A molecular pump turbine stress removal test tool and its use method

Abstract

The present application discloses a molecular pump turbine stress removal test tool and its use method, which belongs to the field of molecular pump turbine stress removal, and its technical key points are: a three-way joint is connected to the test board, one end of the three-way joint is connected to the test board and communicated with the pump port of the molecular pump, and the other two ends of the three-way joint are respectively connected to a flow meter and a vacuum meter; the flow meter is used to control the flow into the test pump; the vacuum meter is used to measure the air pressure at the opening of the molecular pump; the turbine temperature sensor is used to measure the temperature of the turbine; the turbine upper end face vibration sensor and the turbine lower end face vibration sensor are used to detect the vibration values ​​of the upper end face and the lower end face of the turbine respectively; it is used to cool the molecular pump. The technical solution of the present application can quickly remove the stress of the molecular pump turbine.

Description

Technical Field

[0001] The present application relates to the field of molecular pump turbine stress relief, and more specifically, to a molecular pump turbine stress relief test tool and a method for using the tool. Background Art

[0002] <Existing methods for dealing with molecular pump turbine stress>

[0003] Metal parts generally produce stress during processing, which manifests as warping. Stress removal is generally done by the following methods:

[0004] First, heat treatment removal (such as: CN112323003A, CN118621097A). That is, the molecular pump turbine is baked at a higher temperature for a certain period of time to eliminate stress.

[0005] Second, place it naturally, that is, place the structure at room temperature for half a year or even several years to eliminate stress over time.

[0006] Third, vibration treatment (such as: CN118685619A, CN217651286U). Use an exciter to vibrate the metal component at a predetermined frequency to remove the residual stress inside the metal component.

[0007] For the molecular pump turbine, due to the extremely high processing accuracy required, the steps for stress elimination in the production stage are:

[0008] (1) Raw material stage: Heat treatment is required at the raw material stage;

[0009] (2) Processing stage: After heat treatment of the raw materials, rough machining, semi-finishing, finishing and other turning processes and high-speed milling processes are carried out in sequence; between the above two processes, a combination of heat treatment and natural placement is required to remove the stress generated during each process.

[0010] (3) Completion stage: After the parts are processed, they are subjected to stress relief by combining heat treatment and natural placement.

[0011] <The manifestation of molecular pump turbine stress and determination of test indicators>

[0012] For large-diameter molecular pump turbines, the stress performance is different from that of common metal components:

[0013] (1) Failure of warpage measurement. For molecular pump turbines, when the warpage value is greater than or equal to "0.03" mm, it is easy to detect with tools such as vernier calipers; when the warpage value is less than "0.03" mm, it is difficult to accurately measure with tools such as vernier calipers. However, when the molecular pump turbine is treated by heat treatment, natural placement, etc., although the warpage value is less than 0.03 mm, many molecular pump turbines still have stress.

[0014] (2) Based on the fact that the warpage value cannot represent the internal force, it is necessary to determine a new test indicator (i.e., an indicator for determining when stress relief is no longer necessary).

[0015] In summary, the prior art has the following two defects:

[0016] (1) The processing cycle for stress removal of molecular pump turbines is extremely long (ranging from several months to several years), resulting in high material accumulation costs. In other words, how to speed up the stress removal of molecular pump turbines is a difficult problem.

[0017] (2) How to determine new test indicators and how to measure them is also a difficult problem. Summary of the invention

[0018] The purpose of the present application is to provide a molecular pump turbine stress removal test tool to address the deficiencies of the above-mentioned prior art.

[0019] Another object of the present application is to provide a method for using a molecular pump turbine stress removal test tool.

[0020] The technical solution of this application is as follows:

[0021] A molecular pump turbine stress removal test tool, comprising: a test plate, a three-way joint, a monitoring component, a vortex dry pump, and a chiller;

[0022] Wherein, the test board is arranged at the opening end of the molecular pump and connected to the housing of the molecular pump;

[0023] Among them, the monitoring components include: flow meter, vacuum gauge, turbine temperature sensor, turbine upper end surface vibration sensor, turbine lower end surface vibration sensor;

[0024] A three-way joint is connected to the test board, one end of the three-way joint is connected to the test board and communicated with the pump port of the molecular pump, and the other two ends of the three-way joint are respectively connected to a flow meter and a vacuum gauge;

[0025] The flow meter is used to control the flow rate entering the test pump;

[0026] The vacuum gauge is used to measure the air pressure at the opening of the molecular pump;

[0027] The turbine temperature sensor is used to measure the temperature of the turbine;

[0028] The turbine upper end surface vibration sensor and the turbine lower end surface vibration sensor are used to detect the vibration values ​​of the turbine upper end surface and the lower end surface respectively;

[0029] Wherein, the vortex dry pump is connected to the molecular pump, and is used to provide a starting pressure for the molecular pump;

[0030] Wherein, the chiller is connected to the molecular pump and is used to cool the molecular pump.

[0031] Furthermore, the molecular pump turbine stress removal test tooling also includes: a host computer; the flow meter, the vacuum gauge, the turbine temperature sensor, the turbine upper end surface vibration sensor, and the turbine lower end surface vibration sensor are all connected to the host computer.

[0032] Furthermore, the turbine temperature sensor is mounted on the test board.

[0033] Furthermore, the turbine upper end surface vibration sensor and the turbine lower end surface vibration sensor are respectively installed at the upper end of the pump casing of the molecular pump and the pump body purge port of the molecular pump.

[0034] Furthermore, the monitoring component also includes: a motor temperature sensor, and the motor temperature sensor is used to measure the temperature of the motor.

[0035] A method for using a molecular pump turbine stress removal test tool comprises the following steps:

[0036] S100, after the turbine assembly is completed, a dynamic balance test is performed to reduce the turbine imbalance of the molecular pump at full speed to below a predetermined value of the dynamic balance test;

[0037] S200, installing the molecular pump without the stator and the isolation ring and the aforementioned molecular pump turbine stress removal test tool;

[0038] S300, start the molecular pump turbine stress removal test tooling:

[0039] First, the air flow rate through the flow meter is 0 under initial conditions;

[0040] Then, turn on the monitoring component, chiller, and vortex dry pump. When the vacuum degree drops below 100Pa, the molecular pump is powered on and switched to full speed.

[0041] Secondly, after the molecular pump reaches full speed, adjust the flow meter so that the air flow rate increases to 500sccm;

[0042] S400, when the test conditions meet the requirements, the test time starts to be counted and the test conditions meeting the requirements are maintained for at least 24 hours; wherein the test conditions meeting the requirements include: the temperature range of the turbine is 70° C.-90° C., and the air flow rate is 500 sccm;

[0043] During S400, a balance test is performed in real time: the vibration value X of the upper end surface of the turbine and the vibration value A of the lower end surface of the turbine are monitored in real time to determine whether the balance test meets the conditions: if X or A is greater than or equal to the limit preset value, the balance is not met, the test is stopped, and the process returns to step S100; otherwise, the test is continued;

[0044] S500, determine whether stress relief meets the conditions:

[0045] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X and A are less than the long-term preset values, stress release is completed and the turbine dynamic balance is qualified;

[0046] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X or A is higher than the long-term preset value, stress release is completed and the turbine dynamic balance is unqualified, and rebalancing is required;

[0047] Otherwise, the stress is not completely released, and the process returns to step S100.

[0048] Furthermore, the preset value of the dynamic balance test for DN200 is 0.07 μm; the preset value of the dynamic balance test for DN250 is 0.10 μm; the preset value of the dynamic balance test for DN320 is 0.12 μm; and the preset value of the dynamic balance test for DN400 is 0.20 μm.

[0049] Further, the limit preset value of DN200 is 0.10 μm; the limit preset value of DN250 is 0.18 μm; the limit preset value of DN320 is 0.20 μm; and the limit preset value of DN400 is 0.25 μm.

[0050] Further, the long-term predetermined value is 0.05 μm.

[0051] The beneficial effects of this application are:

[0052] The basic inventive concept of the present application is to propose a new test index to address the problem that the stress of the molecular pump turbine is difficult to test. When the molecular pump turbine rotates at high speed, the presence of stress will cause micro-deformation of the turbine, which will cause the mass distribution of the turbine to change, and then cause the center of gravity of the turbine to deviate from the axis of rotation, causing the vibration value to change. Therefore, it is appropriate to use "the change in the vibration value of the vibration measuring point on the upper and lower end faces of the turbine" as the stress test index (i.e., judgment). Specifically, the test conditions of the test index of the present application are: (1) the turbine temperature range is 70°C-90°C for airborne vibration; (2) the air flow rate is 500sccm.

[0053] (2) This application proposes a molecular pump turbine stress removal test fixture. Its key design lies in:

[0054] 2.1, "A flow meter is set at the pump port of the molecular pump (which can control the flow rate of external gas (usually air) entering the molecular pump), and the gas impact is used to realize the vibration of the turbine, thereby eliminating the turbine stress."

[0055] 2.2, the turbine temperature is controlled by a chiller.

[0056] 2.3. Use the turbine upper end surface vibration sensor and turbine lower end surface vibration sensor to determine whether the molecular pump turbine stress relief meets the requirements.

[0057] (3) This application proposes a method for eliminating stress of a molecular pump turbine. The solution of this application is a method combining "gas impact vibration + high temperature" to eliminate the stress (i.e., internal stress) of a molecular pump turbine.

[0058] 3.1. Common ultrasonic vibrations can cause oxidation and stress noise problems in turbines. The vibration amplitude of vibration motors is generally above 0.5 mm, with poor reliability and obvious noise problems, and cannot be applied to precision equipment such as molecular pump turbines. This application proposes the gas impact vibration method for the first time.

[0059] 3.2. For most molecular pumps, the vibration value of the upper and lower surfaces of the turbine varies by less than 0.005 μm from 24 to 32 hours. Therefore, it is more reasonable to select 24 hours as the test aging time.

[0060] 3.3, It is impossible to eliminate the turbine stress problem by using gas impact vibration alone. Test 2 shows that the turbine temperature is best in the range of 70 to 90°C, and further increasing the turbine temperature is not so meaningful for the stress elimination speed.

[0061] 3.4, the stress relief judgment index is (that is, the 20-hour and 24-hour monitoring values ​​are taken as test indicators):

[0062] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X and A are less than the long-term preset values, stress release is completed and the turbine dynamic balance is qualified;

[0063] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X or A is higher than the long-term preset value, stress release is completed and the turbine dynamic balance is unqualified, and rebalancing is required;

[0064] Otherwise, the stress is not completely released and stress relief is performed again (next cycle). BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The present application is further described in detail below in conjunction with the embodiments in the accompanying drawings, but does not constitute any limitation to the present application.

[0066] Figure 1 It is a three-dimensional structural schematic diagram of the molecular pump turbine stress removal test tooling of the present application.

[0067] Figure 2 It is the variation curve of X and A of DN250 molecular pump turbine at different time.

[0068] Figure 3 This is the variation curve of X and A of DN250 molecular pump turbine at different temperatures.

[0069] The reference numerals are as follows:

[0070] Molecular pump turbine stress removal test fixture 1000; test board 100, monitoring component 200, flow meter 201, vacuum gauge 202, turbine temperature sensor 203, upper end surface vibration sensor 204, lower end surface vibration sensor 205, chiller 300, host computer 400, scroll dry pump 500;

[0071] Molecular pump 2000, turbine 2001. DETAILED DESCRIPTION

[0072] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0073] <1. Determination of test indicators and their thresholds>

[0074] For the molecular pump turbine, when the warpage value is less than "0.03" mm, the warpage value can no longer be measured. The R&D team found that when the warpage value is lower than 0.03 mm, the stress is manifested as follows: "When the molecular pump turbine rotates at high speed, the presence of stress will cause the turbine to deform, which in turn causes the mass distribution of the turbine to change, and then causes the center of gravity of the turbine to deviate from the axis of rotation, causing the vibration value to change." After a long period of research, the R&D team found that it is appropriate to use "the change in the vibration value of the vibration measuring points on the upper and lower ends of the turbine" as a stress test indicator. Specifically, the test conditions of this indicator are: (1) The turbine temperature range is 70℃-90℃ for airborne vibration; (2) The air flow rate is 500sccm.

[0075] <2. Concept of molecular pump turbine stress removal>

[0076] For this problem, vibration is also a way to remove stress, such as ultrasonic vibration, vibration motor, etc.

[0077] First, ultrasonic vibration cannot be applied to molecular pump turbines. The reasons are as follows:

[0078] (1) Ultrasonic vibration requires a medium for energy transfer, usually water or alcohol. If the turbine is at 70-90°C during the vibration process, the alcohol medium will evaporate, posing safety hazards such as combustion and explosion. Using water as a medium will also result in the residue of non-volatile substances, requiring secondary cleaning. Because the turbine is made of aluminum, using alcohol or water at high temperatures to clean it is very likely to cause oxidation problems.

[0079] (2) If protective gas is injected for protection, there will be major problems with the equipment investment cost and stress relief efficiency (generally it needs to last at least 7×24 hours, with a power of about 5Kw). The noise problem is difficult to remove using ultrasonic stress relief.

[0080] Second, vibration motors cannot be used in molecular pump turbines. The reasons are as follows:

[0081] When using a vibration motor, the vibration amplitude of the vibration motor is generally above 0.5mm, which has a good effect on removing rough stress, but a poor effect on removing stress from precision parts in the later stage. Specifically, since the vibration amplitude, acceleration and displacement values ​​of the vibration motor are generally uncontrollable, the reliability is poor, the noise problem is obvious, and the vibration generates a large area around the motor, it cannot be used in precision equipment such as molecular pump turbines.

[0082] This application adopts the method of "gas impact turbomolecular pump vibration", that is, using gas to impact the turbine to make it vibrate to remove stress. Specifically, a molecular pump turbine stress removal test fixture 1000 of this application is used for testing. Its advantages are: (1) it will not cause oxidation and other damage to the turbine; (2) the amplitude of the molecular pump turbine is maintained at the micron level under aerodynamic impact, ensuring the stress removal effect; at the same time, the amplitude and temperature of the molecular pump turbine can be adjusted by the temperature of the gas introduced, the type of gas, and the flow rate of the gas; that is, it has high robustness; (3) the aging time of the molecular pump turbine can be greatly shortened.

[0083] <3. Hardware design of a molecular pump turbine stress removal test tool>

[0084] like Figure 1 As shown, a molecular pump turbine stress removal test tool 1000 is used to perform stress testing and stress removal on a turbine 2001 of a molecular pump 2000 .

[0085] The molecular pump turbine stress removal test tool 1000 comprises:

[0086] (1) a test board 100, which is disposed at the open end of the molecular pump 2000 and connected to the housing of the molecular pump 2000, and serves as a carrier for fixing a three-way connector, a flow meter, a vacuum gauge, and a turbine temperature sensor;

[0087] (2) Monitoring component 200; the monitoring component includes: flow meter 201 (with a fine-tuning valve inside), vacuum gauge 202, turbine temperature sensor 203, turbine upper end surface vibration sensor 204, turbine lower end surface vibration sensor 205;

[0088] a. A three-way connector is connected to the test board 100; one end of the three-way connector is connected to the test board 100 and communicated with the pump port of the molecular pump 2000, and the other two ends are respectively connected to a flow meter 201 and a vacuum gauge 202;

[0089] b, flow meter 201 is used to control the flow rate into the test pump;

[0090] c, vacuum gauge 202 is used to measure the air pressure at the opening of the molecular pump;

[0091] d. The turbine temperature sensor 203 is used to measure the temperature of the turbine and the motor;

[0092] e. The turbine upper end surface vibration sensor 204 and the turbine lower end surface vibration sensor 205 are respectively installed at the upper end of the pump housing of the molecular pump 2000 and the purge port of the molecular pump 2000 to detect the vibration values ​​of the turbine upper end surface and the lower end surface;

[0093] (3) a water chiller 300, the water chiller 300 being connected to the molecular pump 2000 and used for cooling the molecular pump;

[0094] (4) a host computer 400, wherein the monitoring component 200 is connected to the host computer 400, that is, the flow meter 201, the vacuum gauge 202, the turbine temperature sensor 203, the turbine upper end surface vibration sensor 204, and the turbine lower end surface vibration sensor 205 are all connected to the host computer 400;

[0095] (5) A vortex dry pump 500 , which is connected to the molecular pump 2000 and is used to provide a starting pressure for the molecular pump 2000 .

[0096] It should also be noted that the monitoring component also includes: a motor temperature sensor, which is used to measure the temperature of the motor.

[0097] <IV. Test 1: The influence of molecular pump speed on turbine stress elimination>

[0098] The molecular pump turbine stress removal test fixture 1000 was used to conduct stress removal test on the DN250 caliber molecular pump. The DN250 caliber molecular pump was selected for test at different frequencies.

[0099] Table 1 shows the treatment results of the DN250 molecular pump.

[0100] Table 1

[0101]

[0102] From Table 1, we can see that: with the increase of turbine rotation frequency, the vibration value (i.e. amplitude value) of the upper and lower end surfaces of the turbine gradually increases. The larger the amplitude value, the more obvious the stress release. Since the full speed state of the DN250 molecular pump is 450Hz, it is easier to achieve the full speed state. Therefore, for the molecular pump turbine, the full speed state is generally directly selected to eliminate stress.

[0103] <V. Test 2: Effect of treatment time on turbine stress relief>

[0104] Record the test results of the same DN250 molecular pump under different turbine temperatures and test times.

[0105] Table 2

[0106]

[0107] From Table 2 and Figure 2It can be seen that as the molecular pump test time increases, the vibration values ​​of the upper and lower ends of the turbine are increasing. However, as time goes by, the increase in vibration value gradually slows down. The R&D team found that for most molecular pumps, the vibration value change of the upper / lower end of the turbine is less than 0.005μm in 24 to 32 hours, so it is more reasonable to choose 24 hours as the test aging time.

[0108] <6. Test 3: Effect of temperature on turbine stress relief>

[0109] The same DN250 molecular pump was selected for testing at different turbine temperatures (during the test: due to the friction between the gas and the turbine, the temperature of the turbine and the molecular pump will rise rapidly; different turbine temperatures can be achieved through a cooler).

[0110] Table 3

[0111]

[0112] As shown in Table 3 and Figure 3 It can be seen that: as the temperature of the test molecular pump turbine increases, the vibration amplitude of the upper and lower ends of the turbine will increase with the increase of temperature. However, in the range of 70 to 90°C, this increase gradually slows down. That is, above 90°, continuing to increase the turbine temperature has little effect on increasing the vibration amplitude of the turbine.

[0113] It should be noted that the molecular pumps in Tests 1, 2 and 3 are not the same molecular pump. Therefore, the vibration values ​​of the upper end surface of the turbine and the vibration values ​​of the lower end surface of the turbine corresponding to 450 Hz, 80°C and 24 hours in Tables 1, 2 and 3 are not the same.

[0114] <7. Removal method>

[0115] A method for quickly removing turbine stress of a molecular pump comprises the following steps:

[0116] S100, after the turbine is assembled, advanced dynamic balance test is performed (dynamic balance test belongs to the existing technology; dynamic balance test belongs to rough balance, and the molecular pump can run safely at high speed only after advanced dynamic balance; if it is unbalanced, the vibration value of the molecular pump is large, and the molecular pump is increased to full speed, and there is a risk of the turbine breaking the pump). By adding weight to the balance pin hole of the turbine, the turbine imbalance of the molecular pump at full speed is reduced to below the preset value of the dynamic balance test (preset value of the dynamic balance test: DN200: 0.07μm; DN250: 0.10μm; DN320: 0.12μm; DN400: 0.20μm);

[0117] S200, installing the test plate and other tools on the molecular pump without the static plate and the isolation ring;

[0118] S300, initially, the flow rate of the flow meter is set to 0, the chiller 300 is turned on, the vortex dry pump 500 is turned on, and when the vacuum degree drops below 100Pa, the molecular pump is powered on and switched to full speed;

[0119] S400, after full speed, adjust the flow meter to make the air flow rate reach 500sccm; monitor the motor temperature, turbine temperature, turbine upper end surface vibration value, turbine lower end surface vibration value and other information under the running state of the test molecular pump through the host computer;

[0120] S500, keep the motor and turbine temperatures within the temperature range after turning on the air carrier:

[0121] The temperature range of the motor is 50℃-55℃: when the motor temperature is higher than 55℃, the chiller 300 starts to work to cool the molecular pump; when it is lower than 50℃, the chiller 300 stops cooling the molecular pump and the motor heats up;

[0122] The temperature range of the turbine is between 70℃ and 90℃: when the turbine temperature is higher than 90℃, turn off the flow meter; when the turbine temperature is lower than 70℃, turn on the flow meter;

[0123] This process repeats itself to keep the motor and turbine within a reasonable temperature range.

[0124] S600, continuous treatment for 24 hours:

[0125] During this period, the vibration value X of the upper end surface of the turbine and the vibration value A of the lower end surface of the turbine are monitored in real time to determine whether the balance test meets the conditions; if the upper and lower vibration measurement point values ​​X and A are higher than the preset limit values, the test is stopped immediately and steps S100 to S600 are repeated;

[0126] Otherwise, proceed to step S700 (i.e., the balance test has always met the conditions during the 24-hour processing period);

[0127] S700, determine whether the stress relief meets the conditions:

[0128] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X and A are less than the long-term preset values, stress release is completed and the turbine dynamic balance is qualified;

[0129] If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X or A is higher than the long-term preset value, stress release is completed and the turbine dynamic balance is unqualified, and rebalancing is required;

[0130] Otherwise, the stress is not completely released, and the process returns to step S100.

[0131] It should be noted that the limit preset value is the condition for keeping the molecular pump running (exceeding this value will cause damage to the turbine): DN200: 0.10μm, DN250: 0.18μm, DN320: 0.20μm, DN400: 0.25μm.

[0132] It should be noted that the long-term preset value is the requirement for the long-term operation of the molecular pump, which is generally 0.05 μm.

[0133] The above-mentioned embodiments are preferred implementation modes of the present application and are only used to facilitate the explanation of the present application. They are not intended to limit the present application in any form. Any person with ordinary knowledge in the relevant technical field, if they do not depart from the scope of the technical features of the present application, can make equivalent embodiments by making partial changes or modifications to the technical contents disclosed in the present application and do not depart from the technical features of the present application. All of these still fall within the scope of the technical features of the present application.

Claims

1. A method for using a molecular pump turbine stress removal test tool, characterized in that: The steps include: S100, after the turbine assembly is completed, a dynamic balance test is performed to reduce the turbine imbalance of the molecular pump at full speed to below a predetermined value of the dynamic balance test; S200, installing the molecular pump without the stator and the isolation ring and the molecular pump turbine stress removal test tooling; The molecular pump turbine stress removal test tool comprises: a test board, a three-way joint, a monitoring component, a vortex dry pump, and a chiller; the test board is arranged at the open end of the molecular pump and connected to the shell of the molecular pump; wherein the monitoring component comprises: a flow meter, a vacuum gauge, a turbine temperature sensor, a turbine upper end surface vibration sensor, and a turbine lower end surface vibration sensor; a three-way joint is connected to the test board, one end of the three-way joint is connected to the test board and communicated with the pump port of the molecular pump, and the other two ends of the three-way joint are respectively connected to a flow meter and a vacuum gauge; the flow meter is used to control the flow rate entering the test pump; the vacuum gauge is used to measure the air pressure at the opening of the molecular pump; the turbine temperature sensor is used to measure the temperature of the turbine; the turbine upper end surface vibration sensor and the turbine lower end surface vibration sensor are respectively used to detect the vibration values ​​of the upper end surface and the lower end surface of the turbine; the vortex dry pump is connected to the molecular pump, which is used to provide a starting pressure for the molecular pump; the chiller is connected to the molecular pump, which is used to cool the molecular pump; S300, start the molecular pump turbine stress removal test tooling: First, the air flow rate through the flow meter is 0 under initial conditions; Then, turn on the monitoring component, chiller, and vortex dry pump. When the vacuum degree drops below 100Pa, the molecular pump is powered on and switched to full speed. Secondly, after the molecular pump reaches full speed, adjust the flow meter so that the air flow rate increases to 500sccm; S400, when the test conditions meet the requirements, the test time starts to be counted and the test conditions meeting the requirements are maintained for at least 24 hours; wherein the test conditions meeting the requirements include: the temperature range of the turbine is 70° C.-90° C., and the air flow rate is 500 sccm; During S400, a balance test is performed in real time: the vibration value X of the upper end surface of the turbine and the vibration value A of the lower end surface of the turbine are monitored in real time to determine whether the balance test meets the conditions: if X or A is greater than or equal to the limit preset value, the balance is not met, the test is stopped, and the process returns to step S100; otherwise, the test is continued; S500, determine whether stress relief meets the conditions: If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X and A are less than the long-term preset values, stress release is completed and the turbine dynamic balance is qualified; If X 24 -X 20 <0.01μm and A 24 -A 20 <0.01μm and X or A is higher than the long-term preset value, stress release is completed and the turbine dynamic balance is unqualified, and rebalancing is required; Otherwise, the stress is not completely released, and the process returns to step S100.

2. The method for using a molecular pump turbine stress removal test tool according to claim 1, characterized in that: The molecular pump turbine stress removal test tool also includes: a host computer; the flow meter, the vacuum gauge, the turbine temperature sensor, the turbine upper end surface vibration sensor, and the turbine lower end surface vibration sensor are all connected to the host computer.

3. The method for using a molecular pump turbine stress removal test tool according to claim 1, characterized in that: The turbine temperature sensor is mounted on the test board.

4. The method for using a molecular pump turbine stress removal test tool according to claim 1, characterized in that: The turbine upper end surface vibration sensor and the turbine lower end surface vibration sensor are respectively installed at the upper end of the pump casing of the molecular pump and the pump body purge port of the molecular pump.

5. The method for using a molecular pump turbine stress removal test tool according to claim 1, characterized in that: The monitoring component also includes: a motor temperature sensor, which is used to measure the temperature of the motor.

6. The method for using a molecular pump turbine stress removal test tool according to claim 1, characterized in that: The long-term preset value is 0.05 μm.

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