A radial magnetic bearing potting base and potting method

Abstract

The present invention discloses a radial magnetic levitation bearing potting base and a potting method, wherein the radial magnetic levitation bearing potting base comprises a magnetic bearing base, a central through hole is opened in the middle of the magnetic bearing base, a positioning plate is arranged in the central through hole of the magnetic bearing base and near its lower end, a mounting position is arranged above the positioning plate in the magnetic bearing base, and an airbag is arranged in the middle of the magnetic bearing base, which is inflated and expands freely; the overall structure of the invention is simple, the manufacturing process is concise, and it can improve the assembly efficiency and achieve a good fixing effect, and can make the coil, silicon steel sheet and base become a whole to form standardized production; and it can also improve the durability of the potted magnetic bearing in corrosive and acidic environments.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic suspension bearing processing, and in particular relates to a radial magnetic suspension bearing potting base and a potting method. Background Art

[0002] Magnetic bearings are a new type of high-performance bearings that use magnetic force to suspend the rotor in the air, eliminating mechanical contact between the rotor and stator. Rapid changes in the magnetic field allow the shaft to remain in the center position at all times.

[0003] Magnetic bearings generally consist of two parts: a magnetic bearing stator and a coil winding. The existing radial magnetic bearing coil assembly process is to manually tie the coils and leads with binding ropes, and insert fiberglass sheets between the coils to fix the relative positions of the coils. This process leaves the magnetic bearing coils fixed exposed, the assembly process is cumbersome, and the durability is poor. In acidic and corrosive environments, the binding ropes and fiberglass sheets fail, which makes the magnetic bearings ineffective in harsh environments. The magnetic bearings also have poor durability and cannot be produced in a standardized manner.

[0004] In order to solve the above-mentioned assembly difficulty, a magnetic bearing stator glue pouring device has been implemented. For example, the patent application number is: CN202020098431.7, which discloses a magnetic bearing stator glue pouring device, including a glue pouring pressure plate, a glue pouring core shaft, a glue pouring base plate and a number of ventilation rods. The glue pouring pressure plate, the glue pouring core shaft and the glue pouring base plate are coaxial, the glue pouring core shaft is connected to the glue pouring base plate, and a number of ventilation rods are fixed to the bottom surface of the glue pouring base plate. The glue pouring pressure plate is a circular ring structure, and the glue pouring base plate is a disc structure. The glue pouring base plate is provided with a number of first countersunk holes for fixing the ventilation rods, and a central groove for limiting the position of the glue pouring core shaft is provided in the middle of the glue pouring base plate. The contact surface between the glue pouring base plate and the magnetic bearing stator is provided with a second sealing ring.

[0005] The above-mentioned existing magnetic bearing stator glue pouring device can assemble radial magnetic bearings, but the existing magnetic bearing stator glue pouring device positions the coil in the middle of the magnetic bearing through a glue pouring core shaft. In the actual production process, due to the existence of production errors, a gap is likely to appear between the coil and the glue pouring core shaft. During the glue pouring process, the glue is likely to flow into the gap between the coil and the glue pouring core shaft, resulting in poor production results.

[0006] Moreover, when there is a gap between the coil and the glue-filled core shaft, the coil is prone to shaking, causing the coil to be easily displaced, thereby seriously affecting the assembly accuracy and manufacturing efficiency of the radial magnetic bearing.

[0007] The present invention can simplify the tedious assembly process so that the coil, silicon steel sheet and base become a whole, thus forming standardized production. On the other hand, it can improve the durability of the potted magnetic bearing in corrosive and acidic environments. Summary of the Invention

[0008] The main technical problem to be solved by the present invention is to provide a radial magnetic bearing potting base and potting method, which has a simple overall structure and a concise manufacturing process, and can improve assembly efficiency and achieve a good fixing effect. It can make the coil, silicon steel sheet and base become a whole, forming standardized production; and it can also improve the durability of the potted magnetic bearing in corrosive and acidic environments.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0010] A radial magnetic bearing potting base includes a magnetic bearing base, a central through hole is opened in the middle of the magnetic bearing base, a positioning plate is arranged in the central through hole of the magnetic bearing base and near its lower end, a mounting position is arranged above the positioning plate in the magnetic bearing base, and an airbag is arranged in the middle of the magnetic bearing base, and the airbag is inflated and expands freely.

[0011] The following is a further optimization of the above technical solution by the present invention:

[0012] The lower end surface of the positioning plate is flush with the lower end surface of the magnetic bearing base; the positioning plate and the magnetic bearing base are connected as one piece.

[0013] Further optimization: a center hole is opened in the middle of the positioning plate, and the center hole and the magnetic bearing base are coaxially arranged.

[0014] Further optimization: a silicon steel sheet is coaxially installed in the central through hole of the magnetic bearing base and above the positioning plate, and a plurality of coils are arranged in the central through hole of the silicon steel sheet; the magnetic bearing base, the silicon steel sheet and the coil constitute a radial magnetic bearing.

[0015] Further optimization: the airbag is arranged in the middle of the cavity enclosed by multiple coils. After the airbag is inflated, a glue injection cavity is formed between the airbag, the silicon steel sheet and the coil.

[0016] Further optimization: the lower end of the airbag passes through the central hole of the positioning plate, and after the airbag is inflated, the outer surface of the airbag is in close contact with the inner surface of the central hole of the positioning plate.

[0017] The present invention also provides a radial magnetic bearing potting method, which includes a coil preparation process, and the coil preparation process includes the following steps:

[0018] S1. After the coil is wound, brush the surface of the coil with insulating paint and place it in a vacuum box to evacuate the coil so that the insulating paint can penetrate into the inner coil.

[0019] S2. After vacuuming, remove the coil and treat the coil surface with a weak acid solution to remove impurities and residual insulating paint on the coil surface in preparation for potting; the pH of the weak acid solution is 5.

[0020] The following is a further optimization of the above technical solution by the present invention:

[0021] The potting method also includes a filling process, which is carried out in the following steps:

[0022] G1. Use alcohol to clean the stains on the surface of the magnetic bearing base and silicon steel sheet, and place the magnetic bearing base in an oven to heat;

[0023] G2. The processed coil is assembled on the silicon steel sheet, and the silicon steel sheet and the magnetic bearing base are positioned, and assembled together with the coil on the magnetic bearing base;

[0024] G3. Then, an airbag is placed in the middle of the cavity formed by the multiple coils, with the lower end of the airbag passing through the central hole of the positioning plate; the airbag is inflated, and the airbag seals the irregular structure of the inner ring of the magnetic bearing;

[0025] G4, forming a glue injection cavity between the airbag, the silicon steel sheet and the coil; heating the epoxy glue to a molten state, and injecting the epoxy glue into the glue injection cavity;

[0026] G5. After the glue injection is completed, the radial magnetic bearing assembly is placed in an environment with a temperature of 22-28°C and left to stand for 120-140 minutes to allow the epoxy glue in the magnetic bearing base to solidify and form a solidified epoxy glue layer.

[0027] Further optimization: The potting method further includes a performance testing process, which is carried out as follows:

[0028] X1. Place the prepared radial magnetic bearing external leads in a sealed box for load testing in an acidic environment. HCL gas is introduced until the pressure reaches 1.5 kPa. A withstand voltage tester is used to detect the voltage load of the magnetic bearing, and a DC resistance meter is used to measure the resistance of the radial magnetic bearing.

[0029] X2. The digital megger pointer turns to 500V, and the detection value reaches 500-550V, indicating good withstand voltage. The DC resistance measurement result is consistent with the coil design resistance range, and the resistance is normal. Both the withstand voltage test and the resistance test meet the requirements, and the performance is qualified.

[0030] X3. Pack the qualified radial magnetic bearings into the warehouse and transfer them to the next process.

[0031] Further optimization: In step G1, the heating temperature of the magnetic bearing base in the oven is 130-150°C, the heating time is 30min-45min, and the magnetic bearing base is taken out after heating is completed.

[0032] The present invention adopts the above-mentioned technical solution, which is ingeniously conceived and reasonably designed. It can simplify the assembly process of radial magnetic bearings. While reducing the original cumbersome assembly process, it optimizes the product structure and improves the assembly efficiency, making the overall assembly process of the radial magnetic bearings simple and achieving a good fixing effect. In addition, after the epoxy glue is cured, it is not easy to react with acidic substances, which effectively improves the durability of the magnetic bearings in acidic corrosive environments, improves the use effect, and extends the service life of the radial magnetic bearings.

[0033] The present invention will be further described below with reference to the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the overall structure of an embodiment of the present invention;

[0035] Figure 2 Schematic diagram of the airbag in operation according to an embodiment of the present invention

[0036] Figure 3 for Figure 2 A top view of

[0037] Figure 4 for Figure 2 Side view of;

[0038] Figure 5 Schematic diagram of a radial magnetic bearing during assembly according to an embodiment of the present invention;

[0039] Figure 6 for Figure 5 A top view of

[0040] Figure 7 Schematic diagram of the structure of the radial magnetic bearing prepared in an embodiment of the present invention;

[0041] Figure 8 for Figure 7 A top view of

[0042] Figure 9 This is a schematic structural diagram of a radial magnetic bearing installed in an embodiment of the present invention;

[0043] Figure 10 for Figure 9 side view.

[0044] In the figure: 1-magnetic bearing base; 11-positioning plate; 2-support rod; 3-airbag; 4-silicon steel sheet; 5-coil; 6-glue injection cavity; 7-cured epoxy glue layer. DETAILED DESCRIPTION

[0045] like Figure 1-10As shown: A radial magnetic bearing potting base, including a magnetic bearing base 1, a central through hole is opened in the middle of the magnetic bearing base 1, a positioning plate 11 is provided in the central through hole of the magnetic bearing base 1 and near its lower end, a mounting position is provided in the magnetic bearing base 1 above the positioning plate 11, and an airbag 3 is provided in the middle of the magnetic bearing base 1, and the airbag 3 is inflated and expands freely.

[0046] A plurality of support rods 2 are provided below the magnetic bearing base 1, and the plurality of support rods 2 are arranged in a ring shape along the axis of the magnetic bearing base 1.

[0047] In this embodiment, the support rod 2 and the magnetic bearing base 1 are fixed and positioned by bolts.

[0048] The lower end surface of the positioning plate 11 is flush with the lower end surface of the magnetic bearing base 1 .

[0049] The positioning plate 11 is integrally connected to the magnetic bearing base 1 .

[0050] A central hole is formed in the middle of the positioning plate 11 , and the central hole and the magnetic bearing base 1 are coaxially arranged.

[0051] A silicon steel sheet 4 is coaxially mounted in the central through hole of the magnetic bearing base 1 and above the positioning plate 11 . A plurality of coils 5 are arranged in the central through hole of the silicon steel sheet 4 . The plurality of coils 5 are arranged in a ring shape along the central axis of the silicon steel sheet 4 .

[0052] In this embodiment, the magnetic bearing base 1 , the silicon steel sheet 4 and the coil 5 constitute a radial magnetic bearing.

[0053] After the radial magnetic bearing coil is assembled, the magnetic bearing is fixed to the radial magnetic bearing potting base using bolts at the corresponding bolt holes.

[0054] The silicon steel sheet 4 and the coil 5 are respectively installed in the central through hole of the magnetic bearing base 1, and the positioning plate 11 is used to position the silicon steel sheet 4 and the coil 5.

[0055] The airbag 3 is arranged in the middle of the cavity surrounded by multiple coils 5. The airbag 3 is inflated so that its outer surface contacts the coil 5, and then the coil 5 can be pressed against the airbag 3, thereby positioning the coil 5 for easy use.

[0056] After the airbag 3 is inflated, a glue injection cavity 6 is formed between the airbag 3 , the silicon steel sheet 4 and the coil 5 .

[0057] Glue is injected into the glue injection cavity 6 . After the glue is solidified, the glue in the glue injection cavity 6 covers the outer surfaces of the coil 5 and the silicon steel sheet 4 , so that the coil 5 and the magnetic bearing base 1 form a whole.

[0058] The lower end of the airbag 3 passes through the center hole of the positioning plate 11. After the airbag 3 is inflated, the outer surface of the airbag 3 is in close contact with the inner surface of the center hole of the positioning plate 11, thereby sealing the center hole of the positioning plate 11.

[0059] With this design, after the airbag 3 is inflated, the airbag 3 seals the central hole of the positioning plate 11 to prevent the glue in the glue injection cavity 6 from leaking there, thereby achieving a good sealing effect.

[0060] The glue liquid adopts epoxy glue.

[0061] like Figure 1-10 As shown: The present invention also provides a radial magnetic bearing potting method, the potting method includes a coil preparation process, and the coil preparation process includes the following steps:

[0062] S1. After the coil 5 is wound, the surface of the coil 5 is brushed with insulating paint and then placed in a vacuum box for evacuation, so that the insulating paint can penetrate into the inner coil.

[0063] S2. After vacuuming, take out the coil 5 and treat the surface of the coil 5 with a weak acid solution to remove impurities and residual insulating paint on the coil surface in preparation for potting.

[0064] The pH of the weakly acidic solution is 5.

[0065] With this design, the surface of the coil 5 can be treated with a weak acid solution to remove impurities and residual insulating paint on the coil surface in preparation for potting, which is easy to operate.

[0066] The encapsulation method further includes a filling process, which includes the following steps:

[0067] G1. Use alcohol to clean the stains on the surface of the magnetic bearing base 1 and the silicon steel sheet 4, and place the magnetic bearing base 1 in an oven for heating.

[0068] The heating temperature of the magnetic bearing base 1 in the oven is 130-150° C., and the heating time is 30 min-45 min. After the heating is completed, the magnetic bearing base 1 is taken out.

[0069] The design is as follows: on the one hand, due to the high requirements for the clearance fit between the silicon steel sheet 4 and the magnetic bearing base 1, the cold installation process is relatively difficult. Heating the magnetic bearing base 1 causes the material to expand, which is beneficial to the fit between the two different metals; on the other hand, when the magnetic bearing base 1 is heated, the glue has better fluidity when it is injected into the magnetic bearing base 1 for potting.

[0070] G2. The processed coil 5 is assembled on the silicon steel sheet 4. Long bolts are used to pass through the bolt holes to position the silicon steel sheet 4 and the magnetic bearing base 1. The coil 5 is assembled on the magnetic bearing base 1 together with the coil 5.

[0071] G3, then place the airbag 3 in the middle of the cavity enclosed by the multiple coils 5, and the lower end of the airbag 3 passes through the center hole of the positioning plate 11; then inflate the airbag 3, at this time the airbag 3 seals the irregular structure of the inner ring of the magnetic bearing (such as Figure 1 shown).

[0072] After the airbag 3 is inflated, its outer surface contacts the coil 5 , and the coil 5 can be supported by the airbag 3 , thereby achieving positioning of the coil 5 for easy use.

[0073] After the airbag 3 is inflated, the outer surface of the airbag 3 is in close contact with the inner surface of the center hole of the positioning plate 11, and the airbag 3 seals the center hole of the positioning plate 11 to prevent the glue in the glue injection cavity 6 from leaking here, thereby improving the sealing effect.

[0074] G4, a glue injection cavity 6 is formed between the airbag 3, the silicon steel sheet 4 and the coil 5; then the epoxy glue is heated to 50-60°C to make it molten, and the epoxy glue is injected into the glue injection cavity 6. Since the epoxy glue is very sensitive to temperature, the temperature change will affect its molecular structure, and the fluidity of the epoxy glue after heating reaches the best.

[0075] G5. After the glue injection is completed, the radial magnetic bearing assembly is placed in an environment with a temperature of 22-28° C. and left to stand for 120-140 minutes to allow the epoxy glue in the magnetic bearing base 1 to solidify and form a solidified epoxy glue layer 7.

[0076] After the epoxy glue in the magnetic bearing base 1 is cured, a cured epoxy glue layer 7 is formed. At this time, the coil 5 and the magnetic bearing base 1 are formed into a whole by forming the cured epoxy glue layer 7. Figure 7-8 shown.

[0077] The potting method further includes a performance testing process, which includes the following steps:

[0078] X1. Place the prepared radial magnetic bearing external leads in a sealed box for load testing in an acidic environment. Pass HCL gas until the air pressure reaches 1.5kPa. Use a withstand voltage tester to detect the voltage load of the magnetic bearing, and use a DC resistance meter to measure the resistance of the radial magnetic bearing.

[0079] X2. The digital megger pointer turns to 500V, and the detection value reaches 500-550V. The withstand voltage is good, and the DC resistance measurement result is consistent with the coil design resistance range. The resistance is normal. Both the withstand voltage test and the resistance test meet the requirements, and the performance is qualified.

[0080] X3. Pack the qualified radial magnetic bearings into the warehouse and transfer them to the next process.

[0081] The present invention adopts the above-mentioned technical solution to simplify the assembly process. While reducing the original cumbersome assembly process, it optimizes the product structure and improves the assembly efficiency, making the overall assembly process of the radial magnetic bearing simple and achieving a good fixing effect. In addition, after the epoxy glue is cured, it is not easy to react with acidic substances, which effectively improves the durability of the magnetic bearing in an acidic corrosive environment, improves the use effect, and extends the service life of the radial magnetic bearing.

[0082] For those skilled in the art, according to the teachings of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, substitutions and variations made to the implementation methods are still within the scope of protection of the present invention.

Claims

1. A radial magnetic bearing potting base, comprising a magnetic bearing base (1), characterized in that: A central through hole is provided in the middle of the magnetic bearing base (1); a positioning plate (11) is provided in the central through hole of the magnetic bearing base (1) and near the lower end thereof; a mounting position is provided in the magnetic bearing base (1) above the positioning plate (11); an air bag (3) is provided in the middle of the magnetic bearing base (1); the air bag (3) is inflated and expands freely; A central hole is provided in the middle of the positioning plate (11), and the central hole and the magnetic bearing base (1) are coaxially arranged; A silicon steel sheet (4) is coaxially mounted in the central through hole of the magnetic bearing base (1) and above the positioning plate (11), and a plurality of coils (5) are arranged in the central through hole of the silicon steel sheet (4); the magnetic bearing base (1), the silicon steel sheet (4) and the coils (5) constitute a radial magnetic bearing; The airbag (3) is arranged in the middle of a cavity enclosed by a plurality of coils (5); after the airbag (3) is inflated, a glue injection cavity (6) is formed between the airbag (3), the silicon steel sheet (4) and the coil (5); The lower end of the airbag (3) passes through the center hole of the positioning plate (11). After the airbag (3) is inflated, the outer surface of the airbag (3) is in close contact with the inner surface of the center hole of the positioning plate (11).

2. The radial magnetic bearing potting base according to claim 1, characterized in that: The lower end surface of the positioning disk (11) is flush with the lower end surface of the magnetic bearing base (1); the positioning disk (11) and the magnetic bearing base (1) are connected as one piece.

3. A radial magnetic bearing potting method, based on the radial magnetic bearing potting base according to any one of claims 1-2, characterized in that: The potting method includes a coil preparation process, which includes the following steps: S1. After the coil (5) is wound, the surface of the coil (5) is brushed with insulating paint and then placed in a vacuum box for evacuation, so that the insulating paint penetrates into the inner coil; S2. After vacuuming, the coil (5) is taken out and the surface of the coil (5) is treated with a weak acid solution to remove impurities and residual insulating paint on the surface of the coil in preparation for potting; the pH of the weak acid solution is 5.

4. A radial magnetic bearing potting method according to claim 3, characterized in that: The potting method also includes a filling process, which is carried out in the following steps: G1. Use alcohol to clean the stains on the surface of the magnetic bearing base (1) and the silicon steel sheet (4), and place the magnetic bearing base (1) in an oven for heating; G2. The processed coil (5) is assembled onto the silicon steel sheet (4), and the silicon steel sheet (4) and the magnetic bearing base (1) are positioned, and the coil (5) is assembled onto the magnetic bearing base (1); G3, then placing the airbag (3) in the middle of the cavity enclosed by the plurality of coils (5), with the lower end of the airbag (3) passing through the central hole of the positioning plate (11); inflating the airbag (3), at which time the airbag (3) seals the irregular structure of the inner ring of the magnetic bearing; G4, forming a glue injection cavity (6) between the airbag (3), the silicon steel sheet (4) and the coil (5); heating the epoxy glue to a molten state, and injecting the epoxy glue into the glue injection cavity (6); G5. After the glue injection is completed, the radial magnetic bearing assembly is placed in an environment with a temperature of 22-28°C and left to stand for 120-140 minutes to allow the epoxy glue in the magnetic bearing base (1) to solidify and form a solidified epoxy glue layer (7).

5. A radial magnetic bearing potting method according to claim 4, characterized in that: The potting method further includes a performance testing process, which is performed in the following steps: X1. Place the prepared radial magnetic bearing external leads in a sealed box for load testing in an acidic environment. HCL gas is introduced until the pressure reaches 1.5 kPa. A withstand voltage tester is used to detect the voltage load of the magnetic bearing, and a DC resistance meter is used to measure the resistance of the radial magnetic bearing. X2. The digital megger pointer turns to 500V, and the detection value reaches 500-550V, indicating good withstand voltage. The DC resistance measurement result is consistent with the coil design resistance range, and the resistance is normal. Both the withstand voltage test and the resistance test meet the requirements, and the performance is qualified. X3. Pack the qualified radial magnetic bearings into the warehouse and transfer them to the next process.

6. A radial magnetic bearing potting method according to claim 5, characterized in that: In step G1, the heating temperature of the magnetic bearing base (1) in the oven is 130-150° C., and the heating time is 30 min-45 min. After the heating is completed, the magnetic bearing base (1) is taken out.

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