A method for evaluating the radial roller bearing condition of a tunnel boring machine main bearing

Abstract

This invention discloses a method for evaluating the load-bearing state of radial rollers in a tunnel boring machine (TBM) main bearing. Based on the crowning characteristics of the radial rollers in the TBM main bearing, this invention determines the roller crowning clearance, establishes and solves static equilibrium equations, overturning moment equilibrium equations, and radial displacement relationship equations. By summing the radial displacement values, the contact deformation of the rollers in the bearing is obtained. The radial displacement records of the rollers in the bearing are measured under actual radial force and overturning moment conditions. The load-bearing state of the rollers is evaluated by comparing the magnitudes of the roller contact deformation and radial displacement records. This evaluation method can more accurately detect the specific locations of potential risks inside the bearing, providing technical guidance for the monitoring and diagnosis of bearing rollers and ensuring the operation and maintenance of TBM bearings.

Description

Technical Field

[0001] This invention belongs to the field of bearing performance testing, specifically relating to a method for evaluating the radial roller bearing load-bearing state of a tunnel boring machine main drive bearing. Background Technology

[0002] As the most delicate component of a tunnel boring machine (TBM), the main bearing must withstand enormous axial, radial, torque, and overturning moments during operation. Severe torsional deformation or wear of the main bearing during TBM operation can easily lead to bearing failure. Replacement of the main bearing is necessary to ensure continued operation of the TBM, which is time-consuming, labor-intensive, and significantly delays the project schedule. Therefore, it is essential to diagnose and evaluate the load-bearing condition of the TBM main bearing to ensure its safe and reliable operation under various working conditions.

[0003] The main bearing of a tunnel boring machine (TBM) is primarily designed with three rows of cylindrical roller bearings. The radial cylindrical roller bearings mainly bear the radial force and overturning moment. Due to the high load capacity, large size, numerous rollers, and relatively low rotational speed of TBM bearings, the radial force borne by the radial cylindrical roller bearings during operation is mainly borne by a very small number of internal radial rollers, while most radial rollers are under low load or even unloaded. Therefore, it is necessary to monitor and diagnose the contact deformation of the radial rollers to prevent individual rollers from deforming and being damaged due to excessive loads, thus affecting the operation of the entire TBM bearing. This also helps to avoid excessive stress concentration in the bearing design. Summary of the Invention

[0004] The purpose of this invention is to address the current lack of evaluation methods for main bearings of tunnel boring machines by establishing a set of evaluation methods for the radial roller load-bearing status of main bearings of tunnel boring machines.

[0005] The objective of this invention is achieved through the following technical solution: a method for evaluating the radial roller bearing condition of a tunnel boring machine main bearing, the method comprising the following steps:

[0006] Step 1: Determine the roller crown clearance based on the crown of the radial rollers of the tunnel boring machine's main bearing; divide a single roller into k segments, and label each segment with a sequence number λ. Set the crown clearance code for each segment as c based on the type of the main bearing rollers. λ ;

[0007] Step 2: Set the tilt angle of the main bearing of the tunnel boring machine after being subjected to the overturning moment as θ, and set the roller azimuth symbol as ψ. j Where j is the roller number; determine the total deformation δ of the roller-raceway at the λ slice of the j-th roller. λj ;

[0008] Step 3: Based on the load-deformation relationship, determine the load q per unit length for each roller slice of the bearing. λj And the load size Q of each roller j :

[0009] Step 4: Establish the static equilibrium equation; the bearing itself must satisfy the static equilibrium equation, that is, the sum of the load vectors of each roller of the bearing and the radial load reach static equilibrium, thus obtaining the load of each roller; the static equilibrium equation is as follows:

[0010]

[0011] In the formula: F r τ is the radial force acting on the main bearing of the tunnel boring machine. j is the shear stress coefficient, and z is the total number of bearing rollers;

[0012] Step 5: Establish the overturning moment balance equation; for the known overturning moment load M acting on the main bearing of the tunnel boring machine, the equation is as follows:

[0013]

[0014] In the formula, e j The eccentricity of roller j;

[0015] Step 6: Establish the radial displacement relationship equation; based on the fact that the sum of the radial displacements of a radial roller bearing at each roller position angle minus the radial clearance equals the sum of the maximum contact deformations of the inner and outer raceways at that position, the equation is established as follows:

[0016]

[0017] In the formula: δ r P represents the radial displacement of the entire tunnel boring machine's radial roller bearings. d This is the radial clearance of the bearing;

[0018] Step 7: Solve the static equilibrium equation, overturning moment equilibrium equation, and radial displacement relationship equation using the numerical iteration method; first, by assigning the unknown quantity δ r The initial value of θ can be obtained by substituting it into the displacement relationship equation. j , q, Q, and finally, these values ​​are substituted into the static equilibrium equation and the overturning moment equilibrium equation, respectively. E is set as the threshold. If the absolute values ​​of the calculation errors of both the static equilibrium equation and the overturning moment equilibrium equation are less than the threshold E, then the iteration is considered converged. At this point, the radial displacement δ of the shield machine's radial roller bearing is... r The tilt angle θ of the main bearing of the tunnel boring machine after being subjected to overturning moment, and the roller deformation Δ caused by radial load. j The solution to the system of equations;

[0019] Step 8: Through θ, Δ j Solve for δ λj By summing the radial displacement values ​​of the same index j, the contact deformation δ of the roller in the roller bearing can be obtained. j ;

[0020] Step 9: Measure and record the radial displacement δ of the j-th roller in the bearing under actual conditions of radial force Fr and overturning moment M. j ′;

[0021] Step 10: By comparing the contact deformation δ of the j-th roller j and radial displacement record δ j The size relationship of the roller is used to evaluate its load-bearing condition.

[0022] Furthermore, in step (1), if the main bearing rollers are fully convex rollers, the formula for determining the roller crown clearance is:

[0023]

[0024] In the formula: c λ The convexity gap is selected for the slice, where λ is the slice number and k is the number of slices.

[0025] If the main bearing rollers are semi-convex rollers, the formula for determining the roller crown clearance is:

[0026]

[0027] In the formula: c λ To select the convexity clearance of the slice, λ is the slice number, k is the number of slices, and l is the roller length. s This represents the length of the roller at the point where there is no convexity.

[0028] Furthermore, in step (2), the total deformation δ of the roller-raceway λj The calculation formula is as follows:

[0029]

[0030] In the formula: Δ j The radial load causes the roller deformation, w = l / k, where k is the length of a single roller slice.

[0031] Furthermore, in step (3), the load q per unit length of each roller slice of the bearing λj And the load size Q of each roller j The calculation formula is as follows:

[0032]

[0033]

[0034] Furthermore, in step (5), the eccentricity e j The calculation formula is:

[0035]

[0036] Furthermore, in step (10), if 0.8δ j <δ j <1.2δ j If the roller is under normal load, there is no risk of damage; if 0.5δ j <δ j <0.8δ j Or 1.2δ j <δ j <1.5δ j If the roller's load-bearing condition is abnormal, there is a risk of damage; if 0 < δ j <0.5δ j Or 1.5δ j <δ j If the value is '′', it indicates that the roller may have been severely deformed or damaged, and inspection and repair are recommended.

[0037] The beneficial effects of this invention are as follows: Addressing the current lack of methods for assessing the load-bearing state of rollers inside tunnel boring machine (TBM) bearings, this invention proposes using the load-deformation mechanical relationship to assess the load-bearing state of all rollers within the TBM bearing. Furthermore, this assessment method can more accurately detect the specific locations of potential risks within the bearing, providing technical guidance for the monitoring and diagnosis of bearing rollers and ensuring the smooth operation and maintenance of TBM bearings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a flowchart of the method of the present invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] like Figure 1 As shown, a method for evaluating the radial roller bearing load state of a tunnel boring machine main bearing includes the following specific steps:

[0042] For example, given bearing parameters: the radial roller bearing of a semi-convex shield machine has a roller length l of 88mm and a non-convex length l. s The diameter is 81.1 mm, the number of rollers z is 22, and the radial clearance P is... d The radial force F is 0.025 mm. r The overturning moment M is 260000 N*m, and the number of slices k is set to 40.

[0043] Step 1: Determine the roller convexity clearance based on the convexity of the radial rollers in the main bearing of the tunnel boring machine. This is done by dividing a single roller into k slices, representing each slice with a number λ, and assigning the convexity clearance code c to each slice. λ If the main bearing rollers are fully convex rollers, the formula for determining the roller crown clearance is:

[0044]

[0045] In the formula: c λ The convexity gap of the selected slice is λ, where λ is the slice position and k is the number of slices.

[0046] If the main bearing rollers are semi-convex rollers, the formula for determining the roller crown clearance is:

[0047]

[0048] In the formula: c λ To select the convexity clearance of the slice, λ is the slice position, k is the number of slices, and l is the roller length. s This represents the length of the roller at the point where there is no convexity.

[0049] Substituting the known parameters into the semi-convex gap formula, we obtain...

[0050] Step 2: Determine the contact deformation of each cylindrical roller and raceway. Define the tilt angle of the main bearing of the tunnel boring machine after being subjected to the overturning moment as θ, and define the roller azimuth angle as ψ. j Where j is the roller number. Then the effective tilt angle of the j-th roller is ±1 / (2θcosθ). j ), in 0≤ψ j Take the plus sign within the range ≤π / 2, and within the range π / 2≤ψ. j Subtract the sign within the range ≤π (assuming the load is symmetrical about the 0-π diameter). The total deformation of the roller-raceway at roller position j and λ slice can be determined as follows:

[0051]

[0052] In the formula: Δ j The roller deformation caused by radial load, w = l / k, is the length of a single roller slice.

[0053] Step 3: Based on the load-deformation relationship, determine the load q per unit length for each roller slice of the bearing. λj And the load size Q of each roller j :

[0054]

[0055]

[0056] Step 4: Establish the static equilibrium equation. To determine the load on each roller, the bearing itself must satisfy the static equilibrium equation, that is, the sum of the load vectors of each roller in the bearing must achieve static equilibrium with the radial load, resulting in the following equation:

[0057]

[0058] In the formula: F r τ is the radial force acting on the main bearing of the tunnel boring machine. j denoted as the shear stress coefficient, and z represents the total number of bearing rollers.

[0059] Step 5: Establish the overturning moment equilibrium equation. For the known overturning moment load M acting on the main bearing of the tunnel boring machine, the equation is as follows:

[0060]

[0061] In the formula: e j Let j be the eccentricity on roller j, and its calculation formula is:

[0062]

[0063] Step 6: Establish the radial displacement relationship equation. Based on the fact that the sum of the radial displacements of a radial roller bearing at each roller position angle minus the radial clearance equals the sum of the maximum contact deformations of the inner and outer raceways at that position, the equation is established as follows:

[0064]

[0065] In the formula: δ r P represents the radial displacement of the entire tunnel boring machine's radial roller bearings. d This is the radial clearance of the bearing.

[0066] Step 7: With l = 88 mm, z = 22, P d =0.025mm, F r=50000N, M=260000N*m, k=40 Substitute these into the above 3 equilibrium equations.

[0067] The static equilibrium equations, overturning moment equilibrium equations, and radial displacement relationship equations are solved using a numerical iterative method. First, the unknown quantity δ is assigned... r The initial value of θ can be obtained by substituting it into the displacement relationship equation. j , q, Q. Finally, substitute these values ​​into the static equilibrium equation and the overturning moment equilibrium equation, respectively. Set E as the threshold, with a value of 1000. If the absolute values ​​of the calculation errors of both the static equilibrium equation and the overturning moment equilibrium equation are less than the threshold E, then the iteration is considered convergent. Solve for δ. r =0.0231mm, θ=0.000151rad.

[0068] Step 8: Through θ, Δ j Solve for δ λj The radial displacement values ​​of the same index j are summed. Finally, the contact deformation of each roller in the roller bearing can be obtained as follows: δ1 = 0.1503 mm, δ2 = 0.1341 mm, δ3 = 0.0868 mm, δ4 = 0.0122 mm, δ5 = 0, δ6 = 0…δ 19 =0, δ 22 =0.0122mm, δ 21 =0.0868mm, δ 22 =0.1341mm.

[0069] Step 9: Measure the radial displacement of each roller in the bearing under the actual conditions of radial force Fr and overturning moment M. Record the values ​​as follows: δ1′=0.178mm, δ2′=0.158mm, δ3′=0.118mm, δ4′=0.014mm, δ5′=0…δ 19 ′=0、δ 20 ′=0.0185mm, δ 21 ′=0.112mm、δ 22 = 0.171 mm.

[0070] Step 10: By comparing δ j ′ and δ j The load-bearing capacity of the roller is evaluated based on the magnitude of the relationship between the roller and the bearing capacity. If 0.8δ j <δ j <1.2δ j If the roller is under normal load, there is no risk of damage; if 0.5δ j <δ j <0.8δ j Or 1.2δ j <δ j <1.5δ jIf the roller's load-bearing condition is abnormal, there is a risk of damage; if 0 < δ j <0.5δ j Or 1.5δ j <δ j If the value is '′', it indicates that the roller may have been severely deformed or damaged, and inspection and repair are recommended.

[0071] The calculation and comparison results show that 0.8δ1 < δ1′ < 1.221, 0.8δ2 < δ2′ < 1.2δ2, 1.2δ3 < δ3′ < 1.5δ3, 0.8δ4 < δ4′ < 1.2δ4, and 1.5δ 20 <δ 20 ′,1.2δ 21 <δ 21 <1.5δ 21 ,1.2δ 22 <δ 22 <1.5δ 22 .

[0072] The assessment results are as follows: Rollers 1, 2, and 4 of the tunnel boring machine's radial bearings are under normal load and have no risk of damage; Rollers 3, 21, and 22 are under abnormal load and have a risk of damage; Roller 20 may have been severely deformed or damaged and is recommended for inspection and repair; The other rollers are not under load.

[0073] The above embodiments are used to explain and illustrate the present invention, but not to limit the present invention. Any modifications and changes made to the present invention within the spirit and scope of the claims shall fall within the protection scope of the present invention.

Claims

1. A method for evaluating a radial roller load state of a main bearing of a shield tunneling machine, characterized by, The method comprises the following steps: Step 1: according to the convexity of the radial roller of the main bearing of the shield machine, determine the roller convexity gap; divide a single roller into slices, and mark each slice number with a serial number, and set the convexity gap code of each slice according to the form of the main bearing roller as ; Step 2: set the inclination angle of the main bearing of the shield machine after the overturning moment as , set the roll azimuth code as , wherein is the roll number; determine the total deformation of the roll-race at the slice of the jth roll ; Step 3: Determine the load per unit length of each roller slice of the bearing based on the load-deformation relationship and the size of the load on each roller : Step 4: establishing a static balance equation; the bearing itself needs to satisfy the static balance equation, that is, the load vector sum of each roller of the bearing and the radial load reaches static balance, and then the load of each roller is obtained; the static balance equation is as follows: In the formula: is the radial force received by the main bearing of the shield machine, is the shear stress coefficient, and Z is the total number of bearing rollers. Step 5: establishing an overturning moment balance equation; for the known overturning moment load M acting on the main bearing of the shield machine, the equation is established as: In the formula, is the eccentricity on the roller ​ Step 6: establishing a radial displacement relationship equation; according to the sum of the radial displacements of the radial roller bearing at each roller position angle minus the radial clearance, the sum of the maximum contact deformations of the inner and outer raceways in the position is established, and the equation is established as: In the formulae: is the radial displacement of the entire shield machine radial roller bearing, is the radial gap of the bearing, is the length of the roller, is the length of a single roller slice; Step 7: Solve the static equilibrium equation, the overturning moment balance equation, and the radial displacement relationship equation by numerical iteration method; first, by assigning unknowns , initial values, after substituting into the displacement relationship equation, the values of , q, and Q can be obtained; finally, these values are respectively brought into the static equilibrium equation and the overturning moment balance equation, and the threshold value E is set; if the absolute values of the calculation errors of the static equilibrium equation and the overturning moment balance equation are both less than the threshold value E, then it is determined that the iteration converges, at which time the radial displacement of the radial roller bearing of the shield tunneling machine, the inclination angle of the shield tunneling machine main bearing after being subjected to the overturning moment, and the roller deformation generated by the radial load are the solutions of the equation set; Step 8: Through , Solve The same serial number The radial displacement values ​​are summed; finally, the contact deformation of the rollers in the roller bearing can be obtained. ; Step 9: Measure the radial displacement record of the jth roller in the bearing under the actual situation of being subjected to the radial force Fr, the overturning moment M ; Step 10: Evaluate the load state of the jth roller by comparing the size relationship between the contact deformation of the jth roller and the radial displacement record <1.2 <0.8 <0.5 <1.5 <0.5 <1.5 <0.8 <0.5 <1.5 <0.8 <0.5 ​​​​ 2. The method according to claim 1, wherein In step (1), if the main bearing roller is a full convex roller, the roller convexity clearance formula is determined as: In the formulae: is the convexity gap of the selected slice, is the slice number, is the number of slices; If the main bearing roller is a semi-convex roller, the roller convexity clearance formula is determined as: In the formulas: is the convexity gap for the selected slice, is the slice number, is the number of slices, is the roller length, is the roller length at the non-convexity.

3. The method according to claim 1, wherein In step (2), the total deformation of the roller-raceway The calculation formula is as follows: In the formulas: is the roller deformation due to the radial load, is the length of a single roller slice.​ 4. The method according to claim 1, wherein In step (3), the load per unit length of each roller slice of the bearing and the size of the load of each roller are calculated by the following formulas. 。 5. The method according to claim 1, wherein In step (5), the eccentricity The calculation formula is: 。

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