motor

Abstract

Ensure the motor coil ends are properly cooled. [Solution] 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 comprises a plurality of first holes into which a coolant is injected toward the first coil ends of the coils protruding from the first end face of the stator core. The plurality of first holes include a first large hole and a first small hole having a smaller opening area than the first large hole.

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] Depending on the positions of the plurality of injection holes in the vertical direction and the pressure gradient of the refrigerant, etc., the injection speeds of the refrigerant injected from the plurality of injection holes may be different from each other. Then, there is a possibility that the injection holes may not obtain a sufficient injection speed to cool the coil end.

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 end face in the axial direction 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 plurality of first holes include a first large hole and a first small hole having an opening area smaller than that of the first large hole.

[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. According to the above configuration, the opening area of ​​the first small hole is smaller than that of the first large hole. Therefore, the injection velocity of the refrigerant injected from the first small hole can be made greater than the injection velocity of the refrigerant injected from the first large hole. This makes it possible to appropriately adjust the injection velocity so that no injection holes are included that do not provide an injection velocity sufficient to cool 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 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 201. [Figure 7] This is a schematic cross-sectional view of motor 301. [Modes for carrying out the invention]

[0008] The first small hole may be located below the first large hole in the vertical direction. The refrigerant injected from the hole located below in the vertical direction has a larger injection velocity component in the direction opposite to gravity compared to the refrigerant injected from the hole located above. As a result, the cooling effect on the coil end may not be sufficient at the hole located below. With the above configuration, the injection velocity of the first small hole located below can be made greater than the injection velocity of the first large hole located above. This makes it possible to ensure a sufficient cooling effect even at the first small hole located below.

[0009] The first large hole may be located at the top of the multiple first holes. The first small hole may be located at the bottom of the multiple first holes. The hole located at the bottom is the hole in which the injection velocity component in the direction opposite to the direction of gravity is maximum. According to the above configuration, the first small hole is located at the bottom. This makes it possible to increase the injection velocity of the refrigerant at the hole located at the bottom, thereby ensuring a sufficient cooling effect.

[0010] The opening area of ​​the first small hole may be 90% or less of the opening area of ​​the first large hole. With this configuration, the refrigerant injection speed of the first small hole can be appropriately increased compared to the refrigerant injection speed of the first large hole.

[0011] The plurality of first holes may further include at least one first medium-sized hole, which has an opening area smaller than the first large hole and a larger opening area than the first small hole. The at least one first medium-sized hole may be located below the first large hole in the vertical direction and above the first small hole in the vertical direction. With this configuration, the injection velocity of the refrigerant injected from the first medium-sized hole can be made greater than the injection velocity of the refrigerant injected from the first large hole and less than the injection velocity of the refrigerant injected from the first small hole. This makes it possible to appropriately adjust the cooling effect in the first medium-sized hole located between the first large hole and the first small hole.

[0012] At least one first medium-sized hole may include a plurality of first medium-sized holes. The opening area of ​​each of the plurality of first medium-sized holes may decrease as they are located lower in the vertical direction. In the plurality of first medium-sized holes, the injection velocity component in the direction opposite to gravity increases as they are located lower in the vertical direction. With this configuration, the injection velocity of the refrigerant injected from each of the plurality of first medium-sized holes can be increased as they are located lower in the vertical direction. Therefore, it is possible to appropriately suppress the influence of the injection velocity component in the direction opposite to gravity in each of the plurality of first medium-sized holes.

[0013] The housing may have a supply port for supplying refrigerant from the outside. A flow path may be formed between the outer surface of the stator core and the inner wall surface of the housing to allow the refrigerant supplied to the supply port to flow toward the first annular member. The plurality of first medium-sized holes may include two first medium-sized holes located at the same height in the vertical direction. The opening area of ​​one of the two first medium-sized holes may be smaller than the opening area of ​​the other of the two first medium-sized holes. The path through which the refrigerant flows from the supply port to one first medium-sized hole may be shorter than the path through which the refrigerant flows from the supply port to the other first medium-sized hole. When the motor starts up, the refrigerant supplied to the supply port leaks out first from one first medium-sized hole and then leaks out later from the other first medium-sized hole. After a predetermined time has elapsed since starting up and the flow path is completely filled with refrigerant, the motor transitions to a steady-state operation. According to the above configuration, the opening area of ​​one first medium-sized hole is smaller than the opening area of ​​the other first medium-sized hole. Therefore, the amount of refrigerant that leaks out first from one first medium-sized hole can be reduced. By reducing the total amount of refrigerant that leaks out before the flow path is completely filled with refrigerant, it becomes possible to transition to a steady-state operation more quickly.

[0014] The housing may be provided with a supply port for supplying refrigerant from the outside. A flow path may be formed between the outer surface of the stator core and the inner wall surface of the housing to allow the refrigerant supplied to the supply port to flow toward the first annular member. The refrigerant flow path from the supply port to the first small hole may be shorter than the refrigerant flow path from the supply port to the first large hole. When the motor starts up, refrigerant is supplied from the supply port into the flow path. The supplied refrigerant reaches the first annular member. The amount of refrigerant in the flow path increases, with some of the refrigerant leaking out at the first hole. After a predetermined time has elapsed since starting up and the flow path is completely filled with refrigerant, the motor transitions to a steady-state operation, and refrigerant is injected from the multiple first holes. According to the above configuration, at startup, the refrigerant supplied to the supply port reaches the first small hole first and then the first large hole. When the refrigerant reaches the first small hole first, the total amount of refrigerant that leaks out before the flow path is completely filled can be reduced compared to when the refrigerant reaches the first large hole first. This makes it possible to transition to a steady-state operation more quickly.

[0015] The opening area of ​​the first small hole may be 90% or less of the opening area of ​​the first large hole. With this configuration, the amount of refrigerant leaking from the first small hole during startup can be appropriately reduced to be less than the amount of refrigerant leaking from the first large hole.

[0016] The plurality of first holes may further include at least one first medium-sized hole, which has an opening area smaller than the first large hole and a larger opening area than the first small hole. The refrigerant flow path from the supply port to at least one first medium-sized hole may be shorter than the refrigerant flow path from the supply port to the first large hole, and longer than the refrigerant flow path from the supply port to the first small hole. With this configuration, it is possible to appropriately adjust the amount of refrigerant leaking from the first medium-sized hole during startup.

[0017] At least one first medium-sized hole may include multiple first medium-sized holes. The opening area of ​​each of the multiple first medium-sized holes may become smaller as the refrigerant flow path from the supply port to the multiple first medium-sized holes shortens. With this configuration, the amount of refrigerant leaking from the first medium-sized holes during startup can be appropriately reduced.

[0018] The stator core may further comprise a plurality of channels arranged to surround the outer surface of the stator core. The plurality of channels may extend in the axial direction. This configuration allows for proper cooling of the stator by flowing a coolant through the plurality of channels of the stator core.

[0019] A second annular member that seals 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 may be further provided. 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. The plurality of second holes may include a second large hole and a second small hole having an opening area smaller than that of the second large hole. According to this configuration, it becomes possible to appropriately cool both the first coil end and the second coil end.

Embodiment

[0020] (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.

[0021] The motor 1 is mounted on an electric vehicle. Electric vehicles include hybrid vehicles and electric vehicles. In an 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 an electric vehicle, the motor 1 is mounted such that the negative direction of the z-axis coincides with the gravitational direction.

[0022] As shown in FIG. 1, the motor 1 includes a central plane CP perpendicular to the rotating shaft 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 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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 described 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 at equal intervals on the circumference. In this embodiment, eight first holes H1 are formed.

[0028] The multiple first holes H1 include a first large hole H1_L, first medium-sized holes H1_M1-H1_M3, and first small hole H1_S. The first small hole H1_S is located below the first large hole H1_L in the vertical direction (z direction). In this embodiment, the first large hole H1_L is located at the top, and the first small hole H1_S is located at the bottom. The first medium-sized holes H1_M1-H1_M3 consist of a pair of holes located at the same height in the vertical direction. The first medium-sized holes H1_M1-H1_M3 are located below the first large hole H1_L in the vertical direction and above the first small hole H1_S. That is, the vertical height gradually increases in the order of the first medium-sized holes H1_M1-H1_M3.

[0029] The openings of the multiple first holes H1 are circular in shape. The multiple first holes H1 have different opening areas due to their different diameters. The first small hole H1_S has a smaller opening area than the first large hole H1_L and the first medium-sized hole H1_M. The first medium-sized holes H1_M1-H1_M3 have smaller opening areas than the first large hole H1_L and larger opening areas than the first small hole H1_S. Furthermore, the opening areas of each of the first medium-sized holes H1_M1-H1_M3 decrease as they are located lower in the vertical direction. That is, the opening areas gradually increase in the order of the first medium-sized holes H1_M1-H1_M3. Note that in Figure 3, for clarity, the diameters of the multiple first holes H1 are shown larger than they actually are. Also, the difference in diameter between the holes is emphasized.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 plurality of second holes H2 include a second large hole H2_L, second medium holes H2_M1-H2_M3, and second small hole H2_S. The second small hole H2_S has a smaller opening area than the second medium holes H2_M1-H2_M3. The second medium-sized holes H2_M1-H2_M3 have a smaller opening area than the second large hole H2_L. Further explanation of the structure on the -x direction side with respect to the central plane CP is omitted here.

[0034] (operation) The operation of motor 1 from startup to the transition to a steady state will be described. When motor 1 starts, the coolant stored in the coolant reservoir flows into the supply port 30p of housing 30 via a pump and supply pipe (not shown). The coolant supplied to the supply port 30p flows into the annular channel 50r. The flowing coolant flows circumferentially within the annular channel 50r (see Figures 2 and 5, arrow A0). The coolant then flows into each of the multiple first channels 50c1 and flows in the +x direction (see Figure 2, arrow A1). At the same time, the coolant flows into each of the multiple second channels 50c2 and flows in the -x direction (see Figure 2, arrow A2).

[0035] The coolant flowing through the first channel 50c1 reaches the first annular member 41. Then, as some of the coolant leaks out through the first hole H1, the amount of coolant in space SP1 increases. Consequently, the liquid level of the coolant in space SP1 rises over time. After a predetermined time has elapsed since startup and space SP1 is completely filled with coolant, the system transitions to a steady-state operation.

[0036] Figure 3 illustrates the coolant injection state in a steady state. In a steady state, coolant is injected from the first large hole H1_L, the first medium hole H1_M, and the first small hole H1_S toward the first coil end 22e1. In Figure 3, the velocity of the injected coolant is shown by the injection velocity vector JS1-JS5. A longer vector indicates a higher flow velocity.

[0037] The opening area of ​​the first small hole H1_S is set to be 90% or less of the opening area of ​​the first large hole H1_M. This makes it possible to significantly increase the injection velocity JS1 of the first small hole H1_S, which is located at the bottom, compared to the injection velocity JS5 of the first large hole H1_L. Furthermore, the opening area of ​​each of the first medium-sized holes H1_M decreases as they are located lower in the vertical direction (z direction). Therefore, the injection velocity JS2 is the largest and the injection velocity JS4 is the smallest. From the above, it can be seen that the injection velocities decrease in the order of JS1-JS5.

[0038] (effect) Cooling oil injected from the first small hole H1_S, located vertically downwards, has a larger injection velocity component in the direction opposite to gravity (z-direction) compared to the cooling oil injected from the first large hole H1_L, located upwards. As a result, the cooling effect on the first coil end 22e1 may not be sufficient at the first small hole H1_S located downwards. As a countermeasure, it is conceivable to increase the pressure applied to the cooling oil in order to increase the injection velocity of the cooling oil. However, in this case, problems arise such as the need to improve the sealing performance of all parts of the cooling oil flow path and an increase in pump losses. Therefore, in the technology of this embodiment, the opening area of ​​the first small hole H1_S is made smaller than the opening area of ​​the first large hole H1_L. Thus, the injection velocity JS1 of the first small hole H1_S can be made greater than the injection velocity JS5 of the first large hole H1_L (see Figure 3). This makes it possible to ensure a sufficient cooling effect at the first small hole H1_S without increasing the pressure applied to the cooling oil.

[0039] Furthermore, in the first large hole H1_L, the opening area is increased to compensate for the smaller injection velocity JS5. This allows the injection flow rate of the first large hole H1_L to be approximately the same as that of the first small hole H1_S. This makes it possible to achieve equivalent cooling effects in each of the multiple first holes H1. Thus, an overall lubrication balance can be ensured.

[0040] In the first medium-sized holes H1_M1-H1_M3, the further down the hole is located in the vertical direction, the larger the injection velocity component in the direction opposite to gravity becomes, making it difficult to obtain a cooling effect. In the technology of this embodiment, the opening area of ​​the first medium-sized holes H1_M1-H1_M3 is made smaller the further down the hole is located in the vertical direction. This makes it possible to increase the injection velocity in the first medium-sized holes H1_M1-H1_M3 the further down the hole is located in the vertical direction. Therefore, it becomes possible to obtain an appropriate cooling effect in each of the first medium-sized holes H1_M1-H1_M3.

[0041] During motor 1 startup, some of the coolant leaks out through the first hole H1, causing the coolant level in space SP1 to rise. In this embodiment, the opening area of ​​the first hole H1 is made smaller the further down it is located in the vertical direction. Therefore, the further down the first hole H1 is located, the smaller the amount of coolant leakage during startup can be. This reduces the total amount of coolant that leaks out before space SP1 is completely filled with coolant. This makes it possible to transition to a steady-state operation more quickly. [Examples]

[0042] (Configuration of the first hole H201 and the second hole H202) In Example 2, the distribution of the opening areas of the multiple first holes H201 and 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 201 according to Example 2. Figure 6 is a cross-sectional view of the same location as in Figure 3 of Example 1. In Figure 6, the vertical position of the supply port 30p of the housing 30 is indicated by arrow A201.

[0043] The first annular member 241 is provided with a plurality of first holes H201. The plurality of first holes H201 include a first large hole H201_L, first medium-sized holes H201_M1-H201_M3, and first small hole H201_S. The first small hole H201_S and the first large hole H201_L are located at the same height as the supply port 30p in the vertical direction. The first small hole H201_S is located on the side closer to the supply port 30p, and the first large hole H201_L is located on the side further away from the supply port 30p. The distance of the first medium-sized holes H201_M1-H201_M3 from the supply port 30p in the horizontal direction gradually increases in this order.

[0044] The opening area of ​​the first small hole H201_S is the smallest, and the opening area of ​​the first large hole H201_L is the largest. The opening area of ​​the first small hole H201_S is 90% or less of the opening area of ​​the first large hole H201_L. The first medium-sized holes H201_M1-H201_M3 have smaller opening areas than the first large hole H201_L, but larger opening areas than the first small hole H201_S. Furthermore, the opening area of ​​each of the first medium-sized holes H201_M1-H201_M3 increases as the distance from the supply port 30p in the horizontal direction increases. That is, the opening areas gradually increase in the order of the first medium-sized holes H201_M1-H201_M3.

[0045] Furthermore, the second annular member 242 of Embodiment 2 is also provided with a plurality of second holes H202. The configuration of the plurality of second holes H202 is the same as the configuration of the plurality of first holes H201 described above, so a description is omitted.

[0046] (Distribution channels) The flow path of the coolant from the supply port 30p to the first small hole H201_S will be explained. As shown in Figure 5, the coolant flowing into the supply port 30p branches into the first channel 50c1 at the branching point P_S immediately adjacent to the supply port 30p. It flows axially (+x direction) through the first channel 50c1 and reaches the first small hole H201_S.

[0047] The flow path of the coolant from the supply port 30p to the first large hole H201_L will be explained. As shown by arrow A0 in Figure 5, the coolant flowing into the supply port 30p passes through the annular channel 50r and reaches the branching point P_L located on the opposite side of the supply port 30p. At branching point P_L, the coolant branches into the first channel 50c1 and flows axially (+x direction) within the first channel 50c1. In this way, the coolant reaches the first large hole H201_L.

[0048] The flow path of the coolant from the supply port 30p to each of the first medium-sized holes H201_M1-H201_M3 will be explained. As shown in Figure 5, the coolant flowing into the supply port 30p reaches each of the branching points P_M1-P_M3 via the annular channel 50r. At each of the branching points P_M1-P_M3, the coolant branches into the first channel 50c1 and flows axially (+x direction) within the first channel 50c1. In this way, the coolant reaches each of the first medium-sized holes H201_M1-H201_M3.

[0049] As explained above, the shortest flow path is from supply port 30p to the first small hole H201_S, and the longest flow path is from supply port 30p to the first large hole H201_L. Furthermore, the flow paths gradually lengthen in the order of the first medium-sized holes H201_M1 to H201_M3.

[0050] (Action and effect) When the motor 201 starts up, some of the coolant leaks out of multiple first holes H201, while the space SP1 is filled with coolant. At this time, the first holes H201 with shorter flow paths from the supply port 30p reach the coolant faster, and therefore the coolant leak occurs earlier. Specifically, the first small hole H201_S is the first to leak coolant, and the first large hole H201_L is the last to leak coolant. After a predetermined time has elapsed since starting, and the space SP1 is completely filled with coolant, the motor transitions to a steady-state operation.

[0051] In the technology of this embodiment, the opening area of ​​the multiple first holes H201 is made smaller as the flow path from the supply port 30p shortens. Therefore, the first hole H201 to which the coolant reaches earlier during startup can have less coolant leakage during startup. This reduces the total amount of coolant that leaks out before the space SP1 is completely filled with coolant. This makes it possible to transition to a steady-state operation more quickly. [Examples]

[0052] (Configuration of the first hole H301 and the second hole H302) In Example 3, the distribution of the opening areas of the multiple first holes H301 and multiple second holes H302 differs from that of Examples 1 and 2. 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. Figure 7 shows a schematic cross-sectional view of the motor 301 according to Example 3. Figure 7 is a cross-sectional view of the same location as in Figure 3 of Example 1. In Figure 7, the vertical position of the supply port 30p of the housing 30 is indicated by arrow A301.

[0053] The first annular member 341 is provided with a plurality of first holes H301. The plurality of first holes H301 include a first large hole H301_L, first medium-sized holes H301_M1L-H301_M3L, first medium-sized holes H301_M1S-H301_M3S, and first small hole H301_S. The first large hole H301_L is located at the top. The first small hole H301_S is located at the bottom. The opening area of ​​the first small hole H301_S is the smallest, and the opening area of ​​the first large hole H301_L is the largest.

[0054] The first medium-sized holes H301_M1S and H301_M1L are a pair of holes located at the same height in the vertical direction. As described above in Example 2, the length of the coolant flow path from the supply port 30p to the first medium-sized hole H301_M1S is shorter than the length of the coolant flow path from the supply port 30p to the first medium-sized hole H301_M1L. Also, the opening area of ​​the first medium-sized hole H301_M1S is smaller than the opening area of ​​the first medium-sized hole H301_M1L.

[0055] Similarly, the first medium-sized holes H301_M2S and H301_M2L are a pair of holes located at the same height in the vertical direction. The flow path length of the first medium-sized hole H301_M2S is shorter than the flow path length of the first medium-sized hole H301_M2L. Also, the opening area of ​​the first medium-sized hole H301_M2S is smaller than the opening area of ​​the first medium-sized hole H301_M2L.

[0056] Similarly, the first medium-sized holes H301_M3S and H301_M3L are a pair of holes located at the same height in the vertical direction. The flow path length of the first medium-sized hole H301_M3S is shorter than the flow path length of the first medium-sized hole H301_M3L. Also, the opening area of ​​the first medium-sized hole H301_M3S is smaller than the opening area of ​​the first medium-sized hole H301_M3L.

[0057] The opening area of ​​each of the first medium-sized holes H301_M1S-H301_M3S decreases as they are located lower in the vertical direction. Similarly, the opening area of ​​each of the first medium-sized holes H301_M1L-H301_M3L decreases as they are located lower in the vertical direction.

[0058] Furthermore, the second annular member 242 of Embodiment 2 is also provided with a plurality of second holes H302. The configuration of the plurality of second holes H302 is the same as the configuration of the plurality of first holes H301 described above, so a description is omitted.

[0059] (effect) In this embodiment, the injection velocity of the cooling oil can be increased for the first hole H301 located lower in the vertical direction. This makes it possible to ensure sufficient cooling effect even for the first hole H301 located lower down. Furthermore, the opening area is reduced as the flow path of the cooling oil from the supply port 30p shortens. This reduces the amount of cooling oil leakage when the motor 301 is started. This makes it possible to transition to a steady-state operation more quickly.

[0060] 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.

[0061] (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. [Explanation of symbols]

[0062] 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 H1_L: First large hole H1_S: First small hole H2: Second hole H2_L: Second large hole H2_S: Second small hole

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 plurality of first holes include a first large hole and a first small hole having a smaller opening area than the first large hole. Motor.

2. The motor according to claim 1, wherein the first small hole is located below the first large hole in the vertical direction.

3. The first large hole is located at the uppermost position among the plurality of first holes, The motor according to claim 1, wherein the first small hole is located at the lowest position among the plurality of first holes.

4. The motor according to claim 1, wherein the opening area of ​​the first small hole is 90% or less of the opening area of ​​the first large hole.

5. The plurality of first holes further include at least one first medium-sized hole having an opening area smaller than the first large hole and a larger opening area than the first small hole. The motor according to claim 1, wherein the at least one first medium-sized hole is located below the first large hole in the vertical direction and above the first small hole in the vertical direction.

6. The at least one first medium-sized hole includes a plurality of first medium-sized holes, The motor according to claim 5, wherein the opening area of ​​each of the plurality of first medium-sized holes decreases as they are located lower in the vertical direction.

7. The housing is equipped with a supply port for supplying the refrigerant from the outside, A flow path is formed between the outer circumferential surface of the stator core and the inner wall surface of the housing, which allows the refrigerant supplied to the supply port to flow toward the first annular member. The plurality of first medium-sized holes include two first medium-sized holes located at the same height in the vertical direction. The opening area of ​​one of the two first medium-sized holes is smaller than the opening area of ​​the other of the two first medium-sized holes. The motor according to claim 5, wherein the path through which the refrigerant flows from the supply port to one of the first medium-sized holes is shorter than the path through which the refrigerant flows from the supply port to the other first medium-sized hole.

8. The housing is equipped with a supply port for supplying the refrigerant from the outside, A flow path is formed between the outer circumferential surface of the stator core and the inner wall surface of the housing, which allows the refrigerant supplied to the supply port to flow toward the first annular member. The motor according to claim 1, wherein the refrigerant flow path from the supply port to the first small hole is shorter than the refrigerant flow path from the supply port to the first large hole.

9. The motor according to claim 8, wherein the opening area of ​​the first small hole is 90% or less of the opening area of ​​the first large hole.

10. The plurality of first holes further include at least one first medium-sized hole having an opening area smaller than the first large hole and a larger opening area than the first small hole. The motor according to claim 8, wherein the refrigerant flow path from the supply port to the at least one first medium-sized hole is shorter than the refrigerant flow path from the supply port to the first large hole, and longer than the refrigerant flow path from the supply port to the first small hole.

11. The at least one first medium-sized hole includes a plurality of first medium-sized holes, The motor according to claim 10, wherein the opening area of ​​each of the plurality of first medium-sized holes decreases as the flow path of the refrigerant from the supply port to the plurality of first medium-sized holes shortens.

12. The stator core further comprises a plurality of channels arranged to surround the outer circumferential surface of the stator core, The motor according to claim 1, wherein the plurality of channels extend in the axial direction.

13. 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 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, The motor according to claim 1, wherein the plurality of second holes include a second large hole and a second small hole having a smaller opening area than the second large hole.

14. The motor according to claim 13, wherein the second small hole is located below the second large hole in the vertical direction.

15. The second large hole is located at the uppermost position among the plurality of second holes. The motor according to claim 13, wherein the second small hole is located at the lowest position among the plurality of second holes.

16. The motor according to claim 13, wherein the opening area of ​​the second small hole is 90% or less of the opening area of ​​the second large hole.

17. The plurality of second holes further include at least one second medium-sized hole having an opening area smaller than the second large hole and a larger opening area than the second small hole. The motor according to claim 13, wherein the at least one second medium-sized hole is located below the second large hole in the vertical direction and above the second small hole in the vertical direction.

18. The at least one second medium-sized hole includes a plurality of second medium-sized holes, The motor according to claim 17, wherein the opening area of ​​each of the plurality of second medium-sized holes decreases as they are located lower in the vertical direction.

19. The housing is equipped with a supply port for supplying the refrigerant from the outside, A flow path is formed between the outer circumferential surface of the stator core and the inner wall surface of the housing, which allows the refrigerant supplied to the supply port to flow toward the second annular member. The motor according to claim 13, wherein the refrigerant flow path from the supply port to the second small hole is shorter than the refrigerant flow path from the supply port to the second large hole.

20. The plurality of second holes further include at least one second medium-sized hole having an opening area smaller than the second large hole and a larger opening area than the second small hole. The motor according to claim 19, wherein the refrigerant flow path from the supply port to the at least one second medium-sized hole is shorter than the refrigerant flow path from the supply port to the second large hole, and longer than the refrigerant flow path from the supply port to the second small hole.

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