scholarly journals Determination of the moment of resistance to turning of a forestry articulated machine

2021 ◽  
Vol 1086 (1) ◽  
pp. 012012
Author(s):  
D Rogachev ◽  
A Alyabiev ◽  
V Latysheva
2021 ◽  
Vol 10 (4) ◽  
pp. 217-226
Author(s):  
Vladislav Klubnichkin ◽  
Evgeniy Klubnichkin ◽  
Aleksey Gorbunov ◽  
Denis Druchinin

The article presents a structural hydraulic diagram of the steering system of the developed forwarder. The main components that make up the steering of the machine are described. The scheme of the articulated joint was selected and the radius and the corridor of the forwarder's turn were determined. In the work, a kinematic analysis of the articulated joint of the forwarder was carried out, which is the determination of the limiting angles of folding of the articulation unit and the stroke of the hydraulic power cylinders according to the developed electronic solid models. The moment of resistance required to fold the car of full weight in place on a solid supporting surface with a high coefficient of adhesion, taking into account the interaction of tires with the supporting surface, was determined using the semi-empirical model of Packa MF-Tire 6.1. Model parameters for tire 750/55-26.5. A dynamic model of a forwarder has been created with the following features: all links of the dynamic system are absolutely rigid; all wheels are not braked and rotate; there is no friction in the hinges; the load (assortments) is modeled absolutely rigid by a single body; the simulation was done for a fully laden forwarder; axle differentials are not locked (free). The vertical loads in the contact patch of the front and rear axles, as well as lateral reactions in the contact patch of the front and rear axles are presented


2021 ◽  
Vol 297 (3) ◽  
pp. 94-99
Author(s):  
Mark ZALYUBOVSKYI ◽  
◽  
Viktor MALYSHEV ◽  
Igor PANASYUK ◽  
◽  
...  

Galvanizing technological operations include the processes of cleaning the surfaces of parts from burrs, burrs, bumps and scale, corrosion products, rounding of sharp edges, separation of parts from castings, as well as processes to improve the quality of product surfaces: grinding or polishing. These technological operations are implemented using different types of equipment: vibrating, rotary and spindle machines, rotating drums, etc. The most promising are considered to be machines with complex spatial movement of working tanks. Analytical researches of definition of dynamic moment of resistance of a driving shaft of the shredding machine on the basis of laws of movement of loose mass in the middle of working capacity are carried out. The positions of the moving parts of the machine and the bulk array in the middle of the tank, which correspond to the maximum dynamic component of the moment of resistance on the drive shaft created by the bulk array loaded to the working tank. An expression is obtained to calculate the value of the dynamic component of the moment of resistance on the drive shaft of the machine, created by the bulk array loaded to the working tank. The obtained research results can be used by the relevant machine-building enterprises at the stage of designing galvanizing types of equipment with tanks performing complex spatial motion.


2020 ◽  
Vol 17 ◽  
pp. 00056
Author(s):  
Marat Fashutdinov ◽  
Kamil Khafizov ◽  
Ilgiz Galiev ◽  
Fanil Gabdrafikov ◽  
Farit Khaliullin

In the article theoretical preconditions of a description of dynamics of manoeuvrability of machine-tractor, aggregates with a wheeled-tracked mover are considered. For a machine-tractor aggregate with half-tracked progress theoretical formulas of determination of an actual turning radius, the moment of resistance of turn and torque for rotation are obtained. The theoretical preconditions are confirmed by experimental research of the manoeuvrability of the machine-tractor aggregate with the tractor on a halftracked progress, made as the experimental sample. The dependences of the turn coefficient and the resistance coefficient of the turn are obtained, and the correlation coefficients and their significance have confirmed the existence of a stable connection between the changing parameter and the response function. Proceeding from theoretical and experimental research, it is possible to draw a conclusion that the manoeuvrability of the tractor with a wheeled-crawler mover does not concede to the tractor in the basic execution.


Author(s):  
Дмитрий Валериевич Судаков ◽  
Олег Валериевич Судаков ◽  
Людмила Валентиновна Кретинина ◽  
Наталья Владимировна Якушева ◽  
Артём Николаевич Шевцов

Статья посвящена построению прогноза эффективности реконструктивных вмешательств на магистральных нервах предплечья в зависимости от протяженности дефекта нервной ткани и особенностей последующего периода реабилитации пациентов. Данная тематика является весьма актуальной, так как с каждым годом во всем мире наблюдается определенный рост случаев травм различного генеза магистральных нервных стволов, которые затем нередко приводят к временной нетрудоспособности и даже инвалидности пациентов. Реконструктивная микрохирургия многие десятилетия пытается решить целый ряд проблем аутотрансплантации нервных стволов и повысить ее общую эффективность. Но из-за определенных проблем связанных с финансированием, некоторые вопросы трансплантологии и реабилитации остаются нерешенными и в настоящий момент. Все это придает представленной работе важное значение не только медицинского, но и социально - экономического плана. Целью работы стала попытка построения прогноза восстановительных операций на нервной ткани, с учетом объема пораженных структур и периода реабилитации. Объектами исследования стало 180 больных, которым по той или иной причине, осуществлялась реконструктивная операция на одном из магистральных нервов предплечья. Все пациенты были разделены на 3 группы по 60 человек, в зависимости от протяженности дефекта магистрального нерва: до 4 см, от 4 до 8 см и от 8 до 12 см. Последующее разделение внутри каждой группы на подгруппы производилось в зависимости от определенного поврежденного нерва (лучевой, локтевой, срединный). В работе изучалось течение раннего послеоперационного воспалительного процесса, с определением бактериальной микрофлоры в ране. Изучались и отдаленные последствия оперативного вмешательства. Своеобразной новизной для данной тематики в целом, стало выявление последующего установления инвалидности пациентов. Кроме того, важные данные были получены и по срокам реабилитации и частичного или полного восстановления утраченных функций по срокам в зависимости от размеров восстанавливаемого дефекта и от наличия или отсутствия необходимой реабилитации. Полученные в работе данные могут представлять интерес не только для врачей хирургов и травматологов, но и для организаторов здравоохранения, позволяя производить прогнозы по выздоровлению пациентов в каждой определенной клинической ситуации The article is devoted to the construction of a forecast of the effectiveness of reconstructive interventions on the main nerves of the forearm, depending on the length of the defect in the nervous tissue and the characteristics of the subsequent period of rehabilitation of patients. This topic is very relevant, since every year all over the world there is a certain increase in cases of injuries of various origins of the main nerve trunks, which then often lead to temporary disability and even disability of patients. For many decades, reconstructive microsurgery has been trying to solve a number of problems of autotransplantation of nerve trunks and improve its overall efficiency. But due to certain problems associated with funding, some issues of transplantation and rehabilitation remain unresolved at the moment. All this gives the presented work important not only medical, but also socio - economic importance. The aim of this work was to attempt to predict restorative operations on the nervous tissue, taking into account the volume of the affected structures and the period of rehabilitation. The objects of the study were 180 patients who, for one reason or another, underwent a reconstructive operation on one of the main nerves of the forearm. All patients were divided into 3 groups of 60 people, depending on the length of the main nerve defect: up to 4 cm, from 4 to 8 cm, and from 8 to 12 cm. Subsequent division within each group into subgroups was performed depending on the specific damaged nerve ( radial, ulnar, median). The work studied the course of the early postoperative inflammatory process, with the determination of bacterial microflora in the wound. The long-term consequences of surgery were also studied. A peculiar novelty for this topic as a whole was the identification of the subsequent establishment of disability in patients. In addition, important data were obtained on the timing of rehabilitation and partial or complete restoration of lost functions in terms of timing, depending on the size of the restored defect and on the presence or absence of the necessary rehabilitation. The data obtained in this work may be of interest not only for surgeons and traumatologists, but also for healthcare organizers, allowing them to make predictions about the recovery of patients in each specific clinical situation


Author(s):  
Carmen-Magdalena Camenidis ◽  
◽  
Irina Băițel ◽  
Amalia Oatu ◽  
Octavian Amzulescu ◽  
...  

The objective of this case study is to observe the existence of an anticipation mechanism at the muscle groups level of the upper limbs. We tried to highlighted this anticipation process by measuring the potential of surface electric for some muscle groups representing the kinematic chain on the right side, involved in the motor action of catching a basketball and a 3kg medicine ball with two hands to the chest. We conducted a case study of a 13-year-old child, female gender. As a measurement method, we used surface electromyography signals of the EMG Trigno Delsys wireless system with 16 electrodes. We determined the moment when the muscles come into action by increasing the potential of surface electric and the moment when the action of catching the ball takes place, using the information provided by the accelerometers incorporated in the sensors of the Delsys equipment used. Therefore, we obtained information about how different muscle groups come into action which helped us to get an idea of how the child's movement is structured. Based on results of accelerations and EMG signals acquired we have formulated conclusions regarding the neuromuscular control of the tested subject. We also planned for the future to test a larger group of participants in the study research of anticipation mechanism in children who do not practice any performance sports.


2007 ◽  
Vol 61 (1-2) ◽  
pp. 37-42 ◽  
Author(s):  
Gabriel Otava ◽  
Calin Mircu ◽  
Horia Cernescu ◽  
Violeta Igna

The timely detection of oestrus presents an important professional procedure with which cattle farmers, in addition to veterinarians, are very often faced, because failure to detect oestrus poses a big economic problem. The objective of this work is to evaluate the efficacy of discovering oestrus in cows by determining the progesterone concentration (P4) in blood plasma. This experiment covered 22 animals, including 15 cows and 7 heifers, in which spontaneous oestrus was discovered. P4 concentration was determined using the ELISA test in samples of blood taken from the animals at the moment of insemination. Of the 15 cows, four cows (26.6%) were not inseminated at the optimal time, and the P4 level in these animals was higher than 1 ng/ml. All the heifers showed a progesterone concentration of over 1 ng/ml, and a percentage of conception which was 85%. The high P4 level in heifers at the moment of insemination could also be a consequence of stress caused by the regrouping and separating of the animals. Even though the heifers were under stress, which is indicated by the high progesteronemia values at the moment of insemination, the percentage of conception among them was beyond expectations. Therefore, the determination of P4 values at the moment of insemination is a suitable method for improving reproduction management on cattle farms. Inappropriate treatment of cows which are expected to show oestrus can cause stress and an increase in the values of the blood concentration of P4. On the grounds of the results obtained in this work, no negative influence of stress on the insemination results in heifers was observed.


2005 ◽  
Vol 33 (4) ◽  
pp. 319-338
Author(s):  
Ron P. Podhorodeski ◽  
Paul Sobejko

Analysis of the forces involved in mechanical systems requires an understanding of the dynamic properties of the system's components. In this work, a project on the determination of both the location of the centre of mass and inertial properties is described. The project involves physical testing, the proposal of approximate models, and the comparison of results. The educational goal of the project is to give students and appreciation of second mass moments and the validity of assumptions that are often applied in component modelling. This work reviews relevant equations of motion and discusses techniques to determine or estimate the centre of mass and second moment of inertia. An example project problem and solutions are presented. The value of such project problems within a first course on the theory of mechanisms is discussed.


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