stata

Abstract

To improve the productivity of the stator. [Solution] The stator comprises a stator core, a first terminal and a second terminal, and a coil attached to the stator core and connecting the first terminal and the second terminal. The coil is constructed by arranging multiple groups of segment coils, each consisting of multiple U-shaped segment coils arranged along the circumference of the stator core, in a concentric pattern. It comprises a first coil end portion from which multiple curved portions protrude from one end face on the axial side of the stator core, and a second coil end portion from which the tips of multiple lead portions protrude from the other end face on the axial side. The second coil end portion is a joint where the tips of different segment coils are twisted and joined together, comprising a first joint portion that joins the tips of segment coils belonging to a common group of segment coils, and a second joint portion that joins the tips of segment coils belonging to different groups of segment coils.

Description

Technical Field

[0001] The technology disclosed in this specification relates to a stator including a stator core and a coil attached to the stator core.

Background Art

[0002] As a coil for forming a stator, it is known to use a segment coil. Patent Document 1 discloses a U-shaped segment coil having a curved portion and a straight portion. Further, Patent Document 2 discloses arranging a plurality of segment coils in an annular shape by an annular alignment method.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since a plurality of segment coils arranged in an annular shape can be inserted into each slot of the stator core from one side in the axial direction of the stator core at once, the process from the arrangement of the segment coils to the insertion is speeded up. On the other hand, in order to connect the coils together, it is necessary to insert a part of a segment coil having a special orientation or bending method so as to straddle between a group of segment coils composed of a plurality of segment coils arranged in an annular shape.

[0005] When such special segment coils exist, the aforementioned method of inserting a group of segment coils arranged in a ring shape as a whole cannot be used. In other words, the overall complexity of the segment coil assembly and insertion order leads to challenges such as increased complexity of production equipment and decreased productivity, requiring the use of multi-axis robots to insert the special segment coils. [Means for solving the problem]

[0006] This specification discloses a stator comprising: a cylindrical stator core having a plurality of teeth protruding radially inward; first terminals and second terminals for connecting power lines or neutral lines; and a coil attached to the plurality of teeth by inserting lead portions into each slot, which is the gap between the teeth, and connecting the first terminal and the second terminal. The coil is constructed by arranging a plurality of segment coil groups concentrically, each segment coil having two lead portions and a curved portion connecting the two lead portions, arranged along the circumferential direction of the stator core. The coil comprises a first coil end portion from which a plurality of the curved portions protrude from one end face in the axial direction of the stator core; and a second coil end portion from which the tips of a plurality of the lead portions protrude from the other end face in the axial direction of the stator core. The second coil end portion is a joint portion formed by joining the respective tip portions of different segment coils in a twisted state, comprising a first joint portion that joins the tip portions of segment coils belonging to a common group of segment coils, and a second joint portion that joins the tip portions of segment coils belonging to different groups of segment coils.

[0007] According to the above configuration, on one end face in the axial direction of the stator core, multiple independent segment coil groups are arranged concentrically, with each lead portion inserted into each slot of the stator core, resulting in only the curved portions protruding. On the other end face in the axial direction of the stator core, the tips of the protruding lead portions are twisted and joined to the tips of other segment coils. The joining portion includes not only a first joining portion but also a second joining portion, connecting the segment coil groups and realizing the necessary paths for the coils. Therefore, it can be said that the above-mentioned high speed and improved productivity are achieved. [Brief explanation of the drawing]

[0008] [Figure 1] A simplified perspective view showing the structure of the stator. [Figure 2] A simplified diagram of a segment coil. [Figure 3] A simplified diagram showing the segment coil group from the curved section side. [Figure 4] A perspective view showing a magnified view of the second end face and a portion of the second coil end. [Figure 5] A diagram showing an example of a coil path diagram. [Figure 6] A diagram showing another example of a route table. [Figure 7] Disassembled perspective view of the motor. [Figure 8] A partial cross-sectional view of the motor. [Figure 9] A partial cross-sectional view of the stator, including a cross-section of the second coil end. [Modes for carrying out the invention]

[0009] This embodiment will be described with reference to the drawings. Each figure is for illustrative purposes only, and this embodiment is not limited to what is shown. Also, since each figure is illustrative, some parts may be omitted.

[0010] 1. First Embodiment Figure 1 shows a simplified perspective view of the stator 10. The stator 10 comprises a stator core 11 and a coil 12. The stator 10 is a component of a motor driven by electric power. The concept of a motor includes various types of motors, such as DC (direct current) motors, AC (alternating current) motors, stepping motors, and servo motors.

[0011] The specific configuration and material of the stator core 11 are not particularly limited. For example, the stator core 11 is generally cylindrical and is constructed by laminating multiple silicon steel plates. Hereinafter, the radial direction, circumferential direction, and axial direction of the stator core 11 will be simply referred to as the radial direction, circumferential direction, and axial direction, respectively. The axial direction is the direction parallel to the axis Ax of the stator core 11. On the inner circumference of the stator core 11, multiple teeth portions 13 are projected toward the radially inner circumference. The multiple teeth portions 13 are arranged along the circumferential direction. Each gap between adjacent teeth portions 13 in the circumferential direction is called a slot 14. All of the multiple slots 14 open to the inner circumferential surface and both end faces facing the axial direction of the stator core 11. One end face of the stator core 11 in the axial direction is called the first end face 15, and the other end face of the stator core 11 in the axial direction is called the second end face 16.

[0012] According to Figure 1, the stator 10 has multiple terminals 30 for connecting power lines or neutral lines. Each of these terminals 30 corresponds to either a "first terminal" or a "second terminal". The coil 12 is attached to multiple toothed sections 13 by inserting lead portions into each slot 14 of the stator core 11. It can also be said that the coil 12 is wound around the multiple toothed sections 13 and extends along the circumference. The coil 12 connects a pair of first and second terminals. For example, the stator core 11 has three coils 12 attached, corresponding to the U-phase, V-phase, and W-phase. The U-phase coil 12 connects the first and second terminals corresponding to the U-phase.

[0013] Similarly, the V-phase coil 12 connects the first and second terminals corresponding to the V-phase, and the W-phase coil 12 connects the first and second terminals corresponding to the W-phase. Power lines (not shown) are connected to the first and second terminals from outside the stator 10. The power lines are electrically connected to an inverter (not shown) and form a path for supplying current to the coils 12. The three coils 12 generate a rotating magnetic field in the stator core 11 when a three-phase alternating current is supplied. Depending on the motor configuration, a so-called neutral wire may also be connected to either the first or second terminal. The first and second terminals may also be considered as part of the coil 12.

[0014] Figure 2 shows a simplified representation of a segment coil 20, which is a unit constituting the coil 12. The segment coil 20 is generally U-shaped and comprises two lead portions 21 and a curved portion 22 connecting the two lead portions 21. The lead portions 21 may be called, for example, straight portions. The curved portion 22 may be called, for example, anti-lead portions. The segment coil 20 is formed, for example, by bending a rectangular conductor having a rectangular cross-sectional shape. A crank portion 22a is formed, for example, near the center of the curved portion 22. The crank portion 22a is formed to change the lane between one lead portion 21 and the other lead portion 21. Reference numeral 23 indicates the tip of each lead portion 21. For a basic explanation of the segment coil, refer to Patent Document 1, etc., as appropriate.

[0015] Figure 3 shows a segment coil group 40. The segment coil group 40 is configured by arranging a plurality of segment coils 20 in an annular shape, for example, by a known annular alignment method. The segment coil group 40 has an annular outer peripheral lane 41 and an inner peripheral lane 42 inside the outer peripheral lane 41. As described above, the curved portion 22 of the segment coil 20 includes a crank portion 22a. Therefore, by arranging a plurality of segment coils 20 in an annular shape as shown in FIG. 3, the segment coil group 40, as a result, has an outer peripheral lane 41 in which one lead portion 21 of each segment coil 20 is arranged in an annular shape with an interval, and an inner peripheral lane 42 in which the other lead portion 21 of each segment coil 20 is arranged in an annular shape with an interval. In FIG. 3, since the segment coil group 40 is shown from the side of the curved portion 22, the lead portion 21 is not drawn.

[0016] In the present embodiment, a plurality of, for example, three segment coil groups 40 as shown in FIG. 3 are prepared. For example, in addition to the segment coil group 40 shown in FIG. 3, another segment coil group 40 having an inner diameter slightly larger than the outer diameter of the segment coil group 40 shown in FIG. 3 and another segment coil group 40 having an outer diameter slightly smaller than the inner diameter of the segment coil group 40 shown in FIG. 3 are prepared. Then, such a plurality of segment coil groups 40 having different diameter sizes and being independent are attached to the stator core 11 by inserting each lead portion 21 into each slot 14 from the side of the first end face 15 of the stator core 11.

[0017] As a result of such attachment, as shown in FIG. 1, it can be said that the coil 12 is configured by arranging a plurality of (for example, three) segment coil groups 40 in which the segment coils 20 are arranged in a plurality along the circumferential direction in a concentric circle shape. The concentric circle arrangement mentioned here refers to a state in which a plurality of segment coil groups 40 are arranged from the side of the first end face 15 of the stator core 11 around the axis Ax. Also, in the state of being attached to the stator core 11, it can be said that the segment coil group 40 includes an outer peripheral lane 41 in which the lead portions 21 are arranged at intervals along the circumferential direction and an inner peripheral lane 42 in which the lead portions 21 are arranged at intervals along the circumferential direction.

[0018] The bent portions 22 of each segment coil 20 protrude axially from the first end face 15. That is, the coil 12 includes a first coil end portion 17 from which a plurality of bent portions 22 protrude from the first end face 15. Further, the tip portions 23 of the lead portions 21 of each segment coil 20 protrude axially from the second end face 16. That is, the coil 12 includes a second coil end portion 18 from which the tip portions 23 of the plurality of lead portions 21 protrude from the second end face 16. FIG. 4 mainly shows, in an enlarged manner, a part of the second end face 16 of the stator core 11 and a part of the second coil end portion 18.

[0019] When inserted from the first end face 15 side and protruding from the second end face 16, the tip portions 23, which were linear at that time, are each appropriately twisted in the circumferential direction and the radial direction, and are joined to the tip portions 23 of the other segment coils 20 by welding or the like to enable conduction. That is, the second coil end portion 18 has a joint portion 24 in which the tip portions 23 of different segment coils 20 are joined to each other in a twisted state.

[0020] According to the present embodiment, the second coil end portion 18 includes, as the joint portion 24, a first joint portion that joins the tip portions 23 of the segment coils 20 belonging to the common segment coil group 40, and a second joint portion 24c that joins the tip portions 23 of the segment coils 20 belonging to different segment coil groups 40.

[0021] Next, the path of the coil 12 connecting from the first terminal to the second terminal will be described with reference to a specific example, including the characteristics of the joint portion 24.

[0022] Figure 5 illustrates the path of a coil 12 connecting a pair of first terminals 30a and second terminals 30b using a path table 50. The first terminal 30a and the second terminal 30b are each one of the terminals 30. In the path table 50, the integers 1 to 48 arranged horizontally represent the numbers of each slot 14 arranged along the circumference. In other words, according to the path table 50, the stator core 11 has 48 slots 14. The number of slots 14 is the same as the number of teeth 13. Hereafter, slots 14 will be identified using S + number, for example, "S1". S1 refers to slot 14 with slot number = 1.

[0023] Furthermore, in the path table 50, the integers 1 to 6 arranged vertically represent the lane numbers arranged radially. Here, we assume that coil 12 is composed of three segment coil groups 40 arranged concentrically. Below, lanes are identified by L + number, for example, "L1". L1 refers to the lane with lane number = 1. Let L1 be the outermost lane in the radial direction, and L6 be the innermost lane in the radial direction.

[0024] As described above, one segment coil group 40 has an outer circumferential lane 41 and an inner circumferential lane 42. Therefore, the outer circumferential lane 41 and inner circumferential lane 42 of the outermost segment coil group 40 of the three segment coil groups 40 correspond to L1 and L2. The outer circumferential lane 41 and inner circumferential lane 42 of the innermost segment coil group 40 correspond to L5 and L6. The outer circumferential lane 41 and inner circumferential lane 42 of the segment coil group 40 sandwiched between the outermost segment coil group 40 and the innermost segment coil group 40 correspond to L3 and L4.

[0025] In Figure 5, due to space limitations, the routing table 50 is divided into two tables, upper and lower. The upper table shows approximately the first half of a continuous route from the first terminal 30a to the second terminal 30b, and the lower table shows approximately the second half of the same continuous route. For convenience in explaining the routing table 50, the position on the coil 12 is identified by a combination of slots 14 and lanes, for example, "S1-L1". The upper table of the routing table 50 shows the route from the first terminal 30a to position S8-L6, and the lower table of the routing table 50 shows the route from position S8-L6 to the second terminal 30b.

[0026] Figure 5 is, for example, a routing table 50 for the U-phase coil 12. According to Figure 5, the U-phase coil 12 uses slots (S1, S2, S7, S8, S13, S14, S19, S20, S25, S26, S31, S32, S37, S38, S43, S44) which are clearly numbered in gray. Using slot 14 means that the lead portion 21 is inserted into that slot 14. The explanations for the V-phase and W-phase coils 12 are omitted because there is no essential difference from the explanation for the U-phase coil 12.

[0027] In the path table 50, the direction of each arrow indicates the direction of the current flowing from the first terminal 30a to the second terminal 30b. Of the arrows, the dashed arrows, excluding those for the first terminal 30a and the second terminal 30b, represent the paths at the first coil end portion 17, and indicate paths formed by the curved portion 22. The shape of these dashed arrows is a crank shape with two bends, which is a simplified representation of the shape of the curved portion 22 having a crank portion 22a. For example, the dashed arrow connecting positions S1-L5 and S43-L6 corresponds to the curved portion 22 of the segment coil 20 having two lead portions 21 inserted from the first end face 15 to positions S1-L5 and S43-L6. In the following explanation of path tables 50 and 60, when simply referred to as a dashed arrow, it means the dashed arrows excluding those for the first terminal 30a and the second terminal 30b.

[0028] Of the arrows in the path table 50, solid arrows indicate the path at the second coil end portion 18, that is, the path formed by the tip portion 23. Each solid arrow is formed by joining two tip portions 23 and has one joint portion 24. For example, the solid arrow connecting positions S43-L6 and S37-L5 is formed by twisting and joining (having one joint portion 24) a tip portion 23 protruding from the second end face 16 at position S43-L6 and a tip portion 23 of another segment coil 20 protruding from the second end face 16 at position S37-L5.

[0029] In Figure 5, both the first terminal 30a and the second terminal 30b are provided on the first coil end portion 17. It can also be seen from Figure 1 that the first terminal 30a and the second terminal 30b, i.e., each terminal 30, are provided on the first coil end portion 17. For example, the first terminal 30a protrudes from the first coil end portion 17, with its other end inserted at position S7-L6 and extending to the second end face 16, where it is joined to the path of the second coil end portion 18. Similarly, the second terminal 30b protrudes from the first coil end portion 17, with its other end inserted at position S14-L5 and extending to the second end face 16, where it is joined to the path of the second coil end portion 18.

[0030] According to the routing table 50, the dashed arrows, i.e., the curved portions 22 of the segment coils 20, all connect pairs of lead portions 21 in the outer lane 41 and lead portions 21 in the inner lane 42, which belong to a common segment coil group 40. Connecting different lanes belonging to a common segment coil group 40 will be called a normal connection. In other words, the dashed arrows are always normal connections. In the routing table 50, a normal connection is either connecting L1 and L2, L3 and L4, or L5 and L6. Therefore, at the first coil end portion 17, the multiple segment coil groups 40 are independent of each other, and there are no special segment coils or other conductors connecting across the segment coil groups 40.

[0031] According to the routing table 50, most of the solid arrows correspond to normal connections. Solid arrows corresponding to normal connections have the first joint described above as a joint 24. However, the concept of the first joint includes a "first pair joint 24a" which joins the tip portions 23 corresponding to a pair of lead portions 21 in the outer lane 41 and lead portions 21 in the inner lane 42 belonging to a common segment coil group 40, and a "second pair joint 24b" which joins the tip portions 23 corresponding to a pair of lead portions 21 in the common outer lane 41 or a pair of lead portions 21 in the common inner lane 42. The first joint that a solid arrow corresponding to a normal connection has is, of course, the first pair joint 24a. For example, the solid arrow connecting positions S43-L6 and S37-L5 described above is one of the normal connections and has a first pair joint 24a.

[0032] A special connection that does not fall under the category of a normal connection is called a special connection. In the routing table 50, the joint 24 indicated by the solid arrow that corresponds to a special connection is either the second pair joint 24b or the second joint 24c described above. There are various specific examples of the second joint 24c, but in the routing table 50, the second joint 24c connects the tip portions 23 of pairs of lead portions 21 included in the inner circumferential lane 42 and the outer circumferential lane 41, which belong to different segment coil groups 40 and are adjacent in the radial direction.

[0033] The inner circumferential lanes 42 and outer circumferential lanes 41, which belong to different segment coil groups 40 and are adjacent in the radial direction, are either a combination of L2 and L3, or a combination of L4 and L5. For example, in the path table 50, the solid arrow indicated by symbol a connects positions S7-L5 and S13-L4, and therefore corresponds to a special connection, having a second joint 24c. Similarly, each of the solid arrows indicated by symbols b, c, d, g, h, i, and j also corresponds to a special connection and has a second joint 24c.

[0034] With respect to the second pair joint 24b, pairs of lead portions 21 within a common outer circumferential lane 41, and pairs of lead portions 21 within a common inner circumferential lane 42, are, for example, pairs of lead portions 21 included in the outermost L1, and pairs of lead portions 21 included in the innermost L6. For example, in the path table 50, the solid arrow indicated by the symbol e connects position S7-L1 and position S13-L1, and therefore corresponds to a special connection, and thus has a second pair joint 24b. Similarly, each of the solid arrows indicated by the symbols f, k, and l also corresponds to a special connection and has a second pair joint 24b.

[0035] Figure 4 shows which of the following applies to some of the joints 24: the first pair joint 24a, the second pair joint 24b, and the second joint 24c. The first pair joint 24a shown in Figure 4 connects L1 and L2 (connecting the tip 23 of the lead portion 21 in L1 to the tip 23 of the lead portion 21 in L2; the same applies hereafter), L3 and L4, and L5 and L6. The second pair joint 24b shown in Figure 4 connects L1 and L1, and L6 and L6. The second joint 24c shown in Figure 4 connects L2 and L3, and L4 and L5.

[0036] In order to realize the path of the continuous coil 12 in this way, the multiple joints 24 formed in the second coil end portion 18 are mostly normal connections (first pair joint 24a) and some are special connections (second joint 24c and second pair joint 24b). According to the path table 50, in the second coil end portion 18, the special connections are formed only in the vicinity of S7 and S14 connected to the first terminal 30a and the second terminal 30b, respectively (for example, in the range of S7 to S20). Joints 24 as special connections can be easily formed by simply changing the direction in which the tip portion 23 is twisted from that of a normal connection, or by changing the pair of lead portions 21 to be joined (the pair of tip portions 23) from that of a normal connection.

[0037] Figure 6 illustrates the path of a coil 12 connecting a pair of first terminals 30a and second terminals 30b using a path table 60. The way to read path table 60 is the same as the way to read path table 50. The main features of path table 60 that differ from path table 50 will be explained below. In Figure 6, of the two tables that make up path table 60, the upper table shows approximately the first half of the continuous path from the first terminal 30a to the second terminal 30b (the path from the first terminal 30a to position S7-L1), and the lower table shows approximately the second half of the same continuous path (the path from position S7-L1 to the second terminal 30b).

[0038] In path table 60, the positions of the first terminal 30a and the second terminal 30b differ from those in path table 50. According to path table 60, the first terminal 30a protrudes from the first coil end portion 17, while its other end is inserted at position S8-L1 and extends to the second end face 16, joining to the path of the second coil end portion 18. Similarly, the second terminal 30b protrudes from the first coil end portion 17, while its other end is inserted at position S1-L2 and extends to the second end face 16, joining to the path of the second coil end portion 18.

[0039] According to routing table 50, the first terminal 30a and the second terminal 30b are located in the inner lanes L5 and L6 of the first coil end section 17. On the other hand, according to routing table 60, the first terminal 30a and the second terminal 30b are located in the outer lanes L1 and L2 of the first coil end section 17. Furthermore, according to routing table 60, in the second coil end section 18, the special connections are formed in a limited area (for example, the range of S43 to S8) near S1 and S8 connected to the first terminal 30a and the second terminal 30b, respectively.

[0040] As described above, according to this embodiment, on the first end face 15 on one side in the axial direction of the stator core 11, a plurality of independent segment coil groups 40 are arranged concentrically, with each lead portion 21 inserted into each slot 14, resulting in each curved portion 22 protruding. On the second end face 16 on the other side in the axial direction of the stator core 11, a joint portion 24 is formed by joining the tip portions 23 of different segment coils 20. The joint portion 24, including the first joint portion and the second joint portion, connects the segment coil groups 40 and realizes the necessary path for the coil 12. In other words, the simultaneous insertion of segment coil groups 40 from the first end face 15 side and the formation of the joint portion 24 on the second end face 16 side enable faster production of the stator 10 and a corresponding improvement in productivity.

[0041] Another advantage of this embodiment is that it eliminates the need to use a segment coil with a shift portion, as disclosed in Patent Document 1. With a segment coil having a shift portion, the position of the lead portion (straight portion) can be adjusted in the radial direction, and special connections such as connecting L6 and L6 on the curved portion side can be made by shifting the shift portion by the length of one lane. On the other hand, it is not easy to form the shift portion with high precision to achieve the required amount of shift. In this embodiment, all special connections required for the coil 12 are realized by the joint portion 24 included in the second coil end portion 18, so a segment coil with such a shift portion is not used. In addition, the phenomenon in which a part of the segment coil protrudes into the space on the inner circumference side of the stator core 11, which may occur when a segment coil with a shift portion is used, does not occur in this embodiment. Therefore, it becomes possible to insert the rotor, which constitutes the motor together with the stator 10, into the space on the inner circumference side of the stator core 11 from the first end face 15 side, improving the degree of freedom in the product assembly process and the layout of various parts.

[0042] Furthermore, according to this embodiment, the first terminal 30a and the second terminal 30b may be provided on the first coil end portion 17. Compared to the second coil end portion 18, which requires twisting and welding the ends 23 together, the first coil end portion 17 has more space from the viewpoint of ensuring insulation distance between conductors. Therefore, by providing the first terminal 30a and the second terminal 30b on the first coil end portion 17, the design flexibility of the first terminal 30a and the second terminal 30b for connecting to power lines and neutral lines is improved. In the first coil end portion 17, for example, as explained with reference to Figures 5 and 6, it is easy to provide the first terminal 30a and the second terminal 30b on the inner circumferential lane, on the outer circumferential lane, or at other locations.

[0043] Furthermore, according to this embodiment, the segment coil group 40 comprises an outer circumferential lane 41 in which lead portions 21 are arranged at intervals along the circumferential direction, and an inner circumferential lane 42 located inside the outer circumferential lane 41, in which lead portions 21 are arranged at intervals along the circumferential direction. The first joint may include a first pair joint 24a that joins the tip portions 23 corresponding to a pair of lead portions 21 in the outer circumferential lane 41 and a lead portion 21 in the inner circumferential lane 42 belonging to the common segment coil group 40, and a second pair joint 24b that joins the tip portions 23 corresponding to a pair of lead portions 21 in the common outer circumferential lane 41 or a pair of lead portions 21 in the common inner circumferential lane 42. With this configuration, since the first joint has not only a first pair joint 24a corresponding to a normal connection but also a second pair joint 24b corresponding to a special connection, the necessary path for the coil 12 can be easily realized on the second end face 16 side.

[0044] Furthermore, according to this embodiment, the second joint portion 24c may join the tip portions 23 of lead portions 21 that belong to different segment coil groups 40 and are included in radially adjacent inner circumferential lanes 42 and outer circumferential lanes 41, respectively. With this configuration, since the second joint portion 24c connects different segment coil groups 40 over a relatively short distance, the second coil end portion 18 can be formed simply and compactly.

[0045] 2. Second Embodiment Next, a second embodiment will be described. The second embodiment can be combined with the first embodiment described above. Therefore, explanations common to both the first and second embodiments will be omitted below.

[0046] Figure 7 shows an exploded perspective view of motor 1. Figure 8 is a partial cross-sectional view of motor 1. Motor 1 generally comprises a rotor 2, a stator 10, and a case 80. The rotor 2 has a shaft 3 at its center. The rotor 2 and stator 10 are arranged coaxially with axis Ax, and the rotor 2 is housed in the space on the inner circumference side of the stator core 11 as described above. The rotor 2 and stator 10 are housed within the case 80. In Figures 7 and 8, the coils 12 of the stator 10 are shown in a simplified manner.

[0047] The case 80 has a so-called bottomed cylindrical shape and has an outer circumferential wall 81 and a partition wall 82 that serves as the bottom. The outer circumferential wall 81 is cylindrical in shape. The partition wall 82 is provided at the other end of the outer circumferential wall 81 in the axial direction. A through hole 82a is provided at the center of the partition wall 82, allowing the shaft 3 to pass through the partition wall 82. The rotor 2, including the shaft 3, is rotatably supported within the case 80 by bearings or the like.

[0048] According to Figure 8, the stator 10 is housed in the case 80 with the radial outer surface 11a of the stator core 11 facing the inner surface 81a of the outer wall 81 of the case 80. The partition wall 82 of the case 80 faces the second end surface 16 of the stator core 11. As shown in Figure 8, a gap is provided between the partition wall 82 and the second end surface 16, and the second coil end portion 18 is positioned within this gap. The outer surface 11a of the stator core 11 is provided with a plurality of protrusions 11b, as shown in Figure 7. The inner surface 81a of the outer wall 81 is also provided with a plurality of recesses 81b. The stator core 11 is housed in the case 80 such that each protrusion 11b is positioned within the corresponding recess 81b. Each protrusion 11b is provided with a bolt fastening hole extending along the axial direction. A bolt 4 is inserted through each bolt fastening hole. The stator core 11 is fastened to the case 80 by the bolts 4.

[0049] As shown in Figures 7 and 8, the motor 1 includes a guide ring 70. It may also be understood that the stator 10 is equipped with the guide ring 70. The guide ring 70 has an annular shape in which its inner diameter is larger than the outer diameter of the second coil end portion 18 and its outer diameter is smaller than the outer diameter of the stator core 11. A guide ring 70 of this size is mounted on the second end face 16, which is the other end face in the axial direction of the stator core 11, so as to surround the second coil end portion 18. The guide ring 70 is housed in the case 80 between the second end face 16 and the partition wall 82, in a state coaxial with the stator core 11 and the rotor 2. In the radial direction, the second coil end portion 18 is positioned inward of the guide ring 70.

[0050] The guide ring 70 divides the space between the second end face 16 and the partition wall 82 into an outer circumferential space 75 and an inner circumferential space 78. Space 75 is the space enclosed by the inner surface of the case 80, the outer circumferential surface 71 of the guide ring 70, and the second end face 16, and has an annular shape. Space 75 is also called an annular refrigerant flow path 75. Figure 7 shows annular O-rings 72 and 73, similar in shape to the guide ring 70. Although omitted in Figure 8, the connection between the second end face 16 and the guide ring 70 may be sealed by O-ring 72, and the connection between the guide ring 70 and the partition wall 82 may be sealed by O-ring 73.

[0051] The case 80 is provided with a refrigerant supply passage 81c. The refrigerant supply passage 81c connects the outside of the case 80 to the annular refrigerant flow path 75. Refrigerant is supplied from the refrigerant supply passage 81c to the annular refrigerant flow path 75. Refrigerant is also called coolant. The refrigerant is, for example, cooling oil. Although details are omitted, the refrigerant supplied to the annular refrigerant flow path 75 flows inside the case 80, cooling the inside of the case 80, and is then discharged to the outside of the case 80.

[0052] As briefly shown in Figure 8, a refrigerant flow path 19 is formed inside the stator core 11. The refrigerant flow path 19 penetrates the inside of the stator core 11 generally along the axial direction. Multiple refrigerant flow paths 19 are formed at intervals along the circumferential direction. The opening at the second end face 16 of the refrigerant flow path 19 is referred to as the opening 19a. The refrigerant flow path 19 communicates with the annular refrigerant flow path 75 through the opening 19a. Therefore, a portion of the refrigerant supplied to the annular refrigerant flow path 75 is supplied to the refrigerant flow path 19 through the opening 19a, cooling the stator core 11. With this configuration, the guide ring 70 can allow the refrigerant received by the outer circumferential surface 71 to flow into the stator core 11 through the opening 19a formed on the second end face 16. The guide ring 70 may have multiple holes connecting the annular refrigerant flow path 75 and the space 78, formed at intervals along the circumferential direction. A portion of the refrigerant supplied to the annular refrigerant flow path 75 is discharged into the space 78 through these holes, cooling the second coil end portion 18.

[0053] Figure 9 shows a partial cross-sectional view of a part of the stator 10, including the second coil end portion 18 and the guide ring 70, in a plane parallel to the axial direction. As already explained, the second coil end portion 18 has multiple joint portions 24, each of which is joined to the other in a twisted state. Generally, when twisting each of the tip portions 23 to form a joint portion 24, the width of the second coil end portion 18 in the radial direction is expanded to create space between pairs of tip portions 23 to be joined and to ensure sufficient insulation distance, etc.

[0054] Conventionally, this expansion was achieved by twisting each of the tip portions 23 while tilting them radially outward, taking into consideration the ability to insert the rotor 2 into the space on the inner circumference side of the stator core 11 from the second end face 16 side. Therefore, conventionally, the difference between the outer diameter of the second coil end portion 18 and the outer diameter of the stator core 11 was small, making it difficult to secure space to attach the guide ring 70 to the second end face 16. Since the guide ring 70 could not be attached to the second end face 16, the guide ring 70 was attached to the first end face 15 side.

[0055] To address these challenges, according to the second embodiment, each of the tip portions 23 is inclined toward the inner circumference rather than the radial outer circumference, as shown in Figure 9. In other words, in the second coil end portion 18, each of the tip portions 23 is twisted while inclined toward the radial inner circumference to form a joint portion 24. With this configuration, the difference D between the outer diameter of the second coil end portion 18 and the outer diameter of the stator core 11 is larger than in the conventional configuration, and as a result, it becomes possible to attach the guide ring 70 to the second end face 16 side. By attaching the guide ring 70 to the second end face 16 side, highly efficient cooling of the stator core 11 using the guide ring 70 is achieved, and the degree of freedom in the layout of the terminals 30 (first terminal 30a, second terminal 30b) on the first end face 15 side, i.e., the first coil end portion 17, is further improved. As described in the first embodiment, since the rotor 2 can be inserted from the first end face 15 side, there is no problem due to the expansion of the width of the second coil end portion 18 radially inward on the second end face 16 side.

[0056] The specific examples of the technologies disclosed herein have been described in detail above, but these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples described above. Furthermore, the technical elements described herein or in the drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technologies illustrated herein or in the drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness in itself. [Explanation of Symbols]

[0057] 10: Stator, 11: Stator core, 12: Coil, 13: Teeth section, 14: Slot, 15: First end face, 16: Second end face, 17: First coil end section, 18: Second coil end section, 20: Segment coil, 21: Lead section, 22: Curved section, 23: Tip section, 24: Joint section, 24a: First pair joint section, 24b: Second pair joint section, 24c: Second joint section, 30: Terminal, 30a: First terminal, 30b: Second terminal, 40: Segment coil group, 41: Outer perimeter lane, 42: Inner perimeter lane, 50, 60: Path chart, 70: Guide ring, 80: Case

Claims

1. A cylindrical stator core with multiple teeth protruding radially inward, First and second terminals for connecting power lines or neutral lines, The system includes a coil that connects the first terminal and the second terminal, with a lead portion inserted into each slot which is the gap between the teeth portions and attached to a plurality of the teeth portions, The aforementioned coil is The stator core is constructed by arranging multiple segments of U-shaped segment coils, each having two lead portions and a curved portion connecting the two lead portions, in a concentric arrangement, with each segment coil being arranged along the circumferential direction of the stator core. A first coil end portion from which a plurality of the curved portions protrude from one end face in the axial direction of the stator core, The stator core comprises a second coil end portion from which the tips of a plurality of lead portions protrude from the other end face in the axial direction of the stator core, The stator is a stator in which the second coil end portion is a joint portion formed by joining the respective tip portions of different segment coils in a twisted state, comprising a first joint portion that joins the tip portions of segment coils belonging to a common group of segment coils, and a second joint portion that joins the tip portions of segment coils belonging to different groups of segment coils.

2. The stator according to claim 1, wherein the first terminal and the second terminal are provided on the first coil end portion.

3. The segment coil group comprises an outer circumferential lane in which the lead portions are spaced apart along the circumferential direction, and an inner circumferential lane inside the outer circumferential lane in which the lead portions are spaced apart along the circumferential direction. The first joint is, A first pair joint is formed by joining the tip portions of a pair of lead portions in the outer circumferential lane and lead portions in the inner circumferential lane that belong to a common group of segment coils, The stator according to claim 1, further comprising: a second pair joining portion formed by joining the tip portions of a pair of lead portions in a common outer circumferential lane or a pair of lead portions in a common inner circumferential lane.

4. The stator according to claim 3, wherein the second joint joins the tip portions of pairs of lead portions that belong to different groups of segment coils and are included in the inner circumferential lane and the outer circumferential lane, respectively, which are adjacent in the radial direction.

5. In the second coil end portion, each of the tip portions is twisted in a state inclined toward the radially inner circumference to form the joint portion. The stator core further comprises a guide ring having an annular shape with an inner diameter larger than the outer diameter of the second coil end portion and an outer diameter smaller than the outer diameter of the stator core, and attached to the other end face of the stator core so as to surround the second coil end portion. The stator according to claim 1, wherein the guide ring is capable of allowing the refrigerant received by its outer circumferential surface to flow into the stator core through an opening formed on the other end face.

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