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Study on structural parameter design and life analysis of large four-point contact ball bearing channel

Published Online: 15 Dec 2022
Volume & Issue: AHEAD OF PRINT
Page range: -
Received: 04 May 2022
Accepted: 08 Jul 2022
Journal Details
License
Format
Journal
eISSN
2444-8656
First Published
01 Jan 2016
Publication timeframe
2 times per year
Languages
English
Introduction

Large rolling bearings are widely used in engineering and construction machinery, such as tower cranes, excavators and concrete pump trucks. On such occasions, the bearing should have a large bearing capacity and high reliability [1, 2]. In addition, large rolling bearings are also used in heavy equipment such as metallurgy and mining. Such bearings have a poor working environment, large load, high temperature, and large dust, which requires bearings to have a large bearing capacity, good sealing and high-temperature resistance [35]. Large rolling bearings are also used in offshore equipment, such as offshore platforms, various port cranes and deck cranes. It requires large rolling bearings to have high safety, good anti-corrosion, sealing and reliability [6]. Large rolling bearings are also used in wind turbine equipment and military equipment such as radar, antenna and airborne vehicles [7, 8]. Therefore, it is very necessary to design the channel structure and study the service life of a large four-point contact ball bearing.

Four-point contact ball bearings are used more and more in the aviation transmission system, automobile transmission systems, precision machinery and other aspects because of their advantages of many balls, large bearing capacity, two-way axial load, small axial space and high limit speed [9, 10]. With the progress of technology, users put forward higher requirements for the accuracy, performance, service life and reliability of bearings. The structural design of the cage directly affects the service performance of the bearing [11, 12]. S. Zupn, Z. pre and others believe that the flexible support of a large four-point contact ball bearing and the deformation of its ferrule have a great impact on the load distribution of the bearing. In this paper, two different models are established. After comparing the results, it is found that the deformation of flexible support and ferrule has a great impact on the load distribution of the bearing [13]. Jose et al. Assuming that the inner and outer rings of the bearing were purely rigid and considering that there was only contact local deformation between the rolling element and the ferrule, using Hertz contact theory and spatial coordinate transformation, the balance equation of a single row four-point contact bearing was derived to calculate the load distribution and contact angle distribution of the bearing [14]. The use of 50K in the finite element method is to replace the rolling element with a special super element with the deformation characteristics of the contact load between the rolling element and the channel. Hence we can calculate the deformation and load distribution of the three-row thrust roller bearing [15]. Moxse et al. established the full model of single row four-point contact bearing and support structure. Considering the deformation of the bearing ring and its support structure, finite element analysis software was used to truly simulate the load distribution and contact angle of the bearing [16]. Kania et al. [17] Established the finite element simplified models of angular contact ball bearing, four-point angular contact ball bearing, double row four point angular contact ball bearing and three-row cylindrical roller combined bearing respectively by using the super element method to analyse the mechanical properties of various bearings. In the analysis process, he considered the deformation of bearing support structure and ferrule and the influence of bearing connecting bolts on the mechanical properties of bearings. The research on the fatigue life of large rolling bearings is generally based on the analysis of rolling contact fatigue life. F. Based on the Lagrange method, the relationship between the contact force and the contact stress in the direction of X W Z and the contact stress on the surface is calculated by using the Lagrange method [18]. R. J. S proposed a new rolling contact fatigue analysis method by comprehensively using the elastic-plastic finite element method and the dangerous plane multiaxial fatigue crack generation model, and analysed the rolling contact fatigue life of railway wheel-rail contact [19]. Abbas et al. [20] Used elastodynamics and optimisation methods to optimise the fatigue life of ordinary bearings. Glode et al. [21] proposed a static strength and fatigue life analysis model of large rotary table bearing. First, they established the static balance equation of large rotary table bearing, solved the load distribution of rolling element and the maximum load of rolling element and channel contact, and calculated the static strength of bearing by using Hertz contact theory, Then, according to the mechanical properties of the bearing ring material, the stress life model and strain life model are used to analyse the fatigue life of the channel and compared with the calculation results. The disadvantage of this method is that it does not consider the influence of the bearing support groove and the deformation of the bearing ring on the load distribution on the rolling element.

First, the channel structure parameters of a large four-point contact ball bearing are optimised by optimisation, and its fatigue life is analysed. At present, the fatigue life of rolling bearings is analysed according to the standard load rating life formula [22], but this formula is established based on ordinary bearings made of steel and does not consider the impact of bearing materials and their attribute changes on bearing life. There is a certain error in using this formula to calculate the life of large rolling bearings.

Simplified bearing fatigue model and four-point finite element method
Structure and simplified model of four-point contact ball bearing

The geometric structure of four-point angular contact ball bearing is shown in Figure 1(a) [23]. The inner diameter of the bearing is Di, the outer diameter is d0, the diameter of the distribution circle of the rolling element is DM, and the diameter of the rolling element is DW. RI and R0 are the radius of curvature of the inner and outer ring channels of the bearing respectively. The bearing channel is composed of four channel surfaces, of which ci1 is the curvature centre of the upper channel of the inner ring, Ci2 is the curvature centre of the lower channel of the inner ring, C01 is the curvature centre of the upper channel of the outer ring, and C02 is the curvature centre of the lower channel of the outer ring, β is the initial contact angle of four-point angular contact ball bearing. The super-element method simplifies the structure of the bearing rolling element. As shown in Figure 1(b), each rolling element is replaced by eight rigid rod elements and two nonlinear spring elements. The two ends of one spring yellow are the curvature centre Ci1 of the upper channel of the inner ring and the curvature centre C02 of the lower channel of the outer ring, and the two ends of the other spring are the curvature centre Ci2 of the lower channel of the inner ring and the curvature centre C01 of the upper channel of the outer ring. Ci1 is connected with the upper channel of the inner ring through two rigid rods, Ci2 is connected with the lower channel of the inner ring through two rigid rods, C01 is connected with the upper channel of the outer ring through two rigid rods, and C02 is connected with the lower channel of the outer ring through two rigid rods. The four-point angular contact ball bearing deforms under the action of external load, and its contact angle β is the included angle between the nonlinear spring and the radial bearing, as shown in Figure 1(c) [24].

Fig. 1

Shows the structural diagram of four-point angular contact ball bearing, (a) geometric structure of four-point angular contact ball bearing; (b) The super element method simplifies the structure of bearing rolling element; (c) Angle structure between nonlinear spring and radial bearing

The simplified finite element model of a large four-point angular contact ball bearing mainly uses the nonlinear spring connecting the centre points of curvature of two channels to simulate the compression of rolling elements [25, 26]. Therefore, the nonlinear spring only acts when in tension to simulate the compression of the bearing rolling element, which can well simulate the mechanical characteristics and geometric structure changes of the bearing under the action of load. As shown in Figure 2, under the action of load, the distance between the compression channels of the rolling element close to the curvature centre of the channel becomes larger. At this time, the compression of the rolling element can be simulated as the tension of the nonlinear spring connecting the curvature centre of the channel, The load-deformation curve of the spring in tension is defined according to the load-deformation relationship when the rolling element and the channel contact are compressed [27]. This method can not only analyse the load on the rolling element but also analyse the change of the contact angle between the rolling element and the channel through the displacement of the centre points Ci1, Ci2, C01 and C02 of the channel curvature.

Fig. 2

Shows the bearing force model of four-point angular contact shaft

The simplified finite element model of four-point angular contact ball bearing is shown in Figure 3.

Fig. 3

Simplified finite element model of four-point angular contact ball bearing

Fatigue life analysis method

General steps of stress life analysis method: first, calculate the isotropic stress, maximum and minimum stress, average stress and stress amplitude at the fatigue part of parts by theoretical method or finite element method, and then calculate the equivalent stress, equal effect stress amplitude and equal effect average stress by distortion energy theory; second, the reverse bending stress is calculated by selecting different fatigue analysis models in Table 1. Finally, the fatigue life is calculated according to the life calculation formula [28].

Calculation of stress in opposite direction

Fatigue modelCalculation formula
Gerber modelσer=σa/[1(σm/σx)]
Modified Gerber modelσer=σa/[1(σm/σn)]
SAE modelσer=σa/[1(σm/σy)]
Soderberg modelσer=σa/[1(σm/σy)]

Midpoint data in S-N diagram

Fatigue modelσfNfσeNe
Toughness and rigidity (σu98.5 MPa)
Gerber theory0.9σu103Kσu/2106
Modified Gerber theory0.9σu103Kσu/2106
SAE theoryσu+500001Kσu/2106
Soderberg theory0.9σu103Kσu/2106
Toughness and rigidity (σu98.5 MPa)
Gerber theory0.9σu103Kσu/3108
Modified Gerber theory0.9σu103Kσu/3108
SAE theoryσu1Kσu/3108
Soderberg theory0.9σu103Kσu/3108

The average amplitude of stress and strain can be calculated by the following formula: σm=σmax+σmin2 σa=σmaxσmin2 εm=εmax+εmin2 εa=εmaxεmin2

σm, σa, εm, εa are all are stress.

Von-Mises equivalent stress calculation formula is: σeq=12(σxσy)2+(σyσz)2+(σxσaz)2+6(τxy2+τyz2+τxz2)

Equivalent force amplitude σa.eq σaeq=12(σaxσay)2+(σayσaz)2+(σaxσaz)2+6(τaxy2+τavz2+τaxz2)

Among σax>σay>σaz , subscript indicates three axial directions of micro elements in dangerous parts of parts. among σn is the tensile limit, σy is the yield limit.

The average equivalent stress is: σmeq=12(σmxσmy)2+(σmvσmz)2+(σmxσmz)2+6(τmxy2+τmzz2+τmaxz2) in σmx>σmy>σmz .

The maximum principal strain criterion is to use the maximum strain amplitude of dangerous parts of parts ξa1 calculate the fatigue life by Manson coffin formula [29]: εa1=σfσmE(2Nf)b+εf(2Nf)c

The maximum shear strain criterion is to calculate the maximum shear strain of the dangerous part γmax , i.e.: γamax=max(εa1εa2,εa2εa3,εa1εa3)

The fatigue life is calculated by Manson’s coffin formula according to the maximum shear strain: γamax=(1+v)σfσmE(2Nf)b+(1+vp)εf(2Nf)c

The maximum strain criterion is to calculate the equivalent strain of dangerous parts of parts by using the Von-Mises principle ξa , namely: ε¯a=12(1+u)(εxεy)2+(εyεz)2+(εxεz)2+32(γxy2+γyz2+γxz2)

Then use the Manson-Coffin formula to calculate the fatigue life of parts: ε¯a=σfσmE(2Nf)b+εf(2Nf)c

Fatigue damage accumulation theory includes Miner linear cumulative damage theory and cortan Dolan [24] modified damage theory. Miner linear cumulative damage theory is generally used for accumulation in the early stage of component design, because Miner linear cumulative damage theory is relatively simple, practical and convenient, but cortan Dolan modified damage theory considers the interaction between various groups of stresses, Therefore, the accuracy of calculating the service life of parts by the modified damage theory is higher than that by miner’s linear cumulative damage theory [30].

The total damage rate D calculated by Miner linear cumulative damage theory is as follows: D=1iDi=1iniNi

The calculation formula of Cortan-Dolan modified damage theory to calculate the life Ng is as follows: Ng=N1αi(σi/σ1)d

Where N1 is the component under the maximum constant amplitude load stress σ1 fatigue life, α is the ratio of the action times of group I constant amplitude load stress to the action times of total load, and D is the material constant [31].

Channel parameter design of four-point contact ball bearing

The structural parameters of double row four-point angular contact ball bearing are shown in Figure 4. The influence of channel spacing x on the distribution of load on the two-channel rolling body is analysed. When the distance between the two channels of the bearing decreases, it is conducive to improve the bearing capacity of the bearing. However, with the decrease of channel spacing, the H-Side decreases, the stiffness of the side begins to decrease, and the deformation will increase under the action of load. The influence is analysed by establishing a simplified finite element model [32].

Fig. 4

Structure diagram of double row four point contact bearing

Analysis of finite element calculation results of bearing

The calculation results of six groups of finite elements are shown in Table 3. According to the analysis results, when the distance between the two channels of the bearing is 105 mm, the maximum load on the first channel rolling element is 101.097 kn, the maximum load on the second channel rolling element is 137.313 kn, and the ratio of the maximum load of the first channel to the second channel rolling element is 0.7499. When the distance between the two channels of the bearing is 65 mm, the maximum load on the rolling element of the first channel is 107.778, the maximum load on the rolling element of the second channel is 126.754, and the ratio of the maximum load of the first channel to the rolling element of the second channel is 0.8503. When the bearing channel spacing gradually decreases from 105 mm to 65 mm, the maximum contact load on the first channel rolling element gradually increases from 103.097 kn to 107.778 kn, the maximum contact load on the second channel rolling element gradually decreases from 137.383 kn to 126.754 kn, and the ratio of the maximum value of the first channel load to the maximum value of the second channel load gradually increases from 0.7504 to 0.85029, which indicates that when the distance between the two channels of the bearing decreases, The closer the load is distributed between the first channel and the second channel.

Load comparison of two channels with different channel spacing

X/mm1059789817365
1-Qmax/kN101.097103.847105.77106.65107.809107.778
2-Qmax/kN137.313137.211133.59131.39129.510126.754
Level0.74990.75680.791750.811700.832440.85029

In the process of reducing the channel spacing, the thickness of the retaining edge between the two channels will be reduced accordingly, which will reduce the stiffness of the retaining edge. Under the action of external load, the deformation of the retaining edge between the two channels will increase, which will reduce the mechanical properties and service life of the bearing. The maximum deformation of the retaining edge of each model is shown in Table 4. When the bearing channel spacing is 105 mm, the maximum deformation of the retaining edge is 0.1714 mm, when the bearing channel spacing is 81 mm, the maximum deformation of the retaining edge is 0.1572 mm, and when the bearing channel spacing is 65 mm, the deformation of the retaining edge is 0.1903 mm. It can be seen from the data in the table that when the bearing channel spacing gradually decreases from 105 mm to 81 mm, since the load on the first channel rolling element tends to be consistent with the load on the second channel rolling element, the load on the first channel rolling element increases, the load on the second channel rolling element decreases, and the deformation of the retaining edge between the first channel and the second channel gradually decreases from 0.1714 mm to 0.1572 mm. When the bearing channel spacing gradually decreases from 81 mm to 65 mm, Although the load on the first channel rolling element continues to be consistent with the load on the second channel rolling element, and the maximum load of the second channel decreases, the deformation of the retaining edge between the two channels increases from 0.1572 mm to 0.1903 mm due to the reduction of the stiffness of the retaining edge between the two channels.

Deformation of retaining edge at different channel spacing

Spacing/mm6573818997105
Deformation/mm0.19030.16170.15720.16010.16480.1714
Optimise bearing channel spacing

The Newton difference method is used to fit the difference between different channel spacing and retaining edge deformation, and the channel spacing at the minimum deformation of retaining edge is obtained. The Newton interpolation fitting curve of different channel spacing and retaining edge deformation is shown in Figure 5. From the fitting curve, it can be seen that the corresponding channel spacing is 78 mm.

Fig. 5

Newton difference fitting

The bearing channel spacing x = 80 mm is selected, and the finite element simplified model of large rolling bearing is used for modelling and analysis. The results are that the maximum load of the first channel is 107.777 kn and the maximum load of the second channel is 129.922 kn. The ratio of the maximum load of the first channel to the maximum load of the second channel is 0.8295. The deformation of the retaining edge between channels is shown in Figure 5. At this time, the maximum deformation of the retaining edge is 0.1569 mm. To sum up, it is reasonable to take 80 mm as the spacing between the two channels of the bearing.

Parameter optimisation of channel curvature radius coefficient

f=rDw

Where r is the channel radius and Dw is the rolling element diameter.

The influence of groove radius of curvature coefficient on bearing performance mainly includes: contact stress, friction torque, lubrication performance (oil film thickness). Since the rotating speed of large rolling bearings is low, generally no more than 10 R/min, and grease lubrication is adopted, the influence on lubrication is not considered here. When the bearing rotates, the steel ball makes a complex three-dimensional motion. That is, the rotation motion, revolution motion and spin sliding of the steel ball, so the friction in the rolling bearing is a complex tribological system. For heavy-duty low-speed rolling bearings with solid lubrication or grease lubrication, due to their low speed, the lubricating oil film cannot be formed, and there is certain friction between the rolling body and the channel. Its manifestation is the friction torque on the rotation axis of the bearing. The factors affecting the bearing friction torque include the micro slip between the rolling body and the channel, the elastic lag of the material at the contact between the rolling body and the channel, and the spin during the revolution of the rolling body, To consider the friction torque formed at the contact between the rolling element and the inner and outer rings of the bearing respectively by these three factors, the following assumptions should be made [33]:

In the process of contact with the inner and outer ring channels, the rolling body pure rolls with one channel and rolls and spins with the other channel.

Micro slip only appears on the channel contact surface where the rolling element and the channel are pure rollings, and the elastic hysteresis of the material at the contact between the rolling element and the channel appears on the inner and outer ring channels in contact with the rolling element at the same time.

The sliding friction coefficient between the rolling element and the channel is a fixed value, which is independent of the contact stress between them.

Because there is a certain speed difference in the contact area during the contact between the rolling body and the channel, there is not only pure rolling but also sliding in the contact area. The following equilibrium equation can be obtained: 01(1Y3)H(2H)(1K3Y2)dY=0

Among Y = y/a

H=K1(γ2Y2)1Y2 K1=πa3bE3QDW2μ K3=2a2Dw2

Q – contact load of rolling element, N; E ‘– equivalent elastic modulus, MPa; μ – Sliding friction coefficient between rolling element and channel, μ = 0.1; a. B – respectively the long and short half axis dimensions of the contact ellipse area between the rolling element and the channel, mm; Dw – diameter of rolling element, mm; γ – Unknown parameter, quantity to be found [34].

The resistance caused by micro sliding is: Fm=K201(1Y2)H(2H)dY

Among: K2=3μQ2

The rolling resistance Fm generated by micro sliding acts on the bearing rolling element. At this time, there are two situations: one is that the micro sliding of the rolling element in contact with the channel appears on the contact surface with the outer channel; Second, the micro slip of the contact between the rolling element and the channel appears on the contact surface with the inner channel. Therefore, there are two forms when the rolling resistance generated by micro sliding is transformed into the friction torque of the bearing [24].

First, micro slip occurs on the contact surface between the rolling element and the outer channel. At this time, there are: Tmo=Fm(Ri+DWcosα)2

First, micro slip occurs on the contact surface between the rolling element and the inner channel. At this time, there are: Tmi=FmRi2

Where Ri is the radius of the contact circle between the rolling element and the inner channel [35].

To sum up, if the groove radius of curvature coefficient is too large, the bearing contact stress is large, and the bearing life is reduced. If it is too small, the total friction resistance moment will increase and the bearing friction will increase proportionally. Normalise the contact stress and friction resistance moment and draw them on the same figure. As shown in Figure 6, the intersection of the two curves is the optimal groove curvature radius coefficient. The best value is 0.524.

Fig. 6

Normalization processing

Atigue life analysis

The stress life and strain life analysis are used to analyse the fatigue life of the bearing after changing the bearing structure. After changing the bearing structure, the maximum contact load between the rolling element and the channel is 130.5 kN, the maximum contact pressure stress between the rolling element and the inner ring channel is 3148.5 MPa, the maximum contact pressure stress between the rolling element and the outer ring channel is 3100 MPa, and the maximum equivalent stress on the contact subsurface between the rolling element and the outer ring is 1976.7 MPa. The maximum shear strain of the contact subsurface between the rolling element and the outer ring is 12.24×10−3 mm. The fatigue life of the bearing after changing the bearing structure is shown in Table 5.

Bearing life

Life calculation method
σ-Nε-N
N (2Nf)[·106cyc]12.1907.26
L[·104cyc]21.81812.91

The bearing life calculated by the stress life model is 21.818×104r. The bearing life calculated by the strain life model is 12.91×104r. The calculation result of the stress life model is 1.699 times that of strain life.

Conclusion

Firstly, the structure and simplified model of four-point contact ball bearing are introduced, and the analysis method of fatigue life is introduced. The channel parameters of four point contact ball bearing are designed and optimised. First, the bearing finite element calculation results are analysed, then the bearing channel spacing is optimised, and finally, the parameters of the channel curvature radius coefficient are optimised. After the design and optimization of the channel parameters of four point contact ball bearing, the fatigue life is analysed, The conclusions are as follows: (1) for double row four-point contact ball bearing, the smaller the channel spacing is, the more uniform the load is in the two channels, which can reduce the maximum load of the bearing, but the deformation of the retaining edge between the two channels will increase after the channel spacing is reduced to a certain extent; (2) For ball bearings, when the load on the rolling element is constant, the maximum contact compressive stress between the rolling element and the channel, the maximum equivalent stress and the maximum shear strain on the secondary surface of the channel decrease with the decrease of the curvature radius coefficient of the channel; (3) For the optimised bearing life, the result of the model calculation is significantly higher than that of the first case of strain calculation.

Fig. 1

Shows the structural diagram of four-point angular contact ball bearing, (a) geometric structure of four-point angular contact ball bearing; (b) The super element method simplifies the structure of bearing rolling element; (c) Angle structure between nonlinear spring and radial bearing
Shows the structural diagram of four-point angular contact ball bearing, (a) geometric structure of four-point angular contact ball bearing; (b) The super element method simplifies the structure of bearing rolling element; (c) Angle structure between nonlinear spring and radial bearing

Fig. 2

Shows the bearing force model of four-point angular contact shaft
Shows the bearing force model of four-point angular contact shaft

Fig. 3

Simplified finite element model of four-point angular contact ball bearing
Simplified finite element model of four-point angular contact ball bearing

Fig. 4

Structure diagram of double row four point contact bearing
Structure diagram of double row four point contact bearing

Fig. 5

Newton difference fitting
Newton difference fitting

Fig. 6

Normalization processing
Normalization processing

Deformation of retaining edge at different channel spacing

Spacing/mm 65 73 81 89 97 105
Deformation/mm 0.1903 0.1617 0.1572 0.1601 0.1648 0.1714

Calculation of stress in opposite direction

Fatigue model Calculation formula
Gerber model σer=σa/[1(σm/σx)]
Modified Gerber model σer=σa/[1(σm/σn)]
SAE model σer=σa/[1(σm/σy)]
Soderberg model σer=σa/[1(σm/σy)]

Bearing life

Life calculation method
σ-N ε-N
N (2Nf) [·106cyc] 12.190 7.26
L [·104cyc] 21.818 12.91

Midpoint data in S-N diagram

Fatigue model σf Nf σe Ne
Toughness and rigidity (σu98.5 MPa)
Gerber theory 0.9σu 103 Kσu/2 106
Modified Gerber theory 0.9σu 103 Kσu/2 106
SAE theory σu+50000 1 Kσu/2 106
Soderberg theory 0.9σu 103 Kσu/2 106
Toughness and rigidity (σu98.5 MPa)
Gerber theory 0.9σu 103 Kσu/3 108
Modified Gerber theory 0.9σu 103 Kσu/3 108
SAE theory σu 1 Kσu/3 108
Soderberg theory 0.9σu 103 Kσu/3 108

Load comparison of two channels with different channel spacing

X/mm 105 97 89 81 73 65
1-Qmax/kN 101.097 103.847 105.77 106.65 107.809 107.778
2-Qmax/kN 137.313 137.211 133.59 131.39 129.510 126.754
Level 0.7499 0.7568 0.79175 0.81170 0.83244 0.85029

Y. Zhang, T. Qian, W. Tang, Buildings-to-distribution-network integration considering power transformer loading capability and distribution network reconfiguration, Energy 244 (2022). Zhang, Y. Qian, T. Tang, W. Buildings-to-distribution-network integration considering power transformer loading capability and distribution network reconfiguration, Energy 244 (2022).10.1016/j.energy.2022.123104Search in Google Scholar

S.L. Lez, M. Arghir, J. Frene, Static and Dynamic Characterization of a Bump-Type Foil Bearing Structure, Journal of Tribology 129(1) (2007). Lez, S.L. Arghir, M. Frene, J. Static and Dynamic Characterization of a Bump-Type Foil Bearing Structure, Journal of Tribology 129(1) (2007).10.1115/1.2390717Search in Google Scholar

B. Zhao, T. Qian, W.H. Tang, A Data-enhanced Distributionally Robust Optimization Method for Economic Dispatch of Integrated Electricity and Natural Gas Systems with Wind Uncertainty, (2021). Zhao, B. Qian, T. Tang, W.H. A Data-enhanced Distributionally Robust Optimization Method for Economic Dispatch of Integrated Electricity and Natural Gas Systems with Wind Uncertainty, (2021).10.1016/j.energy.2022.123113Search in Google Scholar

S.L. Lez, M. Arghir, J. Frene, A New Bump-Type Foil Bearing Structure Analytical Model, Asme Journal of Engineering for Gas Turbines & Power 129(4) (2007) 747-757. Lez, S.L. Arghir, M. Frene, J. A New Bump-Type Foil Bearing Structure Analytical Model, Asme Journal of Engineering for Gas Turbines & Power 129(4) (2007) 747-757.10.1115/1.2747638Search in Google Scholar

J.Q. Hao, R. Feng, J.G. Zhou, S.Q. Qian, J.T. Gao, Resistivity tomography study on samples with water-bearing structure, Acta Seismologica Sinica (2000). Hao, J.Q. Feng, R. Zhou, J.G. Qian, S.Q. Gao, J.T. Resistivity tomography study on samples with water-bearing structure, Acta Seismologica Sinica (2000).Search in Google Scholar

A.M. Gad, S. Kaneko, Tailoring of the bearing stiffness to enhance the performance of gas-lubricated bump-type foil thrust bearing, ARCHIVE Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology 1994-1996 (vols 208-210) (2015) 1350650115606482. Gad, A.M. Kaneko, S. Tailoring of the bearing stiffness to enhance the performance of gas-lubricated bump-type foil thrust bearing, ARCHIVE Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology 1994-1996 (vols 208-210) (2015) 1350650115606482.10.1177/1350650115606482Search in Google Scholar

A.M. Gad, On the performance of foil thrust bearing with misaligned bearing runner, Industrial Lubrication and Tribology 69(2) (2017) 105-115. Gad, A.M. On the performance of foil thrust bearing with misaligned bearing runner, Industrial Lubrication and Tribology 69(2) (2017) 105-115.10.1108/ILT-11-2015-0177Search in Google Scholar

Z. Liu, S. Liu, Y. Liu, Research on transient electromagnetic field of mine water-bearing structure by physical model experiment, Chinese Journal of Rock Mechanics & Engineering 28(2) (2009) 259-266. Liu, Z. Liu, S. Liu, Y. Research on transient electromagnetic field of mine water-bearing structure by physical model experiment, Chinese Journal of Rock Mechanics & Engineering 28(2) (2009) 259-266.Search in Google Scholar

T. Qian, X. Chen, Y. Xin, W.H. Tang, L. Wang, Resilient Decentralized Optimization of Chance Constrained Electricity-gas Systems over Lossy Communication Networks, Energy (2021). Qian, T. Chen, X. Xin, Y. Tang, W.H. Wang, L. Resilient Decentralized Optimization of Chance Constrained Electricity-gas Systems over Lossy Communication Networks, Energy (2021).10.1016/j.energy.2021.122158Search in Google Scholar

A.M. Gad, Effect of misalignment on the durability of gas-lubricated foil thrust bearing, Journal of Engineering Sciences (2016). Gad, A.M. Effect of misalignment on the durability of gas-lubricated foil thrust bearing, Journal of Engineering Sciences (2016).10.21608/jesaun.2016.117588Search in Google Scholar

Tong, Qian, Yang, Liu, Wenhao, Zhang, Wenhu, Tang, Mohammad, Shahidehpour, Event-Triggered Updating Method in Centralized and Distributed Secondary Controls for Islanded Microgrid Restoration, IEEE Transactions on Smart Grid PP(99) (2019) 1-1. Tong, Qian, Yang, Liu, Wenhao, Zhang, Wenhu, Tang, Mohammad, Shahidehpour, Event-Triggered Updating Method in Centralized and Distributed Secondary Controls for Islanded Microgrid Restoration, IEEE Transactions on Smart Grid PP(99) (2019) 1-1.Search in Google Scholar

S. Kimura, K. Hatakenaka, H01 Effect of Misalignment on Stability of Horizontal Rotor Supported in Hydrodynamically Gas -Lubricated Foil Journal Bearings, 2006 (2006) 189-190. Kimura, S. Hatakenaka, K. H01 Effect of Misalignment on Stability of Horizontal Rotor Supported in Hydrodynamically Gas -Lubricated Foil Journal Bearings, 2006 (2006) 189-190.Search in Google Scholar

S. Zupan, I. Prebil, Carrying angle and carrying capacity of a large single row ball bearing as a function of geometry parameters of the rolling contact and the supporting structure stiffness, Mechanism & Machine Theory 36(10) (2001) 1087-1103. Zupan, S. Prebil, I. Carrying angle and carrying capacity of a large single row ball bearing as a function of geometry parameters of the rolling contact and the supporting structure stiffness, Mechanism & Machine Theory 36(10) (2001) 1087-1103.10.1016/S0094-114X(01)00044-1Search in Google Scholar

S. Damián, Load distribution in a four contact-point slewing bearing, Mechanism and Machine Theory (2003). Damián, S. Load distribution in a four contact-point slewing bearing, Mechanism and Machine Theory (2003).Search in Google Scholar

L. Kania, Modelling of rollers in calculation of slewing bearing with the use of finite elements, Mechanism & Machine Theory 41(11) (2006) 1359-1376. Kania, L. Modelling of rollers in calculation of slewing bearing with the use of finite elements, Mechanism & Machine Theory 41(11) (2006) 1359-1376.10.1016/j.mechmachtheory.2005.12.007Search in Google Scholar

M. Olave, X. Sagartzazu, J. Damian, A. Serna, Design of Four Contact-Point Slewing Bearing With a New Load Distribution Procedure to Account for Structural Stiffness, Journal of Mechanical Design 132(2) (2010) 021006. Olave, M. Sagartzazu, X. Damian, J. Serna, A. Design of Four Contact-Point Slewing Bearing With a New Load Distribution Procedure to Account for Structural Stiffness, Journal of Mechanical Design 132(2) (2010) 021006.10.1115/1.4000834Search in Google Scholar

L. Kania, M. Krynke, E. Mazanek, A catalogue capacity of slewing bearings, Mechanism & Machine Theory 58(none) (2012). Kania, L. Krynke, M. Mazanek, E. A catalogue capacity of slewing bearings, Mechanism & Machine Theory 58(none) (2012).10.1016/j.mechmachtheory.2012.07.012Search in Google Scholar

F. Sadeghi, P.C. Sui, Subsurface Stresses in Rolling/Sliding Machine Components, Purdue University (1988). Sadeghi, F. Sui, P.C. Subsurface Stresses in Rolling/Sliding Machine Components, Purdue University (1988).Search in Google Scholar

J.W. Ringsberg, Life prediction of rolling contact fatigue crack initiation, International Journal of Fatigue 23(7) (2001) 575-586. Ringsberg, J.W. Life prediction of rolling contact fatigue crack initiation, International Journal of Fatigue 23(7) (2001) 575-586.10.1016/S0142-1123(01)00024-XSearch in Google Scholar

M.H. Abbas, A. Youssef, S.M. Metwalli, Ball Bearing Fatigue and Wear Life Optimization Using Elastohydrodynamic and Genetic Algorithm, ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2010. Abbas, M.H. Youssef, A. Metwalli, S.M. Ball Bearing Fatigue and Wear Life Optimization Using Elastohydrodynamic and Genetic Algorithm, ASME 2010 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, 2010.10.1115/DETC2010-28849Search in Google Scholar

S. Glode, D. Jelaska, J. Kramberger, A Computational Model for Calculation of Load Capacity of Gears, Strojniški Vestnik. Glode, S. Jelaska, D. Kramberger, J. A Computational Model for Calculation of Load Capacity of Gears, Strojniški Vestnik.Search in Google Scholar

A. Makoto, M. Hiroyuki, D. Hisayo, T. Masahiro, F405 Fatigue crack initiation life prediction of rails using theory of critical distance and critical plane approach, (2011). Makoto, A. Hiroyuki, M. Hisayo, D. Masahiro, T. F405 Fatigue crack initiation life prediction of rails using theory of critical distance and critical plane approach, (2011).Search in Google Scholar

B. Liu, S.C. Li, L.C. Nie, S.H. Zhong, Z.Y. Liu, Forward Modeling and Application of Electrical Resistivity Method for Detecting Water-Bearing Structure in Tunnel, Journal of Jilin University (Earth Science Edition) (2012). Liu, B. Li, S.C. Nie, L.C. Zhong, S.H. Liu, Z.Y. Forward Modeling and Application of Electrical Resistivity Method for Detecting Water-Bearing Structure in Tunnel, Journal of Jilin University (Earth Science Edition) (2012).Search in Google Scholar

S. Soenke, Planetary gearing, for a wind energy generator, has a bearing structure where the load from the external rotor is minimized on the bearings and gear components to increase their life, DE (2004). Soenke, S. Planetary gearing, for a wind energy generator, has a bearing structure where the load from the external rotor is minimized on the bearings and gear components to increase their life, DE (2004).Search in Google Scholar

J.J. Leininger, Tool having integrated electricity generator with external stator and power conditioner, 2013. Leininger, J.J. Tool having integrated electricity generator with external stator and power conditioner, 2013.Search in Google Scholar

V. Shahbazbagian, Co-optimization of resilient gas and electricity networks; a novel possibilistic chance-constrained programming approach, Applied Energy (2020). Shahbazbagian, V. Co-optimization of resilient gas and electricity networks; a novel possibilistic chance-constrained programming approach, Applied Energy (2020).10.1016/j.apenergy.2020.116284Search in Google Scholar

P. Jean, Watertight and thermally insulating tank built into the bearing structure of a ship having a simplified corner structure, US, 1995. Jean, P. Watertight and thermally insulating tank built into the bearing structure of a ship having a simplified corner structure, US, 1995.Search in Google Scholar

R.A. Goodelle, W.J. Derner, L.E. Root, A Practical Method for Determining Contact Stresses in Elastically Loaded Line Contacts, A S L E Transactions 13(4) (1970) 269-277. Goodelle, R.A. Derner, W.J. Root, L.E. A Practical Method for Determining Contact Stresses in Elastically Loaded Line Contacts, A S L E Transactions 13(4) (1970) 269-277.10.1080/05698197008972302Search in Google Scholar

D. Tesar, Self-contained rotary actuator, 2007. Tesar, D. Self-contained rotary actuator, 2007.Search in Google Scholar

N.T. Liao, J.F. Lin, A New Method for the Analysis of Deformation and Load in a Ball Bearing With Variable Contact Angle, Journal of Mechanical Design 123(2) (2001) 304-312. Liao, N.T. Lin, J.F. A New Method for the Analysis of Deformation and Load in a Ball Bearing With Variable Contact Angle, Journal of Mechanical Design 123(2) (2001) 304-312.10.1115/1.1357163Search in Google Scholar

M.G. Price, Molecular analysis of intermediate filament cytoskeleton – a putative load-bearing structure, Am J Physiol 246(4 Pt 2) (1984) H566. Price, M.G. Molecular analysis of intermediate filament cytoskeleton – a putative load-bearing structure, Am J Physiol 246(4 Pt 2) (1984) H566.10.1152/ajpheart.1984.246.4.H5666539082Search in Google Scholar

L.J. Lavitt, Hand-portable self-contained electric plant/watering-wand, US, 2004. Lavitt, L.J. Hand-portable self-contained electric plant/watering-wand, US, 2004.Search in Google Scholar

N.M. Renevier, V.C. Fox, D.G. Teer, J. Hampshire, coating characteristics and tribological properties of sputter-deposited mos rmetal composite coatings deposited 2 by closed field unbalanced magnetron sputter ion plating, Surface and Coatings Technology (2000). Renevier, N.M. Fox, V.C. Teer, D.G. Hampshire, J. coating characteristics and tribological properties of sputter-deposited mos rmetal composite coatings deposited 2 by closed field unbalanced magnetron sputter ion plating, Surface and Coatings Technology (2000).10.1016/S0257-8972(00)00538-7Search in Google Scholar

J. Nitzpon, Gearbox for a wind energy plant, US, 2013. Nitzpon, J. Gearbox for a wind energy plant, US, 2013.Search in Google Scholar

K. Friedrich, Device for manufacturing of annular laminated package for generator around support structure in gearbox-less wind energy plant, has moving unit including bolt, hub and rotating units for rotating support structure around rotational axis, (2013). Friedrich, K. Device for manufacturing of annular laminated package for generator around support structure in gearbox-less wind energy plant, has moving unit including bolt, hub and rotating units for rotating support structure around rotational axis, (2013).Search in Google Scholar

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