electric motor

Abstract

To provide a dynamo-electric motor that cools a rotor with a simple structure, and has a good energy efficiency.SOLUTION: A dynamo-electric motor includes: a stator fixed into a housing; a shaft; a rotor core fixed to the shaft; a first end plate and a second end plate that nip the rotor core from both end sides of a shaft direction of the shaft, and includes: a rotor rotatably supported to an inner side of the stator; and a rotor nozzle that is provided into the housing, and injects a coolant toward the first end plate. By a plurality of penetration holes having the first end plate, the second end plate, and the rotor core, a plurality of coolant flow channels penetrated to the second end plate from the first end plate is formed, and on a front surface on the side opposite to the rotor core of the first end plate, a guide part for guiding the coolant injected from the rotor nozzle to the coolant flow channel is formed to between the plurality of penetration holes.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a structure for cooling the rotor of an electric motor. [Background technology]

[0002] A conventional cooling structure for the rotor of an electric motor is described in Patent Document 1. As shown in Fig. 6, a conventional electric motor 1 has a stator 4 fixed inside a housing 2 of the electric motor 1, and a rotor 6 rotatably supported inside the stator 4. The rotor 6 has a shaft 8 rotatably supported at both ends by bearings 14, a rotor core 10 fixed around the shaft 8, and end plates 12 fixed to both sides of the rotor core 10 in the axial direction of the shaft. A magnet (not shown) is embedded in the rotor core 10.

[0003] To cool the rotor 6, a flow path 16 for a coolant (e.g., oil) is formed in the shaft 8, rotor core 10, and end plate 12. A pair of seal rings 20 are provided on either side of a coolant inlet 18 formed at the end of the shaft 8, and the outlet of a flow path 22 formed in the housing 2 faces between the pair of seal rings 20. This structure allows the coolant to be supplied into the rotor 6 even while the rotor 6 is rotating, thereby cooling the rotor core 10. The arrows in the figure indicate the flow of the coolant.

[0004] A plurality of stator nozzles 25 are provided inside the housing 2, which spray a coolant (for example, oil) for cooling the stator 4 toward the stator 4, so that the coolant is sprayed onto the stator 4 to cool it.

[0005] The refrigerant that has passed through the flow path 16 of the rotor 6 to cool the rotor 6 and the refrigerant that has been applied to the stator 4 to cool the stator 4 are discharged from an outlet (not shown) formed in the housing 2. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-170150 Summary of the Invention [Problem to be solved by the invention]

[0007] Conventional electric motors have complex structures, including seal rings and flow passages for supplying refrigerant to the rotor, which rotates at high speed. Furthermore, the complicated structure, including the provision of seal rings, increases rotational resistance, reducing the energy efficiency of the motor.

[0008] An object of the present disclosure is to provide an electric motor that has a simple structure, cools the rotor, and is energy efficient. [Means for solving the problem]

[0009] The electric motor of the present disclosure includes a stator fixed within a housing, a shaft, a rotor core fixed to the shaft, and first and second end plates that sandwich the rotor core from both axial ends of the shaft; a rotor rotatably supported inside the stator; and a rotor nozzle provided within the housing that sprays a refrigerant toward the first end plate, wherein a plurality of refrigerant flow paths extending from the first end plate to the second end plate are formed by a plurality of through holes in the first end plate, the second end plate, and the rotor core, and guide portions that guide the refrigerant sprayed from the rotor nozzle to the refrigerant flow paths are formed between the plurality of through holes on the surface of the first end plate opposite the rotor core. The plurality of through holes formed in the first end plate are formed on the same circumference around the axis of the shaft, and the guide portion is formed inside the circumference along the circumference so as to connect the plurality of through holes formed in the first end plate. . [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide an electric motor that has a simple structure for cooling the rotor and is energy efficient. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 2 is a diagram showing the internal structure of an electric motor. [Figure 2] FIG. 10 is a view showing a first end plate. [Figure 3] FIG. 10 shows a second end plate. [Figure 4] FIG. 3 is a diagram showing the flow of a refrigerant when cooling an electric motor. [Figure 5] FIG. 10 is a diagram showing a modified example of the first end plate. [Figure 6] FIG. 1 is a diagram showing the internal structure of a conventional electric motor. DETAILED DESCRIPTION OF THE INVENTION

[0012] An example of an electric motor according to the present disclosure will be described below with reference to the drawings. Fig. 1 shows an outline of an electric motor 1 according to the present disclosure. A stator 4 is fixed to a housing 2. The stator 4 has a stator core and a coil wound around the stator core.

[0013] A rotor 6 is journaled on the housing 2 inside the stator 4. The rotor 6 has a shaft 8, a rotor core 10 fixed to the shaft 8, and a first end plate 30 and a second end plate 40 that sandwich the rotor core 10 from both axial sides of the shaft 8. An opening is formed in the rotor core 10 in the axial direction, and a magnet is embedded inside. Both ends of the shaft 8 are supported by bearings 14 on the housing.

[0014] A plurality of through holes are formed in each of the first end plate 30, the second end plate 40, and the rotor core 10. These through holes are aligned in the axial direction, and a plurality of refrigerant passages 46 are formed as a whole.

[0015] A rotor nozzle 24 is provided inside the housing 2, which sprays refrigerant toward the first end plate 30. The rotor nozzle 24 is directed toward the center of the end plate 30. A plurality of stator nozzles 25 are also provided, which spray refrigerant toward the end of the stator 4.

[0016] 2 and 3 show the end plates in detail. Fig. 2 shows the first end plate 30 on the side where the rotor nozzle 24 is provided. The overall shape is circular, with a shaft hole 35 formed in the center through which the shaft 8 passes. Outside the shaft hole 35, a plurality of through holes 31 each having a substantially arc shape are formed at equal intervals on the same circumference. Inside adjacent through holes 31, a guide protrusion 33 having a substantially arc shape is formed to connect the through holes 31.

[0017] 3 shows the second end plate 40 on the opposite side from the rotor nozzle 24. It has a circular shape and is approximately the same size as the first end plate 30, and the shaft hole 45 and through hole 41 are also approximately the same shapes and formed in the same positions as those in the first end plate 30. In addition, an annular protrusion 43 is formed outside the through hole 41 so as to surround the through hole 41.

[0018] The first end plate 30 is fitted onto the shaft 8 so that the guide protrusion 33 faces away from the rotor core 10, and the second end plate 40 is fitted onto the shaft 8 so that the annular protrusion 43 faces away from the rotor core 10, with both end plates 30, 40 sandwiching the rotor core 10. At this time, the through holes 31, 41 of both end plates 30, 40 and the through hole 47 of the rotor core 10 are aligned so as to be in a straight line in the axial direction of the shaft 8.

[0019] 4 shows the state in which refrigerant is sprayed from rotor nozzle 24 and stator nozzle 25 while the rotor is rotating. When refrigerant is sprayed from rotor nozzle 24 near the connection between first end plate 30 and shaft 8, it moves outward on first end plate 30 due to centrifugal force. Then, some of the refrigerant that reaches through hole 31 passes through through hole 31 and through hole 47 and exits rotor 6 from through hole 41 in second end plate 40.

[0020] In addition, a portion of the refrigerant that moves over the first end plate 30 and reaches the guide protrusion 33 is guided toward the through hole 31, and then passes through the through hole 31 and the through hole 47 and exits the rotor 6 through the through hole 41 of the second end plate 40.

[0021] The refrigerant that has left the rotor 6 moves outward on the second end plate 40 due to centrifugal force. Then, the refrigerant that has reached the annular protrusion 43 rides up onto the annular protrusion 43, splashes outward so as not to come into contact with the stator 4, reaches the housing 2, and then reaches the bottom of the housing 2 due to gravity.

[0022] The refrigerant sprayed from the stator nozzle 25 cools the stator 4 and reaches the bottom of the housing 2 by gravity.

[0023] The refrigerant that reaches the bottom of the housing 2 is discharged to the outside of the housing 2 through a discharge port (not shown) provided in the housing 2.

[0024] 5 shows a modified example of the first end plate. In this example, annular catchers 55 are formed on the outside of the plurality of through holes 51. Catchers 55 are annular protrusions formed adjacent to the plurality of through holes 51 on the outside and have approximately the same height as guide protrusions 53.

[0025] According to this modification, the refrigerant that does not enter through-hole 51 is received by catcher 55, so the amount of refrigerant guided to through-hole 51 can be increased, and rotor 6 can be cooled more efficiently.

[0026] The above-described embodiment can be modified as appropriate within the scope specified by the claims. The number, shape, and position of the through holes formed in the first end plate, the second end plate, and the rotor core are designed as appropriate depending on the degree of heat generation of the rotor, etc. The size, shape, and position of the guide protrusions and annular protrusions are designed as appropriate so that the refrigerant is efficiently guided into the through-hole structure. [Industrial Applicability]

[0027] According to the present disclosure, the rotor of the electric motor can be cooled appropriately. [Explanation of symbols]

[0028] 1 electric motor 2. Case 4 Stator 6 rotors 8 shafts 10 rotor core 14 Bearings 24 Rotor nozzle 25 Stator nozzle 30 First end plate 33 Guide protrusion 40 Second end plate 43 Annular convex part 50 First end plate (modified example) 53 Guide protrusion

Claims

1. a stator fixed within a housing; a rotor having a shaft, a rotor core fixed to the shaft, and a first end plate and a second end plate sandwiching the rotor core from both axial ends of the shaft, the rotor being rotatably supported inside the stator; a rotor nozzle provided in the housing and configured to spray a coolant toward the first end plate; and a plurality of through holes formed in the first end plate, the second end plate, and the rotor core define a plurality of refrigerant flow paths extending from the first end plate to the second end plate; a guide portion for guiding the refrigerant sprayed from the rotor nozzle to the refrigerant flow path is formed between the plurality of through holes on a surface of the first end plate opposite to the rotor core, the plurality of through holes formed in the first end plate are formed on the same circumference around the axis of the shaft, and the guide portion is formed along the circumference on the inside of the circumference so as to connect the plurality of through holes formed in the first end plate; Electric motor.

2. a catcher is formed on the surface of the first end plate outside the through hole; 2. The electric motor according to claim 1.

3. an annular protrusion is formed on the outer side of the through hole of the second end plate; 2. The electric motor according to claim 1.

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