WO2024075374A1

WO2024075374A1 - Rotary machine

Info

Publication number: WO2024075374A1
Application number: PCT/JP2023/027824
Authority: WO
Inventors: 海飯嶋; 達哉福井; 達身猪俣
Original assignee: 株式会社Ihi
Priority date: 2022-10-04
Filing date: 2023-07-28
Publication date: 2024-04-11

Abstract

This rotary machine comprises: an electric motor provided with a stator and a rotor; a rotating shaft that rotates due to driving by the electric motor; an impeller that is attached to the rotating shaft; and a case that surrounds the stator, the stator being fixed to the case. The case has a first accommodation space for accommodating the stator, and a second accommodation space for accommodating the rotor so as to face the stator in the first accommodation space in a cross-sectional view that includes the axis of the rotating shaft. The first accommodation space is filled with a resin material in a state of being partitioned from the second accommodation space by a partition member disposed along the inner peripheral edge of the stator.

Description

Rotating Machinery

This disclosure relates to rotating machinery.

A known technology for rotating machines is to fill the gaps in the rotor or stator with a filler to seal at least a portion of the exposed surface of the rotor or stator (e.g., the magnet) and prevent rust (e.g., Patent Document 1).

JP 2009-254204 A

In order to improve waterproofing, rust prevention, and thermal conductivity, the case of an electric motor equipped with a stator and rotor may be filled with a resin material. For example, the case has a first housing space that houses the stator and a second housing space that houses the rotor. In such a case, a known method is to fill the first housing space with resin material using a core placed in the second housing space, from a state in which the first housing space and the second housing space are in communication with each other. With this method, the distance (magnetic gap) between the rotor and stator, which face each other in a cross-sectional view including the axis of the rotating shaft, tends to increase according to the draft angle of the core.

This disclosure describes a rotating machine that can fill the first storage space with resin material without creating a magnetic gap caused by the core draft when the first storage space and the second storage space are in communication with each other.

A rotating machine according to one example of the present disclosure includes an electric motor with a stator and a rotor, a rotating shaft that rotates when driven by the electric motor, an impeller attached to the rotating shaft, and a case that surrounds the stator and to which the stator is fixed. The case has a first housing space that houses the stator and a second housing space that houses the rotor so as to face the stator in the first housing space in a cross-sectional view including the axis of the rotating shaft. The first housing space is filled with a resin material in a state where it is partitioned from the second housing space by a partition member arranged along the inner peripheral edge of the stator.

According to some examples of the present disclosure, when filling the first storage space with resin material from a state in which the first storage space and the second storage space are in communication with each other, the resin material can be filled without creating a magnetic gap due to the core draft.

FIG. 1 is a cross-sectional view of an example of a rotating machine according to an embodiment. FIG. 2 is a cross-sectional view showing a first accommodating space and a second accommodating space of the rotary machine of FIG. FIG. 3 is an enlarged cross-sectional view of a main portion of the rotary machine of FIG. FIG. 4 is a cross-sectional view showing a process of arranging the stator. FIG. 5 is a cross-sectional view showing a process of forming the first accommodation space and the second accommodation space. FIG. 6 is a cross-sectional view showing a partitioning process using a partition member. FIG. 7 is a cross-sectional view showing the resin filling step. FIG. 8 is a perspective view of a split core of a rotary machine according to a modified example. FIG. 9 is a front view of the split core of FIG.

In a rotating machine according to one example of the present disclosure, when the resin material is filled into the first storage space, the first storage space and the second storage space are partitioned by a partition member. In other words, when the resin material is filled into the first storage space, there is no need to seal the first storage space with a core, and therefore no magnetic gap is generated due to the core's draw gradient. Therefore, when the resin material is filled into the first storage space from a state in which the first storage space and the second storage space are connected, the resin material can be filled without generating a magnetic gap due to the core's draw gradient.

In some examples, the partition member may be a pipe member having an outer peripheral surface that conforms to the inner peripheral end of the stator. With this configuration, the partition member can be easily constructed using a pipe member.

In some examples, the case may have an injection hole that communicates with the first storage space. With this configuration, the resin material can be filled into the first storage space through the injection hole of the case while the first storage space and the second storage space are separated by the partition member.

Below, exemplary embodiments will be described with reference to the drawings. In each drawing, identical or corresponding elements are given the same reference numerals, and duplicate explanations will be omitted.

FIG. 1 is a cross-sectional view of an example of a rotary machine according to an embodiment. As an example, the rotary machine 1 is an electric turbocharger used to supply air to a vehicle fuel cell. The rotary machine 1 includes a turbine 2 and a compressor 3. The turbine 2 includes a turbine impeller 22 arranged in a turbine housing 21. The compressor 3 includes a compressor impeller 32 arranged in a compressor housing 31. A motor housing (case) 4 is installed between the turbine housing 21 and the compressor housing 31. The motor housing 4 has a two-piece structure, for example, a first housing 41 on the turbine housing 21 side and a second housing 42 on the compressor housing 31 side.

The electric motor 5 is disposed between the turbine 2 and the compressor 3. The electric motor 5 includes a stator 51 and a rotor 52. The stator 51 is fixed to the motor housing 4 so as to surround the rotor 52. The motor housing 4 surrounds the stator 51. The stator 51 includes a coil 51a for generating a magnetic field and a stator core 51b around which the coil 51a is wound.

The electric motor 5 includes a rotating shaft 6 that is rotatably supported within the motor housing 4. A rotor 52 is attached to the rotating shaft 6. The rotor 52 includes one or more permanent magnets (not shown). The electric motor 5 drives the rotating shaft 6 by the interaction of the magnetic forces of the stator 51 and the rotor 52. In other words, the rotating shaft 6 rotates when driven by the electric motor 5.

The turbine impeller 22 and the compressor impeller 32 are fixed to the rotating shaft 6. The turbine impeller 22 rotates the compressor impeller 32 via the rotating shaft 6. The turbine impeller 22 drives the compressor impeller 32 in cooperation with the electric motor 5.

The rotating shaft 6 is supported for free rotation by a number of bearings. For example, two

radial bearings

61, 62 are provided inside the motor housing 4, arranged axially on either side of the rotor 52. The rotating shaft 6 is supported in the radial direction by these

radial bearings

61, 62. A pair of

thrust air bearings

63, 64 and a thrust collar 65 are provided between the radial bearing 62 and the compressor impeller 32. The thrust collar 65 is a disc-shaped member that protrudes like a brim around the rotating shaft 6. The rotating shaft 6 is supported in the thrust direction by these

thrust air bearings

63, 64.

1 and 2, the motor housing 4 has a first housing space 11 and a second housing space 12. The first housing space 11 is a space that houses the stator 51. The first housing space 11 is formed, for example, inside the motor housing 4 by a first inner wall surface 43 on the turbine 2 side, a second inner wall surface 44 on the compressor 3 side, and a third inner wall surface 45 that connects the first inner wall surface 43 and the second inner wall surface 44. The first inner wall surface 43 and the third inner wall surface 45 are inner wall surfaces of the first housing 41. The second inner wall surface 44 is an inner wall surface of the second housing 42. The first housing space 11 may be a substantially cylindrical space formed inside the motor housing 4 so as to surround the rotating shaft 6 and the rotor 52.

The second accommodation space 12 is a space that accommodates the rotating shaft 6 and the rotor 52. The second accommodation space 12 is formed, for example, inside the motor housing 4 by being surrounded by the radial bearing 61, the radial bearing 62, and the inner peripheral end 51c of the stator 51. The second accommodation space 12 is a substantially cylindrical space that extends along the axis L inside the motor housing 4, with the bearing support portion 41a that supports the radial bearing 61 and the bearing support portion 42a that supports the radial bearing 62 at both ends. The second accommodation space 12 may penetrate the center of the motor housing 4 along the axis L.

As shown in FIG. 2, before the stator 51, the rotating shaft 6, and the rotor 52 are arranged in the motor housing 4, the first housing space 11 and the second housing space 12 are connected. As shown in FIG. 1, when the stator 51, the rotating shaft 6, and the rotor 52 are arranged in the motor housing 4, the rotor 52 accommodated in the second housing space 12 faces the stator 51 accommodated in the first housing space 11 via the partition member 10 in a cross-sectional view including the axis L of the rotating shaft 6.

In the rotating machine 1, the first housing space 11 is filled with a resin material 7. The resin material 7 is filled in the first housing space 11 in a state where it is partitioned from the second housing space 12 by a partition member 10 arranged along the inner circumferential end 51c of the stator 51. The resin material 7 can be, for example, an epoxy resin.

The partition member 10 is, for example, a pipe member having an outer peripheral surface 10a that is aligned with the inner peripheral end 51c of the stator 51. As a material for the partition member 10, a material other than metal, for example, a resin, can be used from the viewpoint of suppressing magnetic leakage. For example, when the rotating machine 1 is used to supply air to a vehicle fuel cell, the partition member 10 may be a heat-resistant and water-resistant (low water absorption) resin pipe such as polyphenylene sulfide (PPS), taking into consideration that the gas flowing into the turbine 2 contains a large amount of moisture. The partition member 10 may be a glass fiber reinforced plastic (GFRP) with two or less layers of laminated glass sheets from the viewpoint of suppressing the gap (magnetic gap) between the stator 51 and the rotor 52. Alternatively, the partition member 10 may be a pipe made of injection molding or extrusion material. Note that the end faces of the cut parts of the partition member 10 are shown in FIG. 2 and FIG. 6.

3 is an enlarged cross-sectional view of a main part of the rotary machine of FIG. 1. As shown in FIG. 3, the partition member 10 is provided to connect the radial bearing 61 and the radial bearing 62. The partition member 10 is provided to connect the bearing support portion 41a supporting the radial bearing 61 and the bearing support portion 42a supporting the radial bearing 62. The outer peripheral surface of the radial bearing 61 abuts against the bearing support portion 41a of the first housing 41. The first housing 41 includes a lip portion 41b that protrudes radially inward from the compressor 3 side end of the bearing support portion 41a. The inner peripheral end surface 41c of the lip portion 41b forms a cylindrical surface centered on the axis L. The outer peripheral surface of the radial bearing 62 abuts against the bearing support portion 42a of the second housing 42. The second housing 42 includes a lip portion 42b that protrudes radially inward from the turbine 2 side end of the bearing support portion 42a. The inner peripheral end surface 42c of the lip portion 42b forms a cylindrical surface centered on the axis L.

1 and 3, the inner peripheral end surface 41c of the lip portion 41b, the inner peripheral end surface 42c of the lip portion 42b, and the inner peripheral end 51c of the stator 51 are located on a common cylindrical surface centered on the axis L, for example. The outer peripheral surface 10a of the partition member 10 here abuts against the inner peripheral end surface 41c of the lip portion 41b, the inner peripheral end surface 42c of the lip portion 42b, and the inner peripheral end 51c of the stator 51. The outer peripheral surface 10a of the partition member 10 does not necessarily have to abut against the inner peripheral end 51c of the stator 51. It is sufficient that the outer peripheral surface 10a of the partition member 10 abuts at least the inner peripheral end surface 41c, which is the sealing surface on the turbine 2 side, and the inner peripheral end surface 42c, which is the sealing surface on the compressor 3 side. Therefore, the partition member 10 partitions the first storage space 11 and the second storage space 12 so that the resin material 7 can be filled therein. "Fillably partitioned" means that the partitioning member 10 does not necessarily have to liquid-tightly seal the first storage space 11 and the second storage space 12. For example, even if a small gap exists, when the resin material 7 is filled, the heated resin material 7 cools and hardens to close the small gap, and this is included in "fillably partitioned."

As shown in Figures 1 and 2, the motor housing 4 has an injection hole 47 that communicates with the first housing space 11. The injection hole 47 may be, for example, a through hole provided in the wall portion 46 on the turbine 2 side of the first housing 41. The injection hole 47 communicates between the inside and outside of the first housing 41 when the turbine housing 21 is removed. When the turbine housing 21 is removed, the resin material 7 is filled into the first housing space 11 through the injection hole 47 in a state where it is partitioned from the second housing space 12 by the partition member 10.

An example of a method for filling the first housing space 11 with the resin material 7 (a manufacturing method for a rotating machine) will be described with reference to Figures 1 and 4 to 7. First, as shown in Figure 4, with the second housing 42 and the compressor housing 31 removed, the stator 51, with the coil 51a wound around the stator core 51b, is placed in the first housing 41 (stator placement process). Note that in Figures 4 to 6, the stator 51 is not shown except in cross-sectional views.

Next, as shown in FIG. 5, the second housing 42 is attached to the first housing 41. This forms the first housing space 11 and the second housing space 12. The mating portion 42d of the second housing 42 is fitted into the opening 41d of the first housing 41 and fastened with a fixing bolt (not shown). At this time, the wiring from the stator 51 is connected to the connector 51d, and the connector 51d is inserted into the connector mounting portion 42e of the second housing 42. This allows the space inside the connector mounting portion 42e to be sealed as part of the first housing space 11.

Next, as shown in FIG. 6, the partition member 10 is arranged so as to partition the first housing space 11 and the second housing space 12 (partitioning process). For example, the partition member 10 is arranged so as to connect the bearing support portion 42a of the second housing 42 and the bearing support portion 41a of the first housing 41. The partition member 10 is arranged so that the outer peripheral surface 10a of the partition member 10 abuts the inner peripheral end surface 41c of the lip portion 41b, the inner peripheral end surface 42c of the lip portion 42b, and the inner peripheral end 51c of the stator 51 (see FIG. 3). As a result, the partition member 10 is arranged along the inner peripheral end 51c of the stator 51. In other words, the partition member 10 partitions the first housing space 11 and the second housing space 12 so that the resin material 7 can be filled in the first housing space 11. Note that an adhesive may be interposed between the inner peripheral end surface 41c and the partition member 10, and between the inner peripheral end surface 42c and the partition member 10.

Next, as shown in FIG. 7, in a state in which the first housing space 11 and the second housing space 12 are partitioned by the partition member 10 arranged along the inner peripheral end 51c of the stator 51, the first housing space 11 is filled with the resin material 7 (filling process). In a state in which the turbine housing 21 is removed, the first housing space 11 is filled with the resin material 7 through the injection hole 47 that connects the inside and outside of the first housing 41. At this time, the motor housing 4 on the injection side may be preheated (for example, 80°C). A vacuum environment is created, and liquid epoxy resin as the resin material 7 is injected into the first housing space 11 through the injection hole 47. Thereafter, the resin material 7 is heated to 100°C to 120°C using a curing furnace to cure the resin material 7 for a predetermined time (for example, 4 hours). A radial bearing 61 is attached to the bearing support portion 41a of the first housing 41. The rotating shaft 6 to which the rotor 52 is fixed is accommodated in the second housing space 12. A radial bearing 62 is attached to the bearing support portion 42a of the second housing 42. While attaching the thrust collar 65 to the rotating shaft 6, attach the

thrust air bearings

63, 64 to the second housing 42.

The rotating machine 1 is thus manufactured. Thereafter, as shown in FIG. 1, the turbine impeller 22 and the compressor impeller 32 may be fixed to the rotating shaft 6. The turbine housing 21 and the compressor housing 31 may be attached to the motor housing 4.

In the rotating machine 1 as described above, when the resin material 7 is filled into the first housing space 11, the first housing space 11 and the second housing space 12 are partitioned by the partition member 10. In other words, when the resin material 7 is filled into the first housing space 11, there is no need to seal the first housing space 11 with a core, so no magnetic gap is generated due to the core's draw gradient. Therefore, when the resin material 7 is filled into the first housing space 11 from a state in which the first housing space 11 and the second housing space 12 are connected, the resin material 7 can be filled without generating a magnetic gap due to the core's draw gradient.

In addition, with the conventional method using a core, the core could not be removed before the resin material 7 was filled and hardened, and the core could not be used to fill another rotating machine with resin material 7. In this regard, with the method using the partition member 10 of this example, the rotating machine 1 is completed without removing the partition member 10. This makes it possible to suppress the increase in costs associated with preparing many cores. In addition, the effort and cost associated with the process of removing the cores can be reduced.

In the rotating machine 1, the partition member 10 is a pipe member having an outer peripheral surface 10a that fits along the inner peripheral end 51c of the stator 51. With this configuration, the partition member 10 can be easily constructed using a pipe member.

In the rotating machine 1, the motor housing 4 has an injection hole 47 that communicates with the first housing space 11. With this configuration, the resin material 7 can be filled into the first housing space 11 through the injection hole 47 of the motor housing 4 while the first housing space 11 and the second housing space 12 are separated by the partition member 10.

The above describes embodiments of the present disclosure, but the present disclosure is not limited to the above embodiments.

In the above embodiment, the partition member 10 is constructed from a single resin pipe, but it may be divided into multiple parts in the axial direction to form a pipe shape as a whole.

In the above embodiment, the partition member 10 is a pipe member, but this is not limited to this example. For example, the inner peripheral end 51c of the stator 51 is arranged discretely around the axis L, and a separate partition member 10 is provided, but the inner peripheral end of the stator may be configured as an inner peripheral surface that is continuous around the axis L to provide the partition member function. For example, as shown in Figures 8 and 9, the stator 53 may have a split core 53X in which the stator core 53b is split into a plurality of divided parts (e.g., six parts) around the axis L. The dashed lines in Figure 9 are division lines that virtually extend radially according to the number of divided parts. The inner peripheral end of the stator 53 may be provided with a resin bobbin 54 whose inner peripheral surface 54a is an arc surface with a central angle corresponding to the number of divided parts of the split core 53X. According to this configuration, by arranging the divided cores 53X in a cylindrical shape around the axis L, the inner circumferential surfaces 54a of the divided resin bobbins 54 become continuous, and the inner circumferential surfaces 54a as a whole form a cylindrical partition member 10X. Note that the end faces of adjacent resin bobbins 54 may be shaped to engage with each other (for example, shapes in which the projections and recesses correspond to each other).

In the above embodiment, adhesive is applied between the inner peripheral end face 41c and the partition member 10, and between the inner peripheral end face 42c and the partition member 10, but adhesive may be omitted. In this case, the resin of the partition member 10 may have a larger thermal expansion than the metal motor housing 4. In this case, the inner peripheral end face 41c and the partition member 10, and the inner peripheral end face 42c and the partition member 10 may be in contact with each other at tapered surfaces inclined relative to the axis L, thereby improving adhesion due to expansion.

In the above embodiment, the motor housing 4 has an injection hole 47 that communicates with the first housing space 11, but the injection hole 47 is not essential. An injection hole may be provided in a member other than the motor housing 4, for example, in the partition member 10.

In the rotary machine 1 of the above embodiment, the turbine impeller 22 and the compressor impeller 32 are fixed to the rotating shaft 6, but the turbine impeller 22 and the compressor impeller 32 may be omitted.

The following describes the constituent elements of several aspects of the present disclosure.
[1]
an electric motor having a stator and a rotor;
A rotating shaft that is rotated by the driving of the electric motor;
a case surrounding the stator and to which the stator is fixed,
the case has a first accommodating space that accommodates the stator, and a second accommodating space that accommodates the rotor so as to face the stator in the first accommodating space in a cross-sectional view including an axis of the rotating shaft,
a partition member disposed along an inner circumferential end of the stator, the partition member separating the first accommodating space from the second accommodating space and filling the first accommodating space with resin material;
[2]
The rotating machine according to [1], wherein the partition member is a pipe member having an outer circumferential surface that conforms to an inner circumferential end of the stator.
[3]
The rotary machine according to [1] or [2], wherein the case has an injection hole communicating with the first accommodating space.
[4]
A method for manufacturing a rotary machine including an electric motor including a stator and a rotor, a rotary shaft that rotates by driving the electric motor, and a case that surrounds the stator and to which the stator is fixed, comprising the steps of:
a stator placement step of placing the stator in the case;
a partitioning step of disposing a partition member along an inner circumferential end of the stator;
a filling process for filling a resin material into a first accommodating space that accommodates the stator and a second accommodating space that accommodates the rotor so as to face the stator in the first accommodating space in a cross-sectional view including the axis of the rotating shaft, the first accommodating space being partitioned by the partition member.

1 Rotating machine 4 Motor housing (case)
Reference Signs List 5 Electric motor 6 Rotating shaft 7

Resin material

10, 10X Partition member 10a Outer circumferential surface 11 First accommodation space 12 Second accommodation space 47 Injection holes 51, 53 Stator 51c Inner circumferential end 52 Rotor L Axis

Claims

an electric motor having a stator and a rotor;
A rotating shaft that is rotated by the driving of the electric motor;
An impeller attached to the rotating shaft;
a case surrounding the stator and to which the stator is fixed,
the case has a first accommodating space that accommodates the stator, and a second accommodating space that accommodates the rotor so as to face the stator in the first accommodating space in a cross-sectional view including an axis of the rotating shaft,
a partition member disposed along an inner circumferential end of the stator, the partition member separating the first accommodating space from the second accommodating space and filling the first accommodating space with resin material;
The rotating machine according to claim 1, wherein the partition member is a pipe member having an outer peripheral surface that conforms to the inner peripheral end of the stator.
The rotary machine according to claim 1 , wherein the case has an injection hole communicating with the first accommodating space.