Air bearing foil and method of forming same, heat setting apparatus

Abstract

The application discloses an air bearing foil and a forming method and a heat setting device thereof. The air bearing foil comprises a main body with a horizontal projection of an outer shape contour in a fan shape, and a corresponding fan-shaped arc edge of the main body is a three-dimensional arc curve; a surface of the main body is a three-dimensional curved surface consistent with a bending direction of the fan-shaped arc edge; and two corresponding fan-shaped radius edges of the main body respectively extend out a first plane and a second plane with different areas in directions away from end points of the fan-shaped arc edge. The application selects an age-hardening alloy with nickel as a main element as a raw material to obtain a fan-shaped rough material through cutting, and then carries out cleaning and drying after removing burrs, and then respectively loads the heat setting device to carry out heat setting treatment. The application considers multiple aspects of the outer shape, material selection, forming method and heat setting device design of the air bearing foil, and can ensure the successful production of the small-size and easy-to-deform air bearing foil, and meets the performance requirements while obtaining accurate outer shape size.

Description

Technical Field

[0001] This invention belongs to the field of air bearing manufacturing technology, specifically the shape characteristics of air bearing foil, the forming method of air bearing foil, and the heat setting device used in the forming process. Background Technology

[0002] Air bearing foil is a key component in air bearings, and the limitations and complexities in its manufacturing process are mainly reflected in the following aspects:

[0003] (1) The parts are small in size and difficult to mold;

[0004] (2) The existing air bearing materials are all in a solution state, and their performance does not meet the requirements. They need to be heat treated, but the foil is prone to irregular deformation at high temperature, resulting in the final size and performance not meeting the requirements.

[0005] (3) The parts are small in size, making welding difficult;

[0006] (4) The small size of the parts and poor consistency after molding affect subsequent assembly and performance.

[0007] In summary, the design of the air bearing foil needs to be considered in terms of its shape, material selection, and forming method. Summary of the Invention

[0008] The present invention aims to provide an air bearing foil and its forming method and heat setting device, to solve the problems of forming difficulties, welding difficulties, poor consistency and unqualified performance caused by factors such as small size, easy deformation and unqualified performance in the air bearing foil manufacturing process.

[0009] To achieve the above objectives, the present invention adopts the following solution:

[0010] The air bearing foil includes a main body with a horizontal projection of its outline in the shape of a fan, and the corresponding arc edge of the fan shape on the main body is a three-dimensional arc curve. The surface of the main body is a three-dimensional curved surface that is consistent with the bending direction of the arc edge of the fan shape. The two corresponding radial edges of the fan shape on the main body extend into a first plane and a second plane with different areas in the direction away from the endpoint of the arc edge of the fan shape.

[0011] A method for forming air bearing foil includes the following steps:

[0012] Step 1: Material cutting. Select an age-hardening alloy with nickel as the main element as the raw material for cutting to obtain a fan-shaped rough material including fan-shaped outer contour features, three-dimensional curved surface features, first plane and second plane.

[0013] Step 2: Deburring, removing burrs from the edges of the fan-shaped fabric;

[0014] Step 3: Perform cleaning and drying in sequence. The cleaning process includes degreasing, hot water washing, cold water washing, weak acid washing, and cold water washing.

[0015] Step 4, heat setting: After cleaning and drying, the fan-shaped material is placed into the heat setting device and then sent into the vacuum furnace for heat setting. During heat setting, the material is set for a long time at 650-750℃. The maximum heat setting temperature is 900℃. During the heat setting process, pressure is continuously applied to the fan-shaped material to ensure that the material fits completely against the setting surface of the heat setting device and ensures the forming size of the fan-shaped material.

[0016] Step 5, surface treatment: a Teflon layer is formed on the surface of the heat-set fan-shaped fabric.

[0017] Alternatively, in step one, a blanking die is used to directly punch out the fan-shaped blank.

[0018] Alternatively, in step one, the thickness of the fan-shaped fabric is less than or equal to 0.12 mm.

[0019] Alternatively, in step two, sandpaper is used to remove burrs.

[0020] Alternatively, in step three, the product is dried at 120–150°C for 20–40 minutes.

[0021] Alternatively, in step four, anti-sticking powder is placed between the fan-shaped fabric and the orientation surface of the heat-setting device to prevent the fan-shaped fabric from being diffusely welded and stuck together with the setting surface of the heat-setting device during the heat-setting process.

[0022] Alternatively, in step four, the air bearing foil heat setting device is divided into a forward air bearing foil heat setting device and a reverse air bearing foil heat setting device, and the fan-shaped material is loaded into the forward air bearing foil heat setting device and the reverse air bearing foil heat setting device respectively.

[0023] An air bearing foil heat setting device, comprising:

[0024] The base and the top cover are provided. The upper plane of the base and the lower plane of the top cover form a heat-setting mold-closing surface. The upper plane of the base is provided with a positioning groove, and the lower plane of the top cover is provided with a positioning boss. When the base and the top cover are molded together, the positioning boss is inserted into the positioning groove.

[0025] The shaping mold includes an upper shaping mold and a lower shaping mold. Multiple upper shaping molds are disposed on the lower end plane of the upper cover, and multiple lower shaping molds are disposed on the upper end plane of the base. The multiple upper shaping molds and multiple lower shaping molds are arranged such that the smaller size ends are close to the center of the base and the upper cover, while the larger size ends are close to the edge of the base and the upper cover.

[0026] Alternatively, the base and top cover are made of high-chromium-nickel austenitic steel.

[0027] Alternatively, the base and top cover also have ventilation holes.

[0028] Alternatively, the forming mold is a combination of a concave mold and a convex mold, with the upper forming mold being a concave mold and the lower forming mold being a convex mold.

[0029] Compared with the prior art, the air bearing foil and forming method of the present invention have the following characteristics:

[0030] (1) Select an age-hardening alloy with nickel as the main element to ensure that the performance meets the requirements while meeting the size requirements. Improve the performance and ensure the size are placed in the heat setting process.

[0031] (2) High-chromium-nickel austenitic steel is used as the material of the heat setting device. The device itself will not deform during heat setting. The flatness and parallelism of the upper plane of the base and the lower plane of the upper cover are good. After the mold is closed, it will not affect the final external dimensions of the air bearing foil.

[0032] (3) Using fan-shaped wool for heat setting makes it easier to control the subsequent dimensional accuracy;

[0033] (4) Two planes of different sizes are extended on both sides of the two radial sides of the fan-shaped material to serve as the splicing surface for subsequent welding of adjacent foils (i.e., two adjacent foils are welded by overlapping the larger plane with the smaller plane), which reduces the difficulty of welding.

[0034] (5) The foil has a fan-shaped overall outline and is slightly bent into an arched structure. Both sides form flat planes, which facilitates the assembly of subsequent components.

[0035] (6) The heat setting devices used during heat setting are separated into forward and reverse directions, and the setting surfaces are symmetrically distributed in a staggered array to ensure the consistency of the same batch of foils. At the same time, in order to reduce the influence of uneven temperature of the heat setting device, the foils are set with the large end facing outward and the small end facing inward. Attached Figure Description

[0036] Figure 1 This is a front view of the forward-facing air bearing foil heat setting device;

[0037] Figure 2 This is a front view of the reverse air bearing foil heat setting device;

[0038] Figure 3 This is a schematic diagram of a fan-shaped piece of raw material;

[0039] Figure 4 This is a schematic diagram of the lower end of the upper cover of the forward-facing air bearing foil heat setting device;

[0040] Figure 5 This is a schematic diagram of the upper plane of the base of the forward-facing air bearing foil heat setting device;

[0041] Figure 6 This is a schematic diagram of the lower end of the upper cover of the reverse air bearing foil heat setting device;

[0042] Figure 7 This is a schematic diagram of the upper plane of the base of the reverse air bearing foil heat setting device;

[0043] In the diagram, 1-base; 2-molding mold; 3-top cover. Detailed Implementation

[0044] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0045] like Figure 3 This is a structural diagram of the air bearing foil. The overall horizontal projection of the foil is fan-shaped. View A shows that the foil is slightly curved into an arched structure. The two sides of the foil are two rectangular flat planes of unequal size. This design facilitates the assembly and welding of subsequent components. Because the material undergoes long-term age-hardening at high temperatures during the foil heat-setting process, and the foil forming size is very small, it is not suitable to use elastic materials. Elastic materials easily lose their elasticity under long-term high-temperature conditions and cannot meet the foil forming requirements. Therefore, this invention selects an age-hardening alloy with nickel as the main element.

[0046] like Figure 1 , 2 As shown in Figures 4 to 7, the base 1 and the upper cover 3 achieve mold closing positioning by means of the positioning grooves at the four corners of the upper plane of the base 1 and the positioning protrusions at the four corners of the lower plane of the upper cover 3. Both the base 1 and the upper cover 3 are made of 06CrNi20, which is not easily deformed at a high temperature of 1200℃, thereby ensuring the parallelism and flatness of the upper and lower planes when the mold is closed, and avoiding affecting the outer dimensions of the air bearing foil in the shaping mold 2.

[0047] like Figure 1 and Figure 2As shown, the heat setting device of this invention is divided into a forward air bearing foil heat setting device and a reverse air bearing foil heat setting device, depending on the type of air bearing foil. Both consist of a base 1 and a top cover 3. The only difference is that the setting surface of the setting mold 2 is mirrored. The cavity of the setting mold 2 in the forward air bearing foil heat setting device is suitable for forward air bearing foil, while the cavity of the setting mold 2 in the reverse air bearing foil heat setting device is suitable for reverse air bearing foil.

[0048] The method for forming air bearing foil includes the following steps:

[0049] Step 1: Material cutting. Cut the material from 0.12mm thick GH4145 sheet. Figure 3 The fan-shaped blank shown. The external dimensions of the fan-shaped blank are calculated based on the unfolded dimensions of the final air bearing foil part, and it is cut directly using a blanking die;

[0050] Step 2: Deburring. Use fine sandpaper to remove burrs from the edges of the fan-shaped blank cut by the die.

[0051] Step 3: Cleaning. The fan-shaped fabric, base 1, and top cover 3 to be heat-treated are degreased, washed with hot water, then washed with cold water, then washed with a weak acid, and finally washed again with cold water. Then, they are dried at 120℃ for 20 minutes.

[0052] Step 4: Assembly. Place the fan-shaped blanks sequentially into the forming mold 2 of the base 1 of the forward-facing air bearing foil heat-setting device and the reverse-facing air bearing foil heat-setting device. Then, align the positioning protrusions of the upper cover 3 with the positioning grooves at the four corners of the base 1 and cover it. Figure 1 and Figure 2 As shown; during the assembly process, a layer of anti-stick powder needs to be applied to the surface of the heat setting device and the foil in contact to prevent the foil and the setting surface from being welded together due to mutual diffusion during the heat setting process;

[0053] Step 5: Heat setting treatment. The assembled heat setting device is placed in a vacuum furnace for heat setting. The maximum heat setting temperature is 900℃, followed by long-term aging at around 700℃. During aging, a certain pressure needs to be applied to the heat setting device to ensure the foil completely adheres to the setting surface and guarantees the foil's formed dimensions. The flatness and parallelism of the heat setting device are strictly required. If the flatness and parallelism of the heat setting device do not meet the standards, the pressure will be uneven, resulting in the foil's formed dimensions not meeting the requirements.

[0054] Step 6: Surface treatment. After heat setting, a layer of Teflon material is sprayed onto the surface of the foil, and then it is assembled and welded with the remaining components of the air bearing.

[0055] The above description is merely one embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the foregoing claims.

Claims

1. A method for forming air bearing foil, characterized in that: The air bearing foil includes a main body with a horizontal projection of a fan shape, and the corresponding arc edge of the fan shape on the main body is a three-dimensional arc curve. The surface of the main body is a three-dimensional curved surface that is consistent with the bending direction of the arc edge of the fan shape. The two corresponding arc radius edges on the main body extend outwards in a direction away from the endpoint of the arc edge of the fan shape to form a first plane and a second plane with different areas, which serve as the splicing surface for subsequent welding of adjacent foils. The molding method includes the following steps: Step 1: Material cutting. Select an age-hardening alloy with nickel as the main element as the raw material for cutting to obtain a fan-shaped rough material including fan-shaped outer contour features, three-dimensional curved surface features, first plane and second plane. Step 2: Deburring, removing burrs from the edges of the fan-shaped fabric; Step 3: Perform cleaning and drying in sequence. The cleaning process includes degreasing, hot water washing, cold water washing, weak acid washing, and cold water washing. Step 4, heat setting: After cleaning and drying, the fan-shaped material is placed into the heat setting device and then sent into the vacuum furnace for heat setting. During heat setting, the material is set for a long time at 650-750℃. The maximum heat setting temperature is 900℃. During the heat setting process, pressure is continuously applied to the fan-shaped material to ensure that the material fits completely against the setting surface of the heat setting device and ensures the forming size of the fan-shaped material. Step 5, surface treatment: a Teflon layer is formed on the surface of the heat-set fan-shaped fabric. In step four, the heat setting device includes: The base (1) and the top cover (3) form a heat-setting mold-closing surface with the upper plane of the base (1) and the lower plane of the top cover (3). The upper plane of the base (1) is provided with a positioning slot, and the lower plane of the top cover (3) is provided with a positioning boss. When the base (1) and the top cover (3) are molded together, the positioning boss is inserted into the positioning slot. The shaping mold (2) includes an upper shaping mold and a lower shaping mold. Multiple upper shaping molds are arranged on the lower end plane of the upper cover (3), and multiple lower shaping molds are arranged on the upper end plane of the base (1). The multiple upper shaping molds and multiple lower shaping molds are arranged such that the smaller size ends are close to the center of the base (1) and the upper cover (3), while the larger size ends are close to the edge of the base (1) and the upper cover (3). In step four, the air bearing foil heat setting device is divided into a forward air bearing foil heat setting device and a reverse air bearing foil heat setting device. The fan-shaped material is loaded into the forward air bearing foil heat setting device and the reverse air bearing foil heat setting device respectively.

2. The air bearing foil forming method according to claim 1, characterized in that: In step one, a blanking die is used to directly punch out fan-shaped blanks.

3. The air bearing foil forming method according to claim 1, characterized in that: In step one, the thickness of the fan-shaped material is less than or equal to 0.12 mm.

4. The air bearing foil forming method according to claim 1, characterized in that: In step two, sandpaper is used to remove burrs.

5. The air bearing foil forming method according to claim 1, characterized in that: In step three, the product is dried at 120–150°C for 20–40 minutes.

6. The air bearing foil forming method according to claim 1, characterized in that: The base (1) and the top cover (3) are made of high-chromium-nickel austenitic steel.

7. The air bearing foil forming method according to claim 1, characterized in that: The base (1) and the top cover (3) are also provided with heat dissipation holes.

Images