Investigations on Dynamic Characteristics of a Mechanical Press Considering Both Translational Clearance Joint and Lubrication Effect

2021 ◽  
pp. 1549-1559
Author(s):  
Xuze Wu ◽  
Yu Sun
Keyword(s):  
Dynamic Characteristics ◽  
Clearance Joint ◽  
Mechanical Press ◽  
Lubrication Effect

Modeling and Simulation of a Slider-Crank Mechanism with Clearance and Lubricant Joint

2012 ◽  
Vol 510 ◽  
pp. 458-466 ◽  
Author(s):  
Li Juan Wu ◽  
Ai Ping Li ◽  
Xue Mei Liu
Keyword(s):  
Dynamic Characteristics ◽  
Screen Printing ◽  
Reynolds Equation ◽  
Continuous Contact ◽  
Clearance Joint ◽  
Dynamics Response ◽  
The Impact ◽  
Printing Machine ◽  
Crank Mechanism ◽  
Vector Approach

The influence of the clearance in the joint must be considered in the modeling and dynamic analysis for the mutibody mechanical systems. The model of the planar revolute clearance joint is built on the base of the clearance vector approach and the continuous contact approach. Furthermore, the friction is included through the modified Coulombs friction law and the lubrication is introduced into the model, with the Reynolds equation employed to evaluate the hydrodynamic forces. A slider-crank drive system of a screen printing machine with a clearance joint is researched as the example, whose dynamic characteristics are simulated by the software ADAMS. It is shown that the clearance has affected the dynamics response of the system and the lubrication is effective to deaden the impact.

Dynamic characteristics of planar linear array deployable structure based on scissor-like element with differently located revolute clearance joints

2017 ◽  
Vol 232 (10) ◽  
pp. 1759-1777 ◽  
Author(s):  
Bo Li ◽  
San-Min Wang ◽  
Viliam Makis ◽  
Xiang-Zhen Xue
Keyword(s):  
Mechanical System ◽  
Dynamic Characteristics ◽  
Equations Of Motion ◽  
Nonlinear Behavior ◽  
Friction Model ◽  
Dynamic Responses ◽  
Force Model ◽  
Clearance Joints ◽  
Deployable Structure ◽  
Clearance Joint

This paper comprehensively investigates the parametric effects of differently located revolute clearance joints on the dynamic behavior of planar deployable structure based on scissor-like element. Considering the real physical mechanical joints, the normal and the tangential forces in the revolute clearance joints are respectively modeled using Flores contact-force model and LuGre friction model. The resulting forces and moments are embedded in the equations of motion of the scissor deployable structure for accurately describing the effect of joint clearance and governing the dynamic response of this structure. The effects of the main parameters such as the location of the clearance joint, the clearance size and the number of clearance joints on the dynamic characteristics of a multibody mechanical system have been numerically evaluated, and the results indicate that joints at different locations in a mechanical system have different sensitivities to the clearance size, and the more sensitive joint should be controlled to reduce the nonlinear behavior of this structure. Also, it can be concluded that the motion in one revolute clearance joint will affect the motion in the other clearance joints and the dynamic interaction of clearance joints is the important source of structural behavior change. Therefore, in order to accurately predict the dynamic responses of the mechanical system, the clearance effect of each joint on the multibody system should be investigated and understood.

scholarly journals A Study on Dynamic Characteristics of Satellite Antenna System considering 3D Revolute Clearance Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Zhengfeng Bai ◽  
Jijun Zhao
Keyword(s):  
Dynamic Characteristics ◽  
Antenna System ◽  
Contact Forces ◽  
Dynamics Analysis ◽  
Satellite Antenna ◽  
Revolute Joint ◽  
Analysis And Design ◽  
Revolute Clearance Joint ◽  
Clearance Joint ◽  
Axial Clearance

Clearances in the joints of real mechanisms are unavoidable due to assemblage, manufacturing errors, and wear. The dual-axis driving and positioning mechanism is one kind of space actuating mechanism for satellite antenna to implement precise guidance and positioning. However, in dynamics analysis and control of the satellite antenna system, it is usually assumed that the revolute joint in the satellite antenna system is perfect without clearances or imperfect with planar radial clearance. However, the axial clearance in an imperfect revolute joint is always ignored. In this work, the revolute joint is considered as a 3D spatial clearance joint with both the radial and axial clearances. A methodology for modeling the 3D revolute joint with clearances and its application in satellite antenna system is presented. The dynamics modeling and analysis of the satellite antenna system are investigated considering the 3D revolute clearance joint. Firstly, the mathematical model of the 3D revolute clearance joint is established, and the definitions of the radial and axial clearance are presented. Then, the potential contact modes, contact conditions, and contact detection of the 3D revolute clearance joint are analyzed. Further, the normal and tangential contact force models are established to describe the contact phenomenon and determine the contact forces in the 3D revolute clearance joint. Finally, a satellite antenna system considering the 3D revolute clearance joint with spatial motion is presented as the application example. Different case studies are presented to discuss the effects of the 3D revolute clearance joint. The results indicate that the 3D revolute clearance joint will lead to more severe effects on the dynamic characteristics of the satellite antenna system. Therefore, the effects of axial clearance on the satellite antenna system cannot be ignored in dynamics analysis and design of the satellite antenna system.

Effects of revolute clearance joint on the dynamic behavior of a planar space arm system

2018 ◽  
Vol 233 (5) ◽  
pp. 1629-1644 ◽  
Author(s):  
Huihui Miao ◽  
Bing Li ◽  
Jie Liu ◽  
Anqi He ◽  
Shangkun Zhu
Keyword(s):  
Mathematical Model ◽  
Dynamic Characteristics ◽  
Degrees Of Freedom ◽  
Multibody System ◽  
Dynamic Performance ◽  
Clearance Joint ◽  
Locking Mechanism ◽  
Operation Stability ◽  
Pointing Accuracy ◽  
The Mathematical Model

Space arm system is a typical multibody mechanical system requiring high operation stability and precision connected by kinematic joints. As joint clearance is inevitable during the manufacturing and mounting process, it turns into a critical problem affecting the dynamic characteristics and kinematic accuracy of the mechanism. A space arm system deploying stably and accurately is the prerequisite to guarantee the final satellite pointing accuracy once it is into its working state. Thus, the space arm system needs to have good dynamic characteristics and stability during its deploying process and to have accurate and reliable positioning characteristics during its locking process. For the deploying process, the mathematical model of a multibody system with clearance joint has been established as a foundation to study the influence of clearance properties, including clearance size, clearance joint locations, numbers of clearance joints and lubrication on the dynamic performance and motion stability of a two-degrees-of-freedom space arm system. The mathematical model of a locking mechanism has been established to study the clearance effects on the pointing accuracy of the space arm system during its locking process. The simulation results show that, the clearance has different effects on the dynamic characteristics of the space arm system during its different working processes.

scholarly journals Nonlinear Dynamic Characteristics Analysis of Shift Manipulator for Robot Driver with Multiple Joint Clearance

2021 ◽  
Author(s):  
Gang Chen ◽  
Xinyao Xu
Keyword(s):  
Dynamic Characteristic ◽  
Contact Force ◽  
Dynamic Characteristics ◽  
Nonlinear Dynamic ◽  
Force Model ◽  
Characteristic Model ◽  
Clearance Joints ◽  
Clearance Joint ◽  
Nonlinear Dynamic Characteristics ◽  
Nonlinear Dynamic Characteristic

Abstract The clearance joint is very important to the nonlinear dynamic characteristics of mechanism. This paper presents a nonlinear dynamic characteristic model of shift manipulator for robot driver based on multiple revolute clearance joints to improve dynamic characteristics. The relative penetration depth and velocity between pin and bushing are obtained by establishing the kinematic model of the shift manipulator with clearance joint. Based on the improved L-N contact force model and the modified Coulomb friction model, the normal contact force and the tangential contact force of clearance joint are analyzed. With full clearance joints, the nonlinear dynamic characteristic model of the shift manipulator for robot driver is established. The nonlinear dynamic characteristic laws of the shift manipulator including the end displacement, velocity, acceleration and active joint driving torque are analyzed by different sizes of clearance joints. And the performance test of the shift manipulator for robot driver is conducted. The results demonstrate that the nonlinear dynamic characteristics are well analyzed and verified through the presented characteristic model with clearance joints.

Dynamic analysis of mechanical system considering radial and axial clearances in 3D revolute clearance joints

2020 ◽  
pp. 107754632095051
Author(s):  
Zheng Feng Bai ◽  
Xin Jiang ◽  
Ji Yu Li ◽  
Ji Jun Zhao ◽  
Yang Zhao
Keyword(s):  
Mechanical System ◽  
Dynamic Characteristics ◽  
Mathematic Model ◽  
Contact Forces ◽  
Dynamic Responses ◽  
Radial Clearance ◽  
Double Pendulum ◽  
Clearance Joints ◽  
Revolute Clearance Joint ◽  
Clearance Joint

In the dynamic modeling and simulation of mechanical system with revolute clearance joint, it is usually assumed that the revolute joint is planar joint with radial clearance, but the axial clearance is ignored. In this article, the dynamic responses of a mechanical system considering both radial and axial clearances in 3D revolute clearance joint are investigated using a computational methodology. First, the mathematic model of 3D revolute clearance joint is established considering the radial and axial clearances. The definitions of the radial and axial clearances, the potential contact modes, contact conditions, and contact detection for 3D revolute clearance joint are presented. Furthermore, the normal and tangential contact force models are established to describe the contact phenomenon and determine the contact forces in revolute clearance joints. Finally, two demonstrative application examples are presented to illustrate the dynamic characteristics of mechanical systems considering both radial and axial clearances in revolute clearance joints. A slider-crank mechanism with planar motion and a double pendulum with spatial motion are investigated. Different cases are presented to analyze the dynamic characteristics of a mechanical system considering radial and axial clearances in 3D revolute clearance joints.

Invited PaperTemperature dependence of SiGe HBT static and dynamic characteristics

1998 ◽  
Vol 08 (PR3) ◽  
pp. Pr3-81-Pr3-86
Author(s):  
F. Aniel ◽  
N. Zerounian ◽  
A. Gruhle ◽  
C. Mähner ◽  
G. Vernet ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Static And Dynamic Characteristics ◽  
Sige Hbt
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