The influence of ball screw drive positioning errors on the accuracy of part manufacturing

2021 ◽  
pp. 40-52
Author(s):  
L. V. Ibaeva ◽  
Yu. M. Orlov
Keyword(s):  
Total Error ◽  
Roll Angle ◽  
Ball Screw ◽  
Numerical Estimation ◽  
Screw Drive ◽  
Lead Screw ◽  
Machine Drive ◽  
Temperature Deformations ◽  
Ball Screw Drive ◽  
Machine Drives

The article considers the components of the total error of mechanical processing that occur when positioning the working units of the machine: ball screw drive elements. The reasons for the loss of positioning accuracy of the machine drives are described. The accuracy of the positioning of the machine spindle in determining the axes of the holes to be processed is analyzed. The numerical estimation of the values of the errors of the temperature deformations of the lead screw is carried out on the example of drilling holes in the workpiece. The causes of heating of the ball screw drive of the machine are identified. The dependence of the unit heating on the speed of movement of the operating elements of the machine is described. The optimal trajectory of the tool movement when processing holes in the workpiece is presented. The criterion of optimality of this trajectory is described. The values of the deviations of each hole in the workpiece from the specified accuracy of their location are obtained. The scheme of accumulation of errors of linear displacements resulting from the temperature deformation of the lead screw of the CNC machine drive is presented. The value of the accumulated total error of the temperature deformations of the ball screw pair is obtained. The error associated with the movement of the machine drive carriage is considered. The geometric characteristics of the carriage orientation are given. The schemes of occurrence of the error caused by the change of the roll angle and the carriage tilt angle are presented. The maximum axial load of the lead screw at translational acceleration is calculated. The scheme of possible carriage deflection under the action of the maximum translational force of a ball screw pair is presented. The numerical estimation of the maximum possible roll angle of the carriage, as well as the maximum deviation from the specified accuracy of the carriage, at the maximum load on the lead screw, is carried out. As a result, it is concluded that the total error of the machine drives positioning can go beyond the tolerances of the linear dimensions of the processed holes, which significantly affects the accuracy of the part manufacturing.

Dynamic Modeling of a Ball-Screw Drive and Identification of Its Installation Parameters

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Yu-Jia Hu ◽  
Yaoyu Wang ◽  
Weidong Zhu ◽  
Haolin Li
Keyword(s):  
Dynamic Model ◽  
Natural Frequencies ◽  
Data Fitting ◽  
Ball Screw ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
Screw Drive ◽  
Log Normal ◽  
Ball Screw Drive ◽  
Log Normal Distribution

Abstract Parametric expressions of equivalent stiffnesses of a ball-screw shaft are obtained by derivation of its geometric parameters, the finite element method (FEM), and data fitting based on a modified probability density function of log-normal distribution. A dynamic model of a ball-screw drive that considers effects of bearing stiffnesses, the mass of the nut, and the axial pretension is established based on equivalent stiffnesses of its shaft. With the dynamic model and modal experimental results obtained by Bayesian operational modal analysis (BOMA), installation parameters of the ball-screw drive are identified by a genetic algorithm (GA) with a new comprehensive objective function that considers natural frequencies, mode shapes, and flexibility of the ball-screw drive. The effectiveness of the methodology is experimentally validated.

Techniques developed for fault diagnosis of long-range running ball screw drive machine to evaluate lubrication condition

Measurement ◽  
2018 ◽  
Vol 126 ◽  
pp. 274-288 ◽  
Author(s):  
Chang-Fu Han ◽  
He-Qing He ◽  
Chin-Chung Wei ◽  
Jeng-Haur Horng ◽  
Yueh-Lin Chiu ◽  
...  
Keyword(s):  
Fault Diagnosis ◽  
Long Range ◽  
Ball Screw ◽  
Screw Drive ◽  
Lubrication Condition ◽  
Ball Screw Drive

scholarly journals Tracking performance of NPID controller for cutting force disturbance of ball screw drive

2017 ◽  
Vol 11 (4) ◽  
pp. 3227-3239
Author(s):  
N. A. Anang ◽  
◽  
L. Abdullah ◽  
Z. Jamaludin ◽  
T.H. Chiew ◽  
...  
Keyword(s):  
Cutting Force ◽  
Tracking Performance ◽  
Ball Screw ◽  
Screw Drive ◽  
Ball Screw Drive

Online Chatter Detection for Milling Operations Using LSTM Neural Networks Assisted by Motor Current Signals of Ball Screw Drives

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Rajiv Kumar Vashisht ◽  
Qingjin Peng
Keyword(s):  
Neural Networks ◽  
Feed Rate ◽  
Short Term Memory ◽  
Ball Screw ◽  
Chatter Detection ◽  
Cnc Machine ◽  
Screw Drive ◽  
Milling Operations ◽  
Milling Tool ◽  
Ball Screw Drive

Abstract For certain combinations of cutter spinning speeds and cutting depths in milling operations, self-excited vibrations or chatter of the milling tool are generated. The chatter deteriorates the surface finish of the workpiece and reduces the useful working life of the tool. In the past, extensive work has been reported on chatter detections based on the tool deflection and sound generated during the milling process, which is costly due to the additional sensor and circuitry required. On the other hand, the manual intervention is necessary to interpret the result. In the present research, online chatter detection based on the current signal applied to the ball screw drive (of the CNC machine) has been proposed and evaluated. There is no additional sensor required. Dynamic equations of the process are improved to simulate vibration behaviors of the milling tool during chatter conditions. The sequence of applied control signals for a particular feed rate is decided based on known physical and control parameters of the ball screw drive. The sequence of the applied control signal to the ball screw drive for a particular feed rate can be easily calculated. Hence, costly experimental data are eliminated. Long short-term memory neural networks are trained to detect the chatter based on the simulated sequence of control currents. The trained networks are then used to detect chatter, which shows 98% of accuracy in experiments.

Finite Element Formulation of Pre-Stressed Ball Screw Drives

Volume 3 ◽  
2004 ◽  
Author(s):  
Michael F. Zaeh ◽  
Thomas Oertli
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Ball Screw ◽  
Element Formulation ◽  
Screw Drive ◽  
Feed Drives ◽  
Drive Systems ◽  
Feed Axis ◽  
Ball Screw Drive ◽  
Ball Screw Drives

In this paper a stiffness matrix of the ball screw drive element is formulated as an approach for substitute modeling of the stiffness conditions at the ball-groove contacts in the engagement region of the ball screw and the nut. A scalar spring model is proposed, for the coupling between the ball screw and the nut with respect to both the stiffness properties and the screw degree of freedom of the ball screw drive. This permits combined modelling and vibration analysis of entire frame structures including ball screw feed drive systems by means of integral finite element models. The feed axis of a feed drives test station serves here as an example for demonstration and for verification of the modelling approach. A reduced order representation of the finite element model is used for simulation of the feed axis in control, the results of which match corresponding measurement results obtained from the test station.

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