Design of one DOF closed-loop statically balanced planar linkage with link-collinear spring arrangement

Jhuang, Chi-Shiun; Kao, Young-Yu; Chen, Dar‐Zen

doi:10.1016/j.mechmachtheory.2018.07.021

Cited by 7 publications

(4 citation statements)

References 19 publications

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“…Based on this methodology, a 4-DoF planar mechanism was developed in 2012 [13]. The static balancing of a closed-loop planar mechanism with one DoF was performed by integrating two colinear springs [14]. Using a spring-gear concept, a planar mechanism based straight open linkage (instead of parallelogram) was statically balanced [15].…”

Section: Static Balancing Of Diversified Mechanical Archtitecturesmentioning

confidence: 99%

Design of a Five-Degrees of Freedom Statically Balanced Mechanism with Multi-Directional Functionality

Essomba

2021

Robotics

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A statically balanced mechanism is designed as a potential solution for the positioning of surgical instruments. Its kinematics with five degrees of freedom that decouples linear and angular motions is proposed for that objective. The linear motion of its end effector is provided by a classical parallelogram linkage. To enhance its adaptability, a mechanical system allows re-orienting the position mechanism in three different working modes (horizontal, upward and downward) while preserving its static balance. Based on the mechanical concept, a uniformized static balancing condition that considers all working modes is given. The orientation of the end effector is provided by a spherical decoupled mechanism. It generates a remote center of motion which is highly representative of kinematics in surgery requirements. Based on the mechanism kinematics, the evolution of its gravitational potential energy is studied. Two different mechanical concepts are then proposed to generate a compensating elastic potential energy. A CAD model of the entire mechanism has allowed the estimation of all mechanical parameters for the selection of the appropriate tension springs and for carrying out validation simulations. A prototype of the statically balanced mechanism is fabricated and successfully tested.

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Section: Static Balancing Of Diversified Mechanical Archtitecturesmentioning

confidence: 99%

Design of a Five-Degrees of Freedom Statically Balanced Mechanism with Multi-Directional Functionality

Essomba

2021

Robotics

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“…Obviously, the parts 1-2-3-4-5-6-7-8 together constitute the driving mechanism of the forward door. For the complex driving mechanism analysis of the forward door, the driving mechanism was reduced as a planar four-link mechanism [21] and spatial four-link mechanism [22] for movement reliability analyses with acceptable accuracy. The two simplifications models will be applied to the reliability of movement precision in the next work.…”

Section: Working Principle Of Emergency Extensionmentioning

confidence: 99%

Efficient Driving Plan and Validation of Aircraft NLG Emergency Extension System via Mixture of Reliability Models and Test Bench

Zhu

Feng

et al. 2019

Applied Sciences

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The emergence extension system (a mechanical system) of nose landing gear (NLG) seriously influences the reliability, safety and airworthiness of civil aircrafts. To efficiently realize the NLG emergence extension, a promising driving plan of emergence extension is proposed in respect of the reliability sensitivity analyses with a mixture of models. The working principle, fault tree analysis and four reliability models are firstly discussed for NLG emergence extension. In respect of the mixture of models, the reliability sensitivity analyses of emergence extension are then performed under different flight speeds (270 Kts, 250 Kts, 220 Kts, and 180 Kts). We find dimpling torque and aerodynamic torques of forward and after doors are the top three failure factors and the start reliability is the most in emergence extension failures. Regarding the results, feasible driving plans of NLG emergence extension are developed by adjusting the aerodynamic torque of NLG forward door, and are validated by the aerodynamic torque experiment of forward door with regard to strut rotational angle under the flight speed 270 Kts. It is indicated that (1) the adverse torque generated by the new driving mechanism obviously reduces by about 24.8% from 1462.8 N·m to 1099.6 N·m, and the transmission ratio of aerodynamic torque (force) is greatly improved when the NLG strut is lowered near to 100 • ; (2) under different flight speeds (180 Kts, 220 Kts, 250 Kts, and 270 Kts), the new driving mechanism realizes the lower tasks of emergence extension which cannot be completed by the initial driving mechanism; and (3) the lowering time of the new driving mechanism shortens with the increasing flight speed. The proposed new driving mechanism is verified to be reliable for emergence extension of aircraft NLG besides normal extension and to be a promising feasible driving plan with high lowering reliability. The efforts of the paper provide an efficient driving mechanism for the design of NLG in civil and military aircrafts.

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“…Many mechanisms for gravity compensation are summarized in [4]. More mechanisms are presented in detail in [5][6][7][8][9][10][11][12][13][14]. These mechanisms achieve different results between complete and partial compensation for links' weight.…”

Section: Introductionmentioning

confidence: 99%

Gravity Compensation for Mechanisms with Prismatic Joints

Demian¹,

Klimchik²

2022

Nelin. Dinam.

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This paper is devoted to the design of gravity compensators for prismatic joints. The proposed compensator depends on the suspension of linear springs together with mechanical transmission mechanisms to achieve the constant application of force along the sliding span of the joint. The use of self-locking worm gears ensures the isolation of spring forces. A constant-force mechanism is proposed to generate counterbalance force along the motion span of the prismatic joint. The constant-force mechanism is coupled with a pin-slot mechanism to transform to adjust the spring tension to counterbalance the effect of rotation of the revolute joint. Two springs were used to counterbalance the gravity torque of the revolute joint. One of the springs has a moving pin-point that is passively adjusted in proportion with the moving mass of the prismatic joint. To derive the model of the compensator, a 2-DoF system which consists of a revolute and a prismatic joint is investigated. In contrast to previous work, the proposed compensator considers the combined motion of rotation and translation. The obtained results were tested in simulation based on the dynamic model of the derived system. The simulation shows the effectiveness of the proposed compensator as it significantly reduces the effort required by the actuators to support the manipulator against gravity. The derived compensator model provides the necessary constraints on the design parameters.

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Design of one DOF closed-loop statically balanced planar linkage with link-collinear spring arrangement

Cited by 7 publications

References 19 publications

Design of a Five-Degrees of Freedom Statically Balanced Mechanism with Multi-Directional Functionality

Design of a Five-Degrees of Freedom Statically Balanced Mechanism with Multi-Directional Functionality

Efficient Driving Plan and Validation of Aircraft NLG Emergency Extension System via Mixture of Reliability Models and Test Bench

Gravity Compensation for Mechanisms with Prismatic Joints

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