Electric compressor device

Abstract

To provide an electric compressor device capable of effectively cooling a stator coil.SOLUTION: An electric compressor device includes: a rotary shaft; a compressor impeller provided on the rotary shaft; a motor including a rotor provided on the rotary shaft at the back side of the compressor impeller, and a stator coil arranged around the rotor; a journal bearing rotatably supporting the rotary shaft between the rotor and the compressor impeller; and a bearing housing for housing the journal bearing and including a radially extending wall part extending in a radial direction of the rotary shaft between the stator coil and the compressor impeller. The inside of the radially extending wall part is formed with a cooling air flow passage for guiding cooling air for the coil introduced from the outside of the bearing housing to the stator coil. All the parts of the cooling air flow passage are positioned radially outward than the journal bearing.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an electrically driven compressor device. [Background technology]

[0002] Conventionally, electric compressor devices that use compressed air to cool a stator coil have been known. For example, the electric compressor disclosed in Patent Document 1 includes a low-pressure side bearing housing, and a compressed air flow path that functions as cooling air is formed inside the low-pressure side bearing housing. The compressed air flows sequentially through a one-side annular flow path, a radial flow path, an annular flow path, and an axial flow path before reaching the stator coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2023 / 162160 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the cooling air flows radially inward to a position close to the axis of the electric compressor, and then flows to an axial flow path located radially outward. Therefore, by the time it reaches the stator coil, the cooling air has already exchanged heat with various components of the electric compressor. As a more specific example, the cooling air exchanges heat with the thrust bearing in the low-pressure side bearing housing or the journal bearing near the thrust bearing, and the temperature of the cooling air is relatively high. This can make it difficult to effectively cool the stator coil.

[0005] An object of the present disclosure is to provide an electric compressor device that can effectively cool a stator coil. [Means for solving the problem]

[0006] According to at least one embodiment of the present disclosure, there is provided an electric compressor device, A rotation axis; a compressor impeller provided on the rotating shaft; a motor including a rotor provided on the rotary shaft on the rear side of the compressor impeller and a stator coil disposed around the rotor; a journal bearing that rotatably supports the rotary shaft between the rotor and the compressor impeller; a bearing housing that accommodates the journal bearing, the bearing housing including a radially extending wall portion that extends in a radial direction of the rotary shaft between the stator coil and the compressor impeller; Equipped with a cooling air flow path is formed inside the radially extending wall portion to guide coil cooling air introduced from outside the bearing housing to the stator coil; The entire cooling air flow path is located radially outward of the journal bearing. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide an electric compressor device that can effectively cool a stator coil. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram of an electric compressor device according to an embodiment; [Figure 2] FIG. 2 is a schematic view of a low-pressure side bearing housing according to one embodiment. [Figure 3] FIG. 3 is a partially enlarged view of FIG. 2. [Figure 4] FIG. 1 is a schematic perspective view of an anti-swirl plate according to one embodiment. [Figure 5] FIG. 2 is a schematic diagram of an injection port and an anti-swirl plate according to an embodiment. [Figure 6] FIG. 10 is a schematic view of an anti-swirl plate according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," or "have" one element are not exclusive expressions that exclude the presence of other elements. Note that the same components will be denoted by the same reference numerals and the description thereof will be omitted.

[0010] <Outline of the electric compressor device 10> 1 is a schematic diagram of an electric compressor device 10 according to one embodiment of the present disclosure. The electric compressor device 10 of this example is a two-stage compression compressor for sending compressed air to a fuel cell mounted on a vehicle. The electric compressor device 10 includes a rotating shaft 12, a low-pressure compressor impeller 13 provided on one side of the rotating shaft 12, and a high-pressure compressor impeller 14 provided on the other side of the rotating shaft 12.

[0011] In the following description, the direction in which the axis of the rotating shaft 12 extends will be referred to as the "axial direction," and the circumferential direction and radial direction based on the axis will sometimes be simply referred to as the "circumferential direction" and the "radial direction," respectively. The outer radial direction is the side away from the axis, and the inner radial direction is the side approaching the axis.

[0012] The electric compressor device 10 further includes a motor 3. The motor 3 includes a rotor 4 provided on the rotary shaft 12 between a low-pressure compressor impeller 13 and a high-pressure compressor impeller 14, a stator 2 extending in the circumferential direction so as to surround the rotor 4, and a stator coil 5 supported by the stator 2.

[0013] The rotor 4 is located on the rear side (i.e., the other axial side) of the low-pressure compressor impeller 13. The stator 2 is supported by the inner circumferential surface of the motor housing 21. A plurality of stator coils 5 are arranged circumferentially, each positioned around the rotor 4. The stator coil 5 has a pair of coil ends 6 that protrude axially from the stator 2. Each of the pair of coil ends 6 may be covered with a resin member (not shown). During the manufacturing process of the motor 3, a filling process is performed in which liquid resin is filled into the stator coil 5 placed inside a mold, and then a cooling process is performed to cool the mold. As a result, the pair of coil ends 6 are covered with the resin member. Hereinafter, when simply referring to a "coil end 6," it refers to the coil end 6 on one side.

[0014] In some embodiments of the present disclosure, a motor cooling water passage 17 extending in the circumferential direction is formed inside the motor housing 21. The axial range of the motor cooling water passage 17 is included in the axial range of the stator 2. In other words, the motor cooling water passage 17 is disposed in an axial position between a pair of coil ends 6. The cooling water flowing through the motor cooling water passage 17 exchanges heat with the stator coil 5, thereby cooling the stator coil 5. In particular, the radially outer portions of the stator coil 5 are cooled by the cooling water.

[0015] The electric compressor device 10 further includes a low-pressure-side journal bearing 15 and a high-pressure-side journal bearing 16 that rotatably support the rotating shaft 12. The low-pressure-side journal bearing 15 is located between the rotor 4 and the low-pressure compressor impeller 13, and the high-pressure-side journal bearing 16 is located between the rotor 4 and the high-pressure compressor impeller 14. The low-pressure-side journal bearing 15 is housed in a low-pressure-side bearing housing 22 that is located on one axial side of the motor housing 21, and the high-pressure-side journal bearing 16 is housed in a high-pressure-side bearing housing 23 that is located on the other axial side of the motor housing 21. In this example, both the low-pressure-side journal bearing 15 and the high-pressure-side journal bearing 16 are air bearings.

[0016] In some embodiments, of the high-pressure side bearing housing 23 or the low-pressure side bearing housing 22, only the high-pressure side bearing housing 23 has the cooling water flow passage 11 formed therein extending in the circumferential direction.

[0017] The electric compressor device 10 further includes a thrust bearing 8 that rotatably supports the rotating shaft 12. The thrust bearing 8 is disposed between the low-pressure side journal bearing 15 and the low-pressure compressor impeller 13, and is housed in a low-pressure side bearing housing 22. A disk 8a of the low-pressure side journal bearing 15 faces the low-pressure side bearing housing 22 (more specifically, the main body 76 described below) in the axial direction. In this example, the thrust bearing 8 is an air bearing. The disk 8a extends radially outward from the cylindrical portion of the low-pressure side journal bearing 15. The rotating shaft 12 is inserted into the cylindrical portion.

[0018] The low-pressure compressor impeller 13 is housed in a low-pressure side housing 43, and both are components of a low-pressure compressor 41. The low-pressure side housing 43 defines an intake port 46, a diffuser 47, a scroll portion 48, and a low-pressure discharge port (not shown).

[0019] The high-pressure compressor impeller 14 is housed in a high-pressure side housing 44, and both are components of the high-pressure compressor 42. The high-pressure side housing 44 defines an intake port 50, a diffuser 51, a scroll section 53, and a high-pressure discharge port (not shown). The low-pressure discharge port of the low-pressure compressor 41 and the intake port 50 of the high-pressure compressor 42 are connected by an intermediate pipe 54.

[0020] The operation of the electric compressor device 10 is outlined as follows. The rotating magnetic field generated by energizing the stator coil 5 acts on the permanent magnets provided on the rotor 4, causing the motor 3 to rotate the rotating shaft 12. The low-pressure compressor impeller 13 and the high-pressure compressor impeller 14 rotate together with the rotating shaft 12. As the low-pressure compressor impeller 13 rotates, external air passes through the suction port 46. The air passing through the suction port 46 is accelerated by the centrifugal force of the low-pressure compressor impeller 13. The accelerated air is decelerated and pressurized by the diffuser 47 before flowing through the scroll section 48. The compressed air in the scroll section 48 is discharged from the low-pressure discharge port and flows through the intermediate piping 54. The intermediate piping 54 directs the compressed air to the suction port 50. The air passing through the suction port 50 is accelerated by the centrifugal force of the high-pressure compressor impeller 14. The accelerated air is decelerated and pressurized by the diffuser 51 before flowing through the scroll section 53. The compressed air in the scroll section 53 is discharged from a high-pressure discharge port and sent to the fuel cell.

[0021] <Cooling system overview> FIG. 2 is a schematic diagram of a low-pressure side bearing housing 22 according to one embodiment of the present disclosure. The low-pressure side bearing housing 22 includes a radially extending wall portion 25 extending radially between the stator coil 5 and the low-pressure compressor impeller 13. A flow path is formed inside the radially extending wall portion 25, which guides compressed air bled from the intermediate piping 54 as cooling air to an object to be cooled (this flow path is omitted in FIG. 1). In this example, the object to be cooled includes a thrust bearing 8 and a stator coil 5. More specifically, a bearing cooling flow path 90 through which bearing cooling air flows and a cooling air flow path 70 through which coil cooling air flows are formed inside the radially extending wall portion 25. The configuration of the bearing cooling flow path 90 will be described later.

[0022] The coil cooling air flowing through the cooling air flow path 70 is supplied to the coil ends 6 of the stator coil 5 (details will be described later). In this embodiment, the entire cooling air flow path 70 is located radially outward from the outermost surface 15a of the low-pressure side journal bearing 15. Furthermore, in some embodiments of the present disclosure, the entire cooling air flow path 70 is located radially outward from a cylindrical outer peripheral surface 29 of a cylindrical wall portion 27 (described later) of the low-pressure side bearing housing 22. Furthermore, in some embodiments, the entire cooling air flow path 70 is located radially outward from a swirl prevention plate 33 (described later) and is also located radially outward from the radial center of the disk 8a of the thrust bearing 8.

[0023] According to the above configuration, it is possible to suppress heat exchange between the coil cooling air flowing through the cooling air flow path 70 and components such as the low-pressure side journal bearing 15 and the thrust bearing 8 located therearound. Since it is possible to suppress a rise in the temperature of the coil cooling air before it reaches the stator coil 5, it is possible to effectively cool the coil ends 6 of the stator coil 5.

[0024] <Bearing cooling channel 90> 2, the bearing cooling flow path 90 includes a bearing upstream flow path 91 and a bearing downstream flow path 93. The bearing upstream flow path 91 is configured to guide low-pressure compressed air bled from the intermediate piping 54 to the thrust bearing 8 as bearing cooling air. The low-pressure compressed air is guided by the bearing upstream flow path 91 and flows into the bearing accommodating space 19 for the thrust bearing 8 formed inside the low-pressure side bearing housing 22. The bearing downstream flow path 93 is configured to guide the bearing cooling air that has completed heat exchange with the thrust bearing 8 in the bearing accommodating space 19 to the outside. Both the bearing upstream flow path 91 and the bearing downstream flow path 93 extend radially.

[0025] <Cooling air flow path 70> As shown in Figure 3, the cooling air flow path 70 has an inlet flow path 71 extending radially and axially, a circumferentially extending flow path 75 connected to the downstream end 72 of the inlet flow path 71, and a plurality of injection ports 78 arranged on the stator coil 5 side (i.e., the other axial side) of the circumferentially extending flow path 75.

[0026] In this example, the upstream end 69 of the inlet flow passage 71 is connected to the bearing upstream flow passage 91, and the bearing cooling air extracted from the bearing upstream flow passage 91 is guided as coil cooling air toward the stator coil 5. Note that, although the inlet flow passage 71 extends along the radial and axial directions in the example of Fig. 3, the present disclosure is not limited thereto, and the inlet flow passage 71 may extend only along the axial or radial direction.

[0027] The circumferentially extending flow passage 75 extends in the circumferential direction so as to surround the rotating shaft 12. In one example in the present disclosure, the radially outer end of the circumferentially extending flow passage 75 is connected to the downstream end 72 of the inlet flow passage 71. A portion of the radial range of the circumferentially extending flow passage 75 overlaps with the radial range of the disk 8a of the thrust bearing 8. However, it is preferable that the circumferentially extending flow passage 75 be located radially outward, and in this example, the entire circumferentially extending flow passage 75 is located outside the radial center of the disk 8a. The multiple injection ports 78 are arranged at intervals in the circumferential direction. Each injection port 78 is configured to inject the coil cooling air in the circumferentially extending flow passage 75 toward the coil ends 6 of the stator coil 5.

[0028] According to the above configuration, coil cooling air is injected from each of the multiple injection ports 78 arranged in the circumferential direction, thereby uniformly cooling the air around the stator coil 5. This allows the electric compressor device 10 to effectively cool the coil ends 6.

[0029] Furthermore, the inlet flow path 71 of the cooling air flow path 70 guides the bearing cooling air bled from the bearing upstream flow path 91 of the bearing cooling flow path 90 to the stator coil 5 as coil cooling air, so that the compressed air bled from the intermediate piping 54 can be used as coil cooling air. Furthermore, the bearing cooling air before exchanging heat with the thrust bearing 8 flows through the inlet flow path 71 as coil cooling air, so the temperature of the coil cooling air before it reaches the stator coil 5 can be lowered. This allows the stator coil 5 to be cooled effectively.

[0030] Returning to Fig. 2, the multiple injection ports 78 will be described. In some embodiments, the multiple injection ports 78 include multiple inner injection ports 79 that are arranged radially inward of the center (two-dot chain line M) of the radial range of the stator coil 5. More specifically, the inner injection ports 79 include first inner injection ports 79a that are arranged at equal intervals in the circumferential direction, and second inner injection ports 79b that are arranged at equal intervals in the circumferential direction and radially inward of the first inner injection ports 79a.

[0031] The pitch angle of the multiple first inner jet ports 79a is equal to or greater than 15 degrees and equal to or less than 20 degrees. In other words, the circumferential distance between the centers of two circumferentially adjacent first inner jet ports 79a is equal to or greater than 15 degrees and equal to or less than 20 degrees, based on the axis of the rotation shaft 12. In this example, the pitch angle is 20 degrees, and there are 18 first inner jet ports 79a. Similarly, the pitch angle of the multiple second inner jet ports 79b is equal to or greater than 15 degrees and equal to or less than 20 degrees. As an example, the pitch angle is also 20 degrees, and there are 18 second inner jet ports 79b. In some embodiments, the centers of the multiple first inner jet ports 79a and the centers of the multiple second inner jet ports 79b are located at the same circumferential position (see FIG. 5).

[0032] According to the inventor's findings, the temperature of the stator coil 5 is more likely to rise radially inside than radially outside. This is because the further radially inside the internal space of the motor housing 21 you go, the more difficult it becomes to dissipate heat from the stator coil 5. In this regard, with a configuration in which multiple inner injection ports 79 are provided, the coil cooling air injected from the multiple inner injection ports 79 can effectively cool the coil ends 6 located inside the center of the radial range of the stator coil 5 (two-dot chain line M).

[0033] 3, the relationship between the low-pressure side bearing housing 22 and the cooling air flow path 70 will be described in detail. The radially extending wall portion 25 of the low-pressure side bearing housing 22 includes a main body portion 76 having the inlet flow path 71 formed therein. The above-mentioned bearing cooling flow path 90 is also formed inside the main body portion 76.

[0034] The radially extending wall portion 25 further includes an extension portion 73 that is configured separately from the main body portion 76. The extension portion 73 is a plate that extends in the radial direction and is attached to the main body portion 76 by a plurality of fastening members (not shown). A plurality of injection ports 78 are formed in the extension portion 73. Each injection port 78 is a circular hole that penetrates the extension portion 73 in the axial direction.

[0035] An end face 77 of the main body portion 76 on the stator coil 5 side includes a concave surface 74 that is recessed toward the low-pressure compressor impeller 13 side (i.e., one axial side). The concave surface 74 extends in the circumferential direction so as to surround the rotating shaft 12, and the radially outer end of the concave surface 74 is connected to the downstream end 72 of the inlet flow passage 71. An end face 73a of the extension portion 73 on the low-pressure compressor impeller 13 side cooperates with the concave surface 74 to define a circumferentially extending flow passage 75.

[0036] According to the above configuration, the extension portion 73 is configured separately from the main body portion 76, which improves the design freedom for arranging the multiple injection ports 78. As a result, the multiple injection ports 78 can be arranged in positions suitable for cooling the coil ends 6 of the stator coil 5.

[0037] <Swivel prevention plate 33> 3, the low-pressure side bearing housing 22 further includes a cylindrical wall portion 27 that extends from a radially inner end portion 76a of the main body portion 76 toward the rotor 4 side (i.e., the other axial side). The cylindrical wall portion 27 has a cylindrical inner circumferential surface 28 that surrounds the low-pressure side journal bearing 15, and a cylindrical outer circumferential surface 29 opposite to the cylindrical inner circumferential surface 28. The cylindrical wall portion 27 and the main body portion 76 are integrally formed from the same material.

[0038] 3 and 4, the low-pressure side bearing housing 22 further includes a plurality of anti-swirl plates 33 arranged on the cylindrical outer peripheral surface 29. Each of the anti-swirl plates 33 has a thickness in the circumferential direction. Each of the anti-swirl plates 33 also includes an axially extending portion 31 that extends along the axial direction.

[0039] According to the inventor's findings, a swirling flow of internal air is generated inside motor housing 21 along the rotational direction of rotating shaft 12 (arrow A in FIGS. 2 and 4). As a more specific example, a high-pressure-side cooling air passage (not shown) is formed inside high-pressure-side bearing housing 23 (see FIG. 1), through which compressed air bled from intermediate piping 54 flows as cooling air. The cooling air flowing from the high-pressure-side cooling air passage into motor housing 21 is given a swirling component by the rotation of rotating shaft 12 and rotor 4 as it flows toward one side in the axial direction. As a result, internal air with a swirling component flows inside motor housing 21.

[0040] If the coil cooling air injected from the injection port 78 flows circumferentially due to the swirling flow of the internal air, the coil cooling air will not hit the coil ends 6, making it difficult to cool the stator coil 5. In this regard, with the above-described configuration, the internal air hits the swirl prevention plate 33, reducing the swirling component of the internal air. This prevents the coil cooling air that merges with the internal air from swirling in the circumferential direction. This allows the stator coil 5 to be cooled effectively.

[0041] 5 is a schematic diagram showing the injection ports 78 and the anti-swirl plates 33 according to one embodiment of the present disclosure. Arrow B in the figure indicates the rotation direction of the rotary shaft 12 (the same applies to FIG. 6). Each of the multiple anti-swirl plates 33 is located radially inward of the multiple injection ports 78, and more specifically, is located radially inward of the multiple second inner injection ports 79b.

[0042] The multiple swirl prevention plates 33 and the multiple injection ports 78 are arranged alternately in the circumferential direction. More specifically, any given swirl prevention plate 33 is located between two circumferentially adjacent first inner injection ports 79a and between two circumferentially adjacent second inner injection ports 79b. The number of swirl prevention plates 33 is the same as the number of first inner injection ports 79a and the number of second inner injection ports 79b.

[0043] According to the above configuration, one of the swirl prevention plates 33 is disposed for each of the multiple injection ports 78 on the upstream side in the rotation direction of the rotating shaft 12 (opposite the arrow B). The swirl component of the swirling internal air is more reliably removed by the swirl prevention plate 33 before it hits the coil cooling air from the injection ports 78. This more reliably prevents the coil cooling air injected from the injection ports 78 from swirling in the circumferential direction.

[0044] 6 is a schematic diagram of a swirl prevention plate 33A (33) according to another embodiment. The swirl prevention plate 33A further includes an inclined extension 32 connected to the rotor 4-side end 31a of the axial extension 31 (the rotor 4 side is synonymous with the other axial side). The inclined extension 32 extends linearly so as to move toward the rotor 4 side, toward the upstream side in the rotation direction of the rotating shaft 12 (the side opposite to the arrow B). Internal air (arrow A) flowing toward one side in the axial direction along the rotation direction of the rotating shaft 12 is guided in turn by the inclined extension 32 and the axial extension 31, and impinges on the extension 73 (see FIG. 3).

[0045] The above configuration can suppress pressure loss when the internal air flowing along the rotation direction of the rotary shaft 12 hits the radially extending wall portion 25. This makes it possible to efficiently remove the swirling component of the internal air.

[0046] <Modification> The electric compressor device 10 illustrated in FIG. 1 may be a turbocharger instead of a two-stage compressor. In this case, a turbine impeller is provided on the other side of the rotary shaft 12 instead of the high-pressure compressor impeller 14, and the intermediate piping 54 is not provided. The compressed air delivered by the low-pressure compressor impeller 13 is delivered to the combustion chamber of the engine. Even in this case, if the entire cooling air flow path 70 is positioned radially outward of the outermost peripheral surface 15a of the low-pressure journal bearing 15, the temperature rise of the coil cooling air before it reaches the stator coil 5 can be suppressed. Therefore, the coil ends 6 of the stator coil 5 can be effectively cooled.

[0047] 2 may extract compressed air directly from the intermediate pipe 54 instead of extracting bearing cooling air from the bearing upstream flow path 91. Even in this case, the extracted compressed air is guided to the stator coil 5 as coil cooling air by the cooling air flow path 70. Furthermore, the bearing upstream flow path 91 and the bearing upstream flow path 92 do not have to be provided.

[0048] 2 and 3 may be integrally formed from the same material. In this case, the low-pressure side bearing housing 22 may be manufactured by additive manufacturing.

[0049] <Summary> The contents of the above-described embodiments can be understood, for example, as follows.

[0050] 1) The electric compressor device (10) according to at least one embodiment of the present disclosure includes: A rotating shaft (12), a compressor impeller (low-pressure compressor impeller 13) provided on the rotating shaft; a motor (3) including a rotor (4) provided on the rotary shaft on the rear side of the compressor impeller and a stator coil (5) arranged around the rotor; a journal bearing (low-pressure side journal bearing 15) that rotatably supports the rotary shaft between the rotor and the compressor impeller; a bearing housing (low-pressure side bearing housing 22) that accommodates the journal bearing and includes a radially extending wall portion (25) that extends in the radial direction of the rotary shaft between the stator coil and the compressor impeller; Equipped with A cooling air flow path (70) is formed inside the radially extending wall portion to guide coil cooling air introduced from outside the bearing housing to the stator coil, The entire cooling air flow path is located radially outward of the journal bearing.

[0051] The configuration of 1) above can prevent the coil cooling air flowing through the cooling air passage from exchanging heat with the journal bearing and the components around it. This can prevent the coil cooling air from rising in temperature before reaching the stator coil, resulting in an electric compressor device that can effectively cool the stator coil.

[0052] 2) In some embodiments, the electric compressor device according to 1) above, The cooling air flow path includes: an inlet flow passage (71) extending along at least one of the radial direction and the axial direction of the rotation shaft; a circumferentially extending flow path (75) connected to a downstream end (72) of the inlet flow path and extending so as to surround the rotary shaft; a plurality of injection ports (78) arranged at intervals in a circumferential direction of the rotary shaft on the stator coil side of the circumferentially extending flow path, each configured to inject the coil cooling air in the circumferentially extending flow path toward the stator coil; It has.

[0053] According to the configuration of 2), the cooling air for the coil is injected from each of the multiple injection ports arranged in the circumferential direction, so the air around the stator coil is cooled uniformly, thereby enabling the electric compressor device to effectively cool the stator coil.

[0054] 3) In some embodiments, the electric compressor device according to 2) above, The plurality of injection ports include a plurality of inner injection ports (78) that are arranged inward from the center of the radial range of the stator coil.

[0055] According to the inventor's knowledge, the temperature of the stator coil is more likely to rise on the inside than on the outside in the radial direction. In this regard, with the configuration of 3) above, the coil cooling air injected from the multiple inside injection ports can effectively cool the stator coil located inside the center of the radial range.

[0056] 4) In some embodiments, the electric compressor device according to 2) or 3) above, The radially extending wall portion a main body portion (76) having the inlet passage formed therein; an extension portion (73) that extends in the radial direction on the stator coil side with respect to the circumferentially extending flow path and in which the plurality of injection ports are formed; and The end surface (77) of the main body portion on the stator coil side is a concave surface (74) that is recessed toward the compressor impeller and to which the downstream end of the inlet flow path is connected, The extension portion is configured separately from the main body portion and is attached to the main body portion so as to cooperate with the concave surface to define the circumferentially extending flow path.

[0057] According to the above configuration 4), the extension portion is configured separately from the main body portion, which increases the design freedom for arranging the multiple injection ports, and the multiple injection ports can be arranged in positions suitable for cooling the stator coil.

[0058] 5) In some embodiments, the electric compressor device according to any one of 1) to 4) above, The bearing housing includes: a cylindrical wall portion (27) extending from the radially inner end portion (76a) of the radially extending wall portion toward the rotor in the axial direction of the rotating shaft, the cylindrical wall portion (27) having a cylindrical inner circumferential surface (28) surrounding the journal bearing; a rotation prevention plate (33) having an axially extending portion (31) extending along the axial direction on the cylindrical outer peripheral surface (29) of the cylindrical wall portion; Further includes:

[0059] According to the inventor's findings, a swirling flow of internal air occurs inside a motor in the direction of rotation of the rotating shaft. If the coil cooling air injected from the injection port flows in a circumferential direction due to the swirling flow, it becomes difficult to cool the stator coil. In this regard, with the configuration of 5) above, the swirling prevention plate reduces the swirling of the internal air, thereby preventing the coil cooling air that merges with the internal air from swirling in the circumferential direction. This allows the stator coil to be cooled effectively.

[0060] 6) In some embodiments, the electric compressor device according to 5) above, The anti-swirl plate is The rotor-side end (31a) of the axial extension portion is connected to an inclined extension portion (32), which extends toward the upstream side in the rotation direction of the rotating shaft as it approaches the rotor side.

[0061] According to the above configuration 6), it is possible to suppress pressure loss when the internal air flowing along the rotation direction of the rotary shaft hits the inclined extension portion, thereby efficiently removing the swirling component of the internal air.

[0062] 7) In some embodiments, the electric compressor device according to any one of 1) to 6) above is The compressor further includes a thrust bearing (8) that rotatably supports the rotary shaft between the journal bearing and the compressor impeller and is housed in the bearing housing, A bearing upstream flow path (91) is further formed inside the bearing housing to guide bearing cooling air introduced from outside the bearing housing toward the thrust bearing, The cooling air flow path is configured to guide the bearing cooling air extracted from the bearing upstream flow path to the stator coil as the coil cooling air.

[0063] According to the configuration of 7) above, the bearing cooling air before heat exchange with the thrust bearing is used as the coil cooling air, which allows the temperature of the coil cooling air before it reaches the stator coil to be lowered, thereby allowing the stator coil to be cooled effectively.

[0064] 8) In some embodiments, the electric compressor device according to any one of 1) to 7) above, The compressor impeller is a low-pressure compressor impeller (13) provided on one side of the rotary shaft, The electric compressor device is a high-pressure compressor impeller (14) provided on the other side of the rotary shaft; an intermediate pipe (54) for guiding compressed air delivered by the low-pressure compressor impeller to the high-pressure compressor impeller; Furthermore, The cooling air flow path is configured to guide the compressed air extracted from the intermediate pipe to the stator coil as cooling air for the coil.

[0065] According to the above configuration 8), the compressed air extracted from the intermediate pipe can be used as cooling air for the coil. [Explanation of symbols]

[0066] 2: Stator 3: Motor 4: Rotor 5: Stator coil 6: Coil end 8: Thrust bearing 8a:Disc 10: Electric compressor device 11: Cooling water flow path 12: Rotation axis 13: Low pressure compressor impeller 14: High-pressure compressor impeller 15: Low-pressure journal bearing 15a: Outermost surface 16: High pressure side journal bearing 17: Motor cooling water flow path 19: Bearing accommodation space 21: Motor housing 22: Low pressure side bearing housing 23: High pressure side bearing housing 25: Radial extending wall 27: Cylindrical wall 28: Inner surface of cylinder 29: Cylinder outer surface 31: Axial extension part 31a: End 32: Inclined extension part 33, 33A: Anti-swirl plate 41: Low pressure compressor 42: High-pressure compressor 43: Low pressure side housing 44: High pressure side housing 46: Intake port 47: Diffuser 48: Scroll section 50: Intake port 51: Diffuser 53: Scroll section 54: Intermediate piping 69:Upstream end 70: Cooling air flow path 71: Inlet channel 72: Downstream end 73 :Extension part 73a: End face 74: Concave 75: Circumferentially extending channel 76: Main body 76a :Inner end 77: End face 78: Injection port 79:Inner injection port 79a: 1st inner injection port 79b: 2nd inner injection port 90: Bearing cooling channel 91: Bearing upstream flow path 93: Bearing downstream flow path A, B: Arrows M: Two-dot chain line

Claims

1. A rotation axis; a compressor impeller provided on the rotating shaft; a motor including a rotor provided on the rotary shaft on the rear side of the compressor impeller and a stator coil disposed around the rotor; a journal bearing that rotatably supports the rotary shaft between the rotor and the compressor impeller; a bearing housing that accommodates the journal bearing, the bearing housing including a radially extending wall portion that extends in a radial direction of the rotary shaft between the stator coil and the compressor impeller; Equipped with a cooling air flow path is formed inside the radially extending wall portion to guide coil cooling air introduced from outside the bearing housing to the stator coil; The entire cooling air flow path is located radially outward of the journal bearing. Electric compressor unit.

2. The cooling air flow path includes: an inlet flow passage extending along at least one of the radial direction and the axial direction of the rotation shaft; a circumferentially extending flow path that is connected to a downstream end of the inlet flow path and that extends to surround the rotary shaft; a plurality of injection ports arranged at intervals in a circumferential direction of the rotary shaft on the stator coil side of the circumferentially extending flow path, the injection ports each configured to inject the coil cooling air in the circumferentially extending flow path toward the stator coil; have The electric compressor device according to claim 1 .

3. The plurality of injection ports include a plurality of inner injection ports arranged inside the center of the radial range of the stator coil. The electric compressor device according to claim 2 .

4. The radially extending wall portion a main body portion having the inlet flow passage formed therein; an extension portion that extends in the radial direction on the stator coil side with respect to the circumferentially extending flow path and in which the plurality of injection ports are formed; and The end surface of the main body on the stator coil side is a concave surface recessed toward the compressor impeller and connected to the downstream end of the inlet flow path, The extension portion is configured separately from the main body portion and is attached to the main body portion so as to cooperate with the concave surface to define the circumferentially extending flow path. The electric compressor device according to claim 2 or 3.

5. The bearing housing includes: a cylindrical wall portion extending from the radially inner end portion of the radially extending wall portion toward the rotor in the axial direction of the rotation shaft, the cylindrical wall portion having a cylindrical inner circumferential surface surrounding the journal bearing; a rotation prevention plate having an axially extending portion extending along the axial direction on the cylindrical outer peripheral surface of the cylindrical wall portion; Also includes The electric compressor device according to any one of claims 1 to 3.

6. The anti-swirl plate is The rotor-side end of the axially extending portion is connected to an inclined extending portion, the inclined extending portion extending toward the upstream side in the rotation direction of the rotating shaft as it approaches the rotor. The electric compressor device according to claim 5 .

7. The compressor further includes a thrust bearing that rotatably supports the rotary shaft between the journal bearing and the compressor impeller and is housed in the bearing housing, a bearing upstream flow passage for guiding bearing cooling air introduced from outside the bearing housing toward the thrust bearing is further formed inside the bearing housing, The cooling air flow path is configured to guide the bearing cooling air extracted from the bearing upstream flow path to the stator coil as the coil cooling air. The electric compressor device according to any one of claims 1 to 3.

8. the compressor impeller is a low-pressure compressor impeller provided on one side of the rotary shaft, The electric compressor device is a high-pressure compressor impeller provided on the other side of the rotary shaft; an intermediate pipe for guiding compressed air delivered by the low-pressure compressor impeller to the high-pressure compressor impeller; Furthermore, The cooling air flow path is configured to guide the compressed air extracted from the intermediate pipe to the stator coil as cooling air for the coil. The electric compressor device according to any one of claims 1 to 3.

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