A method and system for obtaining the thrust bearing clearance of a main pump motor

Abstract

The present invention provides a method for obtaining the thrust bearing clearance of a main pump motor, including determining the linear regression equation between the displacement of the main pump motor rotor and the jack load based on a preset thrust bearing clearance measuring tool and combining the linear relationship between the thrust pad load and deformation; obtaining the load size less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtaining the load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and deriving the linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the upper and lower thrust pad surfaces respectively; substituting the weight of the main pump motor rotor into the above two load and displacement regression equations for calculation, and taking the positive difference between the two calculation results as the thrust bearing clearance output. The implementation of the present invention takes into account the deformation factor of the thrust pad to ensure that the measurement result is more accurate relative to the true value.

Description

Technical Field

[0001] The present invention relates to the technical field of nuclear power commissioning and maintenance, and in particular to a method and system for obtaining the clearance of a thrust bearing of a main pump motor. Background Art

[0002] The thrust bearing of the main pump motor is a bidirectional thrust bearing, and the axial thrust of each thrust bearing is borne by 8 pieces of babbitt alloy bearings installed on the support bearings, so that the thrust load is evenly distributed on each bearing. The thrust head is located between the upper and lower thrust bearings. Once the thrust head contacts one of the upper and lower thrust bearings, there will be a certain gap with the other thrust bearing, and the gap is closely related to the bearing capacity and the temperature of the bearing. Therefore, it is necessary to measure the gap when performing a full disassembly of the main pump motor during the overhaul of the unit.

[0003] The traditional method for measuring the thrust bearing clearance of the main pump motor is to take the displacement value corresponding to the load platform (such as 140 / 160kN) before and after the sudden change in rotor displacement. The difference between the two is the thrust bearing clearance. However, this method does not take into account the deformation factor of the thrust bearing, resulting in the measurement result being larger than the true value.

[0004] In view of this, it is necessary to improve the traditional method of measuring the thrust bearing clearance of the main pump motor. Summary of the invention

[0005] The technical problem to be solved by the embodiments of the present invention is to provide a method and system for obtaining the thrust bearing clearance of the main pump motor, taking into account the deformation factor of the thrust bearing to ensure that the measurement result is more accurate than the true value.

[0006] In order to solve the above technical problems, an embodiment of the present invention provides a method for obtaining the thrust bearing clearance of a main pump motor, the method comprising the following steps:

[0007] Based on the preset thrust bearing clearance measurement tooling, and in combination with the linear relationship between the thrust pad load and deformation, a linear regression equation between the displacement of the main pump motor rotor and the jack load is determined; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor;

[0008] Obtain the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtain the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and derive the determined linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface;

[0009] The weight of the main pump motor rotor is substituted into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and the difference between the two calculation results is taken as the positive output as the thrust bearing clearance.

[0010] Among them, the load and displacement regression equation when the thrust head contacts the lower thrust pad surface is based on the determined linear regression equation, and is derived by the least squares method from the load size less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor being lifted.

[0011] Among them, the load and displacement regression equation when the thrust head contacts the upper thrust pad surface is based on the determined linear regression equation, and is derived by the least squares method from the load size greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor being lifted.

[0012] Among them, the weight of the main pump motor rotor is 153kN.

[0013] Wherein, the method further comprises:

[0014] The thrust bearing clearance measuring tool is pre-installed, and the thrust bearing clearance measuring tool includes a motor frame, a channel steel, the jack, the main pump motor and 4 dial indicators; wherein,

[0015] Install a special tool for jacking the steel ball on the central screw hole of the backrest wheel of the main pump motor, and the center line of the jack should coincide with the center line of the rotor of the main pump motor;

[0016] The four dial indicators are mounted on the backrest wheel of the main pump motor and are 90 degrees apart from each other, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero.

[0017] The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and taking the average.

[0018] The embodiment of the present invention also provides a main pump motor thrust bearing clearance acquisition system, including a basic linear regression equation determination unit, an upper and lower thrust pad surface regression equation derivation unit and a thrust bearing clearance output unit; wherein,

[0019] The basic linear regression equation determination unit is used to determine the linear regression equation between the displacement of the main pump motor rotor and the jack load based on the preset thrust bearing clearance measurement tooling and in combination with the linear relationship between the thrust pad load and deformation; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor;

[0020] The upper and lower thrust pad surface regression equation derivation unit is used to obtain the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtain the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and derive the determined linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface;

[0021] The thrust bearing clearance output unit is used to substitute the weight of the main pump motor rotor into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and take the positive difference between the two calculation results as the thrust bearing clearance output.

[0022] Among them, the weight of the main pump motor rotor is 153kN.

[0023] Among them, it also includes: a preset unit; among them,

[0024] The preset unit is used to pre-install the thrust bearing clearance measuring tool, which includes a motor frame, a channel steel, the jack, the main pump motor and four dial indicators; wherein,

[0025] Install a special tool for jacking the steel ball on the central screw hole of the backrest wheel of the main pump motor, and the center line of the jack should coincide with the center line of the rotor of the main pump motor;

[0026] The four dial indicators are mounted on the backrest wheel of the main pump motor and are 90 degrees apart from each other, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero.

[0027] The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and taking the average.

[0028] Implementing the embodiments of the present invention has the following beneficial effects:

[0029] In the process of calculating the thrust bearing clearance, the present invention establishes a mathematical model (such as a linear regression equation) between the motor rotor displacement and the jack load based on the thrust bearing clearance measuring tool and in combination with the linear relationship between the thrust pad load and deformation. The load and displacement regression equations when the thrust head contacts the upper and lower thrust pad surfaces are derived by obtaining the displacement values ​​of the motor rotor under each load platform of the jack. The rotor gravity is further substituted into the two derived load and displacement regression equations to obtain the thrust bearing clearance, thereby taking into account the deformation factor of the thrust pad, so that the result is more accurate than the traditional measurement and calculation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying creative labor, other drawings obtained based on these drawings still belong to the scope of the present invention.

[0031] Figure 1 A flow chart of a method for obtaining the thrust bearing clearance of a main pump motor provided by an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of the partial structure of a thrust bearing clearance measuring tool in a method for obtaining the thrust bearing clearance of a main pump motor provided by an embodiment of the present invention;

[0033] Figure 3 A curve diagram showing the correlation between the main pump motor rotor displacement and the jack load in a main pump motor thrust bearing clearance acquisition method provided by an embodiment of the present invention;

[0034] Figure 4 A structural schematic diagram of a main pump motor thrust bearing clearance acquisition system provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings.

[0036] like Figure 1 As shown in the figure, a method for obtaining the thrust bearing clearance of a main pump motor provided by the inventor in an embodiment of the present invention comprises the following steps:

[0037] Step S1, based on the preset thrust bearing clearance measurement tooling, and in combination with the linear relationship between the thrust pad load and deformation, determine the linear regression equation between the main pump motor rotor displacement and the jack load; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor;

[0038] The specific process is as follows: before step S1, Figure 2 As shown, a thrust bearing clearance measuring tool is pre-installed, which includes a motor frame, a channel steel, a jack, a main pump motor and four dial indicators (not shown); a special tool for steel ball centering is installed on the central screw hole of the main pump motor backrest wheel, and the center line of the jack should coincide with the center line of the main pump motor rotor; four dial indicators are mounted on the main pump motor backrest wheel and are 90° apart, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero. The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and taking the average.

[0039] The inventors discovered that before traditional measurement, the weight of the main pump motor rotor is entirely borne by the lower thrust bearing, causing the lower thrust bearing to deform, and as the force on the lower thrust bearing decreases during measurement, its own deformation will decrease. Therefore, when measuring the thrust bearing clearance measurement tool, the jack applies a load to the main pump motor rotor, and part of the weight of the main pump motor rotor is borne by the jack. As the load on the jack increases, the displacement of the main pump motor rotor can be increased, thereby simulating the scenario in which the deformation of the lower thrust bearing decreases as the force decreases.

[0040] Taking into account the scenario in which the deformation of the lower thrust bearing is restored while there is a gap between the thrust head and the upper thrust bearing surface during traditional measurement, as well as the scenario in which the deformation of the upper thrust bearing surface increases due to the contact between the thrust head and the upper thrust bearing surface, the thrust bearing clearance measurement tooling is used to measure the deformation of the lower thrust bearing. The jack load is equal to the weight of the main pump motor rotor to simulate the scenario in which the deformation of the lower thrust bearing is restored. At the same time, the jack continues to increase the load to further simulate the scenario in which the gap between the thrust head and the upper thrust bearing surface causes a sudden change in displacement, as well as the scenario in which the jack load is greater than the weight of the main pump motor rotor to simulate the scenario in which the deformation of the thrust head increases due to the contact between the thrust head and the upper thrust bearing surface.

[0041] The inventors also found that the elastic modulus reflects the stiffness of the material and is a constant that measures the deformation of an object when it is subjected to force within the elastic range. Therefore, in the initial stage of stress-strain, the compression modulus of the thrust washer is a constant. The thrust washer compression modulus formula is as follows:

[0042]

[0043] Where, E is the thrust pad compression modulus, Pa; σ is stress, Pa; ε is strain; F is the thrust pad load, N; A is the total area of ​​the thrust pad, m 2 ; h is the thrust pad thickness, m; Δh is the thrust pad deformation, m.

[0044] It can be concluded that the thrust bearing load and deformation are in a linear relationship. If the deformation of the jack support is ignored, it can be concluded that the jack load and the motor rotor displacement are in a linear relationship, thus determining the linear regression equation between the main pump motor rotor displacement and the jack load, i.e., y=kx+b.

[0045] Step S2, obtaining the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtaining the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and deriving the determined linear regression equation to obtain a load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and a load and displacement regression equation when the thrust head contacts the upper thrust pad surface;

[0046] The specific process is to measure and record the displacement of the main pump motor rotor under each load platform of the jack. In one example, the displacement of the main pump motor rotor is lifted by the jack, and the loads are applied in sequence: 40-60-80-100-110-120-140-160-180-200 kN, and a relationship table between the jack load and the displacement of the main pump motor rotor is established (as shown in Table 1 below), and a load-displacement curve is drawn based on Table 1 (as shown in Table 1 below). Figure 3 shown).

[0047] Table 1

[0048]

[0049] Since the weight of the main pump motor rotor is 153kN, the load is 40kN~140kN and the corresponding y 1 ~y 7 , which corresponds to the load and displacement relationship when the thrust head contacts the lower thrust pad surface; and the load 160kN~200kN and the corresponding y 8 ~y 10 , which corresponds to the load-displacement relationship when the thrust head contacts the upper thrust pad surface.

[0050] According to the linear regression equation, the load and displacement regression equation when the thrust head contacts the lower thrust pad surface is derived as follows:

[0051] y 1 =k 1 x+b 1 (2)

[0052] in, For x 1 ~x 7 Find the average.

[0053] According to the linear regression equation, the load and displacement regression equation when the thrust head contacts the upper thrust pad surface is derived as follows:

[0054] y 2 =k 2 x+b 2 (3)

[0055] in, For x 8 ~x 10 Find the average.

[0056] It can be seen that the load and displacement regression equation when the thrust head contacts the lower thrust pad surface is derived based on the determined linear regression equation by using the least square method to derive the load size less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor;

[0057] The load and displacement regression equation when the thrust head contacts the upper thrust pad surface is derived based on the determined linear regression equation by using the least squares method to obtain the load magnitude greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor.

[0058] Step S3, substitute the weight of the main pump motor rotor into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and take the positive difference between the two calculation results as the thrust bearing clearance output.

[0059] The specific process is to substitute the weight of the main pump motor rotor into regression equations (2) and (3) to solve the thrust bearing clearance, that is, to substitute x = 153 into equations (2) and (3) respectively, and we can get y 1 ,y 2 , and |y 2 -y 1 |Output as thrust bearing clearance.

[0060] like Figure 4 As shown in the figure, a main pump motor thrust bearing clearance acquisition system is provided in an embodiment of the present invention, including a basic linear regression equation determination unit 110, an upper and lower thrust pad surface regression equation derivation unit 120 and a thrust bearing clearance output unit 130; wherein,

[0061] The basic linear regression equation determination unit 110 is used to determine the linear regression equation between the displacement of the main pump motor rotor and the jack load based on the preset thrust bearing clearance measurement tooling and in combination with the linear relationship between the thrust pad load and deformation; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor;

[0062] The upper and lower thrust pad surface regression equation derivation unit 120 is used to obtain the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and to obtain the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and to derive the determined linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface;

[0063] The thrust bearing clearance output unit 130 is used to substitute the weight of the main pump motor rotor into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and take the positive difference between the two calculation results as the thrust bearing clearance output.

[0064] Among them, the weight of the main pump motor rotor is 153kN.

[0065] Among them, it also includes: a preset unit; among them,

[0066] The preset unit is used to pre-install the thrust bearing clearance measuring tool, which includes a motor frame, a channel steel, the jack, the main pump motor and four dial indicators; wherein,

[0067] Install a special tool for jacking the steel ball on the central screw hole of the backrest wheel of the main pump motor, and the center line of the jack should coincide with the center line of the rotor of the main pump motor;

[0068] The four dial indicators are mounted on the backrest wheel of the main pump motor and are 90 degrees apart from each other, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero.

[0069] The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and taking the average.

[0070] Implementing the embodiments of the present invention has the following beneficial effects:

[0071] In the process of calculating the thrust bearing clearance, the present invention establishes a mathematical model (such as a linear regression equation) between the motor rotor displacement and the jack load based on the thrust bearing clearance measuring tool and in combination with the linear relationship between the thrust pad load and deformation. The load and displacement regression equations when the thrust head contacts the upper and lower thrust pad surfaces are derived by obtaining the displacement values ​​of the motor rotor under each load platform of the jack. The rotor gravity is further substituted into the two derived load and displacement regression equations to obtain the thrust bearing clearance, thereby taking into account the deformation factor of the thrust pad, so that the result is more accurate than the traditional measurement and calculation method.

[0072] It is worth noting that in the above system embodiment, the various units included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0073] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, CD-ROM, etc.

[0074] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for obtaining the thrust bearing clearance of a main pump motor, characterized in that: The method comprises the following steps: Based on the preset thrust bearing clearance measurement tooling, and in combination with the linear relationship between the thrust pad load and deformation, a linear regression equation between the displacement of the main pump motor rotor and the jack load is determined; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor; Obtain the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtain the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and derive the determined linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface; The weight of the main pump motor rotor is substituted into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and the difference between the two calculation results is taken as the positive output as the thrust bearing clearance.

2. The method for obtaining the thrust bearing clearance of the main pump motor according to claim 1, characterized in that: The load and displacement regression equation when the thrust head contacts the lower thrust pad surface is based on the determined linear regression equation, and is derived by the least squares method from the load size less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor being lifted.

3. The method for obtaining the thrust bearing clearance of the main pump motor according to claim 1, characterized in that: The load and displacement regression equation when the thrust head contacts the upper thrust pad surface is based on the determined linear regression equation, and is derived by the least squares method for each load applied by the jack that is greater than the weight of the main pump motor rotor and the corresponding displacement of the main pump motor rotor.

4. The method for obtaining the thrust bearing clearance of the main pump motor according to claim 1, characterized in that: The main pump motor rotor weighs 153kN.

5. The method for obtaining the thrust bearing clearance of the main pump motor according to claim 1, characterized in that: The method further comprises: The thrust bearing clearance measuring tool is pre-installed, and the thrust bearing clearance measuring tool includes a motor frame, a channel steel, the jack, the main pump motor and 4 dial indicators; wherein, Install a special tool for jacking the steel ball on the central screw hole of the backrest wheel of the main pump motor, and the center line of the jack should coincide with the center line of the rotor of the main pump motor; The four dial indicators are mounted on the backrest wheel of the main pump motor and are 90 degrees apart from each other, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero.

6. The method for obtaining the thrust bearing clearance of the main pump motor according to claim 5, characterized in that: The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and averaging them.

7. A main pump motor thrust bearing clearance acquisition system, characterized in that: It includes a basic linear regression equation determination unit, an upper and lower thrust pad surface regression equation derivation unit and a thrust bearing clearance output unit; wherein, The basic linear regression equation determination unit is used to determine the linear regression equation between the displacement of the main pump motor rotor and the jack load based on the preset thrust bearing clearance measurement tooling and in combination with the linear relationship between the thrust pad load and deformation; wherein, in the preset thrust bearing clearance measurement tooling, the jack abuts against the main pump motor rotor and bears the entire weight of the main pump motor rotor, and the jack applies a load to lift the displacement of the main pump motor rotor; The upper and lower thrust pad surface regression equation derivation unit is used to obtain the magnitude of a load less than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and obtain the magnitude of a load greater than the weight of the main pump motor rotor applied by the jack each time and the corresponding displacement of the main pump motor rotor, and derive the determined linear regression equation to obtain the load and displacement regression equation when the thrust head contacts the lower thrust pad surface, and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface; The thrust bearing clearance output unit is used to substitute the weight of the main pump motor rotor into the load and displacement regression equation when the thrust head contacts the lower thrust pad surface and the load and displacement regression equation when the thrust head contacts the upper thrust pad surface for calculation, and take the positive difference between the two calculation results as the thrust bearing clearance output.

8. The main pump motor thrust bearing clearance acquisition system according to claim 7, characterized in that: The main pump motor rotor weighs 153kN.

9. The main pump motor thrust bearing clearance acquisition system according to claim 7, characterized in that: Also includes: Preset unit; wherein, The preset unit is used to pre-install the thrust bearing clearance measuring tool, which includes a motor frame, a channel steel, the jack, the main pump motor and four dial indicators; wherein, Install a special tool for jacking the steel ball on the central screw hole of the backrest wheel of the main pump motor, and the center line of the jack should coincide with the center line of the rotor of the main pump motor; The four dial indicators are mounted on the backrest wheel of the main pump motor and are 90 degrees apart from each other, and the contact pointer contacts the plane on the back of the backrest wheel and returns to zero.

10. The main pump motor thrust bearing clearance acquisition system according to claim 9, characterized in that: The displacement of the main pump motor rotor is obtained by reading the readings of the four dial indicators and averaging them.

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