Investigation on mechanical behavior of planetary roller screw mechanism with the effects of external loads and machining errors

2021 ◽  
Vol 154 ◽  
pp. 106689
Author(s):  
Xing Du ◽  
Bingkui Chen ◽  
Zhengding Zheng
Keyword(s):  
Mechanical Behavior ◽  
Machining Errors ◽  
Roller Screw ◽  
Screw Mechanism ◽  
External Loads

Load distribution over threads of planetary roller screw mechanism with pitch deviation

2018 ◽  
Vol 233 (13) ◽  
pp. 4653-4666 ◽  
Author(s):  
Wenjie Zhang ◽  
Geng Liu ◽  
Shangjun Ma ◽  
Ruiting Tong
Keyword(s):  
Load Distribution ◽  
Machining Error ◽  
Experimental Conditions ◽  
Load Distributions ◽  
Machining Errors ◽  
Proposed Model ◽  
Roller Screw ◽  
Multiple Threads ◽  
Screw Mechanism ◽  
Pitch Deviation

A model is proposed to calculate load distribution over threads of planetary roller screw mechanism (PRSM) with pitch deviation. Firstly, four kinds of machining errors of threads including pitch deviation, deviation of thread angle, division error of multiple threads and deviation of pitch diameter are analyzed, and the relationships among them are investigated. After analyzing the relationships among the errors, pitch deviation is chosen to be the main machining error to investigate because it can reflect the effects of other machining errors, and is the most influential machining error on the contact condition and deformation compatibility relationship, i.e. the load distribution of PRSM. Based on the proposed model, the effects of pitch deviation on the load distribution of PRSM are studied through numerical analyses, and load distributions under different machining precisions are analyzed. In order to experimentally verify the investigation, two PRSM samples are measured and tested under the same experimental conditions. The experimental results show that load distributions over threads will fluctuate because of the existence of pitch deviations. The pitch deviations, load distributions over threads and wear depths of threads in the samples show obvious accordance, which indirectly demonstrates the effects of pitch deviation on load distribution.

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.

Elasto-plastic contact characteristics of the Planetary Roller Screw Mechanism

2016 ◽  
pp. 181-186
Author(s):  
R.T. Tong ◽  
H. Guo ◽  
G. Liu ◽  
Q. Yao
Keyword(s):  
Roller Screw ◽  
Screw Mechanism

Investigation on the uncertain factors of the elastic–plastic contact characteristics of the planetary roller screw mechanism

2018 ◽  
Vol 233 (5) ◽  
pp. 1795-1806
Author(s):  
Qin Yao ◽  
Yongshou Liu ◽  
Mengchuang Zhang ◽  
Geng Liu ◽  
Shangjun Ma
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mathematic Model ◽  
Contact Analysis ◽  
Secondary Development ◽  
Elastic Plastic ◽  
Development Platform ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Element Method

The scatter of uncertain factors of the planetary roller screw mechanism, which originated from the manufacturing process, has a significant influence on its serving performance. However, this influence remains insufficiently studied. Further, the elastic–plastic contact analysis of the planetary roller screw mechanism with considering the uncertainties needs large numbers of repetitive calculations by traditional finite element method, which is labor intensive and often impractical. In this paper, an uncertain model of the planetary roller screw mechanism, including parameterization and finite element calculation, is established to conduct the elastic–plastic contact analysis automatically. Besides, the finite element method results can be also obtained automatically with the self-compiled flow program and the secondary development platform using the design of experiment method. Then, a mathematic model is applied to value the influence of the uncertain factors on the contact characteristics. The Pareto graphs are plotted to clearly show this sequence of the percent effects of all the uncertain factors. The present work, for the first time, developed an automatic modeling method for analyzing efficiently the uncertain factors of planetary roller screw mechanism, which is worthy in industrial application.

scholarly journals Modelling of Electro-mechanical Servo System Based on the Planetary Roller Screw Mechanism

2020 ◽  
Vol 306 ◽  
pp. 02004
Author(s):  
Jianxin Zhang ◽  
Chuanming Du ◽  
Shangjun Ma ◽  
Geng Liu
Keyword(s):  
Contact Stiffness ◽  
Servo System ◽  
Response Speed ◽  
Load Force ◽  
System Response ◽  
Analysis Model ◽  
Roller Screw ◽  
Fluctuation Amplitude ◽  
Screw Mechanism ◽  
Main Components

Taking the electro-mechanical servo system as the research object, considering the contact stiffness, friction and clearance of the main components in the electro-mechanical servo system, the analysis model of the electro-mechanical servo system based on Planetary roller screw mechanism (PRSM) is established by using AMESim software. The results showed that the response speed of the system slowed down when the friction of PRSM was taken into account. The larger the clearance or the smaller the stiffness, the greater the fluctuation amplitude of the system response. After the controller was adjusted, the steady-state error of the system caused by the load force can be reduced quickly.

Thermal characteristics analysis and experimental study of the planetary roller screw mechanism

2019 ◽  
Vol 149 ◽  
pp. 1345-1358 ◽  
Author(s):  
Guan Qiao ◽  
Geng Liu ◽  
Shangjun Ma ◽  
Yawen Wang ◽  
Pin Li ◽  
...  
Keyword(s):  
Experimental Study ◽  
Thermal Characteristics ◽  
Characteristics Analysis ◽  
Roller Screw ◽  
Screw Mechanism
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