scholarly journals Friction Torque Analysis of Planetary Roller Screw Mechanism in Roller Jamming

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Linjie Li ◽  
Yongling Fu ◽  
Shicheng Zheng ◽  
Jian Fu ◽  
Tianxiang Xia

The load distribution model of the planetary roller screw mechanism (PRSM) is established on the basis of Hertz contact theory. The objective is to obtain a friction torque model of the PRSM in roller jamming. An example is provided to calculate the friction torque of the PRSM in roller jamming. Thereafter, the transmission efficiency is calculated. A static structural analysis is performed using the finite element method to estimate the contact stress between the threads of the PRSM components. Computational results indirectly reveal that roller jamming exerts considerable influence on the friction torque of the PRSM. Results show that the friction torque of the planetary roller screw increases when the roller is jammed and the wear of the parts is accelerated. This condition leads to structural failure. The results of this study can serve as a foundation for electromechanical actuation systems, which can be useful in designing antijamming systems for safety-critical aircraft applications.

2018 ◽  
Author(s):  
Fajin Gan ◽  
Pengcheng Mao ◽  
Shicheng Zheng ◽  
Guangliang Li ◽  
Shupeng Xin

Author(s):  
Guan Qiao ◽  
Geng Liu ◽  
Shangjun Ma ◽  
Zhenghong Shi ◽  
Teik C. Lim

The efficiency analytical model of the inverted planetary roller screw mechanism is formulated based on the friction torque calculation. Firstly, the friction torque model considering the load distribution of thread teeth is established including the components such as curvature friction torque, friction torque due to spinning sliding, pure sliding friction torque between rollers and carriers, friction torque generated by the viscosity of lubricant, and preload torque. Secondly, the contribution of the friction torque components and torque distribution on the roller thread teeth are investigated. Finally, efficiency analysis is conducted by discussing the influences of structure parameters of the inverted planetary roller screw mechanism and operating conditions. Computational results reveal that the total friction torque and efficiency are influenced by axial load, number of roller thread teeth, nut speed, contact angle, and helix angle of nut with different extents. This study provides an understanding of the relationship between friction torque, transmission efficiency, and system design parameters, which can be employed to enhance the inverted planetary roller screw mechanism optimization design.


2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881230 ◽  
Author(s):  
Chuanming Du ◽  
Geng Liu ◽  
Guan Qiao ◽  
Shangjun Ma ◽  
Wei Cai

The thermal behavior of the standard planetary roller screw mechanism needs to be investigated since the large amount of heat generated by the friction torque on multiple contact points during the transmission process. In this article, a simplified transmission system model of standard planetary roller screw mechanism is first established for the finite element analysis. Second, the friction torque of standard planetary roller screw mechanism is calculated and the boundary conditions of thermal analysis are deduced. Then, the transient thermal analysis of the standard planetary roller screw mechanism based on finite element method is conducted by considering the moving heat source and thus temperature field distribution at any time and the temperature rise curve at different positions of the standard planetary roller screw mechanism can be obtained. Finally, the correlation between the experimental data and the calculated values confirms the validity of the proposed thermal model for the transient thermal analysis.


Actuators ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 133
Author(s):  
Tobias Vonderbank ◽  
Katharina Schmitz

Increasing performance in modern hydraulics is achieved by a close investigation of possible enhancements of its components. Prior research has pointed out that electromechanical actuators can form suitable alternatives to hydraulically piloted control systems. Since the requirements at these actuation systems depend on the operating conditions of the system, each actuator can be optimized to the respective hydraulic system. Considering that many different conceptual designs are suitable, the phase of conceptual design plays a decisive role during the design process. Therefore, this paper focuses on the process of developing new conceptual designs for electromechanical valve actuation systems using the method of function structures. Aiming to identify special design features, which need to be considered during the design process of electromechanical actuation systems, an exemplary actuator was designed based on the derived function structure. To highlight the potential of function structures for the development of new electromechanical valve actuation systems, two principal concepts, which allow the reduction of the necessary forces, have been developed by extending the function structure. These concepts have been experimentally investigated to identify their advantages and disadvantages.


Author(s):  
Xiaojun Fu ◽  
Geng Liu ◽  
Xin Li ◽  
Ma Shangjun ◽  
Qiao Guan

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.


2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Matthew H. Jones ◽  
Steven A. Velinsky ◽  
Ty A. Lasky

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.


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

Author(s):  
Qin Yao ◽  
Yongshou Liu ◽  
Mengchuang Zhang ◽  
Geng Liu ◽  
Shangjun Ma

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.


Sign in / Sign up

Export Citation Format

Share Document