Method for manufacturing a motor and a stator

Abstract

To reduce temperature rise of a rotor by reducing temperature of a stator.SOLUTION: A motor 1 of the present invention is constituted by arranging a stator 5 and a rotor 4 to be arranged with a space to the stator 5 in a housing 2, wherein the stator 5 comprises: an annular yoke; and a plurality of teeth projecting from an inner peripheral part of the yoke toward the rotor 4. Slots in which coils 6 wound around the teeth are arranged are respectively formed between the adjacent teeth, and comprises a mold resin part 30 formed by molding the stator 5 and the coils 6, and the mold resin part 30 comprises a flow channel 32 formed in at least one of a plurality of slots, and a cooling medium is supplied to the flow channel 32.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a motor having a coil wound around a stator and a method for manufacturing the stator. [Background technology]

[0002] Conventionally, there is a motor having a rotor, a cylindrical stator disposed around the rotor, and a coil wound in the longitudinal direction of the stator, the stator being supported inside a housing. The coil is disposed in a slot of the stator.

[0003] In the motor of Patent Document 1, in order to improve the heat dissipation of the stator, holes are formed in the laminated plates of the stator, and the holes are connected to form a coolant flow path in the yoke of the stator. In this motor, the stator is cooled by supplying coolant to the flow path formed in the yoke of the stator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-145859 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the motor of Patent Document 1, the coolant flow path is formed in the yoke part of the stator, so that a temperature distribution occurs in the stator due to thermal conduction, and the temperature of the teeth part of the stator around which the coil is wound becomes higher than the temperature of the yoke part. Therefore, there is a problem that the temperature of the rotor rises due to radiation from the stator. In particular, in a motor in which the rotor rotates in a space where the pressure is reduced below atmospheric pressure (reduced pressure space), the generation of convection is significantly reduced even when the rotor rotates, so the heat of the rotor is likely to be trapped and the temperature of the rotor is likely to become high.

[0006] Therefore, the present invention provides a method for manufacturing a motor and a stator that can reduce the temperature of the stator and reduce the temperature rise of the rotor. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention takes the following measures.

[0008] That is, the motor according to the present invention is The motor has a stator having a plurality of teeth, a coil wound around the teeth, and a slot formed between the teeth, with the coil provided in the slot, and is characterized in that it has a molded resin part that fills the slot and covers the coil, and a flow path that is a through hole formed in the molded resin part and passes through the slot, the inner wall of the flow path being made of a resin material that forms the molded resin part, and a cooling medium flows inside the flow path.

[0009] As a result, in the motor according to the present invention, the molded resin part in which the multiple laminates and coils in the stator are molded has a flow path for the cooling medium formed in at least one slot of the stator, and it is possible to form a stator having a flow path for the cooling medium by using conventional laminates without using a dedicated laminate for forming the flow path for the cooling medium. Also, since the flow path for the cooling medium is formed in the molded resin part, it is possible to suppress an increase in eddy current loss due to magnetic flux generated in the stator or rotor, and to prevent a decrease in motor efficiency.

[0010] In the motor according to the present invention, The flow passage is provided on the rotation axis direction side of the coil.

[0011] As a result, in the motor according to the present invention, the flow passage through which the cooling medium is supplied is located on the rotor side of the coil within the slot. Therefore, the flow passage is located near the gap between the stator and the rotor, and by lowering the temperature of the rotor side portion of the stator, it is possible to reduce the temperature rise of the rotor due to radiation from the stator. Therefore, by suppressing the rise in the bearing temperature of the motor shaft that supports the rotor, the life of the bearing is extended.

[0012] In the motor according to the present invention, The flow passage is provided in the internal space of the slot at a position on the inner periphery side of the stator and adjacent to the coil.

[0014] In the motor according to the present invention, The molded resin part has a molded portion that covers each of the coil ends protruding at both axial ends of the stator, and the molded portion has an annular groove portion that is connected to the flow path and centrifugally moves in the circumferential direction in which the cooling medium flows.

[0016] In the motor according to the present invention, The molded portion has a member that faces the end face on which the groove portion is formed, and two annular seal members are arranged radially inside and radially outside the groove portion on the end face.

[0018] The present invention The motor has a housing in which the stator and a rotor arranged with a gap between them are disposed, and the housing is characterized in that it is formed with a cooling medium supply port that communicates with the groove formed in one end face of the molded resin portion, and a cooling medium discharge port that communicates with the groove formed in the other end face of the molded resin portion. Effect of the Invention

[0020] According to the present invention as described above, it is possible to form a stator having a flow passage through which a cooling medium is supplied, using conventional laminate plates, without requiring a dedicated laminate plate for forming a flow passage through which a cooling medium is supplied. [Brief description of the drawings]

[0021] [Figure 1] 1 is a vertical sectional view of a motor according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional perspective view of the motor of FIG. 1. [Diagram 3] FIG. 2 is a horizontal cross-sectional view taken along line AA in FIG. [Figure 4] FIG. [Diagram 5] FIG. 4 is a partial perspective view illustrating a configuration of a molded resin portion. [Figure 6] FIG. 2 is a partially enlarged view of FIG. [Figure 7] 4 is a perspective view of a molded resin portion cut at the axial center thereof as viewed from below. FIG. [Figure 8] 4 is a flowchart illustrating a method for manufacturing the stator of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] 1 and 2, motor 1 has a housing 2, and in housing 2 are provided rotor (movable element) 4 which rotates around motor shaft 3, which is a rotating shaft, and stator (fixed element) 5 which is fixed to housing 2 with a narrow gap (air gap) so as to surround the outer periphery of rotor 4. Stator 5 is press-fitted and fixed in housing 2. Note that a well-known rotor 4 can be used, and detailed description thereof will be omitted.

[0024] The motor 1 may be used, for example, as a drive source for an actuator such as an aircraft electric motor or a robot, as a drive source for a pump or a compressor, as a flywheel power storage device, or for other purposes.

[0025] 3, the stator 5 has a plurality of laminated plates 5t stacked in the axial direction, and includes an annular yoke 51 located on the outside, and a plurality of teeth 52 protruding from the inner peripheral surface of the yoke 51 toward the motor shaft 3. The gaps between adjacent teeth 52 are called slots 53, and there are the same number of slots as the number of teeth 52.

[0026] The coils 6 wound around the teeth 52 are disposed in the slots 53 formed between adjacent teeth 52. The coils 6 wound around the teeth 52 are not shown in Figs. 3, 6, and 7.

[0027] The stator 5 has a molded resin part 30 in which a plurality of laminates 5t and a coil 6 are molded. That is, the molded resin part 30 is formed by molding the coil 6 wound around the teeth 52 of the stator 5 using a resin material such as epoxy resin or polyester resin. The molded resin part 30 has insulating properties, and the adhesion between the molded resin part 30 and the coil 6 is high.

[0028] The molded resin portion 30 has a first molded portion 30a disposed above the stator 5, a plurality of second molded portions 30b disposed inside the respective slots 53, and a third molded portion 30c disposed below the stator 5. The first molded portion 30a and the upper ends of the plurality of second molded portions 30b are connected, and the lower ends of the plurality of second molded portions 30b and the third molded portion 30c are connected.

[0029] That is, in the molded resin portion 30, the first mold portion 30a and the third mold portion 30c are connected by the multiple second mold portions 30b. The first mold portion 30a, the multiple second mold portions 30b, and the third mold portion 30c are connected along the axial direction of the stator 5. The inner peripheries of the multiple second mold portions 30b are connected in the circumferential direction and act as wedges.

[0030] The molded resin part 30 has a cooling medium flow path 32 through which the cooling medium is supplied. One second molded part 30b is arranged in each of the multiple slots 53, and one flow path 32 is arranged in the axial direction of the stator 5 in one second molded part 30b.

[0031] One flow path 32 is formed to pass through one slot 53, and the molded resin part 30 has a plurality of flow paths 32 formed in each of the plurality of slots 53. In this embodiment, the coolant flow paths 32 are formed by through holes that penetrate the second molded part 30b in the axial direction.

[0032] The upper end of flow path 32 formed in second molded portion 30b extends to the upper end surface of first molded portion 30a, and the lower end of flow path 32 extends to the lower end surface of third molded portion 30c. Therefore, flow path 32 penetrates molded resin portion 30 from the upper end surface to the lower end surface.

[0033] The flow passage 32 is disposed in the slot 53 on the rotor 4 side relative to the coil 6 in the radial direction. That is, in the slot 53, the flow passage 32 is disposed radially outside the gap (gap portion) between the stator 5 and the rotor 4 and radially inside the coil 6.

[0034] In second molded section 30b, two coil passing sections 33a, 33b are formed, each disposed radially outside one flow passage 32. Coil passing section 33a is disposed radially outside flow passage 32, and coil passing section 33b is disposed radially outside coil passing section 33a. That is, when a resin material is used to mold coil 6 wound around teeth 52 of stator 5, second molded section 30b is formed around coil 6, thereby forming coil passing sections 33a, 33b.

[0035] An annular groove 61a is formed on the upper end surface of the molded resin part 30, i.e., the upper end surface of the first molded part 30a. An annular groove 61b is formed on the lower end surface of the molded resin part 30, i.e., the lower end surface of the third molded part 30c. The annular grooves 61a and 61b are formed in a concave shape on the upper end surface and the lower end surface of the molded resin part 30. The upper ends of the multiple flow paths 32 open on the bottom surface of the groove 61a, and the lower ends of the multiple flow paths 32 open on the bottom surface of the groove 61b. Therefore, the multiple flow paths 32 communicate with the annular grooves 61a and 61b, respectively.

[0036] The housing 2 has a cylindrical portion 2a and two cover members 2b, 2c that close both sides of the cylindrical portion 2a. The cylindrical portion 2a is arranged along the vertical direction, the cover member 2b closes the upper end of the cylindrical portion 2a, and the cover member 2c closes the lower end of the cylindrical portion 2a. A hole 12a is formed in each of the cover members 2b, 2c, and a bearing portion 12b that rotatably supports the motor shaft 3 is arranged in the hole 12a. The gap between the cover member 2b and the motor shaft 3 and the gap between the cover member 2c and the motor shaft 3 are sealed by annular seal members 12c.

[0037] A cooling medium supply port 60a is formed in the cover member 2b of the housing 2. The supply port 60a is formed to penetrate the cover member 2b in the vertical direction, and the lower end of the supply port 60a is located above a groove portion 61a formed in the upper end surface of the molded resin portion 30, and the supply port 60a is in communication with the groove portion 61a.

[0038] Similarly, a cooling medium outlet 60b is formed in the cover member 2c of the housing 2. The outlet 60b is formed to penetrate the cover member 2c in the vertical direction, and the upper end of the outlet 60b is located below a groove portion 61b formed in the lower end surface of the molded resin portion 30, and the outlet 60b is in communication with the groove portion 61b.

[0039] The outer peripheral surface of the molded resin part 30 contacts the inner peripheral surface of the cylindrical part 2a, and both ends of the molded resin part 30 are disposed to face the two cover members 2b, 2c, respectively. That is, the upper end surface of the molded resin part 30 faces the lower surface of the cover member 2b, and the lower end surface of the molded resin part 30 faces the upper surface of the cover member 2c. A step part 2d is formed at the lower end of the cylindrical part 2a, protruding radially inward, and the upper surface of the step part 2d contacts the lower surface of the stator 5.

[0040] Four annular seal members 62a, 63a, 62b, and 63b are disposed between both end faces of the molded resin part 30 and the two cover members 2b and 2c. That is, two annular seal members 62a and 63a are disposed between the upper end face of the molded resin part 30 and the lower face of the cover member 2b. In addition, two annular seal members 62b and 63b are disposed between the lower end face of the molded resin part 30 and the upper face of the cover member 2c.

[0041] Between the upper end surface of the molded resin portion 30 and the lower surface of the cover member 2b, the annular seal member 62a is disposed radially inside the groove portion 61a, and the annular seal member 63a is disposed radially outside the groove portion 61a. Between the lower end surface of the molded resin portion 30 and the upper surface of the cover member 2c, the annular seal member 62b is disposed radially inside the groove portion 61a, and the annular seal member 63b is disposed radially outside the groove portion 61a.

[0042] In the motor 1 of this embodiment, a reduced pressure state is maintained in the space inside the inner circumferential surface of the stator 5. Therefore, the rotor 4 rotates in the reduced pressure space.

[0043] 2, a pump 65 is connected to the supply port 60a and the discharge port 60b of the cooling medium via connection pipes 64a and 64b. Thus, when the pump 65 is driven, the cooling medium is supplied to the supply port 60a via the connection pipe 64a. The cooling medium supplied to the supply port 60a passes through the groove portion 61a and is supplied to the flow path 32 of the molded resin portion 30. The cooling medium that passes downward through the flow path 32 passes through the groove portion 61b and reaches the discharge port 60b. The cooling medium that reaches the discharge port 60b is returned to the pump 65 via the connection pipe 64b and circulated.

[0044] A method for manufacturing the stator 5 used in the motor 1 of this embodiment will be described with reference to FIG.

[0045] (Step S1) Coils 6 are wound around teeth 52 formed by stacking multiple laminates 5t, and the multiple laminates 5t with the coils 6 wound around them are placed inside a cylindrical molding lower die. A step having the same shape as the step 2d formed in the cylindrical portion 2a of the housing 2 of the motor 1 is formed in the bottom of the molding lower die.

[0046] (Step S2) Inside the lower mold, a cylindrical first die is placed inside the multiple laminated plates 5t around which the coils 6 are wound. The first die is for forming the inner peripheral surface of the stator 5 and for forming a space in which the rotor 4 is disposed radially inside the stator 5. The diameter of the first die is slightly larger than the diameter of the rotor 4.

[0047] (Step S3) Inside the lower mold, one cylindrical second die is placed in each of the slots 53 in the laminates 5t around which the coil 6 is wound. The second die is for forming the cooling medium flow paths 32 in the slots 53. The second die is placed in each of the slots 53.

[0048] (Step S4) A mold upper die is attached to the mold lower die, and the laminates 5t around which the coil 6 is wound are placed inside the mold formed by the mold upper die and the mold lower die. A resin supply port is formed in the mold upper die, and resin is poured into the mold from the resin supply port of the mold upper die. The resin 52 is then hardened in the mold by cooling or heating. This forms the molded resin part 30.

[0049] (Step S5) When the resin 52 hardens in the molding die, the molding die is divided to remove the molded resin part 30 in which the plurality of laminates 5t and the coils 6 are molded. When the first die arranged inside the plurality of laminates 5t and the second die arranged in the plurality of slots 53 of the plurality of laminates 5t are removed from the molded resin part 30, the manufacture of the stator 5 having the molded resin part 30 in which the plurality of laminates 5t and the coils 6 are molded is completed. In the manufactured stator 5, a space in which the rotor 4 is to be disposed is formed in the portion where the first die was removed, and flow paths 32 in the plurality of slots 53 are formed in the portion where the second die was removed.

[0050] As described above, the motor 1 of this embodiment is a motor in which a stator 5 and a rotor 4 arranged with a gap between them are arranged within a housing 2, and the stator 5 has a plurality of laminated plates 5t forming an annular yoke 51 and a plurality of teeth 52 protruding from the inner periphery of the yoke 51 toward the rotor 4, and a slot 53 is formed between each of the adjacent teeth 52 in which a coil 6 wound around the tooth 52 is arranged. The stator 5 has a molded resin part 30 in which the plurality of laminated plates 5t and the coil 6 are molded, and the molded resin part 30 has a flow path 32 formed in at least one of the plurality of slots 53, and a cooling medium is supplied to the flow path 32.

[0051] Thus, according to this embodiment, the molded resin part 30 in which the multiple laminated plates 5t and the coils 6 are molded in the stator 5 has the cooling medium flow paths 32 formed in all the slots 53, and it is possible to form a stator having the flow paths 32 through which the cooling medium is supplied by using conventional laminated plates without using a dedicated laminated plate for forming the flow paths 32 through which the cooling medium is supplied. In addition, since the flow paths 32 through which the cooling medium is supplied are formed in the molded resin part 30, it is possible to suppress an increase in eddy current loss due to magnetic flux generated in the stator 5 or the rotor 4, and prevent a decrease in motor efficiency.

[0052] In this case, the flow passage 32 is disposed on the rotor 4 side of the coil 6 within the slot 53 .

[0053] In this way, the flow passage 32 is disposed on the rotor 4 side of the coil 6 within the slot 53. Therefore, the flow passage 32 is disposed near the gap between the stator 5 and the rotor 4, and by lowering the temperature of the rotor 4 side portion of the stator 5, it is possible to reduce the temperature rise of the rotor 4 due to radiation from the stator 5. Therefore, by suppressing the rise in the bearing temperature of the motor shaft 3 supporting the rotor 4, the life of the bearing 12b is extended.

[0054] Specifically, the housing 2 has a cylindrical portion 2a and two cover members 2b, 2c that cover both sides of the cylindrical portion 2a, and the molded resin portion 30 has a plurality of flow paths 32 that each pass through all of the plurality of slots 53, and annular groove portions 60a, 60b that are formed on both end surfaces of the molded resin portion 30 and communicate with the plurality of flow paths 32, and the outer periphery of the molded resin portion 30 is in contact with the inner periphery of the cylindrical portion 2a, and both end portions of the molded resin portion 30 are arranged to face the two cover members 2b, 2c, respectively.

[0055] As a result, annular grooves 60a, 60b communicating with the multiple flow paths 32 that each pass through all of the slots 53 are formed on both end surfaces of the molded resin part 30. Therefore, by supplying the cooling medium to the grooves 60a, 60b of the molded resin part 30, the cooling medium passes through the multiple flow paths 32.

[0056] In this motor 1, annular seal members 62a, 62b, 63a, 63b are arranged between both end faces of the molded resin portion 30 and the two cover members 2b, 2c, respectively, on the radially inner side and the radially outer side of the groove portions 60a, 60b.

[0057] This makes it possible to prevent the cooling medium from leaking into the motor 1 and to maintain the inside of the housing 2 at a reduced pressure.

[0058] Furthermore, the rotor 4 of the motor 1 rotates in a reduced pressure space.

[0059] As a result, in the reduced pressure space, the generation of convection is significantly reduced even when the rotor 4 rotates, and heat is trapped in the rotor 4. Even in such a case, the present invention makes it possible to lower the temperature of the rotor 4.

[0060] The manufacturing method of the stator 5 is a manufacturing method of the stator 5 having a plurality of laminated plates 5t forming an annular yoke 51 and a plurality of teeth 52 protruding from an inner periphery of the yoke 51 toward the rotor 4, and includes a first step of winding the coils 6 around the teeth 52 and arranging the plurality of laminated plates 5t with the coils 6 wound thereon inside a lower mold for molding; a second step of arranging a first punch for forming an inner periphery of the stator 5 inside the lower mold for molding, inside the lower mold for molding, the plurality of laminated plates 5t with the coils 6 wound thereon; The method includes a third step of placing a second punch die for forming a cooling medium flow path 32 in at least one of the multiple slots 53 formed between adjacent teeth 52 in the multiple laminates 5t obtained by molding, a fourth step of attaching a mold upper die to a mold lower die to form a molding die, pouring resin into the molding die and hardening the resin, and a fifth step of removing the molded resin part 30 in which the multiple laminates 5t and the coils 6 are molded from the molding die after the resin has hardened in the molding die, and removing the first punch die and the second punch die from the molded resin part 30.

[0061] As a result, in the manufacturing method of the stator 5 of this embodiment, the molded resin part 30 in which the multiple laminated plates 5t and the coils 6 are molded in the stator 5 has the flow paths 32 for the cooling medium formed in each of the slots 53, and it is possible to form the stator 5 having the flow paths 32 for the cooling medium by using conventional laminated plates without using a dedicated laminated plate for forming the flow paths 32 for the cooling medium to be supplied. In addition, since the flow paths 32 for the cooling medium to be supplied are formed in the molded resin part 30, in the motor 1 including the stator 5 and the rotor 4, it is possible to prevent a decrease in motor efficiency by suppressing an increase in eddy current loss due to magnetic flux generated in the stator 5 or the rotor 4.

[0062] It should be noted that the specific configuration is not limited to the above-described embodiment.

[0063] In the above embodiment, the molded resin part 30 has a plurality of flow paths 32 formed in each of the plurality of slots 53, but the motor of the present invention includes a motor having a molded resin part 30 having a flow path 32 formed in at least one of the plurality of slots 53.

[0064] In the above embodiment, the flow paths 32 formed in the slots 53 in the molded resin part 30 are formed by through holes penetrating the molded resin part 30, but the flow paths 32 formed in the slots 53 are not limited to through holes. For example, the number, shape, cross-sectional shape, etc. of the flow paths 32 formed in one slot 53 are arbitrary.

[0065] In the above embodiment, the flow passage 32 is disposed on the rotor 4 side of the coil 6 within the slot 53, but the arrangement of the flow passage 32 within the slot 53 is not limited to this.

[0066] In the above embodiment, the multiple flow paths 32 are connected to the groove portions 61a, 61b, and the cooling medium is supplied to the multiple flow paths 32 through the groove portions 61a, 61b, but the cooling medium may be supplied to the multiple flow paths 32 without passing through the groove portions 61a, 61b.

[0067] In the above embodiment, the seal member 12c is disposed between the housing 2 and the motor shaft 3, but this is not limiting. The gap between the housing 2 and the motor shaft 3 may be sealed by, for example, a liquid packing or a metal seal.

[0068] In the above embodiment, the motor 1 in which the rotor 4 rotates in a reduced pressure space has been described, but the motor of the present invention is not limited to a motor in which the rotor rotates in a reduced pressure space.

[0069] In the above embodiment, the inner rotor type motor 1 has been described, but the present invention is also applicable to an outer rotor type motor.

[0070] Furthermore, in the above embodiment, the radial gap type motor 1 has been described, but the present invention is also applicable to an axial gap type motor.

[0071] In the above embodiment, the stator 5 is fixed by being press-fitted into the housing 2, but the method of fixing the stator 5 to the housing 2 is not limited thereto. A hole penetrating in the axial direction may be formed in the laminated plate 5t of the stator 5, and a screw hole may be formed in the surface of the housing 2 that contacts the end face of the stator 5, and the stator 5 may be fixed to the housing 2 using a bolt that passes through the hole in the laminated plate 5t. [Explanation of symbols]

[0072] 1 Motor 2. Chassis 2a Cylindrical part 2b, 2c Cover parts 4 Rotors 5 Stator 5t laminate 6 Coils 30 Molded resin part 32 Flow Path 51 York 52 Teeth 53 Slots 60a, 60b groove 62a, 62b, 63a, 63b Annular seal members

Claims

1. A motor comprising a stator having a plurality of teeth, a coil wound around the teeth, and slots formed between the teeth, the coil being provided in the slots, a mold resin portion that fills the slot and covers the coil; a flow path that is a through hole formed in the mold resin portion and passing through the slot; an inner wall of the flow path is made of a resin material that forms the mold resin portion, A motor, wherein a cooling medium flows inside the flow passage.

2. A motor as described in claim 1, characterized in that the flow path is provided on the rotational axis direction side of the coil.

3. A motor as described in claim 1 or 2, characterized in that the flow path is provided in the internal space of the slot, on the inner side of the stator and adjacent to the coil.

4. The molded resin portion has a molded portion covering each of the coil ends protruding from both axial ends of the stator, 4. The motor according to claim 1, wherein the molded portion has an annular groove that is connected to the flow passage and that centrifugally moves in a circumferential direction in which the cooling medium flows.

5. A member facing an end face of the molded part on which the groove portion is formed, 5. The motor according to claim 4, wherein two annular seal members are disposed on the radially inner side and the radially outer side of the groove on the end surface.

6. A housing having the stator and a rotor arranged with a gap between them disposed therein, 5. The motor according to claim 4, wherein the housing is formed with a cooling medium supply port communicating with the groove formed in one end face of the molded resin portion, and a cooling medium discharge port communicating with the groove formed in the other end face of the molded resin portion.

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