Single-bucket Excavators Research Articles

Justification and static calculation of the adaptive moving counterweight of a single-bucket excavator

The results of an analytical study of the effect of loads on the equipment of a single-bucket excavator are presented, and an analysis of previous studies is performed.
 The work highlights that the work process of a universal single-bucket excavator is a cycle of performing operations - digging and transporting soil.
 Universal excavators can perform work above and below the level of their parking lot with the working equipment of forward and reverse shovels or with the help of additional interchangeable equipment.
 During the work process, static and dynamic loads occur on the machine and mechanisms, which affect the stability of the machine and safety on the work site.
 To increase the stability of single-bucket universal excavators when working on an inclined plane and increase the efficiency of the machine in quarries, construction sites, when disassembling rubble after man-made disasters, accidents, and military operations, it is necessary to create a balancing mechanism of automatic action.
 The calculation of the stability of a universal single-bucket excavator with an adaptive movable counterweight with working equipment forward and reverse shovel in the basic calculation positions, which are performed when calculating universal single-bucket excavators, has been developed. For an excavator equipped with a reverse shovel, the calculation is made for two positions. Calculation of the stability of an excavator with straight shovel equipment, performed for four positions.
 Due to the adaptive movable counterweight, an additional, adjustable, arm appears, which automatically balances the system when necessary.
 Thanks to the automatic system, the single-bucket excavator can work and move on a more inclined plane, the moving counterweight will balance the machine itself, and it is also possible to increase the holding moment and prevent the excavator from tipping over.
 The expediency of using an adaptive moving counterweight for single-bucket excavators is described. Examples of the use of a movable counterweight in other machines are given. The analysis of related studies was performed and the expediency of using an adaptive moving counterweight in them was substantiated. Preliminary studies in the development of a movable counterweight for single-bucket excavators are provided. The calculation of the stability of a single-bucket excavator with an adaptive movable counterweight in the main design positions has been developed.

Determining the maximum turning force of the hydraulic backhoe excavator bucket

Introduction. Single-bucket excavators with both flexible and rigid suspension of work equipment are actively engaged in construction, stripping work and production mining. Excavators with rigid suspension are commonly used in construction, while excavators with flexible suspension are used in mining practice. This work considers the process of excavating rock with a single-bucket hydraulic backhoe excavator. The reliability and durability of excavators depend on the correct choice of the parameters of work equipment elements. Research objective is to determine the maximum turning force of the bucket of a hydraulic backhoe excavator, taking into account soil friction against the bucket bottom and side plates during rock excavation. Methods of research. When the maximum force on the bucket turning hydraulic-cylinder rods in the course of rock excavation is analytically defined, it is advisable to consider digging a trench in plain surface or in the open-pit in plain surface of a stope face provided that per one turn the bucket is filled to capacity. In this case, a segment of soil cut from the rock mass has maximum depth of cut as compared to other excavation methods. Total excavation resistance includes: resistance arising from cutting rock with a bucket with maximum depth of cut; resistance associated with the impact of gravity of the rock mass on the bucket; resistance associated with rock mass friction against the bucket bottom; resistance associated with rock mass friction against the inner surfaces of the bucket side plates. Results. The dependence has been determined between the maximum force on the bucket turning hydraulic-cylinder rods and bucket design parameters as well as the physical and mechanical characteristics of the face rock. The results analysis showed that both excavation process flow scheme and rock characteristics have a significant influence on the total bucket excavation resistance. Conclusions. The developed method of calculating the excavation resistance takes into account the internal forces of bucket interaction with rock and makes it possible to increase the accuracy of maximum digging force calculation. It therefore becomes possible to more reasonably approach the choice of the excavator bucket turning hydraulic cylinder parameters and thereby increase the reliability and durability of the machine as a whole.

Studies of the periodicity of the service Volvo excavator service EW 145 b

At present, the efficient and economical use of road construction machines in the construction, repair and maintenance of roads is a very urgent task. On this aspect of studying and researching the effective and economical use of newly arriving road equipment, incl. single-bucket excavators of foreign countries, when there is no regulatory documentation for their technical operation, is an urgent task. This study is aimed at studying the technical characteristics and frequency of maintenance of a VOLVO single-bucket excavator EW 145B _ By fuel consumption and machine output.

Synthesis of basic geometry parameters of excavator working equipment

Problem. Single-bucket excavators have become one of the most popular machines today, which are widely used to perform a variety of construction works. The working area or service area is one of the main characteristics of the work equipment of the manipulation type. It must meet certain requirements, which are: the largest digging depth, unloading height and digging radius at the level of the parking lot. To ensure the parameters of the given working area, it is necessary to correctly select the basic geometry of the working equipment: the length of the boom and the handle, the turning radius of the bucket edge. Goal. The purpose of the work is to automate the synthesis of basic geometry parameters of the hydraulic excavators, according to the specified parameters of the service area (working area). Methodology. A system of non-linear equations establishing a relationship between the geometric parameters of the working equipment and the parameters of the working area was obtained. Results. The software for the OS Windows was developed. The program outputs not only numerical results. To visualize them, contours of the resulting working area are built. Originality. The relationship between the geometric parameters of the working equipment and the parameters of the working area has been established. A mathematical model and software for automating the synthesis of geometric parameters of working equipment have been developed. Practical value. The developed software can be applied not only at the design stages of new types of excavator working equipment, but also in the process of preparing the machine for specific types of work. The proposed approach can also be extended to the synthesis of parameters of the lever mechanisms of other construction machines, in particular, the working equipment of loaders, looseners, etc.

Analysis of the dynamics of the attached equipment of a single-bucket excavator when working with variable working equipment

The results of an analytical study of the effect of dynamic loads on the equipment of a single-bucket excavator are presented, and an analysis of previous studies is performed. Dynamic and static stability against overturning is considered. The expediency of using an adaptive moving counterweight for single-bucket excavators is described.

Technique for determining the actual parameters of the swing angle of the dragline dragline ESh 10/70 under the conditions of the new scheme mining of pits of refractory clay PJSC "Vesсo"

Purpose. To introduce systematic monitoring of the actual angles of rotation of the dragline boom during field development and to determine the actual parameters of the cycle during excavation and movement of rock mass in order to study the parameters of the implemented mining scheme, and confirm the feasibility of its application. Research methodology. The study of the actual angle of rotation was carried out using a hardware and software calculation method based on data from devices for recording the spatial position of the boom and on the basis of a GPS signal during operation. Actual performance is based on a survey report for the period. Research results. The boom position was measured while working in the open pits of the Andriivske field, and the frequency of manifestation of various angles of rotation was determined. Compared with the planned parameters of the mining scheme. The actual performance for the period has been determined. As a result of the research, the confirmed target indicators of the implemented mining scheme with the EШ10/70 dragline from one position, with re-movement coeficient and contouring of the clay layer, and the angle of rotation up to 220о. Scientific novelty. The complex of studies of the first introduced mining scheme makes it possible to assess the fulfillment of the conditions and the achievement of results to reduce the preparation time for the seam, reduce the overshoot coefficient at boom angles, which were considered ineffective when moving rocks to dumps with a non-transport technology. The positive conclusions of the research make it possible to recommend the use of such a scheme in the development of flat deposits of nonmetallic minerals. Practical value. The technique is stated which can be applied when observing the operation of draglines and other single-bucket excavators in order to determine the parameters of the work cycle and further optimize productivity.The proposed method allows to perform the analysis of the working scheme of the excavator, which leads to the maximum productivity of the mining transport equipment during direct work.

ЭЛЕКТРИЧЕСКИЙ ПРИВОД СТРОИТЕЛЬНО-ДОРОЖНЫХ МАШИН

This article deals with the use of electric drive in the design of mobile road construction vehicles. Despite the fact that electric drive has been used in machine engineering for a long time (span type cranes, tower cranes, machines), this type of drive is not widely used in specialized equipment (single-bucket excavators, bulldozers, single-bucket loaders, etc.). At the same time, based on scientific evidence, the electric drive has been used more and more often in the car engineering. Clearly, the use of electric drives in road construction machines has not been sufficiently investigated and therefore it's limited. This is due to a number of factors associated with the features (a large mass, changes in technological processes of work) and operating conditions (natural, climatic, road) of this road machinery. This must be taken into account in the development of road construction vehicles with an electric drive to improve the efficiency of their use. The authors analyzed the characteristics of machines with electric drive, determined the functional dependences, and based on this made the main conclusions.

Ірі түйіршікті топырақты өңдеуге арналған грейферлі экскаватордың жаңа жұмыс жабдығының негізгі параметрлерін негіздеу

Traditional designs of working bodies of earthmoving machines are not adapted for the development of large-block soils of mudslides and other blockages in emergency situations, which leads to a decrease in their productivity. Therefore, it is necessary to create special working bodies of single-bucket excavators for the development of mudflows with large-block inclusions, allowing to expand the functionality of these machines. The subject of the study is to determine the kinematic and power parameters of the mechanism of extension of a special working body of an excavator based on analytical studies and computer modeling. The article proposes a method for determining the links of the mechanism of a special excavator working body and algorithms and methods for determining the positions, coordinates of the points of the links. As result of the study there have been obtained closure equations of independent contours of the jaw extension mechanism of a special excavator bucket in vector form for determining angular velocities and accelerations of the links and numerical and graphical parameter values.

A study of dynamics of the operational performance of a single-bucket excavator, taking into account the operating time during construction of transport infrastructure of oil and gas facilities

The paper presents the results of studies of the impact of operating time of single-bucket excavators on their operational performance. The results of production experiments made it possible to establish the dependence of the pressure change in the hydraulic system of the excavator during the process of cutting soil on the operating time. This parameter characterizes the variation value of the cutting resistance of soil at the cutting edge of a bucket, the duration of operation cycle and its operational productive capacity. Based on the results of the study, a technique has been developed that permits to determine economically feasible periods of effective operation of excavators, as well as to establish the optimal technological parameters for cutting soil: the thickness of the soil shavings and speed of its cutting by an excavator.

Use of replaceable working equipment to expand the functionality of the excavator

Increasing the range of replaceable working equipment for hydraulic single-bucket excavators allows to expand the scope of application significantly, increase the efficiency of its usage, as well as the mobility of these machines. The purpose of the study is to design working equipment replacement items, used for hydraulic single-bucket excavator for digging frozen soils in the city Vladivostok. The main tasks of the study are to analyze frozen soils in the region and their existing structures, select a layout scheme for further design calculation, evaluate the economic feasibility of the proposed hydraulic excavator working equipment design replacement items, used for digging frozen soils in Vladivostok city. Keywords excavator, replacement equipment, frozen ground, urban conditions, rotary mill, vibro-ripper, hydraulic hammer, bucket-ripper, tusk-ripper, gripper-tongs working body

PID-control Systems on Single-bucket Excavators during Construction Work in Urban Environments

PID-control Systems on Single-bucket Excavators during Construction Work in Urban Environments

Stability and capacity of walking mechanism for moving of excavators

The authors discuss design of waling mechanisms intended for moving of single-bucket excavators. History of engineering and application of these mechanisms is given in brief. The authors also mention relations obtained for determining pressures and deformation of bearing surface under under the walking mechanism support shoes. The stability of walking excavators is considered with an assumption that the bearing surface deformation linearly depends on the pressure transferred to it by the excavator undercarriage. To understand the changes in the pressure on the bearing surface during walking, the cam walking mechanism work diagram is shown, which is divided into four typical phases for the convenience. The shape and dimensions of the bearing surface of the excavator during walking are studied, which makes it possible to find deformation of the bearing surface under the shoes. The analysis of energy consumed to move the excavator takes into account the gravity and friction forces, as well as the energy intake to overcome the inertial forces of lift and simultaneous turn of the machine in the vertical plane. The requirements of the machine movement are: the pressure under the excavator base must be lower than the allowable pressure for rock mass composing the bearing surface under analysis; the radius of the support base should be such that the pressure center is never beyond the core of crosssection. Determination of power for the operation of the walking mechanism is based on calculation of the energy consumption for lifting the excavator and overcoming friction between the excavator base and the bearing surface. Finally, the main outcomes of the study are summarized: the operation of the walking mechanisms is associated with significant dynamic loads induced in the machine steelworks; the power required for the operation of such mechanisms undergoes significant changes during walking and is mostly spent to overcome the resistance of the machine inertia; the power consumption is mostly associated with superstructure lifting and wheel dragging along the bearing surface given there is no backward slip of the shoes.

Ageing Process of Hydraulic Oil in Single-Bucket Excavators in Rock Mining

Abstract The paper presents the problem of ageing processes of hydraulic oils when used in single-bucket excavators in mining of rock raw materials. Working parameters of these excavators are specific, particularly when a hydraulic hammer is mounted in place of the working bucket, therefore the course of the oil degradation process and the change times should be precisely determined as full functionality of hydraulic systems of excavators must be maintained and the wear of individual components of these systems should be reduced. Research on oil ageing processes has been carried out for excavators from various manufacturers that have operated in mines of rock raw materials of various raw material extraction quantities. The methodology adopted for testing the ageing processes of oils in excavators allowed to obtain a number of results that question the hitherto applied criteria for quality assessment of used oils in relation to the time of their actual use in hydraulic systems of excavators, as well as the time of change of such oils.

The Upgrading of the Technological Process of the Main Pipeline Break by Means of the Bucket with the Improved Running Gear

When doing major repair works on underground main pipelines, there is a need to carry out earthworks. The single-bucket excavators are used today since they are the mostly wide spread. When stripping main pipelines with the single-bucket excavator, the sequence moving from one stop to the other in the longitudinal direction upon completing the working cycle, it was revealed that the trench profile turns out to be enlarged. It is caused by the fact that the bucket is turned at a definite angle in relation to the axis of the pipeline. As a result, a redundant earth volume from the trench is extracted which results in the increasing of work execution process in stripping the main pipeline. Target of the proposed engineering solution is the improvement of the stripping process when carrying out the major repairs of the main pipeline. The research object is a single-bucket excavators equipped with the working element – a back hoe. The observations and a detailed study of technological processes of earthworks have been carried out, and the analysis has been done for the existing problem in the topic under examination. In addition, based on 3D modeling, an innovative simulation spatial model of the device was developed. As a result of the development of the proposed engineering solution, the technological process was improved to strip a main pipeline. On this basis, technical and economic features were improved. The reduction in the extracted soil from the trench impacts directly not only the duration of the stripping process but also the duration of the back filling process made by the bulldozer. This results in the reduction of harmful atmospheric emissions. The proposed single-bucket excavator can be used in places with structurally unstable soils as well as in all the climatic areas of this country. The proposed engineering solution enables to improve and to enforce the equipment of the repair and construction site. Moreover, the application of the excavator helps strip the pipelines of any diameters. The device design can be used in combination with any single bucket excavator.

Impact Assessment of Dynamic Characteristics on the Hydraulic Driven Machinery Operation

In civil engineering in Russia, trenching for utilities is currently under digging. To perform such works, it is necessary to use high-precision construction machinery, because inaccurate performance of works can lead to the break down of existing utilities, thereby affecting the residents of nearby houses and demanding the additional works for renewal.The most universal labour saver to perform construction works is hydraulic driven single-bucket excavators, which provide up to 38% of works. Therefore, to improve technical characteristics that affect the accuracy of the work performed is an important task.High requirements for the performance of works are defined by existing construction regulations: an allowable soil layer to remain is at most 0.05 m. To fulfil such requirements, an exact assessment of the working mechanism position and a trench profile is necessary.Examination of a manually operated digging process shows that an operator provides operations untimely, however an automated control system can solve this problem. Dynamic phenomena in the working mechanism have the greatest impact on the accuracy of the works performed.To assess the bucket digging edge position accuracy, a mathematical model of the working mechanism has been created. Based on the cycle scheme of the working process, the excessive displacements of the hydraulic cylinder rods under the load are taken into account. By the end of the cycle, the difference between the specified and obtained positions along the vertical coordinate has been 0.0892 m.A dynamic error of the hydraulic drive system of the working mechanism is considered as a sum of the error due to excessive displacements of the hydraulic cylinder rods and the error due to delay of the hydraulic drive, with the latter being calculated for the average time of delay taking into account the data available in the literature. The total error of the bucket digging edge position of the working mechanism is 0.1176 m, which is 2 times more than the value of 0.05 mConformity of all the links with specification requirements does not guarantee compliance with the required displacement accuracy of the bucket digging edge, and, thus, the soil layer to remain in the base of the trench can exceed the regulated value of 0.05 m.

METHODOLOGY FOR DETERMINING THE AREA OF AROUND THE SQUARE OF THE CHANNELS OF COLLECTOR-DRAINING NETWORKS BY THE BUCKET-MOWER

The article contains information on the KK-2,1 bucket-mower, which is developed in the first in Uzbekistan, which is a one-bucket hydraulic excavator hanging on the handle, consisting of a finger cutting device, a bucket-basket and a chain drive from a hydraulic motor. The bucket-mower of an alogical designation has not been developed to this day either in our country or in the CIS countries of the near abroad. Therefore, the vegetation that grows on the bottom and slopes of the collector-drainage networks was not scraped and annually gave up to 20 cm of siltation in the form of a dried mass, sometimes this mass was destroyed either by burning in early spring (late autumn) or removed by single-bucket excavators from the place of sediment from the bottom collectors in the form of soil glybement with the roots of coarsely fledged vegetation.

Evaluation of Single-bucket Excavators Energy Consumption

It is shown that with the increase in capacity and weight of excavators their specific indices of functioning remain practically at the same level corresponding to the energy consumption value (available power) for excavators of each type (electromechanical or hydraulic). That value depends on the type of operational equipment, the ratio between linear and weight parameters and other factors. New layout of the operational equipment is suggested, featuring an internal closure of workloads within its operating element. The layout includes the operating element in the form of two oppositely arranged buckets and the closure mechanism. Energy efficiency index for single-bucket excavators is proposed.

Low Carbon Benefit Analysis of Single-bucket Excavators with Different Driven Types

The carbon emission of single-bucket excavators with different driven types was analyzed in this paper based on carbon economy and economic theories. Low carbon benefits of the two kinds of excavators were compared by taking WK-27A excavator driven by electric and EX5500-5 excavator driven by internal combustion engine as example. The equilibrium relationship of them was established and the advantage area was identified separately.

Selection of operating machinery parameters for a bucket excavator

The mining industry uses extensively single-bucket excavators of the straight shovel type, like the EKG-4.6, as the most effective way of loading previously loosened hard and abrasive excavated rocks. Therefore, an increase in their working efficiency, mainly as regards increasing productivity, reducing load on the operating machinery, and reducing wear of the operating machinery elements, is of particular importance. Analysis shows that the possibilities for this lie in the correct selection of movement trajectory parameters for the excavator bucket, which for existing excavators are inadequate for loading excavated rock. The authors study here the effect of trajectory parameters on excavator bucket filling, and on their basis they select parameters for the operating machinery.

“Intergormash-67” international exhibition of mining equipment

Single-bucket excavators were displayed on the Belgian, American, Finnish, French, German, and Swedish stands. The French firm of Poclain produces six models of hydraulic, full-swivel excavators with forward and return scoop buckets (0.25-1.5 m 3 capacity) and power of 33-110 h.p. It also produces four models on track mount~ ing, one on a pneumatic tire principle and one with a vehicle chassis. All models are extensively standardized in terms of units and assemblies. Hydraulic drive reduces the weight of the machine by 25-30 % and ensures compactness and handling advantages. The TI-45 (Fig. 1) excavators are wheel mounted with 48-hp diesel motors and can be equipped to suit the ground with forward buckets of 0.3-0.5 m s capacity and 40 types of exchangeable equipment. The excavator has a three-point travel system in which the forward bridge is replaced by a double wheel which turns in plan round a vertical pivot. The platform pivot is displaced towards the rear axle bridge and has a mechanical drive which is fitted with four wheels with 9.00-20 size tyres at pressures of 2.25 kg /cm z. This type of design reduces the turn radius to 4.85 m on a base of 3.25 m and makes the excavator simple to control and more maneuverable. Overall dimensions without the working equipment (length, width, height) are: 5,400 x 2,480 x 3,165 mm and the weight is 10 tons. Additional hydraulic bearings are provided so as to increase the stability of the excavator during operation.