JP2016165224A - Stator for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator for a rotary electric machine capable of securing a satisfactory insulation performance by preventing an insulation defect of a stator coil from being generated during processing and under a high temperature environment.SOLUTION: A stator 2 comprises: an annular stator core 22 including a plurality of slots 25 that are arrayed in a circumferential direction; and a stator coil 21 that is wound around the stator core 22. The stator coil 21 is formed from a conductor segment 23 including a slot housing part 23a and a coil end portion and generates heat by electrification. The conductor segment 23 includes a conductor part 23j and an insulation coating 23k of a double layer structure formed from an insulation layer 231k and a protective layer 232k covering an outer peripheral surface of the conductor part 23j. The protective layer 232k is formed from a material of which the Young's modulus is equal to or more than that of the insulation layer 231k at an ordinary temperature and the Young's modulus is lower than that of the insulation layer 231k under the high temperature environment.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a stator of a rotating electric machine that is mounted on a vehicle or the like and used as an electric motor or a generator.

  2. Description of the Related Art Conventionally, as a rotating electrical machine that is mounted and used in a vehicle, a rotor core that is rotatably provided, and a stator core that has a plurality of slots that are arranged to face the rotor in the radial direction and are arranged in the circumferential direction. And a stator having a stator winding wound around a slot of the stator core are generally known.

  As a stator winding wound around the stator core, for example, as disclosed in Patent Document 1, a segment configured by connecting ends of a plurality of conductor segments formed in a U shape A type of stator winding is known. In this stator winding, a pair of straight portions of each conductor segment is inserted into the slot from one side in the axial direction, and the open end portion extending from the slot to the other side in the axial direction is twisted in the circumferential direction so as to be inclined. Are formed by joining the ends of the oblique portions of the different conductor segments by welding or the like and wound around the stator core. In addition, the conductor segment is comprised by the conductor part and the insulating film which covers the outer peripheral surface of this conductor part.

Japanese Patent No. 4450125

  By the way, when the segment type stator winding as described above is wound around the stator core, the open end of the conductor segment extending from the slot to the other side in the axial direction is applied with a predetermined pressure (constant pressure). The skewed portion is formed by twisting to deform by twisting in the circumferential direction. At this time, since the conductor segment is in contact with the corner where the axial end surface of the stator core and the inner wall surface of the slot intersect, the insulation film covering the surface of the conductor segment is likely to be damaged or crushed. There is a risk of being connected.

  In addition, since the stator winding generates heat and becomes high temperature when energized, the insulating film covering the surface of each conductor segment thermally expands as the temperature rises. For this reason, the slot accommodating portion of the conductor segment accommodated in the slot of the stator core may cause damage to the insulating coating due to stress based on the difference between the thermal expansion coefficient of the insulating coating and the thermal expansion coefficient of the conductor portion or the stator core. Crushing is likely to occur. Therefore, in this case as well, there is a risk of causing insulation failure.

  The present invention has been made in view of the above circumstances, and prevents the occurrence of defective insulation of a stator winding during processing and in a high-temperature environment, so as to ensure good insulation performance. Providing a stator is a problem to be solved.

  The present invention, which has been made to solve the above problems, includes an annular stator core (22) having a plurality of slots (25) arranged in the circumferential direction, and a stator winding wound around the stator core. A wire segment (21), and the stator winding includes a conductor segment (23a) accommodated in the slot, and a coil end portion exposed to the outside in the axial direction from the slot ( 23), the conductor segment includes a conductor portion (23j), an insulating layer (231k) covering the outer peripheral surface of the conductor portion, and an outer peripheral surface of the insulating layer. An insulating film (23k) having a two-layer structure comprising a protective layer (232k) for covering, and the protective layer has a Young's modulus equal to or higher than that of the insulating layer at room temperature, and the stator winding High temperature due to heat generation The boundary under characterized in that the Young's modulus is formed at a lower material than the insulating layer.

  In the present invention, the normal temperature conforms to “normal temperature” defined by JIS, that is, “20 ° C. ± 15 ° C. (5 ° C. to 35 ° C.)”. The high temperature environment refers to an environment in which the rotating electrical machine is activated and the stator winding is heated due to heat generation. The high temperature environment in the present invention varies depending on the specifications of the rotating electrical machine and the stator, and is about 160 ° C to 200 ° C.

  According to the present invention, the conductor segment includes a conductor portion, and an insulating film having a two-layer structure including an insulating layer that covers the outer peripheral surface of the conductor portion and a protective layer that covers the outer peripheral surface of the insulating layer. Is formed of a material having a Young's modulus equal to or higher than that of the insulating layer at room temperature and lower than that of the insulating layer in a high-temperature environment.

  That is, under a normal temperature environment, the Young's modulus of the protective layer of the insulating film is made equal to or higher than that of the insulating layer. Therefore, even if the conductor segment contacts the corner where the axial end surface of the stator core and the inner wall surface of the slot meet during processing, the biting of the corner is stopped by the protective layer with a high Young's modulus, and the insulation layer is reached. It is blocked from reaching. As a result, it is possible to avoid the occurrence of damage and crushing of the insulating layer and more reliably prevent the occurrence of insulation failure.

  Further, the Young's modulus of the protective layer of the insulating film is made lower than that of the insulating layer under a high temperature environment accompanying the heat generation of the stator winding. Therefore, due to thermal expansion of the insulation film or conductor, the insulation film is crushed between the conductor and the stator core in the slot, and the protective layer is crushed against the stress caused by sizing deformation that deforms to a predetermined dimension. Can escape. Thereby, it is possible to avoid the occurrence of damage or crushing of the insulating layer and to prevent the occurrence of insulation failure. Therefore, according to the present invention, it is possible to prevent the occurrence of insulation failure of the stator winding during processing and in a high temperature environment, and to ensure good insulation performance.

  In addition, the code | symbol in the parenthesis after each member and site | part described in this column and the claim shows the correspondence with the specific member and site | part described in embodiment mentioned later.

FIG. 3 is an axial sectional view of the rotating electrical machine according to the first embodiment. 1 is an overall perspective view of a stator according to Embodiment 1. FIG. 2 is a cross-sectional view of a conductor segment used in Embodiment 1. FIG. FIG. 6 is an explanatory diagram showing a state where conductor segments are inserted into slots of the stator core in the first embodiment. It is a graph which shows the relationship between a Young's modulus and environmental temperature regarding the insulating layer and protective layer which comprise an insulating film. 6 is a cross-sectional view of a conductor segment according to Comparative Example 1. FIG. 10 is a cross-sectional view of a conductor segment according to Comparative Example 2. FIG. (A) It is explanatory drawing which shows the state of the conductor segment just before a twist process is performed in Embodiment 1, (b) It is explanatory drawing which shows the state of the conductor segment immediately after a twist process in Embodiment 1. is there. (A) It is explanatory drawing which shows the shape change in FIG. 8 (b) A part of the conductor segment just before a twist process is performed in Embodiment 1, (b) Immediately after the twist process is performed in Embodiment 1. It is explanatory drawing which shows the shape change in FIG.8 (b) A part of a conductor segment. 2 is a schematic perspective view of a conductor segment used in Embodiment 1. FIG. FIG. 3 is a partial cross-sectional view of the stator according to the first embodiment. FIG. 3 is a perspective view showing a part of a joining side end portion of the stator according to the first embodiment. FIG. 3 is a partial cross-sectional view of a stator for explaining slots of a stator core in which conductor segments are accommodated in the first embodiment.

  Hereinafter, embodiments of a rotating electrical machine according to the present invention will be specifically described with reference to the drawings.

Embodiment 1
A rotating electrical machine 1 according to this embodiment is used as an automotive alternator, and as shown in FIG. 1, a stator 2 that works as an armature, a rotor 3 that works as a field, and a stator. 2 and the rotor 3, and a front housing 4a and a rear housing 4b connected and fixed by fastening bolts 4c, a rectifier 5 for converting AC power into DC power, and the like.

  As shown in FIG. 2, the stator 2 includes a stator core 22, a segment-type stator winding 21 composed of a plurality of conductor segments 23, and an electrical connection between the stator core 22 and the stator winding 21. And an insulating sheet member 24 for insulation. The stator 2 is fixed by being sandwiched between the front housing 4a and the rear housing 4b, and is disposed on the outer peripheral side of the rotor 3 via a predetermined air gap G (see FIG. 11). The detailed structure of the stator 2 will be described later.

  As shown in FIG. 1, the rotor 3 rotates integrally with a shaft 33 rotatably supported by the front housing 4 a and the rear housing 4 b, and includes a Landel pole core 32, a field winding 31, and the like. It has. A pulley 20 connected to a traveling engine (not shown) mounted on the automobile via a belt (not shown) or the like is fixed to the front end portion of the shaft 33.

  The Landell-type pole core 32 is configured by combining a pair of pole cores 32a and 32b on the front side and the rear side. Each of the pole cores 32a and 32b has six claw-shaped magnetic pole portions 32c, and sandwiches a field winding 31 formed by winding an insulated copper wire in a cylindrical and concentric manner from both front and rear sides. As shown in FIG. In the present embodiment, the pole cores 32 a and 32 b each have eight magnetic poles, that is, form a 16-pole rotor 3.

  Suction holes 42a and 42b are provided in the axial end face (front end face) of the front housing 4a and the axial end face (rear end face) of the rear housing 4b, respectively. A mixed flow fan 35 for discharging the cooling air sucked from the front suction hole 42a in the axial direction and the radial direction is fixed to the front end surface of the front pole core 32a by welding or the like. Similarly, a centrifugal fan 36 for discharging the cooling air sucked from the rear suction hole 42b in the radial direction is fixed to the rear end face of the rear pole core 32b by welding or the like. The front housing 4a and the rear housing 4b are respectively provided with cooling air discharge holes 41 at portions facing the coil end portions of the stator winding 21 protruding from both axial ends of the stator core 22.

  Slip rings 37 and 38 that are electrically connected to both ends of the field winding 31 are formed at the rear end of the shaft 33, and the field device passes from the brush device 7 via these slip rings 37 and 38. Electric power is supplied to the winding 31.

  In the vehicular AC generator 1 having the above-described configuration, when the rotational force from the engine is transmitted to the pulley 20 via a belt or the like, the rotor 3 rotates in a predetermined direction together with the shaft 33. In this state, by applying an excitation voltage from the brush device 7 to the field winding 31 of the rotor 3 through the slip rings 37 and 38, the claw-shaped magnetic pole portions 32c of the pole cores 32a and 32b are excited. NS magnetic poles are alternately formed along the circumferential direction of the rotor 3. As a result, a three-phase AC voltage can be generated in the stator winding 21, and a predetermined DC current can be extracted from the output terminal of the rectifier 5.

  Next, details of the stator 2 will be described with reference to FIGS. The stator core 22 is formed by laminating a plurality of annular electromagnetic steel plates in the axial direction. The stator core 22 includes an annular back core portion 22a constituting an outer peripheral portion, and a plurality of teeth portions 22b protruding radially inward from the back core portion 22a and arranged at a predetermined distance in the circumferential direction. Have. Between the two adjacent tooth portions 22b of the stator core 22, a slot 25 penetrating in the axial direction is formed so that the multiphase stator winding 21 can be accommodated. In the present embodiment, 96 slots 25 are arranged at equal intervals in the circumferential direction so as to accommodate two sets of three-phase stator windings 21 corresponding to the number of magnetic poles 16 of the rotor 3. .

  The stator winding 21 provided in the slot 25 of the stator core 22 is composed of a plurality of U-shaped conductor segments 23 in which joining end portions 23f (see FIG. 5) are joined to each other. As shown in FIG. 3, the conductor segment 23 has a rectangular cross section composed of a conductor portion 23j made of a conductive metal material such as copper and an insulating film 23k having a two-layer structure covering the outer peripheral surface of the conductor portion 23j. It is formed with a square line. Note that the bonding end 23f is in a state where the insulating film 23k is peeled off and the internal conductor 23j is exposed, and after predetermined bonding ends 23f of different conductor segments 23 are bonded to each other, the insulation treatment is performed. It has been subjected.

  The insulating film 23k includes an insulating layer 231k as an inner layer covering the outer peripheral surface of the conductor portion 23j having a rectangular cross section, and a protective layer 232k as an outer layer covering the outer peripheral surface of the insulating layer 231k. The insulating layer 231k is enamel and has a thickness of about 30 μm. The protective layer 232k is made of a resin such as polyether ether ketone (PEEK) and has a thickness of about 100 μm. The protective layer 232k is formed of a material having a Young's modulus equal to or higher than that of the insulating layer 231k at room temperature and lower than that of the insulating layer 231k in a high temperature environment.

  The thickness of the protective layer 232k is such that the open end portion extending from the slot 25 to the outside in the axial direction is twisted in the circumferential direction to form the skewed portion 23e (hereinafter also referred to as “twisting”). It is set to be larger than the thickness reduction amount of the insulating film 23k that decreases. This prevents the insulation layer 231k from being broken and causing an insulation failure of the stator winding 21 during twisting. The thickness of the protective layer 232k is set to be larger than the thickness reduction amount of the insulating film 23k in the high temperature environment of the slot accommodating portion 23a accommodated in the slot 25 of the conductor segment 23. As a result, in a high-temperature environment, the protective layer 232k is crushed during thermal expansion of the insulating film 23k, thereby releasing the stress and avoiding the occurrence of damage and crushing of the insulating layer 231k and preventing the occurrence of insulation failure. ing.

  As shown in FIG. 5, the PEEK used for the protective layer 232k in this embodiment has a Young's modulus higher than that of the insulating layer 231k in a region including normal temperature (120 ° C. or lower), and in a high temperature environment (160 ° C. or higher). ) Has a characteristic that Young's modulus is lower than that of the insulating layer 231k. Note that the Young's modulus of the enamel constituting the insulating layer 231k gradually decreases gradually as the temperature increases, and there is no temperature band that changes as rapidly as the Young's modulus of PEEK.

  The conductor segment according to Comparative Example 1 shown in FIG. 6 includes a conductor portion 23m made of copper, an insulating layer 231n that covers the outer peripheral surface of the conductor portion 23m, and a protective layer 232n that covers the outer peripheral surface of the insulating layer 231n. And an insulating film 23n having a layer structure. In this case, the insulating layer 231n is formed with the same enamel as in the first embodiment to a thickness of about 30 μm, and the protective layer 232n is formed of polyphenylene sulfide resin (PPS) to a thickness of about 100 μm. As shown in FIG. 5, the PPS used for the protective layer 232n in Comparative Example 1 always has a characteristic that the Young's modulus is lower than that of the insulating layer 231n from a normal temperature environment to a high temperature environment of 200 ° C. or higher. In this respect, the protective layer 232k of the present invention and the protective layer 232n of Comparative Example 1 are significantly different.

  Moreover, the conductor segment according to Comparative Example 2 shown in FIG. 7 is a conventional example, and includes a conductor part 23p made of copper and an insulating film 23q having a single layer structure covering the outer peripheral surface of the conductor part 23p. . The insulating film 23q is formed with the same enamel as in the first embodiment to a thickness of about 80 μm.

  As shown in FIG. 4, the conductor segment 23 is formed in a U-shape having a pair of straight portions 23g and 23g and a turn portion 23h connecting one end portions of the respective straight portions 23g and 23g. Yes. The conductor segment 23 extends from the slot 25 to the outside on the other side in the axial direction after the pair of straight portions 23g, 23g are inserted into the two slots 25 separated by a predetermined slot pitch from the one side in the axial direction. The open ends of the straight portions 23g and 23g are twisted so as to be obliquely inclined at a predetermined angle toward one side in the circumferential direction. This twisting process is performed in a room temperature environment.

  That is, when the twisting process is performed on the open ends of the straight portions 23g and 23g, as shown in FIGS. 8A and 8B and FIGS. 9A and 9B, the stator core 22 is provided. The conductor segments 23 come into contact with the corners where the axial end surfaces of the slots and the inner wall surfaces of the slots 25 intersect, and the corners are in a state of biting into the insulating film 23k (see section A in FIG. 8B and FIG. 9). See b). At this time, the conductor segment 23 has a Young's modulus of the protective layer 232k of the insulating film 23k higher than that of the insulating layer 231k at normal temperature, and the thickness of the protective layer 232k is obtained by twisting applied to the open end. Since the thickness reduction amount of the insulating film 23k that decreases when the inclined portion 23e is formed, the biting of the corner portion is stopped by the protective layer 232k having a high Young's modulus. As a result, the biting of the corners does not reach the insulating layer 231k, so that the insulating layer 231k is prevented from being damaged or crushed, and the occurrence of insulation failure is prevented.

  Thereby, as shown in FIG. 10, the conductor segment 23 is accommodated in the slot 25 and extends in a straight line along the axial direction, and the pair of slot accommodating portions 23a and 23a are exposed in the axial direction from the slot 25 and are circumferentially exposed. And a coil end portion extending to the surface. The coil end portion is integrally provided so as to connect one end of each of the slot accommodating portions 23a, 23a, and is one end side in the axial direction of the slot 25 (the rear side of the vehicle alternator 1 is the right side in FIG. 1). Similarly, a turn-side end portion 23b protruding from the other end of each slot accommodating portion 23a, 23a and the other end in the axial direction of the slot 25 (on the front side of the vehicle alternator 1 in FIG. It is comprised from a pair of joining side end parts 23c and 23c which protrude from the left side.

  The turn-side end portion 23b has a substantially V-shaped turn portion 23h formed by bending deformation at the tip thereof. On the other hand, the joining end portion 23c is twisted in the circumferential direction and obliquely skews at a predetermined angle with respect to the axial end surface of the stator core 22, and is bent at the tip of the skewed portion 23e. And a joining end portion 23f formed integrally by deformation.

  Each slot 25 of the stator core 22 accommodates an even number (four in this embodiment) of electrical conductors (slot accommodating portions 23a of the conductor segments 23). As shown in FIG. 11, the four electric conductors accommodated in one slot 25 are arranged in a line along the radial direction from the inner side to the inner end layer, the inner middle layer, the outer middle layer, and the outer end layer. ing. The stator windings 21 are formed by connecting the electrical conductors accommodated in the slots 25 in a predetermined pattern. The four electric conductors accommodated in one slot 25 form an in-phase stator winding 21.

  The electrical conductor in the slot 25 is electrically connected to the turn-side end portion 23b on one end side in the axial direction via the turn portion 23h. Thus, a first coil end group 21a is formed on one end side in the axial direction of the stator core 22 by a large number of turn portions 23h protruding from the slot 25 (see FIG. 2). Moreover, in the joining side end part 23c of the axial direction other end side, the joining end parts 23f are electrically connected by joining by arc welding. Thus, a second coil end group 21b is formed on the other axial end side of the stator core 22 by a large number of joining side end portions 23c protruding from the slot 25 (see FIGS. 2 and 12).

  One electrical conductor in each slot 25 is paired with one other electrical conductor in another slot 25 that is a predetermined magnetic pole pitch apart. For example, as shown in FIG. 13, the electric conductor 231 a in the inner end layer accommodated in one slot 25 is another magnetic pole pitch (NS magnetic pole pitch) separated in the clockwise direction of the stator core 22. It is paired with the electric conductor 231b of the outer end layer in the slot 25. Similarly, the inner and middle layer electric conductors 232a accommodated in one slot 25 are paired with the outer and middle layer electric conductors 232b in the other slots 25 spaced by one magnetic pole pitch in the clockwise direction of the stator core 22. I am doing.

  Then, in the turn-side end portion 23b on one end side in the axial direction of the stator core 22, the paired electric conductors, that is, the inner end layer electric conductor 231a and the outer end layer electric conductor 231b, are connected to the turn portion 23h. The connection is established via (231c). Further, the inner middle layer electric conductor 232a and the outer middle layer electric conductor 232b are connected via the turn part 23h (232c).

  That is, at the turn-side end portion 23 b on one end side in the axial direction of the stator core 22, the inner end layer electric conductor 231 a and the inner middle layer electric conductor 232 a housed in one slot 25 are fixed from the slot 25. It extends toward the clockwise direction of the child core 22. Further, the outer end layer electric conductor 231b and the outer middle layer electric conductor 232b accommodated in one slot 25 extend from the slot 25 in the counterclockwise direction of the stator core 22.

  On the other hand, the inner and middle layer electric conductors 232a accommodated in one slot 25 are also connected to the inner end layer electric conductors 231a ′ in the other slots 25 which are separated by one magnetic pole pitch in the clockwise direction of the stator core 22. Paired. Similarly, the outer-layer electric conductor 231b ′ accommodated in one slot 25 is connected to the outer middle-layer electric conductor 232b in the other slot 25 which is one magnetic pole pitch away in the clockwise direction of the stator core 22. They are also paired together.

  The pair of electric conductors, that is, the inner and middle layer electric conductors 232a and the inner end layer electric conductor 231a ′, are joined at the bonding end 23c on the other axial end side of the stator core 22. The portions 23f are connected to each other (232d and 231d ′) (see FIG. 10). Further, the outer end layer electric conductor 231b 'and the outer middle layer electric conductor 232b are connected to each other by bonding of the bonding end portions 23f (231e' and 232e) (see FIG. 10).

  That is, at the turn-side end portion 23 b on one end side in the axial direction of the stator core 22, the inner end layer electric conductor 231 a and the outer middle layer electric conductor 232 b housed in one slot 25 are fixed from the slot 25. The child core 22 extends in the counterclockwise direction. Further, the inner and middle layer electric conductors 232b and the outer end layer electric conductors 231b accommodated in one slot 25 extend from the slot 25 in the clockwise direction of the stator core 22.

  Furthermore, as shown in FIG. 4, the inner end layer electric conductor 231a and the outer end layer electric conductor 231b are provided by a large segment 231 formed by forming a series of conductors into a U shape. Then, the inner middle layer electric conductor 232a and the outer middle layer electric conductor 232b are provided by a small segment 232 formed by forming a series of conductors into a U shape. The basic U-shaped conductor segment 23 includes a large segment 231 and a small segment 232.

  The above configuration is repeated for the conductor segments 23 that are the basis of all the slots 25. For each phase of the stator winding 21, a winding (coil) that makes two rounds around the stator core 22 is formed by the basic conductor segment 23. However, for each phase of the stator winding 21, a segment having an output lead wire and a neutral lead wire integrally and a segment having a turn portion 23h connecting the first and second turns are basically The conductor segment 23 is a different shaped segment. Using these deformed segments, the winding ends of each phase of the stator winding 21 are connected by star connection.

  Thus, among the skewed portions 23e of the conductor segments 23 formed on the other end side in the axial direction from the slots 25, the joining end portions 23f (terminals) of the predetermined skewed portions 23e are joined by welding or the like. As a result, the plurality of conductor segments 23 are connected in a predetermined state. As a result, a three-phase stator winding 21 wound around the slot 25 of the stator core 22 is formed. Thereafter, the plurality of electrical conductors (slot accommodating portions 23a of each conductor segment 23) and the insulating sheet member 24 accommodated in each slot 25 are attached to the stator core 22 by a varnish (adhesive member) dropped into the slot 25. Fixed.

  According to the stator 2 of the present embodiment configured as described above, the conductor segment 23 includes the conductor portion 23j and the insulating film 23k having a two-layer structure including the insulating layer 231k and the protective layer 232k. The Young's modulus of the layer 232k is set to be higher than that of the insulating layer 231k at room temperature. Therefore, when the open end of the conductor segment 23 extending from the slot 25 to the other side in the axial direction is twisted in a room temperature environment, the angle at which the axial end surface of the stator core 22 and the inner wall surface of the slot 25 intersect. Even if the conductor segment 23 comes into contact with the portion, the biting of the corner portion is stopped by the protective layer 232k having a high Young's modulus, so that it does not reach the insulating layer 231k. Thereby, it is possible to prevent the insulation layer 231k from being damaged or crushed and to prevent the occurrence of insulation failure.

  Further, the Young's modulus of the protective layer 232k of the insulating film 23k is set to be lower than that of the insulating layer 231k in a high temperature environment accompanying the heat generation of the stator winding 21 by energization of the stator winding 21. Therefore, due to thermal expansion of the insulating film 23k and the conductor part 23j, the insulating film 23k is compressed between the conductor part 23j and the stator core 22 in the slot 25, and is subjected to stress due to sizing deformation that deforms to a predetermined dimension. The stress applied to the insulating layer 231k can be released when the protective layer 232k is crushed. Thereby, it is possible to avoid the occurrence of damage and crushing of the insulating layer 231k and to prevent the occurrence of insulation failure.

  In the present embodiment, the thickness of the protective layer 232k is reduced when the open end portion is twisted in the circumferential direction to form the skewed portion 23e (when twisting is performed). It is set to be larger than the reduction amount. As a result, it is possible to more reliably prevent the occurrence of poor insulation of the stator winding 21 during twisting. Further, the thickness of the protective layer 232k is set to be larger than the thickness reduction amount of the insulating film 23k in the high temperature environment of the slot accommodating portion 23a accommodated in the slot 25 of the conductor segment 23. As a result, it is possible to more reliably prevent the occurrence of poor insulation of the stator winding 21 in a high temperature environment.

  Therefore, according to the stator 2 of the rotating electrical machine of the present embodiment, it is possible to prevent the occurrence of poor insulation of the stator winding 21 during twisting or in a high temperature environment, and ensure good insulation performance.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, in Embodiment 1 described above, the U-shaped conductor segment 23 constituting the stator winding 21 is employed. However, for example, an I-shaped conductor segment may be employed. it can. When this I-shaped conductor segment is adopted, the skewed portion 23e is formed by performing twisting on both sides in the axial direction of the stator core 22, so that the stator winding 21 at the time of twisting is formed. It is possible to more effectively prevent the occurrence of poor insulation and secure good insulation performance.

  In the first embodiment, the example in which the stator of the rotating electrical machine according to the present invention is applied to an AC generator for a vehicle has been described. However, the present invention can be applied to a generator or a rotating electrical machine mounted on a vehicle. The present invention can also be applied to an electric motor, and further to a rotating electric machine that can selectively use both.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle alternator (rotary electric machine), 2 ... Stator, 3 ... Rotor, 21 ... Stator winding, 22 ... Stator core, 23 ... Conductor segment, 23a ... Slot accommodating part, 23e ... Skew Part, 23j ... conductor part, 23k ... insulating film, 231k ... insulating layer, 232k ... protective layer, 25 ... slot.

Claims (5)

An annular stator core (22) having a plurality of slots (25) arranged in the circumferential direction, and a stator winding (21) wound around the stator core, the stator winding The wire is composed of a conductor segment (23) having a slot accommodating portion (23a) accommodated in the slot and a coil end portion exposed to the outside in the axial direction from the slot, and the wire of the rotating electrical machine that generates heat when energized. In the stator,
The conductor segment comprises a conductor portion (23j), an insulating layer (231k) that covers the outer peripheral surface of the conductor portion, and a protective layer (232k) that covers the outer peripheral surface of the insulating layer. And having
The protective layer is formed of a material whose Young's modulus is equal to or higher than that of the insulating layer at room temperature and whose Young's modulus is lower than that of the insulating layer in a high temperature environment due to heat generation of the stator winding. Stator for rotating electric machine.   The stator for a rotating electrical machine according to claim 1, further comprising an insulating sheet member (24) housed in the slot and electrically insulating between the stator core and the stator winding.   The stator of a rotating electrical machine according to claim 1, wherein the slot housing portion is fixed to the stator core by an adhesive member. The insulating layer is formed of enamel;
The stator for a rotating electrical machine according to any one of claims 1 to 3, wherein the protective layer is formed of polyetheretherketone.   The stator of the rotating electrical machine according to any one of claims 1 to 4, wherein the conductor portion is formed in a rectangular cross section.

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