scholarly journals Research on Thermal Characteristics of Ball Screw Feed System Considering Nut Movement

Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 249
Author(s):  
Hongliang Liu ◽  
Zhaofeng Rao ◽  
Ruda Pang ◽  
Yaoman Zhang
Keyword(s):  
Heat Source ◽  
Thermal Characteristic ◽  
Thermal Error ◽  
Ball Screw ◽  
Feed System ◽  
Thermal Errors ◽  
Characteristic Modeling ◽  
Simulation Error ◽  
The Finite Difference Method ◽  
Screw Feed

The heat generated by the ball screw feed system will produce thermal errors, which will cause the positioning accuracy to decrease. The thermal simulation modeling of the ball screw feed system is the basis for compensating thermal errors. The current thermal characteristic modeling method simplifies the reciprocating movement of the nut pair on the screw shaft to varying degrees, which leads to a decrease in simulation accuracy. In this paper, the nut is regarded as a moving heat source, and a novel method is adopted to make the moving process of the heat source closer to the actual nut movement process. The finite difference method is used to simulate the temperature field and thermal error of the ball screw feed system under different working conditions. Firstly, based on the heat transfer theory, the heat conduction differential equation of the feed system is established and discretized. The thermal error model of the ball screw feed system is established. Then, the relationship between nut heat source position and operating time is established to simulate nut reciprocating motion. Finally, the temperature and thermal error experiments of the ball screw feed system were carried out, and the temperature experiment results were compared with the simulation results of the finite difference method. The results show that the maximum simulation error of the average temperature in the operating interval is 11.4%, and the maximum simulation error of thermal error is 16.4%, which verifies the validity and correctness of the method. The thermal characteristic modeling method of the ball screw feed system proposed in this paper has a substantial application value for accurately obtaining the temperature field of the feed system.

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.

Dynamic characteristics and reliability analysis of ball screw feed system on a lathe

2020 ◽  
Vol 150 ◽  
pp. 103890
Author(s):  
Mengtao Xu ◽  
Bing Cai ◽  
Changyou Li ◽  
Hongzhuang Zhang ◽  
Zhendong Liu ◽  
...  
Keyword(s):  
Reliability Analysis ◽  
Dynamic Characteristics ◽  
Ball Screw ◽  
Feed System ◽  
Screw Feed

scholarly journals Screw thermal characteristics analysis and error prediction considering the two-dimensional heat transfer structure

2021 ◽  
Author(s):  
Yu Chen ◽  
Jihong Chen ◽  
guangda xu
Keyword(s):  
Heat Transfer ◽  
Optimal Parameter ◽  
Thermal Characteristic ◽  
Thermal Characteristics ◽  
Thermal Error ◽  
Local Optimum ◽  
Two Dimensional ◽  
Feed System ◽  
One Dimensional ◽  
Transfer Structure

Abstract Thermal error is a common problem in machine tool processing. It is usually proposed to take the screw as one-dimensional rod heat transfer system to solve the thermal error of screw by establishing thermal characteristic equation. This method regards the temperature on the nut as the temperature of the screw contact surface without considering the heat transfer distance between screw and the mounting point on the nut. To solve this problem, this paper takes the screw-nut feed system as a two-dimensional heat transfer structure considering both screw and nut. In addition, to solve the low convergence speed and easy fall into local optimum problem in optimal parameter identification. The improved particle swarm optimization algorithm (IPSOA) is proposed to identify the boundary parameters of thermal characteristics equations. Finally, the temperature and thermal error of the screw-nut feed system is calculated by the identified results. Experiments under different working condition show that the maximum prediction residual error of the two-dimensional method (TDM) is less than 7.2 um and the simulating prediction accuracy can reach 86.2%. Besides, compared with one-dimensional model (ODM), TDM has a higher predict accuracy which verifies the effectiveness of the proposed method.

scholarly journals A Comprehensive Nonlinear Dynamic Model for Ball Screw Feed System With Rolling Joint Characteristics

2021 ◽  
Author(s):  
Mengtao Xu ◽  
Changyou Li ◽  
Hongzhuang Zhang ◽  
Zhendong Liu ◽  
Yimin Zhang
Keyword(s):  
Dynamic Model ◽  
Model Verification ◽  
Machining Process ◽  
Ball Screw ◽  
Nonlinear Phenomena ◽  
Feed System ◽  
Lumped Mass ◽  
Screw Length ◽  
Significant Difference ◽  
Screw Feed

Abstract Modern tendency of machine tools design requires more accurate model to predict the system dynamics, in order to anticipate its interaction with machining process. In this paper, a comprehensive dynamic model of ball screw feed system (BSFS) considering nonlinear kinematic joints is introduced to investigate the varying dynamic characteristics when worktable is subjected to combined load from six directions. The load-deformation relationship of each kinematic joint is dealt with a set of translational and angular spring elements. The nonlinear restoring force function of each joint involving coupling displacement is calculated. Based on the lumped mass method, the analytical 18-DOF dynamic equation is formulated by the analysis of force dependence between joints. Model verification tests are conducted. The worktable response exhibits the abundant and fascinating nonlinear phenomena arising in nonlinear joint and coupling effect. The nonlinear behavior behaves significant difference owing to the variations of excitation, platform position, screw length, preload and damping of joints. Thus, the model is promising for comprehension of machine dynamic behavior and for development of sophisticated control strategy.

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