Motor and coil winding method

Abstract

A motor (1) is provided with: a stator core (4); a plurality of slots (9) arranged in the circumferential direction of the stator core (4); and a coil (5) disposed in the slot (9) so as to be wound in a single layer, the coil (5) being formed by joining the rotor-side ends of a first coil segment (5F) and a second coil segment (5R), the first coil segment (5F) being wound in a spiral shape while being shifted from the back yoke side toward the core side, and the second coil segment (5R) being wound in a spiral shape while being shifted from the back yoke side toward the core side. The second coil segments (5R) are wound in a spiral shape while being shifted from the core side toward the back yoke side, and the first coil segments (5F) and the second coil segments (5R) are disposed so as to intersect with each other at a first coil end (52) on one side in the axial direction and alternately disposed between the rotor side and the back yoke side at a second coil end (53) on the other side in the axial direction.

Description

Technical Field

[0001] The present disclosure relates to a motor and a coil winding method. Background Art

[0002] A rotating electrical machine including a stator and a rotor is known, wherein the stator has concentrated winding coils wound around the teeth of a stator core (see, for example, Patent Document 1). In the technology described in Patent Document 1, the coils are wound in a single-layer winding manner.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2014 / 020755 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the technology described in Patent Document 1, the winding end of the coil is located on the rotor side. As a result, the length of the overlapped wire becomes longer in order to be pulled out toward the back yoke side. If the length of the overlapped wire becomes longer, the vibration resistance may be reduced.

[0008] An object of the present disclosure is to provide a motor and a coil winding method having improved vibration resistance.

[0009] Means for solving problems

[0010] According to the present disclosure, a motor is provided, which comprises: a stator core; a plurality of slots arranged along the circumference of the stator core; and coils arranged in the slots in a single-layer winding manner, the coils being formed by joining the rotor-side ends of a first coil segment and a second coil segment to each other, the first coil segment being wound in a spiral while being offset from the back yoke side to the core side, and the second coil segment being wound in a spiral while being offset from the core side to the back yoke side, the first coil segment and the second coil segment being cross-arranged with varying heights at the first coil end on one axial side, and being alternately arranged between the rotor side and the back yoke side at the second coil end on the other axial side.

[0011] According to the present disclosure, a method for winding a coil is provided, wherein the coil is arranged in a single-layer winding manner in a plurality of slots arranged along the circumference of a stator core, wherein the method for winding the coil includes: winding the first coil segment of the coil in a spiral shape while staggering the position from the back yoke side to the core side, and winding the second coil segment of the coil in a spiral shape while staggering the position from the core side to the back yoke side, the first coil segment and the second coil segment being cross-arranged with varying heights at a first coil end on one axial side, and being alternately arranged between a rotor side and a back yoke side at a second coil end on the other axial side; and joining the rotor-side ends of the first coil segment and the second coil segment to each other.

[0012] Effects of the Invention

[0013] According to the present disclosure, a motor and a coil winding method having improved vibration resistance are provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a diagram schematically showing a motor according to an embodiment.

[0015] Figure 2 It is a plan view schematically showing a stator core and coils according to the embodiment.

[0016] Figure 3 This is a side view schematically showing a coil according to the embodiment.

[0017] Figure 4 It is a plan view schematically showing a coil according to the embodiment.

[0018] Figure 5 This is a front view schematically showing a coil according to the embodiment.

[0019] Figure 6 This is a side view schematically showing a coil according to the embodiment.

[0020] Figure 7 It is a perspective view schematically showing a coil according to the embodiment.

[0021] Figure 8 It is a front view schematically showing a coil according to a modified example. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings, but the present invention is not limited thereto. The constituent elements of the embodiments described below can be combined as appropriate. In addition, some constituent elements may not be used.

[0023] [Implementation Method]

[0024] Motor

[0025] Figure 1 : This is a diagram schematically showing a motor 1 according to an embodiment. In the embodiment, the motor 1 is a three-phase switched reluctance motor. The motor 1 includes a cylindrical stator 2 and a rotor 3 arranged inside the stator 2. The stator 2 includes a cylindrical stator core 4 and a coil 5 supported by the stator core 4. The inner circumferential surface of the stator 2 and the outer circumferential surface of the rotor 3 are opposed to each other with a gap therebetween. The rotor 3 is opposed to the stator core 4. The rotor 3 rotates around a rotation axis AX. The rotation axis AX of the rotor 3 is the same as the central axis of the stator 2. The rotor 3 is connected to an object E via a shaft 8. The object E is, for example, an engine mounted on a hybrid excavator, which is a type of construction machinery. The motor 1 functions as a generator driven by the engine.

[0026] In the following description, the direction parallel to the rotation axis AX is referred to as the axial direction. One side of the axial direction is referred to as the axial first side, and the side opposite to the axial first side is referred to as the axial second side. Furthermore, the direction surrounding the rotation axis AX is referred to as the circumferential direction. One side of the circumferential direction of rotation is referred to as the circumferential first side, and the side opposite to the circumferential first side is referred to as the circumferential second side. Furthermore, the direction radiating from the rotation axis AX is referred to as the radial direction. The side radially away from the central axis AX is referred to as the radially outer side, and the side opposite to the radially outer side is referred to as the radially inner side.

[0027] The rotor 3 is arranged so as to be able to face the stator core 4. The rotor 3 includes a rotor holder 6 and a rotor core 7 held by the rotor holder 6. The rotor holder 6 is formed of a non-magnetic material. The rotor core 7 is formed of a magnetic material.

[0028] The stator core 4 has slots 9 for accommodating the coils 5. Slots 9 are recessed radially outward from the inner circumference of the stator core 4. Multiple slots 9 are circumferentially arranged on the inner circumference of the stator core 4. Slots 9 extend axially. Slots 9 are arranged on the inner circumference of the stator core 4. Slots 9 open axially to one side, axially to the other side, and radially inward.

[0029] The stator core 4 has a plurality of teeth 10 disposed between circumferentially adjacent slots 9. The teeth 10 are portions of the stator core 4 around which the coil 5 is wound. The teeth 10 support the coil 5. The teeth 10 are inserted into openings of the coil 5.

[0030] <Coil>

[0031] Figure 3 This is a side view schematically showing a coil according to the embodiment. Figure 4 It is a plan view schematically showing a coil according to the embodiment. Figure 5 This is a front view schematically showing a coil according to the embodiment. Figure 6 This is a side view schematically showing a coil according to the embodiment. Figure 7: This is a perspective view showing the outline of the coil of the embodiment. In each figure, the number of windings of the coil is simplified for the purpose of explanation, and the thickness of the conductor is increased. Figures 4 and 5 、 Figure 7 In the figure, the circumferential direction is schematically illustrated as a straight line rather than an arc.

[0032] The coil 5 is arranged around the tooth 10. The coil 5 is supported by the tooth 10. The coil 5 has an opening. The tooth 10 is inserted into the opening of the coil 5.

[0033] The coil 5 includes a coil body 51, a coil end 52, and a coil end 53. The portion of the coil 5 housed in the slot 10 is the coil body 51. The portion of the coil 5 that protrudes axially from the stator core 4 to one side is the coil end 52. The portion of the coil 5 that protrudes axially from the stator core 4 to the other side is the coil end 53.

[0034] The coil 5 is formed of a linear or strip-shaped conductor, such as a flat wire, round wire, or a plate-shaped segmented conductor. The coil 5 is formed of a conductor arranged in a spiral. The coil 5 may be formed by winding a single conductor in a spiral, or by connecting multiple conductors in a spiral. The winding and connection methods of the coil 5 are not limited.

[0035] The coil 5 includes a U-phase coil (first-phase coil) 5U, a V-phase coil (second-phase coil) 5V, and a W-phase coil (third-phase coil) 5W.

[0036] The coil 5 is wound in a single layer in the slot 9 , and partially crosses and becomes two layers at the coil end 52 . A portion of the coil 5 is housed in the slot 9 and supported by the teeth 10 .

[0037] The coil 5 is formed by joining a first coil segment 5F wound around the teeth 10 from the back yoke side toward the core side, and a second coil segment 5R wound around the teeth 10 from the core side toward the back yoke side. More specifically, the coil 5 is formed by joining the rotor-side ends of the first coil segment 5F and the second coil segment 5R together. The first coil segment 5F is wound helically while being offset from the back yoke side toward the core side, and the second coil segment 5R is wound helically while being offset from the core side toward the back yoke side.

[0038] The first coil segment 5F1 is formed by crimping a lower segment conductor 5FD1 and an upper segment conductor 5FU1 together. On one circumferential side, the axial end of the lower segment conductor 5FD1 is joined to the other axial end of the upper segment conductor 5FU1. The lower segment conductor 5FD1 is a U-shaped segment conductor. It has no twist in the winding direction. The upper segment conductor 5FU1 is a U-shaped segment conductor. One axial side of the upper segment conductor 5FU1 is located on the tooth 10. The upper segment conductor 5FU1 has twist in the winding direction. The upper segment conductor 5FU1 is bent at bends 5FU1a and 5FU1b. One circumferential side of the upper segment conductor 5FU1 is located closer to the rotor than the other circumferential side. On the other circumferential side, the other axial end of the upper segment conductor 5FU1 is joined to the axial end of the lower segment conductor 5FD2 of the first coil segment 5F2.

[0039] The first coil segment 5F2 is formed by joining a lower segment conductor 5FD2 and an upper segment conductor 5FU2. The lower segment conductor 5FD2 has the same configuration as the lower segment conductor 5FD1. The upper segment conductor 5FU2 has the same configuration as the upper segment conductor 5FU1. On one circumferential side, the axial end of the lower segment conductor 5FD2 is joined to the other axial end of the upper segment conductor 5FU2. On the other circumferential side, the other axial end of the upper segment conductor 5FU2 of the first coil segment 5F1 is joined to the axial end of the lower segment conductor 5FD3.

[0040] The first coil segment 5F3 is a lower segment conductor 5FD3 . At the other circumferential side, one end portion of the lower segment conductor 5FD3 in the axial direction is joined to the other end portion of the upper segment conductor 5FU2 of the first coil segment 5F2 in the axial direction.

[0041] The winding start end of the first coil segment 5F is the lower segment conductor 5FD3 of the first coil segment 5F3. On one circumferential side, one axial side of the lower segment conductor 5FD3 is joined to the jumper 55F.

[0042] The end portion of the first coil segment 5F on the back yoke side is a overlapping line 55F.

[0043] The second coil segment 5R1 is formed by joining an upper segment conductor 5RU1 and a lower segment conductor 5RD1. On one circumferential side, the other axial end of the upper segment conductor 5RU1 is joined to the one axial end of the lower segment conductor 5RD1. The upper segment conductor 5RU1 is located axially above the upper segment conductor 5FU1 of the first coil segment 5F. The upper segment conductor 5RU1 is a U-shaped segment conductor. It exhibits twist in the winding direction. It bends at bends 5RU1a and 5RU1b. The other circumferential side of the upper segment conductor 5RU1 is located closer to the rotor than the first circumferential side. On the other circumferential side, the one axial end of the lower segment conductor 5RD1 is joined to the other axial end of the upper segment conductor 5RU2 of the second coil segment 5R2. The lower segment conductor 5RD1 is a U-shaped segment conductor. It exhibits no twist in the winding direction.

[0044] The second coil segment 5R2 is formed by joining an upper segment conductor 5RU2 and a lower segment conductor 5RD2. The upper segment conductor 5RU2 has the same configuration as the upper segment conductor 5RU1. The lower segment conductor 5RD2 has the same configuration as the lower segment conductor 5RD1. On the other circumferential side, the other axial end of the lower segment conductor 5RD2 of the second coil segment 5R1 is joined to the bonding wire 55R. On the one circumferential side, the other axial end of the upper segment conductor 5RU2 is joined to the one axial end of the lower segment conductor 5RD2.

[0045] The winding start end of the second coil segment 5R is the upper segment conductor 5RU1 of the first coil segment 5R1.

[0046] The end portion of the second coil segment 5R on the back yoke side is a overlapping line 55R.

[0047] The other axial side of the upper segment conductor 5RU1 of the first coil segment 5R1 is joined to one axial side of the lower segment conductor 5FD1 of the first coil segment 5F1 on the radially inner side and the other circumferential side.

[0048] The first coil segment 5F and the second coil segment 5R are arranged to intersect with each other at different heights at the first coil end 52 on one axial side. In other words, the upper segment conductor 5RU of the second coil segment 5R is located on the upper segment conductor 5FU of the first coil segment 5F on one axial side.

[0049] The first coil segments 5F and the second coil segments 5R are alternately arranged between the rotor side and the back yoke side at the second coil end 52 on the other axial side. In other words, the first coil segments 5F and the second coil segments 5R do not intersect at the second coil end 52 on the other axial side.

[0050] The coil width of the first coil end 52 of the coil 5 in the axial direction is the sum of the coil width w1 of the first coil segment 5F and the coil width w2 of the second coil segment 5R at the first coil end 52 and the gap therebetween.

[0051] The axial coil width w3 of the second coil end 52 of the coil 5 is the same as the coil width w1 of the first coil segment 5F and the coil width w2 of the second coil segment 5R at the second coil end 52 .

[0052] The coil width of the first coil end portion 52 in the axial direction is wider than the coil width of the second coil end portion 52 in the axial direction.

[0053] Winding method

[0054] A method of winding the coil 5 arranged in a single-layer manner in the plurality of slots 9 arranged along the circumferential direction of the stator core 4 will be described.

[0055] The first coil segment 5F of the coil 5 is wound helically while being offset from the back yoke side toward the core side. The first coil segment 5F is formed by sequentially joining the lower segment conductor 5FD and the upper segment conductor 5FU from the back yoke side toward the core side. The second coil segment 5R of the coil 5 is wound helically while being offset from the core side toward the back yoke side. The second coil segment 5R is formed by sequentially joining the upper segment conductor 5FU and the lower segment conductor 5FD from the core side toward the back yoke side.

[0056] First, after winding the first coil segment 5F, the second coil segment 5R is wound. This results in the first coil segment 5F and the second coil segment 5R being arranged alternately at varying heights at the first coil end 52. The first coil segment 5F and the second coil segment 5R are alternately arranged between the rotor side and the back yoke side at the second coil end 53.

[0057] The rotor-side ends of the first coil segment 5F and the second coil segment 5R are joined to each other. In this way, the coil 5 is wound.

[0058] Effects

[0059] As described above, in the embodiment, the coil 5 is formed by joining the rotor-side ends of a first coil segment 5F and a second coil segment 5R. The first coil segment 5F is helically wound while being offset from the back yoke side to the core side, while the second coil segment 5R is helically wound while being offset from the core side to the back yoke side. In the embodiment, the first coil segment 5F and the second coil segment 5R are arranged crosswise at varying heights at the first coil end 52 on one axial side, and alternately arranged between the rotor and back yoke sides at the second coil end 53 on the other axial side. In the embodiment, the back yoke-side ends of the first coil segment 5F and the back yoke-side ends of the second coil segment 5R are overlapped strands 55F and 55R. According to the embodiment, the winding ends of the coil 5 can both be located on the back yoke side. According to the embodiment, the length of the overlapped strands 55 can be reduced. According to the embodiment, vibration can be suppressed, thereby improving vibration resistance. The embodiment can reduce the length of the overlapped strands, thereby reducing losses caused by eddy currents.

[0060] In the embodiment, at the first coil end 52, the upper segment conductor 5RU1 is located axially to one side of the upper segment conductor 5FU1 of the first coil segment 5F at the intersection of the first coil segment 5F and the second coil segment 5R. According to the embodiment, the winding ends of the coil 5 can all be located on the rotor side.

[0061] In the embodiment, the axial coil width of the first coil end 52 of the coil 5 is the sum of the coil widths of the first coil segment 5F and the second coil segment 5R at the first coil end 52. The axial coil width of the second coil end 53 of the coil 5 is the same as the coil widths of the first coil segment 5F and the second coil segment 5R at the second coil end 52. According to the embodiment, the coil 5 can be formed from a segmented conductor with a constant coil width. According to the embodiment, a simple structure can be achieved.

[0062] In the embodiment, the axial coil width of the first coil end portion 52 is wider than the axial coil width of the second coil end portion 53. According to the embodiment, the axial size of the second coil end portion 53 can be reduced.

[0063] According to the embodiment, vibration can be suppressed without using additional components. The embodiment can suppress vibration without increasing the number of components.

[0064] [Modification]

[0065] use Figure 8 Modifications of the coil will be described. Figure 8 1 is a front view showing an outline of a coil according to a modified example. Figure 8In the example shown, in the first coil segment 5F and the second coil segment 5R, the coil widths w1 and w2 at the first coil end 52 are narrower than those at other portions. The axial coil width of the first coil end 52 is the same as the axial coil width w3 of the second coil end 53.

[0066] Effects

[0067] As described above, according to the modified example, it is possible to reduce the coil width of the first coil end portion 52. According to the modified example, it is possible to reduce the size in the axial direction.

[0068] In the above embodiment, the method of joining the segment conductors is exemplified by crimping, but the method is not limited thereto and may be welding, riveting or other methods.

[0069] In the above embodiment, the rotor 3 is arranged inside (on the inner circumference of) the stator core 4, making the motor 1 an inner-rotor motor. The rotor 3 can be arranged at a position opposing the stator core 4. The motor 1 can be an outer-rotor motor, in which the rotor 3 is arranged on the outer circumference of the stator core 4; a dual-rotor motor, in which the rotor 3 is arranged on both the inner and outer circumferences of the stator core 4; or an axial-gap motor, in which the rotor 3 is arranged on the axial side of the stator core 4.

[0070] It should be noted that in the above embodiment, the motor 1 is a switched reluctance motor. The motor 1 may be a synchronous reluctance motor, a flux switching motor, a permanent magnet motor, an induction motor, an axial gap motor, or a linear actuator.

[0071] Description of reference numerals:

[0072] 1…Motor; 2…Stator; 3…Rotor; 4…Stator core; 5…Coil; 5A…A-phase coil; 5B…B-phase coil; 5C…C-phase coil; 5F…First coil segment; 5FD1…Lower segment conductor; 5FU…Upper segment conductor; 5R…Second coil segment; 5RD1…Lower segment conductor; 5FU…Upper segment conductor; 5U…U-phase coil (first phase coil); 5V…V-phase coil (second phase coil); 5W…W-phase coil (third phase coil); 6…Rotor holder; 7…Rotor core; 8…Shaft; 9…Slot; 10…Tooth; 51…Coil body; 52…Coil end; 53…Coil end; 55…Banding wire; 55F…Banding wire; 55R…Banding wire; 56…Terminal; 57…Banding wire; 58…Terminal; AX…Rotating shaft; E…Object

Claims

1. A motor, wherein: The motor has: stator core; a plurality of slots arranged along the circumference of the stator core; and The coil is arranged in the slot in a single-layer winding manner, The coil is formed by joining the rotor-side ends of a first coil segment and a second coil segment, wherein the first coil segment is wound helically while being offset from the back yoke side to the core side, and the second coil segment is wound helically while being offset from the core side to the back yoke side. The first coil segments and the second coil segments are cross-arranged with varying heights at a first coil end portion on one axial side, and are alternately arranged between the rotor side and the back yoke side at a second coil end portion on the other axial side.

2. The motor according to claim 1, wherein An end portion of the first coil segment on the back yoke side and an end portion of the second coil segment on the back yoke side are overlapping wires.

3. The motor according to claim 1, wherein At the first coil end, at a portion where the first coil segment intersects the second coil segment, the second coil segment is located on one side in the axial direction relative to the first coil segment.

4. The motor according to claim 1, wherein At the first coil end portion, at a portion where the first coil segment and the second coil segment intersect, one of the first coil segment and the second coil segment is located axially to one side of the other.

5. The motor according to claim 1, wherein The axial coil width of the first coil end of the coil is the sum of the coil width of the first coil segment at the first coil end, the coil width of the second coil segment, and a gap between the first coil segment and the second coil segment.

6. The motor according to claim 3, wherein The coil width of the first coil end in the axial direction is wider than the coil width of the second coil end in the axial direction.

7. The motor according to claim 4, wherein In the first coil segment and the second coil segment, the coil width at the first coil end portion is narrower than that at other portions.

8. A method for winding a coil, wherein the coil is arranged in a single-layer winding manner in a plurality of slots arranged along the circumferential direction of a stator core, in, The coil winding method includes: The first coil segment of the coil is wound spirally while being offset from the back yoke side to the core side, and the second coil segment of the coil is wound spirally while being offset from the core side to the back yoke side, the first coil segment and the second coil segment are cross-arranged with varying heights at a first coil end on one axial side, and are alternately arranged between the rotor side and the back yoke side at a second coil end on the other axial side; and The rotor-side ends of the first coil segment and the second coil segment are joined to each other.

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