motor

Abstract

To appropriately cool a coil end of a motor.SOLUTION: A motor includes a rotor. The motor includes a stator having a stator core and a coil. The motor includes a housing which houses the rotor and the stator. The motor includes a first annular member which seals between a first end surface in the axial direction of the stator core and an inner wall surface of the housing. The first annular member has a cylindrical shape with an axis of the stator core as the center. The first annular member has at least one first hole and at least one second hole which jet a coolant toward a first coil end of the coil protruding from the first end surface of the stator core. The at least one first hole is located on a first plane perpendicular to the axis. The at least one second hole is located on a second plane perpendicular to the axis and axially away from the first plane.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a motor.

[0002] In the motor shown in Patent Document 1, a stator is housed inside a housing. A plurality of injection holes are arranged in an annular member that seals the axial end face of the stator core and the inner surface of the housing. Refrigerant can be injected from each of the plurality of injection holes toward the coil end.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Due to various factors such as the mounting position of the motor and the usage environment (e.g., inclination), the heat generation distribution at the coil end may increase. Then, there may be a region where it is difficult to appropriately cool the coil end.

Means for Solving the Problems

[0005] The motor comprises a rotor. The motor comprises a stator having a stator core and coils. The motor comprises a housing that accommodates the rotor and stator. The motor comprises a first annular member that seals the space between a first axial end face of the stator core and the inner wall surface of the housing. The first annular member has a cylindrical shape centered on the axis of the stator core. The first annular member comprises at least one first hole and at least one second hole into which a coolant is injected toward the first coil end of the coils protruding from the first end face of the stator core. At least one first hole is located on a first plane perpendicular to the axis. At least one second hole is located on a second plane perpendicular to the axis and spaced axially apart from the first plane.

[0006] The refrigerant can be of various types, such as cooling oil. The refrigerant may also be a liquid such as water, or a fluid containing gases, etc. In the above configuration, the axial positions of the first hole and the second hole are different. Therefore, by selecting at least one of the first and second holes, the axial position of the refrigerant injection can be adjusted. This makes it possible to adjust the refrigerant injection area as needed, enabling proper cooling of the coil end. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic cross-sectional view of motor 1. [Figure 2] This is a side view of the stator 20, etc. [Figure 3A] This is a cross-sectional view taken from the first plane P1. [Figure 3B] This is a cross-sectional view taken from the second plane P2. [Figure 4] This is a partially enlarged cross-sectional view along line IV-IV in Figure 2. [Figure 5] This is a schematic cross-sectional view of the VV line passing through the central plane CP in Figure 1. [Figure 6] This is a schematic cross-sectional view of motor 1. [Figure 7A] This is a cross-sectional view taken from the first plane P1. [Figure 7B] This is a cross-sectional view taken from the second plane P2. [Figure 8A] This is a cross-sectional view taken from the first plane P1. [Figure 8B] This is a cross-sectional view taken from the second plane P2. [Figure 9] This is a cross-sectional view taken from the second plane P2. [Figure 10] This is an enlarged view of the same area R10 as in Figure 1. [Modes for carrying out the invention]

[0008] The distance from the second plane to the first end face of the stator core may be greater than the distance from the first plane to the first end face of the stator core. The number of at least one first hole may be greater than the number of at least one second hole. The coil density of the first coil end is higher closer to the first end face than further away from the first end face. With the above configuration, the number of first holes closer to the first end face can be greater than the number of second holes further away from the first end face. Therefore, the total flow rate of refrigerant injected from the first holes can be greater than the total flow rate of refrigerant injected from the second holes. This makes it possible to properly cool regions with high coil density.

[0009] At least one first hole may include a plurality of first holes arranged throughout the circumferential direction of the first annular member. With the above configuration, the first coil end can be cooled throughout the circumferential direction.

[0010] At least one second hole may be located only in the first section in the circumferential direction of the first annular member. With the above configuration, the first section of the first coil end can be cooled intensively by the second hole.

[0011] The first section in the circumferential direction of the first annular member may be located below the horizontal plane passing through the axis. In the region located below the horizontal plane passing through the axis, the cooling effect of the coil end may not be sufficient. For example, this may occur when the injection velocity component in the direction opposite to gravity is larger for the refrigerant injected from a hole located below the horizontal plane compared to the refrigerant injected from a hole located above the horizontal plane. Another example is when the temperature of the refrigerant injected from a hole located below the horizontal plane is higher than the temperature of the refrigerant injected from a hole located above the horizontal plane. With the above configuration, the second hole is placed only in the first section located below the horizontal plane. This makes it possible to properly cool the region located below the horizontal plane.

[0012] The first section in the circumferential direction of the first annular member may be located above the horizontal plane passing through the axis. In the region located above the horizontal plane passing through the axis, the cooling effect of the coil end may not be sufficient. For example, this may occur when the temperature of the refrigerant injected from a hole located above the horizontal plane is higher than the temperature of the refrigerant injected from a hole located below the horizontal plane. According to the above configuration, the second hole is placed only in the first section located above the horizontal plane. This makes it possible to properly cool the region located above the horizontal plane.

[0013] The distance from the second plane to the first end face of the stator core may be greater than the distance from the first plane to the first end face of the stator core. The number of at least one first hole may be less than the number of at least one second hole. The first coil end that is farther from the first end face may have lower cooling efficiency than the first coil end that is closer to the first end face. With the above configuration, the total flow rate of injection from the second hole that is farther from the first end face can be made greater than the total flow rate of injection from the first hole that is closer to the first end face. This makes it possible to properly cool the first coil end that is farther from the first end face.

[0014] The distance from the second plane to the first end face of the stator core may be greater than the distance from the first plane to the first end face of the stator core. The opening area of at least one first hole may be greater than the opening area of at least one second hole. The coil density of the first coil end is higher closer to the first end face than that farther from the first end face. According to the above configuration, the injection flow rate from each of the first holes closer to the first end face can be made larger than the injection flow rate from each of the second holes farther from the first end face. It becomes possible to appropriately cool the region with a high coil density.

[0015] The distance from the second plane to the first end face of the stator core may be greater than the distance from the first plane to the first end face of the stator core. The opening area of at least one first hole may be smaller than the opening area of at least one second hole. The first coil end farther from the first end face may have a lower cooling efficiency than the first coil end closer to the first end face. According to the above configuration, the injection flow rate from each of the second holes farther from the first end face can be made larger than the injection flow rate from each of the first holes closer to the first end face. It becomes possible to appropriately cool the first coil end farther from the first end face.

[0016] Each of at least one first hole and any of at least one second hole may have different positions in the circumferential direction of the first annular member. According to the above configuration, the regions cooled by each of the first holes and the regions cooled by each of the second holes can be made less likely to overlap with each other. It becomes possible to cool the first coil end over a wide range.

[0017] At least one first hole may include a plurality of first holes. At least one second hole may include a plurality of second holes. The plurality of first holes and the plurality of second holes may be alternately arranged along the circumferential direction of the first annular member. According to the above configuration, it becomes possible to cool the first coil end over a wide range and uniformly.

[0018] Each of at least one second hole may coincide with the corresponding one of at least one first hole in the circumferential position of the first annular member. With the above configuration, the first coil end can be cooled over a wide area in the axial direction in the region where the first and second holes are located.

[0019] The angle that each axis of at least one second hole makes with the second plane may be different from the angle that each axis of at least one first hole makes with the first plane. According to the above configuration, the direction of refrigerant injection from each of the first holes and the direction of refrigerant injection from each of the second holes can be made different. It becomes possible to individually set the region cooled by the first holes and the region cooled by the second holes.

[0020] The distance from the second plane to the first end face of the stator core may be greater than the distance from the first plane to the first end face of the stator core. The axis of at least one of the second holes may be inclined toward the first plane. With the above configuration, the direction of injection of the coolant sprayed from each of the second holes farther from the first end face can be directed toward the first end face. The first coil end can be properly cooled.

[0021] The coil may comprise multiple segment coils, each having an insulating coating on its outer surface. At the first coil end, each end of the multiple segment coils may be exposed from the insulating coating. A corresponding pair of segment coils may have a weld where their ends are welded together. This configuration allows for more effective cooling of the area near the weld at the end of the segment coil.

[0022] The system may further include a second annular member that seals the space between the second end face of the stator core, located axially opposite to the first end face, and the inner wall surface of the housing. The second annular member may have a cylindrical shape centered on the axis of the stator core. The second annular member may include at least one third hole for injecting coolant toward the second coil end of the coil protruding from the second end face of the stator core. Each of the at least one third hole may be located on a third plane perpendicular to the axis. With this configuration, it becomes possible to cool the first coil end, which has a welded joint, more intensively than the second coil end. [Examples]

[0023] (Structure of Motor 1) Figure 1 shows a schematic cross-sectional view of the motor 1 according to this embodiment. Figure 2 shows side views of the stator 20, the first annular member 41, and the second annular member 42. In Figure 2, for clarity, the housing 30, rotor 10, and rotating shaft 11 are omitted. The inner wall surface 30w and the supply port 30p of the housing 30 are shown with dashed lines. In Figures 1 and 2, the z-axis direction is vertical, and the x-axis and y-axis directions are horizontal. The x-axis direction is the direction in which the rotating shaft 11 extends. The coordinate relationships are the same in subsequent figures.

[0024] Motor 1 is mounted on an electric vehicle. Electric vehicles include hybrid vehicles and electric vehicles. In an electric vehicle, Motor 1 may be used as a drive motor to generate power for moving the vehicle, or as a generator that generates electricity from regenerative braking force or surplus engine power. In an electric vehicle, Motor 1 is mounted so that the negative direction of the z-axis coincides with the direction of gravity.

[0025] As shown in Figure 1, the motor 1 has a central plane CP perpendicular to the rotation axis 11. The central plane CP is a plane that passes through the axial center of the stator core 21. The motor 1 has a structure that is symmetrical with respect to the central plane CP. Therefore, in this specification, the structure on the +x direction side with respect to the central plane CP will be described mainly.

[0026] Motor 1 mainly comprises a rotor 10, a stator 20, a housing 30, a first annular member 41, and a second annular member 42. The rotor 10 has a rotating shaft 11. The rotating shaft 11 is supported by the housing 30 via bearings (not shown) and is capable of rotation. The rotor 10 is fixed to the rotating shaft 11.

[0027] The stator 20 has a stator core 21 and a coil 22. The stator core 21 is a substantially annular member made of laminated steel plate or the like. A first end face 21e1 is formed at one end of the stator core 21 in the axial direction (x direction), and a second end face 21e2 is formed at the other end. Windings constituting the coil 22 are wound around the stator core 21. The first coil end 22e1 of the coil 22 protrudes axially from the first end face 21e1. The second coil end 22e2 of the coil 22 protrudes axially from the second end face 21e2.

[0028] The coil 22 comprises multiple segment coils (not shown) with an insulating coating on their outer surface. At the first coil end 22e1, each end of the multiple segment coils is exposed from the insulating coating. The ends of corresponding pairs of segment coils are welded together. This forms a welded joint 22w at the first coil end 22e1. On the other hand, the second coil end 22e2 does not have any segment coil ends. Furthermore, at the second coil end 22e2, the segment coils are covered with an insulating coating. Therefore, no welded joint is formed at the second coil end 22e2. In other words, the first coil end 22e1 and the second coil end 22e2 have different shapes. As will be described later, cooling oil is injected from the first coil end 22e1 through the first hole H1 and the second hole H2, while cooling oil is injected from the second coil end 22e2 only through the third hole H3. In other words, the first coil end 22e1, which has a welded joint 22w, can achieve higher cooling efficiency than the second coil end 22e2, which does not have a welded joint. This makes it possible to cool the area around the welded joint 22w more effectively.

[0029] The housing 30 is a component that houses the rotor 10 and the stator 20. The housing 30 surrounds the stator 20. A supply port 30p, described later, is formed on the side of the housing 30. A cooling oil reservoir (not shown) is located at the bottom of the housing 30. The basic structure of the housing 30 can utilize known prior art, so a detailed explanation is omitted here.

[0030] The first annular member 41 has a ring shape centered on the rotation axis 11. The first annular member 41 is made of resin. As shown in Figure 1, the first end 41e1 of the first annular member 41 is connected to the first end face 21e1 of the stator core 21. The second end 41e2 of the first annular member 41 is connected to the inner wall surface 30w of the housing 30. In this way, the first annular member 41 seals the space between the first end face 21e1 and the inner wall surface 30w. Various structures (e.g., seal grooves) to improve airtightness may be formed at the connection between the first end 41e1 and the first end face 21e1, and at the connection between the second end 41e2 and the inner wall surface 30w. A space SP1 is formed between the first annular member 41 and the inner wall surface 30w. The space SP1 is a ring-shaped space centered on the rotation axis 11. The first annular member 41 surrounds the first coil end 22e1. In other words, the first annular member 41 faces the first coil end 22e1.

[0031] The first annular member 41 is provided with a plurality of first holes H1 and a plurality of second holes H2. The first holes H1 and second holes H2 are holes for injecting cooling oil toward the first coil end 22e1. The positions of the first holes H1 and second holes H2 will be described below. The stator core 21 is provided with a central axis CA. The central axis CA of the stator core 21 is common with the central axis of the rotation axis 11. Here, we define a first plane P1 and a second plane P2 perpendicular to the central axis CA. In Figure 1, the first plane P1 and the second plane P2 are shown as dashed lines. The second plane P2 is spaced apart from the first plane P1 in the axial direction (x direction) of the central axis CA. The distance D2 from the second plane P2 to the first end face 21e1 of the stator core 21 is greater than the distance D1 from the first plane P1 to the first end face 21e1. Each of the plurality of first holes H1 is located on the first plane P1. Furthermore, multiple second holes H2 are located on the second plane P2.

[0032] The multiple first holes H1 will be described using Figure 3A. Figure 3A is a cross-sectional view taken from the first plane P1, and is a cross-sectional view passing through the centers of the multiple first holes H1. The multiple first holes H1 penetrate the first annular member 41 in the thickness direction. As shown in Figure 3A, the multiple first holes H1 are arranged over the entire circumference of the first annular member 41. This allows the first coil end 22e1 to be cooled over the entire circumference. In this embodiment, eight first holes H1 are arranged at equal intervals on the circumference.

[0033] The multiple second holes H2 will be explained using Figure 3B. Figure 3B is a cross-sectional view taken along the second plane P2, and is a cross-sectional view passing through the centers of the multiple second holes H2. The multiple second holes H2 penetrate the first annular member 41 in the thickness direction. The multiple second holes H2 are located only in the first section SE1 in the circumferential direction of the first annular member 41. The first section SE1 is located below the horizontal plane HP passing through the central axis CA. In this embodiment, three second holes H2 are located in the first section SE1. The number of first holes H1 (8) is greater than the number of second holes H2 (3).

[0034] The openings of the multiple first holes H1 and multiple second holes H2 are circular in shape. All of the multiple first holes H1 have the same first opening area. All of the multiple second holes H2 have the same second opening area. The first opening area is larger than the second opening area. That is, the diameter of the opening of the first hole H1 is larger than the diameter of the opening of the second hole H2. In Figures 3A and 3B, for clarity, the diameters of the multiple first holes H1 and multiple second holes H2 are shown larger than they actually are. Also, the diameter difference between the first hole H1 and the second hole H2 is emphasized.

[0035] Each of the three second holes H2 located in the first section SE1 coincides with the corresponding first hole H1 in the circumferential direction of the first annular member 41. That is, the yz-plane positions of the three second holes H2 in the first section SE1 (Figure 3B) are the same as the yz-plane positions of the three first holes H1 in the corresponding section SEc (Figure 3A). With this configuration, the first coil end 22e1 can be cooled over a wide axial area in the region where the first holes H1 and second holes H2 are located.

[0036] The stator core 21 will be described using Figures 1, 2, 4, and 5. Figure 4 is a partially enlarged cross-sectional view taken along the line IV-IV in Figure 2. Figure 5 is a schematic cross-sectional view taken along the line VV passing through the central plane CP in Figure 1. The stator core 21 is a cylindrical member. As shown in Figure 2, the stator core 21 includes an annular channel 50r, a first channel 50c1, and a second channel 50c2.

[0037] As shown in Figure 5, the annular channel 50r is a groove formed in the circumferential direction around the stator core 21. The upper surface of the annular channel 50r is open. A flow path is formed by covering this open upper surface with the inner wall surface 30w. The annular channel 50r communicates with the supply port 30p of the housing 30.

[0038] As shown in Figures 2 and 4, the multiple first channels 50c1 are tunnel-shaped flow channels formed on the outer circumferential surface of the stator core 21. In Figure 2, the multiple first channels 50c1 and second channels 50c2 are shown by dotted lines. The multiple first channels 50c1 extend from the annular channel 50r to the first end face 21e1 in the +x direction. The multiple first channels 50c1 extend parallel to each other and are arranged at equal intervals in the circumferential direction. Similarly, the multiple second channels 50c2 have the same shape as the multiple first channels 50c1. The multiple second channels 50c2 extend from the annular channel 50r to the second end face 21e2 in the -x direction.

[0039] The above mainly describes the structure on the +x direction side with respect to the central plane CP. The structure on the -x direction side with respect to the central plane CP is the same as the structure on the +x direction side with respect to the central plane CP. That is, a second annular member 42 is provided that seals the space between the second end face 21e2 of the stator core 21 and the inner wall surface 30w of the housing 30. A space SP2 is formed between the second annular member 42 and the inner wall surface 30w. The second annular member 42 has a plurality of third holes H3. The plurality of third holes H3 are holes for injecting cooling oil toward the second coil end 22e2. Here, a third plane P3 perpendicular to the central axis CA is defined. In Figure 1, the third plane P3 is shown as a dashed line. The distance D3 from the third plane P3 to the second end face 21e2 of the stator core 21 is equivalent to the distance D1 from the first plane P1 to the first end face 21e1. Each of the multiple third holes H3 is located on the third plane P3. The number, opening area, and arrangement of the multiple third holes H3 are the same as those of the multiple first holes H1 described above, so their explanation is omitted. Furthermore, other explanations regarding the structure on the -x direction side with respect to the central plane CP are omitted here.

[0040] (operation) The operation of motor 1 is described below. Cooling oil stored in the cooling oil reservoir flows into the supply port 30p of housing 30 via a pump and supply pipe (not shown). Cooling oil supplied to supply port 30p flows into the annular channel 50r. The incoming cooling oil flows circumferentially within the annular channel 50r (see Figures 2 and 5, arrow A0). The cooling oil then flows into each of the multiple first channels 50c1 and flows in the +x direction (see Figure 2, arrow A1). Simultaneously, the cooling oil flows into each of the multiple second channels 50c2 and flows in the -x direction (see Figure 2, arrow A2). Cooling oil that reaches the +x end of the multiple first channels 50c1 is discharged into space SP1 and reaches the first annular member 41. Similarly, cooling oil that reaches the -x end of the multiple second channels 50c2 is discharged into space SP2 and reaches the second annular member 42.

[0041] Figures 3A and 3B are used to explain the cooling oil injection state. Since the space SP1 is completely filled with cooling oil, pressure is applied to the cooling oil. As shown in Figures 3A and 3B, cooling oil is injected from each of the multiple first holes H1 and second holes H2 toward the first coil end 22e1. In Figure 3A, the flow rate of the cooling oil injected from the multiple first holes H1 is shown by vector JS1. In Figure 3B, the flow rate of the cooling oil injected from the multiple second holes H2 is shown by vector JS2. A longer vector indicates a larger flow rate. The opening area of ​​the second holes H2 is set to be 90% or less of the opening area of ​​the first holes H1. This makes the vector JS1 of the first holes H1 significantly larger than the vector JS2 of the second holes H2.

[0042] (effect) The heat distribution of the first coil end 22e1 may become large due to various factors such as the mounting position of the motor 1 on the vehicle and the operating environment (e.g., incline). As a result, there may be parts of the first coil end 22e1 that require localized strong cooling. In the technology of this embodiment, the axial position of the coolant injection can be adjusted by selecting at least one of the first hole H1 and the second hole H2. This makes it possible to appropriately adjust the coolant injection area with a relatively simple structure of changing the hole position. Since the coolant can be injected to target the parts of the first coil end 22e1 that require cooling, it becomes possible to properly cool the first coil end 22e1.

[0043] The coil density of the first coil end 22e1 is higher closer to the first end face 21e1 than further away from it. In the technology of this embodiment, the number of first holes H1 closer to the first end face 21e1 can be made greater than the number of second holes H2 further away from the first end face 21e1. Therefore, the total flow rate of coolant injected from the first holes H1 can be made greater than the total flow rate of coolant injected from the second holes H2. Furthermore, in the technology of this embodiment, the first opening area of ​​the first holes H1 can be made greater than the number of second opening areas of the second holes H2. Therefore, the injection flow rate from each of the first holes H1 can be made greater than the injection flow rate from each of the second holes H2. This makes it possible to properly cool the region with high coil density (the region closer to the first end face 21e1).

[0044] In the region located below the horizontal plane HP passing through the central axis CA, the cooling effect of the first coil end 22e1 may not be sufficient. For example, this can occur when the injection velocity component in the direction opposite to gravity is larger for the coolant injected from a hole located below the horizontal plane HP compared to the coolant injected from a hole located above the horizontal plane HP. Another example is when the temperature of the coolant injected from a hole located below the horizontal plane HP is higher than the temperature of the coolant injected from a hole located above the horizontal plane. In the technology of this embodiment, the second hole H2 is placed only in the first section SE1 located below the horizontal plane HP. This makes it possible to focus the cooling of the first coil end 22e1 located below the horizontal plane HP using the second hole H2.

[0045] In some cases, the first coil end 22e1 may require more cooling than the second coil end 22e2. For example, this may occur when the first coil end 22e1 has a welded portion 22w. In the technology of this embodiment, the first annular member 41 facing the first coil end 22e1 has a first hole H1 and a second hole H2. On the other hand, the second annular member 42 facing the second coil end 22e2 has only a third hole H3. This makes it possible to properly cool the vicinity of the welded portion 22w of the first coil end 22e1 using the first hole H1 and the second hole H2. Compared to the second coil end 22e2, the first coil end 22e1, which has a welded portion 22w, can be cooled more intensively. Appropriate cooling is also possible even when the coil end shape is asymmetrical. [Examples]

[0046] In Example 2, the arrangement of the multiple second holes H202 differs from that of Example 1. Components common to both Example 2 and Example 1 are given the same reference numerals, and their explanation is omitted. Components unique to Example 2 are distinguished by their reference numerals in the 200s. Figure 6 shows a schematic cross-sectional view of the motor 1 according to Example 2. Figure 6 is a cross-sectional view of the same location as in Figure 3B of Example 1.

[0047] Multiple second holes H202 are located only in the first section SE201 in the circumferential direction of the first annular member 41. The first section SE201 is located above the horizontal plane HP. In this embodiment, three second holes H202 are located in the first section SE201.

[0048] (effect) In regions located above the horizontal plane HP, sufficient cooling of the coil end may not be achieved. For example, this can occur when the temperature of the coolant injected from a hole located above the horizontal plane HP is higher than the temperature of the coolant injected from a hole located below the horizontal plane HP. In the technology of this embodiment, the second hole H202 is placed only in the first section SE201 located above the horizontal plane HP. This makes it possible to properly cool the first coil end 22e1 located above the horizontal plane HP.

[0049] Cooling oil injected from the upper side of the horizontal HP falls due to gravity and moves to the lower side of the horizontal HP. In other words, the cooling oil injected from the upper side of the horizontal HP has a longer contact time with the coil end than the cooling oil injected from the lower side of the horizontal HP. In the technology of this embodiment, the flow rate of the cooling oil injected from the upper side of the horizontal HP can be made larger than that from the lower side. This makes it possible to enhance the cooling effect. [Examples]

[0050] In Example 3, the opening areas of the multiple first holes H301 and second holes H302 are different from those of Example 1. Components common to Example 3 and Example 1 are given the same reference numerals, and their explanation is omitted. Components unique to Example 3 are distinguished by their reference numerals in the 300s. Figures 7A and 7B show schematic cross-sectional views of the motor 1 according to Example 3. Figures 7A and 7B are cross-sectional views of the same locations as those in Figures 3A and 3B of Example 1.

[0051] Multiple first holes H301 all have the same first opening area. Multiple second holes H302 all have the same second opening area. The first opening area is smaller than the second opening area. In Figure 7A, the flow rate of coolant injected from multiple first holes H301 is shown by vector JS301. In Figure 7B, the flow rate of coolant injected from multiple second holes H302 is shown by vector JS302. A longer vector indicates a larger flow rate. The opening area of ​​the first holes H301 is set to be 90% or less of the opening area of ​​the second holes H302. This makes the vector JS301 of the first holes H301 significantly smaller than the vector JS302 of the second holes H302.

[0052] (effect) In some cases, the first coil end 22e1 that is farther from the first end face 21e1 may have lower cooling efficiency than the first coil end 22e1 that is closer to the first end face 21e1. For example, this can occur when the coil 22 is indirectly cooled by cooling the stator core 21. In the technology of this embodiment, the injection flow rate from each of the second holes H302, which are farther from the first end face 21e1, can be made greater than the injection flow rate from each of the first holes H301, which are closer to the first end face 21e1. This makes it possible to properly cool the first coil end 22e1, which is farther from the first end face 21e1. [Examples]

[0053] Example 4 differs from Example 1 in the number of multiple first holes H401 and second holes H402. Components common to both Example 4 and Example 1 are given the same reference numerals, and their explanation is omitted. Components unique to Example 4 are distinguished by their reference numerals in the 400s. Figures 8A and 8B show schematic cross-sectional views of the motor 1 according to Example 4. Figures 8A and 8B are cross-sectional views of the same locations as those in Figures 3A and 3B of Example 1.

[0054] As shown in Figure 8A, multiple first holes H401 are located only in the first section SE401. The first section SE401 is located below the horizontal plane HP. In this embodiment, three first holes H401 are located in the first section SE401. Also, as shown in Figure 8B, multiple second holes H402 are located throughout the circumferential direction of the first annular member 41. The number of second holes H402 (8) is greater than the number of first holes H401 (3).

[0055] The first opening area of ​​the first hole H401 is set to be 90% or less of the second opening area of ​​the second hole H402. This makes it possible to significantly reduce the flow rate of the coolant injected from the first hole H401 (vector JS401) compared to the flow rate of the coolant injected from the second hole H402 (vector JS402).

[0056] (effect) In some cases, the cooling efficiency of the first coil end 22e1 that is farther from the first end face 21e1 may be lower than that of the first coil end 22e1 that is closer to the first end face 21e1. In the technology of this embodiment, the total flow rate of injection from the second hole H402 that is farther from the first end face 21e1 can be made greater than the total flow rate of injection from each of the first holes H401 that are closer to the first end face 21e1. This makes it possible to properly cool the first coil end 22e1 that is farther from the first end face 21e1. [Examples]

[0057] Example 5 differs from Example 1 in the number and circumferential position of the multiple second holes H502. Components common to both Example 5 and Example 1 are denoted by the same reference numerals, and their explanation is omitted. Components unique to Example 5 are distinguished by their reference numerals in the 500 range. Figure 9 shows a schematic cross-sectional view of the motor 1 according to Example 5. Figure 9 is a cross-sectional view of the same location as Figure 3B of Example 1.

[0058] As shown in Figure 9, the multiple second holes H502 are arranged throughout the entire circumferential direction of the first annular member 41. Specifically, eight second holes H502 are arranged at equal intervals along the circumference. Each of the multiple first holes H1 (see Figure 3A) is located at a different position in the circumferential direction of the first annular member 41 from each of the multiple second holes H502 (see Figure 9). That is, the multiple first holes H1 and the multiple second holes H502 are arranged alternately along the circumferential direction of the first annular member 41.

[0059] (effect) The regions cooled by each of the multiple first holes H1 and the regions cooled by each of the multiple second holes H502 can be made less likely to overlap with each other. This makes it possible to cool the first coil end 22e1 over a wide area and uniformly. [Examples]

[0060] In Example 6, the angles of the axes of the multiple second holes H602 are different from those in Example 1. Components common to Example 6 and Example 1 are given the same reference numerals, and their explanation is omitted. Components unique to Example 6 are distinguished by their reference numerals in the 600s. Figure 10 shows a schematic cross-sectional view of the motor 1 according to Example 6. Figure 10 is an enlarged view of the same area R10 as in Figure 1.

[0061] The first hole H601 and the second hole H602 are provided with hole axes HA1 and HA2. The directions of hole axes HA1 and HA2 coincide with the direction in which the holes penetrate the thickness direction of the first annular member 41. Hole axis HA1 and the first plane P1 form an angle G1. Hole axis HA2 and the second plane P2 form an angle G2. Angles G1 and G2 are different. Furthermore, hole axis HA2 is tilted toward the first plane P1. That is, if hole axis HA2 is extended toward the central axis CA (+z direction), hole axis HA2 intersects with the first plane P1.

[0062] Cooling oil is injected from the first hole H601 along the hole axis HA1. Therefore, the cooling oil is injected at an angle G1 with respect to the first plane P1. Cooling oil is also injected from the second hole H602 along the hole axis HA2. Therefore, the cooling oil is injected at an angle G2 with respect to the second plane P2. This makes it possible to direct the injection direction of the cooling oil injected from the second hole H602, which is farther from the first end face 21e1, toward the first end face 21e1. Thus, the first coil end 22e1 can be properly cooled. Note that the features of the hole axis HA1 described above are common to multiple first holes H601. Also, the features of the hole axis HA2 are common to multiple second holes H602.

[0063] (effect) The injection direction of the cooling oil from each of the first holes H601 and the injection direction of the refrigerant from each of the second holes H602 can be made different from each other. The region cooled by the first holes H601 and the region cooled by the second holes H602 can be set individually.

[0064] Although embodiments have been described in detail above, these are merely illustrative and do not limit the scope of the claims. The technologies described in the claims include various modifications and changes to the specific examples illustrated above. The technical elements described in this specification or drawings exhibit technical usefulness individually or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technologies illustrated in this specification or drawings achieve multiple objectives simultaneously, and achieving even one of these objectives constitutes technical usefulness.

[0065] (modified version) The shapes of the openings of the first and second holes are not limited to circles and can be various shapes. Furthermore, the number and arrangement of the first and second holes are not limited to the embodiments described herein and can be various configurations.

[0066] The second annular member 42 may further comprise a plurality of fourth holes H4 located on the fourth plane P4. The fourth plane P4 is perpendicular to the central axis CA and spaced axially apart from the third plane P3. [Explanation of Symbols]

[0067] 10: Rotor 11: Rotating shaft 20: Stator 21: Stator core 22: Coil 21e1: First end face 21e2: Second end face 22e1: First coil end 22e2: Second coil end 30: Housing 30w: Inner wall surface 41: First annular member 42: Second annular member H1: First hole H2: Second hole CA: Central axis P1: 1st plane P2: 2nd plane

Claims

1. Rotor and, A stator having a stator core and coils, A housing that accommodates the rotor and the stator, A first annular member seals the space between the first axial end face of the stator core and the inner wall surface of the housing, Equipped with, The first annular member has a cylindrical shape centered on the axis of the stator core, The first annular member is provided with at least one first hole and at least one second hole for injecting refrigerant toward the first coil end of the coil protruding from the first end face of the stator core, The first hole is located on a first plane perpendicular to the axis, The second hole is located on a second plane that is perpendicular to the axis and spaced apart from the first plane in the axial direction. The angle that the axis of the second hole makes with the second plane is different from the angle that the axis of the first hole makes with the first plane. Motor.

2. Rotor and, A stator having a stator core and coils, A housing that accommodates the rotor and the stator, A first annular member seals the space between the first axial end face of the stator core and the inner wall surface of the housing, Equipped with, The first annular member has a cylindrical shape centered on the axis of the stator core, The first annular member is provided with at least one first hole and at least one second hole for injecting refrigerant toward the first coil end of the coil protruding from the first end face of the stator core, The first hole is located on a first plane perpendicular to the axis, The second hole is located on a second plane that is perpendicular to the axis and spaced apart from the first plane in the axial direction. The distance from the second plane to the first end face of the stator core is greater than the distance from the first plane to the first end face of the stator core. The axis of the second hole is tilted toward the first plane. Motor.

3. The distance from the second plane to the first end face of the stator core is greater than the distance from the first plane to the first end face of the stator core. The number of the first holes is greater than the number of the second holes. The motor according to claim 1 or 2.

4. The motor according to claim 3, wherein the first hole includes a plurality of first holes arranged over the entire circumferential direction of the first annular member.

5. The motor according to claim 4, wherein the second hole is located only in the first section in the circumferential direction of the first annular member.

6. The motor according to claim 5, wherein the first section in the circumferential direction of the first annular member is located below the horizontal plane passing through the axis.

7. The motor according to claim 5, wherein the first section in the circumferential direction of the first annular member is located above the horizontal plane passing through the axis.

8. The distance from the second plane to the first end face of the stator core is greater than the distance from the first plane to the first end face of the stator core. The motor according to claim 1 or 2, wherein the number of the first holes is smaller than the number of the second holes.

9. The distance from the second plane to the first end face of the stator core is greater than the distance from the first plane to the first end face of the stator core. The motor according to claim 1 or 2, wherein the opening area of ​​the first hole is larger than the opening area of ​​the second hole.

10. The distance from the second plane to the first end face of the stator core is greater than the distance from the first plane to the first end face of the stator core. The motor according to claim 1 or 2, wherein the opening area of ​​the first hole is smaller than the opening area of ​​the second hole.

11. The motor according to claim 1 or 2, wherein the position of the first hole is different from that of the second hole in the circumferential direction of the first annular member.

12. The first hole includes a plurality of first holes, The aforementioned second hole includes a plurality of second holes, The motor according to claim 11, wherein the plurality of first holes and the plurality of second holes are arranged alternately along the circumferential direction of the first annular member.

13. The motor according to claim 1 or 2, wherein the second hole is located at the same position as the first hole in the circumferential direction of the first annular member.

14. The coil comprises a plurality of segment coils, each having an insulating coating on its outer surface. In the first coil end, each end of the plurality of segment coils is exposed from the insulating coating. The motor according to claim 1 or 2, wherein a corresponding pair of segment coils have a welded portion where the ends are welded together.

15. The stator further comprises a second annular member that seals the space between the first end face of the stator core, the second end face located on the opposite side in the axial direction, and the inner wall surface of the housing. The second annular member has a cylindrical shape centered on the axis of the stator core, The second annular member is provided with at least one third hole for injecting refrigerant toward the second coil end of the coil protruding from the second end face of the stator core, The motor according to claim 14, wherein the third hole is located on a third plane perpendicular to the axis.

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