Motor

Abstract

To increase the assembly performance and increase the circularity of a stator.SOLUTION: A motor has a rotor and a stator. The stator has a plurality of segments. The segments have a plurality of pieces connected together via a connection part. The pieces are arranged in an arc and the segments are arranged in a circle. The connection part has a first recessed part, a pair of counter surfaces connected to both sides of the first recessed part at one end, and a pair of counter parts provided in another end of the pair of counter surfaces. The distance between the pair of counter surfaces decreases in a direction from the first recessed part to the pair of counter parts.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a motor.

Background Art

[0002] Conventionally, a stator is formed by laminating steel plates having a plurality of segment shapes in the plate thickness direction to form segments, and assembling the plurality of segments annularly. A motor configured by combining this stator and a rotor is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a conventional stator, a segment shape in which a plurality of pieces are connected is punched out from a steel plate, the punched steel plates are laminated, and then bent inward to form a sector-shaped segment. However, the laminated steel plates are bent at the connecting portions of the plurality of pieces, but the starting point for bending may change due to variations in the bending procedure and material characteristics. Then, the gaps remaining at the bent portions of the segments become uneven, the roundness deteriorates when the plurality of segments are assembled annularly, and when the segments are bent at positions different from the design intention, it becomes difficult to assemble them to the housing.

[0005] The present invention takes the above problems as an example, and one of its purposes is to improve the roundness of the stator.

Means for Solving the Problems

[0006] A motor according to one aspect of the present invention includes a rotor and a stator. The stator includes a plurality of segments connected via engagement portions. Each segment includes a plurality of pieces connected via connecting portions. The plurality of pieces are arranged in an arc shape, and the plurality of segments are arranged in an annular shape. Having a pair of protruding portions protruding inward The connecting portion has a first recess, a pair of opposing surfaces with one end continuous on both sides of the first recess, and a pair of opposing portions provided at the other ends of the pair of opposing surfaces. The distance between the pair of opposing surfaces decreases from the first recess to the pair of opposing portions. The pair of opposing surfaces and the pair of opposing portions are flat surfaces. Provided on the pair of protruding portions The pair of opposing portions face each other in contact or with a gap therebetween. Provided on the pair of protruding portions The gap on the inner peripheral side in the pair of opposing surfaces is smaller than the gap on the outer peripheral side.

[0007] According to one aspect of the present invention, the roundness of the stator can be improved.

Brief Description of Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, the motor according to the embodiment will be described with reference to the drawings. Note that the present invention is not limited by this embodiment. Also, the dimensional relationships of the elements in the drawings, the ratios of the elements, etc. may be different from the actual ones. There may also be parts where the dimensional relationships and ratios of the elements are different between the drawings. In addition, the content described in one embodiment or modification is generally applicable to other embodiments and modifications as well.

[0010] FIG. 1 is a perspective view showing a configuration example of the stator 2 according to the present embodiment. In FIG. 1, a stator 21 and an annular substrate (hereinafter referred to as a connection plate) 28 provided on the stator 21 are shown. The stator 21 has upper insulators 24 and lower insulators 25 attached to each piece of the segment 23 in which a plurality (for example, two) of pieces are connected via a bendable connecting portion, and then the coil 26 is wound. After that, the connecting portion is bent to form an annular shape by a plurality (for example, three) of segments 23. Here, the insulator is composed of an upper insulator 24 and a lower insulator 25. Each segment 23 forms a core as a whole stator as a segment. When three segments 23 are used, the number of segments is three. The number of segments is preferably three in order to increase the rigidity against the second- and fourth-order circular vibration modes, but an odd number of three or more may also be used. Further, the number of pieces of the plurality of segments 23 may be an even number, and the number of the plurality of segments 23 may be an odd number or a prime number. Even if the number of pieces is an even number, by setting the number of segments 23 to an odd number or a prime number of three or more, vibrations of the motor and noise associated with the vibrations can be suppressed.

[0011] The connection board 28 collectively wires the terminals 27 provided at the upper part of the upper insulator 24 for each piece (slot) of the segment 23, and is formed by a printed circuit board or a structure in which a printed circuit board and an interconnection conductor (bus bar) are provided on a predetermined substrate or the like. Incidentally, the connection board 28 may be connected to the terminal 27 after the segment 23 in which the coil 26 is wound and temporarily assembled in a ring shape is inserted into the motor housing. By collectively performing the electrical connection of the coils 26 in each slot via the terminal 27 and the connection board 28, it is possible to prevent the jumper wires from crossing. In addition, a guide portion for guiding the jumper wires to the insulator becomes unnecessary, the dimension of the stator in the rotational axis direction can be shortened, and the dead space of the motor can be reduced. In the illustrated example, the end portion 27-a of the terminal 27 is inserted into each of the plurality of hole portions 28a formed in the connection board 28, and a part of the end portion 27-a of the terminal 27 protrudes outward from the surface of the connection board 28. The end portion 27-a of the terminal 27 is electrically connected to a part of the wiring formed in the connection board 28. Protrusions 27-b and 27-c that are fixed to the insulator are continuous with the end portion 27-a.

[0012] Figure 2 is a perspective view showing an example of the shape of the segment, and Figure 3 is a plan view showing an example of the shape of the segment. In Figures 2 and 3, the steel plate 22 is formed by punching from an electromagnetic steel plate using a mold or the like. Further, a plurality of steel plates 22 are stacked to form the segment 23.

[0013] Segment 23 is formed by stacking a plurality of steel plates 22 as magnetic materials. In FIG. 2, the illustration of the end face represented by the stacking of electromagnetic steel plates is omitted. In the illustrated example, two pieces 23a having a substantially T-shaped planar shape are connected via a connecting portion 23b. Teeth 23e are formed on each piece 23a. One end 23e1 (the end facing the rotor 3 in the radial direction) of the tooth 23e serves as a magnetic pole portion. The connecting portion 23b has a first recess 23b-a that is recessed from the inner peripheral side to the outer peripheral side. Further, the connecting portion 23b has a second recess 23b-b that is recessed from the outer peripheral side to the inner peripheral side. The first recess 23b-a has an arc shape, and the second recess 23b-b has a rectangular shape. The connecting portion 23b is formed with a narrow portion between the first recess 23b-a and the second recess 23b-b, and is easily bendable in the direction in which the first recess 23b-a closes.

[0014] A pair of opposing surfaces 23b-c are provided from the first recess 23b-a toward the inner peripheral side. The pair of opposing surfaces 23b-c are connected to a pair of opposing portions 23b-d. The pair of opposing portions 23b-d are located on the inner peripheral side of the connecting portion 23b. That is, the segment 23 is provided with a pair of protruding portions 23f that protrude toward the inner peripheral side between each piece 23a and the connecting portion 23b. The pair of opposing surfaces 23b-c and the pair of opposing portions 23b-d are positioned to face each other on the pair of protruding portions 23f. The pair of opposing surfaces 23b-c are flat surfaces, and the pair of opposing portions 23b-d are opposing lines (designed contact lines) along the rotation axis direction of the motor 1. When the segment 23 is bent, the pair of opposing surfaces 23b-c approach each other and a gap is secured between them. At this time, the pair of opposing portions 23b-d either contact each other or a minute gap is provided between them. That is, the pair of opposing portions 23b-d contact each other or a minute gap is formed between them according to tolerances and errors. Further, the pair of surfaces 23b-e are provided on the inner peripheral side of the pair of opposing portions 23b-d and are set in a region outside the pair of opposing surfaces 23b-c. That is, the pair of surfaces 23b-e are provided on the tip side of the pair of protruding portions 23f.

[0015] Segment 23 is provided with engaging portions 23c and 23d at its left and right ends, and is bent into an annular shape so as to contact and engage with the engaging portions 23c and 23d of the adjacent segment 23. One engaging portion 23c has two convex portions 23c-a and 23c-b protruding to one side in the circumferential direction, and a concave portion 23c-c provided between the two convex portions 23c-a and 23c-b. The other engaging portion 23d has two convex portions 23d-a and 23d-b protruding to one side in the circumferential direction, and a concave portion 23d-c provided between the two convex portions 23d-a and 23d-b.

[0016] Of the two adjacent segments 23, the convex portion 23c-a of one segment 23 engages with the concave portion 23d-c of the other segment 23, and the concave portion 23c-c of one segment engages with the convex portion 23d-b of the other segment. The convex portion 23c-a of one segment 23 has a top portion 23c-d, and the convex portion 23d-b of the other segment 23 has a top portion 23d-d.

[0017] The convex portion 23c-a of one segment 23 and the concave portion 23d-c of the other segment 23 have first planes 23c-e and 23d-e facing each other. The first planes 23c-e and 23d-e extend in the radial direction and the circumferential direction of the stator 2, and extend in a direction intersecting each other toward the top portion 23c-d. The concave portion 23c-c of one segment 23 and the convex portion 23d-b of the other segment 23 have two second planes 23c-h and 23d-h facing each other. The second planes 23c-h and 23d-h extend in the radial direction and the circumferential direction of the stator 2, and extend in a direction intersecting each other toward the top portion 23d-d. Here, the first plane 23c-f and the second plane 23c-g are the same plane. Also, at the engaging portion 23d, the first plane 23d-f and the second plane 23d-g are the same plane. The third planes 23c-f and 23c-g shared by the convex portion 23c-a of one segment 23 and the concave portion 23d-c of the other segment 23 and the concave portion 23c-c of one segment 23 and the convex portion 23d-b of the other segment 23 are the same plane.

[0018] Note that in the linear state shown in FIGS. 2 and 3, the surface 23a-1 of the connecting portion 23b, the surface 23c-1 of the engaging portion 23c, and the surface 23d-1 of the engaging portion 23d are at the same vertical position in FIG. 3 and are arranged in a straight line. Also, in this state, the surface 23c-2 of the engaging portion 23c and the surface 23d-2 of the engaging portion 23d are parallel, and the surface 23a-1 of the connecting portion 23b is orthogonal to the surfaces 23c-2 and 23d-2. The surfaces 23a-1, 23c-1, 23c-2, 23d-1, and 23d-2 serve as positioning surfaces when winding the coil 26 around the segment 23 and when mounting the segment 23 on the device.

[0019] Hereinafter, the shapes of the pair of opposing surfaces 23b-c and the pair of opposing portions 23b-d in the connecting portion 23b will be described in detail. FIG. 4 is a plan view showing an example of the connecting portion of the segment before bending, FIG. 5 is an explanatory view for setting the shape of the connecting portion of the segment, and FIG. 6 is an explanatory view for setting the shape of the connecting portion of the segment. In FIGS. 4 to 6, the connecting portion 23b has a first recess 23b-a formed on the inner peripheral side and a second recess 23b-b formed on the outer peripheral side, so that the radial width is narrowed. The first recess 23b-a is an arc centered at O1 and has an arc shape. For example, it may be an ellipse.

[0020] A design center O2 that is the center of the bending rotation of two adjacent pieces 23a is set for the connecting portion 23b. The design center O2 is preferably at the intermediate position between two adjacent pieces 23a and also at the intermediate position between the first recess 23b-a and the second recess 23b-b. Also, a virtual point O3 for determining the shape of two adjacent pieces 23a is set for the connecting portion 23b. The virtual point O3 is set on the outer peripheral side in the radial direction from the design center O2. The design center O2 and the virtual point O3 are arranged on a bending line L1 along the radial direction passing through the center of the stator 2. Note that the center O1 of the first recess 23b-a is also arranged on the bending line L1.

[0021] First, a first virtual circle C1 passing through the design joint point is set with the design center O2 as the center. Next, a pair of straight lines L2 that spread out at a predetermined angle α (for example, 15 degrees) to the left and right from the design center O2 toward the design joint point are set. In this embodiment, since the stator 2 is composed of six pieces 23a, the predetermined angle α is 15 degrees, but the predetermined angle α is set according to the number of pieces 23a that make up the stator 2. Then, a pair of perpendicular lines L3 to the pair of straight lines L2 passing through the intersection point O4 of the first virtual circle C1 and the pair of straight lines L2 are set. A pair of second virtual circles C2 with the center O5 on the pair of perpendicular lines L3 and having a predetermined radius are set. Here, the predetermined radius of the second virtual circle C2 is set according to the radius of the stator 2. The predetermined radius of the second virtual circle C2 is preferably in the range of, for example, 30% to 100% of the radius of the stator 2. And the pair of opposing surfaces 23b-c are arranged on the tangent line L4 that contacts the pair of second virtual circles C2 from the virtual point O3, that is, the pair of opposing surfaces 23b-c are arranged on the tangent line L4 that contacts the pair of second virtual circles C2 from the virtual point O3, one end is connected to the first recess 23b-a and the other end is connected to the pair of second virtual circles C2, and the second virtual circles C2 form a surface 23b-e on the inner circumferential side of the opposing portion 23b-d.

[0022] FIG. 7 is a plan view showing an example of a stator assembled with a plurality of segments, and FIG. 8 is a plan view showing an example of an engaging portion of the segment after bending. In FIG. 7, the stator 2 is configured by engaging three segments 23 in an arc shape in the circumferential direction. Since the segment 23 has two pieces 23a, the stator 2 is configured by connecting six pieces 23a in an arc shape in the circumferential direction. The stator 2 configured by connecting six pieces 23a forms a hexagon (preferably, a regular hexagon) P with the connecting portion 23b of each piece 23a and the engaging portions 23c, 23d of each piece 23a that make up each segment 23 as vertices. Specifically, the vertex in the connecting portion 23b of each piece 23a is the opposing portion 23b-d.

[0023] In FIG. 8, when each segment 23 is bent inward at the connecting portion 23b, the pair of opposing surfaces 23b-c approach each other, and ideally, the pair of opposing portions 23b-d come into contact with each other, but there are times when a gap is secured between them. At this time, the pair of opposing surfaces 23b-c gradually narrow the distance between each other from the first recess 23b-a to the pair of opposing portions 23b-d. In other words, the pair of opposing surfaces 23b-c have a decreasing distance between each other from the first recess 23b-a to the pair of opposing portions 23b-d. That is, the gap between the pair of opposing surfaces 23b-c at the connecting portion 23b gradually becomes smaller from the outer peripheral side toward the inner peripheral side. For example, the gap S1 on the outer peripheral side of the pair of opposing surfaces 23b-c is 0.08 mm, and the gap S2 on the inner peripheral side of the pair of opposing surfaces 23b-c is 0.02 mm. The magnitudes of these gaps S1 and S2 vary due to tolerances and errors. And the gaps S1 and S2 are smaller (approximately 1 / 10 to 1 / 5) than the gap in the radial direction between the stator 2 and the rotor 3 in the assembled motor 1. That is, when each segment 23 is bent inward at the connecting portion 23b, ideally, since the pair of opposing portions 23b-d are in line contact with each other, the pair of opposing surfaces 23b-c provided from the first recess 23b-a to the opposing portion 23b-d gradually narrow the distance across the entire radial direction.

[0024] Also, the shapes of the convex portions 23c-a, 23c-b and the concave portion 23c-c at the engaging portion 23c, and the convex portions 23d-a, 23d-b and the concave portion 23d-c at the engaging portion 23d will be described in detail. FIG. 9 is a plan view showing an example of the engaging portion of the segment after assembly, and FIG. 10 is an explanatory view for setting the shape of the engaging portion of the segment. In FIG. 9, one engaging portion 23c is provided at the end of one piece 23a of the segment 23, and the other engaging portion 23d is provided at the end of the other piece 23a of the segment 23. Two adjacent segments 23 engage with each other with the engaging portion 23c and the engaging portion 23d in contact. The convex portion 23c-a of one segment 23 engages with the concave portion 23d-c of the other segment 23, and the convex portion 23d-b of the other segment engages with the concave portion 23c-c of one segment.

[0025] In FIG. 10, an engagement line L11 is set along the radial direction passing through the center of the stator 2. Also, a tangent line L12 at the intersection of the circumscribed circle of the hexagon shown in FIG. 7 (a circle passing through the design joint points) centered at the center of the stator 2 and the engagement line L11 is set. Here, a position where the engagement line L11 and the tangent line L12 are orthogonal is set as the virtual engagement point O11. A first inclined line L13 is set that passes through the virtual engagement point O11 and intersects the tangent line L12 at a positive (counterclockwise) angle β. In the present embodiment, from the shapes of the engaging portions 23c and 23d described above, in FIG. 10, the first inclined line L13 is a line extending from the lower left side to the upper right side. However, when the shapes of the engaging portions 23c and 23d are reversed, the first inclined line L13 becomes a line extending from the lower right side to the upper left side.

[0026] A second inclined line L14 and a third inclined line L15 are set that intersect the first inclined line L13 at acute angles θ1 and θ2. The second inclined line L14 intersects the first inclined line L13 on one side in the length direction of the first inclined line L13, and the third inclined line L15 intersects the first inclined line L13 on the other side in the length direction of the first inclined line L13. Here, since the second inclined line L14 and the third inclined line L15 are parallel, the acute angles θ1 and θ2 are the same angle. However, the acute angles θ1 and θ2 may be different angles, and the second inclined line L14 and the third inclined line L15 do not have to be parallel. Also, the second inclined line L14 and the third inclined line L15 preferably intersect the engagement line L11 at an intermediate position between the engaging portion 23c and the engaging portion 23d.

[0027] In one engaging portion 23c, the convex portion 23c-a is composed of a first plane 23c-e along the second inclined line L14 and a third plane 23c-f along the first inclined line L13. The concave portion 23c-c is composed of a third plane 23c-g along the first inclined line L13 and a second plane 23c-h along the third inclined line L15. In the other engaging portion 23d, the concave portion 23d-c is composed of a first plane 23d-e along the second inclined line L14 and a third plane 23d-f along the first inclined line L13. The convex portion 23d-b is composed of a third plane 23d-g along the first inclined line L13 and a second plane 23d-h along the third inclined line L15.

[0028] The convex portion 23c-a in the engaging portion 23c has a top portion 23c-d protruding in the circumferential direction of the stator 2 and toward the inner circumferential side. That is, the convex portion 23c-a and the concave portion 23c-c in the engaging portion 23c, and the convex portion 23d-b and the concave portion 23d-c in the engaging portion 23d are formed by the first inclined line L13, the second inclined line L14, and the third inclined line L15. And the first inclined line L13, the second inclined line L14, and the third inclined line L15 are inclined in the same direction with respect to the tangent line L12 orthogonal to the engaging line L11.

[0029] The convex portion 23c-a engages with the concave portion 23d-c, and the convex portion 23d-b engages with the concave portion 23c-c. The engaging positions of the convex portion 23c-a and the concave portion 23d-c and the engaging positions of the convex portion 23d-b and the concave portion 23c-c are arranged side by side in the radial direction of the stator 2. That is, the first planes 23c-e, 23c-f, 23d-e, 23d-f and the second planes 23c-g, 23c-h, 23d-g, 23d-h are arranged side by side in the radial direction of the stator 2. The second planes 23c-g, 23c-h, 23d-g, 23d-h are arranged on the inner circumferential side with respect to the first planes 23c-e, 23c-f, 23d-e, 23d-f. And the areas of the second planes 23c-h, 23d-h and the areas of the first planes 23c-e, 23d-e are larger than the areas of the first planes 23c-e, 23d-e, but not limited thereto, and the areas of the first planes 23c-e, 23d-e may be larger than the areas of the second planes 23c-h, 23d-h.

[0030] That is, the engaging portions 23c and 23d are provided with bulging portions 23g and 23h protruding to the inner peripheral side of the stator 2. The second planes 23c-h and 23d-h are disposed on the sides of the bulging portions 23g and 23h. The contactable area between the second plane 23c-h of the concave portion 23c-c in the engaging portion 23c and the second plane 23d-h of the convex portion 23-b in the engaging portion 23d is larger than the contactable area between the first plane 23c-e of the convex portion 23c-a in the engaging portion 23c and the first plane 23d-e of the concave portion 23-c in the engaging portion 23d. Here, the engaging portion 23c and the engaging portion 23d do not necessarily contact the first planes 23c-e, 23c-f and the second planes 23c-g, 23c-h, and the first planes 23d-e, 23d-f and the second planes 23d-g, 23d-h. Depending on intersections, manufacturing errors, etc., surface contact, line contact, or point contact states occur, and gaps are formed. The contactable area is the area when there are no design intersections, manufacturing errors, etc. That is, it is the area of the first planes 23c-e, 23d-e and the second planes 23c-h, 23d-h.

[0031] And, the size of the gap formed in the second planes 23c-h and 23d-h is smaller than the size of the gap formed in the first planes 23c-e and 23d-e. Specifically, the area of the convex portion 23d-b and the concave portion 23c-c that can be in contact at the position of the third inclined line L15 is larger than the area of the convex portion 23c-a and the concave portion 23d-c that can be in contact at the position of the second inclined line L14. And, the dimensional tolerance of the convex portion 23d-b and the concave portion 23c-c in terms of design at the position of the third inclined line L15 is smaller than the dimensional tolerance of the convex portion 23c-a and the concave portion 23d-c in terms of design at the position of the second inclined line L14. That is, for adjacent segments 23, the positions of the convex portion 23c-b and the concave portion 23d-b that can be in contact with the third inclined line L15 in the engaging portions 23c and 23d become the path of the magnetic flux (magnetic circuit). However, the first plane may be set as the path of the magnetic flux (magnetic circuit) by reversing the magnitude relationship between the first plane and the second plane.

[0032] FIG. 11 is a plan view showing an example of a stator assembled with a plurality of segments. In FIG. 11, as described above, the stator 2 is configured by engaging three segments 23 in an arc shape in the circumferential direction. Since the segment 23 has two pieces 23a, the stator 2 is configured by connecting six pieces 23a in an arc shape in the circumferential direction. The stator 2 configured by connecting six pieces 23a forms a hexagon P with the connecting portions 23b of each piece 23a and the engaging portions 23c, 23d of each piece 23a constituting each segment 23 as vertices. Specifically, the vertices at the engaging portions 23c, 23d of each piece 23a are the virtual engagement points O11.

[0033] FIG. 12 is a perspective view showing a plurality of segments before assembly, and FIG. 13 is a perspective view showing a plurality of segments after assembly. Note that it conceptually shows the formation of an annular core. Actually, as described above, the upper insulator 24 and the lower insulator 25 are attached to each piece 23a of the segment 23, and bending is performed after the coil is wound. In FIG. 12, an annular core as shown in FIG. 13 is formed by bending three segments 23 in an arc shape and then joining them together.

[0034] In a conventional type of stator in which a continuous strip-shaped core is bent into an annular shape, since the bending into an annular shape is performed in one operation for a range of 360° in one revolution, excessive force acts on some connecting portions, resulting in deterioration of the roundness, and vibration may occur due to the radial exciting force according to the number of magnetic poles of the magnet. On the other hand, in the present embodiment, since a plurality of (for example, three) segments 23 are each bent in an arc shape and then the plurality of segments 23 are joined together, the roundness is improved. As a result, it is possible to expect a reduction in vibration and noise due to the radial exciting force according to the number of magnetic poles of the magnet.

[0035] In addition, in a conventional type of stator in which a continuous strip-shaped core is bent into a ring shape, since the connection of the ends is made at one location in one cycle, the rigidity is low with respect to the second and fourth annular vibration modes, and vibration and noise may occur also from this point. On the other hand, in the present embodiment, since the number of segments, for example three, is odd, the connection portions of the segments do not face each other through the center of the circle, and the rigidity is high with respect to the second and fourth annular vibration modes. As a result, a reduction in vibration and noise can be expected.

[0036] And in a conventional stator, by bending the segment inward at the design position of the connecting portion, a pair of opposing surfaces are brought into surface contact. In this case, if the bending starting point of the segment deviates from the design position, the pair of opposing surfaces become in a line contact state, and a gap is generated between the pair of opposing surfaces. Then, when a plurality of segments are combined in a ring shape, the roundness of the stator decreases. On the other hand, in the stator 2 of the present embodiment, when the segment 23 is bent inward at the design position of the connecting portion 23b, a gap is intentionally generated between the pair of opposing surfaces 23b-c, and ideally, the pair of opposing portions 23b-d are in line contact with each other. And when the segment 23 is bent and then combined in a ring shape, a hexagon P having six vertices is formed. In this case, even if the bending starting point of the segment 23 deviates from the design position, the shape of the hexagon P is regulated so as not to move greatly. Therefore, when a plurality of segments 23 are combined in a ring shape, a high roundness of the stator 2 is ensured. Note that the six vertices of the hexagon P are three opposing portions 23b-d and three virtual engagement points O11.

[0037] In a conventional stator, when a plurality of segments are combined in a circular shape, the engaging portions are simply engaged so as to be in contact with each other. In this case, although the segments can be easily assembled, the engagement between the engaging portions of the segments is insufficient, so that the segments move outward or inward around the engaging portions, which causes deterioration of the roundness. On the other hand, in the stator 2 of the present embodiment, the convex portions 23c-a, 23d-b and the concave portions 23c-c, 23d-c of the engaging portions 23c, 23d are in an acute angle shape and are fitted to each other. Therefore, the segments 23 are prevented from opening outward or inward at the engaging portions 23c, 23d, and deterioration of the roundness is suppressed.

[0038] That is, when combining the three segments 23 in the stator 2, first, as shown in FIG. 12, the three segments 23 are arranged at intervals in the circumferential direction. Next, the three segments 23 are moved inward toward the center, and the engaging portions 23c, 23d are engaged with each other. Then, as shown in FIG. 13, the three segments 23 are combined in a circular shape to form the stator 2. In the stator 2 formed by combining the three segments 23, the movement of one segment 23 or two segments 23 in the radial direction is blocked by the shape of the engaging portions 23c, 23d. Therefore, the roundness is maintained and the handling of the stator 2 becomes easy. However, when combining the three segments 23, the three segments 23 may be moved in the axial direction, and the engaging portions 23c, 23d may be engaged with each other to form the stator 2.

[0039] FIG. 14 is a perspective view showing a configuration example of a motor, and FIG. 15 is an exploded perspective view showing a configuration example of the motor. In FIG. 14, the motor 1 includes a cylindrical portion 11, cover portions 12 and 13, and a shaft 32. The cylindrical portion 11 and the cover portions 12 and 13 form a housing. In FIG. 15, a stator 2 is inserted (press-fitted) into the cylindrical cylindrical portion 11, a rotor 3 is disposed in the space inside the stator 2, and the shaft 32 of the rotor 3 is rotatably supported by upper and lower cover portions 12 and 13 that hold bearings. In the longitudinal direction of the rotor 3, a plurality of holes 12b are provided in the surface 12a of the cover portion 12 facing the stator 2, and a plurality of holes 12d are provided in the outer peripheral portion 12c of the cover portion 12. Similarly, in the longitudinal direction of the rotor 3, a plurality of holes 13b are provided in the surface 13a of the cover portion 13 facing the stator 2, and a plurality of holes 13d are provided in the outer peripheral portion 13c of the cover portion 13. Members such as screws may be inserted into and fixed to the holes 12d and 13d provided in the outer peripheral portions 12c and 13c of the cover portions 12 and 13 and the holes 11a and 11b provided in the outer peripheral portion of the cylindrical portion 11. (Regarding the rotor 3, in the illustrated example, a rotor yoke 3a as a magnetic body is provided on the shaft 32, and an annular magnet 3b is provided on the outer peripheral surface of the rotor yoke 3a.

[0040] Note that the rotor 3 may include a rotor yoke 3a formed in an annular shape by laminating electromagnetic steel sheets as magnetic members, and a shaft 32 provided to penetrate the rotor yoke 3a may be provided at the center of the rotor yoke 3a. For example, the rotor yoke 3a is formed in an annular shape by bending four substantially fan-shaped pieces connected by a connecting portion so as to sandwich a rod-shaped shaft 32, and the connecting portion at the end of the segment is connected by laser welding or the like along the axial direction. Further, the rotor yoke 3a is provided with holes for generating reluctance torque, and magnets are arranged in the holes as necessary. Note that the terminals 27 and the connection plate 28 of the stator 2 are not shown.

[0041] As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0042] As described above, the motor according to the present embodiment includes a stator, the stator includes a plurality of segments, and each segment includes a plurality of pieces connected via a connecting portion. The plurality of pieces are arranged in an arc shape, and the plurality of segments are arranged in an annular shape. The connecting portion has a first recess, a pair of opposing surfaces with one end continuous on both sides of the first recess, and a pair of opposing portions provided at the other ends of the pair of opposing surfaces. The distance between the pair of opposing surfaces decreases from the first recess to the pair of opposing portions. Therefore, by improving the roundness, the vibration of the stator can be reduced and the productivity can be improved.

[0043] Also, the pair of opposing surfaces are flat surfaces. Therefore, a predetermined amount of gap can be ensured between the pair of opposing surfaces.

[0044] Also, the pair of opposing portions are a pair of opposing lines parallel to the rotation axis direction of the motor. Therefore, after ensuring a predetermined amount of gap between the pair of opposing surfaces, line contact can be achieved along the opposing lines.

[0045] Also, the pair of opposing portions face each other in contact or with a minute gap therebetween. Therefore, even if the bending position of the segment is displaced, a decrease in roundness can be suppressed.

[0046] Also, a design center that is the center of the bending rotation in the plurality of pieces is set in the connecting portion, and a virtual point is set outside the design center in the radial direction. The pair of opposing surfaces are arranged on a pair of straight lines connecting the virtual point and the pair of opposing portions. Therefore, a minute gap can be ensured between the pair of opposing surfaces.

[0047] Also, the design center and the virtual point are arranged on a straight line along the radial direction passing through the center of the motor. Therefore, even if the bending position of the segment is displaced, a decrease in roundness can be suppressed.

[0048] In addition, a first virtual circle passing through the design joint is set with the design center as the center, a pair of second virtual circles having a predetermined radius are set with the tangents of the first virtual circle as the centers, and a pair of opposing surfaces are arranged on the tangents that are tangent to the pair of second virtual circles from a virtual point. Therefore, the pair of opposing surfaces can be set with high precision.

[0049] In addition, the region on the inner peripheral side of the pair of opposing surfaces is arranged on the second virtual circle. Therefore, the second virtual circle can be drawn with high precision, and the design accuracy of the pair of opposing surfaces can be improved. In this case, if the second virtual circle is arranged with a slight gap considering tolerances and errors, it becomes possible to perform circularity correction processing in the subsequent process, and the circularity can be further improved.

[0050] In addition, a first recess is provided inside the motor in the radial direction at the connecting portion, and a second recess is provided outside the motor in the radial direction opposite to the first recess. Therefore, the segment can be bent at a predetermined position.

[0051] As described above, the motor according to the present embodiment includes a stator, the stator includes a plurality of segments connected via engaging portions, and each segment includes a plurality of pieces connected via connecting portions. The plurality of pieces are arranged in an arc shape, and the plurality of segments are arranged in an annular shape. The engaging portion has two convex portions protruding in the circumferential direction and a recess provided between the two convex portions. Among the two adjacent segments, the convex portion of one segment engages with the recess of the other segment, and the recess of one segment engages with the convex portion of the other segment. The two convex portions of one and the other segments have tops, and the convex portion of one segment and the recess of the other segment have a first plane and a third plane facing each other. The first plane and the third plane extend in the radial and circumferential directions of the stator and intersect each other toward the top. Therefore, by improving the circularity, the vibration of the stator can be reduced and the productivity can be improved.

[0052] In addition, the convex portions of one and the other segments project with their tops toward the inner peripheral side of the stator. Therefore, the convex and concave portions at the engaging portion can be properly engaged, and assembly can be performed by a simple method, and the stator can be properly assembled with high roundness.

[0053] In addition, the concave portion of one segment and the convex portion of the other segment have a second plane and a third plane facing each other. The second plane and the third plane extend in the radial direction and the circumferential direction of the stator, and extend in a direction intersecting each other toward the top. Therefore, the roundness of the stator can be further improved.

[0054] In addition, the first plane and the second plane form an acute angle with respect to a line along the circumferential direction orthogonal to the center line along the radial direction of the stator, and the third plane forms a positive angle with respect to a line along the circumferential direction perpendicular to the center line along the radial direction of the stator. Therefore, when adjacent segments are combined at the engaging portion, it is possible to suppress the segments from opening to the outer peripheral side and the inner peripheral side at the engaging portion.

[0055] In addition, the first plane and the second plane are arranged side by side in the radial direction of the stator. The second plane is arranged on the inner peripheral side with respect to the first plane, and the area of the second plane is different from the area of the first plane. Therefore, the positions of the convex and concave portions engaged by the second plane form a magnetic path, and the cross-sectional area of the flux path that intersects the stator winding increases, and the magnetic resistance can be reduced. Therefore, a decrease in motor performance can be suppressed.

[0056] In addition, the engaging portion has a bulging portion protruding toward the inner peripheral side, and the second plane is arranged on the bulging portion side. Therefore, it is possible to secure the cross-sectional area of the flux path that intersects the stator winding without reducing the winding area in the bright portion, and suppress an increase in the outer diameter of the motor.

[0057] Also, among the first plane and the second plane, the gap formed in the plane with the larger area is smaller than the gap formed in the plane with the smaller area among the first plane and the second plane. Therefore, the positions of the convex portion and the concave portion that engage with each other on the first plane and the second plane can be used as the magnetic path, and an increase in the outer diameter of the motor can be suppressed.

[0058] Further, the first plane on the outer peripheral side and the second plane on the inner peripheral side are arranged in parallel. Therefore, when adjacent segments are combined at the engaging portion, movement of the segments to the outer peripheral side and the inner peripheral side can be effectively suppressed. In addition, since a plane parallel to the center line of the teeth is formed at each engaging portion of the segment before bending, the segment can be accurately held by the winding machine using this plane, so that the occupation ratio of the winding can be improved and the attachment / detachment time of the segment can be shortened.

[0059] In the above embodiment, the segment has two pieces and three segments are combined to form the stator. However, the number of pieces in the segment and the number of segments to be combined are not limited to these. For example, the segment may have four pieces and three segments may be combined to form the stator.

[0060] Also, the present invention is not limited by the above embodiment. Those configured by appropriately combining the above-described components are also included in the present invention. Further, additional effects and modifications can be easily derived by those skilled in the art. Therefore, a broader aspect of the present invention is not limited to the above embodiment, and various changes are possible.

Explanation of Reference Numerals

[0061] 1 Motor, 11 Cylindrical portion, 2, 21 Stator, 23 Segment, 23a Piece, 23b Connecting portion, 26 Coil, 28 Connection plate, 3 Rotor, 32 Shaft

Claims

1. Comprising a rotor and a stator, the stator comprises a plurality of segments connected via engaging portions, each segment comprises a plurality of pieces connected via connecting portions, the plurality of pieces are arranged in an arc shape, the plurality of segments are arranged in an annular shape, the connecting portion having a pair of protrusions protruding inward has a first recess, a pair of opposing surfaces with one end continuous on both sides of the first recess, and a pair of opposing portions provided at the other ends of the pair of opposing surfaces, the distance between the pair of opposing surfaces decreases from the first recess to the pair of opposing portions, the pair of opposing surfaces and the pair of opposing portions are flat surfaces, the pair of opposing portions provided on the pair of protrusions face each other in contact or with a gap therebetween, the gap on the inner peripheral side in the pair of opposing surfaces provided on the pair of protrusions is smaller than the gap on the outer peripheral side, a motor.

2. the pair of opposing portions are a pair of opposing lines parallel to the rotational axis direction of the motor, the motor according to Claim 1.

3. the distance between the pair of opposing surfaces is smaller than the gap between the rotor and the stator in the radial direction, the motor according to Claim 1 or 2.

4. a design center that is the center of the bending rotation in the plurality of pieces is set in the connecting portion, and a virtual point is set outside the design center in the radial direction, the motor according to any one of Claims 1 to 3.

5. the design center and the virtual point are arranged on a straight line along the radial direction passing through the center of the motor, the motor according to Claim 4.

6. the first recess is provided inside the motor in the radial direction in the connecting portion, and a second recess is provided outside the motor in the radial direction opposite to the first recess, the motor according to any one of Claims 1 to 5.

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