Air blowing device and manufacturing method thereof

Abstract

The blower device includes a fan portion and a housing portion. The fan portion has an impeller that rotates about a central axis. The housing portion accommodates the fan portion. The housing part has a cylindrical wall part. The cylindrical wall portion extends along the central axis and covers the impeller from the outside in the radial direction. The impeller has a plurality of blade parts arranged in the circumferential direction. A cutting mark is formed on at least a part of the inner peripheral surface of the cylinder wall section facing the blade section in the radial direction or on the outer end section of the blade section in the radial direction.

Description

Technical Field

[0001] This invention relates to an air supply device and its manufacturing method. Background Technology

[0002] Conventional air supply devices include: a fan section having an impeller that rotates about a central axis; and a housing section housing the fan section. The housing section has a cylindrical wall section extending along the central axis and covering the impeller radially outward. The impeller has a plurality of blades arranged circumferentially (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-179490 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, in conventional air supply devices, the blades may deform radially outward due to centrifugal force during rotation. In this case, if the radial clearance between the impeller and the casing is small, the impeller will contact the casing, potentially reducing the air supply performance of the device. On the other hand, if the radial clearance between the impeller and the casing is made larger, blade tip vortices are more likely to form, potentially reducing the air supply performance of the device.

[0008] The purpose of this invention is to provide an air supply device that can prevent the reduction of air supply performance, as well as a method for manufacturing the air supply device.

[0009] Solution for solving the problem

[0010] An exemplary air supply device of the present invention has a fan section and a housing section. The fan section has an impeller that rotates about a central axis. The housing section houses the fan section. The housing section has a cylindrical wall section. The cylindrical wall section extends along the central axis and covers the impeller from the radially outer side. The impeller has a plurality of blades arranged circumferentially. Cutting marks are formed on at least a portion of the inner circumferential surface of the cylindrical wall section opposite to the blades in the radial direction or at the radially outer end of the blades.

[0011] An exemplary method for manufacturing an air supply device according to the present invention comprises a fan section and a housing section, wherein a die-forming step and a cutting step are performed sequentially. The fan section has an impeller that rotates about a central axis. The housing section houses the fan section and has a cylindrical wall section that covers the impeller from the radially outer side. The die-forming step molds the housing section. The cutting step performs cutting machining on the inner circumferential surface of the cylindrical wall section. In the cutting step, a cutting edge inserted into the interior of the cylindrical wall section is rotated about a central axis to cut the inner circumferential surface of the cylindrical wall section.

[0012] Invention Effects

[0013] According to the exemplary present invention, an air supply device that can prevent the reduction of air supply performance and a method for manufacturing the air supply device can be provided. Attached Figure Description

[0014] Figure 1 This is an overall perspective view of the air supply device according to an embodiment of the present invention.

[0015] Figure 2 This is a longitudinal sectional view of the air supply device according to an embodiment of the present invention.

[0016] Figure 3 This is a longitudinal sectional view of the housing portion of the air supply device according to an embodiment of the present invention. (Perspective view.)

[0017] Figure 4 This is a flowchart illustrating the manufacturing process of the housing portion of the air supply device according to an embodiment of the present invention.

[0018] Figure 5 This is an explanatory diagram illustrating the manufacturing process of the housing portion of the air supply device according to an embodiment of the present invention.

[0019] Figure 6 This is an explanatory diagram illustrating the manufacturing process of the housing portion of the air supply device according to an embodiment of the present invention.

[0020] Figure 7 This is an explanatory diagram illustrating the manufacturing process of the housing portion of the air supply device according to an embodiment of the present invention. Detailed Implementation

[0021] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification, the direction in which the central axis of the air supply device extends is simply referred to as the "axial direction," the direction orthogonal to the central axis of the air supply device is simply referred to as the "radial direction," and the direction along an arc centered on the central axis of the air supply device is simply referred to as the "circumferential direction." Furthermore, for the sake of convenience, in this specification, the axial direction is defined as the vertical direction, and... Figure 2 The vertical direction is used to describe the shape and positional relationship of each part of the air supply device. The "upper side" of the air supply device is the "inlet side," and the "lower side" is the "exhaust side." It should be noted that this definition of vertical direction does not limit the orientation and positional relationship of the air supply device during use. In addition, in this specification, a cross-section parallel to the axial direction is referred to as a "longitudinal section." Furthermore, the term "parallel" used in this specification does not mean parallel in the strict sense, but includes approximately parallel.

[0022] <1. Overall Composition of the Air Supply Device>

[0023] Figure 1This is an overall perspective view of an example of the air supply device 1 according to an embodiment of the present invention. Figure 2 This is a longitudinal sectional view of the air supply device 1. It should be noted that... Figure 2 In the text, the flange portion 22a is omitted.

[0024] The air supply device 1 includes a fan section 10 and a housing section 20. The fan section 10 includes an impeller 11 and a motor 12.

[0025] The housing portion 20 has an airflow passage 21 inside. The airflow passage 21 extends along the central axis J inside the housing portion 20. The airflow passage 21 has an air inlet 211 at the upper end and an air outlet 212 at the lower end.

[0026] The housing 20 is a resin molded product (mold-molded product) that houses the impeller 11, the motor 12, and the circuit board 13. The housing 20 has a cylindrical wall 22, a base 23, a connecting part 24, and a bearing holding part 25.

[0027] The cylindrical wall portion 22 extends along the central axis J and covers the impeller 11 from the radially outer side. The cylindrical wall portion 22 is cylindrical and extends vertically along the axial direction. An airflow path 21 is arranged on the radially inner side of the cylindrical wall portion 22. An air inlet 211 is arranged at the axially upper end of the cylindrical wall portion 22. An air outlet 212 is arranged at the axially lower end of the cylindrical wall portion 22. In addition, the cylindrical wall portion 22 has flange portions 22a arranged at the corners of the upper and lower ends (see reference). Figure 1 The flange portion 22a has a through mounting hole 22b. The air supply device 1 can be threaded onto the mounting surface via the mounting hole 22b.

[0028] The base portion 23 is disposed on the axially lower side of the motor 12, and the base portion 23 for fixing the motor 12 is in the shape of a circular plate extending radially outward about the central axis J. A connecting portion 24 extends radially outward from the radially outer surface of the base portion 23, connecting the base portion 23 to the cylinder wall portion 22. Multiple connecting portions 24 are arranged circumferentially. Air flowing in the air supply path 21 passes between adjacent connecting portions 24.

[0029] The bearing retaining part 25 is, for example, a metal component such as brass, and is integrally formed with the base part 23. The bearing retaining part 25 protrudes axially upward from the upper surface of the base part 23 and is cylindrical about the central axis J. The bearing retaining part 25 internally holds the bearing 122 (described later) and forms part of the motor 12. It should be noted that the bearing retaining part 25 can also be integrally formed with the base part 23 by resin molding instead of being formed as a separate component from the base part 23.

[0030] The impeller 11 is located radially inside the cylinder wall 22 and axially above and radially outside the motor 12. The impeller 11 is a resin molded product (mold-molded product) and rotates about the central axis J by the motor 12.

[0031] The impeller 11 has an impeller cup 111 and blade portions 112. The impeller cup 111 is fixed to the motor 12. The impeller cup 111 is a generally cylindrical component with a cover on the axially upward side. A plurality of blade portions 112 are arranged circumferentially on the outer surface of the impeller cup 111.

[0032] The motor 12 is fixed to the base portion 23 and housed in the housing portion 20. The motor 12 causes the impeller 11 to rotate about the central axis J. The motor 12 has a shaft 121, a bearing 122, a bearing retainer 25, a stator 123, and a rotor 124.

[0033] Shaft 121 is arranged along the central axis J. Shaft 121 is made of a metal such as stainless steel and is a columnar component extending vertically along the axial direction. Shaft 121 is supported by bearing 122 so that it can rotate about the central axis J.

[0034] At least one pair of bearings 122 are arranged vertically in the axial direction. The bearings 122 are held inside the bearing retaining portion 25. The bearings 122 are, for example, ball bearings, but may also be sleeve bearings or the like. The pair of bearings 122 in the axial direction support the shaft 121 so that it can rotate about the central axis J relative to the housing portion 20.

[0035] The stator 123 is fixed to the outer peripheral surface of the bearing retaining part 25. The stator 123 includes: a stator core 1231, an insulator 1232, and a coil 1233.

[0036] The stator core 1231 is constructed, for example, by stacking silicon steel plates or other electromagnetic steel plates. The insulating member 1232 is made of insulating resin. The insulating member 1232 is provided to surround the outer surface of the stator core 1231. The coil 1233 is constructed by a wire wound around the stator core 1231 through the insulating member 1232.

[0037] The rotor 124 is positioned axially above and radially outside the stator 123. The rotor 124 rotates about the central axis J relative to the stator 123. The rotor 124 has a rotor yoke 1241 and a magnet 1242.

[0038] The rotor yoke 1241 is composed of magnetic materials and is a generally cylindrical component with a cover on its axial upper side. The rotor yoke 1241 is fixed to the shaft 121. The magnet 1242 is cylindrical and fixed to the inner circumferential surface of the rotor yoke 1241. The magnet 1242 is disposed radially on the outer side of the stator 123.

[0039] The circuit board 13 is disposed on the axially lower side of the impeller 11 and the axially upper side of the base portion 23. The circuit board 13 is, for example, a circular plate extending radially outward from the central axis J. The circuit board 13 is electrically connected to the lead wires of the coil 1233. Electronic circuitry for supplying drive current to the coil 1233 is mounted on the circuit board.

[0040] In the air supply device 1 configured as described above, when a drive current is supplied to the coil 1233 of the motor 12 via the circuit board 13, a radial magnetic flux is generated in the stator core 1231. The magnetic field generated by the magnetic flux of the stator core 1231 and the magnetic field generated by the magnet 1242 interact to generate torque in the circumferential direction of the rotor 124. Due to this torque, the rotor 124 and the impeller 11 rotate around the central axis J. When the impeller 11 rotates, airflow is generated through the multiple blade sections 112. That is, the air supply device 1 can generate airflow with the upper side as the intake side and the lower side as the exhaust side for air supply.

[0041] <2. Detailed Structure of the Shell>

[0042] Figure 3 This is a longitudinal sectional view of the shell portion 20. It should be noted that... Figure 3 In the diagram, for illustrative purposes, a dotted pattern is used to represent the cutting mark 222a. Furthermore, in... Figure 3 In the text, the flange portion 22a is omitted.

[0043] The shell portion 20 has a cylindrical wall portion 22 with enlarged diameter portions 221 and 223 and a portion with the same diameter 222. The inner diameter of the portion with the same diameter 222 is constant, and the portion with the same diameter 222 extends axially (parallel to the central axis J). The enlarged diameter portions 221 and 223 are respectively arranged adjacent to each other on both sides (upper and lower axial sides) of the portion with the same diameter 222 in the axial direction, and their inner diameters increase as they move away from the portion with the same diameter 222 in the axial direction. As a result, the inner circumferential surfaces of the enlarged diameter portions 221 and 223 are inclined radially outward as they tend to move axially outward.

[0044] The inner circumferential surface of the same diameter portion 222 has a cutting mark 222a. The inner circumferential surface of the enlarged diameter portion 221 has a non-machined surface 221a without the cutting mark 222a. The inner circumferential surface of the enlarged diameter portion 223 has a non-machined surface 223a. That is, the cutting mark 222a is located on the inner circumferential surface of the same diameter portion 222. Thus, the cutting mark 222a is located at the radially inner end on the inner circumferential surface of the cylinder wall portion 22.

[0045] Furthermore, the unmachined surfaces 221a and 223a are located on the inner circumferential surfaces of the enlarged diameter portions 221 and 223, respectively. That is, the housing portion 20 has an unmachined surface 221a without cutting marks 222a.

[0046] Therefore, a cutting mark 222a is formed on at least a portion of the inner circumferential surface of the cylinder wall portion 22, which is radially opposite to the blade portion 112. In this embodiment, the cutting mark 222a extends throughout the entire circumferential direction of the inner circumferential surface of the cylinder wall portion 22. Here, the cutting mark 222a may extend continuously throughout the entire circumferential direction of the inner circumferential surface of the cylinder wall portion 22, or it may extend continuously intermittently in a portion of the circumferential direction, or it may extend continuously only in a portion of the circumferential direction. When the cutting mark 222a extends continuously throughout the entire circumferential direction of the inner circumferential surface of the cylinder wall portion 22, cutting is performed throughout the entire circumferential direction, thereby reducing the deviation of the inner diameter of the cutting mark 222a. When the cutting mark 222a extends continuously intermittently in a portion of the circumferential direction of the inner circumferential surface of the cylinder wall portion 22, the cutting amount of the cutting mark 222a can be suppressed, the cutting time for forming the cutting mark 222a can be suppressed, and the wear of the cutting edge 71a can be suppressed.

[0047] Cutting marks 222a are formed by cutting the surface of the housing portion 20 formed by the mold. Non-machined surfaces 221a and 223a are the surfaces that abut against the mold during mold forming and are not machined.

[0048] By machining the same-diameter portion 222, the deviation of the inner diameter of the same-diameter portion 222 can be reduced relative to the dimensional deviation of the molded housing portion 20. Therefore, a clearance of a specified width is reliably ensured between the blade portion 112 and the cylinder wall portion 22. This prevents the impeller 11 from contacting the housing portion 20. Consequently, a decrease in the airflow and static pressure of the air supply device 1 can be prevented, thereby preventing a reduction in air supply performance.

[0049] It should be noted that by reducing the minimum radial distance between the cylinder wall portion 22 and the blade portion 112, the generation of blade tip vortices can be suppressed, thereby increasing the air volume and static pressure of the air supply device 1. This further improves the air supply performance of the air supply device 1.

[0050] Furthermore, in the region where the cutting marks 222a are formed, the surface roughness decreases, allowing for smooth airflow along the axial direction. This further increases the air volume and static pressure of the air supply device 1.

[0051] By forming cutting marks 222a along the entire circumference of the inner circumferential surface of the cylinder wall portion 22, the air volume and static pressure of the air supply device 1 can be further improved. In addition, it can further prevent the impeller 11 from contacting the housing portion 20.

[0052] It should be noted that in this embodiment, the cutting mark 222a is formed on the entire surface of the same diameter portion 222, but it may also be formed only on a part of the same diameter portion 222. Although it depends on the shape of the cylinder wall portion 22, if the cutting mark 222a is formed at the radial inner end of the cylinder wall portion 22, it can prevent the impeller 11 from contacting the housing portion 20.

[0053] (3. Manufacturing method of the shell part)

[0054] Figure 4 This is a flowchart showing the manufacturing process of the housing part 20. Figure 5 , Figure 6 , Figure 7 This is an explanatory diagram illustrating the manufacturing process of the housing part 20. It should be noted that... Figure 5 , Figure 6 In the text, the flange portion 22a is omitted.

[0055] In step S1, as Figure 5 As shown, the peripheral portions of mold 31 and mold 32 are brought into contact in the vertical direction, forming a cavity 40 between mold 31 and mold 32. The cavity 40 has a shape corresponding to the shape of the housing portion 20. Furthermore, a bearing retaining portion 25 is disposed in the cavity 40 at a position corresponding to the base portion 23.

[0056] In step S2, molten resin is injected into the cavity 40. In step S3, the resin is cooled and solidified. This forms the housing portion 20 within the cavity 40. At this time, the base portion 23 and the bearing retaining portion 25 are integrally formed. In step S4, as... Figure 6 As shown, the housing portion 20 is demolded from a pair of molds 31 and 32. At this time, the entire surface of the housing portion 20 becomes a non-machined surface without cutting marks 222a.

[0057] In step S5, as Figure 7 As shown, the housing portion 20 is conveyed to the cutting device 70. The cutting device 70 has a cutting section 71 and a worktable 72. The cutting section 71 has a cutting edge 71a and a rotating body 71b. The rotating body 71b is cylindrical and can rotate about a central axis J. In addition, the rotating body 71b has a through hole 71c extending axially upward from its lower surface. Multiple cutting edges 71a are fixed circumferentially on the outer peripheral surface of the rotating body 71b.

[0058] The upper surface of the worktable 72 is orthogonal to the axial direction and is used to mount the housing portion 20 being transported. It has a pin 72a protruding axially from the upper surface of the worktable. The pin 72a is inserted into a mounting hole 22b in the housing portion 20. Thus, the housing portion 20 is positioned on the worktable 72.

[0059] After the housing portion 20 is placed on the worktable 72, the cutting portion 71 is inserted into the interior of the cylinder wall portion 22. At this time, the bearing retaining portion 25 is inserted into the insertion hole 71c. Thus, the rotating body 71b can be inserted into the interior of the cylinder wall portion 22 without contacting the bearing retaining portion 25.

[0060] Subsequently, the rotating body 71b rotates around the central axis J, causing the cutting edge 71a to rotate around the central axis J. Thus, the inner circumferential surface of the cylinder wall 22 is machined by the cutting edge 71a.

[0061] In step S6, the cutting edge 71a is rotated about the central axis J to cut the inner circumferential surface of the cylinder wall portion 22. As a result, a cutting mark 222a is formed on the inner circumferential surface of the portion 222 of the same diameter. By rotating the cutting edge 71a about the central axis J to form the cutting mark 222a, a cutting mark 222a extending throughout the entire circumferential direction can be easily formed on the inner circumferential surface of the cylinder wall portion 22.

[0062] Based on the above, the manufacturing method of the housing part 20, which becomes part of the housing of the air supply device 1, sequentially includes a mold forming process, a conveying process, and a cutting process. In the mold forming process, the housing part 20 is molded using a resin mold (steps S1 to S4). In the conveying process, the housing part 20, formed in the mold forming process, is conveyed, and a cutting edge 71a is inserted into the interior of the cylinder wall part 22 (step S5). In the cutting process, the cutting edge 71a inserted into the interior of the cylinder wall part 22 is rotated around the central axis J to cut the inner circumferential surface of the cylinder wall part 22 (step S6). Because of the conveying process, the cutting process can be performed continuously after the mold forming process, thus improving the manufacturing efficiency of the housing part 20.

[0063] It should be noted that in this embodiment, the cutting mark 222a is formed by the cutting edge 71a, but the cutting mark 222a can also be formed by using an abrasive material instead of the cutting edge 71a.

[0064] (4. Other)

[0065] The above-described embodiments are merely examples of the present invention. The configuration of the embodiments can also be appropriately modified within the scope of the technical concept of the present invention. Furthermore, the embodiments can be combined and implemented within possible ranges. For example, in this embodiment, cutting marks 222a are formed on the inner circumferential surface of the cylinder wall portion 22, but cutting marks can also be formed on the radially outer end portion of the blade portion 112. By machining the radially outer end portion of the blade portion 112, the deviation of the outer diameter of the blade portion 112 can be reduced relative to the dimensional deviation of the molded blade portion 112. Therefore, a gap of a specified width is reliably ensured between the blade portion 112 and the cylinder wall portion 22. This prevents the impeller 11 from contacting the housing portion 20. Therefore, a decrease in the airflow and static pressure of the air supply device 1 can be prevented, thereby preventing a decrease in air supply performance. It should be noted that the area other than the radially outer end portion of the blade portion 112 becomes a non-machined surface without cutting marks.

[0066] In this case, it is preferable that the cutting marks are formed at the radially outer ends of all blade portions 112. This further prevents the impeller 11 from contacting the housing portion 20.

[0067] (5. Postscript)

[0068] As described above, one embodiment of the air supply device 1 disclosed herein includes: a fan section 10 having an impeller 11 that rotates about a central axis J; and a housing section 20 housing the fan section, the housing section having a cylindrical wall section 22 extending along the central axis and covering the impeller from the radially outer side, the impeller having a plurality of blade sections 112 arranged circumferentially, and cutting marks 222a (first configuration) formed on at least a portion of the inner circumferential surface of the cylindrical wall section opposite to the blade sections in the radial direction or at the radially outer end of the blade sections.

[0069] Furthermore, in the first configuration described above, the housing portion and the impeller are molded products with unmachined surfaces 221a and 223a without the cutting marks, and the surface roughness of the cutting marks is smaller than the surface roughness of the unmachined surfaces (second configuration).

[0070] Furthermore, in the first or second configuration described above, the cutting mark is located at the radially inner end of the inner circumferential surface of the cylinder wall portion (third configuration).

[0071] Furthermore, in any of the first to third configurations described above, the cutting mark extends in the entire circumferential direction of the inner circumferential surface of the cylinder wall portion (fourth configuration).

[0072] Furthermore, in any of the first to fourth configurations described above, the cutting marks are formed at the radially outer ends of all the blade portions (fifth configuration).

[0073] Furthermore, in any of the first to fifth configurations described above, the cylinder wall portion has: a constant diameter portion 222, the inner diameter of which is constant and extends axially; and enlarged diameter portions 221 and 223, which are arranged adjacent to the constant diameter portion on both sides in the axial direction, and whose inner diameter increases as they move away from the constant diameter portion in the axial direction, the cutting marks being located on the inner circumferential surface of the constant diameter portion, and the unmachined surface being located on the inner circumferential surface of the enlarged diameter portion (sixth configuration).

[0074] Furthermore, one aspect of this disclosure discloses a method for manufacturing an air supply device 1, the air supply device comprising: a fan section 10 having an impeller 11 that rotates about a central axis J; and a housing section 20 housing the fan section and having a cylindrical wall section 22 that covers the impeller from the radially outer side. The method for manufacturing the air supply device sequentially includes: a mold forming step, in which the housing section is molded; and a cutting step, in which the inner circumferential surface of the cylindrical wall section is cut, wherein in the cutting step, a cutting edge 50 inserted into the interior of the cylindrical wall section is rotated about the central axis to cut the inner circumferential surface of the cylindrical wall section (seventh configuration).

[0075] Industrial availability

[0076] Furthermore, in the seventh configuration described above, there is also a conveying process that conveys the housing portion formed by the mold forming process and inserts the cutting edge into the interior of the cylinder wall portion (eighth configuration).

[0077] This invention can be used, for example, in an air supply device for cooling a personal computer.

[0078] Symbol Explanation

[0079] 1—Air supply device, 10—Fan section, 11—Impeller, 12—Motor, 13—Circuit board, 20—Housing section, 21—Air supply path, 22—Cylinder wall section, 22a—Flange section, 22b—Mounting hole, 23—Base section, 24—Connecting section, 25—Bearing retaining section, 31, 32—Mold, 40—Cavity, 70—Cutting device, 71—Cutting section, 71a—Cutting edge, 71b—Rotating body, 71c—Through hole, 72—Worktable, 72 a—pin, 111—impeller cup, 112—blade section, 121—shaft, 122—bearing, 123—stator, 124—rotor, 211—air inlet, 212—air outlet, 221, 223—expanded diameter section, 221a, 223a—non-machined surface, 222—same diameter section, 222a—cutting mark, 1231—stator core, 1232—insulator, 1233—coil, 1241—rotor yoke, 1242—magnet, J—central shaft.

Claims

1. An air supply device, comprising: The fan section has an impeller that rotates about a central axis; and Housing portion, which accommodates the fan portion. The housing portion has a cylindrical wall portion that extends along the central axis and covers the impeller from the radially outward side. The impeller has multiple blades arranged circumferentially. At least a portion of the inner circumferential surface of the cylinder wall portion that is radially opposite to the blade portion or the radially outer end portion of the blade portion is formed with cutting marks.

2. The air supply device according to claim 1, wherein, The housing and the impeller are molded products, having unmachined surfaces without the cutting marks. The surface roughness of the cutting marks is smaller than that of the unmachined surface.

3. The air supply device according to claim 1 or 2, wherein, The cutting mark is located at the radial inner end of the inner circumferential surface of the cylinder wall.

4. The air supply device according to claim 1 or 2, wherein, The cutting marks extend along the entire circumference of the inner circumferential surface of the cylinder wall.

5. The air supply device according to claim 1 or 2, wherein, The cutting marks are formed at the radially outer ends of all the blade portions.

6. The air supply device according to claim 2, wherein, The cylindrical wall portion has: A portion of the same diameter, wherein the inner diameter of the portion of the same diameter is constant and extends axially; and The enlarged diameter portion is arranged adjacent to the same diameter portion on both sides in the axial direction, and its inner diameter increases as it moves away from the same diameter portion in the axial direction. The cutting mark is located on the inner circumferential surface of the portion with the same diameter. The unmachined surface is located on the inner circumferential surface of the enlarged diameter section.

7. A method for manufacturing an air supply device, the air supply device comprising: a fan section having an impeller rotating about a central axis; and a housing section housing the fan section and having a cylindrical wall section covering the impeller from the radially outer side, the method for manufacturing the air supply device comprising: In the mold forming process, the mold forms the housing portion; and The cutting process involves machining the inner circumferential surface of the cylinder wall. In the cutting process, a cutting edge inserted into the interior of the cylinder wall is rotated around the central axis to cut the inner circumferential surface of the cylinder wall.

8. A method for manufacturing an air supply device, further comprising: In the conveying process, the shell portion formed by the mold forming process is conveyed, and the cutting edge is inserted into the interior of the cylinder wall portion.

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