Single bucket excavator

Contents

Contents

Introduction...............................................................................................................3 1 Review and analysis of a design..............................................................................4 2 Determination of key parameters............................................................... 12 2.1 Calculation of parameters of a ladle...........................................................................12 2.2 Choice of the basic car.............................................................................13 3 Calculation of effort kopaniya14 4 Calculation of parameters of working equipment.................................................14 5 Calculation of mechanisms of management. 16 5.1 Digging by a ladle......................16 5.2 Digging by the turn of a handle......................................................................18 5.3 Definition of efforts in a cylinder of an arrow.................................................19 5.4 Balance of power........................................................................................20 6 Calculation on durability..............................................................................................21 the Conclusion........................................................................................................23 the List of the used sources..............................................................24

Introduction

Earthworks

Earthworks are an integral part of the construction of most engineering structures.

They include: a passage of pits, trenches and reclamation canals; erection of embankments, dams; arrangement of closed penetrations in soil in the form of mines and tunnels for various underground structures; drilling of horizontal, inclined and vertical wells during trenchless laying of pipelines under embankments of railways and highways, for installation of pile supports in dense soils, for laying charges of explosives during development of soils by explosion, etc.

In this course work, we define the main parameters of the working equipment of a single bucket excavator. Define parameters of bucket, handle and boom. And the digging forces of this excavator will also be calculated.

Design Overview and Analysis

Single-bucket excavators are designed to excavate connected and loose soils from the massif, as well as rock soils from the face, loosened by explosion with loading from vehicles or unloading to the dump. Single bucket excavators are used to develop soils up to and including category 6. The use of various types of replaceable working equipment significantly expands the field of application of excavators and makes them universal machines capable of performing a wide variety of types of earthworks, loading and other works.

The main working member of the excavator is a ladle. Buckets of rectangular shape with teeth and buckets with a bottom of semicircular section with a continuous cutting edge protruding forward are most common.

Working cycle of single-bucket excavator includes the following operations: digging, turning of working equipment with rotary platform for unloading, unloading, turning into bottomhole.

Single bucket excavators can be classified according to the following main design features: type of working equipment of the drive system, type of running equipment.

Different types of working equipment are designed to perform the following processes.

For digging soil above the level of excavator standing, direct shovel type equipment is used (Fig. 1). This equipment is used to dig pits and excavate large sections, remove a layer of soil of significant thickness to a given level, erect embankments, develop quarries, load bulk loads and other works.

For digging below the standing level, reverse shovel type equipment is used (Fig. 2) and dragline (Fig. 3). The main area of ​ ​ their application is the digging of trenches and pits.

For the planning and cleaning of sites and slopes, plow-type equipment and special planning equipment of various types are used.

Crane equipment is used for handling and installation operations.

There are also structures of equipment for stumping stumps, piling and filling trenches.

Of all types of working equipment of single-bucket excavators, a direct shovel is the most widely used due to versatility and high productivity. This equipment is the main equipment for all single-bucket excavators, with the exception of low-power hydraulic excavators, which are used mostly with reverse shovel equipment, as well as walking draglines.

By the type of running equipment, pneumatic wheeled, caterpillar and walking single-bucket excavators are distinguished.

Excavators with pneumatic wheeled running equipment (Fig. 4) have special chassis or, in some cases (when the excavator is made on the basis of a car), a car chassis. Characterized by high maneuverability and speed when operating in good road conditions, these excavators are little adapted to move along a loose, humid or uneven surface due to the high specific pressure of pneumatic wheels on the ground (23.5 kG/cm2). It is used mainly on excavators of small sizes, with a bucket with a capacity of up to 0.8 m3.

Excavators with tracked running equipment (Fig. 6) are divided into two- and multifaceted. The multi-tracked travel of single bucket excavators is usually in the form of four two-tracked trolleys. Due to the good adaptability to heavy ground conditions, high maneuverability and relatively small specific pressure on the ground (0.40.2 kG/cm2), the caterpillar track was most widely used on single-bucket excavators.

Excavators with walking running equipment (Fig. 5) have stepping mechanisms made in the form of eccentric crank-valve mechanical systems of various types or in the form of hydraulic system of lever-swinging stroke. Due to the high maneuverability, low specific pressure (0.31.0 kG/cm2) and simpler design, compared to the multifaceted one, the walking stroke became the main type of running equipment of powerful dragline excavators, operating mainly on soil bases. For straight shovels operating in various ground conditions, including on an uneven and rock sole, a walking stroke does not find use.

Depending on the drive system, excavators with a mechanical, hydraulic, electric and combined drive, single-engine and multi-engine are distinguished.

Mechanically driven excavators have internal combustion engines, usually diesel engines, as power equipment. A hydraulic clutch or torque converter is often built in between the engine and the primary shaft of the transmission. The advantage of mechanically driven excavators is that they can be used in a wide range of climatic and soil conditions and are relatively easy to operate.

Excavators with hydraulic drive as power plant have, as a rule, ICE connected to one or several hydraulic pumps feeding hydraulic motors. As hydraulic motors of working equipment, power hydraulic cylinders of rotary and power mechanisms are often used. The main advantages of hydraulic excavators are compact design and low weight, control accuracy, limiting maximum loads, and the ability to automatically control operating modes using relatively simple hydraulic devices.

Excavators with electric drive have one or several electric motors as power equipment. The main advantages are the simplicity of the design, the cheapness of the energy consumed, the ability to combine various operations of the technological cycle. The use of such excavators is feasible only if they are long-term in one place.

According to the design of support-turning devices, single-bucket excavators are divided into full-turn excavators (Fig. 6) and incomplete (Fig. 7). Of the excavators currently produced, only excavators made on the basis of tractors and cars are incomplete/

By purpose, single-bucket excavators are divided into construction and construction barrier, quarry, overburden, walking draglines, special-purpose excavators.

Construction and quarry excavators have ladle capacity from 0.06 to 6 m3 and weight from 1.5 to 250 tons. The main purpose of excavators of this group is earthen civil works in soils of category 3-5.

Excavators with a standard bucket capacity of up to 1.75m3 and weighing up to 70 tons belong to a construction excavator of low capacity, larger models belong to excavators of medium and large capacity.

Construction excavators of low power have many different designs. Excavators with a bucket of up to 0.5 m3 are mostly made with a hydraulic drive, have a pneumatic wheel stroke and are equipped with a large number of replaceable working equipment, reaching 30 or more names. Excavators with a bucket of up to 0.25 m3 are often made on the basis of wheeled tractors and, according to the type of rotary device, belong to incomplete rotating excavators .

Excavators with bucket capacity from 0.65 to 2 m3 are made mainly with single-engine mechanical or multi-engine diesel-electric drive and caterpillar running equipment and have 4-5 or more types of replaceable working equipment.

Construction-quarry excavators with a bucket with a capacity of 2-6 m3 are usually made with an electric multi-engine drive and tracked running equipment.

Quarry excavators have ladles with a capacity of 2 to 20 m3 and a weight of 76 to 1000 tons. The main purpose of quarry excavators is the development of heavy soils of category 4-6 in quarries and at hydraulic construction, with loading into vehicles. Running equipment - caterpillar, mainly low-support.

Open excavators (Fig. 8) have ladle capacity of 6160 m3, weight of 55013000 tons. They are equipped with a straight shovel with an elongated boom and are used in open mining to excavate overburden rocks with their unloading into a dump. Overburden excavators in some cases can be supplied with additional working equipment of dragline.

Walking draglines (Fig. 5) have buckets with a capacity of 4 to 100 m3, arrows with a length of 40 to 100 meters and a weight of 170 to 8500 tons. They are special excavators designed for the development of light and medium soils with the movement of soil over significant (up to 100 meters or more) distances without the use of vehicles, with unloading to dumps. Walking draglines are used mainly in large hydraulic construction and in overburden work.

Technical specifications:

Working weight: 23100 kg;

Engine power: 105 kW;

Ladle volume: 1.20 m3;

Bucket width: 1250 mm;

Ladle weight: 1050 kg;

Soil pressure: 0.40 kg/cm2;

Handle length: 2.20 m;

Digging depth max.: 5.75m;

Unloading height max.: 6.00 m;

Digging height max: 8.75 m;

Conclusion

During the course work in the discipline "Machines for earthworks," calculations were made of the main working equipment of a single-bucket excavator of the 4th dimension group .

In the first section, the main designs of single bucket excitors were considered. The second section defines the basic parameters of the base machine. In the third section, the digging forces were determined, the thickness of the sheared mud by the excavator bucket was calculated. The fourth section defines the forces on the rod of the bucket hydraulic cylinder, handles and booms, and also calculates the diameters of the hydraulic cylinders. During the course work, the power balance at the company was calculated. And they also calculated the handle for strength.

List of sources used

1 Artemyev K. A., Alekseeva T.V. Road cars. Part 1. Earthworks. Ed. 3e, "Mechanical Engineering," 1972.504s.

2 Rodin I. I., Ponomarev V. P Design of single-bucket excavators. Tutorial, Mechanical Engineering, 1973.207s.