Conceptual Design of an Exactly Straight Lifting Forging Manipulator

2014 ◽  
Vol 6 (3) ◽  
Author(s):  
Huafeng Ding ◽  
Zemin Feng ◽  
Hongye Fu ◽  
Yuanyuan Wang
Keyword(s):  
Bearing Capacity ◽  
Conceptual Design ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Coordinated Control ◽  
High Load ◽  
Load Bearing Capacity ◽  
Motion Mechanism ◽  
Straight Line ◽  
Forging Manipulator

The gripper lifting track of a forging manipulator should keep as close to a straight line as possible, especially for the manufacturing of long or high-precision forged pieces. However, the lifting tracks of most forging manipulators are arc, such as DANGO & DIENENTHAL in Siegen (DDS) and Schloemann-SiemagAG Meer (SMS Meer). This paper proposes a new forging manipulator whose gripper lifting track is exactly a straight line. First, a planar 3-degrees-of-freedom (3-DOF) mechanism whose gripper moves along a straight line is proposed. Second, replace the lifting drive of the planar mechanism with a parallel mechanism which only generates one translation, and obtain a major-motion mechanism. Finally, a new forging manipulator is constructed based on this major-motion mechanism. The new manipulator has the advantages of exactly straight lifting, high load-bearing capacity, and decoupling the lifting from other motions. It not only can improve forging precision for long axial forged pieces but also make coordinated control of two forging manipulators much easier.

scholarly journals Constructing a biomimetic robust bi-layered hydrophilic lubrication coating on surface of silicone elastomer

Friction ◽  
2021 ◽  
Author(s):  
Luyao Gao ◽  
Xiaoduo Zhao ◽  
Shuanhong Ma ◽  
Zhengfeng Ma ◽  
Meirong Cai ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Composite Layer ◽  
High Load ◽  
Silicone Elastomer ◽  
Aqueous Lubrication ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lubrication Performance ◽  
Wide Range

AbstractSilicone elastomers-based materials have been extensively involved in the field of biomedical devices, while their use is extremely restricted due to the poor surface lubricity and inherent hydrophobicity. This paper describes a novel strategy for generating a robust layered soft matter lubrication coating on the surface of the polydimethylsiloxane (PDMS) silicone elastomer, by entangling thick polyzwitterionic polyelectrolyte brush of poly (sulfobetaine methacrylate) (PSBMA) into the sub-surface of the initiator-embedded stiff hydrogel coating layer of P(AAm-co-AA-co-HEMA-Br)/Fe, to achieve a unified low friction and high load-bearing properties. Meanwhile, the stiff hydrogel layer with controllable thickness is covalently anchored on the surface of PDMS by adding iron powder to provide catalytic sites through surface catalytically initiated radical polymerization (SCIRP) method and provides high load-bearing capacity, while the topmost brush/hydrogel composite layer is highly effective for aqueous lubrication. Their synergy effects are capable of attaining low friction coefficient (COFs) under wide range of loaded condition in water environment with steel ball as sliding pair. Furthermore, the influence of mechanical modulus of the stiff hydrogel layer on the lubrication performance of layered coating is investigated, for which the COF is the lowest only when the modulus of the stiff hydrogel layer well matches the PDMS substrate. Surprisingly, the COF of the modified PDMS could remain low friction (COF < 0.05) stably after encountering 50,000 sliding cycles under 10 N load. Finally, the surface wear characterizations prove the robustness of the layered lubricating coating. This work provides a new route for engineering lubricious silicon elastomer with low friction, high load-bearing capacity, and considerable durability.

Continuously Growing Ultrathick CrN Coating to Achieve High Load-Bearing Capacity and Good Tribological Property

2018 ◽  
Vol 10 (3) ◽  
pp. 2965-2975 ◽  
Author(s):  
Zechao Li ◽  
Yongxin Wang ◽  
Xiaoying Cheng ◽  
Zhixiang Zeng ◽  
Jinlong Li ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Tribological Property ◽  
High Load ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Crn Coating

scholarly journals Numerical Simulation Study Of Squeezed Branch Piles Based On Post-grouting Technology

2021 ◽  
Vol 292 ◽  
pp. 01038
Author(s):  
LiXing Ma ◽  
ZhuoPeng Shi ◽  
Kai Han ◽  
PengFei Chang ◽  
XiaoDong He
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
High Load ◽  
Single Pile ◽  
Horizontal Force ◽  
Load Bearing Capacity ◽  
Load Transfer Mechanism ◽  
Post Grouting ◽  
Vertical Bearing ◽  
Excellent Stability

The squeezed branch pile has strong resistance to pressure, pullout and horizontal force, and it also has excellent stability, which makes it widely used in the field of electrical engineering. Based on the ABAQUS, the paper simulates the vertical bearing situation of post-grouting squeezed branch piles, by setting up Set two comparisons of single pile and squeezed branch pile, the bearing capacity, load transfer mechanism and failure mode of post-grouting squeezed branch piles were comprehensively analyzed and compared. Studies have shown that the bearing capacity of the squeezed branch piles with post-grouting technology has increased by 68.1% compared with the traditional squeezed branch piles, and the bearing characteristics of the branches have changed greatly. In this process, the end-bearing function of the branch plate is fully exerted, and the high load-bearing capacity of the grouted strata soil is used to reduce the settlement.

scholarly journals Load-carrying capacity of welded K-type joints inside floor truss systems

2019 ◽  
Vol 52 (1) ◽  
pp. 38-52
Author(s):  
Pooya Saremi ◽  
Wei Lu ◽  
Jari Puttonen ◽  
Dan Pada ◽  
Jyrki Kesti
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Carrying Capacity ◽  
Numerical Models ◽  
High Load ◽  
Load Carrying Capacity ◽  
Finite Element Analyses ◽  
Load Bearing Capacity ◽  
Load Carrying ◽  
Joint Behaviour

The load-carrying capacity of a K-type joint inside a floor truss is studied both experimentally and numerically. The joint tested is a scaled-down, isolated joint. The tubular braces, plate chord, and division plate are made of SSAB Domex steel. Comparison of load displacement curves received by finite element analyses with curves obtained from tests confirms that numerical models describe joint behaviour reasonable. The paper demonstrates that joints with high load-bearing capacity can be investigated experimentally by scaling the dimensions of the joint down when testing devices can affect the required capacity of the joint. The results presented can also be used for optimizing failure mechanism of similar joints in practice.

Kinematics and Force Transmission Analysis of a Decoupled Remote Center of Motion Mechanism Based on Intersecting Planes

2020 ◽  
pp. 1-24
Author(s):  
Kaiyu Wu ◽  
Fan Zhang ◽  
Guohua Cui ◽  
Jing Sun ◽  
Minhua Zheng
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Final Part ◽  
Force Transmission ◽  
Transmission Performance ◽  
End Effector ◽  
Motion Mechanism ◽  
Control Scheme ◽  
Rotational Degrees Of Freedom

Abstract A decoupled mechanism based on intersecting planes that can be considered a parallel mechanism with two arms is presented in this paper. The end-effector is connected to the base through two planar serial arms. The new specific characteristics of novel mechanism allow the generation of a Remote Center of Motion (RCM) possessing two decoupled rotational degrees of freedom (DoF) and a tanslational DoF. Compared with the RCM mechanism based on intersecting planes proposed by Li et al, due to the decoupling characteristics of this mechanism make it has a simpler control scheme and a larger workspace. This mechanisms also eliminates the singularity inside its workspace that impairs the original mechanism. In the final part of the paper, through an analysis of the force transmission performance, we derive a method to adjust the length of the linkage to optimize its force transmission performance.

Design and Validation of A Novel Planar 2R1T Remote Center-of-motion Mechanism Composing of Dual-Triangular and Straight-Line Linkages

2021 ◽  
pp. 1-11
Author(s):  
Genliang Chen ◽  
Yuanhao Xun ◽  
Yuchen Chai ◽  
Siyue Yao ◽  
Chao Chen ◽  
...  
Keyword(s):  
Minimally Invasive ◽  
Degrees Of Freedom ◽  
Fast Recovery ◽  
Positioning Accuracy ◽  
Motion Mechanism ◽  
Small Incision ◽  
Pure Rotation ◽  
Differential Motion ◽  
Straight Line ◽  
Motion Characteristics

Abstract Benefiting from small incision and fast recovery, minimally invasive surgeries (MIS) exhibit great advantages in clinical operations. In such kind of surgeries, the remote center-of-motion (RCM) mechanisms play an important role owing to their special motion characteristics. This paper presents the design of a novel planar RCM mechanism of two rotational and one translational degrees-of-freedom. In the proposed design, the mobility of RCM mechanisms is decomposed into one-DOF pure rotation and translation with a remote stationary point. The dual-triangular linkage and the Peaucellier-Lipkin straight-line linkage are introduced to achieve the remote rotation and translation, respectively. Inspired by the concept of virtual screw, a dual-helical differential-motion joint is particularly designed to generate the coaxial rotation and translation. A preliminary prototype is developed to validate the feasibility of the designed RCM mechanism. The experimental results show that the developed prototype is easy to control and of acceptable positioning accuracy, which manifests potential application in MIS.

scholarly journals Synergies in lubrication

2017 ◽  
Vol 19 (35) ◽  
pp. 23677-23689 ◽  
Author(s):  
Andra Dėdinaitė ◽  
Per M. Claesson
Keyword(s):  
Bearing Capacity ◽  
Aqueous Medium ◽  
Water Layer ◽  
High Load ◽  
Low Friction ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Load Bearing ◽  
Living Organisms

In living organisms the aqueous medium is used for providing low friction forces. This is achieved by synergistic actions of different biomolecules that together accomplish a high load bearing capacity and sustain an easily sheared water layer.

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