Molecular pump effective lubricating oil flow test tool, test method and early warning method

Abstract

The application discloses a kind of molecular pump effective lubricating oil flow test tool, test method and early warning method, which belongs to the field of molecular pump test, and its technical points are as follows: including: the oil lubricated molecular pump of additional oil return system, test cover;Front stage pump, oil circuit monitoring system.Oil height sensor of n oil collection groove and oil cup oil height sensor, n oil collection groove oil height sensor is respectively used to monitor the height of lubricating oil in n oil collection groove;Oil cup oil height sensor is used to monitor the oil height in oil cup.The technical scheme of the application can test the effective lubricating oil of oil lubricated molecular pump oil supply cone.

Description

Technical Field

[0001] This application relates to the field of molecular pump testing, and more specifically, to a testing fixture, testing method, and early warning method for testing the effective lubricating oil flow rate of a molecular pump. Background Technology

[0002] Currently, oil-lubricated molecular pumps generally use an oil supply cone for lubrication. Figure 1 The diagram illustrates the structure of an existing molecular pump lubricating oil supply system. The oil supply cone 101 has a vertical pipe and a lower bearing oil hole inside, while the main shaft 104 has a connected oil supply pipe and an upper bearing oil hole inside. The upper oil outlet of the oil supply cone 101 is connected to the oil supply pipe of the main shaft 104, and the lower oil inlet of the oil supply cone 101 is immersed in the lubricating fluid 102 inside the oil cup 103.

[0003] The oil supply cone 101 is connected to the main shaft 104. When the molecular pump starts, the main shaft 104 drives the oil supply cone 101 to rotate at high speed. A portion of the lubricating oil enters the vertical pipe inside the oil supply cone 101 from the lower oil inlet, and then enters the lower bearing through the lower bearing oil hole for lubrication. Another portion of the lubricating oil enters the vertical pipe inside the oil supply cone 101 from the lower oil inlet, then flows upward along the oil supply pipe of the main shaft, and then disperses the lubricating oil onto the upper bearing 106 through the upper bearing oil hole. Some of the lubricating oil dispersed onto the upper bearing 106 drips onto the lower bearing, thus assisting in the lubrication of the lower bearing 105.

[0004] In other words, the upper bearing is mainly lubricated by distributing the lubricating oil to the upper bearing through the oil supply pipe inside the spindle after the oil supply cone is applied; while the lower bearing is lubricated not only by the lower bearing oil hole on the oil supply cone, but also by the lubricating oil that overflows and drips from the upper bearing, thus achieving the purpose of lubricating the lower bearing.

[0005] For molecular pumps, the effective lubricating oil flow rate of the oil supply cone affects the performance of both the upper and lower bearings. Insufficient effective lubricating oil flow rate leads to bearing wear, while excessive effective lubricating oil flow rate increases the motor load. Therefore, there are upper and lower limits for the effective lubricating oil flow rate of the oil supply cone (provided by the bearing manufacturer).

[0006] However, current technology lacks testing fixtures for the effective lubricating oil flow rate of the oil supply cone in oil-lubricated molecular pumps. Summary of the Invention

[0007] The purpose of this application is to provide a tooling for testing the effective lubricating oil flow rate of a molecular pump, addressing the shortcomings of the prior art.

[0008] Another objective of this application is to provide a method for testing the effective lubricating oil flow rate of a molecular pump.

[0009] Another objective of this application is to provide a method for early warning of effective lubrication flow rate of oil-lubricated molecular pump bearings.

[0010] The technical solution of this application is as follows:

[0011] A molecular pump effective lubricating oil flow test fixture, comprising:

[0012] a. An oil-lubricating molecular pump is added to the oil return system, wherein the oil return system includes:

[0013] i. Guide shoulder: The guide shoulder is provided on the main shaft of the molecular pump, and the guide shoulder is located below the upper bearing; circumferential groove, guide channel, oil collection tank;

[0014] ii. Circumferential groove and guide channel: The circumferential groove and n guide channels are provided in the motor base of the molecular pump. The guide channels are connected to the circumferential groove, and the guide shoulder is inserted into the circumferential groove; where n is a natural number greater than or equal to 2.

[0015] iii. n oil collection tanks, which are placed on the base of the molecular pump; each oil collection tank is set up corresponding to each guide channel;

[0016] b. Test shroud: The test shroud is connected above the opening of the molecular pump.

[0017] c. Backing pump: The backing pump is connected to the molecular pump via a vacuum connection pipe and is used to provide the starting pressure for the molecular pump.

[0018] d, Oil circuit monitoring system, which includes: n oil collection tank oil level sensors and oil cup oil level sensor. The n oil collection tank oil level sensors are used to monitor the lubricating oil level in the n oil collection tanks respectively; the oil cup oil level sensor is used to monitor the oil level in the oil cup.

[0019] Furthermore, it also includes: e, an external oil supply system; the external oil supply system includes, in sequence, an oil storage tank, a flow meter, and an oil supply connection pipe; the oil supply connection pipe is connected to the oil container.

[0020] Furthermore, the guide shoulder adopts an inclined design with a high center and a low outer side.

[0021] Furthermore, the circumferential groove maintains a 5° angle with the horizontal plane.

[0022] Furthermore, n guide channels are evenly distributed circumferentially at intervals in the motor base.

[0023] Furthermore, n is 4, and the 4 guide channels are evenly distributed circumferentially at 90° intervals in the motor base.

[0024] Furthermore, the method for obtaining the effective lubricating oil flow rate S of the molecular pump oil supply cone for any time period t1~t2 is as follows:

[0025] t1 and t2 are the start and end times of the time, respectively;

[0026] Step 1: Obtain the volume of lubricating oil solution consumed in the oil cup during the time interval t1~t2, ΔQ.

[0027] First, obtain the lubricating oil levels h1 and h2 in the oil cup at times t1 and t2;

[0028] Secondly, based on the curve of oil height h ~ solution volume Q in the oil cup, the corresponding solution volumes Q1 and Q2 when the lubricating oil height is h1 and h2 are obtained;

[0029] Again, △Q = Q1 - Q2;

[0030] Step 2: Obtain the increase in lubricating oil volume ΔL1~ΔL in the n oil collection tanks during time intervals t1~t2. n ;

[0031] For any i-th oil collection tank, the increase in lubricating oil volume ΔL i The steps to obtain it are as follows:

[0032] First, obtain the lubricating oil height h of the i-th oil collection tank at times t1 and t2. i1 h i2 ;

[0033] Secondly, based on the lubricating oil height h in the i-th oil collection tank i The solution volume L curve yields the lubricating oil height as h. i1 h i2 The corresponding solution volume L i1 L i2 ;

[0034] Again, △L i =L i2 -L i1 ;

[0035] Step 3, solve for S: S = (△Q - △L1 - △L2 - △L3 - ... - △L n ) / (t2 -t1)。

[0036] A method for testing the effective lubricating oil flow rate of a molecular pump, wherein the aforementioned testing fixture is used to test the effective lubricating oil flow rate of the oil supply cone of the molecular pump;

[0037] Includes the following steps:

[0038] S100, add oil to the oil cup until the lubricating oil in the cup reaches the maximum oil level h. max Then, stop refueling;

[0039] S200, start the back pump to evacuate the test chamber and the internal cavity of the molecular pump;

[0040] S300, when the pressure inside the test chamber is lower than or equal to the starting pressure of the molecular pump, start the molecular pump;

[0041] S400, empty the lubricating oil from the n oil collection tanks and begin the test:

[0042] Set the molecular pump speed to the target speed, and gradually increase the lubricating oil level in the oil cup from the highest oil level h. max Reduce to the minimum oil level h in the oil cup min During this process, the lubricating oil height h-time curve of the oil cup and the lubricating oil height-time curve of the n oil collection tanks are read to obtain the effective lubricating oil flow rate S-lubricating oil height h relationship curve at the target speed.

[0043] Furthermore, by using the lubricating oil height h-time curve of the oil cup and the lubricating oil height-time curves in the n oil collection tanks, the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h of the oil cup is solved, including the following sub-steps:

[0044] S401, based on the lubricating oil height h-time curve and the lubricating oil height h-solution volume Q curve of the oil cup, the solution volume Q-time curve of the oil cup can be obtained, and thus the lubricating oil consumption volume Q of the oil cup can be obtained. 耗 -Time curve:

[0045] The height h of the lubricating oil in the oil cup max The corresponding solution volume in the oil cup is Q. max The volume of lubricating oil consumed by the oil cup at any time t, Q 耗t =Q max -Q t Q t Let be the volume of the solution in the oil cup at time t;

[0046] S402, based on the lubricating oil height h of any i-th oil collection tank i ~Time curve and the corresponding lubricating oil height h in the oil collection tank i ~ solution volume (L) i The curve can be used to obtain the volume L of lubricating oil collected in any i-th oil collection tank. i ~Time curve;

[0047] S403, solve for the effective lubricating oil consumption volume Q. 有效耗-Time curve;

[0048] The effective lubricating oil consumption volume Q at time t 有效耗t =Q 耗t -L 1t -L 2t -L 3t -L 4t ;

[0049] Q 耗t The volume of lubricating oil consumed by the oil cup is Q. 耗 - The volume of lubricating oil consumed at time t in the time curve;

[0050] L it The volume L of lubricating oil collected in the i-th oil collection tank i ~The volume of lubricating oil at time t in the time curve;

[0051] S404, based on effective lubricant consumption volume Q 有效耗 -The time curve can obtain the effective lubricating oil flow rate S-time curve;

[0052] S405, based on the effective lubricating oil flow rate S-time curve and the lubricating oil height h-time curve of the oil cup, obtain the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h of the oil cup.

[0053] Furthermore, S200 also includes: an external oil supply system connected to the oil cup via a bottom oil tank cover, with an O-ring sealing the connection; lubricating oil is added to the oil cup via the external oil supply system until the lubricating oil in the oil cup reaches the maximum oil level h. max Then, stop refueling and turn off the switch on the fuel supply connection pipe.

[0054] A method for early warning of effective lubrication flow rate of an oil-lubricated molecular pump bearing, comprising the following steps:

[0055] Step 1, obtain the molecular pump speed P - lower limit value of the lubricating oil level warning [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 ]curve;

[0056] Using (P1, [h 1-下限 ] ), ... (P j 、[h j-下限 ] ), ... (P m 、[h m-下限 Establish a lower limit value for early warning of molecular pump speed P-oil cup lubricating oil level [h]. 下限 ]curve;

[0057] Using (P1, [h 1-上限] ), ... (P j 、[h j-上限 ] ), ... (P m 、[h m-上限 Establish an upper limit value for the warning of molecular pump speed P-oil cup lubricating oil level [h]. 上限 ]curve;

[0058] Among them, P j It is the i-th rotational speed value, [h j-下限 ]、[h j-上限 [These are P] i The corresponding effective lubricating oil flow rate threshold lower limit [S] 下限 ], upper limit value [S 上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 ];

[0059] Step 2, during the operation of the molecular pump, perform real-time early warning analysis: the real-time operating speed of the molecular pump is recorded as k, and the real-time lubricating oil level in the oil cup is recorded as o. Then, determine whether to issue an early warning according to the following method.

[0060] The lower limit of the warning value based on the molecular pump speed P and the lubricating oil level in the oil cup [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curve determines the lower limit of the lubricating oil level warning value in the oil cup when the molecular pump operates at speed k. k下限 ], upper limit of lubricating oil level warning value in oil cup [h k上限 ];

[0061] If o is greater than [h] k下限 And less than [h] k上限 If the condition is as described above, no warning will be issued.

[0062] Otherwise, issue a warning.

[0063] Furthermore, Step 1 also includes the following sub-steps:

[0064] Step 1-1: Using the aforementioned test method, obtain the relationship curves of effective lubricating oil flow rate S-lubricating oil height h of the oil-lubricated molecular pump at m different speeds.

[0065] Step 1-2, determine the lower limit of the effective lubricating oil flow rate threshold [S] at m different speeds. 下限 ], upper limit value [S 上限 The corresponding lower and upper limits for the lubricating oil level in the oil cup;

[0066] Where, for any i-th rotational speed P i Lower limit of effective lubricating oil flow rate threshold [S]下限 ], upper limit value [S 上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 The method for determining ] is:

[0067] The i-th rotational speed P i The effective lubricating oil flow rate S-lubricating oil height h in the oil cup is shown in the curve. The maximum value of S is denoted as S0. max The minimum value is denoted as S. min ;

[0068] For [h] i-上限 Regarding:

[0069] If S max ≥[S 上限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 上限 The corresponding h value is [h] i-上限 ];

[0070] If S max Less than [S] 上限 ], then [h i-上限 ]=h max ;

[0071] For [h] i-下限 Regarding:

[0072] If S min Less than or equal to [S] 下限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 下限 The corresponding h value is [h] i-下限 ];

[0073] If S min Greater than [S] 下限 ], then [h i-下限 ]= h min ;

[0074] Among them, h max h min These represent the highest and lowest levels of oil in the oil cup, respectively.

[0075] The beneficial effects of this application are as follows:

[0076] (1) This application develops a testing fixture for the effective lubricating oil flow rate of the oil supply cone of an oil-lubricated molecular pump. First, the effective lubricating oil of the oil supply cone of the oil-lubricated molecular pump was analyzed. That is, it was first recognized that when testing the lubricating oil of the upper bearing, the above-mentioned overflow problem needs to be taken into account.

[0077] Based on this, a testing fixture was proposed. Its necessary components include:

[0078] a. An oil-lubricated molecular pump with an added oil return system (the test fixture in this application is an oil-lubricated molecular pump), the oil return system comprising:

[0079] i. Guide shoulder: The guide shoulder is provided on the main shaft of the molecular pump, and the guide shoulder is located below the upper bearing; circumferential groove, guide channel, oil collection tank;

[0080] ii. Circumferential groove and guide channel: The circumferential groove and n guide channels are provided in the motor base of the molecular pump. The guide channels are connected to the circumferential groove, and the guide shoulder is inserted into the circumferential groove; where n is a natural number greater than or equal to 2.

[0081] iii. n oil collection tanks, which are placed on the base of the molecular pump; each oil collection tank is set up corresponding to each guide channel;

[0082] b. Test shroud: The test shroud is connected above the opening of the molecular pump.

[0083] c. Backing pump: The backing pump is connected to the molecular pump via a vacuum connection pipe and is used to provide the starting pressure for the molecular pump.

[0084] d, Oil circuit monitoring system, which includes: n oil collection tank oil level sensors and oil cup oil level sensor. The n oil collection tank oil level sensors are used to monitor the lubricating oil level in the n oil collection tanks respectively; the oil cup oil level sensor is used to monitor the oil level in the oil cup.

[0085] (2) This application proposes a method for testing the effective lubricating oil flow rate of a molecular pump's oil supply cone. The goal is to obtain the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h in the oil cup at a target rotational speed. This includes the following sub-steps:

[0086] a. Based on the lubricating oil height h-time curve and the lubricating oil height h-solution volume Q curve in the oil cup, the solution volume Q-time curve in the oil cup can be obtained, and thus the lubricating oil consumption volume Q in the oil cup can be obtained. 耗 -Time curve:

[0087] b, based on the lubricating oil height h of any i-th oil collection tank i ~Time curve and the corresponding lubricating oil height h in the oil collection tank i ~ solution volume (L) i The curve can be used to obtain the volume L of lubricating oil collected in any i-th oil collection tank. i ~Time curve;

[0088] c, Solve for the effective lubricating oil consumption volume Q有效耗 -Time curve;

[0089] The effective lubricating oil consumption volume Q at time t 有效耗t =Q 耗t -L 1t -L 2t -L 3t -L 4t ;

[0090] Q 耗t The volume of lubricating oil consumed by the oil cup is Q. 耗 - The volume of lubricating oil consumed at time t in the time curve;

[0091] L it The volume L of lubricating oil collected in the i-th oil collection tank i ~The volume of lubricating oil at time t in the time curve;

[0092] d, based on the effective lubricant consumption volume Q 有效耗 -The time curve can obtain the effective lubricating oil flow rate S-time curve;

[0093] e. Based on the effective lubricating oil flow rate S-time curve and the lubricating oil height h-time curve of the oil cup, obtain the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h of the oil cup.

[0094] (3) This application proposes a method for early warning of effective lubrication flow rate of oil-lubricated molecular pump bearings. When the molecular pump model and lubricating oil type are determined, the effective lubrication flow rate of oil-lubricated molecular pump bearings is affected by two factors: the molecular pump speed and the lubricating oil level in the oil cup.

[0095] This application first obtains the relationship curves between the effective lubricating oil flow rate S and the lubricating oil level h at different speeds of the molecular pump using a testing method. Then, it obtains the lower warning limit value [h] between the molecular pump speed P and the lubricating oil level h. 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 ]curve.

[0096] The lower limit of the warning value based on the molecular pump speed P and the lubricating oil level in the oil cup [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curve determines the lower limit of the lubricating oil level warning value in the oil cup when the molecular pump operates at speed k. k下限 ], upper limit of lubricating oil level warning value in oil cup [h k上限 ].

[0097] Finally, the warning logic condition is determined: if o is greater than [h] k下限 And less than [h] k上限If the condition is met, no warning will be issued; otherwise, a warning will be issued. Attached Figure Description

[0098] The present application will be further described in detail below with reference to the embodiments in the accompanying drawings, but this does not constitute any limitation on the present application.

[0099] Figure 1 This is a structural diagram of an existing molecular pump oil supply system.

[0100] Figure 2 This is a schematic diagram of the improved molecular pump structure of this application.

[0101] Figure 3 This is a schematic diagram of the improved molecular pump of this application from another perspective.

[0102] Figure 4 This is a schematic diagram of the main shaft and guide shoulder of this application.

[0103] Figure 5 This is a design schematic diagram of the circumferential groove and the guide channel of this application.

[0104] Figure 6 This is a schematic diagram of the lubricant flowing into the lower bearing according to this application.

[0105] Figure 7 This is a schematic diagram of the lubricant flowing into the upper bearing according to this application.

[0106] Figure 8 This is a three-dimensional design schematic diagram of a tooling for testing the effective lubricating oil flow rate of a molecular pump oil supply cone according to this application.

[0107] The attached figures are labeled as follows:

[0108] Oil supply cone 101, lubricant 102, oil cup 103, main shaft 104, lower bearing 105, upper bearing 106, motor base 107;

[0109] Oil return system 200, guide shoulder 201, circumferential groove 202, guide channel 203, oil collection tank 204;

[0110] External oil supply system 300. Detailed Implementation

[0111] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0112] <Basic Understanding of Research and Development>

[0113] First, identify the flow composition of the upper and lower bearings.

[0114] (1) Due to the large linear velocity of the upper bearing and the fact that the lubricating oil is directly discharged from the oil supply hole of the upper bearing on the spindle, there will be a problem of lubricating oil overflowing and dripping (i.e., lubricating oil will fall from the contact surface between the spindle and the upper bearing). The overflowing lubricating oil does not participate in the lubrication of the upper bearing. Therefore, when considering testing the lubricating oil of the upper bearing, the above-mentioned overflow problem needs to be taken into account.

[0115] (2) For the lower bearing, the lubricating oil is supplied directly through the oil supply hole on the oil supply cone, which can accurately throw the oil to the lower bearing, and there is no need to consider the problem of overflow and dripping.

[0116] Second, determine the composition of the lubricating oil in the oil supply cone.

[0117] The lubricating oil is divided into three parts: the lubricating oil that enters the upper bearing, the lubricating oil that enters the lower bearing, and the lubricating oil that overflows from the upper bearing. For the R&D team, the lubricating oil flow rate of the oil supply cone needs to know the amount of lubricating oil entering the upper bearing and the lubricating oil entering the lower bearing, as these two parts are the oil quantities that directly participate in the lubrication of the bearings.

[0118] <Example 1: A Fixture for Testing Effective Lubricating Oil Flow Rate of a Molecular Pump Supply Cone>

[0119] Figure 2 and Figure 8 The three-dimensional structure of a molecular pump oil supply cone effective lubricating oil flow test fixture is illustrated from different angles. The fixture includes:

[0120] a. Add a molecular pump to the oil return system 200. Figure 2 , Figure 3 The improved molecular pump structure is illustrated from different angles. Existing molecular pumps, in order to ensure reliable lubrication of the upper and lower bearings, tend to provide sufficient lubricating oil to both. Specifically, for the lower bearing, lubrication partly relies on lubricating fluid overflowing from the upper bearing and dripping down to it.

[0121] Therefore, the following improvements need to be made to the molecular pump:

[0122] a.1, A guide shoulder 201 is added to the main shaft 104. For example... Figure 4 As shown, a guide shoulder 201 is provided on the outside of the molecular pump main shaft: the guide shoulder 201 is located below the upper bearing, and the guide shoulder 201 adopts an inclined design with the center higher and the outside lower.

[0123] a.2, the motor mount 107 is augmented with a circumferential groove 202 and four guide channels 203. For example... Figure 5 As shown, the guide channel 203 is connected to the circumferential groove 202. A circumferential groove 202 is provided in the motor base 107, and the guide shoulder 201 is inserted into the circumferential groove 202. Four guide channels 203 are evenly distributed circumferentially in the motor base 107 at 90° intervals.

[0124] a.3, Four oil collection tanks 204 are placed on the base. Each oil collection tank 204 is corresponding to each guide channel 203.

[0125] The aforementioned guide shoulder 201, circumferential groove 202, four guide channels 203, and oil collection tank 204 together constitute the oil return system.

[0126] Figure 6 and Figure 7 The diagrams illustrate the flow direction of the lubricating fluid in the lower and upper bearings. Lubricating fluid overflowing from the upper bearing falls onto the guide shoulder 201 and then enters the circumferential groove 202. The circumferential groove 202 maintains a 5° angle with the horizontal plane to ensure that the oil introduced into the circumferential groove 202 is effectively guided by gravity to the oil guide channel 203 in the motor housing. It then flows along the oil guide channel into the dedicated oil collection tank 204 below.

[0127] b, Test cover ( Figure 8 (Not shown in the image). A test chamber is connected above the opening of the molecular pump. A compound vacuum gauge is mounted on the test chamber to detect the pressure inside.

[0128] c, back pump ( Figure 8 (Not shown in the image). The backing pump is connected to the molecular pump via a vacuum connection pipe and is used to provide the starting pressure for the molecular pump.

[0129] e. Oil level monitoring sensors are placed in the four oil collection tanks 204 to measure the lubricating oil level in the oil collection tanks 204.

[0130] f. External oil supply system 300. The external oil supply system 300 includes: an oil storage tank, a flow meter, and oil supply connection pipes ( Figure 8 (Only the oil supply connection pipe is shown in the diagram). The oil supply connection pipe is connected to the oil container. A switch valve is installed on the oil supply connection pipe to open / close the connection between the oil supply connection pipe and the oil container.

[0131] The method for obtaining the effective lubricating oil flow rate S of the molecular pump supply cone for any time period t1~t2 is as follows:

[0132] t1 and t2 are the start and end times of the time, respectively;

[0133] Step 1: Obtain the volume of lubricating oil solution consumed in the oil cup during the time interval t1~t2, ΔQ.

[0134] First, obtain the lubricating oil levels h1 and h2 in the oil cup at times t1 and t2;

[0135] Secondly, based on the oil height h ~ solution volume Q curve of the oil cup (this curve can be calibrated and obtained before the test), the corresponding solution volumes Q1 and Q2 when the lubricating oil height is h1 and h2 are obtained;

[0136] Again, △Q = Q1 - Q2;

[0137] Step 2: Obtain the increase in lubricating oil volume ΔL1~ΔL4 in the four oil collection tanks during the time interval t1~t2;

[0138] For any i-th oil collection tank, the increase in lubricating oil volume ΔL i The steps to obtain it are as follows:

[0139] First, obtain the lubricating oil height h of the i-th oil collection tank at times t1 and t2. i1 h i2 ;

[0140] Secondly, based on the lubricating oil height h in the i-th oil collection tank i The solution volume L curve (this curve can be obtained through calibration before testing) yields the lubricating oil height as h. i1 h i2 The corresponding solution volume L i1 L i2 ;

[0141] Again, △L i =L i2 -L i1 ;

[0142] Step 3, solve for S: S = (△Q - △L1 - △L2 - △L3 - △L4) / (t2 - t1).

[0143] It should be noted that the model numbers for the test shroud and the backing pump can be found in CN118499268B, and will not be repeated here.

[0144] <Example 2: A Method for Testing the Effective Lubricating Oil Flow Rate of a Molecular Pump Supply Cone>

[0145] Given a fixed type of lubricating oil and a fixed supply cone size, the effective lubricating oil flow rate of the molecular pump supply cone is mainly affected by the molecular pump speed and the height in the oil cup.

[0146] A method for testing the effective lubricating oil flow rate of a molecular pump's oil supply cone includes:

[0147] S100, with an added oil return system on the molecular pump;

[0148] S200, a test hood is installed above the opening of the molecular pump, and the backing pump is connected to the molecular pump through a vacuum connection pipe;

[0149] In the S300, the external oil supply system connects to the oil cup via the bottom oil tank cover, and an O-ring is used to seal the connection. Lubricating oil is added to the oil cup via the external oil supply system. Once the lubricating oil in the oil cup reaches the target height (h... max Stop refueling and turn off the switch of the fuel supply connection pipe to ensure that the oil cup becomes an independent fuel supply source during the operation of the molecular pump;

[0150] S400, start the back pump to evacuate the test chamber and the internal cavity of the molecular pump;

[0151] S500, when the pressure inside the test chamber is lower than or equal to the starting pressure of the molecular pump, start the molecular pump;

[0152] S600, empty the lubricating oil from the oil collection tank and begin testing: Set the molecular pump speed to the target speed, and gradually increase the lubricating oil level in the oil cup from h. max Reduce to h min During this process, the lubricating oil height h-time curve of the oil cup and the lubricating oil height-time curve of the four oil collection tanks are read to obtain the effective lubricating oil flow rate S-lubricating oil height h relationship curve.

[0153] It includes the following sub-steps:

[0154] S601, based on the lubricating oil height h-time curve and the lubricating oil height h-solution volume Q curve of the oil cup, the solution volume Q-time curve of the oil cup can be obtained, and thus the lubricating oil consumption volume Q of the oil cup can be obtained. 耗 -Time curve:

[0155] The height h of the lubricating oil in the oil cup max The corresponding solution volume in the oil cup is Q. max The volume of lubricating oil consumed by the oil cup at any time t, Q 耗t =Q max -Q t Q t Let be the volume of the solution in the oil cup at time t;

[0156] S602, based on the lubricating oil height h of any i-th oil collection tank i ~Time curve and the corresponding lubricating oil height h in the oil collection tank i ~ solution volume (L) iThe curve can be used to obtain the volume L of lubricating oil collected in any i-th oil collection tank. i ~Time curve;

[0157] S603, solve for the effective lubricating oil consumption volume Q. 有效耗 -Time curve;

[0158] The effective lubricating oil consumption volume Q at time t 有效耗t =Q 耗t -L 1t -L 2t -L 3t -L 4t ;

[0159] Q 耗t The volume of lubricating oil consumed by the oil cup is Q. 耗 - The volume of lubricating oil consumed at time t in the time curve;

[0160] L it The volume L of lubricating oil collected in the i-th oil collection tank i ~The volume of lubricating oil at time t in the time curve;

[0161] That is, the effective lubricant consumption volume Q 有效耗 - The time-t curve represents the volume of lubricating oil consumed, Q, in the oil cup. 耗 - Subtract the lubricating oil volume (L) collected in the four oil collection tanks from the time curve. i ~Time curve;

[0162] S604, based on S603, effective lubricant consumption volume Q 有效耗 -The time curve can obtain the effective lubricating oil flow rate S-time curve;

[0163] Effective lubricating oil flow rate S=dQ 有效耗 / dt;

[0164] The S-time curve can be obtained using the finite difference method, i.e., the effective lubricating oil flow rate S at time t. t = (Q) 有效耗t -Q 有效耗t-△t ) / △t;Q 有效耗t Q 有效耗t-△t These are the effective lubricating oil consumption volumes at times t and t-Δt, respectively.

[0165] S605, based on the effective lubricating oil flow rate S-time curve and the lubricating oil height h-time curve of the oil cup, obtain the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h of the oil cup.

[0166] <Example 3: A Method for Early Warning of Effective Lubricating Oil Quantity in Oil-Lubricated Molecular Pump Bearings>

[0167] A method for early warning of effective lubrication flow rate of an oil-lubricated molecular pump bearing, comprising the following steps:

[0168] Step 1, establish the lower limit value for the warning of molecular pump speed P-oil cup lubricating oil level [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 ]curve;

[0169] Using (P1, [h 1-下限 ] ), ... (P j 、[h j-下限 ] ), ... (P m 、[h m-下限 Establish a lower limit value for early warning of molecular pump speed P-oil cup lubricating oil level [h]. 下限 ]curve;

[0170] Using (P1, [h 1-上限 ] ), ... (P j 、[h j-上限 ] ), ... (P m 、[h m-上限 Establish an upper limit value for the warning of molecular pump speed P-oil cup lubricating oil level [h]. 上限 ]curve;

[0171] Among them, P j It is the i-th rotational speed value, [h j-下限 ]、[h j-上限 [These are P] i The corresponding effective lubricating oil flow rate threshold lower limit [S] 下限 ], upper limit value [S 上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 ];

[0172] It includes the following sub-steps:

[0173] Step 1-1: Using the aforementioned test method, obtain the relationship curves of effective lubricating oil flow rate S-lubricating oil height h of the oil-lubricated molecular pump at m different speeds.

[0174] Step 1-2, determine the lower limit of the effective lubricating oil flow rate threshold [S] at m different speeds. 下限 ], upper limit value [S 上限 The corresponding lower and upper limits for the lubricating oil level in the oil cup;

[0175] Where, for any i-th rotational speed P i Lower limit of effective lubricating oil flow rate threshold [S] 下限 ], upper limit value [S上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 The method for determining ] is:

[0176] The i-th rotational speed P i The effective lubricating oil flow rate S-lubricating oil height h in the oil cup is shown in the curve. The maximum value of S is denoted as S0. max The minimum value is denoted as S. min ;

[0177] For [h] i-上限 Regarding:

[0178] If S max ≥[S 上限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 上限 The corresponding h value is [h] i-上限 ];

[0179] If S max Less than [S] 上限 ], then [h i-上限 ]=h max ;

[0180] For [h] i-下限 Regarding:

[0181] If S min Less than or equal to [S] 下限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 下限 The corresponding h value is [h] i-下限 ];

[0182] If S min Greater than [S] 下限 ], then [h i-下限 ]= h min ;

[0183] The significance of the above limitation is that, for the effective lubricating oil flow rate S, S increases with increasing rotational speed and decreases with decreasing h. Therefore, it is possible that: S max Less than [S] 上限 ]、S min Greater than [S] 下限 In the case of ], the direct limitation is: [h i-上限 ]=h max 、[h i-下限 ]= h min It is feasible. Because, for an oil cup, the oil level is limited to h. min ~h max middle;

[0184] Step 2, during the operation of the molecular pump, perform real-time early warning analysis: the real-time operating speed of the molecular pump is recorded as k, and the real-time lubricating oil level in the oil cup is recorded as o. Then, determine whether to issue an early warning according to the following method.

[0185] The lower limit of the warning value based on the molecular pump speed P and the lubricating oil level in the oil cup [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curve determines the lower limit of the lubricating oil level warning value in the oil cup when the molecular pump operates at speed k. k下限 ], upper limit of lubricating oil level warning value in oil cup [h k上限 ];

[0186] If o is greater than [h] k下限 And o is less than [h] k上限 If the condition is as described above, no warning will be issued.

[0187] Otherwise, issue a warning.

[0188] It should be noted that, in a method for early warning of effective lubricating oil quantity in an oil-lubricated molecular pump bearing, during normal operation of the oil-lubricated molecular pump, the established warning lower limit value [h] is based on the molecular pump speed P - oil cup lubricating oil level. 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curve was obtained when the model of the oil-lubricated molecular pump and the lubricating oil were the same as those being used. That is, the established lower limit warning value for the molecular pump speed P and the lubricating oil level in the oil cup [h] is... 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curves are all directly related to the molecular pump model and the type of lubricating oil.

[0189] The above-described embodiments are preferred embodiments of this application and are only used to facilitate the illustration of this application. They are not intended to limit this application in any way. Any person with ordinary knowledge in the art can make equivalent embodiments by making partial modifications or alterations to the technical content disclosed in this application without departing from the scope of the technical features of this application. Such equivalent embodiments are still within the scope of the technical features of this application.

Claims

1. A fixture for testing the effective lubricating oil flow rate of a molecular pump, characterized in that, include: a. An oil-lubricating molecular pump is added to the oil return system, wherein the oil return system includes: i. Guide shoulder: The guide shoulder is provided on the main shaft of the molecular pump, and the guide shoulder is located below the upper bearing; circumferential groove, guide channel, oil collection tank; ii. Circumferential groove and guide channel: The circumferential groove and n guide channels are provided in the motor base of the molecular pump. The guide channels are connected to the circumferential groove, and the guide shoulder is inserted into the circumferential groove; where n is a natural number greater than or equal to 2. iii. n oil collection tanks, which are placed on the base of the molecular pump; each oil collection tank is set up corresponding to each guide channel; b. Test shroud: The test shroud is connected above the opening of the molecular pump. c. Backing pump: The backing pump is connected to the molecular pump via a vacuum connection pipe and is used to provide the starting pressure for the molecular pump. d, Oil circuit monitoring system, which includes: n oil collection tank oil level sensors and oil cup oil level sensor. The n oil collection tank oil level sensors are used to monitor the lubricating oil level in the n oil collection tanks respectively; the oil cup oil level sensor is used to monitor the oil level in the oil cup.

2. The molecular pump effective lubricating oil flow test fixture according to claim 1, characterized in that, Also includes: e. External oil supply system; the external oil supply system includes the following components connected in sequence: oil storage tank, flow meter, and oil supply connection pipeline; The oil supply connection pipe is connected to the oil cup.

3. The molecular pump effective lubricating oil flow test fixture according to claim 1, characterized in that, The guide shoulder adopts an inclined design with a high center and a low outer side.

4. The molecular pump effective lubricating oil flow test fixture according to claim 1, characterized in that, The circumferential groove maintains a 5° angle with the horizontal plane.

5. The molecular pump effective lubricating oil flow test fixture according to claim 1, characterized in that, n guide channels are evenly distributed circumferentially at intervals in the motor base.

6. The molecular pump effective lubricating oil flow test fixture according to claim 1, characterized in that, n is 4, and the 4 guide channels are evenly distributed circumferentially at 90° intervals in the motor base.

7. A method for testing the effective lubricating oil flow rate of a molecular pump, characterized in that, The effective lubricating oil flow rate of the molecular pump oil supply cone was tested using the test fixture described in claim 1. Includes the following steps: S100, add oil to the oil cup until the lubricating oil in the cup reaches the maximum oil level h. max Then, stop refueling; S200, start the back pump to evacuate the test chamber and the internal cavity of the molecular pump; S300, when the pressure inside the test chamber is lower than or equal to the starting pressure of the molecular pump, start the molecular pump; S400, empty the lubricating oil from the n oil collection tanks and begin the test: Set the molecular pump speed to the target speed, and gradually increase the lubricating oil level in the oil cup from the highest oil level h. max Reduce to the minimum oil level h in the oil container min During this process, the lubricating oil height h-time curve of the oil cup and the lubricating oil height-time curve of the n oil collection tanks are read to obtain the effective lubricating oil flow rate S-lubricating oil height h relationship curve at the target speed.

8. The method for testing the effective lubricating oil flow rate of a molecular pump according to claim 7, characterized in that, By using the lubricating oil height h-time curve in the oil cup and the lubricating oil height-time curves in n oil collection tanks, the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h in the oil cup is solved, including the following sub-steps: S401, based on the lubricating oil height h-time curve and the lubricating oil height h-solution volume Q curve of the oil cup, the solution volume Q-time curve of the oil cup can be obtained, and thus the lubricating oil consumption volume Q of the oil cup can be obtained. 耗 -Time curve: The height h of the lubricating oil in the oil cup max The corresponding solution volume in the oil cup is Q. max The volume of lubricating oil consumed by the oil cup at any time t, Q 耗t =Q max -Q t Q t Let be the volume of the solution in the oil cup at time t; S402, based on the lubricating oil height h of any i-th oil collection tank i ~Time curve and the corresponding lubricating oil height h in the oil collection tank i ~ solution volume (L) i The curve can be used to obtain the volume L of lubricating oil collected in any i-th oil collection tank. i ~Time curve; S403, solve for the effective lubricating oil consumption volume Q. 有效耗 -Time curve; The effective lubricating oil consumption volume Q at time t 有效耗t =Q 耗t -L 1t -L 2t -L 3t -L 4t ; Q 耗t The volume of lubricating oil consumed by the oil cup is Q. 耗 - The volume of lubricating oil consumed at time t in the time curve; L it The volume L of lubricating oil collected in the i-th oil collection tank i ~The volume of lubricating oil at time t in the time curve; S404, based on effective lubricant consumption volume Q 有效耗 -The time curve can obtain the effective lubricating oil flow rate S-time curve; S405, based on the effective lubricating oil flow rate S-time curve and the lubricating oil height h-time curve of the oil cup, obtain the relationship curve between the effective lubricating oil flow rate S and the lubricating oil height h of the oil cup.

9. A method for early warning of effective lubrication flow rate of an oil-lubricated molecular pump bearing, characterized in that, The method of using the test fixture described in claim 1 to provide early warning of the effective lubrication flow rate of an oil-lubricated molecular pump bearing includes the following steps: Step 1, obtain the molecular pump speed P - lower limit value of the lubricating oil level warning [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 ]curve; Using (P1, [h 1-下限 ] ), ... (P j 、[h j-下限 ] ), ... (P m 、[h m-下限 Establish a lower limit value for early warning of molecular pump speed P-oil cup lubricating oil level [h]. 下限 ]curve; Using (P1, [h 1-上限 ] ), ... (P j 、[h j-上限 ] ), ... (P m 、[h m-上限 Establish an upper limit value for the warning of molecular pump speed P-oil cup lubricating oil level [h]. 上限 ]curve; Among them, P j It is the i-th rotational speed value, [h j-下限 ]、[h j-上限 [These are P] i The corresponding effective lubricating oil flow rate threshold lower limit [S] 下限 ], upper limit value [S 上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 ]; Step 2, during the operation of the molecular pump, perform real-time early warning analysis: the real-time operating speed of the molecular pump is recorded as k, and the real-time lubricating oil level in the oil cup is recorded as o. Then, determine whether to issue an early warning according to the following method. The lower limit of the warning value based on the molecular pump speed P and the lubricating oil level in the oil cup [h] 下限 The curve and the upper limit of the warning value for the molecular pump speed P-oil cup lubricating oil level [h] 上限 The curve determines the lower limit of the lubricating oil level warning value in the oil cup when the molecular pump operates at speed k. k下限 ], upper limit of lubricating oil level warning value in oil cup [h k上限 ]; If o is greater than [h] k下限 And less than [h] k上限 If the condition is as described above, no warning will be issued. Otherwise, issue a warning.

10. The method for early warning of effective lubrication flow rate of an oil-lubricated molecular pump bearing according to claim 9, characterized in that, Step 1 also includes the following sub-steps: Step 1-1: Obtain the relationship curves between the effective lubricating oil flow rate S and the lubricating oil height h of the oil-lubricated molecular pump at m different speeds; Step 1-2, determine the lower limit of the effective lubricating oil flow rate threshold [S] at m different speeds. 下限 ], upper limit value [S 上限 The corresponding lower and upper limits for the lubricating oil level in the oil cup; Where, for any i-th rotational speed P i Lower limit of effective lubricating oil flow rate threshold [S] 下限 ], upper limit value [S 上限 The corresponding lower limit value of lubricating oil level in the oil cup [h] i-下限 ], upper limit value [h i-上限 The method for determining ] is: The i-th rotational speed P i The effective lubricating oil flow rate S-lubricating oil height h in the oil cup is shown in the curve. The maximum value of S is denoted as S0. max The minimum value is denoted as S. min ; For [h] i-上限 Regarding: If S max ≥[S 上限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 上限 The corresponding h value is [h] i-上限 ]; If S max Less than [S] 上限 ], then [h i-上限 ]=h max ; For [h] i-下限 Regarding: If S min Less than or equal to [S] 下限 In the effective lubricating oil flow rate S-lubricating oil height h relationship curve, S is selected as [S]. 下限 The corresponding h value is [h] i-下限 ]; If S min Greater than [S] 下限 ], then [h i-下限 ]= h min ; Among them, h max h min These represent the highest and lowest levels of oil in the oil cup, respectively.

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