A Dynamic Modeling Approach for Spindle Bearing System Supported by Both Angular Contact Ball Bearing and Floating Displacement Bearing

Author(s):  
Songtao Xi ◽  
Hongrui Cao ◽  
Xuefeng Chen ◽  
Linkai Niu

This paper presents a new dynamic modeling approach for spindle bearing system supported by both angular contact ball bearing (ACBB) and floating displacement bearing (FDB). First, a dynamic model of FDB is developed based on the discrete element method with each bearing component having six degrees-of-freedom (DOFs). Based on the developed FDB dynamic model and Gupta ACBB dynamic model, a fully coupled dynamic model of the spindle bearing system combined both ACBBs, and FDB is developed. In the proposed spindle bearing system model, the spindle shaft is modeled using finite element (FE) method based on the Timoshenko beam theory with the consideration of centrifugal force and gyroscopic moment. The coupling restriction between the dynamic bearing models and the FE spindle shaft model are the restoring forces and moments that are transmitted to the shaft by the bearings and the dynamic vibration response shared by both the bearing inner races and the corresponding nodes of the shaft where bearings are installed. A Fortran language-based program has been developed for the spindle bearing system with the dynamic bearing models solved using the Runge–Kutta–Fehlberg integration method and FE shaft model solved by Newmark-β method. Based on the developed model, the effect of the FDB radial clearance, system preload, and spindle rotating speed on the system dynamics, and the effect of the FDB radial clearance on the system unbalanced response have been investigated.

Author(s):  
Xianghong Gao ◽  
Changfeng Yan ◽  
Yaofeng Liu ◽  
Pengfei Yan ◽  
Junbao Yang ◽  
...  

Localized defects in ball bearing components would cause additional vibration and it is imperative to reveal the vibration mechanism. The relationship between fault characteristic frequency (fBPFI and fBPFO) and multiple defect parameters of ball bearing were given in this paper. Considering elastohydrodynamic lubrication (EHL), radial clearance, time-varying displacement and excitation force generated from multiple defects, a 4 degree-of-freedom (DOF) dynamic model for ball bearing with multiple defects on inner or outer raceway was established, and the model has been verified by experiments. Vibration signals of ball bearing with different defects parameters were simulated, the effects of the angle between two defects ( θIAD and θOAD), the number of defects ( NDI and NDO) and the location of defects on outer raceway on dynamic response were studied. Comparing simulated signals with experimental results, it is shown that more impulses of acceleration signals are generated by multiple defects than that by single defect, meanwhile time delay due to two defects on raceways could also be found, fault characteristic frequency and their harmonics frequencies appeared in the envelope spectrums. Harmonics frequencies of fBPFI are modulated mainly by 2 fs instead of fs in frequency domain for multiple defects on inner raceway. The amplitudes of fBPFO and fBPFI change as Fourier curve when θOAD and θIAD varied within a certain range, and a series of Fourier function are given to describe the mathematic relationship.


Author(s):  
Wenwu Wu ◽  
Jun Hong ◽  
Xiaohu Li ◽  
Yang Li ◽  
Baotong Li

With the increasing demand of higher operating speed for bearing system, more challenges have been exposed on the maintaining of the bearing performance. Preloading is an effective method to handle these challenges. Traditionally, the preloading of bearing system has been applied by uniform approaches such as rigid preload and constant preload. However, this treatment may hardly deal with the optimization of preloading problem due to the non-uniformity of the bearing stiffness becomes more apparent under high-speed operating conditions. A novel and practical approach is therefore presented in this paper to incorporate the non-uniformity effect to improve the structural performance of bearing under actual operating conditions. Firstly, the critical relationship between the stiffness behaviour and the non-uniform preload is evaluated for bearing system. The stiffness problem of angular contact ball bearing system is then formulated analytically by Jones’ model. With this approach, boundary conditions are achieved to solve the local contact deformation and predict the bearing life under non-uniform preload. Finally, both the uniform preload and the non-uniform preload cases for bearing system are simulated under various operating conditions. Comparing with traditional methods, the proposed method can provide a better solution in both stiffness and life that will enable a designer to obtain a deep insight on the optimization of bearing system.


2021 ◽  
Author(s):  
Hongfan Long ◽  
Zhao Han ◽  
Shuyun Jiang ◽  
Enlai Zheng ◽  
Yongnian Zhang ◽  
...  

Abstract In order to study the dynamic position accuracy of bottom dead point (BDP) for multilink high-speed precision presses (MHSPPs), it’s essential to develop a dynamic model of planar multilink mechanism with clearance and spindle-bearing structure. Traditional models always neglect the effect of thermal characteristics of spindle-bearing structure, which reduces the prediction accuracy of dynamic model for multilink transmission mechanisms. To overcome the shortcomings of the previous models, a thermal network model (TNM) of the crankshaft-bearing system is established firstly considering the effects of thermal contact resistance and variable stiffness of bearing concerning the temperature rise. Then, dynamic model of the crankshaft-bearing system is built through the finite element method, which includes rigid disk, Timoshenko beam and quasi-statics model of ACBB. On this basis, an improved dynamic model of planar flexible multilink mechanism with clearance considering the thermal-mechanical coupling effect of the crankshaft-bearing structure is developed and the corresponding dynamic error dimension chain between slider and crankshaft is constructed in this work. Compared to the simulation from traditional models, the simulated slider’s BPD position error from the improved model agrees better with experimental data, which verifies the correctness of the proposed model. It’s demonstrated that the punching force and thermally induced variable stiffness of bearing lead to a significant increase of slider’s BDP position error, which reduces the machining precision of MHSPP. Furthermore, the influence of crankshaft speed, contact angle of bearing and clearance size on the slider’s BDP position error is also investigated.


Author(s):  
Zhaoliang Cui ◽  
Rui He ◽  
Wanyu Wu ◽  
Fengtao Wang ◽  
Liu Heng

In this paper, for double row angular contact ball bearing, a five-degrees-of-freedom bearing analysis model based on quasi-statics is proposed. This model is used to study the influence of structural parameters and service conditions on the tilt angle and limit tilt angle of the bearing. The results show that the radial clearance will increase the ultimate tilt angle. The coincidence degree between the roller and the inner raceway will reduce the ultimate tilt angle, but the coincidence degree between the roller and the outer raceway has the opposite effect. The increase in the external load of the bearing will increase the tilt angle. The moment load has the greatest effect on the tilt angle. The rotation speed of the bearing has no effect on the tilt angle. The coincidence degree between the roller and the raceway will reduce the tilt angle; furthermore, the influence of the coincidence degree between roller and different ring on the tilt angle is also different when different rings are fixed. The tilt angle will decrease with the increase of the initial contact angle, and this effect is more and more obvious. The fixation of different ring has no effect on this influence.


2010 ◽  
Vol 97-101 ◽  
pp. 3408-3412 ◽  
Author(s):  
Wei Hua Ni ◽  
Zheng Qiang Yao ◽  
Jun Tong Xi

Based on static analysis, this paper investigates the effects of interference fit and axial preload on the performance of the low-speed angular contact ball bearing. The results show the bearing with heavy preload and large radial clearance has big contact angle and high axial stiffness. Besides, large interference could result in small contact angle but high axial stiffness. When the bearing has large interference the axial stiffness increases rapidly due to the effect of interference on the axial stiffness stronger than that of contact angle. And the stiffness formula in the paper could provide boundary conditions for the finite element analysis of spindle-bearing system.


2013 ◽  
Vol 842 ◽  
pp. 391-396
Author(s):  
Li Gang Cai ◽  
Gen Li ◽  
Ya Hui Cui ◽  
Tie Neng Guo ◽  
Yong Sheng Zhao

This paper established a general mathematical modeling method based on stress analysis of the angular contact ball bearing under high rotation speed. The influence of the centrifugal force and gyroscopic moment generated in the rotation process is taken into account in this mathematical model. This paper conducted in-depth research for these aspects: the stiffness characteristics of angular contact ball bearings under different load conditions and different rotational speed, internal contact deformation and the change of bearing parameters.


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