Design method of large main bearing floating ring and spring mechanism of heading machine

Abstract

The invention belongs to the field of bearing manufacturing, and particularly relates to a design method of a large main bearing floating ring and spring mechanism of a heading machine. The design method of the floating ring of the large main bearing of the heading machine comprises the step of determining the inner diameter, the outer diameter and the thickness of the floating ring according to the nominal length of an auxiliary push roller. The design method of the spring mechanism of the large main bearing of the heading machine comprises the following steps: determining the total pretightening force of the spring mechanism according to the total mass and the maximum static load of a floating ring and a roller; the outer diameter of the spring mechanism is determined according to the difference between the inner diameter and the outer diameter of the floating ring; the number of the spring mechanisms is determined according to the outer diameter sizes of the spring mechanisms; determining the type of the belleville spring by combining the requirements of the compression amount and the service life of the damper spring; and finally, calculating and checking the stress of the floating ring and the spring mechanism of the large main bearing of the heading machine to finish the design of the floating ring and the spring mechanism. According to the invention, compact contact between the roller and the raceway surface during service is ensured, and stable operation, safety and reliability of the large main bearing of the heading machine are ensured.

Description

Technical Field

[0001] This invention belongs to the field of bearing manufacturing, specifically relating to a design method for a floating ring and spring mechanism of a large main bearing for a tunnel boring machine (TBM). Background Technology

[0002] By utilizing the cutting rollers on the cutterhead to crush and shear rock, the working efficiency is far higher than the traditional drill-and-blast method. TBMs are widely used for tunneling in rock formations with good stability, medium to thick burial depth, and medium to high strength. The large random loads generated by the TBM's cutting rollers during rock breaking cause significant impacts on the main bearing system. If conventional shield machine main bearings (such as earth pressure balance shield machine main bearings) are used, the presence of a certain clearance (working clearance) between the auxiliary thrust rollers and the raceway surface during tunneling will cause frequent collisions between the auxiliary thrust rollers and the raceway surface under random loads, resulting in damage and potentially premature failure of the main bearing.

[0003] To address the aforementioned issues, tunneling machine (TBM) main bearings typically incorporate a floating ring on the secondary thrust roller raceway of the fixed bearing. A spring mechanism is installed between the floating ring and the fixed bearing to ensure the floating ring is pressed firmly against the secondary thrust roller, maintaining tight contact at all times. This absorbs the impact generated between the secondary thrust roller and the raceway surface during vibration of the moving bearing. Figure 1 As shown.

[0004] The document "Machining Method for Floating Ring of Main Bearing of Tunnel Boring Machine" introduces a machining method to reduce the quenching deformation of floating rings by using process jigs and double-sided simultaneous quenching. Chinese Invention CN113695845A, "A Machining Method for Floating Ring of Main Drive Bearing of Tunnel Boring Machine," discloses a heat treatment and machining method for floating rings, employing a pre-deformation method to compensate for the deformation caused by quenching, ensuring the final dimensions of the floating ring meet requirements. Chinese Invention CN114970008A, "A Design Method for Vibration Damping Spring Assembly of Main Bearing of Tunnel Boring Machine," discloses a spring assembly determination method, using the "Verification Calculation Method for Three-Row Roller Slewing Bearings" to calculate the load on the auxiliary thrust rollers, and treating this load as the load of the vibration damping spring, serving as the basis for the vibration damping spring design. However, currently available literature rarely systematically designs floating ring and spring mechanisms from the perspective of mitigating the strong impacts caused by vibrations during main bearing operation, aiming to avoid frequent collisions between the auxiliary thrust rollers and the raceway surface, which could cause damage and premature failure of the main bearing, thus ensuring the stable and reliable operation of the main bearing. Summary of the Invention

[0005] The purpose of this invention is to provide a design method for a floating ring and spring mechanism for a large main bearing of a tunneling machine, which solves the problem that under random loads, the auxiliary thrust rollers and raceway surfaces of the main bearing of existing tunneling machines are prone to frequent collisions, causing damage and premature failure of the main bearing.

[0006] The technical solution of this invention is:

[0007] A design method for a floating ring and spring mechanism for a large main bearing of a tunneling machine includes the following steps:

[0008] Step 1: Determine the structural dimensions of the floating ring, including: the inner diameter of the floating ring, the outer diameter of the floating ring, and the thickness of the floating ring;

[0009] Step 2: Determine the total preload of the damping springs;

[0010] Step 3: Determine the parameters of the spring mechanism, including: the structure of the spring mechanism, the number and distribution of spring mechanisms, the number of damping springs and the preload in a single spring mechanism;

[0011] Step 4: Complete the design of the floating ring and spring mechanism by verifying the stress through force calculations.

[0012] The design method of floating ring and spring mechanism for large main bearing of tunneling machine, in step one, determines the inner diameter, outer diameter and thickness of floating ring based on the nominal length and pitch circle diameter of the main bearing auxiliary push roller;

[0013] Based on the pitch circle diameter, subtract 1.2 to 1.5 times the nominal length of the main bearing push roller to determine the inner diameter of the floating ring;

[0014] Based on the pitch circle diameter, add 1.2 to 1.5 times the nominal length of the main bearing rollers to determine the outer diameter of the floating ring;

[0015] The thickness of the floating ring is between 0.4 and 0.8 times the roller diameter to ensure sufficient rigidity for machining and quenching.

[0016] In the design method of floating ring and spring mechanism of large main bearing of tunneling machine, in step two, the principle for determining the total preload of vibration damping spring is: when the inner ring is subjected to vibration, the auxiliary push roller will not separate from the inner ring and floating ring due to vibration and thus collide.

[0017] The design method for the floating ring and spring mechanism of a large main bearing of a tunneling machine, in step two, involves determining the total preload as follows:

[0018] 1) 0.5% to 1% of the maximum value in the load spectrum is taken as the excitation force amplitude, and the static displacement generated under the action of the excitation force is A;

[0019] 2) The maximum excitation frequency generated by the excitation force is f max ;

[0020] 3) The amplification factor of resonance is α;

[0021] 4) The mass of the floating ring is m fThe total mass of the auxiliary thrust roller is m r ;

[0022] 5) The total preload of the damping springs satisfies: F ≥ α(m) f +m r )(2πf max ) 2 A.

[0023] The design method of the floating ring and spring mechanism of a large main bearing for a tunneling machine, as described above, includes a spring mechanism consisting of a T-shaped spring guide rod, a washer, a disc spring, a secondary thrust ring, and a plug in step three. A through hole is provided at the center of the raceway surface of the secondary thrust ring. One side of the through hole corresponds to and matches the T-shaped spring guide rod. A washer and a disc spring are installed in the two gaps between the T-shaped spring guide rod and the secondary thrust ring. The disc spring is located between the washer in the two gaps, compressing the disc spring during assembly. The other side of the through hole corresponds to and matches the plug, which blocks the other side of the through hole to prevent oil leakage during normal operation. An inner ring guide is used to guide the disc spring, and the guide gap between the inner ring and the T-shaped spring guide rod meets the corresponding standard requirements. The hardness of the contact portion between the T-shaped spring guide rod and the inner ring of the disc spring does not exceed 55 HRC, and the surface hardness of the washer is not lower than 55 HRC.

[0024] In the aforementioned design method for a floating ring and spring mechanism of a large main bearing for a tunneling machine, in step three, the maximum outer diameter D of the spring mechanism is... s The number of spring mechanisms is 0.4 to 0.8 times the nominal length of the roller. They are evenly distributed on the auxiliary thrust rings.

[0025] In the design method of the floating ring and spring mechanism of the large main bearing of the tunneling machine, in step three, in the free state, the top of the T-shaped spring guide rod of the spring mechanism is d higher than the surface of the auxiliary push ring. s It is 1-3mm.

[0026] In the design method of the floating ring and spring mechanism of the large main bearing of the tunneling machine, the selection principle of the vibration damping spring in step three is as follows:

[0027] 1) Due to the limitations of the main bearing structure dimensions, the outer diameter of the damping spring shall not exceed the difference between the inner and outer diameters of the floating ring, and the inner diameter of the damping spring shall not be lower than the diameter of the spring guide rod;

[0028] 2) The damping spring meets the requirement of infinite life, that is, the number of cycles > 2e6;

[0029] 3) The compression of a single damping spring shall not be less than 0.15 times the initial height in the free state, i.e., 0.15h0.

[0030] The design concept of this invention is:

[0031] Existing technologies lack a dynamic coordination model for the floating ring and spring mechanism, failing to effectively suppress the runout of the auxiliary thrust roller under vibration conditions, leading to premature main bearing failure. The floating ring dimensions and spring mechanism parameters (such as preload and distribution) lack systematic design, making it impossible to maintain tight contact between the auxiliary thrust roller and the raceway surface under dynamic loads. This invention addresses the issue of mitigating the strong impacts caused by vibrations during main bearing operation. It systematically designs the floating ring and spring mechanism, determining the structural dimensions of the floating ring, the total preload of the damping spring, and the parameters of the spring mechanism, and performing stress calculations and verifications. This ensures the floating ring is pressed firmly onto the auxiliary thrust roller, maintaining tight contact at all times, and mitigating the impact generated between the auxiliary thrust roller and the raceway surface during moving ring vibration.

[0032] This invention systematically designs various parameters of the floating ring and spring mechanism, including the structural dimensions of the floating ring such as its inner diameter, outer diameter, and thickness, the principle and calculation steps for determining the total preload of the vibration damping spring, and the structural composition and parameter determination of the spring mechanism. It is designed from the perspective of vibration and impact during the service of the main bearing, and achieves the effect of avoiding frequent collisions between the auxiliary thrust roller and the raceway surface and ensuring the stable operation of the main bearing, providing a new technical solution for the design of the main bearing of the tunneling machine.

[0033] The advantages and beneficial effects of this invention are:

[0034] 1. This invention effectively avoids damage caused by frequent collisions between the auxiliary push roller and the raceway surface, fundamentally solving the problem of collision damage caused by vibration separation between the auxiliary push roller and the raceway surface, ensuring the stable operation and safety of the main bearing, and improving the service life and working efficiency of the tunneling machine's main bearing.

[0035] 2. This invention uses disc springs to meet the requirements of unlimited life (number of cycles > 2e6 times) and compression (≥ 0.15 times the initial height). At the same time, the differential design of guide rod hardness (≤ 55HRC) and gasket hardness (≥ 55HRC) avoids wear failure.

[0036] 3. Compared with the patent CN113695845A, which discloses a method for processing floating rings of a tunneling machine's main drive bearing, this invention, through the design of a floating ring and spring mechanism, can effectively absorb the strong impacts caused by vibrations during the main bearing's service life, avoiding frequent collisions between the auxiliary thrust rollers and the raceway surface that could cause damage, thereby significantly improving the stability and reliability of the main bearing. Because it effectively avoids frequent collisions between the auxiliary thrust rollers and the raceway surface, it reduces damage caused by collisions, thus significantly improving the service life of the main bearing. This invention, through the design of reasonable floating ring structural dimensions and spring mechanism parameters, ensures that the floating ring can closely contact the auxiliary thrust rollers when the moving ring vibrates, and absorbs the impact energy through the spring mechanism.

[0037] 4. Compared with the patent CN114970008A, which discloses a design method for a disc spring assembly of a tunneling machine main bearing, this invention, starting from the absorption of vibration and impact during the service of the main bearing, considers dynamic parameters such as excitation force amplitude, excitation frequency, and resonance amplification coefficient when determining the total preload of the vibration damping spring. This allows for better handling of vibration during main bearing operation, effectively preventing frequent collisions between the auxiliary thrust roller and the raceway surface due to vibration, reducing the risk of premature main bearing failure, and ensuring stable operation of the main bearing. This invention not only designs the structural dimensions (inner diameter, outer diameter, thickness) of the floating ring in detail, relating them to the dimensions of the auxiliary thrust roller of the main bearing, but also designs the structure, quantity, distribution, and parameters of the spring mechanism, achieving coordinated design of the floating ring and the spring mechanism to form a complete system that more effectively exerts its vibration damping effect. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the cross-section of the main bearing of a tunnel boring machine (TBM).

[0039] Figure 2 This is a schematic diagram of a spring mechanism. The diagram is labeled as follows: 1-T-type spring guide rod, 2-washer, 3-disc spring, 4-secondary push ring, 5-plug. Detailed Implementation

[0040] In practical implementation, a design method for a floating ring and spring mechanism of a large main bearing in a tunnel boring machine (TBM) is achieved through the following steps:

[0041] Step 1: Determine the structural dimensions of the floating ring, including: the inner diameter of the floating ring, the outer diameter of the floating ring, and the thickness of the floating ring.

[0042] Step 2: Determine the total preload of the damping springs.

[0043] Step 3: Determine the parameters of the spring mechanism, including: the structure of the spring mechanism, the number and distribution of spring mechanisms, the number of damping springs and the preload in a single spring mechanism.

[0044] Step 4: Complete the design of the floating ring and spring mechanism by verifying the stress through force calculations.

[0045] In step one, the inner diameter, outer diameter, and thickness of the floating ring are determined based on the nominal length and pitch circle diameter of the main bearing's auxiliary thrust roller. The inner diameter of the floating ring is determined by subtracting 1.2 to 1.5 times the nominal length of the main bearing's auxiliary thrust roller from the pitch circle diameter. The outer diameter of the floating ring is determined by adding 1.2 to 1.5 times the nominal length of the main bearing roller to the pitch circle diameter. The thickness of the floating ring is between 0.4 and 0.8 times the roller diameter to ensure sufficient rigidity for machining and quenching.

[0046] In step two, the principle for determining the total preload of the damping spring is: when the inner ring is subjected to vibration, the auxiliary push roller will not separate from the inner ring and floating ring due to vibration and thus collide.

[0047] In step two, the process of determining the total preload is as follows:

[0048] 1) 0.5% to 1% of the maximum value in the load spectrum is taken as the excitation force amplitude, and the static displacement generated under the action of the excitation force is A.

[0049] 2) The maximum excitation frequency generated by the excitation force is f max .

[0050] 3) The amplification factor of resonance is α.

[0051] 4) The mass of the floating ring is m f The total mass of the auxiliary thrust roller is m r .

[0052] 5) The total preload of the vibration damping springs should satisfy: F≥α(m) f +m r )(2πf max ) 2 A.

[0053] In step three, the spring mechanism consists of a T-shaped spring guide rod 1, a washer 2, a disc spring 3, a secondary push ring 4, and a plug 5, as follows: Figure 2 As shown. A through hole is provided at the center of the raceway surface of the auxiliary push ring 4. One side of the through hole corresponds to and matches the T-shaped spring guide rod 1. A shim 2 and a disc spring 3 are installed in the two gaps between the T-shaped spring guide rod 1 and the auxiliary push ring 4. The disc spring 3 is located between the two gaps where the shim 2 is installed. When assembled, the T-shaped spring guide rod 1 compresses the disc spring 3. The other side of the through hole corresponds to and matches the plug 5. The plug 5 blocks the other side of the through hole to prevent oil leakage during normal operation. The disc spring 3 is guided by an inner ring, and the guide gap between it and the T-shaped spring guide rod 1 meets the corresponding standard requirements. The hardness of the contact part between the inner ring of the T-shaped spring guide rod 1 and the disc spring 3 does not exceed 55HRC, and the surface hardness of the shim 2 is not lower than 55HRC.

[0054] In step three, the maximum outer diameter D of the spring mechanism s The number of spring mechanisms is 0.4 to 0.8 times the nominal length of the roller. The spring mechanism is evenly distributed on the auxiliary push ring.

[0055] In step three, in the free state, the top of the T-shaped spring guide rod of the spring mechanism is d above the surface of the auxiliary push ring. s 1~3mm.

[0056] In step three, the selection principle for damping springs is as follows:

[0057] 1) Due to the limitations of the main bearing structure dimensions, the outer diameter of the damping spring shall not exceed the difference between the inner and outer diameters of the floating ring, and the inner diameter of the damping spring shall not be lower than the diameter of the spring guide rod.

[0058] 2) The damping spring meets the requirement of infinite life, that is, the number of cycles > 2e6 times.

[0059] 3) The compression of a single damping spring shall not be less than 0.15 times the initial height in the free state, i.e., 0.15h0.

[0060] 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.

[0061] Example

[0062] Taking the large main bearing of a tunnel boring machine (TBM) with an outer diameter of Φ6m as an example, this paper briefly explains the basic design process of a floating ring.

[0063] Step 1: When designing the floating ring, the pitch circle diameter and nominal length of the auxiliary thrust roller are known conditions. Pitch circle diameter D0 = 5553mm, nominal diameter of the auxiliary thrust roller l... w =70mm. Therefore:

[0064] Floating ring outer diameter D e The pitch circle diameter of the auxiliary push roller plus 1.2 to 1.5 times (preferably 1.25 times) of the nominal length of the roller is 5640 mm.

[0065] The inner diameter of the floating ring is D i =5458mm D i The pitch circle diameter of the auxiliary push roller is 1.2 to 1.5 times (preferably 1.36 times) of the nominal length of the roller, which is 5458 mm.

[0066] The thickness H of the floating ring is between 0.4 and 0.8 times (preferably 0.57) the diameter of the roller, and is 40 mm.

[0067] Step Two: When designing the floating ring, it is assumed that the total mass of the rollers is known. Based on Step One, the mass of the floating ring can be obtained. The total mass of the rollers is m. r The total mass of the floating ring is 430 kg. f It weighs 483.24 kg.

[0068] Set the maximum vibration frequency f of the inner ring of the main bearing max It is 400Hz.

[0069] The resonance amplification factor α is selected as 6.

[0070] Using the elastic approximation method, the static displacement A = 2.187 μm generated by the excitation force amplitude at 0 Hz was calculated.

[0071] Therefore, the minimum required preload F is calculated. min =α(m f +m r )(2πf max ) 2 A = 75695N.

[0072] Step 3: Maximum outer diameter D of the spring mechanism s It is 0.4 to 0.8 times (preferably 0.7) of the nominal length of the roller, which is 47 mm.

[0073] The spring mechanism consists of 80 springs, evenly distributed.

[0074] The minimum preload provided by each spring mechanism is 946 N.

[0075] Based on the requirement of unlimited life of the spring and the requirement that the compression of a single damping spring is greater than 0.15h0, the B45 disc spring (GB / T 1972) is selected as the damping spring.

[0076] The top of the spring guide rod is 1.5mm above the surface of the collar.

[0077] Step 4: Complete the design of the floating ring and spring mechanism by verifying the stress through force calculations.

[0078] The implementation results show that the present invention incorporates dynamic parameters such as excitation frequency (400Hz), resonance amplification factor (6), and floating ring mass (483.24kg) into the preload calculation to ensure that the auxiliary push roller and the raceway surface always maintain tight contact under vibration conditions (as in the example, the preload is calculated to be 946N); through the precise matching of the inner diameter (pitch circle diameter - 1.36 times the roller length), outer diameter (pitch circle diameter + 1.25 times the roller length), and thickness (0.57 times the roller diameter) of the floating ring, combined with the uniformly distributed design of the spring mechanism (80 spring mechanisms), a "floating ring-spring" dynamic vibration reduction system is formed. This invention provides a design basis for the floating ring and spring mechanism of the large main bearing of the tunnel boring machine (TBM) operating under strong impact and heavy load conditions. It ensures tight contact between the roller and the raceway surface during service, avoids vibration between the roller and the raceway surface caused by strong impact and heavy load conditions, thus preventing premature failure of the roller and the raceway surface, thereby ensuring the stable operation and safe and reliable operation of the large main bearing of the TBM.

Claims

1. A design method for a floating ring and spring mechanism of a large main bearing in a tunneling machine, characterized in that, Includes the following steps: Step 1: Determine the structural dimensions of the floating ring, including: the inner diameter of the floating ring, the outer diameter of the floating ring, and the thickness of the floating ring; Step 2: Determine the total preload of the damping springs; Step 3: Determine the parameters of the spring mechanism, including: the structure of the spring mechanism, the number and distribution of spring mechanisms, the number of damping springs and the preload in a single spring mechanism; Step 4: Complete the design of the floating ring and spring mechanism by verifying the stress through force calculations.

2. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that: In step one, the inner diameter, outer diameter, and thickness of the floating ring are determined based on the nominal length and pitch circle diameter of the main bearing push roller. Based on the pitch circle diameter, subtract 1.2 to 1.5 times the nominal length of the main bearing push roller to determine the inner diameter of the floating ring; Based on the pitch circle diameter, add 1.2 to 1.5 times the nominal length of the main bearing rollers to determine the outer diameter of the floating ring; The thickness of the floating ring is between 0.4 and 0.8 times the roller diameter to ensure sufficient rigidity for machining and quenching.

3. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that, In step two, the principle for determining the total preload of the damping spring is: when the inner ring is subjected to vibration, the auxiliary push roller will not separate from the inner ring and floating ring due to vibration and thus collide.

4. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that, In step two, the process of determining the total preload is as follows: 1) 0.5% to 1% of the maximum value in the load spectrum is taken as the excitation force amplitude, and the static displacement generated under the action of the excitation force is A; 2) The maximum excitation frequency generated by the excitation force is f max ; 3) The amplification factor of resonance is α; 4) The mass of the floating ring is m f The total mass of the auxiliary thrust roller is m r ; 5) The total preload of the damping springs satisfies: F ≥ α(m) f +m r )(2πf max ) 2 A.

5. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that: In step three, the spring mechanism consists of a T-shaped spring guide rod, a washer, a disc spring, a secondary push ring, and a plug. A through hole is located at the center of the raceway surface of the secondary push ring. One side of the through hole corresponds to and matches the T-shaped spring guide rod. A washer and a disc spring are installed in the two gaps between the T-shaped spring guide rod and the secondary push ring. The disc spring is located between the washer in the two gaps. During assembly, the T-shaped spring guide rod compresses the disc spring. The other side of the through hole corresponds to and matches the plug, which blocks the other side of the through hole to prevent oil leakage during normal operation. An inner ring guide is used to guide the disc spring, and the guide gap between the inner ring and the T-shaped spring guide rod meets the corresponding standard requirements. The hardness of the contact portion between the T-shaped spring guide rod and the inner ring of the disc spring does not exceed 55 HRC, and the surface hardness of the washer is not lower than 55 HRC.

6. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that: In step three, the maximum outer diameter D of the spring mechanism s The number of spring mechanisms is 0.4 to 0.8 times the nominal length of the roller. They are evenly distributed on the auxiliary thrust rings.

7. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that: In step three, in the free state, the top of the T-shaped spring guide rod of the spring mechanism is a distance d above the surface of the auxiliary push ring. s It is 1-3mm.

8. The design method of a floating ring and spring mechanism for a large main bearing of a tunneling machine according to claim 1, characterized in that, In step three, the selection principle for damping springs is as follows: 1) Due to the limitations of the main bearing structure dimensions, the outer diameter of the damping spring shall not exceed the difference between the inner and outer diameters of the floating ring, and the inner diameter of the damping spring shall not be lower than the diameter of the spring guide rod; 2) The damping spring meets the requirement of infinite life, that is, the number of cycles > 2e6; 3) The compression of a single damping spring is not less than 0.15 times its initial height in the free state, i.e., 0.15h0.

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