Mechanical Power Transmission Research Articles

Analysis of Design and Material Selection of a Spur gear pair for Solar Tracking Application

The principal intentions of this paper are geometrical modelling and computational study of different static stresses on spur gears of different materials for an indigenous mechanical solar tracker. The analyzed static stress results of the symmetric type involute profiled gear pair are compared on the basis of the material and the best result is selected for the application in the tracker mechanism. Providing importance on the non- renewable energy sources, solar energy is the major primary source of energy which can satisfy the human needs for the future.Gear operated mechanical Solar Tracking System is cheaper, require less skilled worker, easy to maintain and can be placed at hilly areas, remote or dusty or rainy place to help electrical power deficiency in rural areas and also can be installed easily in educational institutions, big offices, etc., which can save non-renewable sources of electrical energy for future use. The gears are one of the most imperative and crucial component in a mechanical power transmission unit, and its robustness led to the choice as mechanical component in the tracking mechanism. Since, the system is open to environment; therefore, the material selection of the gears becomes an important issue.

Hidrostatički sistemi prenosa snage poljoprivrednih mašina - zapreminske pumpe

The paper presents and analyzes the hydrostatic transmission of power and motion. The most important elements of this group of systems and the possibilities of their application in agricultural technology are given. Particular attention is paid to the positive-displacement pumps that have the widest application in agricultural machinery: gear pumps with external and internal gears, vane pumps, piston-axial pumps with inclined swash plate and piston-axial pumps with inclined cylinder block. Two hydrostatic power transmission and control systems are also presented. The first is a very simple mechanical- hydraulic system of automatic leveling of self-propelled berry fruits harvester. In contrast, the other hydrostatic system is very sophisticated. It is implemented as a very complex combination of hydrostatic and mechanical power transmission subsystems, with the accompanying control digital electronic system, and is intended for the wheat harvester propulsion and steering.

Extending the Limits of Wireless Power Transfer to Miniaturized Implantable Electronic Devices.

Implantable electronic devices have been evolving at an astonishing pace, due to the development of fabrication techniques and consequent miniaturization, and a higher efficiency of sensors, actuators, processors and packaging. Implantable devices, with sensing, communication, actuation, and wireless power are of high demand, as they pave the way for new applications and therapies. Long-term and reliable powering of such devices has been a challenge since they were first introduced. This paper presents a review of representative state of the art implantable electronic devices, with wireless power capabilities, ranging from inductive coupling to ultrasounds. The different power transmission mechanisms are compared, to show that, without new methodologies, the power that can be safely transmitted to an implant is reaching its limit. Consequently, a new approach, capable of multiplying the available power inside a brain phantom for the same specific absorption rate (SAR) value, is proposed. In this paper, a setup was implemented to quadruple the power available in the implant, without breaking the SAR limits. A brain phantom was used for concept verification, with both simulation and measurement data.

A statically balanced fully compliant power transmission mechanism between parallel rotational axes

This paper presents a fully compliant, potentially monolithic, power transmission mechanism which can rectify a large lateral offset between two parallel rotational axes. The planar nature of the design makes it ideal for manufacturing-limited applications such as micro/meso-scale power transmissions. The proposed compliant transmission is generated based on the Oldham Coupling and its equivalent Pseudo-Rigid-Body Model (PRBM). Normally, a compliant transmission mechanism cannot achieve a high efficiency due to the internal stiffness, i.e. actuation stiffness is not zero. However, in the proposed design, the internal stiffness is removed by static balancing and results in a statically balanced compliant transmission mechanism, i.e. with zero actuation stiffness. Therefore, the monolithic embodiment and static balancing features compensate for backlash, friction, assembly errors and poor mechanical efficiency inherent in conventional Oldham coupling, resulting in a transmission mechanism with high mechanical efficiency. Possible compliant design configurations based on the importance of different design criteria are discussed. Further, a compliant device based on the Paired Double Parallelogram (DP-DP) linear flexure bearing is designed and dimensioned. Moreover, the transmission stiffness, i.e. input-output rotational stiffness within the maximum allowable stress, and the actuation stiffness, i.e. minimum required actuation torque for certain angular displacement, of the designed device are predicted by the theoretical model and finite element modeling. Besides, the result shows the device is providing a constant transmission stiffness through a full cycle rotation. To prove the concept, a macro scale prototype is constructed and evaluated experimentally. It is shown that the results from the experiment are in agreement with the theoretical and finite element models.

Effect of Load Changes on Hybrid Shipboard Power Systems and Energy Storage as a Potential Solution: A Review

More electric technologies (METs) play an important role in meeting ever-growing demands for energy efficiency and emission reduction in the maritime transportation sector. As a result, ships with electrical power transmission are becoming popular compared to traditional mechanical power transmission based ships. Hybrid electric propulsion is an intermediate step in this trend where both mechanical and electrical propulsion technologies are combined to get the benefits of both technologies. In this arrangement, not only the propulsion loads but also non-propulsion loads are connected to a common electrical power bus that could lead to serious power quality issues due to disturbances such as large load changes. This paper presents a comprehensive review on energy storage-based solutions that have been proposed to reduce their effects. The important aspects of existing as well as emerging energy storage control techniques and challenges in reducing transient effects in hybrid shipboard power systems with the use of energy storage are discussed in the paper.

Experimental study on torsional load of grid coupling

The coupling connects the drive shaft and the driven shaft, and the shaft is used in the industrial field by the power transmission device. The main functions of the coupling are largely divided into the function of transmitting the power and the function of protecting the mechanical system when the coupling member of the coupling is destroyed when an overload occurs between the driving shaft and the driven shaft. Grid coupling, which is one of the mechanical power transmission parts, is composed of hub, grid, seal, cover, etc. and has the characteristic of transmitting power at high speed and high torque. In general use conditions, elasticity of the grid has flexibility to twist generated in misalignment state such as impact load, axis error, parallel error, angular error caused in normal rotation or reverse rotation, and to reduce vibration and impact load to be. In addition, when the overload occurs, the grid is cut off and the transmission power is cut off to protect the equipment connected to the driving shaft and the driven shaft.

A Study on an Analysis and Design of the Internal Structure of Heumgyeonggak-nu

In this study, the internal structure of a Heumgyeonggak-nu (欽敬閣漏) was designed, and the power transmission mechanism was analyzed. Heumgyeonggak-nu is an automated water clock from the Joseon Dynasty that was installed within Heumgyeonggak (欽敬閣), and it was manufactured in the 20th year of the reign of King Sejong (1438). As descriptions of Heumgyeonggak-nu in ancient literature have mostly focused on its external shape, the study of its internal mechanism has been difficult. A detailed analysis of the literature record on Heumgyeonggak-nu (e.g., The Annals of the Joseon Dynasty) indicates that Heumgyeonggaknu had a three-stage water clock, included a waterfall or tilting vessel (欹器) using the overflowed water, and displayed the time using a ball. In this study, the Cheonhyeong apparatus, water wheel, scoop, and various mechanism wheels were designed so that 16 fixed-type scoops could operate at a constant speed for the water wheel with a diameter of 100 cm. As the scoop can contain 1.25 l of water and the water wheel rotates 61 times a day, a total of 1,220 l of water is required. Also, the power gear wheel was designed as a 366-tooth gear, which supported the operation of the time signal gear wheel. To implement the movement of stars on the celestial sphere, the rotation ratio of the celestial gear wheel to the diurnal motion gear ring was set to 366:365. In addition, to operate the sun movement apparatus on the ecliptic, a gear device was installed on the South Pole axis. It is expected that the results of this study can be used for the manufacture and restoration of the operation model of Heumgyeonggak-nu.

An approach for the assessment of the statistical aspects of the SEA coupling loss factors and the vibrational energy transmission in complex aircraft structures: Experimental investigation and methods benchmark

In the application of Statistical Energy Analysis “SEA” to complex assembled structures, a purely predictive model often exhibits errors. These errors are mainly due to a lack of accurate modelling of the power transmission mechanism described through the Coupling Loss Factors (CLF). Experimental SEA (ESEA) is practically used by the automotive and aerospace industry to verify and update the model or to derive the CLFs for use in an SEA predictive model when analytical estimates cannot be made. This work is particularly motivated by the lack of procedures that allow an estimate to be made of the variance and confidence intervals of the statistical quantities when using the ESEA technique.The aim of this paper is to introduce procedures enabling a statistical description of measured power input, vibration energies and the derived SEA parameters. Particular emphasis is placed on the identification of structural CLFs of complex built-up structures comparing different methods. By adopting a Stochastic Energy Model (SEM), the ensemble average in ESEA is also addressed. For this purpose, expressions are obtained to randomly perturb the energy matrix elements and generate individual samples for the Monte Carlo (MC) technique applied to derive the ensemble averaged CLF. From results of ESEA tests conducted on an aircraft fuselage section, the SEM approach provides a better performance of estimated CLFs compared to classical matrix inversion methods. The expected range of CLF values and the synthesized energy are used as quality criteria of the matrix inversion, allowing to assess critical SEA subsystems, which might require a more refined statistical description of the excitation and the response fields. Moreover, the impact of the variance of the normalized vibration energy on uncertainty of the derived CLFs is outlined.

Design and Development of Graphene reinforced Acetal copolymer plastic gears and its performance evaluation

Gears are one of the most critical components in a mechanical power transmission system and most industrial rotating machinery. Metallic gears are more expensive, high noise, high wear and friction during its operating conditions, for avoiding difficulties the metallic gears are replaced by plastic gears.polymers are having self-lubrication properties,better wear resistance, lower friction, low noise and cost, where as these properties are not sufficient for high load conditions.For improving or strengthening the material by reinforcing filler in to polymer. Within this present work initially graphene filler material has been prepared through modified Hummers method on a bulk scale. After that composites with varying weight percentages of grapheme i.e 0.5,1, 1.5, 2% in Acetal copolymer has been fabricated through injection molding process. The prepared composites have been tested for their mechanical and tribological properties based on the obtained results 1.5% filler composition has been found to be optimum when compared with other various combinations of the composition. So 1.5% graphene filled Acetal copolymer composites were used to design spur gears and analysis has been carried out through FEM. These analyses concludes that 1.5% graphene reinforced Acetal copolymer gears were found to be much more superior in case of performance, weight and cost compared to the both metallic and other polymer gears.

ACROBAT-S全方向移動機構のための球駆動解析

In this paper, we analyze the motion of a ball used for robot mechanism and power transmission. The authors group has been proposed an omnidirectional mechanism (ACROBAT-S). The mechanism has a power transmission mechanism using a ball. However, the motion analysis of a ball has no calculation method widely applicable. So, we introduce a method using a rotation vector for the motion analysis of a ball. In order to establish a ball drive analysis method, we analyze a kinematics of a ball transmission used for ACROBAT-S and verify the kinematics by simulations. From the results, it is confirmed that the analyzed kinematics is reasonable and the analysis method is useful.

Characterization of Nickel Alloy 600 with Ultra-Fine Structure Processed by Severe Plastic Deformation Technique (SPD)

High strength nickel based alloys are used in a multitude of advanced systems where lightweight, high power density mechanical power transmission systems are required. Components such as gears, bearings and shafts could be made significantly smaller and more durable if a major improvement in nickel based alloy mechanical properties could be achieved. An important refinement in grain size (includes nanometric level) is thought to be a promising method for achieving fundamental improvements in mechanical properties. Grain size is known to have a significant effect on the mechanical behavior of materials. One of the most favorable methods of achieving extreme grain refinement is by subjecting the materials to severe plastic deformation (SPD). The principal micro-structural variations in superalloys are the precipitation amount and morphology, grain size and the distribution of carbide precipitation that could reduce the mechanical properties of the alloys. This work shows optical and transmission electron microscopy analysis and also hardness data after severe plastic deformation (pure shear stress).

パラレルリンク機構を用いた5自由度HEM<sup>2</sup>の開発

In this paper, Haptic End-effector for Medicine and Manufacturing (HEM2) with five degree of freedom (DoF) motion is developed for safer and more intuitive robotic surgery. In resent years, multi DoF forceps robots have been studied and developed to support surgeons. However, conventional multi DoF forceps robots cannot transmit force sensation to surgeons adequately. Force sensation is important for safe and accurate teleoperation. In this paper, a master-slave five DoF HEM2 is developed as a haptic forceps robot. Five DoF motion corresponds with the motion of human hand which can realize complex tasks. By implementing acceleration based bilateral control, force sensation can be transmitted. Spherical joint driven by parallel link mechanism realizes the bending motion of the end-effector. The coaxial driving power transmission mechanism is used to decrease the weight of movable part and improve backdrivability. Besides, the mechanism is composed of rigid parts. The performance of the five DoF HEM2 is validated by experiments.

Design and analysis of active vibration and stability control of a bio-inspired quadruped robot

The main aim of this research work is to design and develop a bio-inspired quadruped robot for operating in an uneven terrain. The present work focus on development of a gear-train power transmission mechanism, which is more efficient, as the gear assemblies can be optimised for generating different locomotion patterns. The kinematic and dynamic analysis of the limb analysis has been carried out. The modelling of mechanism and measurement and motion analysis has been carried out using ProE Wildfire software and the results have been presented in this paper.

Analysis of the maximization of wind turbine energy yield using a continuously variable transmission system

In this paper, an analytic study of the subject of mechanical power transmission in HAWT wind turbine has been carried out. For the most part, the study analyzes the use of continuously variable transmission (CVT) in order to allow the turbine and the electric generator to couple, allowing in turn, an unremitting transmission ratio adjustment. In low-wind sites, the design criteria suggest an oversizing of the wind turbine in order to generate adequate electrical power even at low wind speed. The proposed solution enhances the space of operating points since it allows the electric generator to release the rotational speed from the turbine one (limited due to structural integrity). Employing a CVT transmission, the modulation system of the input power to the turbine starts operating at higher wind speeds when compared to a conventional direct-drive case: this corresponds with the possibility to fully exploit the wind power at a higher speed range, therefore maximizing the wind turbine’s energy production. The analysis has showed that, in the case of CVT configuration, the annual energy yield increases of about 50% compared to direct-drive solution.

Concept of the magnetic launcher for medium class unmanned aerial vehicles designed on the basis of numerical calculations

The paper presents a concept of a magnetic coil launcher for unmanned aerial vehicles of mass up to 25 kg. The idea is not new, nevertheless in the paper, an innovative application of magnetic launcher technology for selected class of unmanned aerial vehicles is presented. So far, at Bialystok University of Technology, a magnetic coil launcher for micro aerial vehicles of mass up to 2.5 kg has been investigated. In the article, simulations of a conceptual multi-coil launcher with a magnetic core system are presented. The finite element method has been used in calculations. Moreover, in the paper, the concept of a magnetic support for transmission of mechanical power from the magnetic core to the launched payload is proposed. The applied methodology, computational results and potential technical difficulties of practical applications are also widely discussed.

Development of a driveshaft torque transducer for low-cost structural health monitoring of off-highway vehicles

Mechatronic agricultural machines and equipment are continuously increasing their complexity and cost. In order to ensure their efficiency and reliability and preserve their value, it is important to actively monitor the working loads and register damaging and wear occurring on critical components. This approach needs the introduction of sensors on the machine, which allow continuous monitoring and evaluate the residual life of components. The work presents the development and testing of an innovative low-cost systems for monitoring and diagnostic of off-highway vehicles. The sensor measures the torque of a mechanical power transmissions, and it was designed especially for agricultural machinery. The torque transducer monitors the mechanical power flowing from the tractor into the gearbox and the agricultural implement and is fully integrated with the power take-off driveshaft, thus being generally applicable. The design and development of the transducer was performed following a quality function deployment approach. The system is less expensive considering the typical torque measuring system commercially available and, thanks to its wireless module and integrated power supply, it is reliable and generally applicable to many power take-off to implement combinations.

Seismic Performance Study of Fabricated High-strength Reinforced Concrete Shear Wall Horizontal Connection Seam

Block prefabricated shear body and connected to form two types of nodes: one is the shear vertical connecting node, namely, the lower connecting precast shear walls; the other is the level of shear wall connecting node that is connected with the pre-shear layer adjacent to the non-shear and between precast shear walls or with an adjacent layer. Under horizontal earthquake, prefabricated shear vertical connecting node will be directly involved in stress and deformation. Since the horizontal seam to weaken the shear plane, if not handled properly connected measures, it can easily become the weak parts of shear walls, and even affect the overall structural performance. To understand the power transmission mechanism prefabricated shear horizontal seam structure, energy dissipation mechanism and seismic performance, reliable and exploring measures to improve or perfect the various prefabricated ability to work together to improve the structural integrity and seismic performance, prefabricated vertical shear connection has been completed based on the seismic performance of the test, carry out a new connecting node structure prefabricated shear wall structure horizontal seam, by conducting relevant tests, finite element methods and theories analytical tools, be horizontal shear wall structure evaluation and design method of prefabricated joints seismic performance.

Observer-based sensor fault estimation in nonlinear systems

Sensor bias faults and sensor gain faults are two important types of faults in sensor. Simultaneous estimation of these sensor faults in nonlinear systems in the presence of input disturbance and measurement noise is challenging and has not been adequately addressed in literature. Hence, this article develops an observer-based sensor fault estimation method for generalized sector-bounded nonlinear systems in the presence of input disturbance and measurement noise. A generalized sector-bounded nonlinearity was chosen because it encompasses a wide range of nonlinearities including Lipschitz, positive real, and dissipative. This article presents necessary and sufficient conditions to achieve a suboptimal cost for a cost function consisting of the sum of the square integrals of the estimation errors to the square integrals of the disturbances in the form of linear matrix inequality. The linear matrix inequality can be solved offline to explicitly calculate observer gain, and the resulting observer simultaneously estimates the system states as well as both bias and gain faults in the sensors. Compared to previous literature, the proposed methodology is designed to work in the presence of both input disturbance and measurement noise. Additionally, this article considers a generalized sector-bounded nonlinearity which encompasses a variety of different physical nonlinearities. Furthermore, the observer does not require the online solution of the Riccati equation and is thus computationally less intensive compared with the methods of extended Kalman filtering. The observer design procedure is demonstrated through two illustrative examples consisting of a fourth-order double spring–mass system and a third-order wind turbine power transmission mechanism.

Multi-body dynamics simulation and gait pattern analysis of a bio-inspired quadruped robot for unstructured terrains using adaptive stroke length

This paper presents the Finite element analysis (FEA), Multi-body dynamics (MBD) simulation and gait pattern analysis of a bio-inspired quadruped robot. A novel power transmission mechanism with varying gear train centre distance has been designed for generating different gait structures to suit unstructured terrain. The adjustable length of the lower link aids in improving the stability of the robot (or) make the robot to travel longer distances within a stipulated time. MBD simulation has been performed using MSC/ADAMS for torque, speed, energy and force analysis. The novel mechanism designed was able to successfully negotiate unstructured obstacles of different heights and these results have been presented in the paper. The results show a direct relationship between stroke length, lift-off distance and gear centre distance. A full scale experimental setup, along with the suitable supporting mechanisms is developed. The experimental analysis has been carried out for measuring the Ground Reaction Force (GRF). The GRF is found to be 45 N on an average, when the robot is walking.

Towards Quantitative Visual Analytics with Structured Brushing and Linked Statistics

AbstractUntil now a lot of visual analytics predominantly delivers qualitative results—based, for example, on a continuous color map or a detailed spatial encoding. Important target applications, however, such as medical diagnosis and decision making, clearly benefit from quantitative analysis results. In this paper we propose several specific extensions to the well‐established concept of linking&brushing in order to make the analysis results more quantitative. We structure the brushing space in order to improve the reproducibility of the brushing operation, e.g., by introducing the percentile grid. We also enhance the linked visualization with overlaid descriptive statistics to enable a more quantitative reading of the resulting focus+context visualization. Additionally, we introduce two novel brushing techniques: the percentile brush and the Mahalanobis brush. Both use the underlying data to support statistically meaningful interactions with the data. We illustrate the use of the new techniques in the context of two case studies, one based on meteorological data and the other one focused on data from the automotive industry where we evaluate a shaft design in the context of mechanical power transmission in cars.