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Plasto-Elastohydrodynamic Lubrication (PEHL)
Published in Q. Jane Wang, Dong Zhu, Interfacial Mechanics, 2019
Numerical simulations of the PEHL in a rolling contact, having the rigid ball that rolls on the stationary elastic–plastic flat, ought to be conducted for a sufficiently long rolling distance under a constant normal load. The rolling motion repeats for a number of cycles like a ball rolls on the race in a rolling element bearing. After the simulation for a rolling cycle is completed, the material plastic properties at all the cross sections are supposed to be theoretically identical. Therefore, the simulation is focused on the accumulated plastic strain and deformation results only on one cross section. If setting a coordinate origin (0, 0) fixed to the flat, this cross section can be chosen to be at x = 0, and a rolling distance set to be 4a. Thus, for each rolling cycle, the ball rolls from the location of (2a, 0) to that of (−2a, 0), as shown in Figure 12.34.
Field Troubles
Published in Ramnarayan Padmanabhan, Centrifugal Pump Clinic, 2017
Replacement bearings may be improperly mounted on the shaft. In the process of installing, it is best to heat the bearing slightly in an oil bath to expand its inner race. If the bearing is forced on the shaft, an arbor press should be utilized, or a tubular sleeve can be employed. In the latter case, make certain that the blows against the sleeve are gentle and applied alternately on opposite sides of the sleeve held against the inner race (Fig. 6.39). Uneven pressure on the inner race may distort it and preload the bearing unevenly, shortening its life very materially.
Online condition monitoring system for rotating machine elements using edge computing
Published in Australian Journal of Mechanical Engineering, 2023
N. D. Pagar, S. S. Gawde, S. B. Sanap
If the ball or roller bearing spins and surface imperfections of ball or races excites the characteristic frequencies then it can be found with above-mentioned expressions. It is generally known that flaws exist inside a given bearing component when the defect frequencies coincide with peak amplitudes in the vibration spectrum. Given that a ball defect hits both the inner and outer race in one rotation, its frequency is defined to be twice that of the ball spin frequency. Indicative of a bearing problem is the presence of frequencies that are higher than the fundamental frequency. Formulas for estimating antifriction bearing fundamental defect frequencies can be found in Table 3, which can be seen below. A defective bearing rotating at a constant RPM produces a particular frequency of vibration. On bearing components, the defect could be a fracture, pit, wear mark, scratch, or spall.
Numerical model of a single stage gearbox under variable regime
Published in Mechanics Based Design of Structures and Machines, 2023
Mohamed Habib Farhat, Taissir Hentati, Xavier Chiementin, Fabrice Bolaers, Fakher Chaari, Mohamed Haddar
When applying on the bearing’s inner race an external load, a Hertzian deformation force is yielded. This force is dependent on the angular position of each ball, the value of the internal radial clearance and the relative displacements and of the bearing’s inner race center. The resulting deformation force between the ball number and the races and the is given by Eq. (4), (Harsha, Sandeep, and Prakash 2003).
Investigation on Multi-entropy and Multi-statistical Features Fusion Approach for Fault Detection in Rolling Bearing Using VMD
Published in IETE Journal of Research, 2022
Abhishek Anand Singh, C. I. Harikrishnan, S. K. Tiwari, Snehsheel Sharma
The experimental setup as shown in Figure 1 is an electro-mechanical system. The bearing data used for the experimental analysis is derived from Case Western Reserve University database [17]. The signals were acquired for the induction motor bearings at variable load conditions. The load varied from 0 to 3 hp with the speed ranging from 1730 to 1797 rpm. Four different experimental conditions were considered: a healthy and three faulty states. The electro-discharge machining was used to induce faults on inner, outer races, and on ball.