058] 4 , the teeth 111 are formed inside the yoke 112. The teeth 111 extend from the yoke 112 toward the center of the stator core 11. Specifically, the teeth 111 extend from the yoke 112 toward the rotating shaft 31. In other words, the teeth 111 extend so as to protrude radially inward of the stator 10.

[0059] The tooth portions 111 have extension portions 111a that extend to both sides in the circumferential direction from the tip portions on the inner circumferential side of the tooth portions 111. Each of the pair of extension portions 111a is formed to protrude in the circumferential direction from the tip portions on the inner circumferential side of the tooth portions 111. In two adjacent core blocks 110, a gap (slot opening) 111b exists between the extension portion 111a of the tooth portions 111 in one core block 110 and the extension portion 111a of the tooth portions 111 in the other core block 110.

[0060] A slot 11b for arranging the winding 12 is formed between two adjacent teeth 111. In other words, the slot 11b is a spatial region on the side of the teeth 111.

[0061] 2, the winding 12 is wound around the tooth portion 111. Specifically, the winding 12 is wound around the tooth portion 111 with an insulator 130 interposed therebetween.

[0062] As shown in Fig. 4, in the core block 110, the yoke portions 112 are back yokes formed outside the tooth portions 111. The yoke portions 112 extend along the circumferential direction of the stator core 11. The yoke portions 112 extend along the circumferential direction (the rotation direction of the rotating shaft 31) centered on the axis C of the rotating shaft 31. In two adjacent core blocks 110, two adjacent yoke portions 112 are connected by abutting their circumferential end faces against each other. Specifically, in Fig. 4, nine yoke portions 112 are arranged along the circumferential direction of a circle centered on the axis C of the rotating shaft 31 and are connected to form an annular shape as a whole.

[0063] 5, in each core block 110, a first end 112a, which is one circumferential end of the yoke portion 112, is provided with a protruding portion 113a and a first surface 114a and a second surface 115a located on both sides of the protruding portion 113a. The protruding portion 113a, the first surface 114a, and the second surface 115a are formed on an end surface of the first end 112a facing in the circumferential direction. In a top view, the protruding portion 113a is sandwiched between the first surface 114a and the second surface 115a.

[0064] The protrusion 113a is formed to protrude from the first end 112a in the circumferential direction of the stator core 11. The shape of the protrusion 113a in a top view is semicircular. Therefore, when the core block 110 is viewed three-dimensionally, the protrusion 113a has a semicylindrical shape. The shape of the protrusion 113a in a top view is not limited to semicircular.

[0065] The first surface 114a is located on the outer periphery of the protrusion 113a. Specifically, the first surface 114a is a plane parallel to a plane passing through the axis C of the rotation shaft 31. The first surface 114a extends from the base of the protrusion 113a on the outer periphery toward the outer periphery. The first surface 114a is a flat surface.

[0066] The second surface 115a is located on the inner circumferential side of the convex portion 113a. Specifically, the second surface 115a is a plane parallel to a plane passing through the axis C of the rotation shaft 31. The second surface 115a extends from the base of the inner circumferential side of the convex portion 113a toward the inner circumferential side. The second surface 115a is a flat surface.

[0067] The first surface 114a and the second surface 115a are both surfaces facing the circumferential direction of the rotation shaft 31. The inclination angle of the first surface 114a with respect to the radial direction of the rotation shaft 31 is different from the inclination angle of the second surface 115a with respect to the radial direction of the rotation shaft 31. As shown in Fig. 5, when the core block 110 is viewed from above, the intersection of a first straight line L1 obtained by extending the first surface 114a and a second straight line L2 obtained by extending the second surface 115a is located within the convex portion 113a.

[0068] On the other hand, the second end 112b, which is the other circumferential end of the yoke portion 112, is provided with a recess 113b that can fit onto the protrusion 113a, and a third surface 114b and a fourth surface 115b located on both sides of the recess 113b. The recess 113b, the third surface 114b, and the fourth surface 115b are formed on the end surface facing the circumferential direction of the second end 112b. In a top view, the recess 113b is sandwiched between the third surface 114b and the fourth surface 115b.

[0069] The recess 113b is formed so as to recess from the second end 112b in the circumferential direction of the stator core 11. The shape of the recess 113b in a top view is semicircular. In other words, the surface of the recess 113b in a top view is an arc. Therefore, when the core block 110 is viewed three-dimensionally, the recess 113b has a shape in which the second end 112b is recessed into a semicylindrical shape. The shape of the recess 113b is not limited to this. Any shape may be adopted for the recess 113b as long as it can fit into the protrusion 113a.

[0070] The third surface 114b is located on the outer periphery of the recess 113b. Specifically, the third surface 114b is a plane parallel to a plane passing through the axis C of the rotation shaft 31. The third surface 114b extends from the base of the recess 113b on the outer periphery toward the outer periphery. The third surface 114b is a flat surface.

[0071] The third surface 114b is a surface that can come into surface contact with the first surface 114a at the first end 112a of the yoke portion 112. Therefore, the first surface 114a at the first end 112a of the yoke portion 112 is a surface that can come into surface contact with the third surface 114b.

[0072] The fourth surface 115b is located on the inner periphery side of the recess 113b. Specifically, the fourth surface 115b is a plane parallel to a plane passing through the axis C of the rotation shaft 31. The fourth surface 115b extends from the base of the inner periphery side of the recess 113b toward the inner periphery side. The fourth surface 115b is a flat surface.

[0073] The fourth surface 115b is a surface that can come into surface contact with the second surface 115a at the first end 112a of the yoke portion 112. Therefore, the second surface 115a at the first end 112a of the yoke portion 112 is a surface that can come into surface contact with the fourth surface 115b.

[0074] The third surface 114b and the fourth surface 115b are both surfaces facing the circumferential direction of the rotation shaft 31. The inclination angle of the third surface 114b with respect to the radial direction of the rotation shaft 31 is different from the inclination angle of the fourth surface 115b with respect to the radial direction of the rotation shaft 31. As shown in Fig. 5, when the core block 110 is viewed from above, the intersection of a third straight line L3 obtained by extending the third surface 114b and a fourth straight line L4 obtained by extending the fourth surface 115b is located within the recess 113b.

[0075] The circumscribing surface of the yoke portion 112 includes two curved surfaces (R-surfaces) with different radii of curvature. Specifically, as shown in Fig. 5, the outline of the yoke portion 112 in the core block 110 in top view includes multiple arcs with different radii of curvature.

[0076] The outline of one circumferential side of the yoke portion 112, relative to the tooth portion 111, includes a first arc 116a and a second arc 117a, each having a different radius of curvature. The radius of curvature R2 of the second arc 117a is larger than the radius of curvature R1 of the first arc 116a (R2 > R1). In this case, the second arc 117a is located closer to the tip of the yoke portion 112 than the first arc 116a. The arc length of the second arc 117a is shorter than the arc length of the first arc 116a. The first arc 116a and the second arc 117a are continuous.

[0077] Meanwhile, the outline of the other circumferential side of the yoke portion 112 relative to the tooth portion 111 includes a third arc 116b and a fourth arc 117b, which have different radii of curvature. The radius of curvature R4 of the fourth arc 117b is greater than the radius of curvature R3 of the third arc 116b (R4 > R3). In this case, the fourth arc 117b is located closer to the tip of the yoke portion 112 than the third arc 116b. The arc length of the fourth arc 117b is shorter than the arc length of the third arc 116b. The third arc 116b and the fourth arc 117b are continuous.

[0078] The radius of curvature R3 of the third arc 116b is the same as the radius of curvature R1 of the first arc 116a (R1=R3). The radius of curvature R4 of the fourth arc 117b is the same as the radius of curvature R2 of the second arc 117a (R2=R4).

[0079] A plurality of core blocks 110 configured in this manner are arranged in an annular shape and connected together, as shown in Fig. 4. The plurality of core blocks 110 arranged in an annular shape are connected together by connecting the yoke portions 112 of two adjacent core blocks 110. All of the plurality of core blocks 110 have the same shape. In other words, the stator core 11 is composed only of core blocks 110 having the shape shown in Fig. 5.

[0080] 4, focusing on two connected core blocks, a first core block 110a and a second core block 110b, among the plurality of core blocks 110, a convex portion 113a, a first surface 114a located on the outer circumferential side of the convex portion 113a, and a second surface 115a located on the inner circumferential side of the convex portion 113a are provided at the connection portion of the yoke portion 112 of the first core block 110a with the yoke portion 112 of the second core block 110b. In other words, the convex portion 113a, the first surface 114a, and the second surface 115a are provided at the first end portion 112a of the yoke portion 112 of the first core block 110a on the second core block 110b side.

[0081] A recess 113b, a third surface 114b located on the outer periphery of the recess 113b, and a fourth surface 115b located on the inner periphery of the recess 113b are provided at the connection portion of the yoke portion 112 of the second core block 110b with the yoke portion 112 of the first core block 110a. In other words, the recess 113b, the third surface 114b, and the fourth surface 115b are provided at the second end portion 112b of the yoke portion 112 of the second core block 110b on the first core block 110a side.

[0082] At the connection between the first core block 110a and the second core block 110b, a convex portion 113a in the yoke portion 112 of the first core block 110a fits into a concave portion 113b in the yoke portion 112 of the second core block 110b.

[0083] The first core blocks 110a and the second core blocks 110b are alternately connected around the entire circumference of the stator core 11. In other words, the stator core 11 is made up of a plurality of core blocks 110 including the first core blocks 110a and the second core blocks 110b.

[0084] In the stator core 11 shown in FIG. 4 , nine core blocks 110 are connected. That is, the number of slots in the stator 10 having the stator core 11 shown in FIG. 4 is nine. In this case, as shown in FIG. 4 , in the first core block 110a and the second core block 110b that are connected to each other, the first surface 114a of the yoke portion 112 of the first core block 110a and the third surface 114b of the yoke portion 112 of the second core block 110b are in surface contact. That is, in FIG. 4 , the first surface 114a is the contact surface that contacts the third surface 114b. The third surface 114b is the contact surface that contacts the first surface 114a. Therefore, when the core blocks 110 are connected as shown in FIG. 4 , the first surface 114a and the third surface 114b are mating surfaces of the core blocks 110.

[0085] On the other hand, in Fig. 4, the second surface 115a of the yoke portion 112 of the first core block 110a and the fourth surface 115b of the yoke portion 112 of the second core block 110b are not in contact with each other. In other words, a gap exists between the second surface 115a and the fourth surface 115b. The second surface 115a and the fourth surface 115b are separated from each other. Therefore, when the core blocks 110 are joined as shown in Fig. 4, the second surface 115a and the fourth surface 115b are non-contacting surfaces.

[0086] In this way, when the first surface 114a of the first core block 110a and the third surface 114b of the second core block 110b are in surface contact with each other, the number of slots in the stator 10 having the stator core 11 is nine.

[0087] 4, when the first surface 114a of the first core block 110a and the third surface 114b of the second core block 110b are in surface contact, the first arc 116a in the outline of the yoke portion 112 of the first core block 110a and the third arc 116b in the outline of the yoke portion 112 of the second core block 110b are arcs of the same circle. In this case, the diameter of the circle formed by the first arc 116a and the third arc 116b is 50 mm or less.

[0088] As shown in Figure 4, when the first surface 114a of the first core block 110a and the third surface 114b of the second core block 110b are in surface contact (i.e., in the case of the first connection pattern), the first surface 114a and the third surface 114b, which are contact surfaces, are aligned radially with the rotation axis 31 when viewed from above.

[0089] In this way, in two adjacent core blocks 110, the convex portion 113a of the first core block 110a is fitted into the concave portion 113b of the second core block 110b, and the first surface 114a of the first core block 110a is brought into surface contact with the third surface 114b of the second core block 110b, thereby connecting nine core blocks 110. In other words, by connecting nine core blocks 110 to form the stator core 11, a stator 10 with nine slots can be obtained.

[0090] Fig. 6 is a plan view of a stator core 11 according to an embodiment in which a plurality of core blocks 110 are connected using the second connection pattern. As shown in Fig. 6, six core blocks 110 can be connected by fitting the convex portion 113a of the first core block 110a with the concave portion 113b of the second core block 110b and bringing the second surface 115a of the first core block 110a into surface contact with the fourth surface 115b of the second core block 110b. In other words, by connecting six core blocks 110 to form a stator core 11, a stator 10 with six slots can be obtained.

[0091] As shown in Fig. 6 , when multiple core blocks 110 are connected using the second connection pattern, the second surface 115a of the first core block 110a and the fourth surface 115b of the second core block 110b are contact surfaces between two adjacent core blocks, a first core block 110a and a second core block 110b. That is, in Fig. 6 , the second surface 115a is the contact surface that contacts the fourth surface 115b. The fourth surface 115b is the contact surface that contacts the second surface 115a. Therefore, when the core blocks 110 are connected as shown in Fig. 6 , the second surface 115a and the fourth surface 115b are mating surfaces of the core blocks 110.

[0092] In the second connection pattern shown in Fig. 6, the first surface 114a of the yoke portion 112 of the first core block 110a and the third surface 114b of the yoke portion 112 of the second core block 110b are not in contact with each other. In other words, a gap exists between the first surface 114a and the third surface 114b. The first surface 114a and the third surface 114b are separated from each other. In other words, in Fig. 6, the first surface 114a and the third surface 114b are non-contacting surfaces.

[0093] As shown in Fig. 6 , when the second surface 115a of the first core block 110a and the fourth surface 115b of the second core block 110b are in surface contact, the second arc 117a in the outline of the yoke portion 112 of the first core block 110a and the fourth arc 117b in the outline of the yoke portion 112 of the second core block 110b are arcs of the same circle. In this case, too, the diameter of the circle formed by the second arc 117a and the fourth arc 117b is 50 mm or less. The diameter of the stator core 11 in the second connection pattern shown in Fig. 6 is smaller than the diameter of the stator core 11 in the first connection pattern shown in Fig. 4 .

[0094] As shown in Figure 6, when the second surface 115a of the first core block 110a and the fourth surface 115b of the second core block 110b are in surface contact (i.e., in the case of the second connection pattern), the second surface 115a and the fourth surface 115b, which are contact surfaces, are aligned radially with the rotation axis 31 when viewed from above.

[0095] As described above, core block 110 according to this embodiment has teeth 111 and yoke 112. A first circumferential end 112a of yoke 112 is provided with protrusion 113a, a first surface 114a located on the outer periphery of protrusion 113a, and a second surface 115a located on the inner periphery of protrusion 113a. A second circumferential end 112b of yoke 112 is provided with recess 113b that can fit into protrusion 113a, a third surface 114b located on the outer periphery of recess 113b, and a fourth surface 115b located on the inner periphery of recess 113b.

[0096] When a plurality of core blocks 110 having such a shape are connected to produce the stator core 11, two adjacent core blocks 110, a first core block 110a and a second core block 110b, are connected by having their first surfaces 114a and third surfaces 114b in surface contact as shown in Fig. 4, or by having their second surfaces 115a and fourth surfaces 115b in surface contact as shown in Fig. 6. That is, the plurality of core blocks 110 are connected by a first connection pattern in which the first surfaces 114a and third surfaces 114b are in surface contact as shown in Fig. 4, or by a second connection pattern in which the plurality of core blocks 110 are in surface contact with the second surfaces 115a and fourth surfaces 115b as shown in Fig. 6.

[0097] This makes it possible to realize a stator 10 having different numbers of slots when the first surface 114a and the third surface 114b are in surface contact with each other and when the second surface 115a and the fourth surface 115b are in surface contact with each other. Specifically, as shown in Fig. 4, the number of slots is nine when the first surface 114a and the third surface 114b are in surface contact with each other. As shown in Fig. 6, the number of slots is six when the second surface 115a and the fourth surface 115b are in surface contact with each other. In other words, two patterns of slot numbers can be realized by connecting the core blocks 110 using either the first connection pattern shown in Fig. 4 or the second connection pattern shown in Fig. 6, depending on the required number of slots.

[0098] In this way, by using the core block 110, it is possible to realize the stator 10 with two patterns of the number of slots using one core block 110. In other words, one core block 110 can be used in two different ways.

[0099] In two adjacent core blocks, a first core block 110a and a second core block 110b, the outline of the yoke portion 112 in the first core block 110a includes a first arc 116a and a second arc 117a, which have different radii of curvature, and the outline of the yoke portion 112 in the second core block 110b includes a third arc 116b and a fourth arc 117b, which have different radii of curvature.

[0100] This prevents either the connection portion between the first core block 110a and the second core block 110b when the first surface 114a and the third surface 114b are in surface contact (in the case of the first connection pattern in Figure 4), or the connection portion between the first core block 110a and the second core block 110b when the second surface 115a and the fourth surface 115b are in surface contact (in the case of the second connection pattern in Figure 6), from becoming angular.

[0101] For example, if the outline of the yoke portion 112 of the core block 110 were formed by only one arc, as shown in FIG. 6 , when the first core block 110a and the second core block 110b were connected so that the inner second surface 115a and the inner fourth surface 115b were in surface contact, the connection between the first core block 110a and the second core block 110b would be angular, resulting in a corner being formed on the outer surface of the stator core 11. In this case, the outer surface of the stator core 11 would abut against the inner surface of the first bracket 51 (frame), as shown in FIG. 2 . Therefore, if a corner were formed on the outer surface of the stator core 11, this corner would come into point contact with the inner surface of the first bracket 51. Therefore, stress would be applied to the stator core 11 from the first bracket 51. As a result, the stator core 11 could be damaged or misaligned, making it impossible to generate the desired magnetic flux.

[0102] In contrast, in the present embodiment, the contour of the yoke portion 112 of the core block 110 includes arcs with different radii of curvature, which prevents the joint between the first core block 110a and the second core block 110b from becoming angular, as described above. Specifically, as shown in Fig. 6 , when the first core block 110a and the second core block 110b are joined so that the inner second surface 115a and the inner fourth surface 115b are in surface contact, the joint between the first core block 110a and the second core block 110b can be prevented from becoming angular. This reduces the stress load applied to the stator core 11.

[0103] As described above, the electric motor 1 of this embodiment includes the stator 10 having the stator core 11 in which a plurality of core blocks 110 are connected in an annular shape, and the rotor 30 having the rotating shaft 31 and disposed inside the stator 10. The plurality of core blocks 110 include a first core block 110a and a second core block 110b that are connected to each other. Each of the first core block 110a and the second core block 110b has a yoke portion 112 that extends in a circumferential direction centered on the axis of the rotating shaft 31, and teeth portions 111 that extend from the yoke portion 112 toward the rotating shaft 31. The connecting portion of the yoke portion 112 of the first core block 110a with the yoke portion 112 of the second core block 110b is provided with a protrusion 113a, a first surface 114a located on the outer circumferential side of the protrusion 113a, and a second surface 115a located on the inner circumferential side of the protrusion 113a. The connecting portion of the yoke portion 112 of the second core block 110b with the yoke portion 112 of the first core block 110a is provided with a recess 113b that fits into the protrusion 113a, a third surface 114b located on the outer periphery of the recess 113b, and a fourth surface 115b located on the inner periphery of the recess 113b. The first core block 110a and the second core block 110b are connected by surface contact between the first surface 114a and the third surface 114b, or by surface contact between the second surface 115a and the fourth surface 115b.

[0104] This makes it possible to realize a stator with two different numbers of slots using one core block.

[0105] In this embodiment, a plurality of core blocks 110 are connected in an annular shape to form stator core 11, and each core block 110 includes yoke portions 112 extending in the circumferential direction of stator core 11 and teeth portions 111 extending from yoke portions 112 toward the center of stator core 11. One circumferential end of yoke portion 112 is provided with a protrusion 113a, a first surface 114a located on the outer circumferential side of protrusion 113a, and a second surface 115a located on the inner circumferential side of protrusion 113a. The other circumferential end of yoke portion 112 is provided with a recess 113b that can fit into protrusion 113a, a third surface 114b located on the outer circumferential side of recess 113b and capable of surface-to-surface contact with first surface 114a, and a fourth surface 115b located on the inner circumferential side of recess 113b and capable of surface-to-surface contact with second surface 115a.

[0106] The electric motor 1 of this embodiment includes a stator 10 having a stator core 11 and a winding wound around the stator core 11 , and a rotor 30 positioned opposite the stator 10 .

[0107] (Modifications) Although the present disclosure has been described above based on the embodiments, the present disclosure is not limited to the above-described embodiments.

[0108] For example, in the above embodiment, the core block 110 is shaped such that the number of slots is 9 when the first surface 114a and the third surface 114b are in surface contact, and the number of slots is 6 when the second surface 115a and the fourth surface 115b are in surface contact. However, this is not limiting. Specifically, the core block 110 may be shaped such that the number of slots is 12 when the first surface 114a and the third surface 114b are in surface contact, and the number of slots is 9 when the second surface 115a and the fourth surface 115b are in surface contact.

[0109] In the above embodiment, the rotor 30 is an IPM rotor. However, this is not limiting. For example, the rotor 30 may be a surface permanent magnetic (SPM) rotor in which multiple permanent magnets are provided on the outer surface of a rotor core.

[0110] In the above embodiment, the rotor 30 is a laminated body formed by stacking a plurality of steel plates. However, this is not limiting. For example, the rotor 30 may be made of a bulk material.

[0111] In addition, the present disclosure also includes forms obtained by applying various modifications to the above-described embodiments that a person skilled in the art would conceive, or forms realized by arbitrarily combining the components and functions of the above-described embodiments within the scope that does not deviate from the spirit of the present disclosure.

[0112] The technology of the present disclosure can be widely used in electric motors and electrical devices equipped with electric motors.

[0113] REFERENCE SIGNS LIST 1 electric motor 2 stator assembly 10 stator 11 stator core 11a teeth 11b slots 12 windings 20 circuit board 21 through holes 30 rotor 31 rotating shaft 32 rotor core 32a magnet insertion holes 33 permanent magnets 41 first bearing 42 second bearing 51 first bracket 52 second bracket 100 intermediate assembly 110 core block 110a first core block 110b second core block 111 teeth portion 111a extension portion 111b gap (slot opening) 112 yoke portion 112a first end portion 112b second end portion 113a convex portion 113b concave portion 114a first surface 115a second surface 114b third surface 115b fourth surface 116a First circular arc 117a Second circular arc 116b Third circular arc 117b Fourth circular arc 120 Connection terminal 130 Insulator

Claims

1. a stator having a stator core in which a plurality of core blocks are connected in an annular shape; a rotor having a rotation axis and disposed inside the stator; The plurality of core blocks include a first core block and a second core block that are connected together, Each of the first core block and the second core block has a yoke portion extending in a circumferential direction about an axis of the rotating shaft; a teeth portion extending from the yoke portion toward the rotation shaft, a connecting portion of the yoke portion of the first core block with the yoke portion of the second core block is provided with a convex portion, a first surface located on an outer circumferential side of the convex portion, and a second surface located on an inner circumferential side of the convex portion, a connecting portion of the yoke portion of the second core block with the yoke portion of the first core block is provided with a recess adapted to fit into the protrusion, a third surface located on an outer circumferential side of the recess, and a fourth surface located on an inner circumferential side of the recess, The first core block and the second core block are connected by surface contact between the first surface and the third surface, or by surface contact between the second surface and the fourth surface. Electric motor.

2. The first core blocks and the second core blocks are alternately connected to each other around the entire circumference of the stator core, a number of slots of the stator is different between a case where the first surface contacts the third surface and a case where the second surface contacts the fourth surface; 2. The electric motor according to claim 1.

3. the number of slots when the first surface and the third surface are in surface contact is nine; When the second surface and the fourth surface are in surface contact with each other, the number of slots is six.

3. The electric motor according to claim 2.

4. the number of slots when the first surface and the third surface are in surface contact is 12; The number of slots when the second surface and the fourth surface are in surface contact with each other is 9.

3. The electric motor according to claim 2.

5. When viewed from above, an outline of the yoke portion of the first core block includes a first circular arc and a second circular arc having different radii of curvature, When viewed from above, the outer shape of the yoke portion of the second core block includes a third arc and a fourth arc having different radii of curvature.

2. The electric motor according to claim 1.

6. In the yoke portion of the first core block, the second arc is located closer to a tip end of the yoke portion than the first arc, In the yoke portion of the second core block, the fourth arc is located closer to a tip end of the yoke portion than the third arc, When the first surface and the third surface are in surface contact with each other, the first arc and the third arc become arcs of the same circle.

6. The electric motor according to claim 5.

7. In the yoke portion of the first core block, the second arc is located closer to a tip end of the yoke portion than the first arc, In the yoke portion of the second core block, the fourth arc is located closer to a tip end of the yoke portion than the third arc, When the second surface and the fourth surface are in surface contact with each other, the second arc and the fourth arc become arcs of the same circle.

6. The electric motor according to claim 5.

8. In the yoke portion of the first core block, the second arc is located closer to a tip end of the yoke portion than the first arc, In the yoke portion of the second core block, the fourth arc is located closer to a tip end of the yoke portion than the third arc, When the first surface and the third surface are in surface contact with each other, the first arc and the third arc are arcs of the same circle; or When the second surface and the fourth surface are in surface contact with each other, the second arc and the fourth arc become arcs of the same circle.

6. The electric motor according to claim 5.

9. The diameter of the circle is 50 mm or less. The electric motor according to any one of claims 6 to 8.

10. When viewed from above, an intersection point between a first straight line when the first surface is extended and a second straight line when the second surface is extended is located within the convex portion. The electric motor according to any one of claims 1 to 4.

11. The electric motor is a brushless motor. The electric motor according to any one of claims 1 to 4.

12. A core block that constitutes a stator core by being connected in a circular shape, a yoke portion extending along a circumferential direction of the stator core; a teeth portion extending from the yoke portion toward a center portion of the stator core, a protruding portion, a first surface located on an outer circumferential side of the protruding portion, and a second surface located on an inner circumferential side of the protruding portion are provided at one end of the yoke portion in a circumferential direction, The other circumferential end of the yoke portion is provided with a recess that can be fitted into the protrusion, a third surface that is located on the outer circumferential side of the recess and is a surface that can be in surface contact with the first surface, and a fourth surface that is located on the inner circumferential side of the recess and is a surface that can be in surface contact with the second surface. Core block.

13. A core block according to claim 12, The core blocks are connected in an annular shape. Stator core.

14. A stator having the stator core according to claim 13 and a winding wound around the stator core; A rotor positioned opposite the stator. Electric motor.