Excavator An agricultural machine is called for the development (digging and moving) of the soil, light rocks in an array or rock in a fragmented state.

Excavators are used to perform more than half of earthworks in the construction of industrial and civil buildings and structures, roads and railways, airfields, hydraulic systems and oil pipelines, in careers in the extraction of building materials and minerals. With their help, they take off the pitchers, trenches, channels, and also develop the excavations and embankments and discharge the slopes and walls.

In the road troops, excavators are the main earthmoving machine, apply independently and as part of sets and sets of earthmoving and transport vehicles for the construction and restoration of the earth canvas, the construction of embankments and the emergence of recesses, when performing barrier, career and loading and unloading work, for engineering equipment areas, Participate in the work of the movement detachments.

The working process of excavators consists of a soil separation from an array - digging, soil transportation to the place of unloading, unloading and returning the working body to a position for a new digging.

All excavators, depending on the time of the workflow, are divided into two large groups: continuous action - multi-loving; Periodic (cyclic) action - single-line.

Multual-list excavators both operations (soil digging and its movement) are performed simultaneously; Single-line - sequentially, interrupting digging at the time of movement of the soil. Thus, the working time of the machine during which the soil is chosen, and the productivity of multi-loving excavators is higher than single-line. The use of multi-loving excavators is limited to a feature of their design. Mostly apply when digging tranches and mining of nonmetallic materials in careers with homogeneous soils without stone inclusions.

Single-sized excavators are universal and have a wider area of \u200b\u200bapplication:

apply to the development of soils both higher and below the level of the installation of excavators;

used for earthy, loading and unloading and other types of work, for which they are completed with several types of interchangeable work equipment;

used to develop category I-II soils without pre-loosening of the face, soils of the III-IV category, including frozen and rock soils, with preliminary looping of the bottom of the explosion or with the help of rippers;

used in cramping conditions, when developing soil under water, unloading it into vehicles or in the dump.

Industry manufactures various types of excavators that are classified according to the method of movement, by type of main engine used, according to the mechanisms, by type of power transmission, by type of control system, according to the design of the chassis, at the corner of the rotation of the rotary platform, according to the design of the work equipment.

By way of movement Excavators are land and floating. Land excavators are divided into self-propelled and drilled in a tug or trailer both without disassembly and dismantling individual elements.

By type of main (primary) engine used Modern excavators are produced with diesel or electric motors. Diesel engines are used on excavators that have often to move from place to place (on the construction of automotive and railways, construction of oil pipelines, etc.). Electrical engines are used on excavators that are constantly working in one place (for example, in careers). They are easier and cheaper in operation.

On the drive mechanisms Single-engine excavators are distinguished, in which all working mechanisms are launched by one or more engines operating on one shaft, and multi-selective, in which each working mechanism is activated by a separate (individual) engine.

By type of power gear Motion from the engine to working mechanisms, building excavators are divided into mechanical, hydraulic and electric.

Mechanical excavators move directly from the primary engine to all mechanisms using shafts, gears, worm pairs, chain and other mechanical gears (mechanical transmission).

In hydraulic excavators, the role of the transmission is performed hydraulic pump (one or several), pipelines and hydraulic motigables (hydromotors or hydraulic cylinders).

The electric type of power transmission differs from the hydraulic type of the type of power mechanisms - the electric generator, power electrical networks, the electric motor (one or more).

By type of management system There are excavators with lever-mechanical, pneumatic, hydraulic, electric and combined (electropneumatic, electro-hydraulic) control. Level-mechanical management due to a large number of flaws on most machines is replaced by pneumatic or hydraulic. Pneumatic control is installed on machines with single-engine drive and mechanical transmission. Hydraulic and electrical control are used with the appropriate types of drive.

According to the design of the undercoming device, land excavators are divided into tracked, pneumocoles, walking (the latter is used only in single-loving excavators).

The running device perceives and transfers to the base (soil) of the load from the mass of the machine and the load arising during operation, and also provides the movement of the excavator.

The running device of excavators is the following types: G. - tracked with a minimally permissible supporting surface of the caterpillars; G. - tracked (broad) with an increased supporting surface of caterpillars, designed to work on soils with low bearing capacity; P - pneumocole, which allows to increase the mobility of the excavator, facilitate and speed up its transition to his own move from one object to another; School - special car type chassis, differing from type P In addition to the engine installed on the rotary part of the excavator, a more powerful engine is installed on the chassis, providing the movement of the excavator at high speed; Truck type School It has a solid and low special frame that differs in the design from the cargo chassis frame; BUT - chassis of a cargo car; Tr.- tractor (usually used pneumocole tractors); Etc- trailed.

Depending on the angle of rotation of the rotary platform in the horizontal plane, the excavators are called full-turn or non-filler.

The rotary part of the full-time excavator can rotate around the vertical axis on an unlimited angle. The machines of this type are installed on the rotary platform, the engine and main working mechanisms are installed, and work equipment is strengthened.

Inbupported only small excavators on the basis of tractors. These excavators do not have a swivel platform, and the working equipment is strengthened using a rotary speaker directly on the stock device, with respect to which it rotates to a limited angle (180-270 0).

Depending on the constructive performance of work equipment Single-sized excavators are with a flexible, rigid suspension and telescopic arrow.

Arrow, and sometimes the working body (for example, bucket) in excavators with flexible suspension, is suspended on ropes that are powered by. The arrow and the remaining elements of the working equipment of the tight suspension excavator are connected to each other and are driven by hydraulic cylinders. Excavators with a telescopic arrow include excavators, in which the workflow is accompanied by extension and arrows.

In addition to the listed signs of classification, excavators differ from each other with design, appointment, sizes and power. Single-sized excavators depending on the purpose or kind of work performed are divided into construction, career, stripped, special.

Constructionexcavators with buckets with a capacity of up to 4 m 3 are designed to perform earth and loading and unloading.

Career Excavators are designed to work in ore, coal and other careers.

Sewn Excavators with direct shovel and walking dragings with buckets with a capacity of 25-160 m 3 are used on open mountain development and large construction sites (careers) to remove the opening in the dump.

Special Excavators (tunnel, peat, etc.) are intended for use in certain specific conditions.

Indexing (marking) of single-line excavators, operating in our country, reflects their basic characteristics. Excavator indexation is based on a dimensional group of machines.

The stability of the machines and the ability to efficiently use the buckets of various containers on the corresponding arrows, depth, or height of the digging determines the dimensional group of excavators.

The containers of the bucket are given for orientation, because They may differ for this excavator in two or more times, depending on the category of soil developed.

The indexing system of single-line universal excavators includes the following index structure (Fig. 6.1). The excavator index consists of alphabetic and digital groups.

The letter group "EO" means an excavator of a single-line. Excavators of military assignment in the left literal part of the index there is a letter in (Es - an excavator of single-line military).

The digital group means (in order of their location): dimensional group; Type of running device; execution of work equipment; The sequence number of the model.

The letters (A, B, ...) after the figures indicate the next modernization of this model, as well as its special climatic performance (CL - Northern; T - tropical; TV - for wet tropics).

For example, an EO-4125 index denotes an excavator of a single-line, full-turn, universal, IV size group (the capacity of the main bucket of 0.65 m 3), on a tracked rush, with a rigid suspension of work equipment (hydraulic), 5th model, northern execution.

Along with the considered indexing, which includes an alphabetic designation of the type of non-refining part and a digital group denoting the mass of the excavator. For example, the EC-17 index denote an excavator of a single-lines on a pneumocoleration weighing 17 tons.

Single-sized excavators

Excavator(from Lat. . excavato. - Dolblya) - an agricultural machine intended for digging of the soil followed by its unloading to the dump or in any vehicles.

Singochy excavator - Cyclic action machine for development (digging), movement and loading of the soil.

The working body is the movable bucket, fixed on arrows, handles or ropes. The bucket is loaded due to moving relative to the soil developed. In this case, the excavator body relative to the soil remains still - the traction force is created by the mechanisms of the excavator. This features an excavator from a staple and loader, where the traction force when loading the bucket is created by moving the machine housing.

Single-sized excavator is the most common type of earthquakes used in the construction and mining of minerals.

Excavators came to replace farmers, mechanized their labor-intensive manual labor and significantly increased the performance of earthworks. Capacity of buckets of modern building excavators can reach 2-4 m.

Excavators intended :

For the development of recesses and embankments;

For digging pots, canals, trenches;

When building dams and clearing territories,

In overnight work and careers,

When overloading bulk building materials

When planning work and in many other cases.

Each type of work requires the use of equipment adapted for this excavator and intended for each specific case.

Application . The area of \u200b\u200btheir use in construction is practically not limited. Where there is access for this machine, earthworks will be made with a high pace and quality.

What exactly are the work designed excavators? They can be used when digging kittylovanov, channels, trenches, the development of recesses and embankments, the design of dams and clearing areas, at overlooking work and in careers, when overloading bulk building materials and planning work and in many other cases.

Excavators can develop soil as above the site level on which they stand and below this level. They can act in cramped conditions and develop ground under the layer of water, unload the dug in vehicles into vehicles and pour it into a significant distance from the digging site into the blade, can finally separate the bias and surface of the walls of tranches and pita, as well as with sufficient accuracy to plan a horizontal surface. construction site or bottom of tranches and pita.

Obviously, each type of work requires the use of adapted excavators and intended for each specific case of work equipment.

However, excavators were more distributed in construction than multi-loving, due to the fact that they have greater versatility.

Universality is the ability of the excavator to perform a variety of earthworks, ranging from the construction of trenches, kittlers, canals and ending with mounds and dams, as well as lead loading and unloading operations. Of course, all this excavator can only be performed using various interchangeable work equipment.

Classification. Single-sized excavators are classified by the type of chassis, the type of drive, the type of working equipment, the possibility of rotation of the working equipment relative to the supporting surface.

- By the possibility of rotation of the working equipment relative to the reference surface

but). Full-turn

Fig. Schuham of a full-turn excavator

Working equipment, drives, machine driver and engine are installed on a rotary platform, which in turn is installed on the chassis by means of a reflux device (OPU), and can be rotated relative to it in any direction to any angle. Parts of the chassis hydraulic system and the turning platform of full-turn excavators are connected to the use of the collector, which allows the unlimited number of complete revolutions in one direction.

b). Inbolk-speed

Fig. Diagram of the non-fast excavator

on the chassis of the wheel tractor:

1. Frame of the excavator, fixed on the tractor;

2. Rotary column;

3. Arrow;

4. Handle;

5. Board drive hydraulic cylinder;

6. Hydraulic cylinder handle drive;

7. Watercolor hydraulic cylinder;

9. Options for installing a bucket to the position of the reverse shovel;

10. Replaceable cargo hook;

11. Bulldozer dump;

12. Remote supports.

Working equipment is fixed on the chassis using a rotary speaker. On many machines of this type, the rotary column is mounted on transverse guides, which allows you to move it together with the working equipment to the right-left, followed by rigid fixation for a more convenient position of the working equipment. The turn of the work equipment is carried out at an angle of 45-90 degrees from the initial position. Engine, mechanisms, driver cabin placed on a non-turning chassis. Currently, excavators hanging on tractors are performed.

- By type of chassis

but). Hanging on tractors

Fig. Excavator hung at the Belarus tractor.

Fig. Tractor excavator of foreign production.

As a basic chassis, a tractor is used, most often the wheels. Intretable excavator equipment is installed behind (less often from the side) of the tractor, on a special frame. The most common are excavators hanging on class 1.4 tractors. The characteristic volume of the bucket is 0.2-0.5 m³. Used to perform small earthmoving or loading work, most often when repairing engineering networks. The design of the working equipment allows you to quickly rearrange the bucket for the work of direct or reverse shovel. The bucket can be replaced by grab, trucks or hook. The drive uses the engine base tractor. Hydraulic working equipment drive. Due to the relatively high speed, the turn can promptly arrive at the place of work, located at a distance of 20-30 km from the base of the base. A tractor with hung excavator equipment can also be used to perform transport and bulldozer.

b). On car chassis

Fig. EO-4421 excavator (kirassir) on Kraz-255 chassis.

Fig. UDS excavator on Tatra-141 chassis

As a basic chassis, a truck is used, most often increased passability. Have a high movement speed. Apply in cases where high mobility is required: in military affairs (engineering troops, road troops), when performing rescue operations, during the construction of roads, cleaning channels. Work equipment - predominantly reverse shovel. Excavators with a telescopic arrow and a rotary bucket are produced, allowing you to quickly move from direct shovel to the reverse. The drive can be used both the engine of the base car and a separate engine installed on the rotary platform.

in). Pneumocoles

Fig. Modern pneumatic excavator

with hydraulic drive.

Fig. Pneumocole excavator of the 50s - 60s with cable drive

Excavators have their own special chassis based on the wheels with pneumatic tires. Most often are fulfilled. To increase the stability and preventing closing when loading the bucket has remote supports. Have speed speeds up to 30 km / h. Can be touched by trucks at a speed of up to 40 km / h. Patency on weak soils limited. Available in a wide range of dimensional groups - from microexcavators with a bucket volume 0.04 m³ to heavy wheel excavators - with the volume of the bucket 1,5 m³.. Due to the specifics of the work performed: the development of kittlers, trenches, planning work - work equipment - predominantly reverse shovel. Can be used with grab, mining grip, hydraulic hammer for soil loosening. Wound to be widespread when performing various types of construction and repair work.

The wheel drive chassis can be carried out both from the engine of the working equipment through mechanical or hydraulic transmissions (hydraulic motors) and from a single engine.

d). Crawler

Fig. Modern tracked excavator

Fig. Excavator Demag Bagger - one of the largest in its class

Excavators have their own special chassis with a tracked propulsion. Perfect full-turn. They have high patency and low specific pressure on the ground with a large mass. They can work on weak and overwhelmed soils, including peatpooling. Have speed of 2-15 km / h. The place of work transports tractors on special trawls.

The working range of the volume of the bucket is very wide: from the mini-scab with the volume of the bucket 0,04 m³. to career with the volume of the bucket 10 m³.. There are also particularly heavy career caterpillar excavators with a bucket 26 m³. Production of Demag (Germany).

Work equipment: Direct shovel, reverse shovel, dragine. It can be used with a grab, a jewish grip, hydraulic hammer for soil loosening. They were widespread in construction and during mining. A number of models of caterpillar and pneumatic excavators have a unified turning platform and work equipment.

E). Walking. The walking excavator is an excavator on a walking go, usually with Draghun equipment. The use of hydraulic walking (unlike tracked) propulsion allows to reduce the load on the ground (the mass of the machines can reach hundreds and even thousands of tons) and increase the reliability.

Fig. Walking excavator:

but- general form; b. - type of chassis.

The swivel platform with the equipment of the walking excavator is installed on the support plate. The paws are associated with the rotary platform, which are raised when the excavator is raised (do not touch the soil). With the movement of the excavator, the paws are based on the ground. At the same time, the support plate is removed from the soil. The excavator moves one step forward (for some models it is possible to move back). After that, the paws rise and returned to its original position. On the walking goes produce large career excavators with the volume of the bucket 15 m³. - 40 m³. and departure arrows up 65 m. - 150 m.. Working equipment - Dlagine. Overwhelming excavators are performed with overwhelming work (clearing of mineral deposits from empty breed), as well as mining and moving them into the dump (height to 40 m.). Loading minerals by walking excavators cannot be carried out in vehicles.

e). Railway.

A railway platform is used as the excavator chassis. Used for repair work on the railway. Have a bucket of up to 4 m³. Rotary platform and equipment is often unified with tracked excavators.

g). Floating.

Fig. Floating single-line excavator - dredger.

Work equipment (dragline or graon) is installed on the pontoon. Apply for loading and unloading, sand mining, gravel from water bodies, bottomatic and dredging works. From floating cranes equipped with grabes, floating excavators are characterized by a smaller height and a simplified arrow design.

By engine type.

but). Steam excavators - a steam machine is used as a motor. Were distributed at the beginning of the 20th century. Currently not issued. The moment-speed characteristics of the steam machine and the excess equipment of the excavator are well coordinated, which simplifies mechanical transmissions.

Fig. Steam shovel.

b). Excavators with internal combustion engines are the most common type. The excavator has its own engine, most often diesel. This ensures the autonomy of work. The power range of motors installed on modern excavators is very wide (see Dimensional groups).

The moment-high speed characteristics of the internal combustion engine and the work equipment of the excavator are inconsistent. This requires applying on mechanical excavators of matching gear (gearboxes, hydrotransformers). Hydraulic excavators appreciation is provided by hydraulic gears.

in). Electric excavators - Electrical engines that receive energy from the external network or from their own diesel-electric unit are used to drive work equipment. Electric drive with power supply from the external network is used for career excavators. Such excavators are economical and do not contaminate the atmosphere of the career. Electric power drive from its own diesel electrical unit is used in floating excavators.

d). Excavators working in an explosive environment (in mines) of the primary engine do not have. Their hydraulic equipment is powered by a high pressure fluid from an external oil plant.

By type of mechanical gear (operating equipment drives):

but). With group mechanical cable drive (mechanical);

Swanks of a mechanical excavator.

Traction effort to the working bodies is transmitted by means of ropes (or chains) movable swans. The Lebetok drive is carried out from the excavator engine by means of mechanical gear (gear, chain, friction, worm).

The universal excavator with a mechanical drive is equipped with a three-drum winch. The booster boom drum is used to drive (lifting and lowering) arrows. The lifting drum is used for the lifting of the bucket (or return the handle during the operation of the reverse shovel). The traction drum is used to pull up the bucket to the excavator (when the draglock, reverse shovel). When operating a direct shovel, the traction drum is associated with the pressure head mechanism.

Mechanical cable drive was widely used on excavators in the past. In modern models, its use is reduced by the following reasons:

Excavators with mechanical cable drive have a complex design and contain a large number of high-speed products (friction lining, brake tapes, ropes).

Rope drive provides a limited number of independent displacements of work equipment elements;

Rope drive is technically difficult to make automated;

The rope drive does not fully fix the elements of the working equipment in the specified position.

On modern models, the rope mechanical drive applies only for draglaunor grafe.

Fig. Swanks of mechanical excavator

b). With individual electrical drive winches (electromechanical);

Traction effort to the working bodies is transmitted by means of ropes (or chains) movable swans. The drive of each winch and auxiliary mechanisms is carried out by an individual electric motor. Such a drive is applied to heavy careers (including walking) and industrial excavators.

in). With hydraulic drive;

In hydraulic drive excavators (hydraulic excavators), the force on the elements of the working equipment is created by hydraulic cylinders and hydraulic engines. The excavator engine leads to a rotation a hydraulic pump that creates the pressure of the working fluid in the pressure center of the hydraulic system. Through the system of hydraulic distributors of the cavity of the hydraulic cylinders (hydrodal engines), they are connected to the working or drain highways of the hydraulic system, which ensures the movement of the working equipment. In the neutral position (with locked cavities of the hydraulic cylinders), the position of the working equipment is fixed. For the transportation of the excavator using a tug, the possibility of translating the boom hydraulic cylinder and the rotation of the rotation mechanism to neutral transport ("floating") mode.

Indexing.

Stuput the index of single-line universal excavators.

The numerator indicates Mas excavators attached to the tractor.

Specifications.

Table 1

The main characteristics of single-line universal excavators of the 2-4th dimensional groups

Device. The excavator may be different design, depending on the purpose.

Work equipment - These are the nodes of the machine, with which the excavator directly digs the soil (bucket, arrow, handle with the system of their drive). In these cases, the type of transportation of machines also plays a certain role: whether the excavator is supplied with a crawler stroke or it has a pneumatic chassis, which allows you to quickly move the machine from an object to the object. It is also important to turn the work equipment or, in other words, the presence of a swivel platform, which creates ample opportunities for unloading soil and other works. Accordingly, the features of the specific types of earthworks that must be excavator, the use of excavators with certain working equipment, chassis and the type of its drive.

Fig.A. Excavator work equipment - reverse shovel:

1 - swivel frame; 2 - machine driver; 3 and 4 - lower main and upper extension parts of the boom; 5 and 6 - Hydraulic cylinders of the handle and bucket; 7 - handle ; 8 - lever bucket; 9 - bucket; 10 - traction; 11 - boom hydraulic cylinder; 12 - Arrow;

Fig.B. Excavator work equipment - Direct shovel:

1 - Arrow; 2 - handle; 3 - traction; 4 - tooth bucket; 5 - bucket; 6 - loop the bottom of the bucket; 7 -10 - hydraulic cylinders; I.- II. - The position of the bucket is aware.

D o p o l n and t e l

Working equipment of the single-circuit excavator.

Working equipment of single-loving excavators - a set of working equipment of a single-sized excavator.

The base machine of the single-circuit excavator ensures the functioning of various working equipment. The latter can be replaceable. Working equipment for the digging of the soil is called basic, and work equipment for performing other operations is optional.

Basic work equipment.

BUT). Direct shovel

Fig. The scheme of the working cycle of the hydraulic excavator with a straight shovel.

Fig. Career excavator with straight shovel and cable drive.

Direct shovel - Basic work equipment for the development (digging) of the soil is above the level of the excavator parking. Lamps direct shovels are fixed on handles. The handle in turn is fixed on arrows. The arrow is hingedly fixed on the rotary platform of the car. The hydraulic excavators of the ladle on the handle are molded - the bucket unloading is ensured by tipping using a hydraulic cylinder. In mechanical excavators, the position of the bucket on the handle in the process does not change - the bucket unloading is performed when its bottom is opened. Dog soil in the direction from the excavator. Direct shovel provides the greatest digging effort and the greatest performance (due to the minimum number of operations in one digging cycle). It is used for mining and loading work.

The working cycle of the excavator with a straight shovel consists of the following operations:

Rotate the platform - at the end of the loading bucket, the platform is rotated with the operating equipment of the excavator. The bucket moves to the discharge place. His position relative to the rotary platform of the machine does not change.

Rock up the arrows - before unloading the bucket, the arrows of the excavator to increase the loading height.

The discharge of the bucket - on hydraulic excavators is carried out by turning the bucket with respect to the handling (tipping). In mechanical excavators, the bottom of the bucket is opened.

B). Reverse shovel

Fig. Scheme of the hydraulic excavator with a reverse shovel

Reverse shovel - Basic work equipment for the development (digging) of the soil below the level of the excavator parking. It is used in the digging of kittlers, trenches, when planning slopes and sinking in bulk. Can be applied to loading work. When working inverse shovel, the soil is digging towards the excavator. Hydraulic reverse shovel excavators can develop soil and above the level of their parking, though with less efficiency than direct shovel.

Depending on the type of drives used, the operating cycle of the reverse shovel varies.

For hydraulic excavators with independent boom drive, bucket and handle:

but). Blooming the arrows in the boobs with simultaneous positioning of the handle;

in). Scroll through the boom with simultaneous handle and turning the bucket to prevent soil rash.

e). Unloading a bucket with its turn relative to the handle.

For mechanical excavators with a two-channel handle drive, the dependent position of the boom and the fixed position of the bucket:

but). The boost of the boom and the handle in the pit (performed by discharging the lifting rope);

in). The swift of the boom and the handle from the pit (performed by tensioning the lifting rope when tensioned and the inhibited traction rope);

d). Turning the platform with work equipment;

e). Discharge of the ladle with turning of the handle relative to the arrow in the direction from the excavator (performed by tensioning the lifting rope while unwinding the traction rope).

The reverse shovel is the most versatile work equipment. Provides high accuracy of the bucket positioning, both relative to soil and a vehicle in which the soil is loaded.

IN). Excavators with a rotator bucket.

A number of excavators models, such as the UDS-114 (Czechoslovakia production), is equipped with a bucket coup device (rotator), allowing you to quickly switch from direct shovel mode into the reverse shovel mode.

D). Schedule planner.

A variety of reverse shovels intended for the planning of slopes in road, ameliorative and landscape construction. The sloping planns ensures the movement of the cutting edge of the bucket relative to the soil in a straight line directed at a given angle to the horizon. To do this, the automated control system (hydraulic or electronic) is installed on the hydraulic excavator, which provides a coherent movement of the arrows, handle and bucket. As a planner of slopes, excavators with a telescopic arrow have found.

The stroke is also used for planning work. Installed on mechanical excavators. Contributes an arrow in which the rope moves the trolley, with a bucket attached on it. The angle of planning is determined by the angle of inclination of the boom. Popping the chopping stroke can be changed by the launch of the bucket relative to the trolley.

E). Dragline.

Draglain - Working equipment with a bucket, flexible on the ropes. It is used to develop the soil below the level of the excavator parking. The soil is digging towards the excavator. It is used in the development of kittlers, mocking of embankments, mining, dredging work on reservoirs.

Dlagine has the highest radius and depth of digging, as well as the largest loading height compared to other types of working equipment.

To work with the Draghogo hydraulic excavator, a two-drum main winch with a hydraulic system is installed on it.

Re-equipment of the base machine of the mechanical excavator during the work of the draglin is not required.

G). Grab.

The grab is used to develop narrow deep calels (wells), performing loading and unloading. Grafts can be equipped with both hydraulic and mechanical excavators.

In hydraulic excavators, the grab is fixed on the handle instead of the bucket and has a hydraulic drive of the jaws. The graon can be fixed on the pressure rod that ensures its shock in the pit for 6 meters (for excavators manufactured in the CIS) and more. The pressure rod is a telescopic arrow mounted on an excavator instead of handling.

Mechanical excavators graising hangs on the ropes.

Fig. Two-eyed grapple

Fig. Excavator with grapple

H). Additional work equipment:

Ripper;

Fig. Komatsu Excavator with Ripper

Replaceable work equipment designed for loosening solid (murzed) soil, destruction of building structures, asphalt concrete coating.

The ripper for mechanical excavators is a monolithic steel cargo, the lower part of which is made with a wedge-shaped or peak-shaped. It hangs on the rope. When working, the ripper rises due to the tension of the rope to the height of about 3-6 meters and freely falls on the soil (with deficer canate). The mass of the wedge ripper, depending on the size of the excavator group, is 0.5 - 6 tons.

Hydraulic excavators are installed hammer-ripper with hydraulic drive. The principle of its action is similar to the jackhammer. Mounted on the bucket instead.

A diesel-hammer mounted on an excavator arrows can be used as a ripper.

Pile copper;

Fig. Squator with a pileoper

Lifting crane;

Due to the fact that the base machine of the excavator and the lifting crane have a similar design - a number of excavators models can be equipped with crane equipment. Since the speed of vertical movement of the cargo in the crane must be several times less than the speed of the rash of the excavator, the lifting rope is used through the polyspaster.

Manipulator;

Fig. Caterpilar excavator with a manipulator exercises dismantling with reinforced concrete scissors

The manipulator is a grip mounted instead of a bucket used in assembly and dismantling. Currently, a number of firms in Russia and abroad produces special machine-manipulators based on single-loving excavators. Such machines are larger than the excavators of the arrows and a more complex hydraulic system that ensures the positioning of the capture in three planes.

Pnenetpool;

Excavator with hydraulic crusher;

Fig. Excavator with hydraulic crusher

Single-sized excavators can be used to cortify the stumps. On the hydraulic excavators for this purpose, a jaw capture is installed instead of a bucket (see the grab article). For the cortex, the capture is fed to the pni, dilute the jaws, plunge them into the ground, under the root system of the stump. Next, reduce the jaws of the capture and, lifting the arrows, pull the stump. One driver is managed to all this process.

When the stumps of mechanical excavators to the traction and lifting ropes, a special anchor adarces to traction and lifting ropes. The excavator driver sums up an anchor to the pni, and manually helper plunges the lape of anchor under the root of the stump. After that, the traction rope is tensioned with a weakened lifting, while the anchor joins the stump. The simultaneous tension of two ropes is pulled out stumps.

Work. Single excavators (they are sometimes called cyclic action excavators) All operations on the soil digging, its movement and unloading are performed sequentially and cyclically: first fill the bucket ground, then rotate the loaded bucket, at the end of the rotation unloaded the ground from the bucket (in dump or vehicles) Finally, return the empty bucket to the initial position for loading. Next, this cycle of operations is repeated.

Multifungal excavators (they are also called continuous excavators) perform all operating operations on digging, moving and unloading the soil at the same time. While the part of the bucket or knives cuts the soil, others move it, and the third is unloaded. When working these machines there is no pronounced repeating cycle of working operations.

However, excavators got more distribution in

flying than many-loving, due to the fact that they have greater versatility. Universality is the ability of the excavator to perform a variety of earthworks, ranging from the construction of trenches, kittlers, canals and ending with mounds and dams, as well as lead loading and unloading operations. Of course, all this excavator can only be performed using various interchangeable work equipment.

The operating area of \u200b\u200bthe excavator, including the place of vehicle parking, is called zam , move the excavator when developing soil - penetration . Forcing are:

Frontal (with the use of reverse shovel - end),

And side.

Pouch are:

Longitudinal

And transverse.

Depending on the number of penetrations, the height of the excavation distinguishes one - two - and three-tiered soil.

The operating cycle of the excavator has five main operations:

1. Near the soil;

2. Listing bucket;

3. Time for a bucket into a dump or vehicle;

4. Mixed rotation for a dialing;

5. Lowering the bucket for the subsequent set of soil.

To reduce the time of the excavator cycle during the load of the soil into the vehicle, combine the fourth and fifth operation, when the soil is added to the dump - the second and third.

The performance of the excavator and other earthmoving and earthmoving machinery can be enhanced as a result of the following events:

Reduction of the excavation cycle;

Combining operating operations;

Reducing the angle of rotation of the arrow during unloading;

Breaking soil during breaks in transportation, etc.;

An increase in the volume of soil developed in one cycle;

In the case of applying increased capacity, more complete filling ("with cap"), etc.;

Increased QB coefficient in the process of abbreviations of downtime (timely conduct of preventive work, presentation of the front of work, delivery of fuel and lubricants, etc.).

Production of work of excavators.

Fig. Schemes of Zakvatator with straight shovel:

but- frontal hammer; b -side slaughter.

Fig. Scheme for calculating the size of the slaughter of the excavator with a straight shovel:

ABOUT - the standing point is excavato to develop a slaughter element; ABOUT 1 - Excavator parking after moving by magnitude l. n. /

table 2

Fig.Shima location of longitudinal penetrations in the excavator:

but -loading; b -parallel; in -combined (broken);

1 – pioneer trench; 2, 3, 4, 5, 6, 7 - Pouch.

Fig. Broken cross section of the seizure on the penetrations:

1 – excavator movement axis; 2 – axis of movement of vehicles.

Excavators - Purpose and Classification

Excavators (the name comes from the Latin words "EX" and Caveo, "meaning" Food ") differ in high loose abilities. Transporting abilities are small and are determined by the radius of these machines. Excavators are divided into several intended and power groups. If the machine produces all operations in a certain order, repeating them through some spacing gaps, it refers to the interrupted (cyclic) action machines, if performing all operations simultaneously, is a continuous machine. The excavators of discontinuities include single-line, and to continuous excavators - multi-loving, scraper and milling.

Single-line and multi-loving excavators are land and floating. Land excavators have a tracked, pneumatic, rail and walking chassis.

All excavator mechanisms are driven by diesel engines, carburetor, steam or electric motors. Diesel and electric motors are most economical. The selection of the engine is determined by the conditions in which the excavator will work. Thus, at excavators working in a quarry, it is advantageous to use electric motors, since electricity is the cheapest type of energy, and when working on road construction, where the car is often transported from place to place, it is advisable to use diesel engines.

If all excavator mechanisms are driven from one engine, such a drive is called single-engine. If in the excavator, each mechanism (or group of mechanisms) is driven by a separate engine, such a drive is called multi-motor.

In order to transfer movement from the engine to work mechanisms, the following types of drives are used: - mechanical when the movement is transmitted using shafts, gears, worm steam, chain gears; - hydraulic volume, where the role of the drive is performed by hydraulic pumps, oil hydrogen and hydraulic cylinders (or hydraulic cylinders); In oil harvesters, the liquid circulates the energy transmitting energy from the pumps to hydraulic cells (or hydraulic cylinders), leading work mechanisms into motion; - hydromechanical, in which a hydrotransformer is used to transmit energy in combination with a mechanical transmission; - electric used on excavators with multi-motor drive in combination with mechanical; - mixed, consisting of two types of drives, such as mechanical and electric.

Thus, excavators are classified: - according to the method of moving (floating and land); - by type of power equipment (with diesel, carburetor, electric, diesel-electric, etc.); - by the number of engines (single-engine, multi-motor); - by type of drive (mechanical, hydraulic, hydromechanical, electrical); - by type of undercoming device of land excavators (tracked, pneumocoles, rail and with walking chassis).

Each of the groups of excavators is characterized by smaller signs - dimensions, power, appointment.

Single-sized excavators are classified by appointment.

There are three main groups: - Construction and universal - with a container buckets up to 3 m3, intended for the production of earthworks; - careers - with buckets with a capacity from 2 to 8 m3, designed to work in careers on the development of ore and coal deposits; - Convered - with laundry buckets of more than 6 m3, intended for the development of upper layers of rocks (opening).

Single-sized excavators are distinguished by using them with various types of work equipment.

Universal excavators are designed to work with various types of interchangeable equipment; Direct and reverse shovel, draglock, crane arrow with a hook suspension or graon, coprom for a pile hitch, etc.

Semi-universal excavators except the main work equipment have one or two types of additional interchangeable equipment (direct shovel, reverse shovel, dragline).

Special powerful excavators have only one type of equipment, such as a straight shovel.

Single-sized excavators. Singo-universal excavator is called a cyclic action machine intended for the excavation and movement of soils and other materials using one of the types of working equipment with one bucket, and to perform loading welding and other works by other types of interchangeable work equipment.

Single-sized excavators (Fig. 72) consist of the following main nodes: a running device, a turning platform with power equipment and main kinematic links and work equipment.

Tracked driving equipment provides high permeability and good stability when working as an excavator.

In recent years, the release of excavators with a small bucket capacity on a pneumocole trip, which has great mobility and maneuverability when moving the machine from one object to another is significantly increased. When working on weak soils, an extension (or elongated) tracked equipment is used, the presence of which reduces the specific pressure on the ground and improves the passability of the excavator.

Fig. 72. Single Excavator CHEMA

Fig. 74. Scheme of direct shovel

The rotary platform is based on the rollers or special (ball or roller) support-rotary device on the frame of the undercoming device. The platform rotates in the horizontal plane relative to the chassis.

The angle of rotation of the undercarriage equipment in the horizontal plane determines the possibility of an excavator to be a full-turn or incomplete. The rotary part of the full-native excavator can rotate around its axis by 360 °.

These machines on the rotary platform are mounted all the power units, a control panel, working mechanisms and the work equipment is mounted.

Working equipment includes a set of excavator nodes with a working body (bucket, hook, grab, etc.). The soil is developed by the bucket, after which they move to the discharge place in the blade or to the vehicle. Depending on the type of replaceable equipment, use a rigid or flexible suspension of the working body. The nature of the work determines the work equipment: direct shovel, reverse shovel, dragine, crane or grab.

The operating cycle of the excavator is performed in the following sequence: soil digging; Moving the bucket filled with soil to the discharge place; unloading the soil from the bucket into the dump or transporting device; Moving the bucket (rotation of the platform) to the caution; Lowering the bucket to prepare for the next digging operation.

The indexing system of single-line universal excavators. The machine indexing system is called the principle that is laid into the structure of the index (mark), denoting one or another excavator and reflecting its basic characteristic. In 1968, a new system of indexation of single-loving universal excavators was introduced in our country. The excavator index has four main numbers, respectively, indicating: the dimensional group of the machine, the type of undercoming device, the design of the working equipment and the sequence number of the model of this type. Thus, the excavator index contains information about its main characteristic. So, EO-3313 BTV is an excavator of a single-line universal, 3rd dimensional group, on a pneumatic chassis, with a rope suspension of work equipment, the 3rd model that has passed the second modernization, performed for operation in wet tropics.

Direct shovel - equipment designed to develop the soil above the level of the excavator parking. Direct shovel with mechanical drive (Fig. 74) consists of the following main nodes: rope rope, bucket, handle, arrows, saddle bearing. The handle to the arrow is fastened with a saddle bearing, with which the handle rotates in the vertical plane relative to the boom and makes a reciprocating movement along the axis of the handle. When the soil is digging, the ladle needs to pass the position -IV shown in Fig. 74. The bucket rises with a lifting rope envelope head blocks. The pressure of the handle is carried out by a pressure mechanism, which also performs the inverse movement (refund) of the handle. The universal building excavators use rope and gear-roll (pressure mechanisms).

The pressure mechanisms are divided into independent, dependent, the combined, pressure mechanism is called independent if the pressure force can be increased or decreased regardless of the magnitude of the effort in the bucket lifting cable, i.e. when the pressure of the handle with the bucket is made independently of the lifting of the bucket. If the magnitude of the force of the pressure depends on the magnitude of the force in the lifting / broken bucket cable and it is possible only to reduce the pressure, such a pressure mechanism is called dependent.

The pressure mechanism is called combined when the pressure of the pressure depends on the effort in the lifting cable, but when the independent part of the pressure mechanism can be enlarged if desired.

The ladle direct shovel consists of a housing, a folding bottom with a casing and replaceable teeth. The teeth have a shank escaped to the end, which is included in the visor's socket. From the fall out of the teeth are held in the nests with hoptes.

Straight shovels in recent years have been equipped with dipper with a semicircular front wall and with a visor in the form of a scoop without teeth. The bucket of such a design is much easier and has minimal resistance when the soil is digging, which naturally increases the performance of the excavator.

At the excavators with a straight shovel, two types of handles are applied: single-ground (internal type) and two-bit (external type). A single-ground handle passes inside the boom, and two-bit - outside. The handle can perform a reciprocating movement in the guide saddles of the pressure shaft, and also rotate together with the saddle bearing in the vertical plane relative to the pressure shaft. The design of the handle defines the design of the pressure mechanism. In the excavators produced in the USSR, the rope pressure mechanism is used with a single-ground handle, and with a two-bondan - creamers head mechanism.

The straw of direct shovel is made in the form of a welded design of sheet steel. The type of handle defines the arrow design. The arrow is two-ball with a single-ground handle and a single-ground with a two-bit handle.

At the top of the boom, the blocks are mounted on the bearings through which the rope of the bucket lifting and the arright-lifting rope passes. The lower end (fifth) arrow is attached to the rotary platform and can be rotated when it changes its tilt angle. In the middle of the arrows there is a pressure shaft.

The reverse shovel is an equipment designed to develop soils below the level of the excavator parking during the digging of buttons, trenches, recesses.

The reverse shovel (Fig. 75) consists of a bucket, arrows, handles and a two-legged rack. The bucket is fixed rigidly to the handle, hingedly attached to the upper end of the arrows. When pulling up the rope, the handle rotates counterclockwise, the bucket is crashed into the soil (position // position // and /// correspond to the transport position and unloading of the soil from the bucket).

Fig. 75. The work scheme of the reverse shovel:

The process of ground ground bucket. The overall excavation resistance R0 is overcome by the active force W0, aimed at the bucket trajectory, which can be decomposed on the cutting force and the soil shift WVI directional by tangent to the cutting edge of the bucket, and on the WB pushing force, directed normally to the cutting edge of the bucket.

The main parameters of hydraulic single-loving excavators are: Bucket Capacity Q, Mass of the excavator C, engine power N, operations of the excavator, as well as pressure and pump performance.

In the hydraulic drives of excavators, the pumps of permanent performance of gear and blade type (with a pressure of 12-16MPA) and piston with a pressure of up to 30 MP and the pumps of variable performance are used, the prerequisite is an axial-piston.

Pumps with permanent performance are simple on the YCI torture, but do not provide the complete use of the engine power in all modes. Performance variable pumps seminate more rational and stable operation of excavators.

Productivity and technological schemes for the work of single-loving excavators. The productivity of single-line excavators is determined by many factors: the design of the machine, the level of organization of earthworks, the condition and quality of soil and slaughter, the qualification of the machine driver and the technical condition of the machine.

In fig. 77, B is a diagram of the work of the Draghun during the construction of an extract of the earth canvas from the reserve. The excavation of the soil is carried out on two invigays; At one of them, the next layer of soil is pumped and smoothed by a bulldozer, and on the other - freshly added soil is compacted by a bodily removable machine.

Multifungal excavators. Multifungal excavators are earthmoving machines that have a multi-voltage chain or a rotary wheel with buckets, rigidly fixed around the perimeter. They apply: on road construction work; When digging pickles, canals and tranches for laying pipes or for bases Installation, control panel, gearbox, the working body is installed on the stack frame.

Note. EO-1621 excavators (E-153a), EO-1627 (E-1514) are equipped with additional bulldozer equipment: the width of the dust 2000 mm, the height is 680 mm, the cutting depth is 500 mm. EO ZZPB excavators (E-302) are equipped with Draghun equipment with the following parameters: The boom length is 7500 mm, the angle of the boom is 40 °, the depth of cutting 4450 mm, the radius of cutting 6500 and 10 100 mm, the height of the unloading, respectively, 3900 and 6300 mm, happy with Unloading, respectively, 6390 and 8300 mm.

General

Excavators General Information

PART ONE

Chapter I.
§ one

Classification and main parts of excavators

Excavators are called earthmoving machines designed for digging and moving the soil. All excavators, depending on the use of working time, for actually, the soil digging is divided into two large groups: continuous action - multi-loving and periodic (cyclic) action-single-one. Multual-list excavators both operations - soil digging and moving it - perform simultaneously; Single-line these operations are performed consistently, interrupting digging at the time of movement of the soil. Thus, the working time of the machine during which the soil is chosen, and the productivity of multi-loving excavators is higher than single-line. Despite this, single-loving excavators are widerly distributed due to their versatility, i.e. the ability to apply them both on earthlings and on loading and unloading works in the most severe, including rocks (with preliminary explosion), soils. The use of multi-loving excavators is limited: they are mainly used when digging tranches and mining of nonmetallic materials in careers with homogeneous soils without stone inclusions.

According to the method of moving, excavators are land and floating.

By the design of the undercoming device, land excavators are divided into tracked, wheeled and steps (the latter is used only in single-loving excavators). *

By type of main (primary) engine, modern excavators are diesel or electric. The selection of the engine is determined by the conditions in which the excavator will work. So, diesel engines are used in excavators where the car must be relatively often transported from place to place, for example, on the construction of oil and gas pipelines, iron and highways, civil engineering, etc.

At excavators that are constantly working in one place, for example, in careers for nonmetallic materials, it is advantageous to use electric motors that are easier and cheaper in operation.

Single-engine excavators are distinguished by the mechanisms, in which all working mechanisms are provided by one or more engines working for one shaft, and multi-modes, in which working mechanisms are driven by several engines, independently working apart.

In the USSR, all construction single-sized mechanical drive excavators are released single-engine. Multi-motor drive is used on construction hydraulic excavators.

By type of power gear movements from the engine to working mechanisms, building excavators are divided into mechanical and hydraulic.

Mechanical excavators move directly from the primary engine to all mechanisms using shafts, gears, worm pairs, chain and other mechanical gears (mechanical transmission).

In hydraulic excavators, the role of the transmission is performed hydraulic pump (one or several), pipelines and hydraulic motigables (hydromotors or hydraulic cylinders). In the pipelines circulates the working fluid transmitting energy from the pumps to the hydraulic motors, which lead workers in motion.

In addition to the listed signs of classification, the excavators of each group differ from each other by appointment, dimensions and power.

Single-line excavators for their intended purpose divide into three main groups: building universal, intended for earthy and loading and unloading work in construction; Career - for "work in careers on the development of ore and coal deposits, as well as rocks; Running - for the development of minerals (coal, ore) in an open way. The latest group also includes powerful drag-dragled excavators used on mining. Cake of the upper layers of rocks to the developed space, as well as on the construction of large hydraulic structures.

In addition to these basic groups, there are still special excavators intended for use under certain specific conditions: underground - for underground development of minerals at high power of the reservoir, tunnels - for loading the bleeded rock during tunnels, peat - for peat mining, etc.

This textbook describes the most common (weight up to 22 tons) universal building excavators are described in the present textbook.

Single excavator (Fig. 1) consists of the following main parts: the running device of the 1st of the rotary part and the work equipment.

The running device perceives and transmits to the base (soil) "load from the mass of the machine and the load arising during operation, and also provides the movement of the excavator.

The running device of excavators is the following types:

G - tracked with a minimally permissible supporting surface of the caterpillars;

Gu - caterpillar with an increased supporting surface of the caterpillars, designed to work on soils with low bearing capacity;

P-"Pneumocoles, which allows to increase the mobility of the excavator, facilitate and accelerate its transition to his own move from one construction site to another;

W is a special car type chassis, differing from the type that, except the engine installed on the rotary part of the excavator, the chassis has a more powerful engine that provides the movement of the excavator at high speed; The key type W is a solid and low special frame that is different from the design of the chassis frame of the cargo car;

A - chassis of a truck;

Tr - Tractor (usually use pneumocole tractors).

The swivel part consists of a turning platform 2 with mechanisms and power equipment and working equipment 3.

The swivel platform is based on a special roller reference-rotary device on the frame of the undercode and can be rotated relative to it in the horizontal plane. The same swivel platform can be installed on the driving devices of various types.

Depending on the angle of rotation of the rotary platform in the horizontal plane, the escavators are called full-turn or non-filler.

The rotary part of the full-time excavator can rotate around the vertical axis on an unlimited angle. In machines of this type (Fig. 2, a) on the rotary platform, an engine and main working mechanisms are installed, as well as / fastened working equipment.

Only small excavators on the basis of tractors (Fig. 2, 6) are manufactured.

These excavators do not have a swivel platform, and the working equipment is strengthened using a rotary speaker directly on the move device, with respect to which it rotates to a limited angle.

1 Single Single Excavator Scheme:
1 - running device,
2 - swivel platform,
3 - Working equipment

2 Full-turn excavator E-652B with a mechanical drive on a tracked run with a flexible suspension of work equipment (A) and an incomplete-speed excavator EO-2621A with a hydraulic drive based on a tractor with a rigid suspension equipment (6)

The working equipment is called the set of an excavator nodes containing the working body (for example, a bucket, a hook or grab, with the help of which the soil is digging, lifting the cargo, capture the flow and lump materials) and ensures its action in the zone of the excavator.

The main worker of the excavator - bucket - is intended for digging, holding when moving and unloading the soil or other material. The digging is called simultaneous cutting of the soil and filling it with the bucket. Cutting part of the soil is called chip (Fig. 3).

By type of constructive execution of working equipment, excavators are with a flexible suspension, rigid and telescopic arrow. Excavators with flexible suspension boom, and sometimes the working body (for example, bucket) is suspended on ropes that are powered.

In excavators with a rigid suspension boom and the remaining elements of the working equipment are joined with each other and are driven by hydraulic cylinders.

With a telescopic boom, there are excavators-schedulers who have extensions and arrows are working movements.

The universal building excavator usually has several types of working equipment with which it can work depending on the operating conditions. These types of work equipment can easily replace one other, so they are called replaceable.

Working equipment with rigid suspension (hinged-lever) and with a telescopic boom applied only on hydraulic excavators.

The working body to work equipment is also fastened with flexible or tough bond. In fig. 4 shows various fastenings of the working body in different types of working equipment with a flexible (cable) suspension.

The working process of a single-loving excavator consists of a working cycle, G. E. Development and movement of the soil, and movement of the excavator to the bottom, after the place of the excavator is uncomfortable or cannot be continued to continue the further development of the soil. During the movement of the excavator, the work is not produced, so the time spent on the movement should be reduced as much as possible.

The operating cycle of the excavator consists of the following operations:

1. Actually the soil digging (cutting the soil and filling it with a bucket).

2. Emissioning a bucket with a soil from a slaughter to ensure the possibility of unimpeded turning platform.

3. Move the bucket filled with soil to the discharge site, for which or turn the platform with the working equipment (in full-time), or only work equipment (in incomplete machines).

4. Unloading the soil from the bucket into the dump or to the vehicle.

5. Moving the bucket (platform rotation) to the bottom.

6. Lowering the bucket to prepare for the next digging operation.

Until the end of the 60s, in our country, they mainly produced full-time excavators with mechanical drive and flexible suspension of work equipment. In the ninth five-year plan (1970-1975), the production of hydraulic excavators with rigid suspension equipment was rapidly developed (Fig. 5-7). Such an extension of the production of hydraulic excavators is determined by a number of their constructive, technological and economic advantages compared to mechanical drive excavators.

According to the cost of energy, when performing work manually in the first place is the work of the KOST, on the second - excavation. The volumes of earthworks were huge at all times, and now in general are colossal. Construction, roads, career ... Yes, there is not that every adult, and adolescents should be forgotten to shovels. Therefore, earthmock works are practically mechanized everywhere. Execute these works Excavators ("excavo." lat. " dolbly"). The volume of the work of the excavator is incommensurable with manual labor, no matter how the iszovs are thrown on two soldiers from a construction site that replaced the excavator.

Eccavatators manifold

If you recall that the development of earthmoving machines for digging channels was still half a thousand years ago, the great Leonardo, it is clear: during this time, so many different modifications of excavators have been created that the classification will have an branched appearance. Excavators differ from each other by:

The type of chassis (tires, caterpillars, rails, etc.);

Type of operation (for buildings, mines, quarries, etc.);

Power actuator (electric, diesel);

According to the principle of operation (continuously or periodically working).

Naturally, the combinations of these characteristics are a great set, from here and a huge number of modifications.

What is the excavator wish?

On roads with any coating, and if there is no coating, then in the soils of any type freely passexcavators with a tracked running mechanism . If you exclude excavators working in urban infrastructure, then the overwhelming majority of the remaining will have a tracked move. Such excavators will easily pass along loose soil, according to the swampy peatlands when landlocked, according to the illuminated off-road logging, etc.

Excavators on pneumonocoles Well established itself in cities, where the caterpillars simply split asphalt. Pneumocoles and asphalt will leavealone, and well amortized, and when moving do not thunder.

Walking excavator No wheels nor caterpillars. It has a reference plate from below, on which it is located when working. For the movement of the excavator, support shoes on the hydraulic cylinders are used: rose to them, moved itself and dropped again on the support plate. The speed of such movement is up to 80 m / h.

Rail stroke excavators Most often used in mining careers. These are usually chain excavators, loading cars are more convenient to call below the excavator between widely located rails. This space is called the portal, therefore the excavator is considered portal.

Earthmaker with a bucket can be installed on all sorts of chassis, because sometimesexcavator has a car, accommodated, tractor move .

No longer causes surprisecombined chassis : Some pneumatic excavators are equipped with rail wheel pairs, descended in case of movement on rails.

There is even floating excavators , more often calleddredgers .

Principles of operation of excavators

Typically, single-loving excavators are excavators of cyclic effects: scored the bucket - transferred - poured. Next, the cycle is repeated.

Trench and rotary boom excavators are continuous mechanisms. Treshois We see more often, everyone remembers light excavators that serve for cable laying. The rotary excavator has a lot of machines fixed on a large rotating wheel.

Dredgers are gaining sand under water at the expense of vacuum-suction devices.

It is impossible to say that some one way or principle is the best or universal. Each concrete case requires specific technology. As you won't harvest the river sand by one-knitted excavator, you will not dig a pit for a small pond on the dacha rotary.

Dependence of the selection of the excavator from the operating conditions

Let's start from the construction site. Perhaps, it is impossible to diminish the value of wheel excavators for construction. Yes, if you have to produce volumetric soil development, then tracked excavators will lead. But in urban conditions they have more minuses than pluses:wheel excavators are more mobile - they have a greater speed of movement, and the possibility of very fast transit from one object to another appears. Moreover,in the city of caterpillar excavators - enemies of asphalt, for their movement need trawls, which increases the cost of any project.

Mine excavators are distinguished by small sizes, which is invaluable in closed spaces. Most often they are used in underground horizontal workings for loading rocks, for the same purposes - in tunnels.

Since the quarry is already a prepared area for generating minerals in an open way (which means that there are no spatial interference for excavators), it is desirable to increase the profitability of the career, whatever they can open, move and load rocks from the career. Therefore, various excavators are applied in quarries, the main thing is that their buckets be more suitable:

• - Dragles that have no rigid arrows with a bucket. The bucket is held by chain, another chain pulls up or releases the bucket;
• - career caterpillar possessing increased permeability;
• - hydraulic, which are better to apply in reveal works, because due to the fact that the liquid is not compressed, any loss force is transmitted on the breed, on the contrary to increase it;
• - rotary, not allowing even the slightest fossil supply failures.

What drives the excavator?

Movement and the ability to work any excavator provides the engine. It all started with the steam engine, then diesel, carburetor and electrical appeared. Much more often, diesel and electric motors are installed on excavators. The reason is simple: these species are most economical. Which one to choose? It depends on the specific situation. Distinctive feature of a diesel excavator - mobility. If you need to move a lot on the construction object or beyond its limits, you need a diesel excavator. When working with minor movements, it is cost-effective to apply electro-step-resistant, as using the cheapest energy to date. Careers work complies with these requirements. That is, you can trace another tendency: light and mobile excavators with a small bucket - diesel, heavy - electric scatters. Now there is a development of new models of electro-step-resistant - light excavators operating from battery batteries. And the driver of such an excavator is rather not a driver, but the operator: it can control the machine using a tablet, both on the seat of the excavator, and next to the excavator.

Application and value of excavators

First of all, the excavator - earthmoving machine. Therefore, mainly its workit is the removal and transfer of the soil. Moreover, they can produce not only on sites where they themselves, but also at the venues below or higher. For them, the notch of the ground from under the water layer is not a problem. Dipped soil they can load in the means of transportation (wagons, cars, barges, etc.). In the absence of transport, the excavator in any convenient remote location can be squeezed to the dump. Channels and catlovanov, the creation of embankments and recesses, the creation of dams and clearing the territories of excavators produce quickly and efficiently. Building platforms The excavator can be planned with great accuracy, especially with hydraulic drive machines. All the above works can be carried out not only with the soil, but also with any other bulk building materials.

Excavators allowed to fully mechanize earthworks, replacing people. What to talk about career excavators, with one bucket fill-in-deputies, if the ordinary building excavator for one movement transfers 1- 4 m 3 lands.

The best...

It is clear that the excavator with a large bucket is more productive than his smaller counterparts. Were among excavators andsuch who were collected in a single copy.

The dimensions and characteristics of the largest excavator in the world are impressive. Created and gathered his German company ThyssenKrupp Fordertechnik in 1978. It cost about 100 million euros, and they collected it for 5 years. It works so far in Germany in the coal section in Gambakh and gives a brown coal on-mountain.

It works this rotary bucket excavator for 20 hours per day. During this time he produces 240000 m 3. coal. Excavator dimensions: Width - 46 m, length - 240 meters, height - 96 meters . The weight of this monster is 13.5 thousand tons. Arrow having a length 200 meters , ends with a rotor with buckets, the volume of each of them - 6.6 m 3.

Of course, such volumes (240 thousand m 3 / day) download and take out difficult. Yes, it is not necessary, such excavators are needed to extend, and in the revealed mass of more than half of the unnecessary "empty" breed.

Improvement and development of excavators modifications continues continuously. Causes of more than enough: Improving the quality of work, increased demand associated with an increase in the volume of construction and mineral mining, new conditions and new work technologies.