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 plurality of first holes which jet a coolant toward a first coil end of the coil protruding from the first end surface of the stator core. The first annular member includes a first section where at least two of the plurality of first holes are circumferentially disposed at a first pitch. The first annular member includes a second section where at least two of the plurality of first holes are circumferentially disposed at a second pitch greater than the first pitch.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] When the coil end has a temperature distribution, a high-temperature part may occur at the coil end. In this case, it is desirable to make the cooling amount of the high-temperature part larger than the cooling amount of other parts.

Means for Solving the Problems

[0005] The motor includes a rotor. The motor includes a stator having a stator core and coils. The motor includes a housing that houses the rotor and the stator. The motor includes a first annular member that seals between the first axial end face of the stator core and the inner wall surface of the housing. The first annular member includes a plurality of first holes that inject refrigerant toward the first coil end of the coil protruding from the first end face of the stator core. The first annular member includes a first section in which at least two of the plurality of first holes are circumferentially arranged at a first pitch. The first annular member includes a second section in which at least two of the plurality of first holes are circumferentially arranged at a second pitch larger than the first pitch.

[0006] The refrigerant can be of various types, for example, cooling oil. The refrigerant may also be a liquid such as water, or a fluid containing gases, etc. With the above configuration, the amount of refrigerant injected per unit area in the first section can be made greater than the amount of refrigerant injected per unit area in the second section. Therefore, by corresponding the first section to a desired part, the cooling amount of the desired part can be made greater than the cooling amount of other parts. This makes it possible to adequately cool the entire first 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 3] This is a schematic cross-sectional view along line III-III in Figure 1. [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 7] This is a schematic cross-sectional view along line III-III in Figure 1. [Figure 8] This is a schematic cross-sectional view along the line VIII-VIII in Figure 1. [Modes for carrying out the invention]

[0008] Multiple first holes may be arranged asymmetrically with respect to a horizontal plane passing through the axis of the stator core. Multiple first holes may be arranged symmetrically with respect to a vertical plane passing through the axis. The cooling capacity of the first coil end may differ between the coolant injected from the first holes located above the horizontal plane and the coolant injected from the first holes located below the horizontal plane. With the above configuration, the arrangement density of the first holes can be made different above and below the horizontal plane. This makes it possible to appropriately adjust the cooling capacity of the first coil end above and below the horizontal plane.

[0009] The first section may be located above the second section in the vertical direction. The refrigerant injected from the first hole located above in the vertical direction may have a longer contact time with the first coil end than the refrigerant injected from the first hole located below in the vertical direction, thus potentially resulting in higher cooling capacity. With the above configuration, the injection rate per unit area of ​​the refrigerant on the upper side can be made greater than that per unit area of ​​the refrigerant on the lower side. This makes it possible to improve cooling efficiency.

[0010] A portion of the first coil end may be a specific region that generates more heat than other portions of the first coil end. The first section may face the specific region in the radial direction. With the above configuration, the amount of refrigerant injected per unit area into the specific region of the first coil end can be made larger than the amount of refrigerant injected per unit area into other parts of the first coil end. This makes it possible to cool the specific region intensively.

[0011] The first coil end may include a conductive member that is positioned over a portion of the circumferential direction. The conductive member may be located within a specific region. According to the above configuration, it is possible to cool the conductive member intensively.

[0012] The conductive member may include the neutral point of the coil. According to the above configuration, it becomes possible to concentrate the cooling of the coil's neutral point.

[0013] The conductor member may include a plurality of power lines protruding axially from the first coil end. According to the above configuration, it becomes possible to cool the plurality of power lines intensively.

[0014] The first coil end may include a first region with a high coil occupancy rate and a second region with a lower coil occupancy rate than the first region. The specific region may include at least a part of the first region. According to the above configuration, it becomes possible to cool intensively the region with a high coil occupancy rate.

[0015] The first pitch may be 75 percent or less of the second pitch. According to the above configuration, it is possible to appropriately increase the injection amount per unit area of the refrigerant from the first region more than the injection amount per unit area of the refrigerant from the second region.

[0016] It may further include a second annular member that seals between the first end face of the stator core and 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 may include a plurality of second holes that inject refrigerant toward the second coil end of the coil protruding from the second end face of the stator core. According to the above configuration, it becomes possible to appropriately cool both the first coil end and the second coil end.

Example

[0017] (Structure of Motor 1) FIG. 1 shows a schematic cross-sectional view of a motor 1 according to this embodiment. FIG. 2 shows side views of a stator 20, a first annular member 41, and a second annular member 42. In FIG. 2, for clarity, the description of the housing 30, the rotor 10, and the rotating shaft 11 is omitted. Also, the inner wall surface 30w and the supply port 30p of the housing 30 are shown as imaginary lines. In FIGS. 1 and 2, the z-axis direction is the vertical direction, and the x-axis direction and the y-axis direction are the horizontal directions. Also, the x-axis direction is the direction in which the rotating shaft 11 extends. The coordinate relationship is the same in the subsequent figures.

[0018] The motor 1 is mounted on an electric vehicle. The electric vehicle includes a hybrid vehicle and an electric vehicle. In the electric vehicle, the motor 1 may be used as a driving motor that generates power for driving the vehicle, or may be used as a generator that generates electricity by regenerative braking force or surplus power of an engine. In the electric vehicle, the motor 1 is mounted such that the negative direction of the z-axis coincides with the gravitational direction.

[0019] As shown in FIG. 1, the motor 1 has a central plane CP perpendicular to the rotation axis 11. The central plane CP is a plane passing through the axial center of the stator core 21. The motor 1 has a structure that is plane-symmetric with respect to the central plane CP. Therefore, hereinafter in this specification, the structure on the +x direction side with respect to the central plane CP will be mainly described.

[0020] The motor 1 mainly includes 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 rotation axis 11. The rotation axis 11 is supported by the housing 30 via a bearing (not shown) and is rotatable. The rotor 10 is fixed to the rotation axis 11.

[0021] 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 plates 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. A first coil end 22e1 of the coil 22 protrudes axially from the first end face 21e1. A second coil end 22e2 of the coil 22 protrudes axially from the second end face 21e2.

[0022] 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, which will be described later, is formed on the side of the housing 30. A cooling oil reservoir (not shown) is also 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.

[0023] 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.

[0024] The first annular member 41 is provided with a plurality of first holes H1. The plurality of first holes H1 are holes for injecting cooling oil toward the first coil end 22e1. The plurality of first holes H1 will be explained with reference to Figure 3. Figure 3 is a schematic cross-sectional view taken along line III-III in Figure 1. Figure 3 is a cross-sectional view passing through the center of the plurality of first holes H1. The plurality of first holes H1 penetrate the first annular member 41 in the thickness direction. As shown in Figure 3, the plurality of first holes H1 are arranged on the circumference. In this embodiment, six first holes H1 are formed. The shape of the openings of the plurality of first holes H1 is circular. All of the plurality of first holes H1 have the same opening area. Note that in Figure 3, the diameters of the plurality of first holes H1 are shown larger than they actually are for clarity.

[0025] The first annular member 41 comprises a first section SE1 and a second section SE2. The first section SE1 is a section in which at least two of a plurality of first holes H1 are arranged circumferentially at a first pitch P1. The second section SE2 is a section in which at least two of a plurality of first holes H1 are arranged circumferentially at a second pitch P2. The second pitch P2 is larger than the first pitch P1. Specifically, the first pitch P1 is 75 percent or less of the second pitch P2. This makes it possible to make the amount of coolant injected per unit area in the first section SE1 greater than the amount of coolant injected per unit area in the second section SE2.

[0026] In this embodiment, the first section SE1 is located above the second section SE2 in the vertical direction (z-direction in Figure 3). The first pitch P1 is 1 / 8 the length of the circumference. The second pitch P2 is 1 / 4 the length of the circumference. Therefore, the first pitch P1 is 50 percent of the second pitch P2.

[0027] The stator core 21 has a central axis CA. The central axis CA of the stator core 21 is the same as the central axis of the rotation axis 11. The stator core 21 also has a horizontal plane HP passing through the central axis CA and a vertical plane VP passing through the central axis CA. The multiple first holes H1 are arranged asymmetrically with respect to the horizontal plane HP and symmetrically with respect to the vertical plane VP. This allows the arrangement density of the first holes H1 to differ above and below the horizontal plane HP. Furthermore, the arrangement density of the first holes H1 can be made uniform in the left-right direction with respect to the vertical plane VP. Thus, the cooling capacity of the first coil end 22e1 can be individually adjusted in the vertical direction with respect to the horizontal plane HP, and can be made the same in the left-right direction with respect to the vertical plane VP.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 is provided with a plurality of second holes H2. The plurality of second holes H2 are holes for injecting cooling oil toward the second coil end 22e2. The second annular member 42 is provided with a third section SE3 and a fourth section SE4. The third section SE3 is a section in which at least two of the plurality of second holes H2 are arranged circumferentially at a third pitch P3. The fourth section SE4 is a section in which at least two of the plurality of second holes H2 are arranged circumferentially at a fourth pitch P4 which is larger than the third pitch P3. The contents of the third section SE3 and the fourth section SE4 are the same as those of the first section SE1 and the second section SE2 described in Figure 3, so their explanations are omitted. Furthermore, other explanations regarding the structure on the -x direction side with respect to the central plane CP are omitted here.

[0032] (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.

[0033] Figure 3 illustrates 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 Figure 3, cooling oil is injected from each of the multiple first holes H1 toward the first coil end 22e1. In Figure 3, the flow rate of the cooling oil injected from the multiple first holes H1 is shown by vector JS1. The magnitude of vector JS1 is the same for all of them.

[0034] (effect) Cooling oil injected from the first hole H1 located vertically upward has a greater fall distance to the cooling oil reservoir than refrigerant injected from the first hole H1 located vertically downward. Therefore, the cooling oil injected from the first hole H1 located vertically upward has a longer contact time with the first coil end 22e1, which may result in higher cooling capacity. In the technology of this embodiment, the first section SE1 is positioned vertically above the second section SE2. This makes it possible to increase the amount of cooling oil injected per unit area from above compared to the amount of cooling oil injected per unit area from below. This makes it possible to improve cooling efficiency. Since the second hole H2 of the second annular member 42 has the same structure as the first hole H1, the same effect can be obtained. [Examples]

[0035] (Configuration of the first hole H201 and the second hole H202) Example 2 differs from Example 1 in the arrangement of the multiple first holes H201 and the multiple second holes H202. Components common to both Example 2 and Example 1 are denoted by 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 3 of Example 1.

[0036] The first annular member 241 comprises a first section SE201 and a second section SE202. The first section SE201 is a section in which the first holes H201 are arranged circumferentially with a first pitch P201. The second section SE202 is a section in which the first holes H201 are arranged circumferentially with a second pitch P202. The second pitch P202 is a larger pitch than the first pitch P201. In this embodiment, there are four first sections SE201. Furthermore, the first sections SE201 are arranged symmetrically four times with respect to the central axis CA.

[0037] A portion of the first coil end 222e1 includes a specific region SR200. The specific region SR200 is a region that generates more heat than other parts of the first coil end 222e1. In Figure 6, the specific region SR200 is shown by a dashed line. Specific examples of the specific region SR200 will be discussed later.

[0038] At least one of the first sections SE201 faces a specific region SR200 in the radial direction RD. Here, the radial direction RD is the radial direction of a circle centered on the central axis CA. In this embodiment, the first section SE201 located in the lower right of Figure 6 faces the specific region SR200 in the radial direction RD. The other three first sections SE201 do not face the specific region SR200. The multiple second holes H202 of the second annular member 242 have the same structure as the multiple first holes H201 described above. Therefore, a detailed explanation is omitted.

[0039] (effect) In the technology of this embodiment, the first section SE201 can be positioned to correspond to a specific region SR200. The amount of coolant injected per unit area into the specific region SR200 can be made larger than the amount of coolant injected per unit area into other parts of the first coil end 222e1. This makes it possible to cool the specific region SR200 intensively. [Examples]

[0040] (Configuration of the first hole H301 and the second hole H302) Example 3 differs from Examples 1 and 2 in the arrangement of the multiple first holes H301 and the multiple second holes H302. 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 7 and 8 show schematic cross-sectional views of the motor 1 according to Example 3. Figure 7 is a cross-sectional view of the first annular member 341 along the line III-III in Figure 1. Figure 8 is a cross-sectional view of the second annular member 342 along the line VIII-VIII in Figure 1.

[0041] The structure of the first coil end 322e1 and the first annular member 341 will be explained using Figure 7. The first coil end 322e1 comprises a first region RE301 and a second region RE302. The first region RE301 is a region where the coil's packing density is high. The second region RE302 is a region where the coil's packing density is lower than that of the first region RE301. In other words, all regions other than the first region RE301 correspond to the second region RE302.

[0042] A portion of the first coil end 322e1 comprises specific regions SR301 and SR302. These specific regions SR301 and SR302 are areas that generate more heat than other parts of the first coil end 322e1. Within specific region SR301 are power lines 361-363 and a neutral point connecting member 364. The power lines 361-363 and the neutral point connecting member 364 are made of a conductive material such as metal. Within specific region SR302 is the first region RE301. In Figure 7, specific region SR301, power lines 361-363, neutral point connecting member 364, and the first region RE301 are shown by dashed lines.

[0043] Power lines 361-363 are lead wires connected to one end of each of the U, V, and W phase coils. Power lines 361-363 protrude axially (+x direction) from the first coil end 322e1. Power lines 361-363 may also be busbars. The neutral point connecting member 364 is a member that connects the other ends of each phase coil. That is, the neutral point connecting member 364 is a member that includes the neutral point of coil 22. The neutral point connecting member 364 may also be an arc-shaped busbar.

[0044] The first annular member 341 comprises a first section SE301 and a second section SE302. The first section SE301 is a section in which the first holes H301 are arranged circumferentially with a first pitch P301. The second section SE302 is a section in which the first holes H301 are arranged circumferentially with a second pitch P302. The second pitch P302 is a larger pitch than the first pitch P301. In the radial direction RD, the first section SE301 faces specific regions SR301 and SR302.

[0045] The structure of the second coil end 322e2 and the second annular member 342 will be explained using Figure 8. The second coil end 322e2 does not have power lines 361-363 or a neutral point connecting member. In other words, the second coil end 322e2 does not have a specific region, and therefore generates less heat than the first coil end 322e1.

[0046] The second annular member 342 is provided with a plurality of second holes H302. The plurality of second holes H302 are arranged at equal pitches in the circumferential direction. In this embodiment, eight second holes H302 are arranged at equal intervals on the circumference.

[0047] (effect) The high heat generation of the power lines 361-363, the neutral point connecting member 364, and the first region RE301 can sometimes cause a large temperature distribution width at the first coil end 322e1. In the technology of this embodiment, the high heat generation region can be concentrated and cooled by the first section SE301. This makes it possible to suppress the temperature distribution width at the first coil end 322e1.

[0048] In the second coil end 322e2, which does not have power lines 361-363 or neutral point connecting member 364 that generate a large amount of heat, the temperature distribution width is smaller compared to the first coil end 322e1. In the technology of this embodiment, a plurality of second holes H302 are arranged at equal pitches in the circumferential direction in the second annular member 342. This makes it possible to cool the second coil end 322e2 substantially uniformly in the circumferential direction. The cooling capacity of the first coil end 322e1 and the cooling capacity of the second coil end 322e2 can be appropriately adjusted according to the temperature distribution width.

[0049] 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.

[0050] (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.

[0051] In Example 1, the cooling effect may be less pronounced for the first hole H1 located lower in the vertical direction. This is because the injection velocity component in the direction opposite to gravity becomes larger. Therefore, the position of the first section SE1 in the vertical direction (z direction in Figure 3) may be lower than that of the second section SE2. This makes it possible to increase the amount of coolant injected per unit area from the lower side than the amount of coolant injected per unit area from the upper side. This makes it possible to increase the cooling capacity on the vertically downward side. [Explanation of Symbols]

[0052] 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 SE1: First section SE2: Second section P1: First pitch P2: Second pitch HP: Horizontal plane VP: Vertical 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 is provided with a plurality of first holes for injecting refrigerant toward the first coil end of the coil protruding from the first end face of the stator core, The first annular member is At least two of the plurality of first holes are arranged in a first section in the circumferential direction at a first pitch, At least two of the plurality of first holes are provided with a second section in which they are arranged circumferentially at a second pitch that is larger than the first pitch, A portion of the first coil end is a specific region that generates more heat than other portions of the first coil end. The first coil end includes a conductive member that is arranged over a portion of the circumferential direction, The conductor member is located within the specified region, The first section is facing the specific region in the radial direction. Motor.

2. The plurality of first holes are, The stator core is arranged asymmetrically with respect to the horizontal plane passing through the axis, The motor according to claim 1, which is arranged symmetrically with respect to a vertical plane passing through the aforementioned axis.

3. The motor according to claim 2, wherein the first section is located above the second section in the vertical direction.

4. The motor according to claim 1, wherein the conductive member includes the neutral point of the coil.

5. The motor according to claim 1, wherein the conductor member includes a plurality of power lines protruding axially from the first coil end.

6. The motor according to claim 1, wherein the first pitch is 75 percent or less of the second pitch.

7. 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 motor according to claim 1, wherein the second annular member is provided with a plurality of second holes for injecting refrigerant toward the second coil end of the coil protruding from the second end face of the stator core.

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