Stator, motor and engineering machinery

Abstract

The stator includes: a cylindrical stator core in which a plurality of slots are arranged in a circumferential direction; stator coils which are respectively inserted into the plurality of slots, are wound around the stator core, and have a plurality of end-side extension parts which 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 of the plurality of tip-side extension portions that are adjacent in the circumferential direction to each other.

Description

Stator, motor and construction machinery Technical Field

[0001] This disclosure relates to stators, electric motors, and construction machinery.

[0002] This invention claims priority based on Japanese Patent Application No. 2023-201045, filed on November 28, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] Patent Document 1 discloses a structure comprising a stator core having slots for winding insertion, each phase winding extending to the axial end of the stator core, a neutral line separate from each phase winding, and a fixing mechanism for fixing each phase winding connected to the neutral line and each adjacent phase winding.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-15797 Summary of the Invention

[0007] The technical problem that the invention aims to solve

[0008] However, in the structure of Patent Document 1, the fixing portions of adjacent phase windings are located deep in the radial direction, making it highly likely that the fixing mechanism will be difficult to configure. If the fixing mechanism cannot be reliably configured, the fixing strength of each phase winding may be reduced.

[0009] The purpose of this disclosure is to provide stators, electric motors, and engineering machinery that enable improved assemblability and enhanced fixation strength.

[0010] Technical solutions for solving technical problems

[0011] The stator of this disclosure comprises: a cylindrical stator core having a plurality of slots arranged in the circumferential direction; a stator coil, which is respectively inserted into the plurality of slots and wound around the stator core, and has a plurality of end-side extensions extending outward from a first end face in the axial direction of the stator core and arranged in the circumferential direction; and a fixing portion that fixes adjacent portions of the plurality of end-side extensions in the circumferential direction to each other.

[0012] Invention Effects

[0013] According to the present disclosure, stators, electric motors, and engineering machinery that can achieve improved assemblability and enhanced fixing strength can be provided. Attached Figure Description

[0014] Figure 1 is a schematic diagram of the engineering machinery used in the implementation of the method.

[0015] Figure 2 is a cross-sectional view of the electric motor according to the embodiment.

[0016] Figure 3 is a perspective view of the stator in the embodiment.

[0017] Figure 4 is a perspective view of the inner periphery of the stator in the embodiment.

[0018] Figure 5 is a perspective view of the portion of the plurality of end-side extensions of the embodiment in which the fixing part is fixed.

[0019] Figure 6 is a diagram of a slot in the stator of an embodiment cut by a plane orthogonal to the axial direction.

[0020] Figure 7 is a diagram showing the segmented coil before assembly of the stator core in an embodiment.

[0021] Figure 8 is a diagram showing the twisted shape of the segmented coil according to the embodiment.

[0022] Figure 9 is a wiring diagram of the stator coil in the embodiment.

[0023] Figure 10 is a perspective view showing a modified example of a portion in which a fixing part is fixed in one of the multiple end-side extensions of the embodiment.

[0024] Figure 11 is another perspective view showing a modified example of a portion in which a fixing part is fixed in one of the multiple end-side extensions of the embodiment. Detailed Implementation

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In this embodiment, an example of a rotary motor configured to be mounted on an electric rotary excavator (an example of construction machinery) and used to rotate the upper rotating body of the electric rotary excavator will be described as an example of a rotary motor.

[0026] In the following description, terms such as "parallel," "orthogonal," "centered," and "coaxial," indicating relative or absolute configurations, not only strictly mean such configurations or states, but also include configurations or states with relative displacement by tolerances, angles, or distances to achieve the same function. In the accompanying drawings used in the following description, the scale of each component is sometimes appropriately changed to show them as recognizable sizes.

[0027] <Construction Machinery>

[0028] Figure 1 is a schematic diagram of the construction machinery according to the embodiment. The construction machinery 100 in this embodiment is an electric-hydraulic excavator. The construction machinery 100 can be a manned vehicle driven by a driver or an unmanned vehicle.

[0029] The construction machinery 100 includes a traveling body 120, an upper rotating body 140, and a working device 160.

[0030] The traveling body 120 supports the construction machinery 100 for movement. The traveling body 120 includes a traveling mechanism 121, which may be, for example, a pair of tracks. The traveling mechanism 121 is driven by a traveling motor 122. An upper rotating body 140 is rotatably supported on the traveling body 120 about a rotation axis. The upper rotating body 140 rotates relative to the traveling body 120 via a rotary motor 114. The upper rotating body 140 has a partition 141 for accommodating the drive system.

[0031] The working device 160 is operatively supported on the upper rotating body 140. The working device 160 is hydraulically driven. The working device 160 includes a boom 161, a forearm 162, and an auxiliary device 163. The auxiliary device 163 is an example of a working tool. In the example shown in FIG1, the auxiliary device 163 is a bucket. In the example shown in FIG1, the side of the upper rotating body 140 supporting the working device 160 is the front, and with the front as a reference, the opposite side is the rear. In this embodiment, the left-right direction refers to left and right relative to the front, and the up-down direction refers to the direction in which the rotation axis of the upper rotating body 140 extends.

[0032] The rotary motor 114 is an electrically driven motor. The rotary motor 114 causes the upper rotating body 140 to rotate relative to the traveling body 120.

[0033] <Electric motor>

[0034] Figure 2 is a cross-sectional view of the electric motor 1 according to the embodiment.

[0035] In this embodiment, the electric motor 1 is a rotary electric 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 disposed outside the cylindrical rotor 2. The electric motor 1 is longitudinally arranged with the rotor shaft 20 of the rotor 2 parallel to the rotation axis.

[0036] In this embodiment, the upper side corresponds to the 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 will be referred to as the "axial direction", the direction orthogonal to the axial direction will be referred to as the "radial direction", and the direction around the central axis CL of the rotor shaft 20 will be referred to as the "circumferential direction".

[0037] 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 supported by bearings 21A and 21B and can rotate freely relative to the housing 4.

[0038] The rotor core 21 is constructed, for example, by stacking electromagnetic steel plates axially. The rotor core 21 is fitted into 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.

[0039] The upper plate 22 and the lower plate 23 are annular plate components coaxially arranged with the rotor shaft 20. The upper plate 22 and the lower plate 23 are fitted into the rotor shaft 20. The upper plate 22 and the lower plate 23 clamp the rotor core 21 from the axial outside. The upper plate 22 and the lower plate 23 rotate integrally with the rotor shaft 20 and the rotor core 21.

[0040] The stator 3 is fixed to the inner surface of the housing 4 in a manner that covers the outer periphery of the rotor 2. The stator 3 has a cylindrical stator core 30 and a stator coil 31. The stator core 30 is constructed by stacking electromagnetic steel plates axially, similar to the rotor core 21. On the inner periphery of the stator core 30, multiple teeth are provided on the circumference. The stator coil 31 is wound and mounted on the teeth.

[0041] The housing 4 houses the rotor 2 and the stator 3. The housing 4 has a cylindrical body 10, a top 11 that blocks the opening on the upper side of the cylindrical body 10, and a bottom 13 that blocks the opening on the lower side of the cylindrical body 10. Through the cylindrical body 10, the top 11, and the bottom 13, a space 40 for accommodating the rotor 2 and the stator 3 is formed inside the housing 4.

[0042] <Stator>

[0043] Figure 3 is a perspective view of the stator 3 according to the embodiment. Figure 4 is a perspective view of the inner periphery of the stator 3 according to the embodiment. Figure 5 is a perspective view of the portion of the plurality of end-side extensions in the embodiment where the fixing part is fixed.

[0044] Referring to Figures 3 to 5, the stator 3 includes: a cylindrical stator core 30, which is formed by arranging a plurality of slots 30s in a circumferential direction; a stator coil 31, which is inserted into the plurality of slots 30s and wound around the stator core 30, and has a plurality of end-side extensions 32e extending outward from a first end face 30f1 in the axial direction of the stator core 30 and arranged in a circumferential direction; and a fixing portion 38, which fixes the circumferentially adjacent portions of the plurality of end-side extensions 32e to each other.

[0045] On the inner circumference of the stator core 30, multiple slots 30s and multiple teeth 30t are arranged alternately around the entire circumference. The multiple slots 30s are arranged at equal intervals in the circumferential direction of the stator core 30. For example, insulating material may be provided in the slots 30s. Furthermore, the arrangement (configuration, quantity, shape, etc.) of the slots 30s can be changed according to design specifications.

[0046] In this embodiment, the stator coil 31 is composed of multiple segmented coils 39. For example, the segmented coil 39 is a flat wire with an insulating film covering its outer periphery. Furthermore, the segmented coil 39 is not limited to the above and may also be composed of windings with circular or elliptical cross-sections. The shape of the segmented coil 39 can be changed according to design specifications.

[0047] The stator coil 31 includes: a first coil end 32 having a plurality of end-side extensions 32e protruding axially from a first end face 30f1 of the stator core 30; and a second coil end 33 protruding axially from a second end face 30f2 of the stator core 30 opposite to the first end face 30f1. The axial direction of the stator core 30 corresponds to the direction along the central axis CL (see Figure 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. Furthermore, in the stator core 30, the radial direction is perpendicular to the axial direction, and the circumferential direction is the direction around the central axis CL.

[0048] Referring also to FIG2, the electric motor 1 of this embodiment includes a rotor 2, a stator 3, and a housing 4 that houses the rotor 2 and the stator 3. A first coil end 32 is axially disposed on the side opposite to the bottom 13 of the housing 4 (upper side). Conversely, a second coil end 33 is axially disposed on the same side as the bottom 13 of the housing 4 (lower side). In this embodiment, a plurality of end-side extensions 32e are axially disposed on the side opposite to the bottom 13 of the housing 4 (upper side).

[0049] The stator 3 in this embodiment also includes power lines 35U, 35V, and 35W connected to a plurality of end-side extensions 32e. The plurality of end-side extensions 32e include connecting extensions 32j that connect to the power lines 35U, 35V, and 35W, and non-connecting extensions 32u that do not connect to the power lines 35U, 35V, and 35W. The power lines 35U, 35V, and 35W have stranded wires and terminals connected to the ends of the stranded wires. A power line connecting portion 36 for connecting the power lines 35U, 35V, and 35W is connected to the connecting extension 32j. The power line connecting portion 36 is connected to the terminals of the power lines 35U, 35V, and 35W.

[0050] In this embodiment, the connection between the power line connector 36 and the terminals of the power lines 35U, 35V, and 35W is achieved through bolt and nut fastening. Furthermore, the structural forms of the power lines 35U, 35V, 35W, and the power line connector 36 are not limited to those described above and can be modified according to design specifications. For example, the power lines 35U, 35V, and 35W may also include a busbar, which is welded to the connection extension 32j. Alternatively, the power lines 35U, 35V, and 35W may include stranded wires and terminals connected to the ends of the stranded wires, with the terminals welded to the connection extension 32j. Another option is that the power lines 35U, 35V, and 35W may include stranded wires and a first terminal connected to the end of the stranded wires, with a second terminal connected to the connection extension 32j, and the first and second terminals welded together.

[0051] In this embodiment, the stator coil 31 has three-phase winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 connected in parallel. The three-phase winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 are winding groups for phases U, V, and W, respectively. The winding groups 34U1, 34U2, 34V1, 34V2, 34W1, and 34W2 for phases U, V, and W are arranged in pairs along the circumference of the stator core 30, with each pair being two in the order of phase U, phase U, phase V, phase V, phase W, phase W, ...

[0052] In this embodiment, the stator coil 31 includes a plurality of U-shaped segmented coils 39 whose ends are connected to each other. The stator coil 31 is formed by winding the plurality of segmented coils 39, whose ends are connected to each other, into a wave shape. Furthermore, in the example shown in the figure, a segmented coil 39 with a square cross-section is represented, but it may also be a segmented coil 39 with a circular cross-section. The cross-sectional shape of the segmented coil 39 is not limited to the above and can be changed according to design specifications.

[0053] In the illustrated example, when multiple segmented coils 39 inserted circumferentially along the stator core 30 are designated as a single winding section 34A, 34B, 34C, 34D, four winding sections 34A, 34B, 34C, 34D are arranged radially along the stator core 30. The four winding sections 34A, 34B, 34C, 34D include a first winding section 34A, a second winding section 34B, a third winding section 34C, and a fourth winding section 34D. The first winding section 34A, the second winding section 34B, the third winding section 34C, and the fourth winding section 34D are arranged sequentially from the innermost circumference to the outermost circumference of the stator core 30.

[0054] Figure 6 is a diagram of a slot 30s of the stator 3 in the embodiment, which is cut with a plane orthogonal to the axial direction.

[0055] Referring also to Figure 6, the segmented coil 39 is arranged in slot 30s in a multi-layered manner. Slot 30s includes multiple layers L1 to L8 corresponding to multiple layers.

[0056] In the example shown, multiple layers L1 to L8 are arranged sequentially from the radial inner circumference side (lower side in the figure) from layer 1 to layer 8. The first winding section 34A is inserted into layer 1 and layer 2. The second winding section 34B is inserted into layer 3 (L3) and layer 4 (L4). The third winding section 34C is inserted into layer 5 (L5) and layer 6 (L6). The fourth winding section 34D is inserted into layer 7 (L7) and layer 8 (L8). Furthermore, the number of layers is not limited to the above and can be changed according to design specifications.

[0057] Figure 7 is a diagram showing the segmented coil 39 before it is assembled into the stator core 30 of the embodiment. Figure 8 is a diagram showing the segmented coil 39 after it has been twisted and shaped according to the embodiment.

[0058] Referring to Figures 7 and 8, the segmented coil 39 assembled before the stator core 30 is formed into a U-shape.

[0059] Specifically, the segmented coil 39 has a U-shaped portion 39a that protrudes axially to one side in a mountain-like shape (U-shape), and two straight portions 39b1 and 39b2 that extend parallel to each other in a straight line from each end of the U-shaped portion 39a to the other side of the axial direction. Furthermore, the U-shaped portion 39a constitutes the end 33 of the second coil. The straight portions 39b1 and 39b2 are portions inserted into slots 30s, excluding the twisted portions. The segmented coil 39, for example, has a shape in the first winding portion 34A where the end of the straight portion 39b1 is inserted into the first layer L1 and the end of the other straight portion 39b2 is inserted into the second layer L2.

[0060] For example, after inserting the segmented coil 39 into the slot 30s, the first extension 39c1 on one end is twisted and shaped towards the circumferential direction, and the second extension 39c2 on the other end is twisted and shaped towards the other circumferential direction. For example, the end of the twisted first extension 39c1 of one segmented coil 39, which is connected to the other segmented coil 39, is connected to the end of the twisted second extension 39c2 of the other segmented coil 39 by welding or the like. In each segmented coil 39, the connection portions of the ends of the first extension 39c1 and the second extension 39c2 are arranged radially relative to each other. Then, a neutral line 37N, which is composed of a busbar or the like, is connected at a predetermined location on the segmented coil 39 by welding or the like. Furthermore, each extension 39c1, 39c2 constitutes part of the end 32 of the first coil.

[0061] Figure 9 is a wiring diagram of the stator coil 31 in the embodiment.

[0062] Referring also to Figure 9, the stator coil 31 adopts a double star connection. In this embodiment, the first star connection having a U1 phase winding group 34U1, a V1 phase winding group 34V1, and a W1 phase winding group 34W1 is connected in parallel with the second star connection having a U2 phase winding group 34U2, a V2 phase winding group 34V2, and a W2 phase winding group 34W2.

[0063] In the first star connection and the second star connection, the U phases (U1 phase winding group 34U1 and U2 phase winding group 34U2) are electrically connected to each other, the V phases (V1 phase winding group 34V1 and V2 phase winding group 34V2) are electrically connected to each other, and the W phases (W1 phase winding group 34W1 and W2 phase winding group 34W2) are electrically connected to each other.

[0064] The U1-phase winding group 34U1, V1-phase winding group 34V1, and W1-phase winding group 34W1 of the first star connection are electrically connected to the U2-phase winding group 34U2, V2-phase winding group 34V2, and W2-phase winding group 34W2 of the second star connection via a neutral line 37N. Alternatively, the first star connection can be electrically connected by connecting the U1-phase winding group 34U1, V1-phase winding group 34V1, and W1-phase winding group 34W1 via a first neutral line 37N1 (not shown), and the second star connection can be electrically connected by connecting the U2-phase winding group 34U2, V2-phase winding group 34V2, and W2-phase winding group 34W2 via a second neutral line 37N2 (not shown).

[0065] <Fixed Part>

[0066] In this embodiment, the fixing part 38 is an adhesive. For example, epoxy adhesives, organic adhesives, etc., can be used as adhesives. In addition, the type of adhesive is not limited to the above and can be changed according to the design specifications.

[0067] In this embodiment, the adhesive is a high-viscosity adhesive that will not flow downwards even when disposed in the plurality of end-side extensions 32e between adjacent portions in the circumferential direction. For example, two-component epoxy resin adhesives can be cited as high-viscosity adhesives. In addition, the types of high-viscosity adhesives are not limited to the above and can be changed according to design specifications.

[0068] For example, a high-viscosity adhesive is injected (applied) between adjacent portions in the circumferential direction of multiple end-side extensions 32e using a syringe (dispenser). The high-viscosity adhesive has low flowability and is easy to handle, thus allowing for reliable application to the designated location. The high-viscosity adhesive cures over time, thus ensuring gapless and reliable fixation of the designated location.

[0069] In this embodiment, the length AE (adhesion range) of the adhesive along the end-side extension 32e is 10 mm or more. For example, by applying the adhesive between adjacent portions in the circumferential direction within the application range DE (e.g., 20 mm or more) of the end-side extension 32e, the specified location can be reliably fixed over a large area.

[0070] In this embodiment, the plurality of end-side extensions 32e include a first connecting extension 32j1, a second connecting extension 32j2, and a non-connecting extension 32u. The first connecting extension 32j1 and the second connecting extension 32j2 are connected to power lines 35U, 35V, and 35W and are adjacent to each other in the circumferential direction. The non-connecting extension 32u is not connected to power lines 35U, 35V, and 35W. A fixing part 38 fixes at least one of the first connecting extension 32j1 and the second connecting extension 32j2, except for the portions that are adjacent in the circumferential direction, to the non-connecting extension 32u. In the illustrated example, the fixing part 38 does not fix the portions of the first connecting extension 32j1 and the second connecting extension 32j2 that are adjacent in the circumferential direction. The fixing part 38 fixes each of the first connecting extension 32j1 and the second connecting extension 32j2 to the portions of the non-connecting extension 32u that are adjacent in the circumferential direction.

[0071] In this embodiment, the portions of the plurality of end-side extensions 32e for which the fixing portions 38 are fixed are disposed radially inner to the stator core 30. In the illustrated example, the portions of the plurality of end-side extensions 32e for which the fixing portions 38 are fixed are disposed radially innermost to the stator core 30. The fixing portions 38 are disposed on the side surfaces adjacent to and opposite to the radially innermost surfaces of the plurality of end-side extensions 32e.

[0072] In this embodiment, the plurality of end-side extensions 32e each include inclined portions 32s that intersect obliquely with respect to the axial and circumferential directions. A fixing portion 38 fixes the circumferentially adjacent inclined portions 32s of the plurality of end-side extensions 32e to each other. In the example shown in the figure, the bonding range AE and the coating range DE are arranged along the respective inclined portions 32s.

[0073] <Effects>

[0074] As described above, the stator 3 of this embodiment includes: a cylindrical stator core 30 formed by arranging a plurality of slots 30s in the circumferential direction; a stator coil 31, which is inserted into the plurality of slots 30s and wound around the stator core 30, and has a plurality of end-side extensions 32e extending outward from a first end face 30f1 in the axial direction of the stator core 30 and arranged in the circumferential direction; and a fixing portion 38, which fixes the circumferentially adjacent portions of the plurality of end-side extensions 32e to each other.

[0075] For example, when fixing radially adjacent portions of multiple end-side extensions 32e to each other, it is difficult to arrange fixing portions 38 between them radially, thus deteriorating assemblability and reducing fixing strength become technical problems.

[0076] In contrast, according to this embodiment, by fixing the circumferentially adjacent portions of the plurality of end-side extensions 32e to each other, it is easy to arrange the fixing portion 38 between them in the circumferential direction, thereby improving assemblability. Furthermore, the fixing strength between the circumferentially adjacent portions of the plurality of end-side extensions 32e can be improved. Therefore, both improved assemblability and improved fixing strength can be achieved.

[0077] In this embodiment, the fixing part 38 is an adhesive.

[0078] According to this embodiment, by adding an adhesive between adjacent portions in the circumferential direction in a plurality of end-side extensions 32e, a specified portion can be fixed without gaps.

[0079] In this embodiment, the adhesive is a high-viscosity adhesive that will not flow downwards even when disposed in multiple end-side extensions 32e between adjacent portions in the circumferential direction.

[0080] According to this embodiment, by adding a high-viscosity adhesive between adjacent portions in the circumferential direction in the plurality of end-side extensions 32e, the specified portion can be fixed reliably without gaps.

[0081] In this embodiment, the length AE of the portion of the adhesive extending along the end side 32e is 10 mm or more.

[0082] According to this embodiment, by fixing the circumferentially adjacent portions of the plurality of end-side extensions 32e to each other by more than 10 mm, it helps to further improve the fixing strength.

[0083] In this embodiment, the stator 3 also includes power lines 35U, 35V, and 35W connected to the end-side extension 32e.

[0084] According to this embodiment, the fixing strength of the end-side extension 32e connecting the power lines 35U, 35V, and 35W can be improved. Therefore, the risk of terminal breakage caused by resonance of the power lines 35U, 35V, and 35W during vehicle body vibration can be reduced.

[0085] In this embodiment, the plurality of end-side extensions 32e include a first connecting extension 32j1 and a second connecting extension 32j2 that are connected to the power lines 35U, 35V, and 35W and are adjacent to each other in the circumferential direction, and a non-connecting extension 32u that is not connected to the power lines 35U, 35V, and 35W. A fixing part 38 fixes at least one of the first connecting extension 32j1 and the second connecting extension 32j2 (excluding the portions that are adjacent in the circumferential direction) to the non-connecting extension 32u.

[0086] According to this embodiment, by fixing only the minimum required parts, it is possible to further improve the assemblability and the fixing strength.

[0087] In this embodiment, the portion of the plurality of end-side extensions 32e that is fixed with the fixing portion 38 is disposed on the radial inner side of the stator core 30.

[0088] According to this embodiment, the fixing part 38 can be easily disposed from the radial inner side of the stator core 30 in the portion of the plurality of end-side extensions 32e in which the fixing part 38 is fixed, thus contributing to further improvement of assemblability.

[0089] In this embodiment, each of the plurality of end-side extensions 32e includes an inclined portion 32s that intersects with an oblique angle relative to the axial and circumferential directions. The fixing portion 38 fixes the inclined portions 32s that are adjacent in the circumferential direction among the plurality of end-side extensions 32e to each other.

[0090] According to this embodiment, by fixing the inclined portions 32s that are adjacent in the circumferential direction among the plurality of end-side extensions 32e to each other, it is helpful to further improve the fixing strength.

[0091] In this embodiment, the stator coil 31 has three-phase winding groups 34U, 34U2, 34V1, 34V2, 34W1, and 34W2 connected in parallel with each other.

[0092] According to this embodiment, even when there are three-phase winding groups 34U, 34U2, 34V1, 34V2, 34W1, and 34W2 connected in parallel, it is possible to improve the assemblability and fixation strength.

[0093] In this embodiment, the stator coil 31 has a plurality of U-shaped segmented coils 39 with their ends connected to each other.

[0094] According to this embodiment, even when multiple segmented coils 39 in a U-shape with their ends connected to each other are provided, improved assemblability and improved fixing strength can be achieved.

[0095] The electric motor 1 of this embodiment includes a rotor 2, a stator 3 as described above, and a housing 4 that houses the rotor 2 and the stator 3. A plurality of end-side extensions 32e are axially arranged on the side opposite to the bottom 13 of the housing 4.

[0096] According to this embodiment, multiple end-side extensions 32e (which can be configured with fixing parts 38) can be accessed axially from the side (upper side) opposite to the bottom 13 of the housing 4, thus helping to further improve assemblability.

[0097] <Variation Example>

[0098] In the above embodiments, examples of adhesive being used as the fixing part have been described, but the method is not limited thereto. For example, as shown in Figures 10 and 11, the fixing part may also be a resin plate 138 coated with adhesive. The resin plate 138 may also be provided on the radially outer surfaces of adjacent portions in the circumferential direction in a plurality of end-side extensions 32e. When viewed radially, the resin plate may also be a cuboid shape spanning adjacent portions in the circumferential direction. The resin plate may also be a shape having a fixing surface (side surface) larger than the radially outer surfaces of adjacent portions in the circumferential direction.

[0099] For example, the adhesive-coated component is not limited to the above; it can also be a plate, film, or sheet component other than a resin plate. Although not illustrated, the fixing part can also be a rope component (thread, cable tie, etc.) capable of connecting adjacent portions of multiple end-side extensions in the circumferential direction. The fixing part can also be an impregnated component (sponge, cloth, fiber, etc.) impregnated with adhesive. The fixing part can also be a molded component capable of fixing adjacent portions of multiple end-side extensions in the circumferential direction to each other. The fixing part can also be a resin component capable of fixing adjacent portions of multiple end-side extensions in the circumferential direction to each other. In this case, it can be, for example, a molded resin component. When using a resin component for fixing, the coils can also be fixed together by inserting an E-shaped resin molded component from the side of the coil. The shape of the fixing part can be changed according to design specifications.

[0100] In the above embodiments, an example of a high-viscosity adhesive that does not flow downwards even when provided in multiple end-side extensions between circumferentially adjacent portions has been described, but this is not a limitation. For example, it could also be a low-viscosity adhesive that flows downwards when provided in multiple end-side extensions between circumferentially adjacent portions. The viscosity of the adhesive can be varied according to design specifications.

[0101] In the above embodiments, examples were given where the length of the portion of the adhesive extending along the end side is 10 mm or more, but this is not a limitation. For example, the length of the portion of the adhesive extending along the end side may be less than 10 mm. The length of the portion of the adhesive extending along the end side can be varied according to design specifications.

[0102] In the above embodiments, examples have been given of the stator also having a power line connected to the end-side extension, but this is not a limitation. For example, the power line may not be connected to the end-side extension. For example, a neutral line may be connected to the end-side extension. For example, other components (busbars, etc.) may be connected to the end-side extension. The arrangement of the power line can be changed according to design specifications.

[0103] In the above embodiments, the following example is provided: A plurality of end-side extensions include first and second connecting extensions that are connected to the power line and are adjacent to each other in the circumferential direction, and non-connecting extensions that are not connected to the power line. A fixing part secures at least one of the first and second connecting extensions (excluding the circumferentially adjacent portions) to the non-connecting extension, but is not limited thereto. For example, the fixing part may also fix the circumferentially adjacent portions of the first and second connecting extensions. The fixing method of the fixing part can be changed according to design specifications.

[0104] In the above embodiments, an example was described where the portion of the plurality of end-side extensions to which the fixing portion is fixed is arranged radially inside the stator core, but this is not a limitation. For example, the portion of the plurality of end-side extensions to which the fixing portion is fixed may also be arranged radially outside the stator core. The arrangement of the portion of the plurality of end-side extensions to which the fixing portion is fixed can be changed according to design specifications.

[0105] In the above embodiments, an example has been described where multiple end-side extensions each include inclined portions that intersect obliquely with respect to both the axial and circumferential directions, and a fixing portion fixes adjacent inclined portions in the circumferential direction among the multiple end-side extensions to each other; however, this is not a limitation. For example, the multiple end-side extensions may each include straight portions along the axial direction, and the fixing portion may fix adjacent straight portions in the circumferential direction among the multiple end-side extensions to each other. The manner in which adjacent portions in the circumferential direction among the multiple end-side extensions are fixed to each other can be varied according to design specifications.

[0106] In the above embodiments, an example of a stator coil having three-phase windings connected in parallel has been described, but this is not the only possible embodiment. For example, the stator coil may also have three-phase windings connected in series. The structural configuration of the windings and the stator (the relationship between poles, phases, slots, etc.) can be changed according to design specifications.

[0107] In the above embodiments, an example of a stator coil having multiple segmented coils in a U-shape with their ends connected to each other has been described, but the embodiments are not limited to this. For example, the stator coil may also have coils continuously wound into a wavy shape. The structure of the stator coil can be changed according to design specifications.

[0108] In the above embodiments, an example has been described where the motor includes a rotor, the stator described above, and a housing that houses the rotor and stator, with multiple end-side extensions arranged axially on the opposite side of the bottom of the housing; however, this is not a limitation. For example, the multiple end-side extensions may also be arranged axially on the same side as the bottom of the housing (the side opposite to the opening). The arrangement of the multiple end-side extensions can be varied according to design specifications.

[0109] In the above embodiment, the electric motor is mounted on an electric rotary excavator. An electric rotary motor used to rotate the upper rotating body of the electric rotary excavator has been used as an example, but the description is not limited to this. For example, the electric motor can also be mounted on other construction machinery such as wheel loaders, bulldozers, and dump trucks. For example, the electric motor can also be configured as a drive motor for driving the working device or a drive motor for driving the traveling device. The type of construction machinery equipped with the electric motor and the object driven by the electric motor can be changed according to the design specifications.

[0110] In the above embodiments, an example of the motor being longitudinally mounted with its rotor shaft parallel to the rotation axis has been given, but the method is not limited to this. For example, the motor may also be transversely mounted with its rotor shaft orthogonal to the rotation axis. For example, the motor may also be configured at an angle with its rotor shaft intersecting the rotation axis at an angle. The configuration of the motor can be changed according to design specifications.

[0111] In the above embodiments, an example of an inner rotor type motor in which the stator is arranged outside a cylindrical rotor has been described, but the invention is not limited to this. For example, the motor may also be an outer rotor type motor in which the stator is arranged inside a cup-shaped rotor. The type of motor can be changed according to design specifications.

[0112] The above description of one embodiment is based on the accompanying drawings. However, the specific structure is not limited to the structure described above. Without departing from the spirit of this disclosure, additions, omissions, substitutions and other changes to the structure can be made, and the above embodiments can be appropriately combined.

[0113] Explanation of reference numerals in the attached figures

[0114] 1: Electric motor

[0115] 2: Rotor

[0116] 3: Stator

[0117] 4: Casing

[0118] 13: Bottom

[0119] 30: Stator core

[0120] 30f1: First end face

[0121] 30s: slot

[0122] 31: Stator coil

[0123] 32e: End-side extension

[0124] 32j1: First connecting extension

[0125] 32j2: Second connecting extension

[0126] 32u: Non-connecting extension

[0127] 32s: Inclined section

[0128] 34U1, 34U2, 34V1, 34V2, 34W1, 34W2: Winding assemblies

[0129] 35: Power Line

[0130] 38: Fixing part

[0131] 39: Segmented coil

[0132] 100: Construction Machinery

[0133] 114: Rotary electric motor

[0134] 120: Driving body

[0135] 140: Upper Rotational Body

[0136] 160: Working device

[0137] AE: Adhesion Range (the length of the portion of the adhesive extending along the end side)

Claims

1. A stator, characterized in that, It comprises: a cylindrical stator core having a plurality of slots arranged in the circumferential direction; and stator coils, which are respectively inserted into the plurality of slots and wound around the stator core, and have a plurality of end-side extensions extending outward from a first end face in the axial direction of the stator core and arranged in the circumferential direction. A fixing part that fixes adjacent portions of the plurality of end-side extensions in the circumferential direction to each other.

2. The stator according to claim 1, characterized in that, The fixing part is an adhesive.

3. The stator according to claim 2, characterized in that, The adhesive is a high-viscosity adhesive that will not flow downwards even when disposed in the plurality of end-side extensions between adjacent portions in the circumferential direction.

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

5. The stator according to any one of claims 1 to 3, characterized in that, It also has a power line that connects to the end-side extension.

6. The stator according to claim 5, characterized in that, The plurality of end-side extensions include: a first connecting extension and a second connecting extension connected to the power line and adjacent to each other in the circumferential direction; and a non-connecting extension not connected to the power line. The fixing portion fixes at least one of the first connecting extension and the second connecting extension, except for the portions adjacent in the circumferential direction, to the non-connecting extension.

7. The stator according to any one of claims 1 to 3, characterized in that, The portion of the plurality of end-side extensions to which the fixing portion is fixed is disposed radially inside the stator core.

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

9. The stator according to any one of claims 1 to 3, characterized in that, The stator coil has three-phase winding groups connected in parallel.

10. The stator according to any one of claims 1 to 3, characterized in that, The stator coil has multiple segmented coils in a U-shape with their ends connected to each other.

11. An electric motor, characterized in that, It comprises: a rotor; a stator according to any one of claims 1 to 3; and a housing that houses the rotor and the stator.

12. The electric motor according to claim 11, characterized in that, The plurality of end-side extensions are arranged axially on the side opposite to the bottom of the housing.

13. An engineering machinery, characterized in that, The device comprises: a traveling body; an upper rotating body supported on the traveling body in a manner rotatable about a rotation axis; a working device supported on the upper rotating body in a manner operable; and an electric motor as claimed in claim 11, configured as a rotary electric motor for rotating the upper rotating body relative to the traveling body.

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