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Laser surface hardening is used to improve the fatigue performance of the large diameter pitch bearing. Determination of the process parameters by a trial and error method, depending on the experience of the technician, by changing the parameters repeatedly for each laser surface hardening process is time-consuming and costly. In this paper, a meth...
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Context 1
... Gaussian correlation equation is selected for its good calculation. Kriging approximate model with two response variables is established by solving the unconstrained optimization problem based on the sample data listed in Table 4. According to the sample points, twelve sets of the obtained sample points and the simulation results of the output response for these sample points are listed in Table 4. ...Context 2
... approximate model with two response variables is established by solving the unconstrained optimization problem based on the sample data listed in Table 4. According to the sample points, twelve sets of the obtained sample points and the simulation results of the output response for these sample points are listed in Table 4. The Kriging approximate model is established based on the above description in detail. ...Similar publications
To efficiently analyze the time-dependent reliability is still a challenge today for many applications. This paper aims at modifying the original single-loop Kriging surrogate method to make it more efficient especially for assessing the small time-dependent failure probability. The first contribution of the proposed method is that the radial-based...
Citations
... A four-point-contact ball slewing bearing is used as a pitch bearing in small-and medium-sized WTs. 1,2 However, the working conditions of pitch bearings in onshore and offshore WTs are extremely harsh. Moreover, under strong and uncertain wind conditions, the blades have to be adjusted to the optimal angle position at any time, which leads to the overload and enormous overturning moment on pitch bearings, followed by frequent failure. ...
Pitch bearings are the key components of wind turbines (WTs). The reliability of pitch bearings affects the electric energy output efficiency of WTs. Due to its large loading ability, constant contact angle and high stiffness, the three-row roller slewing bearing (TRSB) is becoming a more attractive choice as a pitch bearing, especially in large-scale WTs. The contact force and pressure distributions significantly affect the fatigue life of a three-row roller pitch bearing (TRPB). Therefore, it is essential to propose a precise calculation method for the contact force and pressure. The present work establishes a quasi-static five degree-of-freedom (DOF) mathematical model for TRPBs, in which the bearing under general loading conditions is considered. The influences of combined external forces, overturning moments and inner ring misalignment angle on the contact force and pressure distributions of TRPBs are comprehensively investigated. According to the analysis results, the overturning moment and axial force can significantly affect the number of load-carrying rollers in each row. Furthermore, a slight variation of the inner ring angular misalignment has a significant effect on the contact force and pressure of TRPBs. Finally, it is more prone to pressure concentration in the non-crowned roller than that in the crowned roller, especially in the case of the inner ring with a misalignment angle. Since the high calculation efficiency and accuracy, the proposed method has remarkable potential applications in the fatigue life prediction and design of TRPBs.
