КІНЕТОСТАТИЧНЕ ДОСЛІДЖЕННЯ ШАРНІРНИХ ПРОСТОРОВИХ МЕХАНІЗМІВ ГАЛТУВАЛЬНИХ МАШИН (ЧАСТИНА 2: ДОСЛІДЖЕННЯ МЕХАНІЗМУ МАШИНИ З ДВОМА РОБОЧИМИ ЄМКОСТЯМИ, ЩО З’ЄДНАНІ ПОСТУПАЛЬНОЮ КІНЕМАТИЧНОЮ ПАРОЮ)

Goal. Kinetostatic study of a statically defined hinged spatial mechanism without excessive (passive) connection of the shredding machine with two working tanks connected by a translational kinematic pair. Method. Radial and axial components of reactions in all rotating and translational kinematic pairs of the hinged statically defined spatial mechanism of the machine for processing of details with two working capacities connected among themselves by translational kinematic pair at its work at idling were determined on the basis of kinetostatic research. The study was performed using the computer-aided design system SolidWorks-2016 computer-aided design system, which performed a 3D model of a shredding machine with two working tanks connected by a translational kinematic pair. Results. 3D modeling of a shredding machine with two working tanks connected by translational kinematic pair in the computer-aided design system SolidWorks-2016 computer-aided design system is performed, maximum values of radial and axial components of reactions in all rotating and translational kinematic pairs of machine are determined, and the influence of total two working tanks for the increase of the maximum values of reactions in the kinematic pairs of the spatial mechanism of the machine. Scientific novelty. For the first time, the relationship between the total wheelbase of two working tanks and the change in the maximum values of reactions (axial and radial) in all rotating and translational kinematic pairs of the shredding machine was established. The allowable range of variation of the total wheelbase of two working tanks is determined, which creates conditions for long-term operation of the machine. Practical significance. It is established that the change of maximum values of radial and axial components of reactions in all rotating and translational kinematic pairs of the spatial mechanism of the galvanizing machine depends on the total axial distance of two working capacities of the machine. The obtained research results can be useful in the design of shredding equipment with complex spatial movement of working tanks.

КІНЕТОСТАТИЧНЕ ДОСЛІДЖЕННЯ ШАРНІРНИХ ПРОСТОРОВИХ МЕХАНІЗМІВ ГАЛТУВАЛЬНИХ МАШИН (ЧАСТИНА 1: ДОСЛІДЖЕННЯ МЕХАНІЗМУ З ДОДАТКОВОЮ РУХОМОЮ ЛАНКОЮ – КОРОМИСЛОМ)

Kinetostatic study of a statically determined hinged spatial mechanism without redundant (passive) connection with an additional movable link – a rocker arm of a machine for processing parts, in which the working container performs complex spatial movement. Methodology. The essence of the kinetostatic research was to determine the radial and axial components of the reactions in all rotational kinematic pairs of the hinged statically defined spatial mechanism of the machine for processing parts, when it is idling. The kinetostatic study was implemented using the SolidWorks 2016 computer-aided design system with preliminary 3D modeling of this machine design with an additional moving link – a rocker. Results. In the course of the kinetostatic study, 3D modeling of a machine with an additional movable link – a rocker arm in the SolidWorks 2016 computer-aided design system was carried out, the maximum values of the radial and axial components of reactions in all rotational kinematic pairs of the machine for processing parts were determined, the effect of changing the center distance of the intermediate connecting rod (working capacity ) on the increase in the maximum values of the reactions in all rotational kinematic pairs. Scientific novelty. The relationship between the center distance of the intermediate connecting rod (working capacity) and the change in the maximum values of the reactions in all rotational kinematic pairs of the machine for processing parts is determined. As a result, it becomes possible to determine the maximum permissible center distance of the intermediate connecting rod to ensure the durable operation of the machine. Practical significance. It is determined that the nature of the change in the maximum values of the radial and axial components of the reactions in each rotational kinematic pair of the spatial mechanism depends on the value of the coefficient characterizing the ratio of the center-to-center length of the intermediate connecting rod (working capacity) to the center-to-center length of the driving or driven connecting rods of the machine. The range of variation of this coefficient has been determined, within which it is rational to design this machine design. The results obtained can be used in the corresponding design bureaus of machine-building enterprises at the stage of designing tumbling equipment with a complex spatial movement of working containers.

Tracing London's urban living room

Responding to the rapid development of indoor public interiors motored by commercial activities, this paper argues that an alternative form that is more inclusive is needed to foster healthier and more socially equitable interactions in the city. It frames urban living room, a micro-scale outdoor interior development that aims to inject domestic experiences into the existing urban environment, as the antithesis of the exclusive indoor public interiors. Utilising tracing as a mode of inquiry to look at two case studies of the urban living room in London, UK, this paper aims to reveal the spatial mechanism that makes this public interior provide the much needed intimate experiences that make the city habitable. The finding of this study suggests that the interior mechanisms used by urban living room provide scalar confrontation and heighten sensual experience that fosters intimate social interactions and inclusivity for all urban dwellers.

Spatial Mechanism-Environment Contact Geometric Models

This work proposes a theoretical foundation for a general spatial geometric mechanism-environment contact model. In the proposed model the curvature of the environment in the vicinity of the contact is approximated by a number of spherical surfaces with known radii of curvature that constrain/define the movement of the body. We show how the modeled body-environment contact and curvature constraints can be transformed into conditions on spatial velocity and acceleration (i.e. first and second order effects) of certain points of the moving body that can be incorporated in the kinematic task for designing spatial mechanisms. Further, we explore the exact synthesis of a spatial six degrees-of-freedom TPS kinematic chain which end-effector maintains contact with objects in the environment and varies orientation in the vicinity of a contact location. It is discussed how the higher order motion constraints allow for the introduction of kinematic task variations in the vicinity of a contact, resulting in different behaviors of the designed spatial mechanism. The theoretical foundation presented in this paper is crucial in gaining understanding of the constraints in describing mechanism-environment interactions in the vicinity of a contact and is a new contribution.

СИНТЕЗ ТА АНАЛІТИЧНІ ДОСЛІДЖЕННЯ ГЕОМЕТРИЧНИХ ПАРАМЕТРІВ СТАТИЧНО ВИЗНАЧЕНОГО ПРОСТОРОВОГО ШАРНІРНОГО МЕХАНІЗМУ ГАЛТУВАЛЬНОЇ МАШИНИ

Synthesis of a seven-link statically determined spatial hinge mechanism with an additional movable crank link without redundant (passive) connection of the tumbling machine with a complex spatial movement of the working vessel with subsequent analytical study of its design and geometric parameters. Methodology. The analytical method of research is used on the basis of geometric and structural synthesis of a spatial seven-link hinge mechanism with an additional movable crank link without redundant connection of the tumbling machine with a complex spatial movement of the working vessel. The machine was simulated in the SolidWorks-2016 computer-aided design system. Tumbling types of equipment with containers, which perform a different character of movement, are analyzed. On the basis of structural synthesis, the design of a seven-link statically defined spatial mechanism with an additional movable link, a tumbling machine crank, in which the working capacity performs a complex spatial movement, is proposed. Carried out 3D modeling of the machine in the CAD system SolidWorks 2016. Analytical studies of the main geometric parameters of the developed tumbling machine were carried out. Scientific novelty. A relationship has been established between various geometric parameters of the synthesized seven-link statically determined spatial hinge mechanism, in particular, between the center-to-center length of the intermediate connecting rod (working capacity) and the length of the crank, which makes it possible to calculate the necessary ratios of the lengths of the links of the mechanism to ensure the functioning of the machine without jamming its spatial mechanism. Practical significance. A new design of a machine for processing parts has been developed, based on a seven-link statically determined spatial hinge mechanism with an additional movable crank link. Mathematical dependences are obtained for calculating its basic design and geometric parameters. These dependencies can be used in the corresponding design bureaus of machine-building enterprises at the design stage of tumbling equipment with a complex spatial movement of working containers.

МАШИНА ДЛЯ ОБРОБКИ ДЕТАЛЕЙ З СЕМИЛАНКОВИМ ПРОСТОРОВИМ МЕХАНІЗМОМ - СИНТЕЗ ТА ДОСЛІДЖЕННЯ

Synthesis of a seven-link spatial statically determined mechanism without redundant (passive) connection with an additional moving link of a machine for processing parts, followed by an analytical study of its main structural and geometric parameters. Methodology. An analytical research method was used based on the geometric and structural synthesis of a spatial seven-link statically defined mechanism with an additional movable link without redundant communication of the machine for processing parts; 3D modeling of the machine was performed in the SolidWorks 2016 computer-aided design system. Results. On the basis of structural synthesis, the design of a seven-link spatial statically defined mechanism with an additional movable link of the machine for processing parts is proposed, there is no redundant connection in the kinematic chain of the spatial mechanism, 3D modeling of the machine is performed in the CAD system SolidWorks 2016. Analytical studies of the main geometric and design parameters of the developed machine are carried out. Scientific novelty. The relationship between various geometric parameters of the spatial seven-link statically determined mechanism is established, which makes it possible to calculate the optimal ratio of the lengths of the links of the mechanism to ensure the smooth functioning of the machine without jamming its spatial mechanism. Practical significance. A new design of a machine for processing parts has been developed, based on a seven-section spatial statically determined mechanism with an additional moving link without redundant communication. Mathematical dependences are obtained for calculating its basic design and geometric parameters. These dependencies can be used by the corresponding machine-building enterprises at the design stage of this type of equipment.

Variable degree-of-freedom spatial mechanisms composed of four circular translation joints

This paper deals with the construction and reconfiguration analysis of a spatial mechanism composed of four circular translation (G) joints. Two links connected by a G joint, which can be in different forms such as a planar parallelogram, translate along a circular trajectory with respect to each other. A spatial 4G mechanism, which is composed of four G joints, usually has 1-DOF (degree-of-freedom). Firstly, a 2-DOF spatial 4G mechanism is constructed. Then a novel variable-DOF spatial 4G mechanism is constructed starting from the 2-DOF 4G mechanism using the approach based on screw theory. Finally, the reconfiguration analysis is carried out in the configuration space using dual quaternions and tools from algebraic geometry. The analysis shows that the variable-DOF spatial 4G mechanism has one 2-DOF motion mode and one to two 1-DOF motion modes and reveals how the 4G mechanism can switch among these motion modes. By removing one link from two adjacent G joints each and two links from each of the remaining two G joints, we can obtain a queer-rectangle and a queer-parallelogram, which are the generalization of the queer-square or derivative queer-square in the literature. The approach in this paper can be extended to the analysis of other types of coupled mechanisms using cables and gears and multi-mode spatial mechanisms involving G joints.

Synthesis and analysis of the spatial mechanism

Spatial mechanisms of various types are widely used in technology. Most of them have one or two ball pairs, the presence of which reduces the service life of the device (ball pairs are difficult to protect from dust and dirt. They are more difficult to manufacture and have a lower loadbearing capacity than rotational pairs). Replacing ball pairs with rotary ones, designed, for example, with standard bearings, will greatly simplify and reduce the cost of their manufacturing technology, increase the service life and expand the area of practical application. The difficulty and complexity of creating fivelink and six-link mechanisms and devices with a special structure lies in the fact that the usual combination of links fails to achieve their operability (with rotatable links). Theoretically, this mechanism has been studied by many foreign and Russian scientists. However, Kazan scientists were the first to form and put into practice spatial mechanisms with rotational pairs. The paper presents synthesis and analysis of the spatial five-link mechanism by the degree of irregularity, axial displacement, elliptical law and by the reproduction of a linear function. The mechanism provides intensification and energy saving of mixing, separation, torque transmission of various drives.