Rotating machinery

Abstract

The rotary machine (1) of the present invention comprises: a central portion (2) having a motor (5); a compressor impeller (32) which is rotated by the drive of the motor; a compressor housing (31) which is fixed to the central portion and accommodates the compressor impeller; an impeller setting portion (72) which is provided in the central portion and is arranged opposite to the compressor impeller; and a diffuser portion (8) which is fixed to the compressor housing and is arranged to surround the outer periphery of the impeller setting portion and form a diffuser flow path. The diffuser portion is separated from the impeller setting portion and is engaged with the impeller setting portion.

Description

Technical Field

[0001] The present disclosure relates to rotating machines. Background Art

[0002] Rotating machines such as electric turbochargers and electric compressors are well known (see patent documents 1-3). For example, such rotating machines include: a central portion having a motor, and a compressor connected to the central portion. The compressor includes a compressor impeller housed in a compressor housing. A diffuser flow path is formed around the compressor impeller to convert kinetic energy into pressure. The compressor impeller is arranged to rotate freely relative to the back wall. The back wall includes an impeller installation area close to and opposite to the compressor impeller, and a diffuser area forming the diffuser flow path, and the back wall is, for example, mounted and fixed to the central portion.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 63-302133

[0004] Patent Document 2: Japanese Utility Model Application Laid-Open No. 59-17299

[0005] Patent Document 3: Japanese Patent Application Laid-Open No. 8-312590

[0006] In previous rotating machines, not only an impeller installation area on the back wall was required, but also a diffuser area had to be installed in the central part. The installation structure of the back wall in the central part tended to become complicated, and there was room for improvement from the perspective of design freedom. Summary of the Invention

[0007] The present disclosure describes a rotary machine capable of improving the degree of freedom in design of a central portion.

[0008] A rotary machine according to one embodiment of the present disclosure includes: a central portion equipped with a motor; a compressor impeller rotated by the motor; a compressor housing fixed to the central portion and housing the compressor impeller; an impeller mounting portion disposed in the central portion and facing the compressor impeller; and a diffuser portion fixed to the compressor housing, disposed so as to surround the outer circumference of the impeller mounting portion and form a diffuser flow path. The diffuser portion is provided separately from the impeller mounting portion and is engaged and joined to the impeller mounting portion.

[0009] In this rotary machine, the diffuser is separated from the impeller mounting portion and fixed to the compressor housing rather than the central portion. This simplifies or eliminates the need for mounting the diffuser in the central portion, increasing design freedom in the central portion.

[0010] In some embodiments, the impeller mounting portion may be configured to include at least an area overlapping the compressor impeller when viewed from the direction of the compressor impeller's rotation axis. According to this embodiment, after the compressor impeller is mounted on the impeller mounting portion, the compressor impeller can be mounted so that it passes through the diffuser portion. That is, the compressor impeller can be mounted on the impeller mounting portion before the central portion and the compressor housing are connected. This makes it less likely that the compressor impeller will shift in the direction of the rotation axis, and the mounting position is stable. As a result, when the compressor housing is fixed to the central portion to form the diffuser flow path, it is easier to manage the tip clearance between the compressor impeller and the central portion, thereby improving the design superiority.

[0011] In some embodiments, the compressor housing may also include an outer edge receiving portion that receives and supports the outer edge of the diffuser. The diffuser is stably held in a fixed position by being received in the outer edge receiving portion of the compressor housing, thereby facilitating miniaturization in the direction of the rotation axis.

[0012] In some embodiments, the motor may include a rotor, a stator disposed around the rotor, and a resin molded structure fixed to an end of the stator, wherein the impeller mounting portion is at least a portion of the resin molded structure. By forming the impeller mounting portion in all or part of the resin molded structure, heat generated on the compressor impeller side is less likely to be transferred to the stator side, thereby maintaining or improving motor performance.

[0013] In some embodiments, the motor may also include: a rotor and a stator surrounding the rotor, with a motor housing in the central portion, the motor housing housing an inverter for driving and controlling the motor and having the stator fixed thereto, the inverter and the diffuser portion being arranged opposite each other. Compared to the method of arranging the inverter outside the motor housing, the method of accommodating the inverter in the central portion of the motor housing is susceptible to design restrictions. According to the above method, the diffuser portion is fixed to the compressor housing, so there is no need for a boss or the like for fixing the inverter to the motor housing. Therefore, the constraints on the shape of the inverter are reduced, and the degree of freedom in design is increased.

[0014] In some embodiments, the resin molded structure may include a base portion fixed to an end portion of the stator, and an impeller mounting portion having an outer diameter smaller than that of the base portion and protruding from the base portion in a direction along the rotation axis of the compressor impeller.

[0015] According to some aspects of the present disclosure, the degree of freedom in design of the central portion can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a cross-sectional perspective view showing a rotary machine according to one embodiment of the present disclosure.

[0017] Figure 2It is a perspective view showing a state where a compressor impeller is mounted at the center portion.

[0018] Figure 3 It is a perspective view showing a state in which the diffuser portion is fitted and joined to the impeller installation portion.

[0019] Figure 4 It is a perspective view showing a compressor housing to which a diffuser portion is fixed. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0021] Figure 1 FIG1 shows an example of a rotary machine 1, such as an electric compressor. The rotary machine 1 includes a central portion 2, which is a main portion, and a compressor 3 connected to the central portion 2. The central portion 2 includes a motor 5 that drives a rotating shaft 4, and a motor housing 21 (also called a "bearing housing") that accommodates the motor 5. The motor 5 (see FIG1 ) Figure 2 as well as Figure 3 ) includes a rotor 51 provided on the rotating shaft 4 and a stator 52 disposed around the rotor 51. The stator 52 is formed of an iron core 52a and a conductive wire 52b wound around the iron core 52a, and is fixed to the inner circumference of the motor housing 21.

[0022] A cooling block B is disposed around the stator 52 , and a cooling flow path through which a refrigerant passes is formed in the cooling block B. Furthermore, an inverter 6 for driving and controlling the motor 5 is housed within the motor housing 21 .

[0023] The inverter 6, for example, includes two (or more) control substrates 6a. The two control substrates 6a have different functions: one is a main circuit substrate, and the other is a control circuit substrate. Devices such as IGBTs, bipolar transistors, MOSFETs, or GTOs, as well as power storage devices such as capacitors, are mounted on the control substrates 6a.

[0024] The control board 6a of the inverter 6 has a curved shape along the inner periphery of the motor case 21. In this embodiment, the curved shape is a ring (C-shape) with a portion cut away, and a cooling block B is provided in the cut away portion.

[0025] The control board 6a is mounted to the motor case 21 via mounting members. The connection terminals 52c connected to the lead wires 52b drawn from the stator 52 extend tangentially relative to the circumference of the stator 52 and are connected to the control board 6a of the inverter 6.

[0026] The compressor 3 is a centrifugal compressor and includes a compressor impeller 32 and a compressor housing 31 (see Figure 4 The compressor impeller 32 is fixed to the rotating shaft 4 and is rotated by the drive of the motor 5. The compressor housing 31 accommodates the compressor impeller 32 and includes a suction port 33 for taking in air and a discharge port 34 for discharging compressed air.

[0027] The compressor 3 includes a diffuser flow path Df formed around the compressor impeller 32 and a vortex flow path Sf disposed so as to surround the diffuser flow path Df. The kinetic energy generated by the rotation of the compressor impeller 32 is converted into pressure by the diffuser flow path Df. The compressed air generated in the diffuser flow path Df is discharged from the discharge port 34 via the vortex flow path Sf.

[0028] The compressor housing 31 includes: an inner main body 35, which surrounds the compressor impeller 32 and forms a suction port 33; an outer main body 36, which forms a vortex flow path Sf and a discharge port 34; and a flow path connecting portion 37, which is arranged between the inner main body 35 and the outer main body 36 to form the vortex flow path Sf.

[0029] A flange portion 36a is provided on the outer edge of the outer body portion 36. Meanwhile, a flange portion 21a for attaching the compressor housing 31 is provided on the outer edge of the motor housing 21 of the central portion 2. The flange portion 36a of the compressor housing 31 abuts against the flange portion 21a of the motor housing 21 and is connected to each other via bolts or other fastening members. As a result, the compressor 3 is connected to the central portion 2.

[0030] Next, the structure forming the diffuser flow path Df will be described in detail. Figure 2 、 Figure 3 As shown, in this disclosure, the portion where the compressor impeller 32 is rotatably mounted (the impeller mounting portion 72) and the portion forming the diffuser flow path Df (the diffuser portion 8) are divided, and ultimately interlocked and joined. The impeller mounting portion 72 and the diffuser portion 8 can also be described as being divided in the radial direction of the rotating shaft 4. Specifically, the impeller mounting portion 72 is located in an inner region closer to the rotating shaft 4 than the diffuser portion 8, while the diffuser portion 8 is located in an outer region. First, the inner impeller mounting portion 72 will be described.

[0031] At the end of the stator 52 that is close to the compressor 3, a resin material filled in a mold is fixed into a predetermined shape to form a resin molded structure 7. The resin molded structure 7 includes a base portion 71 and an impeller mounting portion 72. The base portion 71 is fixed to the end of the stator 52 and extends radially (outwardly). The impeller mounting portion 72 has an outer diameter smaller than that of the base portion 71 and protrudes from the base portion 71 in a direction along the rotating shaft 4. In addition, in this embodiment, although the impeller mounting portion 72 is formed by a portion of the resin molded structure 7, the entire resin molded structure 7 may also be the impeller mounting portion 72.

[0032] The impeller installation portion 72 is a portion disposed on the back side of the compressor impeller 32 so as to face the compressor impeller 3. The compressor impeller 32 includes a circular compressor wheel 32a (see FIG. 1 ) provided with a plurality of blades. Figure 2 The compressor wheel 32a is fixed to the rotating shaft 4 and is mounted so that its back surface faces the impeller installation portion 72 and is rotatable without contact. The back surface is a position on the opposite side to the suction port 33.

[0033] The impeller setting portion 72 is arranged opposite to the compressor wheel 32a (compressor impeller 32). When viewed from the direction of the rotation axis of the compressor impeller 32, the impeller setting portion 72 is configured to include at least an area overlapping with the compressor impeller 32. "When viewed from the direction of the rotation axis" means a case where the compressor impeller 32 is visually confirmed in a manner parallel to the extension line of the rotation axis 4. For example, when the compressor impeller 32 is irradiated with light parallel to the extension line of the rotation axis 4, it means that the area where the compressor impeller 32 is projected is entirely included in the interior of the impeller setting portion 72. Specifically, when the outer edges of the impeller setting portion 72 and the compressor wheel 32a are concentric circles, the inner diameter of the impeller setting portion 72 is the same as or larger than the inner diameter of the compressor wheel 32a.

[0034] The diffuser 8 is fitted and joined to the impeller mounting portion 72. The diffuser 8 is an annular (ring-shaped) plate. The end surface (inner circumference) of the diffuser 8, which serves as the inner edge, surrounds the outer circumference of the impeller mounting portion 72 and is in contact with the outer circumference of the impeller mounting portion 72. An O-ring (seal member) 9 is provided between the inner circumference of the diffuser 8 and the outer circumference of the impeller mounting portion 72 to prevent compressed air from leaking from the compressor 3.

[0035] like Figure 1 as well as Figure 4As shown, the outer body portion 36 of the compressor housing 31 is provided with an outer edge receiving portion 36b that receives and supports a portion along the outer edge of the diffuser portion 8. The outer edge receiving portion 36b is shaped to mimic the shape of a portion along the outer edge of the diffuser portion 8 (outer edge portion 81), and is a generally annular groove having a depth sufficient to accommodate the outer edge portion 81. The diffuser portion 8 is configured such that the outer edge portion 81 is received in the outer edge receiving portion 36b and is secured to the compressor housing 31 via mounting members such as bolts.

[0036] The diffuser portion 8 is housed in the outer edge housing portion 36b and fixed in a predetermined position. As a result, the diffuser portion 8 is positioned opposite the flow path connection portion 37 of the compressor housing 31, and is further positioned so as to form a diffuser flow path Df between the diffuser portion 8 and the flow path connection portion 37. Since the diffuser portion 8 of the present disclosure forms the diffuser flow path Df by being fixed to the compressor housing 31, it is easy to manage the gap for forming the diffuser flow path Df, which contributes to improved quality.

[0037] In addition, in the present disclosure, as described above, the inverter 6 that controls the drive of the motor 5 is housed inside the motor housing 21. The two control substrates 6a of the inverter 6 are arranged opposite to the diffuser portion 8. Specifically, the multiple control substrates 6a of the inverter 6 are arranged side by side along the rotating shaft 4. In the present disclosure, the diffuser portion 8 is fixed to the compressor housing 31, so a boss or the like for fixing the diffuser portion 8 is not required in the motor housing 21. As a result, there is no need to worry about studying the shape of the control substrate 6a (inverter 6) in order to avoid the boss or the like, and the design constraints on the shape of the inverter 6 are reduced.

[0038] Next, the effects achieved by the rotary machine 1 of the present disclosure will be described. The diffuser portion 8 of the rotary machine 1 of the present disclosure is separated from the impeller mounting portion 72. Furthermore, the diffuser portion 8 is fixed to the compressor housing 31 rather than the central portion 2. As a result, the structure for mounting the diffuser portion 8 in the central portion 2 can be simplified or omitted, thereby increasing the degree of design freedom in the central portion 2.

[0039] In a comparative example, for example, in a configuration where the impeller housing and diffuser are separated and a single back plate is installed on the back of the compressor impeller, the back plate needs to be fixed to the central portion of the motor housing, etc. In this comparative configuration, the compressor housing needs to be attached to the central portion via the back plate, resulting in a stacked structure along the rotation axis. This results in increased tolerance in the rotation axis direction.

[0040] In contrast, according to the rotary machine 1 of the present disclosure, the impeller mounting portion 72 and the diffuser portion 8 are separated, and the diffuser portion 8 is fixed to the compressor housing 31. In other words, the motor housing 21 of the central portion 2 and the compressor housing 31 can be directly fixed without interposing the diffuser portion 8. This contributes to miniaturization in the direction of the rotation axis and also facilitates management of the tip clearance between the compressor impeller 32 and the compressor housing 31.

[0041] Furthermore, the impeller mounting portion 72 is configured to include at least an area overlapping the compressor impeller 32 when viewed in the direction of the compressor impeller 32's rotation axis. As a result, after the compressor impeller 32 is mounted on the impeller mounting portion 72, it can be installed so that the compressor impeller 32 passes through the diffuser portion 8. In other words, the compressor impeller 32 can be mounted on the impeller mounting portion 72 before the central portion 2 and the compressor housing 31 are connected. Therefore, the compressor impeller 32 is less likely to shift along the rotation axis 4, and the mounting position is stabilized. Consequently, when the compressor housing 31 is secured to the central portion 2 to form the diffuser flow path Df, the tip clearance between the compressor impeller 32 and the compressor impeller 32 is more easily managed, thereby enhancing design superiority.

[0042] Furthermore, the diffuser portion 8 fixed to the compressor housing 31 is housed in the outer edge accommodation portion 36 b of the compressor housing 31 , and is therefore stably held in a fixed position, thereby contributing to miniaturization in the direction of the rotation axis.

[0043] Furthermore, since the impeller installation portion 72 includes the resin mold structure 7 fixed to the stator 52 , heat generated on the compressor impeller 32 side is less likely to be transferred to the stator 52 side, and the performance of the motor 5 can be maintained and improved.

[0044] Furthermore, the inverter 6 of the present disclosure is housed within the motor housing 21 of the central portion 2. Generally, housing the inverter 6 within the motor housing 21 of the central portion 2 is more susceptible to design limitations than disposing the inverter 6 outside the motor housing 21. However, in the rotary machine 1 of the present disclosure, the diffuser portion 8 is fixed to the compressor housing 31, eliminating the need for a boss or the like for securing the inverter 6 to the motor housing 21. Consequently, the inverter 6 and diffuser portion 8 can be easily positioned facing each other in close proximity, contributing to miniaturization.

[0045] For example, in the above embodiment, an electric compressor is described as an example of a rotary machine, but the present disclosure is also widely applicable to rotary machines such as electric-assisted turbochargers that form a diffuser flow path.

[0046] Description of Reference Numerals

[0047] 1...rotating machine; 2...central portion; 5...motor; 6...inverter; 7...resin mold structure; 8...diffuser portion; 21...motor housing; 31...compressor housing; 32...compressor impeller; 36b...outer edge housing portion; 51...rotor; 52...stator; 72...impeller mounting portion; 81...outer edge portion; Df...diffuser flow path; Sf...vortex flow path.

Claims

1. A rotating machine, characterized in that: have: a central portion having a motor; a compressor impeller, which is rotated by the drive of the motor; a compressor housing fixed to the central portion and housing the compressor impeller; an impeller installation portion, which is provided at the central portion and arranged opposite to the compressor impeller; as well as a diffuser portion fixed to the compressor housing and arranged to surround the outer periphery of the impeller installation portion and form a diffuser flow path; The diffuser portion is provided separately from the impeller installation portion and is fitted and joined to the impeller installation portion. The motor further includes a rotor, a stator disposed around the rotor, and a resin mold structure fixed to the stator. The impeller setting portion is at least a part of the resin mold structure, The resin mold structure includes: a base portion fixed to an end portion of the stator, and the impeller installation portion. The impeller installation portion has an outer diameter smaller than that of the base portion and protrudes from the base portion in a direction along the rotation axis of the compressor impeller.

2. The rotary machine according to claim 1, wherein: The impeller installation portion is provided so as to include at least a region overlapping with the compressor impeller when viewed in the direction of the rotation axis of the compressor impeller.

3. The rotary machine according to claim 1 or 2, characterized in that: The compressor housing includes an outer edge accommodation portion that accommodates an outer edge portion of the diffuser portion and supports the diffuser portion.

4. The rotary machine according to claim 1 or 2, characterized in that: The central portion includes a motor housing that houses an inverter for driving and controlling the motor and to which the stator is fixed. The inverter is arranged to face the diffuser portion.

Images