ROTATION JOINTS FRICTION IN A TRANSVERSAL MOBILE COUPLING

The transversal mobile couplings are used in movement and torque transmission between two main shafts having parallel axis, with the possibility to undertake misalignments in the transversal plane. These shaft misalignments are usually named transversal movements. The paper presents, starting from some kinematic aspects regarding relative movements between the coupling parts, the kinematic equations useful in determining position of the intermediary elements, depending by the transversal misalignments. Following this, using the inside relative movement in rotation joints between parts and corresponding adequate materials, the friction coefficient is studied. The friction which appears in coupling’s rotation joints between the involved parts has an important influence on their dynamic behaviour, wear and lifetime. The most significant friction and also wear is given by the alternant rotation movements in joints between parts, at the ends of their angular stroke. Due to this, the study of the friction between some materials to be used in coupling manufacturing is required, but also difficult because of some particularities, as reduced rotation in joints, for reduced transversal misalignments between the main shafts. There are presented, in the paper final part, the results and conclusions.

Verification Methodology for Simulation Models of the Synchronous Generator on Transients Analysis

During transients that occur in an electric network, large currents can flow and large electromagnetic torques can be developed in electric generators. Accurate calculation of currents and magnetic fields during transients is an important element in the optimal design of generators and network parts, as well as mechanical parts of machines and other torque transmission parts. This paper describes the modeling of a sudden three-phase short-circuit on a synchronous generator using the finite element method (FEM) and the dynamic model. The model for simulations that use the FEM was built in the MagNet software package, and the dynamic model is embedded in the MATLAB/Simulink software package. The dynamic simulation model of a part of a network with two identical generators, represented by equivalent parameters, was developed. The results obtained after the simulation of a sudden three-phase fault in the generators by both methods are presented, including three-phase voltages, three-phase currents, machine speeds, excitation voltages, and mechanical power. In particular, the short-circuit current in the phase with the highest peak value was analyzed to determine the accuracy of the equivalent parameters used in the dynamic model. Finally, the results of these two calculation methods are compared, and recommendations are presented for the application of different modeling methods.

Interventional Status Awareness Based Manipulating Strategy for Robotic Soft Endoscopy

Traditional soft endoscopy is operated with naked eyes and use of hands. Robotic soft endoscopy frees the hands of endoscopists, which reduces the labor-intensity and complexity of operation and improves the operational accuracy of endoscope, but it’s hardly to be reliably performed because the operator lacks of situational awareness of endoscopic interventional status when the hands are detached from the endoscope. This paper first presents a method to perceive the interventional status of endoscope based on image processing, the interventional status includes insertion length and velocity. A manipulating strategy was designed according to the perceived endoscope interventional status and construction parameters of dual robotic arms in order to achieve reliable interventional endoscopy. Human phantom experiments are carried out to verify the effectiveness and feasibility of the proposed interventional status awareness method and manipulating strategy. The results show that the robotic soft endoscopy can be well performed with the ability of interventional status awareness and coordinated manipulation of dual arms. The perceived insertion length indicates the position of the tip of endoscope in human body and the designed manipulating strategy is effective in endoscopic shape retention and torque transmission.

Performance Evaluation of Self-Healable Torque Transmission Mechanism Using Phase Change of Low-Melting-Point-Metal and Application to Robot Joints

Self-healing properties of robots can aid in achieving a high level of motion continuity despite the absence of manual maintenance. Therefore, various studies have been conducted on self-healing materials and mechanisms to incorporate self-healing properties in robots. However, the self-healing performance of a motor rotation system, which is the power source of existing robots, has not been realized owing to the unsuitability of the self-healing method and material strength. Therefore, we propose a self-healable torque transmission mechanism using a low-melting-point metal that can be applied to transmission elements because of its strength and rigidity. Additionally, heating for self-healing can be performed without contact through induction heating. Hence, a self-healable torque transmission mechanism with a simple structure can be applied to a motor drive system where continuous rotation occurs. We evaluated the performance of the proposed mechanism experimentally by measuring the transmittable torque and the amount of energy absorbed when the torque transmission is interrupted. The results verify that the healing performance and energy absorption of the proposed mechanism remain stable, and the mechanism can heal without any performance degradation. Furthermore, the proposed mechanism was implemented in a robot to demonstrate its practical applications. It was found that this mechanism enables the robot to re-operate by self-repair even if it receives a load that can destroy the joint due to overload, and the robot's ability to continue motion could thus be improved.

Application of Jaw Type Flexible Clutches in Human Powered Machine: A Literature Review

This article presents the topical progresses in the arena of an approach to articulate an experimental databased model for jaw type flexible clutches. The developing countries are facing very acute problems of the energy crisis. It has become essential to use human energy for energizing the manufacturing process machine. This kind of machine necessitates a flexible clutch for torque transmission. Due to the intricate impact phenomenon, flexible clutches cannot be deliberate without experimental data. Therefore, the experimentation methodology and experimental setup to evaluate the performance of torque transmitted by the clutch have been augment. It is obliging for selection of the optimum clutch-type for various applications in low powered processing machines. This study of analysing suitable material can be useful for the comparative study of Jaw type flexible clutches and their transmission ability. Mathematical model and Artificial Neural Network (ANN) development are essential, to evaluate the belongings of altered components and to make forecasts about behaviour.

Modification of the Tooth Geometry of a Polymer GEAR with a Straight Tooth Line to Adjust the Torque Transmission Capability in One Direction Only

This paper describes a methodology for modifying a tooth for the ability to transmit torque in one direction only. It presents two methods (analytical and numerical) of tooth mass reduction while maintaining functional features of the whole transmission. The results of the above mentioned methodology are presented on the example of a mass-produced transmission.

A Comparative Analysis of Power Consumption in Conventional and Differential – Less Drive for Electric Vehicle

The general design of the methodology of the transmission system is usually used to give efficient power to the driven wheel, such as usually used differential to differentiate speed and motion of the wheel. In this paper; we analyze methods of motion control and power transmission variation for an electric vehicle (EV) with two independently driven in-wheel motors and conventional differential used EV. Compares the power transmission ratio of two different configurations drives energy conversion differential and epicyclic gears train analysis. This investigation gives an orderly examination of compendium an electrical vehicle is driven by transmissions system journals published and about different losses through mechanical differential system transmission and how they affect on torque. These studies present a comprehensive convergent study report of power Variation and torque transmission with simulation result distinction in differential and differential-less EV’s by compendium studies and show some comparative results. After a compendium study author finds few losses in differentials such as Pocketing power losses, WPL, drag mishap, friction, and different slip in gears. We have mention different factors also affect drive trains and illustrate the main reason to generate losses during transmission. In addition, we have explained this through simulation.

Integrated, Multi-Approach, Adaptive Control of Two-Mass Drive with Nonlinear Damping and Stiffness

In numerous electric drive applications, the mechanical phenomena in the velocity or position control loop determine real difficulties and challenges for the control system. So-called two-mass drive systems with a flexible shaft are the most important example of this situation. The problem becomes even more difficult if the characteristics of torque transmission along the shaft are nonlinear, nonlinear friction is present, and the plant parameters are unknown, as it happens in numerous robotic systems. A novel adaptive controller is derived for such a system. The recurrent design procedure is based on proper modifications of the adaptive backstepping scheme, including non-strict-feedback plant application, tuning functions to exclude controller overparameterization, robust adaptive laws, proper means to avoid controller complexity explosion, and a nonlinear PI controller in the initial loop to minimize quasi-steady-state tracking error. The closed-loop system uniform ultimate boundedness is proven using Lyapunov techniques and the design and tuning procedures are described. The attractive features of the obtained drive, including the robustness against the violation of assumptions, are presented using several examples.

Design and testing of a conventional clutch filled with magnetorheological fluid activated by a flexible permanent magnet at low compressive load: Numerical simulation and experimental study

In this research article, the working of conventional clutch (CC) filled with magnetorheological (MR) fluid was tested at low compressive load. The flexible permanent magnetic sheet (FMS) controlled the chain strength of MR fluid. A single clutch plate based on FMS was fabricated and tested on the developed test rig. The characteristics of the developed single plate MR clutch (SPMRC) were found by the testing and mathematical calculations. Magnetic circuit analysis presents the magnetic field distribution in the developed MR clutch. The mathematical expression for the torque transmission due to shear and compression is presented. COMSOL Multiphysics 5.3a software is used for the magnetic field simulation at different loading conditions. The temperature distribution in the developed clutch is simulated and experimented. It is observed from the results that the input shaft oscillation in the reduces more during disengagement in the SPMRC than the CC.