Rotary Mechanism Research Articles

ОЦЕНКА ВЕЛИЧИНЫ ОДНОВРЕМЕННО ПРИСУСТВУЮЩИХ УГЛОВОЙ И ПАРАЛЛЕЛЬНОЙ РАСЦЕНТРОВОК И ДИСБАЛАНСА РОТОРОВ ПО СИГНАЛАМ ВИБРАЦИИ

One of the important tasks of non–destructive testing of rotary mechanisms is to determine the degree of shaft misalignment. Currently, the misalignment is detected based on the analysis of the amplitude spectrum of vibration. Experimental data show that the amplitudes of the vibration components depend on the displacement of the shafts according to a law close to linear, but with different coefficients of proportionality. The coefficients depend on the design of the coupling, and are usually unknown. In well-known works, the vibration of centered shafts is modeled as a rule by introducing forces into the system at different frequencies of equal amplitude. This does not agree with the observational data, in particular with the different dependence of the amplitudes of the components on the magnitude of the misalignment. In addition, there are usually several sources of forces in the system. In particular, parallel and angular misalignment can be expressed simultaneously and create oscillations at three harmonics of the rotor speed. The imbalance of the rotor leads to the appearance of oscillations at the frequency of its rotation. The oscillations can only be summed vector-wise, i.e. taking into account the phase. Without taking into account the phases of the vibration components, it is impossible to make a correct conclusion about the magnitude of the defects present. In this paper, a method is proposed for calculating the magnitude of the parallel alignment of the shafts and the imbalance of one of them

In situ microfluidic assembly and docking method to construct rotary mechanism driven by biomolecular artificial muscle

In situ microfluidic assembly and docking method to construct rotary mechanism driven by biomolecular artificial muscle

Порівняльна динаміка витікання рідини із ємностей певних геометричних форм в залежності від зміни осі обертання

In metallurgical enterprises, in some plants and factories, in technological processes, pouring of various types of liquids (cast iron, steel, gold, silver, chocolate, etc.) from large containers of various geometric shapes into smaller standard forms by the method of turning the container relative to a fixed point or a fixed axis and pouring over the edge It is important that the flow of liquid is uniform, which in reality is not true even at a constant angular speed of rotation. This paper examines the process of pouring from containers of conical and parabolic shapes, which are the most widely used in practice. In the development of the authors' works on this topic, another mechanism of rotation, which is often found, is considered, namely, rotation relative to the diameter of the upper part of the boiler. We analyze the obtained results of the study of the dynamics of changes in fluid consumption depending on the angle of inclination in comparison with the results of the previous works of the authors and provide conclusions and recommendations. Taking into account these theoretical studies, the operation of rotary mechanisms in each specific case can be adjusted by developing an algorithm of sequential actions that ensure the uniformity of the pouring process.

ГЕОМЕТРИЧНЕ МОДЕЛЮВАННЯ РОБОЧИХ ПРОФІЛІВ І ОБ’ЄМІВ РОТОРНО-ПЛАНЕТАРНИХ МАШИН

A method for calculating a rotary planetary machine of the Wankel system is presented. A feature of the Wankel machine is that the movement of the rotor in relation to the body is carried out using a planetary mechanism, which is based on an internal gear. The proposed method makes it possible to take into account the connection between the parameters of the geometric shape of two pairs of mutually conjugate curves characteristic of the Wankel machine. The first pair of curves are the working profiles of the casing and the rotor. The second pair is formed by the tooth profiles of the internal gears. Accounting for this connection made it possible to find a description of the function of the change in time of working volumes limited by the profiles of the body and rotor (i.e., to determine the productivity of the machine). As a result of the research, it was found that the performance of the Wankel machine can be found by taking into account three features of this machine. The shaping of the conjugated working profiles of the rotor and stator is carried out using a planetary mechanism, for the calculation of which the functions of complex variables are used. The performance function of the machine is determined by the change in time of the volumes of space limited by the working profiles of the rotor and housing. An approximate description of the functions of changing the working volumes of the machine with time was carried out using specially developed graphic constructions. To match the geometrical parameters of the Wankel with the parameters of the tooth profiles of the gear train of the internal clutch, a method of graphic running has been developed. The results obtained are useful because the scheme of the considered Wankel machine is embedded in the design of the internal combustion engine of the same name, as well as in the design of various hydraulic machines, pumps, compressors, etc. Key words: geometric modeling, rotary planetary mechanism, Wankel machine, functions of a complex variable, internal gearing.  

УСТАНОВКА ДЛЯ БОНИТИРОВКИ И ИСКУССТВЕННОГО ОСЕМЕНЕНИЯ ОВЕЦ

The existing and currently used technical devices for carrying out operations of bonitation and artificial insemination of sheep are metal-intensive and bulky structures. An installation for bonitization, veterinary care and artificial insemination of small cattle with a neck retainer was designed at the Zhangir Khan West Kazakhstan Agrarian and Technical University. The article describes an installation consisting of a frame, a lifting mechanism with a rotary axis. The countertop frame is raised to the required height by means of a screw mechanism and a rotation lever. The versatility of the installation when performing veterinary care operations is ensured by the possibility of lifting and rotating the table top frame on the rack around the axis of the bracket using a rotary mechanism. To ensure the immobility of the animal, a neck retainer is attached to the installation. To substantiate the design parameters of the installation, anatomical measurements of animals of the same age group were carried out and average values were determined. Taking into account the average results of measurements of animal parameters, experimental installations were manufactured and tested on the basis of the veterinary clinic of the West Kazakhstan Agrarian and Technical University named after Zhangir Khan. The test plan included the determination of the functional capabilities of the installation and chronometric measurements of the bonitation operations: determination of the type of animal; color; density; length and quality of wool; equalization of the fleece; the size and shape of the kurdyuk; live weight with animals recorded on the experimental installation and the average obtained average values are given. The technology of artificial insemination operation by the proposed installation is described. Production tests of the proposed installations have shown wide versatility, ease of operation, good functional qualities, according to veterinary specialists, allow additional sampling of animal blood for analysis, vaccination and immunization of animals.

An ancestral interaction module promotes oligomerization in divergent mitochondrial ATP synthases

Mitochondrial ATP synthase forms stable dimers arranged into oligomeric assemblies that generate the inner-membrane curvature essential for efficient energy conversion. Here, we report cryo-EM structures of the intact ATP synthase dimer from Trypanosoma brucei in ten different rotational states. The model consists of 25 subunits, including nine lineage-specific, as well as 36 lipids. The rotary mechanism is influenced by the divergent peripheral stalk, conferring a greater conformational flexibility. Proton transfer in the lumenal half-channel occurs via a chain of five ordered water molecules. The dimerization interface is formed by subunit-g that is critical for interactions but not for the catalytic activity. Although overall dimer architecture varies among eukaryotes, we find that subunit-g together with subunit-e form an ancestral oligomerization motif, which is shared between the trypanosomal and mammalian lineages. Therefore, our data defines the subunit-g/e module as a structural component determining ATP synthase oligomeric assemblies.

Modulation of the H+/ATP coupling ratio by ADP and ATP as a possible regulatory feature in the F-type ATP synthases.

F-type ATP synthases are transmembrane enzymes, which play a central role in the metabolism of all aerobic and photosynthetic cells and organisms, being the major source of their ATP synthesis. Catalysis occurs via a rotary mechanism, in which the free energy of a transmembrane electrochemical ion gradient is converted into the free energy of ATP phosphorylation from ADP and Pi, and vice versa. An ADP, tightly bound to one of the three catalytic sites on the stator head, is associated with catalysis inhibition, which is relieved by the transmembrane proton gradient and by ATP. By preventing wasteful ATP hydrolysis in times of low osmotic energy and low ATP/ADP ratio, such inhibition constitutes a classical regulatory feedback effect, likely to be an integral component of in vivo regulation. The present miniview focuses on an additional putative regulatory phenomenon, which has drawn so far little attention, consisting in a substrate-induced tuning of the H+/ATP coupling ratio during catalysis, which might represent an additional key to energy homeostasis in the cell. Experimental pieces of evidence in support of such a phenomenon are reviewed.

Research on Continuous Error Compensation of a Sub-Arc-Second Macro/Micro Dual-Drive Rotary System.

In this paper, a sub-arc-second macro/micro dual-drive rotary system is designed, and the continuous compensation of the system error and its experimental research are completed. First, the macro-drive system is driven by a direct-drive motor, and the micro-drive system uses a piezoelectric ceramic to drive the micro-drive rotary mechanism; the system uses a micro-drive system to compensate the motion error of the macro-drive system, and uses circular grating to feedback the displacement of the macro/micro total output turntable to form a macro/micro dual-drive closed-loop control system. Second, based on the establishment of the system error model, the design of the system’s continuous error compensation scheme is completed. Finally, the positioning accuracy testing of the system, direct error compensation of the macro-drive, manual error compensation of the macro-drive, error compensation performance of the micro-drive part and macro/micro compensation of the system are carried out in the study. The results show that the repeated positioning error and the positioning error of the system are reduced by 78.8% and 95.2%, respectively, after macro/micro compensation. The correctness and effectiveness of the designed system design, error compensation and control method are verified through performance tests, and its positioning accuracy is verified to the sub-arc-second (0.1 arcsecond) level. The research in this paper has important reference value for the development of ultra-precision macro/micro dual-drive technology.

Modelling and simulation of a single-motor bi-axial sun tracking mechanism

This work deals with the modelling and simulation in a virtual environment of an innovative bi-axial solar tracker, with two degrees of freedom (DOF), at which the both movements (diurnal and elevation/altitudinal) are driven by a single motor (which is a linear actuator). The tracking mechanism is used for increasing the energetic efficiency of a photovoltaic (PV) platform. The proposed solution allows to reduce the cost of the PV system by minimizing the number of motors, but still preserving the tracking accuracy of the platform. The tracking system in study is one of azimuthal type, at which the main revolute axis, that of the diurnal movement, is positioned vertically. The linear actuator used as motor source directly drives the diurnal movement, and also generates the elevation movement by intercalating a mechanical transmission that contains a bevel gear planetary mechanism and a planar rotary cam-follower mechanism. The virtual prototyping package ADAMS of MSC.Software was used for modeling and simulating the proposed tracking mechanism.

Habitações rotativas: uma viagem em torno do sol ou o insustentável desejo de ver tudo

Rotary mechanisms have been methodologically used, both in the context of architecture and in the most varied objects of our everyday life. The simple revolving plate of an ordinary microwave oven; the drunken movement of the merry- go-rounds that still insist on existing in the context of many popular fairs; the rotating stages of theaters or various television programs; the Ferris wheels of amusement parks; panoramic restaurants; kinetic houses; these are some of the many examples of how the possibility of creating rotating spaces or objects around an axis has gradually become almost commonplace.

A Real-Time Machine Vision System for Grading Quartz Mineral

Abstract Classification is an indispensable process in industrial mass production applications when competitive marketing and increasing the product value by reducing time and saving costs are in concern. In this regard, the machine vision system (MVS) is a prominent technology, especially for automated industrial production flow lines. Recent studies consisted of increasing the accuracy of such systems using advanced technology and complex solutions. Nevertheless, for automated industrial production flow lines, considering only the accuracy rate of an MVS by ignoring the cost and processing speed is not a sufficient parameter to evaluate the success rate concerning the marketing capability. In this study, a relatively low-cost and automated MVS production line for grading white stones in real-time is demonstrated. A conveyor line and a rotary mechanism are integrated into the system for performing a stone grading task. A conditioned cabinet is used for inspecting the flow line continuously. Forty different stone samples in four groups are evaluated in the experimental stage to observe the flow speed and processing accuracy. Different flow speeds of the conveyor line are investigated. The results are demonstrated that the low-cost MVS is successfully operated for grading white stones at relatively high speed with a 92 % accuracy.

DETERMINATION OF KEY FEATURES AND ERRORS OF ROTARY MECHANISMS MEASURING ACCELERATORS

This article describes a sensor that measures the angular acceleration of rotary mechanisms used in agriculture and water management, and describes its main parameters. The article also examines some parameters of the sensor and detects errors. Error correction recommendations have been developed.

A new class of biological ion-driven rotary molecular motors with 5:2 symmetry.

Several new structures of three types of protein complexes, obtained by cryo-electron microscopy (cryo-EM) and published between 2019 and 2021, identify a new family of natural molecular wheels, the “5:2 rotary motors.” These span the cytoplasmic membranes of bacteria, and their rotation is driven by ion flow into the cell. They consist of a pentameric wheel encircling a dimeric axle within the cytoplasmic membrane of both Gram-positive and gram-negative bacteria. The axles extend into the periplasm, and the wheels extend into the cytoplasm. Rotation of these wheels has never been observed directly; it is inferred from the symmetry of the complexes and from the roles they play within the larger systems that they are known to power. In particular, the new structure of the stator complex of the Bacterial Flagellar Motor, MotA5B2, is consistent with a “wheels within wheels” model of the motor. Other 5:2 rotary motors are believed to share the core rotary function and mechanism, driven by ion-motive force at the cytoplasmic membrane. Their structures diverge in their periplasmic and cytoplasmic parts, reflecting the variety of roles that they perform. This review focuses on the structures of 5:2 rotary motors and their proposed mechanisms and functions. We also discuss molecular rotation in general and its relation to the rotational symmetry of molecular complexes.

Perilaku Ramah Lingkungan dan Tidak Ramah Lingkungan dalam Perladangan Berpindah pada Masyarakat Tolaki di Routa Kabupaten Konawe

This article is intended to reveal environmentally friendly and environmentally unfriendly practices in shifting cultivation among the Tolaki people in Southeast Sulawesi. The method of presenting this article is done by first describing the practice of shifting cultivation as it is and then showing environmentally friendly and non-environmentally friendly practices at each stage. The results of this study indicate that there are environmentally friendly and unfriendly behaviors in shifting cultivation practices. Environmentally friendly behaviors include: a ceremony to apply for a permit to clear a field (mohoto o wuta), allowing a number of trees to stand upright in some parts of the field, cleaning the entire side of the cultivated area when they want to burn (mekere), getting to know the fallow and rotary mechanism as well as the practice of hetero-culture inside it. Meanwhile, environmentally unfriendly practices include: the habit of burning on wood stumps that can still grow, slashing and cleaning up new shoots of wood and piling grass and other debris on the stumps.

CryoEM Reveals the Complexity and Diversity of ATP Synthases

During respiration, adenosine triphosphate (ATP) synthases harness the electrochemical proton motive force (PMF) generated by the electron transport chain (ETC) to synthesize ATP. These macromolecular machines operate by a remarkable rotary catalytic mechanism that couples transmembrane proton translocation to rotation of a rotor subcomplex, and rotation to ATP synthesis. Initially, x-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cross-linking were the only ways to gain insights into the three-dimensional (3D) structures of ATP synthases and, in particular, provided ground-breaking insights into the soluble parts of the complex that explained the catalytic mechanism by which rotation is coupled to ATP synthesis. In contrast, early electron microscopy was limited to studying the overall shape of the assembly. However, advances in electron cryomicroscopy (cryoEM) have allowed determination of high-resolution structures, including the membrane regions of ATP synthases. These studies revealed the high-resolution structures of the remaining ATP synthase subunits and showed how these subunits work together in the intact macromolecular machine. CryoEM continues to uncover the diversity of ATP synthase structures across species and has begun to show how ATP synthases can be targeted by therapies to treat human diseases.

Shaping fuel utilization by mitochondria

Mitochondria are central to cellular metabolism. They provide intermediate metabolites that are used in biosynthetic pathways and they process diet-derived nutrients into the energy-rich compound ATP. Mitochondrial ATP biosynthesis is a marvel of thermodynamic efficiency. Via the tricarboxylic acid cycle (TCA) and fatty acid β-oxidation, mitochondria extract electrons from dietary carbon compounds and pass them to nucleotides that ultimately deliver them to the respiratory chain complexes located in invaginations in the inner mitochondrial membrane (IMM) known as cristae. The respiratory chain complexes donate electrons in stepwise redox reactions to molecular oxygen and, with the exception of complex II, use the liberated energy to pump protons across the proton-impermeable IMM, generating a proton electrochemical gradient. This gradient is then utilized by the ATP synthase, which, in a rotary mechanism, catalyzes the formation of the high-energy γ-phosphate chemical bond between ADP and inorganic phosphate. The conversion of the chemical energy of carbon compounds into a physical, vectorial form of energy (the electrochemical gradient) maximizes the yield of the ATP biosynthetic process and is perhaps one of the foundations of life as we know it.

Role of a Polar c‐Ring Residue in the Fo Motor of E. coli ATP Synthase

ATP Synthase is a molecular motor that utilizes a rotary mechanism to synthesize adenosine triphosphate (ATP), the fundamental energy currency of life. The torque for this mechanism is generated in the membrane‐embedded FO motor by harnessing the proton motive force, where protons flow down the electrochemical gradient through two half channels in the motor. The exit half channel on the cytoplasmic side is found at the interface of subunit a (stator) and the subunit c ring (rotor). Previous work on the E. coli ATP synthase has suggested that Thr51 in subunit c is involved in the proton translocation process. To investigate the role of this residue and chemical requirements at this position, we generated six substitution mutants and assayed their in vitro ATP synthesis, H+ pumping, and H+ permeability activities as well as the ability of mutants to carry out oxidative phosphorylation in vivo. Polar and hydrophobic mutations were generally tolerated, except for a notable decrease in function when a negative charge is introduced. Unusually, substitution with Cys completely abolished in vitro functions but only mildly inhibited growth on succinate. Overall, our results suggest that cThr51 may play a supporting role in the interaction between the c‐ring and subunit a in the region of the proton exit channel.

Vector-Controlled Wheel-Like Magnetic Swarms With Multimodal Locomotion and Reconfigurable Capabilities.

Inspired by the biological collective behaviors of nature, artificial microrobotic swarms have exhibited environmental adaptability and tasking capabilities for biomedicine and micromanipulation. Complex environments are extremely relevant to the applications of microswarms, which are expected to travel in blood vessels, reproductive and digestive tracts, and microfluidic chips. Here we present a strategy that reconfigures paramagnetic nanoparticles into a vector-controlled microswarm with 3D collective motions by programming sawtooth magnetic fields. Horizontal swarms can be manipulated to stand vertically and swim like a wheel by adjusting the direction of magnetic-field plane. Compared with horizontal swarms, vertical wheel-like swarms were evaluated to be of approximately 15-fold speed increase and enhanced maneuverability, which was exhibited by striding across complex 3D confinements. Based on analysis of collective behavior of magnetic particles in flow field using molecular dynamics methods, a rotary stepping mechanism was proposed to address the formation and locomotion mechanisms of wheel-like swarm. we present a strategy that actuates swarms to stand and hover in situ under a programming swing magnetic fields, which provides suitable solutions to travel across confined space with unexpected changes, such as stepped pipes. By biomimetic design from fin motion of fish, wheel-like swarms were endowed with multi-modal locomotion and load-carrying capabilities. This design of intelligent microswarms that adapt to complicated biological environments can promote the applications ranging from the construction of smart and multifunctional materials to biomedical engineering.

Computational Design of Inhibitors Targeting the Catalytic β Subunit of Escherichia coli FOF1-ATP Synthase.

With the uncontrolled growth of multidrug-resistant bacteria, there is an urgent need to search for new therapeutic targets, to develop drugs with novel modes of bactericidal action. FoF1-ATP synthase plays a crucial role in bacterial bioenergetic processes, and it has emerged as an attractive antimicrobial target, validated by the pharmaceutical approval of an inhibitor to treat multidrug-resistant tuberculosis. In this work, we aimed to design, through two types of in silico strategies, new allosteric inhibitors of the ATP synthase, by targeting the catalytic β subunit, a centerpiece in communication between rotor subunits and catalytic sites, to drive the rotary mechanism. As a model system, we used the F1 sector of Escherichia coli, a bacterium included in the priority list of multidrug-resistant pathogens. Drug-like molecules and an IF1-derived peptide, designed through molecular dynamics simulations and sequence mining approaches, respectively, exhibited in vitro micromolar inhibitor potency against F1. An analysis of bacterial and Mammalia sequences of the key structural helix-turn-turn motif of the C-terminal domain of the β subunit revealed highly and moderately conserved positions that could be exploited for the development of new species-specific allosteric inhibitors. To our knowledge, these inhibitors are the first binders computationally designed against the catalytic subunit of FOF1-ATP synthase.

F1-ATPase Rotary Mechanism: Interpreting Results of Diverse Experimental Modes With an Elastic Coupling Theory.

In this chapter, we review single-molecule observations of rotary motors, focusing on the general theme that their mechanical motion proceeds in substeps with each substep described by an angle-dependent rate constant. In the molecular machine F1-ATPase, the stepping rotation is described for individual steps by forward and back reaction rate constants, some of which depend strongly on the rotation angle. The rotation of a central shaft is typically monitored by an optical probe. We review our recent work on the theory for the angle-dependent rate constants built to treat a variety of single-molecule and ensemble experiments on the F1-ATPase, and relating the free energy of activation of a step to the standard free energy of reaction for that step. This theory, an elastic molecular transfer theory, provides a framework for a multistate model and includes the probe used in single-molecule imaging and magnetic manipulation experiments. Several examples of its application are the following: (a) treatment of the angle-dependent rate constants in stalling experiments, (b) use of the model to enhance the time resolution of the single-molecule imaging apparatus and to detect short-lived states with a microsecond lifetime, states hidden by the fluctuations of the imaging probe, (c) treatment of out-of-equilibrium “controlled rotation” experiments, (d) use of the model to predict, without adjustable parameters, the angle-dependent rate constants of nucleotide binding and release, using data from other experiments, and (e) insights obtained from correlation of kinetic and cryo-EM structural data. It is also noted that in the case where the release of ADP would be a bottleneck process, the binding of ATP to another site acts to accelerate the release by 5–6 orders of magnitude. The relation of the present set of studies to previous and current theoretical work in the field is described. An overall goal is to gain mechanistic insight into the biological function in relation to structure.