Key parameter design method for three-row roller type large main bearing of shield tunneling machine

Abstract

The invention belongs to the technical field of bearings, and particularly relates to a key parameter design method for a three-row roller type large main bearing of a shield tunneling machine. According to the requirements of the load spectrum and the target comprehensive life, the design method of the key parameters of the three-row roller type large main bearing of the shield tunneling machine is provided by combining the constraint of the space size. According to the method, the target life of a main thrust bearing and the target life of a radial bearing are distributed firstly, then parameters of the radial bearing are determined firstly according to life requirements, and then parameters of the main thrust bearing are determined according to size limitation of a radial raceway surface and life requirements of the main thrust roller bearing. In addition, parameters of the auxiliary thrust bearing can be determined according to size limitation and safety coefficient requirements of the radial raceway surface. Finally, key parameter design of the three-row roller type large main bearing of the shield tunneling machine is completed. According to the method, the space size limitation during installation of the main bearing of the shield tunneling machine is fully considered, the main bearing of the shield tunneling machine with the reasonable size can be designed on the premise that the service life requirement is met, and good economical efficiency is achieved.

Description

Technical Field

[0001] This invention belongs to the field of bearing technology, specifically a key parameter design method for a three-row roller type large main bearing for tunnel boring machines. Background Technology

[0002] Tunnel boring machines (TBMs) integrate optics, mechanics, electronics, hydraulics, sensing, and information technology, and are crucial equipment for infrastructure construction. The main bearing is a key core component of the TBM, often referred to as its "heart," playing a vital role in its normal operation and the smooth progress of tunnel construction. With the increasing demands of tunnel boring machine (TBM) construction, TBM main bearings are developing towards larger diameters, higher load-bearing capacity, longer lifespans, and higher reliability.

[0003] Three-row roller bearings can withstand large radial loads, axial loads, and overturning moments, making them suitable for the complex stress conditions of tunnel boring machines (TBMs). They can provide torque for cutterhead rotation while bearing the entire thrust of the propulsion system, making them the most commonly used bearing type for the main drive of TBMs. The pitch circle diameter, number of rows, number of rollers, nominal diameter, and nominal length of each row of rollers in a three-row roller bearing directly determine the load-bearing capacity and lifespan of the main bearing, and are therefore critical parameters.

[0004] JB / T 10471-2017 "Rolling Bearings - Slewing Bearings", JB / T 10837-2008 "Construction Machinery and Equipment - Three-Row Column Slewing Bearings", and JB / T 2300-2018 "Slewing Bearings" provide the external dimensions of slewing bearings, but do not provide detailed information on their key parameters. JB / T 10837-2008 and JB / T 2300-2018 provide verification methods based on safety factor and load-bearing capacity curves for slewing bearing design verification and selection. However, tunnel boring machine (TBM) main bearings often have specific service life requirements, and the methods in the standards still cannot address the specific service life requirements for designing large three-row roller main bearings for TBMs.

[0005] GB / T 6391-2010 / ISO 281:2007 "Rolling bearings - Rated dynamic loads and rated life" specifies the rated dynamic loads and basic rated life L for thrust roller bearings and radial roller bearings. 10 The calculation method involves substituting the key parameters of the three-row roller bearings into the formula provided in the standard to obtain the service life of each roller. In tunnel boring machine (TBM) design, the external dimensions of the main bearing are often limited by the equipment layout. Taking the main bearing of an internal gear TBM as an example, its outer diameter is approximately half the excavation diameter. However, how to design the key parameters of each row of rollers based on the target service life under geometric constraints is not mentioned in relevant standards and literature.

[0006] Patent CN114139320A discloses a roller design method for a three-row cylindrical roller bearing. After obtaining the contact stress through finite element analysis, it determines the coefficient values ​​in the logarithmic function of the bearing generatrix to control the contact length between the two rows of thrust rollers and the raceway of the bearing rings within a certain range, thereby improving the bearing's stability and lifespan. However, this method only optimizes the roller crown deformation and does not address the system design of the overall key parameters of the three-row roller-type large main bearing for tunnel boring machines. It fails to comprehensively consider factors such as load spectrum, target overall lifespan, and spatial size constraints.

[0007] Patent CN101788009A discloses a three-row cylindrical roller bearing for the main bearing of a tunnel boring machine (TBM). The internal gear type three-row cylindrical roller bearing includes low-thrust rollers, radial rollers, high-thrust rollers, an integrated cage, a lubrication system, and a sealing system, emphasizing improved load-bearing capacity through structural design. However, it does not mention the design methods for key parameters, and therefore cannot meet the design requirements of large three-row roller main bearings for TBMs under different target lifespan and spatial constraints.

[0008] Published invention patents often only provide design methods for the main thrust rollers, without specifying how to design the parameters of a three-row roller bearing that meets process requirements. Therefore, to address these issues, this invention proposes a key parameter design method for a large three-row roller main bearing used in tunnel boring machines. Summary of the Invention

[0009] The purpose of this invention is to provide a key parameter design method for a three-row roller type large main bearing for tunnel boring machines. It comprehensively considers factors such as load spectrum, target comprehensive life, and space size constraints, and establishes the relationship between parameters such as size and life of each row of rollers. Through reasonable calculation, the key parameters of the three-row roller type large main bearing for tunnel boring machines that meet the requirements can be obtained.

[0010] The technical solution of this invention is:

[0011] A method for designing key parameters for a three-row roller type large main bearing for a tunnel boring machine includes the following steps:

[0012] Step 1: Allocate the lifespan of the main propulsion bearing and the radial bearing according to the target overall lifespan;

[0013] Step 2: Select the radial roller model under the condition of meeting the radial roller size constraints, and search and calculate in order of radial roller nominal diameter from small to large until the minimum nominal diameter radial roller that meets the target life of the radial bearing is obtained;

[0014] Step 3: First, set the number of columns of the main push rollers to 1. Under the condition of meeting the size constraints of the main push rollers, select the model of the main push rollers. Search and calculate in order of the nominal diameter of the main push rollers from small to large until the minimum nominal diameter of the main push roller that meets the target life of the main push bearing is obtained. If the roller parameters that meet the life requirements cannot be obtained, set the number of columns of the main push rollers to 2 and search and calculate again.

[0015] Step 4: Select the model of the auxiliary thrust roller under the condition that it meets the size constraints of the auxiliary thrust roller. Search and calculate in order of the nominal diameter of the roller from small to large until the minimum nominal diameter auxiliary thrust roller that meets the safety factor requirements of the auxiliary thrust bearing is obtained.

[0016] The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine, in step one, allocates the target life of the main thrust bearing and the radial bearing according to the following formula:

[0017] 1) Target life L of the main propulsion bearing 10h,goal,z =α L10 L 10h,goal ;

[0018] 2) Target life of radial bearings

[0019] in:

[0020] α L10 —Lifetime allocation coefficient, which is a coefficient greater than 1;

[0021] L 10h,goal,z —Target life of the main bearing, in hours;

[0022] L 10h,goal,j —Target life of the radial bearing, in hours;

[0023] δ—The effect of the auxiliary thrust bearing, which is generally close to 0.

[0024] The key parameter design method for a three-row roller type large main bearing of a tunnel boring machine, in step two, the constraint relationships between the parameters of the radial bearing are as follows:

[0025] 1) The pitch circle diameter of the radial bearing is determined by the following formula:

[0026]

[0027] Where: for internal gear main bearings, the symbol is... Use "-"; for external gear main bearings, the symbol is... Take the "+" sign, the same applies below;

[0028] B1—The distance from the inner or outer diameter to the radial raceway surface of the stationary ring, determined based on factors such as the size of the connecting bolt holes, the size of the sealing groove, and the depth of the hardened layer;

[0029] 2) The number of rollers in a radial bearing is determined by the following formula:

[0030]

[0031] in:

[0032] B j —Average width of the spacer blocks between radial rollers;

[0033] 3) The radial roller dimensions are selected from the standard, and the roller dimensions meet the following constraints:

[0034] 0.7D wj ≤L wj ≤2D wj

[0035] 4) The overall rated life of the radial bearing is determined by the following formula:

[0036]

[0037] The key parameter design method for a three-row roller type large main bearing of a tunnel boring machine, in step three, the constraint relationships between the parameters of the main thrust bearing are as follows:

[0038] 1) The pitch circle diameter of the main thrust bearing is determined by the following formula:

[0039]

[0040] B2—The radial distance from the radial raceway surface of the moving ring to the end face of the main push roller, which is determined according to the manufacturing process;

[0041] 2) The number of rollers in the main thrust bearing is determined by the following formula:

[0042]

[0043] in:

[0044] B z —Average width of the spacer block between the main rollers;

[0045] 3) The main roller size is selected from the standard, and the roller size meets the following constraint:

[0046] 0.7D wz ≤L wz ≤D wz

[0047] 4) The overall rated life of the main propulsion bearing is determined by the following formula:

[0048]

[0049] The key parameter design method for a three-row roller type large main bearing of a tunnel boring machine, in step four, the constraint relationships between the parameters of the auxiliary thrust bearing are as follows:

[0050] 1) The pitch circle diameter of the auxiliary thrust bearing is determined by the following formula:

[0051]

[0052] B3—Radial distance from the radial raceway surface of the moving ring to the end face of the auxiliary push roller, determined according to the manufacturing process;

[0053] 2) The number of rollers in the auxiliary thrust bearing is determined by the following formula:

[0054]

[0055] in:

[0056] B f —Average width of the isolation block between the auxiliary pusher rollers;

[0057] 3) The dimensions of the auxiliary thrust rollers are selected from the standard, and the roller dimensions meet the following constraints:

[0058] 0.7D wf ≤L wf ≤D wf

[0059] 4) The safety factor of the auxiliary thrust bearing is selected based on the operating conditions and determined using the following formula with reference to relevant standards:

[0060]

[0061] In the key parameter design method for a three-row roller type large main bearing for a tunnel boring machine, steps two through four involve estimating the average width of the roller crossbeams for each row using the following formula:

[0062] B≥α[-7+4.3ln(D w -0.2)],D w ∈[10,150], α∈[0.8,1]

[0063] Specifically, for the main thrust cage, α takes a larger value; for the auxiliary thrust cage and the radial cage, α takes a smaller value.

[0064] The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine, wherein the calculations in steps three and four are not sequential.

[0065] The design concept of this invention is:

[0066] Existing design methods cannot simultaneously design three-row roller bearing parameters that meet process requirements, and cannot satisfy the design needs of tunnel boring machine (TBM) main bearings under different target life and spatial size constraints. This invention, based on load spectrum, target comprehensive life requirements, and spatial size constraints, presents a key parameter design method for large three-row roller main bearings used in TBMs. Its initial goal is to establish a relationship between the bearing's comprehensive life and structural dimensions based on load spectrum, target comprehensive life, and spatial size constraints. Using this relationship as a foundation, through step-by-step optimization and search calculations, key parameters such as the nominal diameter, nominal length, number of rows, number of rollers per row, and pitch circle diameter of each row of rollers are determined, ensuring that the large three-row roller main bearing for TBMs meets life requirements.

[0067] This invention takes the load spectrum (axial / radial load, overturning moment), target comprehensive life, and spatial size constraints as inputs. Through life allocation, parameter constraint equations, and iterative search, it achieves global optimization of the parameters of the three rows of rollers. This invention determines the key parameters of the radial, main pusher, and auxiliary pusher rollers sequentially through steps one through four, forming a design flow of "life allocation → radial design → main pusher design → auxiliary pusher design." The search proceeds from smallest to largest roller nominal diameter, and combined with constraint formulas for pitch circle diameter and roller quantity, ensures that the design result tends towards the minimum structural size.

[0068] The advantages and beneficial effects of this invention are:

[0069] 1. The design method of the present invention fully considers the space size limitations when installing the main bearing of the tunnel boring machine. While meeting the service life requirements, it can design a tunnel boring machine main bearing with reasonable size. The design result also tends to take the minimum structural size, achieving higher economy and solving the problem that the parameters of each row of rollers could not be designed at the same time in the previous design method.

[0070] 2. This invention comprehensively considers multiple factors such as load spectrum, target comprehensive life and spatial size constraints. Through the systematic method of steps one to four, it establishes the mathematical relationship between the parameters of each row of rollers, realizes parameter collaborative design, and realizes the systematic design of key parameters of the three-row roller large main bearing of the tunnel boring machine by establishing a mathematical model and optimization algorithm, thus solving the problem of unreasonable life distribution in traditional design.

[0071] 3. This invention can flexibly adjust the parameters of each row of rollers according to different design requirements to achieve the best design effect, and has strong adaptability and practicality.

[0072] 4. Compared with the patent CN101788009A, which discloses a three-row cylindrical roller bearing for a tunnel boring machine main bearing, this invention comprehensively considers factors such as load spectrum, target comprehensive life, and spatial size constraints. Through specific calculation steps, it can accurately design the key parameters of a large three-row roller main bearing that meets the working requirements of a tunnel boring machine, enabling the bearing to better adapt to actual working conditions during the design stage. This invention establishes the relationship between parameters such as size and life of each row of rollers, clearly provides the design steps and interrelationships of the parameters of each row of rollers (main thrust, radial thrust, and auxiliary thrust), and realizes the collaborative design of parameters of multiple rows of rollers, ensuring the stability and reliability of the bearing under complex working conditions.

[0073] 5. Compared with the patent CN114139320A, which discloses a roller design method for a three-row cylindrical roller bearing, this invention comprehensively considers multiple factors such as load spectrum, target comprehensive life, and spatial size constraints. Through the establishment of a mathematical model and optimization algorithm, it achieves a systematic design of the parameters for each row of rollers. Furthermore, through systematic parameter design, this invention ensures that the parameters of each row of rollers meet life requirements while maintaining high reliability. For example, by optimizing parameters such as the nominal diameter, nominal length, number of rows, number of rollers per row, and pitch circle diameter, the bearing's load-bearing capacity and fatigue resistance can be effectively improved. Attached Figure Description

[0074] Figure 1 This is a structural diagram of an internal gear type three-row roller bearing. Detailed Implementation

[0075] In its implementation, this invention first allocates the target lifespan of the main thrust bearing and the radial bearing. Then, based on the lifespan requirements, it first determines the radial bearing parameters, and then determines the main thrust bearing parameters based on the dimensional limitations of the radial raceway surface and the lifespan requirements of the main thrust roller bearing. Furthermore, the auxiliary thrust bearing parameters can be determined based on the dimensional limitations of the radial raceway surface and the safety factor requirements. This ultimately completes the design of the key parameters for the three-row roller-type large main bearing of the tunnel boring machine.

[0076] In the calculation, the following parameters are assumed to be known:

[0077] 1) Roller dimensions are selected from standards such as DIN5402-1 or GB / T 4661.

[0078] 2) Target comprehensive lifespan L 10h,goal .

[0079] 3) Load spectrum (axial load F under various working conditions) a Radial load F r Overturning moment M, rotational speed n, and running time percentage η).

[0080] 4) Spatial dimensional constraints, such as: D k —Inner (outer) diameter (k=i,e), that is, the inner (outer) diameter of the end without gears.

[0081] Based on the above parameters, the key parameters of the three-row roller type large main bearing of the tunnel boring machine can be obtained, including: the nominal diameter D of each row of rollers. w Nominal length L w Number of rows i (main push rollers only), number of rollers per row N, pitch circle diameter D0.

[0082] A key parameter design method for a three-row roller type large main bearing for tunnel boring machines is achieved through the following steps:

[0083] Step 1: Allocate the lifespan of the main propulsion bearing and the radial bearing according to the target overall lifespan.

[0084] Step 2: Select the radial roller model from the rollers that meet the radial roller size constraints, and search and calculate in order of radial roller nominal diameter from small to large until the radial roller with the minimum nominal diameter that meets the target life of the radial bearing is obtained.

[0085] Step 3: First, set the number of columns for the main push rollers to 1. Select the main push roller model from the rollers that meet the main push roller size constraints, and search and calculate in ascending order of the nominal diameter of the main push rollers until the minimum nominal diameter of the main push roller that meets the target life of the main push bearing is obtained. If the roller parameters that meet the life requirements cannot be obtained, set the number of columns for the main push rollers to 2 and search and calculate again.

[0086] Step 4: Select the secondary thrust roller model from the rollers that meet the size constraints of the secondary thrust roller. Search and calculate in order of the nominal diameter of the roller from small to large until the minimum nominal diameter of the secondary thrust roller that meets the safety factor requirements of the secondary thrust bearing is obtained.

[0087] In step one: the target life of the main thrust bearing and the radial bearing is allocated according to the following formula.

[0088] 1) Target life L of the main propulsion bearing 10h,goal,z =α L10 L 10h,goal .

[0089] 2) Target life of radial bearings

[0090] in:

[0091] α L10 —Lifetime allocation coefficient, which is a coefficient greater than 1.

[0092] L 10h,goal,z —Target life of the main bearing, in hours.

[0093] L 10h,goal,j —Target life of the radial bearing, h.

[0094] δ represents the influence of the auxiliary thrust bearing, which is generally close to 0.

[0095] In step two: the constraint relationships between the parameters of the radial bearing are as follows.

[0096] 1) The pitch circle diameter of the radial bearing is determined by the following formula.

[0097]

[0098] Where: for internal gear main bearings, the symbol is... Use "-"; for external gear main bearings, the symbol is... Take the "+" sign, the same applies below.

[0099] B1—The distance from the inner (outer) diameter to the radial raceway surface of the stationary ring, determined based on factors such as the size of the connecting bolt holes, the size of the sealing groove, and the depth of the hardened layer.

[0100] 2) The number of rollers in a radial bearing is determined by the following formula.

[0101]

[0102] in:

[0103] B j — Average width of the spacer block (lintel) between radial rollers.

[0104] 3) The radial roller dimensions shall be selected from standards such as GB / T 4661, and the roller dimensions shall conform to the following constraints.

[0105] 0.7D wj ≤L wj ≤2D wj

[0106] 4) The overall rated life (in hours) of the radial bearing is determined by the following formula.

[0107]

[0108] In step three: the constraint relationships between the parameters of the main thrust bearing are as follows.

[0109] 1) The pitch circle diameter of the main thrust bearing is determined by the following formula.

[0110]

[0111] B2—The radial distance from the radial raceway surface of the moving ring to the end face of the main push roller, which is determined according to the manufacturing process.

[0112] 2) The number of rollers in the main thrust bearing is determined by the following formula.

[0113]

[0114] in:

[0115] B z —The average width of the isolation block (lintel) between the main rollers.

[0116] 3) The main roller size is selected from standards such as GB / T 4661, and the roller size conforms to the following constraints.

[0117] 0.7D wz ≤L wz ≤D wz

[0118] 4) The overall rated life (in hours) of the main propulsion bearing is determined by the following formula.

[0119]

[0120] In step four, the constraint relationships between the parameters of the auxiliary thrust bearing are as follows.

[0121] 1) The pitch circle diameter of the auxiliary thrust bearing is determined by the following formula.

[0122]

[0123] B3—The radial distance from the radial raceway surface of the moving ring to the end face of the auxiliary push roller, which is determined according to the manufacturing process.

[0124] 2) The number of rollers in the auxiliary thrust bearing is determined by the following formula.

[0125]

[0126] in:

[0127] B f —Average width of the isolation block (lintel) between the auxiliary pusher rollers.

[0128] 3) The main roller size is selected from standards such as GB / T 4661, and the roller size conforms to the following constraints.

[0129] 0.7D wf ≤L wf ≤D wf

[0130] 4) Safety factor of the auxiliary thrust bearing. The safety factor is selected based on the operating conditions and determined by the following formula with reference to relevant standards.

[0131]

[0132] It is worth noting that the calculations in steps three and four can be performed in any order. In steps two through four, the average width of each row of roller beams is estimated using the following formula.

[0133] B≥α[-7+4.3ln(D w -0.2)],D w ∈[10,150], α∈[0.8,1]

[0134] Specifically, for the main thrust cage, α takes a larger value; for the auxiliary thrust cage and the radial cage, α takes a smaller value.

[0135] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. The following embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0136] Example:

[0137] Taking the main thrust roller of the three-row roller large main bearing of the earth pressure balance shield machine as an example, the basic process of roller design is briefly explained.

[0138] like Figure 1 As shown, the target life of the three-row roller bearing is 15,000 hours. It is an internal gear type three-row roller bearing with an outer diameter of 6m. Its load spectrum is shown in the table below.

[0139]

[0140] Step 1: Allocate the lifespan of the main propulsion bearing and the radial bearing based on the target overall lifespan. Take α... L10 If it is 1.03, then L 10h,goal,z =15450h, L 10h,goal,j =30506h.

[0141] Step 2: Calculate the radial bearing parameters. Taking B1 = 212mm, the minimum radial roller parameter that meets the requirements is calculated as: D wj =50mm, L wj =90mm, D 0j =5738mm, N j =297, the overall life of the radial bearing is 34922h>30506h.

[0142] Step 3: Calculate the main thrust bearing parameters. Taking B2 = 20mm, after searching and calculating, the minimum required main thrust roller parameters are obtained as follows: number of roller rows i = 2, D... wz =145mm, L wz =145mm, D 0z =5378mm, N z =192, the overall life of the main propulsion bearing is 16769h>15450h.

[0143] Step 4: Calculate the auxiliary thrust bearing parameters. Taking B3 = 20mm, after searching and calculating, the minimum required auxiliary thrust roller parameter is obtained as: D wf =65mm, L wf =65mm, D 0f =5603mm, N f =220.

[0144] The comprehensive service life of the three-row roller large main bearing of the tunnel boring machine is 16356h > 15000h, which meets the design requirements, and the design is completed.

[0145] The implementation results show that the design of this invention simultaneously meets the lifespan requirements and minimum structural dimensions, significantly improving economic efficiency. For example, in the embodiment, the overall lifespan reaches 16356 hours (exceeding the target lifespan of 15000 hours), and the dimensions of each row of rollers are the minimum values ​​that meet the requirements. This invention primarily aims to provide a basis for determining key parameters in the design process of large main bearings for tunnel boring machines (TBMs), ensuring the load-bearing capacity and lifespan requirements of the large main bearings. The bearing designed in this invention has an overall lifespan exceeding the target value and minimizes structural dimensions, demonstrating significant advantages in both economy and reliability compared to existing technologies.

Claims

1. A method for designing key parameters of a three-row roller type large main bearing for a tunnel boring machine, characterized in that, Includes the following steps: Step 1: Allocate the lifespan of the main propulsion bearing and the radial bearing according to the target overall lifespan; Step 2: Select the radial roller model under the condition of meeting the radial roller size constraints, and search and calculate in order of radial roller nominal diameter from small to large until the minimum nominal diameter radial roller that meets the target life of the radial bearing is obtained; Step 3: First, set the number of columns of the main push rollers to 1. Under the condition of meeting the size constraints of the main push rollers, select the model of the main push rollers. Search and calculate in order of the nominal diameter of the main push rollers from small to large until the minimum nominal diameter of the main push roller that meets the target life of the main push bearing is obtained. If the roller parameters that meet the life requirements cannot be obtained, set the number of columns of the main push rollers to 2 and search and calculate again. Step 4: Select the model of the auxiliary thrust roller under the condition that it meets the size constraints of the auxiliary thrust roller. Search and calculate in order of the nominal diameter of the roller from small to large until the minimum nominal diameter auxiliary thrust roller that meets the safety factor requirements of the auxiliary thrust bearing is obtained.

2. The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine according to claim 1, characterized in that, In step one, the target lifespan of the main thrust bearing and the radial bearing is allocated according to the following formula: 1) Target life L of the main propulsion bearing 10h,goal,z =α L10 L 10h,goal ; 2) Target life of radial bearings in: α L10 —Lifetime allocation coefficient, which is a coefficient greater than 1; L 10h,goal,z —Target life of the main bearing, in hours; L 10h,goal,j —Target life of the radial bearing, in hours; δ—The effect of the auxiliary thrust bearing, which is generally close to 0.

3. The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine according to claim 1, characterized in that, In step two, the constraint relationships between the parameters of the radial bearing are as follows: 1) The pitch circle diameter of the radial bearing is determined by the following formula: Where: for internal gear main bearings, the symbol is... Use "-"; for external gear main bearings, the symbol is... Take the "+" sign, the same applies below; B1—The distance from the inner or outer diameter to the radial raceway surface of the stationary ring, determined based on factors such as the size of the connecting bolt holes, the size of the sealing groove, and the depth of the hardened layer; 2) The number of rollers in a radial bearing is determined by the following formula: in: B j —Average width of the spacer blocks between radial rollers; 3) The radial roller dimensions are selected from the standard, and the roller dimensions meet the following constraints: 0.7D wj ≤L wj ≤2D wj 4) The overall rated life of the radial bearing is determined by the following formula:

4. The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine according to claim 1, characterized in that, In step three, the constraint relationships between the parameters of the main thrust bearing are as follows: 1) The pitch circle diameter of the main thrust bearing is determined by the following formula: B2—The radial distance from the radial raceway surface of the moving ring to the end face of the main push roller, which is determined according to the manufacturing process; 2) The number of rollers in the main thrust bearing is determined by the following formula: in: B z —Average width of the spacer block between the main rollers; 3) The main roller size is selected from the standard, and the roller size meets the following constraint: 0.7D wz ≤L wz ≤D wz 4) The overall rated life of the main propulsion bearing is determined by the following formula:

5. The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine according to claim 1, characterized in that, In step four, the constraint relationships between the parameters of the auxiliary thrust bearing are as follows: 1) The pitch circle diameter of the auxiliary thrust bearing is determined by the following formula: B3—Radial distance from the radial raceway surface of the moving ring to the end face of the auxiliary push roller, determined according to the manufacturing process; 2) The number of rollers in the auxiliary thrust bearing is determined by the following formula: in: B f —Average width of the isolation block between the auxiliary pusher rollers; 3) The dimensions of the auxiliary thrust rollers are selected from the standard, and the roller dimensions meet the following constraints: 0.7D wf ≤L wf ≤D wf 4) The safety factor of the auxiliary thrust bearing is selected based on the operating conditions and determined using the following formula with reference to relevant standards:

6. A method for designing key parameters of a three-row roller type large main bearing for a tunnel boring machine according to any one of claims 1 to 5, characterized in that, In steps two through four, the average width of each row of roller beams is estimated using the following formula: B≥α[-7+4.3ln(D w -0.2)],D w ∈[10,150],α∈[0.8,1] Specifically, for the main thrust cage, α takes a larger value; for the auxiliary thrust cage and the radial cage, α takes a smaller value.

7. The key parameter design method for a three-row roller type large main bearing for a tunnel boring machine according to claim 1, characterized in that, The calculations in steps three and four are not performed in any particular order.

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