Vibration characteristics of a ball bearing considering point lubrication and nonuniform surface waviness

Surface waviness is one of the main geometrical errors in ball bearings. Time-varying contact stiffness excitations (TCSEs) produced by the uniform and nonuniform waviness on races of a lubricated ball bearing cannot be accurately described by the previous uniform waviness models considering the time-varying displacement excitation (TDE) in the literature. To overcome this problem, a new dynamic modelling method coupling both the TDE and TCSE produced by the uniform and nonuniform waviness on the races of a lubricated ball bearing is proposed. Effects of the amplitude and nonuniform distribution of waviness on the contact stiffness between one ball and races of the lubricated and unlubricated bearings are investigated, as well as vibrations of the bearings produced by the uniform and nonuniform waviness. Numerical results show that the proposed model can describe the TDE and TCSE produced by the uniform and nonuniform waviness on the races of the lubricated bearing, which cannot be described by the previous uniform waviness models. The results also show that the peak frequencies of spectra of accelerations of the bearing with the waviness will be changed by the lubricating film oil. It seems that the proposed model can provide a new dynamic modelling method for formulating the vibrations of a lubricated bearing with the uniform and nonuniform waviness on its races.