Stator and motor equipped with same

Abstract

This stator is provided with: a stator core that is formed so as to surround the shaft center and that has a plurality of tooth parts; and coils mounted to the respective tooth parts. The coils are each formed such that a conductor wire having a rectangular cross-section is wound and stacked n turns (n being an integer of 2 or greater). The plurality of tooth parts are respectively connected to the inner circumference of the stator core so as to be away from one another at an interval, along the circumferential direction of the motor. One coil of the plurality of coils disposed in the circumferential direction has a coil end which is an end part of the coil in the axial direction and which is located at a height different from those of other coils.

Description

[Technical Field]

[0001] The present disclosure relates to a stator and a motor including the same. [Background technology]

[0002] In recent years, demand for motors has been increasing in industrial and automotive applications, and there is a demand for improved motor efficiency and lower costs.

[0003] One known method for improving motor efficiency is to increase the space factor of the coils placed in the slots of the stator. By increasing the space factor of the coils, it is possible to reduce losses caused by the current flowing through the coils when the motor is running. As a method for increasing the space factor of the coils, a configuration has been proposed in which a cast coil made of copper is placed in the slots (see, for example, Patent Document 1).

[0004] Another known method for improving motor efficiency is to cool the coils placed in the slots by injecting a refrigerant such as oil onto the coils (see, for example, Patent Document 2). In this case, cooling the coils can reduce losses caused by the current flowing through the coils.

[0005] During motor operation, the components that generate the most heat are those through which large currents flow, such as the coils in the stator. The portions of the coils that are housed in the slots of the stator are in contact with the stator core via insulators or the like. Therefore, the heat generated in these portions of the coils is dissipated to the outside via the stator core.

[0006] However, the coil has a portion that protrudes outside the slot (hereinafter referred to as the coil end). Heat is more difficult to dissipate from the coil end than from other parts of the coil, and heat tends to build up in the coil end. This causes more loss to occur in the coil end.

[0007] Taking this into consideration, Patent Document 2 discloses a configuration in which oil is injected as a coolant into the coil end through an oil pump and a supply pipe.

[0008] However, in this case, depending on the method of refrigerant injection, some coils in the stator may not be sufficiently sprayed with refrigerant, making it difficult to cool them. In order to sufficiently cool the coils, an extremely large amount of refrigerant must be supplied.

[0009] If refrigerant is sprayed onto all the coils in the stator to cool them, the structure of the refrigerant supply pipes becomes complicated. To supply refrigerant evenly to each coil end requires a significant increase in supply pressure, which results in an increase in the size of the pump that supplies the refrigerant. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] German Patent Application Publication No. 102012212637 [Patent Document 2] Japanese Patent Application Publication No. 08-130856 Summary of the Invention

[0011] The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide a stator and a motor including the same that ensure heat dissipation from a coil that is insufficiently cooled by a refrigerant when the stator includes the coil inside.

[0012] In order to achieve the above-mentioned object, the stator of the present disclosure is a stator for a motor comprising a stator core formed to surround an axis and having a plurality of teeth, and coils attached to each of the plurality of teeth, wherein the coils are formed by winding a conductor having a rectangular cross section and stacking it for n turns (n ​​is an integer of 2 or more), and the plurality of teeth are each connected to the inner circumference of the stator core at intervals along the circumferential direction of the motor, and among the plurality of coils arranged in the circumferential direction, the height of the coil end, which is the axial end of the coil in the direction in which the axis extends, of one of the coils is different from the height of the other coils.

[0013] Among the plurality of coils, one coil may be arranged between a group of coils whose coil ends have the same height as each other, the coil having a coil end having a different height from the group of coils.

[0014] The motor according to the present disclosure includes a rotor having a rotating shaft extending in the axial direction, a stator arranged coaxially with the rotor and spaced a predetermined distance from the rotor, a motor case that houses the stator and the rotor, and a cooling device that supplies refrigerant toward one of the coils, the cooling device having a pump that discharges the refrigerant, and a supply pipe that is connected to the pump, extends into the motor case, and supplies the refrigerant discharged from the pump toward the coil.

[0015] The supply pipe preferably has a second injection port that injects the refrigerant in the axial direction.

[0016] When the motor is used so that the axial direction intersects with the direction of gravity, it is preferable that the supply pipe further has a first injection port that injects the refrigerant from above in the direction of gravity.

[0017] It is preferable that the height of the coil end of the coil onto which the refrigerant is directly injected is lower than the height of the coil end of the coil onto which the refrigerant is not directly injected.

[0018] It is preferable that the coil end has a first coil end which is one end in the axial direction and a second coil end which is the other end, and the refrigerant is injected toward the first coil end.

[0019] It is preferable that the coolant be injected toward both the first coil end and the second coil end.

[0020] The surface area of ​​the first coil end may be smaller than the surface area of ​​the second coil end.

[0021] The surface area of ​​the first coil end may be greater than the surface area of ​​the second coil end.

[0022] In particular, the motor according to the present disclosure is preferably used so that the axial direction of the motor intersects with the direction of gravity.

[0023] According to the present disclosure, when a stator includes a coil that is insufficiently cooled by a refrigerant, the heat dissipation of the coil can be ensured, thereby efficiently cooling the entire stator, and ultimately the motor. [Brief explanation of the drawings]

[0024] [Figure 1A] FIG. 1A is a schematic axial cross-sectional view of a motor according to a first embodiment. [Figure 1B] FIG. 1B is a schematic cross-sectional view in the radial direction of the motor according to the first embodiment. [Figure 2] FIG. 2 is a schematic diagram of the stator of the motor according to the first embodiment as viewed from the axial direction. [Figure 3] FIG. 3 is a schematic diagram of the k-th turn of the coil as viewed from the radial direction. [Figure 4A] FIG. 4A is a cross-sectional view taken along line IVA-IVA in FIG. [Figure 4B] FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. [Figure 5]FIG. 5 is a schematic view of the stator according to the first modification, as viewed from the axial direction. [Figure 6] FIG. 6 is a schematic axial cross-sectional view of a motor according to the second modification. [Figure 7] FIG. 7 is a schematic cross-sectional view of a main part of a stator of a motor according to the second modification. [Figure 8] FIG. 8 is a schematic axial cross-sectional view of the motor according to the second embodiment. [Figure 9] FIG. 9 is a schematic axial cross-sectional view of another motor according to the second embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view of a main part of the stator of the motor shown in FIG. [Figure 11] FIG. 11 is a schematic axial cross-sectional view of a motor according to another modified example. [Figure 12] FIG. 12 is a schematic axial cross-sectional view of a motor according to yet another modified example. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the present disclosure, its applications, or its uses.

[0026] (Embodiment 1) [Motor configuration] FIG. 1A is a schematic axial cross-sectional view of a motor 1000 according to the first embodiment. FIG. 1B is a schematic radial cross-sectional view of the motor 1000 according to the first embodiment. In the following description, the radial direction of the motor 1000 may be referred to as the "radial direction," the outer circumferential direction as the "circumferential direction," and the direction in which the axis of the rotating shaft 210 of the motor 1000 extends (the direction perpendicular to the paper surface in FIG. 1B) as the "axial direction." In the radial direction, the axis side of the motor 1000 may be referred to as the inner side, and the outer circumferential side as the outer side. The motor 1000 shown in FIG. 1A is attached to equipment or a device (not shown) so that the radial direction is parallel to the direction of gravity. In this case, "parallel" refers to parallelism including manufacturing tolerances of the motor 1000 and mounting tolerances on the device, and does not necessarily mean that the radial direction and the direction of gravity are strictly parallel.

[0027] In the axial direction, the side where end plate 310 is provided may be referred to as the upper side, and the opposite side may be referred to as the lower side. Note that, when viewed from the axial direction, the axis of motor 1000 coincides with the axis of rotating shaft 210.

[0028] 1A and 1B, motor 1000 has stator 100, rotor 200, motor case 300, and end plate 310. A cooling device 400 is attached to motor 1000. The structures of stator 100 and rotor 200 will be described in detail later.

[0029] Motor case 300 is a cylindrical metal member with a bottom and an opening at the top. End plate 310 is a plate-shaped metal member provided to close the opening of motor case 300. End plate 310 may be a resin member.

[0030] The cooling device 400 has an oil pump 410 and a supply pipe 420. The supply pipe 420 is a hollow metal member. The supply pipe 420 has a main pipe 430 and a branch pipe 440. One end of the supply pipe 420 is connected to the oil pump 410. The main pipe 430 passes radially outside the stator 100 and extends into the motor case 300. The main pipe 430 branches inside the end plate 310. The branched branch pipe 440 extends into the motor case 300. Thus, two ends of the supply pipe 420 are disposed inside the motor case 300. A first injection port 431 is provided at the end of the main pipe 430. A second injection port 441 is provided at the end of the branch pipe 440. The first injection port 431 is disposed radially outside the first coil end 41a. The second injection port 441 is disposed axially above the first coil end 41a.

[0031] A metal member may be used for the supply pipe 420. For example, the supply pipe 420 can be formed from a resin member. A supply pipe 420 formed from a resin member can be expected to have high insulating properties.

[0032] Here, the first coil end 41a is the upper axial end of the coil 40. As described above, the first coil end 41a is the portion of the coil 40 that protrudes outside the slot 30. The second coil end 41b is the lower axial end of the coil 40. The second coil end 41b is the portion of the coil 40 that protrudes outside the slot 30. The supply pipe 420 may branch outside the motor case 300 or may branch inside the motor case 300.

[0033] When the oil pump 410 is driven, oil, which serves as a refrigerant, is discharged from the oil pump 410 and pumped through the supply pipe 420 into the motor case 300. The oil is sprayed toward the first coil end 41a from both the first and second injection ports 431 and 441, cooling the first coil end 41a. As is clear from FIG. 1A , the oil is sprayed from the first injection port 431 toward the radially outer surface of the first coil end 41a. The oil is sprayed from the second injection port 441 toward the axially upper surface of the first coil end 41a. The oil sprayed toward the first coil end 41a collects inside the motor case 300 in a portion that is located below the axis of the motor 1000 in the direction of gravity. The sprayed oil is then collected in an oil reservoir (not shown).

[0034] A plurality of first injection ports 431 are provided at the end of main pipe 430, and a plurality of second injection ports 441 are provided at the end of branch pipe 440. Oil is injected toward first coil ends 41a of the plurality of coils 40 (see, for example, FIG. 2). The respective ends of main pipe 430 and branch pipe 440 located inside motor case 300 may extend a predetermined length in the circumferential direction.

[0035] 1B, the stator 100 has an annular yoke 20 and a plurality of teeth (tooth portions) 10 connected to the inner periphery of the yoke 20 and arranged at equal intervals along the inner periphery. The yoke 20 connected to the teeth 10 is sometimes called a stator core 110.

[0036] The stator 100 further has slots 30 provided between the teeth 10 adjacent to each other in the circumferential direction, and coils 40 housed in the slots 30. The stator 100 is disposed radially outside the rotor 200 at a fixed distance from the rotor 200.

[0037] The teeth 10 and the yoke 20 are each formed by, for example, punching and then laminating electromagnetic steel sheets containing silicon or the like. The coils 40 are attached to each of the multiple teeth 10 with insulators 50 (see FIGS. 4A and 4B) sandwiched between them, and are housed in the slots 30. As described above, the coil 40 has a first coil end 41a and a second coil end 41b as the coil ends 41. The shape of the coil 40 will be described in detail later.

[0038] Depending on the phase of the current flowing through the coils 40, the coils 40 may be referred to as coils U1 to U4, V1 to V4, and W1 to W4, respectively.

[0039] The rotor 200 has a rotating shaft 210, a rotor core 220 having the rotating shaft 210 at its axis, and a plurality of magnets 230. The plurality of magnets 230 are embedded inside the rotor core 220, and are arranged with north and south poles facing the stator 100, alternately arranged along the circumferential direction of the rotating shaft 210. The material, shape, and quality of the magnets 230 may be changed as appropriate depending on the output of the motor 1000, etc. The rotor core 220 is formed, for example, by punching out electromagnetic steel sheets containing silicon or the like and then laminating them.

[0040] Coils U1 to U4, V1 to V4, and W1 to W4 are connected in series. Three-phase currents, U, V, and W, which are 120° out of phase with each other in electrical angle, are supplied to coils U1 to U4, V1 to V4, and W1 to W4, respectively, to excite them. As a result, a rotating magnetic field is generated in stator 100. An interaction occurs between this rotating magnetic field and the magnetic field generated by magnet 230 provided in rotor 200, generating torque, and rotating shaft 210 is supported by bearings 320 and rotates.

[0041] The present disclosure can achieve the same advantageous effects even if the coils U1 to U4, V1 to V4, and W1 to W4 are connected in parallel to the stator 100 or if other connection configurations are used.

[0042] [Main parts of the stator and coil configuration] FIG. 2 is a schematic diagram of the stator as viewed from the axial direction. FIG. 3 is a schematic diagram of the kth turn of the coil as viewed from the radial direction. FIG. 4A is a cross-sectional view taken along line IVA-IVA in FIG. 2. FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG. 2. For ease of explanation, the yoke 20 is not shown in FIG. 2 and FIGS. 4A and 4B. Also, the number of windings of the coil 40, i.e., the number of turns, is set to 5, but is not particularly limited to this. The number of turns of the coil 40 may be n (n is an integer equal to or greater than 2).

[0043] As shown in Fig. 2, the coil 40 is a component formed by spirally winding a conductor wire made of copper or the like. The coil 40 is a formed coil formed by shaping the conductor wire. Although not shown, an insulating coating is formed on the surface of the conductor wire that constitutes the coil 40.

[0044] It should be noted that the term "formed coil" in this specification does not include a coil in which a conducting wire having a constant width and thickness is simply wound in a spiral shape.

[0045] The formed coil is formed, for example, by preparing a plurality of rectangular plates of different lengths, widths, or thicknesses and joining these plates by cold welding, welding, or other methods. The plates are made of a low-resistivity material such as copper or aluminum.

[0046] Alternatively, the formed coil may be formed by so-called casting, in which copper or the like is melted and poured into a mold. The formed coil may be formed by bending a plate-shaped conductor wire, which has been formed in advance so that its width or thickness varies along the way, at a predetermined position. Alternatively, the formed coil may be formed by rolling a plate-shaped conductor wire with a constant width and thickness at a predetermined position, changing the width or thickness along the way, and then winding it spirally. In short, the formed coil is formed by adding another process to winding the conductor wire, or by a method other than simple winding.

[0047] Since the coil 40 is a formed coil, the shape of each turn can be freely changed, as will be described later.

[0048] As shown in FIG. 3, the outer shape of the kth turn of coil 40 (k is an integer where 1≦k≦n) is a rectangular ring shape with four sides when viewed radially. Two sides that face each other and extend circumferentially correspond to coil ends 41. As described above, the coil end 41 located on the upper axial side is the first coil end 41a. The coil end 41 located on the lower axial side is the second coil end 41b. Two sides 42 that face each other and extend axially are housed inside slot 30.

[0049] In this embodiment, the first turn is located closer to the axis of the motor 1000, and the nth turn is located closer to the yoke 20. In other words, the nth turn is disposed radially outside the first turn.

[0050] 2, the arrangement order of the 12 coils 40 arranged at equal intervals along the circumferential direction is designated as I to XII. Oil is injected from a first injection port 431 and a second injection port 441 of a supply pipe 420 toward the first coil ends 41a of the coils 40 arranged at positions I, II, and XII, respectively.

[0051] In this embodiment, the height of the first coil end 41a varies depending on the position of the coil 40 within the stator 100.

[0052] Specifically, for the coils 40 arranged at positions I to III, V to IX, and positions XI and XII, the height of the first coil end 41a is H1, while the height of the second coil end 41b is H2 (>H1), as shown in Fig. 4A. For the coils 40 arranged at other positions, i.e., positions IV and X, the heights of both the first coil end 41a and the second coil end 41b are H2, as shown in Fig. 4B.

[0053] As described above, oil, which is a refrigerant, is directly injected into the first coil ends 41a of the coils 40 arranged at positions I, II, and XII, respectively. Also, oil easily flows into the first coil ends 41a of the coils 40 arranged at positions III and XI, respectively, from the coils 40 arranged at adjacent positions II and XII. Therefore, in the coils 40 arranged at positions I to III, XI, and XII, the first coil ends 41a are cooled by heat exchange with the oil. Thus, the temperature rise of the coils 40 is suppressed.

[0054] As described above, the oil injected into the coils 40 is temporarily stored inside the motor case 300 in a portion located below the axis of the motor 1000 in the gravitational direction. For this reason, the coils 40 located at positions V to IX are cooled by directly contacting the accumulated oil. Thus, the temperature rise of the coils 40 is suppressed.

[0055] On the other hand, in the coils 40 arranged at positions IV and X, respectively, due to the influence of gravity, the amount of oil flowing in from the coils 40 arranged at adjacent positions III and XI becomes small. These coils 40 are arranged inside the motor case 300 near the axis of the motor 1000. For this reason, the contact area with the oil accumulated inside the motor case 300 becomes significantly smaller than that of the coils 40 located at positions V to IX, respectively. Due to these factors, in the coils 40 arranged at positions IV and X, respectively, the cooling of the first coil ends 41a becomes insufficient, and the temperature of the coils 40 tends to rise. Thus, the losses in the coils 40 increase, which may be a factor in reducing the efficiency of the motor 1000.

[0056] Therefore, in the present embodiment, in the coils 40 arranged at positions IV and X, which are difficult to be cooled by oil, the height (=H2) of the first coil ends 41a is made higher than the height (=H1<H2) of the first coil ends 41a of the coils 40 arranged at other positions.

[0057] By doing so, the surface area and volume of the first coil ends 41a of the coils 40 arranged at positions IV and X can be increased, and the amount of heat dissipated at the first coil ends 41a can be made greater than that of the coils 40 arranged at other positions. This makes it possible to suppress temperature rise in the coils 40 arranged at positions IV and X. Furthermore, because temperature rise can be suppressed across all of the multiple coils 40 arranged on the stator 100, a decrease in the efficiency of the motor 1000 can be suppressed.

[0058] Note that the coils 40 whose first coil ends 41a are higher than those of the coils 40 at other positions are not limited to the above-described example. For coils 40 with low oil cooling efficiency, the height of the first coil ends 41a may be higher than that of the coils 40 at other positions. For example, if the amount of oil accumulating inside the motor case 300 is small, the coils 40 located at positions V and IX may also be insufficiently cooled by oil. In such a case, the shape of the first coil ends 41a of the coils 40 located at positions V and IX will be the same as that shown in FIG. 4A. Furthermore, if the amount of oil flowing through the coils 40 located at positions III and XI is small, the shape of the first coil ends 41a of these coils 40 will also be the same as that shown in FIG. 4A.

[0059] [Effects, etc.] As described above, the stator 100 of this embodiment comprises at least a stator core 110 formed to surround the axis and having a plurality of teeth (tooth portions) 10, and a coil 40 attached to each of the plurality of teeth 10.

[0060] Coil 40 is formed by winding a conductive wire having a rectangular cross section and laminating n turns (n ​​is an integer of 2 or more).

[0061] The multiple teeth 10 are spaced apart from one another and connected to the inner periphery of the stator core 110 along the circumferential direction, which is the outer periphery direction of the motor 1000. The axial direction, which is the direction in which the shaft center of the motor 1000 extends, intersects with the direction of gravity.

[0062] Of the multiple coils 40 arranged in the circumferential direction, the height of the coil end 41, which is the axial end of the coil 40, in at least one coil, i.e., the height of the first coil end 41a in this embodiment, is different from that of the other coils 40. Specifically, in a coil 40 in which the first coil end 41a may not be sufficiently cooled by oil, the height H2 of the first coil end 41a is made higher than the height H1 of the first coil end 41a of a coil 40 in which the first coil end 41a is sufficiently cooled by oil.

[0063] This increases the surface area and volume of the first coil end 41a, making it possible to dissipate more heat at the first coil end 41a than the amount of heat dissipated by coils 40 arranged at other positions. This makes it possible to suppress temperature increases across the multiple coils 40 arranged on the stator 100, thereby suppressing a decrease in the efficiency of the motor 1000.

[0064] Furthermore, since there is no longer a need to spray oil onto all of the coils 40 in the stator 100, the structure of the oil supply pipe 420 is simplified. The oil supply pressure can be kept low, preventing the oil pump 410 from becoming larger. The amount of oil discharged can also be reduced. These factors contribute to reducing the cost of the cooling device 400 and, ultimately, the motor 1000.

[0065] Since the coil 40 is the formed coil described above, the height of the first coil end 41a of the coil 40 can be easily changed in a desired position.

[0066] The motor 1000 of this embodiment comprises at least a rotor 200 having a rotating shaft 210 as its axis, a stator 100 arranged coaxially with the rotor 200 and spaced a predetermined distance apart from the rotor 200, and a motor case 300 that houses the stator 100 and the rotor 200 inside.

[0067] The motor 1000 further includes a cooling device 400 that supplies oil as a refrigerant to at least one coil 40 .

[0068] The cooling device 400 has an oil pump (pump) 410 that discharges oil, and a supply pipe 420 that is connected to the oil pump 410, extends into the interior of the motor case 300, and supplies the oil discharged from the oil pump 410 toward the first coil end 41a of the coil 40.

[0069] According to this embodiment, oil supplied from the cooling device 400 is sprayed onto the coil 40, thereby reliably cooling the coil 40, which is the main heat source in the motor 1000. This makes it possible to suppress thermal loss generated in the coil 40 and improve the efficiency of the motor 1000.

[0070] Furthermore, for the coils 40 that are not sufficiently cooled by oil, the height H2 of the first coil ends 41a is set higher than the height H1 of the first coil ends 41a of the coils 40 that are cooled by oil. Furthermore, the height H2 of the first coil ends 41a of the coils 40 that are not directly sprayed with oil is set higher than the height H1 of the first coil ends 41a of the coils 40 that are directly sprayed with oil. This increases the amount of heat dissipated from the first coil ends 41a of the coils 40 that are not sufficiently cooled by oil. This suppresses temperature rise across the multiple coils 40 arranged on the stator 100. It also suppresses a decrease in the efficiency of the motor 1000.

[0071] Furthermore, the structure of the supply pipe 420 is simplified, and the oil pump 410 is prevented from becoming larger. Also, the amount of oil discharged can be reduced. As a result, the cost of the cooling device 400, and in turn the cost of the motor 1000, can be reduced.

[0072] Supply pipe 420 has second injection ports 441 that inject oil in the axial direction. This ensures that oil is sprayed onto the region of first coil end 41a with the largest surface area. Supply pipe 420 also preferably has first injection ports 431 that inject oil from above in the direction of gravity. This ensures that first coil end 41a is cooled by oil.

[0073] The coil end 41 has a first coil end 41a which is one end in the axial direction, and a second coil end 41b which is the other end. The oil is injected toward at least the first coil end 41a.

[0074] Furthermore, when oil is supplied to the first coil end 41a but not to the second coil end 41b, as described above, there will be a mixture of coils 40 with first coil ends 41a having a height of H1 and coils 40 with first coil ends 41a having a height of H2 (>H1). On the other hand, the height of the second coil ends 41b of each of the multiple coils 40 is set to the same value (=H2).

[0075] This increases the amount of heat dissipation at the second coil ends 41b, to which no oil is supplied, for all coils 40 in the stator 100. This makes it possible to suppress temperature increases across all of the multiple coils 40 arranged in the stator 100, and to suppress a decrease in the efficiency of the motor 1000.

[0076] <Variation 1> Fig. 5 is a schematic view of the stator 100 according to Modification 1 as viewed from the axial direction. For ease of explanation, in Fig. 5 and the following drawings, the same parts as those in Embodiment 1 are denoted by the same reference numerals, and detailed explanations thereof will be omitted.

[0077] The stator 100, and thus the motor 1000, of this modification differ from the stator 100 and thus the motor 1000 of the first embodiment in the position of the coil 40 to which oil is directly injected. Specifically, as shown in FIG. 5, oil is directly injected to the coils 40 located at positions I, III, and XI. In this case, the coils 40 located at positions I, III, and XI have the same shape as that shown in FIG. 4A. Meanwhile, the coil 40 located at position II, which is between positions I and III, has a height of H2, similar to that shown in FIG. 4B. The coil 40 located at position XI, which is between positions X and XII, also has a height of H2, similar to that shown in FIG. 4B.

[0078] The position of the coil 40 where the height of the first coil end 41a is H2 is not particularly limited to the example shown in Fig. 5. It is sufficient that, among the multiple coils 40, at least one coil 40 whose first coil end 41a has a height different from that of the coil group is disposed between coil groups whose first coil ends 41a have the same height.

[0079] That is, in this modification as well, the height H2 of the first coil ends 41a of the coils 40 to which oil is not directly injected is made higher than the height H1 of the first coil ends 41a of the coils 40 to which oil is directly injected. This increases the amount of heat dissipated from the first coil ends 41a of the coils 40 that are not sufficiently cooled by oil, making it possible to suppress temperature increases across the multiple coils 40 arranged on the stator 100. It also makes it possible to suppress a decrease in the efficiency of the motor 1000.

[0080] <Variation 2> Fig. 6 is a schematic axial cross-sectional view of a motor 1000 according to Modification 2. Fig. 7 is a schematic cross-sectional view of a main portion of a stator 100 of a motor 1000 according to Modification 2. For ease of explanation, in Figs. 6 and 7 and the subsequent drawings, the same parts as those in Embodiment 1 are designated by the same reference numerals, and detailed explanations thereof will be omitted.

[0081] The motor 1000 of this modified example shown in FIG. 6 has a supply pipe 420 with a shape different from that of the motor 1000 of Embodiment 1 shown in FIG. 1A. Specifically, the main pipe 430 extends between the stator 100 and the motor case 300 to the outside in the radial direction of the second coil end 41b. One of the pair of first injection ports, the first injection port 431, is located in the middle part of the main pipe 430 and is arranged on the outside in the radial direction of the first coil end 41a. The other of the pair of first injection ports, the first injection port 432, is located in the middle part of the main pipe 430 and is arranged on the outside in the radial direction of the second coil end 41b. Therefore, the oil injected from the pair of first injection ports 431, 432 is sprayed onto the outer surfaces in the radial direction of the first coil end 41a and the second coil end 41b, respectively.

[0082] As shown in FIG. 6, another branch pipe 450 extends from the end of the main pipe 430 toward the axis of the motor 1000. At the end of the branch pipe 450, a second injection port 451 that faces the lower surface in the axial direction of the second coil end 41b among the pair of second injection ports 441, 451 is provided. Therefore, the oil injected from the second injection port 441 that faces the first coil end 41a among the pair of second injection ports 441, 451 is sprayed onto the upper surface in the axial direction of the first coil end 41a, and the oil injected from the second injection port 451 that faces the second coil end 41b is sprayed onto the lower surface in the axial direction of the second coil end 41b.

[0083] In this modified example, in the coils 40 arranged at positions I to III, V to IX, and positions XI, XII, respectively, as shown in FIG. 7, the heights of the first coil end 41a and the second coil end 41b are set to H1 (<H2), respectively.

[0084] According to this modified example, not only the first coil end 41a but also the second coil end 41b can be sprayed with oil, which is a refrigerant. Also, in the coils 40 at positions where the cooling efficiency by oil is higher compared to the coils 40 arranged at positions IV and X, respectively, not only the height of the first coil end 41a but also the height of the second coil end 41b is lower.

[0085] This configuration can achieve the same effects as those achieved by the configuration shown in embodiment 1. That is, in the coils 40 that are not sufficiently cooled by oil, the amount of heat dissipated from the first coil end 41a and the second coil end 41b can be increased. Temperature increases can be suppressed across the multiple coils 40 arranged on the stator 100. Furthermore, a decrease in the efficiency of the motor 1000 can be suppressed.

[0086] Furthermore, since the amount of oil discharged can be reduced, it is possible to prevent the oil pump 410 from becoming large, thereby reducing the cost of the cooling device 400 and, ultimately, the cost of the motor 1000.

[0087] In the configuration shown in embodiment 1, the supply pipe 420 is not routed to the vicinity of the second coil end 41b. This reduces the space required for arranging the supply pipe 420 within the motor case 300. This reduces the volume of the motor 1000 by the portion surrounded by the dashed line in FIG. 1A compared to the configuration shown in FIG. 6. This allows the motor 1000 to be made smaller.

[0088] (Embodiment 2) Fig. 8 is a schematic axial cross-sectional view of a motor 1000 according to embodiment 2. Fig. 9 is a schematic axial cross-sectional view of another motor 1000 according to embodiment 2. Fig. 10 is a schematic sectional view of a main part of the stator 100 of the motor 1000 shown in Fig. 9.

[0089] 8 has the same configuration as the motor 1000 shown in the first embodiment. However, the surface area of ​​the second coil ends 41b, onto which the oil refrigerant is not sprayed, is larger than the surface area of ​​the first coil ends 41a, onto which the oil is sprayed. Furthermore, the volume of the second coil ends 41b may be larger than the volume of the first coil ends 41a.

[0090] This allows the heat dissipation area to be larger at the second coil end 41b than at the first coil end 41a. This increases the amount of heat dissipated at the second coil end 41b. On the other hand, because oil is sprayed onto the first coil end 41a, which has a smaller heat dissipation area and is prone to trapping heat, the amount of heat dissipated from the first coil end 41a can be increased through heat exchange with the oil. In other words, this eliminates the need to spray oil onto the second coil end 41b, while still ensuring that heat generated in the coil 40 is dissipated. This increases the efficiency of the motor 1000. Furthermore, because the amount of oil discharged can be reduced, the oil pump 410 can be made smaller. This reduces the cost of the cooling device 400 and, ultimately, the motor 1000.

[0091] According to this embodiment, the arrangement space for the supply pipe 420 within the motor case 300 can be reduced, as described in Modification 2. As a result, the volume of the motor 1000 can be reduced by the portion surrounded by the dashed line in FIG. 8 compared to the configuration shown in FIG. 6. This allows the motor 1000 to be made more compact. Furthermore, the volume of the first coil end 41a can be made smaller than the volume of the second coil end 41b. This allows the axial size of the motor 1000 to be reduced. This allows the motor 1000 to be made more compact.

[0092] The surface area of ​​the second coil end 41b is set appropriately depending on the amount of heat required to be dissipated from the second coil end 41b. Furthermore, the shapes of the first coil end 41a and the second coil end 41b can be changed appropriately as long as the surface area of ​​the first coil end 41a is smaller than the surface area of ​​the second coil end 41b.

[0093] 9, in motor 1000, the surface area of ​​first coil end 41a onto which oil as a refrigerant is sprayed may be larger than the surface area of ​​second coil end 41b onto which oil is not sprayed. The volume of first coil end 41a may be larger than the volume of second coil end 41b.

[0094] Injecting oil directly onto the coil end 41 can reliably increase the amount of heat dissipated from the coil 40, rather than dissipating heat from the coil end 41 into the external atmosphere. Therefore, as shown in Figure 9, there are cases where oil is injected onto the first coil end 41a, which has a larger surface area than the second coil end 41b, to actively cool the coil 40.

[0095] Fig. 10 is a schematic cross-sectional view of a main part of the stator 100 of the motor 1000 shown in Fig. 9. Specifically, it corresponds to the coils 40 arranged at positions I to III and V to IX, and further at positions XI and XII shown in Fig. 2.

[0096] As shown in Fig. 10, in the coil 40, the height of the first coil end 41a is H3 (>H2), while the height of the second coil end 41b is H2 (>H1). This allows the surface area and volume of the first coil end 41a to be greater than those of the second coil end 41b in the coil 40, which is actively cooled by oil. However, the structure in which the surface area and volume of the first coil end 41a are greater than those of the second coil end 41b is not limited to the example shown in Fig. 10. Although not shown, the shapes of the coils 40 positioned at positions IV and X are similar to those shown in Fig. 4B.

[0097] 9 and 10, the heat generated in the coil 40 can be reliably dissipated without the need to inject oil into the second coil end 41b, thereby improving the efficiency of the motor 1000. Because the amount of oil discharged can be reduced, the oil pump 410 can be made smaller. This reduces the cost of the cooling device 400 and, ultimately, the motor 1000. Furthermore, the space required for arranging the supply pipe 420 within the motor case 300 can be made smaller. This allows the motor 1000 to be made smaller.

[0098] In the coil 40 shown in FIG. 10, the shapes of the first coil end 41a and the second coil end 41b can be changed as appropriate, as long as the surface area of ​​the first coil end 41a is larger than the surface area of ​​the second coil end 41b.

[0099] In the motor 1000 shown in Fig. 9, the shapes of all of the coils 40 in the stator 100 may be the same as those shown in Fig. 4A. That is, the height of the first coil ends 41a may be shorter than the height of the second coil ends 41b in all of the coils 40. Also, in the motor 1000 shown in Fig. 10, the shapes of all of the coils 40 in the stator 100 may be the same as those shown in Fig. 10. That is, the height of the first coil ends 41a may be longer than the height of the second coil ends 41b in all of the coils 40.

[0100] (Other embodiments) New embodiments can be created by appropriately combining the components shown in Embodiments 1 and 2 and Modifications 1 and 2. For example, the coil 40 of Modification 2 shown in FIG. 7 may be applied to the stator 100 and motor 1000 shown in Embodiment 1 or Modification 1.

[0101] In this specification, the height of the coil end 41 is the same for each turn of one coil 40, but it may be different for each turn. Alternatively, it may be the same for one or more turns and different for the remaining turns.

[0102] In the present specification, a three-phase, 12-slot motor 1000 has been described as an example, but the present invention is not particularly limited to this, and the motor 1000 may have another structure, for example, a three-phase, 6-slot motor.

[0103] The structure of supply pipe 420 is not particularly limited to the examples shown in Figure 1A and Figure 6. For example, first injection ports 431, 432 may be omitted. Alternatively, branch pipes 440, 450 and second injection ports 441, 451 may be omitted.

[0104] The structure of the motor 1000 of the present disclosure is not limited to the examples shown in the first and second embodiments and the first and second modifications, and other structures may also be employed.

[0105] Fig. 11 is a schematic axial cross-sectional view of a motor according to another modified example, and Fig. 12 is a schematic axial cross-sectional view of a motor according to yet another modified example.

[0106] In the above-described first and second embodiments, the supply pipe 420 has been described as having a main pipe 430 and a branch pipe 440. The supply pipe 420 may be formed of only one pipe. For example, as shown in FIG. 11, the supply pipe 420 may have a shape that uses only the main pipe 430 shown in FIG. 1A. Alternatively, the supply pipe may have a shape that uses only the branch pipe 440.

[0107] The cooling device 400 may change the direction in which it is attached to the motor 1000 depending on the direction in which the motor 1000 is attached to the object on which it is installed.

[0108] For example, as shown in Fig. 12, motor 1000 may be installed so that the direction of gravity and the axial direction are the same. In such a case, oil pump 410 may be installed on the outer periphery in the radial direction, as shown in Fig. 12. In this case, supply pipe 420 passes through end plate 310 and extends into motor case 300, similar to branch pipe 440 shown in Fig. 1A. Note that as long as first injection port 431 is located above coil 40 in the direction of gravity, as shown in Fig. 12, the same effects as those of the first and second embodiments can be achieved. [Industrial Applicability]

[0109] The stator of the present disclosure can ensure heat dissipation in each coil in the stator when the coil is cooled with a refrigerant, and is therefore useful for application to high-efficiency motors. [Explanation of symbols]

[0110] 10 Teeth 20 York 30 slots 40 coils 41 Coil end 41a First coil end 41b Second coil end 42 Side 50 insulator 100 Stator 110 stator core 200 rotors 210 Rotational Axis 220 rotor core 230 Magnet 300 motor case 310 End Plate 320 Bearings 400 Cooling device 410 Oil pump (pump) 420 Supply pipe 430 Master 431,432 No. 1 injection port 440,450 Branch pipe 441,451 2nd injection port 1000 motor

Claims

1. A rotor having a rotation axis extending in an axial direction, which is the direction in which the axis extends; a stator for a motor, the stator core being disposed coaxially with the rotor and spaced a predetermined distance from the rotor, the stator core being formed to surround the axis and having a plurality of teeth, and a coil being attached to each of the plurality of teeth, The coil is formed by winding a conductor having a rectangular cross section and laminating n turns (n ​​is an integer of 2 or more), the plurality of tooth portions are connected to an inner periphery of the stator core at intervals along a circumferential direction of the motor, a stator in which, among the plurality of coils arranged in the circumferential direction, a height of a coil end, which is an end portion of the coil in the axial direction, of one of the coils is different from that of the other coils; a motor case that accommodates the stator and the rotor therein; a cooling device that supplies a refrigerant toward one of the coils, The cooling device is a pump that discharges the refrigerant; a supply pipe connected to the pump, extending into the motor case, and supplying the refrigerant discharged from the pump toward the coil; In the motor, the supply pipe has a second injection port that injects the refrigerant in the axial direction, A motor in which the height of the coil end of the coil onto which the refrigerant is directly injected is lower than the height of the coil end of the coil onto which the refrigerant is not directly injected.

2. 2. The stator of claim 1, A motor having a stator in which one of the coils is arranged between a group of coils whose coil ends have the same height as each other, and whose coil ends have a different height from the group of coils.

3. 2. The motor according to claim 1, wherein when the motor is used such that the axial direction intersects with the direction of gravity, The supply pipe further has a first injection port that injects the refrigerant from above in the direction of gravity.

4. The motor according to any one of claims 1 to 3, The coil end has a first coil end which is one end in the axial direction and a second coil end which is the other end, The refrigerant is injected toward the first coil end.

5. 5. The motor according to claim 4, The refrigerant is injected toward both the first coil end and the second coil end.

6. 5. The motor according to claim 4, A motor in which the surface area of ​​the first coil end is smaller than the surface area of ​​the second coil end.

7. 5. The motor according to claim 4, A motor in which the surface area of ​​the first coil end is larger than the surface area of ​​the second coil end.

8. 6. The motor according to claim 5, A motor in which the surface area of ​​the first coil end is smaller than the surface area of ​​the second coil end.

9. 6. The motor according to claim 5, A motor in which the surface area of ​​the first coil end is larger than the surface area of ​​the second coil end.

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