Dynamic Modeling of the Double-Nut Planetary Roller Screw Mechanism Considering Elastic Deformations

2021 ◽  
Author(s):  
Xiaojun Fu ◽  
Geng Liu ◽  
Xin Li ◽  
Ma Shangjun ◽  
Qiao Guan
Keyword(s):  
External Force ◽  
Load Distribution ◽  
Equations Of Motion ◽  
Great Influence ◽  
Compressive Force ◽  
Mass System ◽  
Elastic Deformations ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Nonlinear Equations Of Motion

Abstract With the rising application of double-nut Planetary Roller Screw Mechanism (PRSM) into industry, increasing comprehensive studies are required to identify the interactions among motion, forces and deformations of the mechanism. A dynamic model of the double-nut PRSM with considering elastic deformations is proposed in this paper. As preloads, inertial forces and elastic deformations have a great influence on the load distribution among threads, the double-nut PRSM is discretized into a spring-mass system. An adjacency matrix is introduced, which relates the elastic displacements of nodes and the deformations of elements in the spring-mass system. Then, the compressive force acting on the spacer is derived and the equations of load distribution are given. Considering both the equilibrium of forces and the compatibility of deformations, nonlinear equations of motion for the double-nut PRSM are developed. The effectiveness of the proposed model is verified by comparing dynamic characteristics and the load distribution among threads with those from the previously published models. Then, the dynamic analysis of a double-nut PRSM is carried out, when the rotational speed of the screw and the external force acting on the nut #2 are changed periodically. The results show that if the external force is increased, the preload of the nut #1 is decreased and that of the nut #2 is increased. Although the nominal radii of rollers are the same, the maximum contact force acting on the roller #2 is much larger than that of the roller #1.

Dynamics of the Planetary Roller Screw Mechanism

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Matthew H. Jones ◽  
Steven A. Velinsky ◽  
Ty A. Lasky
Keyword(s):  
Steady State ◽  
Slip Velocity ◽  
Equations Of Motion ◽  
Viscous Friction ◽  
Contact Angles ◽  
Dynamic Equations ◽  
Roller Screw ◽  
Angular Velocities ◽  
Screw Mechanism ◽  
Lagrange’S Method

This paper develops the dynamic equations of motion for the planetary roller screw mechanism (PRSM) accounting for the screw, rollers, and nut bodies. First, the linear and angular velocities and accelerations of the components are derived. Then, their angular momentums are presented. Next, the slip velocities at the contacts are derived in order to determine the direction of the forces of friction. The equations of motion are derived through the use of Lagrange's Method with viscous friction. The steady-state angular velocities and screw/roller slip velocities are also derived. An example demonstrates the magnitude of the slip velocity of the PRSM as a function of both the screw lead and the screw and nut contact angles. By allowing full dynamic simulation, the developed analysis can be used for much improved PRSM system design.

Experimental study of the nature of the load distribution on the turns of the thread of the planetary roller-screw mechanism

2019 ◽  
Author(s):  
O.A. Ryakhovskiy ◽  
A.S. Marokhin ◽  
A.N. Vorobyev ◽  
O.A. Khachirova
Keyword(s):  
Load Distribution ◽  
Axial Load ◽  
Flat Surface ◽  
Experimental Setup ◽  
Feed Drives ◽  
The Press ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Force Displacement ◽  
Made In

The article considers the effect of axial load on the turns of the thread of the planetary roller-screw converter of rotational motion into translational one. For this purpose an experimental setup was made in which the nut lies end-face on the flat surface of the press, a screw is screwed into it. The force is applied to the screw through a ball to distribute the load uniformly. The design of the machine for compression measurement allows automatic recording the axial mutual movement of tested mechanism parts when the loading force changes. Contact and displacement occur when the loading force reaches 300 N. The results are obtained in the form of a "force – displacement" graph. In the course of the experiment, the influence of step error on the uniformity of the contacts of the turns of the mating parts of the planetary roller-screw mechanism was checked. The results of the experiment are analyzed, the influence of inaccuracy of manufacturing thread of planetary roller-screw mechanism parts on its capacity for use in feed drives of various machines is considered.

scholarly journals Thermo-mechanical coupling–based finite element analysis of the load distribution of planetary roller screw mechanism

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401877525 ◽  
Author(s):  
Shangjun Ma ◽  
Chenhui Zhang ◽  
Tao Zhang ◽  
Geng Liu ◽  
Shumin Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Distribution ◽  
Three Dimensional ◽  
Theoretical Models ◽  
Element Model ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Roller Screw ◽  
Screw Mechanism

In this article, 3D or three-dimensional finite element analysis is used to simulate and evaluate the load distribution characteristics of a planetary roller screw mechanism under thermo-mechanical coupling. The finite element model takes into account the installation modes of the planetary roller screw mechanism, which is verified by comparison with theoretical models for a certain load magnitude in four installation modes. In addition, the effects of the installation mode, load magnitude, and temperature condition on the load distribution are also systematically analyzed. The numerical results reveal a phenomenon of threads separating from the meshing, which indicates that the influence of thermo-mechanical coupling on the load distribution cannot be ignored. Furthermore, the influence of the installation mode on the screw–roller interface is larger than that on the nut–roller interface. Compared with the screw–roller interface, the temperature difference is one of the main conditions affecting the load distribution of the planetary roller screw mechanism and has a significant effect on the nut–roller interface. In addition, the influences of the screw rotational speed and the load magnitude on the load distribution on the screw–roller interface are larger than those on the nut–roller interface for the four installation modes.

scholarly journals A Multiscale Accuracy Degradation Prediction Method of Planetary Roller Screw Mechanism Based on Fractal Theory Considering Thread Surface Roughness

2021 ◽  
Vol 5 (4) ◽  
pp. 237
Author(s):  
Junjie Meng ◽  
Xing Du ◽  
Yingming Li ◽  
Peng Chen ◽  
Fuchun Xia ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Adhesive Wear ◽  
Fractal Theory ◽  
Great Influence ◽  
Wear Volume ◽  
Wear Depth ◽  
Asperity Contact ◽  
Thread Surface ◽  
Roller Screw ◽  
Screw Mechanism

The wear problems are vital to the planetary roller screw mechanism (PRSM) as they have a great influence on transmission accuracy, working efficiency, and service life. However, the wear characteristics of the PRSM have been rarely investigated in the past. In this paper, a multiscale adhesive wear model is established by incorporating the effective wear coefficient and considering the thread surface roughness. The variation of surface roughness is characterized by the two-dimension Majumdar–Bhushan (MB) function. The multi-asperity contact regimes are used to estimate microcontact mechanics of the rough interface. Moreover, the influences of surface roughness, material properties, and working conditions on the wear depth and precision loss of the PRSM are studied in detail. The results reveal that as the surface roughness increases, the total actual contact area, wear depth, and precision loss rate rise. In addition, the adhesive wear increases with the growth of the axial load, and decreases with the increase in the material hardness and material elastic modulus ratio to a certain extent. The investigation opens up a theoretical methodology to predict the wear volume and precision loss with regard to thread surface roughness, which lays the foundation for the design, manufacturing, and application of the PRSM.

Load Distribution and Axial Static Rigidity for Planetary Roller Screw Mechanism

2019 ◽  
Author(s):  
Xinhua Zhang ◽  
Xijian Huo ◽  
Jian Huang ◽  
Xiaoshuai Duan ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Load Distribution ◽  
Roller Screw ◽  
Static Rigidity ◽  
Screw Mechanism

scholarly journals Thread Modification Method for Load Balance on Planetary Roller Screw Mechanism

2018 ◽  
Vol 36 (4) ◽  
pp. 685-692
Author(s):  
Hui Guo ◽  
Ruiting Tong ◽  
Geng Liu ◽  
Wenjie Zhang ◽  
Shangjun Ma
Keyword(s):  
Load Balancing ◽  
Load Balance ◽  
Load Distribution ◽  
Load Capacity ◽  
Optimal Value ◽  
Modification Method ◽  
The Future ◽  
Roller Screw ◽  
Screw Mechanism ◽  
The Relationship

Based on the relationship between the load distribution and the load deformation of the thread of the planetary roller screw mechanism (PRSM), a modification method of the roller thread is proposed. The nut side and the screw side of the roller thread are modified by different amount of modification, and the modified thread load distribution is calculated and analyzed. The results show that the effects of roller thread modification on the load distribution are significant, and the sensitivity of the load capacity of the nut and screw to the modification is different. Through the study of the influence of roller thread modification on thread load distribution, the optimal value of the roller thread modification on the nut side and the screw side is obtained under the PRSM parameters given in this paper, which provides a theoretical guidance for the future PRSM load balancing design.

scholarly journals Research on friction torque analysis of planetary roller screw mechanism considering load distribution

2018 ◽  
Author(s):  
Fajin Gan ◽  
Pengcheng Mao ◽  
Shicheng Zheng ◽  
Guangliang Li ◽  
Shupeng Xin
Keyword(s):  
Load Distribution ◽  
Friction Torque ◽  
Roller Screw ◽  
Torque Analysis ◽  
Screw Mechanism

Load distribution of planetary roller screw mechanism and its improvement approach

2016 ◽  
Vol 230 (18) ◽  
pp. 3304-3318 ◽  
Author(s):  
Wenjie Zhang ◽  
Geng Liu ◽  
Ruiting Tong ◽  
Shangjun Ma
Keyword(s):  
Load Distribution ◽  
Applied Load ◽  
Uniform Load ◽  
Contact Conditions ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Deformation Compatibility ◽  
Load Conditions ◽  
Force Equilibrium

A model of load distribution over threads of planetary roller screw mechanism (PRSM) is developed according to the relationships of deformation compatibility and force equilibrium. In order to make the applied load of PRSM uniformly distributed over threads, an improvement approach is proposed, in which the parameters of thread form of roller and nut are redesigned, and the contact conditions of roller with screw and nut are changed to compensate the axial accumulative deformation of shaft sections of screw and nut. A typical planetary roller screw mechanism is taken as example to analyze the load distribution, and the effects of installation configurations, load conditions and thread form parameters on load distribution are studied. Furthermore, the improvement approach is applied to the PRSM, and it is proved to be beneficial to reach uniform load distribution over threads.

Nonlinear Vibrations Analysis of Overhead Power Lines: A Beam With Mass–Spring–Damper–Mass Systems

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Mohammad A. Bukhari ◽  
Oumar R. Barry
Keyword(s):  
Multiple Scales ◽  
Equations Of Motion ◽  
Nonlinear Frequency ◽  
Response Curves ◽  
Mass System ◽  
Parametric Studies ◽  
Overhead Power Lines ◽  
Nonlinear Equations Of Motion ◽  
Mass Spring ◽  
Stockbridge Damper

This paper examines the nonlinear vibration of a single conductor with Stockbridge dampers. The conductor is modeled as a simply supported beam and the Stockbridge damper is reduced to a mass–spring–damper–mass system. The nonlinearity of the system stems from the midplane stretching of the conductor and the cubic equivalent stiffness of the Stockbridge damper. The derived nonlinear equations of motion are solved by the method of multiple scales. Explicit expressions are presented for the nonlinear frequency, solvability conditions, and detuning parameter. The present results are validated via comparisons with those in the literature. Parametric studies are conducted to investigate the effect of variable control parameters on the nonlinear frequency and the frequency response curves. The findings are promising and open a horizon for future opportunities to optimize the design of nonlinear absorbers.

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