Stator for rotating electrical machine

Abstract

This stator for a rotary electric machine comprises: a stator core; a coil inserted into the stator core; a conductor welded to the coil; a temperature sensor for measuring the temperature of the stator core via the conductor; and a clip for attaching the temperature sensor to the conductor. The conductor includes: a weld part where the conductor is welded to a terminal of the coil; and a to-be-measured part that is measured by the temperature sensor. The to-be-measured part includes a first surface on which the temperature sensor is attached, and a second surface that is a surface on the opposite side to the first surface. The clip comprises a leg part that is locked on the second surface side, and a holding part that holds the temperature sensor on the first surface side. The first surface faces one end surface of the stator core in the axial direction, and the temperature sensor is provided between the first surface and the end surface.

Description

Rotating electric machine stator

[0001] The present invention relates to a stator for a rotating electrical machine.

[0002] To prevent motor burnout, if the coil temperature becomes overheated, the applied current is reduced. The temperature for current control at this time is determined by measuring the coil temperature during operation with a temperature sensor. At this time, errors due to measurement variations etc. are corrected for the measured temperature.

[0003] The stator of the motor has a wiring plate structure, and the temperature sensor that measures the coil temperature can be attached to this wiring plate, which has the advantage of simplifying the stator coil. Regarding such a temperature sensor attachment structure, for example, Patent Document 1 listed below discloses a stator having a structure that allows a thermistor holder to be attached to a conductive part without tools.

[0004] Special Publication No. 2021-526345

[0005] In the technology described in Patent Document 1, the temperature sensor is installed further away from the coil than in conventional technology, which creates the problem of a greater likelihood of a numerical discrepancy occurring between the true coil temperature and the temperature measured by the temperature sensor.

[0006] A stator for a rotating electric machine comprising: a stator core; a coil inserted into the stator core; a conductor welded to the coil; a temperature sensor that measures the temperature of the stator core via the conductor; and a clip for attaching the temperature sensor to the conductor, wherein the conductor comprises a welded portion welded to a terminal of the coil and a measured portion that is measured by the temperature sensor, and the measured portion comprises a first surface to which the temperature sensor is attached and a second surface opposite to the first surface, and the clip comprises legs that engage with the second surface and a holding portion that holds the temperature sensor on the first surface, and the first surface faces one end surface of the stator core in the axial direction, and the temperature sensor is provided between the first surface and the end surface.

[0007] According to the present invention, it is possible to provide a stator for a rotating electrical machine that reduces the difference between the true coil temperature and the temperature measured by a temperature sensor, thereby improving the output of the motor.

[0008] 1. Overall view of the stator of a rotating electric machine and a diagram of a connection plate according to one embodiment of the present invention. 2. Explanatory diagram of a conductor and a clip according to one embodiment of the present invention. 3. Explanatory diagram of a temperature sensor and a clip according to one embodiment of the present invention. 4. Explanatory diagram of the installation position of a temperature sensor in a motor according to one embodiment of the present invention.

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and some omissions and simplifications have been made as appropriate for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural.

[0010] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings.

[0011] (One embodiment and overall configuration) (Fig. 1) Fig. 1(a) is an overall perspective view of a stator, and Fig. 1(b) is an enlarged view of a connection plate 18 in Fig. 1(a). The stator of a motor mounted on a vehicle has a stator core 2 and a plurality of coils 17. The plurality of coils 17 are electrically connected to the connection plate 18.

[0012] The stator is held inside the motor housing, and a plurality of coils 17 are inserted into a plurality of slots in the stator core 2. The connection plate 18 is formed by molding the conductor 8 with a resin part 19, and has a plurality of welds 7. A clip 15 for attaching a temperature sensor to the conductor 8 is attached to the connection plate 18.

[0013] The material of the conductor 8 is, for example, copper, and the material of the clip 15 is, for example, stainless steel or iron-based spring steel.

[0014] (Fig. 2) Fig. 2(a) shows the clip 15 attached to the conductor 8, and Fig. 2(b) is an explanatory diagram of the configuration of the clip 15. The clip 15 has legs 15a, a housing 15b, and a holding portion 15c. The temperature sensor 12 is connected to a temperature sensor lead wire 12b covered by a temperature sensor glass tube 12a.

[0015] The clip 15 is attached so that the temperature sensor 12 contacts the conductor 8 while holding the temperature sensor 12. The temperature sensor 12 measures the temperature of the stator core 2 via the conductor 8. The temperature sensor 12 is held by the holding portion 15c on the side opposite to the side that contacts the conductor 8, and the side of the temperature sensor 12 is covered by the housing portion 15b. Because the clip 15 has this structure, the temperature sensor 12 can ensure positional stability with respect to the conductor 8.

[0016] Furthermore, since the legs 15a of the clip 15 are smaller in width, depth, and height than the housing 15b and the holding portion 15c when the conductor 8 is used as the reference, the space can be effectively utilized by engaging the legs 15a with the insulation distance 20 between the cover 5 (described later). This contributes to miniaturization.

[0017] (Fig. 3) Fig. 3(a) is a cross-sectional view showing the relationship between the temperature sensor 12 and the conductor 8, and Fig. 3(b) is an example of a different shape of the measured part 9 of Fig. 3(a). Note that only part of the leg 15a of the clip 15 is shown in the figure.

[0018] The clip 15 is attached to the conductor 8 by the legs 15a, and the temperature sensor 12 is fixed in contact with the conductor 8. The conductor 8 has a measurement target 9, which is the part whose temperature is measured by the temperature sensor 12. The measurement target 9 has a first surface 9a and a second surface 9b. The temperature sensor 12 is provided between the first surface 9a and one end surface 2a of the stator core 2.

[0019] The first surface 9a has a temperature sensor 12 attached thereto and is in contact with the temperature sensor 12. The first surface 9a also faces one end surface 2a of the stator core 2 in the axial direction. The second surface 9b is the surface of the measured part 9 opposite to the first surface 9a, and is fitted with a leg 15a of a clip 15.

[0020] During the shearing process, conductor 8 forms sagging and burrs at each corner of the cross section. Therefore, when viewed in cross section, measurement target 9 has burrs 9d at each corner on the first surface 9a side and sagging curved portions 9c at each corner on the second surface 9b side. When attaching clip 15 to measurement target 9, legs 15a move along the surface of measurement target 9 toward second surface 9b and are engaged by curved portions 9c, thereby securing clip 15. In this way, engagement of legs 15a with curved portions 9c facilitates the process of engaging clip 15. Furthermore, by not involving burrs 9d in the engagement of clip 15, contamination is suppressed and welding can be stabilized.

[0021] In addition, by making the burr 9d side the contact surface during welding when welding the clip 15, a large contact area can be secured between the measured part 9 and the clip 15, which promotes heat transfer between the conductors during welding and suppresses variation in the welding penetration depth.

[0022] This can also be achieved if a curved portion 9c is formed on one side of the first surface 9a of the measured portion 9 and a burr 9d on the other side. Similarly, this can also be achieved if a curved portion 9c is formed on one side of the second surface 9b of the measured portion 9 and a burr 9d on the other side. Even in this case, when engaging the clip 15, one leg 15a can be first hooked onto the burr 9d and then the other leg 15a can be engaged from the curved portion 9c, which makes it easier to attach the clip 15 to the measured portion 9 and also prevents contamination.

[0023] The conductor 8 may be formed by press-molding or by molding a rectangular wire. The drooping shape of the curved portion 9c of the conductor 8 may be formed only at one corner or only at a portion of the first surface 9a or the second surface 9b of the leg portion 15a.

[0024] (Fig. 4) In motor 100, rotor 3 is rotatably held via an air gap on the inner periphery of stator core 2. Rotor 3 has a rotor core fixed to shaft 4, a permanent magnet, and a non-magnetic backing plate. Motor 100 has a pair of end brackets provided with bearings 6, and shaft 4 is rotatably held by these bearings 6.

[0025] A resolver is provided on the shaft 4 to detect the pole positions and rotational speed of the rotor 3. The output from this resolver is input to a control circuit. Based on the input output information, the control circuit outputs a control signal to the drive circuit. The drive circuit outputs a drive signal based on the control signal to the power module. The power module performs switching operations based on the control signal and converts the DC power supplied from the battery into three-phase AC power. This three-phase AC power is supplied to the stator windings, and a rotating magnetic field is generated in the stator. The frequency of the three-phase AC current is controlled based on the output value of the resolver, and the phase of the three-phase AC current relative to the rotor 3 is also controlled based on the output value of the resolver.

[0026] The housing includes a first housing 13 and a second housing 14. The first housing 13 is for fixing the stator core 2 to the motor 100. The second housing 14 is for forming a refrigerant flow path 16 between the first housing 13 and the second housing 14.

[0027] The cover 5 is fixed to the first housing 13 and the second housing 14 by fasteners 10. Because there is a potential difference between the cover 5 and the clip 15 on the second surface 9b side (see FIG. 3), the measured part 9 faces the cover 5 with a spatial insulation distance 20 between them. The clip 15 is attached so that its legs 15a engage with the second surface 9b side, thereby reducing the amount by which the clip 15 protrudes toward the cover 5 while appropriately maintaining the spatial insulation distance 20, which contributes to miniaturization.

[0028] The conductor 8 is welded to the terminal of the coil 17 via the weld 7. The weld 7 is provided at a position opposite the installation position of the temperature sensor 12 in the axial direction with respect to the conductor 8, which contributes to miniaturization.

[0029] With this configuration, the temperature sensor 12 is positioned closer to the stator core 2, so the value measured by the temperature sensor 12 becomes closer to the true temperature of the stator core 2, thereby reducing measurement errors. Furthermore, the margin of temperature that should be taken into account in advance by control is reduced by the amount of error thus reduced, allowing for the application of even greater power, which contributes to improving the output of the motor 100.

[0030] (First Modification) (FIG. 5) The temperature sensor 12 may be attached to the measurement target 9 by other fasteners such as heat shrink tubing or adhesive, without using the clip 15. This reduces the number of parts.

[0031] (Second Modification) (FIG. 6) The measured part 9 is part of the conductor 8, but a part of the coil 17 may be extended and used as the measured part 9. This eliminates the need to provide a conductor 8 that is welded to the coil 17, which contributes to reducing the number of parts.

[0032] According to the embodiment of the present invention described above, the following advantageous effects are achieved.

[0033] (1) A stator for a rotating electric machine includes a stator core 2, a coil 17 inserted into the stator core 2, a conductor 8 welded to the coil 17, a temperature sensor 12 that measures the temperature of the stator core 2 via the conductor 8, and a clip 15 for attaching the temperature sensor 12 to the conductor 8. The conductor 8 includes a welded portion 7 welded to a terminal of the coil 17 and a measurement target 9 that is measured by the temperature sensor 12. The measurement target 9 includes a first surface 9a to which the temperature sensor 12 is attached and a second surface 9b opposite the first surface 9a. The clip 15 includes a leg 15a that engages with the second surface 9b and a retaining portion 15c that holds the temperature sensor 12 on the first surface 9a. The first surface 9a faces one end surface 2a of the stator core 2 in the axial direction, and the temperature sensor 12 is provided between the first surface 9a and the end surface 2a. By doing so, it is possible to provide a stator for a rotating electrical machine that realizes an improvement in the output of the motor 100.

[0034] (2) The welded portion 7 is provided on the opposite side of the conductor 8 in the axial direction from the installation position of the temperature sensor 12. This contributes to the miniaturization of the motor 100.

[0035] (3) When viewed in cross section, the measurement target 9 has curved portions 9c at each corner on the second surface 9b side, which helps prevent contamination and stabilize welding when the clip 15 is attached.

[0036] (4) The curved portion 9c is a drooping shape formed when shearing the conductor 8. This configuration can suppress contamination and stabilize welding when the clip 15 is assembled.

[0037] (5) The leg portion 15a is engaged with the curved portion 9c. This configuration can prevent contamination when the clip 15 is assembled and stabilize welding.

[0038] The present invention is not limited to the above-described embodiments, and various modifications and combinations of other configurations are possible without departing from the spirit of the present invention. Furthermore, the present invention is not limited to those having all of the configurations described in the above-described embodiments, and includes those in which some of the configurations are omitted.

[0039] 2 stator core 2a end face 3 rotor 4 shaft 5 cover 6 bearing 7 welded portion 8 conductor 9 measured portion 9a first surface 9b second surface 9c curved portion 9d burr 10 fastener 12 temperature sensor 12a temperature sensor glass tube 12b temperature sensor lead wire 13 first housing 14 second housing 15 clip 15a leg portion 15b housing portion 15c holding portion 16 refrigerant flow path 17 coil 18 connection plate 19 resin portion 20 spatial insulation distance 100 motor

Claims

1. A stator for a rotating electric machine comprising: a stator core; a coil inserted into the stator core; a conductor welded to the coil; a temperature sensor measuring the temperature of the stator core via the conductor; and a clip for attaching the temperature sensor to the conductor, wherein the conductor comprises a welded portion welded to a terminal of the coil and a measured part measured by the temperature sensor, the measured part having a first surface to which the temperature sensor is attached and a second surface opposite to the first surface, the clip comprises legs engaged on the second surface side and a holding portion for holding the temperature sensor on the first surface side, the first surface facing one end surface of the stator core in the axial direction, and the temperature sensor being provided between the first surface and the end surface.

2. A stator for a rotating electric machine according to claim 1, wherein the welded portion is provided on the opposite side of the conductor in the axial direction to a position where the temperature sensor is installed.

3. A stator for a rotating electric machine according to claim 1, wherein the part to be measured has curved parts at each corner on the second surface side when viewed in cross section.

4. A stator for a rotating electric machine according to claim 3, wherein the bent portion is a drooping shape formed when the conductor is sheared.

5. A stator for a rotating electric machine according to claim 3, wherein the leg portions are engaged with the curved portions.

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