Stator core

Abstract

A stator core for use in a rotating electrical machine, the stator core comprising: a hollow cylindrical core body; and a cooling flow path that has an opening on a first surface and a second surface, which are both end surfaces in the axial direction of the core body, connects the end surfaces, and allows cooling oil to pass therethrough, in which a surface lipophilic region, which is a lipophilic region in contact with the opening, is formed around the opening on the first surface, and in which the surface lipophilic region has a surface lipophilic region in contact with the opening when viewed from the opening. And an oleophobic region is formed on the outer side of the surface lipophilic region.

Description

Technical Field

[0001] The present invention relates to a stator core. Background Art

[0002] Rotating electrical machines generate heat as they operate. The greater the output of a rotating electrical machine, the greater the heat generated. Therefore, cooling using a cooling medium such as oil is widely practiced. Patent Document 1 discloses a rotating electrical machine comprising: a stator having a stator core and a stator coil; a rotor that rotates relative to the stator; a refrigerant supply port for supplying a cooling medium to coil ends protruding from the stator core; and a guide member provided along at least a portion of the coil ends for directing the cooling medium supplied from the refrigerant supply port along the coil ends. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-035992 Summary of the Invention Problems to be solved by the invention

[0004] In the invention described in Patent Document 1, the cooling structure has room for improvement. Technical means to solve the problem

[0005] The first embodiment of the stator core of the present invention is used for a rotating electric machine, and the stator core comprises: a core body in a hollow cylindrical shape; and a cooling flow path, which has openings on a first surface and a second surface which are both axial end surfaces of the core body, and connects the two end surfaces so that cooling oil can pass through the interior. On the first surface, an oleophilic area, i.e., a surface oleophilic area, is formed around the opening and is connected to the opening. When viewed from the opening, an oleophobic area is formed on the outside of the surface oleophilic area. The second embodiment of the stator core of the present invention is used for a rotating electric machine, and the stator core comprises: a core body in a hollow cylindrical shape; and a plurality of cooling passages, which have openings on a first surface and a second surface which are both axial end surfaces of the core body, and connect the two end surfaces so that cooling oil passes through the inside; a plurality of slots for inserting coils are formed on the core body, and at at least one of the openings on the first surface of the core body, an oil-repellent area is formed on a straight line between the opening and the nearest slot. Effects of the Invention

[0006] According to the present invention, the cooling oil can cool a wider area of ​​the stator core. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a cross-sectional view of a rotating electrical machine. Figure 2 This is the main view of the stator core. Figure 3 It is a figure which shows the surface treatment of the core main body in embodiment. Figure 4 This is a diagram illustrating the effect. Figure 5 This is a cross-sectional perspective view of a stator core according to Modification 1. Figure 6 It is a figure which shows the surface treatment of the core main body in the modification example 2. Figure 7 This is a diagram showing a core body in Modification 3. Figure 8 This is an enlarged view of the outer peripheral groove in Modification 3. Figure 9 It is a figure which shows the surface treatment of the core main body in the modification example 5. DETAILED DESCRIPTION

[0008] ―Implementation Method― Below, refer to Figures 1 to 4 An embodiment of the stator core of the present invention will be described.

[0009] Figure 1 It is a cross-sectional view of the rotating electrical machine 100. In each of the drawings of this embodiment, mutually orthogonal XYZ axes are recorded together. The rotating electrical machine 100 has a stator core 10 that generates heat during operation. The stator core 10 has a ring shape, and the axis of the ring is parallel to the X-axis. The stator core 10 has a first surface 10S1 and a second surface 10S2 as two end surfaces in the axial direction. The stator core 10 has a cooling flow path 11 parallel to the axial direction. The cooling flow path 11 passes through the first surface 10S1 to the second surface 10S2, and cooling oil for cooling the stator core 10 flows inside. The cooling oil is supplied, for example, from the oil supply port 21 in the upper right of the figure, and reaches the first surface 10S1 through the cooling flow path 11. The negative side of the Z axis is the direction of gravity, and the cooling oil moves from the positive side of the Z axis to the negative side of the Z axis, that is, from the upper part of the figure to the lower part of the figure. The cooling oil flowing out from the upper portion due to gravity is collected in the oil reservoir 22 at the lower portion shown in the figure, and is moved toward the positive Z-axis direction by a pump (not shown) or the like, thereby cooling the stator core 10 again.

[0010] Figure 2 10 is a front view of the stator core 10. Figure 2 In, it means from Figure 1 The front side of the stator core 10 viewed from the negative direction of the X-axis, i.e., the first side 10S1. Figure 2 As shown in the lower part of FIG, the stator core 10 has a substantially circular ring shape in the front view. Figure 2In the figure, the area surrounded by the dotted trapezoid is enlarged and displayed. In the core body 10C constituting the stator core 10, cooling channels 11 are arranged at equal intervals on the outer periphery, and teeth 12 and slots 13 are arranged on the inner periphery. A coil 14 is arranged in each slot 13. The cooling channel 11 passes through to the other end face of the core body 10C on the positive side of the X-axis, that is, the second face 10S on the inner side of the figure. Hereinafter, the intersection of the cooling channel 11 and the first face 10S1 or the second face 10S2 is also referred to as the opening 11P. Figure 2 In the core body 10C, there are the same number of openings 11P, teeth 12, and slots 13. The slots 13 are located on a straight line connecting the center of the annular ring of the core body 10C and the openings 11P.

[0011] Figure 3 : This is a diagram showing the surface treatment of the core body 10C. The surface of the core body 10C is divided into an oleophilic region 10L where cooling oil easily blends in and an oleophobic region 10R that repels cooling oil. However, a portion of the surface of the core body 10C may not be either the oleophilic region 10L or the oleophobic region 10R, and may be, for example, an untreated region 10N that has not been subjected to any special treatment. Cooling oil easily penetrates the oleophilic region 10L and is difficult to penetrate the oleophobic region 10R. Figure 3 In FIG. 1 , the oleophilic region 10L is indicated by dotted hatching, and the oleophobic region 10R is indicated by oblique hatching. Figure 3 In the figure, the coil 14 is not recorded for the convenience of drawing.

[0012] The oleophilic region 10L and the oleophobic region 10R are formed by applying a known coating. The oleophilic region 10L is arranged around the opening 11P, and the oleophobic region 10R is formed outside the oleophilic region 10L when viewed from the opening 11P. The oleophobic region 10R can also be said to be arranged between the opening 11P and the groove 13. Figure 3 The oleophilic region 10L formed on the illustrated first surface 10S1 is referred to as a "surface oleophilic region 10LF."

[0013] Figure 4 This figure illustrates the effect. In this embodiment, the cooling oil flowing out of the opening 11P moves through the oleophilic region 10L and flows toward the slots 13 or the inner diameter side. Therefore, in this embodiment, the cooling oil can cool a wider area of ​​the stator core 10. In contrast, in a comparative example in which neither the oleophilic region 10L nor the oleophobic region 10R is formed on the surface of the core body 10C, the cooling oil sometimes flows linearly from the opening 11P toward the slots 13, resulting in insufficient cooling of the surface of the core body 10C by the cooling oil.

[0014] According to the above-described embodiment, the following effects can be obtained. (1) The stator core 10 is used for the rotating electric machine 100. The stator core 10 comprises: a core body 10C in a hollow cylindrical shape; and a cooling flow path 11 having openings 11P on a first surface 10S1 and a second surface 10S2, which are both axial end surfaces of the core body 10C, and connecting the two end surfaces so that oil for cooling passes through the inside. On the first surface 10S1, an oleophilic region, namely a surface oleophilic region 10LF, is formed around the opening 11P and in contact with the opening 11P. When viewed from the opening 11P, an oleophobic region 10R is formed on the outside of the surface oleophilic region 11LF. Therefore, as shown in FIG. Figure 4 As described above, the cooling oil can cool a wide range of the stator core 10 .

[0015] (2) The core body 10C is formed with a plurality of slots 13 for inserting the coils 14. The oleophobic region 10R is formed on a straight line connecting the opening 11P and the slots 13. This prevents the cooling oil from flowing linearly from the opening 11P into the slots 13, thereby extending the travel distance of the cooling oil on the first surface 10S1, that is, expanding the cooling area.

[0016] (Variation 1) Figure 5 is a cross-sectional perspective view of the stator core 10 of Modification 1. Figure 5 In FIG, only a portion of the stator core 10 is cut out for illustration. The slot 13 is the area between the teeth 12. Figure 5 The oleophobic region 10R is located near the front and rear sides of the tooth 12. The upper portion of the diagram shows the first surface 10S1. The arrangement of the opening 11P, oleophobic region 10R, and surface oleophilic region 11LF is the same as in the first embodiment. In this variation, an insulating oleophilic region, or side oleophilic region 10LS, is formed on the side surface of the tooth 12, approximately perpendicular to the first surface 10S1.

[0017] According to this modification 1, in addition to the effects of the embodiment, the following effects can be obtained. (3) The core body 10C includes slots 13 and a plurality of teeth 12 separating the slots 13. Side surface lipophilic regions 10LS, which are insulating and oleophilic regions, are formed on the side surfaces of the teeth 12 that are approximately perpendicular to the first surface 10S1. Therefore, no insulating paper is required between the coils 14 and the teeth 12.

[0018] (Variation 2) Figure 6This figure illustrates the surface treatment of the core body 10C in Modification 2. In the embodiment, the entire tooth 12 on the first surface 10S1 forms the surface lipophilic region 11LF. However, the innermost periphery may also be an untreated region 10N that has not undergone any special treatment. In other words, the surface of the tooth 12 other than the innermost periphery may also form the surface lipophilic region 11LF. The length d of the untreated region 10N is not particularly limited and, for example, may exceed the length D of the slot 13.

[0019] According to this modification example 2, in addition to the effects of the embodiment, the following effects can be obtained. (4) On the first surface 10S1, the surfaces of the teeth 12, excluding the innermost circumference, are provided with an oleophilic region. Therefore, the cooling oil easily flows into the slots 13 rather than into the inner circumference of the core body 10C, thereby making contact with the coils 14 disposed in the slots 13 and removing heat.

[0020] (Variation 3) Figure 7 This figure shows a core body 10C in Modification 3. This embodiment differs from the embodiment in that an axially extending outer circumferential groove 15 is provided on the outer periphery. The outer circumferential groove 15 may be provided in one, two, or three or more at a 180-degree angle.

[0021] Figure 8 is an enlarged view of the peripheral groove 15. Specifically, Figure 8 The upper part of the peripheral groove 15 is a three-dimensional diagram. Figure 8 The lower part of the diagram shows a front view of the peripheral groove 15. Figure 8 , the outer peripheral groove 15 extends from the first surface 10S1 to the second surface 10S2. In addition, a groove portion lipophilic region 15L serving as a lipophilic region is formed at the end portion of the outer peripheral groove 15 on the first surface 10S1 side.

[0022] According to this modification example 3, in addition to the effects of the embodiment, the following effects can be obtained. (5) The core body 10C has an axially extending outer peripheral groove 15 on its outer periphery. An oleophilic groove region 15L is formed at the end of the outer peripheral groove 15 on the first surface 10S1 side. Therefore, cooling oil can be guided to the outer peripheral groove 15 while minimizing the reduction in cooling performance. If the entire outer peripheral groove 15 is an oleophilic region, the entire outer peripheral groove 15 is covered by the coating film, narrowing the area of ​​direct contact between the cooling oil and the core body 10C and reducing the cooling effect.

[0023] (6) A plurality of outer peripheral grooves 15 are provided. This facilitates the flow of cooling oil.

[0024] (Variation 4) In the embodiment, the surface oleophilic region 10LF and the oleophobic region 10R are formed on the first surface 10S1. However, the surface oleophilic region 10LF and the oleophobic region 10R are formed not only on the first surface 10S1 but also on the second surface 10S2. Furthermore, the surface oleophilic region 10LF formed on the second surface 10S2 is also referred to as the "second-surface surface oleophilic region."

[0025] According to this modification 4, in addition to the effects of the embodiment, the following effects can be obtained. (7) On the second surface, a second surface lipophilic region is formed around the opening 11P and in contact with the opening 11P. Therefore, the cooling oil can cool a wide range of the stator core 10 on both surfaces of the core body 10C.

[0026] (Variant 5) Figure 9 10 is a diagram showing the surface treatment of the core body 10C in Modification 5. In the embodiment, the surface oleophilic region 10LF and the oleophobic region 10R are formed on the first surface 10S1. However, as Figure 9 As shown, the surface lipophilic region 10LF may not be provided on the first surface 10S1. Figure 9 From the implementation Figure 3 The surface lipophilic region 10LF is changed to an untreated region 10N.

[0027] According to this modification example 5, the following effects can be obtained. (8) In at least one opening 11P of the first surface 10S1, an oleophobic region 10R is formed on a straight line between the opening and the nearest slot 13. Therefore, even without providing an oleophilic region, the cooling oil can cool a wide area of ​​the stator core 10.

[0028] (Variation 6) In the above embodiment, the center of the core body 10C, the slots 13, and the openings 11P are aligned in a straight line. However, they may be arranged in a non-straight line but may be phase-shifted, and the number of slots 13 and openings 11P may be different.

[0029] The above embodiments and modifications may also be combined. In the above, various embodiments and modifications are described, but the present invention is not limited to these contents. Other modes considered within the scope of the technical concept of the present invention are also included in the scope of the present invention. Explanation of symbols

[0030] 10: stator core 10C: Iron core 10L: lipophilic area 10LF: Surface lipophilic area 10LS: Side lipophilic area 10N: Untreated area 10R: Oleophobic area 10S1: First side 10S2: Side 2 11: Cooling flow path 11LF: Surface lipophilic area 11P: Opening 12: Teeth 13: Slot 14: Coil 15: Peripheral groove 15L: Groove lipophilic area 100: Rotating motor.

Claims

1. A stator core for a rotating electrical machine, the stator core comprising: a core body in a hollow cylindrical shape; and A cooling flow path has openings on the first and second surfaces, which are both axial end surfaces of the core body, and connects the two end surfaces so that cooling oil passes through the interior. On the first surface, a lipophilic region, namely, a surface lipophilic region, is formed around the opening and in contact with the opening. When viewed from the opening, an oleophobic region is formed outside the surface oleophilic region.

2. The stator core according to claim 1, characterized in that A plurality of slots for inserting coils are formed on the core body. The oleophobic region is formed on a straight line connecting the opening and the groove.

3. The stator core according to claim 1, wherein: The core body is provided with a plurality of slots for inserting coils and a plurality of teeth for separating the slots from each other. An insulating lipophilic region, namely, a side lipophilic region, is formed on a side surface of the tooth that is substantially perpendicular to the first surface.

4. The stator core according to claim 1, wherein: The core body is provided with a plurality of slots for inserting coils and a plurality of teeth for separating the slots from each other. On the first surface, an oleophilic region is formed on the surface of the teeth except for the innermost periphery.

5. The stator core according to claim 1, wherein: The core body has an outer peripheral groove extending in the axial direction on the outer peripheral portion. An oleophilic region is formed at an end portion of the outer peripheral groove on the first surface side.

6. The stator core according to claim 5, characterized in that The outer peripheral groove is provided in plurality.

7. The stator core according to claim 1, characterized in that On the second surface, a second surface lipophilic region is formed around the opening and in contact with the opening.

8. A stator core for a rotating electrical machine, the stator core comprising: a core body in a hollow cylindrical shape; and A plurality of cooling flow paths have openings on the first and second surfaces, which are both axial end surfaces of the core body, and connect the two end surfaces so that cooling oil can pass through the inside. A plurality of slots for inserting coils are formed on the core body. In at least one of the openings of the first surface, an oleophobic region is formed on a straight line between the opening and the nearest groove.

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