Stator of rotating electric machine and rotating electric machine

Abstract

The present application improves the temperature detection part and the close contact of the segmented coil to improve the temperature following property. The present application has: a stator core; a stator winding which is composed by connecting a plurality of segmented coils installed on the stator core; and a temperature detection part which contacts the segmented coil to detect the temperature; the segmented coil in which the segmented coil provided with the temperature detection part is protrudingly arranged compared with other segmented coils arranged side by side.

Description

Technical Field

[0001] This invention relates to a stator for a rotary electric motor and the rotary electric motor itself. Background Technology

[0002] Since the coil through which current flows is most prone to temperature rise during operation, the temperature of the coil is managed to control the temperature of the motor. For example, Patent Document 1 (Japanese Patent Application Publication No. 2014-90546) describes a rotary motor having a rotor mounted on a shaft supported by journals and a stator disposed around the outer periphery of the rotor with a small gap. The stator includes: a stator core having a plurality of armature slots formed circumferentially; a stator winding consisting of a plurality of segment conductors inserted into the armature slots of the stator core connected together; and a thermistor for measuring the temperature of the stator winding. The stator winding consists of an armature slot portion housed within the armature slot and a connecting portion connecting the ends of the armature slot portion. The temperature-measuring element of the thermistor is housed in a small gap at the end of the stator coil, sandwiched between the connecting portions of the segment conductors (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-90546 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In a stator with a neutral point consisting of three neutral wires, and a temperature sensor is placed on the central V-phase stator winding to measure temperature, temperature management becomes important when current flows through only the two phases other than the temperature-managing coil. The central V-phase winding is sandwiched between the other U-phase and W-phase windings, resulting in high temperature responsiveness due to inter-winding heat transfer. However, one side of the outer U-phase and W-phase windings is unsupported, leading to lower temperatures compared to the central V-phase winding. Therefore, using the central V-phase winding for temperature management is appropriate.

[0008] However, if the contact between the stator winding and the temperature sensor becomes unreliable due to differences in the cross-sectional dimensions of the stator winding at the neutral point or deviations in the connection operation, a gap may form between the temperature sensor and the stator winding, leading to unstable contact. To improve the temperature tracking performance of the temperature sensor, it must reliably contact the surface being measured.

[0009] The purpose of this invention is to improve the temperature tracking performance of the thermistor by increasing the tightness of the connection between the thermistor and the coil.

[0010] Technical means to solve the problem

[0011] A representative example of the invention disclosed in this application is shown below. Specifically, it is characterized by comprising: a stator core; a stator winding, which is configured by connecting a plurality of segmented coils mounted on the stator core; and a temperature detection unit that contacts the segmented coils to detect temperature, wherein the segmented coil for which the temperature detection unit is located is prominently positioned compared to other segmented coils arranged side-by-side.

[0012] The effects of the invention

[0013] According to the present invention, the temperature tracking performance can be improved by enhancing the tightness of the contact between the temperature detection unit and the segmented coil. Issues, configurations, and effects other than those described above will be clarified through the following description of embodiments. Attached Figure Description

[0014] Figure 1 This is a schematic diagram illustrating the overall structure of the rotary motor according to an embodiment of the present invention.

[0015] Figure 2 This is a perspective view showing the stator of the rotary motor in this embodiment.

[0016] Figure 3 This is a perspective view showing the structure of the neutral point of the stator winding in this embodiment.

[0017] Figure 4 This is a diagram showing the neutral point of this embodiment as viewed from the direction of the stator winding extension.

[0018] Figure 5 This is a diagram showing the neutral point of this embodiment viewed radially. Detailed Implementation

[0019] Figure 1 This is a schematic diagram illustrating the overall structure of the rotary motor 1 according to an embodiment of the present invention. Figure 1 In the image, the interior of the rotary motor 1 is shown by setting a portion of the rotary motor 1 as a cross section.

[0020] like Figure 1 As shown, the rotary motor 1 has a housing 10, a stator 2, and a rotor 3. The stator 2 has a stator core 20 fixed inside the housing 10, and the rotor 3 is rotatably disposed inside the stator. The housing of the rotary motor 1 is composed of a front frame 11, a housing 10, and a rear frame 12. The housing 10 and the water jacket 13 together form the cooling water passage of the rotary motor 1.

[0021] The rotor 3 is fixed on a rotating shaft 31 supported by bearing 30A of the front frame 11 and bearing 30B of the rear frame 12, and is rotatably held inside the stator core 20.

[0022] Figure 2 This is a perspective view showing the stator 2 of the rotary motor 1 in this embodiment.

[0023] The stator 2 has a stator core 20, a stator winding 4, and a temperature sensing element 5. The stator core 20 has multiple armature slots formed circumferentially, and the temperature sensing element 5 measures the temperature of the stator winding 4.

[0024] The stator core 20 is formed by stacking magnetic steel plates of a specified thickness along the axial direction to form a ring, and multiple armature slots along the axial direction are formed on the inner circumferential side.

[0025] The stator winding 4, i.e., the stator coil, is installed in the armature slot of the stator core 20 through an insulating member 41 formed in sheet form of insulating resin material. The stator winding 4 is constructed in such a way that a segmented coil formed in a roughly U-shape from a flat copper conductor 40 is inserted axially into the armature slot of the stator core 20, and the open end of the flat conductor 40 is bent, and the bent portions of the flat conductors 40 are electrically connected to each other by welding or the like.

[0026] The welding area of ​​the flat conductor 40 is covered with insulating resin material. Thus, by using the flat conductor 40 to form the stator winding 4, the gap between the stator windings 4 at the coil ends 42 at both ends of the stator core 20 can be made larger compared to continuously winding a single round conductor multiple times. However, in the rotary motor 1 of this embodiment, the stator winding 4 can also be formed using a round conductor.

[0027] Figure 2 The stator winding 4 shown is a three-phase Y-connected winding. The U-phase stator winding, V-phase stator winding, and W-phase stator winding are composed of flat conductors 40. One end of each phase stator winding 4 is configured as the output terminal 43 of the U-phase, V-phase, and W-phase, respectively. The other end of each phase stator winding 4 forms a neutral point 44 where the U-phase, V-phase, and W-phase are connected together, thus forming a three-phase AC circuit.

[0028] Figure 3 This is a perspective view showing the structure of the neutral point 44 of the stator winding 4 in this embodiment. Figure 4 A diagram showing the neutral point 44 as viewed from the extension direction of stator winding 4. Figure 5 This is a diagram showing the view of neutral point 44 from a radial perspective.

[0029] A temperature sensing element 5 for measuring the temperature of the stator winding 4 is fixed at the neutral point 44 of the stator winding 4. The temperature sensing element 5 is a temperature sensor made of a semiconductor whose resistance changes in response to temperature changes. The control unit (e.g., an inverter) of the rotary motor 1 monitors the resistance value of the temperature sensing element 5 to detect the temperature of the stator winding 4. If the detected temperature of the stator winding 4 exceeds a specified upper limit, the control unit limits the performance of the rotary motor 1 or stops the rotary motor 1 to prevent abnormal overheating of the stator winding 4.

[0030] The temperature of the stator winding 4 is transferred to the temperature sensing element 5. The temperature of the temperature sensing element 5 changes, causing a change in its resistance. When the heat transfer from the stator winding 4 to the temperature sensing element 5 is low, the temperature change of the temperature sensing element 5, which is also the change in its resistance, causes a time delay relative to the temperature change of the stator winding 4.

[0031] Thus, if there is a time delay in the temperature change of the temperature sensing element 5 relative to the temperature change of the stator winding 4, the stator winding 4 may overheat. To prevent such overheating of the stator winding 4, measures such as reducing the time delay in setting the temperature limit of the stator winding 4 that restricts the performance of the rotating electric machine 1 are needed. However, this would prevent the rotating electric machine 1 from fully utilizing its performance. To fully utilize the performance of the rotating electric machine 1, the temperature tracking accuracy of the temperature sensing element 5 to the stator winding 4 must be improved.

[0032] To solve this problem, in the rotary motor 1 of this embodiment, a segmented coil 40B connected at the neutral point 44 is offset in the direction away from the stator core 20 and positioned in a position that protrudes from the other segmented coils 40A and 40C, and the temperature sensing element 5 is arranged in such a way that it contacts the protruding segmented coil 40B.

[0033] For example, if the middle segmented coil 40B is recessed compared to the outer segmented coils 40A and 40C, a gap may appear between the temperature sensing element 5 located at the neutral point 44 and the middle segmented coil 40B. This would prevent stable contact between the stator winding 4 and the temperature sensing element 5, resulting in reduced temperature tracking performance. In this embodiment, by arranging the temperature sensing element 5 in contact with the side of the protruding segmented coil 40B, the temperature sensing element 5 is in close contact with the segmented coil 40B, thereby improving the temperature tracking performance of the temperature sensing element 5.

[0034] Specifically, it is preferable that the middle segmented coil 40B of the segmented coils 40A, 40B, and 40C connected at the neutral point 44 protrude beyond the other segmented coils 40A and 40C. Heat from the outer segmented coils 40A and 40C tends to escape to the outside, thus tending to decrease in temperature. If the outer segmented coils 40A and 40C protrude and a temperature sensing element 5 is installed on them, the temperature of the outer segmented coils 40A and 40C, which has a lower temperature than the middle segmented coil 40B, will be measured, making it impossible to measure the temperature of the high-temperature portion within the neutral point 44. Therefore, in this embodiment, the temperature of the high-temperature segmented coil 40B within the neutral point 44 can be managed, thereby enabling proper control of the rotary motor 1 and extending its lifespan.

[0035] like Figure 4 As shown, an adhesive layer 6 is preferably provided between the temperature sensing element 5 and the segmented coil 40B. The adhesive layer 6 is preferably made of an acrylic adhesive and is preferably a double-sided tape structure. Regarding the size of the tape constituting the adhesive layer 6, in the width direction, it is preferably the same width as the segmented coil 40B, or smaller than the temperature sensing element 5 but larger than the segmented coil 40B; in the length direction, it is preferably equal to or slightly smaller than the temperature sensing element 5 (e.g., about 1.0 mm smaller). Through the adhesive layer 6, no air layer with poor thermal conductivity is included between the temperature sensing element 5 and the segmented coil 40B, thereby improving the temperature tracking performance of the temperature sensing element 5.

[0036] like Figure 5 As shown, the tops of the segmented coils 40A, 40B, and 40C at the neutral point 44 are welded. The segmented coils 40A, 40B, and 40C are aligned at the alignment portion 44A to achieve welding. At the deformation portion 44B behind the alignment portion 44A, the middle segmented coil 40B undergoes plastic deformation, forming a convex shape toward the temperature detection area 44C where the temperature detection element 5 is disposed. In this way, the middle segmented coil 40B is plastically deformed in the deformation portion 44B between the alignment portion 44A and the temperature detection area 44C in such a way that it forms a protrusion for the temperature detection element 5 to be disposed within the temperature detection area 44C. Therefore, welding is not performed when the segmented coils 40A, 40B, and 40C are staggered, and the welding cross-sectional area is not reduced. Thus, the convex portion for the temperature detection element 5 to be disposed can be formed while maintaining the welding strength.

[0037] As explained above, according to an embodiment of the present invention, a stator core 20, a stator winding 4, and a temperature detection unit (temperature detection element 5) are provided. The stator winding 4 is formed by connecting multiple segmented coils installed on the stator core 20. The temperature detection unit (temperature detection element 5) contacts the segmented coil 40B to detect the temperature. The segmented coil 40B provided for the temperature detection unit 5 is positioned outward compared to the other segmented coils 40A and 40C arranged side by side. Therefore, even if there are differences in the cross-sectional dimensions of the segmented coils or deviations in the position during connection operations, the middle segmented coil 40B will not be recessed compared to the other segmented coils 40A and 40C. This ensures stable contact between the temperature detection unit 5 and the segmented coil 40B, improving temperature tracking performance and enabling proper management of the motor temperature.

[0038] Furthermore, at least three segmented coils 40A, 40B, and 40C are arranged side by side. The second segmented coil 40B, sandwiched between the first segmented coil 40A and the third segmented coil 40C, is positioned to protrude beyond the first and third segmented coils 40A and 40C. That is, by connecting the coils such that the middle segmented coil 40B protrudes significantly, the high-temperature segmented coil 40B maintains stable contact with the temperature sensing unit 5, thereby enabling accurate measurement of the temperature of the rotary motor 1.

[0039] Furthermore, the first segment coil 40A, the second segment coil 40B, and the third segment coil 40C each carry different three-phase (U, V, W) currents and are connected together at the neutral point 44. The second segment coil 40B, which constitutes the neutral point 44, is staggered from the first segment coil 40A and the third segment coil 40C in a direction perpendicular to the extension direction. The temperature detection unit 5 is disposed on the side of the second segment coil 40B. Therefore, even when no current flows in the outer U-phase segment coil 40A and W-phase segment coil 40C, but current flows in the middle segment coil 40B, the temperature of the rotary motor 1 can be accurately measured, thereby enabling proper control of the rotary motor 1 and extending its lifespan.

[0040] Furthermore, an adhesive layer 6 is provided between the temperature sensing unit 5 and the segmented coil 40B. Viewed from the extending direction of the segmented coil 40B, the adhesive layer 6 is the same size as the segmented coil 40B, or is larger than the segmented coil 40B but smaller than the temperature sensing unit 5. This solves the problem that simply placing the temperature sensing unit 5 on the segmented coil 40B would not secure its position, allowing the temperature sensing unit 5 to be fixed in the correct location. Moreover, by filling the space between the segmented coil 40B and the temperature sensing unit 5 with the adhesive layer 6, the area of ​​air with low thermal conductivity is reduced, improving heat transfer from the segmented coil 40B to the temperature sensing unit 5. Furthermore, the bonding area of ​​the adhesive layer 6 is maximized, increasing the adhesion between the temperature sensing unit 5 and the segmented coil 40B.

[0041] Furthermore, the system includes an alignment portion 44A connecting the ends of the first segmented coil 40A, the second segmented coil 40B, and the third segmented coil 40C; a temperature detection area 44C on the side of the second segmented coil 40B where the temperature detection portion 5 is disposed; and a deformation portion 44B between the alignment portion 44A and the temperature detection area 44C, which deforms the second segmented coil 40B and extends in a direction different from the other segmented coils 40A and 40C by protruding within the temperature detection area 44C. As a result, welding is not performed when the segmented coils 40A, 40B, and 40C are staggered, and the welding cross-sectional area is not reduced. Thus, a protrusion for the temperature detection element 5 can be formed while maintaining the welding strength.

[0042] Furthermore, this invention includes various modifications and equivalents within the spirit of the appended claims and is not limited to the embodiments described above. For example, the embodiments described above are detailed descriptions provided to illustrate the invention in an easily understandable manner, and the invention is not necessarily limited to having all the described configurations. Additionally, a portion of the configuration of one embodiment may be replaced with the configuration of another embodiment. Furthermore, the configuration of one embodiment may be incorporated into the configuration of another embodiment. Furthermore, other configurations may be added to, deleted from, or replaced in parts of the configurations of each embodiment.

[0043] Symbol Explanation

[0044] 1… Rotary motor

[0045] 2…Stator

[0046] 3…rotor

[0047] 4…Stator windings

[0048] 5…Temperature sensing element

[0049] 6… Adhesive layer

[0050] 10…outer shell

[0051] 11…front frame

[0052] 12… rear rack

[0053] 13…water jacket

[0054] 20…Stator core

[0055] 30A… Bearing

[0056] 30B… Bearing

[0057] 31…spindle

[0058] 40…flat conductor

[0059] 40A, 40B, 40C… Segmented Coils

[0060] 41…Insulating components

[0061] 42… coil end

[0062] 43… Output Terminal

[0063] 44… Neutral point

[0064] 44A…Alignment section

[0065] 44B…Deformation section

[0066] 44C… Temperature detection area.

Claims

1. A stator for a rotary electric motor, characterized in that, have: Stator core; A stator winding, which is formed by connecting multiple segmented coils mounted on the stator core; and The temperature detection unit contacts the segmented coil to detect the temperature. In the segmented coil, the first, second, and third segmented coils each supply current for different phases and are connected together at the neutral point. At least the first segmented coil, the second segmented coil, and the third segmented coil are arranged side by side along the radial direction of the stator core. The second segmented coil, which is used for the temperature detection unit, is sandwiched between the first and third segmented coils. The second segment coil protrudes from the stator core in a direction relative to the first and third segment coils. The temperature detection unit is disposed on the side of the second segment coil that is away from the stator core. An adhesive layer is provided between the temperature detection unit and the segmented coil. Viewed from the extension direction of the segmented coil, the adhesive layer is the same size as the segmented coil, or is formed to be larger than the segmented coil and smaller than the temperature detection part.

2. The stator of the rotary electric motor according to claim 1, characterized in that, have: Alignment portion connecting the ends of the first segmented coil, the second segmented coil, and the third segmented coil; A temperature detection area, wherein the temperature detection part is arranged on the side of the second segment coil; as well as A deformation portion, which deforms the second segmented coil between the alignment portion and the temperature detection area in such a way as to form the protrusion within the temperature detection area, extending in a direction different from the other segmented coils.

3. A rotary electric motor, characterized in that, It has a stator according to claim 1 or 2.

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