scholarly journals Dynamic Characteristic Optimization of Ball Screw Feed Drive in Machine Tool Based on Modal Extraction of State Space Model

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 55524-55542 ◽  
Author(s):  
Yang Yong ◽  
Zhang Wei-Min ◽  
Zhu Qi-Xin ◽  
Jiang Quan-Sheng
Keyword(s):  
Machine Tool ◽  
State Space ◽  
Dynamic Characteristic ◽  
State Space Model ◽  
Ball Screw ◽  
Space Model ◽  
Feed Drive ◽  
Screw Feed

scholarly journals Effect of Stiffness of Rolling Joints on the Dynamic Characteristic of Ball Screw Feed Systems in a Milling Machine

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Dazhong Wang ◽  
Yan Lu ◽  
Tongchao Zhang ◽  
Keyong Wang ◽  
Akira Rinoshika
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristic ◽  
Calculation Method ◽  
Ball Screw ◽  
Fe Model ◽  
Milling Machine ◽  
Cnc Milling ◽  
Feed System ◽  
Cnc Milling Machine ◽  
Screw Feed

Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC) milling machine set ermined as a research object, the stiffness of its fixed joint between the column and the body together with the stiffness parameters of the rolling joints is evaluated according to the Takashi Yoshimura method. Then, a finite element (FE) model is established for the machine tool. The correctness of the FE model and the stiffness calculation method of the rolling joints are validated by theoretical and experimental modal analysis results of the machine tool’s workbench. Under the two modeling methods of joints incorporating the stiffness parameters and rigid connection, a theoretical modal analysis is conducted for the CNC milling machine. The natural frequencies and modal shapes reveal that the joints’ dynamic characteristic has an important influence on the dynamic performance of a whole machine tool, especially for the case with natural frequency and higher modes.

A Study on the Feed Rate Optimization of a Ball Screw Feed Drive System for Minimum Vibrations

2005 ◽  
Author(s):  
Young H. Choi ◽  
Jin H. Hong ◽  
Sung H. Jang
Keyword(s):  
Machine Tool ◽  
Feed Rate ◽  
Drive System ◽  
Ball Screw ◽  
Feed Drive ◽  
Rate Optimization ◽  
Feed Rate Optimization ◽  
Feed Drive System ◽  
Screw Feed ◽  
Acceleration Profile

In order to prevent machine tool feed slide system from transient vibrations during operation, machine tool designers usually adopt some typical design solutions; box-in-box typed feed slides, optimizing moving body for minimum weight and dynamic compliance, and so on. Despite all efforts for optimizing design, a feed drive system may experience severe transient vibrations during high-speed operation if its feed-rate control is not suitable. A rough feed-rate curve having discontinuity in its acceleration profile causes serious vibrations in the feed slides system. This paper presents a feed-rate optimization of a ball screw driven machine tool feed slide system for its minimum vibrations. A ball screw feed drive system was mathematically modeled as a 6-degree-of-freedom lumped parameter model. Then, a feed-rate optimization of the system was carried out for minimum vibrations. The main idea of the feed-rate optimization is to find out the most appropriate smooth acceleration profile having jerk continuity. A genetic algorithm, G.A., was used in this feed rate optimization.

The Modeling and Prediction of Gravity Deformation in Precision Machine Tool Assembly

2013 ◽  
Author(s):  
Junkang Guo ◽  
Jun Hong ◽  
Xiaopan Wu ◽  
Mengxi Wang ◽  
Yan Feng
Keyword(s):  
Machine Tool ◽  
State Space ◽  
State Space Model ◽  
Variation Theory ◽  
Assembly Process ◽  
Motion Error ◽  
Space Model ◽  
Precision Machine ◽  
Variation Propagation ◽  
Tool Assembly

The variation propagation in mechanical assembly is an important topic in several research fields, such as computer aided tolerancing (CAT) and product quality control. Mathematical models and analysis methods have been developed to solve this practical problem. Tolerance analysis which is based on the rigid hypothesis can be used to simulate the mass manufacturing and assembly. The state space model and stream of variation theory are mainly applied in flexible part assembly. However, in precision machine tool assembly, both tolerance design and process planning critically impact the accuracy performance, mainly because of the fact that the gravity deformation, including the part deformation and the variation in the joint of two connecting parts, cannot be ignored in variation propagation analysis. In this paper, based on the new generation GPS (Geometrical Product Specification and Verification) standards, the verification and modeling of key characteristics variation due to gravity deformation of single part and adjacent parts are discussed. The accurate evaluation of position and orientation variation taking into account form errors and gravity deformation can be solved from this model by FEM. A mathematical model considering rail error, stiffness of bearings is introduced to simulate the motion error in gravity effect. Based on this work to more accurately calculate the variation propagation considering gravity impact, a state space model describing the assembly process of machine tools is proposed. Then, in any assembly process, the final accuracy can be predicted to find out whether the accuracy is out of design requirement. The validity of this method is verified by a simulation of the assembly of a precision horizontal machining center.

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