Rotary electric machine and manufacturing method of rotary electric machine

Abstract

To block moisture intrusion into a slot part of a stator, and improve insulation reliability of a rotary electric machine.SOLUTION: In a rotary electric machine having a stator 10 and a rotor rotatably disposed about a rotation axis as a central axis, a cylindrical waterproof member 50 covering an inner peripheral surface over an entire circumference is provided on the stator 10 facing the rotor with a gap therebetween. The cylindrical waterproof member 50 is formed by seamless integral molding from a first stator core 11a to a second stator core 11b, and is molded in a resin 71 at both end parts close to a coil end, thereby ensuring waterproofness of the slot of the stator 10.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a rotating electrical machine, and more particularly to preventing moisture from entering a coil portion from the inner peripheral surface of a stator. [Background technology]

[0002] While there is a demand for miniaturization of rotating electrical machines, further improvements in electrical insulation are also required. To miniaturize stators, a structure that increases the winding space factor and achieves high power density is effective. For this reason, a stator structure consisting of segment coils using rectangular wire with a flat cross section is used as the conductor, rather than the general round wire.

[0003] When constructing a stator coil using rectangular wire, multiple segment coils are connected together. In the in-slot connection method, the segment coil is roughly U-shaped and has a pair of straight sections and a sloped section connecting them, with the two straight sections housed in the slots of the stator core. These straight sections are inserted into the slots from both end faces of the stator core in the direction of the rotation axis and connected within the slots. The sloped sections connecting the pair of straight sections of the segment coil protrude outward in the direction of the rotation axis from both axial ends of the stator core.

[0004] Patent Document 1 discloses a known technique for this in-slot connection method. The rotating electric machine described in Patent Document 1 uses a stator core formed by laminating amorphous thin films or electromagnetic steel sheets and split into two at the axial center. The first split stator is manufactured by inserting the straight sections of the segment coils into the slots of one of the split stator cores via a bobbin, and fixing the coil ends in a reference position using fixtures or adhesive resin. The second split stator is manufactured in the same way. The straight sections of the segment coils of the first and second split stators are connected by press-fitting, and then the entire stator coil is placed in a mold and molded with resin to manufacture the stator. The ends of the legs of the two connected conductor segments (the ends of the straight sections) are formed with either a protrusion (convex portion) that protrudes partially in the longitudinal direction or a groove with a recess formed on the tip surface.

[0005] Rotating electric machines can be used as power sources for a variety of devices, including fan drive motors and pump drive motors used in humid environments, as well as motors in which the interior of the motor is directly cooled with a coolant. These rotating electric machines are susceptible to moisture intrusion through gaps between the laminated cores of the stator or in the terminal box, which can cause insulation problems between the core and the coil, making it important to take adequate waterproofing measures. Patent Document 2 discloses a known technology relating to a stator using an in-slot connection method, a stator using a coating layer, and a rotating electric machine. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-49171 [Patent Document 2] Japanese Patent Publication No. 2022-128816 Summary of the Invention [Problem to be solved by the invention]

[0007] Stators using the in-slot connection method disclosed in Patent Document 1 are manufactured by connecting the ends of the straight sections of the segment coils to be connected within the slots while checking their positions. A split stator related to this type of in-slot connection method can operate with sound electrical properties without being affected by moisture when a rotating electric machine is operated in a normal usage environment, but when the rotating electric machine is operated in a special high-humidity environment, it becomes important to take measures to prevent moisture from entering between the laminations of the split stator's laminated core or through tiny gaps between the mold and core in the central divided section of the inner circumferential surface, so as not to destabilize insulation reliability, such as the insulation resistance between the connections between the ends of the straight sections of the stator core and the segment coils.

[0008] In Patent Document 2, a coating layer is provided on the core surface via a primer layer to prevent moisture from penetrating through the core surface on the inner periphery of the stator, preventing insulation problems in a rotating electrical machine used in a high-humidity environment. However, the coating layer may be damaged or peeled off due to contact with the rotor during motor assembly, or due to deterioration during operation. If the coating layer is damaged or peeled off, there is a concern that broken pieces may become the source of driving problems in the motor.

[0009] The present invention has been made in consideration of the above background, and its purpose is to provide a rotating electric machine having a stator structure that prevents moisture from entering from the inner surface side of the stator and improves insulation reliability. Another object of the present invention is to provide a rotating electric machine with significantly improved insulation reliability by providing a waterproof member on the inner surface of the rotor that can prevent damage due to rotor contact during assembly, breakage due to deterioration during long-term operation of the motor, and peeling of the coating layer. Another object of the present invention is to provide a rotating electric machine having a split stator structure, in which an integrally molded cylindrical waterproof member longer than the rotational axis length of the entire stator is interposed inside the stator. [Means for solving the problem]

[0010] To achieve the above object, the present invention provides a rotating electric machine having a stator and a rotor rotatably arranged on the inner periphery of the stator, with a waterproof material (e.g., a cylindrical waterproof member) interposed to cover the entire inner periphery of the stator. The stator is composed of a first stator core and a second stator core, with the first stator core having multiple slots and segment coils inserted into the slots and having convex portions at their ends, and the second stator core having multiple slots and segment coils inserted into the slots and having concave portions at their ends. The first stator core and the second stator core have end faces facing each other in the rotational axis direction, and the convex and concave portions, which are the connection portions of the segment coils, are fitted together. The cylindrical waterproof member is arranged from the coil end of the first stator core to the coil end of the second stator core, and is fixed by being embedded in resin at each coil end. The outer peripheral surface of the cylindrical waterproof member is fixed to the resin that fills the gaps in the divided portions and slots of the stator.

[0011] According to another feature of the present invention, a cylindrical waterproof member provided in a rotating electric machine covers the inner peripheral portion of a stator core, is formed as a one-piece molded product having insulating and waterproof properties, and is fixed so that all portions in the circumferential direction of one end side and the other end side of the cylindrical waterproof member are embedded in a resin mold. The cylindrical waterproof member is formed as a one-piece unit by injection molding using polyethylene terephthalate material with a heat resistance temperature of 120°C or higher, and the thickness of the cylindrical portion is preferably less than half the size of the gap between the stator core and the rotor.

[0012] According to another feature of the present invention, a method for manufacturing a rotating electric machine is realized, which includes a rotor fixed to a rotating shaft, a stator core arranged on the outer periphery of the rotor with a gap therebetween, and a stator coil formed by winding the stator coil into slots at predetermined intervals, the stator coil being connected so as to be exposed to the outside from the end of the stator core in the rotational axis direction, and the exposed portion of the stator coil being molded with resin. The stator is manufactured by inserting an integrated cylindrical waterproof member that covers the inner periphery of the stator core and has insulating and waterproof properties inside the stator core, and forming resin on one and the other sides of the cylindrical waterproof member in the rotational axis direction so as to be embedded in the resin mold. The outer periphery of the rotor and the inner periphery of the cylindrical waterproof member are configured to face each other with a predetermined gap therebetween. [Effects of the Invention]

[0013] According to the present invention, the entire inner surface of the stator core is covered with an integrally structured cylindrical waterproof member, thereby preventing moisture from entering the stator coil and improving the insulation reliability of the connection points of the segment coils. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a rotor 5 and a stator 10 of a rotating electric machine 1 according to a first embodiment of the present invention. [Figure 2] 1 is a side view of a stator 10 of a rotating electric machine 1 according to a first embodiment of the present invention before molding. [Figure 3] This is an exploded perspective view for explaining the method of assembling the stator 10 in Figure 2, showing the state before the first coil segment 30 and the second coil segment 40 made of flat wire are inserted into the stator cores 11a and 11b. [Figure 4]4A is an oblique view of the stator core 11 of FIG. 1, FIG. 4B is an axial projection of the stator core 11 (before the bobbin 65 is attached), FIG. 4C and FIG. 4D are oblique views showing the bobbin 65 alone, and FIG. 4E is an axial projection of the stator core 11 (after the bobbin 65 is attached). [Figure 5] 1 is a side view showing the state after all of the coil segments 30, 40 made of rectangular wire have been inserted into the stator core during assembly of the stator 10. FIG. [Figure 6] 6A is a cross-sectional view of the rotating electric machine 1, showing the state in which the cylindrical waterproof member 50 according to this embodiment is provided, and FIG. 6B is a partial cross-sectional view showing the state in which the cylindrical waterproof member 50 is housed in a mold 90. [Figure 7] FIG. 7A is a perspective view of a cylindrical waterproofing member 50 according to this embodiment, and FIG. 7B is a cross-sectional perspective view showing a state in which the cylindrical waterproofing member 50 is attached to the stator core 11. As shown in FIG. [Figure 8] FIG. 8A is a cross-sectional view of the rotating electrical machine 1, showing the state after resin 71 has been filled into a mold 90, and FIG. 8B is a partial cross-sectional view at a position shifted from the cross-section of FIG. 8A. [Figure 9] 9A to 9D are diagrams showing the manufacturing procedure of stator core 11. FIG. [Figure 10] 10A to 10D are diagrams showing a manufacturing procedure for a stator core 11A according to the second embodiment. [Figure 11] 1 is a perspective cross-sectional view showing an air compressor 100 driven by a rotating electric machine 1 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] A rotating electric machine according to an embodiment of the present invention will be described below with reference to the drawings. The following embodiments are merely illustrative of the present invention, and some omissions and simplifications have been made for clarity of explanation. The present invention can be implemented in various other forms. Unless otherwise specified, each component may be singular or plural. The position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc., disclosed in the drawings. When there are multiple components having the same or similar functions, they may be described using the same reference numeral with different subscripts. Furthermore, when it is not necessary to distinguish between these multiple components, the subscripts may be omitted. [Example]

[0016] FIG. 1 is a perspective view of a rotor 5 and a stator 10 of a rotating electric machine 1 according to a first embodiment. The rotating electric machine 1 is an internal rotation, radial gap type rotating electric machine, and includes a stator 10 that generates magnetic force using electric power, a rotor 5 that rotates due to the magnetic force generated by the stator 10, a shaft 4 that rotates together with the rotor 5, and a housing 2 (described later in FIG. 11) that covers and protects the stator 10 and the rotor 5. The rotor 5, which is fixed to the shaft 4, rotates inside the substantially cylindrical stator 10. When viewed radially, the inner peripheral surface of the stator 10 and the outer peripheral surface of the rotor 5 are not in contact with each other and are arranged so as to have a certain gap between them. The rotor 5 is formed by including a plurality of permanent magnets (not shown) that form magnetic poles. The stator 10 has a stator core 11 (see Figure 2 described later) and a stator coil 20 (see Figure 2 described later) wound around the stator core 11, and the coil end portion of the stator coil 20 on the pull-out side protruding forward from the stator core 11 is covered with molded resin 71, and the coil end portion of the stator coil 20 protruding rearward is also covered with molded resin 71.

[0017] FIG. 2 is a side view of a stator 10 according to this embodiment before molding. The stator core 11 is formed by laminating punched thin electromagnetic steel sheets in the direction of the rotation axis A1 and has a large number of teeth protruding radially inward from the cylindrical portion on the outer periphery. The spaces between adjacent teeth form slots, and a distributedly wound stator coil 20 is formed in each slot. The stator coil 20 is preferably made of copper or aluminum, which have high electrical conductivity, and the surface of the stator coil is coated with an insulating paint such as an enamel coating or an inorganic coating. The cross section of the stator coil 20 perpendicular to the longitudinal direction is circular or rectangular. In this embodiment, an enameled wire made of soft copper and having a rectangular cross section is used.

[0018] The stator core 11 has a total length L in the rotational axis direction and is formed by arranging two divided stator cores, a first stator core 11a and a second stator core 11b, in the axial direction. The axial lengths of the first stator core 11a and the second stator core 11b are approximately equal to L / 2, and the dividing plane of the stator core 11 is near the center. The front side (+Z side) of the stator core 11 is the lead-out side where the lead pieces 21 to 26 of the stator coil 20 are arranged, and the rear side (-Z side) is the opposite lead-out side of the stator coil 20. Once all of the first coil segments 30 and lead pieces 21 to 26 are inserted into the slots 14a of the first stator core 11a, the core end portions are temporarily fixed to the first stator core 11a with temporary fixing resin 71a so as not to move from the first stator core 11a. Similarly, once all of the second coil segments 40 have been inserted into the slots 14b of the second stator core 11b, they are temporarily fixed with temporary fixing resin 71b to prevent the core end portions from moving from the second stator core 11b. In this state, the first stator core 11a and the second stator core 11b are joined together, completing the connection of the stator coil 20. The lead pieces 21 to 26 are also joined to the second coil segments 40. Note that, if the stator coil is three-phase, six lead pieces are used; however, in the side view of FIG. 2, lead piece 26 overlaps with the same lead piece 24, so only five of the lead pieces 21 to 25 are visible.

[0019] FIG. 3 is an exploded perspective view illustrating a method for assembling the stator 10 of FIG. 2 in the rotating electric machine 1 according to this embodiment. Each phase of the stator coil 20 of this embodiment is formed not from a single continuous enameled wire, but by connecting multiple divided enameled wires (coil segments 30, 40). In this specification, these divided coil portions are referred to as "coil segments," and multiple coil segments physically and electrically connected together are referred to as a "coil (for one phase)" or "stator coil 20." The stator coil 20 of this embodiment is formed of multiple wave-wound coils.

[0020] The stator coil 20 is mainly formed by first coil segments 30 inserted into slots 14a from one side of the stator core 11a and second coil segments 40 inserted into slots 14b from the other side of the stator core 11b. A plurality of first coil segments 30 are inserted into slots 14a in the direction of arrow 27 from one side (e.g., the front side) of the stator core 11 in the direction of the rotation axis A1. Opposite to these, a plurality of second coil segments 40 are inserted into slots 14a in the direction of arrow 28 from the other side (e.g., the rear side) in the direction of the rotation axis A1. Ends (35, 36, 45, 46) of the first coil segments 30 and the second coil segments 40 are connected somewhere in the internal space of the slots 14 of the stator core 11. In this embodiment, the ends (35, 36, 45, 46) are located near the dividing plane.

[0021] As described above, multiple enameled wires (e.g., six wires) are radially arranged in the slots 14a, 14b of the first stator core 11a and the second stator core 11b from the inner periphery to the outer periphery. The first coil segment 30 is generally U-shaped and includes straight portions 31, 32 housed in the slots 14a and inclined portions 33, 34 protruding from the front end face of the stator core 11 and exposed from the slots so as to extend in a direction intersecting the axial direction of the stator core 11. Convex portions 35, 36 are formed on the other ends of the straight portions 31, 32, respectively, at the open ends not connected to the inclined portions 33, 34. The convex portion 36 is a protruding portion formed by removing two side surfaces from the tip end face 36a by a predetermined length to form a rectangular parallelepiped. An enlarged view of the convex portion 36 is shown in the upper right circular frame of FIG. 3. The shape of the convex portion 35 is identical to that of the convex portion 36. Enameled wire is used for the first coil segment 30 and the second coil segment 40. Enameled wire is made of copper wire, and by forming an enamel coating on the outer surface of the copper wire, the enamel coating has the characteristic of not conducting electricity.

[0022] The second coil segment 40 is formed in a roughly U-shape and has straight portions 41, 42 housed in the slots 14b, and inclined portions 43, 44 protruding from the other end (rear end face) of the stator core 11 and extending in a direction intersecting the axial direction of the stator core 11, exposed from the slots. Recesses 45, 46 are formed at the open ends of the straight portions 41, 42, not connected to the inclined portions 43, 44. Thus, the basic shape of the second coil segment 40 is similar to that of the first coil segment 30. An enlarged view of the recess 46 is shown in the circled box at the lower right of Figure 3. The shape of the recess 45 is identical to that of the recess 46. The recess 46 is a groove formed by removing a region including the center of the tip end face by a predetermined length in the longitudinal direction. A large number of second coil segments 40 are prepared for assembling the stator coil 20.

[0023] When assembling the stator coil 20, the ends (protrusions 35, 36) of the first coil segment 30 are fitted into the ends (recesses 45, 46) of the second coil segment 40. Welding, crimping, soldering, etc. are often used to join the coil segments in the stator coil 20. However, in this embodiment, the connection is completed by fitting alone, without welding, crimping, soldering, etc. Although not shown in FIG. 3 , a bobbin 65 made of synthetic resin is provided in the slot 14, and the straight portions 31, 32 of the first coil segment 30 are inserted into the bobbin 65, and the straight portions 41, 42 of the second coil segment 40 are inserted into another bobbin 65.

[0024] Next, the detailed shape of the stator core 11 will be described using FIGS. 4A to 4E. FIG. 4A is a perspective view of the front half of the stator core 11 (first stator core 11a alone), showing a state in which a bobbin 65 is attached. However, the stator coil 20 is not wound. FIG. 4B is a partial enlarged view from one side (front side) in the rotation axis direction of FIG. 4A (however, the bobbin 65 is not attached). As shown in FIG. 4B, the stator core 11 has a core-back core 12a formed on the outer periphery. In the teeth portion, a total of 48 slots 14a are formed in the circumferential direction by arranging tooth cores 13a formed by cutting amorphous metal foil strips into trapezoidal shapes and laminating them. In this embodiment, the teeth portion is made of a material different from the material (electromagnetic steel sheet) of the core-back core 12a portion. Note that the teeth portion may be made of other materials instead of amorphous. The second stator core 11b (not shown) has the same configuration as the first stator core 11a, and these can be common parts. The core-back core 12b, tooth cores 13b, and slots 14b (not shown) are formed in the same shapes as the core-back core 12a, tooth cores 13a, and slots 14a shown in the figure.

[0025] FIG. 4C is a perspective view of the bobbin 65 alone, as viewed from the inner circumferential side, and FIG. 4D is a perspective view of the bobbin 65 alone, as viewed from the outer circumferential side. The bobbin 65 is formed to have approximately the same length as the length of the first stator core 11a in the rotational axis direction (strictly speaking, the bobbin 65 is longer by the length of the jaws 67 and 68) and the same width as the slots 14a and 14b in the circumferential direction. Inside the bobbin 65, four insertion holes 66a to 66d are formed radially from the inner to the outer circumferential direction, for inserting rectangular conductors parallel to the rotational axis direction. Partition walls are provided at the boundaries between the insertion holes 66a to 66d, ensuring that each coil piece is insulated individually. Jaws 67 and 68 are provided at both axial ends of the bobbin 65, and also function to hold the bobbin 65 in the axial direction relative to the end faces of the teeth core 13a. Claws 67a, 68a, each having a protruding claw-like contour, are formed on the inner circumferential side of jaws 67, 68, and bobbins 65 are inserted from the radially inner side toward the outer side of stator core 11a. When all bobbins 65 are installed in slots 14a of stator core 11, the teeth cores 13a are constrained not only in the circumferential direction but also in the axial direction. FIG. 4E shows the state after bobbins 65 are attached from the state shown in FIG. 4B. Thus, a first resin bobbin 65 is placed in the slot of first stator core 11a, and a second resin bobbin, housing multiple second coil segments 40 arranged radially, is placed in the slot of second stator core 11b.

[0026] FIG. 5 is a side view showing the state after all of the first and second coil segments 30, 40 have been inserted into the stator cores 11a, 11b during assembly of the stator 10 of this embodiment. Because the stator coil 20 has a structure that can be separated into one side and the other side in the direction of the rotation axis Ax, a large number of first coil segments 30 and lead pieces 21-26 (26 is not visible in the figure) are first inserted into the first stator core 11a. The lead pieces 21-26 are for lead-out and connected to both ends of the regular winding, and are formed from flat wire made of the same material as the first and second coil segments 30, 40. The lead pieces 21-26 are intended to be connected to the second coil segment 40, and a protrusion (not visible in the figure) similar to the protrusion 36 of the first coil segment 30 (see FIG. 3) is formed at the end connected to the second coil segment 40.

[0027] Once the insertion of the first coil segment 30 and the lead pieces 21-26 into all positions of the slots of the first stator core 11a is completed, the exposed portions of the first stator core 11a and parts of the exposed portions of the lead pieces 21-26 are temporarily fixed with resin 71a to prevent relative movement of the first stator core 11a. In this state, the protrusions 35, 36 of the first coil segment 30 and the protrusions of the lead pieces 21-26 are positioned so that they slightly protrude from the dividing surface side (the other side) of the first stator core 11a.

[0028] Similarly, on the second stator core 11b side, once the bobbins 65 and second coil segments 40 have been inserted into all of the slots 14b, the second stator core 11b is temporarily fixed with resin 71b to prevent relative movement of the second stator cores 11b. Thereafter, the first stator core 11a and the second stator core 11b are brought closer in the direction of the rotation axis Ax, so that the protrusions 35, 36 of the first coil segment 30 and the recesses 45, 46 of the second coil segment 40 are press-fit and engaged. Next, the joined stator 10 is housed in a resin mold for final fixing.

[0029] FIG. 6A is a cross-sectional view showing the stator 10 housed in a mold 90. Here, the stator core 11 and the mold 90 are shown cut in half along a cross section including the rotation axis Ax. In this process, the stator core 11 is temporarily fixed with resin 71a before the permanent fixing resin 71 (see FIG. 8A, described later) is formed on the stator core 11. A cylindrical waterproofing member 50, indicated by a thick line, is inserted into the inner periphery of the stator core 11, and then the permanent fixing resin 71 (see FIG. 8, described later) is poured in from above under pressure. The coil ends of the multiple first coil segments 30 (portions exposed to the outside from the first stator core 11a) are previously fixed to each other with the temporary fixing resin 71a, and the coil ends of the multiple second coil segments 40 (portions exposed to the outside from the second stator core 11b) are previously fixed to each other with the temporary fixing resin 71b.

[0030] FIG. 6B is a cross-sectional view of a portion of FIG. 6A. The cross-sectional position is slightly shifted in the circumferential direction, and the segment coils 30, 40 are not located in this cross-section. As can be seen in FIG. 6B, the mold 90 is composed of a cylindrical outer mold 91, an inner mold 92, and a bottom mold 93. The bottom mold 93 and the outer mold 91, and the inner mold 92 and the bottom mold 93 are fixed with a plurality of fixing bolts 96. As shown in FIGS. 6A and 6B, when the stator 10 is placed in the mold 90, a cylindrical waterproofing member 50 is placed between the stator core 11 and the inner mold 92. Next, the cylindrical waterproofing member 50 will be described using FIGS. 7A and 7B.

[0031] FIG. 7A is a perspective view of a cylindrical waterproofing member 50 according to this embodiment, and FIG. 7B is a cross-sectional perspective view showing the positional relationship between the cylindrical waterproofing member 50 and the stator core 11. As shown in FIG. 7A, the cylindrical waterproofing member 50 has a preformed shape having an outer shape sized to follow the contour of the inner circumferential surface of the stator core 11, i.e., the inner circumferential surface of the teeth core 13a shown in FIG. 4B. The cylindrical waterproofing member 50 is formed by a cylindrical portion 51 and a flange portion 52 formed to extend radially from one edge of the cylindrical portion 51. The cylindrical portion 51 and the flange portion 52 are formed by integral molding of the same material. Therefore, unlike waterproofing members formed by rolling a flat sheet, there are no seams, which prevents moisture from penetrating the cylindrical waterproofing member 50.

[0032] The material for the cylindrical waterproofing member 50 may be PET (polyethylene terephthalate) resin, PEN (polyethylene naphthalate) resin, PPS (polyphenylene sulfide) resin, PA (polyamide) resin, PEI (polyetherimide) resin, PI (polyimide) resin, etc., with PET resin and PEN resin being preferred from the viewpoints of heat resistance, thermal shrinkage, mechanical properties, and cost. Furthermore, while there are no regulations regarding the thickness of the cylindrical waterproofing member 50, it should be determined appropriately depending on the clearance between the rotor outer diameter and stator inner diameter of the rotating electrical machine and the mechanical properties required for the manufacturing process.

[0033] In the case of a rotating electrical machine 1 in which the gap between the rotor 5 and the stator 10 is approximately 1.5 mm, the thickness of the cylindrical portion 51 is set to 0.5 mm on the side closer to the flange portion 52 and approximately 0.25 mm near the opening on the opposite side from the flange portion 52. The reason for varying the thickness in this manner is to create a tapered surface in which the inner diameter of the cylindrical waterproofing member 50 becomes smaller as it approaches the flange portion 52. By forming the tapered surface, the cylindrical waterproofing member 50 can be inserted into the inner mold 92 in a state of tight contact with the outer circumferential surface of the inner mold 92.

[0034] FIG. 7B is a diagram showing the state in which the cylindrical waterproofing member 50 is inserted inside the stator core 11. The outer diameter of the flange portion 52 of the cylindrical waterproofing member 50 is formed larger than the inner diameter of the first stator core 11a, so that it can be fixed so as not to move not only in the radial direction but also on one side in the axial direction (the side opposite the flange). The cylindrical waterproofing member 50 is preferably made of a material with small thermal contraction. In this embodiment, by using a cylindrical waterproofing member 50 that has no joints on the inner circumferential side of the stator core 11, unlike when a coating material is applied to the inner circumferential surface of the stator core 11, it is possible to effectively prevent the coating from cracking or peeling due to long-term use of the rotating electric machine 1. In FIG. 7B, the outer diameter D1 of the portion of the cylindrical waterproofing member 50 near the flange portion 52 is formed slightly smaller than the outer diameter D2 near the lower end portion 51a, so that it fits inside the stator core 11a. The cylindrical waterproof member 50 is shaped to be easily inserted.

[0035] Returning to Figures 6A and 6B, the mold 90 is formed by an inner mold 92, an outer mold 91, an annular bottom mold 93, and a lid 94, which will be described later in Figure 9. The stator 10 is placed inside this mold 90. At this time, the second coil segment 40 is held in a state where it is separated (floating) by a predetermined distance from the bottom mold 93. This is because the permanent fixing resin 71 is also filled below the temporary fixing resin 71b. Note that Figure 6A shows the state before the inner mold 92 is attached, so the inner mold 92 is not shown. Figure 6B shows the state where the inner mold 92 is fixed inside. The cylindrical waterproof member 50 and the inner mold 92 are in good contact with each other to prevent the poured resin from entering between them. In addition, to prevent the resin 71 poured into the surface where the tubular waterproofing member 50 and the inner mold 92 come into contact and from adhering the tubular waterproofing member 50 and the inner mold 92 together, a release agent may be applied in advance to the surface of the inner mold 92 that comes into contact with the tubular waterproofing member 50, which will allow the inner mold 92 to be easily removed from the stator 10 after the resin 71 has been molded.

[0036] The flange portion 52 of the cylindrical waterproofing member 50 is positioned so as to contact the outer end portion on the lead-out side of the first stator core 11a. When resin, which will be described later, is poured into the cylindrical waterproofing member 50 in this state, the flange portion 52 is embedded in the resin after molding. Furthermore, a lower end portion 51a on the lower side (opposite the lead-out side) of the cylindrical portion 51 of the cylindrical waterproofing member 50 extends a predetermined length from the end portion of the second stator core 11b in a direction parallel to the rotation axis Ax. However, the length of the lower end portion 51a is set so that it does not reach the bottom mold 93. A stepped portion 92b having a smaller outer diameter is formed in the lower portion of the inner mold 92. By forming the stepped portion 92b in this manner, the resin is sufficiently filled on the inner circumferential side of the end portion 51b, thereby properly fixing the cylindrical waterproofing member 50 on the opposite side to the lead-out side.

[0037] 8A and 8B show the state after resin has been filled from the state shown in FIGS. 6A and 6B. The filled resin is formed so as to entirely cover the temporary fixing resins 71a and 71b shown in FIG. 6B. The temporary fixing resins 71a and 71b and the permanent fixing resin 71 are made of the same resin material, so that the resins 71a and 71b are integrally incorporated into the permanent fixing resin 71. The divided stator core 11 is provided with a cylindrical waterproofing member 50 molded into a cylindrical shape on the inner circumferential surface of the stator, and both ends of the cylindrical waterproofing member 50 adjacent to the coil ends are completely embedded in the resin 71. This cross-sectional shape is the same in the circumferential direction, and the flange portion 52 and the lower end portion 51a are located within the resin 71 at all locations in the circumferential direction. Therefore, moisture is completely prevented from penetrating from the end of the cylindrical waterproofing member 50 to the inside of the coil ends. At the dividing position of the stator core 11, the gap between the joining surfaces of the stator cores 11a and 11b and the outer circumferential surface of the cylindrical waterproof member 50 is also filled with the resin 71 without exception.

[0038] The gap between the inner opening of each slot 14a, 14b (see FIG. 3) and the cylindrical waterproofing member 50 is filled with resin 71, thereby filling the gap and providing a strong bond. Note that the temporary fixing resins 71a, 71b and the permanent fixing resin 71 may be made of different materials. The filling resin 71 may be injected using a transfer mold that applies a predetermined pressure, for example, but may also be formed using other molding methods.

[0039] 9A to 9D are diagrams illustrating a manufacturing procedure for the stator 10 of the rotating electric machine 1 according to this embodiment. In FIG. 9A, the stator 10 is mainly formed by divided stator cores 11a and 11b and the stator coils 20 formed therein. As shown in FIG. 3, the stator cores 11a and 11b are joined near the center in the direction of the rotation axis Ax. As shown in FIG. 4, the coil end portions of the multiple first coil segments 30 and the lead pieces 21 to 26 are temporarily fixed with resin 71a. Similarly, the coil end portions of the multiple second coil segments 40 are temporarily fixed with resin 71b. After the temporary fixing of the first coil segments 30 and the lead pieces 21 to 26 to the stator core 11a and the temporary fixing of the second coil segment 40 to the stator core 11b are completed, the stator cores 11a and 11b are joined so as to be aligned in the direction of the rotation axis Ax. This joining simultaneously brings into a state in which the concave and convex portions formed on the ends of the many second coil segments 40 are fitted with the many first coil segments 30 and lead pieces 21 to 26, thereby forming the stator coil 20.

[0040] Next, as shown in Fig. 9B, cylindrical waterproofing member 50 is inserted into the inner circumferential side of stator core 11. Insertion direction 59 is from one side of stator core 11 as viewed in the direction of rotation axis Ax, and in the example of Fig. 9B, insertion is from the side where lead pieces 21 to 26 (see Fig. 4) of stator coil 20 are provided. However, the insertion direction of cylindrical waterproofing member 50 is arbitrary, and it may be inserted from the stator core 11b side, opposite to Fig. 9B, so that flange portion 52 is located on the bottom surface side.

[0041] After the cylindrical waterproofing member 50 is attached to the stator core 11 as shown in FIG. 9C , they are set inside a mold 90. The mold 90 includes an outer mold 91, an inner mold 92, and a bottom mold 93, which are secured together with a plurality of bolts 96. Then, the upper sides of the outer mold 91 and the inner mold 92 of the mold 90 are closed with a disk-shaped lid 94. A resin injection hole 95 is formed in the lid 94, and the lid 94, the outer mold 91, and the inner mold 92 are secured together with bolts 97. Then, resin is poured in the direction of arrow 99 in FIG. 9D , thereby covering the cylindrical portion 51 and the lower end portion 51 a of the cylindrical waterproofing member 50 as well as the coil end portion with resin 71. The resin 71 is thoroughly filled inside the slots 14 (see FIG. 3 ) of the stator cores 11 a and 11 b, particularly into the gaps inside and outside the bobbin 65. Furthermore, the resin 71 also comes into contact with the outer circumferential surface of the cylindrical waterproofing member 50 , so that the cylindrical waterproofing member 50 is firmly fixed by the resin 71 .

[0042] It is preferable that resin not be filled between the cylindrical waterproofing member 50 and the inner mold 92 of the mold 90. This means that the inner circumferential surface of the cylindrical waterproofing member 50 faces the rotor 5 without any resin interposed between them. The absence of any component (here, resin 71) on the surface of the cylindrical waterproofing member 50 avoids problems such as component peeling, ensuring stable waterproofing and reliability over the long term. Furthermore, compared to a conventionally proposed application method in which a coating agent is applied to the inner surface of the assembled stator and then heat-cured (two-step application), the method of this embodiment reduces manufacturing steps and ensures reliable waterproofing. Furthermore, during the manufacturing process of the rotating electric machine 1, even if the rotor 5 comes into contact with the cylindrical waterproofing member 50 when inserting the rotor 5 into the split stator 10, the cylindrical waterproofing member 50 is a film in the broad sense. Therefore, its mechanical properties are superior to those of conventionally used coating layers, making it less susceptible to the problems of breakage or cracking of the coating agent that have been a problem with conventional coating layers. This significantly improves product reliability.

[0043] As described above, in the stator molding process according to this embodiment, the cylindrical waterproof member 50 is placed on the inner periphery of the stators 11a, 11b via the inner mold 92 before molding so as to fit along the inner periphery of the stators 11a, 11b, and after the outer mold 91 is attached, the stators 11a, 11b and the cylindrical waterproof member 50 are integrated in one step. However, the shape of the cylindrical waterproof member 50 used in the rotating electric machine 1 is not limited to the shapes shown in FIGS. 7A and 7B . In particular, other shapes are possible as long as the cylindrical waterproof member 50 is a seamless, preformed, one-piece molded product in which both end portions of the cylindrical portion can be continuously embedded in the resin 71. [Example]

[0044] 10A to 10D are diagrams showing a manufacturing procedure for a stator core 11A according to a second embodiment. The shape of the stator core 11A before inserting the cylindrical waterproofing member 50A, as shown in FIG. 10A, is the same as that of the stator core 11 shown in FIGS. 9A to 9D. In FIG. 10B, the cylindrical waterproofing member 50A is inserted in the direction of arrow 59. As can be seen in this partial cross-sectional view, the cylindrical waterproofing member 50A has an expanded portion 53 formed on the upper side of the cylindrical portion 51, which expands slightly outward. The mold 90 shown in FIG. 10C is the same as that used in FIG. 9C, and liquid resin 71 is injected under pressure through a resin injection hole 95 in a lid portion 94 in the direction of arrow 99 using the same method, and then cured.

[0045] 10D, expanded portion 53 is fixed so as to be embedded in resin 71 for final fixation. Lower end portion 51a of cylindrical waterproofing member 50A is also fixed so as to be embedded in resin 71 for final fixation. As a result, the entire inner circumferential surface of stator core 11 is covered with cylindrical waterproofing member 50A, which has high waterproofing properties, and therefore, moisture can be ideally prevented from entering the area around bobbin 65 from the inner circumferential surface side of stator core 11.

[0046] The rotating electric machines 1 of Examples 1 and 2 can be used to drive various devices. FIG. 11 shows one example, a screw-type air compressor 100 driven by the rotating electric machine 1. The air compressor 100 includes the rotating electric machine 1, which supplies rotational power, and an air end 101, which generates compressed air using the rotational force of the rotating electric machine 1. The rotating electric machine 1 is an interior permanent magnet synchronous motor (IMM) that houses a rotor 5 and a stator 10 in a housing 2. The rotating electric machine 1 has the structure described in this embodiment, but FIG. 11 omits the cylindrical waterproof member 50 and the resin 71 after full fixing. The housing 2 is composed of a cylindrical body portion 2a having openings on the front and rear sides, a front end bracket 2b attached to the front opening of the body portion 2a, and a rear end bracket 2c attached to the rear opening of the body portion 2a. A through hole is formed in the front end bracket 2b, and one end of the shaft 4, to which the rotor 5 is fixed, protrudes from the interior of the housing 2 toward the front side. The stator 10 is formed with a stator core 11 and a stator coil 20 wound around the stator core 11. Fig. 11 shows a schematic view of the shape of the end core portion of the stator coil 20, and the detailed shape thereof is the shape described in Figs. 2 to 9.

[0047] The M rotor 120 of the airend 101 is connected to the shaft 4 of the rotating electric machine 1 by a connecting means (for example, a spline, a coupling, a gear, etc.) and supplies rotational power from the rotating electric machine 1 to the first shaft 105 of the airend 101. In this example, the shaft 4 and the first shaft 105 are directly connected, and their rotation axis is Ax. A first bevel gear 110 is provided at the tip of the first shaft 105, and the first bevel gear 110 is meshed with an adjacent second bevel gear 130, causing the second bevel gear 130 to rotate at the same speed as the first bevel gear 110 but in the opposite direction. The second bevel gear 130 is provided at the tip of the second shaft 135, and therefore the rotation of the second bevel gear 130 causes the F rotor 140 fixed to the second shaft 135 to rotate at the same speed as the M rotor 120 fixed to the first shaft 105 but in the opposite direction.

[0048] As the rotating electric machine 1 rotates, the M rotor 120 and the F rotor 140 rotate, and air is sucked in through the suction port of the M rotor 120 (not shown in the figure). As the M rotor 120 and the F rotor 140 rotate further, the teeth of each rotor disengage, and air is sucked into the tooth space. As the M rotor 120 and the F rotor 140 rotate further, the air is blocked by the wall of the casing 102, completing the suction. The air trapped between the tooth space and the casing is compressed by the meshing of the rotors 120 and 140. As the rotors 120 and 140 rotate in this way, the air moves axially and is further compressed between the tooth space 145 and the casing 102, reaching a discharge port (not shown in the figure) and reaching a predetermined pressure. The compressed air is discharged from the discharge port on the discharge side opened in the casing 102.

[0049] As described above, the rotating electric machine 1, 1A of the present invention is provided with a seamless cylindrical waterproof member sheet on the inner peripheral surface of the stator core, with both ends of the coil end embedded in molding resin and the inner periphery of the stator bonded with molding resin. This prevents moisture from entering the stator, improving insulation reliability. Furthermore, the present invention makes it possible to integrate the split stator core 11 and the cylindrical waterproof member 50, 50A in a single step. [Explanation of symbols]

[0050] 1 Rotating electric machine 2. Housing 4 shafts 5 rotors 10 Stator 11, 11A stator core 11a First stator core 11b Second stator core 12a Core Back Core 13a Tee Score 14a, 14b slots 15 bobbins 19 Molded cover 20 stator coil 21~26 Drawer pieces 30 First coil segment 31, 32 Straight line (first rectangular line) 33, 34 Slope 35, 36 End (convex part) 36a Tip surface 40 Second coil segment 41, 42 Straight section (second flat wire) 43, 44 Slope section 45, 46 Recess 50, 50A cylindrical waterproof member 51 Cylindrical part 51a Lower end part 52 flange 53 Expanded section 65 Bobbin 66a~66d Insertion holes 67, 68 Jaw 71 (For fixing) Resin 71a, 71b (temporary fixing) resin 90 Molds 91 Outside mold 92 Inner mold 92b Step 93 Bottom mold 94 Lid 95 Resin injection hole 96, 97 volts 100 Air Compressor 101 Airend 102 Casing 105 First Shaft 110 1st bevel gear 120 M rotor 130 2nd bevel gear 135 Second Shaft 140 F rotor 145 Tooth space

Claims

1. a rotor fixed to a rotating shaft; a stator core arranged on an outer circumferential side of the rotor, having a plurality of slots, and formed by being divided in the direction of the rotation axis, A stator coil is disposed in the slot, and is connected so that a portion of the stator coil is exposed to the outside from an end of the stator core, A rotating electric machine in which the exposed portion of the stator coil is molded with resin, a cylindrical waterproof member that is integrally molded and has insulating and waterproof properties and covers an inner peripheral portion of the stator core; a rotating electric machine, characterized in that the cylindrical waterproof member has both one end and the other end fixed with the resin in the rotation axis direction;

2. 2. The rotating electric machine according to claim 1, The stator core is divided into a first stator core and a second stator core in the direction of the rotation axis, A rotating electric machine, characterized in that the axial length of the cylindrical waterproofing member is greater than the total axial length of the divided stator cores.

3. 3. The rotating electric machine according to claim 2, The cylindrical waterproof member has a cylindrical portion and a flange portion extending radially from one end of the cylindrical portion. a flange portion molded to be embedded in the resin, and the other end of the cylindrical portion molded to be embedded in the resin;

4. 4. The rotating electric machine according to claim 3, the stator coil is formed by connecting, inside the slots, a plurality of hairpin-shaped first coil segments inserted into the slots from one side in the rotational axis direction of the stator core and a plurality of hairpin-shaped second coil segments inserted into the slots from the other side in the rotational axis direction, A rotating electric machine characterized in that the cylindrical waterproof member is arranged on the inner side of the first coil segment and the second coil segment, and along the inner surface of the teeth of the stator core.

5. 5. The rotating electric machine according to claim 4, The cylindrical waterproof member has a portion of its outer surface bonded to the resin at a connecting portion of the stator core, the connecting portion being formed in two parts, so as to be continuous in the circumferential direction.

6. 6. The rotating electric machine according to claim 5, a first bobbin made of resin that accommodates a plurality of the first coil segments arranged radially in a slot of the first stator core; a second bobbin made of resin that accommodates a plurality of the second coil segments arranged radially in a slot of the second stator core; A rotating electric machine characterized in that the resin is filled between the inner surface of the first bobbin and the outer surface of the cylindrical waterproof member, and between the inner surface of the second bobbin and the outer surface of the cylindrical waterproof member.

7. 7. The rotating electric machine according to claim 6, The cylindrical waterproof member is integrally formed by injection molding of polyethylene terephthalate material with a heat resistance temperature of 120°C or higher, A rotating electric machine characterized in that the thickness of the cylindrical portion is equal to or less than half the size of the gap between the stator core and the rotor.

8. a stator having a stator core with a large number of slots that open to the inner periphery side, and a stator having a stator coil wound in the slots; a rotor fixed to a rotary shaft and rotating on the inner circumferential side of the stator core; a rotating electric machine in which the stator coil is fixed to the stator coil by molding with resin, a cylindrical waterproof member made of synthetic resin and impermeable to moisture of a non-magnetic material, the waterproof member having a shape that conforms to an inner peripheral edge of the stator core, is provided on the inner peripheral side of the stator core; a cylindrical waterproof member fixed to the stator core together with the stator coil by the resin;

9. 9. The rotating electric machine according to claim 8, The cylindrical waterproof member is integrally formed by injection molding of polyethylene terephthalate material with a heat resistance temperature of 120°C or higher, a cylindrical waterproof member having openings on both sides, the outer edges of which are molded so as to be embedded in the resin;

10. 10. The rotating electric machine according to claim 9, The resin is filled into the gaps within the slots of the stator core, and the resin filled into the gaps within the slots comes into contact with the outer surface of the cylindrical waterproofing member, thereby firmly fixing the cylindrical waterproofing member to the stator core.

11. a rotor fixed to a rotating shaft; a stator core having a plurality of slots and disposed on the outer circumferential side of the rotor with a gap therebetween; a stator coil wound around the slots at predetermined intervals; a method for manufacturing a rotating electric machine, the method including connecting the stator coil so as to be exposed to the outside from an end of the stator core in a rotation axis direction, and molding the exposed portion of the stator coil with resin, an integrated cylindrical waterproof member having insulating and waterproof properties is inserted inside the stator core to cover the inner peripheral end of the stator core; The resin is molded on one side and the other side of the cylindrical waterproofing member in the rotational axis direction so that the cylindrical waterproofing member is embedded in the resin; a cylindrical waterproof member having an outer circumferential surface facing the outer circumferential surface of the rotor and an inner circumferential surface of the cylindrical waterproof member, the outer circumferential surface of the rotor being spaced apart by a predetermined gap;

12. The method for manufacturing a rotating electric machine according to claim 11, The resin molding step includes a temporary fixing step of temporarily fixing the exposed portions of the plurality of coil segments constituting the windings of the stator coil; a main fixing step of fixing one side and the other side of the cylindrical waterproofing member in the rotation axis direction by further forming a resin on the portion that has been temporarily fixed, The method for manufacturing a rotating electric machine, wherein the cylindrical waterproof member is molded with the resin in the main fixing step.

13. 13. The method for manufacturing a rotating electric machine according to claim 12, The stator core is divided into two parts along the rotation axis, The stator coil includes a plurality of hairpin-shaped first coil segments inserted into the slots from one side of the stator core in the rotational axis direction, and a plurality of hairpin-shaped second coil segments inserted into the slots from the other side of the rotational axis direction, and the first coil segments are connected inside the slots, The method for manufacturing a rotating electric machine, wherein the cylindrical waterproof member is manufactured to be longer than the total length of the divided stator core in the direction of the rotation axis.

14. 14. The method for manufacturing a rotating electric machine according to claim 13, A manufacturing method for a rotating electric machine, characterized in that in the main fixing process using the resin, the resin is used to bond the cylindrical waterproofing member not only near both side ends in the rotational axis direction of the cylindrical waterproofing member, but also on the outer surface of the cylindrical waterproofing member.

15. 15. The method for manufacturing a rotating electric machine according to claim 14, The cylindrical waterproof member is integrally formed by injection molding of polyethylene terephthalate material with a heat resistance temperature of 120°C or higher, a flange portion extending in a radial direction is formed on one end side of the cylindrical waterproofing member in the rotational axis direction, and the flange portion is positioned so as to abut against one end surface of the stator core; an end of the cylindrical waterproofing member away from the flange portion is positioned so as to protrude from the other end surface of the stator core; a flange portion and a protruding portion molded with the resin;

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