Papers by Keyword: Spindle System

Abstract: The dynamic characteristics and dynamics parameters of rolling bearings is very important to dynamics and vibration response of rotate machine such as rotor systems, gear systems and Spindle systems. The frequencies of rotate machine are affected by dynamics parameters of rolling bearings at different places. The purpose in the work presented is to research a new approach and multibody model of Spindle systems with equivalent dynamics parameters of rolling bearings. The flexible Spindle body has been constructed by the fixed interface component mode method. The four different models of rolling bearings for Spindle systems have been developed using equivalent spring and damper elements. The experiments of Spindle body and Spindle system have been carried out. Experimental modal frequencies have been got by impulse vibration test and sweep frequency vibration test. The frequencies and vibration response of Spindle systems have been calculated by adjusting equivalent spring and damper elements to minimizing errors between the calculated and experiment frequencies. The results show the errors of frequencies of linear equal and unequal spring and damper models are large except the first frequency. However, the errors of nonlinear equal and unequal spring and damper models are small. The predicted frequencies of nonlinear unequal spring and damper model are the most accurate and agree well with the experiment results. The presented method can be applied to calculate the nonlinear equivalent stiffness parameters accurately for rolling bearings in multibody systems.

Abstract: This paper focus on the spindle system of special friction welder machine with conductive device made up of aluminum electrolytic prebaked anode. The ROMAX software is employed to analyze the spindle system, and the spindle axial force and displacement, radial displacement, and natural frequency are obtained by the analysis. The reasonable result can be got by analyzing the corresponding results, respectively. Thereby, the gist to improve the fiction welder is attained.

Abstract: With the spindle system of a vertical gantry machining center as the research object, based on the vibration theory and finite element method, the modal analysis of spindle system is studied. Firstly, the finite element models of the mandrel box body and motorized spindle frame of spindle system are established by ANSYS. And then do the modal analysis of singleton in the boundary of free constraint. Lastly, based on the analysis results to establish the finite element model of the whole spindle system and do the modal analysis of the whole system which under constraint condition. The result shows that the swing of motorized spindle frame and motorized spindle sleeve of spindle system are more obvious.

Abstract: The paper determines the impact factors of high-speed spindle system including the centrifugal force, gyroscopic moments and the bearing stiffness softening, and builds the general spindle-bearing FEM considering high speeds. Taking a motorized spindle as example, the effect of centrifugal force, gyroscopic effect, the radial stiffness and the coupling factors are analyzed qualitatively and quantitatively. Finally the research shows the variations of bearing radial stiffness, centrifugal force and gyroscopic moments have a significant effect on dynamics of spindle system in high speeds, while modeling the high speed spindle system, above factors must be considered.

Abstract: The thermal deformation of machine tools has a great influence on machining accuracy. Studied on thermal effects of TH6213 CNC boring and milling machine spindle system, bearing heat grows with load and boring spindle extending length, and brings about a changeable temperature difference, which is hard to reduce. A subsection cooling scheme was proposed to reduce the spindle system temperature as well as the temperature difference to reduce the thermal deformation effects.

Abstract: The paper took dish-style separators spindle system as research object, established a finite element dynamic model for spindle system based on rotor dynamic theory, and then obtained vibration characteristic of spindle system considering gyroscopic effect influenced on critical velocity. The result shows that gyroscopic effect decreases the first and second order eddy frequency of spindle system by 36.2%; spindle rotating velocity meets the design requirements for a flexible shaft. The research result indicates that the method in this paper is available, and has a guide for deeper research on vibration characteristic of high speed rotation system, will reduce research expenditure and test time.

Abstract: The paper takes the numerical control milling machine xk8140 as the research object. The machine tools spindle system digital model is established in UG. The spindle systems natural frequency is obtained throng dynamics analysis of milling machine spindle under specific working conditions, as well as the relational of vibration and error in harmony response situation. In view of the result the rational appraisal to the spindle system structure rationality is made. Accordingly, the irrational causes removed, that noise increasing, processing quality reducing obviously and so on attribute to the irrational structure of the spindle system machine tools when the spindle rotational speed achieve 4000rpm or higher.

Abstract: In the dynamic design of spindle system, the better effect should be achieved by optimizing multi-parameters synthetically. A spindle system has numerous design parameters. It is not advisable to optimize every design parameter. So, it is quite essential to analyze the influence extent and their correlation of these design parameters on the system dynamic rigidity. Taking the hob spindle system of YK3610 as an example, an analyzing method based on the orthogonal test is introduced in this paper. In this analysis, the dynamics model of system is built by transfer matrix method. Finally, a multi-parameters optimizing demonstration is provided.

Abstract: The rotation accuracy of the machine spindle is an important accuracy index, and has numerous influence factors. According to the structure characteristic of the spindle system, an integrated model of the spindle rotation error is established in this paper. By this model, the impact law and cumulative effect of various error sources on spindle rotation accuracy can be analyzed. Taking the lathe spindles as an example, the modeling and analysis method for spindle error are introduced. Visualization of spindle center track is achieved by programming.

Abstract: In this study, the effects of clamping toolholders on the dynamic characteristics of spindle systems are evaluated experimentally. In the experiments, the transfer functions are obtained by the impulse response method, and then, the dynamic characteristic parameters are identified based on the vibration model of single-degree of freedom. Two types of machining center spindles and four types of toolholders are evaluated. From the experimental results, the following are revealed: (1) the clamping toolholder enhances the vibration amplitude markedly compared with that of the spindle not clamping toolholder. (2) The different chucking mechanisms clearly change the dynamic stiffness of the spindle systems. (3) The order of magnitude of the dynamic stiffness of the spindle systems agrees well with that of the isolated toolholders. It is confirmed experimentally that clamping of the appropriate toolholder improves the dynamics stiffness of the spindle systems for machining centers.