A dynamic performance test device for turbomolecular pump magnetic bearings with simulated gas loading

Abstract

The present invention relates to the technical field of dynamic performance testing of magnetic bearings of turbomolecular pumps, and in particular to a dynamic performance testing device for magnetic bearings of turbomolecular pumps with simulated gas loading, comprising a frame, an upper three-axis mobile platform provided on the top of the frame, a side three-axis mobile platform provided on one side of the frame, the upper three-axis mobile platform and the side three-axis mobile platform respectively being fixedly connected with a pressure applying assembly, the pressure applying assembly being detachably connected with a simulated rotor, the simulated rotor being detachably connected with a base plate, the base plate being fixedly connected to the bottom of the frame, and a visual detection assembly being fixedly connected to one side of the top surface of the frame. The present invention applies axial force and radial force to the molecular pump respectively, as well as torques in different directions, through the upper three-axis mobile platform and the side three-axis mobile platform, and can measure the static and dynamic load performance of the molecular pump under different combinations of axial force, radial force and torque.

Description

Technical Field

[0001] The invention relates to the technical field of dynamic performance testing of a turbomolecular pump magnetic bearing, in particular to a dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading. Background Art

[0002] A molecular pump is a vacuum-generating device. Its operating principle is that the linear velocity of the blades reaches the thermal motion speed of the molecules through high-speed rotation. The gas, through momentum exchange with the blades, obtains a directional velocity and is discharged from the cavity. Magnetic levitation turbomolecular pumps are used in various industries because they are oil-free, wear-free, low-noise, and can be installed at any angle. Magnetic bearings are key components of magnetic levitation turbomolecular pumps. They are divided into axial magnetic bearings and radial magnetic bearings, respectively, which provide axial and radial forces to suspend the rotor. Their stability is crucial to the normal operation of the molecular pump. When the load exceeds the load limit of the magnetic bearings, the rotor will become unstable and fall at extremely high speeds, causing serious damage. During molecular pump operation, when the gas valve is suddenly opened or the gas flow suddenly increases, the rotor will be subjected to a large impact load. When the flow rate is too high, the impact load and torque on the impeller will increase. All of these may cause the load to exceed the load limit of the magnetic bearings. Therefore, it is very important to measure the load-bearing limit of the molecular pump's magnetic bearings.

[0003] The performance of the magnetic bearing is different when the rotor is stationary and when the rotor is running at high speed. Its static load limit and dynamic load limit must be tested separately.

[0004] Current static testing methods for the performance of magnetic bearings in magnetic levitation molecular pumps primarily involve first suspending the shaft in the bearing in both the axial and radial directions, then applying forces in both directions to calculate the static load capacity. Dynamic testing of molecular pumps involves increasing the speed of the bearing and turbine rotor to rated speed. The dynamic load capacity of the bearing is then calculated by momentarily opening a gas valve to impact the high-speed turbine rotor or by gradually increasing the gas flow rate.

[0005] However, the equipment and procedures required for dynamic performance testing using the above method are much more complex than those for static performance testing. Furthermore, during dynamic performance testing, the molecular pump is prone to instability, leading to impeller damage, which increases economic costs. Furthermore, the applied force cannot be accurately applied during testing, resulting in large errors in the ultimate load.

[0006] Therefore, there is an urgent need for a dynamic performance testing device for turbomolecular pump magnetic bearings that simulates gas loading, which can simultaneously measure the static and dynamic load limits of the magnetic bearings, effectively reduce the complexity and economic cost of the test, and accurately apply the load force. Summary of the Invention

[0007] The purpose of the present invention is to provide a device for testing the dynamic performance of a turbomolecular pump magnetic bearing with simulated gas loading, so as to solve the problems existing in the above-mentioned prior art.

[0008] To achieve the above-mentioned purpose, the present invention provides the following solution: a dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading, comprising a frame, an upper three-axis movable platform is provided on the top of the frame, and a side three-axis movable platform is provided on one side of the frame. The upper three-axis movable platform and the side three-axis movable platform are respectively fixedly connected with a pressure-applying component, the pressure-applying component is detachably connected with a simulated rotor, the simulated rotor is detachably connected with a base plate, the base plate is fixedly connected to the bottom of the frame, and a visual detection component is fixedly connected to one side of the top surface of the frame.

[0009] Preferably, the pressure applying assembly includes a shell, a pressure sensor is installed in the shell, the pressure sensor abuts one end of a pressure spring, the other end of the pressure spring abuts a ball, the ball is rotatably connected to a probe housing, the probe housing is fixedly connected and communicated with the shell, and the pressure spring is arranged in the probe housing.

[0010] Preferably, the ball is arranged in an end of the probe housing away from the housing.

[0011] Preferably, the diameter of the ball is not less than the inner diameter of the probe housing.

[0012] Preferably, the upper three-axis mobile platform includes a symmetrically arranged first X-axis moving part, two of the first X-axis moving parts are fixedly connected to the top of the frame, a first Y-axis moving part is fixedly connected between the moving ends of the two first X-axis moving parts, the moving end of the first Y-axis moving part is fixedly connected to the first Z-axis moving part, and the moving end of the first Z-axis moving part is fixedly connected to one of the shells.

[0013] Preferably, the side three-axis mobile platform includes a symmetrically arranged second Z-axis mobile part, two of the second Z-axis mobile parts are fixedly connected to the side walls of the frame, a second X-axis mobile part is fixedly connected between the moving ends of the two second Z-axis mobile parts, the moving end of the second X-axis mobile part is fixedly connected to the second Y-axis mobile part, and the moving end of the second Y-axis mobile part is fixedly connected to the other shell.

[0014] Preferably, the visual detection component includes a second support fixedly connected to the top crossbeam of the frame, and a camera is fixedly connected to the bottom of the second support.

[0015] Preferably, the camera is arranged at an angle and is parallel to the plane formed by the two shells.

[0016] Preferably, adjacent support rods of the frame are fixedly connected with reinforcing ribs, and the reinforcing ribs are arranged obliquely.

[0017] The present invention discloses the following technical effects:

[0018] The present invention adopts a simulated rotor instead of a real turbine rotor, so that when testing dynamic performance, the molecular pump can be directly increased to the rated speed in the air without the need for a pump casing and after being completely sealed, thereby improving the economy during testing; at the same time, the present invention applies axial force and radial force to the molecular pump respectively, as well as torques in different directions, through the upper three-axis mobile platform and the side three-axis mobile platform, and can measure the static and dynamic load performance of the molecular pump under different combinations of axial force, radial force and torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the structure of the three-axis mobile platform of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the three-axis mobile platform of the present invention;

[0023] Figure 4 This is a schematic structural diagram of the pressure applying assembly of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of the visual detection component of the present invention;

[0025] Among them, 1. frame; 2. upper three-axis moving platform; 3. side three-axis moving platform; 4. pressure applying component; 5. visual detection component; 6. simulated rotor; 11. reinforcing ribs; 12. bottom plate; 21. first X-axis moving part; 22. first Y-axis moving part; 23. first Z-axis moving part; 31. second X-axis moving part; 32. second Y-axis moving part; 33. second Z-axis moving part; 41. shell; 42. pressure sensor; 43. probe housing; 44. pressure spring; 45. ball; 51. second support; 52. camera. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Reference Figure 1-Figure 5 The present invention provides a dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading, comprising a frame 1, an upper three-axis moving platform 2 is provided on the top of the frame 1, a side three-axis moving platform 3 is provided on one side of the frame 1, the upper three-axis moving platform 2 and the side three-axis moving platform 3 are respectively fixedly connected with a pressure applying component 4, the pressure applying component 4 is detachably connected with a simulated rotor 6, the simulated rotor 6 is detachably connected with a bottom plate 12, the bottom plate 12 is fixedly connected to the bottom of the frame 1, and a visual detection component 5 is fixedly connected to one side of the top surface of the frame 1.

[0029] The present invention adopts a simulated rotor 6 instead of a real turbine rotor, so that when testing dynamic performance, the molecular pump can be directly increased to the rated speed in the air without the need for a pump casing and after being completely sealed, thereby improving the economy during testing; at the same time, the present invention applies axial force and radial force to the molecular pump respectively, as well as torques in different directions, through the upper three-axis mobile platform 2 and the side three-axis mobile platform 3, and can measure the static and dynamic load performance of the molecular pump under different combinations of axial force, radial force and torque.

[0030] A further optimized solution is that the pressure applying component 4 includes a shell 41, a pressure sensor 42 is installed in the shell 41, the pressure sensor 42 abuts one end of a pressure spring 44, the other end of the pressure spring 44 abuts a ball 45, the ball 45 is rotatably connected to a probe housing 43, the probe housing 43 is fixedly connected and communicated with the shell 41, and the pressure spring 44 is arranged in the probe housing 43.

[0031] In a further optimized solution, the ball 45 is disposed in an end of the probe housing 43 away from the casing 41 .

[0032] In a further optimized solution, the diameter of the ball 45 is not less than the inner diameter of the probe housing 43. This prevents the ball 45 from escaping from the probe housing 43 during operation, and enables the ball 45 to rotate together with the high-speed simulated rotor 6.

[0033] To further optimize the solution, the upper three-axis mobile platform 2 includes a symmetrically arranged first X-axis moving part 21, the two first X-axis moving parts 21 are fixedly connected to the top of the frame 1, the first Y-axis moving part 22 is fixedly connected between the moving ends of the two first X-axis moving parts 21, the moving end of the first Y-axis moving part 22 is fixedly connected to the first Z-axis moving part 23, and the moving end of the first Z-axis moving part 23 is fixedly connected to a shell 41.

[0034] To further optimize the solution, the side three-axis mobile platform 3 includes a symmetrically arranged second Z-axis mobile part 33, the two second Z-axis mobile parts 33 are fixedly connected to the side wall of the frame 1, the second X-axis mobile part 31 is fixedly connected between the moving ends of the two second Z-axis mobile parts 33, the moving end of the second X-axis mobile part 31 is fixedly connected to the second Y-axis mobile part 32, and the moving end of the second Y-axis mobile part 32 is fixedly connected to another shell 41.

[0035] The first X-axis moving part 21 , the first Y-axis moving part 22 , the first Z-axis moving part 23 , the second X-axis moving part 31 , the second Y-axis moving part 32 , and the second Z-axis moving part 33 use ball screws and are driven by stepping motors respectively.

[0036] According to a further optimized solution, the visual detection component 5 includes a second support 51 fixedly connected to the top crossbeam of the frame 1 , and a camera 52 is fixedly connected to the bottom of the second support 51 .

[0037] In a further optimized solution, the camera 52 is tilted and parallel to the plane formed by the two housings 41. That is, the viewing angle plane of the camera 52 is parallel to the plane formed by the two pressure sensors 42.

[0038] In a further optimized solution, adjacent support rods of the frame 1 are respectively fixedly connected with reinforcing ribs 11, which are arranged obliquely. The reinforcing ribs 11 enable the frame 1 to be stably supported.

[0039] At the same time, the positions of the two pressure applying components 4 can be accurately detected by the visual detection component 5, and the load force can be accurately applied at different positions.

[0040] Through the first X-axis moving part 21, the first Y-axis moving part 22, the first Z-axis moving part 23, the second X-axis moving part 31, the second Y-axis moving part 32, and the second Z-axis moving part 33, the two pressure-applying components 4 can respectively realize free movement in the X, Y, and Z directions, and can be positioned to any position of the axial cross-section and radial cross-section of the simulated turbine. The pressure-applying component 4 can apply axial force and radial force to the simulated turbine, and the applied position can be adjusted at the same time, and the equivalent torque can also be applied; at the same time, the visual detection component 5 can detect the position applied by the pressure-applying component 4 and feed back to the computer, so that the operator can adjust the position of the applied load on the computer.

[0041] Working process: Place the molecular pump of the specified model to be tested on the test bench, match the rotating shaft of the molecular pump with the simulated turbine, and remove the molecular pump casing to facilitate the application of load force; first test its static load-bearing performance, control the molecular pump magnetic bearing, suspend the shaft and prevent it from rotating, then control the upper three-axis mobile platform 2 and the side three-axis mobile platform 3 to drive the pressure-applying component 4 at the end to apply force, and apply force at different positions according to the detection of the visual detection component 5; secondly, measure its dynamic load-bearing performance, increase the molecular pump to the rated speed, and after the molecular pump stabilizes, control the upper three-axis mobile platform 2 and the side three-axis mobile platform 3 to drive the pressure-applying component 4 at the end to apply force, and apply force at different positions according to the detection of the visual detection component 5.

[0042] The present invention uses a simulated turbine to replace a real turbine rotor. The mass and moment of inertia of the simulated turbine are the same as those of the turbine rotor. Since the turbine rotor has multi-stage blades, it cannot be increased to the rated speed in the atmosphere. However, the simulated turbine does not have blades and can be increased to the rated speed. In addition, the processing cost of the turbine rotor is extremely high. The simulated turbine is used to reduce the economic losses caused by possible damage to the turbine rotor during testing.

[0043] The present invention uses the same method to measure the dynamic performance and static performance of the magnetic levitation bearing, solving a series of problems such as the inability to apply static testing devices and methods to dynamic testing, the high complexity and higher economic cost of dynamic testing devices, and the low accuracy of the applied force.

[0044] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A dynamic performance test device for a turbomolecular pump magnetic bearing with simulated gas loading, characterized by: The invention comprises a frame (1), wherein an upper three-axis movable platform (2) is provided on the top of the frame (1), a side three-axis movable platform (3) is provided on one side of the frame (1), the upper three-axis movable platform (2) and the side three-axis movable platform (3) are respectively fixedly connected to a pressure applying component (4), a simulation rotor (6) is detachably connected to a bottom plate (12), the bottom plate (12) is fixedly connected to the bottom of the frame (1), and a visual detection component (5) is fixedly connected to one side of the top surface of the frame (1); The pressure applying assembly (4) includes a housing (41), a pressure sensor (42) is installed in the housing (41), the pressure sensor (42) abuts against one end of a pressure spring (44), the other end of the pressure spring (44) abuts against a ball (45), the ball (45) is rotatably connected to a probe housing (43), the probe housing (43) is fixedly connected and communicated with the housing (41), and the pressure spring (44) is arranged in the probe housing (43); the ball (45) rotates together with the simulated rotor (6); The rotating shaft of the molecular pump is matched with the simulated rotor (6), and the molecular pump magnetic bearing suspends the shaft; The upper three-axis mobile platform (2) and the side three-axis mobile platform (3) are controlled to respectively drive the pressure applying component (4) at the end to apply force, and the force is applied at different positions according to the detection of the visual detection component (5).

2. The dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: The ball (45) is arranged in an end of the probe housing (43) away from the casing (41).

3. The dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: The diameter of the ball (45) is not less than the inner diameter of the probe housing (43).

4. The dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: The upper three-axis moving platform (2) includes symmetrically arranged first X-axis moving parts (21), two of the first X-axis moving parts (21) are fixedly connected to the top of the frame (1), a first Y-axis moving part (22) is fixedly connected between the moving ends of the two first X-axis moving parts (21), a first Z-axis moving part (23) is fixedly connected to the moving end of the first Y-axis moving part (22), and a moving end of the first Z-axis moving part (23) is fixedly connected to one of the shells (41).

5. The dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: The side three-axis moving platform (3) includes a symmetrically arranged second Z-axis moving part (33), two second Z-axis moving parts (33) are fixedly connected to the side wall of the frame (1), a second X-axis moving part (31) is fixedly connected between the moving ends of the two second Z-axis moving parts (33), a second Y-axis moving part (32) is fixedly connected to the moving end of the second X-axis moving part (31), and a moving end of the second Y-axis moving part (32) is fixedly connected to another shell (41).

6. The dynamic performance testing device for a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: The visual detection assembly (5) comprises a second support (51) fixedly connected to the top crossbeam of the frame (1), and a camera (52) is fixedly connected to the bottom of the second support (51).

7. The device for testing dynamic performance of a turbomolecular pump magnetic bearing with simulated gas loading according to claim 6, characterized in that: The camera (52) is arranged at an angle and is parallel to a plane formed by the two shells (41).

8. The device for testing dynamic performance of a turbomolecular pump magnetic bearing with simulated gas loading according to claim 1, characterized in that: Adjacent support rods of the frame (1) are respectively fixedly connected with reinforcing ribs (11), and the reinforcing ribs (11) are arranged obliquely.

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