scholarly journals Dynamic axial contact stiffness analysis of position preloaded ball screw mechanism

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401881928 ◽  
Author(s):  
Jun Liu ◽  
Yi Ou
Keyword(s):  
Axial Load ◽  
Contact Stiffness ◽  
Dynamic Contact ◽  
Ball Screw ◽  
Coupling Relationship ◽  
Stiffness Model ◽  
Static Contact ◽  
Variation Range ◽  
Screw Mechanism ◽  
Feed Drive System

This article establishes an axial contact stiffness model of position preloaded ball screw mechanism based on Hertz contact theory. The analysis of dynamic axial contact stiffness is one of the foundations of the research on the dynamic characteristic of the ball screw feed drive system. The model takes into account the coupling relationship between the contact angle and the normal contact force, as well as the coupling relationship between the elastic deformation and the contact deformation coefficient. The static and dynamic axial contact stiffness characteristics of the preloaded ball screw mechanism are studied. The numerical analysis result shows that the static contact stiffness of the preloaded ball screw mechanism increases with the increase in the preload and decreases with the increase in the axial load. The dynamic contact stiffness of the preloaded ball screw mechanism increases with the increase in the screw’s rotational speed. The variation range of dynamic contact stiffness increases with the increase in axial load under the same preload. And the variation range of dynamic contact stiffness decreases with the increase in preload under the same axial load. The axial contact stiffness model established in this article can be used to analyze either static or dynamic contact stiffness of position preloaded ball screw mechanism.

scholarly journals Analysis on Dynamic Contact Characteristics and Dynamic Stiffness Estimating Method of Single Nut Ball Screw Pair Based on the Whole Rolling Elements Model

2020 ◽  
Vol 10 (17) ◽  
pp. 5795
Author(s):  
Ye Chen ◽  
Chunyu Zhao ◽  
Zhenjun Li ◽  
Zechen Lu
Keyword(s):  
Machine Tool ◽  
Mass Production ◽  
Contact Stiffness ◽  
Dynamic Stiffness ◽  
Dynamic Contact ◽  
Ball Screw ◽  
Cnc Machine Tool ◽  
Cnc Machine ◽  
Feed System ◽  
Stiffness Model

The purpose of this paper is investigating the characteristics of dynamic contact and dynamic stiffness of the single nut ball screw pair (SNBSP). Then a new sensorless method is proposed to extract the SNBSP dynamic contact stiffness of a mass production CNC machine tool feed system. First of all, the transformation relationship between each coordinate system of SNBSP is established. Secondly, the dynamic model of all ball–raceway contact pairs is established. Based on this, a dynamic contact stiffness model is established. The dynamic contact parameters are obtained by the numerical method. It is found that the influence of screw speed on screw and nut raceway normal force distribution are opposite. This will affect the variations of dynamic contact stiffness. It is also clear that the effect of axial load on dynamic stiffness is significant. Then, an effective method is proposed to estimate the dynamic contact stiffness of a mass production CNC machine tool feed system without any external sensors. The axial force of feed system is estimated by using torque current of servo motor. Current signals can be obtained through FANUC Open CNC API Specifications (FOCAS) library functions, and then dynamic contact stiffness can be calculated through the stiffness model without external sensors. Finally, a feed system dynamic model is built, and the contact model and sensorless stiffness estimating method are verified by experiments in this dynamic system.

Modeling of axial contact stiffness of a double-nut with preloads

2016 ◽  
Vol 232 (4) ◽  
pp. 629-638 ◽  
Author(s):  
Tiemin Li ◽  
Fuhua Li ◽  
Yao Jiang ◽  
Haitong Wang ◽  
Yunsong Du
Keyword(s):  
Theoretical Model ◽  
Axial Load ◽  
Contact Stiffness ◽  
Ball Screw ◽  
Axial Stiffness ◽  
Axial Deformation ◽  
Displacement Sensors ◽  
Ball Screw Drive ◽  
Improved Model ◽  
Ball Screw Drives

Ball screw drives are commonly used to provide linear motion in machine tools. And stiffness is one of the most important performance indexes. However, stiffness of nuts with different preloads is difficult to be calculated precisely because of complex structures. In order to improve the calculating accuracy, a new model is proposed with the consideration of geometry errors of grooves and balls based on the existing theoretical model. The influence of geometry errors on axial deformation of double-nut is analyzed and modeled. Meanwhile, a preload-adjustable ball screw drive is constructed on the basis of a modified double-nut mechanism. A novel loading mechanism is designed to apply axial load on the working table and test the force in real time. Two laser displacement sensors are adopted to test axial deformation of the double-nut. The axial stiffness of the double-nut is analyzed based on the axial load and the axial deformation. Stiffness simulations of the new improved model, the theoretical model, and the empirical model are also analyzed. The contrastive analysis shows that the experimental results agree much better with the axial stiffness calculated by the new improved model. This study provides a more accurate model to calculate the stiffness of the double-nut with preloads for preloaded ball screw drives.

Determination of contact stiffness in ball screws considering variable contact angles

2014 ◽  
Vol 228 (12) ◽  
pp. 2193-2203 ◽  
Author(s):  
Yongjiang Chen ◽  
Wencheng Tang
Keyword(s):  
Contact Angle ◽  
Contact Stiffness ◽  
Position Angle ◽  
Contact Angles ◽  
Ball Screw ◽  
Design Parameters ◽  
Operation Condition ◽  
Normal Forces ◽  
Screw Mechanism

The contact angles formed at the position of each ball in ball screws are conventionally assumed to be a constant value in determination of contact stiffness. In this study, instead of being treated as pre-assumed constants, the contact angle is formulated as functions of the position angle of balls to reflect their distribution dependent on the operation condition and design parameters. After establishing a proper transformed coordinate system according to the ball screw mechanism, the variable contact angles and normal forces of the ball screw are predicted. Then the contact stiffness obtained by numerical calculations is validated by experiment and several characteristics arising from the variable contact angle will be discussed.

Precision loss of ball screw mechanism under sliding-rolling mixed motion behavior

2021 ◽  
Vol 28 (5) ◽  
pp. 1357-1376
Author(s):  
Bao-bao Qi ◽  
Qiang Cheng ◽  
Shun-lei Li ◽  
Zhi-feng Liu ◽  
Cong-bin Yang
Keyword(s):  
Ball Screw ◽  
Screw Mechanism ◽  
Motion Behavior

Analysis of Bouncing Vibrations of a 2-DOF Tripad Contact Slider Model With Air Bearing Pads Over a Harmonic Wavy Disk Surface

1999 ◽  
Vol 121 (4) ◽  
pp. 939-947 ◽  
Author(s):  
Kyosuke Ono ◽  
Kan Takahashi
Keyword(s):  
Contact Stiffness ◽  
Disk Surface ◽  
Design Parameters ◽  
Air Bearing ◽  
Static Contact ◽  
Tracking Ability ◽  
The Coefficient Of Friction ◽  
Bearing Stiffness ◽  
Perfect Contact ◽  
Contact Slider

In this study, the authors numerically analyzed the bouncing vibrations of a two-degree-of-freedom (2-DOF) model of a tripad contact slider with air bearing pads over a harmonic wavy disk surface. The general features of bouncing vibrations were elucidated in regard to the modal characteristics of a 2-DOF vibration system and design parameters such as contact stiffness, contact damping, air hearing stiffness, the rear to front air bearing stiffness ratio, static contact force and the coefficient of friction. The design of a contact slider was discussed in terms of tracking ability and wear durability. In addition, two sample designs of a perfect contact slider with sufficient wear durability were also presented.

Sign in / Sign up

Export Citation Format

Share Document