Russia is downright made for articulated dump trucks. There is no better vehicle for off-road spaces. And size restrictions in the taiga and tundra will not bother. Articulated dump trucks are slowly (after all, expensive equipment!), But they are moving into hard-to-reach areas. What hinders this process besides the price, which, by the way, has more weight for the central regions. Climatic conditions require the adaptation of technology, which implies not just a mechanical replacement of lubricants and rubber products, but also the use of other grades of steel and even serious processing of structures. This is not an easy task, and not every supplier can afford large investments in the development of northern specifications.
The circle of manufacturers of articulated dump trucks (ADT - Articulated Dump Truck) is narrow. The main suppliers to the world market are Caterpillar, Volvo CE, Komatsu, Bell, Moxy, Astra, Terex. Bell produces dump trucks for Hitachi and John Deere, Astra dump trucks are also sold under the Case brand.
These companies produce three-axle dump trucks in the range of carrying capacity from 18 to 46 tons. Machines with a carrying capacity (g / p) of 22 ... 25 tons are in greatest demand. we still cannot call this technique in demand.
On the territory of the former USSR, articulated dump trucks are produced by the Belarusian production association BELAZ, which includes the Mogilev Automobile Plant. The model BelAZ-7528/75281 with a capacity of 36 tons is made in accordance with the classical canons. This full-size 6x6 articulated machine is designed for transporting bulk cargo on the surface in off-road conditions and is equipped with a 410 kW MTU S-60 engine coupled with a hydromechanical gearbox.
Underground dump trucks MoAZ and BelAZ are also used on the surface, but in terms of cross-country ability they are inferior to "genuine" articulated dump trucks. Their constant use on the surface is irrational. This group of underground dump trucks includes two-axle machines with a capacity of 22 tons MoAZ-7529 and MoAZ-740-9586, a three-axle MoAZ-7508 with a capacity of 35 tons and a two-axle BelAZ-75800 with a capacity of 40 tons.
The brainchild of the Minsk "Amkodor" - dump truck 20231 is still at the testing stage. The sample presented at the CTT 2008 exhibition pleases the eye with an interesting, modern design. The dump truck with a capacity of 24 tons is equipped with a 194 kW Cummins turbodiesel, a hydromechanical gearbox and ZF axles. NEF axles are considered as an alternative. The dump truck speed is up to 45 km /h, frame rotation angle - 42 °.The interior of the cabin is designed in a modern style, an on-board computer is included in the equipment.In general, the model promises to compete with Western models.
The Chelyabinsk Road Construction Machines plant tried to take on articulated dump trucks. The case was limited to prototypes, and in 2005 ChSDM abandoned this project.
Among Western companies in Russian deliveries, Volvo CE, the progenitor of articulated dump trucks, is in the lead. Its model range includes five models in the range of carrying capacity of 24...39 tons - A25E (6x6), A25E (4x4), A30E, A35E and A40E and modifications A35E FS and A40E FS. The dump trucks are equipped with 6-cylinder in-line Volvo engines with electronic injection control, turbocharger and intercooler. Models A25E and A30E are equipped with a D9 engine with a volume of 9.4 liters and a power of 223 and 251 kW, dump trucks A35E and A40E - with 12- and 16-liter D12D and D16D engines with a power of 309 and 346 kW. The engine is aggregated with a Volvo PowerTronic planetary automatic gearbox, for the "younger" models with six ranges forward and two back, for the "senior" ones - with nine ranges forward and three back. The torque from the automatic transmission is transmitted by cardan gears to the transfer case, and from it to the axles. The middle bridge is through, the front axle is switched off. The design of the transfer case provides high ground clearance. Volvo develops special axles for dump trucks with fully balanced axle shafts, planetary final drives and dog clutches for full differential lock.
For bodies, Volvo offers several options for additional equipment - tailgates of various designs, an superstructure for transporting light materials, an exhaust gas heating system, and a front spill guard. The articulated chassis also serves as a base for tanks, pipe and timber carriers, "multi-lifts" and other superstructures.
The A25E (4x4) dump truck with a capacity of 24 tons is characterized by maneuverability due to a short wheelbase and is convenient for the construction of tunnels, mountain serpentines, etc. With the help of a unique swivel device (installed on request), including two small-sized lifting wheels in front of the rear axle , the dump truck will turn around in a tunnel 9.5 m wide. The turn, or rather the skidding of the rear frame, is carried out by the force of the steering drive. The maneuver is performed on an empty dump truck.
The A35E FS and A40E FS modifications presented at BAUMA 2007 feature FS (Full Suspension) suspension with hydraulic cylinders on each wheel. The suspension is characterized by a soft ride of both a loaded and an empty dump truck.
Volvo dump trucks are more common in temperate countries. Northern specifications are still under development.
Caterpillar equipment is chosen for harsh climatic conditions. The corporation offers four basic models in the range of carrying capacity from 23.6 to 38 tons with a 6x6 wheel arrangement - 725, 730, 735 and 740 and two modifications with forced unloading 730 Ejector and 740 Ejector. Caterpillar installs 6-cylinder inline engines with ACERT Technology - C11 11.2L, 225kW and 237kW on the 725 and 730, and C15 15.2L, 287kW and 325kW on the 735 and 740. dump trucks are specially designed automatic 6- and 7-band gearboxes and axles. Locks of interwheel and interaxal differentials are provided.
Dump trucks with forced unloading are distinguished by a body fixed to the frame. The body is unloaded by the ejector plate using a hydraulic cylinder. The plate moves on rollers along the guides on the bottom of the body and the edges of the side. This system allows you to evenly unload the truck on the move, as well as on slopes, in tunnels and under power lines.
The Italian manufacturer of road, mining and articulated dump trucks Astra has been owned by IVECO since 1986, which, together with Case-New Holland, is part of the FIAT Group. A few years ago, Astra articulated dump trucks were sold under several brands - New Holland, O&K, Case and Astra itself. After the 2005 reform, CNH retained the last two stamps.
The line of Astra articulated dump trucks consists of four models with a wheel arrangement of 6x6 - ADT 25С, ADT 30С, ADT 35С and ADT 40С with a capacity of 23.2; 28.16; 31.5 and 37 tons. Two "younger" models are equipped with IVECO Cursor 10 6-cylinder in-line engines with a displacement of 10.3 liters and a total power of 235 and 260 kW, ZF automatic 6-band gearboxes, Kessler axles. The "senior" models are equipped with 6-cylinder in-line Cursor 13 engines with a volume of 12.8 liters and a total power of 302 and 335 kW, 6-band ZF ErgoPower automatic gearboxes and ZF axles. The first three models have dry disc brakes, the ADT 40C has oil-immersed disc brakes. Unlike competitors, the Astra dump truck body is lifted by two multi-section hydraulic cylinders placed inside the frame for better protection.
The South African company Bell is known as a supplier of articulated haulers worldwide. The company's plant in Eisenach (Thuringia, Germany) produces dump trucks for European markets. The line consists of six models with a 6x6 wheel arrangement with a permanent drive - B20D, B25D, B30D, B35D, B40D and B50D, capacity 18; 23.2; 27.3; 32.5; 37 and 45.4 tons. The German full-cycle plant uses European components, with the exception of axles. Bell supplies bridges of its own design and production from South Africa. Models B20D, the production of which the plant began at the end of 2007, and B25D and B30D are equipped with a 6.37-liter Mercedes-Benz OM906 6-cylinder in-line engine with a net power of 165, 198 and 232 kW and a ZF 6-speed automatic gearbox with integrated retarder. The B35D and B40D dump trucks are equipped with a V-shaped 6-cylinder diesel engine OM501 with a volume of 12 liters and a power of 283 and 308 kW and an Allison 6-band automatic transmission. The “older” B50D model is equipped with an OM502 8-cylinder V-engine with a volume of 16 liters and a power of 382 kW and an Allison automatic transmission. Bell is a supporter of rigid dependent suspension. The front axle suspension includes an A-arm, tie rod and nitrogen-oil accumulators. The rear axles are supported on longitudinal balancing beams through damping elements and are connected to the frame by four pairs of jet rods and transverse rods.
The Norwegian manufacturer of dump trucks Moxy supplies five models of 6x6 dump trucks with permanent drive - MT26, MT31, MT36, MT41 and MT51 with a capacity of 24.1; 28; 32.7; 37.2 and 46.27 tons. They are equipped with 5-cylinder Scania DC9 diesel engines with a volume of 9 liters and a power of 220 and 247 kW for the MT26 and MT31 models, 6-cylinder Scania DC12 diesel engines with a volume of 11.7 liters and a power of 285 and 322 kW for dump trucks MT36 and MT41 and a Cummins QSX15 engine with a volume of 15 liters and a power of 374 kW for the "older" model MT51. The transmission includes 6-band automatic gearboxes ZF and Allison, a transfer case with a locking differential, axles with limited slip differentials. Front axles with independent suspension.
In August 2008, Korean conglomerate Doosan bought Moxy for €55 million. Doosan promised to increase Moxy sales by five times by 2012, bringing them to 250 million euros, as well as to modernize the lineup in the direction of increased payload.
The American Terex offers five models of articulated dump trucks - TA25, TA27, TA30, TA35 and TA40 with a capacity of 23, 25, 28, 34 and 38 tons. with a power of 221, 238 and 248 kW, ZF automatic gearboxes with manual mode, axles with permanent all-wheel drive and manual locking of center and wheel differentials. The torque converter, automatic gearbox and transfer case are combined into a single unit. The features of the "younger" models include custom split axles with independent suspension. The “senior” TA35 and TA40 models are equipped with 6-cylinder in-line Detroit Diesel Series 60 engines with a volume of 14 liters and a power of 289 and 326 kW, an Allison HD456 six-speed automatic gearbox with an integrated retarder, a separate two-stage transfer case with a locking differential, axles with high differentials friction.
The Komatsu Corporation, bulldozers, excavators, whose mining dump trucks have gained recognition among oil and gas workers and builders in Siberia and the North, have relatively recently begun to form northern specifications for articulated dump trucks. There are some successful developments in this direction. The body heating system is recognized as the most efficient, it is copied by other companies.
There are three models HM300-1, HM350-1 and HM400-1 in the model range of Komatsu dump trucks with a capacity of 27.3; 32.3 and 36.5 tons with a 6x6 wheel arrangement and permanent drive. The dump trucks are equipped with Komatsu 6-cylinder in-line turbocharged diesel engines with aftercooling. On HM350-1 and HM400-1, an SAA6D140E-3 engine with a power of 298 and 331 kW is installed, on a dump truck HM300-1 - SAA6D125E-3 with a power of 250 kW. The transmission includes a lockable torque converter and an electronically controlled automatic gearbox K ATOMiCS. Made in a single block with the gearbox, the center differential is equipped with a multi-plate oil-cooled locking clutch. Interaxal and cross-axle differential locks can be switched on and off on the go. Komatsu uses hydropneumatic suspension. The front axle uses De Dion type suspension, which provides smoother overcoming obstacles and comfortable driving. A combined suspension is used on the rear wheeled bogie - at the rear axle there is a hydropneumatic suspension and rubber elastic elements on the middle axle.
Evolving, articulated dump trucks acquired common features - 6x6 wheel arrangement, permanent all-wheel drive, 6-cylinder in-line engine, automatic gearbox, locking differentials, body structure, etc. And outwardly dump trucks of different brands are very similar. The practical difference lies in technical nuances, but to a greater extent in adaptation to specific climatic conditions, as well as in the possibilities and conditions of service.
Back in the 40s of the last century, the first prerequisites for the creation of articulated dump trucks or dump trucks on an articulated frame appeared. At that time, for the first time, the question of the depletion of easily accessible shallow resources in the United States and Europe began to be raised. Which in turn led to a sharp surge in activity regarding the search for alternative ways of mining. As a result of considering all possible options, it was concluded that in this situation it was necessary to create a new machine that could work in difficult conditions.
As a result, the search for the right solutions continued until the mid-1960s, when Volvo engineers invented a new subtype of vehicle, which was a tractor with an uncoupled front axle hinged to the rear frame. And already a body was installed on the rear frame. To avoid confusion, at customs, the new vehicles received the definition of ADT (articulated dump truck), which means “articulated dump truck” in translation.
Articulated dump trucks are dump trucks that have increased maneuverability and maneuverability due to the articulated frame. These are the most versatile vehicles for off-road cargo transportation in various climatic conditions. In addition to their earth moving function, articulated haulers are widely used in the mining industry, as well as in the transportation of containers, camping houses and equipment to inaccessible places. In this regard, it is worth noting right away that this review does not include articulated trucks for underground work.
The main feature of the articulated dump truck market in Russia is the complete absence of competition from domestic companies. Therefore, the main source of updating the fleet of relevant equipment is imports. According to the results of January-December 2012, the volume of imports of articulated dump trucks to Russia amounted to more than 380 units, which is 11% lower than in 2011 and 57% higher than in 2010. The decrease in deliveries last year is primarily due to the introduction of a recycling fee on September 1, 2012. After August 22, 2012, when Russia officially joined the WTO, the prospect of a gradual reduction in import customs duties forced the Russian government to take such measures, which caused a whole storm of indignation on the part of market participants. As a result, import receipts in September 2012 of many types of self-propelled vehicles in general, and articulated dump trucks in particular, decreased significantly. In September, only one articulated dump truck was imported. At the same time, the average monthly rates of import of the equipment in question in January-August 2012 were higher by 3-4 units of equipment than in the same period of 2011.
Volvo is the undisputed leader in the industry. At the end of 2012, the share of this brand in Russian imports amounted to 39%. Over the past three years, there has been a reduction in the share of the Swedish manufacturer, which in 2010 was 61%, in 2011 - 50%. At the same time, it is worth noting a significant decrease in supplies in 2012 and in physical terms by 31.5% at once. As before, the main models remain Volvo A40F, Volvo A35F and Volvo A30F.
At the end of 2010, only 6 Caterpillar articulated dump trucks were imported to Russia. In 2012, the imports of the American manufacturer increased significantly both in quantity and quality (all but two of the machines are new and manufactured no later than 2011) terms. This allowed not only to increase its share in the total volume - but also to secure the second position. Main model: Caterpillar 740B.
The BELL brand is in the third position in terms of import volumes. During the period under review, imports of articulated dump trucks from the South African manufacturer decreased by 24.5%. The main model imported in 2012 is the Bell 40D. In addition, in the period under review, 7 BELL B50D 6x6 dump trucks were imported to Russia - this is the heaviest sixth generation articulated dump truck in the BELL Equipment production line.
In fourth position is Liebherr, a newcomer to the articulated hauler market. And it's not a typo! The company with more than half a century of history only in 2010 at the largest exhibition of construction equipment Bauma 2010 in Munich presented its first articulated dump truck model TA 230 with a load capacity of 30 tons. Up to this point, there were no articulated dump trucks in Liebherr's extensive range of vehicles. The first copies were delivered by Liebherr-Russland LLC, the official representative office of Liebherr in Russia, already in mid-2011. And according to the results of 2012, the brand has firmly established itself among the industry leaders, having increased the volume of imports of the equipment in question last year by 6 times at once!!!
Imports of Komatsu articulated dump trucks have been stable for the last three years. However, given the growing competition from European brands, every year the Japanese manufacturer loses its share. Also among the brands imported in 2012 were Terex, Doosan, John Deere and Mitsubishi.
There have also been some changes in the distribution of countries where articulated dump trucks imported to Russia in 2012 were produced. The first position of Sweden remains unchanged, where, unlike previous years, all Volvo dump trucks imported in the period under review were produced.
The United Kingdom retained its second position as a country producing the equipment in question for the domestic consumer. First of all, thanks to the stable supply of Caterpillar articulated dump trucks throughout 2011 and 2012. Also, 19 Terex articulated dump trucks assembled at the plant in Motherwell (Scotland) were imported to Russia.
The third position of Germany does not raise questions, while the country's share is constantly growing, reaching 16% in 2012. Among the manufacturers are BELL and Liebherr brands. Japan, led by Komatsu, is in fourth place. South Africa closes the top five producing countries. 17 Bell articulated dump trucks and 4 John Deere dump trucks were assembled in the country.
The first position among the companies - recipients of articulated dump trucks remains with CJSC Volvo Vostok. At the same time, the company's share is declining following the fall in import volumes of the respective brand. In 2010, a division of the Swedish concern accounted for 58.8% of imports, in 2011 this value was already 48.7%, and according to the results of the period under review, it amounted to 35.4%
Further, significant changes in the positions of companies involved in the import of articulated dump trucks are already visible. Bell Equipment Russland LLC occupies the second position, having imported all articulated dump trucks of the Bell brand in 2012. The company is responsible for sales of articulated dump trucks and other special equipment of the South African manufacturer in Russia, the CIS countries, Mongolia and Serbia.
LLC "Liebherr-Russland" - for the first time in history, due to its activity, entered the top three importers of articulated dump trucks. Then there are three companies representing the interests of Caterpillar in Russia. All of them imported almost the same amount of the equipment in question. Nevertheless, the first of them, Vostochnaya Tekhnika LLC is the official dealer of Caterpillar, Sullair and Metso Minerals in Western and Eastern Siberia, Yakutia and the north of the Far East, the second Zeppelin Russland LLC is the official dealer of Caterpillar in the Central, North-Western , parts of the Volga and Southern federal districts. Closes this kind of trio LLC "Mantrak Vostok" - the official dealer of Caterpillar in the Urals, the Volga region and the Komi Republic.
Each post-crisis year showed positive dynamics. However, for many types of self-propelled wheeled vehicles, 2012 was rather an exception. The culprit, as noted earlier, was the recycling fee, which made its own adjustments to the volume of imports. Nevertheless, by December, the average monthly level of imports was exceeded, which allows us to hope that the import of articulated dump trucks in the next 2-3 years will remain at least at the level of the past 2012.
At the same time, we should expect new players in our market from among the representatives of Asia. The Chinese special equipment manufacturer XCMG at the last Bauma China exhibition presented to the public an articulated dump truck with a payload capacity of 60 tons - the DAE60 model, which continues the line of similar machines of the Chinese company - it already presents dump trucks with a payload capacity of 30 tons and 45 tons. So far, the domestic consumer has not yet had the opportunity to evaluate the operation of these models in Russia. Let's see what 2013 will bring us!
Andrey Lovkov, ID-Marketing Commercial Director for the April issue of the Basic Assets magazine
V.D. Kovrigin
Starting from the 1960s, in the world practice of creating mobile equipment for the transportation of loose and small-sized building materials and various rocks along difficult routes and off-road, a new direction began to take shape - the creation of wheeled articulated vehicles with high cross-country ability, which are characterized by low sensitivity to the quality of the roadway .
The ancestor of this direction was the well-known company Volvo. In subsequent years, a number of leading companies specializing in the creation and production of mobile earth-moving, road-building and mining equipment expanded this area.
This type of dump trucks is intended for use in various construction industries when transporting goods in difficult conditions, as well as in the extraction of minerals and building materials in an open way for their transportation from the faces to the unloading points. Such dump trucks have found application in overburden and dumping of soil and waste rock into dumps.
It should be noted that the use of articulated dump trucks is not limited to construction and quarry work. Some manufacturers, using the base chassis of such dump trucks, equip them with large-capacity garbage containers, equipment for transporting containers, long loads (pipes during the construction of pipelines for various purposes), as well as equipment for hauling tree-lengths and assortments in logging industry.
Abroad, a number of leading companies are engaged in the creation and production of articulated dump trucks, including Volvo CE (Sweden), Terex (England), Caterpillar (USA), Komatsu (Japan), Astra (Italy), Bell (South Africa and Germany) , Case New Holland - CNH (England, Germany, Italy) and others.
In Russia, work on the creation and organization of production of articulated dump trucks began in the 1990s. at CJSC Chelyabinsk Road Construction Machines. The plant has created two models of such dump trucks with a capacity of 16 and 25 tons.
In Belarus, at the Mogilev Automobile Plant, three models of articulated dump trucks with a capacity of 25 to 50 tons were created, and one model with a capacity of 36 tons was created at the BELAZ Production Association.
Considering the range of articulated dump trucks of domestic and foreign production, which includes 38 models of machines, it is possible to establish their distribution by load capacity levels. The smallest number of models falls on the groups of capacity up to 20 tons (1 model) and over 40 tons (two models). The largest number of models was created with a capacity of 20-25 tons (10 models). This is followed by a group with a capacity of 35-40 tons (9 models), and the groups with a capacity of 25-30 tons and 30-35 tons account for 8 models each. This distribution allows us to conclude that the most popular are articulated dump trucks in the payload range from 20 to 40 tons. The table shows brief technical characteristics of articulated dump trucks from various manufacturers, structured by load ranges.
To date, a clear concept for the creation of articulated dump trucks has developed, which is characterized by the following fundamental design solutions.
It is based on a modular layout based on the principle of separating the engine and cargo modules connected by a special hinged device. The most widely used wheel scheme with three drive axles (6x6 wheel formula). Two-axle schemes are used (wheel formula 4x4), which are used for machines with a capacity of not more than 25 tons. As a rule, the front module, on which the motor unit is mounted, has a single-axle design, and the rear cargo module has a two-axle design.
The principal layout of the articulated dump truck is shown in fig. one.
As power plants, medium-speed liquid-cooled diesel engines with in-line and V-shaped cylinder arrangement are used, equipped in some cases with turbocharging and intercooling systems for charge air. The engines used have an increased torque reserve (20-25%) and meet modern international requirements for the environmental friendliness of exhaust gases. Volvo, Caterpillar and Komatsu are installing their own engines. Moxy uses Scania engines, Bell uses Mercedez Benz engines, Astra uses Iveco engines, and Terex uses Cummins engines. Domestic manufacturers use engines from the Yaroslavl Motor Plant, Cummins and MTU.
A typical type of transmission is a hydromechanical transmission with a lockable torque converter, with a planetary gearbox with automatic control, with shifting under power, providing 6-7 forward gears and up to 3 reverse gears. Transfer boxes are used with locking mechanisms for center differentials with hydraulic speed retarders (used when working on slopes). As a rule, all drive axles with differential locks are used. Wheel drive locks allow you to choose the best operating modes depending on ground conditions and workloads, up to full locking of all differentials, thereby achieving maximum flexibility in choosing traction on the wheels. With the simultaneous activation of the differential lock system, synchronous rotation of all drive wheels is ensured. Schematic diagrams of the differential lock mechanisms are shown in fig. 2. The choice of the blocking mode is carried out directly by the operator.
Commonly used are oil-immersed multi-disc brakes and planetary wheel reduction gears. These components are usually mounted in a single drive axle unit.
Leading articulated haul truck manufacturers Volvo, Caterpillar and Komatsu use their own transmissions. Other companies Terex, Astra, Bell, Moxy use transmissions of well-known companies ZF and Allison. The domestic manufacturer - CJSC Chelyabinsk Road Construction Machines - uses ZF transmissions and Raba axles.
The use of an articulated frame and a feedback hydraulic steering system allows precise and smooth steering control, achieving high machine maneuverability. Typically, the folding angle of the semi-frames is between 38° and 45°, which allows the operator to turn and maneuver the front module in difficult road conditions, achieving high cross-country ability.
The use of a three-point, maintenance-free suspension of the front axle allows for constant contact of the wheels with the ground when overcoming large irregularities and helps to reduce dynamic loads on the front half frame. Suspension cargo te-
the bed provides not only high adaptability to uneven terrain, but also high stability and better retention of cargo in the body. The use of a special rear bogie beam contributes to unloading the rear of the frame and ensuring an even distribution of the load between the rear axles of the machine.
The use of a body of a symmetrical design with an anti-spill guard, which is made of high-strength sheet steels of increased hardness and wear resistance to abrasion, makes it possible to do without the use of anti-wear plates. The optimal dimensions of the body provide easy loading of materials and rocks, as well as unloading both down the slope of the embankment and into the bunker. The use of an engine exhaust system built into the body prevents the transported material from freezing to the walls of the body.
Considerable attention is paid by all firms to the creation of comfortable working conditions for the operator. On all models of dump trucks, all-metal noise-vibration-insulated cabs are installed with a good, and sometimes panoramic, view of the work front. The design of the cabs, topsides of dump trucks and the overall layout emphasize the perfection of the design and functional purpose of the machine. Cabins are equipped with all the necessary instrumentation and systems that allow you to control the main parameters of dump trucks and warn of the possibility of emergency situations. The front dashboard is arranged in the image and likeness of a passenger car panel. The location of the pedals, control handles complies with the requirements of international ISO standards. The location of steps for climbing into the cab, the dimensions of the doorway are made in accordance with international safety requirements. The operator's seat (with seat belts) is adjustable for the height and weight of the driver and is mounted on shock absorbers. The seat is usually located in the center of the front axle, which corresponds to an area less sensitive to vibrations and vibrations. The above, in combination with an adjustable steering column, creates a comfortable working environment for the driver (Fig. 3).
The use of effective cabin soundproofing allows achieving a low noise level, which is in the range of 72-79 dB (A) in various operating modes. Typically, cabins are equipped with an efficient climate control system, which, depending on weather conditions, can operate in three modes: heating, cooling and ventilation. Cabins must contain systems to protect the life of the operator in the event of a rollover of the machine (ROPS) and in the event of heavy objects falling onto the cab (FOPS). These protection systems must fully comply with the requirements of international standards.
Many manufacturers offer a fairly wide range of trim levels and additional equipment. These include a complete set of bodies for the transportation of light materials, with a reduced height dimension, for the transportation of rocks, as well as equipped with the Multi Lift system and special equipment for the transportation of long loads.
The list of additional equipment includes a hinged tailgate, front spill shield, side panels, etc.
All models of dump trucks are equipped with wide-profile radial tires with an all-terrain tread pattern.
Considerable attention has been paid to reducing labor intensity and facilitating access to components requiring maintenance. This is achieved both by increasing the intervals between types of maintenance and by good accessibility for maintenance. Folding hoods, cabins, additional ladders and other devices are used (Fig. 4).
Some companies, taking into account the climatic features of a number of regions of Russia, when the operation of machines is carried out at low negative temperatures, offer the use of a special, so-called "Siberian package", which provides for equipping the most important parts of dump trucks with electric heaters, high-pressure hoses and rubber products (seals, shock absorbers and etc.) from special frost-resistant materials and installation of an autonomous diesel heater in the cab.
To date, articulated off-road dump trucks have not been widely used in Russia. The experience of operating such dump trucks manufactured by Volvo in the North-Western, Central, Ural and Siberian regions shows their effectiveness. The Surgutneftegaz association, as well as the Sibtrans association based in Novy Urengoy, have extensive experience in the use of articulated dump trucks.
The sphere of effective use of dump trucks ends where at least some semblance of a road ends. Where there are only directions, articulated dump trucks, or Articulated Dump Truck (ADT) in foreign terminology, fully reveal their unique qualities.
A real breakthrough in off-road conquest was made in 1966 by Bolinder-Munktell (today - Volvo Construction Equipment), launching the world's first articulated dump truck model DR 631 (4x4). Although it was, in fact, a conventional tractor without a front axle, articulated with a dump trailer, the revolutionary concept caught on and received worldwide recognition with a circulation of more than 50,000 units in 40 years of production.
Two years later, in 1968, the three-axle model DR 860 (6x4) appeared with the layout familiar to us today. The regiment of “hinges” arrived in 1970: the Norwegians from Moxy (today it is Doosan) joined the Swedes. In 1974, the British from DJB released the first models (today it is Caterpillar). The volume of this segment of the world market is constantly growing both due to an increase in production and due to new manufacturing firms.
“Do you remember how it all started…” Volvo DR860, 1968, capacity 12.3 t
Volvo A40F, 2010, capacity 39 t
What is the secret of ADT's popularity? Perhaps in their indispensability. Articulated haulers perform best in difficult and off-road conditions: on soils with low bearing capacity, steep slopes.
Their operation is economically justified and most effective in the development of deposits, the construction and repair of roads, the construction of hydraulic facilities, and in various climatic conditions.
Many years of experience in operating machines in extreme conditions gradually "crystallized" the design of the modern ADT.
Frame. It consists of two welded semi-frames connected by a hinge with two degrees of freedom. Such a frame eliminates the hanging or unloading of one of the wheels when overcoming road irregularities, contributes to the full use of the machine's coupling mass, which improves cross-country ability. At the same time, the hinge increases the durability of the frame by preventing it from twisting.
Steering. The hydromechanical system with two executive hydraulic cylinders rotates the half-frames at a large (up to 45°) angle, providing high maneuverability. The scheme of the rotary mechanism is simplified due to the absence of a steering trapezium, cardan joints of equal angular velocities and pivot pins. Since the wheels of the front axle are fixed, there is free space for installing large-sized wide-profile tires, which is very important for increasing the machine's cross-country ability.
Suspension. The classic version is a front dependent suspension: a solid axle beam is attached to the frame with trailing arms and a transverse link, hydropneumatic cylinders are used as elastic elements; the axles of the rear bogie are also made in one piece, connected to the frame by longitudinal A-shaped levers and transverse rods, and between themselves by balancers, which rest on the axles through rubber-metal cushions.
Rear trolley "grader" type
Rear bogie suspension on rubber-metal (Terex TA300) and hydropneumatic (BelAZ-75281) elastic elements
Doosan and Hydrema stand out from the general range. Their rear bogies are of the "grader" type: the torque is transmitted through gears inside hollow balancers, and the axles of the axles can swing with a large amplitude.
Terex uses Timoney Mobility Systems of Navan (Ireland) independent linkage front suspension as standard on the TA300 and optional on the TA250.
All Komatsu models have a front semi-independent De Dion hydropneumatic suspension, rear bogie balancers interact with the second axle through rubber cushions, and with the third through hydropneumatic elements.
Volvo has introduced its own FS (Full Suspension) system. Balancers and rubber pads have been replaced by hydraulic struts, which, in combination with hydraulic accumulators and a control unit, form a fully hydraulic suspension with roll equalization function. Thanks to the variable characteristics, a comfortable ride is ensured both with a load and on an empty machine. The maximum speed of models A35F, A40F is 57 km/h!
Engine. The systematic tightening of environmental standards forces engine builders to constantly improve the design of power units. In 2006, Stage IIIa (Tier 3) standards came into force, in 2011. - Stage IIIb (Tier 4i), in 2014 Stage IV (Tier 4f) will enter. The machines are equipped with in-line 5-, 6-cylinder or V-shaped 6-, 8-cylinder turbocharged diesel engines with an intercooler with a working volume of 6 to 16 liters, power from 230 to 517 hp. "Native engines" put Caterpillar, Komatsu, Liebherr and Volvo. Astra uses , Bell - Mercedes-Benz; Doosan and Terex - Scania; Hydrema, JCB - Cummins; BelAZ-MoAZ - Cummins and MTU.
Astra ADT35: hinge, slewing cylinder and platform exhaust heating system clearly visible
Bell B50D capacity 45.4 t - only Doosan MT51 capacity 46.3 t can "compete" with it
A beautiful solution for ease of access to the engine from Volvo
High loads at low speeds off-road require a powerful cooling system with hydraulically driven fan. To improve visibility and reduce the hood, the radiator of the engine cooling system is often located on the side of the engine or even behind the cab.
Transmission. The planetary gearbox with torque converter and retarder is fully automatic with the possibility of manual shifting. The number of gears "forward" - 6-9, "backward" - 1-4. Caterpillar, Komatsu and Volvo make their own gearboxes, the rest of the manufacturers use ZF and Allison.
"X-ray" transmission and branded suspension Volvo Full Suspension
Drive axles with wheel planetary gears, if not our own, then from famous manufacturers: ZF, Naf, Kessler. Interaxal and interwheel differentials: self-locking increased friction and forced locking. Hydraulic braking system with fully enclosed, oil-bathed multi-disc brakes. The transmission and engine are electronically matched for smooth running and durability. For example, on Volvo F-series dump trucks, the ATC system automatically selects the optimal combination of differential locks on the go, allowing the operator to concentrate on the job.
Control. The location of the operator's seat in the center of the cabin and the excellent all-round visibility involuntarily evoke associations with the cockpit of an aircraft. Only there is no scattering of devices: all information is displayed on a multifunctional color display. The image of the rear view camera and warnings of the machine diagnostics system are also displayed there. The controls are located on the circular instrument panel and are within the reach of the operator. As a rule, this is a panel with buttons of the “touch pad” type and two levers: control of the gearbox and lifting of the platform. The cab frame provides protection for the operator from falling objects and when the machine rolls over (ROPS/FOPS). For easy access to transmission units, the cab can be tilted to the side or back.
The workplace of the "pilot" of the dump truck
Caterpillar Ejector - an alternative platform unloading system "scraper" type
Optional equipment. Taking into account the harsh climatic conditions of a number of regions of Russia, the cars are equipped with an engine preheater, a fuel heating system in the tank, a heated fuel filter and a water separator, an autonomous cabin heater, and an exhaust gas body heating system.
Options are also provided: a hinged tailgate, additional sides for light bulky cargo, wear-resistant underbody protection, a load weighing system, a centralized lubrication system, engine start without an ignition key, electronic climate control, heated and electrically controlled mirrors, additional spotlights, etc. d.
Model lines and manufacturers. Today, ADTs are produced in the range of carrying capacities from 18 to 46 tons and occupy a niche between dumpers and mining trucks. As a rule, each company has 4-5 models with a lifting capacity of 5 tons. In addition to dump trucks, other options are also offered, often with an elongated frame: timber carriers, pipe carriers, container carriers, swap body superstructures, airfield sweepers, truck tractors and even artillery systems .
The following manufacturers are engaged in the production of ADT: Terex, JCB from the UK, German Liebherr, Danish company Hydrema, Italian Astra, Caterpillar from the USA and Bell from South Africa / Germany. Bell today can also be found under the Hitachi brands in Asia and Australia and John Deere in America. The most important players in the articulated dump truck market are Volvo (Sweden) and Doosan (South Korea, Norway), as well as Komatsu (Japan). The Belarusian tandem BelAZ-MoAZ is also trying its hand at this market.
Articulated dump trucks have long ceased to be a curiosity; today they can be found in various regions of the planet. They harmoniously fit into the technological processes of construction and at the same time made it possible to work more efficiently in the most difficult road and climatic conditions.
Terex are designed for work in a quarry, in the extraction of minerals and building materials, for dumping soil and waste rock into dumps when performing overburden operations, as well as for use in various construction industries for the transportation of goods in off-road conditions.
The basis of articulated dump trucks Terex a modular layout scheme based on the principle of separating the engine and cargo modules connected by a special hinged device is laid. All models have a 6x6 wheel arrangement. The front module, on which the cab and the power plant are installed, has a single-axle design, and the rear cargo module has a two-axle design.
On articulated dump trucks Terex V-shaped medium-speed diesel engines are used as power plants Cummins and Detroit Diezel power from 300 to 450 hp liquid cooling. The engines used have an increased torque reserve and meet modern international requirements for exhaust cleanliness - Tier 3.
Articulated dump trucks Terex equipped with a mechanical transmission with an automatic transmission with the possibility of manual gear shifting, providing 6 forward gears and 3 reverse gears. The modern design of the transmission provides it with a large reserve of reliability and durability.
Hydraulic brake system for articulated dump trucks Terex differs from pneumatic brake systems in high efficiency, reliability and minimal need for maintenance. Multi-disc brake mechanisms in an oil bath on all wheels provide the machine with excellent braking properties in all modes of operation and especially when driving downhill.
The use of an articulated frame and feedback hydraulic steering system allows the articulated dump truck to precisely and smoothly steer Terex , achieving high maneuverability of the machine. The articulation mechanism of the front and rear sections of the frame has two degrees of freedom and is a unit with vertical and horizontal hinges. The vertical hinge allows the front section to rotate relative to the rear section at any angle in the vertical plane. The horizontal hinge allows the rear section of the frame to pump around a vertical axis in a horizontal plane, ensuring constant contact of the wheels with the ground when overcoming obstacles. This angle is 45° (each way), which allows the operator to turn and maneuver the front module in difficult road conditions, achieving high flotation.
Bodies of articulated dump trucks Terex differ in strength and durability. They are welded from steel sheets with a strength of 1000 MPa and a hardness of 360 HB . The dual-slope rear tray and exhaust gas heating of the body make it much easier to unload at low temperatures.
On all models of articulated dump trucks Terex all-metal noise-vibration protected cabs with good visibility for the operator are installed. Cabins are equipped with heaters, air conditioners and all the necessary systems and instrumentation that provide comfort and control over the main parameters of dump trucks and warn of the possibility of emergency situations.
