JP6197462B2 - Stator coil cooling structure and method of manufacturing stator coil cooling structure - Google Patents

Description

  The present invention relates to formation of a cooling passage to a stator coil of a rotating electrical machine such as an electric motor or a generator.

  A stator coil of a rotating electrical machine such as an electric motor or a generator is configured by winding a coil in a slot opened in the inner periphery of a cylindrical stator core. Coil ends, which are bent portions of the coil, protrude in the axial direction from both end faces of the stator core. In order to dissipate the heat generated by the coil associated with the operation of the rotating electrical machine, Patent Document 1 proposes that the coil end is covered with a cooling jacket, and that a refrigerant passage for flowing the refrigerant is provided inside the cooling jacket.

  An insulating base plate is attached to the end surface of the stator core, which is a laminate of steel plates, and an adapter for closing the slot is attached to the inner peripheral surface of the stator core. The cooling jacket seals the coolant passage by being in close contact with the base plate and the adapter.

JP 2006-271150 A

  The stator coil cooling structure according to the prior art requires various parts such as a base plate and an adapter in order to define the refrigerant passage, and there is a problem that the number of parts increases and the cost is high. Since these parts are mounted after winding on the teeth of the stator core, there is a risk of damaging the insulating film of the winding during the mounting operation. In addition, a space for mounting components such as a base plate and an adapter is also required, which causes an increase in the size of the steer core and hence the rotating electrical machine.

  The present invention has been made to solve such problems of the prior art relating to the cooling structure of the steer core, and an object thereof is to provide a simple and compact cooling structure of the stator coil.

In order to achieve the above object, the present invention provides a stator coil cooling structure in which a cooling passage through which a coolant flows is formed inside a cooling cover attached to a coil end of the stator coil. The cooling structure includes a film wall that fills the gap between the wires constituting the coil end and defines a cooling passage.

  The cooling passage is defined by a cooling cover and a film wall provided in the cooling cover. Therefore, the number of parts for defining the cooling passage is small and can be manufactured at low cost. Further, it is not necessary to secure a space in the cooling cover for the cooling passage defining member, and the stator core having the cooling passage can be configured in a compact manner. As a result, the manufacturing cost of the rotating electrical machine can be reduced.

1 is a longitudinal sectional view of an electric motor according to an embodiment of the present invention. It is a principal part perspective view of the membrane wall by embodiment of this invention. It is a longitudinal cross-sectional view of the principal part of a stator coil explaining the injection | pouring process of the filler to the inside of a cover by embodiment of this invention. It is a longitudinal cross-sectional view of the stator coil principal part explaining the film | membrane wall formation process by embodiment of this invention. It is a longitudinal cross-sectional view of the principal part of a stator coil explaining the taking-out process of the filler by embodiment of this invention. It is a longitudinal cross-sectional view of the electric motor explaining the utilization form of the cooling passage by embodiment of this invention. It is a longitudinal cross-sectional view of the electric motor explaining the another utilization form of the cooling channel by embodiment of this invention. It is a longitudinal cross-sectional view of the stator coil principal part which shows another embodiment of this invention regarding the formation position of a membrane wall. It is a longitudinal cross-sectional view of the stator coil principal part which shows another embodiment of this invention regarding support of a membrane wall.

  Embodiments of the present invention will be described below with reference to the drawings.

  An electric motor 1 as a rotating electrical machine includes a stator having a coil wound around a stator core 2 and a rotor 4 that rotates inside the stator. The rotor 4 includes a rotating shaft 5.

  The stator core 2 is formed by laminating steel plates in the axial direction, and has a cylindrical shape. Slots in the axial direction are formed at equal angular intervals on the inner periphery of the stator core 2. Coils are wound around these slots. The bent portion of the winding, that is, the coil end 3 protrudes from the stator core 2 on both sides in the axial direction.

  The coil end 3 is covered with a cooling cover 7 having a ring-like substantially U-shaped cross section. The rotating shaft 5 is rotatably supported by the cooling cover 7 via a bearing 6. A membrane wall 8 is formed inside the cooling cover 7.

  Referring to FIG. 2, the film wall 8 is made of a polymer material such as epoxy resin or silicon resin, and is infiltrated between the wire rods 3 </ b> A of the coil end 3 to be solidified to form the film wall 8. As the polymer material for forming the membrane wall 8, it is desirable to select a material having excellent adhesion to the wall surface of the cooling cover 7 and adhesion to the varnish attached to the coil end 3A.

  Referring to FIG. 1 again, the cooling cover 7 includes three wall surfaces, that is, an outer peripheral wall 7A, an inner peripheral wall 7B, and a bottom surface 7C connecting the outer peripheral wall 7A and the inner peripheral wall 7B. As shown in the figure, the inner peripheral wall 7B and the outer peripheral wall 7A of the cooling cover do not reach the end face of the stator core 2, but between the inner peripheral wall 7B and the end face of the stator core 2, and between the outer peripheral wall 7A and the stator core 2. A ring-shaped gap is formed between each end face. On the other hand, the membrane wall 8 is provided across the coil end 3 between the outer peripheral wall 7A and the inner peripheral wall 7B.

  As a result, a cooling passage 10 is defined inside the cooling cover 7 by the outer peripheral wall 7A, the inner peripheral wall 7B, the bottom surface 7C, and the membrane wall 8. A coolant supply / discharge port 9 communicating with the cooling passage 10 is formed on the bottom surface 7 </ b> C of the cooling cover 7. When the electric motor 1 is in operation, the cooling passage 10 is filled with the refrigerant. As a result, the heat generated by the coil accompanying the movement of the electric motor 1 is released to the outside through the coil end 3 and the refrigerant in the cooling passage 10, thereby cooling the stator coil.

  The stator coil cooling structure described above is manufactured by the manufacturing process described below.

  Referring to FIG. 3, a liquid filler 11 is injected into the cooling cover 7 with the port 9 closed. The filler 11 is made of wax that liquefies when heated, for example. The filling operation of the filler 11 is performed as follows.

  That is, while supporting the stator so that the opening of the cooling cover 7 on the left side of FIG. 1 faces upward, the liquid filler 11 is removed from the gap between the outer peripheral wall 7A of the cooling cover 7 and the end face of the stator core 2 with the cooling cover. Inject into 7. This operation is performed in a state where the rotor 4 is housed inside the stator core 2 and the rotating shaft 5 is rotatably supported by the cooling cover 7 via the bearing 6.

  Next, referring to FIG. 4, after the filler 11 is injected to a predetermined level, the injected filler 11 is solidified. When wax is used for the filler 11, the filler 11 is solidified in the process of being cooled to room temperature.

  In a state where the filler 11 is solidified, a liquid resin such as an epoxy resin or a silicone resin is injected from the gap between the outer peripheral wall 7A of the cooling cover 7 and the end surface of the stator core 2 so as to cover the surface of the filler 11. To do. As shown in FIG. 2, the injected resin permeates between the wire rods 3A of the coil end 3 and forms a thin film between the outer peripheral wall 7A and the inner peripheral wall 7B of the cooling cover 7. A curing agent is mixed in the resin in advance. When a certain time has passed after the injection, the thin film forms the film wall 8 having the outer periphery bonded to the outer peripheral wall 7A of the cooling cover 7 and the inner periphery bonded to the inner peripheral wall 7B of the cooling cover 7 by the action of the curing agent.

  Referring to FIG. 5, the filler 11 is removed from the cooling cover 7 in this state. When wax is used for the filler 11, the cooling cover 7 is heated to liquefy the filler 11 again and flow out from the port 9. With this heating of the filler 11, the membrane wall 8 is also heated. Therefore, the polymer material constituting the membrane wall 8 needs to be composed of a material having a heat resistant temperature exceeding the melting point of the filler 11.

  After the filler 11 is taken out of the cooling cover 7 by the above process, the cooling passage 10 including the coil end 3A and sealed by the film wall 8 is formed inside the cooling cover 7. The cooling structure of the stator coil is completed by filling the cooling passage 10 with the refrigerant through the port 9 of the cooling cover 7.

  When the electric motor 1 is operated in a state where the cooling passage 10 is filled with the refrigerant, the stator coil generates heat. This heat is released from the coil end 3 </ b> A protruding from both ends of the stator core 2 to the refrigerant in the cooling passage 10.

  According to this embodiment, the cooling passage 10 can be formed only by forming the membrane wall 8 that connects the outer peripheral wall 7A and the inner peripheral wall 7B across the coil end 3A inside the cooling cover 7. Therefore, the number of parts for defining the cooling passage 10 is small, and cooling of the stator coil can be realized at low cost. Further, it is not necessary to secure a space for the defining member of the cooling passage 10, and the stator coil provided with the cooling passage 10 can be configured in a compact manner. As a result, the manufacturing cost of the electric motor 1 can be reduced.

  By configuring the membrane wall 8 with a polymer material, the cooling passage 10 can maintain high liquid tightness. In addition, a large number of members for securing liquid tightness used in the prior art can be omitted. Therefore, also in this respect, a favorable effect is brought about in reducing the manufacturing cost of the electric motor 1.

  According to the manufacturing process shown in this embodiment, after forming a thin film of a polymer material on the filler 11, the film 11 is removed after waiting for the thin film to harden, thereby forming an independent film wall 8. To do. Accordingly, it is possible to simplify the operation of forming the membrane wall 8 that defines the cooling passage 10 and to prevent the coil end 3 from being damaged when the cooling passage 10 is formed. Therefore, a favorable effect is obtained for improving productivity in manufacturing the electric motor 1.

  Further, since the filler 11 is taken out using the refrigerant supply / discharge port 9 provided in the cooling cover 7, it is not necessary to provide a dedicated filler outlet in the cooling cover 7. Therefore, the structure of the cooling cover 7 is not complicated, and the manufacturing process can be simplified.

  Various uses of the cooling passage 10 can be considered.

  Referring to FIG. 6, here, a plurality of ports 9 including an inflow port 9A and an outflow port 9B are formed in the cooling cover 7, and the refrigerant is constantly supplied from the inflow port 9A to the cooling passage 10, and the refrigerant is supplied from the outflow port 9B. The refrigerant in the cooling passage 10 is always discharged. The discharged refrigerant is cooled by a cooling mechanism such as a radiator and then supplied to the inflow port 9A again. Thus, the cooling efficiency of the electric motor 1 can be increased by circulating the refrigerant through the cooling passage 10 via the port 9.

  Referring to FIG. 7, here, after the cooling passage 10 is filled with the refrigerant, the port 9 of the cooling cover 7 is closed with a plug 13. In this case, the refrigerant always stays in the cooling passage 10. In this case, although the cooling efficiency is low as compared with the case where the refrigerant is circulated with the external cooling mechanism, the configuration of the electric motor 1 can be simplified while maintaining the appropriate cooling efficiency.

  In this embodiment, the membrane wall 8 is formed between the outer peripheral wall 7A of the cooling cover 7 and the inner peripheral flange. However, the formation position of the film wall 8 is not limited to this. The membrane wall 8 can be formed by connecting any two of the three wall surfaces of the outer peripheral wall 7A and the inner peripheral wall 7B of the cooling cover 7 and the bottom surface 7C connecting them. Thus, the present invention brings about a preferable effect in increasing the degree of freedom in designing the cooling structure of the stator coil.

  With reference to FIG. 8, another embodiment of the present invention relating to the formation position of the membrane wall 8 will be described.

  In this embodiment, the cooling cover 7 is composed only of the outer peripheral wall 7A and the bottom surface 7C, and the inner peripheral wall 7B is omitted. A film wall 8 is formed between the outer peripheral wall 7A and the bottom surface 7C of the cooling cover 7. In this case, a region surrounded by the outer peripheral wall 7A, the bottom surface 7C, and the membrane wall 8 of the cooling cover becomes the cooling passage 10. According to this embodiment, although the cross-sectional area of the cooling passage 10 is reduced, the cooling passage 10 can be defined with the minimum number of parts as in the embodiment of FIG. 1, and the stator coil can be cooled at low cost. Can do. Therefore, it becomes possible to manufacture the electric motor 1 that is compact and excellent in cooling performance at low cost.

  With reference to FIG. 9, still another embodiment of the present invention will be described.

  In this embodiment, the film wall 8 is formed between the outer peripheral wall 7A and the inner peripheral wall 7B of the cooling cover 7 as in the embodiment of FIG. In this embodiment, the grooves 12 are formed in advance at the positions where the outer peripheral wall 7A of the cooling cover 7 and the film wall 8 of the inner peripheral wall 7B are formed. The formation procedure of the membrane wall 8 is the same as the embodiment of FIG. That is, after the filler 11 is injected into the cooling cover 7 and solidified, the polymer material is injected onto the filler 11 and penetrates into the gaps between the wire rods 3 </ b> A of the coil end 3 to form a thin film.

  At this time, when the polymer material enters the groove 12 and solidifies, the film wall 8 is firmly adhered to the outer peripheral wall 7A and the inner peripheral wall 7B of the cooling cover 7. As a result, the strength of the membrane wall 8 after removing the filler 11 can be improved.

  As described above, the present invention has been described through some specific embodiments. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications or changes to these embodiments within the scope of the claims.

  As described above, the present invention has been described through some specific embodiments, but the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications or changes to these embodiments within the scope of the claims.

  For example, each of the above embodiments is directed to an electric motor, but the present invention is also applicable to a generator.

  Further, in each of the above embodiments, the filler 11 is filled into the cooling cover 7 from the gap between the outer peripheral wall 7A of the cooling cover 7 and the end face of the stator core 2. It is also possible to carry out the filling via the port 9.

DESCRIPTION OF SYMBOLS 1 Electric motor 2 Stator core 3 Coil end 3A Wire rod 4 Rotor 5 Rotating shaft 6 Bearing 7 Cooling cover 7A Outer peripheral wall 7B Inner peripheral wall 7C Bottom surface 8 Membrane wall 9 Port 9A Inflow port 9B Outflow port 10 Cooling passage 11 Filler 12 Groove 13 Plug

Claims (6)

In the stator coil cooling structure in which a cooling passage for flowing a coolant is formed inside a cooling cover attached to the coil end of the stator coil,
Cooling structure of the stator coil, characterized in that it comprises a membrane wall defining said cooling passage with fill gaps of the wire constituting the coil end. The cooling cover has a plurality of walls defining said cooling passage, wherein the membrane wall of the stator coil according to claim 1, wherein formed between any two walls, that of the plurality of wall Cooling structure. Cooling structure according to claim 1 or 2 of the stator coil and the membrane wall is characterized by consisting of a polymeric material, it.   The stator coil cooling structure according to any one of claims 1 to 3, wherein a groove is formed in advance at a position corresponding to the film wall inside the cooling cover. In the manufacturing method of the cooling structure of the stator coil in which the cooling passage for flowing the refrigerant is formed inside the cooling cover attached to the coil end of the stator coil,
The inside of the cooling cover attached to the end of the stator coil solidified by injecting a filler,
Solidified by injecting a liquid resin on the filler to diffuse in a film form,
A method for manufacturing a stator coil cooling structure, wherein the filler is taken out after the resin is cured. The cooling cover includes a port for coolant supply and discharge, the filler manufacturing method of the cooling structure of the stator coil according to claim 5, characterized in that, taken out from the port for the refrigerant supply and discharge.

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