The excavator is a classic representative of specialized earthmoving equipment, actively used in various construction and manufacturing industries. It has a fairly simple design, which includes undercarriage, a cab with controls and a block with a bucket. The main feature of excavators is a rotary working body. For more efficient tasks, it is able to move the bucket in any direction, while the chassis remains stationary. The separate movement of the working body and the undercarriage endows excavators with excellent functionality, productivity and versatility.

Areas of use

Excavators are in great demand because they are able to easily cope with tasks of various types and complexity. This special equipment has become truly indispensable in the field of civil and road construction, mining, quarries and other industries. Equipped with a bucket, these machines are used to excavate soil, sand, iron ore, granite and other rocks. Also, excavators are often used for digging trenches and pits. The machines do an excellent job of loading bulk or other materials into cargo vehicles (wagons, barges, dump trucks, etc.). Excavators are also suitable for creating embankments and dumps, arranging dams, clearing territories and other purposes.

Principle of operation

Excavators are characterized by ease of operation. The operator, using the control panel in the cab, moves the bucket, collects soil or other material, transfers it to a certain distance and pours it out. At the same time, the excavator can excavate the earth or hard rocks not only at the level of the site, but also above or below its surface. Almost any model, if necessary, can be equipped with various interchangeable equipment. For example, today special types of buckets, booms, handles, rippers, hooks, pile masts and other working tools are produced for excavators.

Types of excavators

By appointment. Different models of excavators are adapted to specific operating conditions. Depending on this parameter, the following types of equipment are distinguished:

  • universal. Such excavators are commonly used on construction sites. They have medium dimensions, increased maneuverability, good performance;
  • mine. These excavators are small in size, which ensures their free movement in mines, tunnels and other enclosed spaces;
  • career. They can be of any size. Such an excavator is usually equipped with a large bucket, which ensures a high speed of development and loading of mined rocks. .

By type of chassis. This feature determines the ability of equipment to move around a particular area. Depending on the type of chassis, the excavator can be:


According to the principle of work. This feature affects the ability of the excavator to perform certain tasks, as well as its productivity. According to this criterion, the technique is distinguished:

  • cyclic action. This type of excavator has one bucket, which is used according to the "collected - transferred - poured" scheme. Then the cycle repeats;
  • continuous action. Such excavators have a rotary working body - a rotating wheel with several buckets. The production is carried out due to its continuous rotation .

Specifications

Modern excavators are represented by models with different properties and capabilities. The main differences relate not only to the purpose, the appearance of the car and the comfort of the cabin, but also to the main parameters. When choosing an excavator, experts recommend considering such technical characteristics as:

  • type of undercarriage (wheeled, caterpillar);
  • principle of operation (periodic, continuous);
  • engine (diesel, electric);
  • bucket capacity (cubic meters);
  • maximum travel speed (km/h);
  • power plant power (kW);
  • operating weight (kg).

Cat® Excavators

Caterpillar, one of the world leaders in the creation of advanced special equipment, produces a wide range of excavators. The Cat® brand, owned by this American corporation, brings to the market specialized machines with a wide range of operating parameters. You can choose crawler or wheeled excavator. Models differ in control, power, performance, speed of movement and other features. Everyone who is interested in selling or renting equipment will be able to easily pick up a car for any task and budget. You can get acquainted with the models and technical characteristics of excavators.

313D2L

The crawler excavators of this model have a useful power of 68 kW and a weight of 13.7 tons. They are distinguished by improved control, high versatility, a comfortable upgraded cab and are easy to operate. This set of features has allowed the 313D2L excavators to become leaders in their class.

The machines are equipped with efficient powerful Cat C4.4 engines, which, due to the mechanical governor, reduce fuel costs by 14% compared to similar models. At the same time, the digging and lifting efforts remain at the same high level. The engine runs stably even when refueling with poor quality fuel, due to low pressure in the fuel supply system. A wide range of attachments is available to users, which allows you to adapt the excavator to perform various tasks.

318D2L

The caterpillar excavator of this model differs in the power increased up to 84 kW. The operating weight has also increased (17.8 tons). The model also differs from its predecessors in improved handling and a high level of comfort, which makes it a versatile and functional tool for performing diverse production, road and construction tasks.

The 318D2L excavators are equipped with powerful Cat C4.4 ACERT electronically controlled drives and meet the advanced environmental standards of the USA, Japan, China and the EU. Together with an efficient hydraulic system, these engines provide excellent performance with economical fuel consumption. The high-strength load-bearing structures of the excavator can withstand significant operating loads, which allows the machine to be used in the most difficult conditions. The cab offers excellent visibility, which contributes to a safe working environment on site.

M317D2

This is a wheeled excavator with a fairly high useful power - 102 kW. It also has a good travel speed of up to 37 km/h. Caterpillar has incorporated a number of advanced developments to enhance the functionality and performance of this excavator series. The increased lifting capacity of the equipment helps to reduce operating costs and increase productivity.

Also in the M317D2 machines, management is simplified and cycle times are reduced, which allows you to speed up the work. All daily service points are easily accessible from ground level, making it easy to carry out preventive and corrective actions. All critical components are lubricated by a centralized system. The cab is equipped with a rear view camera and a color display, which ensures the safety of excavator operation and convenient operation.

M320D2

This is a 124 kW wheeled excavator that combines speed, versatility and performance. It is able to function on any surface, including various types of soils and road surfaces. A wide range of attachments is available to users to solve various construction and production tasks. The M320D2 is comfortable and easy to operate with the ProductLinkTM system.

By reducing the duration of work cycles, increasing the effort on the arm and bucket, the performance of the excavator was increased. All service points are accessible from the surface of the earth, which simplifies and speeds up the necessary repair or preventive manipulations. All important components are processed with high quality by a centralized lubricant supply system. The cab is designed for maximum safety and comfort.

The main types of working equipment, parameters and indexing of construction excavators. Productivity and ways to improve it. Machinery and equipment for frozen soils. The use of machines with traditional bodies for the development of frozen soils. Types of special machines.

General classification of single-bucket excavators (appointment, device, work processes, technological capabilities, performance, scope). Shovel, backhoe, dragline, grapple

Single-bucket excavators are called positional earth-moving machines of cyclic action, equipped with a bucket working body. O.E. work cycle consists of successively performed operations of digging the soil, moving it in the bucket to the place of dumping, unloading the bucket with soil dumping into a dump or vehicle, and returning the bucket to the position of the beginning of the next working cycle. This is called excavation. After working out the face element, the excavator is moved to a new position. O.E. classify:

1-by purpose: construction, construction-quarry, quarry, overburden, tunnel, mine;

2-by type of working equipment: front and back shovel, dragline, grab, planner;

3-according to the execution of the working equipment: cable, hydraulic

4-by type of undercarriage: pneumatic (automobile and tractor bases), caterpillar, walking;

5-if possible rotation of the rotary part: full-turn and part-turn;

6 - by the number of installed engines: single and multi-engine.

O.E. They can have crane, pile-driving, tamping and other interchangeable equipment. With one type of working equipment - special, and equipped with interchangeable types of working equipment - universal.

Construction freight forwarders are designed to develop soil up to category IV without preliminary loosening, frozen and rocky soil after loosening. Hydraulic excavators are used in 80% of the total production.

The main parameter of the ME is its mass. Depending on the mass, they are divided into size groups.

Size groups are characterized by a set of basic parameters:

1) - power plant power;

2) - bucket capacity;

3) - force on its teeth;

4) - dimensions of the working area;

5) - the duration of the working cycle;

6) - speed of movement;

7) - frequency of rotation of the turntable;

8) - overcome slopes;

9) - specific pressure on the ground;

11) - overall dimensions and others.

size group mass of univ-x O.E., t
O. E. over before
- 6,3 6,3

Indexes. O. E. - EO-0000:

1 digit - size group;

2nd digit - type of undercarriage (1. tracked, 2. tracked with an increased bearing surface, 3. pneumatic wheel, 4. special chassis of an automobile type, 5. truck chassis, 6. based on a tractor);

3digit type of suspension of working equipment (1 and 2 - with flexible and rigid suspension, 3 - telescopic working equipment);

4th digit is the model number of the excavator.

For example EO-4123:

Single-bucket excavator, construction, universal, 4 size groups with a caterpillar undercarriage, with an increased support surface, a rigid suspension of the working equipment, the third model. Letters below - the next modernization and climatic modification.

O.E. technical performance:

,

where q - bucket capacity;

Filling factor;

Soil loosening coefficient;

The duration of the working cycle;

The duration of one move to a new position;

The number of working cycles in one position.

Operating performance:

,

where is the duration of the excavator operation period;

Coefficient of use in time (for single-shift operation Kv = 0.2-0.25).

The main working bodies of hydraulic excavators are the bucket of back and front shovels, loaders and grabs.

Replaceable working bodies: bulldozer blades, single-tooth and multi-tooth rippers, hydraulic hammers, crane suspensions, various modifications of grabs and grippers, auger drills.

The excavator consists of a base part and working equipment.

Base part: consists of a bogie with a lower frame, a turntable, a turntable with a pumping and power plant, hydraulic drive system units and a driver's cab.

Working equipment - a backhoe includes an arrow, a handle and a bucket connected in series with hinges. It is intended for excavation of soils, mainly below the level of the excavator parking lot.

The working area of ​​a full-revolving excavator is a part of the space bounded by a toroidal surface, the radial section of which is called the axial longitudinal profile of the working area.

It determines the working dimensions:

Hmax - maximum digging depth;

Rkcmax - digging radius at the level of the excavator parking lot;

Hvmax - unloading height.

The working equipment - a straight shovel - for excavating the soil above the level of the excavator parking lot consists of an arrow, a handle and a bucket. The boom is shorter than the backhoe. The boom drive is provided by two hydraulic cylinders, and the handle by one. Regarding the handle, buckets can be swivel and non-swivel. Such an excavator develops the soil by moving the bucket from the bottom (from the level of the excavator parking) up (to the upper edge of the face).

Working equipment - grab - used for extracting working pits, cleaning reservoirs and canals, for unloading and loading bulk materials. It consists of a double-jaw bucket mounted on the lower end of a rod suspended from the backhoe handle on two cylindrical hinges, allowing the bucket to take a vertical position. The jaws are opened by hydraulic cylinders.

To start work, the bucket with open jaws is lowered onto the material to be captured, then they are closed. The bucket is introduced into the material and filled with it. Then it is lifted by the handle from the recess With the turn of the platform for unloading. The bucket is unloaded by opening the jaws. For loosening solid and frozen soils, excavators are equipped with equipment: a single-tooth ripper, a hydraulic hammer (destruction of rocks, cracking asphalt during road repairs).

Dragline is the working equipment of O.E. with a bucket suspended from the boom on a lifting rope and moved by a traction rope when digging the soil.

Construction draglines with buckets 0.3 to 3 cubic meters for unloading soil below the parking level when extracting pits and trenches, during underwater excavation, loading and unloading loose and crushed materials. They work mainly with unloading into the dump.

Replaceable working bodies (hydraulic hammers, hydraulic rammers, rippers, forks, grabs, tongs, leveling dumps, etc.) Excavators - planners, semi-rotary excavators, mini excavators (qk = 0.03-0.2 cubic meters) in cramped and hard-to-reach places, inside buildings, during repair work, micro-excavators (b=1m, qk=0.02cub.m)

Classification of continuous excavators (E.N.D.). Purpose, scope, device, workflow, technological capabilities and performance of trench and chain excavators

E. N. D. are earth-moving machines that continuously develop the soil while simultaneously loading it into a transport or into a dump. The working body is equipped with several buckets, scrapers, cutters, alternately separating the soil from the array. They are mounted on a single working body - a rotor or a closed circuit.

They are classified according to:

purpose or type of work performed:

a) trench;

b) career;

c) construction and quarry;

by type of working body:

a) rotary;

b) chain (scraper, milling);

digging method:

a) longitudinal;

b) transverse.

Rotors are used to develop trenches of limited depth (up to 3 m). Chain depths up to 6m or more. They are used for the development of homogeneous soils up to category IV. Large rocky inclusions reduce the resource of these machines. For frozen soils, the main parameter of trench excavators is the depth of the trench to be torn off, the mass and engine power.

ETR-254 is a trench rotary excavator of the fourth model for the development of trenches with a depth of 2.5 m.

ETTs-165 is a fifth model chain trench excavator for trenching up to 1.6 m deep.



The trench excavator consists of two parts - a tractor and working equipment, interconnected by semi-trailer or mounted circuits.

The working equipment of a trench excavator provides separation from the soil mass in a trench of the design depth and width with or without slopes, its complete removal from the trench and backfilling into the parapet (cavalier) next to the trench. The last operation is performed by a belt dump conveyor installed perpendicular to the longitudinal axis of the trench in the cavity of the rotor (on bucket-wheel excavators) or on a tractor (on chain excavators). For the development of narrow trenches (slits), conveyorless scraper milling trench excavators are used.

Most often, a single-bucket excavator is used to perform earthworks in construction and mining development. This is a batch machine. Its main parameter is the capacity of the bucket (in cubic meters). And all because the bucket is the main working body of the earth-moving machine. But do not forget that there is also a bucket-wheel excavator, which is also applicable in specific situations, both in large canal constructions and in quarrying. Thanks to the excavator, it was possible to significantly, dozens of times, increase the speed of open-pit mining and construction work.

According to GOST 17343-83, the indexing of single-bucket excavators of new models includes 4 digits, which indicate:

  • size group of the machine (total 8 positions);
  • type of running system (caterpillars or wheeled chassis);
  • suspension type;
  • serial number of the model.

Models manufactured before the 1970s are indicated by an index that specifies: the nominal capacity of the bucket, the serial number of the model and its upgrades. And the letters EO mean "single-bucket excavator."

Main indicators for machines with one bucket

Important technical specifications of the earthmoving machine:

  • maximum height and depth of digging;
  • the largest radius of work;
  • the highest possible loading height.

Most often, construction work presents machines equipped with a bucket with a volume of 0.15-4.0 cubic meters. On the territory of LNG, soil excavation is most often carried out by single-bucket excavators of groups 4 and 5 (they have a bucket capacity of 0.65 and 1 m³). Enterprises produce separate versions of excavators with full automation of some production processes.


On any device, you can install such types of working equipment as:

  • backhoe;
  • straight shovel;
  • grab;
  • dragline.

This equipment allows the single-bucket machine to:

  • develop;
  • move;
  • load and lay soil.


Single-bucket excavators are made universal, equipped with various types of interchangeable equipment, which makes it possible to automate many processes, for example, cleaning the bottom of excavations or crushing large boulders. In some cases, special nozzles allow you to compact the soil on slopes or loosen frozen soil.

Using an additional body kit for earthmoving machines

Additional working equipment of a single-bucket excavator allows you to very accurately remove soil for high-precision planning work, develop trenches for utilities, supply materials, cargo (acting as a loader or crane).

To obtain recesses of various configurations and sizes, profile buckets are used.

To accomplish the tasks of the “wall in the ground” technology, special rod equipment is used together with an earthmoving machine.

To loosen frozen or very dense soil, single-bucket excavators are equipped with a hydraulic hammer or ripper tooth. To load and remove large stones from the construction site on excavators, additional special equipment can be used, for example, a mounted type of gripping tongs.


The development of soil with the help of an excavator is carried out only strictly positionally. The site where earth-moving equipment works, an array of soil is being developed and dump trucks are parked is called a face. The face has a strictly designated, separate place for the dump of the developed soil. After completing the task, the excavator is moved to a new location.

GENERAL INFORMATION


GENERAL INFORMATION ABOUT EXCAVATORS


PART ONE

Chapter I
§ 1

Classification and main parts of excavators

Excavators are earth-moving machines designed to dig and move soil. All excavators, depending on the use of working time for actually digging the soil, are divided into two large groups: continuous action - multi-bucket and periodic (cyclic) action - single bucket. Bucket excavators perform both operations - digging the soil and moving it - simultaneously; single-bucket these operations are performed sequentially, interrupting digging for the duration of the movement of the soil. Thus, the working time of the machine, during which the soil is selected, and the productivity of multi-bucket excavators are higher than those of single-bucket excavators. Despite this, single-bucket excavators are more widespread due to their versatility, i.e., the ability to use them both in earthworks and in loading and unloading operations in the most difficult, including rocky (with preliminary blasting), soils. The use of bucket-wheel excavators is limited: they are mainly used for digging trenches and mining non-metallic materials in quarries with homogeneous soils without stone inclusions.

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

According to the design of the undercarriage, land excavators are divided into caterpillar, wheeled and walking (the latter is used only in single-bucket excavators). *

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

On excavators that constantly work in one place, for example, in quarries for the extraction of non-metallic materials, it is advantageous to use electric motors, which are simpler and cheaper to operate.

According to the mechanism drive, single-engine excavators are distinguished, in which all working mechanisms are driven by one or more engines running on one shaft, and multi-engine, in which working mechanisms are driven by several engines that operate independently of each other.

In the USSR, all construction single-bucket excavators with a mechanical drive are produced as single-engine. Multi-motor drive is used on construction hydraulic excavators.

According to the type of power transmission of movement from the engine to the working mechanisms, construction excavators are divided into mechanical and hydraulic.

In mechanical excavators, the movement is transmitted directly from the prime mover to all mechanisms using shafts, gears, worm gears, chain and other mechanical transmissions (mechanical transmission).

In hydraulic excavators, the role of transmission is performed by a hydraulic pump (one or more), pipelines and hydraulic motors (hydraulic motors or hydraulic cylinders). The pipelines circulate a working fluid that transfers energy from pumps to hydraulic motors that set the working mechanisms in motion.

In addition to the listed signs of classification, the excavators of each of the groups differ from each other in purpose, size and power.

Single-bucket excavators are divided into three main groups according to their purpose: universal construction excavators designed for excavation and loading and unloading works in construction; quarry - for "work in quarries in the development of ore and coal deposits, as well as rocks; overburden - for the development of minerals (coal, ore) in an open way. The last group also includes powerful walking dragline excavators used in mining for transfer of the upper layers of rocks into the mined-out space, as well as in the construction of large hydraulic structures.

In addition to these main groups, they also produce special excavators designed for use in certain specific conditions: underground - for underground mining with a large reservoir thickness, tunnel - for loading blasted rock during tunneling, peat - for peat extraction, etc.

This textbook describes the most common (weighing up to 22 tons) single-bucket universal construction excavators manufactured by the domestic industry.

A single-bucket excavator (Fig. 1) consists of the following main parts: undercarriage 1U of the rotary part and working equipment.

The undercarriage perceives and transfers to the base (ground) "loads from the mass of the machine and the loads that occur during operation, and also ensures the movement of the excavator.

The undercarriage of excavators is of the following types:

G - caterpillar with the minimum allowable bearing surface of the tracks;

GU - caterpillar with an increased bearing surface of the tracks, designed to work on soils with low bearing capacity;

P-"pneumatic wheel, which allows to increase the mobility of the excavator, facilitate and accelerate its transfer under its own power from one construction site to another;

Sh - a special automobile-type chassis, which differs from type P in that, in addition to the engine mounted on the rotary part of the excavator, a more powerful engine is installed on the chassis, which ensures the movement of the excavator at high speed; undercarriage type Ш has a strong and low special frame, which differs in design from the chassis frame of a truck;

A - truck chassis;

Tr - tractor (pneumowheel tractors are usually used).

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

The turntable rests through a special roller slewing device on the frame of the undercarriage and can be rotated relative to it in a horizontal plane. The same turntable can be installed on different types of undercarriages.

Depending on the angle of rotation of the turntable in the horizontal plane, excavators are called full-turn or part-turn.

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

Only small excavators based on tractors are made semi-rotary (Fig. 2, 6).

These excavators do not have a turntable, and the working equipment is fixed with the help of a turntable directly on the undercarriage, relative to which it rotates at a limited angle.

1 Scheme of a single-bucket excavator:
1 - running gear,
2 - turntable,
3 - working equipment


2 Full-revolving excavator E-652B with mechanical drive on caterpillars with flexible suspension of working equipment (a) and part-revolving excavator EO-2621A with hydraulic drive based on a tractor with rigid suspension of working equipment (6)

Working equipment is a complex of excavator units that contains a working body (for example, a bucket, hook or grab, with which they dig the soil, lift the load, grab loose and lumpy materials) and ensure its operation in the excavator work area.

The main working body of the excavator - the bucket - is designed for digging, holding while moving and unloading soil or other material. Digging is the simultaneous cutting of soil and filling the bucket with it. The cut off part of the soil is called shavings (Fig. 3).

According to the design of the working equipment, excavators come with flexible suspension, rigid and telescopic boom. For excavators with flexible suspension, the boom, and sometimes the working body (for example, a bucket) are suspended on ropes that are driven.

For excavators with a rigid suspension, the boom and other elements of the working equipment are pivotally connected to each other and are driven by hydraulic cylinders.

Planner excavators are produced with a telescopic boom, in which the extension and retraction of the boom are working movements.

A universal construction excavator usually has several types of working equipment with which it can work, depending on the operating conditions. These types of working equipment can be easily replaced with one another, which is why they are called interchangeable.

Working equipment with a rigid suspension (articulated-lever) and with a telescopic boom is used only on hydraulic excavators.

The working body is also attached to the working equipment with a flexible or rigid connection. On fig. 4 shows various fastenings of the working body for different types of working equipment with flexible (rope) suspension.

The workflow of a single-bucket excavator consists of a work cycle, i.e., excavation and movement of the soil, and movement of the excavator to the face, after it becomes inconvenient or impossible to continue further development of the soil from the excavator's parking lot. During the movement of the excavator, work is not performed, so the time spent on the movement should be minimized as much as possible.

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

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

2. Removing the bucket with soil from the face to allow the platform to turn freely.

3. Moving a bucket filled with soil to the place of unloading, for which either the platform with the working equipment is turned (for full-turning machines), or only the working equipment (for part-turning machines).

4. Unloading the soil from the bucket into the dump or into 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, our country mainly produced full-circle excavators with a mechanical drive and flexible suspension of working equipment. In the ninth five-year plan (1970-1975), the production of hydraulic excavators with a rigid suspension of working equipment developed rapidly (Fig. 5-7). Such an expansion in the production of hydraulic excavators is determined by a number of their design, technological and economic advantages compared to mechanically driven excavators.