Stators and rotating electric machines

Abstract

To provide a stator that ensures the insulation of the conductor while simultaneously allowing coolant to flow between the conductor and the slot, without the need for additional equipment. [Solution] A stator having a stator core with slots, a plurality of conductors inserted into the slots, and a coolant flow path formed in the stator core for allowing coolant to flow into the slots, wherein the stator has an insulating flow path forming member that is mounted in the slots together with the plurality of conductors, the flow path forming member is formed in a cylindrical shape that covers the outside of the plurality of conductors in the slots, and has a plurality of coolant flow grooves on its inner surface facing the plurality of conductors, through which coolant flowing in from the coolant flow path into the slots can flow.

Description

Technical Field

[0001] The present disclosure relates to a stator and a rotating electric machine.

Background Art

[0002] There is known a rotating electric machine including a stator in which insulating paper having a foam layer together with a plurality of conductors is inserted into slots. The insulating paper fixes the plurality of conductors in the slots by heat-expanding the foam layer. In this case, the expanded insulating paper may fill the gap between the conductor and the slot, making it impossible to circulate a coolant through the gap between the conductor and the slot.

[0003] Therefore, conventionally, there has been proposed a rotating electric machine having a stator in which a resin composition is filled together with a plurality of conductors in slots, and a cooling flow path is formed in the resin composition (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the structure of the conventional stator described above, after inserting a plurality of conductors into the slots, it is necessary to fill and mold a resin composition so as to form a cooling flow path between the slots and the conductors. Therefore, the man-hours for manufacturing the stator increase, and it is necessary to additionally equip facilities (such as an insert molding device) for filling and molding the resin composition into the slots, increasing the manufacturing cost, which is not economical.

[0006] Therefore, the present disclosure aims to provide a stator that can ensure the insulation of the conductor while simultaneously circulating a cooling liquid between the conductor and the slot, without the need for additional equipment, and a rotating electric machine equipped with the stator. [Means for solving the problem]

[0007] (1) A stator (for example, a stator 3, as described below) having a stator core (for example, a stator core 6, as described below) having a slot (for example, a slot 7, as described below), a plurality of conductors (for example, a conductor 8, as described below) inserted into the slot, and a coolant flow path (for example, a coolant flow path 12, as described below) formed in the stator core for allowing coolant to flow into the slot, wherein the stator has an insulating flow path forming member (for example, a flow path forming member 11, as described below) mounted in the slot together with the plurality of conductors, the flow path forming member is formed in a cylindrical shape that covers the outside of the plurality of conductors in the slot, and has a plurality of coolant flow grooves (for example, a first coolant flow groove 1111, a second coolant flow groove 1112, as described below) on its inner surface (for example, an inner surface 111a, as described below) facing the plurality of conductors, through which the coolant flowing from the coolant flow path into the slot can flow.

[0008] According to (1) above, by simply installing a cylindrical flow path forming member that covers the outside of multiple conductors together with the conductors in the slots of the stator core, it is possible to ensure the insulation of the conductors and at the same time form a stable flow path for the coolant between the conductors and the slots. As a result, the coolant can be smoothly circulated in the slots, and a stator with excellent cooling performance can be constructed. There is no need for additional equipment to fill and mold the material that forms the insulation and coolant flow path in the slots, and there is no need to secure the coolant flow path by crushing the conductors in the width direction in the slots, making it economically advantageous.

[0009] (2) In the stator described in (1) above, an adhesive sheet (for example, an adhesive sheet 40 described later) is provided on the outer surface of the flow path forming member (for example, the outer surface 110 described later) to adhere to the inner wall surface of the slot (for example, the inner wall surface 10 described later).

[0010] According to (2) above, since the flow path forming member can be fixed to the inner wall surface of the slot by an adhesive sheet, there is no risk of misalignment or looseness of the flow path forming member relative to the slot due to the operation of the rotating electric machine.

[0011] (3) In the stator described in (1) or (2) above, each of the plurality of conductors has a self-fusing coating layer (for example, the self-fusing coating layer 82 described later) on its outer surface, and the flow channel forming member and the plurality of conductors are bonded together by the self-fusing coating layer.

[0012] According to (3) above, since the multiple conductors and the flow path forming member are bonded together by the self-fusing coating layer of the conductors, there is no risk of misalignment or looseness occurring between the flow path forming member and the multiple conductors due to the operation of the rotating electric machine.

[0013] (4) In the stator described in any of (1) to (3) above, the flow channel forming member has an adhesive layer (for example, the adhesive layer 116 described later) on its inner surface that adheres the plurality of conductors by heat curing.

[0014] According to (4) above, since the multiple conductors and the flow path forming member are bonded together by the adhesive layer of the flow path forming member, even if the conductors do not have a self-fusing coating layer, there is no risk of misalignment or rattling occurring between the flow path forming member and the multiple conductors due to the operation of the rotating electric machine.

[0015] (5) In the stator described in any of (1) to (4) above, the flow path forming member is formed in a cylindrical shape by combining a pair of flow path forming member halves (for example, flow path forming member halves 11a, 11b) that are divided in the circumferential direction of the stator core.

[0016] According to (5) above, the outside of multiple conductors can be easily covered in a cylindrical shape simply by sandwiching multiple conductors between a pair of flow path forming member halves, thus providing excellent workability for assembly.

[0017] (6) In the stator according to any one of (1) to (5) above, an opening (for example, the opening 1113 described later) for communicating the plurality of coolant flow grooves and the coolant flow path of the stator core is provided on the side surface of the flow path forming member.

[0018] According to (6) above, the coolant can be circulated through the plurality of coolant flow grooves between the flow path forming member and the plurality of conductors through the opening.

[0019] (7) In the stator according to any one of (1) to (6) above, the flow path forming member is a resin molded product.

[0020] According to (7) above, the flow path forming member having a plurality of coolant flow grooves can be easily molded.

[0021] (8) A rotating electric machine (for example, the rotating electric machine 1 described later) including the stator according to any one of (1) to (7) above (for example, the stator 3 described later).

[0022] According to (8) above, a rotating electric machine including the stator having the above effects can be provided.

Advantages of the Invention

[0023] According to the present disclosure, a stator that can circulate coolant between a conductor and a slot while ensuring the insulation of the conductor without the need for additional equipment, and a rotating electric machine including the stator can be provided.

Brief Description of the Drawings

[0024] [Figure 1] It is a conceptual diagram of a coolant circulation mechanism in a rotating electric machine which is an example of the present disclosure. [Figure 2] It is a schematic diagram showing an example of a coolant flow path from a stator core to a conductor in the rotating electric machine of FIG. 1. [Figure 3] It is a perspective view showing a stator in a rotating electric machine which is an example of the present disclosure. [Figure 4]This is a cross-sectional view of a conductor used in the stator of a rotating electric machine. [Figure 5] Figure 3 is a perspective view showing a portion of one slot in the stator. [Figure 6] Figure 3 is a perspective view showing multiple conductors and flow path forming members inserted into the slots of the stator. [Figure 7] This figure shows the state in which multiple conductors and flow path forming members are inserted into the slots. [Figure 8] Figure 6 is a perspective view showing the multiple conductors and the flow path forming member in an exploded view. [Figure 9] Figure 6 is a perspective view showing half of the channel forming member. [Figure 10] This is a cross-sectional view along line AA in Figure 6. [Figure 11] This is a cross-sectional view along line BB in Figure 6. [Figure 12] This is a cross-sectional view along the CC line in Figure 6. [Figure 13] Figure 6 is a conceptual diagram showing the extracted flow path of the coolant, which is formed by the flow path forming member. [Figure 14] This is a cross-sectional view showing another embodiment of a channel forming member that accommodates multiple conductors. [Modes for carrying out the invention]

[0025] Figure 1 is a conceptual diagram of a coolant circulation mechanism in a rotating electric machine 1, which is an example of the present disclosure. In Figure 1, the rotating electric machine 1 is composed of a rotor 2 and a stator 3. The rotor 2 is formed in a cylindrical shape. The stator 3 is arranged around the rotor 2 with a predetermined gap. The stator 3 has a stator core 6 with an annular cross-section. The stator core 6 has a central shaft hole 61 that penetrates axially through its center.

[0026] A casing 4, which forms the outer shell of the rotating electric machine 1, is provided in contact with the outer circumference of the stator 3. A rotating shaft 5 passes through the rotor 2 at its center of rotation. The rotating shaft 5 is supported at both axial ends of the casing 4 by bearings (not shown).

[0027] As shown in Figure 3, the stator core 6 of the stator 3 has a plurality of slots 7 arranged at equal intervals in the circumferential direction. The slots 7 open to both axial end faces of the stator core 6. Each slot 7 may have a slit 71 that opens toward the central shaft hole 61 (see Figure 7). The slits 71 are formed along the axial direction of the stator core 6. A plurality of conductors 8 and a flow path forming member 11 are inserted into each of the plurality of slots 7 of the stator core 6.

[0028] The conductor 8 is a rectangular conductor (square conductor) with a rectangular cross-section. As shown in Figure 4, each conductor 8 is constructed with a self-fusing coating layer 82 on the surface of a square conductor body 81. The self-fusing coating layer 82 melts with heat, pre-bonding adjacent conductors 8,8 to each other before insertion into the slot 7. Multiple conductors 8 in each slot 7 are arranged in a single row along the radial direction of the stator core 6. Multiple conductors 8 in the slot 7 are electrically connected to form a coil 9 arranged on the stator core 6.

[0029] The rotating electric machine 1 generates heat due to copper and iron losses, but the stator core 6 and coils 9 are cooled by coolant circulating in a coolant flow path 12 formed in the stator 3 (described later). For example, ATF (automatic transmission fluid) can be used as the coolant. Coolant from a coolant reservoir 13 provided in the casing 4 is supplied to the suction side of the pump 15 through a filter 14. This coolant is cooled by heat exchange with the coolant flowing in the external coolant flow path 17 in a heat exchanger 16 provided on the delivery side of the pump 15, and is supplied to a coolant supply port 19 opening in the casing 4 through a coolant supply passage 18, and is supplied to the stator core 6 via a coolant flow path 20 inside the stator core that communicates with the coolant supply port 19. The coolant supplied to the stator core 6 flows through a path described later, cooling the conductors 8 in the stator core 6 and slots 7, and is recovered in the coolant reservoir 13, where it is recirculated repeatedly.

[0030] Figure 2 is a schematic diagram showing an example of a coolant flow path 12 from the stator core 6 to the conductor 8 in the slot 7 in the rotating electric machine 1 shown in Figure 1. Referring to Figure 2, the coolant flow path 12 is configured such that coolant flows from the casing 4 side of the stator 3 through the stator core coolant flow path 20 provided in the stator core 6, into the slot 7, and reaches the conductor 8.

[0031] In Figure 2, the coolant flow path 12 is configured such that the coolant supply port 19 of the casing 4 and the outer peripheral end of the slot 7 are connected by a stator core internal coolant flow path 20 provided within the stator core 6. In the coolant flow path 12 of Figure 2, the stator core internal coolant flow path 20 extends straight radially inward from the coolant supply port 19 of the casing 4 to the outer peripheral end of the slot 7 and flows into the flow path forming member 11, which will be described later. The coolant in the flow path forming member 11 flows radially inward (towards the central axis hole 61) of the stator core 6, and then flows along the longitudinal direction of the straight section of the conductor 8.

[0032] Next, the flow path forming member 11 will be described. As shown in Figures 5 and 6, the flow path forming member 11 is a member that forms a flow path for coolant between itself and the conductors 8 by being installed together with the conductors 8 in each of the multiple slots 7 formed in the stator core 6. The flow path forming member 11 has electrical insulating properties and functions as an insulator by being placed between the conductors 8 and the inner wall surface 10 of the slots 7 in place of conventional insulating paper.

[0033] The flow path forming member 11 is formed in a cylindrical shape that covers the outside of the straight sections of the multiple conductors 8 within the slot 7. More specifically, the flow path forming member 11 is formed in a rectangular cylindrical shape and is arranged to surround the entire circumference of all the conductors 8 within the slot 7. The cross-sectional shape of the rectangular cylindrical flow path forming member 11 when cut perpendicular to the axial direction of the stator core 6 is similar to the cross-sectional shape of the slot 7. Therefore, as shown in Figure 7, when the flow path forming member 11 is inserted into the slot 7 together with the multiple conductors 8, it is arranged to follow the inner wall surface 10 of the slot 7. Furthermore, the flow path forming member 11 has a length greater than or equal to the length of the slot 7 along the axial direction of the stator core 6. Both ends of the flow path forming member 11 in the longitudinal direction can be arranged to protrude from both end faces in the axial direction of the stator core 6.

[0034] As shown in Figure 8, the flow path forming member 11 is constructed in a rectangular tubular shape by combining a pair of flow path forming member halves 11a and 11b that are divided in the circumferential direction of the stator core 6. Each of the flow path forming member halves 11a and 11b is formed so as to be able to cover all the conductors 8 arranged in the slot 7 from one side and the other side in the circumferential direction of the stator core 6, along the radial direction of the stator core 6. The joining line JL of the pair of flow path forming member halves 11a and 11b is positioned along the extension direction of the conductors 8 in the slot 7.

[0035] Since the pair of flow path forming member halves 11a and 11b are substantially identical in structure except that they are formed symmetrically in the circumferential direction of the stator core 6, the configuration of the flow path forming member 11 (flow path forming member halves 11a and 11b) will be further explained with reference to the flow path forming member half 11a in Figure 9.

[0036] Each flow path forming member half 11a, 11b is integrally composed of a side plate portion 111, end plate portions 112, 113 formed at both ends of the side plate portion 111 in the width direction, and a flange portion 114.

[0037] The side plate portion 111 is sized to cover all the conductors 8 arranged in the slot 7 in the radial direction of the stator core 6. That is, the side plate portion 111 is sized to correspond to the depth of the slot 7 along the radial direction of the stator core 6. On the inner surface 111a of the side plate portion 111 facing the plurality of conductors 8 in the slot 7, a single first coolant flow groove 1111 and a plurality of second coolant flow grooves 1112 are formed.

[0038] The first coolant flow groove 1111 is located in the longitudinal center of the side plate portion 111 and extends wide in the width direction, i.e., in the radial direction of the stator core 6. The first coolant flow groove 1111 is formed from one end plate portion 112 to the other end plate portion 113.

[0039] The multiple second coolant flow grooves 1112 extend parallel to each other along the longitudinal direction of the side plate portion 111. The multiple second coolant flow grooves 1112 traverse the first coolant flow groove 1111 and are formed along the entire longitudinal length of the side plate portion 111. Both ends of the multiple second coolant flow grooves 1112 are open outward in the longitudinal direction of the flow path forming member 11.

[0040] As shown in Figures 7, 10, and 12, the second coolant flow grooves 1112 are positioned correspondingly between the conductors 8 arranged within the slot 7. In this embodiment, nine conductors 8 are arranged within the slot 7 along the radial direction of the stator core 6. Therefore, eight second coolant flow grooves 1112 are formed in the side plate portion 111, and are positioned correspondingly between adjacent conductors 8, 8. The inner surface 111a of the side plate portion 111 between adjacent second coolant flow grooves 1112, 1112 in the width direction of the side plate portion 111 abuts against each conductor 8. However, the number of conductors 8 inserted into the slot 7 is not limited to nine.

[0041] One end plate portion 112 is positioned on the radial outer circumference side of the stator core 6 in the flow path forming member 11 and is bent at approximately a right angle to the inner surface 111a side of the side plate portion 111. The end plate portion 112 has a rectangular cutout portion 112a that communicates with the first coolant flow groove 1111.

[0042] The other end plate portion 113 is positioned on the radially inner circumference side of the stator core 6 in the flow path forming member 11, and, like the end plate portion 112, is bent at approximately a right angle to the inner surface 111a side of the side plate portion 111. No opening is formed in the end plate portion 113, and it closes the end of the first coolant flow groove 1111 on the radially inner circumference side of the stator core 6.

[0043] The flange portion 114 is formed at one end in the longitudinal direction of the flow path forming member halves 11a and 11b. When the pair of flow path forming member halves 11a and 11b are assembled together to form the flow path forming member 11, the flange portion 114 forms a flange 115 at one end in the longitudinal direction, as shown in Figure 6, which surrounds the outer circumference of the multiple conductors 8 outside the slot 7.

[0044] The channel-forming member halves 11a and 11b are each molded from a resin material that has electrical insulating properties and self-shape-retaining properties. Specifically, the channel-forming member 11 is formed from a thermoplastic resin such as polyphenylene sulfide (PPS). Since the channel-forming member halves 11a and 11b can be easily integrally molded using resin material, the channel-forming member 11, which serves as an insulating member with a stable shape for the coolant flow path, can be easily manufactured.

[0045] A pair of flow path forming member halves 11a and 11b are assembled together so that their end plate portions 112 and 113 engage with each other, with a plurality of conductors 8 sandwiched between them. This forms a rectangular tubular flow path forming member 11. As shown in Figures 10 to 12, the plurality of conductors 8 are sandwiched in the circumferential direction of the stator core 6 by the inner surfaces 111a and 111a of the respective side plate portions 111 and 111 of the flow path forming member halves 11a and 11b. Between adjacent conductors 8, 8, a second coolant flow groove 1112 is arranged along the extension direction of the conductors 8.

[0046] The notches 112a, 112a of the end plate portions 112, 112 of the flow path forming member halves 11a, 11b are integrated to form a rectangular opening 1113. The opening 1113 connects the first coolant flow groove 1111 within the flow path forming member 11 with the coolant flow path 20 inside the stator core when the flow path forming member 11 is installed in the slot 7. This creates a coolant flow path 12 that reaches the conductor 8 from the coolant flow path 20 inside the stator core. As shown in Figure 13, the coolant that flows from the coolant flow path 20 inside the stator core into the opening 1113 flows through the first coolant flow groove 1111 towards the radially inward side of the stator core 6 (towards the central shaft hole 61), and then flows through the second coolant flow groove 1112 along the longitudinal direction of the straight section of the conductor 8.

[0047] The channel forming member 11 is a self-shaping rectangular tube, and as shown in Figure 6, it can maintain its rectangular tube shape while covering the outside of multiple conductors 8. Therefore, it offers excellent workability when installing the channel forming member 11 into the slot 7 together with the multiple conductors 8. Each of the multiple conductors 8 within the channel forming member 11 has a self-fusing coating layer 82 on its outer surface, and by heating, it adheres to the channel forming member 11 together with adjacent conductors 8, 8. Because the rectangular tube shape of the channel forming member 11 can be maintained more effectively, there is no risk of misalignment or rattling between the channel forming member 11 and the multiple conductors 8 due to the operation of the rotating electric machine 1. If it is necessary to temporarily fix the conductors 8 and the channel forming member 11 between the time the conductors 8 are sandwiched between the channel forming member 11 and the time they are fixed by heat bonding, heat-resistant adhesive tapes 30, 30 such as Kapton Tape (registered trademark) may be wrapped around both ends in the longitudinal direction to fix them.

[0048] As shown in Figure 6, an adhesive sheet 40 is wrapped around the outer surface 110 of the flow channel forming member 11 after the flow channel forming member halves 11a and 11b have been assembled. The adhesive sheet 40 is wrapped around the outer surface 110 of the flow channel forming member 11, excluding the areas where the adhesive tapes 30, 30 are wrapped. The adhesive sheet 40 is cut out in the area corresponding to the opening 1113 of the flow channel forming member 11, exposing the opening 1113.

[0049] When the flow path forming member 11 is installed in the slot 7, the adhesive sheet 40 is placed between the flow path forming member 11 and the inner wall surface 10 of the slot 7, as shown in Figure 7, and adheres the flow path forming member 11 to the inner wall surface 10. As a result, the flow path forming member 11 is fixed in the slot 7, so there is no risk of misalignment or rattling of the flow path forming member 11 relative to the slot 7 due to the operation of the rotating electric machine 1.

[0050] The adhesive sheet 40 may be a heat-expandable adhesive sheet that expands when heated. By using a heat-expandable adhesive sheet, it is possible to firmly hold the flow channel forming member 11 within the slot 7.

[0051] Figure 14 shows another embodiment of the flow channel forming member 11. This flow channel forming member 11 has an adhesive layer 116 on its inner surface 111a that adheres to a plurality of conductors 8 by heat curing. The adhesive layer 116 is provided on at least the surfaces that come into contact with the conductors 8 on the inner surfaces 111a, 111a of each of the flow channel forming member halves 11a, 11b. With this configuration, even if the conductors 8 do not have a self-fusing coating layer 82, there is no risk of misalignment or rattling occurring between the flow channel forming member 11 and the plurality of conductors 8 due to the operation of the rotating electric machine 1.

[0052] Thus, with the stator 3 and rotating electric machine 1 having the flow path forming member 11, by simply installing a cylindrical flow path forming member 11 that covers the outside of multiple conductors 8 together with the conductors 8 in the slot 7 of the stator core 6, it is possible to ensure the insulation of the conductors 8 and at the same time form a stable flow path for the coolant between the conductors 8 and the slot 7. Therefore, the coolant can be smoothly circulated in the slot 7, and a stator 3 and rotating electric machine 1 with excellent cooling performance can be constructed. There is no need for additional equipment to fill and mold the material that forms the insulation and coolant flow path in the slot 7, and there is no need to secure the coolant flow path by crushing the conductors 8 in the width direction in the slot 7, so it is economically advantageous.

[0053] In the embodiments described above, a pair of flow path forming member halves 11a and 11b are each formed with the same shape and number of first coolant flow grooves 1111 and second coolant flow grooves 1112, respectively. However, the shape and number of the first coolant flow grooves 1111 and second coolant flow grooves 1112 may differ between the pair of flow path forming member halves 11a and 11b. [Explanation of symbols]

[0054] 1 Rotating electric machine, 3 Stator, 6 Stator core, 7 Slot, 8 Conductor, 10 Inner wall surface, 11 Flow channel forming member, 11a, 11b Flow channel forming member halves, 12 Coolant flow channel, 40 Adhesive sheet, 82 Self-fusing coating layer, 110 Outer surface, 111a Inner surface, 1111 First coolant flow channel, 1112 Second coolant flow channel, 1113 Opening, 116 Adhesive layer

Claims

1. A stator core having slots, Multiple conductors inserted into the aforementioned slot, A stator having a coolant flow path formed in the stator core for allowing coolant to flow into the slot, It has an insulating channel forming member that is installed in the slot together with the plurality of conductors, A stator wherein the flow path forming member is formed in a cylindrical shape that covers the outside of the plurality of conductors within the slot, and has a plurality of coolant flow grooves on its inner surface facing the plurality of conductors through which the coolant flowing from the coolant flow path into the slot can flow, and has openings on the side surface of the flow path forming member that connect the plurality of coolant flow grooves to the coolant flow path of the stator core.

2. A stator core having slots, Multiple conductors inserted into the aforementioned slot, A stator having a coolant flow path formed in the stator core for allowing coolant to flow into the slot, It has an insulating channel forming member that is installed in the slot together with the plurality of conductors, The flow path forming member is a resin molded product, formed in a cylindrical shape that covers the outside of the plurality of conductors within the slot, and has a plurality of coolant flow grooves on its inner surface facing the plurality of conductors, through which the coolant flowing from the coolant flow path into the slot can flow, as a stator.

3. The stator according to claim 1 or 2, wherein an adhesive sheet is provided on the outer surface of the flow path forming member, which adheres to the inner wall surface of the slot.

4. Each of the aforementioned plurality of conductors has a self-fusing coating layer on its outer surface, The stator according to claim 1 or 2, wherein the flow channel forming member and the plurality of conductors are bonded together by the self-fusing coating layer.

5. The stator according to claim 1 or 2, wherein the flow channel forming member has an adhesive layer on its inner surface that adheres the plurality of conductors by heat curing.

6. The stator according to claim 1 or 2, wherein the flow channel forming member is formed in a cylindrical shape by combining a pair of flow channel forming member halves divided in the circumferential direction of the stator core.

7. The stator according to claim 2, wherein an opening is provided on the side surface of the flow path forming member that connects the plurality of coolant flow grooves with the coolant flow path of the stator core.

8. A rotating electric machine comprising a stator according to claim 1 or 2.

Images