Stator, electric motor, and work machine

Abstract

To provide a stator, an electric motor, and a work machine capable of improving assembly and fixing strength.SOLUTION: A stator includes: a cylindrical stator core in which a plurality of slots are formed side by side in a circumferential direction; a stator coil that is inserted into each of the plurality of slots, is wound about the stator core, and has a plurality of end side extending portions extending outward from a first end surface in a shaft direction of the stator core and arranged side by side in the circumferential direction; and a fixing portion that fixes portions adjacent to each other in the circumferential direction in the plurality of end side extending portions.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a stator, an electric motor, and a working machine.

Background Art

[0002] Patent Document 1 discloses a configuration including a stator core having slots for winding insertion, each phase winding drawn out to an axial end of the stator core, a neutral wire separate from each phase winding, and fixing means for fixing between each phase winding to which the neutral wire is connected and each adjacent phase winding.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the configuration of Patent Document 1, since the fixing portions of adjacent phase windings are located deep in the radial direction, it is highly likely that it is difficult to arrange the fixing means. If the fixing means cannot be arranged accurately, the fixing strength of each phase winding may decrease.

[0005] An aspect of the present disclosure aims to provide a stator, an electric motor, and a working machine capable of improving assemblability and fixing strength.

Means for Solving the Problems

[0006] A stator according to an aspect of the present disclosure includes a cylindrical stator core in which a plurality of slots are formed side by side in the circumferential direction, a stator coil that is inserted into each of the plurality of slots and wound around the stator core, and that has a plurality of end-side extending portions that extend outward from a first end surface in the axial direction of the stator core and are arranged in the circumferential direction, and a fixing portion that fixes portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions.

Advantages of the Invention

[0007] According to an aspect of the present disclosure, it is possible to provide a stator, an electric motor, and a working machine that can improve assemblability and fixing strength.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the present embodiment, as an electric motor, an example of a motor mounted on an electric swing excavator (an example of a working machine) and configured as a swing motor for swinging an upper swing body of the electric swing excavator will be described.

[0010] In the following description, expressions indicating relative or absolute arrangements such as "parallel", "orthogonal", "center", "coaxial", etc. not only strictly mean such arrangements or states, but also include arrangements or states that are relatively displaced with tolerances and angles or distances that can obtain the same function. In the drawings used in the following description, the scale of each member may be appropriately changed to show each member in a recognizable size.

[0011] <Working Machine> FIG. 1 is a schematic view showing a working machine according to an embodiment. The working machine 100 according to the present embodiment is an electric hydraulic excavator. The working machine 100 may be a manned vehicle that operates by the driving operation of a driver, or an unmanned vehicle that operates unmanned.

[0012] The working machine 100 includes a traveling body 120, an upper swing body 140, and a working device 160.

[0013] The traveling body 120 supports the working machine 100 so as to be capable of traveling. The traveling body 120 includes a traveling device 121. The traveling device 121 is, for example, a pair of left and right endless tracks. The traveling device 121 is driven by a traveling motor 122. The upper swing body 140 is supported by the traveling body 120 so as to be swingable about a swing axis. The upper swing body 140 performs a swing operation with respect to the traveling body 120 by a swing motor 114. The upper swing body 140 has a section 141 that houses a drive system.

[0014] The working machine 160 is operably supported by the upper slewing body 140. The working machine 160 is hydraulically driven. The working machine 160 includes a boom 161, an arm 162, and an attachment 163. The attachment 163 is an example of a working tool. The attachment 163 in the example shown in FIG. 1 is a bucket. In the example shown in FIG. 1, the side of the upper slewing body 140 where the working machine 160 is supported is the front, and the side opposite to the front is the rear. In the present embodiment, the left - right direction refers to the left and right with respect to the front, and the up - down direction refers to the direction in which the slewing axis of the upper slewing body 140 extends.

[0015] The slewing motor 114 is an electric motor driven by electric power. The slewing motor 114 slews the upper slewing body 140 with respect to the traveling body 120.

[0016] <Electric motor> FIG. 2 is a cross - sectional view of the electric motor 1 according to the embodiment.

[0017] In the present embodiment, the electric motor 1 is the slewing motor 114. The electric motor 1 includes a rotor 2, a stator 3, and a housing 4 that houses the rotor 2 and the stator 3. The electric motor 1 is an inner - rotor type motor in which the stator 3 is arranged outside the cylindrical rotor 2. The electric motor 1 is vertically installed so that the rotor shaft 20 of the rotor 2 is parallel to the slewing axis.

[0018] In the present embodiment, the upper side corresponds to one side parallel to the central axis CL of the rotor shaft 20, and the lower side corresponds to the other side parallel to the central axis CL of the rotor shaft 20. Hereinafter, the direction along the central axis CL of the rotor shaft 20 is referred to as the "axial direction", the direction orthogonal to the axial direction is referred to as the "radial direction", and the direction around the central axis CL of the rotor shaft 20 is referred to as the "circumferential direction".

[0019] The rotor 2 includes a rotor shaft 20, a rotor core 21, an upper plate 22, and a lower plate 23. The rotor shaft 20 is rotatably supported by bearings 21A, 21B with respect to the housing 4.

[0020] The rotor core 21 is formed, for example, by axially laminating electromagnetic steel sheets. The rotor core 21 is fitted onto the rotor shaft 20. The rotor core 21 rotates integrally with the rotor shaft 20. A plurality of permanent magnets (not shown) are embedded in the rotor core 21.

[0021] Each of the upper plate 22 and the lower plate 23 is an annular plate member arranged coaxially with the rotor shaft 20. The upper plate 22 and the lower plate 23 are fitted onto the rotor shaft 20. The upper plate 22 and the lower plate 23 sandwich the rotor core 21 from the outside in the axial direction. The upper plate 22 and the lower plate 23 rotate integrally with the rotor shaft 20 and the rotor core 21.

[0022] The stator 3 is fixed to the inner surface of the housing 4 so as to cover the outer periphery of the rotor 2. The stator 3 includes a cylindrical stator core 30 and a stator coil 31. The stator core 30 is formed by axially laminating electromagnetic steel sheets, similar to the rotor core 21. A plurality of teeth are provided on the inner peripheral side of the stator core 30 in a circumferential direction. The stator coil 31 is wound around the teeth.

[0023] The housing 4 houses the rotor 2 and the stator 3. The housing 4 includes a cylindrical cylindrical body 10, a ceiling portion 11 that closes the upper opening of the cylindrical body 10, and a bottom portion 13 that closes the lower opening of the cylindrical body 10. A space 40 for housing the rotor 2 and the stator 3 is formed inside the housing 4 by the cylindrical body 10, the ceiling portion 11, and the bottom portion 13.

[0024] <Stator> FIG. 3 is a perspective view of the stator 3 according to the embodiment. FIG. 4 is a perspective view of the inner peripheral portion of the stator 3 according to the embodiment. FIG. 5 is a perspective view of a portion where the fixing portion is fixed in a plurality of end-side extending portions according to the embodiment. Referring to FIGS. 3 to 5 together, the stator 3 includes a cylindrical stator core 30 in which a plurality of slots 30s are arranged side by side in the circumferential direction, a stator coil 31 that is inserted into each of the plurality of slots 30s and wound around the stator core 30, and has a plurality of end-side extending portions 32e that extend outward from the first end face 30f1 in the axial direction of the stator core 30 and are arranged side by side in the circumferential direction, and a fixing portion 38 that fixes portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e.

[0025] On the inner circumferential side of the stator core 30, a plurality of slots 30s and a plurality of teeth 30t are arranged alternately over the entire circumference. The plurality of slots 30s are arranged at equal intervals in the circumferential direction of the stator core 30. For example, an insulating material may be provided in the slots 30s. Note that the mode (arrangement, number, shape, etc.) of the slots 30s can be changed according to the design specifications.

[0026] In this embodiment, the stator coil 31 is composed of a plurality of segment coils 39. For example, the segment coil 39 is a flat wire with an insulating coating covering the outer circumference of the strand. Note that the segment coil 39 is not limited to the above, and may be composed of windings with a circular cross-section or an elliptical cross-section. The mode of the segment coil 39 can be changed according to the design specifications.

[0027] The stator coil 31 includes a first coil end 32 having a plurality of end-side extending portions 32e that protrude from the first end face 30f1 in the axial direction of the stator core 30, and a second coil end 33 that protrudes from the second end face 30f2 on the opposite side of the first end face 30f1 of the stator core 30 in the axial direction. The axial direction of the stator core 30 corresponds to the direction along the central axis CL (see FIG. 2) of the rotor shaft 20. The first end face 30f1 of the stator core 30 corresponds to the upper end face of the stator core 30. The second end face 30f2 of the stator core 30 corresponds to the lower end face of the stator core 30. Note that in the stator core 30, the radial direction is the direction orthogonal to the axial direction, and the circumferential direction is the direction that circulates around the central axis CL.

[0028] Referring also to FIG. 2, the electric motor 1 of the present embodiment includes a rotor 2, a stator 3, and a housing 4 that houses the rotor 2 and the stator 3. The first coil end 32 is arranged on the side opposite to the bottom 13 of the housing 4 (upper side) in the axial direction. On the other hand, the second coil end 33 is arranged on the same side as the bottom 13 of the housing 4 (lower side) in the axial direction. In the present embodiment, the plurality of end-side extending portions 32e are arranged on the side opposite to the bottom 13 of the housing 4 (upper side) in the axial direction.

[0029] The stator 3 of the present embodiment further includes power lines 35U, 35V, 35W connected to the plurality of end-side extending portions 32e. The plurality of end-side extending portions 32e include a connection extending portion 32j to which the power lines 35U, 35V, 35W are connected, and a non-connection extending portion 32u to which the power lines 35U, 35V, 35W are not connected. The power lines 35U, 35V, 35W include a stranded wire and a terminal connected to an end of the stranded wire. A power line connection portion 36 for connecting the power lines 35U, 35V, 35W is connected to the connection extending portion 32j. The power line connection portion 36 is connected to the terminals of the power lines 35U, 35V, 35W.

[0030] The connection between the power line connection portion 36 of the present embodiment and the terminals of the power lines 35U, 35V, 35W is made by fastening with bolts and nuts. Note that the configurations of the power lines 35U, 35V, 35W and the power line connection portion 36 are not limited to the above and can be changed according to the design specifications. For example, the power lines 35U, 35V, 35W may include a bus bar, and the bus bar and the connection extending portion 32j may be welded. For example, the power lines 35U, 35V, 35W may include a stranded wire and a terminal connected to an end of the stranded wire, and the terminal and the connection extending portion 32j may be welded. For example, the power lines 35U, 35V, 35W may include a stranded wire and a first terminal connected to an end of the stranded wire, a second terminal may be connected to the connection extending portion 32j, and the first terminal and the second terminal may be welded to each other.

[0031] In this embodiment, the stator coil 31 includes three-phase winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 that are connected in parallel to each other. The three-phase winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 are U-phase, V-phase, and W-phase winding groups. The U-phase, V-phase, and W-phase winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 are arranged in the circumferential direction of the stator core 30 such that the U-phase, U-phase, V-phase, V-phase, W-phase, W-phase, ··· are arranged in pairs.

[0032] In this embodiment, the stator coil 31 includes a plurality of U-shaped segment coils 39 whose ends are connected to each other. The stator coil 31 is formed by winding a plurality of segment coils 39 whose ends are connected to each other in a wave shape. In the example of the figure, a segment coil 39 having a square cross section is shown, but a segment coil 39 having a round cross section may also be used. The cross-sectional shape of the segment coil 39 is not limited to the above and can be changed according to the design specifications.

[0033] In the example of the figure, when the segment coils 39 inserted in the circumferential direction of the stator core 30 are regarded as one winding part 34A, 34B, 34C, and 34D, four winding parts 34A, 34B, 34C, and 34D are arranged in the radial direction of the stator core 30. The four winding parts 34A, 34B, 34C, and 34D include a first winding part 34A, a second winding part 34B, a third winding part 34C, and a fourth winding part 34D. The first winding part 34A, the second winding part 34B, the third winding part 34C, and the fourth winding part 34D are arranged in this order from the innermost circumference to the outermost circumference of the stator core 30.

[0034] FIG. 6 is a view of the stator 3 according to the embodiment cut along a plane orthogonal to the axial direction of one slot 30s. Referring also to FIG. 6, in the slot 30s, the segment coils 39 are arranged so as to form a plurality of layers. The slot 30s includes a plurality of layers L1 to L8 corresponding to the plurality of layers.

[0035] In the example of the figure, a plurality of layers L1 to L8 are configured such that the first layer L1 to the eighth layer L8 are arranged in this order from the inner peripheral side in the radial direction (the lower side in the figure). The first winding portion 34A is inserted into the first layer L1 and the second layer L2. The second winding portion 34B is inserted into the third layer L3 and the fourth layer L4. The third winding portion 34C is inserted into the fifth layer L5 and the sixth layer L6. The fourth winding portion 34D is inserted into the seventh layer L7 and the eighth layer L8. Note that the number of layers is not limited to the above and can be changed according to the design specifications.

[0036] FIG. 7 is a diagram showing the segment coil 39 before being assembled to the stator core 30 according to the embodiment. FIG. 8 is a diagram showing the segment coil 39 after being twisted and formed according to the embodiment. Referring to FIGS. 7 and 8 together, the segment coil 39 before being assembled to the stator core 30 is formed in a U shape.

[0037] Specifically, the segment coil 39 includes a U-shaped portion 39a formed in a mountain shape (U shape) protruding to one side in the axial direction, and two linear portions 39b1 and 39b2 extending linearly and parallel to each other from each end of the U-shaped portion 39a to the other side in the axial direction. Note that the U-shaped portion 39a is a portion constituting the second coil end 33. The linear portions 39b1 and 39b2 are portions inserted into the slots 30s except for the portion to be twisted and formed. In the first winding portion 34A, for example, the segment coil 39 has a shape in which the end of one linear portion 39b1 is inserted into the first layer L1 and the end of the other linear portion 39b2 is inserted into the second layer L2.

[0038] For example, after the segment coil 39 is inserted into the slot 30s, the first extending portion 39c1 on one end side is twisted and formed toward one side in the circumferential direction, and the second extending portion 39c2 on the other end side is twisted and formed toward the other side in the circumferential direction. For example, the end of the first extending portion 39c1 after the twisting and forming of one of the two segment coils 39 whose ends are connected to each other is connected to the end of the second extending portion 39c2 after the twisting and forming of the other segment coil 39 by welding or the like. In each segment coil 39, the connection portions between the end of the first extending portion 39c1 and the end of the second extending portion 39c2 are arranged side by side in the radial direction. Thereafter, a neutral line 37N formed of a bus bar or the like is connected to a predetermined portion of the segment coil 39 by welding or the like. Each of the extending portions 39c1 and 39c2 is a portion constituting the first coil end 32.

[0039] FIG. 9 is a wiring diagram of the stator coil 31 according to the embodiment. Referring also to FIG. 9, the stator coil 31 employs a double-star connection. In the present embodiment, a first star connection including a U1-phase winding group 34U1, a V1-phase winding group 34V1, and a W1-phase winding group 34W1, and a second star connection including a U2-phase winding group 34U2, a V2-phase winding group 34V2, and a W2-phase winding group 34W2 are connected in parallel.

[0040] In the first star connection and the second star connection, U phases (between the U1-phase winding group 34U1 and the U2-phase winding group 34U2), V phases (between the V1-phase winding group 34V1 and the V2-phase winding group 34V2), and W phases (between the W1-phase winding group 34W1 and the W2-phase winding group 34W2) are electrically connected.

[0041] The U1-phase winding group 34U1, V1-phase winding group 34V1, and W1-phase winding group 34W1 of the first star connection and the U2-phase winding group 34U2, V2-phase winding group 34V2, and W2-phase winding group 34W2 of the second star connection are electrically connected by being connected by the neutral line 37N. Note that in the first star connection, the U1-phase winding group 34U1, V1-phase winding group 34V1, and W1-phase winding group 34W1 are electrically connected by being connected by a first neutral line 37N1 (not shown), and in the second star connection, the U2-phase winding group 34U2, V2-phase winding group 34V2, and W2-phase winding group 34W2 may be electrically connected by being connected by a second neutral line 37N2 (not shown).

[0042] <Fixed part> In this embodiment, the fixing part 38 is an adhesive. For example, examples of the adhesive include epoxy adhesives and organic adhesives. Note that the type of the adhesive is not limited to the above and can be changed according to the design specifications.

[0043] In this embodiment, the adhesive has a high viscosity such that it does not flow down even when provided between portions adjacent in the circumferential direction at the plurality of end-side extending portions 32e. For example, examples of the high-viscosity adhesive include two-component mixed epoxy resin adhesives. Note that the type of the high-viscosity adhesive is not limited to the above and can be changed according to the design specifications.

[0044] For example, a high-viscosity adhesive is injected (applied) between portions adjacent in the circumferential direction at the plurality of end-side extending portions 32e using a syringe (dispenser) or the like. Since the high-viscosity adhesive has little fluidity and is easy to handle, it can be accurately arranged at a predetermined position. Since the high-viscosity adhesive solidifies after the curing time elapses, a predetermined position can be fixed accurately without gaps.

[0045] In this embodiment, the length AE (adhesion range) of the portion where the adhesive extends along the end-side extending portion 32e is 10 mm or more. For example, by applying an adhesive between portions adjacent in the circumferential direction at the end-side extending portion 32e within the application range DE in the figure (for example, 20 mm or more), a predetermined position can be accurately fixed over a wide range.

[0046] In this embodiment, the plurality of end-side extending portions 32e include a first connection extending portion 32j1 and a second connection extending portion 32j2 to which the power lines 35U, 35V, and 35W are connected and which are adjacent to each other in the circumferential direction, and a non-connection extending portion 32u to which the power lines 35U, 35V, and 35W are not connected. The fixing portion 38 fixes between at least one of the first connection extending portion 32j1 and the second connection extending portion 32j2 and the non-connection extending portion 32u, excluding the portions adjacent to each other in the circumferential direction in the first connection extending portion 32j1 and the second connection extending portion 32j2. In the example of the figure, the fixing portion 38 does not fix the portions adjacent to each other in the circumferential direction in the first connection extending portion 32j1 and the second connection extending portion 32j2. The fixing portion 38 fixes the portions adjacent to each other in the circumferential direction between each of the first connection extending portion 32j1 and the second connection extending portion 32j2 and the non-connection extending portion 32u.

[0047] In this embodiment, the portions of the plurality of end-side extending portions 32e where the fixing portion 38 is fixed are arranged inside the stator core 30 in the radial direction. In the example of the figure, the portions of the plurality of end-side extending portions 32e where the fixing portion 38 is fixed are arranged at the innermost side in the radial direction of the stator core 30. The fixing portion 38 is arranged on the side surfaces adjacent to and facing each other on the innermost radial surface of the plurality of end-side extending portions 32e.

[0048] In this embodiment, each of the plurality of end-side extending portions 32e includes an inclined portion 32s that obliquely intersects the axial direction and the circumferential direction. The fixing portion 38 fixes the inclined portions 32s adjacent to each other in the circumferential direction in the plurality of end-side extending portions 32e. In the example of the figure, the adhesion range AE and the application range DE are provided along the respective inclined portions 32s.

[0049] <Function and Effect> As described above, the stator 3 of the present embodiment includes a cylindrical stator core 30 in which a plurality of slots 30s are formed side by side in the circumferential direction, and a stator coil 31 that is inserted into each of the plurality of slots 30s and wound around the stator core 30, and has a plurality of end-side extending portions 32e that extend outward from the first end surface 30f1 in the axial direction of the stator core 30 and are arranged side by side in the circumferential direction, and a fixing portion 38 that fixes portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e. For example, when fixing portions adjacent to each other in the radial direction among the plurality of end-side extending portions 32e, it is difficult to arrange the fixing portion 38 between them in the radial direction, so that deterioration of assemblability and reduction of fixing strength become problems. On the other hand, according to the present embodiment, by fixing portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e, it is easy to arrange the fixing portion 38 between them in the circumferential direction, so that the assemblability can be improved. In addition, the fixing strength between portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e can be improved. Therefore, improvement of assemblability and improvement of fixing strength can be achieved.

[0050] In the present embodiment, the fixing portion 38 is an adhesive. According to the present embodiment, by putting an adhesive between portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e, a predetermined portion can be fixed without a gap.

[0051] In the present embodiment, the adhesive has a high viscosity such that it does not flow down even when provided between portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e. According to the present embodiment, by putting a high-viscosity adhesive between portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e, a predetermined portion can be fixed without a gap and accurately.

[0052] In the present embodiment, the length AE of the portion where the adhesive extends along the end-side extending portion 32e is 10 mm or more. According to the present embodiment, by fixing portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions 32e by 10 mm or more, it contributes to further improvement of the fixing strength.

[0053] In this embodiment, the stator 3 further includes power lines 35U, 35V, and 35W connected to the end-side extending portion 32e. According to this embodiment, the fixing strength of the end-side extending portion 32e to which the power lines 35U, 35V, and 35W are connected can be improved. Therefore, the risk of terminal portion breakage or the like due to resonance of the power lines 35U, 35V, and 35W in vehicle body vibration can be reduced.

[0054] In this embodiment, the plurality of end-side extending portions 32e include a first connection extending portion 32j1 and a second connection extending portion 32j2 to which the power lines 35U, 35V, and 35W are connected and adjacent to each other in the circumferential direction, and a non-connection extending portion 32u to which the power lines 35U, 35V, and 35W are not connected. The fixing portion 38 fixes between at least one of the first connection extending portion 32j1 and the second connection extending portion 32j2 and the non-connection extending portion 32u, excluding the portions adjacent in the circumferential direction in the first connection extending portion 32j1 and the second connection extending portion 32j2. According to this embodiment, by fixing the minimum necessary portions, further improvement in assemblability and fixing strength can be achieved.

[0055] In this embodiment, the portion where the fixing portion 38 is fixed in the plurality of end-side extending portions 32e is arranged inside the stator core 30 in the radial direction. According to this embodiment, since it is easy to arrange the fixing portion 38 from the inside in the radial direction of the stator core 30 with respect to the portion where the fixing portion 38 is fixed in the plurality of end-side extending portions 32e, it contributes to further improvement in assemblability.

[0056] In this embodiment, each of the plurality of end-side extending portions 32e includes an inclined portion 32s that intersects obliquely with respect to the axial direction and the circumferential direction. The fixing portion 38 fixes the inclined portions 32s adjacent to each other in the circumferential direction in the plurality of end-side extending portions 32e. According to this embodiment, by fixing the inclined portions 32s adjacent to each other in the circumferential direction in the plurality of end-side extending portions 32e, it contributes to further improvement in fixing strength.

[0057] In this embodiment, the stator coil 31 includes three-phase winding groups 34U, 34U2, 34V1, 34V2, 34W1, and 34W2 that are connected in parallel to each other. According to this embodiment, even when the three-phase winding groups 34U, 34U2, 34V1, 34V2, 34W1, and 34W2 are connected in parallel to each other, it is possible to improve the assemblability and the fixing strength.

[0058] In this embodiment, the stator coil 31 includes a plurality of U-shaped segment coils 39 whose ends are connected to each other. According to this embodiment, even when the stator coil 31 includes a plurality of U-shaped segment coils 39 whose ends are connected to each other, it is possible to improve the assemblability and the fixing strength.

[0059] The electric motor 1 of this embodiment includes a rotor 2, the above-described stator 3, and a housing 4 that houses the rotor 2 and the stator 3. The plurality of end-side extending portions 32e are arranged on the side opposite to the bottom portion 13 of the housing 4 in the axial direction. According to this embodiment, since it is possible to access (and arrange the fixing portion 38) the plurality of end-side extending portions 32e from the side (upper side) opposite to the bottom portion 13 of the housing 4 in the axial direction, it contributes to further improvement in assemblability.

[0060] <Modification Example> In the above-described embodiment, the fixing portion has been described by taking an example of an adhesive, but it is not limited thereto. For example, as shown in FIGS. 10 and 11, the fixing portion may be a resin plate 138 coated with an adhesive. The resin plate 138 may be provided on the radially outer surfaces of portions adjacent to each other in the circumferential direction at the plurality of end-side extending portions 32e. The resin plate may have a rectangular parallelepiped shape that straddles portions adjacent to each other in the circumferential direction when viewed from the radial direction. The resin plate may have a shape having a fixing surface (side surface) larger than the radially outer surfaces of portions adjacent to each other in the circumferential direction.

[0061] For example, the member to which the adhesive is applied is not limited to the above, and may be a plate other than a resin plate, or a film-like or sheet-like member. Although not shown, the fixing portion may be a string member (such as a thread or a binding band) capable of connecting portions adjacent to each other in the circumferential direction at a plurality of end-side extending portions. The fixing portion may be an impregnated member (such as a sponge, cloth, or fiber) impregnated with an adhesive. The fixing portion may be a mold member capable of fixing portions adjacent to each other in the circumferential direction at a plurality of end-side extending portions. The fixing portion may be a resin member capable of fixing portions adjacent to each other in the circumferential direction at a plurality of end-side extending portions. In this case, for example, a resin member formed by molding may be used. In the case of fixing by a resin member, for example, by inserting an E-shaped resin molded member from the side of the coil, the coils may be fixed to each other. The form of the fixing portion can be changed according to the design specifications.

[0062] In the above-described embodiment, the adhesive is described by taking as an example a high-viscosity one that does not flow downwards even when provided between portions adjacent to each other in the circumferential direction at a plurality of end-side extending portions, but it is not limited to this. For example, it may have a viscosity (low viscosity) that flows downwards when provided between portions adjacent to each other in the circumferential direction at a plurality of end-side extending portions. The viscosity of the adhesive can be changed according to the design specifications.

[0063] In the above-described embodiment, the length of the portion where the adhesive extends along the end-side extending portion is described by taking as an example a length of 10 mm or more, but it is not limited to this. For example, the length of the portion where the adhesive extends along the end-side extending portion may be less than 10 mm. The length of the portion where the adhesive extends along the end-side extending portion can be changed according to the design specifications.

[0064] In the above-described embodiment, the stator is described by taking as an example one that further includes a power line connected to the end-side extending portion, but it is not limited to this. For example, the power line may not be connected to the end-side extending portion. For example, a neutral line may be connected to the end-side extending portion. For example, other components (such as a bus bar) may be connected to the end-side extending portion. The installation form of the power line can be changed according to the design specifications.

[0065] In the above-described embodiment, the plurality of end-side extending portions include a first connection extending portion and a second connection extending portion to which power lines are connected and which are adjacent to each other in the circumferential direction, and a non-connection extending portion to which no power line is connected. The fixing portion has been described by way of example as fixing between at least one of the first connection extending portion and the second connection extending portion and the non-connection extending portion, excluding the portions adjacent to each other in the circumferential direction in the first connection extending portion and the second connection extending portion, but is not limited thereto. For example, the fixing portion may fix the portions adjacent to each other in the circumferential direction in the first connection extending portion and the second connection extending portion. The fixing mode of the fixing portion can be changed according to the design specifications.

[0066] In the above-described embodiment, the portion where the fixing portion is fixed in the plurality of end-side extending portions has been described by way of example as being disposed inside the stator core in the radial direction, but is not limited thereto. For example, the portion where the fixing portion is fixed in the plurality of end-side extending portions may be disposed outside the stator core in the radial direction. The arrangement mode of the portion where the fixing portion is fixed in the plurality of end-side extending portions can be changed according to the design specifications.

[0067] In the above-described embodiment, each of the plurality of end-side extending portions includes an inclined portion that intersects obliquely with respect to the axial direction and the circumferential direction. The fixing portion has been described by way of example as fixing the inclined portions adjacent to each other in the circumferential direction in the plurality of end-side extending portions, but is not limited thereto. For example, each of the plurality of end-side extending portions includes a straight portion along the axial direction, and the fixing portion may fix the straight portions adjacent to each other in the circumferential direction in the plurality of end-side extending portions. The mode of fixing the portions adjacent to each other in the circumferential direction in the plurality of end-side extending portions can be changed according to the design specifications.

[0068] In the above-described embodiment, the stator coil has been described by way of example as including a three-phase winding group connected in parallel to each other, but is not limited thereto. For example, the stator coil may include a three-phase winding group connected in series to each other. The configuration mode of the winding group and the stator (such as the relationship between poles, phases, slots, etc.) can be changed according to the design specifications.

[0069] In the above-described embodiments, the stator coil has been described by way of example as including a plurality of U-shaped segment coils whose ends are connected to each other, but the present invention is not limited thereto. For example, the stator coil may include a coil continuously wound in a wave shape. The configuration mode of the stator coil can be changed according to the design specifications.

[0070] In the above-described embodiments, the electric motor includes a rotor, the above-described stator, and a housing that houses the rotor and the stator, and the example in which the plurality of end-side extending portions are arranged on the side opposite to the bottom of the housing in the axial direction has been described, but the present invention is not limited thereto. For example, the plurality of end-side extending portions may be arranged on the same side as the bottom of the housing (opposite to the opening) in the axial direction. The arrangement mode of the plurality of end-side extending portions can be changed according to the design specifications.

[0071] In the above-described embodiments, the electric motor is mounted on an electric swing excavator, and the electric swing motor for swinging the upper swing body of the electric swing excavator has been described by way of example, but the present invention is not limited thereto. For example, the electric motor may be mounted on other work machines such as a wheel loader, a bulldozer, or a dump truck. For example, the electric motor may be configured as a drive motor for driving a work implement or a drive motor for driving a traveling device. The mode of the work machine on which the electric motor is mounted and the object driven by the electric motor can be changed according to the design specifications.

[0072] In the above-described embodiments, the electric motor has been described by way of example as being vertically placed so that the rotor shaft is parallel to the swing axis, but the present invention is not limited thereto. For example, the electric motor may be horizontally placed so that the rotor shaft is orthogonal to the swing axis. For example, the electric motor may be inclined and arranged so that the rotor shaft intersects obliquely with the swing axis. The arrangement mode of the electric motor can be changed according to the design specifications.

[0073] In the above-described embodiment, an example of the electric motor is an inner rotor type electric motor in which the stator is arranged outside the cylindrical rotor, but the present invention is not limited to this. For example, the electric motor may be an outer rotor type electric motor in which the stator is arranged inside the cup-shaped rotor. The type of the electric motor can be changed according to the design specifications.

[0074] As described above, one embodiment has been described with reference to the drawings. However, the specific configuration is not limited to the above, and additions, omissions, substitutions, and other changes of the configuration are possible without departing from the spirit of the present disclosure. It is also possible to appropriately combine the above-described embodiments.

Explanation of Reference Numerals

[0075] 1... Electric motor, 2... Rotor, 3... Stator, 4... Housing, 13... Bottom, 30... Stator core, 30f1... First end face, 30s... Slot, 31... Stator coil, 32e... End-side extending portion, 32j1... First connection extending portion, 32j2... Second connection extending portion, 32u... Non-connection extending portion, 32s... Inclined portion, 34U1, 34U2, 34V1, 34V2, 34W1, 34W2... Coil groups, 35... Power line, 38... Fixed portion, 39... Segment coil, 100... Working machine, 114... Swing motor, 120... Traveling body, 140... Upper swing body, 160... Working implement, AE... Adhesion range (length of the portion where the adhesive extends along the end-side extending portion)

Claims

1. A cylindrical stator core formed with a plurality of slots arranged in the circumferential direction, A stator coil inserted into each of the plurality of slots and wound around the stator core, and having a plurality of end-side extending portions extending outward from a first end surface in the axial direction of the stator core and arranged in the circumferential direction, A fixing portion for fixing portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions, A stator.

2. The fixing portion is an adhesive, The stator according to claim 1.

3. The adhesive has a high viscosity such that it does not flow downwards even when provided between portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions, The stator according to claim 2.

4. The length of the portion where the adhesive extends along the end-side extending portion is 10 mm or more, The stator according to claim 2 or 3.

5. Further comprising a power line connected to the end-side extending portion, The stator according to any one of claims 1 to 3.

6. The plurality of end-side extending portions include a first connection extending portion and a second connection extending portion to which the power line is connected and which are adjacent to each other in the circumferential direction, and a non-connection extending portion to which the power line is not connected, The fixing portion fixes between at least one of the first connection extending portion and the second connection extending portion and the non-connection extending portion, excluding portions adjacent to each other in the circumferential direction in the first connection extending portion and the second connection extending portion, The stator according to claim 5.

7. The portion where the fixing portion is fixed among the plurality of end-side extending portions is arranged inside the stator core in the radial direction, The stator according to any one of claims 1 to 3.

8. Each of the plurality of end-side extending portions includes an inclined portion that obliquely intersects the axial direction and the circumferential direction, The fixing portion fixes the inclined portions adjacent to each other in the circumferential direction among the plurality of end-side extending portions, The stator according to any one of claims 1 to 3.

9. The stator coil includes three-phase winding groups connected in parallel to each other, The stator according to any one of claims 1 to 3.

10. The stator coil includes a plurality of U-shaped segment coils whose ends are connected to each other, The stator according to any one of claims 1 to 3.

11. A rotor, The stator according to any one of claims 1 to 3, And a housing for housing the rotor and the stator, An electric motor.

12. The plurality of end-side extending portions are arranged on the side opposite to the bottom of the housing in the axial direction. The electric motor according to claim 11.

13. A traveling body, An upper slewing body rotatably supported on the traveling body around a slewing axis, A working machine operably supported on the upper slewing body, The electric motor according to claim 11, configured as a slewing motor for slewing the upper slewing body with respect to the traveling body, A working machine comprising the same.

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