Numerical and Experimental Investigation on the Effects of Crooked Shaft Washer and Housing Washer in a Single Row Thrust Ball Bearing on its Vibrational Response

Numerical and Experimental Investigation on the Effects of Crooked Shaft Washer and Housing Washer in a Single Row Thrust Ball Bearing on its Vibrational Response


Numerical and Experimental Investigation on the Effects of Crooked Shaft Washer and Housing Washer in a Single Row Thrust Ball Bearing on its Vibrational Response

نوع: Type: thesis

مقطع: Segment: PHD

عنوان: Title: Numerical and Experimental Investigation on the Effects of Crooked Shaft Washer and Housing Washer in a Single Row Thrust Ball Bearing on its Vibrational Response

ارائه دهنده: Provider: Seyed Hosein Razavian

اساتید راهنما: Supervisors: Dr. Alireza Shooshtari

اساتید مشاور: Advisory Professors:

اساتید ممتحن یا داور: Examining professors or referees: Dr. Mehdi Karimi - Dr. Abdoreza ohadi - Dr. Seyed Ali Asghar Hoseini

زمان و تاریخ ارائه: Time and date of presentation: 9/20/2023 - 3pm

مکان ارائه: Place of presentation: No.7 class of mechanical engineering department

چکیده: Abstract: One of the most important types of misalignments is crooked ball bearing rings. In this study, effects of crooked shaft washer related to a single-row thrust ball bearing on the system vibrating response have been investigated. For this purpose, a new dynamic model including 4-dof is considered for this bearing, housing and shaft mounted on it. Contact forces between rings and balls are described according to hertzian equation. In the following, nonlinear Euler's equilibrium is used to describe dynamic motion of the rings solved by numerical method. It is shown that these responses contain frequencies and phases that support the specialized signature of crookedness of the shaft washer in thrust ball bearing. Verification of responses has been done by Ansys software. The effect of amount of crookedness in the shaft washer and external axial force on the responses have also been investigated. To verify results, a vertical structural thrust ball bearing test rig was considered. In the following, effects of rotational shaft speed, crookedness value and axial external force on the shaft washer crookedness signature were studied at several relative positions of sensors. It is shown that crookedness of thrust ball bearing shaft washer has specific frequency signature and sensor phase difference pattern in the fast Fourier transform (FFT) diagram. Also, by comparing input and output amplitude, it is illustrated that this system is a nonlinear dynamical experimental system. A quasi-flip bifurcation is another reason of the nonlinearity of the system. In additional, by the phase portrait of recalling of the sensor response and the relative error value of the inner race ball pass frequency (BPFI), it is clear that the crookedness of thrust ball bearing shaft washer creates a type of chaotic behavior supporting washer shaft crookedness frequency signature and the phase difference pattern of the sensors. This was investigated by definition of Poincare map point density function at real and ideal signature frequency results. Finally, it is demonstrated that this detection method is applied to single channel vibration analyzer as a novel application. Since this research includes all three characteristics of mathematical modeling, finite element simulation and laboratory work, this is a successful scientific structure

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